JP2938876B2 - Image recording method and apparatus - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording method and an image recording apparatus (hereinafter, referred to as a printer) for recording an image by driving a recording element such as an LED (light emitting diode).

[Related Art] In recent years, as an output device in a computer, a facsimile receiver, or the like, a printer that records images by arranging a number of light emitting elements such as LEDs (light emitting diodes) has been provided.

This type of printer is generally constructed as shown in FIG. 11, and the LED head used in these printers is shown in FIG.
(B) and FIG. 13.

Here, reference numeral 1 denotes an LED printer head in which a plurality of LED elements 2 are arranged in a line in a line. As shown in detail in FIG. 13, the LED printer head has an LED element 2 and an LED driving IC 2A, and a metal substrate 2 on which these are formed.
B is mounted on the heat sink 7. The drive signal for the LED element 2 is transmitted from the connector 1A via the flexible board 1B.

In front of the LED element 2, a rod array lens 5 for imaging (collecting) the light of the LED element 2 on the photosensitive drum 3 as shown in detail in FIGS. 12 (A) and 12 (B). A rod array lens unit 4 is provided to obtain an image 6 on the photosensitive drum 3.

In FIG. 11, reference numeral 8 denotes a cleaner,
Clean the exposed surface of. After the surface potential of the photosensitive drum 3 is made uniform by the erasing lamp 9, the charging device
Charged at 10. After a while, LED printer head 2
The toner is exposed according to the image signal and developed by the developing device 11, and the toner is applied to the surface of a recording medium such as paper fed from a paper cassette 13 through a paper feed roller 14 and a registration roller 15.
The sheet 12 is transferred by the transfer charger 16 and fixed by the fixing unit 17, and the recorded sheet is discharged to the stacker 18.

FIGS. 14 (A) and (B) show the appearance of a conventional LED printer head, and FIG. 15 shows the drive circuit thereof. A4 portrait feed, that is, the length (width) of the short side of an A4 size recording medium ) Is shown as a head with a recording density of 400 dots / inch, which enables sequential recording in units of). In this example, the number of LED elements is 3414, and the length of the array is 25.4 mm / (400 dot /
Inch x 3414 = 216.8 mm.

In these figures, CN1 is a connector for supplying an LED driving power supply Vcc to the LED driving IC 2A of the printer head,
CN2 is the shift register SR1 built in the LED driving IC 2A
A connector for connecting a signal for sending serial image data DATA in synchronization with the clock CLK to SR6.

FIG. 16 shows a timing chart of each part signal shown in FIG. 15, and the operation of each signal will be described with reference to FIG. T is a signal indicating recording timing in the sub-scanning direction, and has a period T
_{At 0 (400)} , output is performed at the timings of A ₀ , A ₁ , A ₂ ,. From the timing A _0, the image data for one line as a DATA signal is serially output in synchronization with the CLK signal. At this time, the number of image data to be transmitted is 341 elements of the LED array.
Equals 4. Transmission of image data for one line is T _{0 (400)}
The transmission is completed before the time elapses, that is, before reaching A1. This allows the shift register
3414 registers SR1 to SR6 have LED array elements D1 to D34
Image data corresponding to 14 is stored.

Thereafter, a latch pulse LT is output to transfer the data stored in the shift registers SR1 to SR6 to a register array REG having 3414 registers. As a result, the register array REG stores 3414 parallel data. 3414 pieces each output of the register array REG AND gate g _1, g _2, ... is connected to g _3414, LED driving elements T ₁ and the output thereof, T _2, is connected to a ... T ₃₄₁₄ LED array elements D ₁ ~ D ₃₄₁₄ is configured to be driven _individually .
The other inputs of the AND gates g _{1 to} g ₃₄₁₄ are roughly divided into four blocks BLK _{1 to} BLK 4, and the gate signals G ₁ , G ₂ ,
It is connected to G ₃ and G ₄ .

At the timing A1, the gate signals G1 to G4 become “H” level, and at this time, the LED array elements D1 to D3414 are turned on according to the image data stored in the register array REG. At this timing A1, the next one line of pixel data is serially output in synchronization with the CLK signal, and thereafter the photosensitive drum surface is sequentially exposed by this repetition to form a latent image.

In the above conventional example is lit LED array elements in the "H" 100% of the time gate G1~G4 for the duration of T _{0 (400),} but as shown in FIG. 17, T _{0 (400 )} , The gate G1 is set to “H” for a period of time T _{0 (400)} / 4, the gate G2 is set to “H” for the next synchronization, and then the gate is set only for the synchronization.
A driving method has been proposed in which time series driving is performed such that G3 is set to "H" and then the gate G4 is set to "H" only during the same period, thereby reducing the current capacity of the driving power supply.

FIG. 18 is a circuit for performing the above-described operation control including the output of the image data DATA. In the figure, the CPU
Controls the circuit unit that generates the image data,
The exposure timing of the photosensitive drum 3 and the paper feed timing are synchronized to control the transmission timing of image data and the like.

DCT is a data control circuit which converts parallel data stored in a data memory M for storing dot information sent from a host computer HOST by an interface means (not shown) into a parallel-serial data by a parallel-serial conversion circuit PS to convert the image into an image. In addition to generating data DATA, it controls the operation of transmitting 3414 data of serial data converted by the data control counter CNT, and simultaneously generates the serial clock CLK and latches the signal LT.
And the generation of the gate signals G1 to G4.

The LED array printer according to the conventional example described above has an LED
The recording dot density is determined corresponding to the arrangement pitch of the elements of the array 2 on a one-to-one basis.

FIG. 19 shows this state. FIG. 1A shows an LED array head having a print dot density of 300 dots / inch, which is 1/1.
LED elements are arranged at an arrangement pitch of 3 dots per 00 inch. FIG. 4B shows an LED array head having a print dot density of 400 dots / inch, and 4 dots per 1/100 inch.
LED elements are arranged at the arrangement pitch of.

[Problems to be Solved by the Invention] Conventionally, the LED array printer cannot change the recording dot density. That is, the recording dot density is LE
This is because it is determined by the arrangement pitch of the D array elements. This is a disadvantage compared to other types of printers, for example, a laser beam printer.

In other words, if the same printer is used, 300 dots / inch is mainly used for recording characters, and 400 dots / inch is used for mainly printing photographs and graphics. For example, if such an attempt is made, an LED array printer with a recording density of 300 dot / inch and an LED array printer with a recording density of 400 dot / inch are used.
One printer must be prepared, which is inconvenient in terms of cost and installation space.

The present invention has been made in view of such a problem, and an image recording method and an image recording apparatus that perform image recording using a recording head including a plurality of recording elements that perform dot recording are provided. Is to be executed easily and efficiently.

Means for Solving the Problems The present invention relates to an image recording method for performing image recording by a recording head including a plurality of recording elements for performing dot recording, and a method for recording images at mutually different dot densities. It is characterized in that various types of recording heads can be mounted, and an image recording operation is controlled to record an image at a recording density according to the recording dot density of the mounted recording head.

Further, the present invention is an image recording apparatus which performs image recording by a recording head having a plurality of recording elements each of which performs dot recording, and is capable of mounting a plurality of types of recording heads which perform image recording at mutually different dot densities. And a control means for controlling an image recording operation to record an image at a recording density corresponding to a recording dot density of a recording head mounted on the mounting means.

EXAMPLES Hereinafter, the present invention will be described in detail with reference to the drawings.

1 to 5 show a first embodiment according to the present invention,
In these drawings, the components denoted by the same reference numerals as those described above indicate members configured in the same manner.

FIG. 1 shows an example of an arrangement configuration of a main part of a printer according to the present embodiment. In the present embodiment, an LED array head 101 is configured to be detachable along a slide guide member 104 such as a plate.
Microswitches SW1 and SW2 are juxtaposed at a portion of the printer body where the end of the head 101 in the sliding direction abuts.

