JP6233276B2 - Image reading apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to an image reading apparatus capable of reading images on both sides of a document, and an image forming apparatus including the image reading apparatus.

  In general, an image reading apparatus having an ADF receives two light sources that emit light from both sides of a document conveyance path to the surface of a document, and reflected light from both surfaces of the document to receive received light amount data. In many cases, two image sensors that output image data of a document are provided (for example, see Patent Document 1).

  In order to make it possible to eliminate jamming of the original in the original conveying path, the image reading device is normally displaceable between a closed state that covers the original conveying path and an open state that exposes the original conveying path. An ADF cover is provided.

JP-A-1-171360

  By the way, in order to read an image normally, the ADF cover needs to be closed. For this reason, the conventional image reading apparatus includes an open / close sensor that detects whether or not the ADF cover is open.

  However, recently, it is required to further reduce the number of parts in the image reading apparatus, the number of assembling steps of the image forming apparatus, and the cost, and it is preferable that the opening / closing sensor can be omitted.

  An object of the present invention is to provide an image reading apparatus capable of detecting that the ADF cover is closed while reducing the number of parts, the number of assembling steps of the image forming apparatus, and the cost, and an image including the image reading apparatus. A forming apparatus is provided.

  An image reading apparatus according to one aspect of the present invention includes a first image reading unit, a second image reading unit, a cover member, a reading control unit, and a cover position determination unit. The first image reading unit includes a first light source that emits light toward a first position of the document conveyance path, and a first light source that is reflected by a first surface of the document conveyed to the first position. A first light receiving portion for detecting the light. The second image reading unit includes a second light source that emits light toward a second position of the document conveyance path, and a second light source opposite to the first surface of the document conveyed to the second position. A second light receiving unit for detecting light from the second light source reflected by the surface; The cover member is displaceable between an open position that exposes the second image reading unit and a closed position that covers the second image reading unit. The reading control unit controls the second image reading unit, and sets the control mode of the second image reading unit to output a light amount detection result to the second light receiving unit with the second light source turned on. It is possible to switch to the first mode and the second mode in which the second light receiving unit outputs the light amount detection result with the second light source turned off. The cover position determination unit determines whether or not a light amount detected by the second light receiving unit when the control mode of the second image reading unit is the second mode exceeds a predetermined light amount. Thus, it is determined whether or not the cover member is in the closed position.

  An image forming apparatus according to another aspect of the present invention includes the image reading device and an image forming unit that forms an image read by the image reading device on a sheet member.

  According to the present invention, an image reading apparatus capable of detecting that the ADF cover is closed while reducing the number of parts, the man-hours for assembling the image forming apparatus, and the cost, and image formation provided with the image reading apparatus. An apparatus can be provided.

FIG. 1 is a configuration diagram showing an internal configuration of an image forming apparatus including an image reading apparatus according to the first embodiment of the present invention. FIG. 2 is a diagram illustrating a configuration of the ADF. FIG. 3 is a diagram showing the configuration of the CIS. FIG. 4 is a block diagram showing the configuration of the image forming apparatus including the image reading apparatus according to the first embodiment of the present invention. FIG. 5 is a flowchart showing processing by the control unit. FIG. 6 is a block diagram showing a configuration of an image forming apparatus including an image reading apparatus according to the second embodiment of the present invention. 7A is a time chart showing the detection signal of the sheet sensor during the continuous reading process, FIG. 7B is a time chart showing the on / off operation of the light source during the continuous reading process, and FIG. It is a time chart which shows the light reception operation | movement of the line sensor of the 2nd image reading part in the continuous reading process.

  An image forming apparatus 100 according to a first embodiment of the present invention will be described.

  The image forming apparatus 100 is a multifunction machine having an image reading function, a facsimile function, an image forming function, and the like. Note that the image forming apparatus 100 is not limited to a multifunction peripheral, and may be, for example, a printer, a facsimile machine, or a copier.

  As shown in FIGS. 1 and 4, the image forming apparatus 100 includes an image reading device 1 and an image forming unit 2. The image reading apparatus 1 includes an apparatus main body 3 and a document cover 4.

  The apparatus main body 3 includes a first image reading unit 5 that reads an image from a document and executes a reading job for outputting image data of the document image. The first image reading unit 5 includes a contact glass 10, a reading unit 11, mirrors 12 and 13, an optical lens 14, a CCD (Charge Coupled Device) 15, and the like.

