JP2007267187A - Apparatus, method, and system for reading image and printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To smoothly read an image even if the moving speed of an image reading sensor is increased. <P>SOLUTION: The image reading apparatus is provided with the image reading sensor moving relatively to an original and reading an image from the original; a signal output unit for outputting a signal corresponding to the movement of the image reading sensor relative to the original; a timing signal generating circuit 112 for generating a timing signal for defining a timing used as a reference for acquiring the data of the image read from the original by the image reading sensor from the image reading sensor, on the basis of the signal output from the signal output unit; and a timing delay circuit for delaying a latter timing so that an interval between itself and a one former timing may be not less than a predetermined time, if the latter timing in which the interval between itself and the one former timing is shorter than a predetermined time is included in the timing defined by the timing signal generated by the timing signal generating circuit. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image reading apparatus, an image reading method, an image reading system, and a printing apparatus that read an image from an original by a sensor that moves relative to the original.

  Various image reading apparatuses such as an image scanner include an image reading sensor such as an image sensor for reading an image from a document. The image reading sensor moves relative to the document when reading an image from the document. Here, the image reading sensor sequentially outputs image data read from the document while moving relative to the document. The timing at which the image data read from the document is output from the image reading sensor is determined based on the moving distance and moving speed of the image reading sensor. That is, the timing at which image data read from the document is output from the image reading sensor is changed in accordance with the moving distance or moving speed of the image reading sensor. As a result, even when the moving speed of the image reading sensor fluctuates, the image can be read from the document with a predetermined pitch.

However, when the moving speed of the image reading sensor suddenly increases due to an external impact or the like while reading an image from a document, the following problem occurs. That is, since the movement speed of the image reading sensor suddenly increases, the data output from the image reading sensor cannot be acquired in time, and the image cannot be read properly from the document. For this reason, a method has been proposed for smoothly reading an image from a document even when the moving speed of the image reading sensor suddenly increases (see Patent Document 1).
JP 7-271905 A

  However, in the method proposed here, the data is continuously overwritten unless all the image data read from the document is stored in the memory, so that the moving speed of the image reading sensor is high for a long time. In some cases, the image data read from the original is not easily written in the memory. As a result, there arises a problem that the image cannot be smoothly read from the document.

  The present invention has been made in view of such circumstances, and an object of the present invention is to enable smooth image reading even when the movement speed of a sensor that reads an image from a document suddenly increases. Is to make it.

The main invention for achieving the object is as follows:
(A) an image reading sensor that moves relative to the document and reads an image from the document;
(B) a signal output unit that outputs a signal corresponding to a relative movement of the image reading sensor with respect to the document;
(C) A timing signal that defines a reference timing for acquiring data of the image read from the document by the image reading sensor from the image reading sensor based on the signal output from the signal output unit. A timing signal generation circuit for generating
(D) When the timing defined by the timing signal generated by the timing signal generation circuit includes a later timing that is shorter than a predetermined time from the previous timing, the 1 A timing delay circuit that delays the subsequent timing so that an interval between the two previous timings is equal to or longer than the predetermined time;
An image reading apparatus comprising (E).

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

  At least the following matters will become apparent from the description of the present specification and the accompanying drawings.

(A) an image reading sensor that moves relative to the document and reads an image from the document;
(B) a signal output unit that outputs a signal corresponding to a relative movement of the image reading sensor with respect to the document;
(C) A timing signal that defines a reference timing for acquiring data of the image read from the document by the image reading sensor from the image reading sensor based on the signal output from the signal output unit. A timing signal generation circuit for generating
(D) When the timing defined by the timing signal generated by the timing signal generation circuit includes a later timing that is shorter than a predetermined time from the previous timing, the 1 A timing delay circuit that delays the subsequent timing so that an interval between the two previous timings is equal to or longer than the predetermined time;
An image reading apparatus comprising (E).

  In this image reading apparatus, when the timing defined by the timing signal generated by the timing signal generation circuit includes a later timing that is shorter than a predetermined time from the previous timing. In addition, since the later timing can be delayed by the timing delay circuit so that the interval between the preceding timing is equal to or longer than the predetermined time, the moving speed of the image reading sensor suddenly increases due to an external impact or the like. Even in this case, there is no case where data acquisition from the image reading sensor is not in time, and the image can be read smoothly.

  In such an image reading apparatus, the signal output unit may output a signal corresponding to a relative moving speed of the image reading sensor with respect to the document as the signal. As described above, the signal output unit outputs a signal corresponding to the relative moving speed of the image reading sensor with respect to the document as a signal, so that the timing signal can be easily generated by the timing signal generation circuit.

  In the image reading apparatus, the signal output unit may output a signal corresponding to a relative movement distance of the image reading sensor with respect to the document as the signal. As described above, the signal output unit outputs a signal corresponding to the relative movement distance of the image reading sensor with respect to the document as a signal, so that the timing signal can be easily generated by the timing signal generation circuit.

  In such an image reading apparatus, the signal output unit may include an encoder for outputting the signal. By providing such an encoder in the signal output unit, it is possible to easily output a signal corresponding to the relative movement of the image reading sensor with respect to the document.

  In such an image reading apparatus, the image reading sensor may include a plurality of photoelectric conversion elements that generate charges according to the amount of received light. By providing a plurality of such photoelectric conversion elements, the image reading sensor can smoothly read an image from a document.

  In the image reading apparatus, the image reading sensor may include a charge transfer unit that transfers charges generated respectively to the photoelectric conversion elements. If such a charge transfer unit is provided, the charges generated in the photoelectric conversion elements can be easily transferred.

  In the image reading apparatus, the timing signal generation circuit may generate a signal having a pulse generated corresponding to the timing as the timing signal. If such a signal is generated by the timing signal generation circuit, a timing that becomes a reference for acquiring data of an image read from the original by the image reading sensor from the image reading sensor can be easily defined in the timing signal. .

  In the image reading apparatus, the predetermined time may be set to be longer than a time set for the image reading sensor to read the image from the document. As described above, even when the moving speed of the image reading sensor suddenly increases because the predetermined time is set to be longer than the time set for the image reading sensor to read an image from the document, the image reading sensor The sensor can smoothly read an image from the document.

  In the image reading apparatus, the predetermined time may be set to be longer than a time necessary for acquiring the image data from the image reading sensor. Even when the moving speed of the image reading sensor suddenly increases because the predetermined time is set to be longer than the time necessary for acquiring the image data from the image reading sensor, the image reading sensor Image data can be obtained smoothly.

  In the image reading apparatus, the timing delay circuit may include a timer that measures an elapsed time from the occurrence of the previous timing. If such a timer is provided, it is possible to easily measure the elapsed time from the occurrence of one previous timing.

