JP2014014004A - Image reader and image forming apparatus equipped with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image reader which can suppress decrease of an irradiation light amount to an image face of a document, can improve irradiation efficiency and can improve reading productivity by increase of image reading speed.SOLUTION: An image reader includes: a document platen unit 61 for making a transferred document P pass on a slit glass 42; a light source unit 51 for irradiating an image face of the document P with light from a light source 51a; a light receiving unit 54; and a case unit 55 which is movably arranged in a position detached from the document platen unit 61; and a reflector unit 34 which is installed between the document platen unit 61 and the case unit 55 and reflects light from the light source 51a toward the document P. The reflector unit 34 includes a movable bracket 62 having a bent section 62c which is brought into contact with the case unit 55 and a document platen unit side reflector 63a which moves by following the case unit 55 via the bent section 62c and reflects the light from the light source 51a toward the document P.

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus and an image forming apparatus including the image reading apparatus, and more particularly to an image reading apparatus that reads a two-dimensional image such as characters or figures drawn on a document or a book, and a facsimile apparatus including the image reading apparatus, The present invention relates to an image forming apparatus such as a copying machine or a multifunction peripheral.

This type of image reading apparatus guides light from a light source unit to irradiate a document, and receives an image of reflected light reflected from the document into an electrical signal corresponding to the intensity of the light, for example, an image sensor. The document image is configured to be read.
In this image reading apparatus, an optical system in which the focal length on the optical axis of the reflected light is shortened, that is, a short focus optical system is used, and the image reading apparatus is miniaturized.

In image reading apparatuses, a so-called sheet-through type reading method is widely used in which a document is automatically conveyed from a bundle of documents set on a document conveying device and is read at a reading position. On the other hand, there is also widely used a book type reading method that performs reading while fixing an original at a reading position and moving an image reading apparatus without conveying the original.
The sheet-through type reading method has an advantage that the image reading speed, that is, the productivity of image reading can be increased as compared with the book type reading method.

Conventionally, in the sheet-through type reading method, the image reading speed has been increased in order to further improve productivity.
In order to increase the image reading speed while maintaining the image reading performance such as the accuracy and quality of image reading, in the image reading apparatus using the above-mentioned short focus optical system, the irradiance of light irradiating the document (MW / cm ² ) needs to be increased. That is, it is necessary to increase the amount of light applied to the document.

In this image reading apparatus, it is necessary to move the light source unit that irradiates light to the original while irradiating light to the fixed original so as to correspond to the book-type reading method.
For this reason, a structure is required in which a gap for movement is required between the light source unit and the sheet-through type reading position or book type document table. In this structure, when light is emitted from the light source unit to the original, a part of the light emitted from the gaps described above leaks, and the irradiation efficiency decreases due to a decrease in the amount of light applied to the image surface of the original. There is a problem that the performance is degraded.

Conventionally, an image reading apparatus of this type is known which includes a light guide that guides light from a light source to an image surface of a document and a reflector that reflects light from the light source and irradiates the image surface of the document. (For example, refer to Patent Document 1).
In this image reading apparatus, the light guide has an incident surface on which the light source is incident, a reflecting surface that reflects incident light toward the image surface of the document, and an emitting surface that emits incident light toward the reflecting plate. doing. In this image reading apparatus, the light reflected from the reflecting surface is applied to the image surface of the document and the light reflected from the reflecting plate is applied to the image surface of the document. Therefore, the irradiation efficiency is improved.

  Further, as a conventional image reading apparatus, a main reflector that reflects and irradiates light on an image surface of a document, and provided at both ends of the main reflector in the width direction of the document, reflects light on the image surface of the document. What has a sub reflector to irradiate is known (for example, refer to patent documents 2).

  This sub-reflector has a first reflector and a second reflector, and the image surface of the document is illuminated by the reflected light reflected by the sub-reflector and the reflected light reflected by the main reflector. . As a result, the variation in the amount of irradiation light for each part of the image surface becomes stepless, density unevenness is reduced, and the irradiation efficiency is improved.