  The contact glass 10 is provided on the upper surface of the apparatus body 3. The upper surface of the contact glass 10 is a document placement surface M1.

  The reading unit 11 is provided below the contact glass 10. The reading unit 11 includes a light source 16 and a mirror 17 and is configured to be movable in the sub-scanning direction D1 (left and right direction in FIG. 1) by a moving mechanism (not shown) using a driving motor such as a stepping motor. . The light source 16 is, for example, an LED (Light Emitting Diode) light source. The light source 16 corresponds to a first light source.

  When the light is emitted from the light source 16, the mirror 17 reflects the reflected light reflected by the document placed on the document placement surface M <b> 1 toward the mirror 12. The mirror 12 reflects incident light toward the mirror 13. The mirror 13 reflects toward the optical lens 14. The light transmitted through the optical lens 14 travels to the CCD 15.

  The CCD 15 is a photoelectric conversion element that receives the reflected light and outputs an electrical signal (voltage) corresponding to the amount of received light (intensity of luminance). The electrical signal corresponding to the received light amount is digitized and transmitted as light amount data to an image processing unit (not shown) described later. The CCD 15 corresponds to a first light receiving unit.

  The image reading by the first image reading unit 5 for the document placed on the contact glass 10 (document placing surface M1) is performed in the following procedure.

  The document is placed on the contact glass 10 by the user, and the document cover 4 is set to the closed position. Thereafter, the user performs an image reading start operation on an operation display unit 6 described later.

  When the image reading start operation is performed, the reading job is executed by the first image reading unit 5. In the reading job, the drive motor 11 moves the reading unit 11 located at a predetermined home position in the sub-scanning direction D1, and the light source 16 continuously emits light for one line in parallel with this. Processing is performed. Thereby, the light emitted from the light source 16 toward the contact glass 10 provided on the upper surface of the apparatus main body 3 is scanned in the sub-scanning direction D1.

  Then, the reflected light from the original is guided to the CCD 15 via the mirrors 17, 12, 13 and the optical lens 14, and the light amount data corresponding to the amount of light received by the CCD 15 is sequentially transmitted to the image processing unit. The image processing unit generates image information of a document from the light amount data by processing the light amount data.

  The document cover 4 is provided on the upper part of the apparatus body 3. The document cover 4 is rotatably supported by the apparatus body 3 between an open position where the document placement surface M1 is opened and a closed position which covers the document placement surface M1.

  The document cover 4 is separated from the document placement surface M1 when the document cover 4 is in the open position, and close to the document placement surface M1 when the document cover 4 is in the closed position. In the closed position, the document cover 4 presses the document placed on the document placement surface M1 so that the lower surface thereof is along the document placement surface M1, and blocks external light toward the reading unit 11.

  The document cover 4 has an ADF (Auto Document Feeder) 18. As shown in FIG. 2, the ADF 18 includes a document setting unit 19, a document transport unit 20, and a paper discharge unit 21.

  In the document setting unit 19, one document P1 or a plurality of documents P1 are placed. The document setting unit 19 corresponds to a document receiving unit. The document conveying unit 20 conveys the document P1 set in the document setting unit 19 one by one. The document P1 transported by the document transport unit 20 is discharged to the paper discharge unit 21.

  The document setting unit 19 is provided with a sheet sensor 22 (see FIG. 4). The sheet sensor 22 outputs a signal indicating whether or not the document P1 is set on the document setting unit 19 to the control unit 9. For example, the sheet sensor 22 may be a mechanical switch that can output a contact signal. The sheet sensor 22 corresponds to a placed document sensor that detects whether or not the document P1 is placed on the document setting unit 19 on the entrance side of the document conveyance path R1.

  The document setting unit 19 is located above the paper discharge unit 21. The document transport unit 20 transports the document P1 from the document setting unit 19 to the paper discharge unit 21 along a document transport path R1 formed in a U shape. The document transport path R1 includes a first transport path R11, a second transport path R12, and a third transport path R13.

  The first conveyance path R11 is a substantially linear conveyance path connected to the document placement space S1 of the document setting unit 19. The second transport path R <b> 12 is a substantially linear transport path that is connected to the document discharge space S <b> 2 of the paper discharge unit 21. The first transport path R11 is located above the second transport path R12. The third conveyance path R13 is a curved conveyance path that is connected to the first conveyance path R11 and the second conveyance path R12 at a position opposite to the document setting unit 19.

