JPH08149251A - Automatic cleaning mechanism for close contact image sensor and information reader provided with the mechanism - Google Patents

Abstract

PURPOSE: To extend the utility range when an environment of paper is not excellent by providing a mechanism automatically cleaning a close contact image sensor in interlocking with a carrying state of the paper in the image processing unit using the close contact image sensor. CONSTITUTION: A shaft 7 and a ball screw 9 are penetrated through a cleaning block 8 arranged in a gap between a close contact image sensor 1 and a reading guide 5, and the cleaning block 8 is moved horizontally by the turning of the ball screw 9. A motor 10 delivers a rotary motion to the ball screw 9 via a 1st gear 11 and a 2nd gear 12. First and second limit switches 13,14 are used to detect the position of the cleaning block 8 and a sensor 18 detects the position of the paper to make cleaning synchronously with the carrying of the paper.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic cleaning mechanism for a contact image sensor, and more particularly to an automatic cleaning mechanism for a contact image sensor of an optical character reader (hereinafter referred to as OCR) and an image scanner.

[0002]

2. Description of the Related Art Conventionally, an automatic cleaning mechanism for a sensor is an OCR.
In an apparatus, it is used for the purpose of preventing erroneous detection due to a decrease in sensitivity of an optical sensor that detects the position of paper sheets.
According to Japanese Utility Model Laid-Open No. 4-25361 (hereinafter, referred to as Conventional Example 1), a link driving unit driven in synchronization with a light receiving signal of a sensor is automatically cleaned by a cleaning unit. The technique of wiping off is described. Further, Japanese Utility Model Laid-Open No. 62-9875 (hereinafter referred to as Conventional Example 2) describes a technique for automatically cleaning the sensor surface in conjunction with a guide plate for removing accumulated paper sheets. A similar cleaning mechanism for a magnetic head is disclosed in Japanese Patent Laid-Open No. 62-
In Japanese Patent No. 88124 (hereinafter referred to as Conventional Example 3), the positions of the cleaning portion and the cleaned portion are detected using a limit switch,
A technique is described in which the inserted magnetic sheet pack does not interfere.

In the above-mentioned OCR device, an automatic cleaning device is shown. However, image reading sensors such as contact image sensors do not have an automatic cleaning mechanism for the sensor unit.

FIG. 5 is a side view of an information reading apparatus having a conventional contact image sensor. 6 is a diagram provided for explaining the operation of the information reading device of FIG. As shown in FIG. 5, the information reading device is a contact image sensor 1
And the guide plate 6a and the leading guide 5 facing the guide plate 6a, and a pair of conveying paths are formed for a sheet conveyed from the upstream side of the apparatus (not shown), and the contact image sensor 1 and the leading guide 5 To the image input unit 22 composed of Drive roller 2a and driven roller 3a
Holds the paper sheets conveyed from the upstream side of the apparatus (not shown) and conveys them to the image input unit 22. The driving roller 2a receives a driving force from a device driving system 21 (not shown) and rotates.
The driven roller 3a is arranged in parallel with the drive roller 2a and is pressed with an appropriate pressure for conveying the paper sheets.
It should be noted that the holding method and the pressing method of the driven roller 3a may be any method.

Further, the contact image sensor 1 is attached to the frame 4 via a hinge 15 as shown in FIG. The hinge 15 allows the contact image sensor 1 to be moved to the position shown in FIG. 6 when removing the accumulated paper leaves, which is normally at the position shown in FIG. The contact image sensor 1 is cleaned at the position where the accumulated paper sheets are removed.

