CN1235393C - Image pickup device and method thereof - Google Patents

Abstract

The invention provides an image pickup device, which is used for detecting an image and generating pixel data of the image. The image pickup device includes a sensor, a light source, and a controller. The sensor has a plurality of detecting units, which are exposed in turn during the exposure time and generate pixel data, and the exposure time is overlapped. The light source then illuminates the image and causes the image to be detected by the sensor. The controller starts the light source in the exposure time overlapping period of the detection unit, and achieves the effects of preventing the picked image from generating deflection and saving electricity.

Description

Image pickup device and method thereof

technical field

The present invention relates to an image pick-up device and its method, especially designed to obtain the pixel data in the same picture at the same time, so as to avoid the distortion of the picture when picking up dynamic images.

Background technique

FIG. 1 shows a circuit block diagram of an image pickup device, which includes an exposure controller 11 , a sensor array 12 and a light source 13 . The exposure controller 11 also has a vertical counter 111 and a horizontal counter 112 . The sensor array 12 is composed of a plurality of detection units (not shown) arranged in a matrix. The detection units continuously receive external light and accumulate corresponding charges. The light source 13 is used to irradiate the image to be detected, so that the image can generate light incident on the sensor array 12 to expose the detection unit.

The image pickup device in Fig. 1 operates as follows. Taking the sensor array 12 with 16 horizontal lines (that is, the sensor array 12 has 16 lines of detection units) as an example, the exposure controller 11 respectively outputs read signals R0-R15 and reset signals R0_reset-R15_reset to row 0 in the sensor array 12 to the detection unit on line 15. When the reset signals R0_reset˜R15_reset are at a high potential, the charges accumulated in the detection unit due to exposure will be released, and the detection unit will be exposed and charged again. When the read signals R0 - R15 are at a high potential, the detection unit will output the voltage value generated by the accumulated charge as a pixel data value output by the detection unit. These pixel data values are combined into a picture with 16 horizontal lines. In addition, the reset signals R0_reset˜R15_reset and the read signals R0˜R15 enable the detection unit to perform re-exposure and output pixel data row by row, as shown in FIG. 2 .

FIG. 2 shows a timing diagram of conventional sensor array scanning of the image pickup device in FIG. 1 . First, the reset signal R0_reset generates a high potential to re-expose the detection unit in row 0 in the sensor array 12, and after an exposure time t1, the read signal R0 generates a high potential to enable the detection unit in the sensor array 12 The detection unit of row 0 outputs the voltage value generated by its accumulated charge as the pixel data of the horizontal line (row). Next, the reset signals R1_reset~R15_reset generate high potentials sequentially at the scanning interval of one horizontal line, and make the detection units in the 1st to 15th rows sequentially re-exposed. After the same time as t1, following the counting operation of the horizontal counter 112, a high potential is sequentially generated at the scanning interval time of one horizontal line (that is, the counting interval time of the horizontal counter 112), and the detection units of the 1st to 15th rows are also sequentially turned on. The voltage value generated by the accumulated charge is output as pixel data.

In addition, the generation frequency of the high-potential pulses representing the read operation in the read signals R0 - R15 is the frame frequency of the image pickup device, and its relative frame time is T. Traditionally, the generation time of the high potential is controlled by the level counter 112 in the exposure time controller 11 . The horizontal counter 112 has a final count value that is the same as the number of horizontal lines (16) of the screen, and it continuously repeats the operation from counting from 1 to 16 (or 0 to 15), and the read signals R0-R15 complete a counting cycle with the horizontal counter The time of the high potential is regarded as the cycle of generating the high potential, that is, the screen time.

