JP2010273028A - Image reader, and image formation device including the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately determine an opening/closing state of an opening/closing body without arranging a dedicated opening/closing detection sensor. <P>SOLUTION: The opening/closing state of the opening/closing body is determined based on a variation state in a main scanning direction of the quantity of light received by a CCD when emitting light of a lamp toward the opening/closing body. Based on the determination result of an opening/closing state determination section and the detection result of a document detection sensor of an ADF, selection of a first reading mode for reading a document by the ADF and a second reading mode for reading a document on a document table and determination of possibility of reading operation are carried out. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image reading apparatus in which an open / close body integrally provided with a platen cover and an ADF is supported so as to be openable / closable with respect to an apparatus main body, and an image forming apparatus including the image reading apparatus.

  Image forming apparatuses such as copiers, facsimile machines, and multi-function machines, and scanner apparatuses are equipped with a scanner on a paper feed stand to improve the convenience of placing a document on a document table and reading the document. A document feeder that automatically pulls in the documents loaded on the printer and causes the image reading sensor to read the document image while conveying the document inside, so-called ADF (Auto Document Feeder) can be opened and closed with the platen cover. Some are provided integrally with the supported opening / closing body.

  In an apparatus in which the ADF is provided on the opening / closing body as described above, when a document is read by the ADF with the opening / closing body in a half-open state, reading failure, document jamming, or damage to the apparatus occurs. For this reason, it is preferable to permit reading of a document by the ADF only when the open / close state of the open / close body is detected and it is confirmed that the open / close body is fully closed.

  Further, in the image forming apparatus and the scanner apparatus, when a thick original such as a book is placed on the reading glass of the original table and read, the platen cover that covers the original cannot be completely closed. If the reading is performed in such a state, a black frame region is formed around the image corresponding to the reading surface of the actual document, and not only the printed matter becomes unsightly but also the toner consumption increases. Some have a frame erasing function that removes the frame area around the document.

  In an apparatus having such a frame erasing function, when the document is read and the frame erasing process is performed with the opening / closing body in a half-open state, the reading sensor receives the reflected light of the opening / closing body and the same as in the document area. In addition, since a region with high brightness appears on the read image, there arises a problem that this region is mistakenly extracted as a part of the document. For this reason, it is preferable to allow the frame erasing process only when the open / close state of the open / close body is detected and it is confirmed that the open / close body is in the open state.

  However, in order to detect the open / closed state of the open / close body, it is common to provide a dedicated open / close detection sensor. However, in order to reduce costs, the open / close state of the open / close body is not used instead of the dedicated open / close detection sensor. It is desirable to have a technology to detect this. As such a technique, there is known a technique for determining an open / close state of an open / close body by comparing a signal value output from a reading sensor with a predetermined reference value when light is irradiated toward the open / close body ( Patent Document 1).

Japanese Patent No. 2591471

  However, in the conventional technique, the signal value output from the reading sensor is only averaged and compared with a predetermined reference value. Therefore, when the open / close body is in a half-open state or when the document is placed on the reading glass of the document table. There is a possibility that an erroneous determination may be made in a fully open state such as when the device is placed, and the open / closed state of the opening / closing body cannot be determined with high accuracy.

  The present invention has been devised to solve such problems of the prior art, and its main purpose is to accurately determine the open / close state of the open / close body without providing a dedicated open / close detection sensor. Another object of the present invention is to provide an image reading apparatus configured to be able to perform the above and an image forming apparatus including the image reading apparatus.

  An image reading apparatus of the present invention includes a document table on which a document is placed, a light source that irradiates light on the document on the document table, an imaging unit that receives reflected light from the document and converts it into an electrical signal, The document table is integrally provided with a platen cover that presses the document against the document table, a document feeding unit that transports the document so as to pass a document reading position by the imaging unit, and the document feeding unit and the platen cover. An opening / closing body supported to be openable / closable with respect to an apparatus main body provided with the light source and the imaging means, and receiving the light from the light source toward a reference position of the opening / closing body. And an open / close state determination means for determining the open / close state of the open / close body based on the fluctuation state of the light quantity in the main scanning direction.

  The image forming apparatus of the present invention is configured to include the image reading apparatus configured as described above.

  According to the present invention, in addition to the case where the opening / closing body is in the fully open state or the fully closed state, the opening / closing body is in the fully open state, such as when the opening / closing body is in the half open state or when the document is placed on the reading glass of the document table. Since the open / closed state of the opening / closing body can be determined in consideration of the state, the determination accuracy can be increased.

Schematic configuration diagram of a copying machine (image forming apparatus) to which the present invention is applied Schematic configuration diagram of the document reading section shown in FIG. 1 is a block diagram showing a schematic configuration of a control unit of the image forming apparatus shown in FIG. The figure which shows the change condition of the main scanning direction of the output voltage (light quantity) of CCD for every pattern obtained by the test reading which reads the white reference member for 1st reading modes shown in FIG. The perspective view which shows the state of the original reading part corresponding to each pattern shown in FIG. The figure which shows an example of the conditions of the pattern determination performed by the opening-and-closing state determination part shown in FIG. The figure which shows the outline | summary of the control performed by the main control part shown in FIG. The flowchart which shows the process sequence in the control part shown in FIG.

