JP2007086356A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress a manufacturing cost by reducing the component cost of a member for holding a scanning unit and reducing the number of processes required for the assemblage, consequently, to attain an image forming apparatus at a low cost, regarding the image forming apparatus equipped with an image reading function. <P>SOLUTION: Regarding the resin member 4, a shaft bearing 4a which is slidably fitted on a guide shaft arranged in a housing so that the sub scanning direction may be a longitudinal direction and a sheet-like bracket 4b extending from a part where the shaft bearing 4a is arranged toward both ends in a main scanning direction are molded into one body. The scanning unit 3 is held by the bracket 4b of the resin member 4 in such a state that the supporting projection 3d of the scanning unit 3 is fitted to the holding part 4c of the resin member 4 while press-inserting a spring 6 into the spring attachment part 4e of the resin member 4. Since the shaft bearing 4a and the bracket 4b are molded into one body, the component cost of the member for holding the scanning unit 3 is reduced, and the number of processes required for the assemblage is reduced. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus having an image reading function.

  Conventionally, an image forming apparatus having a function of reading a document as image data using an image reading apparatus has been put into practical use. As an image forming apparatus having such an image reading function, for example, a scanning unit such as a CIS (Contact Image Sensor) equipped with an imaging means for imaging a predetermined range in the main scanning direction is moved in the sub scanning direction. In some cases, a document placed on a document table is read as image data (see, for example, Patent Documents 1 to 3). In general, such a scan unit is held by a support member and is in close contact with the document table, and a driving force is applied to the support member by a driving unit, so that the scan unit is arranged along the sub-scanning direction. It is moved along the guide shaft.

  FIG. 5 shows an example of a scan unit and a support member used in the conventional image forming apparatus as described above. Arrows A and B in the figure indicate the main scanning direction and the sub-scanning direction, respectively. The scan unit 83 is arranged in the housing of the image forming apparatus so that the main scanning direction is the longitudinal direction so as to face a document table (not shown). The scan unit 83 includes an illuminating unit 83b that illuminates a predetermined range of a document placed on the document table in the main scanning direction, and an imaging unit 83c that captures an image of the part illuminated by the document illuminating unit 83b. Yes. As shown in the drawing, support protrusions 83d are provided on the side portions of both ends of the scan unit 83 in the main scanning direction. Further, spacers 83e that are in contact with the document table are provided at both ends of the upper surface of the scan unit 83 in the main scanning direction.

  The support member that holds the scan unit 83 includes a resin-made shaft bearing 841 having a bearing portion 841a that is slidably engaged with a guide shaft (not shown) disposed in a housing of the image forming apparatus, and a main scanning direction. The bracket 842 is arranged in the longitudinal direction, and a screw 843 that couples the bracket 842 and the shaft bearing 841 to each other. Since the bracket 842 needs to have a rigidity that is difficult to bend when the scan unit 83 is held as will be described later, the bracket 842 is formed of a metal plate, and is attached to the shaft bearing 841 at a substantially central portion in the main scanning direction. It is connected. At both ends of the bracket 842 in the main scanning direction, holding portions 842c for holding the support protrusions 83d of the scan unit 83 are arranged. A spring mounting portion 842e into which the spring 86 is press-fitted is formed on the upper surface of the bracket 842.

  The scan unit 83 is held by the bracket 842 by attaching the support protrusion 83d to the holding portion 842c of the bracket 842 in a state where the two springs 86 are attached to the spring attachment portion 842e. In the housing of the image forming apparatus, a bearing portion 841a is slidably engaged with the guide shaft, and a spacer 83e of the scan unit 83 is disposed in contact with the inner surface of the document table. At this time, the spring 86 is in a compressed state, and the scan unit 83 is urged so that the spacer 83e is surely brought into contact with the document table.