Next, the operation of the conventional information reader will be described with reference to FIGS. The paper sheet conveyed from the upstream side of the apparatus passes through the conveyance path formed by the guide plate 6a and the leading guide, is sandwiched by the drive roller 2a and the driven roller 3a, and is conveyed to the image input unit 22.
The image input unit 22, which is a gap formed by the contact image sensor 1 and the leading guide 5, has a thickness of paper of 0.1 mm.
Is adjusted to a value obtained by adding .about.0.2 mm, and when the paper sheet passes through the image input section 21, the image drawn on the surface of the paper sheet is input to the contact image sensor 1. In the contact image sensor 1, the surface of the conveyed sheet is further conveyed while being in contact with the sensor surface of the contact image sensor 1.
At this time, the image drawn on the surface of the paper sheet is input to the contact image sensor 1. The series of conveyance operations has an effect of self-cleaning for removing dust and the like adhering to the contact image sensor 1 and the leading guide 5.

[0007]

Since the image input mechanism using the conventional contact image sensor having no automatic cleaning mechanism is expected to have an effect of removing dirt due to friction between the contact image sensor or the leading guide and the sheet. It was not possible to clean the entire effective visual field of the contact image sensor. In addition, self-cleaning has no effect on the adhesion of stains generated from the paper sheets themselves, and periodical manual cleaning is required.

On the other hand, since the automatic sensor cleaning mechanism shown in the conventional examples 1 to 3 is intended for a relatively small sensor for the purpose of position detection, cleaning of a contact image sensor having a wide cleaning area is applied. In this case, it is necessary to control the synchronization with the paper sheet transportation in consideration of the cleaning time. Also,
Since it is necessary to clean not only the sensor (contact image sensor) but also the leading guide, a cleaning mechanism for the leading guide was also necessary. Furthermore, in the automatic cleaning mechanism of the sensor that cleans in conjunction with the operation of the guide plate, the opportunity to clean the dirt that adheres when there is no opportunity to operate the guide plate or when the device is left unoperated for a long time is lost.

Further, in the cleaning mechanism using the limit switch, since only the limit switch is used for changing the direction of the reciprocating motion, there is a problem in the treatment when the failure occurs on the return path during operation and the origin cannot be restored. is there.

Therefore, a first technical object of the present invention is to provide an automatic cleaning mechanism for a contact image sensor which can clean the contact image sensor and the leading guide in one operation.

A second technical problem of the present invention is that it is possible to clean the conveyed paper sheet without stopping the apparatus according to the state of dirt on the contact image sensor and the leading guide. It is to provide an automatic cleaning mechanism for a contact image sensor.

A third technical problem of the present invention is that automatic cleaning can be performed regardless of the length of cleaning time of a sensor having a large area. Therefore, the contact image sensor is conveyed every time one sheet is conveyed. The purpose is to provide an automatic cleaning mechanism for a contact image sensor that can be used for paper sheets that have bad conditions such as the need to clean the leading guide and expand the range of use of the device.

A fourth technical object of the present invention is to provide an automatic cleaning mechanism for a contact image sensor which can prevent secondary obstacles such as retention of paper sheets due to defective cleaning mechanism. is there.

Further, a fifth technical object of the present invention is to provide an information reading apparatus having an automatic cleaning mechanism for the contact image sensor having the above-mentioned advantages.

[0015]

In order to solve the above-mentioned problems, in the automatic cleaning mechanism of the contact image sensor of the present invention, the contact image sensor and the leading guide are passed through between the contact image sensor and the leading guide. Cleaning block for cleaning the cleaning block, drive means for driving the cleaning block independently of other functions, cleaning block position confirmation means for confirming the moving position of the cleaning block, and detection result from the cleaning block position confirmation means And a control means for controlling the operation of the cleaning block based on the above.

Further, according to the present invention, in the automatic cleaning mechanism for the contact image sensor, the cleaning block position confirming means includes a pair of switches arranged at both ends of the moving position of the cleaning block. The drive means drives the cleaning block to move toward the other of the pair of switches when the block contacts one of the pair of switches.

Further, in the present invention, in the automatic cleaning mechanism for the contact image sensor, there is provided a sensor for detecting the presence or absence of the information medium, which is provided in a conveyance path of the information medium read by the contact image sensor, When the detection sensor detects the information medium, the drive means is driven for a predetermined time after a time period over which the sheet passes the contact image sensor.

Further, the information reading apparatus of the present invention is characterized by including an automatic cleaning mechanism for any one of the contact image sensors described above.