  According to a first aspect of the present invention, there is provided a document table on which a document is placed, a light source that irradiates light on the document on the document table, and an electrical signal that receives reflected light from the document. An image pickup means for converting the document into the document table, a platen cover for pressing the document on the document table, a document feed means for transporting the document so as to pass a document reading position by the image pickup means, and the document feed means and the platen cover. The opening / closing body supported to be openable / closable with respect to the apparatus main body provided with the document table, the light source, and the imaging means, and the light of the light source is irradiated toward the reference position of the opening / closing body. And an open / close state determination means for determining the open / close state of the open / close body based on the fluctuation state of the amount of light received by the image pickup means in the main scanning direction.

  According to this, in addition to the case where the open / close body is in the fully open state or the fully closed state, the fully open state such as when the open / close body is in the half open state or when the document is placed on the reading glass of the document table is not. Considering this, it is possible to determine the open / closed state of the opening / closing body, so that the determination accuracy can be improved.

  According to a second invention for solving the above-mentioned problems, in the first invention, the open / close state determining means has a fluctuation range in the main scanning direction of the amount of light received by the imaging means having a predetermined threshold value. If the representative value of the light quantity in the main scanning direction is less than a predetermined threshold value, the opening / closing body is determined to be in a substantially fully opened state.

  When the opening / closing body is in the fully open state, the light from the light source hardly reaches the opening / closing body, and the reflected light of the opening / closing body diffuses to the surroundings and is hardly received by the imaging means. Since it is small and uniform throughout the main scanning direction, it is possible to accurately determine the substantially fully open state of the opening / closing body by performing the determination under the above-described determination conditions.

  According to a third invention for solving the above-mentioned problems, in the first and second inventions, the open / close state determination means has a predetermined fluctuation range in the main scanning direction of the amount of light received by the imaging means. The opening / closing body is determined to be in the fully closed state when it is below the threshold value and the representative value of the light quantity in the main scanning direction exceeds a predetermined threshold value.

  When the opening / closing body is in the fully closed state, the reflected light of the opening / closing body is received by the imaging means without diffusing to the surroundings, so the amount of light received by the imaging means is large and uniform throughout the main scanning direction. Therefore, by performing the determination under the determination conditions as described above, the fully closed state of the opening / closing body can be determined with high accuracy.

  According to a fourth aspect of the present invention for solving the above-described problems, in the first to third aspects of the invention, the opening / closing body is supported by the apparatus main body via a pivotal support provided on one end side in the main scanning direction. The open / close state determination means has a fluctuation range in the main scanning direction of the amount of light received by the imaging means exceeding a predetermined threshold value, and a representative value of the light quantity in the main scanning direction exceeds the predetermined threshold value. When exceeding, it is set as the structure which determines with the said opening-and-closing body being in a half-open state.

  When the opening / closing body is in a half-open state, the distance of the opening / closing body with respect to the apparatus main body provided with the imaging means is gradually increased from one end side to the other end side where the pivot is provided. The amount of light received by the means has a characteristic of gradually decreasing from one end side to the other end side, and is large and non-uniform over the entire main scanning direction. Thus, the half-open state of the opening / closing body can be accurately determined.

  In addition, when the fluctuation range of the light amount in the main scanning direction exceeds a predetermined threshold value and the minimum value of the light amount in the main scanning direction is lower than the predetermined threshold value, the opening / closing body is substantially fully opened or half open. It may be determined that the original is placed so as to cover a part of the reading glass of the original table. Further, when the fluctuation range of the light amount in the main scanning direction is less than a predetermined threshold value and the minimum value of the light amount in the main scanning direction is between the two threshold values, the opening / closing body is in a substantially full open state or a half open state. It may be determined that the original is placed so as to cover the entire reading glass of the original table.

  Note that the fluctuation range of the light amount in the main scanning direction is preferably a difference between the maximum value and the minimum value of the light amount in the main scanning direction. The representative value of the light quantity in the main scanning direction may be the minimum value or the average value of the light quantity in the main scanning direction.

  According to a fifth aspect of the present invention for solving the above-described problems, in the first to fourth aspects of the present invention, document detection means for detecting the presence or absence of a document placed on a paper feed table of the document feed means, Based on the determination result of the open / close state determination means and the detection result of the original detection means, the selection of the first reading mode for reading the original by the original feeding means and the second reading mode for reading the original on the original table; And a control unit that determines whether or not the reading operation is possible.

  According to this, it is possible to select an appropriate reading mode, and it is possible to avoid starting a reading operation in a reading mode different from the intention of the operator. Further, by prohibiting the reading operation as necessary, various problems relating to reading can be prevented in advance.

  A sixth invention made to solve the above-mentioned problems is that, in the fifth invention, the control means determines that the open / close body is in a fully closed state by the open / close state determining means, and the document detection. Only when it is detected by the means that there is an original in the original feeding means, the reading is performed in the first reading mode.

  According to this, since the first reading mode in which the document is read by the document feeding means is permitted only when the opening / closing body is in the fully closed state, the first reading is performed when the opening / closing body is in the substantially fully opened state or the half open state. It is possible to prevent inadequate reading, document jamming, and damage to the apparatus that occur when the mode is executed.

