JP6439290B2 - Image reading apparatus and program - Google Patents

Description

  The present invention relates to an image reading apparatus and a program.

  Patent Document 1 discloses an image reading apparatus having a lighting time rate adjustment unit that turns on a plurality of LEDs of the same color only during a predetermined period when a line synchronization signal is input from a sensor control unit.

  Patent Document 2 discloses an image reading apparatus that reads images on the front and back sides of a document by a line sequential method using a pair of CISs (Contact Image Sensors) arranged at opposing positions. . The image reading apparatus described in Patent Document 2 synchronizes the lighting of the light source in one CIS and the lighting of the light source in the other CIS by inputting a main scanning synchronization signal to the pair of CISs at the same timing. I am letting.

JP 2008-124985 A JP 2010-81369 A

An object of the present invention is to provide an image reading apparatus and a program capable of shortening a period during which current consumption increases as compared with a case where light irradiation periods of each of a plurality of light sources are matched .

The image reading apparatus according to claim 1 is to move the surface relative recording medium, and the surface for irradiating means for irradiating light onto said surface, and movement of the rear face relative said recording medium, said back face to A combination of a back irradiation unit for irradiating light, a first irradiation period during which light is irradiated by the front surface irradiation unit, and a second irradiation period during which light is irradiated by the back surface irradiation unit. each to an output unit which light is output periodic signal defining the period to be irradiated, the sum of the said first irradiation period the second irradiation period or Taka not exceed a predetermined time following the period The period input from the output means is determined only when it is determined that the total does not exceed the predetermined time , compared to the case where the first irradiation period and the second irradiation period coincide with each other. Within the period defined by the signal Control means for controlling at least one of a pulse width defining the first irradiation period and a pulse width defining the second irradiation period so as to reduce overlap between the irradiation period and the second irradiation period. .

In the image reading apparatus according to claim 1, as in the invention according to claim 2 , each of the front surface irradiation unit and the back surface irradiation unit moves relative to the recording medium, and the relative During the movement, the recording medium is irradiated with light of each of a plurality of colors circulating in a predetermined order, and the first irradiation period is performed in the order by the surface irradiation unit. Each light is irradiated once, and the second irradiation period is a period in which each light of the plurality of colors is irradiated once in the order by the back surface irradiation means.

According to a second aspect of the present invention, as in the third aspect of the present invention, the control unit is configured to perform a control between the light of each of the plurality of colors irradiated on one of the front surface and the back surface. Thus, the other surface is controlled so that one color of the plurality of colors is irradiated once.

In the image reading apparatus according to claim 1, as in the invention according to claim 4, wherein, when said sum exceeds the time the predetermined, the said first irradiation period second The maximum consumption current among the consumption current values required for irradiation of each of the plurality of colors that overlap with the irradiation period and circulate in a predetermined order by one of the front surface irradiation unit and the back surface irradiation unit It becomes the minimum consumption current value of the irradiation period during which the light of the color color is irradiated and the consumption current value required for irradiation of each of the plurality of colors by the other of the irradiation means for the front surface and the irradiation means for the back surface The front surface irradiating means and the back surface irradiating means are controlled so that the irradiation period during which the colored light is irradiated overlaps.

A program according to a fifth aspect is a program for causing a computer to function as a control unit in the image reading apparatus according to any one of the first to fourth aspects.

According to the invention concerning Claim 1 and Claim 5 , compared with the case where the irradiation of the light by each of several light sources is synchronized, the period when consumption current increases can be shortened. Further, according to the first and fifth aspects of the invention, it is possible to irradiate the light of each of a plurality of colors on the front and back surfaces of the recording medium within one period without overlapping.

According to the second aspect of the present invention, compared to the case where light of each of a plurality of colors circulating in a predetermined order is irradiated to each of the front and back sides of the recording medium in synchronization, the front and back sides of the recording medium are Even when light of each of a plurality of colors that circulate in a predetermined order is irradiated to each, the period during which current consumption increases can be shortened.

According to the invention of claim 3 , compared to a case where a plurality of colors of light are irradiated to one of the front and back sides of the recording medium, a plurality of colors of light are irradiated to the other. Thus, it is possible to reduce a deviation between a portion irradiated with light and a portion not irradiated with light.

According to the fourth aspect of the present invention, the irradiation period during which the light having the maximum current consumption value among the current consumption values of the plurality of colors irradiated to the surface of the recording medium is irradiated and the back surface of the recording medium. Compared to the case where the irradiation period in which the light of the color having the maximum current consumption value among the current consumption values due to the irradiation of each of the plurality of colors is overlapped, the plurality of colors for each of the front and back sides of the recording medium An increase in current consumption during a period in which each color light is irradiated can be suppressed.

It is a schematic block diagram which shows an example of the structure of the structure system of the image reading apparatus which concerns on 1st and 2nd embodiment. FIG. 3 is a block diagram illustrating an example of an electric system configuration of the image reading apparatus according to the first embodiment. It is a flowchart which shows an example of the flow of the periodic signal transmission process which concerns on 1st and 3rd embodiment. It is a flowchart which shows an example of the flow of the 1st lighting control process which concerns on 1st Embodiment. It is a flowchart which shows an example of the flow of the 2nd lighting control process which concerns on 1st Embodiment. It is a time chart which shows an example of each transition mode of the periodic signal which concerns on 1st Embodiment, the irradiation period of the light by a surface lamp, and the irradiation period of the light by a back lamp. It is a block diagram which shows an example of a structure of the electric system of the image reading apparatus which concerns on 2nd Embodiment. It is a flowchart which shows an example of the flow of the periodic signal transmission process which concerns on 2nd Embodiment. It is a flowchart which shows an example of the flow of the 1st lighting control process which concerns on 2nd Embodiment. It is a flowchart which shows an example of the flow of the 2nd lighting control process which concerns on 2nd Embodiment. It is a time chart which shows an example of each transition mode of the 1st periodic signal concerning the 2nd embodiment, the irradiation period of light by a surface lamp, the 2nd periodic signal, the irradiation period of light by a back lamp, and consumption current. It is a schematic block diagram which shows an example of a structure of the structure system of the image reading apparatus which concerns on 3rd Embodiment. It is a block diagram which shows an example of a structure of the electric system of the image reading apparatus which concerns on 3rd Embodiment. It is a flowchart which shows an example of the flow of the LED specific information transmission process which concerns on 3rd Embodiment. It is a flowchart which shows an example of the flow of the surface LED setting process which concerns on 3rd Embodiment. It is a flowchart which shows an example of the flow of the 1st lighting control process which concerns on 3rd Embodiment. It is a continuation of the flowchart shown in FIG. It is a flowchart which shows an example of the flow of the LED setting process for back surfaces which concerns on 3rd Embodiment. It is a flowchart which shows an example of the flow of the 2nd lighting control process which concerns on 3rd Embodiment. It is a continuation of the flowchart shown in FIG. It is a time chart which shows the 1st example of each transition mode of the periodic signal concerning the 3rd embodiment, the lighting period of LED for front, the lighting period of LED for back, and consumption current. It is a time chart which shows the 2nd example of each transition aspect of the periodic signal which concerns on 3rd Embodiment, the lighting period of LED for front surfaces, the lighting period of LED for back surfaces, and current consumption. It is a block diagram which shows an example of the structure for implement | achieving each process contained in a 1st lighting control process and the surface LED setting process with a software structure. It is a block diagram which shows an example of the structure for implement | achieving each process contained in a 2nd lighting control process and LED setting process for back surfaces with a software configuration.

  Hereinafter, an example of an embodiment for carrying out the present invention will be described in detail with reference to the drawings.

[First Embodiment]
As an example, as illustrated in FIG. 1, the image reading apparatus 10 includes a document conveying unit 12 (DADF: Dual Auto Document Feeder) and a surface image reading unit 14.

  The document transport unit 12 includes a document table 20, a plurality of transport roll pairs 26, a back image reading unit 28, a paper discharge unit 30, and a reference plate 46. A document 18 on which an image is recorded is placed on the document table 20. The transport path 24 is provided with a take-out roll 22 and a plurality of transport roll pairs 26, and the original 18 placed on the document table 20 is taken out by the take-out roll 22, and the taken-out original 18 is a plurality of transport roll pairs. 26 is conveyed. The document 18 that has been read by at least one of the front image reading unit 14 and the back image reading unit 28 is discharged to the paper discharge unit 30. The document 18 is an example of a recording medium according to the present invention.

  The back surface image reading unit 28 includes a back surface line sensor 28A and a back surface lamp 28B which is an example of a back surface irradiation unit according to the present invention. The back surface lamp 28 </ b> B is formed in a long shape along the main scanning direction, and irradiates light to the back surface of the document 18 passing over the reference plate 46 or the upper surface of the reference plate 46.