  A feeding roller 23 and a feeding roller 24 are provided at a position upstream of the first transport path R11. The feeding roller 23 is in pressure contact with the uppermost layer of the document P1 set in the document setting unit 19, and feeds the document P1 one sheet at a time downstream. The document P1 fed by the feeding roller 23 is guided to the feeding roller 24 by the guide plate 27. The feeding roller 24 supplies the incoming document P1 to the first transport path R11.

  The feeding roller 23 and the feeding roller 24 are connected by a connecting member 26. The connecting member 26 is a plate extending in one direction. The connecting member 26 is pivotally supported by the rotating shaft 24 </ b> A of the feeding roller 24 at a position near one end thereof. The rotating shaft 23 </ b> A of the feeding roller 23 is rotatably supported at a position near the other end that is opposite to the one end of the connecting member 26.

  With this configuration, the height position of the feeding roller 23 is variable according to the thickness of the bundle of documents P1 placed on the document setting unit 19, and the feeding roller 23 feeds the document P1 at that height position. I do.

  A plurality of transport roller pairs 25 are provided in the document transport path R1. By driving each pair of transport rollers 25 by a motor (not shown), the document P1 transported by the feeding roller 24 transports the first transport path R11, the third transport path R13, and the second transport path R12 in this order. Is done.

  The ADF 18 includes a second image reading unit 28 that executes the reading job. The second image reading unit 28 is provided on the opposite side to the side where the first image reading unit 5 is located with respect to the document conveyance path R1. That is, each of the first image reading unit 5 and the second image reading unit 28 is disposed on each of the first side and the second side of both sides of the document transport path R1. It can be said that the first side and the second side of the document transport path R1 are the sides to which the first and second surfaces of the document moving along the document transport path R1 face. In the present embodiment, the second image reading unit 28 is a CIS (Contact Image Sensor).

  As shown in FIG. 3, the CIS includes a contact glass 31, a light source 32, a lens 33, and a line sensor 34. The light source 32, the lens 33, and the line sensor 34 are provided at positions opposite to the original P1 with respect to the contact glass 31. The light source 32 corresponds to a second light source, and the line sensor 34 corresponds to a second light receiving unit.

  For example, it is conceivable that the light source 32 is an LED array having a plurality of LEDs arranged along the main scanning direction. It is also conceivable that the second image reading unit 28 includes a light guide member (not shown) that diffuses the light from the light source 32 to a width corresponding to the entire region in the main scanning direction to form sheet-like light.

  The line sensor 34 is a CMOS (Complementary Metal Oxide Semiconductor) image sensor in which a large number of photoelectric conversion elements that convert incident light into electrical signals are arranged in the main scanning direction. The line sensor 34 outputs image data corresponding to the amount of received light to the image processing unit. Note that the line sensor 34 may be another imaging element such as a CCD instead of the CMOS image sensor.

  When reading the image of the document P1, the second image reading unit 28 outputs the light amount data of the reflected light when the light is emitted from the light source 32 to the document P1 as image data.

  A white reference member 35 is provided in the first transport path R11. The white reference member 35 faces the contact glass 31 at a position opposite to the line sensor 34 with respect to the contact glass 31 in a state where an ADF cover 40 described later is in a closed position.

  The entire surface of the white reference member 35 is uniformly white. The white reference member 35 is used to acquire white reference data that is a white reference for image reading processing in the second image reading unit 28. The white reference member 35 brings the document P1 into close contact with the contact glass 31.

  In the second image reading unit 28, the light source 32 emits light from the second side of the document conveying path R1 toward a predetermined reading position L2 in the first conveying path R11. Then, the line sensor 34 detects the amount of light that travels from the reading position L2 toward the second side of the document transport path R1, thereby performing a document image reading operation. The reading position L2 corresponds to the second position.

  The document P1 is brought into close contact with the contact glass 31 at the reading position L2 by the white reference member 35. Accordingly, the second image reading unit 28 detects light from the light source 32 reflected by the second surface that is in close contact with the contact glass 31 among the second surface of the document P1 being conveyed through the first conveyance path R11. As a result, the image on the second surface is read line by line at the reading position L2. The second surface of the document P1 moving along the first transport path R11 is the lower surface in FIG.