  A seventh invention made to solve the above-mentioned problems is that, in the fifth and sixth inventions, a document is obtained from an image obtained by performing reading in the second reading mode with the opening / closing body in the open state. The image forming apparatus further includes a frame erasing processing unit that performs a frame erasing process for erasing the outer region, wherein the control unit determines that the opening / closing body is substantially fully open by the open / close state determination unit, and the document detection unit When it is detected that there is no document in the document feeding means, reading is performed in the second reading mode and the frame erasing processing means is subjected to frame erasing processing, while the opening / closing state determining means causes the opening / closing body to be opened. If it is determined that the document is not fully opened, and the document detection unit detects that there is no document on the document feeding unit, the document is read in the second reading mode and the frame deletion processing unit deletes the frame. A structure that does not perform the process.

  According to this, since the frame erasing process in the second reading mode for reading the document on the document table is permitted only when the opening / closing body is in the fully open state, the frame erasing process is performed when the opening / closing body is in the half-open state. As a result, it is possible to prevent a problem that the reflected light of the opening / closing body is erroneously recognized as the document area.

  An eighth invention made to solve the above-described problems further includes a warning means for warning an operator in the fifth to seventh inventions, and the control means is configured to open and close the open / close state by the open / close state determination means. A configuration in which when the body is determined not to be fully closed and the original detection unit detects that there is an original in the original feeding unit, the reading unit is prohibited and a warning is issued by the warning unit. And

  According to this, it is possible to avoid reading in a reading mode different from the intention of the operator.

  In this case, since the opening / closing member is not fully closed, it is determined that the operator intends to read the document on the document table in the second reading mode, and the document is in the document feeding means. In this reading mode, it is determined that the operator intends to read the document by the document feeding means, and the operator's intention is unknown. For this reason, it is necessary to make the operator clear in which reading mode the warning is issued and the reading is being performed. In view of this, it is preferable to output a warning message that prompts the user to remove the document from the document feeding means or to fully close the opening / closing member.

  Note that the warning means can be constituted by a voice output means in addition to a display means for displaying a warning message or the like.

  A ninth invention made to solve the above-mentioned problem is the first to eighth inventions, wherein a white reference member for shading correction data acquisition processing in the first reading mode is provided in the opening / closing body. Provided at the document reading position of the document feeding means, the control means causes the light source and the imaging means to perform a process of reading the white reference member for the first reading mode, and based on the amount of light received at this time, the control means The open / close state determination means is configured to determine the open / close state.

  According to this, when the state in which the white reference member for the first reading mode can be read is set to the initial state, the first reading mode is immediately used in response to the reading start operation such as the start button operation by the operator. Reading of the white reference member can be executed to determine the open / close state of the open / close body.

  In this case, the reading of the white reference member for the first reading mode may be performed in the same procedure as the shading correction data acquisition process in the first reading mode.

  According to a tenth aspect of the present invention, there is provided a white reference member for shading correction data acquisition processing in the second reading mode in the first to ninth aspects. Provided at a position adjacent to the document table, the control means reads the white reference member for the second reading mode when the opening / closing state determination means determines that the opening / closing body is substantially fully open. Processing is performed by the light source and the imaging unit, and it is determined whether or not the light source is abnormal based on the amount of light received at this time.

  According to this, since the white reference member for the second reading mode is provided on the apparatus main body side, the abnormality of the light source can be determined without being affected by the open / close state of the open / close body.

  In this case, the reading of the white reference member for the second reading mode may be performed in the same procedure as the shading correction data acquisition process in the second reading mode. Further, in the light source abnormality determination, an abnormality may be determined when a change corresponding to the lighting of the light source does not appear in the output signal of the imaging means.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of a copying machine (image forming apparatus) to which the present invention is applied. The copying machine includes a document reading unit 1 that reads a document image, and an electrophotographic method based on the image data obtained by reading, that is, charging, exposure, development, transfer, and fixing processes. And the image forming unit 2 to be formed on the recording paper, and the recording paper accommodated in the paper accommodating unit 3 is sequentially fed to the image forming unit 2, where the recording paper on which a required image is formed is discharged. It is discharged to part 4.

  The image forming unit 2 forms a plurality of process units 5 to 8 that form toner images of yellow, magenta, cyan, and black, and image formation of the photosensitive drums 5a to 8a in each of the process units 5 to 8. An LSU (laser scanning unit) 9 that scans the surface with a laser beam for exposure, and an intermediate transfer belt 10 to which toner images of respective colors formed on the photosensitive drums 5a to 8a are sequentially transferred, and The photosensitive drums 5a to 8a of the respective colors are arranged along the intermediate transfer belt 10 and have a tandem structure.

  In each of the process units 5 to 8, an electrostatic latent image is obtained by scanning exposure laser light from the LSU 9 on the image forming surfaces of the photosensitive drums 5a to 8a that are uniformly charged by a charger (not shown). The electrostatic latent images on the respective photoconductive drums 5a to 8a are developed with the respective color toners supplied from a developing device (not shown), and the respective color toner images are formed on the image forming surfaces of the respective photoconductive drums 5a to 5a. Formed. The developing devices in the process units 5 to 8 are supplied with toner of each color from the toner bottles 11 to 14.

  The respective color toner images formed on the photosensitive drums 5 a to 8 a in the process units 5 to 8 are sequentially transferred onto the intermediate transfer belt 10, and further between the intermediate transfer belt 10 and the transfer roller 15. It is transferred to the fed recording paper. Then, the recording paper on which the toner image of each color is transferred is conveyed to the fixing device 16, and a process for fixing the toner image on the recording paper to the recording paper by the action of heat and pressure is performed.

  FIG. 2 is a schematic configuration diagram of the document reading unit shown in FIG. The document reading unit 1 receives a document table 21 on which a document is placed, a lamp (light source) 22 that irradiates light on the document on the document table 21, and reflected light from the document and converts it into an electrical signal. A CCD (imaging means) 23, a platen cover 24 that presses the document against the document table 21, and an opening / closing body 26 that is integrally provided with the platen cover 24 and is supported to be openable / closable with respect to the apparatus main body 25. ing.

  The opening / closing body 26 is integrally provided with an ADF (original feeding means) 27 that conveys the original so as to pass through the original reading position by the CCD 23, and the first reading mode for reading the original by the ADF 27 and the original A second reading mode for reading a document on the table 21 can be selected. The ADF 27 is provided with a document detection sensor (document detection means) 29 that detects the presence or absence of a document placed on the paper feed table 28.

  In the apparatus main body 25, in addition to the lamp 22 and the CCD 23, an imaging lens 31 that forms an image of light on the CCD 23 and mirrors 32 to 34 that guide reflected light from the document to the imaging lens 31 are provided. . The CCD 23 is arranged in the main scanning direction for each color of RGB to form a line sensor. The reading carriage 35 on which the lamp 22 and the mirror 32 are mounted and the reading carriage 36 on which the mirrors 33 and 34 are mounted are arranged in the sub-scanning direction. By moving to, scanning in the sub-scanning direction is performed.

  The ADF 27 is provided with a document conveyance path, and scanning in the sub-scanning direction is performed by conveying the document along the conveyance path. That is, the original on the paper feed tray 28 is conveyed to the original reading position on the reading glass 38, and after the image of the original is read here, the original is discharged onto the paper discharge tray 39. The original is reversed when the second side is read, and the original after the second side is read is reversed and discharged onto the paper discharge tray 39.

  Further, the opening / closing body 26 is provided with a first white reference member 40 for shading correction data acquisition processing in the first reading mode facing the reading glass 38 at the document reading position of the ADF 27. On the other hand, the apparatus main body 25 is provided with a second white reference member 42 for shading correction data acquisition processing in the second reading mode on the lower surface of the document regulating plate 41 adjacent to the document table 21.

  As shown in FIG. 2A, the reading carriages 35 and 36 have a state where the white reference member 40 for the first reading mode can be read as an initial state, and in the first reading mode in which a document is read by the ADF 27, After the shading correction data acquisition process is performed with the reading carriages 35 and 36 being stationary in this initial state, the original image is read by passing the original between the white reference member 40 and the reading glass 38. .

  On the other hand, in the second reading mode for reading the document on the document table 21, as shown in FIG. 2B, the reading carriages 35 and 36 can be moved to read the white reference member 42 for the second reading mode. In this state, after the shading correction data acquisition process is performed, the original image is read while gradually moving the reading carriages 35 and 36 in the sub-scanning direction.

  FIG. 3 is a block diagram illustrating a schematic configuration of a control unit of the image forming apparatus illustrated in FIG. 1. The control unit includes a shading correction unit 51, a read image processing unit 52, an image memory 53, and a recorded image processing unit 54.

  The shading correction unit 51 corrects variations between pixels based on correction data obtained by the shading correction data acquisition process. The read image processing unit 52 performs, for example, edge enhancement processing and smoothing processing and gradation conversion processing as necessary. The image memory 53 stores image data. The recorded image processing unit 54 performs necessary processing so that image formation by the image forming unit 2 is appropriately performed.

  Further, the control unit performs frame erasing processing for erasing the area outside the original from the image obtained by performing reading in the second reading mode for reading the original on the original table 21 with the opening / closing body 26 opened. A processing unit (frame erasure processing means) 55 is provided.

  The frame deletion processing unit 55 includes a document area detection unit 56, a document area memory 57, a document area correction unit 58, and a signal generation unit 59. The document area detecting unit 56 detects a candidate point estimated as the document end point located at the end of the document area when the density difference (density change amount) with a pixel in the vicinity of the target pixel is higher than a predetermined threshold. It is. The document area memory 57 stores position information of candidate points detected on the line. The document area correction unit 58 determines the document end point based on the position information of the candidate points. The signal generator 59 generates an effective width signal that defines the document area on the read image.

  The control panel 61 includes an operation unit 62 for instructing various operations and a display unit 63 for displaying various setting contents and device states. Particularly here, a warning message is displayed on the display unit (warning means) 63 in order to give the operator a required warning. Note that the warning for the operator may be given by the voice output means in addition to the display means.

  In particular, here, an open / close state determination unit (open / close state determination means) 65 for determining the open / close state of the open / close body 26 based on the fluctuation state of the light amount in the main scanning direction acquired by the CCD 23 by the test reading is provided. The unit 66 causes the lamp 22 and the CCD 23 to perform processing for reading the white reference member 40 for the first reading mode, and causes the open / close state determination unit 65 to determine the open / close state based on the amount of light acquired at this time. The reading of the white reference member for the first reading mode may be performed in the same procedure as the shading correction data acquisition process in the first reading mode.

