JP2010089851A - Image reader - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image reader for returning a cleaning member to a home position without damaging the cleaning member and a remaining document when stopping the image reader by the occurrence of abnormality. <P>SOLUTION: This image reader is provided for optically reading a document image in a reading position A while carrying a document immediately above reading glass 40 by an automatic document carrying device. The brush-like cleaning member 45 is oppositely reciprocally and rotatably arranged at the reading position A immediately above the reading glass 40. The cleaning member 45 cleans a reading glass surface 40 by normally rotating to the downstream side in the document carrying direction B. When the abnormality of the image reader is detected, document carrying and cleaning operation are stopped, and the cleaning member 45 is returned to a home position by normally rotating or reversely rotating so as not to interfere with the remaining document according to a carrying stopping position of the remaining document or a rotation stopping position of the cleaning member 45. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image reading apparatus, and more particularly to a sheet-through type image reading apparatus used as an image input apparatus in a copying machine, a scanner, or the like.

  Conventionally, as an image reading apparatus for optically reading an image of a document, a platen set method for reading an image of a document placed on a platen glass, and a document are conveyed one by one, and an image of the document is read during conveyance. The sheet-through method was used alone or in combination. The sheet-through method has advantages in downsizing, low cost, low noise, high-speed image reading, and high print productivity, and has become the mainstream of image reading devices in monochrome copiers and color copiers. .

  In the case of the sheet-through method, the image reading position is fixed, that is, fixed on a transparent member (long reading glass), and the reading optical system is focused on the image surface of the document conveyed through the reading glass. Due to the configuration, it is easily affected by foreign matter such as dust attached to the reading glass and residual dust, and a portion shielded by the foreign matter becomes streak-like image noise in the read image. If the manuscript is paper, it is inevitable that fine foreign substances such as fillers and fibers contained in the paper such as calcium carbonate adhere to the reading glass.

  In order to solve such problems, conventionally, in the process of processing a read image, dust on the image is detected and a warning is given to the user, streak noise is eliminated as image processing, or the reading glass is moved. Measures were taken to prevent them from reading garbage continuously. However, these measures cannot eliminate the accumulation of dust on the reading glass, and eventually a service person needs to clean the reading glass surface.

  Further, as disclosed in Patent Document 1, an image reading apparatus has been proposed in which a cleaning member having elasticity is rotated at a reading position to clean the reading glass. As described above, the method of rotating the cleaning member can shorten the cleaning time, and thus can be operated between the conveyed document and the document, which is advantageous for image reading productivity.

  However, since a cleaning operation is performed at intervals while conveying a plurality of documents continuously, when an abnormality such as a document jam occurs and the apparatus stops, the cleaning member is in a cleaning state where the cleaning member is in contact with the reading glass. It can happen to stop. If the document transport path of the reading device is opened in this state, the cleaning member is exposed to the outside. Therefore, the user may carelessly touch the cleaning member when taking out the remaining document, and the cleaning member may be damaged.

Therefore, it is desirable to stop the apparatus after returning the cleaning member to the home position when an abnormality occurs. However, even when such stop control of the apparatus is executed, depending on the stop position of the remaining document, the cleaning member that attempts to return to the home position interferes with the leading or trailing edge of the remaining document, and the document or cleaning member May be damaged. Patent Document 1 does not mention solution of this problem.
JP 2000-270152 A

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an image reading apparatus in which the cleaning member returns to the home position without causing damage to the cleaning member or the remaining original when the apparatus is stopped due to an abnormality. is there.

In order to achieve the above object, an image reading apparatus according to a first aspect of the present invention comprises:
A document conveying means for sending out the documents one by one and passing the reading position;
Reading means for optically reading an image of a document conveyed at the reading position;
A transparent member disposed between the document conveyed at the reading position and the reading unit;
An elastically deformable cleaning member that rubs and cleans the original passage surface of the transparent member;
Drive means for rotating the cleaning member forward or backward from the upstream side to the downstream side in the document conveying direction;
Control means for controlling rotation of the cleaning member and driving of other members;
First detection means for detecting a document conveyance stop position when an abnormality of the apparatus is detected;
Second detection means for detecting whether or not the cleaning member is located at a home position;
With
The controller stops the document conveyance and cleaning operation when an abnormality of the apparatus is detected, and returns the cleaning member to the home position according to the conveyance stop position of the remaining document detected by the first detection unit. Determining the direction of rotation and returning to the home position;
It is characterized by.

An image reading apparatus according to a second embodiment of the present invention is
A document conveying means for sending out the documents one by one and passing the reading position;
Reading means for optically reading an image of a document conveyed at the reading position;
A transparent member disposed between the document conveyed at the reading position and the reading unit;
An elastically deformable cleaning member that rubs and cleans the original passage surface of the transparent member;
Drive means for rotating the cleaning member forward or backward from the upstream side to the downstream side in the document conveying direction;
Control means for controlling rotation of the cleaning member and driving of other members;
A first detecting means for detecting a rotation stop position of the cleaning member when an abnormality of the apparatus is detected;
Second detection means for detecting whether or not the cleaning member is located at a home position;
With
The controller stops the document conveyance and the cleaning operation when an abnormality of the apparatus is detected, and returns the cleaning member to the home position according to the rotation stop position of the cleaning member detected by the first detection unit. Determining the direction of rotation and returning to the home position;
It is characterized by.

  When an abnormality occurs and the document conveyance and cleaning operations are stopped, the following three states can occur. (1) Stop in a state where the leading edge of the remaining document is in or near the operation locus of the cleaning member, (2) Stop in a state where the trailing edge of the remaining document is in or near the operation locus of the cleaning member, 3) Stop in a state where the remaining original covers the reading position.

  In the state of (3), since the cleaning member is not operating and is at the home position, no special control is required. In the state (1) or (2), the document or the cleaning member may be damaged depending on the direction in which the cleaning member returns to the home position. Therefore, in the first embodiment, the rotational direction in which the cleaning member is returned to the home position is determined according to the conveyance stop position of the remaining original, and the home position is returned. In the second embodiment, the rotation direction for returning the cleaning member to the home position is determined according to the rotation stop position of the cleaning member, and the home member is returned to the home position. This prevents the document or the cleaning member from being damaged when the cleaning member returns to the home position.

  More specifically, in the first embodiment, when the leading edge of the remaining document is stopped in or near the operation locus of the cleaning member, the cleaning member is rotated in the document transport direction to the home position. When the trailing edge of the remaining document is stopped in or near the operation locus of the cleaning member, the cleaning member is rotated in the direction opposite to the document conveying direction to return to the home position. In the second embodiment, when the cleaning member is stopped upstream from the reading position, the cleaning member is rotated in the document conveying direction to return to the home position, and the cleaning member is positioned downstream from the reading position. When stopped, the cleaning member is rotated in the direction opposite to the document conveying direction to return to the home position.

  Embodiments of an image reading apparatus according to the present invention will be described below with reference to the accompanying drawings. In addition, in each drawing, the same code | symbol is attached | subjected to the same component and the same part, and the overlapping description is abbreviate | omitted.

(Image reader, see FIGS. 1 and 2)
As shown in FIG. 1, an image reading apparatus 10 according to an embodiment of the present invention is conveyed by a platen set method for reading an image of a document placed on a platen glass (not shown) and an automatic document conveying device 20. A reading optical system (scanner) 50 is installed.

  The reading optical system 50 is known per se and includes a lamp 53, mirrors 54, 55, and 56, an imaging lens (not shown), and an imaging unit (CCD color line sensor) 58. In order to read a document image by the platen set method, the lamp 53 and the mirror 54 are mounted on the first slider 51, and the mirrors 55 and 56 are mounted on the second slider 52, and each can move in the sub-scanning direction Y. . Reading of a document image by the sheet-through method is performed in a state where the optical system 50 is stationary at a reading position A shown in FIG.

  The automatic document feeder 20 includes a document placing tray 21, a pickup roller 22, a paper feed roller 23a and a separating roller 23b, a registration roller 24, reading unit rollers 25 and 26, discharge unit rollers 27 and 28, A document discharge tray 29 is included. A transparent member (hereinafter referred to as a reading glass 40) is installed at the reading position A.

  Further, in this embodiment, as shown in FIG. 2, the guide sheet 41 that guides the document so that the image surface does not contact the reading glass 40 directly above the reading glass 40 is upstream of the reading glass 40 in the conveyance direction B. It is installed on the side. The original conveyed on the reading glass 40 is guided by sliding on the guide sheet 41, so that the original is conveyed in a state where the image surface is not in contact with the surface of the reading glass 40.

  When the document is transported in contact with the reading glass 40, adhesive foreign matter (adhesive material such as adhesive tape or glue, correction liquid lump, ball pen ink lump, eraser powder, etc.) adhering to the original is read glass. 40 is transferred and adhered onto the surface. By conveying the document to the reading glass 40 in a non-contact manner, such transfer and adhesion of foreign matter can be prevented in advance. Of course, in this embodiment, even if an adhesive foreign material adheres to the reading glass 40, it can be eliminated by the cleaning member 45 described below.

  In addition to providing the guide sheet 41, such non-contact conveyance is achieved by conveying the document while curving the document with a certain curvature by the reading unit rollers 25 and 26.

  Further, in this embodiment, it is also possible to invert the front and back of a document on which images are formed on both sides and pass the reading position A again to continuously read the front and back images. Such a double-sided reading mechanism for a document is well known and will not be described.

(See cleaning member, FIGS. 2-5)
As shown in FIG. 2, a brush-like cleaning member 45 is rotatably disposed facing the reading position A of the reading glass 40. Further, a striking member 46 is disposed downstream of the cleaning member 45 in the document conveyance direction B. The cleaning member 45 is a member in which a cleaning brush 45b that is elastically deformable on a flat surface of the shaft member 45a is fixed in a line shape in a direction perpendicular to the conveyance direction B. The motor M1 (see FIG. 5) has a predetermined timing, Driven forward or reverse at speed. A white reference discriminating member (white film) 45c may be attached to the outer peripheral surface of the shaft member 45a facing the cleaning brush 45b for shading correction.

  The cleaning brush 45b is, for example, a 6 mm long, 2D (denier) conductive (11.5 LogΩ) polyimide resin implanted in a width of 5 mm and a length of 309 mm, and is used when the reading glass 40 is rubbed. The amount of biting is set to 1.5 mm, and the pressure is set to 6N.

  The striking member 46 is fixed in position, and scrapes off foreign matter captured by the cleaning brush 45b after the cleaning brush 45b rubs on the reading glass 40.

  As shown in FIG. 3A, the cleaning member 45 stands by as a home position when the cleaning brush 45b faces upward, and an arrow c from the home position to the downstream side in the document transport direction. Start normal rotation in the direction. Thereafter, the tip of the brush 45b rubs the surface of the reading glass 40 (see FIGS. 3B and 3C), captures foreign matter on the reading glass 40, and removes the foreign matter from the reading position A. Thereafter, the brush 45b contacts the hammering member 46 and returns to the home position.

  The captured foreign matter is knocked out of the brush 45 b by the hitting member 46, is caught in a document conveyed on the reading glass 40, and is discharged to the outside of the apparatus 10. As a result, the surface of the reading glass 40 (in particular, the reading position A) and the brush 45b are always kept clean, and foreign matter collected from the reading glass 40 by the brush 45b does not adhere to the reading glass 40 again. Therefore, it is possible to prevent streak noise from occurring in the read image. It should be noted that the foreign matter knocked out from the brush 45b may be removed by suction by a suction means (not shown).

  The brush 45b has conductivity and is connected to the ground. Therefore, the foreign matter on the reading glass 40 can be electrostatically attracted and recovered efficiently.

  Here, the shape of the tip portion of the cleaning brush 45b will be described with reference to FIG. FIG. 4A shows a first example, in which the tip portions of the brush bristles are aligned to the same length up to the tangent line C of the rotation locus F. FIG. FIG. 4B shows a second example, in which the tip of each bristle is aligned with the rotation locus F. FIG. 4C shows a third example, in which the tip of each bristle has a length up to a straight line that forms an angle θ with the tangent C. FIG. 4 (D) shows a fourth example. The brush bristles consist of two bundles 45d and 45e, the brush bundle 45d has a length up to the tangent C, and the tip of the brush bundle 45e is along the rotation locus F. It is cut diagonally in a line.

  In the example shown in FIGS. 4B, 4 </ b> C, and 4 </ b> D, when the brush 45 b rotates and rubs on the reading glass 40, the tip of each bristle pops out from the rotation locus F. In other words, it is possible to keep the contact amount and contact pressure of the brush 45b to the reading glass 40 constant.

  By the way, the cleaning of the reading glass 40 by the cleaning member 45, that is, the normal rotation of the cleaning member 45 at the reading position A is performed at an arbitrary timing at which the brush 45b does not interfere with the original conveyed at the reading position A. In this embodiment, as will be described below, basically, the cleaning member 45 is rotated forward once between the preceding document and the next document. Of course, cleaning may be performed immediately before the reading job is started or immediately after the reading job is completed. Further, cleaning may be performed when the number of read sheets reaches an arbitrary value.

  If the cleaning member 45 is always driven to rotate forward in one direction to clean the reading glass 40, the tip of the brush 45b is deformed to bend in the rotational direction due to long-term use, and the cleaning function may be deteriorated. . In order to correct this deformation, the cleaning member 45 may be reversed at an arbitrary timing. As a result of this reverse rotation, the cleaning brush 45b rubs against the hammering member 46 and the reading glass 40 in the reverse direction to receive the deformation force in the reverse direction, the deformation is corrected, and a good cleaning function is maintained for a long time.

  Next, the drive means of the cleaning member 45 will be described with reference to FIG. The sprocket 31 fixed to one end of the shaft member 45a is connected to the output sprocket 32 of the cleaning motor M1 via the timing belt 33. The cleaning motor M1 is a stepping motor that can be driven forward and reverse.

  Further, an arc-shaped protruding piece 35 is attached to the sprocket 31, and a home position sensor SE2 for detecting the protruding piece 35 is disposed. When the sensor SE2 detects the end 35a of the protruding piece 35, it is detected that the cleaning brush 45b is located at the home position.

(Control unit, see FIG. 6)
The control unit of the image reading apparatus 10 will be described with reference to FIG. The control unit is configured with the CPU 60 as the center, and the CPU 60 includes a ROM 61, a RAM 62, and a memory 63 that store programs and the like. Information input to the CPU 60 is a detection signal of the leading and trailing edges of the document from the document sensor SE1 (see FIG. 2) arranged upstream of the reading position A, a detection signal from the home position sensor SE2 of the cleaning member 45, and the like. is there. Further, the CPU 60 controls a document conveying system such as various rollers, a cleaning motor M1, and the like.

(Abnormality detection, detection of document position and rotation position of cleaning member)
The abnormality of the image reading apparatus 10 is mainly caused by a jam of a document being conveyed. The document jam is detected by various document detection sensors arranged on the conveyance path such as the sensor SE1, and the detection timing is detected in combination with a timer. This type of detection means is well known, and detailed description thereof is omitted. . When an abnormality of the apparatus 10 is detected, the document conveyance and cleaning operations are stopped, and the cleaning member 45 is returned to the home position. This control will be described in detail below.

  The document conveyance stop position when an abnormality occurs can be detected by a combination of the detection timing of the leading edge or trailing edge of the sensor SE1 and a timer. Further, the rotation stop position of the cleaning member 45 at the time of occurrence of an abnormality can be detected by counting the number of drive pulses of the cleaning motor M1, which is a stepping motor.

(Operation of cleaning member and conveyance state of document, see FIG. 7)
Here, the operation of the cleaning member 45 and the conveyance state of the document will be described with reference to FIG. As shown in FIG. 7A, the cleaning member 45 is driven to rotate forward at an interval E between the preceding document D1 and the next document D2. When the cleaning operation is not being performed, the cleaning member 45 stands by at the home position where the brush 45b faces upward. The cleaning member 45 starts normal rotation so that the cleaning member 45 does not interfere with the rear end of the document D1 after a predetermined time has passed after the trailing end of the document D1 passes the sensor SE1. Then, as shown in FIG. 7B, the cleaning member 45 completes normal rotation so that the cleaning member 45 does not interfere with the leading edge of the document D2 until the leading edge of the next document D2 reaches the reading position A. .

(Refer to FIG. 8 for the positional relationship between the document stop position and the cleaning member)
When the document conveyance speed is high or the conveyance interval (interval E shown in FIG. 7A) is short, it is necessary to advance the start timing of the forward rotation operation of the cleaning member 45. As shown in FIG. 8A, the forward rotation of the cleaning member 45 is started immediately after the trailing edge of the preceding document D1 passes through the reading position A, or in some cases, immediately before the trailing edge of the preceding document D1 passes through the reading position A. It is necessary to start operation.

  Here, a region from when the cleaning member 45 starts the cleaning operation (forward rotation) until the tip of the brush 45b starts to contact the reading glass 40 until the contact ends is defined as an operation locus N. Immediately after the start of the cleaning operation, as shown in FIG. 8B, when the occurrence of an abnormality in the apparatus 10 is detected when the trailing edge of the preceding document D1 is in or near the operation locus N, the document transport and The cleaning operation is stopped in this state. Here, if the cleaning member is rotated in the forward rotation direction to return to the home position, the front end of the brush 45b catches the rear end of the document D1, and the document D1 or the brush 45b may be damaged. In such a state, the cleaning member 45 is reversed and returned to the home position.

  On the other hand, immediately before the end of the cleaning operation, as shown in FIG. 8C, when an abnormality is detected in the apparatus 10 when the leading edge of the next original D2 reaches the operation locus N or the vicinity thereof, The document conveyance and cleaning operations are stopped in this state. Here, by reversely rotating the cleaning member 45 and returning to the home position, the brush 45b does not interfere with the leading edge of the document D2.

  With respect to the document D1, by detecting whether or not the trailing end of the document D1 has left the movement locus N, the rotation direction for returning the cleaning member 45 to the home position can be determined. That is, if the trailing edge of the document D1 has not moved the distance of the conveyance length L1 + L2 shown in FIG. 8A through the sensor SE1, it is determined that the trailing edge of the document D1 is within the operation locus N. At this time, the cleaning member 45 is reversed and returned to the home position. The conveyance length L1 is a conveyance distance from the detection point of the sensor SE1 to the reading position A, and the conveyance length L2 is a conveyance distance from the reading position A to the end of the operation locus N.

  The detection of the trailing edge stop position of the document D1 is actually detected by time by operating a timer from the timing when the trailing edge of the document D1 passes the sensor SE1. That is, when the document conveyance speed is V, the time T during which the trailing edge of the document D1 passes through the operation locus N is T = (L1 + L2) / V. Accordingly, if the trailing edge of the document D1 passes the sensor SE1 and the time T has not elapsed, the trailing edge of the document D1 remains on the operation locus N, so that the cleaning member 45 is reversed and returned to the home position. . On the other hand, if the time T has passed since the trailing edge of the document D1 has passed the sensor SE1, the trailing edge of the document D1 has passed the operation locus N, so the cleaning member 45 is rotated forward to return to the home position. Let

(Refer to Control Example 1 and FIG. 9)
A control example 1 for determining the return rotation direction of the cleaning member 45 by detecting the trailing edge stop position of the document will be described with reference to FIG.

  When an abnormality is detected in the apparatus 10 (step S1), the document conveyance and cleaning operations are stopped (step S2), and whether or not the cleaning member 45 is at the home position is detected by the sensor SE2. If it is in the home position (YES in step S3), the control ends as it is. On the other hand, if not at the home position (NO in step S3), as described above, the trailing edge stop position of the document is determined by the combination of the trailing edge detection signal from the sensor SE1 and the timer. If the trailing edge of the document is stopped within the motion trajectory N (YES in step S4), the cleaning member 45 is reversely rotated to avoid interference (step S5). If the trailing edge of the document does not stop within the operation locus N (NO in step S4), the cleaning member 45 is rotated forward to avoid interference (step S6). Then, after confirming that the cleaning member 45 has returned to the home position by the sensor SE2 (YES in step S7), the apparatus 10 is stopped (step S8).

  When the leading edge of the next document is stopped within the operation locus N, the return of the cleaning member 45 to the home position needs to be rotated forward to avoid interference. Actually, if the trailing edge of the preceding document is not within the operation locus N in the determination in step S4, in any case, there is no problem if the cleaning member 45 is rotated forward to return to the home position. In this case, even if the leading edge of the next original remains in the operation locus N, interference with the next original by the cleaning member 45 can be avoided if it is normal rotation.

  As shown in FIG. 8B, when the cleaning member 45 is positioned upstream of the reading position A immediately after the start of the cleaning operation, the trailing edge of the preceding document D1 is at or near the operation locus N. Is located. Therefore, when the cleaning member 45 is stopped on the upstream side when an abnormality occurs, the cleaning member 45 may be reversed and returned to the home position. On the other hand, as shown in FIG. 8C, when the cleaning member 45 is positioned downstream of the reading position A immediately before the end of the cleaning operation, the leading edge of the next original D2 is at or near the operation locus N. positioned. Therefore, when the cleaning member 45 is stopped on the downstream side when an abnormality occurs, the cleaning member 45 may be rotated forward to return to the home position.

(Refer to Control Example 2 and FIG. 10)
A control example 2 for determining the return rotation direction of the cleaning member 45 by detecting the rotation stop position of the cleaning member 45 will be described with reference to FIG. The rotation stop position of the cleaning member 45 can be detected by counting the number of drive pulses of the cleaning motor M1 as described above.

  First, when an abnormality is detected in the apparatus 10 (step S11), the document conveyance and cleaning operations are stopped (step S12), and the sensor SE2 detects whether or not the cleaning member 45 is at the home position. If it is in the home position (YES in step S13), the control ends as it is. On the other hand, if it is not at the home position (NO in step S13), the rotation stop position of the cleaning member 45 is detected. If the stop position is upstream of the reading position A (YES in step S14), the cleaning member 45 is reversely rotated to avoid interference (step S15). If the stop position is downstream of the reading position A (NO in step S14), the cleaning member 45 is rotated forward to avoid interference (step S16). Then, after confirming that the cleaning member 45 has returned to the home position by the sensor SE2 (YES in step S17), the apparatus 10 is stopped (step S18).

(See Control Example 3, FIG. 11)
Incidentally, as shown in FIG. 11, the cleaning member 45 may stop at the reading position A. In this case, as shown in FIG. 11A, if the trailing edge of the preceding document D1 is stopped at or near the operation locus N, the cleaning member 45 is reversed to return to the home position. On the other hand, as shown in FIG. 11B, if the leading edge of the next original D2 is stopped at or near the operation locus N, the cleaning member 45 is rotated forward to return to the home position.

(Refer to Control Example 4 and FIG. 12)
Next, control example 4 for determining the return rotation direction of the cleaning member 45 by detecting the leading edge stop position of the document will be described with reference to FIG.

  Here, when the leading edge of the document is detected by the sensor SE1 (YES in step S21), a timer is started (step S22). When an abnormality is detected in the apparatus 10 (step S23), the document conveyance and cleaning operations are stopped (step S24), and whether or not the cleaning member 45 is at the home position is detected by the sensor SE2. If it is in the home position (YES in step S25), the control is terminated as it is. On the other hand, if it is not at the home position (NO in step S25), the count value of the timer and time T are compared.

  The time T is (L1 + L2) / V until the leading edge of the document leaves the motion locus N from the sensor SE1 (see FIG. 8A for L1 and L2). If the timer count value is greater than or equal to time T (YES in step S26), the leading edge of the document has passed through the operation locus N, so that the cleaning member 45 is reversed (step S27). If the timer count value is within the time T (NO in step S26), the leading edge of the document is positioned on the operation locus N, so the cleaning member 45 is rotated forward (step S28). Then, after confirming that the cleaning member 45 has returned to the home position by the sensor SE2 (YES in step S29), the apparatus 10 is stopped (step S30).

(Refer to Control Example 5, FIGS. 13 and 14)
In this control example 5, instead of the sensor SE1, as shown in FIG. 13, document detection sensors SE1A and SE1B are arranged close to the operation locus N on the upstream side and downstream side of the reading position A, and the sensor SE1A , SE1B based on the document leading edge detection signal, the rotation direction of the cleaning member 45 to the home position is determined.

  Specifically, as shown in FIG. 14, when the leading edge of the document is detected by the upstream sensor SE1A (YES in step S31) and then an abnormality is detected by the apparatus 10 (step S32), The cleaning operation is stopped (step S33), and whether or not the cleaning member 45 is at the home position is detected by the sensor SE2. If it is in the home position (YES in step S34), the control is terminated as it is. On the other hand, if it is not at the home position (NO in step S34), it is determined whether or not the leading edge of the document is detected by the downstream sensor SE1B.

  If it has been detected (YES in step S35), the leading edge of the document has left the movement locus N, so that the cleaning member 45 is reversed (step S36). If it is not detected (NO in step S35), the leading edge of the document is located on the movement locus N, so that the cleaning member 45 is rotated forward (step S37). Then, after confirming that the cleaning member 45 has returned to the home position by the sensor SE2 (YES in step S38), the apparatus 10 is stopped (step S39).