And corresponding to these two switches, LE of 3414 elements
As shown in the solid line of FIG. 1 and FIG. 2 (A), the micro switch SW2 is pressed while the micro switch SW2 is pressed, and the micro switch SW1 is not pressed, as shown in the solid line of FIG. Is formed. Also, corresponding to micro switches SW1 and SW2, 256
Head 10 for 300 dots / inch consisting of 0-element LED array
As shown in the broken line of FIG. 1 and FIG.
There is provided a top 102 'formed so as to press 1 and not to press the microswitch SW2.

The LED array head 101 or 101 '
03 can be fixed to the printer body by aligning the hole 105 provided in the guide member 104 with a screw or by inserting a pin or the like. The mounting or fixing can be performed by an appropriate member, and it is also easy to perform the mounting or fixing by cooperation of the spring and the latch member.

That is, in this example, the mounting of the head 101 'for 300 dots / inch or the head 101 for 400 dots / inch can be detected according to the on / off of the micro switches SW1 and SW2. This detection can be performed, for example, as follows.

FIG. 4A shows an example of the configuration of a control system of a printer using the head 101 or 101 'according to the present embodiment. The micro switches SW1 and SW2 are connected to the CPU 150. And CP
The U150 activates a procedure as shown in FIG. 4B when the apparatus is started, for example, when the power is turned on, and determines whether or not the printer head is mounted and the type of the printer head.

That is, when the states of the micro switches SW1 and SW2 are SW1 = OFF and SW2 = ON (steps S1 and S3), the CPU 150
It recognizes that the dot / inch LED array head 101 is mounted (step S5), and when SW1 = ON and SW2 = OFF (steps S1 and S7), the 300 dot / inch LED array head 101 '.
Is determined to be implemented (step S9). further,
When SW1 = OFF and SW2 = OFF, it is determined that the LED array head is not mounted (step S11). In this case, an appropriate notification means such as a lamp and a buzzer is driven to notify the operator of the fact and to mount the LED array head. Prompt. In addition, when both switches are ON, it is also possible to notify that the abnormality is abnormal (step S13).

Note that the switches SW1 and SW2 are turned on / off and the frames 102 and 102 '.
The shape can be arbitrarily desired. For example, when the head 101 is mounted, both the switches are turned on, and when the head 101 'is mounted, only the switch SW1 is turned on. Further, the form of the switch is not limited to the micro switch, but may be, for example, an optical switch.

Also, instead of performing the above detection by the processing of the CPU 150,
An appropriate logic circuit may be combined to generate a signal indicating the type of head, the presence or absence of mounting, and the like.

The information recognized by the CPU 150 as described above, that is, whether the mounted LED array head is for 400 dots / inch or 300 dots / inch,
To the host computer HOST by the serial communication SRT1. This causes the host computer HOST
In this case, the transmission data of the data to be transmitted to the data memory M may be switched, and data transmission corresponding to each information dot density may be performed. For example, if the data length of one line is 400 dots / inch, it is 3414 dot data, and if it is 300 dots / inch, it is 2560
Dot data can be transmitted.

Secondly, the number of one line of serial image data DATA sent from the data control counter CNT to the LED array head is 400d.
Control can be performed to transmit only 3414 dot data for ot / inch and 2560 dot data for 300 dot / inch.

Third, as shown in the timing chart of FIG. 5, the exposure cycle in the sub-scanning direction is varied according to the recording dot density, and the duty of the "H" time of the gates G1 to G4 is set to 400 dots.
/ Inch and 300dot / inch are different,
The higher the recording dot density, the higher the "H" time, that is, the control to increase the ON duty of the LED. In general, if the LED array pitch is made denser, the amount of light obtained from one LED becomes smaller. Therefore, in this example, if the ON duty is controlled so that the drum exposure becomes uniform even if the recording head density is changed, the image quality will be improved. Stability can be measured.

This applies even when a time-series lighting method as shown in FIG. 6 is used.

7 to 9 show a second embodiment according to the present invention, and the same parts as those described above are denoted by the same reference numerals and the description thereof will be omitted.

FIG. 7 shows an LED array head 201 having a recording dot density of 400 dots / inch according to a second embodiment of the present invention. In the figure, signal lines S1 and S2 are connected to a connector CN2, and DIP switches DS1 and DS2 are connected to each signal line. These DIP switches DS1 and DS2 are connected to S
It is set so that 1 = “H” and S2 = “L”.

FIG. 8 shows an LED array head 201 'having a recording dot density of 300 dots / inch according to this embodiment, and signal lines S1 and S2 are connected to the connector CN2 in the same manner as in FIG.
DIP switches DS1 and DS2 connected to this switch are connected to S1 =
“L” and S2 are set to be “H”.

FIG. 9 shows an example of a configuration of a control system using the LED array head shown in FIG. 7 or FIG. The signals of S1 and S2 of the connector CN2 are input to the CPU 250, and the CPU 250 receives the signal of FIG. 4 (B).
The determination of the head type, the presence / absence of mounting, and the like are performed in substantially the same manner as in the above procedure. That is, 400 when S1 = "H" and S2 = "L".
It is determined that the dot / inch LED array head 201 is mounted on the printer, and when S1 = "L" and S2 = "H", 300
It is determined that the dot / inch LED array head 201 'is mounted on the printer.

In this example, the CPU 250 is a first host computer HOST
Of 400 dots / inch by serial communication SRT1
ED array head 201 is mounted or 300dot /
Informs whether the inch LED array head 201 'is mounted.

Secondly, the number of one line of serial image data DATA sent from the data control counter CNT to the LED array head is 400d.
In the case of ot / inch, control is performed so that only 3414 dot data is sent, and in the case of 300 dot / inch, 2560 dot data is controlled.

Third, the CPU 250 changes the output voltage Vcc of the variable voltage power supply VCP according to the recording dot density.

For example, in the case of 300 dots / inch, control is performed so that Vcc = 9 V, and in the case of 400 dots / inch, control is performed so that Vcc = 12 V. As a result, the value of the current flowing per LED array element can be changed, and as a result, the light quantity of each element of the LED array can be changed.

In the above-described two embodiments, the 400 dot / inch LED array head and the 300 dot / inch LED array head can be replaced and mounted. However, the present invention is not limited to two heads. It is needless to say that if the number of micro switches or DIP switches, etc. is determined appropriately and made compatible, LED array heads with even more different recording dot densities can be handled.

In the above example, the case where the LED array head having the heat radiating plate 7 is detachable from the printer has been described.
As shown in FIG. 10, when attaching the LED array head, connect the heat sink 7 to the frame ground G of the printer.
It can also be configured to be electrically connected via CAB.

By doing so, it is possible to prevent the potential of the heat sink 7 from becoming unstable, and as a result, it is possible to obtain the effect of preventing the LED array chip and the driver IC from malfunctioning due to external noise. Of course, without passing through such a cable CAB, the heat radiating plate 7 may be appropriately engaged with, for example, the guide member 104, and may be grounded via this, and the configuration thereof is arbitrarily selected. It is possible.

Further, the heat radiating plate 7 and the LED array head may be formed separately, and the LED array head may be detachably attached to the heat radiating plate 7 fixed to the printer.

In addition, in the above example, an LED array printer using an LED array head has been described. However, the present invention is not limited to an LED array printer, and is provided corresponding to a dot and transmits / blocks light from a light source. Needless to say, the present invention can be similarly applied to a printer having a liquid crystal element formed as possible.

[Effects of the Invention] As described above, according to the present invention, it is possible to mount a plurality of types of recording heads each including a plurality of recording elements for performing dot recording and performing image recording at mutually different dot recording densities. Since the image recording operation is controlled to record an image at a recording density corresponding to the recording dot density of the attached recording head, image recording at different recording densities can be performed easily and efficiently.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of an arrangement configuration of a main part of a printer according to a first embodiment of the present invention. FIGS. 2 (A) and 2 (B) and FIGS. 3 (A) and 3 (B) show a first embodiment. FIGS. 4A and 4B are explanatory diagrams for explaining the configuration of two types of LED array heads applicable to the illustrated embodiment. FIGS. 4A and 4B are each a configuration of a control system according to the first illustrated embodiment. FIG. 5 is a block diagram showing an example and a flowchart showing an example of its control procedure. FIGS. 5 and 6 are timing charts for explaining two examples of operation according to the first embodiment of the present invention. FIG. 8 is a circuit diagram for explaining the configuration of two types of LED array heads applicable to the second embodiment of the present invention. FIG. 9 is a configuration of a control system according to the second embodiment of the present invention. FIG. 10 is a block diagram showing an example, and FIG. 10 is a view showing the potential of the heat sink in the configuration of the first and second embodiments of the present invention. FIG. 11 is a perspective view showing an example of a configuration for stabilizing, FIG. 11 is an explanatory diagram showing a general configuration example of a printer using an LED array head, and FIGS. 12 (A) and (B) are main parts of FIG. FIGS. 13, 14 (A) and (B) are a perspective view, a plan view and a side view, respectively, showing an LED array head in a printer, and FIG. 15 is a conventional LED array. 16 and 17 are timing charts for explaining a driving method of the conventional LED array head, FIG. 18 is a block diagram showing a control system of a conventional printer, and FIG. It is explanatory drawing for demonstrating two types of LED array heads from which a head density differs. 1, 101, 101 ', 201, 201' ... LED array head, 2 ... LED element, 3 ... photosensitive drum, 4 ... rod lens array unit, 5 ... rod lens, 7 ... heat sink, 102, 102 '... frame, 104 …… Guide member, 150,250 …… CPU, SW1, SW2 …… Micro switch, HOST …… Host computer, M …… Data memory, PS …… Parallel-serial converter, DCT …… Data control circuit, VCP …… Variable voltage Power supply, CN1, CN2… Connector, CAB… Cable, G… Device frame ground.

Claims (16)

(57) [Claims] An image recording method for recording an image by a recording head having a plurality of recording elements each of which performs dot recording, wherein a plurality of types of recording heads for recording images at mutually different dot densities can be mounted. An image recording method, comprising: controlling an image recording operation to record an image at a recording density according to a recording dot density of a mounted recording head. 2. The image recording method according to claim 1, wherein the number of image data for one line is controlled according to the recording dot density. 3. The driving cycle of the plurality of recording elements is controlled according to the recording dot density.
The image recording method described in the above. 4. The image recording method according to claim 1, wherein a drive duty of said plurality of recording elements is controlled according to said recording dot density. 5. The image recording method according to claim 1, wherein the driving energy of the plurality of recording elements is controlled according to the recording dot density. 6. The image recording method according to claim 1, wherein recording dot density information generated by recording dot density information generating means provided in said recording head is detected. 7. The image recording method according to claim 1, wherein whether or not said recording head is mounted is detected, and when the recording head is not mounted, the fact is notified. 8. An image recording method according to claim 1, wherein said recording element is an exposure element. 9. An image recording apparatus for recording an image by a recording head having a plurality of recording elements each for performing dot recording, wherein a plurality of types of recording heads for recording images at mutually different dot densities can be mounted. An image recording apparatus comprising: a mounting unit; and a control unit that controls an image recording operation to record an image at a recording density according to a recording dot density of a recording head mounted on the mounting unit. 10. An image recording apparatus according to claim 9, further comprising means for controlling the number of image data for one line according to the recording dot density. 11. An image recording apparatus according to claim 9, further comprising means for controlling a driving cycle of said plurality of recording elements according to said recording dot density. 12. An image recording apparatus according to claim 9, further comprising means for controlling a driving duty of said plurality of recording elements according to said recording dot density. 13. An image recording apparatus according to claim 9, further comprising means for controlling driving energy of said plurality of recording elements according to said recording dot density. 14. An image recording apparatus according to claim 9, further comprising means for detecting recording dot density information generated by recording dot density information generating means provided in said recording head. 15. A detecting means for detecting whether or not the recording head is mounted, and a notifying means for notifying when the detecting means detects that the recording head is not mounted. The image recording apparatus according to claim 9, wherein: 16. An image recording apparatus according to claim 9, wherein said recording element is an exposure element.