KR20090084204A - Image sensor for motion detection and optic pointing device using it - Google Patents

Abstract

An image sensor and an optic pointing device using the same are provided to perform an image data signal processing function without an A/D converter and a pre-filter, thereby outputting a digital signal. A photo cell(1121) generates an analog signal having a voltage level corresponding to a received light amount. A comparator(1122) compares the analog signal of the photo cell with an analog signal of an adjacent pixel in response to a shutter control signal to output a digital signal for motion calculation. The comparator compares the analog signal of the photo cell with a reference voltage to output a digital signal for controlling a shutter. A switch(1123) transmits a digital signal for calculating motion and the digital signal for controlling the shutter in response to a pixel selection signal.

Description

Image sensor and optical pointing device using same {IMAGE SENSOR FOR MOTION DETECTION AND OPTIC POINTING DEVICE USING IT}

The present invention relates to an image sensor and an optical pointing device, and more particularly, to an image sensor that detects light and processes an image data signal, and an optical pointing device that can variously control a shutter-on time using the same.

Conventional image sensors consist of an N x N pixel array to obtain a two-dimensional image of the subject, each pixel in the pixel array generates an analog signal having a voltage value corresponding to the brightness of the corresponding image area, and the image sensor Outputs N ² analog signals generated from each pixel.

1 shows an internal block diagram of an optical pointing device including a conventional image sensor, wherein the conventional optical pointing device includes an image sensor 1, an A / D converter 2, and a pre-filter 3. And an image processor 4 and a shutter control circuit 5.

Accordingly, the image sensor 1 acquires a two-dimensional image of the object, and generates and outputs N ² output signals having analog voltage values corresponding to the brightness of each of the areas of the acquired image.

The A / D converter 2 converts each of the output signals output from the image sensor 1 into a digital signal having an n bit structure (hereinafter referred to as an "n bit digital signal"), and is pre-filtered. (3) converts each n-bit digital signal output from the converted A / D converter 2 into a digital signal having a 1-bit structure (hereinafter referred to as "1 bit digital signal").

The image processor 4 detects the image of the object using the 1-bit digital signals converted through the pre-filter 3, and detects the image of the currently detected object and previously. The motion value V (K) is calculated by comparing the calculated images of the object, and the calculated motion value V (K) is output.

At this time, the shutter control circuit 5 generates the shutter control signal CSH and provides it to the image sensor 1 in response to the n-bit digital signal output from the A / D converter 2.

The shutter control signal CSH controls the exposure time of the image sensor 1 so that the amount of light incident on the image sensor 1 is always kept within a certain range, so that the image sensor 1 displays an image of an accurate object. It plays a role to acquire.

As described above, the conventional optical pointing device minimizes the number of bits of data necessary for calculating a motion value and provides the image processor with fast response.

However, in the conventional optical pointing device, an A / D converter and a prefilter must be provided in order to provide a minimized 1-bit digital signal to the image processor. Therefore, the layout of the optical pointing device is different from that of the A / D converter. There was a problem of increasing by the area of the prefilter. That is, when the conventional optical pointing device is implemented as a semiconductor integrated circuit, there is a problem that the chip size becomes large.

In addition, the shutter control signal CSH in which the image sensor 1 controls the exposure time in order to acquire an image of the correct object is simply proportional to the amount of light incident by the image sensor 1 to acquire the image of the object. Since it is adjusted in proportion to the signal having a voltage value, there was a limit that the shutter on time cannot be controlled in various ways.

It is an object of the present invention to provide an image sensor capable of outputting a digital signal by performing an image data signal processing function without having an A / D converter and a prefilter.

Another object of the present invention is to provide an optical pointing device capable of controlling the shutter on time in various ways compared with output signals, various reference voltages or shutter control signals of a plurality of adjacent pixels in the image sensor to achieve the above object. will be.

The image sensor of the present invention for achieving the above object comprises a photo cell for receiving light and generating an analog signal having a voltage level corresponding to the received light amount; A comparator for comparing the analog signal of the photocell and the analog signal of an adjacent pixel in response to the shutter control signal and outputting a digital signal for motion calculation or comparing the analog signal of the photocell with a reference voltage and outputting a shutter control digital signal ; And a switch for transmitting the motion calculation digital signal and the shutter control digital signal in response to a pixel selection signal.

The photocell of the image sensor of the present invention for achieving the above object is characterized in that it comprises a photodiode for generating a photocurrent corresponding to the amount of light received.

The comparator of the image sensor of the present invention for achieving the above object outputs a first signal when the analog signal of the photocell is greater than the analog signal or reference voltage of the adjacent pixel, and the analog signal of the photocell is adjacent to the photocell. And a latch type comparator for outputting a second signal if the pixel is smaller than the analog signal or the reference voltage of the pixel.

The first signal of the image sensor of the present invention for achieving the above object is the motion calculating digital signal and the shutter control digital signal of which the voltage level is a high level, and the second signal is the voltage level of the low level And a digital signal for motion calculation and a digital signal for shutter control.

According to another aspect of the present invention, there is provided an optical pointing device including: a reference voltage generator configured to generate a reference voltage; The apparatus includes a plurality of pixels and receives light to generate a plurality of analog signals corresponding to the received light amount, and compares the analog signals of adjacent pixels among the plurality of pixels in response to a shutter control signal for motion calculation. An image sensor outputting a digital signal or outputting a shutter control digital signal by comparing the analog signal of the plurality of pixels with the reference voltage; A signal selector which receives the motion calculation digital signal and the shutter control digital signal and selects and outputs in response to a shutter control section selection signal; Receives the motion calculation digital signal to obtain an image of a subject to output a motion value of the optical pointing device and the shutter control section selection signal, and receives the shutter control digital signal to obtain a high level count value and a maximum count value and And a shutter controller and a motion controller for outputting a shutter control signal in comparison with the minimum count value.

The motion calculation and shutter control unit of the optical pointing device according to the present invention for achieving the above another object generates a reset signal and a pixel selection signal, and receives an image of a subject by receiving the motion calculation digital signal to receive the optical signal. An image processor configured to output a movement value of the pointing device and the shutter control section selection signal; The maximum count value and the minimum count value of which the voltage level is high level are preset in response to the shutter control digital signal, and the number of the high level of the shutter control digital signal is compared with the maximum count value and the minimum count value. And a shutter control circuit for outputting the shutter control signal.

The image sensor of the optical pointing device according to the present invention for achieving the above another object comprises: a photo cell for receiving the light and generating the analog signal having a voltage level corresponding to the received light amount; In response to the shutter control signal, the analog signal of adjacent pixels among the plurality of pixels is output to output the motion calculation digital signal, or the analog signal of the plurality of pixels is compared with the reference voltage to control the shutter digital. A comparator for outputting a signal; And a switch configured to receive the motion calculation digital signal and the shutter control digital signal to switch in response to the pixel selection signal.