  The first image reading unit 5 can read not only the document placed on the contact glass 10 but also the image on the first surface of the document P1 conveyed by the ADF 18.

  The first image reading unit 5 reads an image on the first surface of the document P1 moving on the document transport path R1 while stopped at a predetermined stop position on the first side of the document transport path R1. At that time, the light source 16 of the first image reading unit 5 emits light from the first side of the document conveying path R1 to the predetermined reading position L1 of the second conveying path R12.

  Then, the CCD 15 detects the amount of light that travels from the reading position L1 toward the first side of the document conveyance path R1, thereby performing a document image reading operation. The reading position L1 corresponds to the first position.

  A white reference member 36 is provided at a position facing the reading unit 11 located at the stop position across the second transport path R12. The white reference member 36 has a function similar to that of the white reference member 35, and causes the document P 1 to be in close contact with the contact glass 10.

  The first image reading unit 5 emits light from the light source 32 toward the reading position L1 and receives the reflected light. The document P1 is brought into close contact with the contact glass 10 at the reading position L1 by the white reference member. Therefore, the first image reading unit 5 detects the light from the light source 16 that is reflected by the portion of the first surface of the document conveyed through the second conveyance path R12 that is in close contact with the contact glass 10, thereby The image on the first surface is read by predetermined lines at the reading position L1. In this way, the first image reading unit 5 reads an image on the surface opposite to the surface read by the second image reading unit 28.

  As described above, the image reading apparatus 1 reads the image on the first surface by the first image reading unit 5 while conveying the document on the document conveying unit 20 from the document setting unit 19 to the paper discharge unit 21. The second image reading unit 28 can perform double-sided reading for reading the image on the second surface.

  A first passing document sensor 37 is provided at a predetermined position upstream of the reading position L1. Based on the timing at which the original is detected by the first passage original sensor 37, the timing of reading the original image by the first image reading unit 5 is determined by the control unit 9. For example, the document image reading start timing of the first image reading unit 5 is set to a timing when a predetermined time has elapsed from the time when the document P1 starts to be detected by the first passing document sensor 37. In addition, the timing of the end of reading the document image of the first image reading unit 5 is set to a timing when a predetermined time has elapsed since the time when the document P1 is no longer detected by the first passing document sensor 37.

  A second passing document sensor 38 is provided at a predetermined position in the document transport path R1. The second passing original sensor 38 is provided at a position upstream of the reading position L2. In the present embodiment, the first passing document sensor 37 and the second passing document sensor 38 output an H (high) signal when the document P1 passes through the respective detection areas, and the document P1 is in the detection area. When not passing, an L (low) signal is output.

  Based on the timing at which the document is detected by the second passage document sensor 38, the timing of reading the document image by the second image reading unit 28 is determined by the control unit 9. For example, the document image reading start timing of the second image reading unit 28 is set to a timing when a predetermined time has elapsed from the time when the document P1 starts to be detected by the second passing document sensor 38. Further, the end timing of the document image reading of the second image reading unit 28 is set to a timing when a predetermined time has elapsed from the time when the document P1 is no longer detected by the second passing document sensor 38.

  The document transport unit 20 is provided in the casing 18 </ b> A of the ADF 18. An ADF cover 40 is provided on the casing 18A. The ADF cover 40 is provided on the upper portion of the housing 18A, and is rotatably supported by the housing 18A. Thus, the ADF cover 40 closes the opening X1 formed in the housing 18A and covers the second image reading unit 28 (FIG. 2A), and opens the opening X1 to open the document transport path R1 and It can be displaced between the open position where the second image reading unit 28 is exposed (FIG. 2B).

  Note that, on the inner surface 40A (see FIG. 2B) of the ADF cover 40, one transport roller 25A of the transport roller pair 25 provided in the first transport path R1 and the white reference member 35 of the second image reading unit 28. Etc. are attached. Therefore, when the ADF cover 40 is displaced to the open position, the transport roller 25A and the white reference member 35 are also displaced.

  When the ADF cover 40 is displaced from the closed position toward the open position, external light enters the document conveyance unit 20 from the outside of the housing 18A through the opening X1. At least a part of the incident light goes directly to the reading position L2 of the second image reading unit 28.

  The image forming unit 2 receives image information read by at least one of the first image reading unit 5 and the second image reading unit 28 or an information processing apparatus such as an external personal computer through a communication I / F unit (not shown). Based on the input image forming job, an image forming process is performed on the recording sheet by electrophotography.

