JP2008034912A - Image reading apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a means for improving fitting position accuracy of a carriage sensor for sensing passing of a scanning carriage without a cost increase in an image reading apparatus where the carriage sensor is fitted to a main body chassis. <P>SOLUTION: The image reading apparatus 1 is provided with the main body chassis 30 on the upper side of which a platen glass 6 is arranged, the scanning carriages 15, 16 which are stored in the main body chassis 30 and read image information of an original P located on the platen glass 6 while moving along the platen glass 6, and the carriage sensor 29 for sensing the passing of the scanning carriages 15, 16, wherein a sensor fitting part 36 for fitting the carriage sensor 29 is formed integrally with the main body chassis 30. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image reading apparatus comprising a main body chassis having a platen glass disposed on an upper surface thereof, and a scanning carriage provided inside the main body chassis so as to be movable in parallel with the platen glass. The present invention relates to an image reading apparatus in which a carriage detection sensor that detects passage of a scanning carriage is attached to a main body chassis.

  Copiers, facsimiles, scanners, and the like are equipped with an image reading device for reading image information of a document to be copied or a document to be facsimile-transmitted. As a document reading method by this image reading device, there are a flat bed method and a sheet through method. The flatbed method is mainly used when reading a thick book-like document, and is realized by a flatbed scanner (hereinafter referred to as “FBS”). On the other hand, the sheet-through method is mainly used when a plurality of sheet-like documents are read, and is realized by an auto document feeder (hereinafter referred to as “ADF”).

  FIG. 7 is a schematic longitudinal sectional view showing an example of a conventional image reading apparatus capable of reading an image by both a flat bed system and a sheet through system. The image reading apparatus 70 includes an apparatus main body 72 equipped with an FBS 71, and a document pressing plate 74 equipped with an ADF 73 that can be opened and closed with respect to the apparatus main body 72. In the image reading apparatus 70, when the FBS 71 is used, the document P is placed on the platen glass 75 provided on the upper surface of the apparatus main body 72, and the image information of the document P is read by the reading unit 76 provided below the platen glass 75. . On the other hand, when the ADF 73 is used, the originals P stacked on the paper feed tray 77 are sequentially fed into the conveyance path 78 and conveyed downstream, and when passing through the reading position X, the image is read by the reading unit 76 through the slit glass 79. After the information is read, the information is discharged to a discharge tray 80.

  As shown in FIG. 7, the reading unit 76 irradiates the original P with light and guides the reflected light in the return direction, and a half-rate carriage that guides the reflected light from the full rate carriage 81 in the forward direction. 82 and an imaging unit 83 that converts the reflected light from the half-rate carriage 82 into an electrical signal. Here, the full rate carriage 81 and the half rate carriage 82 are movable in parallel to the platen glass 75 by being driven by a stepping motor (not shown).

  In the reading unit 76, when the original P is not read, the full-rate carriage 81 and the half-rate carriage 82 are stopped at the home positions Hf and Hh shown in FIG. 7, respectively, and wait for the start of the next reading operation. is doing. When the ADF 73 is used from this state, the original P conveyed on the conveyance path 78 passes over the slit glass 79 while the full rate carriage 81 and the half rate carriage 82 are stopped at the home positions Hf and Hh, respectively. Meanwhile, the full-rate carriage 81 irradiates the document P with light, and the half-rate carriage 82 guides the reflected light to the image forming unit 83, whereby the entire document P is read. On the other hand, when the FBS 71 is used, the full-rate carriage 81 irradiates the original P on the platen glass 75 while moving in the forward direction, and the half-rate carriage 82 follows the full-rate carriage 81 at a substantially half speed. By guiding the reflected light from the document P to the imaging unit 83, the entire document P is read. Here, in order to return the carriages 81 and 82 moved in the forward direction to the home positions Hf and Hh in preparation for the next reading operation, a carriage for detecting the passage of the carriages 81 and 82 is provided inside the apparatus main body 72. A detection sensor 84 is provided. That is, the carriage detecting sensor 84 detects the carriages 81 and 82 and then stops the stepping motor after sending a predetermined number of steps, thereby accurately stopping the carriages 81 and 82 at the home positions Hf and Hh. (See, for example, Patent Document 1).

  The carriage detection sensor 84 is generally attached to the apparatus main body 72. FIG. 8 is an exploded perspective view showing the configuration of the apparatus main body 72. The members housed inside the apparatus main body 72 are not shown. The apparatus main body 72 is disposed at the bottom of the main body chassis 85, a main body chassis 85 that is a housing with an upper opening, a platen glass 75 and a chassis cover 86 that covers the upper opening of the main body chassis 85. A guide rail 87 for guiding the movement of the carriages 81 and 82 is provided. As shown in FIG. 8, the carriage detection sensor 84 is first attached to a side surface of the main body chassis 85 with a sensor attachment member 88 by screws 89 or the like, and a carriage detection sensor 84 (not shown) is attached to the sensor attachment member 88. Do by attaching.

  By the way, the main body chassis 85 is generally manufactured by resin molding. FIG. 9 is a schematic diagram for explaining a process of resin molding the main body chassis 85. As shown in FIG. 9A, the main body chassis 85 is formed into a casing shape by pouring heated and softened resin between the outer mold 89 and the inner mold 90 arranged at a predetermined interval. Molded. Here, a pair of projecting portions 91 projecting vertically upward are provided on the bottom surface of the outer mold 89. As shown in FIG. 9B, the outer mold 89 and the inner mold 90 are cured after the resin is cured. Is removed, the completed body chassis 85 is formed with a pair of rail attachment holes 92 penetrating the bottom surface thereof. As a result, as shown in FIG. 8, the guide rail 87 can be attached to the main body chassis 85 by being fitted into the rail attachment hole 92.

JP-A-5-328050

  However, in the conventional image reading apparatus 70, since the carriage detection sensor 84 is fixed to the main body chassis 85 via the sensor mounting member 88, there is a problem that the work for assembling the sensor mounting member 88 to the main body chassis 85 is costly. . Further, there is a problem that the mounting position accuracy of the carriage detection sensor 84 is deteriorated due to an assembly error generated when the sensor mounting member 88 is assembled to the main body chassis 85.

  The present invention has been made in view of such a problem. In an image reading apparatus in which a carriage detection sensor for detecting passage of a scanning carriage is attached to a main body chassis, the carriage detection sensor is not increased in cost. Means for improving mounting position accuracy are provided.

  In order to achieve the above object, an image reading apparatus according to claim 1, wherein a platen glass is disposed on an upper surface of the main body chassis and the platen glass is accommodated in the main body chassis while moving along the platen glass. A sensor for attaching the carriage detection sensor to the main body chassis in an image reading apparatus comprising: a scanning carriage for reading image information of a placed document; and a carriage detection sensor for detecting passage of the scanning carriage. The mounting portion is integrally formed.

  The image reading apparatus according to claim 2, wherein the main body chassis is made of resin, and the guide is supported in the bottom direction of the main body chassis directly below the sensor mounting portion and supports the scanning carriage in the moving direction. A rail mounting hole for mounting the rail is formed through.

  According to the image reading apparatus of the present invention, since the sensor mounting portion for mounting the carriage detection sensor is integrally formed with the main body chassis, the number of parts is reduced compared to the case where the sensor mounting portion is a separate member from the main body chassis. Therefore, cost reduction and parts management can be facilitated. Further, since there is no error in assembling the main body chassis in the sensor mounting portion, it is possible to improve the mounting position accuracy of the carriage detection sensor.

  Further, according to the image reading apparatus of the present invention, the mold for resin molding the main body chassis is only a slight change to the conventional mold used when molding the main body chassis without the sensor mounting portion. Can be produced. Accordingly, since it is not necessary to newly manufacture a mold having a complicated configuration, it is possible to easily improve the mounting position accuracy of the carriage detection sensor without increasing the cost.

  Hereinafter, a configuration of an image reading apparatus according to an embodiment of the present invention will be described with reference to the drawings. The image reading apparatus is capable of reading an image by both a flat bed system and a sheet through system, and FIG. 1 is a schematic longitudinal sectional view showing an internal configuration thereof. The image reading apparatus 1 includes an apparatus main body 3 equipped with an FBS 2 and a document pressing plate 5 provided so as to be openable and closable with respect to the apparatus main body 3 and equipped with an ADF 4. In the image reading apparatus 1, when the FBS 2 is used, the original P is placed on the platen glass 6 provided on the upper surface of the apparatus main body 3, and the image information of the original P is received by the first reading unit 7 provided below the original P. Read. On the other hand, when the ADF 4 is used, the originals P stacked on the paper feed tray 8 are fed one by one from the uppermost paper by the paper feed unit 9 and supplied to the transport path 10. The document P is conveyed downstream by a conveyance roller 11 appropriately disposed in the conveyance path 10, and is read by the first reading unit 7 when the image information on the first surface passes through the reading position X. The image information is read by the second reading unit 12 and then discharged to the paper discharge tray 14 by the paper discharge roller 13.

  The first reading unit 7 is a moving image reading unit called a so-called CCD (Charge Coupled Device) image sensor. As shown in FIG. 1, the first reading unit 7 irradiates the original P with light and guides the reflected light in the return direction, and forwards the reflected light from the full-rate carriage 15. A half-rate carriage 16 (scanning carriage) that guides in the direction, an imaging unit 17 that converts reflected light from the half-rate carriage 16 into an electrical signal, and a first belt that moves the full-rate carriage 15 in parallel with the platen glass 6. A drive mechanism 18 and a second belt drive mechanism 19 that moves the half-rate carriage 16 in parallel with the platen glass 6 are provided. The first belt driving mechanism 18 and the second belt driving mechanism 19 are driven by a stepping motor (not shown). In this embodiment, two scanning carriages, a full-rate carriage 15 and a half-rate carriage 16, are provided separately. However, it is also possible to configure as one scanning carriage having these functions. It is also possible to accommodate the imaging unit 17 in the scanning carriage.

  FIG. 2 is a schematic perspective view showing an end portion of the full-rate carriage 15 on the front side of the apparatus. In FIG. 2, the illustration of the light source and the reflecting mirror is omitted for convenience of explanation. As shown in the drawing, the carriage main body 20 constituting the full-rate carriage 15 is supported at both ends by sliders 21 from below, and a clamp member 22 is fixed to the front end of the apparatus with screws 23. The clamp member 22 includes a fixing portion 24 for fixing to the carriage main body 20, and a clamp portion 26 for holding the first belt 25 constituting the first belt driving mechanism 18 between the carriage main body 20 and the clamp member 26. And a filler portion 27 used for detecting the position of the full-rate carriage 15. Here, the filler portion 27 is a flat plate erected upward from the fixed portion 24, and the thickness direction thereof is provided so as to be substantially orthogonal to the moving direction of the full rate carriage 15. Although the full-rate carriage 15 has been described as an example here, similarly to this, a filler portion 27 (not shown) used for detecting the position of the half-rate carriage 16 is also provided at the end of the half-rate carriage 16 on the front side of the apparatus. ing.

  The operation of the first reading unit 7 during non-document reading, when using the ADF 4, and when using the FBS 2 is the same as the reading unit 76 of the conventional image reading apparatus 70. That is, as shown in FIG. 1, at the time of non-document reading, the full rate carriage 15 stands by at the home position Hf and the half rate carriage 16 stands by at the home position Hf. When the ADF 4 is used, the scanning carriages 15 and 16 read the image information of the document P passing over the slit glass 28 while stopping at the home positions Hf and Hh. On the other hand, when the FBS 2 is used, the scanning carriages 15 and 16 read the image information of the document P on the platen glass 6 while moving in the forward direction. In the same manner as the conventional image reading apparatus 70, the image reading apparatus 1 also returns the scanning carriages 15 and 16 moved in the forward direction when the FBS 2 is used to return to the home positions Hf and Hh for the next reading operation. A carriage detection sensor 29 for detecting the passage of each scanning carriage 15, 16 is provided, and this carriage detection sensor 29 is attached to the apparatus main body 3.

  FIG. 3 is an exploded perspective view showing the configuration of the apparatus main body 3. In addition, illustration is abbreviate | omitted about each member accommodated in the inside of the apparatus main body 3. FIG. The apparatus main body 3 is disposed at the bottom of the main body chassis 30, a main body chassis 30 that is a housing with an upper opening, a platen glass 6 and a chassis cover 31 that covers the upper opening of the main body chassis 30. And a guide rail 32 for guiding the movement of the scanning carriages 15 and 16.

  The main body chassis 30 is formed by molding resin or the like, and as shown in FIG. 3, an operation panel unit 33 for inputting various operation instructions is provided on the front side of the apparatus. A sensor mounting wall 35 is erected at a position adjacent to the operation panel portion 33 in the main body chassis 30 slightly inside the side wall 34 on the front side of the apparatus so as to be parallel to the side wall 34. A sensor mounting portion 36 for mounting the carriage detection sensor 29 is provided so as to protrude inward from the mounting wall 35. In addition, a pair of rail mounting holes 38 having a shape that fits into the guide rail 32 are formed through the bottom surface 37 of the main body chassis 30 so as to be parallel to each other. Also, a pair of hinge insertion holes 39 is formed on the rear side of the main body chassis 30, and a base end portion of a hinge member (not shown) that supports the document pressing plate 5 is a hinge insertion hole 40 formed in the chassis cover 31. The document pressing plate 5 is supported on the apparatus body 3 so as to be openable and closable by being inserted into the hinge insertion hole 39.

  FIG. 4 is a schematic perspective view of the sensor mounting portion 36 as viewed from the inside of the apparatus main body 3. The sensor mounting portion 36 is formed integrally with the sensor mounting wall 35 of the main body chassis 30, and includes a protruding portion 41 that protrudes toward the inside of the apparatus at an angle of approximately 90 ° with the sensor mounting wall 35, and this protruding portion. It is comprised from the reinforcement part 42 which reinforces the part 41 structurally. The protrusion 41 has a substantially H-shaped vertical cross section, and a pair of sensor engagement holes 43 for engaging the carriage detection sensor 29 are formed through the intermediate portion in the longitudinal direction. As shown in FIG. 4, the protruding portion 41 is provided so as to be positioned vertically above a rail mounting hole 38 formed through the bottom surface 37 of the main body chassis 30. On the other hand, the reinforcing portion 42 is provided on each of the left and right side portions and the bottom portion of the protruding portion 41, and the protruding portion 41 is connected to the sensor mounting wall 35 by connecting the longitudinal intermediate portion of the protruding portion 41 and the sensor mounting wall 35. This prevents the connecting part from being damaged. Further, a substantially cylindrical positioning concave portion 44 and a substantially columnar positioning convex portion 45 are formed between the sensor mounting wall 35 and the side wall 34 on the front side of the apparatus. These correspond to positioning protrusions and positioning recesses (not shown) formed on the chassis cover 31 shown in FIG. 3. The positioning protrusions of the chassis cover 31 are placed in the positioning recesses 44 of the main body chassis 30. The chassis cover 31 can be positioned with respect to the main body chassis 30 by inserting the positioning protrusions 45 into the positioning recesses of the chassis cover 31.

  As described above, the sensor mounting portion 36 for mounting the carriage detection sensor 29 is integrally formed with the main body chassis 30, so that the number of parts can be reduced as compared with the case where the sensor mounting portion 36 is a separate member from the main body chassis 30, Cost reduction and parts management can be facilitated. Furthermore, since no error in assembling to the main body chassis 30 occurs in the sensor mounting portion 36, the mounting position accuracy of the carriage detection sensor 29 can be improved.

  The projecting portion 41 constituting the sensor mounting portion 36 only needs to protrude from the sensor mounting wall 35 toward the inside of the apparatus and can be engaged with the carriage detection sensor 29, and the shape thereof is not limited to the present embodiment and is appropriately designed. It can be changed. In addition, the reinforcing portion 42 is not an essential component of the present invention, and the sensor mounting portion 36 can be configured with only the protruding portion 41.

  By the way, in the present embodiment, as described above, the main body chassis 30 in which the sensor mounting portion 36 is integrally formed is produced by resin molding. FIG. 5 is a schematic view for explaining a process of resin molding the main body chassis 30. As shown in FIG. 5A, the main body chassis 30 is heated between an outer mold 46 and an inner mold 47 arranged at a predetermined interval, like the main chassis 85 according to the conventional example. It is molded into a casing shape by pouring softened resin. Further, in order to form a pair of rail mounting holes 38 through the bottom surface 37 of the main body chassis 30, a pair of protruding portions 41 are provided so as to protrude vertically upward from the bottom surface 37 of the outer mold 46. This is the same as the main body chassis 30. However, the main body chassis 30 according to the present invention needs to integrally mold the sensor mounting portion 36 on the front side of the apparatus. Accordingly, as shown in FIG. 5A, the outer mold 46 has one of the pair of projecting portions 41 that has a smaller height than the other projecting portion 41 depending on the projecting position of the sensor mounting portion 36. Is formed. Further, the upper side of the inner mold 47 is shaped to match the shape of the sensor mounting portion 36. As a result, as shown in FIG. 5B, when the outer mold 46 and the inner mold 47 are removed after the resin is cured, a sensor mounting portion 36 is formed on the front surface side of the completed main body chassis 30.

  Thus, in the present invention, since the sensor mounting portion 36 is formed at a position immediately above the rail mounting hole 38, the sensor can be obtained by making a slight change to the configuration of the outer mold 46 and the inner mold 47 according to the conventional example. The attachment portion 36 can be integrally formed with the main body chassis 30. If there is no rail mounting hole 38 at a position directly below the sensor mounting portion 36, the protrusion 41 is not formed on the outer mold 48 as shown in FIG. In order to form, the 1st inner side metal mold | die 49 and the 2nd inner side metal mold | die 50 are needed as an inner side metal mold | die. Thereby, there exists a problem that a metal mold | die structure becomes complicated and costs increase. Further, after the resin is cured, as shown in FIG. 6B, when the outer mold 48 is pulled downward, the first inner mold 49 is pulled upward, and then the second inner mold 50 is pulled laterally. As shown in FIG. 6C, the main body chassis 30 in which the sensor mounting portion 51 is integrally molded is completed. In this case, however, as shown in FIG. 6, the upper and lower surfaces of the second inner mold 50 are formed with a drop gradient 52 for smooth removal in the lateral direction. Therefore, the bottom surface 37 of the main body chassis 30 cannot be horizontally molded due to the influence of the draft 52. On the other hand, the main body chassis 30 of the present invention has an advantage that the mold configuration is not complicated. In addition, the inner mold 47 is pulled upward, and it is not necessary to form a drop gradient on the lower surface of the inner mold 47. Therefore, there is an advantage that the bottom surface 37 of the main body chassis 30 can be molded horizontally. In FIG. 6, for convenience of explanation, only the slipping gradient of the second inner mold 50 is exaggerated.

  The carriage detection sensor 29 shown in FIG. 4 is a so-called transmission-type optical sensor in which a light emitting element 52 and a light receiving element 53 are arranged opposite to each other with a concave groove 51 interposed therebetween. A pair of snap fits 54 is provided. The carriage detection sensor 29 is attached to the sensor attachment portion 36 by engaging each snap fit 54 with the sensor engagement hole 43 of the protrusion 41. As a result, the carriage detection sensor 29 is arranged with the opening of the concave groove 51 facing downward, and the filler portion 27 provided at the end of the scanning carriage on the front side of the apparatus passes through the inside of the concave groove 51. It is like that. The passage / non-passage of each scanning carriage can be detected based on whether or not the light emitted from the light emitting element 52 is received by the light receiving element 53. Although not shown in detail in FIG. 4, the electrical wiring from the carriage detection sensor 29 is drawn out from the sensor engagement hole 43 to the upper surface side of the protrusion 41 and is formed between the sensor mounting wall 35 and the side wall 34. After being drawn into the gap, it is connected to a substrate or the like (not shown). Thus, the electrical wiring from the carriage detection sensor 29 does not get in the way inside the apparatus main body 3.

  The guide rail 32 shown in FIG. 3 is formed by bending a metal plate, and includes a pair of left and right carriage support portions 55 that support the scanning carriages 15 and 16 from below, and each carriage support portion 55. And a connecting plate portion 56 for connecting the bottoms of each other. As shown in FIG. 3, the guide rail 32 has the carriage support portions 55 inserted through the rail mounting holes 38 of the main body chassis 30 from below the main body chassis 30, and the connection plate portions 56 are connected to the bottom surface of the main body chassis 30. By being brought into contact with 37 and being fixed, it is attached to the bottom of the main body chassis 30. As a result, as shown in FIG. 4, the carriage support portion 55 of the guide rail 32 protrudes from the rail mounting hole 38 inside the apparatus main body 3.

  The second reading unit 12 shown in FIG. 1 is a fixed image reading unit called a so-called CIS (Contact Image Sensor). In the present embodiment, the second reading unit 12 is provided to configure the image reading apparatus 1 as a so-called double-sided reader. However, the second reading unit 12 is not provided, and the image reading apparatus 1 is configured as a so-called single-sided reader. It is also possible to configure as.

  The present invention can be applied to an image reading apparatus in which a carriage detection sensor for detecting passage of a scanning carriage is attached to a main body chassis constituting the apparatus main body.

1 is a schematic longitudinal sectional view showing a configuration of an image reading apparatus 1 according to an embodiment of the present invention. FIG. 2 is a schematic perspective view showing an end portion of the full-rate carriage 15 on the front side of the apparatus. FIG. 3 is an exploded perspective view showing the configuration of the apparatus body 3. FIG. 3 is a schematic perspective view of the sensor mounting portion 36 as viewed from the inside of the apparatus main body 3. The schematic diagram for demonstrating the process of resin-molding the main body chassis. The schematic diagram for demonstrating the process of resin-molding the main body chassis. FIG. 3 is a schematic longitudinal sectional view showing a configuration of an image reading apparatus 1 according to a conventional example. FIG. 3 is an exploded perspective view showing the configuration of the apparatus body 3. The schematic diagram for demonstrating the process of resin-molding the main body chassis 85. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image reader 6 Platen glass 15 Full-rate carriage 16 Half-rate carriage 29 Carriage detection sensor 30 Main body chassis 36 Sensor attachment part P Original

Claims (2)

A main body chassis having a platen glass disposed on the upper surface, a scanning carriage that reads image information of a document placed on the platen glass while being moved along the platen glass accommodated in the main body chassis, and the scanning carriage An image reading apparatus comprising a carriage detection sensor for detecting the passage of
An image reading apparatus, wherein a sensor mounting portion for mounting the carriage detection sensor is integrally formed on the main body chassis.   The main body chassis is made of resin, and a rail mounting hole for mounting a guide rail that supports the scanning carriage and guides it in the moving direction passes through a position directly below the sensor mounting portion on the bottom surface of the main body chassis. The image reading apparatus according to claim 1, wherein the image reading apparatus is formed.

Images