  The test reading for reading the white reference member 40 for the first reading mode can be performed in the initial state as shown in FIG. For this reason, it is possible to determine the open / closed state of the opening / closing body by immediately performing a test reading in response to a reading start operation such as a start button operation by the operator.

  FIG. 4 is a diagram showing a change state in the main scanning direction of the output voltage (light quantity) of the CCD for each pattern obtained by the test reading for reading the white reference member for the first reading mode shown in FIG. FIG. 5 is a perspective view showing a state of the document reading unit corresponding to each pattern shown in FIG. FIG. 6 is a diagram illustrating an example of conditions for pattern determination performed by the open / close state determination unit illustrated in FIG. 3.

  The first pattern shown in FIG. 4A shows a characteristic in which the output voltage (light quantity) of the CCD 23 gradually changes from one end side to the other end side in the main scanning direction. This first pattern appears when the opening / closing body 26 is in a half-open state (for example, an opening degree of 10 °) as shown in FIG. The opening / closing body 26 is supported by the apparatus main body 25 via a pivotal support portion 44 provided on one end side (back side) in the main scanning direction. When the opening / closing body 26 is in a half-open state, the opening / closing body for the reading glass 38 is provided. The separation distance of 26 gradually increases from one end side (back side) to the other end side (front side). For this reason, the amount of light that the CCD 23 receives the reflected light of the opening / closing body 26 gradually decreases from one end side (the back side) toward the other end side (the near side).

  When the opening / closing body 26 is in the half-open state as described above, the light amount varies greatly and non-uniformly in the main scanning direction. Therefore, in the open / close state determination unit 65, the fluctuation range of the light amount in the main scanning direction is predetermined. When the representative value of the light amount in the main scanning direction exceeds a predetermined threshold value, the opening / closing body 26 is determined to be the first pattern in the half-open state. In the example of FIG. 6, if the difference ΔV between the maximum value Vmax and the minimum value Vmin of the output voltage of the CCD 23 is 1.5 V or more and the minimum value Vmin is 2 V or more, the first pattern is determined. Thereby, the half-open state of the opening / closing body 26 can be determined with high accuracy.

  In the second pattern shown in FIG. 4B, the output voltage (light quantity) of the CCD 23 shows a characteristic that varies greatly depending on the position in the main scanning direction. In the second pattern, as shown in FIG. 5B, the opening / closing body 26 is substantially fully opened or half-opened, and the document D is placed so as to cover a part of the document table 21. Appears when In this state, the reading glass 38 adjacent to the document table 21 is partially covered with the document D, and the amount of light received by the CCD 23 differs greatly between the portion covered with the document D and the portion not covered.

  As described above, when the opening / closing body 26 is in a substantially full open state or a half open state and the original is placed so as to cover a part of the original table 21, the amount of light varies greatly depending on the position in the main scanning direction. In order to show the characteristics, the open / close state determination unit 65 determines whether the fluctuation amount of the light amount in the main scanning direction exceeds a predetermined threshold value and the minimum value of the light amount in the main scanning direction is lower than the predetermined threshold value. 2 pattern is determined. In the example of FIG. 6, if the difference ΔV between the maximum value Vmax and the minimum value Vmin of the output voltage of the CCD 23 is 1.5V or more and the minimum value Vmin is less than 2V, the second pattern is determined.

  The third pattern shown in FIG. 4C shows a characteristic that the output voltage (light quantity) of the CCD 23 is uniform and slightly smaller over the entire main scanning direction. In the third pattern, as shown in FIG. 5C, the opening / closing body 26 is in a substantially fully open state or a half open state, and the document D is placed so as to cover the entire document table 21. Appears when In this state, although the document D covers the reading glass 38 as a whole, the opening / closing body 26 is open, so that the document D is not in close contact with the document table 21 and slightly floats, and the document D is reflected. Since light leaks, the amount of light received by the CCD 23 is slightly reduced.

  Thus, when the opening / closing body 26 is in a substantially fully open state or a half open state and the document is placed so as to cover the entire document table 21, the amount of light is uniform over the entire main scanning direction. Since the level is intermediate, the open / close state determination unit 65 determines that the fluctuation range of the light amount in the main scanning direction is below a predetermined threshold value and the minimum value of the light amount in the main scanning direction is between the two threshold values. The third pattern is determined. In the example of FIG. 6, if the difference ΔV between the maximum value Vmax and the minimum value Vmin of the output voltage of the CCD 23 is less than 1.5V and the minimum value Vmin is 1V or more and less than 4V, it is determined as the third pattern.

  In the fourth pattern shown in FIG. 4D, the output voltage (light quantity) of the CCD 23 is 0 throughout the main scanning direction. As shown in FIG. 5D, the fourth pattern appears when the opening / closing body 26 is in a substantially fully opened state (for example, an opening degree of 45 ° or more). In this state, the opening / closing body 26 and the reading glass 38 are largely separated, so that the light from the lamp 22 hardly reaches the opening / closing body 26, and the reflected light of the opening / closing body 26 is diffused to the surroundings and received almost by the CCD 23. Can not.