  However, in this image forming apparatus, the member for holding the scan unit 83 is composed of the shaft bearing 841, the bracket 842, and the screw 843, which increases the number of parts and increases the part cost. There's a problem. In addition, in the assembly process, when the shaft bearing 841 and the bracket 842 are connected, the positional relationship is important, so it is necessary to use a jig, and a lot of man-hours are required for assembly. There is a problem of becoming high.

Note that in the image reading apparatus described in Patent Document 1, the scan unit 83 is fixed to the shaft with high accuracy by providing the above-described scan unit 83 with positioning means that engages with the guide shaft. It is what I did. In the image reading apparatus described in Patent Document 2, even if the scan unit 83 is warped by heat, the mounting portion of the scan unit 83 is not deformed. The image reading apparatus described in Patent Document 3 is configured such that the document table is shaped to match the warp of the scan unit 83 so that no out-of-focus occurs when the scan unit 83 reads the document. However, these Patent Documents 1 to 3 do not disclose effective solutions for the above-described problems.
Japanese Patent Laying-Open No. 2005-3778 JP 2003-87504 A JP 2000-138803 A

  The present invention has been made in view of the above problems, and by reducing the number of parts constituting the member that holds the scan unit, the parts cost is low, the number of man-hours required for assembly is reduced, and the manufacturing cost is suppressed. An object of the present invention is to provide an inexpensive image forming apparatus.

  In order to achieve the above object, the invention of claim 1 includes a casing having a rectangular opening formed on an upper surface thereof, a flat platen that is formed of a light-transmitting material and is attached to the opening of the casing, and Inside the housing, the upper surface is arranged to contact the inner surface of the document table so that the main scanning direction is the longitudinal direction, and the main scanning direction of the document table and the sub-scanning direction orthogonal to the main scanning direction An illuminating unit that illuminates a predetermined range of the image sensor, and an imaging unit that captures an image of the predetermined range illuminated by the illuminating unit, and is placed on the document table by being moved in the sub-scanning direction. A scanning unit that reads a document as image data; a guide shaft disposed in the casing so that a sub-scanning direction is a longitudinal direction; and a shaft bearing slidably engaged with the guide shaft; The main scanning direction is the longitudinal direction. Arranged to be in a compressed state between a bracket for holding the scan unit from below and an upper surface of the bracket and a lower surface of the scan unit. A spring that urges the scan unit so that the upper surface of the scan unit contacts the inner surface of the document table, a driving unit that applies a driving force to the shaft bearing and moves the scan unit in the sub-scanning direction, In the image forming apparatus comprising image forming means for forming an image on recording paper based on image data read by a scan unit or image data input from the outside, both the shaft bearing and the bracket are one A part that is integrally molded with the resin member and that corresponds to the bracket of the resin member It is one in which the reinforcing ribs are formed as rigid resin member increases.

  The invention of claim 2 includes a housing having a rectangular opening formed on the upper surface, a flat platen that is formed of a light-transmitting material and is attached to the opening of the housing, and an interior of the housing. The upper surface of the platen is in contact with the inner surface of the document table so that the main scanning direction is the longitudinal direction, and illuminates a predetermined range in the main scanning direction of the document table and the sub-scanning direction orthogonal to the main scanning direction. And an imaging unit that captures an image of a predetermined range illuminated by the illumination unit, and reads the document placed on the document table as image data by being moved in the sub-scanning direction. A scan unit, a guide shaft disposed in the casing so that the sub-scanning direction is a longitudinal direction, a shaft bearing slidably engaged with the guide shaft, and a shaft bearing connected to the shaft bearing And said A bracket for holding the can unit from below, and a compressed state between the upper surface of the bracket and the lower surface of the scan unit, and the upper surface of the scan unit abuts against the inner surface of the document table An image on the recording paper based on a spring for urging the scan unit, a driving means for moving the scan unit in the sub-scanning direction, and image data read by the scan unit or image data input from the outside. In the image forming apparatus comprising the image forming means for forming the shaft, the shaft bearing and the bracket are both integrally formed of resin.

