JP2004004304A - Image reader - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image reader equipped with a document read part which is in simple structure and is easy to wire. <P>SOLUTION: The image reader is equipped with a 1st shield plate 11 which is provided nearby a read start position for a book document, a 2nd shield plate 12 which is provided nearby a sheet document read position, a sensor 6 which is provided on a reader part 3 and generates a signal when detecting the 1st or 2nd shield plate, a book document read position control part which performs control for moving the reader part to the read start position for the book document according to the position when the sensor 6 detects the 1st shield plate 11 and generates the signal, and a sheet document read position control means which performs control for moving the reader part 3 to the sheet document read position according to the position when the sensor 6 detects the 2nd shield plate 12 and generates the signal. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image reading apparatus that can be installed in a copying machine or the like that performs facsimile or image formation.
[0002]
[Prior art]
2. Description of the Related Art In a conventional image reading apparatus, for example, an image reading apparatus provided in a copying machine, a book original reading mode used when copying a book original (hereinafter, book original) and a sheet original (hereinafter, sheet original) are used. And a sheet document reading mode used when copying a document.
[0003]
FIG. 4 is a schematic diagram showing a document reading section of a conventional image reading apparatus. The conventional image reading apparatus shown in FIG. 4 includes a platen glass 1 on which a document is placed, a document feeder 2 that feeds and conveys a sheet document, and a document scanning unit that scans the document line by line in the main scanning direction. (Hereinafter, also referred to as a leader unit) 3, a shielding plate 50 provided on the leader unit 3, a leader slide rail 4 for guiding the leader unit when the leader unit moves in the sub-scanning direction, and a leader unit 3. A reader motor 5 that moves in the sub-scanning direction; a reader home position detection sensor 51 that detects a shield plate of the reader unit when the reader unit 3 is at the home position and emits a signal; A sheet document reading position detection sensor 52 that detects a shield plate of the reader unit and emits a signal when the reader unit is in the position, a platen 8, and a flat cable for transferring image data to the reader unit 3. Has a 0 and. Note that 9a and 9b are originals.
[0004]
In the image reading apparatus shown in FIG. 4, the reader unit 3 is moved to the book original reading start position P1 in the book original reading mode, and the reader unit 3 is moved to the sheet original reading position P2 in the sheet original reading mode. A means for detecting the position of the reader unit 3 is required. As such detecting means, in the conventional image reading apparatus, a leader home position detecting sensor 51 for detecting that the reader is located at the home position, and a sheet original reading position detecting for detecting that the reader is at the sheet original reading position. A sensor 52 is provided on the document table 8. A photo interrupter sensor is used for these detection sensors. The book document reading start position P1 is a position separated by a distance D51 from the detection position of the leader home position detection sensor 51, and the sheet document reading position P2 is a position separated by a distance D52 from the detection position of the leader home position detection sensor 51. ing. The sheet document position detection sensor 52 is provided on the document table 8 such that the detection position overlaps the position of the distance D52 from the reader home position detection sensor 51. In the conventional image reading apparatus having the above-described configuration, the position detection and the movement control of the reader unit 3 are performed by using the shield plate 50 provided in the reader unit and the two sensors 51 and 52.
[0005]
[Problems to be solved by the invention]
However, in the conventional image reading apparatus described above, the two sensors 51 and 52 are arranged in a complicated mechanism in which the reader unit 3 is slid in the sub-scanning direction. In addition, the processing of the bundled wires for connecting the sensors becomes complicated. Also, the use of two sensors 51 and 52 including the bundled wires not only complicates the structure of the document reading unit but also is disadvantageous from the viewpoint of cost reduction of the product.
