JP2007079076A - Image forming apparatus and image reader applicable in the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image reader for an image forming apparatus, the image reader being deigned so as to be less likely to cause operation failure and easy to handle, by making it possible to determine a home position even if an area near home position detection patterns is soiled or part of the imaging means of a scan unit is in an abnormal state. <P>SOLUTION: The two home position detection patterns 8a and 8b are formed on the internal surface of a housing 100 and in different positions in the main scanning direction. On determination of the home position, while the scan unit 3 is moved in a sub-scanning direction and an imaging device 5 is operated for imaging on a pattern sheet 8, the home position detection pattern 8a is detected in a prescribed range S1 and thus the home position for the scan unit 3 is determined. If the home position detection pattern 8a is not detected, the home position detection pattern 8b is detected in a prescribed range S2 and thereby the home position is determined. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus having an image reading function and an image reading apparatus applicable thereto.

  Conventionally, an image forming apparatus having a function of reading an original as image data using an image reading apparatus has been put into practical use. As an image reading apparatus used in such an image forming apparatus, a document placed on a document table is moved by moving a scan unit having an imaging unit that images a predetermined range in the main scanning direction in the sub-scanning direction. Some are read as image data (see, for example, Patent Document 1).

  FIG. 4 shows an example of an image reading apparatus used in the conventional image forming apparatus as described above. Arrows A and B in the figure indicate the main scanning direction and the sub-scanning direction, respectively. In this image reading device 81, a scan unit 83 is disposed so as to face the document table 82 mounted on the housing 800. The scan unit 83 is a so-called CIS (Contact Image Sensor), an illuminating unit 84 that illuminates a predetermined range of a document (not shown) placed on the document table 82 in the main scanning direction, and an illuminating unit 84 for the document. The image pickup means 85 for picking up an image of the part illuminated by the. In the image reading device 81, a control unit (not shown) moves the scan unit 83 in the sub-scanning direction by a driving mechanism (not shown) while causing the imaging unit 85 to capture a predetermined range in the main scanning direction of the document. Are read as image data.

  By the way, in general, in the image reading apparatus 81 as described above, the control unit relatively recognizes the position of the scan unit 83 in the sub-scanning direction with respect to the housing 800 with reference to a home position that is a predetermined reading reference position. . The home position is determined by the scan unit 83 detecting the home position detection pattern 88a formed on the inner surface of the housing 800 before the image reading operation is performed, for example, every time the image forming apparatus is activated. As shown in the figure, this home position detection pattern 88a is black, for example, at one location on the white pattern sheet 88 arranged along the main scanning direction in the vicinity of one end of the document table 82 in the sub scanning direction. Is formed. When detecting the home position, the control unit causes the imaging unit 85 to image the pattern sheet 88 while detecting the home position detection pattern 88a set in advance in the imaged range. In the range S, the home position detection pattern 88a is detected. When the home position detection pattern 88a is detected, the home position is determined based on the position of the scan unit 83 at that time.

  However, when the scan unit 83 detects the home position detection pattern 88a as described above, the vicinity of the home position detection pattern 88a of the pattern sheet 88 is dirty due to dust, rubbing, or the like. If an abnormality occurs in the output of the part corresponding to the range S of the imaging means 85, the home position detection pattern 88a may not be detected. If the home position detection pattern 88a cannot be detected, the home position cannot be determined as described above, and the image cannot be read. Since the pattern sheet 88 is inside the housing 800 and is difficult to clean or replace, once the pattern sheet 88 becomes dirty or an abnormality occurs in the scan unit 83 as described above, the image reading apparatus Then, the image cannot be read.

Patent Document 1 describes a scanner in which an error detection pattern different from the home position detection pattern 88a is provided on a pattern sheet 88. When the scanner moves the scan unit 83 toward the home position when the power is turned on or the like, even if the home position detection pattern 88a is not detected, the scanner detects the error detection pattern, stops the scan unit 83, and then returns to the home position. Control is performed to detect the position detection pattern 88a. Further, in Patent Document 2, in a dot impact printer, a detected portion of an optical sensor is divided into a plurality of parts in the carriage movement direction, and a combination of detection of each divided detected portion by the optical sensor is used to determine the home of the recording head. It describes what can detect the position accurately. However, neither Patent Document 1 nor Patent Document 2 discloses an effective solution to the above-described problem.
Noto 3093723 publication JP 2002-301845 A

  The present invention has been made to solve the above problems, and determines the home position even if the vicinity of the home position detection pattern is dirty or an abnormality occurs in a part of the imaging means of the scan unit. It is an object of the present invention to provide an image forming apparatus which can be operated easily and is less likely to cause malfunction and easy to handle, and an image reading apparatus applicable thereto.