Here, in the present invention, information refers to information that can be visually sensed and detected, such as characters and graphic images, and the information medium is a paper sheet or a film such as a plastic sheet for recording this information, or A sheet-shaped material is called.

[0020]

In the present invention, the cleaning block passes between the contact image sensor and the leading guide to clean the contact image sensor and the leading guide. The drive means drives this cleaning block independently of other functions. The cleaning block position confirmation means confirms the moving position of the cleaning block. The control means controls the operation of the cleaning block based on the movement position detection result of the cleaning block position confirmation means.

[0021]

Embodiments of the present invention will now be described with reference to the drawings. FIG. 1 is a perspective view showing an automatic cleaning mechanism of a contact image sensor of an information reading apparatus according to an embodiment of the present invention. In the example shown in FIG. 1, the contact image sensor 1 is provided with cleaning block guide guides 16 and 17. The cleaning block guide guide 17 also serves as a bracket for fixing the contact image sensor 1, and is attached to the frame 4 via a hinge 15. Further, the guide plate 6a and the leading guide 5 attached to the frame 4 form a pair of conveyance paths for the paper sheets conveyed from the upstream of an information reading device (not shown) (hereinafter simply referred to as a device). Then, the image is guided to the image input unit 22 including the contact image sensor 1 and the leading guide 5. Drive roller 2a and driven roller 3a
Holds the paper sheet conveyed from the upstream side of the apparatus (not shown) and conveys it to the image input unit 22. The drive roller 2a is attached to the frame 4 and is connected to the device drive system 21 (see FIG.
Refer to) to receive driving force and rotate. The driven roller 3a is arranged in parallel with the drive roller 2a and is pressed with an appropriate pressure for conveying the paper sheets. The driven roller 3a
Any of the holding method and the pressurizing method can be used as in the conventional example shown in FIGS.

The image input section 22 which is a gap formed by the contact image sensor 1 and the leading guide 5 is adjusted to a value obtained by adding 0.1 mm to 0.2 mm to the thickness of the paper sheet. When the paper sheet passes, the image drawn on the surface of the paper sheet is input to the contact image sensor 1.

The cleaning block 8 moves the image input section 22 in a direction intersecting the direction in which the paper sheets are conveyed, and removes dirt adhering to the contact image sensor 1 and the leading guide 5. The cleaning block 8 has a shaft 7 and a ball screw 9
Through, and both the shaft 7 and the ball screw 9 are attached to the frame 4 so as to be parallel to the contact image sensor 1. The cleaning block 8 can be moved parallel to the contact image sensor 1 by the rotation of the ball screw 9. Further, the shaft 7 has a function of stopping rotation of the cleaning block 8 and a function of guiding movement.

First and second attached frame 4
Limit switches 13 and 14 move cleaning block 8
The stop position of is detected.

Motor 1 mounted on the outside of frame 4
The 0 rotation shaft penetrates the frame and reaches the inside of the frame 4, and the first first gear 11 is attached to the inner portion of the rotation shaft. A second gear 12 is attached to the ball screw 9 and the first gear 11
Are in mesh with each other. The rotation of the motor 10 is transmitted to the ball screw 9 and the cleaning block 8 can be moved.

The sensor 18 attached to the guide plate 6a detects the passing condition of the paper sheets passing through the conveying path formed by the leading guide 5 and the guide plate 6a.

FIG. 2 is a sectional view taken along the line AA of FIG. The guide plates 6b and 6c attached to the frame 4 constitute a conveying path as a set and guide the paper sheets to the downstream side of the apparatus. The driving roller 2b and the driven roller 3b are combined as a set to form the image input unit 22.
Paper sheets are conveyed to the downstream of the device outside the mechanism. The drive roller 2b is attached to the frame 4 and receives a drive force from an apparatus drive system 21 described later to rotate. The driven roller 3b is pressed against the drive roller 2b with a pressure suitable for conveying the paper sheets.

