JP5811812B2 - Image reading device - Google Patents

Description

  The present invention relates to an image reading apparatus having a sensor unit that is slidably disposed below a document placement table and reads an image from a document on the document placement table.

  Conventionally, as an image reading apparatus, a document placing table composed of a transparent glass plate mounted on the upper surface of a housing, and an elongated shape extending in a predetermined main scanning direction. 2. Description of the Related Art A flat bed type image scanner having a sensor unit arranged to be reciprocally movable in a sub-scanning direction orthogonal to a scanning direction is known.

  As an invention relating to such an image reading apparatus, an invention described in Patent Document 1 is known. An image scanner described in Patent Document 1 is composed of a flat glass, and a guide plate on which a document is placed, and an image sensor disposed below the guide plate so as to be slidable in a predetermined sub-scanning direction. It has a head and is configured to read an image of a document placed on a guide plate while sliding the image sensor head.

  The image sensor head described in the cited document 1 is formed in an elongated shape in the main scanning direction, and has a contact image sensor (CIS: Contact Image Sensor). Spacers provided with a rotating body are attached to both ends of the image sensor in the main scanning direction. The rotating body protrudes upward from the upper surface (spacer upper surface) of the image sensor head and is attached so as to contact the lower surface of the guide plate. The rotating body is attached so as to rotate while contacting the lower surface of the guide plate as the image sensor head moves. That is, the rotating body realizes a smooth movement of the image sensor head while keeping the distance between the reading surface of the image sensor and the lower surface of the guide plate constant.

JP 2004-266314 A

  Here, when a contact image sensor is used as in the image scanner described in Patent Document 1, the distance between the lower surface of the guide plate and the upper surface of the image sensor head needs to be very narrow. Is maintained at a constant interval by the rotating body as described above.

  However, even with the image sensor head described in Patent Document 1, it is assumed that the components of the image sensor head are distorted or the image sensor head itself is inclined with respect to the glass surface. . Further, in the image sensor head described in Patent Document 1, it is assumed that the spacer is attached in a state of being inclined with respect to the normal position. In such a case, there is a possibility that the rotating body and the glass surface do not contact each other, and the upper surface of the spacer contacts the lower surface of the guide plate in a linear shape extending in the sub-scanning direction.

  If the image sensor head is slid in the sub-scanning direction in order to read the image of the document while the spacer upper surface is in linear contact with the guide plate lower surface, the spacer upper surface and the guide plate lower surface There was a case where abnormal noise due to friction occurred. This abnormal noise becomes larger as the contact area between the spacer upper surface and the guide plate lower surface becomes larger. Therefore, if the spacer upper surface and the guide plate lower surface come into contact with each other in a line extending in the sub-scanning direction, it is a serious problem. turn into.

  Furthermore, in this case, the image sensor head itself vibrates due to friction between the spacer upper surface and the guide plate lower surface. That is, if vibration is generated in the process of sliding the image sensor head, the distance between the lower surface of the guide plate and the upper surface of the image sensor head will fluctuate finely. As a result, the quality of the read image is deteriorated.

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading apparatus having a sensor unit that is slidably disposed below a document placement table and reads an image from a document on the document placement table. An image reading apparatus that can prevent the above is provided.

An image reading apparatus according to an aspect of the present invention includes a document placement table and a sensor unit, and is placed on the document placement table while moving the sensor unit in the first direction below the document placement table. Read the original image. And the said sensor unit is long formed in the 2nd direction, and has an image sensor, a unit housing | casing, and a holder member. The holder member is attached to both ends of the sensor unit along the second direction, and is positioned outside the reading range of the image sensor. The holder member has a protrusion and a protrusion. Protruding portions are upper surfaces of the holder member constituting the upper surface of the sensor unit, and are arranged at a plurality of locations along the first direction, and come into contact with the lower surface of the document mounting table, The distance from the upper surface of the image sensor is kept constant. The protrusion is an upper surface of the holder member constituting the upper surface of the sensor unit, and protrudes at a height lower than the top of the protrusion at a position different from the formation position of the protrusion in the second direction. Therefore, according to the image reading apparatus, even when the sensor unit is distorted or the sensor unit is tilted with respect to the document placement table, the protrusion contacts the lower surface of the document placement table. It will be. As a result, the contact area can be reduced at the end of the sensor unit as compared with the case where the entire length in the first direction is in contact with the lower surface of the document table. As a result, it is possible to prevent the generation of noise due to friction between the sensor unit and the document placement table lower surface, and to reduce image disturbance due to friction with the document placement table lower surface.