  However, the conventional image reading apparatuses described in Patent Document 1 and Patent Document 2 described above have a structure that requires a gap between a light source and a sheet-through type reading position or a book-type document table. ing. In the conventional image reading apparatuses described in Patent Document 1 and Patent Document 2, the problem that a part of the light emitted from the gap leaks is not considered, and the amount of light applied to the image surface of the document is not considered. The problem that the irradiation efficiency decreases and the image reading performance decreases due to the decrease has not been solved.

  The present invention has been made to solve such a problem, and can suppress a decrease in the amount of light applied to the image surface of the document, improve the irradiation efficiency, and increase the image reading speed to improve the reading productivity. An object of the present invention is to provide an image reading apparatus capable of improving the image quality.

  In order to solve the above-described problem, an image reading apparatus according to the present invention irradiates an image surface of a document through a light source plate with a document table unit passing a conveyed document on a transparent member and a light source plate. A light source unit; a light receiving unit that receives reflected light reflected from the image plane; and the light source unit and the light receiving unit are housed and spaced from the document table unit with respect to the document table unit. An image reading apparatus including a casing unit movably provided upstream and downstream in a conveyance direction, and disposed between the document table unit and the casing unit, and from a light source of the light source unit A reflector unit that reflects the light toward the document, the reflector unit being in contact with the housing unit; A reflecting portion of the light from the light source is reflected toward the manuscript with moves following to the housing unit, characterized by having a movable bracket which is formed.

  According to the present invention, there is provided an image reading apparatus capable of suppressing a decrease in the amount of light applied to an image surface of a document, improving irradiation efficiency, and improving reading productivity by increasing an image reading speed. be able to.

1 is a perspective view illustrating an entire copying machine including an image reading apparatus according to an embodiment of the present invention. 1 is a perspective view illustrating an image reading apparatus according to an embodiment of the present invention. 1 is a perspective view showing an image reading apparatus according to an embodiment of the present invention, and shows a state where a scanner cover part and a scanner frame part are disassembled. FIG. FIG. 3 is a cross-sectional view of the integrated optical scanning unit of the image reading apparatus according to the embodiment of the present invention, showing a state where the integrated optical scanning unit is positioned below the white reference plate. It is sectional drawing of the integrated optical scanning unit of the image reading apparatus which concerns on embodiment of this invention, and shows the state which an integrated optical scanning unit is located in the lower part of slit glass. 5A is a cross-sectional view of an integrated optical scanning unit of an image reading apparatus according to an embodiment of the present invention, FIG. 5A is a partial cross-sectional view enlarging a part of FIG. 4, and FIG. It is the fragmentary sectional view which expanded the part. It is a top view of the reflecting plate unit of the image reading apparatus which concerns on embodiment of this invention, and shows the state in which a part of integrated optical scanning unit is located in the lower part of a white reference | standard board. 8A and 8B are cross-sectional views of the reflector unit of the image reading apparatus according to the embodiment of the present invention, in which FIG. 7A shows the AA cross section of FIG. 7 and FIG. 7B shows the BB cross section of FIG. It is a top view of the reflecting plate unit of the image reader which concerns on embodiment of this invention, and shows the state in which a part of integrated optical scanning unit is located in the lower part of slit glass. FIGS. 10A and 10B are cross-sectional views of a reflecting plate unit of an image reading apparatus according to an embodiment of the present invention, in which FIG. 9A shows a CC cross section of FIG. 9 and FIG. 9B shows a DD cross section of FIG. 1 is a perspective view in which a part of an integrated optical scanning unit of an image reading apparatus according to an embodiment of the present invention is broken.

  An embodiment in which an image forming apparatus including an image reading apparatus according to the present invention is applied to a copying machine 1 will be described.

  As shown in FIG. 1, the copying machine 1 includes a document conveying device 11, an image reading device 12, and an image recording device 13.

The document transport device 11 includes a document tray 21, a paper discharge tray 22, a document transport unit 23, and an opening / closing mechanism 24.
The document tray 21 is a tray on which documents are stacked and the discharge tray 22 is a tray on which discharged documents, so-called discharged sheets, are stacked. The document transport unit 23 automatically transports documents one by one from the document tray 21 to the paper discharge tray 22. The opening / closing mechanism 24 has a pair of hinges for opening and closing the document conveying device 11 with respect to the image reading device 12.

