Image reading device

Abstract

To provide an image reading device capable of attenuating an impact applied to a reading sensor when a contact glass is closed.SOLUTION: An image reading device includes a reading sensor 37 that is supported so as to be movable in an up-down direction and reads a document transported to an upper surface of a contact glass 11B, a biasing member for biasing the reading sensor 37 downward, a positioning portion 45R that comes into contact with the contact glass 11B to position the reading sensor 37 when the contact glass is closed, and a support member 47R that cushions an impact applied to the reading sensor 37 when the contact glass is closed. The support member 47R comes into contact with the contact glass 11B before the positioning portion 45R comes into contact with the contact glass 11B, and moves the reading sensor 37 upward. Thereafter, the support member 47R separates from the reading sensor 37, and the positioning portion 45R comes into contact with the contact glass 11B to position the reading sensor 37.SELECTED DRAWING: Figure 8A

Description

[Technical field]

[0001] The present invention relates to an image reading device equipped with a document transport unit that opens and closes a contact glass. [Background technology]

[0002] As described in Patent Document 1, the image reading device includes a document transport unit that opens and closes a contact glass, and is capable of reading an image of a document by either a sheet fixing method or a sheet-through method. The contact glass includes a first contact glass and a second contact glass. A document to be read by the sheet fixing method is placed on the first contact glass. The second contact glass is disposed adjacent to the second contact glass, and in the sheet-through method, a document transported by the document transport unit passes over its upper surface.

[0003] The reading sensor is disposed below the contact glass. When reading an image using the fixed sheet method, the reading sensor moves to a reading position below the first contact glass and reads the image while moving below the first contact glass. When reading an image using the sheet-through method, the reading sensor moves to a reading position below the second contact glass and reads the image on one side of the document being transported. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2022-68985 Summary of the Invention [Problem to be solved by the invention]

[0005] The document transport unit of the image reading device in Patent Document 1 above is equipped with a reading sensor (e.g., a contact image sensor (CIS)) that reads the other side of the document being transported. The reading sensor is disposed upstream of the document transport path. In other words, the reading sensor of the image reading device and the reading sensor of the document transport unit are spaced apart along the transport path. Since the document needs to be transported stably near the reading sensor, the configuration of the transport path becomes complex, which causes problems such as an increase in the number of parts and an increase in the size of the device.

[0006] On the other hand, the reading sensor of the document transport unit may be disposed at a position facing the second contact glass. The reading sensor is positioned relative to the second contact glass by a positioning unit. In the sheet-through method, when the document passes over the top surface of the second contact glass, the images on both sides of the document are read by the reading sensor of the image reading device and the reading sensor of the document transport device. Therefore, since it is only necessary to stabilize the transport of the document near the second contact glass, the configuration of the transport path can be simplified.

[0007] However, with two reading sensors arranged in this way, when the document transport unit is rotated forcefully to close the contact glass, the positioning portion of the reading sensor of the document transport unit may hit the second contact glass, causing an impact on the reading sensor, which may cause the position of the reading sensor to shift.

[0008] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide an image reading device capable of attenuating the impact applied to a reading sensor when a contact glass is closed by a document transport unit. [Means for solving the problem]

[0009] The image reading device of the present invention is an image reading device comprising an image reading unit having a contact glass over which a document to be read passes, and a document transport unit for opening and closing the upper surface of the contact glass, the document transport unit comprising a transport section for transporting a document to the upper surface of the contact glass, a reading sensor supported so as to be movable in the vertical direction and for reading an image of the document transported to the upper surface of the contact glass by the transport section, a sensor biasing member for biasing the reading sensor downward, and a sensor biasing member for biasing the reading sensor downward when the contact glass is closed and for biasing the reading sensor against the contact glass. The device is equipped with a positioning portion which positions the device relative to the contact glass, and a support member which cushions the impact applied to the reading sensor when the contact glass is closed, and the support member abuts against the image reading unit before the positioning portion abuts against the contact glass when the contact glass is closed, and engages with the reading sensor to move the reading sensor upward against the biasing force of the sensor biasing member, and then moves away from the reading sensor, and the positioning portion abuts against the contact glass, thereby positioning the reading sensor relative to the contact glass.

