JP2007243664A - Image reader and position adjustment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image reader and the like which sense a position relation without adding a special sensing means in adjusting read combination by each CIS (contact image sensor) of a staggered system. <P>SOLUTION: In the image reader in which a plurality of image sensors CIS 1, CIS 2, CIS 3 are arranged in staggered layout, and read ranges of adjacent sensors among the image sensors CIS 1, CIS 2, CIS 3 are arranged so as to be overlapped in a main scanning direction, the reader has original read ranges and a position sensing range (a left position detection range and a right range detection range) for sensing positions of the image sensors CIS 1, CIS 2, CIS 3 within the read ranges of the respective image sensors CIS 1, CIS 2, CIS 3, and senses position relations among the respective image sensors CIS 1, CIS 2, CIS 3 due to an image signal read within the position sensing ranges. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image reading apparatus that adjusts a reading position in a main scanning direction or a sub-scanning direction by a CIS (contact image sensor) arranged in a predetermined pattern.

  There is a staggered method that realizes A3 and A4 size CIS in a staggered manner at a low cost when reading A0 size CIS. A4 size CIS is low cost because it is produced in large quantities for consumers. On the other hand, the A0 size CIS is less demanded, and the cost of the component part SELFOC lens array and the like is also expensive.

  In the staggered method, each CIS needs to be read in the main scanning direction or the sub-scanning direction as if it were read with a single CIS. Connection adjustment in the main scanning direction is performed by adjusting the reading range of each CIS, and connection adjustment in the sub-scanning direction is performed by adjusting the delay amount of the delay memory. However, even if the adjustment is performed at the time of manufacturing or maintenance (including user calibration), the displacement of the joints will increase due to environmental changes and time. It was generated. In order to adjust such a shift, it is necessary to detect the positional relationship between the CISs using dedicated detection means, but this hinders downsizing and cost reduction of the image reading apparatus.

Regarding the adjustment of the reading position in the image reading apparatus, for example, as disclosed in Patent Document 1, one straight line extending in the main scanning direction is read by each reading sensor, and based on the image data of the straight line image. There is a method of automatically obtaining each regression line by a control circuit constituted by a CPU or the like and setting a delay amount of image data. However, in performing this method, the width of the general-purpose reading sensor in the sub-scanning direction generally requires the width of the substrate on which the light receiving element is mounted and driven and the width of the housing. For this reason, when the reading sensors are arranged in a staggered manner, the deviation in the sub-scanning direction between the upstream and downstream reading sensors becomes large.
Japanese Patent Application Laid-Open No. 08-97980

  In view of the above circumstances, an object of the present invention is to provide an image reading apparatus and the like that can detect the positional relationship without adding a special detection means when adjusting the connection of reading by each CIS of the staggered method. And

  An aspect of the present invention that achieves the above object is an image reading apparatus in which a plurality of image sensors are arranged in a staggered manner, and reading ranges of adjacent ones of the image sensors are arranged overlapping in the main scanning direction. Each image sensor has a reading range and a position detection range for detecting the position of the image sensor, and the positional relationship between the image sensors is detected by an image signal read within the position detection range. The present invention relates to an image reading apparatus.

  Here, the image signal includes an image signal related to a mark for detecting the positional relationship, and the mark has a line segment perpendicular to the main scanning direction and a predetermined angle with respect to the main scanning direction. It is characterized by combining the line segments it has.

  Further, the relative positional relationship between the document reading range of one image sensor and the document reading range of another image sensor is set to a predetermined value based on the image signal read in the position detection range, and the relative positional relationship Is characterized in that the document reading range of one image sensor and the document reading range of an image sensor adjacent to the image sensor have a range that overlaps in the main scanning direction.

  The delay amount is adjusted by an image signal read in the position detection range.

  Another aspect of the present invention is a position adjustment method for an image reading apparatus in which a plurality of image sensors are staggered and the reading ranges of adjacent image sensors are overlapped in the main scanning direction. The image sensor reading range has a position detection range for detecting the document reading range and the position of the image sensor, and the positional relationship between the image sensors is determined by the image signal read in the position detection range. At the time of detection, the relative positional relationship between the document reading range of one image sensor and the document reading range of another image sensor is set to a predetermined value based on the image signal read in the position detection range, and the position in the main scanning direction is set. A step of performing adjustment, and a step of adjusting the amount of delay based on the image signal read in the position detection range and performing position adjustment in the sub-scanning direction. Those relating to the position adjusting method comprising Rukoto.

  In the image reading apparatus of the present invention, when the image sensors are arranged in a zigzag pattern, a part of the image sensor is used to detect the position of the image sensor and the interval between the image sensors, that is, the positional relationship. Therefore, it is possible to adjust the reading linkage without requiring a special detection means.