[0006]
The present invention has been made based on the above circumstances, and an object of the present invention is to provide an image reading apparatus including a document reading unit having a simple structure and easy wiring work.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the image reading apparatus according to the first aspect of the present invention includes a document scanning unit that scans a document one line at a time in the main scanning direction, and one sheet from a document bundle at a sheet document reading position on a platen glass. A document feeder that feeds and conveys the original, and scans the book original placed on the platen glass one line at a time in the main scanning direction by the original scanning unit in the sub-scanning direction orthogonal to the main scanning direction. A book original reading mode for reading an original placed on a platen glass by scanning and driving the original scanning means, and moving the original scanning means to a sheet original reading position for reading a sheet original, and then feeding the original Reading apparatus for reading a document by scanning the document fed in the sub-scanning direction line by line in the main scanning direction by the means. A first detection object provided near a reading start position of the book document, a second detection object provided near the reading position of the sheet document, and a first detection object provided at the document scanning means. Detecting means for generating a signal when the first or second object is detected; and detecting the signal by detecting the first object when the book document reading mode is selected. Book document reading position control means for performing control to move the document scanning means to the reading start position based on the position at which the document is emitted, and wherein the detecting means detects the second detected state in the sheet document reading mode. Sheet document reading position control means for controlling the movement of the document scanning means to the sheet document reading position based on the position at which the body was detected and a signal was issued. .
[0008]
In the image reading apparatus according to the present invention, the length of the first object in the sub-scanning direction is longer than the length of the second object in the sub-scanning direction. Things.
[0009]
According to a third aspect of the present invention, in the image reading apparatus, the detecting means is a photo interrupter, and the first and second detected objects are a shielding plate or a reflecting plate.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
[Configuration of Embodiment] An image reading apparatus according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram illustrating a document reading unit of the image reading apparatus according to the present embodiment. In the present embodiment, those having the same functions as those of the conventional image reading apparatus shown in FIG. 4 are denoted by the same reference numerals, and detailed description thereof will be omitted. In the present embodiment, the position of the reader unit 3 is controlled by using one reader position detection sensor 6 provided on the reader unit 3 and the shield plates 11 and 12 which are two detection objects.
[0011]
As the reader position detection sensor 6, a photo interrupter sensor having a light emitting unit and a light receiving unit is used. The sensor 6 is set to 0 V (OFF) when the light emitted from the light emitting unit is received by the light receiving unit, and when the light emitted from the light emitting unit is blocked by the shielding plate and the light is not detected by the light receiving unit. Outputs 0V (ON). Further, the reader position detection sensor 6 and the shield plates 11 and 12 are provided such that when the reader unit 3 moves along the reader slide rail 4, the light of the light emitting unit is shielded by the shield plates 11 and 12. . An output signal of the reader position detection sensor 6 is sent to a control unit (not shown) via the flat cable 10.
[0012]
The shielding plate includes a book document shielding plate 11 which is a first detection object provided near a book document reading start position and a second detection object sheet provided near a sheet document reading position. There is a document shielding plate 12, and the control unit controls the reader based on a signal when the reader position detection sensor 6 detects the right edge of the book document shielding plate 11 (the edge at the center of the apparatus). Is moved to the reading start position P1 of the book document, and based on the signal when the reader position detection sensor 6 detects the left edge of the sheet document shielding plate 12 (the center edge of the apparatus), The reader unit 3 is moved to the sheet document reading position P2.
[0013]
The book document reading start position P1 is a position separated by a distance D1 from the right edge of the book document shielding plate 11, and the sheet document reading position P2 is a distance D3 from the left edge of the sheet document shielding plate 12. It is only a distance away. The distance from the right edge of the book document shielding plate 11 to the left edge of the sheet document shielding plate 12 is D2. Further, in this embodiment, the length L1 of the book document shielding plate 11 in the sub-scanning direction is made longer than the length L2 of the sheet document shielding plate 12 in the sub-scanning direction.
