JP7103014B2 - Reader, image forming device, reference pattern reading method and program - Google Patents

Description

The present invention relates to a reader, an image forming apparatus, a reference pattern reading method and a program.

Conventionally, for the purpose of correcting the transport position of the transported object and the processing position for the transported object, the outer edge position of the transported object and the processing position for the transported object are measured by a reading device such as a CIS (Contact Image Sensor). The reading technique is disclosed.

Further, a technique for detecting a deviation in the mounting position of a reading device by reading a calibration sheet is also disclosed.

However, according to the conventional technique, there is a problem that the accuracy may not be obtained when detecting the deviation of the mounting position of the reading device.

The present invention has been made in view of the above, and an object of the present invention is to provide a reading device, an image forming device, a reference pattern reading method, and a program capable of accurately detecting a deviation in the mounting position of a reading device. ..

In order to solve the above-mentioned problems and achieve the object, in the reading device of the present invention, a reference pattern including a line extending in a predetermined direction is arranged and moves relatively in a direction orthogonal to the predetermined direction. A position reference member and a reading device for arranging a plurality of sensor chips having a plurality of pixels in the predetermined direction are provided, and the reference pattern includes a vertical line extending in a direction orthogonal to the predetermined direction and the vertical line. The horizontal line includes a horizontal line extending in a predetermined direction, the horizontal line is in contact with the position where the vertical line exists, and is arranged corresponding to the central portion of the sensor chip of the reading device. After reading, the vertical line is read.

According to the present invention, there is an effect that the deviation of the mounting position of the reading device can be detected with high accuracy.

FIG. 1 is a schematic view showing an example of the hardware configuration of the printing system according to the embodiment. FIG. 2 is a schematic view showing a reading device, a position reference member, and an installation mode. FIG. 3 is a schematic view showing the corresponding positional relationship between the reading device and the position reference member. FIG. 4 is a schematic view showing an example of a reference line arranged on the position reference member. FIG. 5 is a diagram showing a positional relationship between the position reference member and the reading device in the depth direction. FIG. 6 is a block diagram showing an example of electrical connection of hardware of a printing system. FIG. 7 is a functional block diagram showing a functional configuration of the printing system. FIG. 8 is a schematic diagram showing an example of coordinate calculation in the sub-scanning direction of each sensor chip of the reading device. FIG. 9 is a schematic diagram showing an example of coordinate calculation in the main scanning direction of each sensor chip of the reading device. FIG. 10 is a diagram showing a method of generating a correction value. FIG. 11 is a flowchart schematically showing the flow of the correction process. FIG. 12 is a schematic view showing the corresponding positional relationship between the reading device and the position reference member. FIG. 13 is a diagram showing an example of data obtained by averaging the readings. FIG. 14 is a diagram showing a coordinate position calculation method in the main scanning direction by the second correction value calculation unit. FIG. 15 is a diagram showing a case where the reading device is deformed. FIG. 16 is an enlarged view showing a part of the deformed reading device.

The reading device, the image forming device, the reference pattern reading method, and the embodiment of the program will be described in detail with reference to the accompanying drawings. In the following, a case where the reading device and the image forming device are applied to a printing system including a printing device such as a commercial printing machine (production printing machine) that continuously prints a large number of sheets in a short time will be described as an example. However, it is not limited to this.

[Explanation of printing system hardware configuration]
FIG. 1 is a schematic view showing an example of the hardware configuration of the printing system 1 according to the embodiment. As shown in FIG. 1, the printing system 1 which is an image forming apparatus includes a printing apparatus 100, a medium position detecting apparatus 200 (an example of a position detecting apparatus), and a stacker 300.

The printing apparatus 100 includes an operation panel 101, a tandem electrophotographic image forming unit 103Y, 103M, 103C, 103K, a transfer belt 105, a secondary transfer roller 107, a paper feeding unit 109, and a transfer roller pair. It includes 102, a fixing roller 104, and an inversion path 106.

The operation panel 101 is an operation display unit that inputs various operations to the printing device 100 and the medium position detecting device 200 and displays various screens.

In each of the image forming units 103Y, 103M, 103C, and 103K, a toner image is formed by performing an image forming process (charging step, exposure step, developing step, transfer step, and cleaning step), and the formed toner image is formed. Is transferred to the transfer belt 105. In the present embodiment, a yellow toner image is formed on the image forming section 103Y, a magenta toner image is formed on the image forming section 103M, a cyan toner image is formed on the image forming section 103C, and the cyan toner image is formed on the image forming section 103K. A black toner image is formed in, but the present invention is not limited to this.

