JP2013058959A - Document reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a document reader in which, even when a foreign matter enters inside a reading unit to generate a defective image such as a black stripe, the maintenance of the reading unit is easy and which is easy to handle.SOLUTION: A reading mechanism for reading a document comprises: a first unit 62 comprising a contact glass 20; a second unit 61 comprising a light source; plural mirrors 24, 25, 26, and 27 and a lens 28; and a third unit 60 comprising a photoelectric converter. The first, second, and third units are interconnected to form the reading unit.

Description

  The present invention relates to a document reading apparatus including a reading unit that reads a document transported along a document transport path, and particularly relates to a configuration of a reading unit.

  2. Description of the Related Art Conventionally, a document reading apparatus that reads a double-sided document with images formed on both sides is equipped with a reversing mechanism that reverses the front and back of the document. A first reading unit for reading the other side of the original by conveying the original again to the reading unit, a first reading unit for reading one side of the original, and a second reading unit for reading the other side of the original. One that reads a manuscript with a copy is known.

  In the latter document reading device, a first reading unit is provided on the upper surface of the document reading device body, and a second reading unit is provided in the document feeding device. The second reading unit provided in the document feeder is provided in the transport path upstream or downstream of the first reading unit. The second reading unit includes a reading unit for reading a document (for example, Patent Document 1 and Patent Document 2).

  The reading unit of the second reading unit provided in the document feeder includes a contact glass that also serves as a document transport surface, a light source that irradiates light on the document through the contact glass, and a reflected light from the document. And a plurality of mirrors for guiding the reflected light guided by the plurality of mirrors, and a photoelectric conversion element (CCD) for photoelectrically converting the light converged by the lenses. Further, most of the reading unit is covered with a unit cover and sealed so that foreign matter does not enter the inside of the unit.

JP 2008-162775 A JP 2005-15100 A

  However, the conventional reading unit is covered with a resin cover so that foreign matter such as dust, dust, paper dust, and roller shavings do not enter. When foreign matter enters from a small gap, maintenance such as removal of the foreign matter is difficult, and there is a problem that the entire reading unit must be replaced. In particular, paper dust and roller wrinkles are generated around the contact glass that also serves as the document transport surface, so paper dust and wrinkles easily adhere to the inside of the contact glass. When printing, the problem of being printed as a black streak arises.

  The present invention has been made in view of the above-described problems. Even when a foreign matter enters the inside of the reading unit and an image defect such as a black streak occurs, maintenance of the reading unit is easy. An object of the present invention is to provide a document reading apparatus that can be easily handled.

  In order to solve the above problems, the document reading apparatus of the present invention includes a first unit having a contact glass provided with a reading position, and a second unit having a light source that irradiates the document with light through the contact glass. And a third mirror having a plurality of mirrors for guiding the reflected light of the document in a predetermined direction, a lens for converging the reflected light guided by the plurality of mirrors, and a photoelectric conversion element for photoelectrically converting the light converged by the lens. And a reading mechanism comprising the first, second, and third units, and the reading mechanism is connected to the first, second, and third units to form one reading unit. Is detachably attached to the transport mechanism, and the first unit can be removed while the reading unit removed from the transport mechanism is connected to the second unit and the third unit.

  With the above-described configuration, after the reading mechanism unitized as a reading unit is removed from the transport mechanism, the third unit and the second unit in the reading unit are connected to each other from the second unit to the first unit. Can be removed, so that foreign matter that has entered between the first and second units can be easily removed.

1 is a cross-sectional view illustrating the entire configuration of a document reading apparatus main body and a document conveying apparatus according to the present invention. It is an expanded sectional view showing the 2nd reading unit concerning the present invention. It is a schematic diagram which shows the removal state of the reading unit which concerns on this invention. It is a disassembled perspective view which shows the structure of the 2nd reading unit which concerns on this invention. It is a disassembled perspective view which shows the attachment structure of each component in the optical unit which concerns on this invention. It is a state perspective view which shows the attachment state of each component in the optical unit which concerns on this invention. It is an expansion perspective view which shows the structure of the principal part of the light source unit which concerns on this invention. It is a disassembled perspective view which shows the structure of the principal part of the light source unit which concerns on this invention. It is a disassembled perspective view which shows the structure of the glass unit which concerns on this invention. It is sectional drawing which shows the connection structure which connects the light source unit and glass unit which concern on this invention. It is a schematic diagram which shows the movement state of the glass unit which concerns on this invention. It is a schematic diagram which shows the cleaning state of the 3rd contact glass which concerns on this invention.

