JP3689657B2 - Image reading apparatus, control method therefor, control program, and storage medium - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image reading apparatus having a movable image reading means, a control method thereof, a control program, and a storage medium.
[0002]
[Prior art]
Conventionally, an image reading apparatus having a movable image reading means has a sensor for detecting the home position of the image reading means, so that the image reading means is reliably moved to the home position for each reading operation. .
[0003]
[Problems to be solved by the invention]
However, having a home position sensor has a problem that it is difficult to improve the productivity of the apparatus and to make it compact.
[0004]
The present invention has been made to solve the above-described problems of the prior art, and an object of the present invention is to provide an image reading apparatus, a control method, a control program, and a storage medium that are highly productive and can be made compact. It is to provide.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, an apparatus according to the present invention provides:
Movable image reading means for reading a document;
Moving means for moving the image reading means;
Position detecting means for detecting the position of the image reading means by measuring a moving distance from a reference position;
Determination means for determining whether or not the position detection means is normal;
When the determination unit determines that the position detection unit is normal, the moving unit moves the image reading unit to the reference position, and the moving unit further moves the image reading unit from the reference position. The reference position is updated by reading the position detection image while moving the position detection unit. When the position detection unit determines that the position detection unit is abnormal by the determination unit, the image reading unit is moved by the movement unit. Reference position update means for controlling to update the reference position by moving the image to the movement limit position and reading the position detection image while moving the image reading means from the movement limit position by the movement means. When,
It is characterized by having.
[0006]
The reference position updating means determines that the position detecting means is normal by the determining means, and the position detecting image cannot be detected even if the moving means moves the image reading means from the reference position by a predetermined distance. In this case, the position detecting image is read by moving the image reading means to the movement limit position by the moving means, and further moving the image reading means from the movement limit position by the moving means. The reference position is updated .
[0007]
The reference position update unit performs error notification when the position detection image cannot be detected .
[0008]
When it is determined by the determination means that the position detection means is abnormal, the reference position update means causes the movement means to move the image reading means to the movement limit position, and a predetermined distance from the movement limit position. The position is set as a new reference position .
[0009]
The position detection image includes a black image .
[0010]
The reference position update means, among the image by the image reading means has read a predetermined ratio or more pixels in the case of black, characterized in that it is determined that I read the position detecting image.
[0011]
The position detection image includes a white image .
[0012]
The reference position update unit determines that the position detection image has been read when pixels of a predetermined ratio or more are white in the image read by the image reading unit.
[0013]
The reference position update means, characterized in that the updating of the reference position at power-up of the image reading apparatus.
[0014]
In order to achieve the above object, the method according to the present invention comprises:
A method for controlling an image reading apparatus having movable image reading means for reading a document,
A position detection step of detecting the position of the image reading means by measuring a moving distance from a reference position;
A determination step of determining whether or not position detection in the position detection step is normal;
When it is determined by the determination step that the position detection is normal, the image reading unit is moved to the reference position, and the image for position detection is moved while moving the image reading unit from the reference position. A first reference position update step of updating the reference position by reading;
When the determination unit determines that the position detection is abnormal, the image reading unit is moved to the movement limit position, and further, the position detection image is moved while moving the image reading unit from the movement limit position. A second reference position update step for updating the reference position by reading
It is characterized by including.
[0015]
In order to achieve the above object, a program according to the present invention provides:
A control program for an image reading apparatus having a movable image reading means and a processor for reading a document,
In the processor,
A position detection step of detecting the position of the image reading means by measuring a moving distance from a reference position;
A determination step of determining whether or not position detection in the position detection step is normal;
When it is determined by the determination step that the position detection is normal, the image reading unit is moved to the reference position, and the image for position detection is moved while moving the image reading unit from the reference position. A first reference position update step of updating the reference position by reading;
When the determination unit determines that the position detection is abnormal, the image reading unit is moved to the movement limit position, and further, the position detection image is moved while moving the image reading unit from the movement limit position. A second reference position update step for updating the reference position by reading
Is executed.
[0016]
In order to achieve the above object, a storage medium according to the present invention stores the above control program.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the relative arrangement of components, the display screen, and the like described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified.
