WO2009072748A1

WO2009072748A1 - Camera module using polymer metal composite

Info

Publication number: WO2009072748A1
Application number: PCT/KR2008/006460
Authority: WO
Inventors: He-Won Jung; Jae-Wook Ryu
Original assignee: Hysonic Co Ltd
Current assignee: Hysonic Co Ltd
Priority date: 2007-12-04
Filing date: 2008-11-03
Publication date: 2009-06-11
Anticipated expiration: 2010-06-04

Abstract

The present invention provides a camera module using a polymer metal composite capable of controlling precisely a driving displacement to make a linear driving. Additionally, the present invention provides a camera module using a polymer metal composite in which polymer metal composites are arranged in a circular shape along the outer surface of the lens holder svch that they are formed separately up and bottom to minimize a leaning of the lens holder and improve driving amount of the lens holder. A camera module using a polymer metal composite according to the present invention comprises a lens holder into which lens is installed; a polymer member which is deformed for a voltage to be inputted thereto and raises the lens holder; a placement sensor for detecting placement information of the lens holder; an image sensor which is placed on the lower part of the lens holder and pictures a subject to be pictured through the lens; a control unit which applies a voltage to the polymer member to deform and then control the polymer member; and a cover which covers the lens holder, the polymer member, the placement sensor, the image sensor and the control unit wherein the control unit controls the voltage applied to the polymer member using a measurement value of the placement sensor.

Description

CAMERA MODULE USING POLYMER METAL

COMPOSITE

Technical Field

[1] The present invention relates to a camera module using a polymer metal composite, and more specifically, to a camera module using a polymer metal composite capable of controlling precisely a driving displacement thereof which is subject to a bending deformation according to a voltage input. Background Art

[2] Recently, as technologies of communication and digital information processing has been developed, a portable terminal on which various functions svch as information processing, calculation, communication, and image information input and output, etc., are integrated has been appeared.

[3] A PDA having a digital camera function and communication function, and a cellular phone having a digital camera function and a PDA function are illustrated as the examples of the aforementioned technologies wherein a digital camera module of highly qualified- specification has been popular due to a development of a digital camera technology and a storage capacity.

[4] An image sensor of a mega pixel level due to developments of various technologies has been used in a digital camera mounted to a portable terminal, etc., and thus additional functions such as a auto focusing and optical zooming, etc., has been important.

[5] A driver which occupies a relative smaller space, is driven rapidly, consumes lower power and has a large displacement is necessary in order to implementing the functions of an auto focusing and an optical zooming in a smaller digital camera module.

[6] Accordingly, recently a study of a driver using a piezo-electric element, a shape- memory alloy and an electroactive polymer (EAP) has been performed vigorously.

[7] In particular, the electroactive polymer called as an artificial muscle includes various metal substances to fabricate a polymer metal composite having various characteristics.

[8] The polymer metal composite is light-weighted and flexible, and further is promptly reactive, is driven continuously and yields a relative displacement. Additionally, a mi- crostructure of the polymer metal composite is fabricated easily to apply properly to a smaller camera module. [9] The polymer metal composite is provided with two electrodes of different polarity on both ends thereof, respectively, and a voltage is applied to the polymer metal composite through the two electrodes.

[10] The polymer metal composite applied with the voltage is subject to a bending deformation due to a movement of internal ions caused from a voltage difference. [11] The aforementioned polymer metal composite is disclosed in detail in US patent registration publication No. 7, 169, 822 and in Japanese paten laid-open publication No.

2006-172635.

[12] A camera module using the polymer metal composite is configured as follows.

[13] Eg. 1 an exploded perspective view showing a camera module using a conventional polymer metal composite. [14] As shown in Eg. 1, the camera module using a conventional polymer metal composite includes a polymer member 10, a lens holder 20, electrodes 30, a case 40 and a cover 50. [15] A through hole is formed on a center of the polymer member 10 and a plurality of projections is formed along an internal peripheral surface thereof. [16] The plurality of projections is faced with the lens holder 20 and further a plurality of lens for controlling a magnification of a subject to be pictured is installed inside the lens holder 20. [17] Additionally, electrodes 30 of different polarity are arranged on the upper and lower side of the polymer member 10, respectively to apply voltage to the polymer member

10. [18] The polymer member 10 configured as aforementioned is screwed to the case 40 together with the cover 50 arranged on the upper side of the polymer member 10 and as a result the lens holder is inserted into the case 40. [19] Referring to the camera module using the polymer metal composite configured as aforementioned, a voltage is applied to the polymer member 10 through the electrodes

30 and thus the projections are deformed upward or downward to move the lens holder

20 up and down. [20] IHbwever, there arises a problem in the camera module using a conventional polymer metal composite in that a precise displacement driving is difficult due to a non-linear driving characteristic of the polymer metal composite. [21] Additionally, there arises another problem in an actuator using a conventional polymer metal composite in that lens is difficult to be horizontal and further a driving amount is small to decrease a performance capability thereof.

[22] Eg. 2 is a graph showing an operation of the camera module using a conventional polymer metal composite wherein when a voltage is applied to the polymer member at a time interval, a displacement amount of the lens holder 20 is measured and illustrated. Here, a horizontal axis of the illustrated graph denotes time and a vertical axis denotes a position of the lens holder 20.

[23] As shown in Eg. 2, the positions of the lens holder 20 varies in a parabolic shape at every time interval and further displacement amounts at every step corresponding to same voltage input are different.

[24] In particular, the displacement amount of the lens holder 20 is decreased rapidly at descending state and thus initial position and return position of the lens holder 20 are much different.