[0010] In the present invention, the support member may be supported so as to be movable in the up-down direction, and may be biased downward by a biasing member.

[0011] In the present invention, the support member has an elastic piece that can engage with the reading sensor, and further includes a biasing member that biases the elastic piece in a direction to engage with the reading sensor, and a regulating portion that elastically deforms the elastic piece in a direction away from the reading sensor, and when the contact glass is closed and the support member abuts against the image reading unit, the support member moves relatively upward against the biasing force of the biasing member, and the elastic piece engages with the reading sensor, causing the reading sensor to move upward against the biasing force of the sensor biasing member, and then the elastic piece abuts against the regulating portion and elastically deforms against the biasing force of the biasing member and moves away from the reading sensor, causing the positioning portion to abut against the contact glass and the reading sensor to be positioned relative to the contact glass.

[0012] In the present invention, the elastic piece has a hook having an engagement surface capable of engaging with the reading sensor and an inclined surface that slopes diagonally downward from the engagement surface toward the reading sensor, and the reading sensor descends along the inclined surface after separating from the engagement surface of the hook of the elastic piece, and at that time, the elastic piece is pushed by the inclined surface in a direction away from the reading sensor, compressing the biasing member, thereby providing resistance to the reading sensor and cushioning the descent of the reading sensor. Effect of the Invention

[0013] According to this aspect of the invention, the positioning projection comes into contact with the contact glass at a speed slower than the speed at which the document transport unit rotates downward, so that the impact applied to the reading sensor from the contact glass can be cushioned. [Brief description of the drawings]

[0014] [Figure 1A] 1 is a perspective view showing an image reading device according to an embodiment of the present invention (when the contact glass is closed). [Figure 1B] 1 is a perspective view showing an image reading device according to an embodiment of the present invention (when the contact glass is open). [Diagram 2] 1 is a front view showing a schematic internal configuration of an image reading device according to an embodiment of the present invention; [Diagram 3] 1 is a cross-sectional view showing a schematic diagram of a document transport unit of an image reading device according to an embodiment of the present invention. [Figure 4A] 4 is a perspective view of a positioning portion and a support member on the front side of the document transport unit, as viewed from below, in the image reading device according to the embodiment of the present invention; FIG. [Figure 4B] 4 is a perspective view of a positioning portion and a support member on the rear side of the document transport unit, as viewed from below, in the image reading device according to the embodiment of the present invention; FIG. [Figure 5A] 4 is a cross-sectional view showing a rear support member of the document transport unit of the image reading device according to the embodiment of the present invention. FIG. [Figure 5B] 4 is a perspective view showing a rear support member of the document transport unit of the image reading device according to the embodiment of the present invention; FIG. [Figure 6A] 4 is a cross-sectional view showing a support member (when the contact glass is open) in the image reading device according to one embodiment of the present invention. FIG. [Figure 6B] 4 is a cross-sectional view showing a support member (immediately after it comes into contact with the contact glass) in the image reading device according to one embodiment of the present invention. FIG. [Figure 7A] 4 is a cross-sectional view showing a support member (after it has come into contact with a contact glass) in an image reading device according to one embodiment of the present invention. FIG. [Figure 7B] 4 is a cross-sectional view showing a support member (in a state where an elastic piece is in contact with a regulating portion) in the image reading device according to the embodiment of the present invention. FIG. [Figure 8A] 4 is a cross-sectional view showing a support member (in a state where an elastic piece is detached from a reading sensor) in the image reading device according to one embodiment of the present invention. FIG. [Figure 8B] 4 is a cross-sectional view showing a support member (when the contact glass is closed) in the image reading device according to one embodiment of the present invention. FIG. [Figure 9] 4 is a cross-sectional view showing a support member (when the contact glass is open) in the image reading device according to one embodiment of the present invention. FIG. [Figure 10A] 13 is a diagram showing a schematic diagram of a support member (in contact with a contact glass) according to a modified example of the image reading device according to one embodiment of the present invention. FIG. [Figure 10B] 13 is a schematic diagram showing a support member according to a modified example (in a state where the elastic piece abuts against a restricting portion) in the image reading device according to the embodiment of the present invention. FIG. [Figure 11A] 13 is a diagram showing a support member according to a modified example (in a state in which the elastic piece is separated from the reading sensor) in the image reading device according to the embodiment of the present invention. FIG. [Figure 11B] FIG. 13 is a schematic diagram showing a support member (in a state in which the reading sensor is lowered) according to a modified example of the image reading device according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an image reading apparatus according to an embodiment of the present invention will be described with reference to the drawings.