[0028]
(One embodiment)
First, an MFP (Multi Function Peripheral) having both a scanning function, a printing function, and a FAX transmission / reception function will be described as an embodiment of an image reading apparatus according to the present invention.
[0029]
FIG. 1 is a block diagram showing a circuit configuration of the MFP as the present embodiment.
[0030]
A CPU 101 is a system control unit of the MFP, and controls the entire MFP.
[0031]
The ROM 102 stores an MFP system control program. The CPU 101 executes various operations related to the MFP based on a control program stored in the ROM 102. Such a control program for the CPU 101 is not limited to the one stored in the ROM 102, but may be one stored in an external storage medium such as a floppy disk or a CD-ROM. May be read into the RAM (e.g., SRAM 104), and the CPU 101 may decode and execute it.
[0032]
The printer 103 is for printing input image data on a recording sheet.
[0033]
The SRAM 104 mainly stores MFP registration data and the like, and the DRAM 105 mainly stores image data.
[0034]
The PC I / F 106 is an interface for connecting the MFP and the PC 107, and the PC 107 is a host computer that can change various setting data of the MFP and start activation of various operations via the PC I / F 106.
[0035]
The image processor 108 performs various image processing on the image data input by the image sensor 109. The image sensor 109 is an image reading unit such as a contact-type reading sensor for reading an image on a document.
[0036]
The operation panel 110 has a display 111 for displaying the state of the apparatus and the like, and is used for confirming the state of the apparatus through an operation instruction input from the operator, various data registration, and the display 111.
[0037]
The NCU 112 controls the public line network, and the modem 113 modulates and demodulates digital signals and analog signals.
[0038]
FIG. 2 is a diagram showing a positional relationship between the image reading range and the sensor home position on the document table of the MFP.
[0039]
The home position of the image sensor is set near the edge of the document table, and the document table at a position facing the image sensor near the home position is colored white by a predetermined width a as shown in the figure.
[0040]
On the other hand, a black belt-like image having a predetermined width b is prepared in advance at a position away from the home position of the image sensor by a predetermined distance in the sub-scanning direction.
[0041]
Such an image composed of two colors of a white portion a (for example, 10 mm) and a black portion b (for example, 5 mm) is referred to as a position mark. A position e (for example, 3 mm) to the left from the color boundary position of the position mark is the home position of the image sensor, and a position further to the left (for example, 2 mm) is the left end movement limit position of the image sensor. Has been. The document readable range is c (for example, 350 mm) from the right end of the black portion of the position mark, and the image sensor can be moved further to the right by f (for example, 2 mm). This position is the right limit movement limit position of the image sensor. Then, g (d + e + b + c + f in this example, 362 mm) from the left end movement limit position to the right end movement limit position is the movable range of the image sensor.
[0042]
In the present embodiment, the apparatus is configured with the above-described positional relationship. However, the present invention is not limited to this, and it is needless to say that the positional relationship of each unit can be changed according to the shape, size, and the like of the apparatus.
[0043]
FIG. 3 is a flowchart showing the home position detection process of the image sensor when the power is turned on.
[0044]
First, as a premise of this processing, in order to detect the home position of the image sensor, the reading mode of the apparatus is set to a monochrome binarization mode, and a predetermined resolution (for example, 8 pixels / mm) is set in the main scanning direction of the image sensor. ) To read the image.
[0045]
In step S301, the position counter sum stored in the SRAM backup memory is checked. Thereby, it is confirmed whether or not the value of the position counter is normal. If it is determined that the position counter is normal, the process proceeds to S302, and the image sensor is moved to a position that is considered to be the home position (a position where the counter value is 0) based on the position counter.
[0046]
The position counter is a counter that counts the number of steps of the reading motor driven to move the image sensor when the home position of the image sensor is zero. The right direction is a positive number, and the left direction is a negative number. Every time the reading motor is driven, the value stored in the backup area on the SRAM is counted up or down. Therefore, when this value is other than 0, the image sensor is in a position other than the home position, and the approximate position from the home position is also known. However, when the reading motor is idle due to a hardware problem, the actual position of the image sensor deviates from the value of the position counter, so that it is not possible to return to the home position only with the position counter. That is, the position (reference position) at which the value of the position counter becomes 0 deviates from the actual home position. In this case, it is necessary to perform an operation for returning the reference position to the actual home position. Therefore, in the following processes from S303 to S311, the boundary of the black and white reference plate is searched and the reference position is updated.