  In this way, when the opening / closing body 26 is in the substantially fully opened state, the light amount is small and uniform throughout the main scanning direction. Therefore, in the open / close state determination unit 65, the fluctuation range of the light amount in the main scanning direction is predetermined. When the representative value of the light quantity in the main scanning direction is below a predetermined threshold value, the opening / closing body 26 is determined to be the fourth pattern in the substantially fully opened state. In the example of FIG. 6, if the difference ΔV between the maximum value Vmax and the minimum value Vmin of the output voltage of the CCD 23 is less than 1.5V and the minimum value Vmin is less than 1V, the fourth pattern is determined. Thereby, the substantially fully open state of the opening / closing body 26 can be accurately determined.

  In the fifth pattern shown in FIG. 4E, the output voltage (light quantity) of the CCD 23 is uniform and large over the entire main scanning direction. The fifth pattern appears when the opening / closing body 26 is fully closed as shown in FIG. In this state, the opening / closing body 26 and the reading glass 38 are close to each other, and the reflected light of the opening / closing body 26 is received by the CCD 23 without diffusing to the surroundings.

  In this way, when the opening / closing body 26 is in the fully closed state, the light amount is large and uniform throughout the main scanning direction. Therefore, the open / close state determination unit 65 has a predetermined fluctuation amount of the light amount in the main scanning direction. When the representative value of the light quantity in the main scanning direction is below the threshold value and exceeds a predetermined threshold value, it is determined that the opening / closing body 26 is the fifth pattern in the fully closed state. In the example of FIG. 6, if the difference ΔV between the maximum value Vmax and the minimum value Vmin of the output voltage of the CCD 23 is less than 1.5V and the minimum value Vmin is 4V or more, it is determined as the fifth pattern. Thereby, the fully closed state of the opening / closing body 26 can be determined with high accuracy.

  Note that the output voltage of the CCD 23 is divided into blocks for each unit pixel number (for example, 500 pixels) in order to avoid the influence of dust, and an average value thereof is calculated and used for determination.

  By the way, the fourth pattern that appears when the opening / closing body 26 is in a substantially fully opened state is the same when the lamp 22 is abnormally lit. For this reason, when it is confirmed that the lamp 22 is normally lit in the fourth pattern, it can be determined that the opening / closing body 26 is in a substantially fully opened state.

  Therefore, the main control unit 66 reads the white reference member 42 for the second reading mode as shown in FIG. 2B when the open / close state determination unit 65 determines the fourth pattern. Is performed by the lamp 22 and the CCD 23, and it is determined whether or not the lamp 22 is abnormal based on the amount of light acquired at this time. In this case, since the white reference member 42 for the second reading mode is provided on the apparatus main body 25 side, the abnormality of the lamp 22 can be determined without being affected by the open / close state of the open / close body 26. it can.

  In this case, the reading of the white reference member 42 for the second reading mode may be performed in the same procedure as the shading correction data acquisition process in the second reading mode. Further, in determining whether the lamp 22 is abnormal, it may be determined that the output voltage of the CCD 23 is abnormal when no change corresponding to the lighting of the lamp 22 appears.

  FIG. 7 is a diagram showing an outline of the control performed by the main control unit shown in FIG. In the main control unit (control means) 66, the determination result in the pattern determination based on the output voltage (light quantity) of the CCD 23 performed by the open / close state determination unit 65 and the detection by the document detection sensor 29 for detecting the presence or absence of the document in the ADF 27. Based on the result, the selection of the reading mode and the determination of whether or not the reading operation is possible are performed.

  Here, only when the open / close state determination unit 65 determines that the open / close body 26 is in the fully closed state, that is, the fifth pattern and the original detection sensor 29 detects that there is an original in the ADF 27, the original document is detected by the ADF 27. Is read in the first reading mode. Thus, by permitting the first reading mode only when the opening / closing body 26 is in the fully closed state, the first reading mode is executed when the opening / closing body 26 is in a substantially fully open state or a half open state. Can be prevented in advance from being poorly read and jammed or damaged.

  Further, when the open / close state determination unit 65 determines that the open / close body 26 is substantially fully open, that is, the fourth pattern, and the original detection sensor 29 detects that there is no original in the ADF 27, the second reading mode is set. And the frame erasure processing unit 55 performs the frame erasure processing. On the other hand, the open / close state determination unit 65 does not open the opening / closing body 26, that is, the first to third patterns or the fifth pattern. If the document detection sensor 29 detects that there is no document in the ADF 27, the document is read in the second reading mode and the frame erasure processing by the frame erasure processing unit 55 is not performed. .

  According to this, only when the opening / closing body 26 is in the substantially fully opened state, the frame erasing process in the second reading mode for reading the document on the document table 21 is permitted, so that the opening / closing body 26 is in the half-opened state. By performing the frame erasing process, it is possible to prevent a problem that the reflected light of the opening / closing body 26 is erroneously recognized as the document area.

  When there is no document on the ADF 27 in the fifth pattern, normal reading is performed by reading the document on the document table 21 with the opening / closing body 26 fully closed, and therefore no frame erasing process is required. If there is no document on the ADF 27 in the first to third patterns, it is determined that the operator is trying to read the document on the document table 21, and the second reading mode for reading the document on the document table 21 is performed. In this case, the frame erasing process should not be performed.

