JP3912605B2 - Image reading device - Google Patents

Description

  The present invention relates to a flat bed type image reading apparatus and a sheet-through type image reading apparatus.

  Image reading devices used in scanners, facsimiles, copiers, etc. include a flatbed system that reads an image by placing the document on a platen glass and an image reading device that feeds multiple documents sequentially. There is a thing of the sheet through method to perform. The flat bed method is realized by a flat bed scanner (hereinafter referred to as “FBS”), and the sheet-through method is mainly realized by an auto document feeder (hereinafter referred to as “ADF”).

  FIG. 11 is a schematic perspective view showing the appearance of an image reading apparatus 900 equipped with both ADF and FBS. As shown in the figure, the image reading apparatus 900 has a platen glass 901 on which a document to be read is placed. An arranged reading table 902, a document pressing cover 903 that presses and fixes the document on the platen glass 901, an operation panel 904 for inputting reading start of the document, etc., and recording an image on a recording sheet An image recording unit for transmitting the image, a transmission unit for transmitting the image, and a main body 905 including a paper feed cassette for supplying a recording sheet for recording the read image. The main unit 905 is mounted on the platen glass 901. An image reading unit such as a CCD provided in the reading table 902 moves with respect to the original document to read the image, thereby functioning as an FBS. Also, the ADF is provided in the document presser cover 903, and the ADF transports the document on the document tray to the paper discharge tray with the document presser cover 903 closed, and the platen glass 901 is moved in the transport process. When the document passes through the reading position, an image of the original is read by a scanner unit such as a CCD provided in the reading table 902 (see, for example, Patent Document 1 and Patent Document 2). In addition, from the viewpoint of reducing the size and weight of the image reading apparatus, the image reading apparatus 900 is not equipped with both ADF and FBS, but an image reading apparatus capable of only reading an image by ADF, or an image by FBS. An image reading apparatus capable of only reading is also provided.

JP-A-1-194658 Japanese Patent Application No. 2002-120074

  In an image reading apparatus capable of only reading an image by ADF, a scanner unit is fixed in the apparatus body. On the other hand, in an image reading apparatus capable of only reading an image by FBS, the scanner unit is arranged along a guide member such as a guide rail. The belt is slidably arranged and is also connected to a belt of a belt driving mechanism. Therefore, the sheet-through type scanner unit and the flat-bed type scanner unit adopt different structures designed to be adapted to the sheet-through type or the flat-bed type in consideration of their respective functions. . However, in addition to the reduction in size and weight of the image reading apparatus, there is a demand for cost reduction, and the cost reduction of the scanner unit employed in the sheet-through method or the flat bed method is also desired.

  The present invention has been made to solve such a problem, and provides a scanner unit that can be arbitrarily selected and disposed in either a sheet-through type image reading apparatus or a flat bed type image reading apparatus. For the purpose.

The present invention is an image reading apparatus in which a scanner unit that irradiates a document with light and reads an image with reflected light is housed in a reading table having a bottom frame and a frame cover, and the scanner unit includes: The frame cover is provided so as to be movable in the scanning direction and fixed at a predetermined position. The frame cover is provided with an automatic document conveying mechanism for conveying the document from the document tray to the paper discharge tray through the reading position. By fixing the scanner unit directly below the reading position, a configuration in which a document can be read only by a sheet-through method, a platen glass is disposed on the frame cover, and the scanner unit can be moved. Can be selected to be a configuration that can read documents by flatbed method. Characterized in that that.

The present invention also provides a belt driving mechanism for applying a driving force to the scanner unit, and guiding the scanner unit in the scanning direction when a configuration capable of reading a document by a flat bed method is selected. A guide rod is further attached to the inside of the reading table .

Further, the present invention is characterized in that the bottom frame is shared by a configuration in which a document can be read only by the sheet through method and a configuration in which the document can be read by the flat bed method.

According to the present invention, the scanner unit is provided so as to be movable in the scanning direction and to be fixed at a predetermined position. Therefore, when the scanner unit is disposed in a flat bed type image reading apparatus, a sheet as a movable scanner unit is provided. When a through-type image reading apparatus is provided, it can be used as a fixed scanner unit in accordance with each function. As a result, the versatility of the scanner unit is enhanced, and the cost can be reduced by mass production.

Also, according to the present invention, when a document can be read by the flat bed method, the belt drive mechanism and the guide rod are attached to the inside of the reading table, while the document can be read only by the sheet through method. In such a case, the image reading apparatus can be reduced in weight and cost can be reduced by omitting the belt driving mechanism and the guide rod.

In addition, according to the present invention , since the bottom frame is shared by the configuration in which the document can be read only by the sheet-through method and the configuration in which the document can be read by the flat bed method, The cost can be reduced by mass production.

  1 and 2 are schematic perspective views of an image reading apparatus 100 according to an embodiment of the present invention. As shown in the figure, the image reading apparatus 100 includes a reading table 101 on which a platen glass 10 on which a document to be read is placed is disposed, and a document pressing cover that presses and fixes the document onto the platen glass 10. 102. Further, the reading table 101 is provided with an operation panel 103 for inputting the reading start of the document and the like. Although not shown in detail in the drawing, the apparatus main body records an image on a recording sheet. An image recording unit for transmitting images, a transmission unit for transmitting images, and a paper feed cassette for supplying recording paper for recording the read images, and the like, and functions as a copy / facsimile multifunction peripheral. . Whether the image reading apparatus is used in a copy / facsimile multifunction peripheral or a facsimile alone is arbitrary. Such an image reading apparatus 100 can perform image reading by a flat bed method and a sheet through method. When reading an original by the flat bed method, the original pressing cover 102 is opened as shown in FIG. An original is placed on the platen glass 10 of the reading table 101, and an image is read by scanning a scanner unit (not shown) in the reading table 101 with the original pressing cover 102 closed, and sheet-through is performed. When the original is read by this method, the original is automatically conveyed by the ADF 1 with the original pressing cover 102 closed as shown in FIG. 1, and the image is read by the scanner unit in the reading table 101 during the conveyance process.

  The ADF 1 is disposed in the document pressing cover 102 and continuously feeds the document to the reading position P of the platen glass 10. As shown in FIG. 3, the ADF 1 transports the document from the document tray 2 to the conveyance path. The original fed in is reversed so as to make a U-turn from the upper side to the lower side along the paper guide 3 and reaches the reading position P. When the original passes through the reading position P, the scanner unit 11 reads the image of the original. Then, the paper is discharged to a paper discharge tray 4 below the document tray 2. The original conveyed by the ADF 1 can be curved along a horizontal U-shaped conveyance path having a thickness that can pass through the conveyance path in addition to so-called plain paper of various sizes generally used for copying and printers. Is.

  As shown in the figure, the ADF 1 carries a document tray 2 that carries a plurality of documents in a stacked state, a paper guide 3 provided on the downstream side of the document tray 2, and a document after conveyance in a stacked state. A paper discharge tray 4, a pick-up roller 5 and a paper feed roller 6 for feeding a document on the document tray 2 to the transport path, a separation pad 7 that is in pressure contact with the paper feed roller 6, and a transport roller for transporting the document in the transport path 8.

  The document tray 2 is provided on the upper part of the document pressing cover 102 so as to be slightly inclined in the direction in which the document is supplied, and a plurality of documents are stacked on the upper surface of the document tray 2. When the user places a document on the document tray 2, the document is placed so that the front end of the document is aligned with the inclined lower end side of the document tray 2. Further, the document tray 2 is provided with a variable guide member 2a that regulates the position of the document in the width direction to prevent the document from being obliquely fed.

  On the downstream side of the document tray 2, a paper guide 3 is disposed in the document pressing cover 102. The paper guide 3 serves as an inner guide surface of the conveyance path, and the cover main body 102a and the ADF cover 102b of the document pressing cover 102 are provided. Serves as an outer guide surface of the conveyance path, and forms a laterally U-shaped conveyance path communicating with the paper discharge tray 4. The outer guide surface constituting the conveyance path may be provided with a guide plate formed by curving an iron plate or the like in the document pressing cover 102 separately. However, the cover main body 102a and the ADF cover 102b of the document pressing cover 102 and the outer guide surface It is preferable to integrally mold with a plastic material because the number of parts is reduced and assembly is facilitated.

  As shown in the figure, the paper guide 3 is assembled with the pickup roller 5, paper feed roller 6, separation pad 7, separation pad holder 70, conveyance roller 8 and the like, and is attached to the cover body 102 a of the document pressing cover 102. It is arranged. Although not shown in the figure, the paper guide 3 is also assembled with a drive unit such as a motor and a drive gear, and the ADF cover 102b is disposed on the cover body 102a so as to be opened and closed.

  The paper feed roller 6 is disposed above the paper guide 3 and rotates while being in pressure contact with the original fed from the original tray 2 to feed the original into the conveyance path. A roller made of silicon and EPDM (Ethylene-Propylene-Diethylene Methylene Linkage) is fixed to the roller shaft, and the roller shaft is rotatably supported by a paper guide 3. Further, a pickup roller 5 for feeding the uppermost sheet of the document placed on the document tray 2 is disposed upstream of the paper feed roller 6. Similarly to the paper feed roller 6, the pick-up roller 5 is rotated while being pressed against the original so that the original is fed into the conveyance path, and a roller made of silicon or EPDM is fixed to a metal roller shaft. It becomes. The pickup roller 5 is supported by a swing arm 51 swinging up and down by a paper feed clutch (not shown), and the pickup roller 5 can be seated on the document tray 2 by swinging of the swing arm 51. is there. In a normal state such as when a document is placed on the document tray 2, the pickup roller 5 is separated from the document tray 2, and is lowered so as to come into contact with the uppermost sheet of the document when the document is fed. As the paper supply roller 6 rotates, the uppermost paper of the original is fed into the conveyance path. Although not shown in the drawing, the presence or absence of the document on the document tray 2 is detected by a document set sensor, and based on the detection signal, the control means controls the pickup roller 5, the swing arm 51, and the paper feed roller 6. The operation is controlled.

  The documents fed from the document tray 2 to the conveyance path are reliably separated one by one at the nip portion between the paper feed roller 6 and the separation pad 7. The separation pad 7 has a friction coefficient with respect to the original that is lower than the friction coefficient with respect to the original of the paper feed roller 6 and higher than the friction coefficient between the originals, and can be formed of, for example, urethane resin. Such a separation pad 7 is stuck on the upper surface of the separation pad holder 70 and is in pressure contact with the paper feed roller 6. The separation pad holder 70 supports the separation pad 7 and is swingably attached to the paper guide 3, and is biased upward by a coil spring 71. Thus, for example, if the original conveyed by the pickup roller 5 to the nip portion between the paper supply roller 6 and the separation pad 7 is fed in a stacked state, the upper original is fed on the upper surface. Since the lower surface is in contact with the roller 6 and the lower surface is in contact with the lower document, the roller 6 is fed into the conveyance path according to the rotation of the paper feed roller 6. On the other hand, since the lower document is in a state where the upper surface is in contact with the upper document and the lower surface is in pressure contact with the separation pad 7, it is restrained by the separation pad 7 at the nip portion. In this way, the original is reliably separated at the nip portion between the paper feed roller 6 and the separation pad 7.

  The originals separated one by one by the paper feed roller 6 and the separation pad 7 and fed into the conveyance path are then conveyed by the conveyance roller 8 along the horizontal U-shaped conveyance path. As shown in the drawing, a transport roller 8 for transporting a document is disposed at a position immediately downstream of the folded portion of the laterally U-shaped transport path and at the most downstream position of the transport path. The roller shaft is rotated by a rotational force transmitted from a driving source such as a motor, and is rotatably supported by the paper guide 3. A driven roller 81 that is driven by the rotation of the conveying roller 8 is provided at a position facing the conveying roller 8 so as to sandwich the conveying path, and the document is conveyed while being nipped by the conveying roller 8 and the driven roller 81. It has become. As a result, the original is conveyed to the paper discharge tray 4 through the reading position P, and the scanner unit 11 performs image reading at the reading position P. The arrangement of the conveyance rollers 8 is an example, and it is of course possible to appropriately increase or decrease the number of the conveyance rollers 8 according to the shape and distance of the conveyance path.

  The scanner unit 11 is a CCD reading unit of a so-called reduction optical system that is mounted in the reading table 101 and irradiates light on a document and converts the reflected light from the document into an electrical signal to read an image. 4 and 6, a light source 13, a reflection mirror 14, a condensing lens 15, and a CCD image sensor 16 are disposed in a substantially rectangular parallelepiped casing 12. As shown in FIG. 6, a pair of guide rod bushes 17 is provided on one end side of the housing 12, and a belt clamp 18 is provided below the guide rod bush 17. The guide rod bush 17 is for inserting a guide rod (guide member) 26 provided in the reading mounting table 101. The guide rod bush 17 protrudes laterally from the housing 12 and penetrates in the horizontal direction (rod hole). 17a is formed, and the through holes 17a are arranged at predetermined intervals in the scanning direction so as to be coaxial. As a result, the scanner unit 11 can move along the guide rod 26. The belt clamp 18 is for fixing the belt 30 of the belt driving mechanism provided in the reading mounting table 101, and sandwiches the belt 30 by sandwiching pieces 18a arranged vertically at a predetermined interval. It is like that. Thereby, the rotational motion of the belt 30 wound between pulleys (not shown) is transmitted to the scanner unit 11 and the scanner unit 11 moves together with the belt 30. On the other hand, as shown in FIG. 4, a sliding portion 19 is formed at the bottom of the housing 12 on the other end side. The sliding portion 19 is formed by notching the bottom portion on the other end side of the housing 12 with a predetermined width in the scanning direction. The sliding portion 19 is a guide rail (guide member) 24 ( 7 (see FIG. 7), the scanner unit 11 with the guide rod inserted at one end thereof is kept horizontal and slides on the guide rail 24. In addition, in order to reduce sliding friction, you may stick the sliding tape which consists of a raw material with small friction coefficients, such as a fluororesin, to the sliding part 19. FIG.

  A light source 13 is provided on the top surface of the housing 12 in the width direction. As shown in FIG. 6, a reflection mirror 14, a condenser lens 15, and a CCD image sensor 16 are arranged in the housing 12. It is installed. An opening 12 a is formed in the housing 12 along the light source 13, and reflected light of the document enters the housing 12 from the opening 12 a. The reflected light R that has entered the housing 12 is sequentially reflected by the appropriately disposed reflecting mirror 13 and guided to the condenser lens 15. Such an arrangement of the reflection mirror 13 is appropriately set according to the optical path length necessary for imaging the reflected light R on the CCD image sensor 16. The reflected light R guided to the condenser lens 15 is imaged on the CCD image sensor 16, converted into an electrical signal by the CCD image sensor 16, and output. Based on this electrical signal, an image of the original is recorded on a recording sheet by a recording unit or transmitted by a transmission unit. Since the recording unit and the transmission unit are well-known and arbitrary configurations, detailed description is omitted.

  As shown in FIGS. 4 to 6, a fixing piece 20 protrudes from the vicinity of the bottom of the housing 12 to the upstream side on the upstream side in the scanning direction of the housing 12 (left side in FIG. 3). The fixing piece 20 is for fixing the scanner unit 11 at a predetermined position in the reading mounting table 101 so that the scanner unit 11 can be used also in an image reading apparatus that reads an image only by a sheet through method. Each fixing piece 20 is provided in the vicinity of both ends of the housing 12, and a fixing insertion hole 20 a for allowing a fixing screw (not shown) to pass therethrough is formed. Similarly, a fixing piece 20 is also provided on the downstream side in the scanning direction of the housing 12 (right side in FIG. 3) from the approximate center of the side surface of the housing to the downstream side. The arrangement of each of the fixed pieces 20 is not limited to three, and can be set as appropriate as long as the scanning of the scanner unit 11 is not hindered.

  As shown in FIG. 2, the casing of the reading table 101 includes a bottom frame 21 and a frame cover 22, and a platen glass 10 is disposed in an opening of the frame cover 22. As shown in FIG. 7, the bottom frame 21 is provided with a guide rod fixing portion 23, a guide rail 24, and belt drive mechanism attachment portions 25 </ b> R and 25 </ b> L. The guide rod fixing portions 23 are for fitting and fixing guide rods 26 for restricting the scanning direction of the scanner unit 11, and a pair of guide rod fixing portions 23 are provided at predetermined positions on the inner surface of the bottom frame 21. The guide rod 26 is installed in the scanning direction by the guide rod fixing portion 23 so as to correspond to the back end of the scanner unit 11. On the other hand, the guide rail 24 is provided along the front side surface of the bottom frame 21 so as to be parallel to the guide rod 26.