[0047]
According to the position counter, the position of the image sensor can be easily grasped, and the processing time can be shortened.
[0048]
If there are multiple motor drive patterns (for example, 150 dpi drive, 300 dpi drive, 600 dpi drive, 1200 dpi drive, etc. at 1-2 phase (monochrome reading) and microstep (color reading)), the position counter is the smallest The number of steps when driving in steps (for example, the number of microsteps at the time of color reading (6 divisions: 3600 dpi driving) may be calculated. In this example, the motor is driven one step during monochrome driving. Every time the motor is driven by one step, it is only necessary to count up or count down by 1 every time when driving the color, for example, the image sensor stops at a position 30.0mm rightward from the home position. The position counter value at that time is (30.0 × 3600 ÷ 25 4 becomes ÷ 3) × 3 = 4251.
[0049]
After moving the image sensor, the following processing is performed to confirm whether or not the position is really the home position.
[0050]
If the image sensor is really located at the home position, all white data should be obtained when image data is obtained at that position. This is because, as shown in FIG. 2, the position of the home position is white as the color of the position mark.
Therefore, in S303, one line of image data is acquired, and in S304, it is checked whether the data is all white data. If it is determined that the line is an all white line, the process returns from S305 to S303, and one line of image data is obtained again for reconfirmation, and it is checked whether the line is all white data. If it can be reconfirmed that the data is all white data, the process proceeds from S305 to S306 to search for the color boundary of the position mark.
[0051]
First, in step S306, one line of image data is acquired at that position, and in step S307, it is checked whether the data is all black data. If it is not all black data, the process proceeds to S308, moves n (for example, 0.02 mm) to the right, acquires one line of image data again, and checks whether it is all black data. This is repeated until all black data is found in S307, or until the movement distance becomes b + e (for example, 8 mm) in S309. This is because the image sensor itself may be in an abnormal state when there is no change in the acquired image data even if the position of the position mark exceeds the position b + e (for example, 8 mm) from the home position. . If all black data is found, the process proceeds from S307 to S310, moved e (for example, 3 mm) from the position to the left, and in S311, the position counter is initialized to 0 and the process ends.
[0052]
If the position counter is determined to be abnormal, cannot be determined as all white data, or all black data is not found during the above processing, the process proceeds to S312 and the following processing is performed.
[0053]
First, in S312, it is checked whether or not the processing home position check in S313 and S314 has already been performed twice. That is, the number of movements to the left end movement limit position is counted, and it is checked whether the count value is 1 or less. In the case of 1 or less, the process proceeds to S313, and the image sensor is reliably moved to the left end movement limit position. That is, for example, it is moved to the left by g or more (eg, 364 mm). This moving distance includes a margin (for example, 2 mm) considering a case where there is a backlash on the mechanism structure. Next, in S314, the left end movement limit position is moved to the right by d (for example, 2 mm). If the image sensor is moving normally, this position becomes the home position.
[0054]
Here, in order to reliably move the image sensor to the right end movement limit position, the image sensor may be moved to the right by g (eg, 364 mm), and then moved to the home position by f + c + b + e (eg, 360 mm) to the right. In this case, since the distance from the home position is shorter from the left end movement limit position than from the right end movement limit position, the processing time is shortened as a whole when the distance is moved to the left end movement limit position. However, even if it is moved to the right end movement limit position, there is no problem if it is moved reliably.
[0055]
Next, whether or not this position is really the home position is repeated in the same manner as the processing in S303 and subsequent steps. Here, when it is not determined that the data is all white data or all black data is not found, it is checked whether the home position check has already been performed twice.
[0056]
In S312, if the home position check has already been performed twice (when the number of movements to the left end movement limit position in S313 is 2), in order to move the image sensor to the left end movement limit position reliably, in S315 The position is temporarily set to the home position by moving g to the left (for example, 364 mm) and then moving to the right by d (for example, 2 mm) in S316. In this case, as described above, the process of moving to the right end movement limit position may be performed. If it is temporarily moved to the home position, the process proceeds to S317, where the position counter is initialized to zero. However, in this case, there is a possibility that the image sensor is in the middle of movement and the motor has failed and is not moved properly. It is not certain whether this is the home position. To do.
