JP5996247B2 - Image reading apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to an image reading apparatus and an image forming apparatus that read an original or the like using an image sensor.

  2. Description of the Related Art Conventionally, in an image reading apparatus, a CCD image sensor (Charge Coupled Device) or a contact image sensor (CIS: Contact Image Sensor) is used as an image sensor for reading a document.

  Here, in the image reading apparatus using the CIS, there is a problem that the reading accuracy of the image is deteriorated unless the relative depth of the original and the CIS is high because the focal depth of the CIS is as extremely as about 0.4 mm. . Therefore, the focal length is made constant by bringing the CIS into close contact with the lower surface of the document placing glass on which the document is placed. When reading a document, a first mode in which the position of the CIS is fixed and the document is read and a second mode in which the CIS is moved and read with respect to the placed document are selectively performed. Therefore, the image reading apparatus is provided with a document reading glass having a small area used in the first mode and a document placing glass having a large area used in the second mode.

  When the first mode described above is performed, the document is conveyed by an ADF (Auto Document Feeder) combined with the image reading device, but reading is completed when the document is brought into close contact with the document reading glass. It is difficult to scoop up and collect the original. Therefore, in order to surely scoop up the read original, a scoop member for scooping up the original conveyed from the ADF is provided between the original reading glass and the original placement glass.

  By the way, since the scooping member and the glass member (document reading glass and document placing glass) are provided as separate members, a gap is formed in the abutting portion, and the paper dust or dust of the document is generated from the gap. There was a problem of getting in.

  In order to solve the above-described problem, it is possible to incorporate a structure in which an end portion of the original reading glass and an end portion of the original placement glass are arranged in a stacked manner in the thickness direction of the glass member in the image reading apparatus. It has been proposed (see, for example, Patent Document 1).

  In addition, it has been studied to prevent stagnation of dust or the like on the glass member by inclining one glass member with respect to the other glass member (see, for example, Patent Document 2).

JP 2010-239489 A JP 2010-239490 A

  By the way, when the document reading glass and the document placing glass are provided apart from each other, when the scanning body passes between the document reading glass and the document placing glass, the subject is vibrated by a load at a boundary step. was there. As a result, when the scanning body vibrates, abnormal noise may be generated, or the moving speed of the scanning body may fluctuate and the read image may be blurred.

  In the image reading apparatus described in Patent Document 1, the original reading glass and the original placing glass are not separated in the moving direction of the scanning body, but are disposed so as to overlap in the thickness direction of the glass member. There is a step at the boundary. Therefore, the above problem cannot be solved.

  Further, in the image reading apparatus described in Patent Document 2, the document reading glass is disposed to be inclined with respect to the document placing glass, and a guide member is provided between the document reading glass and the document placing glass. The scanning body can avoid collision with the original reading glass. However, since the height of the connection portion between the inclined document reading glass and the guide member differs in the thickness direction of the glass member, the scanning body may be vibrated in the same manner as the step, and thus the above-described problems can be solved. Can not.

  SUMMARY An advantage of some aspects of the invention is that it provides an image reading apparatus and an image forming apparatus that can suppress vibration during reading of an original and reduce distortion of a read image. And

The image reading apparatus according to the present invention, a flat original placing glass, and a document reading glass which are spaced apart by the original placing glass and the sub-scanning direction, opposite to the lower surface of the original placing glass An image reading apparatus that reads the original placed on the original placement glass with the scanning body moved in the sub-scanning direction, and is latched by the scanning body, comprising a sliding member that slides in contact with the original placing glass and the document reading glass, under surface of the original placing glass is a bottom and the same plane of the document reading glass, the sliding member A flat surface that contacts each of the lower surfaces is formed, and the sliding member has a flat surface that contacts the lower surfaces, and the flat surface has a width in the sub-scanning direction of the document reading. The glass and the original placing glass face each other. Characterized in that it is larger than the distance of the end.

  According to this configuration, it is possible to suppress vibration when reading a document and reduce distortion of a read image. In other words, there is a risk of vibration when the scanning body passes between the document placement glass and the document reading glass due to a step at the boundary. However, it has a flat surface having a width larger than the interval between the opposed ends of the document reading glass and the document placing glass, and sliding members are provided on the lower surfaces of both the document placing glass and the document reading glass. Since they are in contact with each other, vibration due to a step can be suppressed.

  In the image reading apparatus according to the present invention, the image reading apparatus includes a biasing member that biases the sliding member toward the document placing glass or the document reading glass, and the biasing member is the document placing glass or the document. It is arranged at a position that coincides with the center of gravity of the sliding member that presses the reading glass in the sub-scanning direction.

  According to this configuration, the sliding member can be evenly adhered to the document placing glass and the document reading glass by the urging member, so that the distance from the scanning body to the document can be prevented from changing. Reading accuracy can be improved. Also, by making the position of the urging member coincide with the center of gravity of the sliding member, the bias of the urging force can be reduced, and the structure of the scanning body can be easily designed.

  In the image reading apparatus according to the present invention, the sliding member is formed with inclined surfaces that are inclined in a direction away from the document placing glass toward the end portion at both ends in the sub-scanning direction. And

  According to this configuration, by forming the inclined surface, the sliding member can gradually come into contact with the document placing glass or the document reading glass when the scanning body passes the boundary. Can be moved to.

In the image reading apparatus according to the present invention, in a reading operation of reading the document placed on the document placing glass by moving the scanning body in the sub-scanning direction, the sliding member is configured to move the document placing glass and the document placing glass. An image reading apparatus, wherein a position in contact with both lower surfaces of the document reading glass is set as a document reading start position of the scanning body.

  According to this configuration, since the scanning body starts moving from the boundary of the glass, it is possible to avoid distortion of the read image due to speed fluctuation immediately after the movement starts. That is, since the scanning body starts to move outside the reading area in the moving scanning, the moving speed of the scanning body can be stabilized before the scanning body reaches the reading area.

In the image reading apparatus according to the present invention, when the center of gravity of the sliding member that presses the document placing glass or the document reading glass is set as the center of gravity of the scanning body, the scanning body is moved in the sub-scanning direction. In the reading operation of reading the document placed on the document placement glass, when the sliding member is brought into a non-contact state from the contact state with respect to the document reading glass, It is set in the position which touches mounting glass.

  According to this configuration, it is possible to reduce vibration when the sliding member and the document reading glass are not in contact with each other. That is, since the center of gravity is in contact with the document placing glass, the force by which the sliding member presses the document placing glass becomes dominant, and the influence of the force by which the sliding member presses the document reading glass is ignored. Can do.

In the image reading apparatus according to the present invention, the image reading apparatus includes a document conveying unit that conveys the document placed on the document placing tray to the upper surface of the document reading glass, and stops the scanning body via the document reading glass . In a reading operation for reading a document conveyed by the document conveying unit, a position where the sliding member is in contact with the lower surfaces of both the document placing glass and the document reading glass is a reading position where the scanning body stops and reads. It is characterized by being set.

According to this configuration, the slide member is stopped at the reading position (stop reading position) so as not to be affected by the step at the boundary, so that the sliding member is securely adhered to both the document placing glass and the document reading glass. Can be made. Therefore, the image reading accuracy can be further improved by reducing the distance from the scanning body to the original as much as possible.

  An image forming apparatus according to the present invention includes the image reading apparatus according to the present invention.

  According to this configuration, by providing the image reading apparatus according to the present invention, the same operational effects as the image reading apparatus according to the present invention can be obtained.

  According to the present invention, it is possible to suppress vibration when reading a document and reduce distortion of a read image. In other words, there is a risk of vibration when the scanning body passes between the document placement glass and the document reading glass due to a step at the boundary. However, it has a flat surface having a width larger than the interval between the opposed ends of the document reading glass and the document placing glass, and sliding members are provided on the lower surfaces of both the document placing glass and the document reading glass. Since they are in contact with each other, vibration due to a step can be suppressed.

1 is a side view showing a schematic configuration of an image forming apparatus according to an embodiment of the present invention. 1 is a cross-sectional view illustrating a schematic configuration of an image reading apparatus according to an embodiment of the present invention. It is a top view which extracts and shows the reading part of an image reading device. It is an expanded sectional view which expands and shows the inside of an image sensor. It is a perspective view of an image sensor. It is an external view of an image sensor, (a) is a top view, (b) is a front view. It is a perspective view of a scanning base. It is an external view of a scanning base, Comprising: (a) is a top view, (b) is a front view. FIG. 8 is an enlarged side view of FIG. 7. It is an external view which shows the state which combined the image sensor and the scanning base, Comprising: (a) is a top view, (b) is a front view. It is an enlarged side view of FIG. It is an enlarged side view of a sliding member. It is a perspective view of a scanning body. It is an external view of a scanning body, (a) is a top view, (b) is a front view. FIG. 14 is an enlarged side view of FIG. 13. It is sectional drawing in the arrow DD of FIG. It is sectional drawing in the arrow EE of Fig.14 (a). It is sectional drawing in the arrow FF of Fig.14 (a). It is a figure which shows the internal structure of a reading part, Comprising: (a) is a top view, (b) is a side view. It is explanatory drawing which shows the scanning body in a movement start position or a stop reading position. It is explanatory drawing (the 1) which shows the scanning body in movement. It is explanatory drawing (the 2) which shows the scanning body in movement.

  Hereinafter, an image forming apparatus according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a side view showing a schematic configuration of an image forming apparatus according to an embodiment of the present invention.

  The image forming apparatus 1 according to the embodiment of the present invention includes an image reading device 2, an optical scanning device 11, a developing device 12, a photosensitive drum 13, a drum cleaning device 14, a charger 15, an intermediate transfer belt 21, and a fixing device 17. The paper transport path R1, the paper feed tray 18, and the paper discharge tray 39 are provided, and a color image indicated by the image data is formed on the paper.

  The image reading device 2 reads an original placed on the original placement glass 43 and outputs an image of the read original as image data. The image reading device 2 will be described in detail with reference to FIGS. 2 and 3 described later.

  A color image is formed by overlapping toner images of black (K), cyan (C), magenta (M), and yellow (Y). For this reason, the developing device 12, the photoconductor drum 13, the drum cleaning device 14, and the charger 15 are provided four by four so as to form four types of toner images corresponding to the respective colors. Four image stations Pa, Pb, Pc, and Pd are configured in association with magenta and yellow.

  In each of the image stations Pa, Pb, Pc, and Pd, the same operation as described below is performed. The drum cleaning device 14 removes and collects residual toner on the surface of the photosensitive drum 13. The charger 15 uniformly charges the surface of the photosensitive drum 13 to a predetermined potential. The optical scanning device 11 exposes the surface of the photosensitive drum 13 to form an electrostatic latent image. The developing device 12 develops the electrostatic latent image on the surface of the photosensitive drum 13 to form a toner image on the surface of the photosensitive drum 13. Through the above-described series of operations, a toner image of each color is formed on the surface of each photosensitive drum 13.

  Subsequently, the intermediate transfer belt 21 rotates in the direction of arrow C, and the residual toner is removed and collected by the belt cleaning device 25, and the toner images of the respective colors formed on the surfaces of the photosensitive drums 13 are sequentially transferred. As a result, a color toner image is formed on the surface of the intermediate transfer belt 21.

  A nip area is formed between the transfer roller 26a of the secondary transfer device 26 and the intermediate transfer belt 21, and the recording paper conveyed through the paper conveyance path R1 is sandwiched and conveyed in the nip area. When the recording paper passes through the nip region, the toner image on the surface of the intermediate transfer belt 21 is transferred. The fixing device 17 sandwiches the recording paper on which the toner image is transferred between the heating roller 31 and the pressure roller 32 and heats and presses the recording paper to fix the toner image on the recording paper.

  Recording paper is stacked on the paper feed tray 18. The recording paper is pulled out from the paper feed tray 18 by the pickup roller 33, transported through the paper transport path R 1, passes through the secondary transfer device 26 and the fixing device 17, and then passes through the paper discharge roller 36 to the paper discharge tray 39. Discharged.

  In the paper transport path R1, after the recording paper is stopped once and the leading edge of the recording paper is aligned, the recording paper is fed in accordance with the transfer timing of the toner image in the nip area between the intermediate transfer belt 21 and the transfer roller 26a. A registration roller 34 for starting conveyance, each conveyance roller 35 for urging conveyance of the recording paper, and a paper discharge roller 36 are arranged.

  When image formation is performed not only on the front side of the recording paper but also on the back side, the recording paper is conveyed in the reverse direction from the paper discharge roller 36 to the reverse path Rr, and the front and back sides of the recording paper are reversed to the registration roller 34. Then, the toner image is fixed on the back surface of the recording paper and discharged to the paper discharge tray 39 in the same manner as the front surface of the recording paper.

  Next, the configuration of the image reading apparatus will be described with reference to the drawings.

  FIG. 2 is a sectional view showing a schematic configuration of the image reading apparatus according to the embodiment of the present invention, and FIG. 3 is a plan view showing the reading unit of the image reading apparatus. In FIG. 3, the scanning body SU is shown in perspective to clarify the positional relationship.

  The image reading apparatus 2 according to the embodiment of the present invention includes a plate-like document placing glass 43, an image sensor 48 arranged in the main scanning direction Y along the lower surface 43a of the document placing glass 43, and an image. A scanning base 71 that supports the sensor 48 is provided, and the document placed on the document placement glass 43 is read by the image sensor 48. The scanning body SU composed of the image sensor 48, the scanning base 71, the urging member 90, and the sliding member 100 will be described with reference to FIGS.

  Specifically, the image reading apparatus 2 includes a lower reading unit 41 and an upper document conveying unit 61. The document conveying unit 61 is configured to be rotatable about an axis connecting the reading unit 41 and the document conveying unit 61, and the document reading glass 42 and the document placing glass 43 are opened by opening the reading unit 41. Is done. In the following, for the sake of explanation, the direction orthogonal to the lower surface 43a of the document placement glass 43 is referred to as the vertical direction Z, and in the vertical direction Z, the document transport unit 61 side with respect to the document placement glass 43 is referred to as the upper side. The scanning body SU side with respect to the document placement glass 43 may be referred to as the lower side. A direction parallel to the lower surface 43 a of the document placement glass 43 and orthogonal to the main scanning direction Y is referred to as a sub-scanning direction X.

  The scanning body SU is disposed below the document reading glass 42 and the document placing glass 43. The scanning body SU reads the document placed on the document placement glass 43 while being moved in the sub-scanning direction X along the lower surface 43a of the document placement glass 43 by the pulling member MU (this is the first mode). And the moving reading operation), the document is stopped below the document reading glass 42 and the document passing on the document reading glass 42 is read (this is referred to as the second mode and the stop reading operation). Note that the moving reading operation and the stop reading operation will be described with reference to FIGS.

  The reading unit 41 includes a scanning body SU, a pulling member MU, and a guide unit 80 (see FIG. 19 described later) inside a housing 44. The internal configuration of the reading unit 41 will be described with reference to FIG.

  The casing 44 is provided with a rectangular document reading glass 42 and a document placing glass 43 in the upper opening. The housing 44 further includes side plates 44a that cover the side surfaces, an edge plate 44b that is disposed on the top surface and has an opening, and a bottom plate 44d that covers the bottom surface of the housing. Further, a rectangular frame member 45 that borders four sides of the document reading glass 42 and one side of the document placing glass 43 is provided on the upper surface of the housing 44. The rectangular member 45 is provided with a document scooping portion 47 on one side (the right side in the figure) sandwiched between the document reading glass 42 and the document placement glass 43 among the two opposing sides. A document guide portion 46 is provided on the left side in the drawing.

  The document guide section 46 is bonded to the two surfaces of the front end surface of the document reading glass 42 (the end surface facing away from the document placement glass 43) and the upper surface. The document scooping portion 47 is adhered to two surfaces of the rear end surface of the document reading glass 42 and the front end surface of the document placement glass 43 (end surface facing the document reading glass 42). That is, the document reading glass 42 and the document placement glass 43 are connected and integrated through the rectangular frame member 45.

  The document reading glass 42 and the document placement glass 43 have the same thickness and are spaced apart in the sub-scanning direction X. The distance between the end faces of the document reading glass 42 and the document placing glass 43 facing each other in the sub-scanning direction X (the distance from the rear end face of the document reading glass 42 to the front end face of the document placing glass 43) is 5 to 6 mm. Yes. Further, the lower surface 42a of the document reading glass 42, the lower surface 43a of the document placing glass 43, and the lower surface 46a of the document guide portion 46 are the same plane and form a smooth flat surface. Note that the lower surface 47a of the document scooping portion 47 will be described with reference to FIGS.

  Further, in the document scooping portion 47, a portion bonded to the upper surface of the document placing glass 43 is a document position restricting portion 47b. The document position restricting portion 47b is bonded to the document placing glass 43 via a film-like white reference member W, but is not limited thereto, and the document position restricting portion 47b is formed of a white material. The document position restricting portion 47b itself may be used as a white reference member, or a white reference member may be formed by applying white paint on the back surface of the document position restricting portion 47b.

  The document transport unit 61 is used in the first mode in which a document transported along the upper surface of the document reading glass 42 is read with the scanning body SU fixed at a position below the document reading glass 42. In the document transport unit 61, the document set on the document tray 62 is pulled out by the reading side pickup roller 63 and supplied to the document transport path 64. In the document conveyance path 64, the document is conveyed by the reading-side conveyance roller 69, and the leading edge of the document is aligned by the reading-side registration roller 68 and conveyed above the document reading glass 42. The conveyed document is guided by the document guide unit 46, the leading end thereof is guided to the upper surface of the document reading glass 42, and conveyed in close contact with the document reading glass 42. The image sensor 48 reads an image of a document that passes over the document reading glass 42. The read document is discharged to a document discharge tray 67 by a reading-side discharge roller 66.

  Next, each part of the scanning body will be described.

  4 is an enlarged cross-sectional view showing the inside of the image sensor, FIG. 5 is a perspective view of the image sensor, FIG. 6 is an external view of the image sensor, and FIG. It is a top view, (b) is a front view.

  The image sensor 48 is, for example, a CIS, and a pair of light sources 51 that illuminate a document through the document placement glass 43 or the document reading glass 42, a condensing lens array 52 that collects reflected light from the document, and An imaging element 53 is provided that photoelectrically converts reflected light from the original received through the condenser lens array 52 and outputs image data. The image pickup elements 53 are arranged in the main scanning direction Y, and scan and read a document in the main scanning direction Y.