The image processor of the optical pointing device according to the present invention for achieving the other object is the reset signal for initializing the plurality of pixels, the pixel selection signal for selecting at least one of the plurality of pixels, the The shutter control section selection signal for selecting a shutter control frame time section for comparing the output signal of the selected pixel with the reference voltage is generated and output to the image sensor, and the motion calculation digital signal is applied to the image sensor. Acquiring an image of the subject, comparing the image of the currently acquired subject with the image of the subject previously acquired, and calculating and outputting a motion value of the optical pointing device.

The shutter control circuit of the optical pointing device according to the present invention for achieving the above another object outputs the shutter control signal for reducing the shutter on time if the number of the high levels of the shutter control digital signal is equal to or greater than the maximum count value. The shutter control signal for increasing the shutter on time is output when the number of times the shutter control digital signal is high level is less than the minimum count value. If the value is greater than the shutter control time for maintaining the shutter on time, characterized in that for outputting.

The shutter control circuit of the optical pointing device according to the present invention for achieving the above another object sets in advance a maximum count value and a minimum count value at which the shutter control digital signal is at a high level, and the shutter control digital signal is at a high level. The reference voltage selection signal may be output by comparing the number of phosphors with the maximum count value and the minimum count value.

The reference voltage generator of the optical pointing device according to the present invention for achieving the above object to generate a plurality of reference voltages by receiving the voltage from the outside; The method may further include a multiplexer configured to receive the plurality of reference voltages and select one reference voltage in response to the reference voltage selection signal.

The shutter control circuit of the optical pointing device according to the present invention for achieving the above another object is a reference of the lower voltage level among the plurality of reference voltages when the number of the high level of the shutter control digital signal is greater than or equal to the maximum count value. Outputs the reference voltage selection signal for selecting a voltage, and if the value is less than the maximum count value, compares the number of the shutter control digital signals with a high level with the minimum count value and is less than the minimum count value, among the plurality of reference voltages. And outputting the reference voltage selection signal for selecting a reference voltage having a high voltage level, and outputting the reference voltage selection signal for maintaining the reference voltage if the minimum count value is exceeded.

The optical pointing device according to the present invention for achieving the above another object is an image sensor having a plurality of pixels for receiving light in response to the reset signal and the pixel selection signal, and generates and outputs an analog signal corresponding to the received light amount ; Receiving the plurality of analog signals in response to a shutter control signal to compare the voltage level to generate a first comparison digital signal, and one of the plurality of analog signals and the maximum reference voltage or the minimum reference voltage, respectively A comparator configured to receive and compare voltage levels to generate and output second and third comparison digital signals; The first comparison digital signal is applied to calculate a motion value of the optical pointing device, and the second and third comparison digital signals are applied to the count value having a high level and the maximum count value at which the first comparison digital signal is a high level. And a motion controller and a shutter controller for outputting a shutter control signal in comparison with the minimum count value.

The comparison unit of the optical pointing device according to the present invention for achieving the above another object is a first to generate and output a first comparison digital signal by comparing the voltage level in response to the shutter control signal by receiving the plurality of analog signals Comparator; And a second comparator configured to receive one of the plurality of analog signals and the maximum reference voltage or the minimum reference voltage, respectively, to compare voltage levels to generate and output second and third comparison digital signals. It is done.

The motion calculation and shutter control unit of the optical pointing device according to the present invention for achieving the above another object generates the reset signal and the pixel selection signal, and receives the first comparison digital signal to obtain an image of the subject. An image processor configured to calculate and output a motion value of the optical pointing device; The maximum count value and the minimum count value at which the first comparison digital signal is at a high level are preset, and the maximum number is the number at which the second comparison digital signal is at a high level, and the number at which the third comparison digital signal is at a high level. And a shutter control circuit for outputting the shutter control signal in comparison with a count value and the minimum count value, respectively.

According to another aspect of the present invention, there is provided an optical pointing device including: a reference voltage generator configured to generate a maximum reference voltage and a minimum reference voltage by receiving a voltage from an external device; A row selector configured to output a plurality of row select signals for selecting pixels in a vertical direction by designating row addresses of a plurality of pixels in the image sensor; A column selector configured to designate pixels in a horizontal direction in response to the pixel select signal, and to select one pixel at a point that intersects a row address designated as one of the plurality of row select signals to receive and transmit the analog signal; It is characterized by including.

To achieve the above object, the column selector of the optical pointing device according to the present invention includes a plurality of switches that are switched in response to the pixel selection signal to receive and transmit the analog signal of the pixel selected from the image sensor. Characterized in that.

The image sensor of the optical pointing device according to the present invention for achieving the above another object performs an initialization operation in response to the reset signal and at least one pixel is selected in response to the pixel selection signal to obtain an image of the subject And the plurality of pixels composed of photo cells for generating the analog signal having a voltage value proportional to the received light amount.

The first comparator of the optical pointing device according to the present invention for achieving the above another object is applied to the voltage signals of the selected pixels to compare the voltage level in response to the shutter control signal, one of the selected pixels If the output signal voltage value of the other than the output signal voltage value of one pixel is greater than the first comparison digital signal having a high level, and if the first comparison digital signal having a low level is generated and outputs. It is done.

The image processor of the optical pointing device according to the present invention for generating the above object to generate and output the reset signal for initializing the plurality of pixels and the pixel selection signal for selecting the at least one pixel, Receiving an image of a subject by receiving a first comparison digital signal, and comparing the image of the currently acquired object with the image of the previously acquired object to calculate and output a motion value of the optical pointing device. It features.

The second comparator of the optical pointing device according to the present invention for achieving the above another object is to receive a signal of one of the voltage signals of the selected pixels and the maximum reference voltage to compare the voltage level, Generating a second comparison digital signal having a high level when the signal voltage value of one of the voltage signals is greater than the maximum reference voltage voltage value, and generating and outputting the second comparison digital signal having a low level when the signal voltage value is greater than the maximum reference voltage voltage value; It features.

The second comparator of the optical pointing device according to the present invention for achieving the above another object is to receive a signal of one of the voltage signals of the selected pixels and the minimum reference voltage to compare the voltage level, When the signal voltage value of one of the voltage signals is greater than the minimum reference voltage voltage value, generating the third comparison digital signal having a high level, and generating and outputting the third comparison digital signal having a low level if small. It features.

The shutter control circuit of the optical pointing device according to the present invention for achieving the above another object may receive the shutter control signal for reducing the shutter on time if the number of the second comparison digital signals is at a high level is greater than or equal to the maximum count value. Outputs the shutter control signal that increases the shutter on time when the number is less than the maximum count value when the third comparison digital signal is less than the minimum count value when the number is less than the maximum count value; When the minimum count value is exceeded, the shutter control signal for maintaining the shutter on time may be output.

In accordance with another aspect of the present invention, an optical pointing device performs an initialization operation in response to the reset signal, and at least one pixel is selected in response to the pixel selection signal so that the voltage value is proportional to the received light amount. A plurality of shutter control pixels for generating and outputting a plurality of shutter control analog signals having a; And a shutter control signal selector which receives the plurality of shutter control analog signals and selects and outputs at least one shutter control analog signal in response to a shutter control analog signal selection signal from the shutter control circuit. It is done.