[0057]
In the present embodiment, the number of home position detection operations is two, but it goes without saying that other numbers may be adopted in accordance with the configuration of the apparatus.
[0058]
FIG. 4 is a flowchart showing home position detection processing of the image sensor after completion of reading and after interruption.
[0059]
After the reading is finished, the image sensor home position detection operation flow after interruption does not check whether the position counter is normal at the start of processing, and all other processing is performed when the power is turned on as shown in FIG. This is the same as the home position detection operation flow. Accordingly, the boxes having the same processing contents are denoted by the same reference numerals and description thereof is omitted.
[0060]
FIG. 5 is a diagram illustrating a method for determining all white data during the home position detection process of the image sensor.
[0061]
For example, when the image sensor of the present apparatus has an A4 width (216 mm) in the main scanning direction, it is possible to acquire a maximum of 216 bytes of data per line in the monochrome binarization mode and a resolution of 8 pixels / mm. . However, the data at both ends may be invalid due to the structure of the device and the influence of light. Therefore, the 8-byte data at both ends are ignored, and in S501, it is determined whether the 200-byte data in the central portion is white data (0x00) for each byte (every 8 pixels). In S502, if 90% or more of the 200 bytes is white data, the process proceeds to S503 and is determined to be all white data. If it is less than 90%, the process proceeds to S504 and it is determined that the data is not all white data. In this way, the determination condition is made stricter by determining every byte (every 8 pixels), but the processing time can be shortened. In the present embodiment, the numerical values as described above are given, but the present invention is not limited to this, and it goes without saying that various combinations can be made in consideration of the width of the image sensor, the structure of the apparatus, and the like. Yes.
[0062]
FIG. 6 is a diagram illustrating a method for determining all black data during the home position detection process of the image sensor.
[0063]
For example, when the image sensor of the present apparatus has an A4 width (216 mm) in the main scanning direction, it is possible to acquire a maximum of 216 bytes of data per line in the monochrome binarization mode and a resolution of 8 pixels / mm. . However, the data at both ends may be invalid due to the structure of the device and the influence of light. Therefore, the 8-byte data at both ends is ignored, and it is determined in S601 whether the 200-byte data in the center is black data (0xFF) for each byte (every 8 pixels). In S602, if 50% or more of the 200 bytes is black data, the process proceeds to S603, where it is determined that the data is all black data. If it is less than 50%, the process proceeds to S604, and is not all black data. to decide. When the white part is detected, the surface is read, but in this case, the boundary line from white to black is detected. It is a numerical value that takes into account. In this way, the determination condition is made stricter by determining every byte (every 8 pixels), but the processing time can be shortened. In the present embodiment, the numerical values as described above are given, but the present invention is not limited to this, and it goes without saying that various combinations can be made in consideration of the width of the image sensor, the structure of the apparatus, and the like. Yes.
[0064]
Note that the present invention can be applied to a system including a plurality of devices (for example, a host computer, an interface device, a reader, and a printer), and a device (for example, a copying machine and a facsimile device) including a single device. You may apply to.
[0065]
Another object of the present invention is to supply a storage medium (or recording medium) in which a program code of software that realizes the functions of the above-described embodiments is recorded to a system or apparatus, and the computer (or CPU or CPU) of the system or apparatus. Needless to say, this can also be achieved by the MPU) reading and executing the program code stored in the storage medium. In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention. Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an operating system (OS) running on the computer based on the instruction of the program code. It goes without saying that a case where the function of the above-described embodiment is realized by performing part or all of the actual processing and the processing is included.
[0066]
Furthermore, after the program code read from the storage medium is written into a memory provided in a function expansion card inserted into the computer or a function expansion unit connected to the computer, the function is based on the instruction of the program code. It goes without saying that the CPU or the like provided in the expansion card or the function expansion unit performs part or all of the actual processing and the functions of the above-described embodiments are realized by the processing.
[0067]
When the present invention is applied to the above storage medium, the storage medium stores program codes corresponding to the flowcharts described above (shown in FIGS. 3 and / or 4).