  The back surface line sensor 28 </ b> A receives the reflected light obtained by irradiating the original 18 or the reference plate 46 with light by the lit back surface lamp 28 </ b> B for each pixel, so that the back surface of the original 18 or the upper surface of the reference plate 46. And reading data obtained by photoelectric conversion is output.

  The reference plate 46 is a white plate formed in a long shape in the main scanning direction, and is disposed to face the back image reading unit 28. Examples of the reference plate 46 include a white resin plate or a metal plate painted in white.

  The surface image reading unit 14 includes a platen glass 32 having translucency, and a reference plate 35 is attached to the platen glass 32. The reference plate 35 is a white plate formed in a long shape in the main scanning direction.

  On the upper surface of the platen glass 32, there is provided a surface reading position that is adjacent to the reference plate 35 and is a position for reading the surface of the document 18 conveyed by the document conveying unit 12. On the lower side of the platen glass 32, a surface lamp 34, which is an example of the surface irradiation means according to the present invention, a first reflection mirror 36, a second reflection mirror 38, and a third reflection mirror 40 are provided.

  The surface lamp 34 is formed in a long shape along the main scanning direction, and irradiates light toward the surface of the document 18 passing through the surface reading position or the lower surface of the reference plate 35.

  The first reflecting mirror 36 receives the reflected light reflected by the surface of the document 18 or the lower surface of the reference plate 35, changes the traveling direction of the reflected light, and guides it to the second reflecting mirror 38. The second reflecting mirror 38 receives the reflected light guided by the first reflecting mirror 36, changes the traveling direction of the reflected light, and guides it to the third reflecting mirror 40. The third reflecting mirror 40 receives the reflected light guided by the second reflecting mirror 38, changes the traveling direction of the reflected light, and guides it to the lens 42.

  The surface image reading unit 14 includes a surface line sensor 44. Reflected light obtained by irradiating light on the surface of the document 18 or the lower surface of the reference plate 35 by the lit surface lamp 34 is a surface line sensor via the first reflecting mirrors 36, 38, 40 and the lens 42. 44 is incident. The front line sensor 44 receives incident reflected light for each pixel, reads the surface of the document 18 or the lower surface of the reference plate 35, and outputs read data obtained by photoelectric conversion.

  In the image reading apparatus 10 according to the first embodiment configured as described above, the documents 18 placed on the document table 20 are taken out one by one by the take-out roll 22 and sent to the conveyance path 24. The document 18 sent to the transport path 24 is transported to the surface reading position by the surface image reading unit 14 by the transport roller pair 26, and the surface of the document 18 is read by the surface image reading unit 14. Thereafter, the document 18 is transported to the back image reading unit 28 installed downstream in the transport direction from the front surface reading position. After the back surface of the document 18 is read by the back image reading unit 28, the document 18 is sent to the paper discharge unit 30. The paper is ejected.

  In the image reading apparatus 10 according to the first embodiment, the surface lamp 34, the first reflecting mirror 36, the second reflecting mirror 38, and the third reflecting mirror 40 are arranged in the sub-scanning direction (in the example shown in FIG. It is possible to move along the direction of arrow A and the opposite direction. Accordingly, the surface lamp 34, the first reflecting mirror 36, the second reflecting mirror 38, and the third reflecting mirror 40 that are lit are moved in the sub-scanning direction with the document 18 placed on the upper surface of the platen glass 32. Thus, the image recorded on the document 18 can be read.

  In the image reading apparatus 10 according to the first embodiment, a CCD line sensor formed of a plurality of CCDs (Charge Coupled Devices) is employed as an example of the back surface line sensor 28A and the front surface line sensor 44. However, the present invention is not limited thereto, and a solid-state imaging device such as a CMOS (Complementary Metal-Oxide Semiconductor) image sensor may be applied. Further, instead of the front surface line sensor 44, for example, a CIS as shown in the back image reading unit 28 may be used, or the CIS may be moved in the arrow A direction. In this case, the first reflection mirror 36, the second reflection mirror 38, the third reflection mirror 40, and the lens 42 are unnecessary.

  In the image reading apparatus 10 according to the first embodiment, LEDs (Light Emitting Diodes) are employed as an example of the back lamp 28B and the front lamp 34, but the present invention is not limited to this. For example, a fluorescent lamp may be used. Moreover, when employ | adopting LED, what arranged LED along the main scanning direction, what arrange | positions LED in the edge part of a main scanning direction, etc. may be sufficient.

  As an example, as shown in FIG. 2, the image reading apparatus 10 includes a controller 50, an image reading control unit 52 that is an example of an output unit according to the present invention, a DADF control unit 54, a back image reading control unit 56, and a UI (User Interface) 60.

  The controller 50 controls the entire image reading apparatus 10. Further, the controller 50 receives an image signal corresponding to the read data from each of the image reading control unit 52 and the back surface image reading control unit 56. Further, the controller 50 receives a signal indicating a user instruction or the like input from the UI 60.

  The image reading control unit 52 controls the entire image reading process in the image reading apparatus 10. Specifically, the DADF control unit 54, the back surface image reading control unit 56, the front surface line sensor 44, the scanning control unit 72, and the front surface illumination control unit 76 which is an example of the control unit according to the present invention are controlled. In the first embodiment, the image reading control unit 52 is realized by a CPU (Central Processing Unit).

  The image reading control unit 52 is connected to a front surface ROM (Read Only Memory) 68, a front surface RAM (Random Access Memory) 70, and a front surface NVM (Non Volatile Memory) 71. The front surface ROM 68 and the front surface NVM 70 store various programs related to reading the surface of the document 18 and various information used at that time. The various programs include a periodic signal transmission program 68 </ b> A. In the example shown in FIG. 2, the periodic signal transmission program 68 </ b> A is stored in the surface ROM 68. The front surface RAM 70 is a memory used when the image reading control unit 52 operates. Various programs for reading the surface of the document 18 are developed in the front surface RAM 70. The front surface RAM 70 temporarily stores various data necessary for reading the front surface of the document 18.

  In the example shown in FIG. 2, the state in which the periodic signal transmission program 68A is stored in the front surface ROM 68 is illustrated, but it is not always necessary to store the periodic signal transmission program 68A in the front surface ROM 68 from the beginning. For example, a periodic signal transmission program 68A is first stored in a portable storage medium such as an SSD (Solid State Drive), an IC card, a magneto-optical disk, or a CD-ROM that is connected to the image reading apparatus 10 and used. May be. The image reading control unit 52 may acquire the periodic signal transmission program 68A from these portable storage media and execute it. Further, the periodic signal transmission program 68A may be stored in a storage unit of an external electronic computer such as a computer or a server device connected to the image reading apparatus 10 via a communication unit. In this case, the image reading control unit 52 acquires the periodic signal transmission program 68A from the external electronic computer and executes it.

  The scanning control unit 72 performs control related to scanning when reading the document 18 and also controls the motor 74. The motor 74 is a motor that integrally moves the surface lamp 34 and various mirrors described in FIG.

  The surface illumination control unit 76 controls the surface lamp 34. The image reading apparatus 10 includes a back side illumination control unit 77 which is an example of a control unit according to the present invention, and the back side illumination control unit 77 controls the back side lamp 28 </ b> B under the control of the front side illumination control unit 76. In the first embodiment, the front surface illumination control unit 76 and the back surface illumination control unit 77 are realized by an ASIC (Application Specific Integrated Circuit). However, the present invention is not limited to this, and may be realized by a CPU. .

  The DADF control unit 54 controls the document conveying unit 12. The DADF control unit 54 receives information from each roller control unit 64 and each sensor 62 that controls each motor 66 for rotating the take-out roll 22 and the conveyance roll pair 26 described above. As an example of each sensor 62, there is a sensor that detects whether or not the document conveying unit 12 is not opened above the surface image reading unit 14.

  The back image reading control unit 56 controls the back image reading unit 28. Further, the back surface image reading control unit 56 is connected to the back surface ROM 82, the back surface RAM 84, and the back surface NVM 86.

  The back ROM 82 and the back NVM 86 store a program for operating the back image reading control unit 56, various information used at that time, and the like. The back surface RAM 84 is a memory used when the back surface image reading control unit 56 operates.

  Next, referring to FIG. 3, when the image reading start instruction, which is an instruction to start reading the front and back images of the document 18 placed on the document table 20, is received by the UI 60, the image reading control unit 52. The periodic signal transmission process to be executed will be described. The periodic signal transmission process is realized by the image reading control unit 52 executing the periodic signal transmission program 68A.

  In the periodic signal transmission process shown in FIG. 3, first, in step 100, the image reading control unit 52 transmits a periodic signal to the surface illumination control unit 76 as shown in FIG. 2 as an example, and then proceeds to step 102. To do. Here, the periodic signal refers to a signal that defines a period in which light is irradiated for each set when the first irradiation period and the second irradiation period are set as one set. As an example, as shown in FIG. 6, the first irradiation period refers to the lighting period of the surface lamp 34, that is, the period during which light is irradiated by the surface lamp 34, and the second irradiation period refers to the lighting of the back lamp 28B. Period, that is, a period in which light is irradiated by the back lamp 28B. Note that the interval between periodic signals, that is, the period defined by the periodic signal is determined according to the resolution of image reading. For example, the period becomes shorter as the resolution of image reading becomes higher.