Next, the operation of the automatic cleaning mechanism for the contact image sensor shown in FIGS. 1 and 2 will be described with reference to FIG. FIG. 3 is a sectional view taken along line BB in FIG. With reference to FIG. 3, the rotation of the motor 10 is transmitted to the first gear 11, the second gear 12, and the ball screw 9, and the cleaning block 8 moves left or right depending on the rotation direction of the motor 10.
First and second limit switches 13 and 14 are provided at opposing portions of the left and right frames, respectively. When cleaning is performed when the second limit switch 14 is in the detection state,
A current flows in the motor 10 in a direction to move the cleaning block 8 to the right. The cleaning block 8 follows the gap between the cleaning block guide guide 16 attached to the contact image sensor 1 and the leading guide 5, and moves to the right to clean the effective field of view of the contact image sensor 1 and the leading guide 5, and the first limit The switch 13 moves to the right until it is in the detection state. On the other hand, when cleaning is performed while the first limit switch 13 is in the detection state, a current is passed through the motor 10 in a direction to move the cleaning block 8 to the left, that is, a current in a direction opposite to the current to move the cleaning block 8 to the right. . As a result, the cleaning block 8 follows the gap between the cleaning block guide guide 17 attached to the contact image sensor 1 and the leading guide 5 and moves to the left to clean the effective field of view of the contact image sensor 1 and the leading guide 5, The limit switch 14 moves to the left until the detection state is reached.

Next, according to the block diagram of the control shown in FIG.
The control of the operation of the automatic cleaning mechanism shown in FIGS. 1 to 3 will be described. The control unit 19 controls the automatic cleaning mechanism of the contact image sensor of this embodiment.

The control unit 19 receives the cleaning instruction command from the device control unit 20 which controls the entire apparatus, and enters the cleaning state. The control unit 19 stores in advance a time T1 for transporting the paper sheet to the drive roller 2b, and when the cleaning state is reached, the sensor 18 for detecting the paper sheet (see FIGS. 1 and 2). If the sheet does not detect paper sheets, the cleaning operation is started with a delay of time T1. If the sensor 18 detects paper sheets at the time of the cleaning state, the cleaning operation is started with a delay of time T1 from the time when the sensor 18 switches from the state where the sensor 18 does not detect it to the state where it detects it. . As a result, it is possible to avoid a state where the paper sheets interfere with the cleaning block 8. When the sensor 18 detects the next conveyed paper sheet while the control unit 19 is in the cleaning state, the control unit 19 issues a temporary stop request for paper sheet feeding to the apparatus control unit 20. Drive device 21 to drive roller 2a
Pause. The temporary stop state of the drive roller 2a is continued until the control unit 19 is released from the cleaning state for a certain period of time.

After the sheets are completely conveyed from the cleaning mechanism, the states of the first and second limit switches 13 and 14 are detected. The first limit switch 13 is in the detection state,
When the second limit switch 14 is in the non-detection state, the control unit 1
9 applies current to the motor 10 so that the cleaning block 8 moves away from the first limit switch 13. Then, the control unit 19 applies a current to the motor 10 until the second limit switch 14 is in the detection state. When the first limit switch 13 is in the non-detection state and the second limit switch 14 is in the detection state, the control unit 19 causes the cleaning block 8 to be in the second state.
A current is applied to the motor 10 to move it away from the limit switch 14. Then, the control unit 19 applies a current to the motor 10 until the second limit switch 14 is in the detection state. The control unit 19 uses the first limit switch 13
Alternatively, when the second limit switch 14 is in the detection state, the cleaning state is released. When starting the device, the control unit 19 confirms the states of the first and second limit switches 13 and 14. If neither is in the detection state, the control unit 1
9 to the motor 10 to the cleaning block 8 the first and second
Time T2 for moving between the limit switches 13 and 14 of
Apply current for a period of time. The value of the time T2 is stored in the control unit 19 in advance. The direction of the current at this time may be arbitrary. If any of the first and second limit switches 13 and 14 is in the detection state on the way, the control unit 19 stops the motor 10 and turns on the first and second limit switches 13 and 14 during the time T2. If both of them remain in the non-detection state, an abnormality of the device is transmitted to the device control unit 20.

