JP2008054117A - Image reader and image reading system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase a reading speed while preventing image quality deterioration caused by output delay of a detection signal. <P>SOLUTION: This image reader is provided with a detection sensor which detects a relative movement amount between a photoelectric converter and an original and outputting a detection signal in each predetermined relative movement amount, and a control part which makes the photoelectric converter receive color components of light from the original to store charges on the basis of the detection signal outputted by the detection sensor, performs an operation for opening a first gate to move the charges from the photoelectric converter and stored in a read data generating part about each of a red component, a green component and a blue component in a predetermined color order and subsequently opening a second gate to move the charges stored by the photoelectric converter from the photoelectric converter, and closes the second gate on the basis of the next output detection signal outputted after the detection signal. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image reading apparatus and an image reading system.

  An image reading apparatus for reading an image from a document is already well known. This image reading apparatus selectively receives a red component, a green component and a blue component of light from the light source for irradiating light on the document, and an amount corresponding to the amount of light received. A photoelectric conversion element for accumulating the electric charge, a read data generation unit for receiving the electric charge accumulated by the photoelectric conversion element and generating the read data of the image based on the amount of the electric charge, and openable and closable A first gate for moving the electric charge from the photoelectric conversion element to the read data generation unit by opening, a drive mechanism for relatively moving the photoelectric conversion element and the document in a predetermined direction, and the predetermined direction A detection sensor for detecting a relative movement amount between the photoelectric conversion element and the document, and an encoder as an example of a detection sensor that outputs a detection signal for each predetermined relative movement amount. There.

In the image reading apparatus, based on the detection signal output from the encoder, the photoelectric conversion element receives the color component of the light from the document, accumulates the charge, and opens the first gate. The operation of moving the electric charge accumulated from the photoelectric conversion element to the read data generation unit is executed in a predetermined color order for each of the red component, the green component, and the blue component.
JP-A-8-223418

  Some of such image reading apparatuses perform the above-described operation based on the detection signal and clock pulses output at predetermined intervals from the detection signal.

  FIG. 14A is an explanatory diagram of operation timing of the operation according to the first comparative example. As shown in FIG. 14A, three clock pulses CP (# 1), CP (# 2), CP (# 3) from the first to the third every predetermined time t from the output of the detection signal EP of the encoder as a starting point. Is output. Specifically, the first clock pulse CP (# 1) is output in synchronization with the detection signal EP, and the second clock pulse CP (# 2) is output after the elapse of a predetermined time t, and further from there. After elapse of time t, the third clock pulse CP (# 3) is output. Incidentally, in the same figure, the time between the third clock pulse CP (# 3) and the first clock pulse CP (# 1) of the next cycle is expressed as t ′. This is because the output timing of the first clock pulse CP (# 1) varies according to the output delay of the signal EP. That is, in the ideal state where there is no output delay of the detection signal EP, the t 'coincides with the predetermined time t as shown in FIG.

  In the first comparative example, based on the first clock pulse CP (# 1) output at the output timing of the detection signal EP from the encoder, the first color (for example, R) The light receiving operation of the component light is performed, and as a result, charges corresponding to the amount of light received during the light receiving time T are accumulated in the photoelectric conversion element. Then, based on the second clock pulse CP (# 2), the first gate is opened, and the accumulated charge is taken out from the photoelectric conversion element as the first color charge (moves to the read data generation unit). To do).

  Based on the second clock pulse CP (# 2), the light receiving operation of the light of the second color (for example, G component) is also performed. As a result, the photoelectric conversion element receives the light received at the light receiving time T. The charge corresponding to the amount of is accumulated. Then, based on the third clock pulse CP (# 3), the first gate is opened, and the accumulated charge is taken out from the photoelectric conversion element as the second color charge (moved to the read data generation unit). To do).

  Based on the third clock pulse CP (# 3), the light receiving operation of the light of the third color (for example, B component) is also performed, so that the photoelectric conversion element receives the light received at the light receiving time T. The charge corresponding to the amount of is accumulated. Based on the first clock pulse CP (# 1) output at the output timing of the next detection signal (next output detection signal) EP of the encoder, the first gate is opened, and the accumulated charge is The charge of the third color is taken out from the photoelectric conversion element (moves to the read data generation unit).

  As a result, the charges of all three colors of RGB are taken out, so that an image for one pixel is read in the predetermined direction.

  However, in the first comparative example, in particular, the charge of the third color (for example, B component) becomes larger than the amount of charge that should be accumulated during the light receiving time T, and the image quality of the read image is degraded. Have the problem of inviting. This is because, when there is a variation in moving speed with respect to the relative movement in the predetermined direction, due to this variation, as shown in FIG. 14B, from the end of the light reception time T of the third color (for example, B component) This is because the time until the detection signal EP is output is longer than the ideal state shown in FIG. 14A by the delay time td. That is, even if the light receiving operation is not performed after the light receiving time T is over, charges may be accumulated in the photoelectric conversion element due to dark current or the like, and the output of the detection signal from the encoder is only for the delay time td. This is because if it is delayed, only the charge of the third color (for example, B component) is accumulated more than the original accumulation amount. The accumulation of the extra charge of the third color (for example, the B component) directly affects the accuracy of the image data generated based on the charge, thereby causing the image quality of the image data obtained by reading to be deteriorated. become.

  Therefore, the following second comparative example can be considered as a measure for suppressing such image quality degradation. FIG. 14C is an explanatory diagram of operation timing of the operation according to the second comparative example. Here, the main difference from the first comparative example is that in the first comparative example, three clock pulses CP are output for each output of the detection signal EP of the encoder, and based on each clock pulse CP, When the first gate is opened and each of the accumulated charges of three colors is taken out from the photoelectric conversion element, in this second comparative example, four clock pulses CP, which is one more than in the first comparative example, are obtained. And the first gate is opened on the basis of each clock pulse CP, and in addition to each of the accumulated three color charges, the accumulated charge due to dark current or the like is taken out from the photoelectric conversion element. is there.

  That is, as shown in FIG. 14C, in the second comparative example, as in the first comparative example, first, the first color (for example, R component) light receiving operation based on the first clock pulse CP (# 1). And the light extraction operation for the first color and the light reception operation for the second color (for example, G component) are performed based on the second clock pulse CP (# 2), and the third clock pulse CP (# 3). Based on the above, a charge extracting operation for the second color and a light receiving operation for the third color (for example, B component) are performed. The photoelectric conversion element that has received the light of the third color only for the light receiving time accumulates electric charges according to the amount of light received during the light receiving time. So far, it is the same as the first comparative example.

  Then, in this second comparative example, the charge of the third color (for example, B component) is not the output timing of the next detection signal (next output detection signal) EP from the encoder, but the fourth clock pulse CP ( Based on # 4), the first gate is opened and taken out from the photoelectric conversion element. Then, at the output timing of the next detection signal (next output detection signal) EP, the first gate is opened, and after the charge extraction operation for the third color from the photoelectric conversion element to the output of the detection signal EP. Charges accumulated due to dark current or the like are taken out (taken out charges are discarded).