  In step 102, the image reading control unit 52 determines whether or not one cycle has elapsed since the execution of the processing in step 100 was completed. In step 102, when one cycle has elapsed since the execution of the process in step 100 has ended, the determination is affirmed and the process proceeds to step 100. If it is determined in step 102 that the time corresponding to one cycle has not elapsed since the execution of the process in step 100 has been completed, the determination is negative and the routine proceeds to step 104.

  In step 104, the image reading control unit 52 determines whether or not a condition for ending this periodic signal transmission process is satisfied. As an example of the condition for ending this periodic signal transmission process, there is a condition that reading of the front and back images of all the documents 18 placed on the document table 20 is completed. Further, as other examples, a condition that an image reading end instruction, which is an instruction to end reading images on the front and back sides of the document 18 placed on the document table 20, is received by the UI 60, the controller 50, and image reading control. The condition that the malfunction of the image reading apparatus 10 was detected by the part 52, the DADF control part 54, or the back surface image reading control part 56 is mentioned.

  If the condition for ending this periodic signal transmission process is not satisfied in step 104, the determination is negative and the process proceeds to step 102. In step 104, when the condition for ending the periodic signal transmission process is satisfied, the determination is affirmed and the periodic signal transmission process is ended. Note that the transmission process itself of the periodic signal, that is, the horizontal synchronization signal LSync, may be continuously performed.

  Next, the first lighting control process executed by the surface illumination control unit 76 when the image reading start instruction is received by the UI 60 will be described with reference to FIG.

  In the first lighting control process shown in FIG. 4, first, at step 110, the surface illumination control unit 76 has received the periodic signal transmitted by executing the process of step 100 of the periodic signal transmission process. Determine. If it is determined in step 110 that a periodic signal has not been received, the determination is negative and the routine proceeds to step 120. If the periodic signal is received at step 110, the determination is affirmed and the routine proceeds to step 112.

  In step 112, the surface illumination control unit 76 turns on the surface lamp 34 and then proceeds to step 114. Note that turning on the surface lamp 34 by executing the processing of step 112 means, for example, the start of the first irradiation period as shown in FIG.

  In step 114, the surface illumination control unit 76 determines whether or not the turn-off time of the surface lamp 34 has come. The extinguishing timing of the surface lamp 34 indicates, for example, a time point when a half cycle has elapsed since the rising edge of the periodic signal. If the turn-off time of the front lamp 34 has not come in step 114, the determination is negative and the determination in step 114 is performed again. If the turn-off time of the front lamp 34 has come in step 114, the determination is affirmed and the routine proceeds to step 116.

  In step 116, the surface illumination control unit 76 turns off the surface lamp 34, and then proceeds to step 118. It should be noted that the fact that the surface lamp 34 is turned off by executing the processing of this step 116 means the end of the first irradiation period and the first irradiation period as shown in FIG. 6, for example. It means that the pulse width is modulated.

  In step 118, as shown in FIG. 2 as an example, the front surface illumination control unit 76 transmits a back lamp lighting start signal instructing the start of lighting of the back surface lamp 28B to the back surface lighting control unit 77, and then proceeds to step 120. Transition.

  In step 120, the surface illumination control unit 76 determines whether or not a condition for ending the first lighting control process is satisfied. An example of the condition for ending the first lighting control process is the same condition as the condition for ending the periodic signal transmission process. If it is determined in step 120 that the condition for ending the first lighting control process is not satisfied, the determination is negative and the routine proceeds to step 110. In step 120, when the conditions for ending the first lighting control process are satisfied, the determination is affirmed and the first lighting control process is ended.

  Next, the second lighting control process executed by the back lighting control unit 77 when the first lighting control process 76 starts to be executed will be described with reference to FIG.

  In the second lighting control process shown in FIG. 5, first, in step 130, the back surface illumination control unit 77 receives the back lamp lighting start signal transmitted by executing the process of step 118 of the first lighting control process. Determine whether or not. If the back lamp lighting start signal has not been received in step 130, the determination is negative and the routine proceeds to step 138. If the back lamp lighting start signal is received in step 130, the determination is affirmed and the routine proceeds to step 132.

  In step 132, the back surface illumination control unit 77 turns on the back surface lamp 28B, and then proceeds to step 134. Note that turning on the back lamp 28B by executing the processing of step 132 means, for example, the start of the second irradiation period and defining the second irradiation period as shown in FIG. It means that the pulse width is modulated.

  In step 134, the back surface illumination control unit 77 determines whether or not the turn-off time of the back surface lamp 28B has come. For example, as shown in FIG. 6, the turn-off timing of the back lamp 28 </ b> B indicates a point in time when one cycle has elapsed from the rising edge of the periodic signal. If the turn-off time of the back lamp 28B has not come in step 134, the determination is negative and the determination in step 134 is performed again. If it is determined in step 134 that the back lamp 28B has been turned off, the determination is affirmed and the routine proceeds to step 136.

  In step 136, the back surface illumination control unit 77 turns off the back surface lamp 28B, and then proceeds to step 138. Note that the fact that the back lamp 28B is turned off by executing the process of step 136 means, for example, the end of the second irradiation period and the second irradiation period as shown in FIG. It means that the pulse width is modulated.

  In step 138, the backside illumination control unit 77 determines whether or not a condition for ending the second lighting control process is satisfied. An example of the condition for ending the second lighting control process is the same condition as the condition for ending the periodic signal transmission process. If it is determined in step 138 that the condition for ending the second lighting control process is not satisfied, the determination is negative and the routine proceeds to step 130. In step 138, when the conditions for ending the second lighting control process are satisfied, the determination is affirmed and the second lighting control process is ended.

  In addition, although the case where the 2nd lighting control process shown in FIG. 5 is performed is illustrated in this 1st Embodiment, this invention is not limited to this, The half cycle of a periodic signal has just arrived. In such a case, the processing of steps 132, 134, and 136 may be forcibly executed. Further, in the case of reading an image by the line sequential method described later, in the example shown in FIG. 21, the lighting process may be executed with a period divided into six, and in the example shown in FIG. 22, the period is divided into three. What is necessary is just to perform a lighting process.

  As described above, when the periodic signal transmission process, the first lighting control process, and the second lighting control process are executed in the image reading apparatus 10, as shown in FIG. 6 as an example, the first irradiation period and the second irradiation are performed. Duplication with period is avoided. Therefore, an overlap between a period in which current is consumed by the front lamp 34 in the first irradiation period and a period in which current is consumed by the back lamp 28B in the second irradiation period is also avoided. Therefore, according to the image reading apparatus 10, an increase in current consumption during the period of light irradiation is suppressed as compared with the case where the first irradiation period and the second irradiation period overlap.

[Second Embodiment]
In the first embodiment, the example in which the front lamp 34 and the rear lamp 28B are turned on according to one periodic signal has been described, but in the second embodiment, according to two periodic signals having different phases. An example in which the front lamp 34 and the rear lamp 28B are turned on will be described. In the second embodiment, the same components as those described in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As an example, as shown in FIG. 7, the image reading apparatus 200 according to the second embodiment is different from the image reading apparatus 10 described in the first embodiment in place of the periodic signal transmission program 68A. Is stored in the ROM 68 for the back surface. Further, the image reading apparatus 200 is different from the image reading apparatus 10 in that an image reading control unit 87 is provided instead of the image reading control unit 52. Furthermore, the image reading device 200 is different from the image reading device 10 in that it has a front surface illumination control unit 88 instead of the front surface illumination control unit 76 and a back surface illumination control unit 90 instead of the back surface illumination control unit 77. .

  The image reading control unit 87 differs from the image reading control unit 52 in that the first periodic signal and the second periodic signal are alternately transmitted instead of the periodic signal. The first periodic signal is transmitted to the front surface illumination control unit 88, and the second periodic signal is transmitted to the back surface illumination control unit 90.

  The surface illumination control unit 88 differs from the surface illumination control unit 76 in that it receives the first periodic signal instead of the periodic signal and does not transmit the back lamp lighting start signal. The surface illumination control unit 88 controls the surface lamp 34 in response to receiving the first periodic signal.

  The back side illumination control unit 90 is different from the back side illumination control unit 77 in that it receives the second periodic signal instead of receiving the back side lamp lighting start signal. The back surface illumination control unit 90 controls the back surface lamp 28B in response to the reception of the second periodic signal.