  In the document transport device 11, the document placed on the document tray 21 is automatically transported by a document transport unit 23 onto a slit glass 42 of the image reading device 12 described later, and the document being transported on the slit glass 42. A so-called sheet-through type reading method in which a drawn image is read is employed.

  Further, in the document conveying device 11, the document placed on the contact glass 43 of the image reading device 12 described later is fixed by closing the document conveying device 11 without being conveyed, and is drawn on the document. A so-called book-type reading method in which an image is read is also employed.

As shown in FIG. 2, the image reading apparatus 12 moves the scanner cover portion 31, the scanner frame portion 32, the integrated scanning optical unit 33, the reflection plate unit 34, and the integrated scanning optical unit 33 (not shown). And a unit moving mechanism.
As shown in FIG. 3, the scanner cover portion 31 includes a cover 41, a slit glass 42 as a transparent member, a contact glass 43, a slit glass holder 44, a contact glass holder 45, and a white reference plate 46. doing.

The cover 41 is formed on a flat flat plate, and has a square glass mounting hole 41a. A slit glass 42 and a contact glass 43 are mounted in the glass mounting hole 41a.
The slit glass 42 is made of flat transparent glass so that light emitted from the light source can pass therethrough. The slit glass 42 only needs to be transparent, and may be formed of other materials such as plastic. The slit glass 42 is formed in a rectangular shape having a small width in the sub-scanning direction, which is the conveyance direction of the document to be conveyed, and a large width in the main scanning direction orthogonal to the document conveyance direction.

An image drawn on the document conveyed by the document conveying device 11 through the slit glass 42 is read.
Similar to the slit glass 42, the contact glass 43 is made of flat transparent glass so that light emitted from the light source can pass therethrough. The contact glass 43 may be transparent and may be formed of other materials such as plastic.
The contact glass 43 is formed in a square having a large width in both the sub-scanning direction and the main scanning direction.
Through this contact glass 43, an image drawn on an original fixed to the original conveying device 11 is read.

  As shown in FIGS. 3, 4, and 5, the slit glass holder 44 has a slit glass holding portion 44a and a document guide portion 44b having an inclined surface. One end portion of the slit glass 42 is held by the slit glass holding portion 44a, and the conveyance of the original entering the slit glass 42 is guided by the inclined surface of the original guide portion 44b.

The contact glass holder 45 includes a contact glass holding part 45a, a slit glass holding part 45b, a document guide part 45c having an inclined surface, and a white reference plate holding part 45d.
In the contact glass holder 45, one end portion of the contact glass 43 is held by the contact glass holding portion 45a, and the other end portion of the slit glass 42 is held by the slit glass holding portion 45b. In addition, the inclined surface of the document guide portion 45c guides the conveyance of the document exiting from the slit glass 42. Further, the white reference plate 46 is held by the white reference plate holding portion 45 d so as to be pressed against the contact glass 43.

  The white reference plate 46 is sandwiched and fixed between the contact glass 43 and the contact glass holder 45. That is, the integrated scanning optical unit 33 is provided near the stop position where the operation of the integrated scanning optical unit 33 ends and the integrated scanning optical unit 33 stops. The unit 33 can irradiate the white reference plate 46 with light. Therefore, the white reference plate 46 only needs to be positioned in the vicinity of the stop position of the integrated scanning optical unit 33, and is disposed on the left side of the slit glass 42 on the paper surface of FIG. The glass 42 and the contact glass 43 may be arranged in this order.

The white reference plate 46 is used for correcting various distortions generated in the reading optical system in the integrated scanning optical unit 33, so-called shading correction, and has an image surface on which a reference white image is formed. Yes.
Note that image reading for shading correction is performed, for example, until the document is conveyed. That is, until the document is conveyed, the integrated scanning optical unit 33 emits light to the white reference plate 46, and the white image on the white reference plate 46 is read and stored as shading data in the storage unit. This shading data is used as a reference for the gray level of the image.

