CN102752562A - Method for operating CMOS image sensor - Google Patents

Abstract

A method of operating a CMOS image sensor, the method comprising: sensing an object through a pixel array unit, wherein the pixel array unit comprises M pixels and P multiplexers, each of the M pixels is electrically connected with one of the P multiplexers, M is a positive integer, and P is a positive integer less than or equal to M; calculating a sensing area corresponding to the object, wherein the sensing area comprises N pixels in the M pixels, and N is a positive integer less than or equal to M; generating a column selection signal; and controlling Q multiplexers electrically connected with the N pixels to supply the column selection signals to the N pixels, wherein Q is a positive integer less than or equal to N and less than or equal to P; signals generated by N pixels of the sensing area are read in a column-major sequence. The invention only needs to output the pixel data in the sensing area corresponding to the object track, thereby greatly reducing the operating frequency and the power consumption of the system.

Description

Method of operation of complementary metal oxide semiconductor image sensor

This patent application is a divisional application of the Chinese patent application with the application number 200910212315.1 and the invention title "Complementary Metal Oxide Semiconductor Image Sensor and Its Operation Method" submitted on November 4, 2009.

technical field

The present invention relates to a complementary metal oxide semiconductor (complementary metal oxide semiconductor, CMOS) image sensor and its operating method, especially to a CMOS image sensor that can improve assembly yield by self-calibration and its operation method.

Background technique

Due to the development of image sensors and the improvement of image processing speed in recent years, more and more attention has been paid to photoelectric touch screens. Currently, image sensors can be roughly classified into charge coupled device (CCD) image sensors and CMOS image sensors. In general, CCD image sensors have less noise than CMOS image sensors and can produce better image quality. However, the CMOS image sensor can integrate signal processing circuits on a single chip, making the product easy to miniaturize. In addition, the power consumption of the CMOS image sensor is very low, therefore, the application of the CMOS image sensor is becoming more and more extensive.

Please refer to FIG. 1 , which is a schematic diagram of a photoelectric touch screen 1 in the prior art. As shown in FIG. 1 , the photoelectric touch screen 1 includes a touch panel 10 and two CMOS image sensors 12 , 14 . The CMOS image sensors 12 and 14 are respectively disposed on two sides of the touch panel 10 . When the user uses an object 16 such as a finger or a stylus to operate on the touch panel 10, the CMOS image sensors 12 and 14 will sense the projection of the object 16 respectively. The coordinates of the touch position can be calculated by measuring the angle of the touch position and measuring the distance between the two CMOS image sensors 12 and 14 .

Please refer to FIG. 2 and FIG. 3. FIG. 2 is a schematic diagram of the projection of the moving track 160 of the object 16 on the CMOS image sensor 12 in FIG. 1, and FIG. 3 is a CMOS image of the moving track 160' of the object 16 in FIG. Schematic diagram of the projection on the sensor 12. Taking the CMOS image sensor 12 as an example, if the CMOS image sensor 12 and the touch panel 10 are not deviated or skewed during assembly, the moving track 160 of the object 16 will be in the pixel array unit 120 of the CMOS image sensor 12 The projection above will present a square quadrilateral as shown in Figure 2. However, if the CMOS image sensor 12 and the touch panel 10 are deviated or skewed due to the influence of assembly tolerances during assembly, the moving track 160 ′ of the object 16 will be on the pixel array unit 120 of the CMOS image sensor 12 The projection then presents a skewed parallelogram as shown in Figure 3. At this time, the readout circuit 122 needs to capture more pixel data for the back-end algorithm to judge, so as to eliminate the influence of the assembly tolerance, thereby increasing the operating frequency and power consumption of the system.

Contents of the invention

Therefore, one of the objectives of the present invention is to provide a method for operating a CMOS image sensor, which can improve assembly yield by self-calibration, so as to solve the above-mentioned problems.

According to an embodiment, the operation method of the CMOS image sensor of the present invention includes the following steps: sensing an object through a pixel array unit, the pixel array unit includes M pixels and P multiplexers, the M Each of the pixels is electrically connected to one of the P multiplexers, M is a positive integer, and P is a positive integer less than or equal to M; calculating a sensing area corresponding to the object, The sensing area includes N pixels among the M pixels, N is a positive integer less than or equal to M; generating a column selection signal; and controlling Q multiplexers electrically connected to the N pixels supplying the column selection signal to the N pixels, Q being a positive integer less than or equal to N and less than or equal to P; reading the N pixels of the sensing area in a column-based order generated signal.