  In order to achieve the above object, the invention of claim 1 includes a casing having a rectangular opening formed on an upper surface thereof, a flat platen that is formed of a light-transmitting material and is attached to the opening of the casing, and A scan unit that moves in a first direction while facing the inner surface of the document table inside the housing, and a scan unit that is provided on the scan unit and that is orthogonal to the first direction and the first direction. Illuminating means for illuminating a predetermined range in two directions, imaging means provided on the scan unit and capturing an image of a predetermined range illuminated by the illuminating means, and the imaging means on the inner surface of the casing The home position detection pattern provided so as to be able to image, the drive mechanism for moving the scan unit in the first direction, the control means for controlling the illumination means and the drive mechanism, and the image pickup by the image pickup means Image forming means for forming an image on recording paper based on image data that has been input or image data that has been input from the outside, and the control means causes the imaging means to image the inner surface of the housing. On the other hand, the home position in the first direction of the scan unit is determined by detecting the home position detection pattern in a predetermined range in the second direction in the range to be imaged, and based on the determined home position In the image forming apparatus that controls the image pickup unit to read a document placed on the document table as image data, the home position detection pattern is at a position shifted from each other in the first direction and the second direction. The control means determines one home position by detecting one of the two home position detection patterns. When one home position detection pattern is not detected, the other home position in a predetermined range in the second direction in the vicinity of the other home position detection pattern in the range imaged by the imaging means. The home position is determined by detecting the detection pattern.

  The invention of claim 2 includes a housing having a rectangular opening formed on the upper surface, a flat platen that is formed of a light-transmitting material and is attached to the opening of the housing, and the inside of the housing. A scan unit that moves in a first direction while facing the inner surface of the document table, and a predetermined unit that is provided on the scan unit and that is in a second direction orthogonal to the first direction and the first direction. Illumination means for illuminating a range, imaging means provided on the scan unit for capturing an image of a predetermined range illuminated by the illumination means, and an inner surface of the housing are shifted from each other in the second direction. A plurality of home position detection patterns provided so as to be capable of being imaged by the imaging means, a drive mechanism for moving the scan unit in a first direction, and a control means for controlling the illumination means and the drive mechanism. Preparation The control means determines the home position in the first direction of the scan unit by selecting any one of the home position detection patterns, causing the imaging means to pick up an image, and detecting the home position. Based on the above, the image pickup means controls to read the document placed on the document table as image data.

  According to a third aspect of the present invention, there is provided an image on a recording sheet based on the image reading device according to the second aspect and image data picked up by an image pickup unit of the image reading device or image data input from the outside. And image forming means for forming the image.

  According to the first aspect of the present invention, two home position detection patterns are arranged, and when one home position detection pattern is not detected, the control means detects the other home position detection pattern to detect the home position detection pattern. Since the position is determined, the home position can be determined even if the vicinity of one home position detection pattern is dirty or an abnormality occurs in the part corresponding to the home position detection pattern of the imaging unit of the scan unit. it can. Therefore, it is possible to make it difficult for image reading operation failures to occur, and to make the image forming apparatus easier to handle. Further, since the home position detection patterns are arranged at positions shifted from each other also in the first direction, even when one of the home position detection patterns cannot be detected, the image of the other home is detected as it is. A position detection pattern can be detected. Therefore, even when one home position detection pattern cannot be detected, the home position can be determined by moving the scan unit once in the first direction, and the image forming apparatus becomes easier to handle.

  According to the invention of claim 2, a plurality of home position detection patterns are provided, and the control means selects and detects any one of these home position detection patterns to determine the home position. Therefore, even if the home position detection pattern cannot be detected because the vicinity of the home position detection pattern becomes dirty or an abnormality occurs in the part corresponding to the position of the home position detection pattern of the imaging means, The home position can be determined by detecting the position detection pattern. Accordingly, it is possible to make it difficult for image reading operation failures to occur, and to make the image reading device easier to handle.