The second comparator of the optical pointing device according to the present invention for achieving the above another object is to compare the voltage level by receiving one of the plurality of analog signals and the at least one shutter control analog signal 4 can be generated and output the comparison digital signal.

The second comparator of the optical pointing device according to the present invention for achieving the above another object has a high level if the signal voltage value of one of the voltage signals of the selected pixels is greater than the analog signal voltage value for the shutter control. A fourth comparison digital signal is generated, and if it is small, the fourth comparison digital signal having a low level is generated and output.

The shutter control circuit of the optical pointing device according to the present invention for achieving the above another object may receive the shutter control signal for reducing the shutter on time if the number of the fourth comparison digital signals is at a high level is greater than or equal to the maximum count value. Outputs the shutter control signal that increases the shutter on time when the number of the fourth comparison digital signals is high level is less than the minimum count value when the number is less than the maximum count value; The shutter control signal for outputting the shutter control signal maintaining the shutter on time when the minimum count value is exceeded, and the shutter control analog signal selection signal for selecting the at least one shutter control analog signal by receiving the plurality of shutter control analog signals. It characterized in that the output.

The plurality of shutter control pixels of the optical pointing device according to the present invention for achieving the above another object are a part of the outside of the plurality of pixels, a periphery of the outside of the plurality of pixels, or a part of the inside of the plurality of pixels. Characterized in that can be arranged in.

In accordance with another aspect of the present invention, an optical pointing device is connected in parallel with the shutter control signal selector to receive a plurality of shutter control analog signals to compare outputs to determine whether the optical pointing device is picked up. A pick-up state detector for outputting a hold request signal; The apparatus may further include a surface state detection unit connected in parallel with the shutter control signal selection unit and outputting a surface information signal for identifying a state of the surface of the work bench by receiving the plurality of shutter control analog signals to compare outputs to an external host computer. It is characterized by being.

The image sensor of the present invention and the optical pointing device using the same can output a digital signal without having a separate high-resolution A / D converter and a prefilter, thereby not only reducing the layout area, but also in the image sensor. The shutter-on time is varied by comparing the voltage level of the output signal of the photocell positioned in the pixel and the photocell positioned in the pixels adjacent to the top, bottom, left, and right with the reference voltage or the shutter control signals when each pixel is composed of only the photo cells. It can be adjusted.

Hereinafter, an image sensor and an optical pointing device using the same according to the present invention will be described with reference to the accompanying drawings.

FIG. 2 is a block diagram of an optical pointing device including an image sensor according to a first embodiment of the present invention, and includes a reference voltage generator 14, an image sensor 10, a demultiplexer 16, and an image processor 11. And a shutter control circuit 12.

Here, the image processor 11 and the shutter control circuit 12 may be merged to constitute a motion calculation and shutter control unit, or the demultiplexer 16 may be merged to the motion calculation and shutter control unit. May be integrated into a single semiconductor chip.

3 is a configuration diagram of an image sensor 10 in an optical pointing device according to a first embodiment of the present invention, and includes a plurality of pixels 111 to 1 (N) N configured as an N × N pixel array. Each pixel 112 includes a photo cell 1121, a comparator 1122, and a switch 1123.

FIG. 4 is a diagram illustrating a relationship between frames divided by each operation time and a shutter control section selection signal SCS of the optical pointing device according to the first embodiment of the present invention, and includes a plurality of motion calculation frames M-1. To Mm) and the plurality of shutter control frames S-1 to Sn are multiplexed while sharing time.

For example, in FIG. 4, if the image consists of 3400 frames per second, the output signal of the photo cell 1121 positioned in the pixel 112 by receiving image data from the N × N pixels during each motion calculation frame time. (PC12) is compared with the output signal PC13 of the photo cell 1121 located in the adjacent pixel 113, and image data is applied from the N × N pixels during each shutter control frame time to receive the image data in the corresponding pixel 112. The output signal PC12 of the located photo cell 1121 is compared with a reference voltage.

When the shutter control signal CSH is at a high level, the motion calculation frames M-1 to Mm and the shutter control frames S-1 to Sn are combined and multiplexed so that a total of 3400 pieces share a time of 1 second. As a time interval in which the shutter control frames S-1 to Sn are selected in the state, it is also possible to select one or a plurality of shutter control frames.

The functions of the respective blocks of the optical pointing device according to the second embodiment of the present invention will be described with reference to FIGS. 2 to 4.

The reference voltage generator 14 receives a voltage VDD from an external source and generates a reference voltage Vref for comparing a level with voltage signals output from each of the plurality of pixels 111-1 (N) (N). do.

The image sensor 10 performs an initialization operation in response to the reset signal RS of the image processor 11, acquires a two-dimensional image of the subject, and generates an analog signal having a voltage value proportional to the amount of incident light. And an output signal of the photo cell 1121 provided in the comparator 1122 of the pixel 112 and the comparator 1132 of the adjacent pixel 113 and positioned within the adjacent pixel 113 in response to the shutter control signal CSH. The 1 bit digital signal sig_m for motion calculation or the 1 bit digital signal sig_sh for shutter control is output in comparison with the PC13 or the reference voltage Vref.

The demultiplexer 16 receives and outputs a 1 bit digital signal sig_m for motion calculation and a 1 bit digital signal sig_sh for shutter control in response to the shutter control section selection signal SCS.

The image processor 11 may include a reset signal RS for initializing the image sensor 10, a pixel selection signal PS for selecting one pixel among the plurality of pixels 111-1 (N), and a plurality of pixels. Shutter control for receiving image data from the plurality of pixels 111-1 (N) (N) and comparing the output signal PC12 of the photo cell 1121 positioned in the pixel 112 with the reference voltage Vref. A shutter control section selection signal (SCS) for selecting a frame time section is output, and a 1-bit digital signal sig_m for motion calculation is received from the demultiplexer 16 to obtain an image of an object to obtain a motion value (V ( Calculate and print K)).

The shutter control circuit 12 receives the 1-bit digital signal sig_sh for shutter control and counts the number of high level signals to adjust the shutter on time by comparing the maximum and minimum count values of the preset high level signal, respectively. The shutter control signal CSH is outputted.

The operation of the optical pointing device according to the second embodiment of the present invention will be described with reference to FIGS. 2 and 4 as follows.

First, assuming that the image sensor 10 is composed of an 18 x 18 pixel array and a total of 324 pixels, the voltage value of the output signal PC12 of the photo cell 1121 located in the pixel 112 is When the number of shutter control 1-bit digital signals sig_sh having a high level greater than the voltage value of the reference voltage Vref is 200 or more, the incident light amount is the maximum count value which is too large. It is exemplified as a case where the minimum count value is too small.

When the reference voltage generator 14 receives the voltage VDD from the outside and generates the reference voltage Vref, the plurality of pixels 111-1 (N) (N) of the image sensor 10 are reset signals. A two-dimensional image of the subject is acquired under the control of the RS and the shutter control signal CSH, and the photo cells embedded in each pixel are applied to the amount of incident light after performing an initialization operation in response to the reset signal RS. Generate an analog signal with a proportional voltage value.