  The belt drive mechanism attachment portions 25R and 25L are spaces for disposing a belt drive mechanism 27 including pulleys 28 and 29, a belt 30, a motor 31 and the like that apply a drive force for moving the scanner frame 11. Yes, the bracket to which the motor and pulley are fixed is fixed by screwing or the like. As shown in FIGS. 3 and 7, the belt drive mechanism 27 includes a belt 30 wound around a drive pulley 28 and a driven pulley 29, and the drive pulley 28 is driven by a driving force of a motor 31. The belt 30 is configured to rotate and rotate, and the belt 30 is fixed to the scanner unit 11 by the belt clamp (belt fixing portion) 18 as described above. The drive pulley 28 and the belt 30 are fixed to a bracket 32, respectively, disposed in a belt drive mechanism mounting portion 25R provided at the right back corner of the bottom frame 21, and fixed by a fixing tool such as a screw. On the other hand, the driven pulley 29 is also fixed to the bracket 33, and is disposed on the belt drive mechanism mounting portion 25L provided at the left back corner of the bottom frame 21, and is fixed by a fixing tool such as a screw. When the belt 30 is wound around the drive pulley 28 and the driven pulley 29, the belt 30 is stretched along the guide rod 26, and the motor 31 is controlled to control the scanner unit 11 via the belt 30. Scanning is controlled. As a result, the scanner unit 11 can move below the platen glass 10 when reading a document by the flat bed method. The output from the CCD image sensor 16 of the scanner unit 11 and the power supply to the light source 13 are performed by electrically connecting the scanner unit 11 and the apparatus main body (not shown) by a harness 34.

  Further, the bottom frame 21 can also be used in an image reading apparatus that reads an image only by a sheet through method, and a fixing screw hole 35 for fixing the scanner unit 11 is formed. More specifically, in the sheet-through type image reading apparatus, the scanner unit 11 is fixed at the reading position P shown in FIG. 3. For this purpose, as shown in FIG. 8, when the scanner unit 11 is arranged at the position. Corresponding to the fixing piece 20, fixing screw holes 35 are formed in the bottom of the bottom frame 21 so as to be coaxial with the fixing insertion hole 20a. Therefore, the scanner unit 11 can be fixed to the bottom frame 21 by inserting a screw through the fixing insertion hole 20 a of each fixing piece 20 of the scanner unit 11 and screwing it into the fixing screw hole 35 of the bottom frame 21.

  As described above, the image reading apparatus 100 can be used in the image reading apparatus 200 that reads an image only by the sheet-through method using the scanner unit 11 and the bottom frame 21. As shown in FIG. 9, the image reading apparatus 200 includes an apparatus main body 201 provided with an ADF 9 similar to the ADF 1 and an operation panel 203 for inputting reading start of a document. Since the image reading is not performed, the document pressing cover 102 is not provided unlike the image reading apparatus 100. Accordingly, the document is automatically conveyed by the ADF 9, and the image is read by the scanner unit 11 in the apparatus main body 201 in the conveyance process. The ADF 9 has the same configuration as the ADF 1 and will not be described in detail. It is optional whether the image reading apparatus 200 is used for a copy / facsimile multifunction peripheral or a facsimile alone, and is not shown in the figure. Although not necessary, the apparatus main body 201 includes an image recording unit that records an image on a recording sheet, a transmission unit that transmits the image, and a paper feed cassette that supplies the recording sheet for recording the read image. Etc. can be provided.

  FIG. 10 shows the configuration of the bottom frame 21 when the scanner unit 11 is fixed. As shown in the figure, the scanner unit is arranged so that each fixed piece 20 is positioned at the reading position of the document conveyed by the ADF 9. A screw 36 is inserted into the fixing insertion hole 20 a, and the screw is screwed into the fixing screw hole 35 of the bottom frame 21 to be fixed to the bottom frame 21. In the image reading apparatus 200, since the scanner unit 11 does not need to be scanned, the guide rod 26 and the belt driving mechanism 27 are not provided. Of course, the scanner unit 11 can be fixed with the guide rod 26 and the belt drive mechanism 27 provided, and the sheet-through type image reading apparatus 200 can be used. However, if the guide rod 26 and the belt drive mechanism 27 are omitted, the weight is reduced. This is preferable because it can reduce the cost and cost. A frame cover 37 having an ADF 9 is arranged on the bottom frame 21 configured as described above to form an image reading apparatus 200 as shown in FIG.

  As described above, when the image reading apparatus 100 capable of reading an image by the flat bed method and the image reading device 200 for reading an image only by the sheet through method are used in common, the scanner unit 11 is used as a guide when the scanner unit 11 is provided. It can be moved along the rail 24 and the guide rod 26. When the image reading apparatus 200 is disposed, it can be fixed to the bottom frame 21 and used in accordance with each reading method. Thereby, the versatility of the scanner unit 11 is enhanced, and the cost can be reduced by mass production. Further, the same effect can be obtained by sharing the bottom frame 21 between the image reading apparatus 100 and the image reading apparatus 200.

  Note that the configurations of the ADFs 1 and 9 and the belt driving mechanism 27 shown in the present embodiment are merely examples, and it is needless to say that the design can be changed as appropriate without departing from the gist of the present invention. A so-called contact image sensor (hereinafter referred to as “CIS”) may be used instead of the reading unit of the reduction optical system using the CCD. Of course, the ADF 1 may be omitted as a flatbed type dedicated machine without using the image reading apparatus 100 as a combination of the flatbed type and the sheet through type.

1 is a schematic perspective view showing an appearance of an image reading apparatus 100 according to the present embodiment. 1 is a schematic perspective view showing an external appearance of an image reading apparatus 100 in a state where a document pressing cover 102 is opened. 2 is a cross-sectional view showing an internal structure of the image reading apparatus 100. FIG. 2 is a perspective view illustrating an appearance of a scanner unit 11. FIG. FIG. It is AA sectional drawing of FIG. 2 is a plan view showing an internal configuration of a bottom frame 21 in the image reading apparatus 100. FIG. 2 is a plan view of a bottom frame 21. FIG. 1 is a schematic perspective view showing an external appearance of an image reading apparatus 200. FIG. 3 is a plan view showing an internal configuration of a bottom frame 21 in the image reading apparatus 200. FIG. FIG. 10 is a schematic perspective view showing an appearance of a conventional image reading apparatus 900.

Explanation of symbols

11 Scanner unit 17a Through hole (rod hole)
18 Belt clamp (belt fixing part)
19 Sliding part 20 Fixing piece 20a Fixing insertion hole 21 Bottom frame (frame)
23 Guide rod fixing part 24 Guide rail (guide member)
25R, 25L Belt drive mechanism mounting portion 26 Guide rod (guide member)
27 Belt drive mechanism 30 Belt 35 Fixing screw hole 100, 200 Image reading device

Claims (3)

A scanner unit that irradiates a document with light and reads an image with reflected light is an image reading device housed in a reading table having a bottom frame and a frame cover ,
The scanner unit is provided so as to be movable in a scanning direction and fixed at a predetermined position;
The frame cover is provided with an automatic document transport mechanism for transporting a document from the document tray to the paper discharge tray through the reading position, and the scanner unit is fixed immediately below the reading position in the bottom frame, so that the sheet through A configuration in which a document can be read only by a method, and a configuration in which a platen glass is disposed on the frame cover and the scanner unit is movable so that a document can be read by a flat bed method. An image reading apparatus that is selectable . When a configuration capable of reading a document by a flat bed method is selected, a belt driving mechanism for applying a driving force to the scanner unit and a guide rod for guiding the scanner unit in the scanning direction are provided. The image reading apparatus according to claim 1 , further attached to the inside of the reading mounting table . 3. The bottom frame is shared by a configuration capable of reading a document only by the sheet through method and a configuration capable of reading a document by the flat bed method. Image reading apparatus.

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