  According to the third aspect of the present invention, the image forming apparatus includes the image reading apparatus in which the image reading operation is less likely to occur. Therefore, the image reading apparatus can be prevented from being used. It will be easier to handle.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an image forming apparatus according to an embodiment of the present invention. In the image forming apparatus 1, an image is read as image data by moving the scan unit 3 in the sub-scanning direction (second direction) as shown by an arrow B in the figure, as will be described later, on the top of the housing 100. A reading unit (image reading device) 11 is provided. In addition, an image forming unit (image forming unit) 21 that forms an image on the recording paper P based on image data read by the image reading unit 11 or image data input from the outside in the lower part of the housing 100. And a recording paper transport unit 22 that transports the recording paper P to the image forming unit 21. In other words, the image forming apparatus 1 is a so-called printer multifunction machine having an image reading function performed by the image reading unit 11 and an image forming function performed by the image forming unit 21 and the recording paper transport unit 22. The image reading function and the image forming function are provided in the housing 100 and are controlled by a control unit (control unit) 9 including, for example, an ASIC or a memory. A lid 110 for bringing a document (not shown) placed on the document table 2 as will be described later into close contact with the document table 2 is rotatably provided by a hinge on the upper part of the image reading unit 11 of the housing 100. ing. A paper feed tray 120 on which recording paper P is loaded is provided above the rear portion of the housing 100. The recording paper P is transported from the paper feed tray 120 to the inside of the housing 100 by the recording paper transporting portion 22, and after an image is formed by the image forming portion 21, the paper discharge tray 130 provided on the front surface of the housing 100. Paper is discharged to the top. Note that the positions of the paper feed tray 120 and the paper discharge tray 130, the transport operation of the recording paper P, and the like are not limited thereto. Further, the image forming unit 21 forms an image by dropping ink on a recording sheet by, for example, an ink jet method, or forms an image by an electrophotographic method such as a laser beam printer. However, it is not limited to a specific method.

  2 and 3 show the image reading unit 11. Arrows A and B in the figure indicate the main scanning direction (second direction) and the sub-scanning direction (first direction), respectively. As shown in the figure, a rectangular opening is formed on the upper surface of the housing 100, and a flat platen 2 made of a light-transmitting material such as glass is mounted on the opening. A scan unit 3 is provided inside the housing 100 so as to face the inner surface of the document table 2. The scanning unit 3 is a so-called CIS (Contact Image Sensor), and a linear light source (illuminating means) 4 provided upward along the main scanning direction and an imaging provided in parallel to the linear light source 4. A device (imaging means) 5 is provided. The linear light source 4 includes, for example, a plurality of LEDs arranged in the main scanning direction. The linear light source 4 illuminates the entire area of the main scanning direction with a predetermined width in the sub-scanning direction with substantially uniform brightness. . The imaging device 5 includes a lens array in which micro lenses are arranged in the main scanning direction, and a light receiving element array in which light receiving elements are arranged in the main scanning direction corresponding to each lens. Each lens is focused on the outer surface of the document table 2. Among the documents placed so as to be in close contact with the outer surface of the document table 2, each lens receives each image in a predetermined range illuminated by the linear light source 4. An image is formed on the light receiving surface of the element, and an image in a predetermined range is picked up by each light receiving element.

  Inside the housing 100, a rod-shaped shaft 6 arranged along the sub-scanning direction, a drive mechanism 7 having a belt 7a and a motor 7b are provided. The scan unit 3 is engaged with a part of the belt 7a, and a bearing portion (not shown) below the scan unit 3 is supported on the shaft 6 so as to be slidable in the sub-scanning direction. Is arranged. The scan unit 3 is configured to reciprocate in the sub-scanning direction along the shaft 6 by driving the motor 7b and rotating the belt 7a. The drive mechanism 7 is not limited to the one using the belt 7a and the motor 7b as shown in the figure, and may be one using a linear motor or other mechanisms, for example.

  Further, as shown in FIG. 3, in the vicinity of one end in the sub-scanning direction of the document table 2 on the upper inner surface of the housing 100, the imaging device 5 of the scan unit 3 can capture an image along the main scanning direction. A pattern sheet 8 is arranged. In the present embodiment, the pattern sheet 8 is, for example, white, and also serves as a calibration sheet for adjusting the signal level of an image captured by the imaging device 5. As shown in the figure, black home position detection patterns 8a and 8b are formed at two locations on the pattern sheet 8, for example. These home position detection patterns 8a and 8b are arranged at positions shifted from each other in the main scanning direction, and the home position detection pattern 8a is closer to the document table 2 than the home position detection pattern 8b. Also, they are arranged at positions shifted from each other in the sub-scanning direction. These home position detection patterns 8a and 8b are provided for determining the home position of the scan unit 3 in the sub-scanning direction, as will be described later.

  The image reading function performed by the image reading unit 11 will be described below. First, the control unit 9 determines the home position of the scan unit 3 before reading an image in order to recognize the position of the scan unit 3 with respect to the housing 100, that is, the position of the document placed on the document table 2. Perform the action. This operation is performed mainly as shown by S1 in FIG. 3 while causing the image pickup apparatus 5 to pick up an image on the pattern sheet 8 on the inner surface of the housing 100 while moving the scan unit 3 away from the document table 2 in the sub-scanning direction. This is performed by detecting the home position detection pattern 8a in a predetermined range in the scanning direction. In this embodiment, the control unit 9 determines the position of the scan unit 3 when the imaging device 5 images the home position detection pattern 8a as the home position of the scan unit 3, and stops the movement of the scan unit 3. Let The control unit 9 may be configured to determine a position shifted in the sub-scanning direction by a predetermined distance from the position of the scan unit 3 at this time as the home position. In the control unit 9, the positional relationship between the position of the home position and the document table 2 mounted on the housing 100 is set in advance. The control unit 9 uses the determined home position as a reading reference position in the sub-scanning direction to move the scan unit 3 in the sub-scanning direction by the drive mechanism 7 and the document placed on the document table 2 by the imaging device 5. The document is scanned as image data by scanning while imaging the surface of the document. After reading the document, the scan unit 3 is moved again in the sub-scanning direction toward the home position. Note that the above-described operation for determining the home position may be performed every time the document is read, or may be performed when the power of the image forming apparatus 1 is turned on.

  As described above, in the present embodiment, the control unit 9 detects, for example, one of the two home position detection patterns 8a and 8b, which is closer to the document table 2, and detects the home position. Is configured to determine. Here, when the image is picked up by the image pickup device 5, when the home position detection pattern 8a is not detected, the control unit 9 continues to move the scan unit 3 and continue to pick up the pattern sheet 8, which is indicated by S2 in FIG. The home position of the scan unit 3 is detected by detecting the home position detection pattern 8b in a predetermined range in the main scanning direction near the other home position detection pattern 8b. At this time, since the position in the sub-scanning direction of the home position detection pattern 8a and the home position detection pattern 8b is different, the control unit 9 uses the preset difference in the position in the sub-scanning direction of the scan unit 3. Recognize by correcting the home position. The ranges in the main scanning direction as indicated by S1 and S2 in the figure are set as appropriate. For example, even if the width of the document table 2 is divided into two in the main scanning direction, respectively. Good.

  As described above, in the present embodiment, dirt, dust or the like adheres to the home position detection pattern 8a or becomes dirty due to rubbing or the like, and the range S1 of the imaging device 5 in the main scanning direction. Even if an abnormality occurs in a region where the vicinity is imaged and the home position detection pattern 8a is not detected, the home position is determined by detecting the home position detection pattern 8b. Accordingly, it is possible to make it difficult to cause a defect in an image reading operation that makes it impossible to read an image without determining the home position, and it is possible to make the image forming apparatus 1 easier to handle. Further, even when the home position detection pattern 8a cannot be detected, the home position detection pattern 8b can be detected by continuously moving the scan unit 3 in the sub-scanning direction and continuously capturing images by the imaging device 5. The operation for causing the image pickup apparatus 5 to repeatedly pick up the same position in the sub-scanning direction is not necessary, and the image forming apparatus becomes easier to handle.