In the above-mentioned traditional scanning method, it can be seen from the timing diagram of FIG. 2 that since the counting cycle of the horizontal counter 112 is the same as the time from scanning from the detection unit of the 0th row to the detection unit of the 15th row, the exposure time t1 of the 0th row is It must be less than the time from scanning the 0th line to the 15th line detection unit (i.e. frame time T), otherwise the level counter 112 has completed a counting cycle in one frame time, so that the detection unit of the 0th line has not yet completed the exposure operation is reset. In this way, the exposure time t1 of the 0th line and the exposure time t2 of the 15th line cannot overlap under this structure (because the exposure time of the detection unit of the 15th line is delayed by one frame time compared with the exposure time of the detection unit of the 0th line, And the exposure time of row 0 is less than one frame time).

Since the exposure time of the detection units of the 0th line and the 15th line cannot overlap, the pixel data in the same picture will be obtained at different times, and the resulting picture will be skewed and distorted. When the scanning frequency is not high , this phenomenon is especially serious due to the large time difference between the acquisition time of the first and last rows of pixel data.

Contents of the invention

In order to solve the above-mentioned problems, the present invention provides a method for obtaining pixel data in the same frame at the same time, so as to avoid the phenomenon of frame distortion when picking up dynamic images.

An object of the present invention is to provide an image pickup device for detecting an image and generating a plurality of pixel data of the image. Expose and output the pixel data within the exposure time, and the exposure time partially overlaps; the light source illuminates the image and causes the image to be detected by the sensor; The light source, wherein these detection units form an array, the controller includes a horizontal counter, these detection units follow the count of the horizontal counter and output the pixel data row by row, and the horizontal counter has a final count value, The final count value is greater than the number of rows of the array so that the exposure times partially overlap.

Another object of the present invention is to provide an image pickup method for using an image pickup device to detect an image and generate a plurality of pixel data of the image. The image pickup device includes: a light source; a plurality of detection units forming an array; and A controller of a level counter, the image pickup method comprising the steps of: sequentially using the detection units to detect the image within a plurality of exposure times, the detection units follow the counting of the level counter and sequentially output the pixel data line by line, and These pixel data are generated, and these exposure times are partially overlapped; during the period during which the exposure times of these detection units are partially overlapped, the light source is turned on by the controller to illuminate the image, so that the image is detected; and the horizontal counter The final count value is greater than the number of rows of the array so that these exposure times partially overlap.

Therefore, the present invention uses the operation of "imaginary number" to prolong the counting cycle of the horizontal counter, so that the exposure time can be greater than the time difference between the first and last rows of pixel data. They are all within the exposure time, and at the same time, the light source is only turned on during this specific time, so that the final picture is mainly composed of pixel data picked up within this specific time, which can avoid the phenomenon of skew and distortion in the traditional picture.

Description of drawings

Hereinafter, an embodiment of an image pickup device and its method according to the present invention will be described with reference to the accompanying drawings.

Fig. 1 shows the circuit block diagram of image pick-up device;

FIG. 2 shows a timing diagram of conventional sensor array scanning of the image pickup device in FIG. 1;

FIG. 3 shows a timing diagram of sensor array scanning of an image pickup device according to an embodiment of the present invention;

Figure 4 shows the light source in this embodiment of the invention;

Figure 5 shows another light source in this embodiment of the invention;

FIG. 6 shows a flow chart of the image pickup method in this embodiment of the present invention.

Symbol Description

11～exposure controller;

111～vertical counter;

112～horizontal counter;

12～sensor array;

13 ~ light source;

131～transistor;

132, 132a, 132b, 132c - light emitting diodes;

133, 133a, 133b, 133c～Resistor

Detailed ways

The image pickup device in this embodiment has the same circuit structure as the image pickup device in FIG. Figure 3 illustrates.

Please refer to FIG. 1 again. The image pickup device in this embodiment includes an exposure controller 11 , a sensor array 12 and a light source 13 . The exposure controller 11 also has a vertical counter 111 and a horizontal counter 112 . The sensor array 12 is composed of a plurality of detection units (not shown) arranged in a matrix. The detection units continuously receive external light and accumulate corresponding charges. The light source 13 is used to irradiate the image to be detected, so that the image can generate light incident on the sensor array 12 to expose the detection unit.