  According to the first aspect of the present invention, since the shaft bearing and the bracket are both integrally formed in one resin member, the number of parts is reduced and the part cost is reduced. Further, since there is no need for an assembly operation such as using a jig to couple the shaft bearing and the bracket, man-hours required for the assembly are reduced, and the manufacturing cost can be suppressed. Therefore, the image forming apparatus can be made inexpensive. Furthermore, since the reinforcing rib is formed in the part corresponding to the bracket of the resin member, the rigidity of this part can be efficiently ensured. Therefore, it is possible to form a robust bracket that can securely hold the scan unit, and to move the scan unit more stably when reading an image.

  According to the invention of claim 2, since both the shaft bearing and the bracket are integrally molded into one resin member, it is possible to suppress the component cost and the manufacturing cost as described above, and the image forming apparatus can be reduced. It becomes possible to make it cheap.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an image forming apparatus according to this embodiment. The image forming apparatus 1 is a so-called printer complex machine. For example, the image forming apparatus 1 includes an image reading unit 10 having an image reading function at the upper part of the housing 100 and an image forming part (image forming unit) 20 having an image forming function at the lower part. I have. As shown in the figure, on the upper part of the image reading unit 10 of the housing 100, a lid 110 to which a pad 111 for bringing a document (not shown) placed on the document table 2 into close contact with the document table 2 is attached is a hinge. Is provided so as to be rotatable. In addition, a paper feed tray 120 on which the recording paper P is loaded is provided at the rear upper part of the housing 100, and an image is formed on the front surface of the housing 100 by the image forming unit 20 as described later. A paper discharge tray 130 for discharging the recording paper P is provided.

  As will be described later, the image reading function of the image reading unit 10 is such that the scan unit 3 arranged in the casing 100 so that the main scanning direction (arrow A in the figure) is the longitudinal direction is orthogonal to the main scanning direction. By moving in the sub-scanning direction (arrow B in the figure), the document placed on the document table 2 is read as image data. The image forming unit 20 includes a recording paper transport unit (not shown) that transports the recording paper P loaded in the paper feed tray 120 into the housing 100 and discharges it to the paper discharge tray 130. The image forming function of the image forming unit 20 is, for example, an ink jet on the recording paper P conveyed inside the housing 100 based on image data read by the image reading unit 10 or image data input from the outside. An image is formed by a method. Note that the image forming unit 20 may form an image by an electrophotographic method such as a laser beam printer, and is not limited to a specific method.

  Inside the housing 100, for example, an ASIC or a memory is provided, and a control circuit 30 that controls operations of the image reading unit 10 and the image forming unit 20 is provided. An operation panel unit 31 having an operation button (not shown) that can be operated from the outside, a display unit (not shown) having a function of displaying the state of the image forming apparatus 1 and the like, for example, is provided on the top of the housing 100. Is provided. The image forming apparatus 1 is configured such that the image reading unit 10 and the image forming unit 20 are controlled by the control circuit 30 based on, for example, the operation of an operation button by a user. Note that the position and configuration of the operation panel unit 31, the positions of the paper feed tray 120, the paper discharge tray 130, and the like are not limited thereto.

  FIG. 2 shows the image reading unit 10. The arrows A and B in the figure indicate the main scanning direction and the sub-scanning direction of the image reading unit 10, respectively, similarly to the arrows A and B shown in FIG. A rectangular opening 100 a is formed on the upper surface of the upper portion of the housing 100 of the image reading unit 10. In the opening 100a of the housing 100, a flat platen platen 2 made of a translucent material such as glass is mounted. Inside the housing 100, the scan unit 3, the resin member 4 that holds the scan unit 3, and a substantially center in the main scanning direction of the housing 100 so that the sub-scanning direction is the longitudinal direction are arranged, for example, circular A guide shaft 5 that has a cross section and engages with the resin member 4, two coil-like springs 6 disposed between the resin member 4 and the scan unit 3, and the scan unit 3 in the sub-scanning direction. A drive mechanism (drive means) 7 for moving is housed. In the present embodiment, the drive mechanism 7 includes a belt 7a that is rotatably disposed along the guide shaft 5, and a motor 7b that rotates the belt 7a via a pulley or the like. In addition, the drive mechanism 7 may use a linear motor or other structures, for example. Further, the number of springs 6 is not limited to two, and may be one or three or more, and may be another type of spring such as a leaf spring.