The generated analog signal PC12 is provided to the comparator 1122 of the corresponding pixel 112 and the comparator 1132 of the adjacent pixel 113, and the comparator 1122 responds to the shutter control signal CSS. The output signal PC12 of the photo cell 1121 located in 112 is compared with the output signal PC13 or reference voltage Vref of the photo cell 1131 located in the adjacent pixel 113.

That is, when the shutter control signal CSH is at the low level, the output signal PC12 of the photocell 1121 positioned in the pixel 112 is output from the photocell 1131 positioned in the adjacent pixel 113. Compared to PC13, the voltage of the output signal PC12 of the photocell 1121 located in the pixel 112 is the voltage of the output signal PC13 of the photocell 1131 located in the adjacent pixel 113. If the value is greater than the value, the 1-bit digital signal sig_m for motion calculation having a high level is generated, and if the value is smaller, the 1-bit digital signal sig_m for the motion calculation with a low level is generated and output.

When the shutter control signal CSH is at the high level, the photocell positioned in the pixel 112 is compared with the reference voltage Vref by comparing the output signal PC12 of the photocell 1121 positioned in the pixel 112 with the reference voltage Vref. When the voltage value of the output signal PC12 of 1121 is greater than the voltage level of the reference voltage Vref, a 1-bit digital signal sig_sh for controlling the shutter is generated having a high level, and 1-bit for controlling the shutter having a low level if small. A digital signal sig_sh is generated and output.

The demultiplexer 16 receives the 1-bit digital signal sig_m for motion calculation and the 1-bit digital signal sig_sh for the shutter control in response to the shutter control section selection signal SCS. The signal sig_m is selected and output, and in the case of the high level, the 1-bit digital signal sig_sh for shutter control is selected and output.

The image processor 11 receives the N ² motion calculation 1 bit digital signals sig_m from the demultiplexer 16 and acquires an image of the object using the same, and obtains an image of the currently obtained object. The motion value V (K) is calculated and output by comparing an image of a previously obtained object.

The shutter control circuit 12 receives the 1-bit digital signal sig_sh for shutter control from the demultiplexer 16 to count the number of high level signals, and compares them with the maximum count value and the minimum count value of the preset high level signal. A shutter control signal CSH for adjusting the shutter on time is output.

That is, when the number of high-level shutter control 1-bit digital signals sig_sh output from the demultiplexer 16 is 200 or more, which is the maximum count value of the preset high level signal, the shutter control signal CSH decreases the shutter-on time. If it is less than 200 which is the maximum count value, it compares with 100 which is the minimum count value of the preset high level signal.

If the minimum count value is 100 or less, the shutter control signal CSH for increasing the shutter on time is output. If the minimum count value is more than 100, the shutter on time is maintained.

FIG. 5 is a block diagram of an improved reference voltage generator 14 in the optical pointing device according to the first embodiment of the present invention. The reference voltage generator 14, the image sensor 10, and the demultiplexer 16 are illustrated in FIG. ), An image processor 11, a shutter control circuit 12, and the reference voltage generator 14 includes a reference voltage generator 15 and a multiplexer 17.

Compared to the optical pointing device according to the first embodiment of the present invention shown in FIGS. 2 to 4, the functions and operations of the blocks except for the reference voltage generator 14 are the same, and thus detailed descriptions thereof will be omitted.

However, the difference is that the reference voltage Vref generated by the reference voltage generator 14 may be adaptively variable to a count value obtained in a time interval in which the shutter control frame is selected. The maximum reference voltage and the minimum reference voltage It can be selected and used after generating a plurality of voltage levels, including.

That is, the reference voltage Vref generated by the reference voltage generator 14 is adaptively changed according to the count value obtained in the time interval in which the shutter control frame is selected. The high level shutter 1 is output from the demultiplexer 16. If the number of bit digital signals (sig_sh) is 200 or more, which is the maximum count value of the preset high level signal, the reference voltage Vref is increased or decreased. Compare with 100 count values.

If the minimum count value is 100 or less, the reference voltage Vref is increased or decreased. If the minimum count value is more than 100, the reference voltage Vref is maintained.

To this end, the reference voltage generator 14 receives the voltage VDD from the outside and selects the reference voltage from the shutter control circuit 12 among the reference voltage generator 15 and the plurality of reference voltages to generate the plurality of reference voltages. The multiplexer 17 may select one reference voltage in response to the signal and apply the same to the image sensor 10.

As described above, the optical pointing device according to the second embodiment of the present invention not only provides the same effect as employing an A / D converter having a considerable resolution because the comparator in the unit pixel operates in a latched manner, and also a shutter control signal. The output signal PC13 or the reference voltage of the photocell 1131 selectively located in the adjacent pixel 113 with the output signal PC12 of the photocell 1121 located in the pixel 112 in response to (CSH). Compare the reference voltage (Vref) to control the shutter on time, and adaptively vary the reference voltage (Vref) according to the count value of the high-level shutter control 1-bit digital signal (sig_sh) in the time interval when the shutter control frame is selected It can be used to control the shutter on time in various ways.

In the above description, the number of pixels of the image sensor 10 is the same as the x-axis and the y-axis for convenience of understanding, but it is obvious that the number of pixels on the x-axis and the y-axis may vary, and the output of the reference voltage generator 14 Although the selection can be selected in the multiplexer 17, it is natural that a variable reference voltage can be made by implementing various circuits as part of the reference voltage generator 15.

Next, FIG. 6 is an overall block diagram of the optical pointing device including the image sensor 100 according to the second embodiment of the present invention. The image sensor 100, the row selector 18, and the column selector 19 are illustrated. ), A reference voltage generator 24, first to third comparators 20, 23, and 25, an image processor 11, and a shutter control circuit 22.

FIG. 7 is a detailed block diagram of an image sensor 100, a row selector 18, a column selector 19, and a first comparator 20 in an optical pointing device according to a second embodiment of the present invention. The selector 19 includes a plurality of column switches SW1 to SWN.

Referring to FIG. 6, the image sensor 100 of the present invention includes a plurality of pixels 211 to 2 (N) (N) formed of an N × N pixel array, and each pixel 212 is illustrated in FIG. 2. Unlike the image sensor 10 according to the first exemplary embodiment of the present invention, the photo cell 1121 is configured only, and the comparator 1122 and the switch 1123 of FIG. 2 are provided outside the pixel 212.

Here, the image processor 11 and the shutter control circuit 22 may be merged to form a motion calculation and shutter control unit, or the first to third comparators 20, 23, and 25 may be merged to form one comparator. In addition, all the blocks may be integrated into one semiconductor chip.

6 and 7, the functions of the respective blocks of the optical pointing device according to the second embodiment of the present invention will be described below.

The plurality of pixels 211 to 2 (N) N of the image sensor 100 obtain a two-dimensional image of the subject under the control of the reset signal RS and the shutter control signal CSH, and apply to each pixel. The built-in photo cells generate an analog signal having a voltage value proportional to the amount of incident light after performing an initialization operation in response to the reset signal RS.

The row selector 18 selects a plurality of row select signals PS_r1 to pixels in the vertical direction by specifying row addresses of the plurality of pixels 211 to 2 (N) (N) in the image sensor 100. PS_rN) is output.