The transfer belt 105 conveys a toner image (full-color toner image) superimposed and transferred from the image forming units 103Y, 103M, 103C, and 103K to the secondary transfer position of the secondary transfer roller 107. In the present embodiment, the yellow toner image is first transferred to the transfer belt 105, and then the magenta toner image, the cyan toner image, and the black toner image are sequentially superimposed and transferred. It is not limited.

A plurality of recording media to be processed (objects to be transported) are superposed and accommodated in the paper feeding unit 109, and the recording media are fed. Examples of the recording medium include, but are not limited to, recording paper (transfer paper), and images such as coated paper, thick paper, OHP (Overhead Projector) sheet, plastic film, and copper foil can be recorded. Any medium may be used. In the present embodiment, the recording medium on which the image is formed is the processing target (the object to be transported), but the processing target is not limited to this, and a sheet or the like that is not the target for forming the image such as a prepreg is the processing target (the object to be transported). It may be an object to be transported).

The transport roller pair 102 transports the recording medium fed by the paper feed unit 109 on the transport path a in the direction of the arrow s.

The secondary transfer roller 107 collectively transfers the full-color toner image conveyed by the transfer belt 105 onto the recording medium conveyed by the transfer roller pair 102 at the secondary transfer position.

The fixing roller 104 fixes the full-color toner image on the recording medium by heating and pressurizing the recording medium on which the full-color toner image is transferred.

In the case of single-sided printing, the printing device 100 sends a printed matter, which is a recording medium on which a full-color toner image is fixed, to the medium position detecting device 200. On the other hand, in the case of double-sided printing, the printing apparatus 100 sends a recording medium on which a full-color toner image is fixed to the inversion path 106.

The inversion path 106 reverses the front and back surfaces of the recording medium by switching back the transmitted recording medium, and conveys the recording medium in the direction of the arrow t. The recording medium conveyed by the inversion path 106 is retransmitted by the transfer roller pair 102, the full-color toner image is transferred to the surface opposite to the previous one by the secondary transfer roller 107, and fixed by the fixing roller 104 as printed matter. , Is sent to the medium position detection device 200 and the stacker 300.

The medium position detecting device 200 located downstream of the printing device 100 includes a reading device 201 and a position reference member 202.

The reading device 201 can be realized by, for example, a CIS (Contact Image Sensor) in which a plurality of image pickup elements (CMOS image sensors) are arranged in a line. The reading device 201 receives the reflected light from the reading target and outputs an image signal. Specifically, the reading device 201 targets the transport position of the recording medium sent from the printing device 100 and the processing position (printing position) with respect to the recording medium as the reading target. Further, the reading device 201 targets the position reference member 202 as a reading target.

The CIS applied to the reading device 201 is generally configured to secure a required effective reading length in the main scanning direction by arranging a plurality of sensor chips 210 (see FIG. 4) having a plurality of pixels in the main scanning direction. Is known for.

The position reference member 202 is a reference plate for correcting the mounting position of each sensor chip 210 of the reading device 201 composed of a plurality of sensor chips 210. By correcting the mounting position of each sensor chip 210 of the reading device 201 using the position reference member 202 in this way, highly accurate image position detection is performed.

Then, the medium position detecting device 200 discharges the read-completed recording medium to the stacker 300.

The stacker 300 includes a tray 301. The stacker 300 stacks the recording medium discharged by the medium position detecting device 200 on the tray 301.

Next, the reading device 201 and the position reference member 202 in the medium position detecting device 200 will be described.

By the way, the method of reading the outer edge position of the transported object and the processing position for the transported object with a reading device such as CIS and correcting the transport position of the transported object and the processing position for the transported object does not provide accuracy. There was a problem that there were cases.

FIG. 2 is a schematic view showing a reading device 201, a position reference member 202, and an installation mode. As shown in FIG. 2, the position reference member 202 is provided on the rotating member 203 that is rotationally driven by the motor 204. The position reference member 202 is moved by a rotating member 203 that is rotated at a constant speed by the motor 204. The position reference member 202 is arranged on the facing surface of the reading device 201 at a predetermined timing as the rotating member 203 rotates.

In order to rotate the position reference member 202 in this way, the position reference member 202 is moved in the sub scan direction at a constant speed in order to detect the attachment inclination of the reading device 201 in the sub scan direction, and the position reference member 202 is moved on the position reference member 202. This is for reading the reference line X (see FIG. 4), which is a reference pattern including a line extending in a predetermined direction arranged in.