(A) an image reading sensor that moves relative to the document and reads an image from the document;
(B) a signal output unit that outputs a signal corresponding to a relative movement of the image reading sensor with respect to the document;
(C) A timing signal that defines a reference timing for acquiring data of the image read from the document by the image reading sensor from the image reading sensor based on the signal output from the signal output unit. A timing signal generation circuit for generating
(D) When the timing defined by the timing signal generated by the timing signal generation circuit includes a later timing that is shorter than a predetermined time from the previous timing, the 1 A timing delay circuit that delays the subsequent timing so that an interval between the two previous timings is equal to or longer than the predetermined time;
(E)
(F) The signal output unit outputs, as the signal, a signal according to a relative moving speed of the image reading sensor with respect to the document or a signal according to a relative moving distance of the image reading sensor with respect to the document. And
(G) The signal output unit includes an encoder for outputting the signal,
(H) The image reading sensor includes a plurality of photoelectric conversion elements that generate charges according to the amount of received light,
(I) The image reading sensor includes a charge transfer unit that transfers charges generated respectively to the photoelectric conversion elements,
(J) the timing signal generation circuit generates a signal having a pulse generated corresponding to the timing as the timing signal;
(K) The predetermined time is set to be equal to or longer than a time set for the image reading sensor to read the image from the document, and a time required for acquiring the image data from the image reading sensor. Set to above,
(L) The image reading apparatus, wherein the timing delay circuit includes a timer for measuring an elapsed time from the occurrence of the one previous timing.

(A) a step of reading an image from the original by moving an image reading sensor relative to the original;
(B) outputting a signal corresponding to a relative movement of the image reading sensor with respect to the document;
(C) generating a timing signal that defines a reference timing for acquiring data of the image read from the document by the image reading sensor from the image reading sensor based on the output signal;
(D) When the timing defined by the generated timing signal includes a later timing that is shorter than a predetermined time, the interval from the previous timing Delaying the subsequent timing so that is equal to or longer than the predetermined time;
An image reading method characterized by comprising (E).

An image reading system comprising a computer and an image reading device connected to the computer,
The image reading device includes an image reading sensor that moves relative to a document and reads an image from the document;
A signal output unit that outputs a signal corresponding to a relative movement of the image reading sensor with respect to the document;
Based on the signal output from the signal output unit, a timing signal that defines a reference timing for acquiring data of the image read from the document by the image reading sensor from the image reading sensor is generated. A timing signal generation circuit;
When the timing defined by the timing signal generated by the timing signal generation circuit has a later timing that is shorter than a predetermined time from the previous timing, the previous one A timing delay circuit that delays the subsequent timing so that an interval between the timing is equal to or longer than the predetermined time;
An image reading system comprising:

(A) an image reading sensor that moves relative to the document and reads an image from the document;
(B) a signal output unit that outputs a signal corresponding to a relative movement of the image reading sensor with respect to the document;
(C) A timing signal that defines a reference timing for acquiring data of the image read from the document by the image reading sensor from the image reading sensor based on the signal output from the signal output unit. A timing signal generation circuit for generating
(D) When the timing defined by the timing signal generated by the timing signal generation circuit includes a later timing that is shorter than a predetermined time from the previous timing, the 1 A timing delay circuit that delays the subsequent timing so that an interval between the two previous timings is equal to or longer than the predetermined time;
(E) a printing unit that prints the image read by the image reading sensor on a medium;
A printing apparatus comprising (F).

=== Overview of Image Reading System etc. ===
Embodiments of an image reading system and the like according to the present invention will be described below. 1 to 4 describe an embodiment of an image reading system. FIG. 1 illustrates an embodiment of an image reading system. FIG. 2 is a diagram illustrating an example of the internal configuration of the image reading apparatus. FIG. 3 is a diagram illustrating an example of a system configuration of the image reading apparatus. FIG. 4 is a diagram illustrating the system configuration of the computer apparatus.

  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 by wire or wireless. As shown in FIG. 1, the image reading device 10 is a device generally called an image scanner, and includes a document table 12 and a document table cover 14 that opens and closes the upper surface of the document table 12. A document 15 from which an image is read is set on the document table 12. The document table cover 14 is provided at the rear end portion of the document table 12 through a hinge portion 18 so as to be freely opened and closed.

  On the other hand, 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. The computer main body 22 includes various computers such as a personal computer. Here, the computer main body 22 includes a reading device 32 such as an FD drive device 28 or a CD-ROM drive device 30 therein. In addition, the computer main body 22 may include, for example, an MO (Magnet Optical) disk drive device or a DVD drive device. The display device 24 includes various display devices such as a CRT display, a plasma display, and a liquid crystal display. The input device 26 includes a keyboard 34, a mouse 36, and the like.

<Image reading device>
As shown in FIG. 2, inside the document table 12 of the image reading apparatus 10, a carriage 40 and the carriage 40 are parallel to each other along the direction of arrow A in FIG. A driving mechanism 42 for moving the guide 40 and a guide 44 for guiding the movement while supporting the carriage 40 are provided.

  The carriage 40 has an exposure lamp 46 as a light source for irradiating light to the document 15 via the document table 12, a lens 48 on which reflected light reflected by the document 15 is incident, and the inside of the carriage 40 through the lens 48. And an image sensor 50 for receiving the reflected light taken in. The image sensor 50 includes a linear CCD sensor or the like in which photoelectric conversion elements such as photodiodes that convert optical signals into electric signals are arranged in a line. The image data read by the image sensor 50 is output to the control unit 52.

  The drive mechanism 42 includes a timing belt 54 connected to the carriage 40, a pair of pulleys 55, 56 around which the timing belt 54 is stretched, and a drive motor 58 that rotationally drives one pulley 55. Yes. The drive motor 58 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, a sensor control unit 66, an AFE (Analog Front End) unit 68, a digital processing circuit 70, And an interface circuit 72. Further, the AFE (Analog Front End) unit 68 includes an analog signal processing circuit 74 and an A / D conversion circuit 76.

  The controller 60 controls the motor control unit 62, the lamp control unit 64, the sensor control unit 66, the AFE (Analog Front End) unit 68, the digital processing circuit 70, and the interface circuit 72 based on commands 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 from the controller 60. The lamp control unit 64 controls the light emission of the exposure lamp 46. The sensor control unit 66 controls the image sensor 50.

  An analog signal processing circuit 74 of an AFE (Analog Front End) unit 68 performs signal processing on an analog signal of an image read by the image sensor 50. An A / D conversion circuit 76 of an AFE (Analog Front End) unit 68 performs A / D conversion on 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 (Analog Front End) unit 68. Here, specifically, various 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 apparatus 10 is connected in this case. The In addition to this, the interface circuit 72 receives commands (commands) and the like from the computer main body 22 to the image reading apparatus 10.