The column selector 19 switches a plurality of column switches SW1 to SWN in response to the pixel column select signal PS_c to designate pixels in the horizontal direction, thereby mapping them to the row address designated by the row selector 18. After selecting one pixel to be applied, voltage signals proportional to the amount of light are received from the pixel and transmitted.

The reference voltage generator 24 receives a voltage VDD from an external source, and the maximum and minimum reference voltages Vref_max to compare a level with voltage signals output from each of the plurality of pixels 211 ˜ 2 (N) (N). , Vref_min).

The first comparator 20 receives the voltage signals of the selected pixels transmitted from the column selector 19 and compares the voltage levels in response to the shutter control signal CSH to have a first comparison digital signal having a high level or a low level. Generate and output (Sig_c1).

The second and third comparators 23 and 25 of FIG. 6 may include one signal among voltage signals of pixels selected from the column selector 19 of FIG. 7 and a maximum reference voltage or a minimum reference from the reference voltage generator 24. The voltages Vref_max and Vref_min are respectively applied to generate and output second and third comparison digital signals Sig_c2 and Sig_c3 having high or low levels by comparing voltage levels.

The image processor 11 generates a reset signal RS and pixel selection signals PS_r and PS_c for initializing a pixel and provides the same to the image sensor 100 and outputs N ² output from the first comparator 20. The first comparison digital signal Sig_c1 is applied to acquire an image of the object using the first comparison digital signal Sig_c1, and the motion value (B) is compared by comparing the image of the currently acquired object with the image of the previously obtained object. Calculate V (K)) and output it.

The shutter control circuit 22 compares the count value of the high level signal output from the second and third comparators 23 and 25 with the maximum count value and minimum count value of the preset high level signal, respectively, for the shutter on time. The shutter control signal CSH for controlling the output is output to the first comparator 20.

An operation of the optical pointing device according to the third embodiment of the present invention will be described with reference to FIGS. 6 and 7 as follows.

First, as in the second embodiment of the present invention, assuming that the image sensor 100 is composed of an 18 x 18 pixel array and a total of 324 pixels, the photo cell 1121 positioned in the pixel 212 is provided. The number of 1-bit digital signals having a high level is greater than the voltage value of the output signal PC13 of the photo cell 1131 located in the left pixel 213 at which the voltage value of the output signal PC12 is selected. It is exemplified as a case where the amount of incident light is too large when there are more than two, and when it is 100 or less, it is a case where the amount of incident light is too small by a minimum count. Although the pixel 213 positioned on the left side is taken as an example for convenience of understanding, the pixel 213 may be a pixel located at an arbitrary position in the image sensor 100.

The plurality of pixels 211 to 2 (N) N of the image sensor 100 receive a reset signal RS and a shutter control signal CSH from the image processor 11 in response to the two-dimensional image of the subject. Acquire an image.

For example, the photo cell 1121 embedded in one pixel 212 of the plurality of pixels 211-2 (N) (N) performs an initialization operation in response to the reset signal RS, and initializes. When is completed, an analog signal PC12 having a voltage value proportional to the amount of incident light is generated.

The row selector 18 and the column selector 19 sequentially designate pixels having a row address and a column address corresponding to the selection time set in the image processor 11 and the address number of the pixel to be selected, and read each one at a time. The analog image data output from the photo cell in the pixel is applied.

For example, when the image processor 11 designates the first row address (PS_r1), the image processor 11 receives the image data by designating the first row address up to the Nth column address and then designates the second row address (PS_r2). In this case, image data is applied by starting from the first column address up to the Nth column address, and when the entire pixel data is sequentially obtained, image data of one frame is received.

In this case, the row selector 18 specifies row addresses of the plurality of pixels 211 to 2 (N) (N) in the image sensor 100 to select row selection signals PS_r1 to PS_rN) is output, and the column selector 19 switches each column in response to the pixel column selection signal PS from the image processor 11 to designate pixels in the horizontal direction.

Accordingly, one pixel mapped at a point intersecting with the row address designated by the row select signals PS_r1 to PS_rN output from the row selector 18 is selected, and voltage signals proportional to the amount of light are transmitted from the corresponding pixel and output. do.

The first comparator 20 receives voltage signals Vsig_A and Vsig_B of pixels selected from the column selector 19 to compare voltage levels in response to the shutter control signal CSH from the shutter control circuit 22. If the voltage value of the output signal PC12 of the photo cell 1121 located in the pixel 212 is greater than the voltage value of the output signal PC13 of the photo cell 1131 located in the selected pixel 213 on the left A first comparison digital signal Sig_c1 having a high level is generated, and if it is small, a first comparison digital signal Sig_c1 having a low level is generated and output.

On the other hand, when the reference voltage generator 24 receives the voltage VDD from the outside and generates the maximum and minimum reference voltages Vref_max and Vref_min, the second comparator 23 performs the selection of the pixels selected from the column selector 19. One of the voltage signals Vsig_A and Vsig_B is applied with the maximum reference voltage Vref_max from the reference voltage generator 24 to compare the voltage levels and output the photocell 1121 positioned in the pixel 212. When the voltage value of the signal PC12 is greater than the voltage value of the maximum reference voltage Vref_max, the second comparison digital signal Sig_c2 having a high level is generated, and when the voltage value of the signal PC12 is low, the second comparison digital signal Sig_c2 having a low level is generated. Create and print

The third comparator 25 receives one of the voltage signals Vsig_A and Vsig_B of the pixels selected from the column selector 19 and the minimum reference voltage Vref_min from the reference voltage generator 24 to adjust the voltage level. In comparison, when the voltage value of the output signal PC12 of the photo cell 1121 positioned in the corresponding pixel 212 is greater than the voltage value of the minimum reference voltage Vref_min, a third comparison digital signal Sig_c3 having a high level is generated. If small, a third comparison digital signal Sig_c3 having a low level is generated and output.

The image processor 11 receives N ² first comparison digital signals Sig_c1 from the first comparator 20, obtains an image of the object by using the first comparison digital signal Sig_c1, and obtains an image of the currently acquired object. The motion value V (K) is calculated and output by comparing an image of a previously obtained object.

The shutter control circuit 22 compares the maximum reference voltage Vref_max with the voltage level from the second comparator 23 and the minimum reference voltage Vref_min from the third comparator 25 and the second comparison digital signal Sig_c2. And the third comparison digital signal Sig_c3 generated by comparing the voltage level with each other, the number of high level signals is counted, and the shutter on time is compared with the maximum count value and the minimum count value of the preset high level signal, respectively. Outputs a shutter control signal (CSH) for controlling

That is, 200 or more, which is the maximum count value of the high level signal in which the number of the high level second comparison digital signals Sig_c2 generated by comparing the maximum reference voltage Vref_max and the voltage level in the second comparator 23 is preset. In this case, the shutter control signal CSH for reducing the shutter-on time is output. If the maximum count value is less than 200, the second comparator 25 compares the minimum reference voltage Vref_min with the voltage level to generate a second high level. The number of comparison digital signals Sig_c2 is compared with 100, which is a minimum count value of a preset high level signal.

If the minimum count value is 100 or less, the shutter control signal CSH is increased to increase the shutter on time. If the minimum count value is more than 100, the shutter on time is maintained.

As described above, in the optical pointing device according to the second embodiment of the present invention, the first to third comparators 20, 23, and 25 are operated in a latch type like the comparator in the unit pixel according to the first embodiment of the present invention. In addition to providing the same effect as employing an A / D converter with a significant level of resolution, each pixel 212 in the image sensor 100 is positioned within the pixel 112 with only the photo cell 1121. Shutter by comparing the voltage level of the photocell 1121 and the output signal PC12 of the photocell 1131 positioned within the selected one pixel 113 with the maximum reference voltage Vref_max or the minimum reference voltage Vref_min. The on time can be adjusted in various ways.

Next, FIG. 8 is an overall block diagram of the optical pointing device including the image sensor 100 according to the third embodiment of the present invention. The image sensor 100, the row selector 18, and the column selector 19 are shown. ), A plurality of shutter control pixels 100-1 to 100-4, a shutter control signal selector 34, first and second comparators 30 and 33, an image processor 11, and a shutter control circuit 32. ).

FIG. 9 is a block diagram of another optical pointing device including the image sensor 100 according to the third embodiment of the present invention, and the voltage level of the optical pointing device according to the third embodiment of the present invention shown in FIG. The comparison unit 36, the pick-up state detection unit 37, and the surface state detection unit 39 are further provided.

The image sensor 100 according to the present exemplary embodiment includes a plurality of pixels 211 to 2 (N) (N) configured as an N × N pixel array, and each pixel 212 includes only a photo cell 1121 and a comparator. The location of 1122 and the switch 1123 outside the pixel 212 is the same as that of the optical pointing device according to the second embodiment of the present invention shown in FIG. 6, except that the reference voltage generator 24 is not provided. Instead, the plurality of shutter control pixels 100-1 to 100-4 and the shutter control signal selector 34 are separately provided.

Similarly, the image processor 11 and the shutter control circuit 32 may be merged to form a motion calculation and shutter control unit, or the first and second comparators 30 and 33 may be merged to form a single comparator. In addition, all the blocks may be integrated into one semiconductor chip.

8 and 9, the functions of the respective blocks of the optical pointing device according to the third embodiment of the present invention will be described below.

The functions of the image sensor 100, the row selector 18, the column selector 19, the first comparator 30, and the image processor 11 are optical pointing according to the second embodiment of the present invention illustrated in FIG. 3. Since it is the same as the apparatus, further detailed description is omitted here.

The plurality of shutter control pixels 100-1 to 100-4 are reset signals of the image processor 11 in the same manner as the plurality of pixels 211-2 (N) (N) of the image sensor 100. After performing the initialization operation in response to RS), a two-dimensional image of the subject is acquired to generate an analog signal having a voltage value proportional to the amount of incident light, but this is different for the shutter control, not the motion value calculation. There is a difference from the plurality of pixels 211 ˜ 2 (N) (N).

The shutter control signal selector 34 receives a plurality of shutter control signals S1 to S4 from the plurality of shutter control pixels 100-1 to 100-4 and receives a shutter control signal from the shutter control circuit 32. In response to the selection signal SCSS, at least one shutter control signal is selected and output (Sig_sh).

The second comparator 33 applies one of the voltage signals Vsig_A and Vsig_B of the pixels selected from the column selector 19 and one shutter control signal Sig_sh selected from the shutter control signal selector 34. The second comparison digital signal Sig_c2 for shutter control having a high level or a low level is generated by comparing the voltage levels.

The shutter control circuit 32 compares the count value of the high level signal output from the second comparator 33 with the maximum count value and minimum count value of the preset high level signal, respectively, to control the shutter on time. The signal CSH is output and provided to the first comparator 30.

Here, the plurality of shutter control pixels 100-1 to 100-4 may be disposed in a portion of the outer pixel array as shown in FIG. 8, but the outer periphery of the outer pixel array is further improved in order to further improve sensitivity characteristics. It may be arranged in a long area, or may be disposed in a part of the pixel array without a separate area outside in order to reduce the manufacturing cost of hardware and to spend more time for motion value calculation.

In addition, as shown in FIG. 9, the shutter control signal selector 34 is connected in parallel to apply the plurality of shutter control signals S1 to S4 from the plurality of shutter control pixels 100-1 to 100-4. It compares the output and judges whether the pick-up is separated from the worktable surface of the optical pointing device according to the relative difference of the voltage level and restricts the output of the motion signal to the outside of the optical pointing device, or generates the motion signal as "0". Surface information signal Sur_st for grasping the state of the work surface according to the relative difference between the pick-up state detector 37 for outputting the hold request signal Hold_req and the voltage levels of the plurality of shutter control signals S1 to S4. ) May additionally be provided with a surface state detection unit 39 for outputting the external host computer.

An operation of the optical pointing device according to the third embodiment of the present invention will be described with reference to FIGS. 8 and 9 as follows.

The operation of the image sensor 100, the row selector 18, the column selector 19, the first comparator 30, and the image processor 11 is performed by the optical pointing device according to the third embodiment of the present invention illustrated in FIG. 3. Since it is the same as the apparatus, further detailed description is omitted here.

First, as in the first and second embodiments of the present invention, assuming that the image sensor 100 is composed of an 18 x 18 pixel array, a total of 324 pixels, a photo cell located within the pixel 112. When the voltage value of the output signal PC12 of 1121 is greater than the voltage value of the selected shutter control signal Sig_sh, the number of the second comparison digital signals Sig_c2 for shutter control having a high level is 200 or more. It is a case where the light quantity is the maximum count value too much, and when it is 100 or less, it is illustrated that it is the case where the amount of incident light is a minimum count value with too little light.

The plurality of shutter control pixels 100-1 to 100-4 perform an initialization operation in response to the reset signal RS of the image processor 11, and then acquire a two-dimensional image of the subject to be proportional to the amount of incident light. When the shutter control analog signal having the voltage value is generated, the shutter control signal selector 34 receives the shutter control signals S1 to S4 from the plurality of shutter control pixels 100-1 to 100-4. In response, the at least one shutter control signal is selected and output (Sig_sh) in response to the shutter control signal selection signal SCSS from the shutter control circuit 32.

The second comparator 33 applies one of the voltage signals Vsig_A and Vsig_B of the pixels selected from the column selector 19 and one shutter control signal Sig_sh selected from the shutter control signal selector 34. The shutter control agent having a high level when the voltage value of the output signal PC12 of the photo cell 1121 positioned in the pixel 112 is greater than the voltage value of the selected shutter control signal Sig_sh. A second comparison digital signal Sig_c2 is generated, and if it is small, a second comparison digital signal Sig_c2 for shutter control having a low level is generated and output.

The shutter control circuit 32 reduces the shutter-on time when the number of the high level second comparison digital signals Sig_c2 generated by the second comparator 33 is 200 or more, which is a maximum count value of a preset high level signal. The shutter control signal CSH is output, and if it is less than 200 which is the maximum count value, it is compared with 100 which is the minimum count value of the preset high level signal.

If the minimum count value is 100 or less, the shutter control signal CSH for increasing the shutter on time is output. If the minimum count value is more than 100, the shutter on time is maintained.

Meanwhile, in FIG. 9, the pick-up state detector 37 is connected in parallel with the shutter control signal selector 34 so that the shutter control signals S1 through the shutter control pixels 100-1 through 100-4 may be connected. S4) is applied to compare the voltage levels, analyze the relative difference value, determine whether the optical pointing device is picked up, and output the hold request signal Hold_req.

In addition, the surface state detection unit 39 is connected in parallel with the shutter control signal selection unit 34 and the pick-up state detection unit 37 to output a plurality of shutter control signals from the plurality of shutter control pixels 100-1 to 100-4. Fields S1 to S4 are applied to compare the voltage levels, and output a surface information signal Sur_st that grasps the state of the work surface according to the relative difference of the voltage levels to an external host computer.

As described above, in the optical pointing device according to the third embodiment of the present invention, the first comparator 30 operates as a latch type like the comparator in the unit pixel according to the first embodiment of the present invention, and has a high resolution A /. Not only does it provide the same effect as employing the D converter, but it also selects the photocell 1121 positioned within the pixel 112 with each pixel 212 in the image sensor 100 composed of only the photocell 1121. Shutter control for outputting the voltage level of the output signal PC12 of the photo cell 1131 positioned in one pixel 113 of the top, bottom, left, and right sides, instead of the reference voltage, to the shutter control pixels 100-1 to 100-4. By comparing the signals S1 to S4, the shutter on time can be adjusted in various ways.

Although described above with reference to a preferred embodiment of the present invention, those skilled in the art various modifications and changes to the present invention without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

1 is a block diagram illustrating an interior of an optical pointing device including a conventional image sensor.

2 is a block diagram illustrating an optical pointing device including an image sensor according to a first embodiment of the present invention.

3 is a block diagram of the image sensor 10 in the optical pointing device according to the first embodiment of the present invention.

FIG. 4 is a diagram illustrating a relationship between frames divided by each operation time and a shutter control section selection signal SCS of the optical pointing device according to the first embodiment of the present invention.

5 is an overall block diagram of an improved reference voltage generator 14 in the optical pointing device according to the first embodiment of the present invention.

6 is a block diagram illustrating an optical pointing device including an image sensor 100 according to a second embodiment of the present invention.

FIG. 7 is a detailed block diagram of an image sensor 100, a row selector 18, a column selector 19, and a first comparator 20 in an optical pointing device according to a second embodiment of the present disclosure.

8 is a block diagram illustrating an optical pointing device including an image sensor 100 according to a third exemplary embodiment of the present invention.

9 is a block diagram of another optical pointing device including the image sensor 100 according to the third embodiment of the present invention.

Claims (29)