  The image sensor 48 having the above-described configuration has a substantially rectangular shape formed of resin or the like, and a part of the upper surface is opened along the main scanning direction Y, and the lens that fixes the condenser lens array 51 to the opening. A fixing portion 54 is provided. In the following description, for the sake of explanation, among the side surfaces of the image sensor 48, a surface facing in the sub-scanning direction X is sometimes called a side surface, and a surface facing in the main scanning direction Y is sometimes called an end surface.

  One side surface 48d of the image sensor 48 is provided with two sensor mounting portions 48a and 48a at a constant distance in the main scanning direction Y, and each sensor mounting portion 48a and 48a has a scanning base. Mounting shafts 48b and 48b that are locked to 71 are formed. Specifically, the two attachment shafts 48b and 48b are extended in the same direction along the main scanning direction Y from the sensor attachment portion 48a. Specifically, it extends in a direction from a sensor urging portion 72b, which will be described later, toward the sensor support portion 75a (see FIG. 10). Although the interval between the two sensor attachment portions 48a can be designed as appropriate, in this embodiment, sensor attachment portions 48a and 48a are provided in the vicinity of both end portions of the image sensor 48 in the main scanning direction Y. Further, two sensor side holding portions 48c and 48c are provided on the lower surface of the image sensor 48 at a constant distance in the main scanning direction Y, and an urging member 90 (see FIG. 10), which will be described later, It arrange | positions in the position corresponding to the side holding | maintenance part 48c. The sensor side holding portion 48c is formed to be recessed from the periphery, and one end of the urging member 90 is inserted and held in the sensor side holding portion 48c.

  7 is a perspective view of the scanning base, FIG. 8 is an external view of the scanning base, (a) is a plan view, (b) is a front view, and FIG. 7 is an enlarged side view of FIG.

  The scanning base 71 has a rectangular parallelepiped shape with one side surface and an upper surface opened. That is, the scanning base 71 includes a base bottom plate 72 that is parallel to the lower surface 43 a of the document placement glass 43, a guide side plate 73 and a bearing side plate 74 that face each other in the sub-scanning direction X, and a support side plate 75. The image sensor 48 is housed and supported inside. As shown in FIGS. 10 and 11 to be described later, the guide side plate 73 and the bearing side plate 74 are disposed to face the side surface of the image sensor 48, and the support side plate 75 is opposed to the end surface of the image sensor 48. Has been placed. The scanning base 71 is made of, for example, an acrylonitrile / butadiene / styrene copolymer (ABS resin).

  The base bottom plate 72 is provided with base side holding portions 72a at positions facing the two sensor side holding portions 48c of the image sensor 48, respectively. The base side holding part 72a is formed to be recessed from the periphery, and the other end of the urging member 90 is inserted and held in the base side holding part 72a. That is, the biasing member 90 is positioned with both ends held by the base side holding portion 72a and the sensor side holding portion 48c. Further, the base bottom plate 72 is provided with a sensor urging portion 72 b that urges the image sensor 48 at the end opposite to the support side plate 75. The sensor urging portion 72b is formed to extend upward from the end portion of the base bottom plate 72, and the upper end urges the image sensor 48 toward the sensor support portion 75a. The distance from the sensor urging portion 72 b to the support side plate 75 (particularly, the sensor support portion 75 a described later) is shorter than the image sensor 48.

  Further, a base connection portion 76 connected to a guide portion 80 and a driven belt 85 described later is fixed to the lower surface of the base bottom plate 72. In addition, the base connection part 76 is demonstrated with reference to FIG. 19 mentioned later.

  On the outer surface side of the guide side plate 73, a guide piece 73a protruding toward the outside of the scanning base 71 and a second locking groove 73d recessed on the inner surface side of the guide side plate 73 are provided. The second locking groove 73d is provided at an end portion on the support side plate 75 side. A first sliding restricting portion 73 b is provided on the inner surface side of the guide side plate 73 on the end opposite to the support side plate 75. The first sliding restricting portion 73b is formed in a substantially quadrangular prism shape, and a first restricting hole 73c drilled along the vertical direction Z is provided on the upper surface thereof.

  The bearing side plate 74 is provided with two bearing portions 74a into which the two mounting shafts 48b of the image sensor 48 are respectively inserted. The two bearing portions 74a are opened in the same direction so as to face the two mounting shafts 48b. What is necessary is just to design the position and shape of the bearing part 74a suitably according to the attachment shaft 48b.

  On the outer surface side of the bearing side plate 74, a first locking groove 74d that is recessed on the inner surface side of the bearing side plate 74 is provided. The first locking groove 74d is provided at the end opposite to the support side plate 75. Further, a second sliding restriction portion 74b is provided on the inner surface side of the bearing side plate 74 and on the end portion on the support side plate 75 side. The second sliding restricting portion 74b is formed in a substantially quadrangular prism shape, and a second restricting hole 74c drilled along the vertical direction Z is provided on the upper surface thereof. In the following, in order to simplify the description, the first restriction hole 73c and the second restriction hole 74c are collectively referred to as a restriction hole, and the first engagement groove 74d and the second engagement groove 73d are collectively engaged. Sometimes called a groove. Moreover, the 1st latching groove 74d and the 2nd latching groove 73d should just be made into the recessed part into which the latching convex part 102a (refer FIG. 12) mentioned later is inserted, and the bearing side side board 74 or the guide side side board 73 is sufficient. It may be a hole formed through the hole.

  In the above configuration, the first restriction hole 73c and the first locking groove 74d are arranged at positions facing each other in the sub-scanning direction X, and the second restriction hole 74c and the second locking groove 73d are opposed in the sub-scanning direction X. It is arranged at the position to do. The first sliding member 100a described later is locked by the first restriction hole 73c and the first locking groove 74d, and the second sliding member described later is locked by the second restriction hole 74c and the second locking groove 73d. 100b is configured to be locked (refer to FIGS. 13 to 15 for details).

  A sensor support portion 75 a that faces the end surface of the image sensor 48 is provided on the inner surface side of the support side plate 75. In the present embodiment, the sensor support portion 75a is, for example, a rib and is formed to protrude inward from the periphery.

  10A and 10B are external views showing a state in which the image sensor and the scanning base are combined, where FIG. 10A is a plan view, FIG. 10B is a front view, and FIG. 11 is an enlarged side view of FIG. FIG.