  As shown in FIG. 3, the scanner frame portion 32 is formed of a rectangular plastic or metal material box having an upper opening, and the integrated scanning optical unit 33 and the unit moving mechanism are accommodated therein. . The scanner frame portion 32 has a scanner rod 32a and a scanner guide 32b arranged along the sub-scanning direction. The scanner rod 32a and the scanner guide 32b guide the movement of the integrated scanning optical unit 33 in the sub-scanning direction.

  The integrated scanning optical unit 33 is integrated as one unit. As shown in FIGS. 4 and 5, the light source unit 51, the reflection mirror unit 52, the lens unit 53, and the light receiving unit 54 are integrated. The housing unit 55 and a moving mechanism connecting unit (not shown) are included.

As shown in FIGS. 6A and 6B, the light source unit 51 includes a light source 51a, a substrate 51b that holds the light source 51a, and a light guide plate 51c.
The light source unit 51 is disposed at a position facing the image surface of the document P in the housing unit 55, and directly irradiates light from the light source through the light guide plate 51c.
The light source 51a includes a plurality of point light sources such as high-intensity LEDs (Light Emitting Diodes) arranged in the main scanning direction. The light source 51a may be a light source having an elongated tubular single structure such as a cold cathode tube, or may be a surface light source such as an organic EL (Electro Luminescence) panel.
The light guide plate 51c is fixed to the housing unit 55, holds the substrate 51b, and reflects the light emitted from the light source 51a in the direction of the arrows in FIGS. It is configured to lead to the image plane.

The reflection mirror unit 52 includes a first mirror 52a, a second mirror 52b, a third mirror 52c, a fourth mirror 52d, and a fifth mirror 52e. Each mirror is fixed to the housing unit 55.
As shown in FIG. 4, the first mirror 52 a is disposed below the image surface of the document P so as to receive and reflect the reflected light reflected from the image surface of the document P first.
The second mirror 52b is disposed below the contact glass 43 side in the housing unit 55 so as to receive and reflect the reflected light reflected by the first mirror 52a.
The third mirror 52c is disposed below the slit glass 42 side of the housing unit 55 so as to receive and reflect the reflected light reflected by the second mirror 52b and to face the second mirror 52b.

The fourth mirror 52d is positioned above the second mirror 52b so as to receive and reflect the reflected light reflected by the third mirror 52c, and is disposed to face the third mirror 52c.
The fifth mirror 52e is positioned below the third mirror 52c so as to receive and reflect the reflected light reflected by the fourth mirror 52d, and is disposed to face the fourth mirror 52d. The reflected light reflected by the fifth mirror 52e enters the light receiving unit 54.

  Therefore, the reflected light reflected from the image surface of the document P is repeatedly reflected in the order of the first mirror 52a, the second mirror 52b, the third mirror 52c, the fourth mirror 52d, and the fifth mirror 52e and enters the light receiving unit 54. It becomes. Since this reflected light channel is arranged so as to intersect between the first mirror 52a to the fifth mirror 52e, it is accommodated in the housing unit 55 in a relatively compact manner. Further, since the number of reflections of the reflected light is increased to increase the optical path length, a so-called color mixing effect that suppresses deterioration in image quality such as chromaticity unevenness can be obtained.

The lens unit 53 includes a mirror-side lens 53a that passes reflected light reflected by the reflection mirror unit 52, a sensor-side lens 53b disposed on the sensor side, and a lens holder 53c that holds the sensor-side lens 53b. Yes.
The lens unit 53 further includes a lens unit base 53d that supports the mirror-side lens 53a and the lens holder 53c, and a mounting bracket 53e that attaches the lens unit base 53d to the housing unit 55.
The lens unit 53 is configured so that the reflected light reflected by the reflection mirror unit 52 is imaged on the light receiving unit 54 by the mirror side lens 53a and the sensor side lens 53b.

The light receiving unit 54 includes an image sensor 54a, a substrate 54b on which the image sensor 54a is mounted, and a sensor bracket 54c that adjusts and fixes the position of the image sensor 54a. The image sensor 54a is composed of a light receiving element that converts light imaged by the lens unit 53 into an electric signal, for example, a photoelectric conversion element such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS).
The sensor bracket 54 c is supported by the lens unit cradle 53 d of the lens unit 53.