  In the image reading apparatus according to another aspect of the present invention, the protrusion is an upper surface of the sensor unit, connects a plurality of protrusions, and extends on a straight line extending in parallel with the straight line extending in the first direction. Are formed at a plurality of locations. Therefore, according to the image reading apparatus, even when the sensor unit is distorted or tilted in various directions, the protrusion can be brought into contact with the lower surface of the document table. The contact area between the sensor unit and the lower surface of the document table can be reduced. As a result, according to the image reading apparatus, it is possible to prevent the generation of abnormal noise and the disturbance of the read image due to the friction with the document placing table.

The configuration Te another image reading apparatus odor according to aspects of the present invention, the front Symbol protrusions on the upper surface of the holder member, the roller member which is rotatably supported by a rotation shaft extending along the second direction Is done. Therefore, according to the image reading device, the holder member and the roller member can be easily molded, and the roller member can smoothly form the sensor while keeping the distance between the upper surface of the image sensor and the document table. Units can be moved.

  In the image reading apparatus according to another aspect of the present invention, the protruding portion is positioned outside the image sensor accommodated in the sensor unit in the first direction. Therefore, according to the image reading apparatus, the size of the sensor unit in the second direction can be reduced as compared with the case where the protrusion is formed on the outer side in the second direction of the sensor unit. Further, the protrusion is located on the end side in the second direction with respect to the position of the image sensor housed in the unit housing and the protruding portion on the upper surface of the sensor unit. In the case of the sensor unit in the image reading apparatus, the portion that is highly likely to come into contact with the lower surface of the document table due to the inclination of the sensor unit is the end side in the second direction. Therefore, according to the image reading apparatus, by forming the protrusion at an appropriate position, it is possible to suppress abnormal noise caused by friction with the lower surface of the document table.

  Further, in the image reading apparatus according to another aspect of the present invention, the projecting portion is constituted by a roller member disposed on the holder member, and the image sensor accommodated in the unit casing in the first direction. Located outside. Therefore, according to the image reading apparatus, the size of the sensor unit in the second direction can be reduced as compared with the case where the protrusion is formed on the outer side in the second direction of the sensor unit. Further, the protrusion is formed on the upper surface of the holder member. Since it is only necessary to form a protrusion on the holder member, the protrusion can be easily formed at a desired position by molding. Further, when the holder member is attached, the protrusion is positioned closer to the center in the second direction than the position of the protrusion on the upper surface of the sensor unit. In the case of a configuration in which the holder member is attached, the holder member may be inclined such that the center side of the sensor unit is close to the lower surface of the document placing table. According to the image reading apparatus, even in such a case, the protrusion can be brought into contact with the lower surface of the document placing table, and abnormal noise caused by friction with the lower surface of the document placing table or disturbance of the read image can be prevented. Can be suppressed.

  In the image reading apparatus according to another aspect of the present invention, the protrusion has a curved surface formed with a predetermined curvature at a vertex portion located on the document placing table side. Therefore, according to the image reading apparatus, the contact area between the lower surface of the document placement table and the protrusion can be reduced to point contact, the generation of abnormal noise due to friction with the document placement table, and the disturbance of the read image. Can be suppressed.

  In the image reading apparatus according to another aspect of the present invention, the width of the protrusion in the second direction is smaller than the width of the protrusion in the second direction. Therefore, in the image reading apparatus, it is possible to suppress the generation of abnormal noise and disturbance of the read image due to friction with the lower surface of the document table while sufficiently reducing the space for forming the protrusion.

1 is an external perspective view of a multi-function device according to a first embodiment. It is a top view which shows the internal structure of a scanner unit. It is sectional drawing which shows the internal structure of a scanner unit. It is an external appearance perspective view of the sensor unit which concerns on 1st Embodiment. It is explanatory drawing regarding the structure of the sensor unit which concerns on 1st Embodiment. It is the perspective view which expanded the rear-end part of the sensor unit which concerns on 1st Embodiment. It is a top view of the rear end portion of the sensor unit according to the first embodiment. It is sectional drawing of the XX cross section in FIG. It is a top view of the rear end portion of the sensor unit according to the second embodiment.

  Hereinafter, an embodiment in which an image reading apparatus according to the present invention is embodied in a multi-function device 1 having a scanner unit 15 will be described in detail with reference to the drawings.

(First embodiment)
First, a schematic configuration of the multi-function device 1 according to the first embodiment will be described with reference to FIG. In the following description, the vertical direction of the multi-function device 1 is defined with reference to the state in which the multi-function device 1 is installed, and the side on which the operation panel 11 is disposed is the front side (front). Will be described by defining the front-rear direction. Further, the left-right direction of the multi-function device 1 will be described as being defined as the left-right direction when viewed from the front side (front) of the multi-function device 1.

  As shown in FIG. 1, the multi-function device 1 includes an upper cover 5 and a main body housing 10. The upper cover 5 is disposed so as to be openable and closable around the rear edge of the upper surface of the main body housing 10 and covers the upper surface of the main body housing 10 (that is, the document placement table 16) when the upper cover 5 is closed. The main body housing 10 has a scanner unit 15 in the upper part of the main body housing 10. The scanner unit 15 includes a document placing table 16, a slide shaft 19, a sensor unit 20, a reading and conveying motor, a flat cable, and the like formed on the upper surface of the main body housing 10 (see FIG. 2). Thus, the image of the document placed on the document placement table 16 is read. The configuration of the scanner unit 15 will be described in detail later with reference to the drawings.

  The upper cover 5 has an automatic document feeder 6 (ADF: Auto Document Feeder). The automatic document feeder 6 is disposed on the left side of the upper cover 5 and continuously feeds documents in a document tray (not shown) one by one and conveys them along a predetermined conveyance path. The paper is discharged to a paper discharge tray (not shown). The multi-function device 1 can read an image of a document by a method of reading an image by the scanner unit 15 while the document is being transported by the automatic document transport device 6. Since the upper cover 5 covers the upper surface of the main body housing 10 when closed, the upper cover 5 functions to fix the document set on the document table 16 at that position.

  As described above, the main body housing 10 has the scanner unit 15 in the upper part thereof, and stores a control unit, a facsimile unit, an image forming unit, and the like below the scanner unit 15. The control unit includes a CPU, a ROM, a RAM, and the like. The control unit plays a central role in the control for realizing the scanner function, copy function, printer function, and facsimile function in the multi-function device 1.

  The facsimile unit performs facsimile communication of the image of the document read by the scanner unit 15 to a desired destination of the user via the network based on the control by the control unit. Further, the facsimile unit can receive facsimile data via a network. The received facsimile data is printed out on paper or the like in the paper feed cassette 13 by controlling the image forming unit by the control unit. That is, the multi-function device 1 realizes a facsimile function by controlling the scanner unit 15, the facsimile unit, and the image forming unit.

  The image forming unit prints and outputs the input image data onto the paper in the paper feed cassette 13 based on control by the control unit. The multi-function device 1 realizes a copy function by controlling an image forming unit for image data based on an image read by the scanner unit 15. The multi-function device 1 realizes a printer function by controlling an image forming unit for print data input via a network.

  Further, an operation panel 11 and a liquid crystal display 12 are disposed on the front upper surface of the main body casing 10. The operation panel 11 is operated when inputting various instructions to the multi-function device 1. The liquid crystal display 12 displays various information regarding the multi-function device 1 and notifies the user of the contents.

  A paper feed cassette 13 is detachably attached to the front surface of the main body housing 10. The paper feed cassette 13 stores sheets as recording media in a stacked state. The paper is used for printing out an image by the image forming unit.

  Next, the configuration of the scanner unit 15 in the multi-function device 1 will be described in detail with reference to FIGS. As described above, the scanner unit 15 is configured to include the document placing table 16, the slide shaft 19, the sensor unit 20, the reading and conveying motor, the flat cable, and the like in the upper part of the main body housing 10. The unit 20 reads an image of the document placed on the document placement table 16. The portion of the main body housing 10 where the scanner unit 15 is disposed is partitioned by the scanner bottom surface 18 from storage portions such as a facsimile unit and an image forming unit.

  The document placing table 16 constitutes the upper surface of the main body housing 10 and is a portion on which a document to be read by the scanner unit 15 is placed. The document placing table 16 has a contact glass 17. The contact glass 17 is so-called “platen glass”, and is formed in a rectangular shape that is slightly larger than the maximum document size in which the long side is positioned along the left-right direction of the main body housing 10. The contact glass 17 is used when an image of an original set on the contact glass 17 is read while moving the sensor unit 20.

  As shown in FIGS. 2 and 3, the slide shaft 19 is configured by a round bar-shaped shaft member, and extends on the scanner bottom surface 18 in the left-right direction (that is, the sub-scanning direction) of the main body housing 10. It is arranged like this. The slide shaft 19 holds the sensor unit 20 so as to be slidable in the left-right direction. The reading and conveying motor slides the sensor unit 20 along the slide shaft 19 via a drive transmission mechanism such as a pulley / belt mechanism based on drive control by the control unit.

  The sensor unit 20 includes an image sensor 25 for reading an image of a document located on the contact glass 17, a carriage 30, and a holder member 35. As described above, the sensor unit 20 extends along the slide shaft 19. And is slidably mounted. As shown in FIG. 2, the sensor unit 20 can be normally positioned at a standby position S (so-called home position) below the left end of the contact glass 17. Then, the sensor unit 20 slides along the lower surface of the contact glass 17 from the standby position S to a position separated by a distance corresponding to the long side of the maximum document size (hereinafter, “final position T”). Obtain (see FIG. 3).

  The sensor unit 20 reads an image from a document set on the contact glass 17 when moving between the standby position S and the final position T in the sub-scanning direction (the left-right direction of the multi-function device 1). Accordingly, as shown in FIG. 1, the scanner unit 15 has a maximum reading range R corresponding to a document of the maximum document size and can read an image of a document having a maximum document size or less.

  Then, the structure of the sensor unit 20 in 1st Embodiment is demonstrated in detail, referring FIGS. 3-5. As described above, the sensor unit 20 is configured by unitizing the image sensor 25, the carriage 30, and the holder member 35.

  The image sensor 25 is configured by a so-called contact image sensor (CIS). The image sensor 25 is composed of a light source, an image sensor, and the like, and the upper surface 26 of the image sensor 25 faces the contact glass 17 side. The image sensor 25 has a reading range having a length corresponding to the short side of the maximum document size in the front-rear direction (that is, the main scanning direction) of the main body housing 10. The image sensor 25 is formed in a substantially rectangular parallelepiped shape having a longitudinal dimension in the main scanning direction, and is housed in a sensor housing portion 31 of the carriage 30 described later. The carriage 30 and the sensor storage unit 31 are an example of a unit housing in the present invention.

  As shown in FIGS. 3 to 5, the carriage 30 supports the image sensor 25 from below and is slidable in the sub-scanning direction along the slide shaft 19. As shown in FIG. 5, the carriage 30 has long sides in the front-rear direction (that is, the main scanning direction) of the multi-function device 1, and includes a sensor storage portion 31, a spring 32, and a shaft holding portion 33. Have.

  The sensor storage portion 31 extends along the longitudinal direction of the carriage 30 (that is, the front-rear direction of the multi-function device 1), and is formed in a groove shape in which an upper portion facing the contact glass 17 is opened. The sensor storage unit 31 stores the image sensor 25 with the upper surface 26 of the image sensor 25 facing the contact glass 17 side, and supports the image sensor 25 from below.

  The spring 32 is disposed on the bottom surface of the sensor housing portion 31 at the front end portion and the rear end portion of the sensor unit 20, and biases the image sensor 25 housed in the sensor housing portion 31 toward the lower surface of the contact glass 17. To do.

  The shaft holding portion 33 is formed on the lower surface side of the carriage 30 in the central portion in the longitudinal direction of the carriage 30, and holds the carriage 30 slidably along the slide shaft 19. The shaft holding portion 33 is formed in a groove shape that extends along the short side direction of the carriage 30 and that opens below the contact. As shown in FIG. 4, by attaching the shaft holding portion 33 so as to straddle the slide shaft 19 from above, the carriage 30 is attached to be slidable in the sub-scanning direction according to the slide shaft 19.

  The holder member 35 is attached to the front end portion and the rear end portion of the sensor unit 20, respectively, and holds the roller member 40 rotatably. As shown in FIGS. 5 to 8, the roller member 40 includes a main body portion formed in a substantially disc shape, and a rotation shaft 41 erected perpendicularly to the main body portion at the center portion of the main body portion. Have.

  As shown in FIGS. 4 and 5, the holder member 35 has two roller support portions 36 and two protrusions 37 on its upper surface. The formation positions of the roller support portion 36 and the protrusion 37 in the first embodiment will be described in detail later with reference to the drawings.

  The roller support portion 36 rotatably supports the roller member 40 in a state where the rotation shaft 41 of the roller member 40 is in the same direction as the main scanning direction of the sensor unit 20. Thereby, the roller member 40 is rotatably attached to the holder member 35 in a state where the roller member 40 partially protrudes upward from the upper surface of the holder member 35. As a result, as shown in FIGS. 3 and 8, the roller member 40 comes into contact with the lower surface of the contact glass 17 and maintains a constant distance between the lower surface of the contact glass 17 and the upper surface 26 of the image sensor 25. To do.

  The protrusion 37 is formed to protrude from the upper surface of the holder member 35 upward at a predetermined height. As shown in FIG. 8, the protrusion 37 is formed in a substantially hemispherical shape, and has a curved surface portion 37A formed with a predetermined curvature at the apex portion located on the contact glass 17 side. Therefore, even when the protrusion 37 contacts the lower surface of the contact glass 17, the protrusion 37 and the lower surface of the contact glass 17 can be point-contacted, and the contact area between the two can be reduced.

  Next, the positional relationship between the protrusion 37 and the roller member 40 in the sensor unit 20 according to the first embodiment will be described in detail with reference to the drawings. As shown in FIGS. 4 to 7, the holder member 35 has two protrusions 37 and two roller support portions 36 on its upper surface, and each roller support portion 36 has a roller member 40 respectively. It is attached.

  As shown in FIGS. 6 and 7, in the holder members 35 attached to the front end portion and the rear end portion of the sensor unit 20, the two roller support portions 36 have the image sensor 25 accommodated in the sensor accommodating portion 31. It is located on the left side and the right side of the image sensor 25 so as to sandwich it. The two roller support portions 36 are both positioned on a single straight line parallel to the sub-scanning direction (that is, the left-right direction of the multi-function device 1) (see FIG. 7). Since the roller members 40 are respectively attached to the roller support portion 36, the two roller members 40 are both positioned on a single straight line parallel to the sub-scanning direction (that is, the left-right direction of the multi-function device 1).

  Further, the two protrusions 37 are formed on the upper surface of the holder member 35 on the end side with respect to the two roller members 40. As shown in FIGS. 6 and 7, in the case of the holder member 35 attached to the rear end side of the sensor unit 20, the two protrusions 37 are formed on the rear end side of the two roller members 40. In the case of the holder member 35 attached to the front end side of the sensor unit 20, the two protrusions 37 are formed on the front end side of the two roller members 40.

  The two protrusions 37 are both positioned on a straight line parallel to the sub-scanning direction (that is, the left-right direction of the multi-function device 1). In other words, in each holder member 35, the straight line connecting the two protrusions 37 connects the two roller members 40 on the end side (outside in the main scanning direction) of the sensor unit 20 rather than the straight line connecting the two roller members 40. It extends parallel to the connecting straight line.

  As shown in FIG. 7, the main body portion of the roller member 40 is formed in a disk shape having a predetermined roller width WA, and is supported by a rotating shaft 41 extending in the main scanning direction. Therefore, the width of the contact area between the lower surface of the contact glass 17 and the roller member 40 in the main scanning direction is the roller width WA. On the other hand, the protrusion 37 is formed in a hemispherical shape on the upper surface of the holder member 35 and is formed to have a protrusion width WB smaller than the roller width WA in the main scanning direction (see FIG. 7). . Therefore, in the multi-function device 1, it is possible to suppress the generation of abnormal noise and disturbance of the read image due to friction with the lower surface of the contact glass 17 while sufficiently reducing the space for forming the protrusion 37.

  Next, the protrusion 37 in the holder member 35 according to the first embodiment and the height of the roller member 40 will be described in detail with reference to the drawings. The height of the protrusion 37 and the roller member 40 will be described with reference to the reference height HS. The reference height HS means the height of the upper surface of the holder member 35 on which the protrusion 37 is formed.

  As described above, the protrusion 37 is formed integrally with the upper surface of the holder member 35, and is formed in a hemispherical shape so as to protrude upward from the upper surface of the holder member 35 toward the contact glass 17. As shown in FIG. 8, the protrusion 37 has a protrusion height HB with reference to the reference height HS.

  The roller member 40 is attached to the roller support portion 36 formed on the upper surface of the holder member 35 so that the upper end portion thereof is in contact with the lower surface of the contact glass 17. That is, the roller member 40 protrudes above the reference height HS at the roller height HA.

  As shown in FIG. 8, the protrusion height HB is smaller than the roller height HA. That is, a gap corresponding to the difference between the roller height HA and the protrusion height HB is formed between the protrusion 37 and the lower surface of the contact glass 17. Accordingly, if the holder member 35 is normally attached at the front end portion and the rear end portion of the sensor unit 20, the four protrusions 37 do not contact the lower surface of the contact glass 17, and the four roller members 40. Will be in contact. As a result, the sensor unit 20 can be in a state parallel to the lower surface of the contact glass 17 while forming a very small gap with the lower surface of the contact glass 17.

  Here, when the holder member 35 is attached to the front end portion and the rear end portion of the sensor unit 20, the holder member 35 is inclined so that the end portion side of the sensor unit 20 is higher. There is a case. For example, in the process of manufacturing the component parts of the sensor unit 20, if an error has occurred in the dimensional accuracy of each component part, the sensor unit 20 is inclined so that the end side of the sensor unit 20 becomes higher due to the accumulation of error. In some cases, the holder member 35 may be attached to the front end or the rear end of the sensor unit 20.

  Even in such a case, according to the multi-function device 1 according to the first embodiment, since the protrusion 37 is formed on the end surface side of the roller member 40 on the upper surface of the holder member 35, the contact glass 17. Only the apex of the protrusion 37 is in contact with the lower surface of. As a result, since the contact area can be reduced at the end of the sensor unit 20 as compared with the case where the entire length in the sub-scanning direction is in contact with the lower surface of the contact glass 17, the multi-function device 1 has the lower surface of the contact glass 17. The generation of abnormal noise due to the friction with the contact glass 17 can be prevented, and the disturbance of the image due to the friction with the lower surface of the contact glass 17 can be reduced.

  Further, as shown in FIGS. 6 and 7, on the upper surface of the holder member 35 attached to the front end and the rear end of the sensor unit 20, the two roller members 40 are located on a straight line extending in the sub-scanning direction, The two protrusions 37 are positioned on a straight line extending in the sub-scanning direction on the end side of the roller member 40. Therefore, according to the multi-function device 1, the protrusion 37 can be brought into contact with the lower surface of the contact glass 17 even when the holder member 35 is distorted or inclined in various directions. The contact area with the lower surface of the contact glass 17 can be reduced. As a result, according to the multi-function device 1, it is possible to prevent the generation of abnormal noise and disturbance of the read image due to friction with the contact glass 17.

  As shown in FIGS. 4 to 7, the two roller members 40 are located outside the image sensor 25 housed in the sensor unit 20 (that is, the image sensor housed in the sensor housing portion 31) in the sub-scanning direction. 25 on the right and left). Therefore, according to the multi-function device 1, the size of the sensor unit in the main scanning direction can be reduced as compared with the case where the roller member 40 is disposed outside the sensor unit 20 in the main scanning direction.

  As shown in FIG. 8, each projection 37 is formed in a hemispherical shape on the upper surface of the holder member 35, and has a curved surface portion 37 </ b> A at the apex portion located on the contact glass 17. Therefore, according to the multi-function device 1, the contact area between the lower surface of the contact glass 17 and the protrusion 37 can be reduced to point contact, generation of abnormal noise due to friction with the document placement table, and read image. Disturbance can be suppressed.

(Second Embodiment)
Next, an embodiment (second embodiment) different from the above-described first embodiment will be described in detail with reference to the drawings. The multi-function device 1 according to the second embodiment has the same basic configuration as the multi-function device 1 according to the first embodiment, and the configuration of the holder member in the sensor unit 20 is different. Therefore, the description regarding the same structure as 1st Embodiment is abbreviate | omitted.

  Similar to the first embodiment described above, the sensor unit 20 according to the second embodiment includes an image sensor 25, a carriage 30, and a holder member. Here, the configurations of the image sensor 25 and the carriage 30 in the second embodiment are the same as those in the first embodiment described above, and a description thereof will be omitted. Also in the second embodiment, the holder member is attached to the front end portion and the rear end portion of the sensor unit 20.

  As shown in FIG. 9, the holder member 45 according to the second embodiment has two roller support portions 46 and two protrusions 47 on the upper surface thereof, like the holder member 35 according to the first embodiment. doing. The roller support portion 46 has the same configuration as that of the roller support portion 36 according to the first embodiment except that the formation position is different, and supports the roller member 40 rotatably. Accordingly, also in the second embodiment, the roller member 40 is in contact with the lower surface of the contact glass 17 and maintains a constant distance between the lower surface of the contact glass 17 and the upper surface 26 of the image sensor 25. That is, also in the second embodiment, the roller member 40 protrudes upward by the roller height HA with reference to the reference height HS.

  Further, the protrusion 47 according to the second embodiment is also formed in a hemispherical shape that protrudes upward from the upper surface of the holder member 45, similarly to the protrusion 37 according to the first embodiment. That is, in the second embodiment, the protrusion 47 has a curved surface portion at the apex portion on the contact glass 17 side, and protrudes upward by the protrusion height HB with reference to the reference height HS. Therefore, even when the protrusion 47 is in contact with the lower surface of the contact glass 17, the protrusion 47 and the lower surface of the contact glass 17 can be in point contact, and the contact area between the two can be reduced.

  As shown in FIG. 9, in the holder member 45, the two roller support portions 46 are located on the left and right sides of the image sensor 25 so as to sandwich the image sensor 25 accommodated in the sensor accommodation portion 31. The two roller support portions 46 are both positioned on a single straight line parallel to the sub-scanning direction (that is, the left-right direction of the multi-function device 1). Accordingly, also in the second embodiment, the two roller members 40 are both located on a single straight line parallel to the sub-scanning direction.