=== Image sensor ===
FIG. 4 illustrates an example of the image sensor 50. In this embodiment, the image sensor 50 is installed inside the carriage 40. As shown in the figure, the carriage 40 is formed long along a direction intersecting the moving direction of the carriage 40 (carriage moving direction). When reading an image, the carriage 40 slides in parallel along the carriage moving direction. To do. A lens 48 for allowing light to enter the image sensor 50 is provided on the carriage 40 so as to face the document table 12. The light reflected from the document is incident on the lens 48. The lens 48 is arranged along the longitudinal direction of the carriage 40, that is, the direction intersecting the carriage movement direction. An exposure lamp 46 for irradiating the original 15 with light via the original table 12 is provided in parallel with the lens 48 on the carriage 40. The length Lk of the lens 48 and the exposure lamp 46 is set corresponding to the maximum width of the document 15 placed on the document table 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 corresponding to the lens 48 along the longitudinal direction of the carriage 40, that is, the direction intersecting the carriage movement direction, as with the lens 48. The length dimension Ls of the image sensor 50 is set corresponding to the length Lk of the lens 48. On the upper surface portion of the image sensor 50, for example, a plurality of photoelectric conversion elements such as photodiodes are arranged side by side along the longitudinal direction.

  FIG. 5 illustrates the arrangement of the lens 48 and the image sensor 50 in detail. 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 direction intersecting the carriage movement direction. The light incident on each individual lens 49 is received by a plurality of photoelectric conversion elements such as photodiodes provided in the image sensor 50.

=== Exposure lamp ===
FIG. 6A explains an example of the exposure lamp 46. As shown in the figure, the exposure lamp 46 includes a light guide 47A and three types of LEDs 47B, 47C, and 47D having different emission colors. The three types of LEDs are a red (R) LED 47B, a green (G) LED 47C, and a blue (B) LED 47D, respectively. These three types of LEDs 47B, 47C, and 47D are provided at the end 47E of the light guide 47A.

  On the other hand, the light guide 47A is arranged in parallel with the lens 48 along the longitudinal direction of the lens 48, that is, the direction intersecting the carriage movement direction, as shown in FIG. The light guide 47A introduces light emitted from the three types of LEDs 47B, 47C, and 47D provided at the end thereof, and emits light from the exposure surface 47F provided at the upper portion thereof. Yes. That is, the light guide 47 </ b> A functions as a light source that emits light toward the document 15. Moreover, the color of the light emitted from the light guide 47A varies depending on the colors of the LEDs 47B, 47C, and 47D that are turned on. That is, when the red (R) LED 47B is turned on, the light guide 47A emits light in the red (R) color. When the green (G) LED 47C is turned on, the light guide 47A emits light in the green (G) color. When the blue (B) LED 47D is turned on, the light guide 47A emits light in the blue (B) color.

  When an image is read from the document 15 by the image sensor 50, the three types of LEDs 47B, 47C, and 47D are individually turned on at different timings. That is, when the red (R) LED 47B is lit, the green (G) LED 47C and the blue (B) LED 47D are not lit. Further, when the green (G) LED 47C is lit, the red (R) LED 47B and the blue (B) LED 47D are not lit. Further, when the blue (B) LED 47D is lit, the red (R) LED 47B and the green (G) LED 47C are not lit.

  The three types of LEDs 47B, 47C, and 47D are lit in a predetermined order. That is, for example, the three types of LEDs 47B, 47C, and 47D are lit in the order of red (R) → green (G) → blue (B). Accordingly, the light guide 47A also emits light in the order of red (R) → green (G) → blue (B).

  FIG. 6B explains an example of the light emission sequence of the exposure lamp 46. In the exposure lamp 46, as shown in the figure, three types of LEDs, namely, a red (R) LED 47B, a green (G) LED 47C, and a blue (B) LED 47D are individually lit at different timings. Thus, light is emitted in red (R), green (G) and blue (B) colors. The light emission order of the exposure lamp 46 is set, for example, in the order of red (R) → green (G) → blue (B). The exposure lamp 46 repeats the period T with the light emission order of these three colors, for example, the order of red (R) → green (G) → blue (B) as one period T.

=== Photoelectric Conversion Element ===
FIG. 7A illustrates an example of a photoelectric conversion element provided in the image sensor 50. As shown in the figure, the image sensor 50 of the present embodiment includes a plurality of photoelectric conversion elements arranged in a line along a predetermined direction, here, a direction intersecting the moving direction of the carriage 40. A photodiode 80, a charge transfer unit 82 (CCD: charge-coupled device), and a plurality of gates 84 provided between the plurality of photodiodes 80 and the charge transfer unit 82 are provided.

  Electric charges are generated in the plurality of photodiodes 80 according to the amount of received light. In the present embodiment, each of the plurality of photodiodes 80 receives light emitted from the exposure lamp 46 and reflected from the document 15 placed on the document table 12 as light. That is, each photodiode 80 receives light of three colors emitted from the exposure lamp 46, that is, light of each color of red (R), green (G), and blue (B). The plurality of photodiodes 80 generate charges according to the amounts of the three colors of light received. That is, electric charges are generated in each photodiode 80 by receiving red (R) light. In addition, charges are generated by receiving the green (G) light. Further, electric charges are generated by receiving blue (B) light. In this manner, each of the photodiodes 80 is charged by the three colors of light reflected from the document 15 placed on the document table 12, so that the image sensor 50 is connected to the document 15 placed on the document table 12. The image is read.

  The charges generated in each photodiode 80 are moved to the charge transfer unit 82, respectively. FIG. 7B shows how the charges generated in each photodiode 80 for each emission color of the exposure lamp 46 (in the order of red (R) → green (G) → blue (B)) are moved to the charge transfer unit 82. Shows about. When the charge generated in each photodiode 80 is sent to the charge transfer unit 82, each gate 84 (see the gray portion in the figure) is opened. When each gate 84 is opened, the charge generated in each photodiode 80 moves quickly to the charge transfer unit 82 due to the potential well relationship.

  The charge transfer unit 82 temporarily accumulates the charges transferred from each photodiode 80. The charge transfer unit 82 sequentially transfers the temporarily accumulated charges to the detection circuit 86. The detection circuit 86 sequentially detects the amount of charge transferred by the charge transfer unit 82. Here, the amount of charge detected by the detection circuit 86 is data for one pixel constituting the image of the document 15 on the document table 12 read by the image sensor 50. The detection circuit 86 outputs the detection result of the transferred charge amount to the AFE (Analog Front End) unit 68 (see FIG. 3).

=== Encoder ===
<Configuration>
FIG. 8 illustrates the encoder 90 for acquiring information related to the movement of the carriage 40. The encoder 90 is a rotary encoder, and detects the position, moving distance, moving speed, and the like of the carriage 40 by detecting the rotation amount of the drive motor 58.