In FIG. 2, the position reference member 202 is attached to the rotating member 203 so that the position reference member 202 is moved at a constant speed in the sub-scanning direction, but the present invention is not limited to this. For example, the position reference member 202 may be provided so as to be movable in a straight line. Further, in FIG. 2, the position reference member 202 is configured to move in the sub-scanning direction at a constant speed, but the present invention is not limited to this, and the reading device 201 may be moved in the sub-scanning direction at a constant speed.

FIG. 3 is a schematic view showing the corresponding positional relationship between the reading device 201 and the position reference member 202. As shown in FIG. 3, the position reference member 202 has a position corresponding to the first pixel, which is an image pickup element, at one end (tip) in the main scanning direction of the reading device 201 as a reference position (support point).

Further, the reading device 201 also has a reference position (support point) at a position corresponding to the first pixel corresponding to the reference position of the position reference member 202.

Here, problems when applying CIS to the reading device 201 will be described. The gaps between adjacent sensor chips 210 are usually mounted at intervals of a predetermined physical length (eg, one pixel), which is known to have tolerances. The spacing between adjacent sensor chips 210 of the reading device 201 varies and is not necessarily equal.

It is also known that the adjacent sensor chips 210 of the reading device 201 also vary in the sub-scanning direction.

Therefore, in consideration of the above-mentioned problems, the following configuration can be considered in order to further improve the position detection accuracy.

Here, FIG. 4 is a schematic view showing an example of the reference line X arranged on the position reference member 202. As shown in FIG. 4, a predetermined reference line X is arranged on the position reference member 202. The reference line X arranged on the position reference member 202 is a line parallel to the main scanning direction (predetermined direction) of the reading device 201 (hereinafter, “horizontal line”) and the main scanning direction of the reading device 201. It is composed of orthogonal lines (hereinafter referred to as "vertical lines") extending in orthogonal directions.

As shown in FIG. 4, the vertical line of the reference line X is arranged corresponding to the central portion of each sensor chip 210 on the substrate of the reading device 201. The vertical lines of the reference line X are arranged on the position reference member 202 at equal intervals corresponding to the sensor chips 210 so that they can be read by each sensor chip 210 on the substrate of the reading device 201. Further, the horizontal line of the reference line X is arranged between the vertical lines over the plurality of sensor chips 210 on the substrate of the reading device 201.

As shown in FIG. 4, by creating a gap between the vertical line and the horizontal line on the position reference member 202, even if the horizontal line is within the reading range of the reading device 201, the coordinates of the vertical line are calculated. You can do it. The reference line X is not limited to the one in which there is a gap between the vertical line and the horizontal line on the position reference member 202, and the vertical line and the horizontal line may be in contact with each other.

If the position reference member 202 expands or contracts due to the influence of heat generation of the peripheral members, the position reference member 202 does not function as an absolute position reference, and the position detection accuracy is deteriorated. Therefore, the position reference member 202 is made of a material having a lower coefficient of linear expansion than the substrate of the reading device 201 and a negligible amount of expansion and contraction due to the influence of the ambient temperature in position detection. In the present embodiment, the position reference member 202 is made of glass in consideration of the assumed temperature change range and the coefficient of linear expansion. The material of the position reference member 202 is not limited to this, and it is more preferable to use quartz glass or the like in order to realize highly accurate medium position detection when the temperature change range of the reading device 201 is wide. be.

FIG. 5 is a diagram showing a positional relationship between the position reference member 202 and the reading device 201 in the depth direction. Usually, the reading device 201 such as CIS has a characteristic that the image characteristic changes depending on the height (depth) direction. As a typical example of such image characteristics, in general,
・ MTF (Depth of Focus)
・ Lighting depth can be mentioned. Further, some reading devices 201 have a property that the characteristics differ depending on the position in the main scanning direction in addition to the height (depth) direction dependence.

Therefore, in the present embodiment, the position in the depth (height) direction when the reading device 201 reads the recording medium and the depth (height) when the reading device 201 reads the reference line X on the position reference member 202. The position reference member 202 and the reading device 201 are arranged so that the directional positions match. As a result, the accuracy of position detection can be improved by reducing the influence of the difference in image characteristics of the reading device 201, which depends on the depth direction, as much as possible.

FIG. 6 is a block diagram showing an example of electrical connection of the hardware of the printing system 1.

As shown in FIG. 6, the printing system 1 has a configuration in which the controller 10, the engine unit (Engine) 60, and the engine unit (Engine) 70 are connected by a PCI bus. The controller 10 is a controller that controls overall control, drawing, communication, and input from the operation panel 101, which is an operation display unit, of the printing system 1. The engine unit 60 is an engine that can be connected to the PCI bus, and is, for example, a scanner engine such as a reading device 201. In addition to the engine portion, the engine portion 60 also includes an image processing portion such as error diffusion and gamma conversion. The engine unit 70 is an engine that can be connected to the PCI bus, and is, for example, a print engine such as a plotter including image forming units 103Y, 103M, 103C, and 103K.