  Hereinafter, a document reading apparatus provided with a document conveying device according to the present invention will be described. FIG. 1 is a cross-sectional view illustrating the entire configuration of the document reading apparatus main body and the document conveying apparatus.

  As shown in FIG. 1, the document reading apparatus includes a document reading apparatus main body H and a document conveying apparatus A as a conveying mechanism for conveying an original. The document conveying apparatus A includes a hinge (not shown) on the document reading apparatus main body H. Is attached through. The hinge supports the document feeder A so that it can be opened and closed with respect to the upper surface of the document reader main body H.

  The document reading device main body H is provided with a first reading unit 2 for reading one side of a document conveyed on the upper surface of the contact glass 1a by the document conveying device A. The document feeder A is provided with a second reading unit 3 in which a reading mechanism for reading the other surface of the document that has passed through the upper surface of the contact glass 1a of the main body H is unitized.

  The document feeder A is attached to the body H so as to be openable and closable so as to open the upper surface of the document reading apparatus body H, and the document placed on the contact glass 1b of the body H is first read. The unit 2 is moved and read.

  The first reading unit 2 provided in the document reading apparatus main body H is a unit in which photoelectric conversion means including a light source, a plurality of mirrors, a lens, and a photoelectric conversion element (CCD) are integrated. Then, light from the light source is irradiated onto the conveyed document through the first contact glass 1a, the reflected light is reflected by a mirror, and photoelectrically converted by a photoelectric conversion means including a CCD through a lens, thereby being a document image. Read. The first reading unit 2 moves in the sub-scanning direction to open and close the document conveying device A to read a thick document image such as a book placed on the contact glass 1b.

  As shown in FIG. 1, the document feeder A includes a paper feed tray 10 on which a plurality of documents can be placed, a paper discharge tray 11 that is disposed below the paper feed tray and stores read documents, A transport unit for transporting the document is provided.

  In the transport section of the document transport apparatus A, a U-shaped document transport path 12 extending from the paper feed tray 10 to the paper discharge tray 11, a feed roller 13 for feeding the document in contact with the document, and the fed document A paper feed roller 14 that feeds the paper, a separation roller 15 that presses against the paper feed roller 14 and separates the original into a single sheet, and a leading edge of the original that is separated into a single sheet and abuts and aligns A pair of registration rollers 16 to be sent downstream, a first conveyance roller pair 17 disposed on the upstream side of the first contact glass 1a, and a second conveyance roller disposed on the downstream side of the first contact glass 1a. A pair 18 and a paper discharge roller pair 19 disposed on the downstream side of the second transport roller pair 18 and discharging a document to the paper discharge tray 11 are provided.

  The document feeder A is provided with a second reading unit 3 for reading a document surface opposite to a document surface read by the first reading unit 2. The second reading unit 3 is disposed in a space that gradually becomes narrower toward the paper discharge direction inside the U-shaped document conveyance path 12. The second reading unit 3 is provided with a third contact glass 20 at the end in the paper discharge direction. The third contact glass 20 is disposed between the second transport roller pair 18 and the paper discharge roller pair 19 and functions as a part of a guide for the document transport path, and passes through the surface of the third contact glass 20. The document is configured to be read by the second reading unit.

  With such a configuration, the document on the paper feed tray 10 is fed by the feed roller 13 and separated into one sheet by the paper feed roller 14 and the separation roller 15. Then, after the originals separated into one sheet are aligned by the rage roller pair 16, the original is conveyed to the first contact glass 1 a by the first conveyance roller pair 17. Thereafter, the document that has passed through the first contact glass 1 a is transported to the third contact glass 20 by the second transport roller pair 18, and discharged to the discharge tray 11 by the discharge roller 19. In the process of transporting the original, the surface of the original is read by the first reading unit 2 when the original passes through the first contact glass 1 a, and the second when the original passes through the third contact glass 20. The reading unit 3 reads the back side of the document.

  Next, the second reading unit 3 will be described in detail. FIG. 2 is an enlarged sectional view showing the second reading unit 3. The second reading unit 3 includes a light source including an LED 21 and a light guide 22 for irradiating light on a document conveyed through the contact glass 20, and a plurality of mirrors 24 and 25 for guiding reflected light from the document in a predetermined direction. , 26, 27, a lens 28 for converging the reflected light guided by the plurality of mirrors 24, 25, 26, 27, and a CCD (photoelectric conversion element) 29 for photoelectrically converting the light converged by the lens 28. ing.

  Then, the document is irradiated with light emitted from the light source through the third contact glass 20, the reflected light is reflected by a plurality of mirrors 24, 25, 26, and 27, and photoelectrically converted by the CCD 29 through the lens 28. Scan the original image.

  As described above, in the above document feeder A, the image on the front surface of the document passing through the first contact glass 1 a is read by the first reading unit 2, and the image on the back surface of the document passing through the third contact glass 20. Is read by the second reading unit 3, the image reading time of the double-sided document can be greatly shortened.

  Here, the second reading unit 3 is detachably attached to the document feeder A for maintenance. FIG. 3 is a schematic diagram showing a removed state of the second reading unit 3. The second reading unit is attached to a support piece 73 provided in the document feeder A with screws 74.

  When the maintenance of the second reading unit 3 is performed, as shown in FIG. 3, as shown in FIG. 3, the feeding roller 13, the paper feeding roller 14, the resist driving roller 16 a, and the upper guide 71 that forms a part on the upstream side of the conveying path 12. Is rotated counterclockwise in the drawing with a shaft 70a provided on the downstream side of the guide 71 as a fulcrum, and the separation roller 15 and the resist driven roller 16b are attached to the upstream side of the conveying path 12. The lower guide 72 forming a part on the side is removed. As a result, the second reading unit 3 is exposed, so that the screws 74 connecting the second reading unit 3 and the support piece 73 are loosened, and the second reading unit 3 is removed from the transport mechanism of the document transport apparatus A.

  When the maintenance is completed, the second unit 3 is attached to the support piece 73 again with the screws 74, and then the lower guide 72 is attached. Then, the apparatus cover 70 is rotated in the clockwise direction in the drawing to return the document conveying apparatus A to the state before the second reading unit 3 is removed.

  Next, the second reading unit 3 will be described in detail. FIG. 4 is an exploded perspective view of the second reading unit 3 for each unit. As shown in FIGS. 4 and 2, the second reading unit 3 includes an optical unit 60 (third unit) provided with four mirrors 24, 25, 26, and 27, a lens 28, and a CCD 29, an LED 21, The light source unit 61 (second unit) provided with the light guide 22 and the glass unit 62 (first unit) provided with the third contact glass 20 are configured.

  The optical unit 60, the light source unit 61, and the glass unit 62 are connected in this order to form the second reading unit 3. That is, the optical unit 60 and the light source unit 61 are connected by a connecting member such as a screw, and the light source unit 61 and the glass unit 62 are connected by a connecting member such as a screw.

  With this configuration, only the optical unit 60 is removed in a state where the light source unit 61 and the glass unit 62 are connected, and dust, dirt, soot, dust, and the like that have entered between the optical unit 60 and the light source unit 61 are removed. Foreign matter can be removed, and maintenance of the plurality of mirrors 24, 25, 26, and 27 can be facilitated. Further, when the optical unit 60 and the light source unit 61 are connected, only the lens unit 62 is removed, and foreign matters such as dust, dust, soot and dirt that have entered between the light source unit 61 and the lens unit 62 are easily removed. Easy maintenance.

  The optical unit 60 is provided with a resin-formed first frame 30 having a substantially L-shaped cross section that also serves as an exterior cover of the second reading unit 3, and extends in the document width direction orthogonal to the document transport direction. It is composed of a CCD substrate 31 on which four mirrors 24, 25, 26 and 27, a lens 28, and a CCD 29 are mounted. As shown in FIG. 4, a plurality of mirror mounting portions 30 a (only a part of which are shown) are formed inside the first frame 30 formed of resin, to which the mirrors 24, 25, 26, 27 are attached. Each mirror 24, 25, 26, 27 is attached to each mirror attachment portion 30 a with its both ends sandwiched between U-shaped leaf springs 35.

