CN102984848A - A Method for Controlling Adaptive Illumination Brightness of Optical Discriminator - Google Patents

Abstract

The invention provides an adaptive illumination brightness control method of an optical identifier, the optical identifier at least comprises a signal processor, an image sensor and at least two light-emitting elements, the method provides light sources by a plurality of light-emitting elements to irradiate the surface of a target object at different angles, and the image sensor transmits measured image signals to the signal processor; the signal processor performs brightness adjustment on the light-emitting element with the brightness to be changed after the image signal is subjected to operation processing, rather than maintaining the light-emitting element at a fixed brightness, so that the power of the power supply unit can be effectively used and the problem of paper reflection light can be effectively solved on the basis of continuously obtaining a good image signal.

Description

A Method for Controlling Adaptive Illumination Brightness of Optical Discriminator

technical field

The invention relates to the technical field of an optical discriminator, in particular to a design capable of effectively controlling illumination brightness, allowing limited power to be used most efficiently and solving the problem of paper reflected light.

Background technique

Optical Identification (OID) is a technology that can hide digital data in general printed matter and retrieve hidden digital data. The digital data is composed of a plurality of dot matrix patterns formed by the distribution of a plurality of tiny dots according to preset rules. The dot matrix patterns are so small that they are easily overlooked visually and do not affect the identification of the information to be conveyed by the main graphics in the printed matter. However, when the digital data is to be read, an optical identifier must be used to capture the dot matrix pattern, and optical and image processing techniques are used to perform identification and decoding operations to identify the signal represented by the dot matrix pattern. In actual products, this technology will be used to cooperate with an image display device or a sound playback device, etc., to generate relative image or sound effects according to the previous signal. Related products such as children's teaching or entertainment point reading pens.

The optical identifiers that dominate this type of identification are generally portable or handheld devices. Considering the convenience of operation, most products have built an independent power supply unit (such as a battery, etc.) inside to provide the power required for the overall operation and last for a long time. For users, it can avoid frequent replacement of batteries, reduce the inconvenience of operation, reduce the cost of batteries, and improve product satisfaction.

In order to effectively use the power of the optical identifier, there are many methods. For example, the present invention designs a method for defining a two-dimensional information coding area, which can overcome the problems of dot matrix pattern rotation, or pattern deformation caused by skewed camera angles, etc. , allowing greater distortion tolerance and improved decoding resolution, so image sensors with lower resolution can be used, and power consumption is relatively reduced. However, in the structure of the optical identifier, the light-emitting element consumes the most power, but the light-emitting element is also the main key component of the structure. The brightness of the light source provided directly affects the quality of the captured image, and has a direct impact on the subsequent optical identification. However, if the power consumption of the light-emitting element is blindly reduced, although the battery life can be extended, it is easy to cause identification errors or failure to identify, which will make the product lose its main purpose.

In addition, most of the current optical identifiers use a single light-emitting element to irradiate the surface of the target at an oblique angle. In this way, the image sensor of the optical identifier can easily obtain an image with non-uniform brightness, that is, the distance from the light-emitting element is relatively small. The closest image is brighter, and vice versa, it is darker. Although this problem can be improved by using printing technology and paper selection, the cost will increase relatively, and it cannot be completely solved. The hand-held optical sensor cannot limit the user's holding habit or angle. Sometimes when the internal light-emitting element illuminates the paper at a specific angle, the impact of reflected light will be more obvious, so the image sensor obtained If the signal-to-noise ratio (S/N) of the image signal is poor, it cannot be used.

Therefore, the present invention provides an adaptive lighting brightness control method, which can properly adjust the brightness and project it to the target according to the obtained image signal, and provide an image with balanced brightness, in order to obtain a good image signal for identification and decoding. .

Contents of the invention

The main purpose of the present invention is to provide an adaptive illumination brightness control framework for an optical identifier, which enables efficient use of power while obtaining the best image quality, prolongs the battery life, and reduces this type of optical identification frequency of battery replacement.

In order to achieve the above-mentioned purpose, the optical identifier of the present invention includes at least a signal processor, an image sensor, and at least two light-emitting elements. The image sensor transmits the measured image signal to the signal processor. After the signal processor processes the image signal, it adjusts the brightness of the light-emitting element whose brightness is to be changed instead of maintaining the light-emitting element at a fixed value. brightness.

The design of the present invention is to provide a control method of adaptive lighting brightness, that is, a design that does not provide fixed lighting brightness. This method will statistically analyze the brightness and darkness of each position of the gray-scale image according to the image signal, and then adjust different positions. The adjusted brightness is the minimum brightness of the light-emitting elements for image signal identification and decoding, so that the power can be used efficiently; in addition, it can also allow the image sensor to obtain images with balanced brightness and maintain Good image signal, while solving the problem of paper reflecting light.

In order to clearly understand the detailed process and technical content of the present invention, the present invention will be accompanied by the following drawings and detailed explanations in order to clearly understand the spirit of the present invention.

Description of drawings

Fig. 1 is the block diagram of framework of the present invention;

2 is a plan view of the optical pickup head of the optical identifier of the present invention;

Fig. 3 is a flowchart of the present invention.

Wherein, the reference signs are explained as follows:

10 subject matter

11 signal processor

12 image sensor

13 light emitting elements

14 Power supply unit

2 optical read head

21 lens

Detailed ways

As shown in FIG. 1 , FIG. 1 is a schematic block diagram of the internal structure of the optical identifier of the present invention. The optical identifier includes at least a signal processor 11 , an image sensor 12 , at least two light emitting elements 13 , and a power supply unit 14 .

As shown in FIG. 2 , which is a schematic structural diagram of the optical pickup head of the optical identifier of the present invention, the light emitting element 13 and the image sensor 12 are arranged inside the optical pickup head 20 . During operation, the light source 13 provides a light source to irradiate the surface of a target 10. The target 10 is a paper printed with a plurality of dot matrix patterns, and part of the light will be focused and projected by the lens 21 in the optical pickup head 20 after being reflected. To the image sensor 12, the optical image is converted into an electronic image signal by the image sensor 12 and output. Wherein the light emitting element 13 is a light emitting diode in this embodiment, but not limited thereto. The image sensor 12 can be an image sensing element such as a CCD (Charge Couple Device) or a CMOS (Complementary Metal-Oxide-Semiconductor).

Since the optical identifier of the present invention is a handheld device, for the convenience of operation, the power supply unit 14 is composed of a plurality of batteries to provide the power required for the overall operation. The signal processor 11 is respectively connected with the power supply unit 14, the image sensor 12, and the light emitting element 13, and can output the power provided by the power supply unit 14 to the light emitting element 13, and control the light emitting element 13 through the output voltage value. The brightness of the light emitting element 13. In addition, the signal processor 11 connected to the image sensing sensor 12 can analyze and process the electronic signal of the image, for example, perform identification and decoding processing, and can also determine whether the obtained electronic signal of the image is a valid signal.

As shown in FIG. 3 , it is a flow chart of the method for controlling the adaptive illumination brightness of the optical identifier. Method of the present invention is:

Step 301: Illuminating a target object at different angles by a plurality of light emitting elements;

Step 302: the image sensor transmits the sensed image signal to the signal processor;

Step 303: After the signal processor processes the image signal, it adjusts the brightness of the light-emitting element whose brightness is to be changed, instead of maintaining the light-emitting element at a fixed brightness.

As shown in FIG. 2, in the present invention, a plurality of light-emitting elements 13 in the optical identifier are equiangularly distributed in the front area of the image sensor 12, that is, if a circle is used in the optical identifier The edge of the shape passes through a plurality of light-emitting elements 13 , and the light-emitting elements 13 located on the edge of the circle are spaced at the same angle, and the extension through the center of the circle passes through the image sensor 12 . In this embodiment, the number of light emitting elements 13 is two, separated by 180 degrees. This purpose is to provide an image with balanced brightness to the image sensor, so that the signal-to-noise ratio of the image signal obtained by the image sensor is improved. .

In step 303, the signal processor performs statistical analysis on the grayscale image provided by the image signal, judges the light and dark positions of the grayscale image, and then adjusts the brightness of the light-emitting elements at relative positions to obtain an image with balanced brightness.

The specific method is that the signal processor calculates the gray-scale gradient distribution of the first axis (Y-axis) and the second axis (X-axis) according to the gray-scale image provided by the image signal, and then adjusts the relative position of the light-emitting element Brightness, which averages the grayscale gradients of the first axis and the second axis, so as to obtain an adaptive lighting brightness.

And using the method of the present invention, the power of the power supply unit can also be used more effectively. For example, when the gray-scale image obtained is too bright, the brightness of all light-emitting elements 13 is lowered to maintain the lowest brightness that can be recognized by the image signal. This reduces power consumption. In addition, when the paper is reflective, it means that the local area of the obtained grayscale image will be too bright, which will easily cause the signal-to-noise ratio (S/N) to be too poor to be used. At this time, the signal processor finds out the The light-emitting element 13 that causes light reflection, reduces the brightness of the light-emitting element 13 or even turns it off, so that the signal-to-noise ratio of the image signal is improved.

To sum up the above, the present invention uses the signal processor to control the brightness of the light-emitting elements at different positions through the internal calculation mechanism according to the image signal of the image sensor, so as to provide appropriate illumination brightness on the surface of the target object and provide a balance Bright image to the image sensor, in addition to continuously obtain good image signals, it can also use the power of the power supply most efficiently to prolong the use time and reduce the frequency of replacing the battery of the power supply, in line with the patent Application Requirements.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the scope of the embodiments of the present invention. That is, all equivalent changes and modifications made according to the claims of the present invention are covered by the patent scope of the present invention.

Claims (5)

1. the adaptability brightness of illumination control method of an optical identification device includes signal processor, image sensor and at least two light-emitting components at least in this optical identification device, it is characterized in that the method comprises:

Shine a subject matter by described at least two light-emitting components with different angles;

This image sensor is sent to this signal processor with the picture signal of institute's sensing;

After calculation process, the light-emitting component that changes brightness for wish carries out brightness adjustment to this signal processor with this picture signal.

2. such as the adaptability brightness of illumination control method of the optical identification device of claim 1, it is characterized in that described at least two light-emitting components are distributed in the front region of this image sensor in this optical identification device.

3. such as the adaptability brightness of illumination control method of the optical identification device of claim 1, it is characterized in that, if in this optical identification device, pass through described at least two light-emitting components with a circular sideline, described at least two light-emitting components that are positioned on the described circular sideline are interval equal angular, and the line stretcher by circular central is by this image sensor.

4. such as the adaptability brightness of illumination control method of the optical identification device of claim 1, it is characterized in that, this signal processor carries out statistical analysis with the gray scale image that this picture signal provides, declare the light and shade position that this gray scale image, adjust again the brightness of the light-emitting component of relative position, to obtain the image of equilibrium brightness.

5. such as the adaptability brightness of illumination control method of the optical identification device of claim 4, it is characterized in that, this gray scale image statistics first that this signal processor obtains according to this picture signal axially reaches the second axial GTG gradient and distributes, adjust again the brightness of the light-emitting component of relative position, make first axially and the second axial GTG gradient homogenizing, and first is axially axially mutual vertical with second.

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