The controller 10 includes a CPU (Central Processing Unit) 11, a north bridge (NB) 13, a system memory (MEM-P) 12, a south bridge (SB) 14, a local memory (MEM-C) 17, and an ASIC. It has a (Application Specific Integrated Circuit) 16 and a hard disk drive (HDD) 18, and the north bridge (NB) 13 and the ASIC 16 are connected by an AGP (Accelerated Graphics Port) bus 15. Further, the MEM-P12 further has a ROM 12a and a RAM 12b.

The CPU 11 controls the entire printing system 1, has a chipset including NB13, MEM-P12, and SB14, and is connected to other devices via this chipset.

The NB 13 is a bridge for connecting the CPU 11 to the MEM-P12, SB14, and AGP bus 15, and has a memory controller that controls reading and writing to the MEM-P12, a PCI master, and an AGP target.

The MEM-P12 is a system memory used as a memory for storing programs and data, a memory for expanding programs and data, a memory for drawing a printer, and the like, and includes a ROM 12a and a RAM 12b. The ROM 12a is a read-only memory used as a memory for storing programs and data, and the RAM 12b is a writeable and readable memory used as a memory for expanding programs and data, a memory for drawing a printer, and the like.

The SB14 is a bridge for connecting the NB13 to a PCI device and peripheral devices. The SB 14 is connected to the NB 13 via a PCI bus, and a network interface (I / F) unit and the like are also connected to the PCI bus.

The ASIC 16 is an IC (Integrated Circuit) for image processing applications having hardware elements for image processing, and has a role of a bridge connecting the AGP bus 15, the PCI bus, the HDD 18 and the MEM-C17, respectively. The ASIC 16 includes a PCI target and an AGP master, an arbiter (ARB) that forms the core of the ASIC 16, a memory controller that controls the MEM-C17, and a plurality of DMACs (Direct Memory) that rotate image data by hardware logic or the like. It is composed of an Access Controller) and a PCI unit that transfers data between the engine unit 60 and the engine unit 70 via the PCI bus. A USB 40 and an IEEE 1394 (the Institute of Electrical and Electronics Engineers 1394) interface (I / F) 50 are connected to the ASIC 16 via a PCI bus. The operation panel 101 is directly connected to the ASIC 16.

The MEM-C17 is a local memory used as a copy image buffer and a code buffer, and the HDD 18 is a storage for accumulating image data, programs, font data, and forms.

The AGP bus 15 is a bus interface for a graphics accelerator card proposed to speed up graphic processing, and accelerates the graphics accelerator card by directly accessing the MEM-P12 with a high throughput. Is.

The program executed by the printing system 1 of the present embodiment is a file in an installable format or an executable format, and is a computer such as a CD-ROM, a flexible disk (FD), a CD-R, or a DVD (Digital Versatile Disk). It may be configured to be recorded and provided on a recording medium that can be read by.

Further, the program executed by the printing system 1 of the present embodiment may be stored on a computer connected to a network such as the Internet and provided by downloading via the network. Further, the program executed by the printing system 1 of the present embodiment may be configured to be provided or distributed via a network such as the Internet.

[Explanation of functional configuration of printing system 1]
Next, the function exhibited by the CPU 11 of the printing system 1 by executing the program stored in the HDD 18 or the ROM 12a will be described. Here, the description of the conventionally known functions will be omitted, and the characteristic functions exhibited by the printing system 1 of the present embodiment will be described in detail.

FIG. 7 is a functional block diagram showing a functional configuration of the printing system 1.

As shown in FIG. 7, the CPU 11 of the printing system 1 includes a reading control unit 110, a motor control unit 111, a horizontal line detection unit 112, a vertical line detection unit 113, a first correction value calculation unit 114, and a second correction value calculation unit 115. Functions as ,. The CPU 11 includes a reading control unit 110, a motor control unit 111, a horizontal line detection unit 112, a vertical line detection unit 113, a first correction value calculation unit 114, a second correction value calculation unit 115, and a reading device 201. Needless to say, it is possible to realize a function such as a moving unit that moves an object (recording medium) to be read relatively in the sub-scanning direction.

In the present embodiment, the characteristic functions exhibited by the printing system 1 are realized by the CPU 11 executing the program, but the present invention is not limited to this, and for example, the functions of the above-described parts are realized. Some or all of them may be realized by a dedicated hardware circuit.

The motor control unit 111 outputs a drive signal to the motor 204 and rotationally drives the rotating member 203. Further, the motor control unit 111 outputs a drive stop signal to the motor 204 to stop the rotation of the rotating member 203.

The reading control unit 110 outputs a reading start signal to the reading device 201 to start reading by the reading device 201. When the reading control unit 110 receives the reading signal from the reading device 201, the reading control unit 110 outputs a reading end signal to the reading device 201 to end the reading by the reading device 201.

The horizontal line detection unit 112 moves the position reference member 202 in the sub-scanning direction via the motor control unit 111. Further, the horizontal line detection unit 112 reads the position reference member 202 that moves in the sub-scanning direction via the reading control unit 110 with the reading device 201. Then, the horizontal line detection unit 112 detects the coordinate position in the sub-scanning direction of each sensor chip 210 of the reading device 201.

Here, FIG. 8 is a schematic diagram showing an example of coordinate calculation in the sub-scanning direction of each sensor chip 210 of the reading device 201. As shown in FIG. 8A, the horizontal line detection unit 112 refers to the position of each sensor chip 210 of the reading device 201 in the region of An, An + 1, ..., An + m or Bn, Bn + 1, ..., Bn + m. The horizontal line of the member 202 is read to detect the coordinate position of each sensor chip 210 of the reading device 201 in the sub-scanning direction.

As described above, it is computationally advantageous to read the horizontal line of the position reference member 202 at substantially the same pixel position for each sensor chip 210. However, the present invention is not limited to this, and the pixel position for reading the horizontal line of the position reference member 202 may be changed to an arbitrary pixel for each sensor chip 210.

More specifically, the horizontal line detection unit 112 reads a region (width m pixel) of A or B of each sensor chip 210 of the reading device 201 while rotating the position reference member 202 in the sub-scanning direction. As shown in FIG. 8B, the reading values for m pixels are averaged for each line of each sensor chip 210 of the reading device 201, and the data is stored in the storage unit. The horizontal line detection unit 112 detects the coordinate position of each sensor chip 210 of the reading device 201 from the positions of the rising edge and the falling edge from the obtained data.

After the horizontal line detection unit 112 reads the horizontal line, the vertical line detection unit 113 stops the movement of the position reference member 202 via the motor control unit 111 at a position where the horizontal line does not enter the reading range. Further, the vertical line detection unit 113 reads the position reference member 202 in the stopped state by the reading device 201 via the reading control unit 110. Then, the vertical line detection unit 113 detects the coordinate position in the main scanning direction of each sensor chip 210 of the reading device 201.

The vertical line detection unit 113 is designed to stop the movement of the position reference member 202 at a position where the horizontal line does not enter the reading range, but the present invention is not limited to this, and the position reference is performed at a position where the horizontal line does not enter the reading range. It is not necessary to stop the movement of the member 202. Even when the movement of the position reference member 202 is stopped at a position where a horizontal line enters the reading range, a gap is created between the vertical line and the horizontal line as described above, so that the vertical line detection unit 113 Can detect vertical lines.

Here, FIG. 9 is a schematic diagram showing an example of coordinate calculation in the main scanning direction of each sensor chip 210 of the reading device 201. As shown in FIG. 9, the vertical line detection unit 113 has a position reference member 202 in the region of Cn, Cn + 1, ..., Cn + m or Dn, Dn + 1, ..., Dn + m for each sensor chip 210 of the reading device 201. Is read, and the coordinate position in the main scanning direction of each sensor chip 210 of the reading device 201 is detected.

More specifically, the vertical line detection unit 113 starts reading the vertical line with the position reference member 202 stopped. The number of reading lines at this time can be specified from the outside. The vertical line detection unit 113 detects the falling edge and the rising edge at the time of reading the vertical line within the range of m pixels at the center of the chip for each sensor chip 210 of the reading device 201, and detects the center coordinate position.

It should be noted that the reading of the vertical line by the vertical line detection unit 113 may be executed before the reading of the horizontal line by the horizontal line detection unit 112 or after the reading of the horizontal line by the horizontal line detection unit 112. good. In the present embodiment, the horizontal line detection unit 112 first reads the horizontal line, and then the vertical line detection unit 113 reads the vertical line in the corrected state.

The first correction value calculation unit 114 corrects the variation in the sub-scanning direction based on the coordinate position in the sub-scanning direction of each sensor chip 210 of the reading device 201 detected by the horizontal line detection unit 112.

Here, FIG. 10 is a diagram showing a method of generating a correction value. As shown in FIG. 10, the first correction value calculation unit 114 generates the first correction value from the amount of deviation of the coordinate position of each sensor chip 210 of the reading device 201 from the reference coordinates. The first correction value calculation unit 114 stores the generated first correction value in the storage unit. Then, the first correction value stored in the storage unit is used as a correction value at the time of reading the image.

If the falling edge or the rising edge cannot be detected, or if it is determined that dust is attached to the edge detection range, the first correction value calculation unit 114 is the sensor chip of the corresponding reading device 201. The correction value of 210 is not updated, and the previously generated correction value is retained as it is.

The second correction value calculation unit 115 corrects the variation in the spacing between the sensor chips 210 of the reading device 201 based on the coordinate positions in the main scanning direction of the sensor chips 210 of the reading device 201 detected by the vertical line detection unit 113. do.

Specifically, the second correction value calculation unit 115 generates the second correction value from the center coordinate position and the reference coordinate of each sensor chip 210 of the reading device 201 detected by the vertical line detection unit 113. The second correction value calculation unit 115 stores the generated second correction value in the storage unit. Then, the second correction value stored in the storage unit is used as a correction value at the time of reading the image.

If the falling edge or the rising edge cannot be detected, or if it is determined that dust is attached to the edge detection range, the second correction value calculation unit 115 may use the sensor chip of the corresponding reading device 201. The correction value of 210 is not updated, and the previously generated correction value is retained as it is.

Next, the correction process executed by the printing system 1 will be described.

Here, FIG. 11 is a flowchart schematically showing the flow of the correction process. Further, FIG. 12 is a schematic view showing a corresponding positional relationship between the reading device 201 and the position reference member 202. As shown in FIG. 12, here, a case where two reading devices 201 (201A and 201B) are used side by side will be described. The sensor chips 210 of the two reading devices 201 located outside the paper transport path are not masked and corrected.

The two reading devices 201 (201A and 201B) do not need to read the horizontal line of the position reference member 202 at substantially the same pixel position of each sensor chip 210. The two reading devices 201 (201A, 201B) may change the pixel position for reading the horizontal line of the position reference member 202 for each device.

As shown in FIG. 11, when the horizontal line reading start trigger is detected, the horizontal line detection unit 112 starts reading the horizontal line of the position reference member 202 while moving the position reference member 202 in the sub-scanning direction (step S1). .. More specifically, the horizontal line detection unit 112 moves the position reference member 202 in the sub-scanning direction via the motor control unit 111. Further, the horizontal line detection unit 112 reads the position reference member 202 that moves in the sub-scanning direction via the reading control unit 110 with the reading device 201. When the reading by the reading device 201 is completed, the reading device 201 outputs a reading end trigger to the horizontal line detection unit 112.

When the horizontal line detection unit 112 receives the reading end trigger, the horizontal line detection unit 112 stops the movement of the position reference member 202 in the sub-scanning direction and puts it in the standby state. Further, when the horizontal line detection unit 112 receives the reading end trigger, it detects the coordinate position of each sensor chip 210 of the reading device 201 in the sub-scanning direction (step S2).

Specifically, the horizontal line detection unit 112 has 10 pixels at the rear end of each sensor chip for the sensor chips 4 to 12 of the reading device 201A shown in FIG. 12, and 10 pixels at the tip of each chip for the sensor chips 1 to 9 of the reading device 201B. The falling edge and the rising edge are detected from the averaged data. FIG. 13 is a diagram showing an example of data obtained by averaging the readings. When the horizontal line detection unit 112 detects the falling edge and the rising edge (FIG. 13A), the horizontal line detecting unit 112 detects the coordinate position of each sensor chip 210 of the reading device 201 in the sub-scanning direction.

When the edge is close to the detection area and a part of the data used for calculating the H level and the L level is outside the detection area, the horizontal line detection unit 112 uses the data at the end of the detection area to determine the position of the edge. Judgment is made and the coordinate position of the sensor chip 210 is detected.

Next, the first correction value calculation unit 114 corrects the variation in the sub-scanning direction based on the coordinate position in the sub-scanning direction of each sensor chip 210 of the reading device 201 detected by the horizontal line detection unit 112. Generate (step S3).

Specifically, the first correction value calculation unit 114 uses the minimum value of the coordinate position of the reading device 201A shown in FIG. 12 from the 4th chip to the 8th chip as the reference coordinate in the sub-scanning direction of each sensor chip 210. The amount of deviation is calculated, and a value converted to 4800 dpi is generated as the first correction value.

When one falling edge and one rising edge cannot be detected (FIG. 13 (b)), or when two or more falling edges or rising edges are detected (FIG. 13 (c)), dust is contained in the data extraction area of 10 pixels. If is included, the first correction value calculation unit 114 does not generate the correction value of the corresponding sensor chip 210, and leaves the previously generated correction value as it is.

The first correction value calculation unit 114 stores the obtained first correction value in a storage unit (register) (step S4).

Next, as shown in FIG. 11, when the vertical line reading start trigger is detected, the vertical line detection unit 113 stops the position reference member 202 at a position where the horizontal line does not enter the reading range, and the vertical line detection unit 202 vertically. Line reading is started (step S5). More specifically, the vertical line detection unit 113 stops the movement of the position reference member 202 via the motor control unit 111 at a position where the horizontal line does not enter the reading range. Further, the vertical line detection unit 113 reads the position reference member 202 in the stopped state by the reading device 201 via the reading control unit 110. When the reading by the reading device 201 is completed, the reading device 201 outputs a reading end trigger to the vertical line detection unit 113.

The vertical line detection unit 113 is designed to stop the movement of the position reference member 202 at a position where the horizontal line does not enter the reading range, but the present invention is not limited to this, and the position reference is performed at a position where the horizontal line does not enter the reading range. It is not necessary to stop the movement of the member 202. Even when the movement of the position reference member 202 is stopped at a position where a horizontal line enters the reading range, a gap is created between the vertical line and the horizontal line as described above, so that the vertical line detection unit 113 Can detect vertical lines.

Upon receiving the reading end trigger, the vertical line detection unit 113 detects the coordinate position of each sensor chip 210 of the reading device 201 in the main scanning direction (step S6).

Specifically, the vertical line detection unit 113 detects the falling edge and the rising edge of the vertical line in the area of 50 pixels at the center of each sensor chip 210 of the reading device 201, and detects the coordinate position of the sensor chip 210. ..

Next, the second correction value calculation unit 115 varies the spacing between the sensor chips 210 of the reading device 201 based on the coordinate positions in the main scanning direction of the sensor chips 210 of the reading device 201 detected by the vertical line detection unit 113. A second correction value for correcting the above is generated (step S7).

Specifically, the second correction value calculation unit 115 generates a value obtained by converting the coordinate position in the main scanning direction of each sensor chip 210 of the reading device 201 detected by the vertical line detection unit 113 into 4800 dpi as the second correction value. ..

If the falling edge and the rising edge cannot be detected one by one, if two or more falling edges or rising edges are detected, or if dust is contained in the data extraction area, the second correction value calculation is performed. The unit 115 does not generate the correction value of the corresponding sensor chip 210, and leaves the previously generated correction value as it is.

The second correction value calculation unit 115 stores the obtained second correction value of the reading device 201A and the second correction value of the reading device 201B in the storage unit (register) (step S8).

Here, FIG. 14 is a diagram showing a coordinate position calculation method in the main scanning direction by the second correction value calculation unit 115. As shown in FIG. 14, the ideal distance of the vertical line in the position reference member 202 includes the distance between the sensor chips 210 of the reading device 201. On the other hand, the actual detection result of the vertical line in the position reference member 202 does not include the distance between the sensor chips 210 of the reading device 201. Therefore, the second correction value calculation unit 115 adds "ideal position of vertical line-detection position of vertical line" to the edge detection position as shown in the following equation.

P _THadj = P _TH + ideal position of vertical line (n) -detection position of vertical line (n)
_PTHadj : Detection position after correction of edge of recording medium and mark center coordinates
_PTH : The detection position of the edge of the recording medium and the mark center coordinates on the reading device 201.
Ideal position of vertical line: Ideal design value of position reference member 202 in sensor chip with edge detection + 1/2 of sensor chip
Vertical line detection position: Vertical line detection coordinates on the sensor chip that detected the edge

In the above formula, since the vertical line of the position reference member 202 is arranged at the center of each sensor chip 210 based on one pixel of the reading device 201, 1/2 of the sensor chip 210 is added.

As described above, according to the present embodiment, it is possible to accurately detect the deviation of the mounting position of the reading device. Further, according to the present embodiment, the position of the transported object and the position of the transported object are corrected by correcting the image data obtained at the time of detecting the position of the transported object and the image position by the correction value stored in the storage unit (register). The accuracy of image position detection can be improved.

Even when the reading device 201 (201A, 201B) is deformed by an external load, a vertical line and a horizontal line are drawn for each sensor chip 210, so that a correction value can be generated. Here, FIG. 15 is a diagram showing a case where the reading device 201 is deformed, and FIG. 16 is a diagram showing a part of the deformed reading device 201 in an enlarged manner. As shown in FIGS. 15 and 16, when the reading device 201 (201A, 201B) is greatly deformed by an external load, the inclination of the sensor chip 210 also changes. At this time, the horizontal line detection unit 112 calculates and compares the coordinate position of the a-th pixel in the area A and the coordinate position of the b-th pixel in the area B at the time of reading the horizontal line to determine the inclination of the sensor chip 210 itself. A correction value to be corrected can be generated.

In the present embodiment, CIS, which is a so-called 1x optical system, is applied as the reading device 201, but the present invention is not limited to this. For example, the reading device 201 may be a so-called reduction optical reading device composed of a light source, a plurality of reflecting members (mirrors), an imaging lens, a linear image sensor, and the like, and may be a reading object. If the device can detect the position of, the position detection accuracy can be improved.

In each of the above embodiments, the reading device and the image forming device of the present invention have been described with reference to an example of being applied to a printing system including an electrophotographic printing device, but the present invention is not limited to this, and the inkjet method is not limited thereto. It can also be applied to a printing system including a printing device of.

Further, in each of the above embodiments, an example in which the reading device and the image forming device of the present invention are applied to a printing system including a printing device such as a commercial printing machine (production printing machine) has been described, but the present invention is limited to this. It should be applied to any image forming device such as a multifunction device, a copier, a printer, a scanner device, a facsimile machine, etc., which has at least two functions of a copy function, a printer function, a scanner function, and a facsimile function. Can be done.

Further, in each of the above embodiments, the reading device of the present invention has been described with reference to an example of application to position detection in the image forming field, but the present invention is not limited to this, and various fields such as inspection in the FA field are described. It can be applied to the position detection application of.

Further, the reading device of the present invention can also be applied to a bill reading device that discriminates whether or not a bill is printed in a correct position and shape for the purpose of discriminating bills and preventing counterfeiting.

1 Reading device, image forming device 201 Reading device 202 Position reference member

Japanese Unexamined Patent Publication No. 2010-173069 JP-A-2015-201843

Claims (7)

A reference pattern including a line extending in a predetermined direction is arranged, and a position reference member that moves relatively in a direction orthogonal to the predetermined direction, and a position reference member.
A reading device that arranges a plurality of sensor chips having a plurality of pixels in the predetermined direction, and
With
The reference pattern includes a vertical line extending in a direction orthogonal to the predetermined direction and a horizontal line extending in the predetermined direction, and the horizontal line is in contact with the position where the vertical line exists. Arranged corresponding to the central portion of the sensor chip of the reading device,
The reading device reads the vertical line after reading the horizontal line.
A reader characterized by this. A reference pattern including a line extending in a predetermined direction is arranged, and a position reference member that moves relatively in a direction orthogonal to the predetermined direction, and a position reference member.
A reading device that arranges a plurality of sensor chips having a plurality of pixels in the predetermined direction, and
With
The reference pattern includes a vertical line extending in a direction orthogonal to the predetermined direction and a horizontal line extending in the predetermined direction, and the horizontal line is interrupted at a position where the vertical line exists. The horizontal line and the vertical line are not in contact with each other, and are arranged so as to correspond to the central portion of the sensor chip of the reading device.
The reading device reads the vertical line after reading the horizontal line.
A reader characterized by this. The position reference member moves relatively in a direction orthogonal to the arrangement direction of the sensor chips of the reading device.
The reading device according to claim 1 or 2. The reading device is
The horizontal line is read from the position reference member that moves relatively in the orthogonal direction, and the horizontal line is read.
The vertical line is read from the position reference member stopped at a position where the horizontal line does not enter the reading range.
The reading device according to any one of claims 1 to 3. A moving unit that relatively moves an object to be read by the reading device in the orthogonal direction is further provided.
The reading device according to any one of claims 1 to 4. The first correction value is generated from the amount of deviation of the coordinate position in the orthogonal direction from the reference coordinate of each of the sensor chips detected based on the read horizontal line.
A second correction value is generated from the center coordinate position and the reference coordinate in the predetermined direction of each sensor chip detected based on the read vertical line.
The reading device according to any one of claims 1 to 4. Print engine part and
A moving unit that moves the recording medium with respect to the print engine unit in a direction orthogonal to the predetermined direction of the reference pattern including a line extending in a predetermined direction, and a moving unit.
A position detection unit that detects the outer shape of the recording medium moved by the moving unit and the position of the image pattern on the recording medium from the image read by the reading device.
The reading device according to any one of claims 1 to 6.
An image forming apparatus comprising .

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