  In addition, this invention is not limited to the structure of the said embodiment, A various deformation | transformation is possible suitably in the range which does not change the meaning of invention. For example, the home position detection pattern is not limited to two as described above, and a plurality of three or more home position detection patterns may be formed. At this time, the control unit 9 selects and detects one of the home position detection patterns to determine the home position, and when this home position detection pattern cannot be detected, A home position is determined by selecting and detecting one. By forming a plurality of home position detection patterns in this way, it is possible to make the image reading apparatus defective more unlikely to occur and to make the image forming apparatus 1 easier to handle. Further, the home position detection patterns provided in two or a plurality are not necessarily provided at positions shifted from each other in the sub-scanning direction. For example, when a plurality of home position detection patterns have the same position in the sub-scanning direction, the home position detection pattern is detected in a predetermined range in the main scanning direction near one selected home position detection pattern. By doing so, it is possible to determine the home position. At this time, if the selected home position detection pattern cannot be detected, the scan unit 3 is moved to cause the imaging device 5 to pick up an image again, and another home position detection pattern is selected and detected. What is necessary is just to comprise. Further, the image reading unit 11 may be configured such that the pattern sheet 8 is not provided. At this time, the home position detection patterns 8a and 8b are only required to be provided on the inner surface of the housing 100 in a color different from the color of the inner surface of the housing 100, for example. It becomes possible.

  In addition, the present invention is not only applied to the above-described printer complex machine, but can also be applied to an image reading apparatus having no image forming function such as a so-called flatbed scanner. Even when applied to an image reading device, it is possible to make it difficult for image reading operations to occur, and the image reading device can be made unusable, making the image reading device easier to handle. It becomes.

1 is a front view illustrating a configuration of an image forming apparatus according to an embodiment of the present invention. The figure which looked at the state which opened the cover of the apparatus same as the above from the upper surface. The figure which looked at the original stand of the apparatus same as the above from inside the housing | casing. The figure which looked at the original stand of the conventional image forming apparatus from the inside of a housing | casing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Document stand 3 Scan unit 4 Linear light source (illumination means)
5 Imaging device (imaging means)
7 Drive mechanism 8a, 8b Home position detection pattern 9 Control unit (control means)
11 Image forming unit (image forming means)
A Main scanning direction (second direction)
B Sub-scanning direction (first direction)

Claims (3)

A housing having a rectangular opening formed on the upper surface;
A flat platen that is formed of a translucent material and is attached to the opening of the housing;
A scan unit that moves in a first direction while facing the inner surface of the document table inside the housing;
Illuminating means provided on the scan unit and illuminating a predetermined range of the first direction and a second direction orthogonal to the first direction;
An imaging unit that is provided on the scan unit and captures an image of a predetermined range illuminated by the illumination unit;
A home position detection pattern provided on the inner surface of the housing so as to be imageable by the imaging means;
A drive mechanism for moving the scan unit in a first direction;
Control means for controlling the illumination means and the drive mechanism;
Image forming means for forming an image on recording paper based on image data captured by the imaging means or image data input from the outside;
The control unit causes the imaging unit to capture an image of the inner surface of the housing, and detects the home position detection pattern in a predetermined range in the second direction out of a range to be captured. In the image forming apparatus that determines the home position in the direction of and controls the imaging unit to read the document placed on the document table as image data based on the determined home position.
Two home position detection patterns are arranged at positions shifted from each other in the first direction and the second direction,
The control means is configured to detect one of the two home position detection patterns and determine the home position, and when one of the home position detection patterns is not detected, the image is picked up by the imaging means. An image forming apparatus, wherein a home position is determined by detecting the other home position detection pattern in a predetermined range in the second direction in the vicinity of the other home position detection pattern in the range. A housing having a rectangular opening formed on the upper surface;
A flat platen that is formed of a translucent material and is attached to the opening of the housing;
A scan unit that moves in a first direction while facing the inner surface of the document table inside the housing;
Illuminating means provided on the scan unit and illuminating a predetermined range of the first direction and a second direction orthogonal to the first direction;
An imaging unit that is provided on the scan unit and captures an image of a predetermined range illuminated by the illumination unit;
A plurality of home position detection patterns provided on the inner surface of the housing at positions shifted from each other in the second direction so as to be imaged by the imaging means;
A drive mechanism for moving the scan unit in a first direction;
Control means for controlling the illumination means and the drive mechanism,
The control means determines the home position in the first direction of the scan unit by selecting any one of the home position detection patterns, causing the image pickup means to pick up an image, and detecting the home position in the first direction. An image reading apparatus characterized in that the image pickup unit controls the document placed on the document table as image data. An image reading apparatus according to claim 2, and image forming means for forming an image on a recording sheet based on image data picked up by image pickup means of the image reading apparatus or image data input from outside An image forming apparatus comprising:

Images