  5 and 6 are explanatory views for explaining a state in which the lens 28 and the CCD substrate 31 on which the CCD 29 is mounted in the optical unit 60 are attached. FIG. 5 shows the lens 28 and the CCD substrate 31 on the first frame 30. FIG. FIG. 6 is an exploded perspective view in which the components for attachment are disassembled, and FIG. 6 is a perspective view of the lens 28 and the CCD substrate 31 attached.

  The lens 28 is held by a lens holder 28a. As shown in FIG. 5, the lens holder 28 a is disposed so as to fit into a concave lens mounting portion 30 b formed on the outer side of the first frame 30. A first metal plate 32 for positioning and holding the lens holder 28 a is attached to the first frame 30. The first metal plate 32 is provided with a through hole 32a and a fitting hole 32b corresponding to the two pins 28b and the two bosses 28c provided in the lens holder 28a. Then, the two pins 28b and the two bosses 28c provided on the lens holder 28a are penetrated and fitted into the holes 32a and 32b of the first metal plate 32, and the first metal plate 32 is first as shown in FIG. The lens holder 28 a is positioned and held by the first metal plate 32 by being fixed to the frame 30 with the screws 37.

  The CCD substrate 31 is attached to a second metal plate 33 as shown in FIG. 6, and the second metal plate 33 is fixed to the first metal plate 32 with screws 38. The screw hole through which the screw 38 of the second metal plate 33 passes is formed in the long hole 33a. With the screw 38 loosened, the second metal plate 33 is moved along the long hole 33a and After adjusting the distance from the lens 28, the screw 38 is tightened to fix the second metal plate 33. Further, a screw hole through which the screw 37 of the first metal plate 32 passes is also formed in the long hole 32c, and the first metal plate 32 is moved with respect to the first frame 30 in a state where the screw 37 is loosened. After adjusting the distance between the 4 mirror 27 and the lens 28, the screw 37 is tightened to fix the first metal plate 32.

  Thus, since the lens holder 28a and the CCD substrate 31 are fixedly held by the metal plate, the positions of the lens holder 28a and the CCD substrate 31 do not shift even if the environment around the optical unit 60 changes. In addition, since the lens holder 28a and the CCD substrate 31 are attached to the outside of the first frame 30 so that the positions can be adjusted by the first and second metal plates 32 and 33, the three units 60, 61 and 62 are connected. Thus, the positions of the lens 28 and the CCD 29 can be adjusted with the second reading unit 3 configured. Furthermore, since the positions of the lens holder 28a and the CCD substrate 31 can be adjusted by the first and second metal plates 32 and 33, the adjustment work is facilitated.

  In addition, the code | symbol 39 in FIG. 5 is a black film member attached so that the part of the 1st, 2nd metal plates 32 and 33 in the 1st flame | frame 30 might be covered. This prevents foreign matter such as dust, dirt, and dust from entering the first frame 30, that is, the second reading unit 3. Reference numeral 36 denotes an elastically deformable sponge member provided between the CCD substrate 31 and the first frame 30. The sponge member 36 fills the gap between the CCD substrate 31 and the first frame 30 so that foreign matter such as dust, dust, and dirt does not enter the light source unit 3.

  The light source unit 61 includes a second frame 40 attached to the first frame 30 so as to cover the inside of the first frame 30 to which the mirrors 24, 25, 26, 27 are attached, and one surface side of the second frame 40. Two light guides 22 that are attached and extend in the document width direction perpendicular to the document transport direction, and are disposed on one end side of the light guide 22 in the document width direction and enter the light guide 22. It comprises a chip-like LED 21 that emits light, an LED substrate 41 on which the LED 21 is mounted, and a radiator 43 for radiating the heat of the LED 21.

  FIG. 7 is an enlarged perspective view in which the end of the light source unit 31 on the side where the LED is attached is enlarged, and FIG. 8 is an exploded perspective view in which each part of the light source unit is disassembled. The second frame 40 is formed of a resin, and as shown in FIGS. 7 and 8, the original 40 is placed between the recess 40a to which the light guide 22 is attached and the two light guides 22 attached to the recess 40a. A slit 40 b for guiding the reflected light to the first mirror 24 in the optical unit 30 is formed. In addition, an LED substrate attachment portion 40c to which the LED substrate 41 is attached is formed on a side portion in the longitudinal direction of the second frame 40, and a large opening 40d through which the light guide 22 passes is formed in the LED substrate attachment portion 40c. Yes.

  The LED substrate 41 is a metal substrate made of a copper plate having excellent thermal conductivity, and releases heat generated by a semiconductor (such as a chip-shaped LED) to the substrate. In addition, a reflector 42 disposed so as to surround the LED 21 is attached to the LED substrate 41. The reflector 42 is provided between the LED substrate 41 and one side surface in the longitudinal direction of the light guide 22 and allows light emitted from the LED 21 to enter the light guide 22 without leaking outside. In the present embodiment, two LEDs 21 are used for one light guide 22, and the reflector 42 is disposed so as to surround the two adjacent LEDs 21.

  The light guide 22 is made of an amorphous acrylic resin having high light transmittance. Projecting pieces 22 a are provided at two locations on one end side in the longitudinal direction of the light guide 22. The protruding piece 22a of the light guide 22 penetrates outward from the opening 40d of the LED board mounting portion 40c in the second frame 40, and the reflector 42 and the restricting portion 40e of the second frame 40 protrude as shown in FIG. The light guide 22 is configured to be held at a predetermined position by sandwiching the piece 22a. Further, film members 46 for preventing the light guide 22 from coming out of the recess 40 a of the second frame 40 are provided on both ends of the light guide 22. The film member 46 is attached to the second frame 40 with a double-sided tape or the like, and holds the light guide 22 in the recess 40 a of the second frame 40.

  The radiator 43 lowers the temperature by dissipating heat of the LED 21 and the LED substrate 41. In the present embodiment, in order to improve the performance, a heat radiator having a fin shape that uses aluminum that is easy to conduct heat and has a large surface area is employed. In addition, an elastic member 44 having a high thermal conductivity is provided between the LED substrate 41 and the radiator 43. The elastic member 44 deforms along the shape of both surfaces even when there are minute undulations on the surfaces of the LED substrate 41 and the radiator 43. Thereby, the heat of the LED substrate 41 can be efficiently conducted to the radiator 43. In the present embodiment, a mixed material of a silicone polymer and a ceramic is used as the elastic member 44 having excellent thermal conductivity.

  The radiator 43 is attached to the second frame 40 by screws 45, and the radiator 43 holds the LED substrate 41 and the elastic member 44 with the second frame 40 therebetween. Accordingly, the reflector 42 contacts the side surface of the light guide 22 and the protruding piece 22 a, and the LED 21 is positioned with respect to the light guide 22. The elastic member 44 is given an appropriate pressing force for deformation along the surfaces of the LED substrate 41 and the radiator 43.

  FIG. 9 is an exploded perspective view showing the structure of the glass unit 62. The glass unit 62 will be described with reference to FIGS. The glass unit 62 includes a third frame 50 made of resin, and a third contact glass 20 attached to a reading opening 50 a formed in the third frame 50.

  One surface of the third contact glass 20 is a part of the document transport path 12 and is disposed at a reading position X for reading a document. Further, a sheet-like white plate 51 for obtaining shading correction white reference data is attached to the original conveying surface of the third contact glass 20. The white plate 51 is attached to a part of the third contact glass 20 on the upstream side in the document conveying direction along the longitudinal direction. In the present embodiment, a white sheet 56 that covers the white plate 51 is provided, and the white sheet 56 extends from the third frame 50 beyond the upstream end of the third contact glass 20 in the document conveying direction to the white plate 51. And attached so as to cover approximately half of the third contact glass.

  The glass unit 62 is disposed so as to cover the light guide 22 part of the light source unit 61, and the glass unit 62 moves the white plate 51 to the reading position X and the position retracted from the reading position X. It is configured to be able to reciprocate in the short direction.

  FIG. 10 is a cross-sectional view showing a connection structure for connecting the glass unit 62 to the light source unit 61. As shown in FIG. 9, attachment portions 50 b for attaching the glass unit 62 to the light source unit 61 are formed on both side portions in the longitudinal direction of the third frame 50. A through hole 50 c is formed in the mounting portion 50 b as shown in FIG. 10, and a through hole 40 f is also formed in the second frame 40 of the light source unit 61. A cylindrical support member 52 is passed through the through hole 40f of the second frame 40 and the through hole 50c of the third frame 50, and E-shaped retaining rings are fitted to both ends of the support member 52, so that the glass unit 62 and the light source The unit 61 is connected.

  Here, the configuration for moving the glass unit 62 will be described. The light source unit 3 is provided with a compression spring 53 for urging the glass unit 62 in one direction, and the side plate (not shown) of the document feeder A is made of glass. A solenoid 54 and a link member 55 for moving the unit 62 in the other direction are provided. The compression spring 53 is attached between the through hole 40 f of the second frame 40 and the through hole 50 c of the third frame 50 in the support member 52, and the urging force of the compression spring 53 causes the glass unit 62 to move as shown in FIG. Move to the upstream position in the document conveyance direction shown in FIG. On the other hand, the solenoid 54 moves the link member 55 attached to the plunger by the suction operation. The contact portion 55a of the link member 55 contacts the protruding portion 50d of the third frame 50, and the glass unit 62 is positioned at the downstream side in the document conveying direction shown in FIG. 10B against the urging force of the compression spring 53. Move to.

  FIGS. 11A and 11B are schematic views showing the relationship between the third contact glass 20 and the reading position due to the movement of the glass unit 62. FIG. The above-described moving configuration will be specifically described with reference to FIG. In the initial state (the solenoid 54 is in the OFF state), the glass unit 62 is urged in the direction of the arrow indicated by the solid line in the drawing as shown in FIG. The portion is stopped in a state where it abuts on the portion of the second frame 40 where the through hole 40f is formed. At this time, the white plate 51 is in a retracted position retracted from the reading position X.

  In this state, that is, when the white plate 51 in the retracted position is moved to the reading position X, the solenoid 54 is turned on (energized). When the solenoid 54 is turned on, the plunger is sucked and the link member 55 moves in the direction of the arrow indicated by the broken line in the drawing as shown in FIG. As a result, the contact portion 55a formed on the distal end side of the link member 55 contacts the protruding portion 50d of the third frame 50, and the link member 55 is shown by a broken line in the figure against the urging force of the compression spring 53. The glass unit 62 is moved in the direction of the arrow. Then, when the suction operation of the solenoid 54 ends, the glass unit 62 stops. As a result, the white plate 51 moves from the retracted position to the reading position X.

  When the white plate 51 is moved again from the reading position X to the retracted position, the solenoid 54 is turned OFF (non-energized). As a result, the suction of the plunger is released, the plunger and the link member 55 are brought into a free state, and the glass unit 62 is moved in the direction indicated by the solid line in the drawing as shown in FIG. It is energized by and moves. By this movement, the white plate 51 moves to the retracted position.

  Next, as shown in FIG. 4, the first frame 30 and the second frame 40 are provided with cleaning openings 65 and 66 for cleaning the back surface of the document conveying surface of the third contact glass 20, respectively. The cleaning opening 65 of the first frame 30 is formed along the longitudinal direction of the first frame 30 at the end portion in the document conveying direction, and is normally closed by a film member so that foreign matter does not enter and is cleaned. Only when the film member is removed. The cleaning opening 66 of the second frame 40 is located at a position corresponding to the cleaning opening 65 of the first frame 30, that is, at the same position as the cleaning opening 65 of the first frame 30 in the document transport direction, along the longitudinal direction of the second frame 40. Is formed.

  As shown in FIG. 12, the cleaning opening 65 of the first frame 30 and the cleaning opening 66 of the second frame 40 are penetrated to the back surface of the third contact glass 20 of the third frame 50. 66, a cleaning member 67 such as a cotton swab is inserted to clean the back surface of the third contact glass 20. At this time, the lens unit 62 is moved from the cleaning openings 65 and 66 to a position where the back surface of the third contact glass 20 can be seen for cleaning.

  As a result, even if foreign matter such as dust, dirt, and soot entering between the glass unit 62 and the light source unit 61 adheres to the back surface of the third contact glass 20, it can be easily removed. In the case where foreign matter cannot be easily removed with a cleaning member such as a cotton swab or the attached foreign matter is difficult to find in the cleaning openings 65, 66, the glass unit is connected with the optical unit 60 and the light source unit 61 as described above. 62 is removed from the light source unit 61 and cleaning is performed using a cleaning liquid or the like.

  The optical path of the second reading unit 3 will be described with reference to FIGS. The light emitted from the LED 21 is incident from the end face of the light guide 22 made of a transparent resin, travels while reflecting between the reflecting surfaces in the light guide 22 over the longitudinal direction of the light guide 22, A part of the light is emitted to the outside from the emission surface extending in the longitudinal direction of the light guide 22. The emitted light is applied to the document sent through the conveyance path 12 via the third contact glass 20.

  The light irradiated on the original is reflected from the original surface as shown in FIG. 2 and guided into the second reading unit 3 through the third contact glass 20. Then, the light that has entered the second reading unit 3 is reflected by the first mirror 24 from the slit 40 b of the second frame 40, and then reflected by the second mirror 25 and the third mirror 26 in this order. The reflected light reflected by the third mirror 26 is again reflected by the second mirror 25 and then enters the final fourth mirror 27. Then, the light reflected by the fourth mirror 27 is collected by the lens 28, and the collected light is imaged on the CCD 29 to read the document image. The second mirror 25 reflects the light from the first mirror 24 toward the third mirror 26 and the second reflection that reflects the light from the third mirror 26 toward the fourth mirror 27. It has a surface 25b.

  Here, the above-described U-shaped document conveyance path 12 has a substantially straight line on the upstream side from the sheet feed port 12a through which the document on the sheet feed tray 10 is fed to the registration roller pair 16 as shown in FIG. The path from the registration roller pair 16 to the first contact glass 1 is formed in a curved shape, and the downstream path from the first contact glass 1a to the paper discharge port 12b where the paper discharge roller pair 19 is located is It is formed so as to be inclined upward toward the paper feed port side. The second reading unit 3 is disposed in an area inside the U-shaped document conveyance path 12, and an area inside the U-shaped document conveyance path 12 in which the second reading unit 3 is disposed. The (space) is gradually narrowed toward the discharge tray 11 side.

  The outline of the outer shape of the light source unit 3 is a shape in which a part of one corner of the rectangle is cut away. As shown in FIG. A first surface 3a below the linear path leading to the pair 16, a second surface 3b on the curved side of the U-shaped path, a third surface 3c above the first contact glass 1, On the fourth surface 3d, which is inclined along the path from the two conveying roller pairs 18 to the paper discharge roller pair 19 and corresponding to a part of the one corner described above, and on the paper discharge tray 11 side, And a fifth surface 3e facing the second surface 3b. That is, the outer shape of the second reading unit in the present embodiment is formed along the document transport path 12 and the height dimension is gradually reduced toward the paper discharge tray 11 side. As a result, the entire apparatus is reduced in size.

  The second reading unit 3 is provided with a reading position X for reading a document at a portion on one end side thereof. That is, the second reading unit 3 has the third contact glass 20, the two light guides 22, and the first mirror 24 disposed at the end on the fifth surface 3 e side (discharge tray 11 side). Further, the CCD substrate 31 on which the second, third, and fourth mirrors 25, 26, and 27, the lens 28, and the CCD 29 are mounted is different from the first mirror 24 on the second surface 3b side (different from the discharge tray 11 side). Side). That is, in the second reading unit 3, the reflected light of the original is taken in from the portion where the space on the fifth surface 3e side in the unit 3 is narrow, and the captured light is reflected a plurality of times on the side where the space is wide to increase the optical path length. Secured.