As shown in FIGS. 4 and 5, the housing unit 55 is formed of a box-shaped case having an internal space. The top surface opening 55a, the bottom surface opening 55b, the lens unit mounting portion 55c, and the structure shown in FIG. The mounting portion 55d has a connecting portion that connects a unit moving mechanism (not shown).
The upper surface opening 55a is formed at a position facing the image surface of the document P on the upper surface. The light source unit 51 is provided and reflected light reflected from the image surface of the document P passes therethrough.

The upper surface opening 55a has a protruding portion 55t formed to protrude toward the reflecting plate unit 34 at the edge portion facing the light guide plate 51c. A housing unit side reflecting plate 63b, which will be described later, is attached to the outer wall surface of the protruding portion 55t facing the light guide plate 51c.
Further, the protrusion 55t moves together with the reflector unit 34 by pressing the reflector unit 34 in the arrow b direction when the housing unit 55 moves in the arrow b direction of FIGS. 6A and 6B. It is supposed to be.

The bottom opening 55b is formed at a position facing the lens unit 53 on the bottom surface, so that reflected light reflected from the fifth mirror passes therethrough.
The lens unit attachment portion 55c is provided on the bottom surface opposite to the upper surface opening 55a, and is attached to the lens unit attachment portion 55c so that the lens unit 53 protrudes downward from the bottom surface.
As shown in FIG. 3, the mounting portion 55d is configured to mount the scanner rod 32a and the scanner guide 32b of the scanner frame portion 32.

The unit moving mechanism includes a drive motor such as a stepping motor, a pulley connected to the drive motor, a pulley provided in the sub-scanning direction with respect to the pulley, and a timing belt set on both pulleys. I have.
The integrated scanning optical unit 33 is connected to the timing belt, and when the drive motor rotates, the integrated scanning optical unit 33 is guided by the scanner rod 32a and the scanner guide 32b so as to reciprocate in the sub-scanning direction. It has become.

The reflection plate unit 34 includes a document table unit 61, a movable bracket 62, a reflection plate 63, and guide screws 64 and 65, as shown in FIGS. It consists of
The document table unit 61 includes a base bracket 61a fixed to the cover 41 of the scanner cover portion 31, a tension spring 61b as a pressing member, and one end side fixing pin 61c that fixes the tension spring 61b on one end side. ing.

  The base bracket 61a is formed in an elongated flat plate shape in the main scanning direction, and an elongated guide hole 61d is formed through the central portion in the main scanning direction in a direction perpendicular to the main scanning direction. The base bracket 61a is formed with fixing holes 61e and 61f for fixing the guide screws 64 and 65, and a fixing hole 61g for fixing the one end side fixing pin 61c.

The tension spring 61b is composed of a tension coil spring having a round hook whose both ends are bent in a semicircular shape in opposite directions. A predetermined initial tension (N) is applied to the tension spring 61b so that no play occurs at the set position shown in FIG.
The one end side fixing pin 61c is fixed to the fixing hole 61g of the base bracket 61a so that one end of the tension spring 61b is hooked.
The tension spring 61b pulls the movable bracket 62 in the direction of arrow a. Note that the tension spring 61b may be formed of a compression coil spring, and the reflector unit 34 may be configured to push the movable bracket 62 in the direction of arrow a.
Further, the tension spring 61b is provided at one place in the central portion of the base bracket 61a. However, the tension spring 61b is configured at a plurality of places, and the plurality of tension springs 61b cooperate to move the movable bracket 62 in the direction of arrow a. You may make it pull.