  Further, when the opening / closing state determination unit 65 determines that the opening / closing body 26 is not fully closed, that is, the first to third patterns or the fourth pattern, and the document detection sensor 29 detects that there is a document in the ADF 27. First, the reading operation is prohibited, and the operator is warned by the display unit (warning means) 63 of the control panel 61. Thereby, it is possible to avoid reading in a reading mode different from the intention of the operator.

  In this case, since the opening / closing body 26 is not fully closed, it is determined that the operator intends to read the document on the document table 21 in the second reading mode, and the ADF 27 has the document. In this reading mode, it is determined that the operator intends to read the document by the ADF 27, and the operator's intention is unknown. For this reason, it is necessary to make the operator clear in which reading mode the warning is issued and the reading is being performed. Therefore, it is preferable to output a warning message that prompts the user to remove the document of the ADF 27 or to make the opening / closing body 26 fully closed.

  FIG. 8 is a flowchart showing a processing procedure in the control unit shown in FIG. Here, when the operator operates the start button on the control panel 61 (ST101), the lamp 22 is turned on and the first white reference member 40 provided on the opening / closing body 26 is read (ST102). Based on the output voltage (light quantity) of the CCD 23 at this time, it is determined which of the first to fifth patterns is applicable (ST103).

  In this pattern determination (ST103), the first pattern, that is, the opening / closing body 26 is in a half-open state as shown in FIG. 5A, or the second pattern, that is, as shown in FIG. Is placed so as to partially cover the reading glass 38, or the third pattern, that is, as shown in FIG. 5C, the document is placed so as to cover the reading glass 38 as a whole. If it is determined that there is an original on the ADF 27 based on the signal from the original detection sensor 29 (ST104), and if there is no original on the ADF 27 (No in ST104), the second is determined. The reading mode is entered, and the document on the document table 21 is read. At this time, the frame erasing process is not performed.

  On the other hand, when there is a document on the ADF 27 (Yes in ST104), a warning message prompting the operator to remove the document on the ADF 27 or to fully close the opening / closing body 26 (for example, “Remove the document, Close the ADF firmly and press the start button. ”) Is displayed on the display section 63 of the control panel 61, and the operation of the start button is awaited.

  In the pattern determination (ST103), as shown in the fourth pattern, that is, as shown in FIG. 5D, when it is determined that the opening / closing body 26 is substantially fully open or the lamp 22 is abnormally lit. Next, reading of the second white reference member 42 provided on the apparatus main body 25 side is performed (ST106), and whether or not the lamp 22 is normally lit based on the output voltage (light quantity) of the CCD 23 at this time. (ST107). If the lamp 22 is not lit, it is determined that the lamp 22 has failed, the lamp shifts to the lamp failure mode, the apparatus is stopped, and a warning notifying the lamp failure is displayed. .

  On the other hand, when it is determined that the lamp 22 is lit (Yes in ST107), it is next determined whether or not there is a document on the ADF 27 based on the signal from the document detection sensor 29 (ST108), and the document is stored on the ADF 27. If not (No in ST108), the second reading mode is set, and the original on the original table 21 is read. At this time, a frame erasing process is performed.

  On the other hand, if there is a document on the ADF 27 (Yes in ST108), a warning message (for example, "" that prompts the operator to remove the document on the ADF 27 or to fully close the opening / closing body 26, as described above. Remove the original or close the ADF firmly and press the start button. ”) Is displayed on the display section 63 of the control panel 61, and the start button is ready for operation.

  If it is determined in the pattern determination (ST103) that the fifth pattern, that is, the opening / closing body 26 is fully closed as shown in FIG. Based on this, it is determined whether or not there is a document on the ADF 27 (ST110). If there is no document on the ADF 27 (No in ST110), the second reading mode is set and the document on the document table 21 is read. At this time, the frame erasing process is not performed.

  On the other hand, when there is a document in ADF 27 (Yes in ST110), the first reading mode is set, and the document is read by ADF 27.

  In the second to fourth patterns, there is a high probability that the operator is trying to read the original on the original table 21, and when the original on the original table 21 is read in the second reading mode, the original on the ADF 27 is read. Does not interfere with reading. Therefore, in the second to fourth patterns, the document on the document table 21 may be read as the second reading mode without determining whether there is a document in the ADF 27.

  On the other hand, in the first pattern, the operator intends to read the document with the ADF 27, but the opening / closing body 26 is not fully closed and is in a half-open state, or the document on the document table 21 is intended to be read. Since it is unclear whether the opening / closing body 26 has been opened, as described above, a warning message that prompts the operator to remove the document of the ADF 27 or to fully close the opening / closing body 26 may be displayed.

  Further, the content of the warning message may be changed for each pattern, for example, a word explaining each situation may be displayed. As a result, the operator can be alerted.

  As described above, in order to determine the open / close state of the open / close body 26 based on the fluctuation state in the main scanning direction of the light amount acquired by the CCD 23 by the test reading, the open / close body 26 is in the half open state in addition to the fully open state and the fully closed state Therefore, the open / close state of the opening / closing body 26 can be determined in consideration of a special state such as the case where the document is placed on the document table 21, and the determination accuracy can be improved.