  As an example, as shown in FIG. 11, the first periodic signal is a signal that defines a period in which light is irradiated by the surface lamp 34, and is determined according to the resolution of image reading. The second periodic signal is a signal that defines the period in which light is irradiated by the back lamp 28B, and is determined according to the resolution of image reading. The interval at which the first periodic signal is generated and the interval at which the second periodic signal is generated are intervals corresponding to the intervals at which the periodic signal described in the first embodiment is generated, but the first periodic signal and the second periodic signal are used. One of the two is shifted in phase by half a cycle from the other.

  Next, the periodic signal transmission processing according to the second embodiment will be described with reference to FIG. Note that the periodic signal transmission processing according to the second embodiment is realized by the image reading control unit 87 executing the periodic signal transmission program 68B.

  In the periodic signal transmission process shown in FIG. 8, first, in step 210, the image reading control unit 87 transmits the first periodic signal to the surface illumination control unit 88 as shown in FIG. Migrate to

  In step 212, the image reading control unit 87 determines whether or not the time of one cycle specified by the first cycle signal has elapsed since the execution of the processing of step 210 has ended. In step 212, if the time of one cycle specified by the first cycle signal has elapsed after the execution of the processing of step 210 has ended, the determination is affirmed and the routine proceeds to step 210. In step 212, if the time for one cycle specified by the first cycle signal has not elapsed since the execution of the processing of step 210 has ended, the determination is negative and the routine proceeds to step 214.

  In step 214, the image reading control unit 87 determines whether or not the second periodic signal transmission time, which is the time for transmitting the second periodic signal, has arrived. The second period signal transmission time refers to the time when a half period has elapsed since the first period signal was transmitted by executing the process of step 210. If it is determined in step 214 that the second periodic signal transmission time has not arrived, the determination is negative and the routine proceeds to step 218. If it is determined in step 214 that the second periodic signal transmission time has arrived, the determination is affirmed and the process proceeds to step 216.

  In step 216, the image reading control unit 87 transmits the second periodic signal to the back surface illumination control unit 90 as shown in FIG. 7 as an example, and then proceeds to step 218.

  In step 218, the image reading control unit 87 determines whether a condition for ending this periodic signal transmission process is satisfied. As an example of the condition for ending this periodic signal transmission process, the same condition as the condition for ending the periodic signal transmission process described in the first embodiment can be given.

  If the condition for ending this periodic signal transmission process is not satisfied in step 218, the determination is negative and the routine proceeds to step 212. In step 218, when the condition for ending this periodic signal transmission process is satisfied, the determination is affirmed and the periodic signal transmission process is ended.

  Next, the first lighting control process according to the second embodiment that is executed by the surface illumination control unit 88 when the image reading start instruction is received by the UI 60 will be described with reference to FIG. 9.

  In the first lighting control process shown in FIG. 9, first, in step 220, has the surface illumination control unit 88 received the first periodic signal transmitted by executing the process of step 210 of the periodic signal transmission process? Determine whether or not. If it is determined in step 220 that the first periodic signal has not been received, the determination is negative and the process proceeds to step 228. If the first periodic signal is received at step 220, the determination is affirmed and the routine proceeds to step 222.

  In step 222, the surface illumination control unit 88 turns on the surface lamp 34 and then proceeds to step 224. Note that turning on the surface lamp 34 by executing the process of step 222 means, for example, the start of the first irradiation period as shown in FIG.

  In step 224, the surface illumination control unit 88 determines whether or not the turn-off time of the surface lamp 34 has come. The extinguishing time of the surface lamp 34 indicates the end of the first irradiation period as shown in FIG. 11, for example. As an example of the turn-off time in this step 224, there is a point in time when half a period of time has elapsed from the rising edge of the first periodic signal.

  If it is determined in step 224 that the front lamp 34 has not been extinguished, the determination is negative and the determination in step 224 is performed again. If it is determined in step 224 that the front lamp 34 has been turned off, the determination is affirmed and the process proceeds to step 226.

  In step 226, the surface illumination control unit 88 turns off the surface lamp 34 and then proceeds to step 228. Note that turning off the surface lamp 34 by executing the processing of step 226 means, for example, the end of the first irradiation period as shown in FIG.

  In step 228, the surface illumination control unit 88 determines whether or not a condition for ending the first lighting control process is satisfied. As an example of the conditions for ending the first lighting control process, the same conditions as the conditions for ending the periodic signal transmission process described in the first embodiment can be given. If it is determined in step 228 that the condition for ending the first lighting control process is not satisfied, the determination is negative and the routine proceeds to step 220. In step 228, when the conditions for ending the first lighting control process are satisfied, the determination is affirmed and the first lighting control process is ended.

  Next, the second lighting control process according to the second embodiment, which is executed by the back side illumination control unit 90 when an image reading start instruction is received by the UI 60, will be described with reference to FIG.

  In the second lighting control process shown in FIG. 10, first, in step 230, has the back surface illumination control unit 90 received the second periodic signal transmitted by executing the process of step 216 of the periodic signal transmission process? Determine whether or not. If it is determined in step 230 that the second periodic signal has not been received, the determination is negative and the process proceeds to step 238. If the second periodic signal is received at step 230, the determination is affirmed and the routine proceeds to step 232.

  In step 232, the back side illumination control unit 90 turns on the back side lamp 28 </ b> B, and then proceeds to step 234. Note that turning on the back lamp 28B by executing the processing of step 232 means, for example, the start of the second irradiation period as shown in FIG.

  In step 234, the back surface illumination control unit 90 determines whether or not the turn-off time of the back surface lamp 28B has come. The turn-off time of the back lamp 28B refers to the end of the second irradiation period as shown in FIG. 11, for example. As an example of the turn-off time in this step 234, there is a time point when a half cycle time has elapsed since the rising of the second cycle signal.

  If it is determined in step 234 that the back lamp 28B has not turned off, the determination is negative and the determination in step 234 is performed again. If it is determined in step 234 that the back lamp 28B has been turned off, the determination is affirmed and the process proceeds to step 236.

  In step 236, the back surface illumination control unit 90 turns off the back surface lamp 28B, and then proceeds to step 238. Note that turning off the back lamp 28B by executing the processing of step 236 means, for example, the end of the second irradiation period as shown in FIG.

  In step 238, the back side illumination control unit 90 determines whether or not a condition for ending the second lighting control process is satisfied. As an example of the condition for ending the second lighting control process, the same condition as the condition for ending the periodic signal transmission process described in the first embodiment can be given. If it is determined in step 238 that the condition for ending the second lighting control process is not satisfied, the determination is negative and the routine proceeds to step 230. In step 238, if the condition for ending the second lighting control process is satisfied, the determination is affirmed and the second lighting control process is ended.

  As described above, in the image reading apparatus 200, when the periodic signal transmission process, the first lighting control process, and the second lighting control process are executed, as shown in FIG. 11 as an example, similarly to the first embodiment. The overlap between the first irradiation period and the second irradiation period is avoided. Therefore, as in the first embodiment, overlapping of periods during which current is consumed is also avoided.

  In the second embodiment, the case where the first irradiation period and the second irradiation period are not overlapped by controlling the pulse width defining the second irradiation period is exemplified, but the present invention is limited to this. It is not a thing. For example, the first irradiation period and the second irradiation period may be prevented from overlapping by controlling the pulse width that defines the first irradiation period. Further, the first irradiation period and the second irradiation period may be prevented from overlapping by controlling both the pulse width that defines the first irradiation period and the pulse width that defines the second irradiation period.

Moreover, in the said 1st and 2nd embodiment, although the case where a 1st irradiation period and a 2nd irradiation period were not overlapped was illustrated, this invention is not limited to this, A 1st irradiation period and 2nd compared with the case to match the irradiation period, if such overlap between the first irradiation period and the second irradiation period is reduced, compared with the case to match the lighting period of the lighting period of the surface lamp 34 and the back ramp 28B, The period during which current consumption increases can be shortened.

[Third Embodiment]
In each of the above embodiments, the reading method for reading an image by receiving reflected light obtained by irradiating white light is exemplified. However, in the third embodiment, a case of reading an image by a line sequential method will be described. To do. Here, the line-sequential method refers to a method of reading one line in a line by one reading operation by switching on and turning on the red, green, and blue light sources for each line. In the following, for convenience of explanation, red is referred to as “R”, green is referred to as “G”, and blue is referred to as “B”. In the third embodiment, the same components as those described in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As an example, as shown in FIG. 12, an image reading apparatus 300 according to the third embodiment has a document conveying section 302 instead of the document conveying section 12 as compared with the image reading apparatus 10 described in the first embodiment. The difference is that a surface image reading unit 304 is provided instead of the surface image reading unit 14.

  The document transport unit 302 is different from the document transport unit 12 in that it includes a back image reading unit 306 instead of the back image reading unit 28. The back image reading unit 306 is different from the back image reading unit 28 in that it includes a light guide 91, a back surface first LED 98A, a back surface second LED 98B, and a back surface third LED 98C instead of the back surface lamp 28B. The back image reading unit 306 is different from the back image reading unit 28 in that it includes a back surface line sensor 307 instead of the back surface line sensor 28A. In the following description, for convenience of description, the backside first LED 98A, the backside second LED 98B, and the backside third LED 98C are referred to as backside LEDs 98 when it is not necessary to distinguish between them.

  The back side first LED 98A is an LED having an R emission wavelength, the back side second LED 98B is an LED having a G emission wavelength, and the back side third LED 98C is an LED having a B emission wavelength. The back surface LED 98 is an example of a back surface irradiation unit according to the present invention. In addition, the period in which the light from the first LED 98A for the back surface is irradiated, the period in which the light from the second LED 98B for the back surface is irradiated, and the period in which the light from the third LED 98C for the back surface is irradiated are examples of the second irradiation period according to the present invention. It is.

  The first LED 98A for the back surface, the second LED 98B for the back surface, and the third LED 98C for the back surface are driven so that the light of each color of RGB is emitted in the order of the circulating colors, which is a predetermined order. Here, the circulation color order is the order in which RGB circulates in the order of “R” → “G” → “B” → “R” → “G” → “B”... ⇒ Indicates the order in which the cycle “G” ⇒ “B” is repeated. Hereinafter, for convenience of explanation, one cycle of “R” → “G” → “B” is referred to as “one cycle” regardless of the first color and the last color.

  The light guide 91 is formed in an elongated shape along the main scanning direction. A back surface LED 98 is attached to one end of the light guide 91, and the light guide 91 turns the light emitted from the back surface LED 98 linearly to the document 18 or the reference plate 46 by turning on the back surface LED 98. Lead.

  The back surface line sensor 307 is a monochrome image sensor in which a plurality of photoelectric conversion elements (not shown) are linearly arranged in the main scanning direction. The back-side line sensor 307 receives (images) reflected light obtained by irradiating the original 18 or the reference plate 46 with light from the back-side LED 98 and performs photoelectric conversion, whereby an electrical signal corresponding to the amount of received light. Is generated and output. The image information generated and output by the back surface line sensor 307 is image information indicating an R image, image information indicating a G image, and image information indicating a B image.

  The surface image reading unit 304 is different from the surface image reading unit 14 in that it includes a light guide 93, a first LED for surface 96A, a second LED for surface 96B, and a third LED for surface 96C instead of the surface lamp. Further, the surface image reading unit 304 is different from the surface image reading unit 14 in that it has a surface line sensor 308 instead of the surface line sensor 44. In the following description, for convenience of description, when it is not necessary to distinguish between the first LED for front surface 96A, the second LED for front surface 96B, and the third LED for front surface 96C, they are referred to as front surface LEDs 96. In the following description, for convenience of explanation, when it is not necessary to distinguish between the front surface LED 96 and the back surface LED 98 for description, the front surface LED 96 and the back surface LED 98 will be referred to as “LEDs” without reference numerals.

  The first LED for surface 96A is an LED having an emission wavelength of R, the second LED for surface 96B is an LED having an emission wavelength of G, and the third LED for surface 96C is an LED having an emission wavelength of B. The surface LED 96 is an example of the surface irradiation means according to the present invention. Moreover, the period in which the light of the first LED for surface 96A is irradiated, the period in which the light of the second LED for surface 96B is irradiated, and the period in which the light of the third LED for surface 96C is irradiated are examples of the first irradiation period according to the present invention. It is.

  The first LED for front surface 96A, the second LED for front surface 96B, and the third LED for front surface 96C are driven so that light of each color of RGB is emitted in the order of the circulating colors, similarly to the LED for back surface 98.

  The light guide 93 is formed in a long shape along the main scanning direction. A surface LED 96 is attached to one end of the light guide 93, and the light guide 93 linearly emits light emitted from the surface LED 96 to the document 18 or the reference plate 35 when the surface LED 96 is turned on. Lead.

  The surface line sensor 308 is a monochrome image sensor in which a plurality of photoelectric conversion elements (not shown) are linearly arranged in the main scanning direction. The front line sensor 308 receives (images) reflected light obtained by irradiating the original 18 or the reference plate 35 with light from the front LED 96, and performs photoelectric conversion, whereby an electrical signal corresponding to the amount of light received. Is generated and output. The image information generated and output by the front line sensor 308 is image information indicating an R image, image information indicating a G image, and image information indicating a B image.

  As an example, as shown in FIG. 13, in the image reading apparatus 300, the periodic signal transmission program 68 </ b> C and the LED specific information transmission program 68 </ b> D are stored in the back surface ROM 68 instead of the periodic signal transmission program 68 </ b> A. Is different. Further, the image reading apparatus 300 is different from the image reading apparatus 10 in that an image reading control unit 310 is provided instead of the image reading control unit 52. Further, the image reading device 300 has a point that it has a front surface illumination control unit 92 instead of the front surface illumination control unit 76 and a back surface illumination control unit 94 instead of the back surface illumination control unit 77, as compared with the image reading device 10. Different. In the following description, for convenience of explanation, when it is not necessary to distinguish between the front surface illumination control unit 92 and the back surface illumination control unit 94, the front surface illumination control unit 92 and the back surface illumination control unit 94 are referred to as illumination control units without reference numerals.

  The image reading control unit 310 is different from the image reading control unit 52 in that a periodic signal is transmitted to the front surface illumination control unit 92 and the back surface illumination control unit 94. In addition, the image reading control unit 310 transmits the below-described front-side LED specifying information to the front-side illumination control unit 92 and the back-side LED specifying information described below to the back-side lighting control unit 94 as compared to the image reading control unit 52. The point of sending is different.

  The surface illumination control unit 92 is different from the surface illumination control unit 76 in that it includes a counter 92B. Further, the surface illumination control unit 92 is different from the surface illumination control unit 76 in that it controls the surface LED 96 instead of the surface lamp 34.

  The back side illumination control unit 94 is different from the back side illumination control unit 77 in that it includes a counter 94B. Further, the back side illumination control unit 94 is different from the back side illumination control unit 77 in that it controls the back side LED 98 instead of the back side lamp 28B.

  Next, with reference to FIG. 14, an LED specific information transmission process executed by the image reading control unit 310 when an image reading start instruction is received by the UI 60 will be described. The LED specific information transmission process is realized by the image reading control unit 310 executing the LED specific information transmission program 68D. The LED specifying information transmission process is a process executed before the document 18 to be transported by the document transport unit 302 is transported to the front surface reading position.

  In the LED specific information processing shown in FIG. 14, first, in step 360, the image reading control unit 310 turns on the front LED 98 for one cycle so that the light from the front LED 98 is irradiated on the reference plate 35. The controller 72 and the surface illumination controller 92 are controlled. Further, the image reading control unit 310 controls the back side illumination control unit 94 so that the light from the back side LED 96 is irradiated to the reference plate 46 by turning on the back side LED 96 for one cycle. As a result, the front surface LEDs 98 are lit in the order of the circulating colors, and the back surface LEDs 96 are lit in the order of the circulating colors. In addition, the lighting period and current consumption value of each LED are determined according to the set value set by the illumination control unit.

  In the next step 362, the image reading control unit 310 acquires reference plate reading data. The reference plate reading data is roughly divided into front surface data and back surface data. The surface data refers to an electrical signal for each color of RGB obtained by the surface line sensor 308 receiving reflected light obtained by irradiating the reference plate 35 with light by the surface LED 98. The back surface data refers to an electrical signal for each RGB color obtained by the back surface line sensor 307 receiving reflected light obtained by irradiating the reference plate 35 with light from the back surface LED 96.

  In the next step 364, the image reading control unit 310 determines whether or not the output level for each of the RGB colors of the front surface data and the back surface data acquired in step 362 is within a specified range. In step 364, if the output level for each of the RGB colors of the front surface data and the back surface data acquired in step 362 is out of the specified range, the determination is negative and the routine proceeds to step 366. In step 364, if the output level for each of the RGB colors of the front surface data and the back surface data acquired in step 362 is within the specified range, the determination is affirmed and the process proceeds to step 368.

  In step 366, the image reading control unit 310 instructs the lighting control unit to change the setting period of the LED lighting period and the current consumption value corresponding to the reference plate reading data whose output level is determined to be out of the specified range. Thereafter, the process proceeds to step 360. When the processing of step 366 is executed, the illumination control unit changes the LED lighting period and the set current consumption value corresponding to the reference plate reading data whose output level is determined to be out of the specified range.

  In step 368, the image reading control unit 310 determines whether or not the total lighting period exceeds the period of time defined by the periodic signal. The total lighting period refers to the total lighting period of each LED that has been turned on for one cycle by executing the process of step 360. Here, the total lighting period is exemplified as the total lighting period of each LED that is lit for one cycle, but the present invention is not limited to this and is lit for one cycle. A period shorter than the total lighting period of each LED may be set as the lighting period total.

  If it is determined in step 368 that the total lighting period does not exceed the time for one cycle defined by the periodic signal, the determination is negative and the LED specific information transmission process is terminated. If it is determined in step 368 that the total lighting period exceeds the time corresponding to one cycle defined by the periodic signal, the process proceeds to step 370.

  In this step 368, an example in which the total lighting period is compared with the time for one cycle is described, but the present invention is not limited to this, and the lighting time of one LED and 1 / 3 periods of time may be compared. In the determination in step 368, the magnitude relationship between the lighting time of one LED and the time corresponding to 1/3 cycle is the same as the magnitude relationship between the lighting period total and the time corresponding to one cycle.

  In step 370, the image reading control unit 310 transmits, to the surface illumination control unit 92, surface LED specifying information for specifying the LED to be lit first among the surface LEDs 96. In addition, the image reading control unit 310 transmits back side LED specifying information for specifying the first LED to be lit among the back side LEDs 98 to the back side illumination control unit 94. When the execution of the process of step 370 is finished, the LED specific information transmission process is finished.

  In step 370 described above, as an example of the surface LED specifying information, the surface LED that specifies the surface LED 96 having the maximum current consumption value among the surface LEDs 96 that are turned on by executing the process of step 360 is identified. LED specific information is adopted. Further, in step 370 described above, as an example of the backside LED specifying information, the backside LED 98 that specifies the backside LED 98 having the smallest current consumption value among the backside LED 98 that is turned on by executing the process of step 360 is used. Refers to LED specific information.

  Next, with reference to FIG. 15, the surface LED setting process executed by the surface illumination control unit 92 when the image reading start instruction is received by the UI 60 will be described.

  In the surface LED setting process shown in FIG. 15, first, in step 380, the surface illumination control unit 92 receives the surface LED specific information transmitted by executing the process of step 370 of the LED specific information transmission process. Determine whether or not.

  In step 380, if the front-surface LED specific information transmitted by executing the processing of step 370 of the LED specific information transmission process is not received, the determination is negative and the process proceeds to step 386. In step 380, when the front-surface LED specific information transmitted by executing the processing of step 370 of the LED specific information transmission process is received, the determination is affirmed and the process proceeds to step 382.

  In step 382, the surface illumination control unit 92 sets the count value of the counter 92B to a count value corresponding to the surface LED identification information.

  The count value corresponding to the surface LED identification information is any one of “0”, “1”, and “2”. In the third embodiment, “0” is assigned to the first LED for front surface 96A, “1” is assigned to the second LED for front surface 96B, and “2” is assigned to the third LED for front surface 96C. . In the third embodiment, when 1 is added to the count value “2” in order to realize lighting in the color circulation color order, the count value returns to “0”. In the third embodiment, “0” is adopted as the initial setting value of the counter 92B. However, the present invention is not limited to this, and a value other than “0” may be used as the initial setting value.

  In the next step 384, the surface illumination control unit 92 turns on the surface LED setting flag indicating that the count value of the counter 92B has been changed to the count value corresponding to the surface LED identification information in step 382, and then The process proceeds to step 386.

  In step 386, the surface illumination control unit 92 determines whether or not a condition for ending the front surface LED setting process is satisfied. As an example of the condition for ending the front surface LED setting process, a condition that a predetermined time (for example, 5 seconds) has elapsed since the completion of the LED specific information transmission process can be given. If it is determined in step 386 that the condition for ending the front surface LED setting process is not satisfied, the determination is negative and the routine proceeds to step 380. In step 386, if the condition for ending the front surface LED setting process is satisfied, the determination is affirmed and the front surface LED setting process is ended.

  Next, referring to FIG. 3, the third embodiment is executed by the image reading control unit 310 when a periodic signal transmission process start condition that is a condition for starting the periodic signal transmission process according to the third embodiment is satisfied. The periodic signal transmission process according to FIG. The periodic signal transmission process according to the third embodiment is realized by the image reading control unit 310 executing the periodic signal transmission program 68C.

  The period signal transmission process start condition is, for example, a condition that the front LED setting process is completed, a condition that the rear LED setting process is completed, or the determination in step 368 of the LED specific information transmission process is negative. The LED specific information transmission process is completed. Further, in the following description of the periodic signal transmission process according to the third embodiment, the same steps as those included in the periodic signal transmission process according to the first embodiment are denoted by the same step numbers. Description is omitted.

  In the periodic signal transmission processing according to the third embodiment shown in FIG. 3, in step 350, the image reading control unit 310 transmits the periodic signal to the front surface illumination control unit 92 and the back surface illumination control unit 94.

  The periodic signal according to the third embodiment is a signal that defines the maximum allowable lighting period for three lines as one period, and is determined according to the resolution of image reading. The maximum allowable lighting period for three lines is determined in advance as a period in which the sum of the maximum allowable lighting period for one line for R, the maximum allowable lighting period for one line for G, and the maximum allowable lighting period for one line for B falls. Refers to the period. The maximum allowable lighting period for one line relating to R indicates a maximum allowable lighting period when the first LED for front surface 96A and the first LED for rear surface 98A are turned on in synchronization. The maximum allowable lighting period of one line for G refers to the maximum allowable lighting period when the back side second LED 96B and the back side second LED 98B are turned on in synchronization. The maximum permissible lighting period for one line for B refers to the maximum permissible lighting period when the back side third LED 96C and the back side third LED 98C are turned on in synchronization.

  Next, the first lighting control process executed by the surface illumination control unit 92 when the image reading start instruction is received by the UI 60 will be described with reference to FIG.

  In the first lighting control process shown in FIG. 16, first, in step 400, the surface illumination control unit 92 transmits the period transmitted by executing the process of step 350 of the periodic signal transmission process according to the third embodiment. It is determined whether or not a signal has been received. In step 400, if the periodic signal transmitted by executing the process of step 350 of the periodic signal transmission process according to the third embodiment is not received, the determination is negative and the determination of step 400 is performed. Do it again. In step 400, when the periodic signal transmitted by executing the process of step 350 of the periodic signal transmission process according to the third embodiment is received, the determination is affirmed and the process proceeds to step 402.

  In step 402, the front surface illumination control unit 92 determines whether or not the front surface LED setting flag is turned on. If the front LED setting flag is turned on in step 402, the determination is affirmed and the routine proceeds to step 404.

  In step 404, the surface illumination control unit 92 turns on the surface LED 96 corresponding to the count value of the counter 92B, and then proceeds to step 406.

  In step 406, the surface illumination control unit 92 determines whether or not the turn-off time of the surface LED 96 turned on in step 404 has come. As an example of the turn-off time in this step 406, the time when 1/3 period has elapsed since the processing of step 404 was executed.

  In step 406, when the turn-off time of the front LED 96 turned on in step 404 has not arrived, the determination is negative and the determination in step 406 is performed again. If it is determined in step 406 that the turn-off time of the front LED 96 lit in step 404 has come, the determination is affirmed, and the routine proceeds to step 408.

  In step 408, the surface illumination control unit 92 turns off the surface LED 96, and then proceeds to step 410.

  In step 410, the surface illumination control unit 92 adds 1 to the count value of the counter 92 </ b> B, and then proceeds to step 412.

  In step 412, the surface illumination control unit 92 determines whether a condition for ending the first lighting control process is satisfied. An example of the condition for ending the first lighting control process is the same condition as the condition for ending the periodic signal transmission process. If it is determined in step 412 that the condition for ending the first lighting control process is not satisfied, the determination is negative and the process proceeds to step 414. In step 412, when the condition for ending the first lighting control process is satisfied, the determination is affirmed and the first lighting control process is ended. If the determination in step 412 is affirmative, the count value of the counter 92B is returned to the initial setting value, and the front LED setting flag is turned off.

  In step 414, the surface illumination control unit 92 determines whether or not lighting for one cycle by the surface LED 96 has been completed. If it is determined in step 414 that lighting for one cycle by the front LED 96 has not been completed, the determination is negative and the routine proceeds to step 404. If it is determined in step 414 that lighting for one cycle by the front surface LED 96 has been completed, the determination is affirmed and the routine proceeds to step 400.

  On the other hand, if the front LED setting flag is not turned on in step 402, the determination is negative and the routine proceeds to step 416 shown in FIG.

  In step 416, the surface illumination control unit 92 turns on the surface LED 96 corresponding to the count value of the counter 92B, and then proceeds to step 418.

  In step 418, the surface illumination control unit 92 determines whether or not the turn-off time of the surface LED 96 lit in step 416 has come. In addition, as an example of the extinguishing time in this step 418, the lighting period specified from the set value used when the front LED 96 is turned on by executing the process of step 360 of the LED specifying information transmission process. The end is mentioned.

  If it is determined in step 418 that the turn-off time of the front LED 96 lit in step 416 has not arrived, the determination is negative and the determination in step 418 is performed again. If it is determined in step 418 that the turn-off time of the front LED 96 that has been turned on in step 416 has come, the determination is affirmed and the routine proceeds to step 420.

  In step 420, the surface illumination control unit 92 turns off the surface LED 96, and then proceeds to step 422.

  In step 422, the surface illumination control unit 92 adds 1 to the count value of the counter 92B, and then proceeds to step 424.

  In step 424, as shown in FIG. 13 as an example, the front surface illumination control unit 92 transmits a back side LED lighting start signal instructing start of lighting of the back side LED 98 to the back side illumination control unit 94, and then step 426. Migrate to

  In step 426, the surface illumination control unit 92 determines whether or not a condition for ending the first lighting control process is satisfied. If it is determined in step 426 that the condition for ending the first lighting control process is not satisfied, the determination is negative and the process proceeds to step 428. In step 426, when the conditions for ending the first lighting control process are satisfied, the determination is affirmed and the first lighting control process is ended. If the determination in step 426 is affirmative, the count value of the counter 92B is returned to the initial set value.

  In step 428, the surface illumination control unit 92 determines whether or not lighting for one cycle by the surface LED 96 has been completed. If it is determined in step 428 that lighting for one cycle by the front LED 96 has not been completed, the determination is negative and the routine proceeds to step 416. If it is determined in step 428 that lighting for one cycle by the front surface LED 96 has been completed, the determination is affirmed and the routine proceeds to step 400.

  Next, a backside LED setting process executed by the backside illumination control unit 94 when an image reading start instruction is received by the UI 60 will be described with reference to FIG.

  In the backside LED setting process shown in FIG. 18, first, in step 430, the backside illumination control unit 94 receives the backside LED specifying information transmitted by executing the processing of step 370 of the LED specifying information transmission process. Determine whether or not.

  In step 430, if the back side LED specific information transmitted by executing the process of step 370 of the LED specific information transmission process is not received, the determination is negative and the process proceeds to step 436. In step 430, when the back side LED specifying information transmitted by executing the processing of step 370 of the LED specifying information transmission process is received, the determination is affirmed, and the process proceeds to step 432.

  In step 432, the back surface illumination control unit 94 sets the count value of the counter 94B to a count value corresponding to the back surface LED identification information.

  The count value corresponding to the backside LED identification information is any one of “0”, “1”, and “2”. In the third embodiment, “0” is assigned to the first LED for back surface 98A, “1” is assigned to the second LED for back surface 98B, and “2” is assigned to the third LED for back surface 98C. . In the third embodiment, “0” is adopted as the initial setting value of the counter 94B. However, the present invention is not limited to this, and a value other than “0” may be used as the initial setting value.

  In the next step 434, the back side illumination control unit 94 turns on the back side LED setting flag indicating that the count value of the counter 92B has been changed to the count value corresponding to the back side LED specifying information in the above step 432, and thereafter The process proceeds to step 436.

  In step 436, the back surface illumination control unit 94 determines whether a condition for ending the back surface LED setting process is satisfied. As an example of the condition for ending this backside LED setting process, there is a condition that a predetermined time has elapsed after the LED specific information transmission process is completed. If it is determined in step 436 that the conditions for ending the backside LED setting process are not satisfied, the determination is negative and the routine proceeds to step 430. In step 436, when the conditions for ending the backside LED setting process are satisfied, the determination is affirmed and the backside LED setting process is ended.

  Next, the second lighting control process executed by the backside illumination control unit 94 when an image reading start instruction is received by the UI 60 will be described with reference to FIG.

  In the second lighting control process shown in FIG. 19, first, in step 440, the backside illumination control unit 94 transmits a cycle transmitted by executing the process of step 350 of the periodic signal transmission process according to the third embodiment. It is determined whether or not a signal has been received. In step 440, if the periodic signal transmitted by executing the process of step 350 of the periodic signal transmission process according to the third embodiment is not received, the determination is negative and the determination of step 440 is performed. Do it again. In step 440, when the periodic signal transmitted by executing the process of step 350 of the periodic signal transmission process according to the third embodiment is received, the determination is affirmed and the process proceeds to step 442.

  In step 442, the back surface illumination control unit 94 determines whether or not the back surface LED setting flag is turned on. If the back side LED setting flag is turned on in step 442, the determination is affirmed and the routine proceeds to step 444.

  In step 444, the back surface illumination control unit 94 turns on the back surface LED 98 corresponding to the count value of the counter 94B, and then proceeds to step 446.

  In step 446, the back surface illumination control unit 94 determines whether or not the turn-off time of the back surface LED 98 turned on in step 444 has come. An example of the extinguishing time in step 446 is the time when 1/3 period has elapsed since the processing in step 444 was executed.

  In step 446, when the turn-off time of the back-side LED 98 lit in step 444 has not arrived, the determination is negative and the determination in step 446 is performed again. If it is determined in step 446 that the back-side LED 98 turned on in step 444 is turned off, the determination is affirmed and the process proceeds to step 448.

  In step 448, the back side illumination control unit 94 turns off the back side LED 98 and then proceeds to step 450.

  In step 450, the back surface illumination control unit 94 adds 1 to the count value of the counter 94B, and then proceeds to step 452.

  In step 452, the back surface illumination control unit 94 determines whether or not a condition for ending the second lighting control process is satisfied. An example of the condition for ending the second lighting control process is the same condition as the condition for ending the periodic signal transmission process. If it is determined in step 452 that the condition for ending the second lighting control process is not satisfied, the determination is negative and the process proceeds to step 454. If the condition for ending the second lighting control process is satisfied in step 452, the determination is affirmed and the second lighting control process is ended. If the determination in step 452 is affirmative, the count value of the counter 94B is returned to the initial setting value, and the back side LED setting flag is turned off.

  In step 454, the back surface illumination control unit 94 determines whether or not lighting for one cycle by the back surface LED 98 has been completed. If it is determined in step 454 that lighting for one cycle by the back surface LED 98 has not been completed, the determination is negative and the routine proceeds to step 454. If it is determined in step 454 that lighting for one cycle by the back surface LED 98 has been completed, the determination is affirmed and the routine proceeds to step 440.

  On the other hand, if the back side LED setting flag is not turned on in step 442, the determination is negative and the routine proceeds to step 456 shown in FIG.

  In step 456, the back surface illumination control unit 94 determines whether or not the back surface LED lighting start signal transmitted by executing the process of step 424 of the first lighting control process is received. In step 456, if the back side LED lighting start signal transmitted by executing the process of step 424 of the first lighting control process is not received, the determination is negative and the determination of step 456 is performed again. Is called. In step 456, when the back side LED lighting start signal transmitted by executing the process of step 424 of the first lighting control process is received, the determination is affirmed and the process proceeds to step 458.

  In step 458, the back surface illumination control unit 94 turns on the back surface LED 98 corresponding to the count value of the counter 94B, and then proceeds to step 460.

  In step 460, the back surface illumination control unit 94 determines whether or not the turn-off time of the back surface LED 98 lit in step 458 has come. As an example of the extinguishing time in this step 460, the lighting period specified from the set value used when the back side LED 98 is turned on by executing the processing of step 360 of the LED specifying information transmission processing. The end is mentioned.

  In step 460, when the turn-off time of the back-side LED 98 lit in step 458 has not come, the determination is negative and the determination in step 460 is performed again. If it is determined in step 460 that the back-side LED 98 turned on in step 458 has been turned off, the determination is affirmed and the process proceeds to step 462.

  In step 462, the back surface illumination control unit 94 turns off the back surface LED 98, and then proceeds to step 464.

  In step 464, the back side illumination control unit 94 adds 1 to the count value of the counter 94B, and then proceeds to step 466.

  In step 466, the back side illumination control unit 94 determines whether or not a condition for ending the second lighting control process is satisfied. If it is determined in step 466 that the condition for ending the second lighting control process is not satisfied, the determination is negative and the process proceeds to step 468. In step 466, when the conditions for ending the second lighting control process are satisfied, the determination is affirmed and the second lighting control process is ended. If the determination in step 466 is affirmative, the count value of the counter 94B is returned to the initial set value.

  In step 468, the back surface illumination control unit 94 determines whether or not lighting for one cycle by the back surface LED 98 has been completed. If it is determined in step 468 that lighting for one cycle by the back surface LED 98 has not been completed, the determination is negative and the routine proceeds to step 456. If it is determined in step 468 that lighting of one cycle by the back surface LED 98 has been completed, the determination is affirmed and the process proceeds to step 440.

  As described above, in the image reading apparatus 300, when the processing from step 416 to step 428 of the first lighting control processing and the processing from step 456 to step 468 of the second lighting control processing are executed, as an example, FIG. As shown in FIG. 5, the overlap between the lighting period of the front LED 96 and the lighting period of the rear LED 96 is avoided. Therefore, as shown in FIG. 21 as an example, overlap between a period in which current is consumed by the front LED 96 and a period in which current is consumed by the rear LED 96 is also avoided. Therefore, according to the image reading apparatus 300, compared to a case where the lighting period of the front surface LED 96 and the lighting period of the rear surface LED 96 overlap, an increase in current consumption during a period in which light of each color is irradiated in the order of the circulating colors is suppressed. The

  Further, in the image reading apparatus 300, when the process from step 404 to step 414 of the first lighting control process and the process from step 444 to step 454 of the second lighting control process are executed, as shown in FIG. In addition, the lighting period is controlled. In the example shown in FIG. 22, the light irradiation period by the front surface LED 96 and the light irradiation period by the rear surface LED 98 overlap. However, the lighting period of the front LED 96 having the largest current consumption value among the front LEDs 96 and the lighting period of the rear LED 98 having the smallest current consumption among the back LEDs 98 overlap. Thereby, compared with the case where the lighting period of the front surface LED 96 having the largest current consumption value among the front surface LEDs 96 and the lighting period of the rear surface LED 98 having the largest current consumption among the rear surface LEDs 98 overlap, An increase in current consumption during a period in which light of each color is irradiated is suppressed.

  In the third embodiment, the lighting period of the front LED 96 having the largest current consumption value among the front LEDs 96 and the lighting period of the rear LED 98 having the smallest current consumption value among the back LEDs 98 are overlapped. However, the present invention is not limited to this. For example, the lighting period of the front surface LED 96 having the smallest current consumption value in the front surface LED 96 and the lighting period of the rear surface LED 98 having the largest current consumption value in the rear surface LED 98 may be overlapped.

  In the third embodiment, the light irradiation period by the front LED 96 and the light irradiation period by the rear LED 98 are not overlapped by controlling the pulse width that defines the light irradiation period by the rear LED 98. Although illustrated, this invention is not limited to this. For example, the light irradiation period by the front LED 96 and the light irradiation period by the rear LED 98 may be prevented from overlapping by controlling the pulse width that defines the light irradiation period by the front LED 96. Further, by controlling both the pulse width that defines the light irradiation period by the front surface LED 96 and the pulse width that defines the light irradiation period by the back surface LED 98, the light irradiation period by the front surface LED 96 and the back surface LED 98 are controlled. You may make it not overlap with the irradiation period of light.

Moreover, in the said 3rd Embodiment, although the case where the irradiation period of the light by LED for front surface 96 and the irradiation period of light by LED for back surface 98 were not overlapped was illustrated, this invention is not limited to this, For surface use Compared with the case where the light irradiation period by the LED 96 and the light irradiation period by the back surface LED 98 are made to coincide, the overlap between the light irradiation period by the front surface LED 96 and the light irradiation period by the back surface LED 98 is reduced. Compared with the case where the lighting period of the front surface LED 96 and the lighting period of the rear surface LED 98 are matched , the period during which the current consumption increases can be shortened.

  In addition, the periodic signal transmission process, the first lighting control process, the second lighting control process, the LED specific information transmission process, the front surface LED setting process, and the back surface LED setting process described in the above embodiments are merely examples. . Therefore, it goes without saying that unnecessary steps may be deleted, new steps may be added, and the processing order may be changed within a range not departing from the spirit.

  In each of the above embodiments, the periodic signal transmission process and the LED specific information transmission process are realized by a software configuration, but the present invention is not limited to this, and is realized by a hardware configuration such as an ASIC or FPGA. You may be made to do. Further, it may be realized by a combination of a software configuration and a hardware configuration.

  In addition, the first lighting control process, the second lighting control process, the front LED setting process, and the back LED setting process described in each of the above embodiments are executed by the ASIC, but by executing the program, You may implement | achieve by a software structure using a computer.

  In order to realize each process included in the first lighting control process and the front LED setting process with a software configuration, for example, as shown in FIG. 23, a surface illumination control unit 500 equipped with a CPU and a memory 504 are used. That's fine.

  The memory 504 is connected to the surface illumination control unit 500. The memory 504 stores a first lighting control program 508, 510, 512 and a front LED setting program 514. In this case, the first lighting control process according to the first embodiment is realized by the first lighting control program 508 being executed by the surface illumination control unit 500. In addition, the first lighting control process according to the second embodiment is realized by executing the second lighting control program 510 by the surface lighting control unit 500. Further, the third lighting control process according to the third embodiment is realized by the third lighting control program 512 being executed by the surface lighting control unit 500. Furthermore, the surface LED setting process according to the third embodiment is realized by executing the surface LED setting program 514 by the surface illumination control unit 500.

  To realize each process included in the second lighting control process and the backside LED setting process with a software configuration, for example, as shown in FIG. 24, a backside illumination control unit 502 equipped with a CPU and a memory 506 are used. That's fine.

  The memory 506 is connected to the back side illumination control unit 502. The memory 506 stores a second lighting control program 516, 518, 520 and a backside LED setting program 522. In this case, the second lighting control process according to the first embodiment is realized by the second lighting control program 516 being executed by the back side illumination control unit 502. Further, the second lighting control process according to the second embodiment is realized by executing the second lighting control program 518 by the back side illumination control unit 502. In addition, the second lighting control process according to the third embodiment is realized by the second lighting control program 520 being executed by the back side illumination control unit 502. The backside LED setting process according to the third embodiment is realized by the backside LED setting program 522 being executed by the backside illumination control unit 502.

  23 and 24 illustrate the state in which the program is stored in the memories 504 and 506, it is not always necessary to store the program in the memories 504 and 506 from the beginning. For example, the program may first be stored in a portable storage medium that is connected to the image reading apparatus 10, 200, 300 and used. Then, the front surface illumination control unit 500 and the back surface illumination control unit 502 may acquire and execute a program from these portable storage media. Further, the program may be stored in a storage unit of an external electronic computer such as a computer or a server device connected to the image reading apparatuses 10, 200, and 300 via a communication unit. In this case, the front surface illumination control unit 500 and the back surface illumination control unit 502 acquire and execute a program from an external electronic computer.

10, 200, 300 Image reader 18 Original 28B Back lamp 34 Front lamp 52, 87, 310 Image reading controller 68A, 68B, 68C Periodic signal transmission program 68D LED specific information transmission program 76, 88, 92, 500 Surface illumination control 77, 90, 94, 502 Back illumination control unit 96A First LED for front surface
96B Second LED for surface
96C 3rd LED for surface
98A 1st LED for back side
98B 2nd LED for back side
98C 3rd LED for back side
508, 510, 512 First lighting control program 514 Front LED setting program 516, 518, 520 Second lighting control program 522 Back LED setting program 602 Image forming unit

Claims (5)

Surface irradiation means for moving relative to the surface of the recording medium and irradiating the surface with light;
Move the back relative said recording medium, and a back irradiation means for irradiating light to the back surface,
A period of light irradiation is defined for each set when the first irradiation period in which light is irradiated by the front surface irradiation unit and the second irradiation period in which light is irradiated by the rear surface irradiation unit is set as one set. An output means for outputting a periodic signal;
If the sum of the said first irradiation period second irradiation period is determined Taka whether exceeds a predetermined time following the period, the sum is determined not to exceed the time said predetermined Only compared with the case where the first irradiation period and the second irradiation period coincide with each other, the first irradiation period and the second irradiation period within the period defined by the periodic signal input from the output means. Control means for controlling at least one of a pulse width defining the first irradiation period and a pulse width defining the second irradiation period, so as to reduce overlap with
An image reading apparatus. Each of the front surface irradiating means and the back surface irradiating means relatively moves with respect to the recording medium and has a plurality of colors that circulate in a predetermined order with respect to the recording medium during the relative movement. Irradiate each light,
The first irradiation period is a period in which the light of each of the plurality of colors is irradiated once in the order by the surface irradiation unit,
2. The image reading apparatus according to claim 1, wherein the second irradiation period is a period in which the light of each of the plurality of colors is irradiated once in the order by the back surface irradiation unit. The control means is configured such that light of one of the plurality of colors is 1 with respect to the other surface between the light of each of the plurality of colors irradiated on one surface of the front surface and the back surface. The image reading apparatus according to claim 2 , wherein the image reading apparatus is controlled so as to be irradiated once. When the total exceeds the predetermined time, the control means overlaps the first irradiation period and the second irradiation period, and one of the front surface irradiation means and the back surface irradiation means. The irradiation period in which the light of the color having the maximum consumption current value among the consumption current values required for irradiation of each of the plurality of colors circulating in a predetermined order is applied, and the front surface irradiation means and the back surface The surface irradiating means and the surface irradiating means and the irradiating means are overlapped with an irradiation period in which light of a color having a minimum current consumption value among current consumption values required for irradiation of each of the plurality of colors by the other of the irradiating means is overlapped. The image reading apparatus according to claim 1 , wherein the image forming apparatus controls the back surface irradiation unit. Computer
The program for functioning as a control means in the image reading apparatus of any one of Claims 1-4 .

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