  The encoder 90 includes an encoder code plate 92 and a detection unit 94 provided adjacent to the encoder code plate 92 as shown in FIG. A large number of small slits 96 are formed at predetermined intervals on the outer peripheral edge of the encoder code plate 92. The encoder code plate 92 is integrally provided on a rotation shaft 59 of a drive motor 58 that constitutes a drive mechanism 42 that moves the carriage 40. When the drive motor 58 is driven, the encoder code plate 92 rotates together with the rotation shaft 59 of the drive motor 58.

<Detector>
FIG. 9 illustrates an example of the configuration of the detection unit 94 of the encoder 90. The detection unit 94 of the encoder 90 includes a light emitting diode 98, a collimator lens 100, and a detection processing unit 102. The detection processing unit 102 includes a plurality of (for example, four) photodiodes 104, a signal processing circuit 106, and, for example, two comparators 108A and 108B.

  When the voltage Vcc is applied to both ends of the light emitting diode 98 via a resistor, light is emitted from the light emitting diode 98. This light is condensed into parallel light by the collimator lens 100 and passes through the encoder code plate 92. The encoder code plate 92 is provided with slits 96 at predetermined intervals (for example, 1/2400 inch, 1/1200 inch, 1/600 inch, etc. (1 inch = 2.54 cm)).

  The parallel light that has passed through the encoder code plate 92 enters each photodiode 104 through the slit 96 and is converted into an electrical signal. The electric signals output from the four photodiodes 104 are processed in the signal processing circuit 106, the signals output from the signal processing circuit 106 are compared in the comparators 108A and 108B, and the comparison results are output as pulse signals, respectively. The Pulse signals ENC-A and ENC-B respectively output from the comparators 108A and 108B are output signals of the encoder 90.

<Output signal>
10A and 10B are timing charts showing waveforms of two output signals of the encoder 90 when the drive motor 58 is rotating forward and when the drive motor 58 is rotating forward. FIG. 10A is a timing chart of the waveform of the output signal when the drive motor 58 is rotating forward. FIG. 10B is a timing chart of the waveform of the output signal when the drive motor 58 is reversed.

  As shown in FIGS. 10A and 10B, the phase of the pulse signal ENC-A and the pulse signal ENC-B differ by 90 degrees in both cases of the forward rotation and the reverse rotation of the drive motor 58. When the drive motor 58 is rotating forward, the phase of the pulse signal ENC-A is advanced by 90 degrees relative to the pulse signal ENC-B. On the other hand, when the drive motor 58 is reversed, the phase of the pulse signal ENC-A is delayed by 90 degrees from the pulse signal ENC-B. One cycle T of each pulse signal is such that the rotation axis of the drive motor 58 is the distance between the slits 96 of the encoder code plate 92 (for example, 1/2400 inch, 1/1200 inch, 1/600 inch, etc. (1 inch = 2.54 cm). )) Equivalent to time to rotate by minutes.

  Then, if each edge of the pulse signals ENC-A and ENC-B output from the encoder 90 is detected and the number of detected edges is counted, the rotational position of the drive motor 58 is based on the counted value. Can be calculated. For example, when the driving motor 58 is rotating forward, “+1” is added when one edge is detected. When the driving motor 58 is rotating backward, one edge is detected. When detected, “−1” is added. The period of each of the pulses ENC-A and ENC-B is equal to the time from when one slit 96 of the encoder code plate 92 passes through the detection unit 94 to when the next slit 96 passes through the detection unit 94. The pulse signal ENC-A and the pulse signal ENC-B are different in phase by 90 degrees. For these reasons, the count value “1” of the count corresponds to ¼ of the interval between the slits 96 of the encoder code plate 92. Thus, if the count value is multiplied by 1/4 of the interval of the slit 96, the drive amount of the drive motor 58 from the rotational position corresponding to the count value “0” can be obtained based on the multiplication value. . From this, the movement amount of the carriage 40 from the position corresponding to the count value “0” can be obtained, and the current position can be derived.

=== Timing signal ===
The control unit 52 is provided with a timing signal output circuit 110 that outputs a timing signal that defines the timing of light emission by the exposure lamp 46 and the timing of reading an image by the image sensor 50.

  FIG. 11 illustrates the timing signal output circuit 110. The timing signal output circuit 110 is controlled by the controller 60 of the control unit 52 as shown in FIG. The timing signal output circuit 110 receives an output signal from the encoder 90, that is, pulse signals ENC-A and ENC-B. The timing signal output circuit 110 generates a timing signal St based on these pulse signals ENC-A and ENC-B input from the encoder 90.

  FIG. 12 illustrates an example of the timing signal St generated by the timing signal output circuit 110. The timing signal St is generated based on the edges of the pulse signals ENC-A and ENC-B output from the encoder 90, as shown in FIG. Here, the timing signal St is generated based on the rising edge of the pulse signal ENC-A. The timing signal St generated here is provided with a pulse Wt corresponding to the timing at which a rising edge occurs in the pulse signal ENC-A.

  The timing signal St thus generated is output from the timing signal output circuit 110 to the lamp control unit 64 and the sensor control unit 66 as shown in FIG. The lamp control unit 64 and the sensor control unit 66 control the exposure lamp 46 or the image sensor 50 based on the timing signal St output from the timing signal output circuit 110.

  Here, based on the timing signal St output from the timing signal output circuit 110, the lamp control unit 64 has three types of LEDs, that is, a red (R) LED 47B, a green (G) LED 47C, and a blue (B). The timing for turning on the LED 47D is controlled. Specifically, the lamp control unit 64 includes three types of LEDs 47B, 47C, from the time when the pulse Wt is generated in the timing signal St output from the timing signal output circuit 110 to the time when the next pulse Wt is generated. 47D is lit in the order of, for example, red (R) → green (G) → blue (B).

  On the other hand, the sensor control unit 66 controls the timing of acquiring the accumulated charges from the plurality of photodiodes 80 provided in the image sensor 50 based on the timing signal St output from the timing signal output circuit 110. Specifically, the sensor control unit 66 opens the gates 84 with reference to the timing at which the pulse Wt is generated in the timing signal St output from the timing signal output circuit 110, and a plurality of sensors provided in the image sensor 50 are provided. The charges accumulated in the photodiodes 80 are moved to the charge transfer unit 82. Here, the sensor control unit 66 emits light of three colors, that is, red (R), green (G), and blue (B) in a predetermined order from the exposure lamp 46 by the lamp control unit 64. Each time the charges accumulated in the plurality of photodiodes 80 are moved to the charge transfer unit 82. Thereby, the sensor control unit 66 acquires the charges accumulated in the plurality of photodiodes 80 for each color of light emitted by the exposure lamp 46.

  In this way, the lamp control unit 64 and the sensor control unit 66 control the exposure lamp 46 or the image sensor 50 based on the timing signal St output from the timing signal output circuit 110.

  Note that the pulse signals ENC-A and ENC-B output from the encoder 90 are also input to the motor control unit 62 as shown in FIG. The motor control unit 62 acquires information on the moving speed and moving distance (current position) of the carriage based on the pulse signals ENC-A and ENC-B output from the encoder 90, and the drive motor 58 is based on these information. To control.

=== Conventional Problems and Solutions ===
<Conventional problems>
By the way, in such an image reading apparatus 10, when reading an image from the document 15, the moving speed of the carriage 40 may suddenly increase due to an external impact or the like. As described above, when the moving speed of the carriage 40 suddenly increases, there is a problem in that data acquisition from the image sensor 50 is not in time and the image on the document 15 cannot be read properly.

<Solution>
In order to solve such a problem, in the present embodiment, even when the moving speed of the carriage 40 suddenly increases due to an external impact or the like when reading an image from the document 15, the image is read from the document. In order to read an image smoothly, the following configuration is provided. In other words, a timing delay circuit is provided that delays the timing defined by the timing signal St generated by the timing signal output circuit 110 when the moving speed of the carriage 40 suddenly increases due to an external impact or the like.

  This timing delay circuit shortens the period of the pulse signals ENC-A and ENC-B output from the encoder 90 when the moving speed of the carriage 40 suddenly increases due to an external impact or the like, and these pulse signals ENC- Using the fact that the timing interval to be defined by the timing signal St generated by the timing signal output circuit 110 based on A and ENC-B is shortened, the interval from the previous timing is shorter than the predetermined time. When there is a short later timing, the later timing is delayed so that the interval from the previous timing is a predetermined time or more. As a result, when the moving speed of the carriage 40 suddenly increases due to an external impact or the like, the timing at which the image data read by the image sensor 50 is acquired from the image sensor can be delayed. Thus, it is possible to smoothly read an image from a document.

=== Timing signal output circuit ===
FIG. 13 illustrates an example of the configuration of the timing signal output circuit 110 for outputting such a timing signal St. The timing signal output circuit 110 includes a timing signal generation circuit 112 and a timing delay circuit 116. Further, the timing delay circuit 116 includes a delay timer 114.

  The timing signal generation circuit 112 generates the original signal S0 based on the pulse signals ENC-A and ENC-B output from the encoder 90. The original signal S0 generated here is a reference signal for the timing signal St output from the timing signal output circuit 110. The original signal S0 is generated based on the edges of the pulse signals ENC-A and ENC-B output from the encoder 90. Here, based on the rising edge of the pulse signal ENC-A, the original signal S0 is generated. That is, the original signal S0 generated here has a pulse Wt generated corresponding to the timing at which a rising edge occurs in the pulse signal ENC-A.

  The original signal S 0 generated and output by the timing signal generation circuit 112 is input to the timing delay circuit 116. The timing delay circuit 116 generates a timing signal St based on the original signal S0 output from the timing signal generation circuit 112. Specifically, the timing delay circuit 116 measures the elapsed time from the generation of the timing defined by the original signal S 0 output from the timing signal generation circuit 112 by the delay timer 114. If the next timing occurs in the original signal S0 output from the timing signal generation circuit 112 before the predetermined time has elapsed since the occurrence of the timing defined by the original signal S0, the timing delay circuit 116 delays the next timing. Here, the timing delay circuit 116 delays the next timing so that it occurs after a predetermined time has elapsed from the occurrence of the previous timing. That is, the timing delay circuit 116 delays the next timing so that the interval between the next timing and the previous timing becomes a predetermined time or more. And after delaying about this next timing, the timing delay circuit 116 measures the elapsed time from the next timing. If the next timing occurs again in the original signal S0 output from the timing signal generation circuit 112 before the elapsed time from the next timing elapses a predetermined time, the timing delay circuit 116 Delay timing. The timing delay circuit 116 delays the timing defined by the original signal S0 output from the timing signal generation circuit 112 in this way, and then outputs the signal as the timing signal St. This timing signal St becomes the output signal of the timing signal output circuit 110.

<Actual timing signal St>
The timing signal St actually output from the timing signal output circuit 110 will be described. 14 shows the pulse signals ENC-A and ENC-B output from the encoder 90, the original signal S0 output from the timing signal generation circuit 112, the time measurement by the delay timer 114, and the timing delay circuit 116. The timing signal St to be output is described.

  The original signal S0 generated and output by the timing signal generation circuit 112 is a rising edge in the pulse signal ENC-A based on the pulse signals ENC-A and ENC-B output from the encoder 90, as shown in FIG. An original signal S0 having a pulse Wt generated corresponding to the timing at which is generated is generated. The original signal S0 has a pulse Wt that defines a timing that serves as a reference for the timing signal St output from the timing signal output circuit 110.

  The time measurement by the delay timer 114 is started at the timing at which a pulse Wt that defines the timing is generated in the original signal S0 generated and output by the timing signal generation circuit 112, as shown in FIG. The delay timer 114 measures the time from when the pulse Wt defining the timing is generated in the original signal S0 generated and output by the timing signal generation circuit 112 until a predetermined time Tm elapses. If the next pulse Wt is generated in the original signal S0 output from the timing signal generation circuit 112 before the predetermined time Tm has elapsed from the time measurement start by the delay timer 114, the timing delay circuit 116 Until the measurement time by the timer 114 reaches a predetermined time Tm, generation of the next pulse Wt is suspended and delayed.

  Then, after delaying the next pulse Wt in this manner, the timing delay circuit 116 starts time measurement by the delay timer 114 again. When the next pulse Wt is generated in the original signal S0 output from the timing signal generation circuit 112 before the elapsed time from the generation of the next pulse Wt reaches the predetermined time Tm again, the timing delay circuit 116 is used. Until the time measured by the delay timer 114 reaches the predetermined time Tm, the generation of the next pulse Wt is suspended and delayed.

  In this way, the timing delay circuit 116 sequentially delays the generation of the pulse Wt that defines the timing in the original signal S0 generated and output by the timing signal generation circuit 112. Then, the signal in which the generation of the pulse Wt defining the timing in this way is delayed is output from the timing signal output circuit 110 as the timing signal St.

<Predetermined time Tm>
Here, it is preferable that the predetermined time Tm, which serves as a reference when the timing specified by the original signal S0 output from the timing signal generation circuit 112 is delayed by the timing delay circuit 116, is set as follows.