(Other examples)
The image reading apparatus according to the present invention is not limited to the above-described embodiments, and can be variously modified within the scope of the gist.

  For example, in the above-described embodiment, the document is conveyed in a non-contact manner with respect to the reading glass, but it is not always necessary to convey the document in a non-contact manner. Further, the striking member for the cleaning member is optional in its configuration and operation, and may be omitted.

It is a schematic block diagram which shows one Example of the image reader which concerns on this invention. It is sectional drawing which shows the vicinity of an image reading position. It is explanatory drawing which shows the cleaning operation | movement of the reading glass by a cleaning member. It is explanatory drawing which shows the various brush shape of a cleaning member. It is a perspective view which shows the drive means of the cleaning member. It is a block diagram which shows the control part of an image reading apparatus. It is explanatory drawing which shows operation | movement of a cleaning member, and the conveyance state of a document. FIG. 6 is an explanatory diagram showing a positional relationship between a document stop position and a cleaning member. It is a flowchart figure which shows the example 1 of control. It is a flowchart figure which shows the example 2 of control. It is explanatory drawing which shows the control example 3. FIG. It is a flowchart figure which shows the example 4 of control. It is explanatory drawing which shows the control example 5. FIG. It is a flowchart figure which shows the example 5 of control.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Image reading device 20 ... Automatic document feeder 40 ... Reading glass 45 ... Cleaning member 45b ... Cleaning brush 50 ... Reading optical system 60 ... CPU
M1 ... Cleaning motor A ... Reading position B ... Original transport direction D1, D2 ... Original N ... Operation locus SE1, SE1A, SE1B ... Original sensor SE2 ... Home position sensor

Claims (5)

A document conveying means for sending out the documents one by one and passing the reading position;
Reading means for optically reading an image of a document conveyed at the reading position;
A transparent member disposed between the document conveyed at the reading position and the reading unit;
An elastically deformable cleaning member that rubs and cleans the original passage surface of the transparent member;
Drive means for rotating the cleaning member forward or backward from the upstream side to the downstream side in the document conveying direction;
Control means for controlling rotation of the cleaning member and driving of other members;
First detection means for detecting a document conveyance stop position when an abnormality of the apparatus is detected;
Second detection means for detecting whether or not the cleaning member is located at a home position;
With
The controller stops the document conveyance and cleaning operation when an abnormality of the apparatus is detected, and returns the cleaning member to the home position according to the conveyance stop position of the remaining document detected by the first detection unit. Determining the direction of rotation and returning to the home position;
An image reading apparatus.   The control means rotates the cleaning member in the document transport direction to return to the home position when the leading edge of the remaining document is stopped in or near the operation locus of the cleaning member, and the trailing edge of the remaining document is 2. The image according to claim 1, wherein when the cleaning member is stopped in or near the operation locus of the cleaning member, the cleaning member is rotated in a direction opposite to the document conveying direction to return to the home position. Reader. A document conveying means for sending out the documents one by one and passing the reading position;
Reading means for optically reading an image of a document conveyed at the reading position;
A transparent member disposed between the document conveyed at the reading position and the reading unit;
An elastically deformable cleaning member that rubs and cleans the original passage surface of the transparent member;
Drive means for rotating the cleaning member forward or backward from the upstream side to the downstream side in the document conveying direction;
Control means for controlling rotation of the cleaning member and driving of other members;
A first detecting means for detecting a rotation stop position of the cleaning member when an abnormality of the apparatus is detected;
Second detection means for detecting whether or not the cleaning member is located at a home position;
With
The control means stops the document conveying and cleaning operation when an abnormality of the apparatus is detected, and returns the cleaning member to the home position according to the rotation stop position of the cleaning member detected by the first detection means. Determining the direction of rotation and returning to the home position;
An image reading apparatus.   When the cleaning member is stopped upstream of the reading position, the control means rotates the cleaning member in the document transport direction to return to the home position, and the cleaning member is positioned downstream of the reading position. 4. The image reading apparatus according to claim 3, wherein, when stopped, the cleaning member is rotated in a direction opposite to the document conveying direction to return to the home position.   5. The cleaning member according to claim 1, wherein the cleaning member is a brush, and at least a portion of the brush that contacts the transparent member is less rigid than the transparent member and elastically deforms by contact. Image reader.

Images