[0068]
【The invention's effect】
As described above, according to the present invention, it is possible to provide an image reading apparatus that is highly productive and that can be made compact, a control method thereof, a control program, and a storage medium.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a schematic configuration of an MFP as an embodiment of the present invention.
FIG. 2 is a diagram illustrating a positional relationship between an image reading range of an MFP and a sensor home position according to an embodiment of the present invention.
FIG. 3 is a flowchart showing home position detection processing of the image sensor at power-up in the MFP as one embodiment of the present invention.
FIG. 4 is a flowchart illustrating home position detection processing of the image sensor after the end of reading and after interruption in the MFP as one embodiment of the present invention;
FIG. 5 is a flowchart illustrating processing for determining whether the data is all white data in the MFP according to the embodiment of the present invention.
FIG. 6 is a flowchart illustrating processing for determining whether the data is all black data in the MFP according to the embodiment of the present invention.

Claims (12)

Movable image reading means for reading a document;
Moving means for moving the image reading means;
Position detecting means for detecting the position of the image reading means by measuring a moving distance from a reference position;
Determination means for determining whether or not the position detection means is normal;
When the determination unit determines that the position detection unit is normal, the moving unit moves the image reading unit to the reference position, and the moving unit further moves the image reading unit from the reference position. The reference position is updated by reading the position detection image while moving the position detection unit. When the position detection unit determines that the position detection unit is abnormal by the determination unit, the image reading unit is moved by the movement unit. Reference position update means for controlling to update the reference position by moving the image to the movement limit position and reading the position detection image while moving the image reading means from the movement limit position by the movement means. When,
An image reading apparatus comprising: The reference position updating means determines that the position detecting means is normal by the determining means, and the position detecting image cannot be detected even if the moving means moves the image reading means from the reference position by a predetermined distance. In this case, the position detecting image is read by moving the image reading means to the movement limit position by the moving means, and further moving the image reading means from the movement limit position by the moving means. The image reading apparatus according to claim 1, wherein the reference position is updated . The image reading apparatus according to claim 1, wherein the reference position updating unit performs error notification when the position detection image cannot be detected . When it is determined by the determination means that the position detection means is abnormal, the reference position update means causes the movement means to move the image reading means to the movement limit position, and a predetermined distance from the movement limit position. The image reading apparatus according to claim 1 , wherein the position is a new reference position . The position detection image, the image reading apparatus according to any one of claims 1 to 4, characterized in that it comprises a black image. The reference position updating unit determines that the position detection image has been read when pixels of a predetermined ratio or more are black in the image read by the image reading unit. The image reading apparatus according to 5 . The image reading apparatus according to claim 1, wherein the position detection image includes a white image. The reference position updating unit determines that the position detection image is read when pixels of a predetermined ratio or more are white in the image read by the image reading unit. 8. The image reading device according to 7. The image reading apparatus according to any one of claims 1 to 8 wherein the reference position update means during power-up of the image reading apparatus is characterized in that updating of the reference position. A method for controlling an image reading apparatus having movable image reading means for reading a document,
A position detection step of detecting the position of the image reading means by measuring a moving distance from a reference position;
A determination step of determining whether or not position detection in the position detection step is normal;
When it is determined by the determination step that the position detection is normal, the image reading unit is moved to the reference position, and the image for position detection is moved while moving the image reading unit from the reference position. A first reference position update step of updating the reference position by reading;
When it is determined in the determination step that the position detection is abnormal, the image reading unit is moved to a movement limit position, and further, the position detection image is moved while moving the image reading unit from the movement limit position. A second reference position update step for updating the reference position by reading
A control method for an image reading apparatus. A control program for an image reading apparatus having a movable image reading means and a processor for reading a document,
In the processor,
A position detection step of detecting the position of the image reading means by measuring a moving distance from a reference position;
A determination step of determining whether or not position detection in the position detection step is normal;
When it is determined by the determination step that the position detection is normal, the image reading unit is moved to the reference position, and the image for position detection is moved while moving the image reading unit from the reference position. A first reference position update step of updating the reference position by reading;
When it is determined in the determination step that the position detection is abnormal, the image reading unit is moved to a movement limit position, and further, the position detection image is moved while moving the image reading unit from the movement limit position. A second reference position update step for updating the reference position by reading
A control program characterized by causing A storage medium storing the control program according to claim 11 .

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