  The second comparative example can solve the problem of the first comparative example, that is, the problem of image quality deterioration due to the extra charge when the aforementioned output delay of the detection signal EP occurs. However, when the number of clock pulses CP is changed from three to four, there arises a problem that a time that is 4/3 times that of the first comparative example is required (that is, the reading speed is remarkably reduced).

  An object of the present invention is to solve both of the problems of the first comparative example and the second comparative example. That is, the purpose is to increase the reading speed while preventing the image quality from being deteriorated due to the output delay of the detection signal.

  The main present invention is (A) an image reading apparatus for reading an image from an original, wherein (B) a light source for irradiating the original with light, and (C) a red component of light from the original, green A photoelectric conversion element for selectively receiving the component and the blue component, and accumulating an amount of charge corresponding to the amount of received light; and (D) receiving the charge accumulated by the photoelectric conversion element; A read data generating unit for generating read data of the image based on the amount of the charge; and (E) openable and closable to open and move the charge from the photoelectric conversion element to the read data generating unit (F) a first gate for opening and closing, and a second gate for moving the charge away from the photoelectric conversion element to dispose of the charge accumulated by the photoelectric conversion element by opening; G) Predetermined direction A drive mechanism for moving the photoelectric conversion element and the document relative to each other; and (H) a detection sensor for detecting a relative movement amount between the photoelectric conversion element and the document in the predetermined direction. A detection sensor for outputting a detection signal to (I), based on the detection signal output by the detection sensor, causing the photoelectric conversion element to receive a color component of light from the document and storing the charge, An operation of opening the first gate and moving the charge accumulated from the photoelectric conversion element to the read data generation unit is performed in a predetermined color order for each of the red component, the green component, and the blue component, and then A control unit that opens the second gate and moves the charge accumulated in the photoelectric conversion element from the photoelectric conversion element, based on a next output detection signal output next to the detection signal An image reading apparatus comprising: a control unit that closes the second gate; and (J).

  Other features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

  At least the following will be made clear by the description of the present specification and the accompanying drawings.

(A) An image reading apparatus for reading an image from an original, wherein (B) a light source for irradiating the original with light, and (C) a red component, a green component, and blue of light from the original A photoelectric conversion element for selectively receiving a component and accumulating an amount of electric charge corresponding to the amount of received light; and (D) receiving the electric charge accumulated by the photoelectric conversion element, A reading data generation unit for generating reading data of the image based on the first gate, and (E) a first gate that is openable and closable and that can be opened to move the charge from the photoelectric conversion element to the reading data generation unit (F) is openable and closable, and when opened, the second gate for moving the charge from the photoelectric conversion element to discard the charge accumulated in the photoelectric conversion element; and (G) in a predetermined direction. The photoelectric conversion element A drive mechanism for relatively moving the document; and (H) a detection sensor for detecting a relative movement amount between the photoelectric conversion element and the document in the predetermined direction, and outputting a detection signal for each predetermined relative movement amount. And (I) based on the detection signal output from the detection sensor, causes the photoelectric conversion element to receive a color component of light from the document, accumulates the charge, and opens the first gate. The operation of moving the charge accumulated from the photoelectric conversion element to the read data generation unit is performed in a predetermined color order for each of the red component, the green component, and the blue component, and then the second gate A control unit for moving the charge accumulated in the photoelectric conversion element from the photoelectric conversion element by opening the second gate based on a next output detection signal output next to the detection signal. And closing control unit, the image reading apparatus characterized by comprising (J).
According to such an image reading apparatus, it is possible to increase the reading speed while preventing deterioration in image quality due to output delay of the detection signal.

  The predetermined relative movement amount may correspond to a minimum unit of the image reading area.

Further, the control unit performs the operation in a predetermined color order for each of the red component, the green component, and the blue component, and then opens the second gate, and then, based on the next output detection signal. Until the second gate is closed, the second gate may be open.
In such a case, the charge accumulated by dark current or the like is surely discarded.

Further, the control unit may start the operation based on the next output detection signal after closing the second gate.
In such a case, it is ensured that the operation based on the next output detection signal is executed after the second gate is completely closed.

  In addition, the document table includes a document table on which the document is placed and a carriage that is moved in the predetermined direction by the drive mechanism, and the light source and the photoelectric conversion element are fixed to the carriage. It is good as well. Further, a plurality of the photoelectric conversion elements may be provided in a crossing direction crossing the predetermined direction.

Further, (A) an image reading apparatus for reading an image from a document, (B) a light source for irradiating the document with light, (C) a red component, a green component of light from the document, and A photoelectric conversion element for selectively receiving a blue component and accumulating an amount of electric charge according to the amount of received light; and (D) receiving the electric charge accumulated by the photoelectric conversion element, A read data generation unit for generating the read data of the image based on the quantity; and (E) a first openable / closable opening for moving the charge from the photoelectric conversion element to the read data generation unit. (F) a second gate for moving the charge from the photoelectric conversion element so as to dispose of the charge accumulated in the photoelectric conversion element by being opened, and (G) a predetermined gate. Said photoelectric transformation in the direction A drive mechanism for moving the element and the document relative to each other; and (H) a detection sensor for detecting a relative movement amount between the photoelectric conversion element and the document in the predetermined direction, and a detection signal for each predetermined relative movement amount. (I) based on the detection signal output from the detection sensor, causing the photoelectric conversion element to receive a color component of light from the document and accumulate the charge, and And moving the accumulated charge from the photoelectric conversion element to the read data generation unit in a predetermined color order for each of the red component, the green component, and the blue component, and then A control unit that opens two gates and moves the charge accumulated in the photoelectric conversion element from the photoelectric conversion element, the second output based on a next output detection signal output next to the detection signal; And (J) the predetermined relative movement amount corresponds to a minimum unit of the image reading area, and (L) the control unit performs the operation in red. After performing in a predetermined color order for each of the component, the green component, and the blue component, from opening the second gate to closing the second gate based on the next output detection signal, The second gate is open, and (M) the controller closes the second gate and then starts the operation based on the next output detection signal, and (N) places the document. And a carriage that is moved in the predetermined direction by the drive mechanism. The light source and the photoelectric conversion element are fixed to the carriage, and (O) the photoelectric conversion element Are a plurality of crossing directions intersecting the predetermined direction. An image reading device characterized by being provided can also be realized.
In this way, the effects of the present invention can be achieved more effectively because all the effects described above can be achieved.