  The image forming unit 2 includes a paper feed cassette 7. The image forming unit 2 includes a photosensitive drum 50, a charging unit 51, a developing unit 52, a toner container 53, a transfer roller 54, a charge eliminating unit 55, a fixing roller 56, and a pressure roller 57.

  The image forming unit 2 performs an image forming process on the recording sheet supplied from the paper feed cassette 7 according to the following procedure.

  When an image forming job is input, the photosensitive drum 50 is uniformly charged to a predetermined potential by the charging unit 51. Next, the output intensity of light emitted from the LSU (Laser Scanning Unit) to the surface of the photosensitive drum 50 is controlled based on image information included in the image forming job.

  As a result, an electrostatic latent image is formed on the surface of the photosensitive drum 50. The electrostatic latent image on the photosensitive drum 50 is developed (visualized) as a toner image by the developing unit 52. The developing unit 52 is supplied with toner (developer) from the toner container 53.

  Subsequently, the toner image formed on the photosensitive drum 50 is transferred to a recording sheet by the transfer roller 54. Thereafter, the toner image transferred to the recording sheet is heated and fixed by the fixing roller 56 when the recording sheet passes between the fixing roller 56 and the pressure roller 57 and is discharged. The electric potential of the photosensitive drum 50 is neutralized by the neutralization unit 55.

  The image reading apparatus 1 has an operation display unit 6. The operation display unit 6 includes a display unit 29 and an operation unit 30.

  The display unit 29 includes, for example, a color liquid crystal display and displays various types of information to the user who operates the operation display unit 6. The operation unit 30 includes one or more of various push button keys arranged adjacent to the display unit 29 and a touch panel sensor arranged on the display screen of the display unit 29, and the user of the image forming apparatus 100. Accepts operations for inputting various instructions. The operation display unit 6 outputs an operation signal corresponding to the operation to the control unit 9 when receiving an operation instruction for performing various processes such as an image reading operation from the user.

  The image reading apparatus 1 includes a control unit 9. The control unit 9 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The CPU is a processor that executes various arithmetic processes. The ROM is a non-volatile storage unit in which information such as a control program for causing the CPU to execute various processes is stored in advance. The RAM is a volatile storage unit used as a temporary storage memory (working area) for various processes executed by the CPU. The control unit 9 controls the operation of the image reading apparatus 1 by the CPU executing a program stored in the ROM.

  The ROM of the control unit 9 stores a processing program for causing the CPU of the control unit 9 to execute processing described later (see the flowchart in FIG. 5). The processing program may be stored in the ROM when the image forming apparatus 100 is shipped. Alternatively, the processing program is recorded on a computer-readable recording medium such as a CD (Compact Disc), a DVD (Digital Versatile Disc), or a flash memory, and after the shipment, the processing program is transferred from the recording medium to the control unit 9. May be stored in the ROM.

  By the way, in order to read an image normally, the ADF cover 40 needs to be in the closed position. Therefore, the conventional image reading apparatus includes an open / close sensor that detects whether or not the ADF cover 40 is in the open position.

  However, recently, it is required to further reduce the number of parts, the number of assembling steps of the image forming apparatus, and the cost in the image reading apparatus 1, and it is preferable that the opening / closing sensor can be omitted.

  Accordingly, the image reading apparatus 1 has the following configuration to detect that the ADF cover 40 is closed while reducing the number of parts, the number of assembling steps of the image forming apparatus, and the cost.

  In the present embodiment, the control unit 9 includes a reading control unit 61 and a cover position determination unit 62.

  The reading control unit 61 controls the second image reading unit 28. The reading control unit 61 switches the control mode of the second image reading unit 28 between a first mode and a second mode described below. The first mode is a mode in which the light quantity detection result is output to the line sensor 34 with the light source 32 turned on. The second mode is a mode in which the line sensor 34 outputs a light amount detection result in a state where the light source 32 is turned off.

  The reading control unit 61 sets the control mode of the second image reading unit 28 to the first mode when the reading job is being executed. Further, the reading control unit 61 sets the control mode of the second image reading unit 28 to the second mode before the sheet sensor 22 detects the document and the ADF 18 starts conveying the document.