  Hereinafter, the best mode for carrying out the image reading apparatus of the present invention will be described. In the description, the drawings submitted at the same time as this specification will be referred to as appropriate.

  FIG. 1 is a cross-sectional view of the image reading apparatus, and FIG. 2 is a top view of the image reading apparatus, showing an outline of the mechanism. An example using CIS for an image sensor will be described.

  As shown in FIG. 2, three CIS1, CIS2, and CIS3 are arranged in a staggered pattern. In FIG. 1, the document is inserted from the right. When the document insertion sensor 1 detects a document, a transport motor (not shown) rotates a transport roller: front 2 and a transport roller: rear 6 to turn on a light source for document illumination (not shown) in the CIS. . Thereafter, the registration sensor 3 detects the leading edge of the document and sequentially recognizes the position of the document in the conveyance path. The original image (lower surface) is read by CIS2 and then read by CIS1 and CIS3.

  The CIS2 read signal is delayed by the time required for sub-scanning between CIS2 and CIS1, the CIS3 read signal is delayed by the time required for sub-scanning between CIS3 and CIS1, and the CIS1, CIS2, and CIS3 signals are combined, A one-line read signal is obtained. The document image is sequentially read and discharged through the transport roller 6.

  In FIG. 2, the document is conveyed from top to bottom (when the operation is viewed from the top). The effective reading range of each CIS overlaps with the effective reading range of the adjacent CIS. The effective reading range of each CIS has an effective reading range for obtaining an image signal to be used at each time point. Each effective reading range has a constant reading width (in the main scanning direction) and within the effective reading range (in the main scanning direction). In FIG. 2, left and right direction) can be arbitrarily set independently. This setting is performed by setting the reading start position P1a for CIS1, P2a for CIS2, and P3a for CIS3.

  Each execution reading range has a document reading range, a left position detection range, and a right position detection range. Each document reading range has a left overlapping reading range and a right overlapping reading range. When the effective reading range is moved, the document reading range including the left and right overlapping reading range and the left and right position detection range move in the same amount and in the same direction. In this embodiment, the CIS1 left position detection range, left overlap reading range, CIS3 right position detection range, and right overlap reading range are not used. In addition, the document reading ranges do not necessarily have to be overlapped, but in the present embodiment, description will be made on the case where they overlap.

  The seam using the duplicated signal (for every two sets of seams) is corrected (described later) to obtain a read signal. In this reading, it is necessary that the positional relationship of the CIS1, CIS2, and CIS3 in the main scanning direction and the sub-scanning direction is accurately adjusted and held. A method for adjusting and maintaining the positional relationship will be described below.

  The contact glass 5 (or the reading back member 4, hereinafter referred to as the contact glass 5) in FIGS. 1 and 2 is a thin line L1a parallel to the sub-scanning direction at a position corresponding to each CIS left / right position detection range. Fine lines L1b, L2b, and L3b inclined by 45 ° and L2a and L3a are provided.

  The image reading apparatus of this embodiment also has a function of switching the reading range of each CIS between the adjustment mode and the document reading mode. The position adjustment is based on CIS1, and the reading range is not changed. Also, no delay in the sub-scanning direction is performed (there is no delay means corresponding to CIS1). After adjusting CIS2 (reading range and delay amount), CIS3 is adjusted.

  The reading range in the adjustment mode uses the execution reading range of each CIS. Further, the reading range in the document image reading mode uses the document reading range including the overlapping reading ranges of CIS1, CIS2, and CIS3. The image signal in the overlapping reading range is corrected (a method will be described later) and incorporated into the image signal that has been made into one line.

  FIG. 3 shows an image signal when a thin line of the contact glass is read in the adjustment mode. The main scanning sequence starts at the left end P1a of the CIS1 execution reading range, reaches the right end P1b of the CIS1 execution reading range, jumps to the left end P2a of the CIS2 execution reading range, and reaches the right end P2b of the CIS2 execution reading range. At the same time, it jumps to the left end P3a of the CIS3 execution reading range, reaches the right end P3b of the CIS3 execution reading range, forms one main scanning period, and repeats scanning.

  The waveform of group A corresponds to the connection between CIS1 and CIS2, and group B corresponds to CIS2 and CIS3. The valley peak waveforms 1b, 1a, 2b, 2a, 3b, 3a, 4a, 4b correspond to signals obtained by reading the thin lines L1b, L1a, L2b, L2a, L3b, L3a, L4a, L4b on the contact glass 5.