An image reading system comprising a computer and an image reading device that is communicably connected to the computer and reads an image from a document, wherein the image reading device is a light source for irradiating the document with light. A photoelectric conversion element for selectively receiving a red component, a green component, and a blue component of light from the document, and accumulating an amount of electric charge according to the amount of received light, and the photoelectric conversion A read data generation unit for receiving the charge accumulated in the element and generating read data of the image based on the amount of the charge, and is openable and closable by opening the read from the photoelectric conversion element A first gate for moving to the data generation unit; and openable and closable to open the photoelectric conversion element to discard the charge accumulated by the photoelectric conversion element. A second gate for moving from the element, a driving mechanism for moving the photoelectric conversion element and the document in a predetermined direction, and detection for detecting a relative movement amount between the photoelectric conversion element and the document in the predetermined direction A sensor that outputs a detection signal for each predetermined amount of relative movement; and the photoelectric conversion element receives a color component of light from the document based on the detection signal output by the detection sensor. The operation of accumulating the electric charge and moving the electric charge accumulated from the photoelectric conversion element to the read data generating unit by opening the first gate is predetermined for each of the red component, the green component, and the blue component. The control unit moves the charges accumulated in the photoelectric conversion element from the photoelectric conversion element by opening the second gate and then moving the detection signal of the detection signal. Based on the following output detection signal output to the image reading system, characterized in that it comprises a control unit for closing said second gate can also be implemented.
According to such an image reading system, it is possible to increase the reading speed while preventing deterioration in image quality due to output delay of the detection signal.

=== Image Reading System 2 ===
1 to 3 are explanatory diagrams of the image reading system 2. FIG. 1 is a perspective view of the image reading system 2. FIG. 2 is an explanatory diagram of the internal configuration of the image reading apparatus 10. FIG. 3 is an explanatory diagram of the system configuration of the image reading apparatus 10.

  As shown in FIG. 1, the image reading system 2 includes an image reading device 10 and a computer device 20 connected to the image reading device 10 so as to be communicable.

  The image reading apparatus 10 is an apparatus generally called an image scanner, and includes an original table glass 12 (corresponding to an original table) and an original table cover 14 that opens and closes the upper surface of the original table glass 12. A document 15 from which an image is read is set on the upper surface of the document table glass 12. An operation panel 18 (corresponding to an input unit) is provided in front of the platen glass 12, and various settings can be input from the operation panel 18.

  As shown in FIG. 1, for example, the computer device 20 includes a computer main body 22, a display device 24, and an input device 26. A so-called personal computer or the like is used as the computer main body 22, and a reading device 32 such as an FD drive device 28 and a CD-ROM / DVD drive device 30 is provided in addition to a CPU (central processing unit), a memory such as a RAM and a ROM. ing. As the display device 24, a CRT display, a liquid crystal display, or the like is used. As the input device 26, a keyboard 34, a mouse 36, or the like is used.

=== Image Reading Device 10 ===
As shown in FIG. 2, inside the image reading apparatus 10, a carriage 40 and a drive mechanism that moves the carriage 40 in parallel along the sub-scanning direction while maintaining a predetermined distance from the document table glass 12. 42 and a guide 44 that guides the carriage 40 so as to be movable in the sub-scanning direction while supporting the carriage 40.

  The carriage 40 has an exposure lamp 46 as a light source for irradiating the document 15 with light through the document table glass 12, a lens 48 on which reflected light reflected by the document 15 enters, and the carriage 40 through the lens 48. An image sensor 50 that receives the reflected light taken in is provided. The image sensor 50 includes a linear CCD in which photoelectric conversion elements 80 that convert an optical signal into an electrical signal are arranged in a row along a main scanning direction (direction passing through the paper surface in FIG. 2) orthogonal to the sub-scanning direction. It is composed of sensors and the like. Image data read by the image sensor 50 is output to the control unit 52 in the form of an analog signal.

  The drive mechanism 42 includes a timing belt 54 connected to the carriage 40, a pair of pulleys 55 and 56 around which the timing belt 54 is stretched, and a drive motor 58 that rotationally drives one pulley 55. The drive motor 58 is a so-called DC motor or the like, and is driven and controlled by a control signal from the control unit 52.

  As shown in FIG. 3, the control unit 52 includes a controller 60, a motor control unit 62, a lamp control unit 64, an image sensor control unit 66, an AFE (Analog Front End) unit 68, and a digital processing circuit 70. The interface circuit 72 is provided. These control units and circuits 62, 64, 66, 68, 70 and 72 including the operation panel 18 described above are connected to the controller 60 so as to be communicable.

  The controller 60 controls the motor control unit 62, the lamp control unit 64, the image sensor control unit 66, the AFE unit 68, the digital processing circuit 70, and the interface circuit 72 based on the read command signal from the computer main body 22.

  The motor control unit 62 performs drive control of the drive motor 58 for moving the carriage 40 according to a command signal from the controller 60. As the drive control, so-called feedback control is performed to move the carriage 40 at a constant speed at a predetermined target value. Information on the target value of the moving speed is attached to the command signal from the controller 60. The actual value of the moving speed is obtained by a rotary encoder 90 (corresponding to a detection sensor) provided in the drive motor 58. That is, as shown in FIG. 4, each time the carriage 40 moves in the sub-scanning direction by a predetermined movement amount corresponding to one pixel by the drive motor 58, the detection signal EP is output from the encoder 90. The detection signal EP is sent to the motor control unit 62, and the actual value of the moving speed of the carriage 40 is calculated at an appropriate control cycle based on the detection signal EP. Then, the motor control unit 62 performs feedback control of the drive motor 58 so that the actual value is aligned with the target value. Note that the above-described pixel is a minimum unit of an image reading area, and the size thereof is determined according to the reading resolution. For example, when the reading resolution is 360 dpi (dot / inch), the pixel size is 1/360 inch.

  The lamp controller 64 in FIG. 3 controls the light emission operation of the exposure lamp 46. The image sensor control unit 66 controls various operations of the image sensor 50.

  The AFE unit 68 includes an analog signal processing circuit 74 and an A / D conversion circuit 76. The analog signal processing circuit 74 performs signal processing on an analog signal that is image data output from the image sensor 50. The A / D conversion circuit 76 A / D converts the image signal processed by the analog signal processing circuit 74 into a digital signal.

  The digital processing circuit 70 performs digital signal processing on the digital signal sent from the A / D conversion circuit 76 of the AFE unit 68. Here, image processing and the like are performed, including correction processing such as shading correction. The digital signal subjected to the digital signal processing is output as image data (image data) read from the document 15 to the outside, that is, to the computer main body 22 to which the image reading device 10 is connected through the interface circuit 72. In addition to this, the interface circuit 72 receives various commands (commands) from the computer main body 22 to the image reading apparatus 10.

=== Carriage 40 ===
FIG. 5 is an exploded perspective view of the carriage 40. As shown in the figure, the carriage 40 is a long body that is long in the main scanning direction orthogonal to the sub-scanning direction (movement direction of the carriage 40), and slides in the sub-scanning direction when reading an image.