  In a situation where the control mode of the second image reading unit 28 is set to the second mode, when the ADF cover 40 is positioned closer to the open position than the closed position, it passes through the opening X1 from the outside of the housing 18A. The line sensor 34 detects the amount of external light that goes directly to the reading position L2.

  On the other hand, in the situation where the control mode of the second image reading unit 28 is set to the second mode, when the ADF cover 40 is located at the closed position, the ADF cover 40 blocks outside light, so that the line sensor 34 is almost not used. In this state, no light is detected.

  The cover position determination unit 62 determines whether the detected light amount of the line sensor 34 when the control mode of the second image reading unit 28 is the second mode exceeds a predetermined light amount (threshold value). . And the cover position determination part 62 determines whether the ADF cover 40 exists in the said closed position by this determination result. That is, the cover position determination unit 62 determines that the ADF cover 40 is not in the closed position when it is determined that the amount of light detected by the line sensor 34 exceeds the threshold value, and otherwise, the ADF cover 40. Is in the closed position.

  Whether or not the ADF cover 40 is in the closed position is determined based on whether or not the amount of light detected by the line sensor 34 when the control mode of the second image reading unit 28 is the second mode exceeds the threshold value. It is not limited to what is performed based on only. The determination may be performed by adding whether or not other conditions are satisfied to the condition that the amount of light detected by the line sensor 34 is large.

  Next, processing performed by the control unit 9 will be described with reference to FIG. 5, steps S501, S502,... Represent processing procedure (step) numbers.

<Step S501>
In step S501, the control unit 9 determines whether a start condition for starting the light receiving operation in the second mode by the second image reading unit 28 is satisfied. As the start condition, for example, a condition that the sheet sensor 22 detects the document P1 and an image reading start operation is performed on the operation display unit 6 by the user can be considered. In this case, the control of the second mode by the second image reading unit 28 is executed before the ADF 18 starts conveying the document P1.

<Step S502>
When the start condition is satisfied, the reading control unit 61 controls the second image reading unit 28 in the second mode. Thereby, the second image reading unit 28 outputs the light amount detection result with the light source 32 turned off. And the control part 9 advances a process to step S503.

<Step S503>
In step S <b> 503, the cover position determination unit 62 determines whether the level (light reception amount) of the signal output from the second image reading unit 28 under the control of the read control unit 61 indicates a light reception amount that exceeds the threshold value. .

  If the cover position determination unit 62 determines that the level of the signal indicates the amount of light received that exceeds the threshold (YES in step S503), the cover position determination unit 62 advances the process to step S504. On the other hand, when it is determined that the level of the signal does not indicate the amount of received light exceeding the threshold value (NO in step S503), the control unit 9 advances the process to step S507.

<Step S504>
When the control unit 9 determines that the level of the signal indicates the amount of light received that exceeds the threshold value, the control unit 9 stops the document conveyance unit 20. As a result, it is possible to prevent the document transport unit 20 from starting to transport the document P1 while the ADF cover 40 remains open. As a result, it is possible to avoid a reading failure of the original image due to the second image reading unit 28 operating in the first mode with the ADF cover 40 being opened.

  That is, if the ADF cover 40 remains open, a conveyance failure of the document P1 occurs. Further, external light enters the second image reading unit 28 from the outside of the housing 18A through the opening X1, and the image read by the second image reading unit 28 is not an image faithful to the original image.

  Here, when the external light is incident on the line sensor 34 by opening the ADF cover 40, the level of the signal output from the line sensor 34 indicates a received light amount exceeding the threshold value.

  Therefore, the control unit 9 determines whether or not the level of the signal indicates the amount of received light exceeding the threshold, and when the control unit 9 determines that it is, the control of the document conveying unit 20 is stopped. Thus, it is possible to avoid reading an abnormal image by the second image reading unit 28. After the processing in step S504, the control unit 9 advances the processing to step S505.

<Step S505>
The control unit 9 performs notification processing that prompts the user to close the ADF cover 40. As this notification process, a process of outputting a predetermined sound through a sound output unit (not shown) or a process of displaying a predetermined message by the display unit 29 can be considered. And the control part 9 advances a process to the process of step S506.

<Step S506>
The control unit 9 sets an error flag indicating that the ADF cover 40 is not in the closed state to ON. Note that the initial value of the error flag is OFF. After the process of step S506, the control unit 9 returns the process to the process of step S502.

<Step S507>
If the control unit 9 determines that the level of the signal does not indicate the amount of received light exceeding the threshold, whether or not an end condition for ending the control in the second mode for the second image reading unit 28 is satisfied. Determine whether. As the termination condition, for example, the condition that the error flag is OFF, or a condition that a confirmation operation predetermined by the user is performed on the operation display unit 6 under the situation where the error flag is ON is adopted. Is possible. The confirmation operation may be the same operation as the image reading start operation, for example.

  When it is determined that the termination condition is not satisfied (NO in step S507), the control unit 9 returns the process to the process in step S502. On the other hand, when it is determined that the end condition is satisfied (YES in step S507), the control unit 9 advances the process to step S508.

<Step S508>
When it is determined that the end condition is satisfied, the control unit 9 sets the error flag to OFF and then ends the process. The satisfaction of the end condition is a condition that allows the ADF 18 to carry the original P1.

  As described above, in the image forming apparatus 100, when the reading job is not being executed, the line sensor 34 outputs the light amount detection result with the light source 32 turned off, and the ADF cover 40 is output using the output signal. The controller 9 determines whether or not is located at the closed position. That is, in the image forming apparatus 100 according to the present embodiment, instead of the conventional open / close sensor, the second image reading unit 28 that reads the image of the document detects whether the ADF cover 40 is in the closed position. It is used. Therefore, the conventional open / close sensor can be omitted.

  Thereby, it is possible to detect that the ADF cover 40 is closed while reducing the number of parts, the number of assembling steps of the image forming apparatus, and the cost.

  In the embodiment, the control unit 9 controls the second image reading unit 28 in the second mode during a period before the sheet sensor 22 detects the document and the conveyance of the document is started. Let it begin. However, the present invention is not limited to this, and it is also conceivable to periodically control the second image reading unit 28 in the second mode from the end of a certain reading job to the execution of the next reading job. .

[Second Embodiment]
In the image forming apparatus 100 according to the embodiment, the control in the second mode with respect to the second image reading unit 28 is performed before the sheet sensor 22 detects the document and the conveyance of the document is started. Done in the period. However, the present invention is not limited to this, and during the period in which a continuous reading process is performed in which a plurality of documents are continuously conveyed by the ADF 18 along the document conveyance path R1, the second image reading unit 28 is subjected to the above-described process. It is also conceivable that control in the second mode is performed. Hereinafter, this point will be described.

  In the image forming apparatus 200 according to the second embodiment, as illustrated in FIG. 6, the control unit 9 includes a timing determination unit 63 in addition to the reading control unit 61 and the cover position determination unit 62.

  When the continuous reading process is performed, the timing determination unit 63 performs a first timing, which is a period during which the document passes through the reading position L2 of the second image reading unit 28 based on the detection result of the second passing document sensor 38. judge. Further, the timing determination unit 63 determines a second timing that is a period from when the original passes through the reading position L2 to before the next original reaches the reading position L2.

  Then, the reading control unit 61 controls the second image reading unit 28 in the first mode at the first timing. Further, the reading control unit 61 controls the second image reading unit 28 in the second mode at the second timing. This process will be described with reference to FIG.

  As shown in FIG. 7A, when the leading edge of the document reaches the detection area of the second passing document sensor 38, the level of the output signal of the second passing document sensor 38 changes from L (low) to H (high). Change. When the trailing edge of the document passes through the detection area of the second passing document sensor 38, the level of the output signal of the second passing document sensor 38 changes from H (high) to L (low). When the continuous reading process is performed, the level change of the output signal is repeated.

  When the level of the output signal of the second passage original sensor 38 changes from L (low) to H (high) at time T1, the timing determination unit 63 reaches the detection area of the second passage original sensor 38. Is determined. Then, the timing determination unit 63 determines that the leading edge of the document reaches the reading position L2 of the second image reading unit 28 at a time T2 after a predetermined time Δt1 has elapsed from the time T1.

  Further, when the level of the output signal of the second passing document sensor 38 changes from H (high) to L (low) at time T3, the timing determination unit 63 causes the trailing edge of the document to be detected by the second passing document sensor 38. Is determined to have passed. Then, the timing determination unit 63 determines that the trailing edge of the document passes the reading position L2 of the second image reading unit 28 at the time T4 after the lapse of the time Δt1 from the time T3.

  The first timing is, for example, between time T2 and time T4, and after the leading edge of the document reaches the reading position L2 of the second image reading unit 28, the trailing edge passes through the reading position L2. Until.

  Further, when the level of the output signal of the second passing document sensor 38 changes from L (low) to H (high) at time T5, the timing determination unit 63 detects the leading edge of the next document by the second passing document sensor 38. It is determined that the area has been reached. Then, the timing determination unit 63 determines that the leading edge of the next document reaches the reading position L2 of the second image reading unit 28 at the time T6 after the lapse of the time Δt1 from the time T5.

  In the second timing, for example, between the time T4 and the time T6, the leading edge of the next original is read after the trailing edge of the original passes the reading position L2 of the second image reading unit 28. This is until the position L2 is reached.

  Here, as shown in FIG. 7C, the reading control unit 61 determines that the trailing edge of the document conveyed last after the leading edge of the first conveyed document reaches the reading position L2 is the reading position L2. Until the line sensor 34 passes through, the line sensor 34 of the second image reading unit 28 performs a light receiving operation. The image processing unit generates the image information of the document from the light amount data by processing the light amount data output from the line sensor 34 by the light receiving operation while the document passes through the reading position L2. To do. As shown in FIG. 7B, the reading control unit 61 turns on the light source 32 at the first timing and turns it off at the second timing.

  That is, the reading control unit 61 controls the second image reading unit 28 in the first mode at the first timing, and controls the second image reading unit 28 in the second mode at the second timing.

  By performing such processing, it is possible to avoid the occurrence of the problem when the ADF cover 40 is opened at the second timing. Such an effect can be achieved by the second image reading unit 28 without using a conventional open / close sensor.

  Note that the first image reading unit 5 detects the amount of light traveling toward the first side of the document transport path R1 with the CCD 15 only while the document passes through the reading position L1, thereby allowing the image of the document to be detected. The reading operation is performed. The light source 16 may be lit only while the document passes through the reading position L1, or may remain lit until the image reading operation for all the documents is completed.

100, 200: Image forming device 1: Image reading device 2: Image forming unit 5: First image reading unit 9: Control unit 11: Reading unit 15: CCD
16: Light source 18: ADF
18A: Housing 19: Document setting unit 20: Document conveying unit 22: Sheet sensor 28: Second image reading unit 32: Light source 34: Line sensor 37: First passing document sensor 38: Second passing document sensor 40: ADF cover 61: Reading control unit 62: Cover position determination unit 63: Timing determination unit R1: Document transport path L1, L2: Reading position X1: Opening

Claims (3)

A first light source that emits light toward the first position of the document transport path and a first light source that detects light from the first light source reflected by the first surface of the document transported to the first position. A first image reading unit having one light receiving unit;
The second light source that emits light toward the second position of the document conveyance path and the second light source that is reflected by the second surface opposite to the first surface of the document conveyed to the second position. A second image reading unit having a second light receiving unit for detecting light from the light source;
A cover member that is displaceable between an open position that exposes the second image reading unit and a closed position that covers the second image reading unit;
The second image reading unit is controlled, the control mode of the second image reading unit is set to a first mode and a second mode in which the second light receiving unit outputs a light amount detection result with the second light source turned on. A read control unit capable of switching to a second mode in which the second light receiving unit outputs a light amount detection result in a state where the light source is turned off;
By determining whether or not the detected light amount of the second light receiving unit when the control mode of the second image reading unit is the second mode exceeds a predetermined light amount, the cover member is A cover position determination unit for determining whether or not the closed position;
A passing document sensor for detecting the presence or absence of a document at a predetermined position in the document transport path;
When a continuous reading process is performed in which a plurality of documents are continuously conveyed at intervals along the document conveyance path, a first timing during which the document passes the second position, and the document A timing determination unit that determines a second timing after the document passes through the second position and before the next document reaches the second position;
The image reading apparatus, wherein the reading control unit controls the second image reading unit in the first mode at the first timing, and controls the second image reading unit in the second mode at the second timing . A placement document sensor for detecting whether or not the document is placed on the document receiving portion on the entrance side of the document conveyance path;
The reading control unit, before the conveyance of the document is started when the placing document sensor is detecting the document, to claim 1 for controlling the second image reading unit in the second mode The image reading apparatus described. The image reading apparatus according to claim 1 or 2 ,
An image forming unit that forms an image read by the image reading device on a sheet member;
An image forming apparatus comprising:

Images