  Specifically, the first mirror 24 is closest to the fifth surface 3e and close to the slit 40b of the second frame 40, and the light that has passed through the slit 40b immediately passes through the third mirror 26 and the fourth mirror 27. It arrange | positions so that it may reflect toward between. The second mirror 25 is disposed below the reflecting surface 24 a of the first mirror 24 and in a wide space on the second surface 20 b side, and the reflected light from the first mirror 24 is directed toward the third mirror 25. reflect. The third mirror 26 is located below the reflecting surface 24a of the first mirror 24 and in a space adjacent to the outer side of the recess 40a of the second frame 40 formed for the light guide 22 to hold. The reflected light from the second mirror 25 is reflected toward the second mirror 26 again. The fourth mirror 27 is disposed above the reflection surface 24 a of the first mirror 24 and adjacent to the first mirror 24, and reflects the reflected light from the second mirror 25 toward the lens 28. The lens 28 is disposed above the first mirror 24 and directly above the second mirror 25 in a wide space on the second surface 20b side, and the CCD substrate 31 is second closest to the second surface 20b. It arrange | positions along the surface 20b. As described above, each optical component is optimally laid out so that light incident from one end portion where the space is narrow is reflected a plurality of times on the side where the space is wide, and the second reading unit 3 is small while ensuring a predetermined optical path length. We are trying to make it.

  According to the present embodiment, the second reading unit 3 is configured by connecting the optical unit 60, the light source unit 61, and the glass unit 62 in this order, and the optical unit 60 in a state where the light source unit 61 and the glass unit 62 are connected. Since the lens unit 62 can be removed while the optical unit 60 and the light source unit 61 are connected to each other, it is possible to easily remove foreign matter that has entered between the optical unit 60, the light source unit 61, and the glass unit 62. Can do. In addition, maintenance of parts arranged between the units is facilitated. In particular, since paper dust and wrinkles of rollers are generated around the third contact glass 20 that also serves as a document conveyance surface, when paper dust or wrinkles adhere to the inside of the third contact glass 20, a light source The third contact glass 20 can be easily cleaned by removing the lens unit 62 from the unit 61.

A Document feeder H Document reader main body 1a First contact glass 2 First reading unit 3 Second reading unit (reading unit)
12 Document transport path 20 Third contact glass 21 LED
22 Light guide 24 First mirror 25 Second mirror 26 Third mirror 27 Fourth mirror 28 Lens 29 CCD (photoelectric conversion element)
60 Optical unit (third unit)
61 Light source unit (second unit)
62 Glass unit (first unit)

Claims (8)

In a document reading apparatus comprising: a transport mechanism that transports a document along a transport path that guides the document to a reading position that reads the document; and a reading mechanism that reads the document that is transported through the reading position;
A first unit having a contact glass provided with the reading position; a second unit having a light source for irradiating light on the document through the contact glass; and a plurality of light guides for reflecting light reflected from the document in a predetermined direction. A third unit having a mirror, a lens that converges the reflected light guided by the plurality of mirrors, and a photoelectric conversion element that photoelectrically converts the light converged by the lens constitutes the reading mechanism and the reading The mechanism is connected to the first, second and third units to form one reading unit,
The reading unit composed of the first, second and third units is detachably attached to the transport mechanism, and the reading unit removed from the transport mechanism is connected to the second unit and the third unit. An original reading apparatus characterized in that the first unit can be removed in a state where the two are connected. The light source includes a semiconductor element that emits light, and a light guide that extends in the document width direction and emits the light of the semiconductor element toward the document surface,
The document reading apparatus according to claim 1, wherein the second unit includes a substrate on which the semiconductor is mounted, and a radiator that suppresses heat generation of the semiconductor. The second unit has a concave portion for attaching the light guide on one surface side and a slit for guiding reflected light from a document to the mirror of the third unit, and an attachment portion for attaching the substrate on the side surface side of the second unit. The document reading apparatus according to claim 2, further comprising a formed resin frame. The third unit includes a resin frame in which a mirror mounting portion for mounting a plurality of mirrors on one surface side and a lens mounting portion for mounting a lens on the other surface side are formed. The document conveying apparatus as described in any one. 5. The document reading unit according to claim 1, wherein the first unit is connected to the second unit so as to be movable in the document transport direction. 6. The third unit and the second unit are each provided with an opening that leads from the outside of the reading unit to the back side of the contact glass of the first unit with respect to the document conveying surface. The document reading apparatus described. 6. The first unit according to claim 5, wherein the first unit includes a white sheet for obtaining shading correction data, and the white sheet is attached so as to cover a part of the contact glass in the document conveying direction. The document reading apparatus described. 2. The document reading apparatus according to claim 1, wherein the third unit is detachable from the second unit in a state where the first unit and the second unit are connected to each other.

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