The movable bracket 62 has a main body 62a and a second end side fixing pin 62b that fixes the tension spring 61b on the other end side and functions as a restricting member. The main body 62a is formed in a flat plate shape elongated in the main scanning direction, and a bent portion 62c formed by bending so that one side in the sub scanning direction indicated by an arrow in FIG. 8B protrudes toward the housing unit 55. have. Further, as shown in FIG. 7, guide holes 62d and 62e elongated in the sub-scanning direction are formed in the main body 62a. Guide screws 64 and 65 are inserted into the guide holes 62d and 62e, respectively, and are configured to reciprocate in the sub-scanning direction while being guided by the guide screws 64 and 65. Further, as shown in FIG. 8A, a fixing hole 62f for fixing the other end side fixing pin 62b is formed in the main body 62a.
The other end side fixing pin 62b is fixed to the main body 62a so that the other end of the tension spring 61b is hooked, and the moving range of the movable bracket 62 is regulated by the other end side fixing pin 62b. Yes. That is, the movable bracket 62 is configured to be movable within a range in which the other end side fixing pin 62b moves through the guide hole 61d of the base bracket 61a.

The reflection plate 63 includes a document table unit side reflection plate 63 a attached to the bent portion 62 c of the movable bracket 62 and a case unit side reflection plate 63 b attached to the case unit 55.
The platen unit side reflecting plate 63a is provided with a reflective material such as aluminum foil on the surface of a base material sheet formed in the same shape as the outer wall surface of the bent portion 62c, and this base material sheet is provided on the outer wall surface of the bent portion 62c. It consists of things to be affixed. The platen unit-side reflecting plate 63a may be any plate that reflects light. For example, the platen unit-side reflecting plate 63a may have a surface treatment such as vapor deposition of aluminum on the outer wall surface of the bent portion 62c. Alternatively, a coating material in which a reflecting material is kneaded may be applied to the outer wall surface of the bent portion 62c. Further, the outer wall surface of the bent portion 62c itself may be formed of a material that reflects light, for example, a glossy metal material.
The housing unit side reflecting plate 63b is configured in the same manner as the document table unit side reflecting plate 63a.

  The guide screw 64 has a guide portion 64a inserted into the guide hole 62d and a fixing portion 64b fixed to the fixing hole 61e of the base bracket 61a, and is constituted by a so-called stepped screw. The guide screw 65 is also a stepped screw similar to the guide screw 64.

  Since the reflecting plate unit 34 is configured as described above, as shown in FIGS. 6A and 6B, the light emitted from the light source 51a of the light source unit 51 is changed to FIGS. 6A and 6B. It is configured to be guided to the image surface of the original P by reflecting in the direction of the arrow indicated by the alternate long and short dash line. In the conventional image reading apparatus, since the reflecting plate 63 is not provided, light leaks from a gap between the document table unit and the housing unit, and there is a problem of a decrease in irradiation efficiency. The reflecting plate 63 of the embodiment is configured to fill a gap between the document table unit and the housing unit, so that light emitted from the light source does not leak from the conventional gap, and the irradiation efficiency is improved. The problem of light leakage is eliminated.

The movable bracket 62 in the reflecting plate unit 34 has a white reference plate reading position for reading the white reference plate as shown in FIG. 8A and a document image for reading the image surface of the document as shown in FIG. 10A. It moves back and forth in the directions of arrows a and b together with the housing unit 55 between the surface reading position.
At the white reference plate reading position shown in FIG. 8A, the movable bracket 62 is pushed in the direction of arrow a by the tension (N) of the tension spring 61b. When the housing unit 55 further moves in the direction of the arrow a and the protrusion 55t of the housing unit 55 is separated from the bent portion 62c of the movable bracket 62, the other end side fixing pin 62b of the movable bracket 62 is The movable bracket 62 is restricted so as not to move further in the direction of the arrow a by hitting the inner wall of the guide hole 61d of the base bracket 61a.

  On the other hand, at the document image surface reading position shown in FIG. 10A, the movable bracket 62 moves in the direction of arrow b of the housing unit 55, so that the bent portion 62c of the movable bracket 62 moves in the direction of arrow b at the protruding portion 55t. It is pushed and moved against the tension (N) of the tension spring 61b to stop.

  The image recording apparatus 13 includes an exposure unit and a photosensitive drum (not shown), a developing unit, a transfer belt, a fixing unit, a paper feeding unit, a transport unit, and a paper discharge tray 13a shown in FIG. The image recording device 13 exposes the photosensitive drum by the exposure unit based on the read image read by the image sensor 54a of the image reading device 12, forms a latent image on the photosensitive drum, and the photosensitive unit by the developing unit. The drum is configured to supply toner of different colors and develop it. The image recording device 13 is adapted to transfer the image developed on the photosensitive drum by the transfer belt to the recording paper fed from the paper feeding unit and transported by the transport unit. The transferred recording sheet is further conveyed to a fixing unit, and the toner of the toner image transferred to the recording sheet by the fixing unit is melted, so that the color image is fixed on the recording sheet. The recording paper on which the color image is fixed is sequentially placed on the paper discharge tray 13a.

Since the image reading apparatus 12 according to the embodiment is configured as described above, the following effects can be obtained.
That is, the image reading apparatus 12 according to the embodiment irradiates the image surface of the document P via the light guide plate 51c with the document table unit 61 that passes the conveyed document P through the slit glass 42 and the light source 51a. The light source unit 51 that receives the reflected light reflected from the image plane, and the upstream side and the downstream side in the transport direction of the document P relative to the document table unit 61 at a position separated from the document table unit 61. And a reflector unit 34 that is disposed between the document table unit 61 and the housing unit 55 and reflects the light from the light source 51a toward the document P. The reflector unit 34 moves following the housing unit 55 via the bent portion 62c that contacts the housing unit 55 and the bent portion 62c, and emits light from the light source 51a. And a movable bracket 62 and the platen unit side reflector 63a for reflecting are formed toward the document P.

As a result, in the image reading apparatus 12 according to the embodiment, it is possible to suppress a decrease in the amount of light applied to the image surface of the document, improve the irradiation efficiency, and improve the reading productivity by increasing the image reading speed. The effect of being able to be obtained.
That is, in the conventional image reading apparatus, since the reflecting plate unit 34 is not provided, the light emitted from the light source 51a leaks from the gap between the document table unit and the housing unit, resulting in a problem of a decrease in irradiation efficiency. It was. The reflector unit 34 of the embodiment is configured to fill a gap between the document table unit 61 and the housing unit 55, so that light emitted from the light source 51a does not leak from the conventional gap, and the document table unit side. Since light is reflected by the reflecting plate 63a, the irradiation efficiency is improved and the conventional light leakage problem is solved.
Further, since the reflector unit 34 moves following the housing unit 55, a gap is generated between the document table unit 61 and the housing unit 55 even if the housing unit 55 moves. There is nothing, and the effect that the irradiation efficiency is reliably improved is obtained.
In the image reading apparatus 12 according to the embodiment, the housing unit 55 has a protruding portion 55t formed to protrude toward the document table unit 61, and the bent portion 62c of the movable bracket 62 contacts the protruding portion 55t. Therefore, the movable bracket 62 can reliably follow the housing unit 55 and move. Since the projecting portion 55t is formed in the housing unit 55, a space can be secured between the housing unit 55 and the document table unit 61, and the housing unit 55 can be moved smoothly.

In the image reading apparatus 12 according to the embodiment, the reflecting plate unit 34 is provided on the base bracket 61a fixed to the document table unit 61 and the base bracket 61a, and the movable bracket 62 is arranged downstream in the conveyance direction of the document P. It has a tension spring 61b that acts to press against the side.
Therefore, when the casing unit 55 moves downstream, the movable bracket 62 can be moved following the casing unit 55 by the tension of the tension spring 61b.
On the other hand, when the housing unit 55 moves to the upstream side, the housing unit 55 can move the movable bracket 62 to the upstream side against the tension of the tension spring 61b.
As described above, since the tension of the tension spring 61b is used, it is possible to ensure that the housing unit 55 and the movable bracket 62 are always in contact with each other. Can be efficiently emitted toward the original P.

  In the image reading apparatus 12 according to the embodiment, since the housing unit-side reflecting plate 63b is also provided on the projecting portion 55t of the housing unit 55, the document table provided on the bent portion 62c of the movable bracket 62 is provided. Together with the unit-side reflector 63a, the light from the light source 51a can be reflected. As a result, a decrease in the amount of light applied to the image surface of the document can be further suppressed, the irradiation efficiency can be improved, and the image reading speed can be further increased. Therefore, an effect that reading productivity can be remarkably improved is obtained.