  FIG. 3 shows the scan unit 3 and the resin member 4. The arrows A and B in the figure indicate the main scanning direction and the sub-scanning direction of the image reading unit 10, respectively, similarly to the arrows A and B shown in FIGS. The scan unit 3 is a so-called CIS (Contact Image Sensor), and is arranged such that the main scanning direction is the longitudinal direction. The scan unit 3 is connected to the control circuit 30 via a flat cable 3a. The scan unit 3 is connected to a linear light source (illuminating means) 3b provided along the main scanning direction and a linear light source 3b. An imaging device (imaging means) 3c provided in parallel is provided. Further, support protrusions 3d are provided in the main scanning direction at both ends of the scanning unit 3 in the main scanning direction. At both ends of the upper surface of the scan unit 3 in the main scanning direction, spacers 3e are provided so as to rise from the upper surface of the scan unit 3 by a predetermined height (for example, about 0.1 mm). The spacer 3 e is in contact with the inner surface of the document table 2 in a state where the scan unit 3 is arranged inside the housing 100. That is, the scan unit 3 is configured such that the distance from the document table 2 is always kept constant by the spacer 3e coming into contact with the inner surface of the document table 2. The spacer 3e is formed of a resin or the like made of a material that reduces frictional resistance and hardly wears down when the scan unit 3 is moved in contact with the document table 2 as will be described later. The spacer 3e is formed as a separate body from the housing of the scan unit 3, and may be assembled by being fitted into the housing, or formed integrally with the housing of the scan unit 3. It may be a thing.

  The linear light source 3b of the scan unit 3 is, for example, a plurality of LEDs arranged in the main scanning direction, and has a uniform brightness in the entire area in the main scanning direction of the document table 2 with a predetermined width in the sub scanning direction. Now illuminate. The imaging device 3c includes a lens array in which micro lenses are arranged in the main scanning direction, and a light receiving element array in which light receiving elements are arranged in the main scanning direction corresponding to each lens. Each lens is focused on the outer surface of the document table 2, and among the documents placed so as to be in close contact with the outer surface of the document table 2, each lens receives an image in a predetermined range illuminated by the linear light source 3b. An image is formed on the light receiving surface of the element, and an image in a predetermined range is picked up by each light receiving element. The scan unit 3 is driven by the drive mechanism 7 to capture an image of the document on the document table 2 while moving in the sub-scanning direction, and transmits the captured image data to the control circuit 30 via the flat cable 3a. Is.

  4A, 4 </ b> B, and 4 </ b> C show the resin member 4. The resin member 4 extends to both sides in the main scanning direction from a groove-shaped shaft bearing 4a that is slidably fitted to the guide shaft 5 and a portion where the shaft bearing 4a is provided. The provided plate-like bracket 4b is integrally molded. As will be described later, the resin member 4 is a composite with increased rigidity, such as POM mixed with glass fiber, so that the resin member 4 is not easily deformed even when a force causing warping in the main scanning direction is applied. Although it is molded of plastic, it is not limited to this.

  As shown in the figure, holding portions 4c are provided at both ends of the bracket 4b in the main scanning direction so as to hold the support protrusions 3d of the scan unit 3. One holding portion 4c is formed, for example, in a hole shape in the main scanning direction, and the other holding portion 4c is formed, for example, in a groove shape opened upward. Further, for example, lattice-shaped reinforcing ribs 4d are provided on the upper surface of the bracket 4b so that the rigidity of the resin member 4 is increased. As shown in the figure, spring attachment portions 4e to which the springs 6 are fitted are provided in the vicinity of both ends in the main scanning direction on the upper surface of the bracket 4b. Further, a belt attachment portion 4f to which the belt 7a of the drive mechanism 7 is attached is formed near the shaft bearing 4a on the lower surface.

  As shown in FIG. 3, in the scan unit 3, one support protrusion 3 d is inserted into the hole-shaped holding portion 4 c in a state where the spring 6 is fitted to the spring mounting portion 4 e of the resin member 4, and the other support is supported. The protrusion 3d is held in the bracket 4b of the resin member 4 by being fitted into the groove-like holding portion 4c. In the scan unit 3 and the resin member 4, the shaft bearing 4a is lubricated by, for example, grease and slidably engaged with the guide shaft 5, and the belt 7a of the drive mechanism 7 is attached to the belt mounting portion 4f. It is housed inside the housing 100 in the attached state. At this time, as described above, the spacer 3e of the scan unit 3 is in contact with the document table 2, and the spring 6 is compressed between the bracket 4b of the resin member 4 and the lower surface of the scan unit 3. It has become. That is, the scan unit 3 is urged by the spring 6 so that the spacer 3 e on the upper surface contacts the inner surface of the document table 2.

  In the scan unit 3, the belt 7 a is driven by the motor 7 b of the drive mechanism 7, and a driving force is applied to the belt mounting portion 4 f in the vicinity of the shaft bearing 4 a of the resin member 4. It is moved in the sub-scanning direction. At this time, the scan unit 3 is moved while keeping a predetermined distance from the document table 2 while being biased toward the document table 2 by the spring 6, and the imaging device 3c images the upper surface of the document table 2 with high image quality. As a result, the document placed on the document table 2 is read as image data.

  Thus, in this embodiment, since both the shaft bearing 4a and the bracket 4b are integrally molded as one resin member 4, the number of parts is smaller than the conventional one as shown in FIG. , Parts cost is lower. Further, since there is no need for an assembling operation for joining the shaft bearing 4a and the bracket 4b by using a jig or the like, man-hours necessary for assembling are reduced, and the manufacturing cost can be suppressed. Therefore, the image forming apparatus 1 can be made inexpensive.

  As described above, when the scan unit 3 is biased by the spring 6, the bracket 4b is bent downward on the resin member 4 with the shaft bearing 4a engaged with the guide shaft 5 as a fulcrum. A downward force is applied to the spring mounting portion 4e. In order to ensure that the scan unit 3 is urged to the document table 2 and to read an image with high accuracy, the resin member 4 is made to prevent the bracket 4b from warping at this time. It must be configured to be highly rigid. In the present embodiment, since the reinforcing rib 4d is formed on the upper surface of the bracket 4b, the thickness of the portion where the reinforcing rib 4d is not provided is reduced compared to the case where the reinforcing rib 4d is not formed. Also, the bracket 4b can be made to have high rigidity. That is, by providing the reinforcing rib 4d, it is possible to efficiently secure the rigidity of the bracket 4b and to form a robust resin member 4 that can securely hold the scan unit 3 and to reduce the image. When reading, the scan unit 3 can be moved more stably.

  In addition, this invention is not limited to the structure of the said embodiment, A various deformation | transformation is possible suitably in the range which does not change the meaning of invention. For example, the scan unit 3 may not have the support protrusion 3d, and the method for the resin member 4 to hold the scan unit 3 is not limited to the above. Further, the shape of the reinforcing rib 4d may not be a lattice shape, but may be another shape, or may protrude downward from the lower surface of the bracket 4b. Further, the resin member 4 may be one in which the reinforcing rib 4d is not provided on the bracket 4b, or may be one in which rigidity is ensured by forming the bracket 4b thick. That is, by integrally molding the shaft bearing 4a and the bracket 4b into one resin member, it is possible to reduce the component cost and the manufacturing cost as described above, and to make the image forming apparatus 1 inexpensive. It becomes possible.

1 is a perspective view showing an image forming apparatus according to an embodiment of the present invention. The disassembled perspective view which shows the structure of the image reading part of an apparatus same as the above. The perspective view explaining the structure of the scan unit and resin member of an apparatus same as the above. (A) is a top view of the resin member of the same apparatus, (b) is a side view of (a), (c) is a bottom view of (a). The perspective view explaining the structure of the scanning unit of the conventional image forming apparatus, and its supporting member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Document stand 3 Scan unit 3b Linear light source (illumination means)
3c Imaging device (imaging means)
4 Resin member 4a Shaft bearing 4b Bracket 4d Reinforcement rib 5 Guide shaft 6 Spring 7 Drive mechanism (drive mechanism)
20 Image forming unit (image forming means)
100 Housing 100a Opening A Main scanning direction B Sub scanning direction

Claims (2)

A housing having a rectangular opening formed on the upper surface;
A flat platen that is formed of a translucent material and is attached to the opening of the housing;
Inside the housing, the upper surface is arranged so as to contact the inner surface of the document table so that the main scanning direction is the longitudinal direction, and the sub-scanning is perpendicular to the main scanning direction and the main scanning direction of the document table. An illumination unit that illuminates a predetermined range of directions, and an imaging unit that captures an image of a predetermined range illuminated by the illumination unit, and is placed on the document table by being moved in the sub-scanning direction. A scanning unit that reads the scanned original as image data,
Inside the housing, a guide shaft arranged so that the sub-scanning direction is the longitudinal direction,
A shaft bearing slidably engaged with the guide shaft;
A bracket that is arranged so that a main scanning direction is a longitudinal direction, is connected to the shaft bearing, and holds the scan unit from below;
A spring that is arranged so as to be compressed between the upper surface of the bracket and the lower surface of the scan unit, and biases the scan unit so that the upper surface of the scan unit contacts the inner surface of the document table;
Driving means for applying a driving force to the shaft bearing and moving the scan unit in a sub-scanning direction;
In an image forming apparatus provided with image forming means for forming an image on recording paper based on image data read by the scan unit or image data input from the outside,
The shaft bearing and the bracket are both integrally molded into one resin member,
An image forming apparatus, wherein a reinforcing rib is formed at a portion corresponding to the bracket of the resin member so as to increase the rigidity of the resin member. A housing having a rectangular opening formed on the upper surface;
A flat platen that is formed of a translucent material and is attached to the opening of the housing;
Inside the housing, the upper surface is arranged so as to contact the inner surface of the document table so that the main scanning direction is the longitudinal direction, and the sub-scanning is perpendicular to the main scanning direction and the main scanning direction of the document table. An illumination unit that illuminates a predetermined range of directions, and an imaging unit that captures an image of a predetermined range illuminated by the illumination unit, and is placed on the document table by being moved in the sub-scanning direction. A scanning unit that reads the scanned original as image data,
Inside the housing, a guide shaft arranged so that the sub-scanning direction is the longitudinal direction,
A shaft bearing slidably engaged with the guide shaft;
A bracket connected to the shaft bearing, and holding the scan unit from below;
A spring that is arranged so as to be compressed between the upper surface of the bracket and the lower surface of the scan unit, and biases the scan unit so that the upper surface of the scan unit contacts the inner surface of the document table;
Driving means for moving the scan unit in the sub-scanning direction;
In an image forming apparatus provided with image forming means for forming an image on recording paper based on image data read by the scan unit or image data input from the outside,
2. The image forming apparatus according to claim 1, wherein both the shaft bearing and the bracket are integrally formed of resin.

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