When combining the image sensor 48 and the scanning base 71, the mounting shaft 48b is inserted into the bearing portion 74a. At this time, the two mounting shafts 48b protrude in the same direction, and the two bearing portions 74a corresponding to the two mounting shafts 48b are also open in the same direction. Therefore, the image sensor 48 is mounted with the mounting shaft 48b facing the bearing portion 74a. The two mounting shafts 48b can be inserted into the corresponding bearing portions 74b only by moving in one direction (main scanning direction Y).
Then, the image sensor 48 is housed inside the scanning base 71 by rotating the image sensor 48 with the mounting shaft 48b as a fulcrum while the mounting shaft 48b is inserted into the bearing portion 74b. Here, the urging member 90 is sandwiched between the image sensor 48 and the scanning base 71 by inserting and holding the urging member 90 in the base side holding portion 72 a in advance. In the present embodiment, the urging member 90 is, for example, a coil spring.

  In combination with the scanning base 71, the image sensor 48 is biased toward the sensor support portion 75a by the sensor biasing portion 72b, and the sensor support portion 75a positions the scanning base 71 in the main scanning direction Y. Yes. According to this configuration, by positioning the image sensor 48 with respect to the scanning base 71, it is possible to prevent the image sensor 48 from being displaced and to improve the accuracy in image reading.

  FIG. 12 is an enlarged side view of the sliding member.

  The sliding member 100 includes an abutting portion 101 that abuts on the document placement glass 43 and a locking portion that extends from one end of the abutment portion 101 in a direction opposite to the document placement glass 43 (downward in the vertical direction Z). 102 is a rod-shaped member that is formed in an L-shape as a whole. The locking portion 102 is configured to be locked to the scanning base 71.

  The contact portion 101 is provided with a contact convex portion 101a that is inserted into a restriction hole (the first restriction hole 73c or the second restriction hole 74c). Specifically, the contact convex portion 101a is provided on the lower surface side of the contact portion 101 and near the end opposite to the locking portion 102, and has substantially the same shape as the restriction hole in plan view. Has been. Further, the upper surface of the contact portion 101 is a flat surface 101b that contacts the document placing glass 43, and both end portions thereof are inclined surfaces 101c. The inclined surface 101c is inclined in a direction (downward) away from the document placing glass 43 toward the end.

  The flat surface 101b is in contact with the lower surface 43a of the document placing glass 43 and the lower surface 42a of the document reading glass 42, and the width in the sub-scanning direction X is the distance between the opposite ends of the document reading glass 42 and the document placing glass 43. It is formed larger. That is, the flat surface is formed to be larger than the interval between the end faces of the document reading glass 42 and the document placement glass 43 facing each other in the sub-scanning direction X (refer to FIG. 20 described later). Specifically, the width of the sliding member 100 in the sub-scanning direction is 25 mm, and the width of the flat surface 101b is about 20 mm. Note that the width of the inclined surface 101c with respect to the flat surface 101b can be appropriately designed.

  The locking portion 102 is provided with a locking projection 102a that is inserted into the locking groove (the first locking groove 74d or the second locking groove 73d). Specifically, the locking projection 102a is provided near the lower end of the locking portion 102 and on the inner surface side (the surface side continuous with the lower surface of the contact portion).

  The sliding member 100 is formed of a material having slidability. According to this configuration, damage to the scanning body SU due to friction can be prevented, and the scanning body SU can be moved smoothly. Specifically, the sliding member 100 is made of, for example, polyoxymethylene (POM). Further, the sliding member 100 has elasticity, and when it is attached to the scanning base 71, it is deformed by applying a force such as pulling, so that it can be easily assembled.

  In the present embodiment, by providing the locking portion 102, the sliding member 100 and the scanning base 71 can be locked so as not to be separated from each other. Further, since the sliding member 100 is not fixed to the scanning base 71, the sliding member 100 can be structured to be detachable from the scanning base 71.

  Further, by forming the inclined surface 101c, the sliding member 100 is gradually moved when the scanning body SU passes the boundary with the document placing glass 43 or the document reading glass 42 (the end portion of the document scooping portion 47). It is possible to have a structure in contact with the document placing glass 43 or the document reading glass 42, and the scanning body SU can be moved smoothly.

  13 is a perspective view of the scanning body, FIG. 14 is an external view of the scanning body, (a) is a plan view, (b) is a front view, and FIG. 15 is a plan view of FIG. It is an enlarged side view. 16 is a cross-sectional view taken along arrow DD in FIG. 14A, FIG. 17 is a cross-sectional view taken along arrow EE in FIG. 14A, and FIG. It is sectional drawing in the arrow FF of Fig.14 (a).

  The scanning body SU is configured by attaching the sliding member 100 to the state in which the image sensor 48 and the scanning base 71 shown in FIGS. 10 and 11 are combined.

  The scanning body SU is configured to have two sliding members 100, and the sliding members 100 are arranged at both ends of the scanning base 71 in the main scanning direction Y. According to this configuration, since the sliding member 100 is disposed at both ends, the image sensor 48 can be reliably held, and only the sliding member 100 is in contact with the document placement glass 43. it can. Hereinafter, in order to simplify the description, the sliding member 100 locked in the first restriction hole 73c and the first locking groove 74d is referred to as a first sliding member 100a, and the second restriction hole 74c and the second locking hole. The sliding member 100 locked in the groove 73d may be referred to as a second sliding member 100b.

  The first sliding member 100a and the second sliding member 100b have the same shape and are attached in different directions.

  As shown in FIG. 16, the first sliding member 100a is scanned by inserting the contact convex portion 101a into the first restricting hole 73c and inserting the locking convex portion 102a into the first locking groove 74d. Locked to the base 71. Further, the contact portion 101 is in close contact with the upper surface of the image sensor 48.

  On the other hand, as shown in FIG. 18, in the second sliding member 100b, the abutting convex portion 101a is inserted into the second restricting hole 74c, and the engaging convex portion 102a is inserted into the second engaging groove 73d. It is locked to the scanning base 71. Further, the contact portion 101 is in close contact with the upper surface of the image sensor 48.

  Note that the first sliding member 100a and the second sliding member 100b are pressed by the image sensor 48 and biased upward, but the upward movement is restricted by the locking projection 102a. In FIG. 16 and FIG. 18, there is a gap above the locking projection 102a. This is because the sliding member 100 is moved downward by being pressed by the document placing glass 43 or the like. When the document placement glass 43 or the like is removed, the above-described gap disappears.

  As shown in FIG. 17, the image sensor 48 is urged upward by the urging member 90, but only the first sliding member 100 a and the second sliding member 100 b are placed on the lower surface 43 a of the document placing glass 43. The image sensor 48 is in contact with the original placing glass 43. Therefore, when the scanning body SU is moved in the sub-scanning direction X, it is possible to prevent the image sensor 48 from being damaged due to friction with the document placement glass 43 or the like. The first sliding member 100 a and the second sliding member 100 b are in contact with the document reading glass 42 in the same manner as the document placing glass 43.

  As described above, the first sliding member 100a has the locking portion 102 attached along the bearing side plate 74, whereas the second sliding member 100b has the locking portion 102 having the guide side plate. 73 is attached. Therefore, by holding the image sensor 48 along the surfaces facing each other, it is possible to reliably prevent the image sensor 48 from floating.

  The first sliding member 100a and the second sliding member 100b are attached so as to protrude upward from the upper surface of the image sensor 48 at the same height.

  When combining the sliding member 100, for example, the contact protrusion 101a is inserted into the restriction holes (first restriction hole 73c, second restriction hole 74c) from above, and the engagement grooves (first engagement groove 74d, first The sliding member 100 is locked to the scanning base 71 by inserting the locking projection 102a into the second locking groove 73d). When inserting the locking projection 102a into the locking groove (first locking groove 74d, second locking groove 73d), the locking part 102 is moved downward along the guide side plate 73 or the bearing side plate 74. If it moves to, the latching convex part 102a will contact | abut to the guide side side plate 73 or the bearing side side plate 74, and the sliding member 100 will deform | transform elastically. When the locking projection 102a reaches the locking groove (first locking groove 74d, second locking groove 73d), the sliding member 100 returns to its original shape, and the locking projection 102a naturally. Is inserted into the locking grooves (the first locking groove 74d and the second locking groove 73d). Accordingly, as the abutting convex portion 101a is inserted, the locking convex portion 102a is inserted by moving the sliding member 100 downward, so that the sliding member 100 can be easily attached and assembled. Work can be simplified.

  As described above, the scanning base 71 faces the locking grooves (the first locking groove 74 d and the second locking groove 73 d) formed on the surface facing the locking portion 102 and the document placement glass 43. Restriction holes (a first restriction hole 73c and a second restriction hole 74c) formed in the surface to be formed are provided.

  The locking grooves (first locking groove 74d and second locking groove 73d) are formed such that the width in the direction (vertical direction Z) toward the document placement glass 43 is larger than the outer width of the locking projection 102a. . According to this configuration, the locking grooves (the first locking groove 74d and the second locking groove 73d) have a width in the direction (vertical direction Z) toward the document placing glass 43 that is larger than the locking projection 102a. A structure in which the stopper protrusion 102a is movable in the vertical direction Z within the locking grooves (the first locking groove 74d and the second locking groove 73d) can be adopted. Therefore, by adjusting the distance between the sliding member 100 and the scanning base 71 in the vertical direction Z, it is possible to correct a gap in the distance between the scanning base 71 and the document placement glass 43 caused by component tolerances. .

  The sliding member 100 is restricted from moving relative to the scanning base 71 in the main scanning direction Y and in the direction (upward) toward the document placement glass 43 by the locking convex portion 102a, and the main surface by the contact convex portion 101a. Movement in the scanning direction Y and the sub-scanning direction X is restricted. According to this configuration, it is possible to reliably lock the sliding member 100 and the scanning base 71 by providing two portions for locking. That is, since the direction in which the movement is regulated is different between the locking projection 102a and the contact projection 101a, even if a force is applied in a direction in which the movement is not regulated on the one hand, the movement is restrained by the other.

  Next, the internal configuration of the reading unit will be described in detail.

  19A and 19B are diagrams illustrating the internal structure of the reading unit, in which FIG. 19A is a plan view and FIG. 19B is a side view. That is, FIG. 19 shows a state in which the document reading glass 42, the document placement glass 43, the edge plate 44b of the housing 44, the rectangular frame member 45, and the like are removed from the reading unit 41.

  The guide unit 80 is arranged along the sub-scanning direction X at the center of the housing 44 in the main scanning direction Y, and supports the scanning body SU to guide the reciprocating movement of the scanning body SU. Specifically, the guide portion 80 is a columnar shaft, and is fixed to the side plates 44 a on the front and rear sides of the housing 44 so as to extend in parallel with the sub-scanning direction X. On the other hand, on the lower surface of the base bottom plate 72 of the scanning base 71, a base connecting portion 76 is provided at the center in the main scanning direction Y, and a guide connecting portion 76a is formed on the base connecting portion 76. Yes. The guide connecting portion 76a is a semi-cylindrical concave portion facing downward, and has a structure that can be fitted into the guide portion 80. In other words, the scanning base 71 is placed on the guide part 80 via the base connection part 76 and is supported by the guide part 80 so as to be movable in the sub-scanning direction X. The guide portion 80 is not limited thereto, and may be a convex portion that protrudes upward from the bottom plate 44d and is formed along the sub-scanning direction X.

  The pulling member MU includes a pair of shafts 81 and 82, small pulleys 83 and 84, a driven belt 85, a large pulley 86, a motor 87, a driving pulley 88, and a driving belt 89, and scanning. The body SU is pulled and reciprocated in the sub-scanning direction X.

  Specifically, the pair of shafts 81 and 82 are provided so as to protrude perpendicularly to the bottom plate 44 d of the housing 44 and are spaced apart in the sub-scanning direction X. Small pulleys 83 and 84 are rotatably supported at the upper ends of the shafts 81 and 82, respectively, and an endless driven belt 85 is bridged around the small pulleys 83 and 84. The peripheral surface of the driven belt 85 is connected to a traction connection part 76b (see also FIG. 8B) formed in the base connection part 76.

  On one shaft 82, a large pulley 86 is fixed concentrically with the small pulley 84, and the small pulley 84 and the large pulley 86 rotate together. The motor 87 is fixed to the bottom plate 44 d in the vicinity of one shaft 84. A drive pulley 88 is fixed to the output shaft of the motor 87, and an endless drive belt 89 is bridged between the drive pulley 88 and the large pulley 86.

  In the pulling member MU, when the motor 87 is driven to rotate the driving pulley 88, the rotation of the driving pulley 88 is transmitted to the large pulley 86 through the driving belt 89. Then, the small pulley 84 rotates together with the large pulley 86, and the rotation of the small pulley 84 is transmitted to the small pulley 83 via the driven belt 85, so that the small pulley 83 rotates. As a result, the driven belt 85 moves around, the base connecting portion 76 connected to the driven belt 85 slides on the guide portion 80, and the scanning body SU moves in the sub-scanning direction X. Further, the rotation direction of the output shaft of the motor 87 corresponds to the movement direction of the scanning body SU, and the movement direction of the scanning body SU and the image sensor 48 is controlled by controlling the rotation direction and the rotation angle of the output shaft of the motor 87. And the moving distance can be controlled.

  A position sensor 49 is provided on the side plate 44 a at a position corresponding to the guide piece 73 a of the scanning base 71. In the position sensor 49, the light emitting element and the light receiving element are disposed to face each other, and the guide piece 73a that has entered between the light emitting element and the light receiving element is detected. Based on the detection result of the position sensor 49, the image sensor 48 can be positioned at the initial position below the document reading glass 42.

  As described above, since the image sensor 48 is held by the sliding member 100, it is possible to prevent the image sensor 48 from being lifted from the scanning base 71 and becoming unstable during assembly. Therefore, a stable assembly operation can be performed by configuring the scanning body SU by combining the image sensor 48, the scanning base 71, the biasing member 90, and the sliding member 100.

  Next, the moving reading operation and the stop reading operation of the image reading apparatus will be described.

  FIG. 20 is an explanatory view showing the scanning body at the movement start position or the stop reading position, FIG. 21 is an explanatory view (No. 1) showing the scanning body during movement, and FIG. 22 is a scanning body during movement. It is explanatory drawing (the 2) which shows this.

  As shown in FIG. 20, when the above-described moving reading operation is started and when the stop reading operation is performed, the scanning body SU has the sliding member 100 on the lower surfaces of both the document placing glass 43 and the document reading glass 42. Stops at a touching position. In the image reading apparatus 2, the position at which the scanning body SU is stopped at the start of the moving reading operation is set as the movement start position, and the position at which the scanning body SU is stopped at the time of executing the stop reading operation is set as the stop reading position. Has been. For example, the scanning body SU is stopped at a preset movement start position or stop reading position by controlling the movement direction and movement distance of the scanning body SU with the initial position detected by the position sensor 49 as a base point. In the present embodiment, the movement start position and the stop reading position are the same position. However, the present invention is not limited to this, and the movement start position and the stop reading position may be different positions.

  On the lower surface 47 a of the document scooping portion 47, a document scooping recess 47 c that is recessed upward is formed. Specifically, the lower surface 47a on which the document scooping recess 47c is formed is the same plane as the lower surface 42a of the document reading glass 42 and the lower surface 43a of the document placing glass 43, and the rear end surface of the document reading glass 42 and the document placing glass. A document scooping recess 47 c is provided between the front end surface of 43. The lower surface 47a of the document scooping portion 47 may not be the same plane as the lower surface 42a of the document reading glass 42 and the lower surface 43a of the document placing glass 43, and is recessed above the lower surface 42a and the lower surface 43a. Also good. That is, the document scooping portion 47 may have a structure in which a step in the vertical direction Z is provided with respect to the document reading glass 42 and the document placing glass 43.

  The biasing member 90 is disposed at a position that coincides with the center of gravity of the sliding member 100 that presses the document placement glass 43 or the document reading glass 42 in the sub-scanning direction X. According to this configuration, the sliding member 100 can be evenly adhered to the document placing glass 43 and the document reading glass 42 by the urging member 90, so that the distance from the scanning body SU to the document does not vary. Image reading accuracy can be improved. Also, by making the position of the urging member 90 coincide with the center of gravity of the sliding member 100, the bias of the urging force can be reduced, and the structure of the scanning body SU can be easily designed. For example, by appropriately designing the positions of the base side holding part 72a and the sensor side holding part 48c according to the size and weight of the image sensor 48, the scanning base 71, and the sliding member 100, the position of the biasing member 90 Can be made to coincide with the center of gravity of the sliding member 100. In the following description, the center of gravity of the sliding member 100 that presses the document placement glass 43 or the document reading glass 42 is referred to as the center of gravity of the scanning body SU for simplification of description.

  When performing the moving reading operation, the scanning body SU is moved in the sub-scanning direction X from the movement start position in a direction away from the document reading glass 42 (right direction in the drawing). Here, the flat surface 101b is formed so that the width in the sub-scanning direction X is larger than the interval between the opposite ends of the document reading glass 42 and the document placing glass 43, so that vibration when reading the document is suppressed. The distortion of the read image can be reduced. In other words, there is a possibility that the scanning body SU may vibrate between the document placing glass 43 and the document reading glass 42 due to a step at the boundary. However, the flat surface 101b formed with a width larger than the distance from the document reading glass 42 to the document placing glass 43 is provided, and the sliding member 100 has lower surfaces of both the document placing glass 43 and the document reading glass 42. Since it is in contact with, the vibration due to the step can be suppressed.

  In order to make the sliding member 100 abut on the lower surfaces (lower surface 42a and lower surface 43a) of both the document placing glass 43 and the document reading glass 42 at the movement start position, It is desirable that the document reading glass 42 be disposed as close as possible. Specifically, the document scooping portion 47 disposed between the document placing glass 43 and the document reading glass 42 is formed with a small width in the sub-scanning direction X. This facilitates a structure that contacts both the document placement glass 43 and the document reading glass 42 without enlarging the sliding member 100.

  As described above, the scanning member SU is stopped at the stop reading position so as not to be affected by the step at the boundary, so that the sliding member 100 is securely adhered to both the document placing glass 43 and the document reading glass 42. Can be made. Therefore, the image reading accuracy can be further improved by reducing the distance from the scanning body SU to the original as much as possible.

  As shown in FIG. 21, when the moving reading operation is performed, the scanning member SU is moved from the contact state to the non-contact state with respect to the document reading glass 42 by moving the scanning body SU. Specifically, when the boundary between the flat surface 101 b on the guide side plate 73 side and the inclined surface 101 c reaches the rear end surface of the document reading glass 42, the sliding member 100 is not in contact with the document reading glass 42. It becomes a contact state. Here, since the center of gravity of the scanning body SU is in contact with the document placing glass 43, vibration when the sliding member 100 and the document reading glass 42 are not in contact with each other can be reduced. That is, since the center of gravity is in contact with the document placement glass 43, the force by which the sliding member 100 presses the document placement glass 43 is dominant, and the force by which the sliding member 100 presses the document reading glass 42 is dominant. The influence can be ignored.

  As shown in FIG. 22, by further moving the scanning body SU from the state shown in FIG. 21, the scanning body SU passes through the document scooping portion 47. Specifically, when the boundary portion between the flat surface 101 b on the guide side plate 73 side and the inclined surface 101 c reaches the front end surface of the document placing glass 43, the sliding member 100 passes through the document scooping portion 47. . The image reading apparatus 2 starts to read an image after further moving the scanning body SU from the state shown in FIG. In the moving reading operation in the image reading apparatus according to the present embodiment, the movement start position is different from the position at which image reading is started. Therefore, since the scanning body SU starts moving from the boundary of the glass, it is possible to avoid the distortion of the read image due to the speed fluctuation immediately after the movement starts. That is, since the scanning body SU starts to move outside the reading area in the moving scanning, the moving speed of the scanning body SU can be stabilized before the scanning body SU reaches the reading area.

  It should be noted that the embodiment disclosed herein is illustrative in all respects and does not serve as a basis for limited interpretation. Therefore, the technical scope of the present invention is not interpreted only by the above-described embodiment, but is defined based on the description of the scope of claims. Moreover, all the changes within the meaning and range equivalent to a claim are included.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Image reading apparatus 42 Original reading glass 42a Lower surface (lower surface of original reading glass)
43 Document placement glass 43a Lower surface (lower surface of document placement glass)
46 Document guide section 46a Lower surface (lower surface of document guide section)
47 Document scoop portion 47a Bottom surface (bottom surface of document scoop portion)
48 Image sensor 71 Scan base 72 Base base plate 73 Guide side plate 74 Bearing side plate 75 Support side plate 90 Energizing member 100 Sliding member 101 Abutting portion 101b Flat surface 101c Inclined surface 102 Locking portion SU Scanning body X Sub Scanning direction Y Main scanning direction Z Vertical direction

Claims (8)

A plate-shaped document placing glass, a document reading glass disposed apart from the document placing glass in the sub-scanning direction, and a scanning body provided to face the lower surface of the document placing glass, An image reading device that reads the original placed on the original placement glass with the scanning body moved in the sub-scanning direction,
A sliding member that is locked to the scanning body and that slides in contact with the original placing glass and the original reading glass;
The lower surface of the original placing glass is a bottom and the same plane of the document reading glass,
The sliding member is formed with a flat surface that comes into contact with each lower surface,
The flat surface is formed such that a width in the sub-scanning direction is larger than an interval between opposite ends of the document reading glass and the document placing glass .
In the reading operation of reading the document placed on the document placement glass by moving the scanning body in the sub-scanning direction, the sliding member is placed on the lower surfaces of both the document placement glass and the document reading glass. An image reading apparatus characterized in that a contact position is set as a document reading start position of the scanning body . The image reading apparatus according to claim 1,
A document transport unit that transports a document placed on a document placement tray to the upper surface of the document reading glass;
In a reading operation in which the scanning member is stopped and the original conveyed by the original conveying unit is read through the original reading glass, the sliding member is provided on both lower surfaces of the original placing glass and the original reading glass. The position in contact with the scanning body is set as a reading position where the scanning body stops and reads.
An image reading apparatus. A plate-shaped document placing glass, a document reading glass disposed apart from the document placing glass in the sub-scanning direction, and a scanning body provided to face the lower surface of the document placing glass, An image reading device that reads the original placed on the original placement glass with the scanning body moved in the sub-scanning direction,
A sliding member that is locked to the scanning body and slides in contact with the document placement glass and the document reading glass ;
A document conveying section that conveys the document placed on the document placing tray to the upper surface of the document reading glass ;
The lower surface of the original placing glass is a bottom and the same plane of the document reading glass,
The sliding member is formed with a flat surface that comes into contact with each lower surface,
The flat surface is formed such that a width in the sub-scanning direction is larger than an interval between opposite ends of the document reading glass and the document placing glass .
In a reading operation in which the scanning member is stopped and the original conveyed by the original conveying unit is read through the original reading glass, the sliding member is provided on both lower surfaces of the original placing glass and the original reading glass. An image reading apparatus, wherein a position in contact with the scanning body is set as a reading position where the scanning body stops and reads . The image reading apparatus according to claim 3,
In the reading operation of reading the document placed on the document placement glass by moving the scanning body in the sub-scanning direction, the sliding member is placed on the lower surfaces of both the document placement glass and the document reading glass. The contact position is set as the document reading start position of the scanning body.
An image reading apparatus. An image reading apparatus according to any one of claims 1 to 4 , wherein
An urging member that urges the sliding member toward the document placing glass or the document reading glass;
The image reading apparatus, wherein the urging member is disposed at a position that coincides with the center of gravity of the sliding member that presses the document placing glass or the document reading glass in the sub-scanning direction. An image reading apparatus according to any one of claims 1 to 5 , wherein
The image reading apparatus according to claim 1, wherein the sliding member has inclined surfaces formed at both end portions in the sub-scanning direction that are inclined in a direction away from the document placing glass toward the end portion. An image reading apparatus according to any one of claims 1 to 6 ,
When the center of gravity of the sliding member that presses the document placement glass or the document reading glass is the center of gravity of the scanning body,
In a reading operation in which the scanning member is moved in the sub-scanning direction to read a document placed on the document placing glass, the sliding member is brought into a non-contact state with respect to the document reading glass. The image reading apparatus is characterized in that the center of gravity of the scanning body is set at a position in contact with the document placing glass. An image forming apparatus comprising the image reading apparatus according to claim 1 .

Images