  An image sensor 50 is installed in the lower part of the carriage 40. A lens 48 for allowing light to enter the image sensor 50 is provided on the upper portion of the carriage 40 so as to face the document table glass 12. Light reflected by the document 15 is incident on the lens 48. The lens 48 is disposed along the longitudinal direction (main scanning direction) of the carriage 40. An exposure lamp 46 that irradiates light to the document 15 through the document table glass 12 is provided in parallel with the lens 48 at the upper portion of the carriage 40. The length Lk in the longitudinal direction of the lens 48 and the exposure lamp 46 is set corresponding to the maximum dimension in the main scanning direction of the document 15 placed on the document table glass 12.

  A substrate 51 provided with an image sensor 50 is arranged inside the carriage 40. As shown in the figure, the image sensor 50 is provided along the longitudinal direction of the carriage 40 corresponding to the main scanning direction so as to correspond to the lens 48 described above. The total length Ls of the image sensor 50 is set corresponding to the total length Lk of the lens 48. On the upper surface of the image sensor 50, a plurality of photoelectric conversion elements 80 are arranged side by side along the longitudinal direction (main scanning direction) (see FIG. 9).

  FIG. 6 is a diagram illustrating a positional relationship between the lens 48 and the image sensor 50. The lens 48 has a plurality of individual lenses 49. The plurality of individual lenses 49 are arranged side by side along the longitudinal direction of the lens 48, that is, the main scanning direction. The light incident on each individual lens 49 is received by a plurality of photoelectric conversion elements 80 provided in the image sensor 50.

=== Exposure lamp 46 ===
FIG. 7 is a perspective view of the exposure lamp 46. As shown in the drawing, the exposure lamp 46 includes a light guide 47A and three types of light emitting diodes (hereinafter also referred to as LEDs) having different emission colors. The three types of LEDs are a red LED that emits red (R) light, a green LED that emits green (G) light, and a blue LED that emits blue (B). These three types of LEDs are provided at the end 47E of the light guide 47A.

  The light guide 47A is disposed in parallel with the lens 48 along the longitudinal direction of the lens 48, which is the main scanning direction. The light guide 47A introduces light emitted from three types of LEDs provided at its end 47E into the interior, and emits light from the exposure surface 47F provided at the top thereof toward the upper document 15. Thus, the light guide 47A irradiates the document 15 with light over the entire width in the main scanning direction.

  The color of light emitted from the light guide 47A is determined according to the color of the LED to be lit. That is, if the red LED is turned on, the light guide 47A emits red light, if the green LED is turned on, the light guide 47A emits green light, and if the blue LED is turned on, The light guide 47A emits blue light.

  Then, when an image is read from the document 15 by the image sensor 50, these three types of LEDs are individually lit at different timings. That is, when the red LED is lit, the green LED and the blue LED are turned off. When the green LED is lit, the red LED and the blue LED are turned off, and the blue LED is turned on. When red, the red LED and the green LED are off.

  FIG. 8 is an explanatory diagram of the light emission order. Here, the three types of LEDs are lit in the order of red (R) → green (G) → blue (B) for a predetermined lighting time T, whereby the exposure lamp 46 is red (R). ) → green (G) → blue (B) in the color order, and as a result, the document 15 is also illuminated in this color order. The light emission operation of red (R) → green (G) → blue (B) is set as one cycle, and the cycle is repeated. This cycle is executed every time the detection signal EP is output from the encoder 90, that is, the cycle is performed once every time the carriage 40 moves in the sub-scanning direction by a movement amount corresponding to one pixel. Done one by one.

=== Image Sensor 50 ===
FIG. 9 is an explanatory diagram of the configuration of the image sensor 50. As shown in FIG. 9, the image sensor 50 includes a photoelectric conversion element 80, a read data generation unit 82, a first gate 84, a second gate 86, and a disposal transfer path 88.

  The photoelectric conversion elements 80 are, for example, photodiodes 80, and a plurality of the photoelectric conversion elements 80 are arranged at a predetermined pitch P in one row along the main scanning direction. The photoelectric conversion element 80 generates and accumulates charges according to the amount of received light.

  The read data generation unit 82 receives charge accumulated by the photoelectric conversion element 80 and generates image read data based on the amount of the charge, and includes a charge transfer unit 82A and a detection circuit 82B. ing.

  The charge transfer unit 82A is configured by a so-called CCD (charge-coupled device), and transfers the charge received from each photoelectric conversion element 80 toward the detection circuit 82B in a predetermined transfer direction. The detection circuit 82B is connected to one end of the charge transfer unit 82A in the transfer direction, detects charges sequentially sent from the charge transfer unit 82A, and outputs an analog signal (read data) corresponding to the detected amount of charge. Generate and output for each charge.

  The first gate 84 is openable and closable, and opens to move the charge from the photoelectric conversion element 80 to the read data generation unit 82 (the charge transfer unit 82A). That is, the first gate 84 takes out the charge of the photodiode 80 to the charge transfer portion 82A in the open state, but does not take out the charge in the closed state. The charge extraction operation by such an opening / closing operation uses a so-called potential well. Has been achieved. The first gate 84 is provided between each photoelectric conversion element 80 and the charge transfer unit 82A.

  FIG. 10 is an explanatory diagram of the operation of the image sensor 50. When the exposure lamp 46 emits light, and the light is reflected by the document 15 and received by each photodiode 80, a charge is generated and accumulated in each photodiode 80. Then, the charges accumulated in each photodiode 80 are moved all at once from the photodiode 80 to the charge transfer section 82A by opening all the first gates 84 at the same time. The electric charge is taken out from all at once. Then, the charges arranged in the main scanning direction in the charge transfer unit 82A are sequentially transferred to the detection circuit 82B in the manner of a bucket relay, and the detection circuit 82B outputs an analog signal corresponding to the detected amount of charge. (Read data) is output for each charge.

  Such an operation of the image sensor 50, that is, a series of operations from the generation of electric charge of the photodiode 80 to the output of an analog signal is performed every time the exposure lamp 46 emits light, that is, red (R), green (G ) And blue (B) light emission operations. Then, a total of three color analog signals generated by such three light emission operations become data for one pixel in the sub-scanning direction constituting the image of the document 15 read by the image sensor 50.

  Further, the image sensor 50 is provided with a second gate 86 different from the first gate 84 described above. The second gate 86 is for moving charges accumulated by a dark current or the like (details will be described later) from the photodiode 80 to be discarded instead of the charges accumulated by the light from the exposure lamp 46. It is. The second gate 86 can be opened and closed. By opening the second gate 86, the charge is transferred from the photodiode 80 to the disposal transfer path 88. That is, the first gate 84 takes out the charge of the photodiode 80 to the disposal transfer path 88 in the open state but does not take out the charge in the closed state. Has been achieved using. The second gate 86 is provided between each of the photodiodes 80 and the disposal transfer path 88.

  FIG. 11 is an explanatory diagram of the operation of the image sensor 50. The charges accumulated in each photodiode 80 are moved all at once from the photodiode 80 to the disposal transfer path 88 by opening all the second gates 86 at the same time. Are taken out all at once. Then, the charges arranged in the main scanning direction in the discard transfer path 88 are sequentially transferred and discarded.

=== Regarding the Operation Timing of the Image Sensor 50 etc. ===
Here, the operation timing of the image sensor 50 and the like in the image reading apparatus 10 having the above-described configuration will be described. In this section, first, the operation timing and its problems according to the two comparative examples (first comparative example and second comparative example) listed in the section of the problem to be solved by the invention will be described again in more detail. To do. Subsequently, the operation timing according to the present example (the present embodiment) and the effectiveness thereof (the point where the above-described problems are solved) will be described.

<<< First Comparative Example >>>
FIG. 12A is an explanatory diagram of operation timing according to the first comparative example.
The clock signal Sc is generated every time the detection signal EP is output from the encoder 90. The clock signal Sc has three clock pulses CP (# 1), CP (# 2), and CP (# 3). The first clock pulse CP (# 1) is output in synchronization with the detection signal EP of the encoder 90, and the second clock pulse CP (# 2) is the first clock pulse CP (# 1). The third clock pulse CP (# 3) is output after a predetermined time t has elapsed from the rising edge of the second clock pulse CP (# 2). The Any of the clock pulses CP (# 1), CP (# 2), and CP (# 3) are rectangular pulses having the same shape. In the figure, the time from the rising edge of the third clock pulse CP (# 3) to the rising edge of the first clock pulse CP (# 1) of the next cycle is expressed as t ′. However, this is because the output timing of the first clock pulse CP (# 1) fluctuates according to the output delay of the detection signal EP and does not always reach the predetermined time t. That is, in the ideal state with no output delay of the detection signal EP, the t ′ coincides with the predetermined time t as shown in FIG.

  As shown in the figure, when the first clock pulse CP (# 1) is output, the red LED of the exposure lamp 46 is turned on for a predetermined time after a predetermined time tl starting from the falling edge. Lights for time T only. Then, charges corresponding to the amount of red light received during the lighting time T are accumulated in each photodiode 80 of the image sensor 50.

  Each of these charges is taken out from each photodiode 80 to the charge transfer section 82A when the first gates 84 are simultaneously opened in synchronization with the rising edge of the second clock pulse CP (# 2). Note that the time width of the open state of the first gate 84 is the same as the pulse width tc of the clock pulse CP. Then, after a lapse of a predetermined time tt from the falling edge of the clock pulse CP (# 2), which is the time when the first gate 84 is closed, the charge transfer unit 82A starts a charge transfer operation to the detection circuit 82B, Thereafter, when the detection of charges by the detection circuit 82B is completed for all charges, the transfer operation is stopped. As a result, an analog signal related to red is output from the detection circuit 82B for each charge.

  Further, based on the falling edge of the second clock pulse CP (# 2), the green LED of the exposure lamp 46 is lit for the lighting time T after a predetermined time tl starting from the falling edge. . Then, this time, each photodiode 80 accumulates a charge corresponding to the amount of green light received during the lighting time T. These charges are taken out from the photodiodes 80 to the charge transfer section 82A when the first gates 84 are simultaneously opened in synchronization with the rising edge of the third clock pulse CP (# 3). Then, after a lapse of a predetermined time tt from the falling edge of the clock pulse CP (# 3) at the time when the first gate 84 is closed, the charge transfer unit 82A starts the transfer operation of the charge to the detection circuit 82B. Thereafter, when the detection of charges by the detection circuit 82B is completed for all charges, the transfer operation is stopped. As a result, an analog signal related to green is output from the detection circuit 82B for each charge.

  Further, based on the falling edge of the third clock pulse CP (# 3), the blue LED of the exposure lamp 46 is lit for the lighting time T after a predetermined time tl starting from the falling edge. . Then, this time, each photodiode 80 accumulates a charge corresponding to the amount of blue light received during the lighting time T. These electric charges are simultaneously transmitted from the first gate 84 in synchronization with the rising edge of the first clock pulse CP (# 1) output in synchronization with the next detection signal EP (next output detection signal) of the encoder 90. Open to the charge transfer unit 82A from the photodiode 80. Then, after a lapse of a predetermined time tt from the falling edge of the clock pulse CP (# 1), which is the time when the first gate 84 is closed, the charge transfer unit 82A starts the charge transfer operation to the detection circuit 82B. Thereafter, when the detection of charges by the detection circuit 82B is completed for all charges, the transfer operation is stopped. As a result, an analog signal relating to blue is output from the detection circuit 82B for each charge.

  As described above, a total of three analog signals of red, green and blue (RGB) are output from the detection circuit 82B, so that an image for one pixel is read in the sub-scanning direction. Then, assuming this as one cycle, this cycle is repeated each time the detection signal EP is output from the encoder 90, and thereby an image is read from the document.

<Problems of the first comparative example>
However, in the first comparative example, there is a possibility that the image quality of the read image is deteriorated due to the charge of blue light as the third color. That is, the charge of the blue light of the third color may be larger than the amount of charge that should be accumulated during the lighting time T.

  This is because, when there is a variation in the movement speed of the carriage 40 in the sub-scanning direction, as shown in FIG. 12B, the encoder 90 starts from the end of the lighting time T for the third color blue light. This is because the time until the detection signal EP is output is longer than the ideal state shown in FIG. 12A by the delay time td. That is, even if the blue LED is not turned on after the lighting time T of the blue LED is over, charges may be accumulated in the photodiode 80 due to dark current or the like, and the detection signal EP from the encoder 90 This is because, if the output is delayed by the delay time td, only the blue light charge is accumulated more than the original accumulation amount. The accumulation of the extra charge of the blue light directly affects the accuracy of the image data generated based on the charge, thereby degrading the image quality of the image obtained by reading.

<<< Second Comparative Example >>>
FIG. 12C is an explanatory diagram of operation timings according to the second comparative example. Here, the main difference from the first comparative example is that, in the first comparative example, three clock pulses CP are output for each output of the detection signal EP of the encoder 90, and based on each clock pulse CP. When the first gate 84 is opened and each of the accumulated three color charges is taken out from the photodiode 80, four clocks are added in the second comparative example, one more than in the first comparative example. A pulse CP is output, and on the basis of each clock pulse CP, the first gate 84 is opened, and charges accumulated by dark current and the like are taken out from the photodiode 80 in addition to the accumulated charges of the three colors. There is in point.

  That is, as shown in FIG. 12C, in the second comparative example, as in the first comparative example, first, the red LED lighting operation and the red light receiving operation are performed based on the first clock pulse CP (# 1). Based on the second clock pulse CP (# 2), the operation of taking out the red light charge to the charge transfer unit 82A, the transfer operation to the detection circuit 82B, the lighting operation of the green LED, and the reception of the green light In addition, on the basis of the third clock pulse CP (# 3), the operation of taking out the green light charge to the charge transfer unit 82A, the transfer operation to the detection circuit 82B, the lighting operation of the blue LED, A blue light receiving operation is performed. The photodiode 80 that has received blue light for the lighting time T of the blue LED of the third color accumulates electric charges according to the amount of blue light received during the lighting time T. Up to this point, it is the same as the first comparative example described above.

