JP3809834B2 - Image reading device - Google Patents

Description

  The present invention relates to an image reading apparatus used as a flatbed scanner having a reading unit built therein in a scanner, a facsimile machine, a copying machine or the like.

  In scanners, facsimiles, copiers, etc., a flat bed scanner (hereinafter referred to as “FBS”) in which a reading unit of a reduction optical system such as a CCD (Charge Coupled Device) is incorporated in a reading table is used as image reading means. There is. A chassis formed of sheet metal or the like is used as the casing of the reading table, and mainly includes a frame that forms a side wall of the casing and a bottom chassis that forms the bottom of the casing (see Patent Document 1). .

  FIG. 5 is a schematic perspective view showing the external appearance of the upper portion of a conventional copy / facsimile multifunction peripheral 900. As shown in FIG. 5, the copy / facsimile multifunction peripheral 900 has a platen glass 901 on which a document to be read is placed. And a document holding cover 903 for pressing and fixing the document on the platen glass 901 and an operation panel 904 for inputting reading start of the document. Although not shown, the main body of the copy / facsimile multifunction peripheral 900 is supplied with an image recording unit for recording an image on a recording sheet, a transmission unit for transmitting the image, and a recording sheet for recording the read image. A paper feeding cassette is provided.

  The reading table 902 includes a reading unit such as a CCD. As shown in FIG. 6, the reading unit includes a light source for irradiating light on the document and a carriage 905 provided with a reflection mirror for guiding a reflection hole from the document to the CCD. A pair of guide rails 906 are slidably provided, and the carriage 905 is scanned with respect to the original on the platen glass 901, and reflected light from the original is imaged by a CCD image sensor (not shown). It is designed to read as a signal. The guide rail 906 is formed by attaching a sheet metal bent into a U-shaped cross section at a predetermined position inside a frame 902a that constitutes a side wall of the housing of the reading mounting table 902.

  The image signal read by the reading unit and converted into an electrical signal is subjected to analog / digital conversion, shading processing, etc. by a control unit, and then recorded on a recording sheet by an image recording unit such as a printer, or CODEC, etc. It is transmitted by the transmitter. The circuit board constituting the control unit is also accommodated in the reading mounting table 902. In general, since the copy / facsimile multifunction peripheral 900 is operated from the front, the reading mounting is performed in consideration of user operability. An operation panel 904 is provided on the front side of the mounting table 902, and a circuit board or the like is often housed in the back of the reading mounting table 902. Therefore, as shown in FIG. 6, the circuit board 907 is fixed to the portion where the bottom chassis 902b constituting the bottom of the housing of the reading table 902 protrudes from the frame 902a on the rear back side of the reading table 902 by screws. Has been.

Japanese Patent Laid-Open No. 2001-238011

  In recent years, for the purpose of improving the efficiency of office space and the like, a multifunction device in which one device has a plurality of functions such as the copy / facsimile multifunction device 900 has been developed. Multi-functions such as those equipped with a scanner function and a printer function, and those capable of reading both sides and color images are progressing, and as a result, the number of circuits constituting the control unit of the apparatus increases, so that the circuit board 907 It is getting bigger. Therefore, in order to fix the enlarged circuit board 907 in the housing of the reading table 902, it is necessary to enlarge the portion where the bottom chassis 902b protrudes from the frame 902a. If the protruding portion of the bottom chassis 902b is made larger, the reading table 902 also becomes larger. However, a multifunction device such as a copy / facsimile multifunction device 900 is originally intended to improve the installation space. It is not preferable that 902 is enlarged.

  The present invention has been made to solve such a problem. In an image reading apparatus including a reading unit and a reading mounting table that functions as a flat bed scanner, which includes a reading unit and a circuit board constituting a control unit. The object is to secure a circuit board installation space without increasing the size of the mounting table.

  The present invention relates to an image reading apparatus including a reading unit and a reading table that functions as a flatbed scanner and includes a reading unit and a circuit board constituting a control unit. The reading table is formed in a substantially rectangular shape in plan view. A chassis comprising a frame made up of side walls and a bottom plate that is assembled to the bottom of the frame and protrudes outward from the first side wall of the side walls; and a platen glass disposed on the top of the chassis; And a pair of guide rails are formed along the inside of the first side wall and the inside of the second side wall facing the first side wall, and the scanning unit constituting the reading unit is formed on the guide rail. A carriage is slidably provided, and a portion of the first side wall lower than the guide rail is recessed toward the inside of the frame, and a portion protruding from the frame of the bottom plate including the recessed portion Wherein the circuit board is disposed.

  In the image reading apparatus according to the aspect of the invention, the first side wall may be bent in a horizontal direction from a predetermined position of a plate-like member constituting the first side wall so that an upper surface thereof is the guide rail. A horizontal portion is formed, and a lower portion of the first side wall is formed by bending the inside of the horizontal portion downward.

  According to the image reading apparatus of the present invention, the bottom plate area of the portion protruding from the side wall is widened by recessing the lower portion of the side wall that constitutes the chassis frame from the guide rail toward the inside of the frame. Therefore, it becomes possible to attach a larger circuit board than before without increasing the size of the chassis. As a result, it is possible to reduce the size of the multifunctional image reading apparatus.

  According to the present invention, since the horizontal portion of the first side wall is used as a guide rail, it is not necessary to separately provide a member constituting the guide rail on the plate-like member constituting the first side wall. And the assembly process can be simplified.

  FIG. 1 is a diagram showing a cross section of an upper part of a copy / facsimile multifunction peripheral 100 which is an image reading apparatus according to an embodiment of the present invention. As shown in the figure, the copy / facsimile multifunction peripheral 100 has a document holding cover 102 provided with an auto document feeder (hereinafter referred to as “ADF”) 1 with respect to a reading table 101 functioning as an FBS. Although not shown in the figure, the copy / facsimile multifunction peripheral 100 has an operation panel for inputting the start of reading of an original, and an image recording unit for recording an image on a recording sheet. And a well-known configuration such as a transmission unit for transmitting an image and a paper feed cassette for supplying a recording sheet for recording the read image. Is.

  As shown in FIG. 1, the reading table 101 is configured such that a platen glass 11 is disposed on the top surface of a substantially rectangular parallelepiped housing 10 and a CCD reading unit 12 is built in the housing 10. The original placed on the platen glass 11 is fixed by closing the original pressing cover 102 and the CCD reading unit 12 reads the image. On the other hand, the document presser cover 102 includes a document tray 2 that holds a plurality of documents in a stacked state, a laterally U-shaped transport path 3, and a paper discharge tray that supports the transported documents in a stacked state. 4, a pickup roller 5 and a paper feed roller 6 for feeding the original on the original tray 2 to the conveyance path 3, a conveyance roller 7 for nipping and conveying the original in the conveyance path 3, and an exit near the conveyance path 3. An ADF 1 including a paper discharge roller 8 and a CIS reading unit 9 for reading an image of a document at a reading position P2 is provided. According to the ADF 1, the original fed from the original tray 2 to the conveyance path 3 is reversed so as to make a U-turn from the upper side to the lower side along the horizontal U-shaped conveyance path 3, and reaches the reading position P 1. An image on the surface of the original is read by the CCD reading unit 12 when passing through the reading position P1, and a contact image sensor (hereinafter referred to as Contact Image Sensor) when passing through the conveying path 3 and passing through the reading position P2. An image on the back side of the document is read by a CIS reading unit 9 having “CIS”), and is then discharged to a discharge tray 4 below the document tray 2. In the copy / facsimile multifunction peripheral 100, the ADF 1 has an arbitrary configuration.

  The casing 10 of the reading table 101 is formed by appropriately attaching a resin cover (not shown) to the chassis 13 shown in FIG. 3, and the chassis 13 has a platen glass 11, a CCD reading unit 12, a circuit board 14, and the like. Are fixed respectively. That is, the chassis 13 is a framework of the housing 10. The platen glass 11 serves as a top plate of the reading table 101 on which a document is placed with the reading surface facing downward. The CCD reading unit 12 is scanned below the platen glass 11 to scan the platen glass 11. The image of the original is read.

  As shown in FIG. 1, the CCD reading unit 12 includes a full rate carriage 120 and a half rate carriage 121 that are scanned in parallel with the platen glass 11, and a scanner unit 122. The full-rate carriage 120 reflects a light source 124 for irradiating the original with light and a reflected light R from the original in the scanning direction to the carriage body 123 moving on a guide rail (not shown) and guides it to the half-rate carriage 121. The half-rate carriage 121 includes two reflecting mirrors 127 that guide reflected light from the full-rate carriage 120 to the scanner unit 122. The half-rate carriage 121 includes a carriage body 126 that moves on a rail. It is provided. The scanner unit 122 includes an imaging lens 128 that converges the reflected light R from the half-rate carriage 121, and a CCD image sensor 129 for converting the converged light into an electrical signal. The CCD image sensor 129 is adjusted and disposed so as to be positioned on the optical axis of the image lens 128. By the scanner unit 122 configured as described above, the reflected light is read by the CCD image sensor 129 and output as an electrical signal, and based on the electrical signal, an image of a document is recorded on a recording sheet by a recording unit or transmitted. Are transmitted by the part.

  On the other hand, the full-rate carriage 120 and the half-rate carriage 121 are slidably supported by guide rails (not shown) and are scanned by the belt drive mechanism 130. As shown in the figure, the belt drive mechanism 130 is configured such that belts 135 and 136 wound between drive pulleys 131 and 132 and driven pulleys 133 and 134, respectively, move circumferentially by the rotation of the drive shaft 137. The full rate carriage 120 and the half rate carriage 121 are fixed to the belt 135 and the belt 136, respectively. The drive pulleys 131 and 132 are both fixed to the drive shaft 137, and the scanning ranges of the full rate carriage 120 and the half rate carriage 121 are set by the gear ratio of the drive pulleys 131 and 132, and drive the full rate carriage 120. In order to drive the half-rate carriage 121 with respect to the driving pulley 131, the gear ratio of the driving pulley 132 is approximately ½. As a result, the full rate carriage 120 and the half rate carriage 121 scanned by the belts 135 and 136 wound around the drive pulleys 131 and 132, respectively, are half rate at a speed approximately half the scanning speed of the full rate carriage 120. The carriage 121 is scanned, and the scanning distance of the half-rate carriage 121 is halved with respect to the scanning distance of the full-rate carriage 120.

  The full-rate carriage 120 and the half-rate carriage 121 configured as described above move under the platen glass 11 in parallel with the original to scan the image of the original, and light is emitted from the light source 124 of the full-rate carriage 120 to the original. The reflected light R from the document is sequentially reflected by the reflection mirrors 125 and 127 and guided to the scanner unit 122. It should be noted that the configuration of the CCD reading unit 12 shown in the present embodiment is merely an example, and can naturally be changed without departing from the scope of the present invention.

  A circuit board 14 shown in FIG. 3 is obtained by arranging various electronic devices on a printed circuit board made of, for example, PCB (polyvinyl chloride). Image reading control for controlling the operation of the CCD reading unit 12 when reading an image with 100 as an FBS, and the operations of the CCD reading unit 12, the CIS reading unit 9, and various rollers for conveying an original when reading an image with the ADF 1 Part. FIG. 2 is a block diagram illustrating an example of the image reading control unit configured by the circuit board 14. The image reading control unit includes the document set sensor provided on the document tray 2, the CCD reading unit 12, and the CIS reading unit. In order to control image reading of the CCD reading unit 12 and the CIS reading unit 9 based on each detection signal of each read sensor provided on the upstream side of the unit 9 and to drive various rollers such as the conveyance roller 7. The operation of the sheet feeding clutch and the like for moving up and down the motor and the pickup roller 5 is controlled. Although not shown in the figure, an image processing circuit for performing analog / digital conversion, shading processing, etc. on image data read by the CCD reading unit 12 and the CIS reading unit 9 is provided in the image reading control unit. Also good.

  As shown in FIG. 3, the chassis 13 constitutes a frame (frame body) 16 composed of four side wall members 15 a, 15 b, 15 c, and 15 d and a bottom portion of the chassis 13 disposed below the frame 16. And a bottom chassis (bottom plate) 17. The CCD reading unit 12 is disposed in a chassis 13 surrounded by a frame 16, and a platen glass 11 (not shown) is disposed on the frame 16. Therefore, the chassis 13 is a framework of the housing 10 of the reading table 102 and also plays a role of preventing dust from entering the CCD reading unit 12 and its optical path. The circuit board 14 is disposed on the bottom chassis 17 on the rear rear side of the chassis 13 and outside the frame 16.

  The four side wall members constituting the frame 16 are arranged in a frame shape so that a rear side wall member 15a, a front side wall member 15b, and both side wall members 15c and 15d are substantially rectangular in plan view. It is provided and connected by welding at both ends of each side wall member. Each of the side wall members 15a, 15b, 15c, and 15d is formed by bending an upper end portion of a sheet metal inward in an L-shaped cross section, and supports the platen glass 11 at the upper end portion. The side wall members 15a and 15b are also bent inwardly in a L-shaped cross section at the lower ends and are connected to the bottom chassis 17 by screws at the lower ends. Further, the side wall members 15a, 15b, 15c, and 15d are inserted with screw holes for screwing and fixing the platen glass 11, the bottom chassis 17, and other members, through holes for electric wiring, and drive shafts. However, since these are appropriately designed according to the configuration of the reading table 101, a detailed description thereof will be omitted.

  As shown in FIG. 4, the side wall member 15a on the rear back side is formed with an upper end 150 and a lower end 151 in the horizontal direction by bending the upper and lower ends of the sheet metal into an L shape. The side wall portion (first side wall) 152 formed by the portion is further bent to form a side wall upper portion 153, a horizontal portion 154, and a side wall lower portion 155. In detail, in the vertical side wall portion 152 serving as the side wall of the chassis 13, the lower side from the predetermined position is bent in the horizontal direction and substantially at right angles to the inside of the frame 16, so A portion 154 is formed, and a side wall lower portion 155 is formed by further bending the inner side of the horizontal portion 154 downward at a substantially right angle. Thereby, the rear side wall portion 152 has a shape in which the lower portion is recessed toward the inside of the frame 16.

  The horizontal portion 154 formed across the width direction of the side wall member 15a has a width sufficient to support the end portions of the full-rate carriage 120 and the half-rate carriage 121 slidably in the horizontal direction on its upper surface. The full-rate carriage 120 and the half-rate carriage 121 are formed at a height suitable for scanning. On the upper surface of the horizontal portion 154, a sliding tape 18 for reducing the frictional resistance with the full rate carriage 120 and the half rate carriage 121 is attached to form the guide rail 19.

  As shown in FIG. 3, the front side wall member 15 b facing the rear side wall member 15 a is also bent in an L shape in the same manner as the rear side wall member 15 a. Thus, an upper end 156, a lower end 157, and a side wall (second side wall) 157 are formed, and the side wall 152 is further bent to form a side wall upper part 158, a horizontal part 159, and a side wall lower part 160. The sliding tape 18 is affixed to the upper surface of the horizontal portion 159 in the same manner as the horizontal portion 154 of the first side wall member 15a. A pair of parallel guide rails 19 are constituted by the horizontal portions 154 and 159 of the rear side wall member 15a and the front side wall member 15b. Thus, by forming the side wall portions 152 and 157 of the frame 16 and the guide rail 19 integrally with the side wall members 15a and 15b, the number of parts of the reading table 102 can be reduced, and the assembly process is simplified. Can be

  As shown in FIG. 3, the bottom chassis 17 is a flat plate-like member that is rectangular in plan view. The bottom chassis 17 is attached to the lower side of the frame 16 so as to block the bottom of the frame 16 to prevent dust from entering the frame 16. In addition to preventing, it is a fixing member for fixing various members such as the circuit board 14. The bottom chassis 17 can be produced, for example, by pressing a sheet metal, and the peripheral edge 170 of the bottom chassis 17 is bent upward to increase the strength. Further, a part of the bottom chassis 17 protrudes outward from a side wall portion 152 formed by the first side wall member 15a of the frame 16, and a convex portion 171 having a screw hole is appropriately formed on the protruding portion 17a. The circuit board 14 is screwed to the convex portion 171. In addition to the circuit board 14, a motor, a drive transmission gear, and the like are disposed on the projecting portion 17a. However, the arrangement of the projecting portion 17a is a matter of design and can be changed as appropriate. In the frame 16, convex portions similar to the convex portion 171 are formed in order to fix various members to the bottom chassis 17, but these are also design matters and will not be described in detail. Further, although not shown in the drawing, the projecting portion 17 a is covered with a cover made of a plastic material like the other portions of the chassis 13 to form the housing 10.

  As shown in FIG. 4, the circuit board 14 is fixed to a position including the protruding portion 17 a of the bottom chassis 17 and the side wall portion 152 being recessed. As described above, since the lower portion of the side wall 152 formed by the rear side wall member 15a, that is, the side wall lower portion 155 is recessed toward the inside of the frame 16, the area of the upper surface of the protrusion 17a is the protrusion width. In the direction, the side wall 152 is widened by a dimension d corresponding to the depression. The dimension d is set in consideration of the size of the circuit board 14 and the like. However, since no other member is attached below the guide rail 19, there is an empty space. Therefore, the dimension d is at least the guide rail. About 19 rail widths can be secured. On the other hand, since the height of the side wall lower portion 155 is lower than the horizontal portion 154 serving as the guide rail 19, the height of a member that can be accommodated in the widened portion is limited, but a flat plate like the circuit board 14 is used. The member can be sufficiently accommodated if there is a height space below the horizontal portion 154. As a result, by utilizing the empty space below the guide rail 19, the circuit board 14 larger than the conventional one can be fixed without increasing the protrusion width of the protrusion 17 a of the bottom chassis 17. This copy / facsimile multifunction peripheral 100 can be downsized. Further, in the portion where the side wall portion 152 is recessed, the inside and outside of the frame 16 are blocked by the horizontal portion 154 and the side wall lower portion 155, so that the dustproof action into the frame 16 is also maintained.

  It should be noted that the configuration of the copy / facsimile multifunction peripheral 100 shown in the present embodiment is merely one aspect of the image reading apparatus according to the present invention, and it is needless to say that the design can be changed as appropriate without departing from the gist of the present invention. In addition, functions such as a scanner and color copy can be added, and a communication means with a general-purpose personal computer such as a wireless LAN can be provided.

  An image reading apparatus according to the present invention includes a reading unit that has a reading unit and a circuit board that constitutes a control unit and functions as a flatbed scanner, and has a function of a scanner, a facsimile machine, a copying machine, etc. In particular, the utility value is high.

1 is a cross-sectional view showing a schematic configuration of an upper part of a copy / facsimile multifunction peripheral 100 according to an embodiment of the present invention. 2 is a block diagram illustrating an example of an image reading control unit configured by a circuit board. FIG. 2 is a schematic perspective view showing a configuration of a chassis 13. FIG. It is an expanded sectional view which shows the AA cross section of FIG. FIG. 10 is a schematic perspective view showing an upper configuration of a conventional copy / facsimile multifunction peripheral 900. 4 is an enlarged cross-sectional view showing a part of a cross section of a rear portion of a reading mounting table 902. FIG.

Explanation of symbols

11 Platen glass 12 CCD reading unit (reading unit)
13 Chassis 14 Circuit board 15a First side wall member 15b Second side wall member 16 Frame (frame body)
17 Bottom chassis (bottom plate)
17a Projecting portion 19 Guide rail 100 Copy / facsimile multifunction machine (image reading device)
101 Reading stage 120 Full rate carriage (scanning carriage)
121 Half-rate carriage (scanning carriage)
152 side wall (first side wall)
154 Horizontal portion 157 Side wall portion (second side wall)

Claims (2)

In an image reading apparatus including a reading mounting table that includes a reading unit and a circuit board constituting a control unit and functions as a flatbed scanner,
The reading mounting table includes a frame including a side wall formed in a substantially rectangular shape in plan view, and a bottom plate that is assembled to the bottom of the frame and protrudes outward from the first side wall among the side walls. And a pair of guide rails formed along the inside of the first side wall and the inside of the second side wall facing the first side wall. A scanning carriage constituting the reading unit is slidably provided on the guide rail, and a portion of the first side wall lower than the guide rail is recessed to the inside of the frame, and the recessed portion An image reading apparatus characterized in that the circuit board is disposed in a portion protruding from a frame of the bottom plate including the portion.   The lower side of the first side wall is bent in a horizontal direction from a predetermined position of the plate-like member constituting the first side wall to form a horizontal portion whose upper surface serves as the guide rail. 2. The image reading apparatus according to claim 1, wherein a lower portion of the first side wall is formed by bending the inner side downward.

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