[0016] First, the overall configuration of an image reading device 1 according to this embodiment will be described with reference to Figures 1A, 1B, and 2. Figures 1A and 1B are perspective views showing the image reading device 1, and Figure 2 is a cross-sectional view that typically shows the internal configuration of the image reading device 1. Fr, Rr, L, and R in each figure indicate the front, rear, left, and right sides of the image reading device 1, respectively.

[0017] The image reading device 1 includes an image reading unit 3 and an original transport unit 5. The original transport unit 5 is supported so as to be rotatable in the vertical direction on a rotary shaft (not shown) provided at the left and right rear corners of the upper surface of the image reading unit 3. As will be described later, the image reading device 1 is capable of reading an image of an original by either a sheet fixed method or a sheet-through method.

[0018] First, the image reading unit 3 will be described with reference to Fig. 2. The image reading unit 3 includes a contact glass 11 on which a document is placed, and a reading sensor 13 that reads an image of the document placed on the contact glass 11. The contact glass 11 includes a first contact glass 11A on which a document is placed in the fixed-sheet type, and a second contact glass 11B over which a document conveyed by the document conveying unit 5 passes in the sheet-through type. The first contact glass 11A is disposed over most of the top surface of the image reading unit 3, except for the left end portion. The second contact glass 11B is disposed at the left end portion of the top surface of the image reading unit 3.

[0019] The reading sensor 13 is disposed below the contact glass 11 and is supported so as to be movable in the left-right direction. When reading an image using the sheet fixing method, the reading sensor 13 moves to a first reading position (see solid line in FIG. 2) below the first contact glass 11A and reads the image while moving below the first contact glass 11A. When reading an image using the sheet-through method, the reading sensor 13 moves to a second reading position (see two-dot chain line in FIG. 2) below the second contact glass 11B and reads an image on one side of the document transported by the document transport unit 5.

[0020] Next, the document transport unit 5 will be described with reference to Fig. 2, Fig. 3, Fig. 4A and Fig. 4B. Fig. 3 is a cross-sectional view of the document transport unit 5, and Fig. 4A and Fig. 4B are perspective views showing the front and rear ends of the reading sensor 37.

[0021] 2, the document transport unit 5 includes a transport section 21 through which documents (paper) are transported, a paper feed tray 23 on which the documents transported by the transport section 21 are placed, and a discharge tray 25 on which the documents transported by the transport section 21 are stacked. A document presser plate 27 that faces the upper surface of the first contact glass 11A of the image reading unit 3 is provided on the lower surface of the document transport unit 5. When the document transport unit 5 rotates upward (see FIG. 1B), the contact glass 11 is opened, and when the document transport unit 5 rotates downward (see FIG. 1A), the contact glass 11 is closed, and the document placed on the first contact glass 11A is pressed down by the document presser plate 27.

[0022] 2, a paper feed opening 29 and a discharge opening 31 are formed vertically side by side on the right side of the transport section 21. A first transport path 33 and a second transport path 35 along which the document is transported are formed in the transport section 21. The first transport path 33 extends substantially horizontally leftward from the paper feed opening 29, and then curves downward toward the image reading position P1. The second transport path 35 extends diagonally upward from the image reading position P1 to the discharge opening 31.

[0023] The image reading position P1 is a position facing the second contact glass 11B of the image reading unit 3 when the contact glass 11 is closed by the document transport unit 5. An image reading sensor 37 (CIS (contact image sensor)) is disposed at the image reading position P1. The reading sensor 37 is supported by a frame-shaped housing 39 that exposes the image reading surface, with the image reading surface facing downward.

[0024] The housing 39 is supported by the conveying section 21 so as to be movable in the vertical direction. In detail, a guide groove (not shown) along the vertical direction is formed in the conveying section 21, and a guide piece (not shown) that engages with the guide groove is formed in the housing 39. As shown in FIG. 3, the housing 39 is biased downward with respect to the conveying section 21 by a coil spring 41. The coil spring 41 is an example of a sensor biasing member that biases the reading sensor 37 downward. The reading sensor 37 can move downward while remaining in a horizontal position until the guide piece abuts against the bottom of the guide groove.

[0025] 3, hooks 43 protruding outward are formed at both ends (front and rear ends) in the longitudinal direction (front-rear direction) of the housing 39. Each hook 43 has a flat lower surface and an inclined surface that slopes inwardly from the lower surface toward the upper side.

[0026] 4A and 4B, two rectangular parallelepiped front and rear positioning protrusions 45F, 45R (collectively referred to as positioning protrusions 45) are formed at both longitudinal ends (front end and rear end) of the housing 39 and protrude downward from the bottom surface. The front and rear positioning protrusions 45 are spaced apart in the short side direction (left and right direction) of the housing 39. Furthermore, outside both longitudinal ends (front end and rear end) of the housing 39, front and rear support members 47F, 47R (collectively referred to as support members 47) are supported so as to protrude downward from the bottom surface (document pressing plate 27) of the transport section 21. The support members 47 will be described later.

[0027] 2 again, the first transport path 33 is provided with, in order from the upstream side in the transport direction, a pickup roller 51, a separation roller pair 53, a first transport roller pair 55, and a second transport roller pair 57. The second transport path 35 is provided with, in order from the upstream side in the transport direction, a third transport roller pair 59 and a discharge roller pair 61.

[0028] Next, the paper feed tray 23 and the discharge tray 25 will be described. The paper feed tray 23 is a plate-shaped member having dimensions that allow a maximum size document that can be transported to be placed thereon. The upper surface of the paper feed tray 23 is a document placement surface on which the document is placed. The paper feed tray 23 supports a side cursor 24 (see FIG. 1A) that aligns the document placed on the document placement surface to the center in the width direction so as to be slidable in the width direction of the document (direction intersecting the transport direction). The paper feed tray 23 is supported below the paper feed port 29 of the transport unit 21 in a position inclined downward toward the paper feed port 29. The discharge tray 25 is formed below the paper feed tray 23 so as to be inclined upward from below the discharge port 31 toward the downstream side in the transport direction.

[0029] Next, the image reading operation of the document by the image reading device 1 will be described. As described above, the image reading device 1 can read the image of the document in the fixed reading type and the sheet-through type. In the fixed reading type, the reading sensor 13 of the image reading device 1 moves to the first reading position (see the solid line in FIG. 2). As shown in FIG. 1B, the document transport unit 5 is rotated upward to open the contact glass 11, and the document is placed on the first contact glass 11A with the surface to be read of the image facing down. Then, when the document transport unit 5 is rotated downward, the document is pressed against the first contact glass 11A by the document pressing plate 27 of the document transport unit 5. After that, the reading sensor 13 moves to the right, and the image of the document is read.

[0030] On the other hand, in the sheet-through method, the reading sensor 13 of the image reading device 1 moves to the second reading position (see the two-dot chain line in FIG. 2). The document transport unit 5 rotates downward to close the contact glass 11 (see FIG. 1A). The document is placed on the paper feed tray 23, fed by the pickup roller 51, separated by the separation roller pair 53, and transported to the first transport path 33. The document is then transported to the image reading position P1 along the first transport path 33 by the first transport roller pair 55 and the second transport roller pair 57. At the image reading position P1, the document passes over the upper surface of the second contact glass 11B of the image reading unit 3. At this time, the images on both sides of the document are read by the reading sensors 13 and 37. The document is then transported along the second transport path 35 by the third transport roller pair 59, discharged from the discharge port 31 by the discharge roller pair 61, and stacked on the discharge tray 25.

[0031] When the document transport unit 5 rotates downward to close the contact glass 11, the front and rear positioning protrusions 45F, 45R provided on the housing 39 of the reading sensor 37 of the document transport unit 5 come into contact with the second contact glass 11B of the image reading unit 3. This positions the reading sensor 37 relative to the second contact glass 11B. Therefore, when a document passes between the reading sensor 37 and the second contact glass 11B in the sheet-through method, the image of the passing document can be read with high accuracy by the reading sensor 37.

[0032] Furthermore, when the document transport unit 5 rotates downward to close the contact glass 11, the front and rear support members 47F, 47R provided on the transport section 21 of the document transport unit 5 come into contact with the second contact glass 11B of the image reading unit 3 (or the upper surface of the image reading unit 3 near the second contact glass 11), and then the positioning protrusion 45 provided on the housing 39 comes into contact with the second contact glass 11B. This cushions the impact applied to the reading sensor 37 when the contact glass is closed. Details will be described below.

[0033] First, the support member 47 will be described with reference to Figures 5A and 5B. Figure 5A is a cross-sectional view showing the support member 47, and Figure 5B is a perspective view showing the support member 47. The support member 47 has a substantially rectangular parallelepiped main body 71 along the up-down direction, and an elastically deformable elastic piece 73. Here, the rear support member 47R will be described.

[0034] The upper half of the main body 71 has a U-shaped cross section with one side open, and the lower half has a U-shaped cross section with the opposite side open. The lower end of the main body 71 is tapered and the lower end surface is flat.

[0035] The elastic piece 73 has an arc-like shape in a cross-sectional view. A lower end of the elastic piece 73 is connected to a lower end of one side surface of the main body 71. An outwardly protruding hook 75 is formed on the outer surface of the elastic piece 73. The hook 75 is disposed at approximately the center in the height direction of the elastic piece 73. The hook 75 has a substantially horizontal upper surface 75a (engagement surface) and an inclined surface 75b that inclines obliquely from the upper surface toward the outer surface of the elastic piece 73.

[0036] A first coil spring 77 is disposed between the main body 71 and the approximate center of the elastic piece 73 in the height direction. The first coil spring 77 maintains the elastic piece 73 in a position protruding in an arc shape from one side surface of the main body 71. When the elastic piece 73 is elastically deformed toward the main body 71 against the biasing force of the first coil spring 77, the upper end of the elastic piece 73 enters the main body 71 from the opening surface in the upper half of the main body 71.

[0037] As shown in Figure 3, the front and rear support members 47F, 47R are positioned in an opposing position with their elastic pieces 73 facing each other, and as described above, are positioned further outboard in the longitudinal direction of the reading sensor 37 than the front and rear positioning protrusions 45F, 45R (see also Figures 4A and 4B), and the elastic pieces 73 of the front and rear support members 47F, 47R face the front and rear hooks 43 of the housing 39 of the reading sensor 37.

[0038] 5A and 5B, the support member 47 is supported by the transport section 21 so as to be vertically movable, and is biased downward by the second coil spring 79. When the support member 47 is biased downward by the second coil spring 79, the lower surface of the main body section 71 is positioned lower than the positioning protrusion 45.

[0039] As described above, the first coil spring 77 is an example of a biasing member that biases the elastic piece 73 in a direction to engage with the reading sensor 37. The second coil spring 79 is an example of a biasing member that biases the support member 47 downward.

[0040] Furthermore, the conveying section 21 is provided with a restricting portion 81 above the elastic piece 73 of the support member 47. In a state in which the support member 47 is biased downward relative to the conveying section 21 by the second coil spring 79 (see FIGS. 5A and 5B), the restricting portion 81 is spaced upward from the upper end of the elastic piece 73. When the support member 47 moves upward relative to the conveying section 21 against the biasing force of the second coil spring 79, the outer surface of the upper end of the elastic piece 73 abuts against the restricting portion 81. As a result, the elastic piece 73 elastically deforms against the biasing force of the second coil spring 79 and enters the main body section 71 from the opening surface of the upper half of the main body section 71.

[0041] 6A to 9B, a description will be given of the supporting operation of the reading sensor 37 by the supporting member 47 having the above configuration when the contact glass 11 is closed by the document transport unit 5. In the following description, the operation of the rear supporting member 47R will be described.

[0042] 6A, in a state in which the contact glass 11 is opened by the document transport unit 5, the support member 47 is urged downward by the second coil spring 79. The lower end of the main body 71 of the support member 47 is spaced downward from the positioning protrusion 45 of the housing 39 of the reading sensor 37. Furthermore, the elastic piece 73 is spaced downward from the restricting portion 81. Furthermore, the hook 75 of the elastic piece 73 is spaced downward from the hook 43 of the housing 39 of the reading sensor 37. The housing 39 of the reading sensor 37 is urged downward by the coil spring 41, and the guide piece abuts against the bottom surface of the guide groove (both not shown).

[0043] When the document transport unit 5 rotates downward to close the contact glass 11, first, the lower end surface of the main body 71 of the support member 47 abuts against the second contact glass 11B, as shown in Fig. 6B. This causes the support member 47 to start moving upward relative to the transport section 21 against the biasing force of the second coil spring 79.

[0044] 7A, when the support member 47 starts to move upward relative to the transport section 21 (see arrow A), the hook 75 of the elastic piece 73 of the support member 47 eventually comes into contact with the hook 43 of the housing 39 of the reading sensor 37 from below. In detail, the upper surface 75a (see FIG. 5A) of the hook 75 of the support member 47 comes into contact with the lower surface of the hook 43 of the housing 39 from below.

[0045] 7B, when the support member 47 further moves upward relative to the transport section 21 (see arrow A), the reading sensor 37 (housing 39) is lifted by the elastic piece 73 against the biasing force of the coil spring 41 (see arrow B). That is, the guide piece of the reading sensor 37 moves upward from the bottom surface of the guide groove. Furthermore, the upper end of the elastic piece 73 of the support member 47 abuts against the restricting portion 81.

[0046] 8A, when the support member 47 further moves upward relative to the transport section 21 (see arrow A), the elastic piece 73 is elastically deformed by the restricting portion 81 against the biasing force of the first coil spring 77, and is pushed toward the main body portion 71 (see arrow C). Then, the hook 75 of the support member 47 is disengaged from the hook 43 of the reading sensor 37 (housing 39).

[0047] 8B, the reading sensor 37 (housing 39) is biased by its own weight and the coil spring 41 to move slightly downward (see arrow D), and the positioning protrusion 45R comes into contact with the second contact glass 11B. At this time, the reading sensor 37 (housing 39) is slightly above the lowest position (the position where the guide piece abuts the bottom surface of the guide groove). In other words, since the reading sensor 37 is biased downward by the coil spring 41, it is stably maintained at a predetermined height.

[0048] On the other hand, when the document transport unit 5 is rotated upward to open the contact glass 11, the support member 47 moves upward away from the second contact glass 11B and moves downward relative to the transport section 21. At this time, as shown in Fig. 9, the inclined surface 75b of the hook 75 of the elastic piece 73 is guided along the inclined surface of the hook 43 of the reading sensor 37 (housing 39) and passes through the hook 43 while elastically deforming towards the main body section 71, and the support member 47 returns to its original state (see Fig. 6A).

[0049] As described above, according to the present invention, after the document transport unit 5 rotates downward and the support member 47 abuts against the contact glass 11, the positioning protrusion 45 of the reading sensor 37 abuts against the second contact glass 11B. In other words, when the reading sensor 37 moves downward away from the support member 47 when the contact glass 11 is closed, the distance until the positioning protrusion 45 of the reading sensor 37 abuts against the second contact glass 11B (the distance between the positioning protrusion 45 and the second contact glass 11B in FIG. 8A) is short. In this way, the positioning protrusion 45 abuts against the second contact glass 11B at a speed slower than the speed at which the document transport unit 5 rotates downward, so that the impact applied to the reading sensor 37 from the second contact glass 11B can be cushioned.

[0050] Furthermore, during image reading in the sheet-through method, the reading sensor 37 is biased against the second contact glass 11B by the coil spring 41, so that the reading sensor 37 can be stably supported.

[0051] Furthermore, since the support member 47 is biased downward by the second coil spring 79, the impact caused when the support member 47 first comes into contact with the second contact glass 11B (or its periphery) when the contact glass is closed is cushioned.

[0052] Next, modified examples of the support member 47 will be described with reference to Figures 10A to 11B. Figures 10A to 11B are diagrams that diagrammatically show the support member 47, a restricting portion 81, and the reading sensor 37.

[0053] In the modified example, a hook 75 provided on the elastic piece 73 of the support member 47 has a substantially horizontal upper surface 75a (engagement surface) and an inclined surface 75b that slopes diagonally downward from the upper surface 75a in a direction away from the elastic piece 73 (towards the reading sensor 37).

[0054] As shown in Fig. 10A, before the contact glass is closed, hook 75 of support member 47 is spaced downward from hook 43 of reading sensor 37. As shown in Fig. 10B, when support member 47 abuts against contact glass 11B and rises relatively (see arrow E), the upper end of elastic piece 73 abuts against restricting portion 81. Thereafter, as shown in Fig. 11A, elastic piece 73 is pushed by restricting portion 81 and elastically deformed toward main body portion 71 (see arrow F), and hook 75 comes off hook 43 of reading sensor 37. In detail, hook 43 of reading sensor 37 (housing 39) comes off upper surface 75a of hook 75 of elastic piece 73.

[0055] 11B, the hook 43 of the reading sensor 37 descends along the inclined surface 75b of the hook 75 of the elastic piece 73. As described above, the inclined surface 75b is inclined obliquely downward in a direction away from the elastic piece 73, so that the elastic piece 73 is pushed toward the main body part 71 by the hook 43 of the reading sensor 37 (see arrow G). This causes the first coil spring 77 to be compressed, and resistance is applied from the elastic piece 73 to the hook 43, i.e., the reading sensor 37.

[0056] As described above, according to the modified example, resistance is provided to the downward movement of the reading sensor 37 after the reading sensor 37 separates from the support member 47, so that the impact applied to the reading sensor 37 when the contact glass is closed can be further cushioned.

[0057] Although the present invention has been described with reference to specific embodiments, the present invention is not limited to the above embodiments, and those skilled in the art may modify the above embodiments without departing from the scope and spirit of the present invention. [Explanation of symbols]

[0058] 1 Image reader 3 Image reading unit 5 Document transport unit 11 Contact Glass 21 Conveyor 37 Reading Sensor 41 Coil spring (sensor biasing member) 45 Positioning part 47 Support member 73 Elastic piece 75 Hook 75a Top 75b Slope 77 First coil spring (biasing member) 79 Second coil spring (biasing member) 81 Regulatory Department

Claims

1. An image reading device comprising: an image reading unit having a contact glass over which an original to be read passes; and an original transport unit for opening and closing an upper surface of the contact glass, The document transport unit includes: a conveying unit that conveys a document to an upper surface of the contact glass; a reading sensor that is supported so as to be movable in the vertical direction and that reads an image of the document conveyed to the upper surface of the contact glass by the conveying unit; a sensor biasing member that biases the reading sensor downward; a positioning portion that abuts against the contact glass when the contact glass is closed to position the reading sensor relative to the contact glass; a support member that absorbs an impact applied to the reading sensor when the contact glass is closed, The support member is when the contact glass is closed, the positioning portion abuts against the image reading unit before abutting against the contact glass and engages with the reading sensor to move the reading sensor upward against the biasing force of the sensor biasing member; Thereafter, the reading sensor is separated from the positioning portion, and the positioning portion comes into contact with the contact glass, thereby positioning the reading sensor relative to the contact glass.

2. 2. The image reading device according to claim 1, wherein the support member is supported so as to be movable in the vertical direction and is biased downward by a biasing member.

3. the support member has an elastic piece engageable with the read sensor, a biasing member that biases the elastic piece in a direction to engage with the reading sensor; a restricting portion that elastically deforms the elastic piece in a direction away from the reading sensor, when the contact glass is closed and the support member comes into contact with the image reading unit, the support member moves relatively upward against the biasing force of the biasing member, and the elastic piece engages with the reading sensor, so that the reading sensor moves upward against the biasing force of the sensor biasing member; The image reading device described in claim 2, characterized in that the elastic piece then abuts against the regulating portion and elastically deforms against the biasing force of the biasing member to move away from the reading sensor, thereby causing the positioning portion to abut against the contact glass and positioning the reading sensor relative to the contact glass.

4. the elastic piece has a hook having an engagement surface that can be engaged with the reading sensor and an inclined surface that is inclined obliquely downward from the engagement surface toward the reading sensor, The image reading device according to claim 3, characterized in that the reading sensor descends along the inclined surface after the elastic piece separates from the engagement surface of the hook, and at that time, the elastic piece is pushed by the inclined surface in a direction away from the reading sensor, compressing the biasing member, thereby providing resistance to the reading sensor and cushioning the descent of the reading sensor.

Images