  In the second embodiment, the two protrusions 47 are formed on the upper surface of the holder member 35 closer to the center side in the main scanning direction of the sensor unit 20 than the two roller members 40, and both are parallel to the sub-scanning direction. It is located on the same straight line. That is, also in each holder member 45, the straight line connecting the two protrusions 47 is parallel to the straight line connecting the two roller members 40 on the center side in the main scanning direction of the sensor unit 20 rather than the straight line connecting the two roller members 40. It extends to.

  As shown in FIG. 7, the main body portion of the roller member 40 is formed in a disk shape having a predetermined roller width WA, and is supported by a rotating shaft 41 extending in the main scanning direction. Therefore, the width of the contact area between the lower surface of the contact glass 17 and the roller member 40 in the main scanning direction is the roller width WA. On the other hand, the protrusion 37 is formed in a hemispherical shape on the upper surface of the holder member 35 and is formed to have a protrusion width WB smaller than the roller width WA in the main scanning direction (see FIG. 7). . Therefore, in the multi-function device 1, it is possible to suppress the generation of abnormal noise and disturbance of the read image due to friction with the lower surface of the contact glass 17 while sufficiently reducing the space for forming the protrusion 37.

  Here, when the holder member 45 is attached to the front end portion and the rear end portion of the sensor unit 20, the holder member 35 is inclined so as to be higher toward the center portion in the main scanning direction of the sensor unit 20. It can be assumed that this would happen. For example, if an error occurs in the dimensional accuracy of each component in the process of manufacturing the component of the sensor unit 20, the error is accumulated so that the center of the sensor unit 20 in the main scanning direction becomes higher. In some cases, the holder member 35 may be attached to the front end or rear end of the sensor unit 20 in a state where the sensor unit 20 is inclined.

  According to the multi-function device 1 according to the second embodiment, since the protrusion 47 is formed on the upper surface of the holder member 45 on the center side in the main scanning direction of the sensor unit 20 rather than the roller member 40, the contact glass 17 Only the apex of the protrusion 47 contacts the lower surface. As a result, in the holder member 45 attached to the sensor unit 20, the entire length in the sub-scanning direction of the end located on the central side in the main scanning direction does not contact the lower surface of the contact glass 17, and the contact area is reduced. be able to. As a result, the multi-function device 1 can prevent the generation of abnormal noise due to friction with the lower surface of the contact glass 17 and can also reduce image disturbance due to friction with the lower surface of the contact glass 17. .

  Further, as shown in FIG. 9, on the upper surface of the holder member 45 attached to the front end and the rear end of the sensor unit 20, the two roller members 40 are located on a straight line extending in the sub-scanning direction, and two protrusions 47 is located on a straight line extending in the sub-scanning direction on the central side in the main scanning direction of the sensor unit 20 relative to the roller member 40. Therefore, according to the multi-function device 1, the protrusion 47 can be brought into contact with the lower surface of the contact glass 17 even when the holder member 45 is distorted or inclined in various directions. The contact area with the lower surface of the contact glass 17 can be reduced. As a result, according to the multi-function device 1, it is possible to prevent the generation of abnormal noise and disturbance of the read image due to friction with the contact glass 17.

  Also in the second embodiment, the two roller members 40 are outside the image sensor 25 housed in the sensor unit 20 in the sub-scanning direction (that is, the right side of the image sensor 25 housed in the sensor housing portion 31). (Refer to FIG. 9). Therefore, according to the multi-function device 1, the size of the sensor unit in the main scanning direction can be reduced as compared with the case where the roller member 40 is disposed outside the sensor unit 20 in the main scanning direction.

  Each projection 47 is formed in a hemispherical shape on the upper surface of the holder member 45, and has a curved surface portion at the apex portion located on the contact glass 17. Therefore, according to the multi-function device 1, the contact area between the lower surface of the contact glass 17 and the protrusion 37 can be reduced to point contact, generation of abnormal noise due to friction with the document placement table, and read image. Disturbance can be suppressed.

  Although the present invention has been described based on the embodiments, the present invention is not limited to the above-described embodiments, and various improvements and modifications can be made without departing from the spirit of the present invention. For example, in the present embodiment, a multi-function device having various functions such as a printer function and a facsimile function in addition to the scanner function has been described as an example. However, the present invention is not limited to this mode. In other words, the present invention can be applied to any apparatus having a scanner function. For example, the present invention is configured as a scanner apparatus having only a scanner function (a so-called flatbed scanner) or a copier having a scanner function and a printer function. You may do it.

  In the above-described embodiment, the holder member is attached to both ends of the sensor unit 20 in the front-rear direction, the protrusion is formed on the upper surface of the holder member, and the roller member is attached. Is not to be done. That is, the protrusion and the roller member may be located on the upper surface side of the sensor unit, and may be disposed on the upper surface portion of the image sensor or the carriage.

  Further, in the above-described embodiment, the “projecting portion” in the present invention is configured by the roller member 40, but is not limited to this mode. That is, the projecting portion may be configured by projecting part of the upper surface of the holder member 35 and the holder member 45. In this case, it is desirable that the surface of the protruding portion be subjected to surface processing for reducing friction associated with contact with the contact glass.

  In the above-described embodiment, the protrusion is on the end side or the center side of the sensor unit 20 in the main scanning direction with respect to the arrangement position of the roller member in the holder member. It is not limited to the embodiment. That is, the protrusions may be formed on both the end side and the center side of the sensor unit 20 in the main scanning direction with respect to the arrangement position of the roller member in the holder member. For example, protrusions may be formed at the four corners on the upper surface of the holder member. According to this configuration, even if the holder member is tilted in any direction, the protrusion is in contact with the lower surface of the contact glass 17, thereby preventing the generation of abnormal noise due to friction with the lower surface of the contact glass 17. Image disturbance due to friction with the lower surface of the contact glass 17 can be reduced.

  In the above-described embodiment, the image sensor according to the present invention is referred to as “image sensor 25 configured by storing a light source, an image sensor, etc. in a case”, and the unit casing according to the present invention is referred to as “sensor storage unit 31”. However, the present invention is not limited to this mode. That is, the image sensor according to the present invention may be “various components including a light source and an image sensor”, and the unit housing according to the present invention may be “a case that accommodates various components including a light source and an image sensor”. In this case, the case itself is attached to be slidable along the first direction via a slide shaft or the like.

DESCRIPTION OF SYMBOLS 1 Multifunctional device 15 Scanner unit 16 Document mounting stand 17 Contact glass 19 Slide shaft 20 Sensor unit 25 Image sensor 26 Upper surface 30 Carriage 35 Holder member 37 Projection 37A Curved surface part 40 Roller member

Claims (7)

An original table on which an original is placed;
A sensor unit that is disposed below the document table and moves in a predetermined first direction and reads an image of the document placed on the document table;
The sensor unit is
An image sensor formed long in a second direction orthogonal to the first direction and facing a lower surface of the document table;
A unit casing that is formed long in the second direction and accommodates the image sensor;
A holder member attached to both ends of the sensor unit along the second direction and positioned outside the reading range of the image sensor;
The holder member is
The upper surface of the holder member constituting the upper surface of the sensor unit, disposed at a plurality of locations along the first direction, and in contact with the lower surface of the document mounting table, the document mounting table and the upper surface of the image sensor A protrusion that maintains a constant distance from
A protrusion that protrudes at a height lower than the top of the protrusion at a position different from a position where the protrusion is formed with respect to the second direction on the upper surface of the holder member constituting the upper surface of the sensor unit;
An image reading apparatus comprising: The image reading apparatus according to claim 1,
The protrusion is
An upper surface of the sensor unit,
An image reading apparatus characterized in that the plurality of protrusions are connected and formed at a plurality of locations on a straight line extending in parallel to the straight line extending in the first direction. What claim 1 or claim 2 image reading apparatus der description,
The protrusion is
An image reading apparatus comprising a roller member rotatably supported by a rotation shaft extending along the second direction on an upper surface of the holder member. An image reading apparatus according to any one of claims 1 to 3,
The protrusion is
In the first direction, located outside the image sensor accommodated in the sensor unit,
The protrusion is
An image reading apparatus, wherein the image sensor is located on an end side in the second direction with respect to the position of the image sensor housed in the unit casing and the protrusion on the upper surface of the sensor unit. The image reading apparatus according to claim 3,
The protrusion is
It is constituted by a roller member disposed on the holder member,
In the first direction, located outside the image sensor accommodated in the unit housing,
The protrusion is
Formed on the upper surface of the holder member,
When the holder member is attached, the image reading apparatus is located closer to the center in the second direction than the position of the protrusion on the upper surface of the sensor unit. An image reading apparatus according to any one of claims 1 to 5,
The protrusion is
An image reading apparatus having a curved surface formed with a predetermined curvature at a vertex portion located on the document placing table side. An image reading apparatus according to any one of claims 1 to 6,
The width of the protrusion in the second direction is smaller than the width of the protrusion in the second direction.

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