  In the waveform of the A group, the interval SL1 corresponds to the thin line L1a and the thin line L2a, and represents the positional relationship between the CIS1 and CIS2 in the main scanning direction. When the relative position in the main scanning direction of CIS1 and CIS2 (that is, the length of the overlapping section) changes, the interval SL1 changes. The interval SG1 also changes. Even if CIS1 and CIS2 move in the sub-scanning direction, the interval SL1 does not change. However, since the thin lines L1b and L2b are inclined, the interval SG1 changes.

  Similarly, in the waveform of group B, the interval SL2 corresponds to the thin line L3a and the thin line L4a, and represents the positional relationship between the CIS2 and CIS3 in the main scanning direction. When the relative position in the main scanning direction of CIS2 and CIS3 (that is, the length of the overlapping section) changes, the interval SL2 changes. The interval SG2 also changes. Even if CIS1 and CIS2 move in the sub-scanning direction, the interval SL1 does not change. However, since the thin lines L1b and L2b are inclined, the interval SG2 changes.

The adjustment method will be described. The adjustment of the joints of CIS1, CIS2, and CIS3 is to make each of the sections SL1, SG1, SL2, and SG2 coincide with preset constants K1, K2, and K3 (adjustment target values).
SL1 = SL2 = K1
SG1 = K2
SG2 = K3

  Depending on the configuration, adjustment target values of SL1, SG1, SL2, and SG2 need to be set individually. Here, there is no problem even if the valley peak waveforms 1b, 1a, 2b, 2a, 3b, 3a, 4a, and 4b are moved left and right on the time axis without changing the relative relationship of the respective positions. CIS1, CIS2, and CIS3 do not change relative positions over time or due to environmental fluctuations, etc., and there are only a few dimensions that cause position fluctuations. If the relative position changes, even a slight problem will be a problem on the read image.

  As values corresponding to the adjustment target values that are the preconditions for adjustment, the overlapping section of CIS1 and CIS2 in the main scanning direction is 2.709 mm (64 pixels), and the interval in the sub-scanning direction is 25.400 mm (600 pixels). The overlap section between CIS1 and CIS2 is 2.709 mm (64 pixels), and the adjustment in the sub-scanning direction is 23.368 mm (552 pixels, that is, 552 lines). The interval target value in the sub-scanning direction is a value that minimizes the level difference of the joint in the read (or copy) image of the test chart on which the straight line in the main scanning direction is drawn by adjusting the delay amount of CIS2 or CIS3. It may be a target value. Note that the time axis in FIG. 3 corresponds to the pixel interval, and thus the dimensions on each mechanism.

  In the adjustment, first, the reading start position P2a of CIS2 (the left end of the execution reading range) is adjusted in order to set SL1 in the relationship between CIS1 and CIS2 to the target value K1. Since the effective reading length is constant, when the reading start position P2a is determined, the reading end position P2b of the effective reading range is naturally determined. SL1 is matched with K1 by adjusting the reading start position P2a. Thereafter, the interval between the CIS1 and CIS2 in the sub-scanning direction is adjusted by adjusting the image signal delay amount of the CIS2, and the interval SG1 is adjusted to the target value K2. The execution reading range of CIS1 is fixed. The CIS1 signal is not delayed.

  Thereafter, the reading start position P3a of CIS3 (the left end of the execution reading range) is adjusted in order to set SL2 in the relationship between CIS2 and CIS3 to the target value K2. Since the effective reading length is constant, when the reading start position P3a is determined, the reading end position P3b of the effective reading range is naturally determined. SL2 is made to coincide with K1 by adjusting the reading start position P3a. Thereafter, the interval between the CIS2 and CIS3 in the sub-scanning direction is adjusted by adjusting the image signal delay amount of the CIS3, and the interval SG2 is adjusted to the target value K3.

  In the document image reading mode, an image signal in which only one document reading range of each CIS is made into one line is used. The overlap reading range processing (joint signal processing) will be described later.

  FIG. 4 illustrates the signal processing at the joint between CIS1 and CIS2. The CIS1 right overlapping reading section on the right side of CIS1 and the CIS2 left overlapping reading section on the left side of CIS2 are configured to perform 64 pixel overlapping reading. The left side of the CIS1 right overlapping reading section has a CIS1 original image reading range other than the overlapping reading, and the right side of the CIS2 left overlapping reading section has a CIS2 original image reading range other than the overlapping reading. There is a CIS1 right position detection section on the right side of the CIS1 right overlap reading section, and a CIS2 left position detection section on the further left side of the CIS2 left overlap reading section.

Using the image signal D1-2 (n) in the CIS1 right overlap reading section and the image signal D2-2 (n) in the CIS2 left overlap reading section, the image signal D12 (n) in the CIS1 and CIS2 joint correction section is Generate using.
D12 (n) = (k−n) / k × D1-2 (k−n) + n / k × D2-2 (n)

  The image signal D12 (n), the image signal D1-1 of the CIS1 original image reading range other than the duplicate reading, and the image signal D2-3 of the CIS2 original image reading range other than the duplicate reading are 1 near the joint of CIS1 and CIS2. The lined read signal is shown in the lower part of FIG. By smoothly changing the image signal on the right side of CIS1 to the level of the image signal on the left side of CIS2, it aims to make the image inconspicuous even if there is a characteristic difference between CIS1 and CIS2.

  The signal processing at the joint between CIS2 and CIS3 is performed in the same manner as the signal processing at the joint between CIS1 and CIS2.

  By implementing this embodiment, the following effects can be obtained. In other words, in an image reading apparatus in which image sensors are arranged in a staggered pattern, a part of the image sensor is used to detect the position of the image sensor and the interval (positional relationship) between the image sensors. Accurate detection is possible without the need for detection means.

  Further, since the thin line that serves as a reference for the position of the image sensor (the positional relationship is accurately managed) is drawn on the contact glass 5 or the reading back member 4, the accurate positional relationship can be detected.

  In addition, since the thin lines serving as the reference for the position of the image sensor (the positional relationship is accurately managed) are composed of a plurality of sets of two sets as one set, the main and sub-scanning directions of the connecting portions of each image sensor reading Can be easily detected simultaneously with the same member.

  In an image reading apparatus in which the image reading ranges of adjacent image sensors overlap and the image sensors are arranged in a staggered manner, the size of the overlapping document reading range (related to the position of the image sensor in the main scanning direction) is detected as described above. Since the adjustment is performed based on the signal using the method, it is possible to accurately adjust the dimension of the overlapping document reading range in the main scanning direction.

  In the image reading apparatus in which the image sensors are arranged in a staggered pattern, the above detection method is used to delay the image signal read earlier in order to cancel the positional relationship of the image sensors in the sub-scanning direction. Since the amount of delay is adjusted based on the signal, it is possible to accurately adjust the connection in the sub-scanning direction.

  In an image reading apparatus in which image sensors are arranged in a staggered pattern, the main scanning direction is adjusted first, and then the sub scanning direction is adjusted before adjusting the positional relationship between the main scanning direction and the sub scanning direction. Thus, the overall positional relationship can be adjusted quickly.

  The above-described embodiment is the best for carrying out the image reading apparatus of the present invention. However, the present invention is not limited to this embodiment, and various modifications can be made to the embodiment without departing from the scope of the present invention. Is possible.

  Development of a FAX, scanner, MFP (Multi Functional Peripheral), etc., equipped with the image reading apparatus of the present invention is desired.

It is sectional drawing of an image reading apparatus. It is a top view of an image reading apparatus. It is an image signal when a thin line of contact glass is read in the adjustment mode. The state of signal processing at the joint between CIS1 and CIS2 is illustrated.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Document insertion sensor 2 Conveyance roller: Front 3 Registration sensor 4 Reading back member 5 Contact glass 6 Conveyance roller: Rear

Claims (7)

In the image reading apparatus in which a plurality of image sensors are arranged in a staggered manner and the reading ranges of the image sensors adjacent to each other are overlapped in the main scanning direction,
Within the reading range of each image sensor, a document reading range and a position detection range for detecting the position of the image sensor,
An image reading apparatus for detecting a positional relationship between image sensors based on an image signal read within the position detection range.   The image reading apparatus according to claim 1, wherein the image signal includes an image signal related to a mark for detecting the positional relationship.   The image reading apparatus according to claim 2, wherein the mark is a combination of a line segment perpendicular to the main scanning direction and a line segment having a predetermined angle with respect to the main scanning direction.   4. The relative positional relationship between a document reading range of one image sensor and a document reading range of another image sensor is set to a predetermined value based on an image signal read in the position detection range. The image reading apparatus according to any one of the above.   5. The relative positional relationship is a relationship in which a document reading range of one image sensor and a document reading range of an image sensor adjacent to the image sensor overlap with each other in the main scanning direction. The image reading apparatus described.   4. The image reading apparatus according to claim 1, wherein a delay amount is adjusted based on an image signal read in the position detection range. In the position adjustment method of the image reading apparatus in which a plurality of image sensors are staggered and the reading ranges of the image sensors adjacent to each other are overlapped in the main scanning direction,
Each image sensor has a reading range and a position detection range for detecting the position of the image sensor, and the positional relationship between the image sensors is detected by an image signal read within the position detection range. When doing
A step of adjusting the position in the main scanning direction by setting a relative positional relationship between a document reading range of one image sensor and a document reading range of another image sensor to a predetermined value based on an image signal read in the position detection range; ,
A position adjustment method comprising adjusting a delay amount based on an image signal read in the position detection range and performing position adjustment in the sub-scanning direction.

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