[0014]
FIG. 2 is a block diagram of a control unit of the image reading apparatus according to the present embodiment. The image reading apparatus according to the present embodiment includes a CPU 21 that controls the entire apparatus, a ROM 22 that stores a control program and various data in a nonvolatile manner, and a work area used for processing by the CPU 21 and a temporary storage area for data. A RAM 23 used, a document feed / conveyance control unit 24 for controlling sheet feed / conveyance of a sheet document, a document scan control unit 25 for performing control for scanning the document line by line in the main scanning direction, and a reader unit 3 A reader position detecting sensor 6 provided, a reader motor driving unit 26 for controlling the driving of the reader motor 5 for moving the reader unit 3 in the sub-scanning direction, and an operation unit 27 for performing operations such as copying and various settings. And a display unit 28 and the like. Further, a stepping motor is used for the reader motor 5 of the present embodiment.
[0015]
FIG. 3 is a functional block diagram of control of a reader motor of the image reading apparatus according to the present embodiment. As shown in FIG. 3, when the copy start button is pressed, the image reading apparatus according to the present embodiment, for example, detects whether or not a document is set at the entrance of the document in the document feeding / conveying apparatus. A determination unit 31 that determines whether the mode is a book document reading mode for copying a book document or a sheet document reading mode for copying a sheet document based on an output signal from When it is determined that the current mode is the book original reading mode, a book original for performing control to move the reader unit 3 to a reading start position of the book original or to move in the sub-scanning direction based on an output signal from the reader position detection sensor 6. When the reading position control unit 32 and the determination unit 31 determine that the sheet document reading mode is set, the reader unit 3 is controlled based on the output signal of the reader position detection sensor 6. And a sheet document reading position control unit 33 for controlling to move the sheet original reading position.
[0016]
[Operation of Embodiment]
When the power is turned on, the position of the reader unit 3 (sensor 6) is unknown, so that control is performed to move the reader unit 3 to the home position. If the output of the sensor 6 is turned on when the power is turned on, the sensor 6 is at a position where the shield plate 11 or the shield plate 12 is detected. At this time, the reader unit 3 is temporarily moved rightward in FIG. 1 until the output of the sensor 6 is turned off. When the sensor 6 is turned off, the reader unit 3 is moved leftward in FIG. When the output of the sensor 6 is off when the power is turned on, the sensor 6 is in a position where the shield plates 11 and 12 are not detected. At this time, the reader unit 3 is moved leftward in FIG.
[0017]
In either case, when the reader unit is moved to the left, the sensor 6 eventually detects the shielding plate, and the output is turned on. At this time, the reader unit is further moved leftward in FIG. 1 by L2, which is the length of the shielding plate 12. Since the shielding plate 11 and the shielding plate 12 are formed so that L1> L2, if the sensor 6 is turned off when moving by L2, the sensor 6 has detected the shielding plate 12 at this time. That is, the leader portion is located at the left edge of the shielding plate 12. Further, if the sensor 6 remains on even after moving by L2, the shielding plate detected by the sensor 6 at that time is the shielding plate 11. By the above operation, the control unit can recognize the position of the reader unit 3 (sensor 6) immediately after the power is turned on, and moves the reader unit to the home position based on the recognized position. For example, when the sensor 6 detects the right edge of the shield plate 11, it moves further by L2, and drives the reader motor for a few more steps from there, and sets the position where the reader unit has moved as the home position.
[0018]
When the copy start button is pressed, the determination unit 31 determines whether the mode is the book document reading mode or the sheet document reading mode. The determination as to whether the document is a book document or a sheet document can be made based on an output signal of a document detection sensor (not shown) that detects whether a document has been set at the document entrance of the document feeder 2. it can. When the document feeder 2 is opened and closed by the user and the document is placed on the platen glass 1, the document detection sensor is off, and the determination unit 31 determines that the book document reading mode is set. A signal to that effect is sent to the book document reading position control unit 32. Upon receiving this signal, the book document reading position control unit 32 moves the reader unit 3 from the home position to the book document reading start position P1 along the leader slide rail 4 by the reader motor 5 connected by a drive belt (not shown). Then, control for further moving in the sub-scanning direction (indicated by a thick arrow) is performed. As a result, the entire book document is read by the reader unit 3.
[0019]
More specifically, after the sensor 6 detects the right edge of the shielding plate 11 (after the output of the sensor 6 is turned off), the book document reading position control unit 32 determines a predetermined distance corresponding to the distance D1. The reader motor 5 is further driven by the step to move the reader unit to the position P1. When the reader unit 3 moves to the position P1, reading by the one-line sensor is started. The control unit 32 further moves the reader unit 3 rightward from the position P1 according to the size of the set document. In conjunction with this movement, the reader 3 reads the placed book document. The original placed on the platen glass 1 is scanned line by line by a reader unit 3 having a line sensor (not shown). Image data read for each sensor element by the one-line sensor is output through a flat cable 10 connected to the reader unit 3. The flat cable 10 bends and expands following the operation of the reader unit 3.
[0020]
On the other hand, when the document is set in the document feeder 2 by the user, since the document detection sensor is on, the determination unit 31 determines that the mode is the sheet document reading mode, and outputs a signal to that effect to the sheet document reading mode. It is sent to the reading position control unit 33. Upon receiving this signal, the sheet document reading position control unit 33 moves the reader unit 3 from the home position to the document reading position P2 and stops, and the document is fed to the sheet document reading position P2 by the document feed roller 2a. Wait for it to come. The original feeder 2 feeds the set originals one by one by an original feeder roller 2a and conveys the originals to a platen roller 2b arranged at a sheet original reading position P2. Specifically, the sheet reading position control unit 33 moves the reader unit 3 to the right from the home position, and after the sensor 6 detects the left edge Px of the shielding plate 12, a predetermined value corresponding to D3 is obtained. By further driving the reader motor by the number of steps, the reader unit 3 is moved to the position P2. The reason why the motor moves by a predetermined step without stopping the motor immediately after detecting the left edge Px of the shielding plate 12 is in consideration of the inertia of the motor. In addition, it is possible to move the reader unit 3 to the position P2 with reference to the right edge of the shield plate 11, but this method increases the moving distance of the leader unit and makes it impossible to perform high-precision position control. On the other hand, by controlling the movement of the reader unit with reference to the left edge of the shielding plate 12 provided near the sheet document reading position, the control of moving the lead unit 3 to the position P2 can be performed with high accuracy. Can do it. The document fed to the sheet document reading position P2 is conveyed in the sub-scanning direction by the platen roller 2b, and is discharged from the document feeding / conveying device 2. When the reader unit 3 is stopped at the document reading position P2, the whole document is read by reading the document conveyed in the sub-scanning direction line by line.
[0021]
After the copy processing is completed, when the book document is read, the reader unit is returned to the position P1. When the next book original is placed and the copy start button is pressed, the reading operation is started, and after the reading operation, the reader unit 3 is moved to the position P1. If a new book document is not placed even after a certain period of time after copying is completed, the reader unit 3 is moved to the home position and the standby mode is set. When a sheet document is read, the reader unit 3 is held at the position P2 without moving. If a sheet document remains, the next reading operation is performed, and if there is no sheet document, the reader unit is returned to the home position after a certain period of time, and a standby state is set. Thereafter, as long as the power is not turned off, the control unit 25 recognizes that the reader unit is at the home position. Therefore, every time the copy start button is pressed, the control unit 25 determines the number of steps when the reader unit moves from the home position. By storing the information in the RAM, the position of the reader unit can always be recognized.
[0022]
[Effects of the Embodiment] According to the image reading apparatus of the present embodiment, the position of the reader unit can be accurately controlled by the document reading unit having one sensor 6 and two shielding plates 11 and 12. .
[0023]
Further, according to the image reading apparatus of the present embodiment, since only one sensor for controlling the movement of the reader unit is required on the document table, the configuration of the document reading unit is simplified, and Is much easier than conventional devices having two sensors.
[0024]
[Other Embodiments] The present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, in the above-described embodiment, the transmission type photo interrupter sensor 6 is used. However, the sensor 6 may be a reflection type photo interrupter sensor, and in this case, a reflection plate is used as a detection target instead of a shielding plate. .
[0025]
Further, in the above embodiment, the case where the stepping motor is used as the leader motor has been described, but the present invention is not limited to this, and the leader motor may be a DC motor. In this case, for example, when the reader unit 3 is moved by the distance D1, the stepping motor is driven by a predetermined step corresponding to the distance D1, but the DC motor is driven by a timer or the like using a timer or the like. Drive only for hours.
[0026]
Further, the present invention is not limited to the copying machine of the above-described embodiment, and may be used for an image reading apparatus such as a multifunction peripheral having a book function and a sheet function and having a printer function and a facsimile function.
[0027]
Further, in the above embodiment, the shielding plate 11 is provided at the left end of the document table 8, but the shielding plate 11 may be located anywhere near the reading start position of the book document.
[0028]
Further, in the above-described embodiment, the control for moving the leader unit to the position P2 using the left edge of the shielding plate 12 is performed. However, this control is performed using the right edge of the shielding plate 12. May be.
[0029]
【The invention's effect】
As described above, according to the present invention, by controlling the movement of the document scanning means in the sub-scanning direction by using one detecting means and two detected objects, a document having a simple structure and easy wiring work can be obtained. An image reading device including a reading unit can be provided.
[Brief description of the drawings]
FIG. 1 is a schematic diagram illustrating a document reading unit of an image reading apparatus according to an embodiment of the invention.
FIG. 2 is a block diagram of a control unit of the image reading apparatus according to the embodiment of the present invention.
FIG. 3 is a functional block diagram of control of a reader motor of the image reading apparatus according to one embodiment of the present invention.
FIG. 4 is a schematic diagram illustrating a document reading unit of a conventional image reading apparatus.
[Explanation of symbols]
1: platen glass 2: document feeder 2a: roller
2b: Platen roller, 3: Leader part, 4: Leader slide rail,
5: reader motor, 6: sensor, 8: platen, 10: flat cable,
11: shielding plate, 12: shielding plate, 21: CPU, 22: ROM,
23: RAM, 24: Document feed / transport control unit, 25: Document scan control unit,
26: reader motor drive unit, 27: operation unit, 28: display unit,
31: determination unit, 32: book document reading position control unit,
33: Sheet document reading position control unit

Claims (3)

Document scanning means for scanning a document one line at a time in the main scanning direction, and document feeding and conveying means for feeding and conveying documents one by one from a document bundle to a sheet document reading position on a platen glass, The original placed on the platen glass is scanned by driving the original scanning unit in the sub-scanning direction orthogonal to the main scanning direction while scanning the placed book original in the main scanning direction line by line by the original scanning unit. In the book original reading mode for reading an original, the original scanning means is moved to the sheet original reading position for reading the sheet original, and then the original fed and conveyed in the sub-scanning direction by the original feeding means is scanned one line at a time. An image reading apparatus having a sheet document reading mode for reading a document by scanning in a direction,
A first detection object provided near a reading start position of the book document,
A second detection object provided near the sheet document reading position;
A detection unit provided in the document scanning unit, which emits a signal when the first or second detection target is detected;
In the book original reading mode, a book for performing control to move the original scanning unit to the reading start position based on a position at which the detection unit detects the first object and emits a signal. Document reading position control means,
In the sheet document reading mode, control is performed to move the document scanning unit to the sheet document reading position based on a position at which the detection unit detects the second object and emits a signal. Sheet document reading position control means,
An image reading apparatus comprising: 2. The image reading apparatus according to claim 1, wherein a length of the first object in the sub-scanning direction is longer than a length of the second object in the sub-scanning direction. The image reading apparatus according to claim 1, wherein the detection unit is a photo interrupter, and the first and second detection objects are a shielding plate or a reflection plate.

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