The operation of the image pickup device in this embodiment is as follows: Taking the sensor array 12 with 16 horizontal lines (that is, the sensor array 12 has 16 lines of detection units) as an example, the exposure controller 11 outputs the read signals R0-R15 and the reset signal R0_reset respectively ~R15_reset to the detection units of row 0 to row 15 in sensor array 12. When the reset signals R0_reset˜R15_reset are at a high potential, the charge accumulated in the detection unit due to exposure will be released, and the detection unit will be exposed and charged again. When the read signals R0 - R15 are at a high potential, the detection unit will output the voltage value generated by the accumulated charge as a pixel data value output by the detection unit. These pixel data values are combined into a picture with 16 horizontal lines. In addition, the reset signals R0_reset˜R15_reset and the read signals R0˜R15 enable the detection unit to perform re-exposure and output pixel data row by row, as shown in FIG. 3 .

FIG. 3 shows a timing diagram of scanning the sensor array of the image pickup device in this embodiment. First, the reset signal R0_reset generates a high potential to re-expose the detection unit in the 0th row of the sensor array 12, and after a period of exposure time t1, the read signal R0 generates a high potential to make the 0th row in the sensor array 12 The detection unit of a row outputs the voltage value generated by its accumulated charge as the pixel data of the horizontal line (row). Next, the reset signals R1_reset~R15_reset generate high potentials sequentially at the scanning interval of one horizontal line, and make the detection units in the 1st to 15th rows sequentially re-exposed. After the same time as t1, following the counting operation of the horizontal counter 112, a high potential is sequentially generated at the scanning interval time of one horizontal line (that is, the counting interval time of the horizontal counter 112), and the detection units of the 1st to 15th rows are also sequentially turned on. The voltage value generated by the accumulated charge is output as pixel data.

In addition, the generation frequency of the high potential pulses representing the read operation in the read signals R0 - R15 is the frame frequency of the image pickup device, and the corresponding frame time is T. The generation time of the high potential is controlled by the level counter 112 in the exposure time controller 11 . The horizontal counter 112 has a final count value 32 greater than the number of horizontal lines (16) of the picture, and constantly repeats the operation of counting from 1 to 32 (or 0 to 31), and the read signals R0～R15 complete a counting cycle with the horizontal counter The time is regarded as the cycle of generating high potential, that is, the screen time.

In the above-mentioned scanning mode, it can be seen from the timing diagram of FIG. 3 that the counting cycle of the horizontal counter 112 is twice (32/16=2) the time from scanning the detection unit of the 0th row to the detection unit of the 15th row (32/16=2), which means that when When scanning to the detection unit of the 15th row, for the detection unit of the 0th row, the horizontal counter 112 has not yet completed a counting cycle (only half of the counting cycle is completed), so it is not like a traditional horizontal counter that returns to zero and performs the next count cycle, but continues to count to complete the second half of the count cycle. During this period, the horizontal counter 112 performs an "imaginary number" operation, that is, the counting of the horizontal counter 112 is not followed by the horizontal line scanning operation, and no corresponding pixel data is generated, which only has the effect of lengthening the frame time. In this way, the exposure time t1 of the 0th row can be longer than the time from the scanning of the 0th row to the 15th row of detection units (that is, half of the frame time, 1/2T), and the detection unit of the 0th row will not be generated. It is reset when the exposure operation is completed (because the horizontal counter 112 has not yet completed a counting cycle, the detection unit of the 0th row will not be reset). In this way, the exposure time t1 of the 0th row and the exposure time t2 of the 15th row can be overlapped within the time period t3 under this structure. The overlapping time value t3 is equal to the exposure time value t1 minus the scanning time value of the detection units from the 0th row to the 15th row.