In addition, the first and second limit switches 1
Even when both 3 and 14 are in the detection state, the control unit 19
Transmits an abnormality of the apparatus to the apparatus control unit 20, and the apparatus control unit 20 performs a corresponding operation such as a signal for stopping the apparatus to the apparatus drive system 21.

[0033]

As described above, in the automatic cleaning mechanism for the contact image sensor according to the present invention, since the block for cleaning the gap between the contact image sensor and the leading guide forming the optical system is cleaned, the cleaning is performed. , The contact image sensor and the leading guide can be cleaned in one operation.

Further, in the automatic cleaning mechanism for the contact image sensor according to the present invention, a mechanism for driving the cleaning block independently of other functions of the apparatus, a set of limit switches for confirming the position of the cleaning block, By having a control unit that controls the drive of the block in conjunction with the conveyance of the paper sheets, the paper sheets to be conveyed can be cleaned without stopping the device in accordance with the state of dirt on the contact image sensor and the leading guide. It becomes possible to do. Further, it is possible to automatically clean a sensor having a large area regardless of the length of cleaning time. For this reason, it becomes possible to use paper sheets under bad conditions in which the contact image sensor and the leading guide must be cleaned every time one sheet is conveyed, and the range of use of the apparatus is expanded.

Further, in the automatic cleaning mechanism for the contact image sensor according to the present invention, since the position of the cleaning block is detected by a set of two limit switches, it is possible to reliably detect the occurrence of an abnormality. It is effective in preventing secondary obstacles such as retention of paper sheets due to defects.

Further, according to the present invention, it is possible to provide an information reading apparatus having an automatic cleaning mechanism for a contact image sensor having various advantages as described above.

[Brief description of drawings]

FIG. 1 is a perspective view showing an automatic cleaning mechanism of a contact image sensor of an information reading apparatus according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA in FIG.

3 is a sectional view taken along line BB in FIG.

FIG. 4 is a block diagram of an automatic cleaning mechanism for the contact image sensor according to the embodiment of the present invention.

FIG. 5 is a side view mainly showing a contact image sensor of an information reading device according to a conventional example.

FIG. 6 is a diagram which is provided for explaining the operation of the information reading device in FIG.

[Explanation of symbols]

 1 Contact image sensor 2a, 2b Drive roller 3a, 3b Driven roller 4 Frame 5 Leading guide 6a, 6b, 6c Guide plate 7 Shaft 8 Cleaning block 9 Ball screw 10 Motor 11 First gear 12 Second gear 13 First limit switch 14 Second limit switch 15 Hinge 16 Cleaning block guide guide 17 Cleaning block guide guide 18 Sensor 19 Control unit 20 Device control unit 21 Device drive system 22 Image input unit

Claims (4)

[Claims] 1. A cleaning block that passes between a contact image sensor and a leading guide to clean the contact image sensor and the leading guide; and a drive unit that drives the cleaning block independently of other functions. An automatic contact image sensor, comprising: a cleaning block position confirmation means for confirming the moving position of the cleaning block; and a control means for controlling the operation of the cleaning block based on the detection result of the cleaning block position confirmation means. Cleaning mechanism. 2. The automatic cleaning mechanism for a contact image sensor according to claim 1, wherein the cleaning block position confirmation means includes a pair of switches arranged at both ends of a position where the cleaning block moves. When one of the pair of switches contacts, the drive means drives the cleaning block to move toward the other of the pair of switches. . 3. The automatic cleaning mechanism for a contact image sensor according to claim 3, further comprising a sensor provided in a conveyance path of the information medium read by the contact image sensor, the sensor detecting presence or absence of the information medium, When the sensor detects the optical information medium, the drive means is driven for a predetermined time after a time period over which the sheet passes through the contact image sensor. Automatic cleaning mechanism. 4. An information reading device comprising an automatic cleaning mechanism for the contact image sensor according to claim 1. Description: