JP2006222709A - Image reader - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an image reader capable of preventing an abnormal image from being formed owing to application of vibration or a shock and a traveling body from breaking. <P>SOLUTION: The image reader includes traveling bodies 11 and 13 equipped with a light source irradiating a document with light and a mirror imaging reflected light from the document on a read means; a driving motor 31 which reciprocally moves the traveling bodies 11 and 13 in vertical scanning directions; and a motor control section 35 which controls the driving motor 31. The traveling bodies 11 and 13 are reciprocally moved from reference positions in the vertical scanning directions when a document is read, but stopped at the reference positions when no document is read. The motor control section 35 supplies a current such that the traveling bodies 11 and 13 do not shift from the reference positions to the driving motor 13 when the traveling bodies 11 and 13 are at the reference positions. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image reading apparatus.

  In Patent Document 1, in an image reading apparatus that reads a document placed on a document table, a traveling body equipped with a scanning optical system that irradiates the read document with light and forms an image of reflected light from the document on a reading unit. And a driving means for moving the traveling body in the sub-scanning direction, and a technique for waiting the traveling body at a reference position (home position) when image reading is not performed is disclosed.

JP 2002-229134 A

  However, in the conventional technique described in Patent Document 1 described above, when the traveling body is waiting at the reference position, the current flowing to the driving motor of the traveling body is turned off, and the traveling body is torque of the driving motor. And is stopped only by friction of the drive system including the drive motor.

  For this reason, when a driving motor with a small torque or a driving system with a small friction is used, if a vibration or impact is applied to the image reading apparatus from the outside, the traveling body may be displaced from the reference position. For example, when a stepping motor is used as the drive motor, the amount of movement of the traveling body is controlled by the pulse of the stepping motor. Cannot be read, and an abnormal image may occur due to color adjustment by the white reference plate and registration shift in the sub-scanning direction.

  An object of the present invention is to provide an image reading apparatus capable of preventing a traveling body from being shifted from a reference position even when vibration or impact is applied, and preventing an abnormal image from occurring.

  In order to solve the above-mentioned problem, the invention described in claim 1 includes a traveling body including a light source that irradiates light on a document and a mirror that forms an image of reflected light from the document on a reading unit. A driving motor that reciprocates in the sub-scanning direction and a motor control unit that controls the driving motor are provided, and when the document is read, the traveling body is reciprocated from the reference position in the sub-scanning direction, so When not performed, the traveling body is stopped at the reference position, and when the traveling body is at the reference position, the motor control unit supplies a current to the drive motor so that the traveling body does not deviate from the reference position. .

  The invention described in claim 2 is the invention described in claim 1, wherein the image reading apparatus does not apply the residual heat to at least the transfer portion in the normal mode in which the image formation is immediately possible and at least the transfer portion. In the normal mode, the motor controller sends a current to the drive motor so that the traveling body does not deviate from the reference position. In the energy saving mode, the motor control unit does not deviate from the reference position in the drive motor. Such a current is prevented from flowing.

  According to a third aspect of the present invention, there is provided a traveling body including a light source that irradiates light on a document and a mirror that focuses reflected light from the document on a reading unit, and a drive that reciprocates the traveling body in the sub-scanning direction. A motor, a motor control unit that controls the drive motor, and reference position detection means that detects whether or not the traveling body is at the reference position, and when reading a document, the traveling body is moved from the reference position in the sub-scanning direction; In the energy saving mode where the reciprocating movement is performed and at least no residual heat is applied to the transfer portion, when the energy saving mode is canceled, the reference position detecting means detects whether or not the traveling body is at the reference position. When it is determined by the detection means that the traveling body is not at the reference position, the traveling body is returned to the reference position by driving the drive motor.

  According to a fourth aspect of the present invention, there is provided a traveling body including a light source that irradiates light on a document and a mirror that focuses reflected light from the document on a reading unit, and a drive that reciprocates the traveling body in the sub-scanning direction. A motor, a motor control unit that controls the drive motor, a reference position detection unit that detects whether or not the traveling body is at the reference position, and an impact detection sensor that detects an impact, and travels when reading a document. When the body is reciprocated in the sub-scanning direction from the reference position and the impact detection sensor detects an impact, the reference position detection means detects whether the traveling body is at the reference position, and the traveling body is When it is determined that it is not in the position, the traveling body is returned to the reference position by driving the drive motor.

  According to the present invention, when the traveling body is at the reference position, a current that does not deviate from the reference position is supplied to the drive motor. Therefore, even if vibration or impact is applied, the traveling body is moved from the reference position. It can prevent shifting. Therefore, the reading operation is not started from the position where the traveling body deviates from the reference position, and the occurrence of an abnormal image can be prevented.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a perspective view showing an image reading apparatus of the present invention, FIG. 2 is a sectional view showing the image reading apparatus shown in FIG. 1, and FIG. 3 is a flowchart showing control of a drive motor of the image reading apparatus according to the first embodiment. is there.

  The image reading apparatus 1 according to the present embodiment includes a main body housing 5 attached to the upper part of the image forming apparatus main body 3 and a contact glass 7 provided on the upper surface of the main body housing 5. Inside the main body housing 5, a first traveling body 11 and a second traveling body 13, a condenser lens 15, and a CCD (Charge Coupled Device) 17 are arranged.

  The first traveling body 11 includes a light source 19 that irradiates light on a document placed on the contact glass 7, and a first mirror 21 that forms an image of reflected light from the document on the condenser lens 15. .

  The second traveling body 13 has two reflecting mirrors (second mirror 23 and third mirror 25), and is movable in the sub-scanning direction together with the first traveling body 11. The second mirror 23 is inclined by 45 degrees so as to face the first mirror 21 of the first traveling body 11, and the reflected light from the first mirror 21 is sent to the third mirror 25. . The third mirror 25 is inclined by 45 degrees so as to face the condenser lens 15, and transmits the light received from the second mirror 23 to the condenser lens 15.

  Next, the drive mechanism of the 1st traveling body 11 and the 2nd traveling body 13 is demonstrated. Inside the main body housing 5, a pair of scanner wires 24, 24 that are long in the sub-scanning direction are arranged apart from each other in the left-right direction, and the first traveling body 11 and the second traveling body are separated by these scanner wires 24, 24. 13 is supported movably. A drive shaft 27 is connected to the scanner wires 24 and 24, and the scanner wires 24 and 24 are moved by the rotation of the drive shaft 27, and the first traveling body 11 and the second traveling body 13 are moved in the sub-scanning direction. It is like that. The drive shaft 27 is connected to a stepping motor 31 that is a drive motor via a timing belt 29.

  A home position sensor (reference position detection means) 33 is provided at one end of the main body housing 5 in the sub-scanning direction, and the sensor 33 detects the filler attached to the first traveling body 11, so that the first traveling is performed. It is detected whether or not the body 11 is at the position of the home position sensor 33. When the home position sensor 33 detects the first traveling body 11, the detection result is transmitted to the motor control unit 35 and the stepping motor 31 is controlled according to the detection result.

  Next, operations and effects of the image reading apparatus according to the present embodiment will be described. First, an image reading operation will be described. When a document is set on the contact glass 7 and a copy start button is pressed from the operation panel 4 of the image forming apparatus main body, a print start signal is sent to the motor control unit 35. When the motor control unit 35 receives a print start signal, a drive start control signal is transmitted to the stepping motor driver, a current flows through the stepping motor 31 and the motor starts driving. When the motor is driven, the drive shaft 27 rotates forward via the timing belt 29, and the scanner wire 24 moves as the drive shaft 27 rotates.

  When the scanner wire 24 moves, the first traveling body 11 and the second traveling body 13 move from the position of the home position in the reading direction to start reading a document. When the reading of the document is completed, the driving of the stepping motor 31 is stopped at the reading end position, and a reverse current flows through the stepping motor 31 to rotate the motor in the reverse direction. When the motor is driven to rotate in the reverse direction, the scanner wire 24 also moves in the direction opposite to the reading direction, the first traveling body 11 is returned to the home position, and the home position sensor 33 removes the filler of the first traveling body 11. By detecting, a detection signal is transmitted to the motor control part 35, and the stepping motor 31 stops.

  In the normal mode (a mode in which residual heat is applied to the transfer portion so that image formation is possible immediately), the flow of steps S12 to S14 in FIG. That is, in the normal mode, it is determined by the home position sensor 33 whether the first traveling body 11 is at the home position before starting the reading operation (step S12). If it is determined that the first traveling body 11 is at the home position, a current is passed through the stepping motor 31 so that the first traveling body 11 does not deviate from the home position (step S13).

  Further, at least in the energy saving mode in which no residual heat is applied to the transfer portion, the flow of steps S15 to S17 in FIG. 3 is performed. That is, in the energy saving mode, it is determined whether or not the first traveling body 11 is at the home position by the home position sensor 33 (step S15), and it is determined that the first traveling body 11 is at the home position. However, no current flows through the stepping motor 31 (step S16).

  As described above, in the normal mode, when the first traveling body 11 is at the home position, the first traveling body 11 passes a current that does not deviate from the home position. Can prevent the first traveling body 11 from deviating from the home position, preventing the first traveling body 11 from starting from the position deviating from the home position, and preventing the occurrence of abnormal images. . In addition, since the first traveling body 11 is held at the reference position, the first traveling body 11 does not move due to acceleration due to an impact, and the first traveling body 11 is prevented from colliding with the scanner frame and being damaged. wear.

  Further, in the energy saving mode, current is prevented from flowing through the stepping motor 31 at the home position, so that waste of electric power can be saved and problems associated with a rise in motor temperature can be prevented. And a reduction in the life of the motor driver can be prevented.

  Next, other embodiments will be described. In the following description, parts having the same functions and effects as those of the first embodiment described above are denoted by the same reference numerals, and detailed description of the parts is given. In the following description, differences from the first embodiment will be mainly described. The second embodiment will be described with reference to the flowchart of FIG.

  As shown in FIG. 4, when the image forming operation is not performed in the image forming apparatus for a predetermined time, the image forming apparatus enters the energy saving mode (step S21). When the image forming apparatus enters the energy saving mode, the supply of power to the transfer unit or the like in the image forming unit is stopped. When the start button for starting copying is pressed on the operation panel 4 of the image forming apparatus, the energy saving mode is canceled (step S22). When the energy saving mode is canceled, electric power is supplied to the transfer unit and the like, and residual heat is applied. At this time, the home position sensor 33 detects whether or not the first traveling body 11 is at the home position (step S23), and the home position sensor 33 determines that the first traveling body 11 is not at the reference position. In this case, the traveling body is returned to the reference position by driving the drive motor (step S24).

  As described above, when the home position sensor 33 determines that the first traveling body 11 is not at the home position, the first traveling body 11 is returned to the home position by driving the stepping motor 31. Since the first traveling body 11 does not start the reading operation from the position deviated from the home position, the occurrence of an abnormal image can be prevented.

  A third embodiment will be described with reference to the flowchart of FIG. In the third embodiment, an impact detection sensor 37 that detects an impact is provided inside the main body housing 5. When an impact of a certain level or more is applied to the apparatus due to a person hitting the image forming apparatus main body 3, the impact detection sensor 37 is turned on (step S31). When the impact detection sensor 37 is turned on, the home position sensor 33 detects whether or not the first traveling body 11 is at the reference position (step S32), and the home position sensor 33 is not at the reference position. If it is determined that the first traveling body 11 is returned to the home position by driving the stepping motor 31 (step S33).

  Thus, when the impact detection sensor 37 detects an impact of a certain amount or more, the home position sensor 33 detects whether or not the first traveling body 11 is in the home position, and the first traveling body 11 is in the home position. If the first traveling body 11 is determined not to be in the home position by the home position sensor 33 determined not to be in the position, the first traveling body 11 is returned to the home position by driving the stepping motor 31. Therefore, the first traveling body 11 does not start the reading operation from the position deviated from the home position, and the occurrence of an abnormal image can be prevented.

  Further, only when the impact detection sensor 37 detects an impact of a certain amount or more, the home position sensor 33 detects whether or not the first traveling body 11 is in the home position, so that the document reading time can be shortened.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention. In the above-described embodiment, an error message may be displayed on the operation panel 4 when the home position sensor 33 detects that the first traveling body 11 has shifted from the home position.

1 is a perspective view showing an image reading apparatus of the present invention. It is sectional drawing which shows the image reading apparatus shown in FIG. 3 is a flowchart illustrating control of a drive motor of the image reading apparatus according to the first embodiment. 6 is a flowchart illustrating control of a drive motor of an image reading apparatus according to a second embodiment. 10 is a flowchart illustrating control of a drive motor of an image reading apparatus according to a third embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image reader 11 1st traveling body 13 2nd traveling body 31 Stepping motor (drive motor)
33 Home position sensor (reference position detection means)
35 Motor control unit 37 Impact detection sensor

Claims (4)

  A traveling body provided with a light source for irradiating light on the document and a mirror for forming an image of reflected light from the document on the reading means, a drive motor for reciprocating the traveling body in the sub-scanning direction, and motor control for controlling the drive motor The traveling body reciprocates in the sub-scanning direction from the reference position when reading the document, and the traveling body stops at the reference position when the document reading operation is not performed. An image reading apparatus characterized in that when the traveling body is at a reference position, a current is supplied to the drive motor so that the traveling body does not deviate from the reference position.   The image reading apparatus has a normal mode in which residual heat can be applied to at least the transfer section where image formation can be performed immediately, and an energy saving mode in which at least no residual heat is applied to the transfer section, and the motor control section travels to the drive motor in the normal mode. The image reading apparatus according to claim 1, wherein a current that does not deviate from the reference position is passed, and in the energy saving mode, a current that does not cause the running body to deviate from the reference position does not flow to the drive motor. .   A traveling body provided with a light source for irradiating light on the document and a mirror for forming an image of reflected light from the document on the reading means, a drive motor for reciprocating the traveling body in the sub-scanning direction, and motor control for controlling the drive motor And a reference position detecting means for detecting whether or not the traveling body is at the reference position, and when reading a document, the traveling body is reciprocated in the sub-scanning direction from the reference position, and at least in the transfer section In the energy saving mode in which no residual heat is applied, when the energy saving mode is canceled, the reference position detection unit detects whether or not the traveling body is at the reference position, and the reference position detection unit does not have the traveling body at the reference position. An image reading apparatus that returns the traveling body to a reference position by driving a drive motor when it is determined that A traveling body provided with a light source for irradiating light on the document and a mirror for forming an image of reflected light from the document on the reading means, a drive motor for reciprocating the traveling body in the sub-scanning direction, and motor control for controlling the drive motor And a reference position detecting means for detecting whether or not the traveling body is at the reference position, and an impact detection sensor for detecting an impact, and when reading a document, the traveling body is reciprocated from the reference position in the sub-scanning direction. When the impact detection sensor detects an impact, the reference position detection means detects whether or not the traveling body is at the reference position, and when it is determined that the traveling body is not at the reference position, it is driven. An image reading apparatus that returns a traveling body to a reference position by driving a motor.

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