  Then, in this second comparative example, the charge of the blue light of the third color accumulated in each photodiode 80 is not the output timing of the next detection signal (next output detection signal) EP from the encoder 90, At the rising edge of the fourth clock pulse CP (# 4), the light is extracted from each photodiode 80 to the charge transfer portion 82A. That is, the first gate 84 is opened at the rising edge of the fourth clock pulse CP (# 4). Then, after a lapse of a predetermined time tt from the falling edge of the clock pulse CP (# 4), which is the time when the first gate 84 is closed, the charge transfer unit 82A starts the transfer operation of the charge to the detection circuit 82B. Thereafter, when the detection of the charges by the detection circuit 82B is completed for all charges, the transfer operation is stopped.

  Then, in the first clock pulse CP (# 1) output in synchronization with the rising edge of the next detection signal (next output detection signal) EP, the first gate 84 is opened and the photodiode 80 Then, the charge accumulated due to dark current or the like is taken out after the blue light charge taking-out operation until the detection signal EP is outputted (the taken-out charge is discarded).

<Problems of the second comparative example>
In the second comparative example, the charge accumulated due to dark current or the like is appropriately discarded, so the problem of the first comparative example, that is, the extra charge when the aforementioned output delay of the detection signal EP occurs. The problem of image quality degradation caused by the problem is solved. However, when the number of clock pulses CP is changed from three to four, there is a problem that a time that is 4/3 times that of the first comparative example is required (that is, the reading speed is remarkably reduced) ( FIG. 12A and FIG. 12C).

<<< Example of this case >>>
FIG. 13 is an explanatory diagram of operation timing according to this example. Before describing the details of the operation timing according to the present example, the main differences from the first comparative example and the second comparative example are listed. First, in the first comparative example and the second comparative example, Although the two gates 86 are not provided (or even if provided, the second gate 86 is not used), the second gate 86 is used in this example. That is, in this example, the charge accumulated due to dark current or the like is discarded as in the second comparative example described above, but in the second comparative example, the charge is read from the photodiode 80 and the data generation unit 82 (charge Whereas the first gate 84 for moving to the transfer unit 82A) is opened and the charge accumulated due to dark current or the like has been discarded via the charge transfer unit 82A, in this example, The charge accumulated by the dark current or the like is opened by opening the second gate 86 for moving the charge from the photodiode 80 in order to discard the charge accumulated by the photodiode 80 (in other words, only for disposal). Is discarded.

  In the first comparative example and the second comparative example, the operations of the image sensor 50 and the exposure lamp 46 are controlled based on the clock signal (pulse). In this example, the clock signal (pulse) is generated. Instead, the control unit 52 controls the operation based on the detection signal EP of the encoder 90. That is, it is determined in advance how many seconds the various operations of the image sensor 50 and the exposure lamp 46 are executed after the detection signal EP is output, and the various operations are performed by timers provided in the control unit 52. It is executed based on.

  As shown in FIG. 13, when the detection signal EP is output (time when the detection signal EP is output is t0), the red LED of the exposure lamp 46 is lit for a predetermined lighting time T2 after the predetermined time T1 has elapsed. Lights up (the time when the red LED is turned on is t1 = t0 + T1, and the time when the red LED is finished is t2 = t1 + T2) Then, electric charges corresponding to the amount of red light received during the lighting time T2 are accumulated in each photodiode 80 of the image sensor 50.

  These charges are taken out from the respective photodiodes 80 to the charge transfer section 82A when the first gates 84 are simultaneously opened at time t3 (after a predetermined time T3 has elapsed since the red LED has been turned on). The first gate 84 is kept open until time t4 (= t3 + predetermined time T4) (that is, the first gate 84 is closed at time t4). After a predetermined time Ta has elapsed after the first gate 84 is closed, the charge transfer unit 82A starts a charge transfer operation to the detection circuit 82B. Thereafter, the detection of the charge by the detection circuit 82B is performed for all charges. When finished, stop the transfer operation. As a result, an analog signal related to red is output from the detection circuit 82B for each charge.

  Further, at time t5 (after a predetermined time T1 has elapsed since the first gate 84 is closed), the green LED of the exposure lamp 46 is lit for a predetermined lighting time T2 (the time when the green LED is turned off is t6 = t5 + T2). To do). Then, this time, each photodiode 80 accumulates a charge corresponding to the amount of green light received approximately during the lighting time T2.

  These charges are taken out from the photodiodes 80 to the charge transfer section 82A when the first gates 84 are simultaneously opened at time t7 (after the predetermined time T3 has elapsed since the lighting of the green LED is finished). The first gate 84 is kept open until time t8 (= t7 + predetermined time T4) (that is, the first gate 84 is closed at time t8). After a predetermined time Ta has elapsed after the first gate 84 is closed, the charge transfer unit 82A starts a charge transfer operation to the detection circuit 82B. Thereafter, the detection of the charge by the detection circuit 82B is performed for all charges. When finished, stop the transfer operation. As a result, an analog signal related to green is output from the detection circuit 82B for each charge.

  Further, at time t9 (after a predetermined time T1 has elapsed since the first gate 84 is closed), the blue LED of the exposure lamp 46 is lit for a predetermined lighting time T2 (the time at which the blue LED is turned off is t10 = t9 + T2). To do). Then, this time, each photodiode 80 accumulates a charge corresponding to the amount of blue light received approximately during the lighting time T2.

  These charges are taken out from the photodiodes 80 to the charge transfer section 82A when the first gates 84 are simultaneously opened at time t11 (after the predetermined time T3 has elapsed since the lighting of the blue LED is finished). The first gate 84 is kept open until time t12 (= t11 + predetermined time T4) (that is, the first gate 84 is closed at time t12). After a predetermined time Ta has elapsed after the first gate 84 is closed, the charge transfer unit 82A starts a charge transfer operation to the detection circuit 82B. Thereafter, the detection of the charge by the detection circuit 82B is performed for all charges. When finished, stop the transfer operation. As a result, an analog signal relating to blue is output from the detection circuit 82B for each charge.

  In this way, the operation of causing the photodiode 80 to receive the color component of the light from the original and storing the charge, and opening the first gate 84 to move the stored charge from the photodiode 80 to the read data generation unit 82. However, based on the detection signal EP, the red component, the green component, and the blue component are executed in a predetermined color order. As a result, a total of three analog signals of red, green, and blue (RGB) are output, and an image for one pixel is read in the sub-scanning direction.

  Further, after the operation is performed in a predetermined color order for each of the three color components based on the detection signal EP, more specifically, immediately after the first gate 84 is closed at time t12, the second gate 86 may be opened at the same time (a slight time lag may occur between the time when the first gate 84 is closed and the time when the second gate 86 is opened. As with the time when one gate 84 is closed, it is t12). While the second gate 86 is open, the charge accumulated in the photodiode 80 due to dark current or the like moves to the disposal transfer path 88 and is discarded as needed.