  Further, according to the determination result of the open / close state determination unit 65 and the detection result of the document detection sensor 29, the selection of the first reading mode for reading the document by the ADF 27 and the second reading mode for reading the document on the document table 21 and In order to determine whether or not the reading operation is possible, an appropriate reading mode can be selected, and the reading operation can be prevented from being started in a reading mode different from the intention of the operator. Further, by prohibiting the reading operation as necessary, various problems relating to reading can be prevented in advance.

  The image reading apparatus according to the present invention and the image forming apparatus including the image reading apparatus have an effect of accurately determining the open / closed state of the open / close body without providing a dedicated open / close detection sensor. The opening / closing body provided integrally is useful as an image reading apparatus pivotally supported so as to be openable / closable with respect to the apparatus main body, and an image forming apparatus including the image reading apparatus.

1 Document Reading Unit 21 Document Table 22 Lamp (Light Source)
23 CCD (imaging means)
24 Platen cover 25 Main body 26 Opening / closing body 27 ADF (document feeding means)
28 Paper feed table 29 Document detection sensor (document detection means)
38 Reading Glass 39 Paper Discharge Stand 40 White Reference Member 41 Document Restriction Plate 42 White Reference Member 44 Pivot 55 Frame Erasing Processing Unit (Frame Erasing Processing Means)
63 Display (Warning means)
65 Opening / closing state determination unit (opening / closing state determination means)
66 Main control unit (control means)

Claims (11)

A document table on which a document is placed;
A light source for irradiating light on the document on the document table;
Imaging means for receiving reflected light from a document and converting it into an electrical signal;
A platen cover for pressing the document against the document table;
A document feeding means for transporting a document so as to pass a document reading position by the imaging means;
An opening / closing body integrally provided with the document feeding means and the platen cover, and supported to be openable / closable with respect to an apparatus main body provided with the document table, the light source, and the imaging means;
An open / close state determining means for determining an open / close state of the open / close body based on a fluctuation state in a main scanning direction of a light amount received by the imaging means when the light of the light source is irradiated toward a reference position of the open / close body; An image reading apparatus comprising:   The open / close state determination unit is configured such that the fluctuation range in the main scanning direction of the light amount received by the imaging unit is less than a predetermined threshold value, and the representative value of the light amount in the main scanning direction is lower than the predetermined threshold value. The image reading apparatus according to claim 1, wherein the open / close body is determined to be in a substantially fully open state.   The open / close state determining means has a fluctuation range in the main scanning direction of the amount of light received by the imaging means being lower than a predetermined threshold value, and a representative value of the light quantity in the main scanning direction is higher than a predetermined threshold value. The image reading apparatus according to claim 1, wherein the open / close body is determined to be in a fully closed state. The opening / closing body is supported by the apparatus main body via a pivotal support provided on one end side in the main scanning direction,
The open / close state determining means has a fluctuation range in the main scanning direction of the amount of light received by the imaging means exceeds a predetermined threshold value, and the representative value of the light quantity in the main scanning direction exceeds a predetermined threshold value, The image reading apparatus according to claim 1, wherein the open / close body is determined to be in a half-open state. Document detection means for detecting the presence or absence of a document placed on a paper feed tray of the document feeding means;
Selection of a first reading mode for reading a document by the document feeding unit and a second reading mode for reading a document on the document table based on the determination result of the open / close state determination unit and the detection result of the document detection unit The image reading apparatus according to claim 1, further comprising a control unit that determines whether or not the reading operation is possible.   The control means performs the first reading only when the open / close state determination means determines that the open / close body is fully closed and the original detection means detects that there is an original in the original feed means. The image reading apparatus according to claim 5, wherein reading is performed in a mode. A frame erasing processing means for performing a frame erasing process for erasing an area outside the document from an image obtained by performing reading in the second reading mode as an open state of the opening and closing body;
The control means determines the second reading mode when the open / close state determining means determines that the open / close body is substantially fully open and the original detecting means detects that there is no original in the original feeding means. And the frame erasure processing means performs the frame erasure processing. On the other hand, it is determined by the open / close state determination means that the opening / closing body is not substantially fully open, and the document detection means is the document feeding means. 7. The apparatus according to claim 5 or 6, wherein when it is detected that there is no original, the reading is performed in the second reading mode and the frame erasing process by the frame erasing processing unit is not performed. Image reading apparatus. A warning means for warning the operator;
The control means prohibits the reading operation when the open / close state determination means determines that the open / close body is not fully closed and the original detection means detects that there is an original in the original feed means. The image reading apparatus according to claim 5, wherein the warning unit performs a required warning. A white reference member for shading correction data acquisition processing in the first reading mode is provided at a document reading position of the document feeding means in the opening / closing body,
The control unit causes the light source and the imaging unit to perform a process of reading the white reference member for the first reading mode, and the open / close state determination unit determines the open / close state based on the amount of light received at this time. The image reading apparatus according to claim 1, wherein the image reading apparatus is configured as described above. A white reference member for shading correction data acquisition processing in the second reading mode is provided at a position adjacent to the document table in the apparatus main body,
The control means performs a process of reading the white reference member for the second reading mode to the light source and the imaging means when the open / close state determining means determines that the open / close body is substantially fully open. 10. The image reading apparatus according to claim 1, wherein whether or not the light source is abnormal is determined based on the amount of light received at this time.   An image forming apparatus comprising the image reading apparatus according to claim 1.

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