According to another embodiment, the operating method of the CMOS image sensor of the present invention includes the following steps: sensing an object through a pixel array unit, wherein the pixel array unit includes M pixels, and M is a positive integer; calculating a sensing area corresponding to the object, wherein the sensing area includes N pixels among the M pixels, and N is a positive integer less than or equal to M; generating a column selection signal to control all The M pixels output the signals they generate; calculate a first pixel and a last pixel of each column located in the sensing area; use column-based order from the first pixel of each column reading pixels up to the last pixel; and outputting signals generated by the N pixels.

Therefore, according to the operating method of the CMOS image sensor of the present invention, the present invention only needs to output the pixel data in the sensing area corresponding to the object track, which can eliminate the influence of assembly tolerance, thereby greatly reducing the operating frequency and work of the system. consumption.

The advantages and spirit of the present invention can be further understood through the following embodiments and accompanying drawings.

Description of drawings

FIG. 1 is a schematic diagram of a photoelectric touch screen in the prior art;

Fig. 2 is a schematic diagram of the projection of the object track on the CMOS image sensor in Fig. 1;

Fig. 3 is a schematic diagram of the projection of the object track on the CMOS image sensor in Fig. 1;

4 is a schematic diagram of a CMOS image sensor according to an embodiment of the present invention;

FIG. 5 is a schematic diagram showing that the pixel array unit in FIG. 4 has a 3*3 pixel matrix;

FIG. 6 is a circuit diagram of the CMOS image sensor in FIG. 5;

FIG. 7 is a schematic diagram of adding a dummy pixel to the sensing area in FIG. 5;

8 is a flowchart of a method of operating a CMOS image sensor;

FIG. 9 is a flowchart of an operating method of a CMOS image sensor according to another embodiment of the present invention;

10 is a circuit diagram of a CMOS image sensor according to another embodiment of the present invention;

11 is a schematic diagram of a CMOS image sensor according to another embodiment of the present invention;

FIG. 12 is a timing diagram of pixel data reading sequence conversion;

13 is a schematic diagram of a CMOS image sensor according to another embodiment of the present invention;

FIG. 14 is a schematic diagram of the pixel array unit in FIG. 13 having a 3*3 pixel matrix;

FIG. 15 is a circuit diagram of the CMOS image sensor in FIG. 14;

FIG. 16 is a schematic diagram of adding a dummy pixel to the sensing area in FIG. 14;

17 is a schematic diagram of a sensing region according to another embodiment of the present invention;

18 is a flowchart of a method of operating a CMOS image sensor according to another embodiment of the present invention;

FIG. 19 is a flowchart of an operating method of a CMOS image sensor according to another embodiment of the present invention.

Reference number

1 photoelectric touch screen

10 touch panel

12, 14, 3, 3', 5CMOS image sensor

16 objects

30, 30', 50, 70, 120 pixel array units

32, 72 row drive units

34, 54, 74 logic circuits

36, 56, 76, 122 readout circuits

52 row driver unit

58 image registers

160, 160' moving track

300, 700, P1-P32 pixels

302, 302a-302c multiplexer

304, 504, 704, 704' sensing area

P0, P10 virtual pixels

S100-S108, S200-S212, S300-S310, S400-S414 process steps

Detailed ways

Please refer to FIG. 4 , which is a schematic diagram of a CMOS image sensor 3 according to an embodiment of the present invention. As shown in FIG. 4 , the CMOS image sensor 3 includes a pixel array unit 30 , a column driving unit 32 , a logic circuit 34 and a readout circuit 36 . The column driving unit 32 , the logic circuit 34 and the readout circuit 36 are respectively electrically connected to the pixel array unit 30 .

The pixel array unit 30 is used for sensing an object (not shown in the figure) or its moving track. In this embodiment, the pixel array unit 30 includes M pixels 300 and P multiplexers 302, wherein each pixel 300 is electrically connected to one of the P multiplexers 302, and M is a positive Integer, P is a positive integer less than or equal to M. To further illustrate, if P is equal to M, it means that the number of pixels 300 and multiplexers 302 is the same, and each multiplexer 302 is electrically connected to a unique pixel 300; if P is less than M, it means that the number of multiplexers 302 is The number is less than the number of pixels 300 , at this time, each multiplexer 302 can be electrically connected to at least one pixel 300 respectively. The pixel array unit 30 in FIG. 4 is an embodiment including the same number of pixels 300 and multiplexers 302 . For example, if the pixel array unit 30 has a 640*480 pixel matrix, and the number of pixels 300 and multiplexers 302 is the same, then M and P are both equal to 640*480, that is, the pixel array unit 30 includes 640*480 pixels 300 and 640*480 multiplexers 302. In addition, the pixel 300 can absorb light reflected from an object and convert the absorbed light into an electrical signal. The pixel 300 is generally a structure having a transistor and a photodiode. It should be noted that the structural features and working principles of the pixel 300 can be easily realized by those skilled in the art, and will not be repeated here.

The column driving unit 32 receives a timing signal and a control signal from a controller (not shown in the figure), and generates a column selection signal. The column selection signal is a signal used to control the data output of the pixels 300 in the pixel array unit 30 . The logic circuit 34 is used to calculate a sensing area corresponding to the object sensed by the pixel array unit 30 or its moving track, wherein the sensing area includes N pixels 300 in the M pixels 300, and N is a value less than Or a positive integer equal to M. Next, the logic circuit 34 controls Q multiplexers 302 electrically connected to the N pixels 300 to supply the column selection signal to the N pixels 300 , where Q is a positive integer less than or equal to N and less than or equal to P. Taking the pixel array unit 30 in FIG. 4 as an example, Q is equal to N and smaller than P. The readout circuit 36 is used for reading the signals generated by the N pixels 300 in the sensing area.

Please refer to FIG. 5 , which is a schematic diagram of the pixel array unit 30 in FIG. 4 having a 3*3 pixel matrix. The following uses the 3*3 pixel matrix shown in FIG. 5 to illustrate the technical features of the present invention. In this embodiment, the pixel array unit 30 includes the same number of pixels 300 and multiplexers 302 , that is, the above-mentioned M and P are both equal to 9. Please also refer to FIG. 6 , which is a circuit diagram of the CMOS image sensor 3 in FIG. 5 .

When the user operates on a photoelectric positioning system (not shown in the figure) with a CMOS image sensor 3 using objects such as a finger and a stylus (not shown in the figure), the pixel array unit 30 The object or its movement track will be sensed. Next, the logic circuit 34 calculates the corresponding sensing area 304 according to the object or its moving track sensed by the pixel array unit 30 . As shown in FIG. 5 , the sensing area 304 includes five pixels (that is, the above-mentioned N and Q are both equal to 5), that is, P1 , P2 , P5 , P6 and P9 . Next, the logic circuit 34 controls the multiplexer 302 electrically connected to the five pixels to supply the column selection signal to the five pixels, and enables the readout circuit 36 to use the sequence of row-major The signals generated by the five pixels in the sensing area 304 are read. In other words, the sequence of pixels read by the readout circuit 36 from the sensing region 304 is P2, P6, P1, P5, and P9. That is, the first column of pixels read by the readout circuit 36 is P2, P6, and the second column of pixels is P1, P5, P9. In this embodiment, the sensing area 304 is variable and can be set according to the self-calibration result when the device is turned on. In addition, when the object or its moving track has an irregular shape, in order to avoid the complexity of subsequent calculations, the logic circuit 34 may calculate a parallelogram containing the object or its moving track as the sensing area.

It should be noted that since the sensing area 304 in FIG. 5 exceeds the physical area of the pixel array unit 30 , the scanning time of each time will not be fixed, and the calculation of the exposure time will be increased. At this time, the readout circuit 36 of the present invention can add dummy pixels in the excess part when reading the pixel data, so as to keep the time of each scan constant, thereby simplifying the calculation of the exposure time. Please refer to FIG. 7 , which is a schematic diagram of adding a dummy pixel P0 to the sensing area 304 in FIG. 5 . As shown in FIG. 7 , after the dummy pixels P0 are added, the pixels in the sensing region 304 are arranged in a parallelogram, and each column includes the same number of pixels, thereby maintaining a constant scanning time.

Please refer to FIG. 8 , which is a flow chart of the operation method of the CMOS image sensor. Please refer to FIGS. 4 to 6 together. In conjunction with the above-mentioned CMOS image sensor 3, the operation method of the CMOS image sensor of the present invention includes the following steps:

Step S100: Sensing the object or its moving track through the pixel array unit 30;

Step S102: Calculate the sensing area 304 corresponding to the object or its movement track;

Step S104: generating a column selection signal;

Step S106: controlling the multiplexer 302 electrically connected to the pixels P2, P6, P1, P5, and P9 in the sensing area 304 to supply the column selection signal to the pixels P2, P6, P1, P5, and P9; and

Step S108 : Read the signals generated by the pixels P2 , P6 , P1 , P5 , and P9 in the sensing area 304 in a column-based order.

Please refer to FIG. 9 . FIG. 9 is a flowchart of an operating method of a CMOS image sensor according to another embodiment of the present invention. Please refer to FIG. 7 together. With the above-mentioned CMOS image sensor 3, if the sensing area 304 exceeds the physical area of the pixel array unit 30, the operation method of the CMOS image sensor of the present invention may include the following steps:

Step S200: Sensing the object or its moving track through the pixel array unit 30;

Step S202: Calculate the sensing area 304 corresponding to the object or its movement track;

Step S204: generating a column selection signal;

Step S206: controlling the multiplexer 302 electrically connected to the pixels P2, P6, P1, P5, and P9 in the sensing area 304 to supply the column selection signal to the pixels P2, P6, P1, P5, and P9;

Step S208: determine whether the sensing area 304 exceeds the solid area of the pixel array unit 30, if yes, execute step S210, if not, execute step S212;

Step S210: adding a dummy pixel P0 to the excess part; and

Step S212 : Read the signals generated by the dummy pixel P0 (if any) and the pixels P2 , P6 , P1 , P5 , and P9 in the sensing area 304 in a column-based order.

Please refer to FIG. 10 , which is a circuit diagram of a CMOS image sensor 3 ′ according to another embodiment of the present invention. As shown in FIG. 10, the CMOS image sensor 3' includes a pixel array unit 30', a column driver unit 32, a logic circuit 34 and a readout circuit 36, wherein the column driver unit 32, the logic circuit 34 and the readout circuit The working principle of 36 is as mentioned above, and will not be repeated here. In this embodiment, the pixel array unit 30' has a 4*5 pixel matrix, that is, the pixel array unit 30' includes 20 pixels P1-P20. Compared with the pixel array unit 30 in FIG. 6 , the number of multiplexers in the pixel array unit 30 ′ is less than the number of pixels. As shown in FIG. 10, the pixel array unit 30' only includes 17 multiplexers, wherein the pixels P1 and P2 are electrically connected to the same multiplexer 302a, and the pixels P3 and P4 are electrically connected to the same multiplexer 302b. And the pixels P11 and P12 are electrically connected to the same multiplexer 302c. In other words, the present invention can utilize one multiplexer to simultaneously control multiple pixels, thereby reducing the number of multiplexers. The number of pixels electrically connected to a single multiplexer can be designed according to practical applications, and is not limited to two as shown in FIG. 10 . It should be noted that if multiple pixels are electrically connected to a multiplexer at the same time, the multiple pixels must be located in different rows in the pixel array unit 30 ′. As shown in FIG. 10 , pixels P1 and P2 are located in different rows, pixels P3 and P4 are located in different rows, and pixels P11 and P12 are also located in different rows. In particular, a plurality of pixels electrically connected to one multiplexer at the same time may be located in the same column in the pixel array unit 30 ′, but not limited thereto. As shown in FIG. 10 , pixels P1 and P2 are located in the same column, pixels P3 and P4 are located in the same column, and pixels P11 and P12 are also located in the same column.

Please refer to FIG. 11 and FIG. 12 , FIG. 11 is a schematic diagram of a CMOS image sensor 5 according to another embodiment of the present invention, and FIG. 12 is a timing diagram of pixel data reading sequence conversion. As shown in FIG. 11 , the CMOS image sensor 5 includes a pixel array unit 50 , a row driving unit 52 , a logic circuit 54 , a readout circuit 56 and a frame buffer 58 . The row driving unit 52 , the logic circuit 54 and the readout circuit 56 are respectively electrically connected to the pixel array unit 50 , and the image register 58 is electrically connected to the readout circuit 56 . The 4*3 pixel matrix shown in FIG. 11 is only used to illustrate the technical features of the present invention, and the present invention is not limited thereto. The pixels P1-P12 can absorb light reflected from an object, and convert the absorbed light into an electrical signal. The pixels P1-P12 are generally structured with transistors and photodiodes. It should be noted that the structural features and functional principles of the pixels P1-P12 can be easily realized by those skilled in the art, and will not be repeated here.

The row driving unit 52 receives a timing signal and a control signal from a controller (not shown in the figure), and generates a row selection signal. The row selection signal is a signal used to control the data output of the pixels P1 - P12 in the pixel array unit 50 . The logic circuit 54 is used to calculate a sensing area corresponding to the object sensed by the pixel array unit 50 or its moving track. Then, the readout circuit 56 first reads the signals generated by the pixels in the sensing area in column-major order. Afterwards, the image register 58 converts the output data in the row-major order to the column-major order.

For example, when the user operates on a photoelectric positioning system (not shown in the figure) with a CMOS image sensor 5 using objects such as a finger and a stylus (not shown in the figure), The pixel array unit 50 will sense the object or its moving track. Next, the logic circuit 54 calculates the corresponding sensing area 504 according to the object or its moving track sensed by the pixel array unit 50 . As shown in FIG. 11 , the sensing area 504 includes five pixels, namely P2, P3, P7, P8 and P12. It should be noted that, since the sensing area 504 in FIG. 11 exceeds the physical area of the pixel array unit 50 , the scanning time of each time will not be fixed, and the calculation of the exposure time will be increased. At this time, the readout circuit 56 of the present invention can add a dummy pixel P0 in the excess part when reading the pixel data, so as to keep the scanning time of each time fixed, thereby simplifying the calculation of the exposure time.

Controlled by the row selection signal generated by the row drive unit 52, the readout circuit 56 first reads the signals generated by the pixels in the sensing region 504 in a row-based order, and the readout sequence is P0, P2, P3, P7, P8 and P12. Next, the image register 58 converts the output data in the row-major order to the column-major order. As shown in FIG. 12 , after conversion by the image register 58 , the reading sequence becomes P0 , P3 , P8 , P2 , P7 and P12 . In addition, in this embodiment, the scanned result will output a skewed outline because the scan line is not perpendicular to the object outline. The present invention can use the image register 58 to rearrange the read pixel data to improve the above phenomenon.

Please refer to FIG. 13 , which is a schematic diagram of a CMOS image sensor 7 according to another embodiment of the present invention. As shown in FIG. 13 , the CMOS image sensor 7 includes a pixel array unit 70 , a column driver unit 72 , a logic circuit 74 and a readout circuit 76 . The column driving unit 72 and the readout circuit 76 are respectively electrically connected to the pixel array unit 70 , and the logic circuit 74 is electrically connected to the readout circuit 76 .

The pixel array unit 70 is used for sensing an object (not shown in the figure) or its moving track. In this embodiment, the pixel array unit 70 includes M pixels 700, where M is a positive integer. In addition, the pixel 700 can absorb light reflected from an object and convert the absorbed light into an electrical signal. The pixel 700 is generally a structure having a transistor and a photodiode. It should be noted that the structural features and working principles of the pixel 700 can be easily realized by those skilled in the art, and will not be repeated here.

The column driving unit 72 receives a timing signal and a control signal from a controller (not shown in the figure), and generates a column selection signal. The column selection signal is a signal used to control the data output of the pixels 700 in the pixel array unit 70 . The readout circuit 76 is used for reading signals generated by the pixels 700 of the pixel array unit 70 . The logic circuit 74 is used to calculate a sensing area corresponding to the object sensed by the pixel array unit 70 or its moving track, wherein the sensing area includes N pixels 700 in the M pixels 700, and N is a value less than Or a positive integer equal to M. Next, the logic circuit 74 calculates the first pixel and the last pixel of each column located in the sensing area, and controls the readout circuit 76 to read from the first pixel to the last pixel of each column in a column-based order. pixels to output signals generated by N pixels in the sensing area.

Please refer to FIG. 14 and FIG. 15 , FIG. 14 is a schematic diagram of the pixel array unit 70 in FIG. 13 having a 3*3 pixel matrix, and FIG. 15 is a circuit diagram of the CMOS image sensor 7 in FIG. 14 . The technical features of the present invention will be described below using the 3*3 pixel matrix shown in FIG. 14 and FIG. 15 .

When the user uses objects such as fingers and stylus (not shown in the figure) to operate on a photoelectric positioning system (not shown in the figure) with a CMOS image sensor 7, the pixel array unit 70 The object or its movement track will be sensed. Next, the logic circuit 74 calculates the corresponding sensing area 704 according to the object or its moving track sensed by the pixel array unit 70 . As shown in FIG. 14 , the sensing area 704 includes five pixels (that is, the above-mentioned N is equal to 5), namely P1, P2, P5, P6 and P9, wherein the pixels P1 and P2 are located in the first column in the sensing area 704 , the pixels P5 and P6 are located in the second column in the sensing area 704 , and the pixel P9 is located in the third column in the sensing area 704 . Next, the logic circuit 74 calculates the first pixel and the last pixel of each column in the sensing region 704 . As shown in Figure 14, the first pixel of the first column in the sensing area 704 is P1 and the last pixel is P2, the first pixel of the second column in the sensing area 704 is P5 and the last pixel is P6, the first pixel and the last pixel of the third column in the sensing region 704 are both P9. Then, the logic circuit 74 controls the readout circuit 76 to read from the first pixel to the last pixel of each column in a column-based order, so as to output the signals generated by the five pixels in the sensing region 704 . In this embodiment, the output sequence of the five pixels in the sensing area 704 is P1, P2, P5, P6, P9.

In this embodiment, the sensing area 704 is variable and can be set according to the self-calibration result when the device is turned on. In addition, when the object or its moving track has an irregular shape, in order to avoid the complexity of subsequent calculations, the logic circuit 74 can calculate a parallelogram containing the object or its moving track as the sensing area.

It should be noted that since the sensing area 704 in FIG. 14 exceeds the physical area of the pixel array unit 70 , the scanning time of each time will not be fixed, and the calculation of the exposure time will be increased. At this time, the readout circuit 76 of the present invention can add dummy pixels in the excess part when reading the pixel data, so as to keep the time of each scan constant, thereby simplifying the calculation of the exposure time. Please refer to FIG. 16 , which is a schematic diagram of adding a dummy pixel P10 to the sensing area 704 in FIG. 14 . As shown in FIG. 16 , after adding the dummy pixels P10 , the pixels in the sensing region 704 are arranged in a parallelogram, and each row includes the same number of pixels, thereby maintaining a constant scanning time. At this time, the first pixel in the third column in the sensing region 704 is P9 and the last pixel is the dummy pixel P10 .

Please refer to FIG. 17 , which is a schematic diagram of a sensing region 704 ′ according to another embodiment of the present invention. In addition to the above-mentioned parallelogram, the readout circuit 76 can also read and output the pixel data of the sensing area 704 ′ as shown in FIG. 17 after being properly set in the present invention. It should be noted that since the sensing area 704' includes six pixels P10, P11, P12 and P14, P15, P16 in the second column, and the pixels P10, P11, P12 are not continuous with the pixels P14, P15, P16, At this time, the logic circuit 74 will respectively calculate the first pixel and the last pixel among the pixels P10, P11, P12 and pixels P14, P15, P16, that is, the first pixel among the pixels P10, P11, P12 is P10 and The last pixel is P12, and the first pixel among the pixels P14, P15, P16 is P14 and the last pixel is P16. Therefore, for the second column shown in FIG. 17 , the readout circuit 76 will read sequentially from the first pixel P10 to the last pixel P12, and then sequentially read from another first pixel P14 to The last pixel P16. In other words, the pixels read by the readout circuit 76 in the same column may be continuous or discontinuous, depending on the range covered by the sensing area.

Please refer to FIG. 18 . FIG. 18 is a flowchart of an operating method of a CMOS image sensor according to another embodiment of the present invention. Please refer to FIG. 13 to FIG. 15 together. In conjunction with the above-mentioned CMOS image sensor 7, the operation method of the CMOS image sensor of the present invention includes the following steps:

Step S300: Sensing the object or its moving track through the pixel array unit 70;

Step S302: Calculate the sensing area 704 corresponding to the object or its movement track;

Step S304: generating a column selection signal to control the pixels in the pixel array unit 70 to output the generated signal;

Step S306: Calculate the first pixel and the last pixel of each column located in the sensing area 704;

Step S308: read from the first pixel to the last pixel of each column in a column-based order; and

Step S310 : Output signals generated by the pixels P1 , P2 , P5 , P6 , and P9 in the sensing area 704 .

Please refer to FIG. 19 . FIG. 19 is a flowchart of an operating method of a CMOS image sensor according to another embodiment of the present invention. Please also refer to FIG. 16 , in conjunction with the above-mentioned CMOS image sensor 7, if the sensing area 704 exceeds the physical area of the pixel array unit 70, the operation method of the CMOS image sensor of the present invention may include the following steps:

Step S400: Sensing the object or its moving track through the pixel array unit 70;

Step S402: Calculate the sensing area 704 corresponding to the object or its movement track;

Step S404: generating a column selection signal to control the pixels in the pixel array unit 70 to output the generated signal;

Step S406: Determine whether the sensing area 704 exceeds the solid area of the pixel array unit 70, if yes, execute step S408, if not, execute step S410;

Step S408: add virtual pixel P10 to the excess part;

Step S410: Calculate the first pixel and the last pixel of each column in the sensing area 704;

Step S412: Read from the first pixel to the last pixel of each column in a column-based order; and

Step S414 : Output the signals generated by the pixels P1 , P2 , P5 , P6 , and P9 in the sensing area 704 and the virtual pixel P10 (if any).

Compared with the prior art, the present invention uses a multiplexer to control the pixel data output, so that the logic circuit can define the slope of the scan line selected by each column selection signal by controlling the multiplexer. In addition, the present invention can also first read the pixel data in the sensing area in a row-based order, and then convert the output data in the row-based order into a column-based order through the image register. Furthermore, the present invention can also add a logic circuit to the readout circuit to calculate the starting point (that is, the first pixel) and the end point (that is, the last pixel) of each column in the sensing area according to the sensed object or its moving track. pixel), and then control the readout circuit to output the pixel data of the sensing area. Since the present invention only needs to output the pixel data in the sensing area corresponding to the object or its moving track, the operating frequency and power consumption of the system can be greatly reduced. In addition, when the logic circuit judges that the sensing area exceeds the physical area of the pixel array unit, the readout circuit will add dummy pixels in the excess part to keep the time of each scan constant, thereby simplifying the calculation of the exposure time.

The above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made according to the claims of the present invention shall fall within the scope of the present invention.

Claims (5)

1. the method for operation of a complementary MOS image sensor is characterized in that, said method comprises the following steps:

Through a pixel-array unit sensing one object; Said pixel-array unit comprises M pixel and P multiplexer; In the said M pixel each respectively with one of them electric connection of a said P multiplexer, M is a positive integer, P one is less than or equal to the positive integer of M;

Calculate a sensing region of corresponding said object, said sensing region comprises N pixel in the said M pixel, and N one is less than or equal to the positive integer of M;

Produce an array selecting signal; And

Control is supplied to a said N pixel with Q multiplexer of said N pixel electric connection with said array selecting signal, and Q one is less than or equal to N and is less than or equal to the positive integer of P;

In order to classify said N the signal that pixel produced that main order reads said sensing region as.

2. method of operation as claimed in claim 1 is characterized in that said method also comprises the following steps:

When said sensing region exceeds an entity area of said pixel-array unit, add at least one virtual pixel in the part that exceeds, and said sensing region is a parallelogram.

3. method of operation as claimed in claim 1; It is characterized in that; As P during less than M, at least two pixels in the said M pixel are electrically connected to a multiplexer in the said P multiplexer simultaneously, and said at least two pixels are arranged in the different rows and the same row of said pixel-array unit.

4. the method for operation of a complementary MOS image sensor is characterized in that, said method comprises the following steps:

Through a pixel-array unit sensing one object, said pixel-array unit comprises M pixel, and M is a positive integer;

Calculate a sensing region of corresponding said object, said sensing region comprises N pixel in the said M pixel, and N one is less than or equal to the positive integer of M;

Produce an array selecting signal, to control said M the pixel output signal that it was produced;

Calculating is arranged in first pixel and last pixel of each row of said sensing region;

Read to said last pixel in order to classify main order as from said first pixel of each row; And

Export a said N signal that pixel produced.

5. method of operation as claimed in claim 4 is characterized in that said method also comprises the following steps:

When said sensing region exceeds an entity area of said pixel-array unit, add at least one virtual pixel in the part that exceeds, and said sensing region is a parallelogram.

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