  Based on the next detection signal (next output detection signal) EP, more specifically, the second gate 86 closes immediately after the next detection signal (next output detection signal) EP is output (the next detection signal). The time when the signal (next output detection signal) EP is output is t13, and during the period from when the next detection signal (next output detection signal) EP is output until the second gate 86 is closed, Although a time lag may occur, in this section, for convenience, the time for the second gate 86 to close is set to t13 as is the time for the next detection signal (next output detection signal) EP to be output). That is, after the above operation is performed in a predetermined color order for each of the three color components based on the detection signal EP, the second gate 86 is opened at time t12, and then the next detection signal (next output detection signal). ) Until the second gate 86 is closed at time t13 based on EP, the second gate 86 is open. During this period, the charge accumulated in the photodiode 80 due to dark current or the like It will be discarded.

  As described above, an output delay may occur for the detection signal EP. Accordingly, in contrast to the opening time of the first gate 84 being a predetermined (ie, predetermined) time T4, the opening time of the second gate 86 is variable (the second time in FIG. 13). (See the two pulses shown in the state of the gate).

  When the next detection signal (next output detection signal) EP is output at time t13 and the second gate 86 is closed, the operation based on the next detection signal (next output detection signal) EP (that is, The operation of causing the photodiode 80 to receive the color component of the light from the original and storing the charge and opening the first gate 84 to move the charge accumulated from the photodiode 80 to the read data generation unit 82 is started. The Thereafter, each time the detection signal EP is output, the above-described procedure from the time t0 to the time t13 is repeated, whereby the image reading from the document is executed.

<Effectiveness of this example>
As described above, in the image reading apparatus 10 according to the present example, the control unit 52 causes the photodiode 80 to receive the color component of the light from the document 15 based on the detection signal EP output from the encoder 90 to generate the charge. The operation of storing and opening the first gate 84 to move the charge accumulated from the photodiode 80 to the read data generating unit 82 is performed in a predetermined color order for each of the red component, the green component, and the blue component. After that, the second gate 86 is opened to move the charge accumulated in the photodiode 80 from the photodiode 80. Further, the control unit 52 closes the second gate 86 based on the next output detection signal EP output next to the detection signal EP. Thereby, both the problem of the first comparative example and the problem of the second comparative example can be solved.

  That is, in this example, even if the output delay of the detection signal occurs, the blue light charge is not accumulated more than the original accumulation amount. Is appropriately avoided (solution of the problem of the first comparative example). In this example, the accumulated charges of the three colors are added to the period of three clock pulses for extracting from the photodiode 80, and the accumulated charges due to dark current or the like are extracted from the photodiode 80. Therefore, there is no need to prepare a period for one clock pulse, so that the problem that the reading speed is remarkably slowed is appropriately avoided (solving the problem of the second comparative example). Therefore, according to this example, it is possible to increase the reading speed while preventing deterioration in image quality due to output delay of the detection signal.

=== Other Embodiments ===
The image reading apparatus and the like according to the present invention have been described above based on the above-described embodiment. However, the above-described embodiment is intended to facilitate understanding of the present invention and limits the present invention. is not. The present invention can be changed and improved without departing from the gist thereof, and the present invention includes the equivalents thereof.

  In the above embodiment, the encoder 90 detects a detection signal for each predetermined relative movement amount (predetermined movement amount of the carriage 40) between the photodiode 80 corresponding to the minimum unit of the image reading area and the document 15. However, the present invention is not limited to this, and the predetermined relative movement amount may not necessarily correspond to the minimum unit of the image reading area.

In the above embodiment, the control unit 52 causes the photodiode 80 to receive the color component of the light from the document 15 and accumulate the charge, and opens the first gate 84 to read from the photodiode 80. The operation of moving the charge accumulated in the data generation unit 82) is executed in a predetermined color order for each of the red component, the green component, and the blue component, and then the second output is detected after the second gate 86 is opened. Based on the signal, the second gate 86 is open until the second gate 86 is closed. However, the present invention is not limited to this. For example, the second gate 86 may be closed for a very short time during this period.
However, the above embodiment is more preferable in that the charge accumulated by dark current or the like is surely discarded.

Moreover, although the control part 52 decided to start the said operation | movement based on the said next output detection signal EP after closing the 2nd gate 86, it is not limited to this. For example, the operation may be started simultaneously with closing the second gate 86.
However, the above-described embodiment is more preferable in that it is reliably ensured that the operation based on the next output detection signal is executed after the second gate 86 is completely closed.

  In the above-described embodiment, the document table glass 12 for placing the document 15 and the carriage 40 moved in a predetermined direction by the drive mechanism 42 are provided. The carriage 40 has an exposure lamp 46 and a photo. The diode 80 is fixed. That is, in the above-described embodiment, the document 15 is placed and fixed on the document table glass 12, and the photodiode 80 of the carriage 40 is moved in the sub-scanning direction with respect to the document 15. However, the present invention is not limited to this. It is not a thing and may be reversed. That is, the photodiode 80 is fixed at a predetermined position in the sub-scanning direction of the image reading device 10, and the document 15 is moved in the sub-scanning direction with respect to the photodiode 80 by an automatic document feeder or the like. Also good.

  Moreover, in the said embodiment, although the said photoelectric conversion element was provided with two or more in the crossing direction which cross | intersects the said predetermined direction, it is not limited to this, Only one is provided. It is good also as multiple being provided in the direction different from the said crossing direction.

1 is a perspective view of an image reading system 2. FIG. 2 is an explanatory diagram of an internal configuration of the image reading apparatus 10. FIG. 2 is an explanatory diagram of a system configuration of the image reading apparatus 10. FIG. It is explanatory drawing of the detection signal EP output from the encoder 90. FIG. 3 is an exploded perspective view of a carriage 40. FIG. It is a figure which shows the positional relationship of the lens 48 and the image sensor 50. FIG. 3 is a perspective view of an exposure lamp 46. FIG. It is explanatory drawing of the light emission order of the exposure lamp. 2 is an explanatory diagram of a configuration of an image sensor 50. FIG. It is explanatory drawing of operation | movement of the image sensor 50. FIG. It is explanatory drawing of operation | movement of the image sensor 50. FIG. It is explanatory drawing of the operation timing which concerns on a 1st comparative example. It is explanatory drawing for demonstrating the problem about the operation timing which concerns on a 1st comparative example. It is explanatory drawing of the operation timing which concerns on a 2nd comparative example. It is explanatory drawing of the operation timing which concerns on this example. It is explanatory drawing of the operation timing which concerns on a 1st comparative example. It is explanatory drawing for demonstrating the problem about the operation timing which concerns on a 1st comparative example. It is explanatory drawing of the operation timing which concerns on a 2nd comparative example.