In order to make the final image mainly consist of pixel data obtained during the overlapping time t3, the exposure controller 11 further controls the light source 13 so that the light source 13 is only turned on during the overlapping time t3 and turned off during the non-overlapping time . Its control signal LED_CS is shown in Figure 3. In this way, if it is applied to a wireless optical mouse, it can not only avoid skewing and distortion of the captured dynamic image, but also have the effect of saving power.

4 and 5 show the composition of the light source 13 in this embodiment. In FIG. 4 , the light source can be composed of a transistor 131 as a switch, a light emitting diode 132 and a resistor 133 . Wherein, the gate of the transistor is connected to the exposure controller 11 and receives the signal LED_CS, the source thereof is connected to the negative terminal of the LED 132 , and the drain is grounded. The resistor 133 is connected between the voltage source VDD and the positive terminal of the LED 132 . FIG. 5 shows another circuit that can be used as light source 13 . Similar to the circuit in Figure 4, it is connected to the source of the transistor 131 with three light-emitting diodes 132a, 132b, 132c connected in parallel, and three resistors 133a, 133b, 133c are respectively connected to the light-emitting diodes 132a, 132b, 132c and the voltage source between VDD.

FIG. 6 shows a flow chart of the image pickup method in this embodiment of the present invention.

First, in step 61, a sensor array and a light source are provided. The sensor array has a plurality of detection units arranged in a matrix.

Next, in step 62 , the detection units of the sensor array are sequentially used at different exposure times to detect the image and generate pixel data of the image, and the exposure time of each detection unit is overlapped.

Finally, in step 63, the light source is turned on to illuminate the image during the overlapping period of the exposure time of the detection unit, so that the image is detected.

To sum up the above, the present invention uses the operation of "imaginary number" to extend the counting cycle of the horizontal counter, so that the exposure time can be greater than the time difference between the first and last rows of pixel data, so that within a certain period of time, all detection units in the sensor array are During the exposure time, the light source is only turned on during this specific time, so that the final image is mainly composed of pixel data picked up within this specific time, which can avoid the distortion and distortion of the traditional image.

Although the present invention has been disclosed above with a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make a small amount of changes and modifications without departing from the spirit and scope of the present invention. Therefore, The scope of protection of the present invention should be defined by the scope of the appended claims.

Claims (4)

1. An image pickup device for detecting an image and generating a plurality of pixel data of the image, the image pickup device comprising: The sensor has a plurality of detection units, and these detection units sequentially perform exposure and output the pixel data within a plurality of exposure times, and these exposure times partially overlap; a light source that illuminates the image and causes the image to be detected by the sensor; and a controller that turns on the light source during a period in which the exposure times of the detection units partially overlap, Wherein, these detection units form an array, and the controller includes a horizontal counter, and these detection units follow the counting of the horizontal counter and output these pixel data row by row, The horizontal counter has a final count value greater than the number of rows of the array such that the exposure times partially overlap. 2. The image pickup device according to claim 1, wherein the light source comprises: led; a resistor connected between a voltage source and the positive terminal of the LED; and One end of the switch is connected to the negative end of the LED and the other end is grounded, and the switch is controlled by the controller to be opened and closed. 3. The image pickup device as claimed in claim 2, wherein the switch is a transistor, the gate of which is connected to the controller, the source is connected to the negative terminal of the LED and the drain is grounded. 4. An image pickup method for detecting an image using an image pickup device and generating a plurality of pixel data of the image, the image pickup device comprising: a light source; a plurality of detection units forming an array; and a controller including a level counter, The image pickup method includes the following steps: Using these detection units to detect the image in a plurality of exposure times in sequence, these detection units follow the counting of the horizontal counter and sequentially output the pixel data row by row, and generate the pixel data, and partially overlap these exposure times; The light source is turned on by the controller to illuminate the image during the period when the exposure times of the detection units partially overlap, so that the image is detected; and The final count value of the horizontal counter is made greater than the number of rows of the array so that these exposure times partially overlap.

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