(A) Time More than Time Ts Required for Charge Transfer by Charge Transfer Unit 82 If the predetermined time Tm is set to a time longer than time Ts required for charge transfer by the charge transfer unit 82, the image sensor 50 causes the original 15 The image reading operation can be performed smoothly. That is, if the predetermined time Tm is set to a time longer than the time Ts required for the charge transfer by the charge transfer unit 82, the next timing is set before the time required for the charge transfer by the charge transfer unit 82 elapses. Therefore, the image can be smoothly read from the document 15.

  That is, as shown in FIG. 14, even when the timing interval defined by the original signal S0 output from the timing signal generation circuit 112 is shortened, the timing signal St output from the timing signal output circuit 110 is shortened. Does not become shorter than the predetermined time Tm. Therefore, the next charge transfer timing does not occur before the time Ts required for the charge transfer elapses after the charge transfer unit 82 starts the charge transfer.

(B) Time longer than the setting time Tr of the exposure lamp 46 If the predetermined time Tm is set to a time longer than the setting time Tr of the exposure lamp 46, the image quality of the image read from the document 15 by the image sensor 50 is deteriorated. Can be prevented. In other words. When the predetermined time Tm is set to be shorter than the set time Tr of the exposure lamp 46, each photodiode of the image sensor 50 is passed before the set time Tr elapses after the exposure lamp 46 starts exposure. The accumulated charge from 80 must be taken out. For this reason, each photodiode 80 is underexposed, and there is a possibility that sufficient image quality may not be obtained.

  On the other hand, if the predetermined time Tm is set to be equal to or longer than the set time Tr of the exposure lamp 46, sufficient charges can be accumulated in each photodiode 80 of the image sensor 50. Thereby, it is possible to avoid that each photodiode 80 is underexposed. Therefore, it is possible to prevent the deterioration of the image quality of the image read from the document 15.

  That is, as shown in FIG. 14, even when the timing interval defined by the original signal S0 output from the timing signal generation circuit 112 is shortened, the timing signal St output from the timing signal output circuit 110 is shortened. Does not become shorter than the predetermined time Tm. Therefore, the next light emission start timing does not occur before the set time Tr elapses after the exposure lamp 46 starts issuing.

  Here, the predetermined time Tm is set so as to satisfy these requirements (A) or (B), but only one of these requirements (A) and (B) is satisfied. The predetermined time Tm may be set, and the predetermined time Tm may be set so as to satisfy both of the requirements (A) and (B). Preferably, the predetermined time Tm is set so as to satisfy at least the requirement (A).

=== Measures when the moving speed is too fast ===
If the moving speed of the carriage 40 is too high, the operation of reading an image from the document 15 is stopped as a mechanical error. FIG. 15 illustrates a case where the operation of reading an image from the document 15 is stopped when the moving speed of the carriage 40 is too fast.

  First, when the moving speed of the carriage 40 increases and reaches the predetermined speed Va, the timing interval defined by the original signal S0 generated by the timing signal generation circuit 112 becomes shorter than the predetermined time Tm, and the original signal S0. Is delayed by the timing delay circuit 116. At this time, the lamp control unit 64 and the sensor control unit 66 control the exposure lamp 46 or the image sensor 50 based on the timing signal St output from the timing signal output circuit 110. That is, an operation for reading an image from the document 15 is allowed.

  Further, when the moving speed of the carriage 40 increases and exceeds the allowable speed Vb, the controller 60 of the image reading apparatus 10 detects this and determines that it is a mechanical error, and immediately controls the exposure lamp 46 by the lamp controller 64 and The control of the image sensor 50 by the sensor control unit 66 is stopped, and the operation of reading an image from the document 15 is stopped.

=== Summary ===
As described above, in the present embodiment, the original signal S0 is generated by the timing signal generation circuit 112 based on the pulse signals ENC-A and ENC-B output from the encoder 90 as signals corresponding to the movement of the carriage 40. In the timing defined by the original signal S0, when there is a later timing whose interval from the previous timing is shorter than a predetermined time, the timing delay circuit 116 sets the timing to the previous timing. Subsequent timing is delayed so that the interval is equal to or greater than the predetermined time Tm. Thus, the timing interval defined by the timing signal St output from the timing signal output circuit 110 can be made longer than the predetermined time. Since the lamp control unit 64 and the sensor control unit 66 control the exposure lamp 46 or the image sensor 50 based on the timing signal St, even when the moving speed of the carriage 40 suddenly increases due to an external impact or the like. The image can be smoothly read from the document 15.

  In particular, the predetermined time Tm, which is a reference when the timing is delayed by the timing delay circuit 116, is set to a time longer than the time Ts required for the charge transfer by the charge transfer unit 82, so that the charge transfer unit 82 After the transfer is started, the next charge transfer timing does not occur before the time Ts required for the charge transfer elapses. Thus, the image can be read smoothly from the document 15.

  Further, the predetermined time Tm, which is a reference when the timing is delayed by the timing delay circuit 116, is set to a time equal to or longer than the set time Tr of the exposure lamp 46, thereby preventing each photodiode 80 from being underexposed. can do. Therefore, it is possible to prevent the image quality of the image read from the document 15 from being deteriorated.

=== Application to printing apparatus ===
Such an image reading apparatus 10 may be mounted on a printing apparatus. FIG. 16 illustrates a configuration example of a printing apparatus 120 including such an image reading apparatus 10. The printing apparatus 120 includes a scanner function for reading an image from a document and generating image data, a printer function for printing on various media such as printing paper based on print data sent from the host computer 148, and a reading function from the document. And a local copy function for copying a printed image on a medium. The printing apparatus 120 includes a scanner unit 122 that reads an image from a document (including the scanner control unit 138 and corresponds to the “image reading apparatus 10” herein), and a printer unit 124 that performs printing on a medium S such as printing paper. And.

  Further, the control unit 126 of the printing apparatus 120 includes a CPU 128, a memory 130, an external communication interface 132, an operation input interface 134, a display control unit 136, a scanner control unit 138, as shown in FIG. An image processing unit 140, a printer control unit 142, a card interface 144, and a bus 146 that connects these components to each other are provided.

  The CPU 128 controls the entire printing apparatus 120. The memory 130 stores a program executed by the CPU 128, data used in the program, and the like. The external communication interface 132 communicates with the host computer 148 by wire or wireless. The operation input interface 134 receives an operation input from the user through the operation button 150 or the like. The display control unit 136 controls a display unit such as the liquid crystal display 152.

  On the other hand, the scanner control unit 138 controls the scanner unit 122 to execute a reading operation for reading an image from a document. The image processing unit 140 executes print processing on the image data output from the scanner unit 122 by the printer unit 124 in order to print the image read from the document by the scanner unit 122 on the medium by the printer unit 124. To play a role in converting data. The printer control unit 142 controls the printer unit 124. The card interface 144 performs processing for reading image data stored in the memory card from various memory cards set in the card reader unit 154.