Explanation of symbols

2 image reading system, 10 image reading device, 12 platen glass,
14 Document cover, 15 Document, 18 Operation panel,
20 computer device, 22 computer body, 24 display device,
26 input device, 28 FD drive device,
30 CD-ROM / DVD drive device, 32 reading device,
34 keyboard, 36 mouse, 40 carriage,
42 drive mechanism, 44 guide, 46 exposure lamp,
47A light guide, 47E end, 47F exposure surface,
48 lenses, 49 individual lenses,
50 image sensor, 51 substrate, 52 control unit,
54 timing belt, 55 pulley, 56 pulley, 58 drive motor,
60 controller, 62 motor controller, 64 lamp controller,
66 Image sensor control unit, 68 AFE unit,
70 digital processing circuit, 72 interface circuit,
74 analog signal processing circuit, 76 A / D conversion circuit,
80 photoelectric conversion element (photodiode),
82 read data generation unit, 82A charge transfer unit, 82B detection circuit,
84 1st gate, 86 2nd gate, 88 transfer path for disposal, 90 encoder

Claims (8)

(A) An image reading apparatus for reading an image from a document,
(B) a light source for irradiating the original with light;
(C) a photoelectric conversion element for selectively receiving a red component, a green component, and a blue component of light from the document and storing an amount of electric charge according to the amount of received light;
(D) a read data generation unit for receiving charge accumulated by the photoelectric conversion element and generating read data of the image based on the amount of the charge;
(E) a first gate that is openable and closable to move the charge from the photoelectric conversion element to the read data generation unit by opening;
(F) is openable and closable, and when opened, a second gate for moving the charge from the photoelectric conversion element to discard the charge accumulated in the photoelectric conversion element;
(G) a drive mechanism for relatively moving the photoelectric conversion element and the document in a predetermined direction;
(H) a detection sensor for detecting a relative movement amount between the photoelectric conversion element and the document with respect to the predetermined direction, the detection sensor outputting a detection signal for each predetermined relative movement amount;
(I) Based on the detection signal output by the detection sensor,
An operation of causing the photoelectric conversion element to receive a color component of light from the document and storing the charge, and opening the first gate to move the charge stored from the photoelectric conversion element to the read data generation unit;
Is executed in a predetermined color order for each of the red component, the green component, and the blue component, and then the second gate is opened to move the charge accumulated in the photoelectric conversion element from the photoelectric conversion element Because
Based on the next output detection signal output next to the detection signal, a controller that closes the second gate;
An image reading apparatus comprising (J). The image reading apparatus according to claim 1,
The image reading apparatus according to claim 1, wherein the predetermined relative movement amount corresponds to a minimum unit of the image reading area. The image reading apparatus according to claim 1 or 2,
The control unit is
After performing the operation in a predetermined color order for each of the red component, the green component, and the blue component, after opening the second gate,
Based on the next output detection signal, until the second gate is closed,
The image reading apparatus, wherein the second gate is open. The image reading apparatus according to any one of claims 1 to 3,
The controller is
An image reading apparatus, wherein after the second gate is closed, the operation based on the next output detection signal is started. The image reading apparatus according to any one of claims 1 to 4,
An original table for placing the original and a carriage moved in the predetermined direction by the drive mechanism;
The image reading apparatus, wherein the light source and the photoelectric conversion element are fixed to the carriage. The image reading apparatus according to any one of claims 1 to 5,
An image reading apparatus, wherein a plurality of the photoelectric conversion elements are provided in a crossing direction crossing the predetermined direction. (A) An image reading apparatus for reading an image from a document,
(B) a light source for irradiating the original with light;
(C) a photoelectric conversion element for selectively receiving a red component, a green component, and a blue component of light from the document and storing an amount of electric charge according to the amount of received light;
(D) a read data generation unit for receiving charge accumulated by the photoelectric conversion element and generating read data of the image based on the amount of the charge;
(E) a first gate that is openable and closable to move the charge from the photoelectric conversion element to the read data generation unit by opening;
(F) is openable and closable, and when opened, a second gate for moving the charge from the photoelectric conversion element to discard the charge accumulated in the photoelectric conversion element;
(G) a drive mechanism for relatively moving the photoelectric conversion element and the document in a predetermined direction;
(H) a detection sensor for detecting a relative movement amount between the photoelectric conversion element and the document with respect to the predetermined direction, the detection sensor outputting a detection signal for each predetermined relative movement amount;
(I) Based on the detection signal output by the detection sensor,
An operation of causing the photoelectric conversion element to receive a color component of light from the document and storing the charge, and opening the first gate to move the charge stored from the photoelectric conversion element to the read data generation unit;
Is executed in a predetermined color order for each of the red component, the green component, and the blue component, and then the second gate is opened to move the charge accumulated in the photoelectric conversion element from the photoelectric conversion element Because
Based on the next output detection signal output next to the detection signal, a controller that closes the second gate;
(J)
(K) The predetermined relative movement amount corresponds to a minimum unit of the reading area of the image,
(L) The control unit
After performing the operation in a predetermined color order for each of the red component, the green component, and the blue component, after opening the second gate,
Based on the next output detection signal, until the second gate is closed,
The second gate is open;
(M) The control unit
After closing the second gate, start the operation based on the next output detection signal,
(N) a document table for placing the document, and a carriage moved in the predetermined direction by the drive mechanism;
The light source and the photoelectric conversion element are fixed to the carriage,
(O) An image reading apparatus, wherein a plurality of the photoelectric conversion elements are provided in an intersecting direction intersecting the predetermined direction. An image reading system comprising a computer and an image reading device connected to the computer so as to communicate with each other and reading an image from a document,
The image reading device includes:
A light source for irradiating the original with light and a red component, a green component, and a blue component of the light from the original are selectively received, and an amount of electric charge corresponding to the amount of received light is accumulated. A photoelectric conversion element for receiving the charge accumulated in the photoelectric conversion element, and a read data generation unit for generating read data of the image based on the amount of the charge, which can be opened and closed, and opened A first gate for moving the charge from the photoelectric conversion element to the read data generation unit; and openable and closable to open the charge to discard the charge accumulated in the photoelectric conversion element. A second gate for moving from the conversion element; a drive mechanism for moving the photoelectric conversion element and the document in a predetermined direction; and a relative movement between the photoelectric conversion element and the document in the predetermined direction. A detection sensor for detecting the amount of light, and a detection sensor for outputting a detection signal for each predetermined relative movement amount; and on the basis of the detection signal output by the detection sensor, the photoelectric conversion element receives light from the document. Receiving the color component, accumulating the charge, and opening the first gate to move the accumulated charge from the photoelectric conversion element to the read data generation unit, the red component, the green component, and the blue component A control unit that executes each of the components in a predetermined color order, and then opens the second gate to move the charge accumulated in the photoelectric conversion element from the photoelectric conversion element, and is output next to the detection signal. A controller that closes the second gate based on the detected next output detection signal;
An image reading system comprising: