JP2005195910A - Image reader - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a means for realizing improvement in assembling and disassembling workabilities and the restraint of cost rise by simplifying the supporting structure of a driving shaft, on which a driving pulley is fixed in an image reader equipped with a reading unit having a scanning carriage moved by a driving mechanism, where an annular body, such as a belt or a wire, is wound and laid between pulleys. <P>SOLUTION: In a copying/facsimile compound machine 100, a through-hole 140 is formed on the chassis 13 of a reading platen 101, and a bearing member 138 is fit and inserted in the through-hole 140, in a state where its flange part 138a is set inside, then the driving shaft 137 is pivotally supported on the bearing member 138; then the driving pulleys 131 and 132 are fixed on the driving shaft 137 so as to hold the flange part 138a in between with the chassis 13. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a drive shaft support structure in an image reading apparatus such as a scanner, a facsimile machine, and a copying machine.

  In scanners, facsimiles, copying machines, 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. FIG. 4 is a schematic perspective view showing the external appearance of the upper part of a conventional copy / facsimile multifunction peripheral 900. As shown in FIG. 4, 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 feed cassette or the like is provided.

  The reading table 902 includes a reading unit such as a CCD. As shown in FIG. 5, the reading unit includes a full-rate carriage 905 and a half-rate carriage 906 in which a light source for irradiating light on a document and a reflection mirror for guiding a reflection hole from the document to the CCD are appropriately disposed. Is slidably provided on a guide rail (not shown) provided in the reading table 902, and scans the original on the platen glass 901 by scanning the full-rate carriage 905 and the half-rate carriage 906. The reflected light R from the original is read as an image signal by the scanner unit 907.

  The full rate carriage 905 and the half rate carriage 906 are moved by a belt driving mechanism 908. As shown in the figure, the belt drive mechanism 908 is configured such that the belts 84 and 85 wound between the drive pulleys 80 and 81 and the driven pulleys 82 and 83 are rotated by the rotation of the drive shaft 86, respectively. A full rate carriage 905 is fixed to the belt 84 and a half rate carriage 906 is fixed to the belt 85. Although not shown in detail in the drawing, the driven pulleys 82 and 83 are respectively supported by support brackets, and each support bracket is biased in the direction of tensioning the belts 84 and 85 by an elastic member such as a coil spring. Tension is applied to the belts 84 and 85. The driving pulley 80 and the driven pulley 82 around which the belt 84 is wound have the same diameter, and the driving pulley 81 and the driven pulley 83 around which the belt 85 is wound have the same diameter, and the diameters of the driving pulley 80 and the driven pulley 82 are the same. On the other hand, the diameters of the driving pulley 81 and the driven pulley 83 are approximately ½, and the gear ratio causes the half-rate carriage 906 to move by about ½ with respect to the moving distance of the full-rate carriage 905. ing.

  FIG. 6 shows an example of a conventional support structure of the drive shaft 86. As shown in the figure, the drive shaft 86 is a bearing member that is fitted into the through hole 88 of the chassis 87 of the reading table 902. Both end portions are pivotally supported by 89. The bearing member 89 is a so-called ball bearing, and supports both ends of the drive shaft 86 in the radial direction. The bearing member 89 is formed with a flange portion 89a. The flange portion 89a is fitted into the through hole 88 so as to abut on the outer surface of the chassis 87. Further, an e-ring is formed outside the flange portion 89a. The bearing member 89 is fixed in the thrust direction by fitting 90 to the drive shaft 86.

  However, in the conventional structure for supporting the drive shaft 86 described above, the e-ring 90 is fitted so as to push the drive shaft 86 into the ring, so that there is a problem that the assembly workability is not good. Further, when disposing of a scanner, a facsimile, a copying machine, etc., it is desirable that the disassembling workability is good in order to separate each member such as the drive shaft 86 constituting the reading table 902 for each material. Reducing the number of parts is desirable not only from workability during assembly or disassembly, but also from the viewpoint of cost reduction.

  The present invention has been made to solve such a problem, and includes an image reading unit including a reading unit having a scanning carriage that is moved by a driving mechanism in which an annular body such as a belt or a wire is wound between pulleys. It is an object of the present invention to provide means for improving the assembly and disassembling workability and suppressing the cost by simplifying the support structure of the drive shaft to which the drive pulley is fixed.

  The present invention provides a reading unit that includes a scanning carriage that is moved along an original by an annular body wound between a driving pulley and a driven pulley, and an image scanner that converts an optical image of the original into an image signal. In the image reading apparatus accommodated in the mounting table, a through hole is formed in the chassis of the reading mounting table, and a bearing member is fitted into the through hole with a flange portion inside, and a drive shaft is attached to the bearing member. A drive pulley is fixed to the drive shaft so as to sandwich the flange portion of the bearing member with the chassis.

  The scanning carriage is scanned while irradiating light on the document, and includes a full rate carriage that guides reflected light from the document in a predetermined direction, and a half rate carriage that guides reflected light from the full rate carriage to the image scanner. Thus, the drive pulley is formed by integrally forming a large-diameter pulley for driving the full-rate carriage and a small-diameter pulley for driving the half-rate carriage.

  According to the image reading apparatus of the present invention, the bearing member is fitted and inserted into the through hole in the chassis of the reading mounting table with the flange portion inside, and the flange portion of the bearing member is supported on the drive shaft supported by the bearing member. The drive pulley is fixed so that it is sandwiched between the chassis and the e-ring for fixing the bearing member in the thrust direction is not required. Assembling and disassembling workability is improved, and the number of parts is reduced and image reading is performed. The cost of the apparatus can be reduced.

  Further, since the drive pulley is formed by integrally forming a large-diameter pulley for driving the full-rate carriage and a small-diameter pulley for driving the half-rate carriage, the assembly and disassembly workability of the drive pulley is further improved. Be improved.

  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 housing 10 of the reading table 101 is formed by appropriately attaching a resin cover (not shown) to the chassis 13 shown in FIG. As shown in the figure, the chassis 13 is provided with a frame (frame body) 15 including four side wall members 14a, 14b, 14c, and 14d, and a bottom portion of the chassis 13 that is disposed below the frame 15. It consists of a bottom chassis (bottom plate) 16. Although not shown in the drawing, the CCD reading unit 12 is disposed in a chassis 13 surrounded by a frame 15, and a platen glass 11 is disposed on the upper portion of the frame 15. 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.

  Each of the side wall members 14a, 14b, 14c, and 14d has a sheet metal whose upper end is bent inward in an L-shaped cross section, and supports the platen glass 11 at the upper end. Each of the side wall members 14a, 14b, 14c, and 14d has a lower end portion bent inward in an L-shaped cross section, and is connected and fixed to the bottom chassis 16 with screws at the lower end portion. Further, the side wall member 14a on the back and back side of the reading table 101 and the side wall member 14b on the front side have a predetermined height and are bent substantially inwardly in the horizontal direction to form a horizontal plane. The horizontal plane serves as a guide rail 17 that slidably carries a full rate carriage (scanning carriage) 120 and a half rate carriage (scanning carriage) 121 (not shown) constituting the CCD reading unit 12. A resin-made sliding tape is attached to the guide rail 17 for the purpose of reducing friction when the full-rate carriage 120 and the half-rate carriage 121 slide. Further, the side wall members 14a, 14b, 14c, and 14d are inserted with screw holes for screwing and fixing the platen glass 11, the bottom chassis 16, 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.

  The CCD reading unit 12 scans the document with two scanning carriages, irradiates the document with light, guides the reflected light from the document to a predetermined position where the image sensor is provided, and electrically transmits the reflected light. As shown in FIG. 1, it is composed of 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 (image scanner) 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 main body 123 moving on the guide rail 17 (not shown), and is a half-rate carriage. The half-rate carriage 121 is provided with two reflecting mirrors 125 for guiding the reflected light from the full-rate carriage 120 to the scanner unit 122 to the carriage main body 126 moving on the guide rail. A reflection mirror 127 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 an optical image generated by the converged light into an electrical signal. The CCD image sensor 129 is adjusted and disposed on the optical axis of the imaging lens 128. When reading an image of a document, the full-rate carriage 120 is moved in parallel to the document on the platen glass 11 while emitting light from the light source 124, so that the light of the light source 124 scans the document reading surface. The light is sequentially irradiated in the direction, and the reflected light R of the light is reflected to the half-rate carriage 121 by the reflection mirror 125. The half-rate carriage 121 is also moved simultaneously with the full-rate carriage 120, and the reflected light R from the full-rate carriage 120 is reflected by the two reflecting mirrors 127 and guided to the scanner unit 122. Then, the reflected light R is read by the CCD image sensor 129 by the scanner unit 122 and output as an electrical signal, and an image of the document is recorded on the recording paper by the recording unit based on the electrical signal, or by the transmission unit. Sent. Since the recording unit and the transmission unit are publicly known and have arbitrary configurations, detailed description thereof is omitted.

  On the other hand, the full-rate carriage 120 and the half-rate carriage 121 are slidably supported by the guide rail 17 and are scanned by a pair of belt drive mechanisms 130 provided on both sides thereof. FIG. 1 shows one of a pair of belt drive mechanisms 130. The belt drive mechanism 130 is a belt (annular body) 135 wound around drive pulleys 131 and 132 and driven pulleys 133 and 134, respectively. , 136 are configured to move circumferentially by the rotation of the drive shaft 137, and the full rate carriage 120 is fixed to the belt 135 and the half rate carriage 121 is fixed to the belt 136. The drive pulleys 131 and 132 are 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 are used for driving the full rate carriage 120. In order to drive the half-rate carriage 121 with respect to the drive pulley (large diameter pulley) 131, the gear ratio of the drive pulley (small diameter pulley) 132 is approximately ½. When the drive shaft 137 is rotated by a rotational force applied from a drive source such as a motor (not shown), the drive pulleys 131 and 132 are rotated, and belts 135 and 136 wound around the drive pulleys 131 and 132, respectively. The full-rate carriage 120 and the half-rate carriage 121 are scanned, and the scanning speed and scanning distance of the half-rate carriage 121 are approximately ½ each of the scanning speed and scanning distance of the full-rate carriage 120. The full-rate carriage 120 and the half-rate carriage 121 configured as described above move below the platen glass 11 in parallel with the original placed on the platen glass 11 to scan the image of the original, and the light source 124 of the full-rate carriage 120. The original is irradiated with light, and the reflected light R from the original is sequentially reflected by the reflection mirrors 125 and 127 and guided to the scanner unit 122. In this embodiment, belts 135 and 136 are used as the annular body. However, if the belt is wound between pulleys for driving transmission, a belt or the like is used instead of the belt-like annular body. It is also possible to use a cord-like annular body.

Hereinafter, a support structure for the drive shaft 137 will be described.
As shown in FIGS. 2 and 3, through-holes 140 are formed in the side wall members 14 a and 14 b of the chassis 13 of the reading table 101 near the scanning end of the full-rate carriage 120 and below the guide rails 17. Has been. The through hole 140 is for inserting the drive shaft 137 and the bearing member 138, and is formed in a circular shape so as to match the outer shape of the substantially cylindrical bearing member 138. The bearing member 138 is a so-called ball bearing for supporting the drive shaft 137, and although not shown in detail in the drawing, a steel ball is sandwiched between the outer race and the inner race with the rolling element, The drive shaft 137 inserted in the inner race is supported in the radial direction. A flange portion 138a having a diameter larger than that of the through hole 140 is formed on one end side of the bearing member 137. As shown in the drawing, the flange portion 138a is located inside the side wall members 14a and 14b. Each is inserted into the through hole 140 and positioned by bringing the flange portion 138a into contact with the inner side surfaces of the side wall members 14a and 14b.

  Both end portions of the drive shaft 137 are inserted into and supported by the bearing member 138, and drive pulleys 131 and 132 are fixed inside the drive shaft 137, respectively. The drive pulleys 131 and 132 are integrally formed of synthetic resin with a large-diameter drive pulley 131 for driving the full-rate carriage 120 on the outside and a small-diameter drive pulley 132 for driving the half-rate carriage 121 on the inside. A screw hole 132a is formed in the inner portion of the drive pulley 132 in the radial direction. Corresponding to the screw holes 132a, screw holes 137a are formed in the drive shaft 137 at predetermined positions where the drive pulleys 131 and 132 are to be fixed, and screws 139 are screwed into the screw holes 132a and 137a. Thus, the pair of drive pulleys 131 and 132 are fixed at predetermined positions on both ends of the drive shaft 137, respectively. Each bearing member 138 fitted in each through-hole 140 of the side wall member 14a, 14b by each driving pulley 131, 132 screwed to the driving shaft 137 has a flange portion 138a that drives the side wall member 14a, 14b. It is pinched by the pulley 131 and is also fixed in the thrust direction. The drive pulleys 131 and 132 may be independent and fixed to the drive shaft 137. However, by integrally forming the drive pulleys 131 and 132, assembling and disassembling operations can be simplified, which is preferable. is there.

  In order to assemble the drive shaft 137 in such a support structure, first, a pair of drive pulleys 131 and 132 are fitted to the drive shaft 137 and a pair of bearing members 138 are further fitted. At this time, the drive pulleys 131 and 132 are not fixed and are brought close to the center of the drive shaft 137, and the bearing member 138 is also brought in the same manner. Both end portions of the drive shaft 137 are inserted into the respective through holes 140 of the side wall members 14a and 14b of the chassis 13 assembled in advance, and then each bearing member 138 is moved on the drive shaft 137 to both end sides. Fit into the through hole 140. Similarly, the drive pulleys 131 and 132 are also moved to both ends, the screw holes 132a and the screw holes 137a are aligned, and the screws 139 are screwed and fixed. Thereby, each bearing member 138 is also fixed. When disassembling, the assembly procedure may be reversed. Therefore, a fixing member such as an e-ring for fixing each bearing member 138 in the thrust direction is unnecessary, and both the assembly work and the disassembly workability are improved. Moreover, since the number of parts is reduced, the cost of the apparatus can be reduced.

  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. is there.

  The image reading apparatus according to the present invention can be used in a support structure of a drive shaft for driving a scanning carriage in a scanner, a facsimile, a copying machine, or the like.

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. FIG. 3 is an exploded perspective view showing configurations of a chassis 13, a drive shaft 137, a bearing member 138, and drive pulleys 131 and 132. It is an expanded sectional view showing a support structure of drive shaft 137. FIG. 10 is a schematic perspective view showing an upper configuration of a conventional copy / facsimile multifunction peripheral 900. 3 is a cross-sectional view illustrating a schematic structure of a reading unit in a reading mounting table 902. FIG. It is an expanded sectional view showing an example of the conventional support structure of drive shaft 86.

Explanation of symbols

12 CCD reading unit (reading unit)
13 Chassis 100 Copy / facsimile multifunction peripheral (image reading device)
101 Reading stage 120 Full rate carriage (scanning carriage)
121 Half-rate carriage (scanning carriage)
122 Scanner unit (image scanner)
131 Drive pulley (large diameter pulley)
132 Drive pulley (small diameter pulley)
133,134 Followed pulley 135,136 Belt (annular body)
137 Drive shaft 138 Bearing member 138a Flange portion 140 Through hole

Claims (2)

A reading unit including a scanning carriage that is moved along an original by an annular body wound between a driving pulley and a driven pulley and an image scanner that converts an optical image of the original into an image signal is accommodated in the reading table. In the image reading apparatus formed,
A through hole is formed in the chassis of the reading table, a bearing member is fitted into the through hole with the flange portion inside, a drive shaft is supported on the bearing member, and a flange of the bearing member is supported on the drive shaft. An image reading apparatus, wherein a driving pulley is fixed so as to hold the portion with a chassis.   The scanning carriage includes a full-rate carriage that scans a document while irradiating light and guides reflected light from the document in a predetermined direction, and a half-rate carriage that guides reflected light from the full-rate carriage to the image scanner, 2. The image reading device according to claim 1, wherein the driving pulley is formed by integrally forming a large-diameter pulley for driving the full-rate carriage and a small-diameter pulley for driving the half-rate carriage. apparatus.

Images