  In the scanner function, the printing apparatus 120 outputs image data read from the original by the scanner unit 122 to the host computer 148. In the printer function, the printing apparatus 120 prints various media by the printer unit 124 based on the print data sent from the host computer 148. In the local copy function, the printing apparatus 120 prints an image read from an original by the scanner unit 122 on various media by the printer unit 124 and copies it.

=== Other Embodiments ===
The image reading apparatus and the like according to the present invention have been described above by taking an embodiment as an example. However, the above-described embodiment is intended to facilitate understanding of the present invention, and is interpreted in a limited manner. Not meant to be The present invention can be changed or improved without departing from the gist thereof, and needless to say, the present invention includes equivalents thereof. In particular, the embodiments described below are also included in the present invention.

<About image reading sensor>
In the above-described embodiment, the image sensor 50 provided in the carriage 40 has been described as an example of the “image reading sensor”. However, in the “image reading sensor” here, such a carriage 40 is not necessarily used. It is not restricted to the sensor provided in. That is, any type of sensor may be used as long as the sensor moves relative to the document 15 and reads an image from the document. That is, the “image reading sensor” referred to here includes a sensor that reads an image from the document by moving the document relative to the “image reading sensor”.

  In the “image reading sensor” here, the image sensor 50 including a plurality of photodiodes 80 is described as an example of the photoelectric conversion element. However, in the “image reading sensor” herein, Is not necessarily limited to a sensor having a plurality of such photodiodes 80. That is, any type of sensor may be used as long as it reads an image from a document. That is, any method for reading an image from the document 15 may be used.

<Signal output unit>
In the above-described embodiment, the encoder 90 that outputs the pulse signals ENC-A and ENC-B having a period corresponding to the moving speed of the carriage 40 has been described as an example of the “signal output unit”. The “signal output unit” is not necessarily limited to such an encoder 90. That is, in the “signal output unit” here, any type of “signal output unit” may be used as long as a signal corresponding to the relative movement of the image reading sensor (image sensor 50) with respect to the document is output. It does not matter. That is, as long as the signal corresponds to the relative movement of the image reading sensor (image sensor 50) with respect to the document, the signals other than the pulse signals ENC-A and ENC-B having a period corresponding to the moving speed of the carriage 40 as described above. In addition, various types of signals such as a signal corresponding to the moving distance of the carriage 40 may be output.

<About timing signal>
In the above-described embodiment, the “timing signal” is described by taking, as an example, a signal that defines a reference timing for the lamp control unit 64 and the sensor control unit 66 to control the exposure lamp 46 or the image sensor 50. However, the “timing signal” herein is not necessarily limited to a signal that defines a reference timing for controlling the exposure lamp 46 or the image sensor 50 as described above. That is, other control units except the lamp control unit 64 and the sensor control unit 66 acquire data of an image read from the document 15 by the image reading sensor (image sensor 50) from the image reading sensor (image sensor 50). In addition, any signal may be used as long as it is a reference signal.

  Further, here, the “timing signal” corresponds to a reference timing for acquiring image data read from the document 15 by the image reading sensor (image sensor 50) from the image reading sensor (image sensor 50). However, the “timing signal” here is not necessarily limited to the signal having the pulse Wt. In other words, any type of signal may be used.

<About timing signal generation circuit>
In the above-described embodiment, a circuit that generates a timing signal based on the edges of the pulse signals ENC-A and ENC-B output from the encoder 90 has been described as the “timing signal generation circuit”. The “timing signal generation circuit” is not necessarily limited to such a circuit. That is, as long as a signal that defines a reference timing for acquiring data of an image read from the document 15 by the image reading sensor (image sensor 50) from the image reading sensor (image sensor 50) is generated. Such a type of “timing signal generation circuit” may be used.

<About the predetermined time>
In the above-described embodiment, as the “predetermined time”, the predetermined time Tm is longer than (A) the time Ts required for charge transfer by the charge transfer unit 82 or (B) the set time Tr of the exposure lamp 46. Although it was set to a long time, the “predetermined time” here may be set according to requirements other than the requirements (A) and (B). That is, the “predetermined time” may be set in any form as long as it is set to a time that allows the image reading sensor to smoothly read the image from the document.

<About timing delay circuit>
In the above-described embodiment, the case where the timing delay circuit 116 includes the delay timer 114 and delays the timing based on the time measured by the delay timer 114 has been described as an example. The “timing delay circuit” is not necessarily limited to such a configuration. That is, in the “timing delay circuit” referred to here, when there is a later timing that is shorter than a predetermined time in the timing defined by the timing signal, As long as it is a circuit that delays later timing, the delay timer 114 or the like need not be provided, and the timing may be delayed by any method.

<About image reader>
In the above-described embodiment, the “image reading device” has been described by taking an example of an image reading device provided on a carriage in which an image reading sensor moves relative to a document set on a document table. The “image reading device” here is not necessarily limited to this type of “image reading device”. That is, any type of image reading apparatus may be used as long as the image reading apparatus includes an image reading sensor that moves relative to the document 15 and reads an image from the document. That is, the “image reading apparatus” here includes an image reading apparatus in which an original is moved relative to an “image reading sensor” and an image is read from the original.

1 is an explanatory diagram of an embodiment of an image reading system. FIG. FIG. 3 is an explanatory diagram illustrating an example of an internal configuration of an image reading apparatus. 1 is an explanatory diagram illustrating an example of a system configuration of an image reading apparatus. FIG. Explanatory drawing of an example of an image sensor. Explanatory drawing of the arrangement | positioning relationship between a lens and an image sensor. Explanatory drawing of an example of a structure of an exposure lamp. Explanatory drawing of an example of the light-emission method of an exposure lamp. Explanatory drawing of an example of the photoelectric conversion element provided in the image sensor. Explanatory drawing of the transfer method of the electric charge which generate | occur | produced in the photoelectric conversion element. An explanatory view of an example of an encoder. Explanatory drawing of an example of a structure of the detection part of an encoder. Explanatory drawing of an example of the output signal of the detection part of an encoder. Explanatory drawing of the other example of the output signal of the detection part of an encoder. FIG. 6 is an explanatory diagram of an example of a circuit that outputs a timing signal. Explanatory drawing of an example of a timing signal. FIG. 6 is an explanatory diagram illustrating an example of a configuration of a circuit that outputs a timing signal. Explanatory drawing of an example of the timing signal produced | generated by the circuit which outputs a timing signal. Explanatory drawing when the moving speed of a carriage is too fast. FIG. 3 is an explanatory diagram illustrating an embodiment of a printing apparatus.