A photo cell for receiving light and generating an analog signal having a voltage level corresponding to the received amount of light; A comparator for comparing the analog signal of the photocell and the analog signal of an adjacent pixel in response to the shutter control signal and outputting a digital signal for motion calculation or comparing the analog signal of the photocell with a reference voltage and outputting a shutter control digital signal ; And  And a plurality of pixels including a switch for transmitting the motion calculation digital signal and the shutter control digital signal in response to a pixel selection signal. The method of claim 1, wherein the photo cell is And a photodiode for generating a photocurrent corresponding to the received amount of light. The method of claim 2, The comparator Outputs a first signal when the analog signal of the photocell is greater than the analog signal or reference voltage of the adjacent pixel; and outputs a second signal if the analog signal of the photocell is less than the analog signal or reference voltage of the adjacent pixel An image sensor comprising a latch type comparator for outputting. The method of claim 3, wherein The first signal is The motion calculation digital signal and the shutter control digital signal having a high voltage level, The second signal is And the motion calculation digital signal having a low voltage level and the shutter control digital signal. A reference voltage generator for generating a reference voltage; It includes a plurality of pixels and receives light to generate a plurality of analog signals corresponding to the received light amount, and compares the analog signals of adjacent pixels of the plurality of pixels in response to a shutter control signal for digital motion calculation An image sensor outputting a signal or outputting a shutter control digital signal by comparing the analog signal of the plurality of pixels with the reference voltage; A signal selector which receives the motion calculation digital signal and the shutter control digital signal and selects and outputs in response to a shutter control section selection signal; Receives the motion calculation digital signal to obtain an image of a subject to output a motion value of the optical pointing device and the shutter control section selection signal, and receives the shutter control digital signal to obtain a high level count value and a maximum count value and And a shutter control unit for calculating a motion and outputting a shutter control signal in comparison with a minimum count value. The method of claim 5, wherein The motion calculation and shutter control unit An image processor generating a reset signal and a pixel selection signal, receiving an image of a subject by receiving the motion calculation digital signal, and outputting a motion value of the optical pointing device and a shutter control section selection signal; The maximum count value and the minimum count value of which the voltage level is high level are preset in response to the shutter control digital signal, and the number of the high level of the shutter control digital signal is compared with the maximum count value and the minimum count value. And a shutter control circuit for outputting the shutter control signal. The method of claim 6, The image sensor is A photo cell that receives the light and generates the analog signal having a voltage level corresponding to the received amount of light; In response to the shutter control signal, the analog signal of adjacent pixels among the plurality of pixels is output to output the motion calculation digital signal, or the analog signal of the plurality of pixels is compared with the reference voltage to control the shutter digital. A comparator for outputting a signal; And  And a switch configured to receive the motion calculation digital signal and the shutter control digital signal to switch in response to the pixel selection signal. The method of claim 7, wherein The image processor A shutter control frame time interval for comparing the reset signal for initializing the plurality of pixels, the pixel selection signal for selecting at least one of the plurality of pixels, and the output signal of the selected pixel with the reference voltage Generating the shutter control section selection signal to be output to the image sensor; Receives the image of the subject by using the motion calculation digital signal, compares the image of the currently acquired subject with the previously acquired image of the subject, calculates and outputs a motion value of the optical pointing device. Optical pointing device, characterized in that. The method of claim 8, The shutter control circuit Outputting the shutter control signal for reducing the shutter-on time if the number of the high levels of the shutter control digital signal is equal to or greater than the maximum count value; Outputting the shutter control signal for increasing the shutter on time when the number of the shutter control digital signals is at a high level is less than the maximum count value when the number is less than the minimum count value; And outputting the shutter control signal that maintains the shutter on time if the minimum count value is exceeded. The method of claim 9, The shutter control circuit A maximum count value and a minimum count value at which the shutter control digital signal is at a high level are preset; And a reference voltage selection signal may be output by comparing the number of the high level of the shutter control digital signal with the maximum count value and the minimum count value. The method of claim 10, The reference voltage generator A reference voltage generator configured to receive the voltage from an external source and generate a plurality of reference voltages; And a multiplexer configured to receive the plurality of reference voltages and select one reference voltage in response to the reference voltage selection signal. The method of claim 11, The shutter control circuit Outputting the reference voltage selection signal for selecting a reference voltage having a low voltage level among the plurality of reference voltages when the number of the high levels of the shutter control digital signal is greater than or equal to the maximum count value; The reference voltage selection selects a reference voltage having a high voltage level among the plurality of reference voltages when the number of times that the shutter control digital signal is high level is less than the minimum count value when the value is less than the maximum count value. Outputs a signal, And outputting the reference voltage selection signal that maintains the reference voltage when the minimum count value is exceeded. An image sensor receiving light in response to a reset signal and a pixel selection signal, and generating and outputting a plurality of analog signals corresponding to the received light amount; The first comparison digital signal is generated by receiving the plurality of analog signals and comparing voltage levels in response to a shutter control signal, and generating one of the plurality of analog signals and the maximum reference voltage or the minimum reference voltage. A comparator configured to receive and compare voltage levels, respectively, to generate and output second and third comparison digital signals; The first comparison digital signal is applied to calculate a motion value of the optical pointing device, and the second and third comparison digital signals are applied to the count value having a high level and the maximum count value at which the first comparison digital signal is a high level. And a motion controller and a shutter controller for outputting a shutter control signal in comparison with a minimum count value. The method of claim 13, The comparison unit A first comparator receiving the plurality of analog signals to generate a first comparison digital signal by comparing voltage levels in response to a shutter control signal; And a second comparator configured to receive one of the plurality of analog signals and the maximum reference voltage or the minimum reference voltage, respectively, to compare voltage levels to generate and output second and third comparison digital signals. Optical pointing device. The method of claim 14, The motion calculation and shutter control unit An image processor configured to generate the reset signal and the pixel selection signal, obtain an image of a subject by receiving the first comparison digital signal, and calculate and output a motion value of the optical pointing device; The maximum count value and the minimum count value at which the first comparison digital signal is at a high level are preset, and the maximum number is the number at which the second comparison digital signal is at a high level, and the number at which the third comparison digital signal is at a high level. And a shutter control circuit for outputting the shutter control signal in comparison with a count value and the minimum count value, respectively. The method of claim 15, The optical pointing device A reference voltage generator configured to receive a voltage from an external source to generate the maximum reference voltage and the minimum reference voltage; A row selector configured to output a plurality of row select signals for selecting pixels in a vertical direction by designating row addresses of a plurality of pixels in the image sensor; A column selector configured to designate pixels in a horizontal direction in response to the pixel select signal, and to select one pixel at a point that intersects a row address designated as one of the plurality of row select signals to receive and transmit the analog signal; Optical pointing device characterized in that it comprises. The method of claim 16, The column selector And a plurality of switches switched in response to the pixel selection signal to receive and transmit the analog signal of the selected pixel from the image sensor. The method of claim 17, The image sensor is An initializing operation in response to the reset signal, and at least one pixel is selected in response to the pixel selection signal to obtain an image of a subject to generate the analog signal having a voltage value proportional to the received light amount And the plurality of pixels configured. The method of claim 19, The first comparator Receiving voltage signals of the selected pixels and comparing voltage levels in response to the shutter control signal, If the output signal voltage value of one of the selected pixels is greater than the output signal voltage value of the other pixel, the first comparison digital signal having a high level is generated, and the first comparison digital signal having a low level is small. Optical pointing device, characterized in that for generating and outputting a signal. The method of claim 19, The image processor Generating and outputting the reset signal for initializing the plurality of pixels and the pixel selection signal for selecting the at least one pixel, Receiving an image of a subject by receiving the first comparison digital signal, and comparing the image of the currently acquired object with the previously obtained image of the subject to calculate and output a motion value of the optical pointing device Optical pointing device, characterized in that. The method of claim 20, The second comparator Receiving a signal of one of the voltage signals of the selected pixels and the maximum reference voltage to compare a voltage level, When the signal voltage value of one of the voltage signals of the selected pixels is greater than the maximum reference voltage voltage value, the second comparison digital signal having a high level is generated, and when the signal voltage value is small, the second comparison digital signal having a low level is generated. Optical pointing device characterized in that for outputting. The method of claim 21, The second comparator Receiving a signal of one of the voltage signals of the selected pixels and the minimum reference voltage to compare a voltage level, When the signal voltage value of one of the voltage signals of the selected pixels is greater than the minimum reference voltage voltage value, the third comparison digital signal having a high level is generated, and when the signal voltage value is smaller, the third comparison digital signal having a low level is generated. Optical pointing device characterized in that for outputting. The method of claim 22, The shutter control circuit Outputting the shutter control signal for reducing the shutter on time if the number of the high level of the second comparison digital signal is greater than or equal to the maximum count value; Outputting the shutter control signal for increasing the shutter on time when the number of the third comparison digital signals is high level is less than the maximum count value and the minimum count value is less than the minimum count value; And outputting the shutter control signal that maintains the shutter on time if the minimum count value is exceeded. The method of claim 20, The optical pointing device A plurality of shutters configured to perform an initialization operation in response to the reset signal and generate and output a plurality of shutter control analog signals having a voltage value proportional to the received light amount by selecting at least one pixel in response to the pixel selection signal Control pixels; And a shutter control signal selector which receives the plurality of shutter control analog signals and selects and outputs at least one shutter control analog signal in response to a shutter control analog signal selection signal from the shutter control circuit. Optical pointing device. The method of claim 24, The second comparator And a fourth comparison digital signal may be generated by outputting a fourth comparison digital signal by comparing a voltage level by receiving one of the plurality of analog signals and the at least one shutter control analog signal. The method of claim 25, The second comparator The fourth comparison digital signal having the high level is generated when the signal voltage value of one of the voltage signals of the selected pixels is greater than the analog signal voltage value for the shutter control. The fourth comparison digital signal having the low level is small. Optical pointing device, characterized in that for generating and outputting. The method of claim 26, The shutter control circuit Outputting the shutter control signal for reducing the shutter on time if the number of the fourth comparison digital signals is at a high level is equal to or greater than the maximum count value; Outputting the shutter control signal for increasing the shutter-on time when the number of the fourth comparison digital signals is high level is less than the maximum count value and the minimum count value is less than the minimum count value; Outputting the shutter control signal for maintaining the shutter on time if the minimum count value is exceeded; And receiving the plurality of shutter control analog signals to output the shutter control analog signal selection signal for selecting the at least one shutter control analog signal. The method of claim 27, The plurality of shutter control pixels And a portion of an outer portion of the plurality of pixels, a circumference of the outer portion of the plurality of pixels, or a portion of an inner portion of the plurality of pixels. The method of claim 28, The optical pointing device A pick-up state detection unit connected in parallel with the shutter control signal selection unit and receiving a plurality of shutter control analog signals to compare outputs to determine whether the optical pointing device is picked up and to output a hold request signal; The apparatus may further include a surface state detection unit connected in parallel with the shutter control signal selection unit and outputting a surface information signal for identifying a state of the surface of the work bench by receiving the plurality of shutter control analog signals to compare outputs to an external host computer. There is an optical pointing device.

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