[25] As a result, there arises still another problem in that even though a constant voltage is inputted to the camera module using a conventional polymer metal composite, the displacement amounts are different, causing to degrade a reliability of driving the camera module.

Disclosure of Invention Technical Problem

[26] Accordingly, the first object of the present invention relates to provide a camera module using a polymer metal composite capable of controlling precisely a driving displacement to make a linear driving.

[27] The second object of the present invention relates to provide a camera module using a polymer metal composite in which polymer metal composites are arranged in a circular shape along the outer surface of the lens holder sirh that they are formed separately up and bottom to minimize a leaning of the lens holder and improve driving amount of the lens holder. Technical Solution

[28] In order to accomplish the first object, the present invention provides a camera module using a polymer metal composite, comprising: a lens holder into which lens is installed; a polymer member which is deformed for a voltage to be inputted thereto and raises the lens holder; a placement sensor for detecting placement information of the lens holder; an image sensor which is placed on the lower part of the lens holder and pictures a subject to be pictured through the lens; a control unit which applies a voltage to the polymer member to deform and then control the polymer member; and a cover which covers the lens holder, the polymer member, the placement sensor, the image sensor and the control unit wherein the control unit controls the voltage applied to the polymer member using a measurement value of the placement sensor.

[29] The camera module using a polymer metal composite further includes a polymer holder which is arranged on the lower part or upper part of the polymer member to fix the polymer member.

[30] The polymer holder includes a first holder arranged on the upper part of the polymer member and a second holder arranged on the lower part of the polymer member wherein a fixing clip for adhering and fixing the first holder, the polymer member, and the second holder each other is installed on both sides of the polymer holder.

[31] The camera module using a polymer metal composite further includes an elastic member for guiding the lens holder up and down.

[32] The control unit compares a reference value for the lens holder to be moved by a voltage input and a measurement placement value measured by the placement sensor, and controls the voltage applied to the polymer member for the measurement placement value to be the same as the reference value.

[33] A reflection plate for the placement sensor to sense a position of the lens holder is formed on the lens holder.

[34] The polymer member includes: a first polymer arranged on one side of the lens holder; a second polymer arranged on the other side of the lens holder; a first driving projection formed on both ends of the first polymer protrudingly toward the second polymer; and a second driving projection formed on both ends of the second driving projection protrudingly toward the first polymer wherein a through path is formed between the first driving projection and the second driving projection for incident light passing through the lens to be irradiated to the image sensor.

[35] A caught projection faced with the first and second driving projections is formed on both sides of the lens holder so that the lens holder is moved by the first and second driving projections when the polymer member is deformed.

[36] In order to accomplish the first object, the present invention provides a camera module using a polymer metal composite, comprising: a base placed on the upper part of the image sensor;

[37] a lens holder which is placed on the upper part of the base and in which lens is installed; a polymer metal composite which is faced with the lens holder and is bent to move the lens holder up and down when a voltage is applied; an electrode member which is installed on the upper and lower ends of the polymer metal composite to apply a power; and a control unit which controls the power supplied to the polymer metal composite in order for the lens holder to be moved up and down wherein a plurality of the polymer metal composite is arranged along the outer peripheral surface of the lens holder, and wherein each polymer metal composite includes a fixing end faced with the electrode member and fixed to the base and a movable end formed ex- tendingly from the fixing end and bent when a power is applied, and wherein the fixing end and the movable end of different polymer metal composite are arranged adjacently each other.

[38] A first support projection formed horizontally and a second support projection arranged on the lower part of the first support projection and formed protrudingly in a parallel with the first support projection are formed on an external surface of the lens holder, and wherein the polymer metal composite includes a first polymer part faced with the first support projection and a second polymer part arranged on the lower part of the first polymer part and faced with the second support projection.

[39] The fixing ends of the first and second polymer parts are arranged opposingly based on the first and second support projections placed in one direction and the movable ends thereof are extended from the fixing ends toward an adjacent direction.

Advantageous Effects

[40] The camera module using the polymer metal composite according the first embodiment of the present invention has following advantageous effects. [41] The voltage applied to the polymer member is controlled using the measurement value of the placement sensor and thus can control precisely a displacement value of the polymer member. [42] Additionally, the polymer member is fixed to the polymer holder and thus the polymer member is deformed stably. [43] The polymer member and the polymer holder are fixed by the fixing clip and thus overall duration thereof can be improved. [44] The elastic member for guiding the lens holder is provided and thus the lens holder can be avoided being leaned driven stably when the lens holder is driven. [45] The control unit compares the placement measurement value and the reference placement value of the lens holder to control the polymer member and thus can control the displacement amount of the polymer member for the lens holder to arrive the reference value. [46] The refection plate for reflecting the emitted light from the placement sensor is formed on the lens holder and thus a measurement deviation of the placement sensor can be decreased.

[47] The first and second polymers are installed on both sides of the lens holder and the through path is formed between the first and second driving projections and thus the polymer member and the lens are not intervened and the whole size of the polymer member can be decreased.

[48] The camera module using the polymer metal composite according the first embodiment of the present invention has following advantageous effects.

[49] The caught projection faced with the first and second driving projections is formed on the lens holder and thus a contact area of the first and second driving projections and the lens holder can be widened to drive stably the lens holder.

[50] The polymer metal composites are arranged as a plurality along the outer peripheral surface of the lens holder and the respective polymer metal composite includes a fixing end faced with the electrode member and fixed to the base, and a movable end extended from the fixing end and bent when a power is applied thereto, and the fixing end and the movable end of the different polymer metal composite are arranged adjacently and thus the contact area with the lens holder is increased to improve a stability and to decrease the size of the polymer metal composite, thereby utilizing an empty space to decrease the whole size thereof.

[51] The polymer metal member includes the first polymer part faced with the first support projection and the second polymer part arranged on the lower part of the first polymer part and faced with the second support projection and thus the numbers of the polymer metal composite increases to enlarge the driving amount of the lens holder and the contact area of the lens holder, thereby improving a stability.

[52] The fixing ends of the first and second polymer parts are arranged opposingly based on the first and second support projections placed in one direction and the movable ends thereof are extended from the fixing ends toward an adjacent direction, and thus the movable ends of the first and second polymer parts faced with the first and second support projections are intercepted to improve a balance of the lens holder. Brief Description of Drawings

[53] Further objects and advantages of the invention can be more fully understood from the following detailed description taken in conjunction with the aαjompanying drawings in which:

[54] Eg. 1 is an exploded perspective view of a camera module using a conventional polymer metal composite;

[55] Eg. 2 is a graph showing an operation of the camera module using a conventional polymer metal composite; [56] Eg. 3 is a perspective view of a camera module using a polymer metal composite according to a first embodiment of the present invention; [57] Eg. 4 is an exploded perspective view oriented in a direction of the camera module using a polymer metal composite according to a first embodiment of the present invention; [58] Eg. 5 is an exploded perspective view oriented in another direction of the camera module using a polymer metal composite according to a first embodiment of the present invention; [59] Eg. 6 is a cross-sectional view of the camera module using a polymer metal composite, taken in line A-A of Eg. 3; [60] Eg. 7 is a perspective view of an assembled state of a polymer member and a lens holder according to the first embodiment of the present invention; [61] Eg. 8 is a perspective view of an assembled state of a polymer holder and a fixing clip according to the first embodiment of the present invention; [62] Eg. 9 is a view of an operation state of the camera module using a polymer metal composite, taken in line A-A of Eg. 3; [63] Eg. 10 is a flowchart showing a control configuration of the camera module using a polymer metal composite according to a first embodiment of the present invention; [64] Eg. 11 is a graph showing an operation of the camera module using a polymer metal composite according to a first embodiment of the present invention; [65] Eg. 12 is a perspective view of a small photographing device of three-dimensional images provided with the camera module using a polymer metal composite according to a second embodiment of the present invention;

[66] Eg. 13 is an exploded perspective view of a small photographing device of three- dimensional images provided with the camera module using a polymer metal composite according to a second embodiment of the present invention; [67] Eg. 14 is a perspective view of the camera module using a polymer metal composite according to a second embodiment of the present invention; [68] Eg. 15 is an exploded perspective view of the camera module using a polymer metal composite according to a second embodiment of the present invention; [69] Eg. 16 is a perspective view of an assembled state of the lends holder and the polymer metal composite according to a second embodiment of the present invention; [70] Eg. 17 is a partially exploded perspective view of the enlarged part "B" in Eg. 15;

[71] Egs. 18 and 19 are views of operation states of a left and right driving units, taken in line of A-A in Eg. 12; and

[72] Egs. 20 and 21 are views of operation states of a camera module using a polymer metal composite, taken in line of C-C in Eg. 16. Best Mode for Carrying out the Invention

[73] The preferred first embodiment of the present invention will be hereafter described in detail with reference to the accompanying drawings. Eg. 3 is a perspective view of a camera module using a polymer metal composite according to a first embodiment of the present invention, Eg. 4 is an exploded perspective view oriented in a direction of the camera module using a polymer metal composite according to a first embodiment of the present invention, Eg. 5 is an exploded perspective view oriented in another direction of the camera module using a polymer metal composite according to a first embodiment of the present invention, Eg. 6 is a cross-sectional view of the camera module using a polymer metal composite, taken in line A-A of Eg. 3, Eg. 7 is a perspective view of an assembled state of a polymer member and a lens holder according to the first embodiment of the present invention, Eg. 8 is a perspective view of an assembled state of a polymer holder and a fixing clip according to the first embodiment of the present invention, and Eg. 9 is a view of an operation state of the camera module using a polymer metal composite, taken in line A-A of Eg. 3.

[74] As shown in Egs. 3-6, the camera module using a polymer metal composite includes a cover 200, an elastic member 300, a lens holder 400, a placement sensor 500, a polymer holder 600, a fixing clip 650, a polymer member 700, a control unit 800 and an image sensor 900.

[75] The cover 200 is configured as a hexahedral shape and a circular hole is formed thereon, and the lens holder 400 is arranged below the hole.

[76] Additionally, the cover 200 houses the elastic member 300, the lens holder 400, the placement sensor 500, the polymer holder 600, the fixing clip 650, the polymer member 700, the control unit 800 and the image sensor 900, and is connected to the polymer holder 600.

[77] The lens holder 400 is configured as a cylindrical shape and a plurality of lens for adjusting an amplification of the subject to be pictured is installed therein, and the lens receive images of the subject to be pictured through the hole formed on the cover 200.

[78] Addtionally, a caught projection 410 to be faces with the polymer member 700 and a reflection plate 420 arranged opposingly to the placement sensor 500 are formed on an outer surface of the lends holder 400.

[79] The caught projections 410 are formed on both lower ends of the lens holder 400, re- spectively and are protruded as plate forms for enlarging a contact area with the polymer member 700. [80] The reflection plate 420 is formed angled at about 90°from the caught projection 410 not to be overlapped, as shown in Eg. 5, and two reflection plates 420 are formed on both side ends of the lens holder 400, respectively. [81] Of course, the reflection plate 420 may be formed only one side of the lens holder

400; however, in the present embodiment the reflection plates are formed on both sides of the lens holder 400, respectively, for a symmetrical configuration. [82] The lens holder 400 configured as aforementioned is arranged over the image sensor

900 and irradiates the image of the subject to be pictured to the image sensor through the lens installed therein. [83] In order to adjust a focus distance of the image of the subject to be pictured which is irradiated to the image sensor 900, the polymer member 700 is arranged below the lens holder 400 sirh that the lens holder can be moved up and down. [84] The polymer members 700 are configured of a thin plate as a 'C character form, and are arranged on both sides of the lens holder 400, respectively, in the same direction as the reflection plate 420, and further spaced at a predetermined distance from the reflection plates 420. [85] In more detail thereof, the polymer member 700 includes a first polymer 710 displaced on one side of the lens holder 400 and a second polymer 720 displaced on the other side of the lens holder 400. [86] Here, the first and second polymer 710, 720 are spaced from the reflection plate 420 at a predetermined distance in a horizontal direction so that it can not be intercepted when the reflection plate 420 is moved up and down. [87] Additionally, first driving projections 715 protruded toward the second polymer 720 are formed on both ends of the first polymer 710 and second driving projections 725 protruded toward the first polymer 710 are formed on both ends of the second polymer

720. [88] The first and second driving projections 715, 725 are protruded lengthy toward the lens holder 400 on which the caught projections 410 are formed to face with the caught projections 410. [89] Accordingly, as shown in Eg. 7, the first and second driving projections 715, 725 are faced with the lower side of the caught projection 410, respectively. [90] In addition, a through passage 750 is formed between the first and second polymers

710, 720 enough size for the lend holder 400 to pass through. [91] The through passage 750 allows incident light passing through the lens installed on the lens holder 400 not to be intercepted by the polymer member 700 and to be irradiated to the image sensor 900. [92] The polymer member 700 configured as aforementioned is fixed by a polymer holder

600. [93] The polymer holder 600 includes a first holder 610 arranged over the polymer member 700 and a second holder 620 arranged below the polymer 700. [94] The first holder 610 is configured as a square form and further a through path 615 into which the lens holder 400 is inserted and moved up and down is formed on a middle part thereof. [95] Here, the reflection plate 420 is inserted into the through path 615 and moved therealone up and down, and further the placement sensor 500 is arranged on the through path 615 to be opposed to the refection plate 420. [96] Likewise, the second holder 620 is configured as a square form and further a open hole 621 into which the image sensor 900 is inserted is formed on a middle part thereof to allow the incident light passing through the lens to be irradiated to the image sensor

900. [97] In addition, clip pins 622 are formed protrudingly on the second holder 620 through which the polymer member 700 and the first holder 610 are stacked and fastened subsequently. [98] Exing clips 650 for pressing up and down the first and second holders 610, 620 and fixing them are arranged on both sides of the first and second holders 610, 620 stacked as aforementioned. [99] The fixing clip 650 is configured as a "¹^ " character and assembled such that one end of which is faced with the first holder 610 and the other end of which is faced with the second holder 620, as shown in Eg. 8. [100] Additionally, two fixing clips 650 are arranged on both of the respective side of the first and second holders 610, 620. [101] Therefore, the first and second holders 610, 620 are compressed to adhere and fix the polymer member 700 arranged between them. [102] As aforementioned, the polymer member 700 and the polymer holder 600 are fixed by the fixing clip 650, thereby improving an overall durability thereof. [103] Meanwhile, electrodes 550 are arranged on the respective upper side and lower side of the polymer member 700, respectively, fixed to the polymer holder 600 to apply a voltage to the polymer member 700. [104] Erst electrodes 551 installed on the upper side of the polymer member 700 are separately in both directions of the first and second polymer 710, 720 and further second electrodes 552 installed on the lower side of the polymer member 700 are formed facedly with both of the first and second polymer 710, 720. [105] When a voltage is applied through the electrode 550 to the polymer member 700, the first and second driving projections 715, 725 are subject to a bent deformation upward, as shown in Eg. 9. [106] As a result, the lens holder 400 is moved upward through the caught projection faced with the first and second driving projections 715, 725. [107] At this time, elastic members 300 are provided on the upper and lower ends of the lens holder 400 to guide it. [108] The elastic member 300 is a spring of thin plate material and supports the lens holder

400 not to be leaned right, left, up and down when the lens holder 400 is moved upward. [109] Of course, the elastic member 300 may be provided only on one end of the upper and lower ends according a driving feature of the lend holder 400 and the lens holder 400 may be supported using a wire spring or liquid phase damper. [110] As aforementioned, the elastic member 300 is provided to guide the lens holder 400 and thus the lens holder 400 can be avoided leaning when it is driven, thereby driving stably the lens holder 400. [I l l] Meanwhile, when the lens holder 400 is driven, the placement sensor 500 arranged over the lens holder 400 senses a location of the lens holder 400 and transmits to the control unit 800. [112] The placement sensor 500 is installed on the first holder 610 and arranged opposingly to the reflection plate 420 inserted into the through path 615. [113] The placement sensor 500 measures a light amount according to a distance between the reflection plate 420 and the placement sensor 500 and detects a position value of the lens holder 400 and then transmits to the control unit 800. [114] The control unit 800 is arranged below the second holder 620, together with the image sensor 900 and is connected with the electrode 550 and the placement sensor

500 to control the polymer member 700. [115] Eg. 10 is a flowchart showing a control configuration of the camera module using a polymer metal composite according to a first embodiment of the present invention. [116] As shown in Eg. 10, the control unit 800 includes a microcomputer 810 and a driving driver 820. [117] The microcomputer 810 is connected to the placement sensor 500 and a preset reference position value of the lens holder 400 based on a voltage density and the measurement position value of the lens holder detected by the placement sensor 500 are input to the microcomputer 810.

[118] The microcomputer 810 compares the reference position value preset based on a voltage density and the measurement position value measured by the placement sensor 500 and then transmits an output value required for the measurement position value to meet the reference position value to the driving driver 820.

[119] Here, the output value is a voltage value for driving the polymer member 700.

[120] The driving driver 820 is connected to the electrode 550 installed on the polymer member 700 and drives the polymer member 700 pursuant to the output value transmitted from the microcomputer 810, that is, a compensation voltage value.

[121] In a summary, the control unit 800 applies to the polymer member 700 the required voltage to meet a difference between the reference position value and the measurement position value of the lens holder 400 and thus the polymer member 700 allows the lens holder 400 to be moved through an application of the voltage.

[122] At this time, the placement sensor 500 detects a measurement position value of the lens holder 400 which is moved through the voltage input and transmits to the control unit 800 wherein the control unit 800 determines whether the measurement position value is different from the reference position value, and if so, controls again the voltage applied to the polymer member 700 to make the measurement position value be the same as the reference position value.

[123] Actually, the camera module using the polymer metal composite configured as aforementioned was fabricated and then a displacement amount of the lens holder 400 to be moved was measured according to input voltages.

[124] Eg. 11 is a graph of showing an operation of the camera module using a polymer metal composite according to a first embodiment of the present invention wherein when voltages are applied to the polymer member 700 at every stage per 100 seconds, the displacement amount of the lens holder 400 to be moved is illustrated. Here, a horizontal axis of the graph in Eg. 11 refers to time, and a vertical axis refers to a position of the lens holder 400.

[125] As shown in Eg. 11, the position of the lens holder 400 is varied stepwise wherein a fluctuation is shown at each step, and an ascending displacement amount based on the voltage input and a descending displacement amount based on a voltage cut off are illustrated to be the same. [126] That is, an initial position of the lens holder 400 prior to applying a voltage and a return position of the lens holder 400 after applying a voltage and then shutting off become same.

[127] As described above, the control unit 800 controls the voltage applied to the polymer member 700 using the measurement value of the placement sensor 500 and thus can control precisely the driving placement of the lens holder 400.

[128] Additionally, the measurement position value of the lens holder 400 is the same as the reference value thereof and thus the lens holder 400 can be driven in a linear displacement.

[129] The camera module using the polymer metal composite according to the present invention is not limitative the aforementioned embodiment and can be varied alternatively without departing from a scope of the present invention. Mode for the Invention

[130] Hereinafter, a second embodiment of the present invention will be described with reference to the accompanied drawings.

[131] Eg. 12 is a perspective view of a small photographing device of three-dimensional images provided with the camera module using a polymer metal composite according to a second embodiment of the present invention, Eg. 13 is an exploded perspective view of a small photographing device of three-dimensional images provided with the camera module using a polymer metal composite according to a second embodiment of the present invention, Eg. 14 is a perspective view of the camera module using a polymer metal composite according to a second embodiment of the present invention, Eg. 15 is an exploded perspective view of the camera module using a polymer metal composite according to a second embodiment of the present invention, Eg. 16 is a perspective view of an assembled state of the lends holder and the polymer metal composite according to a second embodiment of the present invention, and Eg. 17 is a partially exploded perspective view of the enlarged part "B" in Eg. 15.

[132] As shown in Eg. 12, a small photographing device of three-dimensional images includes a housing 1100, a first actuator 1200, a second actuator 1300, a left and right driving unit 1400, a wire spring 1500, an image sensor 1600 and a control unit 1700.

[133] The housing 1100 is configured as a quadrangle form to house the first and second actuators 1200, 1300 and is installed over the control unit 1700.

[134] In addition, the upper part of the housing 1100 is configured to be separated for opening and closing and further open holes through which the first and second actuators 1200, 1300 are communicated are formed on both sides thereof. [135] Furthermore, the first actuator 1200 into which a first lens 1800 is embedded and the second actuator 1300 into which a second lens is embedded are installed movably rightward and leftward. [136] Here, the first and second actuators 1200, 1300 are configured using the polymer metal composite according to the present invention. [137] More concretely, as shown in Egs. 14 to 17, the first actuator 1200 includes a base

1210, a lens holder 1220, a polymer metal composite 1230, an electrode member 1240, a placement sensor 1250 and a plate spring 1260. [138] The base 1210 is arranged over the image sensor 1600 and configured as an overall quadrangle form and an open hole through which is communicated with the image sensor 1600 is formed on a middle part thereof. [139] In addition, fixing projections are formed upward on each edge of the base 1210 and further the polymer metal composite 1230 and the electrode member 1240 are inserted into the fixing projections.

[140] Here, the lens holder 1220 is arranged over the base 1210. [141] The lens holder 1220 is configured as a cylinder form and the first lens 1800 is inserted therein and further a first and a second support projections 1221, 1222 with which the polymer metal composite 1230 is faced are formed on external surface thereof. [142] The first support projections 1221 are protruded horizontally along an outer surface of the lens holder 1220 and formed symmetrically and separately around the lens holder 1220. [143] Namely, four first support projections 1221 are formed at interval of 90° along an outer peripheral surface of the lens holder 1220. [144] The second support projection 1222 is arranged on the lower part of the first support projection 1221 and further is configured to protrude horizontally alone an outer surface of the lens holder 1220. Here, the second support projection is formed integrally with the lens holder 1222. [145] That is, the second support projection 1222 is formed as a circular plate shape on an outer surface of the lens holder 1220 and is spaced downward from the first support projection 1221. [146] Furthermore, the polymer metal composites 1230 are arranged on the lower ends of the first and second support projections 1221, 1222, respectively, and the polymer metal composite allows the lens holder 1220 to be moved up and down using a bending deformation characteristic when a voltage is applied thereto. [147] More concretely, as shown in Eg. 17, the polymer metal composite 1230 is configured as a thin quadrangle plate and further includes a fixing end 1230a which is faced with the electrode member 1240 and is inserted into the base 1210 and a movable end 1230b which is extended from the fixing end 1230a and is deformed to be bent up and down when a voltage is applied.

[148] The fixing end 1230a the upper and lower ends of which are faced with the electrode member 1240, respectively, applies a voltage to the polymer metal composite 1230 and is inserted into the fixing projection of the base 1210, together with the electrode member 1240.

[149] The movable end 1230b the upper end of which is faced with the lower end of the first support projection 1221 or the lower end of the second support projection 1222 of the lens holder 1220 supports upward the lens holder 1220.

[150] The polymer metal composites 1230 configured as aforementioned are arranged horizontally as a plurality along the outer peripheral surface of the lens holder 1220 wherein the fixing end 1230a of one polymer metal composite 1230 is arranged adjacently to the movable end 1230b of another polymer metal composite 1230.

[151] Namely, the polymer metal composites 1230 are arranged at an angle distance of 90°along an outer peripheral surface of the lens holder 1220 wherein one fixing end 1230a of the polymer metal composite is directed toward another movable end 1230b thereof arranged horizontally.

[152] Accordingly, extending lines of the adjacent polymer metal composite 1230 arranged adjacently are crossed.

[153] A plurality of the polymer metal composite 1230 is arranged along the outer peripheral surface of the lens holder 1220 wherein each polymer metal composite 1230 includes the fixing end 1230a faced with the electrode member 1240 and fixed to the base 1210, and the movable end 1230b formed extendingly from the fixing end 1230a and bent when a voltage is applied. Furthermore, the fixing end 1230a and the movable end 1230b of the different polymer metal composites 1230 are arranged adjacently and thus a contact area of the lens holder 1220 to improve a stability and decrease a size of the polymer metal composite 1230, thereby utilizing an empty space and decreasing a whole size thereof.

[154] Additionally, the polymer metal composites 1230 are classified a first polymer part 1231 faced with the first support projection 1221 and a second polymer part 1232 faced with the second support projection 1232 depending on a top and bottom arrangement of the polymer metal composite 1230. [155] The first polymer part 1231 is arranged on the lower part of the first support projection 1221 and thus the movable end 1230b thereof is faced with the lower end of the first support projection 1221, and further the second polymer part 1232 is arranged on the lower part of the second support projection 1222 and thus the movable end 1230b thereof is faced with the lower end of the second support projection 1222.

[156] Furthermore, the fixing ends 1230a of the first polymer part 1231 and second polymer part 1232 are arranged in an opposing direction based on the first and second support projections 1221, 1222 which are placed in one direction and the movable end 1230b thereof is extended from the fixing end 1230a toward an adjacent direction.

[157] That is, referring to the first and second polymer parts 1231, 1232 which are arranged horizontally top and bottom, the fixing ends 1230a of the respective polymer part are arranged in an opposing direction and the movable ends 1230b are projected in a facing direction.

[158] Therefore, the movable end 1230b of the first polymer part 1231 and the movable end 1230b of the second polymer part 1232 are overlapped horizontally.

[159] Since the polymer metal composite 1230 includes the first polymer part 1231 faced with the first support projection 1221 and the second polymer part 1232 arranged on the lower part of the first polymer part 1231 and faced with the second support projection 1222 and thus the numbers of the polymer metal composite 1230 can be increased to increase driving amount of the lens holder 1220 and the contact area with the lens holder 1220, thereby improving a stability.

[160] In addition, the first and second polymer parts 1231, 1232 are bent in left and right direction of an opposing direction, respectively, when they are subject to a bending deformation and thus the lens holder 1220 can be avoided leaning on one direction.

[161] Meanwhile, the electrode member 1240 is installed on the upper and lower ends of the polymer metal composite 1230 to apply power to the polymer metal composite 1230.

[162] The electrode members 1240 are made with a conductive metal material and are formed separately on the upper and lower parts of the polymer metal composite 1230 and have different polarity.

[163] The electrode members 1240 are faced with the upper and lower surfaces of the polymer metal composite 1230, respectively to apply current to the polymer metal composite 1230.

[164] Meanwhile, the plate springs 1260 are installed on the upper and lower ends of the lens holder 1220 and they support elastically the lens holder 1220 downward to be returned its initial position after being raised. [165] Additionally, the placement sensor 1250 is arranged on the upper part of the lens holder 1220 to measure upper and lower positions thereof. Here, the reflection plate

1270 is installed on the second support projection 1222 of the lens holder 1220 to reflect emitting beam of the placement sensor 1250 through the parts between the first support projection 1221. [166] Meanwhile, the second actuator 1300 arranged spacedly on the side surface of the first actuator 1200 is configured as the same way as the first actuator 1200 except for the second lens 1900 is inserted into the lens holder 1220. [167] And also, the left and right driving units 1400 are installed on the side surfaces of the first and second actuators 1200, 1300, respectively, to move the first and second driving units leftward and right ward, respectively. [168] More concretely, the left and right driving unit 1400 includes a first driving unit

1400a which is installed on the first actuator 1200 and is arranged on an opposing direction to one side adjacent to the second actuator 1300, and a second driving unit

1400b which is installed on the second actuator 1300 and is arranged on an opposing direction to one side adjacent to the first actuator 1200. [169] Namely, the left and right driving units 1400 are arranged on the respective first and second actuators 1200, 1300 in an opposing direction wherein the distance between the first and second actuators 1200, 1300 is minimized. [170] [171] * Additionally, each of the first and second driving units 1400a, 1400b includes a coil member 1410, an iron plate member 1420, and a magnet 1430. [172] The coil member 1410 is configured sirh that wires coated with insulation material are wound plural times in one direction and further is fixed to one lateral side of the first actuator 1200 or the second actuator 1300.

[173] Here, the iron plate member 1420 is inserted into a center of the coil member 1410. [174] One end of the iron plate member 1420 is inserted into the center of the coil member

1410 and installed in a predetermined space therefrom and the other end thereof is fixed to the housing 1100 adjacent to the first actuator 1200 or the second actuator

1300. [175] In addition, the magnets 1430 are installed on the upper and lower end of the iron plate member 1420, respectively. [176] At this time, referring to the polarities of the magnets 1430 installed on the upper and lower ends of the iron plate member 1420, respectively, the magnets having same polarity are arranged to face with the iron plate member 1430.

[177] In a summary, the first driving unit 1400a or the second driving unit 1400b includes the coil member 1410 installed on the first actuator 1200 or the second actuator 1300, the iron plate member 1420 one end of which is inserted into the coil member 1410 and the other end of which is fixed to the housing 1100, and the magnet 1430 installed on the respective upper and lower end of the iron plate member 1420, thereby simplifying an overall configuration and improving the left and right driving amount of the first and second actuators 1200, 1300.

[178] Meanwhile, the wire spring 1500 is formed lengthwise up and down and one end of which is installed on the control unit 1700 and the other end of which is installed on the upper part of the first actuator 1200 or the upper part of the second actuator 1300 to support elastically the first actuator 1200 or the second actuator 1300 upward and downward.

[179] In more detailed description thereof, the wire springs 1500 are formed as a plurality wherein the wire springs are installed on the four points placed symmetrically each other external to the first actuator 1200, and on the four points placed symmetrically each other external to the second actuator 1300, respectively.

[180] The wire spring 1500 has an elastic force and is made with a metal material with a conduction property.

[181] Accordingly, two wire springs among the four wire springs 1500 connected to the first actuator 1200 are used as power supply wires for the first actuator 1200 and the rest two wire springs are connected to the coil member of the first driving unit 1400a to supply power thereto.

[182] Likewise, the other four wire springs 1500 connected to the second actuator 1300 and the second driving unit 1400b supply power thereto.

[183] Since the spring wires 1500 are formed as a plurality and further are connected to the left and right driving unit 1400, the first and second actuators 1200, 1300, respectively, to supply power from the control unit 1700, the numbers of the whole components can be minimized to simplify an assembly thereof.

[184] Meanwhile, the image sensors 1600 are arranged on the lower parts of the first and second actuators 1200, 1300, respectively, to take pictures of the subject to be pictured through the first and second lens 1800, 1900.

[185] The image sensor 1600 is installed on the control unit 1700 which is arranged on the lower part of the housing 1500.

[186] The control unit 1700 controls the power supplied to the left and right driving unit 1400, the first and second actuators 1200, 1300 through the wire spring 1500.

[187] In some cases, the control unit 1700 may include a placement sensor to control precisely the left and right driving unit 1400 using placement information of the first and second actuators 1200, 1300.

[188] The operations of a small photographing device provided with the camera module using the polymer metal composite configured as aforementioned and the camera module using the polymer metal composite according to the present invention will be described as follows.

[189] Egs. 18 and 19 are views of operation states of a left and right driving units, taken in line of A-A in Eg. 12, and Egs. 20 and 21 are views of operation states of a camera module using a polymer metal composite, taken in line of C-C in Eg. 16.

[190] Erst, as shown in Eg. 18, the first and second actuators 1200, 1300 are attached and supported to the upper part of the image sensor 1600 by the wire spring 1500 before the power is applied to the left and right driving unit 1400 wherein the wire spring 1500 is placed orthogonally to the control unit 1700.

[191] When the control unit 1700 applies power to the left and right driving unit 1400 for adjusting a view angle of the subject to be pictured, an image of which is pictured to the image sensor 1600, the first and second actuators 1200, 1300 are moved to left and right horizontally depending on the input value of the control unit 1700.

[192] Namely, as shown in Eg. 19, when the power is applied to the coil member 1410, the first actuator 1200 is moved to left horizontally and the second actuator 1300 is moved right horizontally due to electromagnetic filed created in the coil member 1410 and the magnet 1430, thereby widening a gap between the first and second actuators 1200, 1300.

[193] At this time, the wire spring 1500 installed on the first actuator 1200 is leaned to rightward like the first actuator 1200, and the wire spring 1500 installed on the second actuator 1300 is leaned like the second actuator 1300.

[194] The left and right driving units 1400 are installed on the first and second actuators 1200, 1300, respectively, and further the gap between the first and second actuators 1200, 1300 is adjusted to control the view angle with respect to the subject to be pictured, the image of which is pictured to the image sensor 1600, thereby making concrete images using the image to be pictured to the image sensor 1600.

[195] In the following, an operation of an actuator 1200 using the polymer metal composite according to the present invention, as shown in Egs. 20 and 21.

[196] As shown in Eg. 20, before applying power the first polymer part 1231 and the second polymer part 1232 are face-contacted with the first and second support projections 1221, 1222 horizontally each other. [197] When the control unit 1700 takes a picture of the subject to be pictured through the image sensor 1600, power is applied to the first actuator 1200 in order to adjust a focus of the subject to be pictured. [198] As shown in Eg. 21, when the power is applied to the first actuator 1200, the movable ends 1230b of the first and second polymer parts 1231, 1232 are bent upward, respectively. [199] Accordingly, the first support projection 1221 faced with the movable end 1230b of the first polymer part 1231 and the second support projection 1222 faced with the second polymer part 1232 are moved upward. [200] At this time, the first polymer part 1231 is bent from right to left, and the second polymer part 1232 is bent from left to right, and thus the lens holder 1220 is minimized to be leaned leftward and rightward. [201] The different fixing end 1230a and movable end 1230b of the polymer metal composite 1230 is installed adjacently each other and thus the whole sizes of the first and second actuators 1200, 1300 can be decreased, and up and down driving amount of the first and second actuators 1200, 1300 can be increased.

Industrial Applicability [202] As described above, the compact module using the polymer metal composite according to the present invention can be applied to a small camera such as a camera provided on a cellular phone to control precisely a driving displacement of a driving lens assembly. [203] Although the present invention has been described with reference to two exemplary embodiments, the description is illustrative of the invention and is not to be construed as limiting the invention. Various modifications and variations may occur to those skilled in the art, without departing from the spirit and scope of the invention, as defined by the appended claims.

Claims

[1] A camera module using a polymer metal composite, comprising: a lens holder into which lens is installed; a polymer member which is deformed for a voltage to be inputted thereto and raises the lens holder; a placement sensor for detecting placement information of the lens holder; an image sensor which is placed on the lower part of the lens holder and pictures a subject to be pictured through the lens; a control unit which applies a voltage to the polymer member to deform and then control the polymer member; and a cover which covers the lens holder, the polymer member, the placement sensor, the image sensor and the control unit wherein the control unit controls the voltage applied to the polymer member using a measurement value of the placement sensor.

[2] A camera module using a polymer metal composite as claimed in claim 1, further including a polymer holder which is arranged on the lower part or upper part of the polymer member to fix the polymer member.

[3] A camera module using a polymer metal composite as claimed in claim 2, wherein the polymer holder includes a first holder arranged on the upper part of the polymer member and a second holder arranged on the lower part of the polymer member wherein a fixing clip for adhering and fixing the first holder, the polymer member, and the second holder each other is installed on both sides of the polymer holder.

[4] A camera module using a polymer metal composite as claimed in claim 1, further including an elastic member for guiding the lens holder up and down.

[5] A camera module using a polymer metal composite as claimed in any one of claims 1 to 4, wherein the control unit compares a reference value for the lens holder to be moved by a voltage input and a measurement placement value measured by the placement sensor, and controls the voltage applied to the polymer member for the measurement placement value to be the same as the reference value.

[6] A camera module using a polymer metal composite as claimed in any one of claims 1 to 4, wherein a reflection plate for the placement sensor to sense a position of the lens holder is formed on the lens holder.

[7] A camera module using a polymer metal composite as claimed in any one of claims 1 to 4, wherein the polymer member includes: a first polymer arranged on one side of the lens holder; a second polymer arranged on the other side of the lens holder; a first driving projection formed on both ends of the first polymer protrudingly toward the second polymer; and a second driving projection formed on both ends of the second driving projection protrudingly toward the first polymer wherein a through path is formed between the first driving projection and the second driving projection for incident light passing through the lens to be irradiated to the image sensor.

[8] A camera module using a polymer metal composite as claimed in claim 7, wherein a caught projection faced with the first and second driving projections is formed on both sides of the lens holder so that the lens holder is moved by the first and second driving projections when the polymer member is deformed.

[9] A camera module using a polymer metal composite, comprising: a base placed on the upper part of the image sensor; a lens holder which is placed on the upper part of the base and in which lens is installed; a polymer metal composite which is faced with the lens holder and is bent to move the lens holder up and down when a voltage is applied; an electrode member which is installed on the upper and lower ends of the polymer metal composite to apply a power; and a control unit which controls the power supplied to the polymer metal composite in order for the lens holder to be moved up and down wherein a plurality of the polymer metal composite is arranged along the outer peripheral surface of the lens holder, and wherein each polymer metal composite includes a fixing end faced with the electrode member and fixed to the base and a movable end formed extendingly from the fixing end and bent when a power is applied, and wherein the fixing end and the movable end of different polymer metal composite are arranged adjacently each other.

[10] A camera module using a polymer metal composite as claimed in claim 9, wherein a first support projection formed horizontally and a second support projection arranged on the lower part of the first support projection and formed protrudingly in a parallel with the first support projection are formed on an external surface of the lens holder, and wherein the polymer metal composite includes a first polymer part faced with the first support projection and a second polymer part arranged on the lower part of the first polymer part and faced with the second support projection.

[11] A camera module using a polymer metal composite as claimed in claim 10, wherein the fixing ends of the first and second polymer parts are arranged opposingly based on the first and second support projections placed in one direction and the movable ends thereof are extended from the fixing ends toward an adjacent direction.