Explanation of symbols

2 image reading system, 10 image reading device, 12 document table,
14 Document cover, 15 Document, 18 Hinge, 20 Computer device,
22 computer body, 24 display device, 26 input device,
28 FD drive device, 30 CD-ROM drive device, 32 reading device,
34 keyboard, 36 mouse, 40 carriage, 42 drive mechanism,
44 guide, 46 exposure lamp, 47A light guide, 47B LED,
47C LED, 47D LED, 47E end,
47F exposure surface, 48 lenses, 49 individual lenses, 50 image sensors,
51 substrate, 52 control unit, 54 timing belt, 55 pulley, 56 pulley,
58 drive motor, 60 controller, 62 motor controller, 64 lamp controller,
66 sensor control unit, 68 AFE (Analog Front End) unit,
70 digital processing circuit, 72 interface circuit,
74 analog signal processing circuit, 76 A / D conversion circuit,
80 photodiodes, 82 charge transfer units, 84 gates,
90 encoder, 92 encoder code plate, 94 detector, 96 slit,
98 light emitting diode, 100 collimator lens, 102 detection processing unit,
104 photodiode, 106 signal processing circuit, 108A comparator,
108B comparator, 110 timing signal output circuit,
112 timing signal generation circuit, 114 delay timer,
116 timing delay circuit, 120 printer, 122 scanner unit,
124 printer unit, 126 control unit, 128 CPU, 130 memory,
132 external communication interface, 134 operation input interface,
136 Display control unit, 138 Scanner control unit, 140 Image processing unit,
142 Printer control unit, 144 card interface,
146 bus, 148 host computer, 150 operation buttons,
152 LCD display, 154 card reader

Claims (14)

(A) an image reading sensor that moves relative to the document and reads an image from the document;
(B) a signal output unit that outputs a signal corresponding to a relative movement of the image reading sensor with respect to the document;
(C) A timing signal that defines a reference timing for acquiring data of the image read from the document by the image reading sensor from the image reading sensor based on the signal output from the signal output unit. A timing signal generation circuit for generating
(D) When the timing defined by the timing signal generated by the timing signal generation circuit includes a later timing that is shorter than a predetermined time from the previous timing, the 1 A timing delay circuit that delays the subsequent timing so that an interval between the two previous timings is equal to or longer than the predetermined time;
An image reading apparatus comprising (E).   The image reading apparatus according to claim 1, wherein the signal output unit outputs a signal corresponding to a relative moving speed of the image reading sensor with respect to the document as the signal.   The image reading apparatus according to claim 1, wherein the signal output unit outputs a signal corresponding to a relative movement distance of the image reading sensor with respect to the document as the signal.   The image reading apparatus according to claim 1, wherein the signal output unit includes an encoder for outputting the signal.   The image reading apparatus according to claim 1, wherein the image reading sensor includes a plurality of photoelectric conversion elements that generate charges according to the amount of received light.   The image reading apparatus according to claim 5, wherein the image reading sensor includes a charge transfer unit that transfers charges generated respectively to the photoelectric conversion elements.   The image reading apparatus according to claim 1, wherein the timing signal generation circuit generates a signal having a pulse generated corresponding to the timing as the timing signal.   8. The image reading according to claim 1, wherein the predetermined time is set to be equal to or longer than a time set for the image reading sensor to read the image from the document. apparatus.   The image reading apparatus according to claim 1, wherein the predetermined time is set to be equal to or longer than a time necessary for acquiring the image data from the image reading sensor.   The image reading apparatus according to claim 1, wherein the timing delay circuit includes a timer that measures an elapsed time from the occurrence of the one previous timing. (A) an image reading sensor that moves relative to the document and reads an image from the document;
(B) a signal output unit that outputs a signal corresponding to a relative movement of the image reading sensor with respect to the document;
(C) A timing signal that defines a reference timing for acquiring data of the image read from the document by the image reading sensor from the image reading sensor based on the signal output from the signal output unit. A timing signal generation circuit for generating
(D) When the timing defined by the timing signal generated by the timing signal generation circuit includes a later timing that is shorter than a predetermined time from the previous timing, the 1 A timing delay circuit that delays the subsequent timing so that an interval between the two previous timings is equal to or longer than the predetermined time;
(E)
(F) The signal output unit outputs, as the signal, a signal according to a relative moving speed of the image reading sensor with respect to the document or a signal according to a relative moving distance of the image reading sensor with respect to the document. And
(G) The signal output unit includes an encoder for outputting the signal,
(H) The image reading sensor includes a plurality of photoelectric conversion elements that generate charges according to the amount of received light,
(I) The image reading sensor includes a charge transfer unit that transfers charges generated respectively to the photoelectric conversion elements,
(J) the timing signal generation circuit generates a signal having a pulse generated corresponding to the timing as the timing signal;
(K) The predetermined time is set to be equal to or longer than a time set for the image reading sensor to read the image from the document, and a time required for acquiring the image data from the image reading sensor. Set to above,
(L) The image reading apparatus, wherein the timing delay circuit includes a timer for measuring an elapsed time from the occurrence of the one previous timing. (A) a step of reading an image from the original by moving an image reading sensor relative to the original;
(B) outputting a signal corresponding to a relative movement of the image reading sensor with respect to the document;
(C) generating a timing signal that defines a reference timing for acquiring data of the image read from the document by the image reading sensor from the image reading sensor based on the output signal;
(D) When the timing defined by the generated timing signal includes a later timing that is shorter than a predetermined time, the interval from the previous timing Delaying the subsequent timing so that is equal to or longer than the predetermined time;
An image reading method characterized by comprising (E). An image reading system comprising a computer and an image reading device connected to the computer,
The image reading device includes an image reading sensor that moves relative to a document and reads an image from the document;
A signal output unit that outputs a signal corresponding to a relative movement of the image reading sensor with respect to the document;
Based on the signal output from the signal output unit, a timing signal that defines a reference timing for acquiring data of the image read from the document by the image reading sensor from the image reading sensor is generated. A timing signal generation circuit;
When the timing defined by the timing signal generated by the timing signal generation circuit has a later timing that is shorter than a predetermined time from the previous timing, the previous one A timing delay circuit that delays the subsequent timing so that an interval between the timing is equal to or longer than the predetermined time;
An image reading system comprising: (A) an image reading sensor that moves relative to the document and reads an image from the document;
(B) a signal output unit that outputs a signal corresponding to a relative movement of the image reading sensor with respect to the document;
(C) A timing signal that defines a reference timing for acquiring data of the image read from the document by the image reading sensor from the image reading sensor based on the signal output from the signal output unit. A timing signal generation circuit for generating
(D) When the timing defined by the timing signal generated by the timing signal generation circuit includes a later timing that is shorter than a predetermined time from the previous timing, the 1 A timing delay circuit that delays the subsequent timing so that an interval between the two previous timings is equal to or longer than the predetermined time;
(E) a printing unit that prints the image read by the image reading sensor on a medium;
A printing apparatus comprising (F).