  In the image reading apparatus 12 according to the embodiment, the reflector unit 34 has the other end side fixing pin 62 b as a regulating member that regulates the moving range of the movable bracket 62. As a result, the movement range of the movable bracket 62 is restricted to the range in which the other end side fixing pin 62b moves within the guide hole 61d of the base bracket 61a, so that even if the housing unit 55 moves further downstream, The movable bracket 62 does not follow the casing unit 55 any more, and does not hinder the movement of the casing unit 55. That is, there is an effect that the movable bracket 62 can reliably move following the housing unit 55 within a necessary range.

In the reflector unit 34 in the embodiment, guide holes 62d and 62e are formed in the movable bracket 62, and guide screws 64 and 65 are inserted into the guide holes 62d and 62e to be fixed to the base bracket 61a. The case where the movable bracket 62 is configured to reciprocate in the sub-scanning direction while being guided by 65 has been described.
However, the reflector unit in the present invention may be configured with a structure other than the guide structure by the guide screws 64 and 65.
For example, as shown in FIG. 11, a key-shaped hook portion 101a is formed on the movable bracket 101 by a molding process such as pressing, and guide holes 102a and 102b are formed in the base bracket 102 to guide the hook section 101a. You may make it comprise with the structure which inserts from the hole 102a and moves the inside of the guide hole 102b.

1 Copying machine (image forming device)
DESCRIPTION OF SYMBOLS 11 Document conveying apparatus 12 Image reading apparatus 13 Image recording apparatus 33 Integrated scanning optical unit 34 Reflecting plate unit 42 Slit glass (transparent member)
51 light source unit 51a light source 51c light guide plate 54 light receiving unit 55 housing unit 55t protrusion 61 document table unit 61a, 102 base bracket 61b tension spring (pressing member)
61c One end side fixing pin 61d Guide hole 62, 101 Movable bracket 62b Other end side fixing pin (regulating member)
62c Bending part 63 Reflecting plate 63a Original plate unit side reflecting plate (reflecting part)
63b Case unit side reflector (projecting reflector)
64,65 Guide screw

JP 2011-071608 A JP 2002-330264 A

Claims (6)

A document table unit for passing the conveyed document on the transparent member;
A light source unit that irradiates the image surface of the document with light from a light source through a light guide plate;
A light receiving unit that receives reflected light reflected from the image plane;
A housing unit that accommodates the light source unit and the light receiving unit, and is movably provided upstream and downstream in the document conveyance direction with respect to the document table unit at a position separated from the document table unit; ,
In an image reading apparatus comprising:
A reflector unit that is disposed between the document table unit and the housing unit and reflects light from the light source of the light source unit toward the document;
A reflector that contacts the housing unit; a reflector that moves following the housing unit via the contact and reflects light from the light source toward the document; An image reading apparatus having a movable bracket on which are formed. The housing unit has a protrusion formed to protrude toward the document table unit;
The image reading apparatus according to claim 1, wherein the contact portion of the movable bracket is in contact with the protruding portion.   The reflector unit includes a base bracket fixed to the document table unit, and a pressing member that is provided on the base bracket and presses the movable bracket to the downstream side in the document transport direction. When moving to the downstream side, the movable bracket moves following the casing unit by the pressing force of the pressing member, and when the casing unit moves to the upstream side, the casing The image reading apparatus according to claim 1, wherein the unit moves the movable bracket to the upstream side against a pressing force of the pressing member.   4. The protruding reflection surface for reflecting light from the light source of the light source unit toward the original is formed on the protruding portion of the housing unit. 5. The image reading device according to claim.   5. The image reading apparatus according to claim 1, wherein the reflecting plate unit includes a restricting member that restricts a moving range of the movable bracket. 6.   An image for recording an image on a recording medium based on the image reading apparatus according to any one of claims 1 to 5, an original conveying apparatus for conveying an original, and information on an image read by the image reading apparatus. An image forming apparatus comprising a recording device.

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