JP4519741B2 - Image reading apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to an image reading apparatus that reads an image of a document placed on contact glass such as a copying machine, a facsimile machine, or a scanner on an image pickup device, and particularly to a holding member to which an imaging lens is fixed. The present invention relates to an image reading apparatus including a lens block unit configured by fixing a substrate on which an imaging element is fixed.

  With the spread of digital technology, image reading devices such as copiers, facsimiles, and scanners are widely used. In this type of image reading apparatus, an image of a document placed on a contact glass is guided to an imaging lens through an optical mirror that is moved and scanned, and the image is connected to an image pickup device such as a CCD by the lens. This is imaged and photoelectrically converted to realize reading.

  In a widely used type of image reading apparatus, the imaging lens and the image sensor are provided in a lens block unit. The image sensor is fixed on the substrate in the lens block unit, and signals obtained by photoelectric conversion with the image sensor are transmitted to the outside through a harness connected to a connector provided on the substrate. Is done.

  On the other hand, due to the demand for higher definition of video representation of digital devices, the accuracy and productivity of image readers are increasing, and along with this, the amount of information handled per unit time when reading images is dramatically increased. Has increased. Such an increase in the amount of information results in an increase in the number of connectors and harness connection terminals for transmitting the signal to the outside.

  From such a background, the connector on the substrate of the image sensor and the harness connected to the connector are increased in size or diameter, and it is necessary to apply a suitable force at the time of connection. As a result, a large load is applied to the substrate on which the image sensor is mounted when the harness is connected, and at the same time a load is applied to the image sensor itself, which may cause damage to the image sensor, poor terminal contact, and the like. It is high.

  In particular, the connector mounting position on the board is usually placed in the peripheral part of the board due to noise and circuit configuration restrictions, which increases the bending moment applied to the board when connecting the harness. The problem is likely to occur.

  In order to deal with such a problem, for example, a method of connecting a harness at a location other than the substrate of the image sensor by adopting a relay substrate or the like provided with a connector is conceivable. There is a problem that the demand for cost reduction and cost reduction is strict and cannot be answered. Patent Document 1 describes an image reading apparatus that takes measures against heat of an image sensor.

Japanese Patent No. 3667022

  In view of the above-described conventional problems, the present invention provides an image reading apparatus capable of reducing a load applied to a substrate and an image sensor when the harness is connected to the substrate on which the image sensor is mounted, and an image provided with the image reader. An object is to provide a forming apparatus.

  According to a first aspect of the present invention, there is provided an image reading apparatus including a lens block unit configured by fixing a substrate on which an imaging element is fixed to a holding member on which an imaging lens is fixed. A connector for connecting a harness for transmitting a signal from the image sensor on the substrate surface; and the lens block unit has a substrate receiving member on the back surface side of the substrate surface provided with the connector. It is characterized by having.

  According to a second aspect of the present invention, in the image reading apparatus according to the first aspect, the receiving member is disposed in a non-contact state with respect to the substrate surface.

  According to a third aspect of the present invention, in the image reading apparatus according to the first or second aspect, the receiving member has a rib shape on the surface that receives the substrate.

  According to a fourth aspect of the present invention, in the image reading apparatus according to any one of the first to third aspects, the receiving member is attached to a holding member to which the imaging lens is fixed.

  According to a fifth aspect of the present invention, in the image reading apparatus according to the fourth aspect, the receiving member is attached to a holding member to which the imaging lens is fixed so that the position thereof can be adjusted.

  According to a sixth aspect of the present invention, in the image reading apparatus according to the fifth aspect, the receiving member is disposed in a non-contact state with respect to the substrate surface, and a separation distance between the surface of the receiving member that receives the substrate and the substrate surface. Satisfying the relationship of αL <d, where d is the distance from the mounting position of the receiving member to the holding member to the surface receiving the substrate of the receiving member is L, and the linear expansion coefficient of the receiving member is α. It is characterized by.

  According to a seventh aspect of the present invention, in the image reading apparatus according to any one of the first to sixth aspects, the receiving member is formed of a resin.

  According to an eighth aspect of the present invention, there is provided an image forming apparatus comprising the image reading apparatus according to any one of the first to seventh aspects.

  According to the present invention, when the harness is connected to the substrate, the receiving member supports the substrate against the pressing force, so that the load on the substrate and the image sensor mounted on the substrate is reduced. Damage and malfunction can be prevented.

  The best mode for carrying out the present invention will be described below with reference to the embodiments shown in the drawings.

  FIG. 1 is a diagram showing a schematic configuration of an image reading apparatus of this kind that is widely used, (A) is a schematic side view showing an internal optical system thereof, and (B) is an attachment of an internal lens block unit. It is a top view which shows a state. In the figure, the image reading apparatus includes an optical unit 101, and a first carriage 102 supporting a lamp and a first mirror as a light source, and a second carriage supporting a second mirror and a third mirror are included in the optical unit. 103 and a lens block unit 104 provided with an image sensor for photoelectrically converting reflected light of the document. In response to an image reading request signal for each line sent from the host computer, the first carriage 102 and the second carriage 103 sequentially move along the document at a speed ratio of 2: 1. Is read.

  The lens block unit 104 includes an imaging lens 105, a lens holding member 107, an image sensor 109 such as a CCD, an image sensor substrate 110, and the like. That is, in the lens block unit 104, the imaging lens 105 is fixed to the lens holding member 107 via the lens fixing member 106. The image sensor 109 is fixed substantially at the center of the substrate surface of the image sensor substrate 110, and the image sensor substrate 110 is attached to the lens holding member 107 by bonding or fastening with screws. When the image pickup device substrate 110 is attached to the lens holding member 107, the positional relationship between the lens and the image pickup device is adjusted in order to absorb variations in the optical system, and the image on the original surface is optimally connected to the image pickup device. To be imaged. The lens holding member 107 is further supported by the lens support member 108 and attached to the rail 111 on which the second carriage 103 moves.

  In such an arrangement, when reading an image, the image reading apparatus moves the first carriage 102 at a constant speed, and the second carriage 103 follows this at a half speed of the first carriage 102. Move forward. Thereby, the document on the contact glass is optically scanned. The document on the contact glass is illuminated by a light source or the like, and the reflected light image is guided to the lens block unit 104 via the first mirror, the second mirror, and the third mirror on the first and second carriages. In the lens block unit 104, the reflected light image is guided to the imaging lens 105 and imaged on the image sensor 109 by the imaging lens 105.

  The image sensor 109 photoelectrically converts the reflected light image of the imaged document into an analog image signal, thereby reading the document. The analog image signal output from the image sensor 109 is converted into a digital image signal by an analog / digital converter, and each image processing, that is, binarization, multi-value conversion, floor conversion, is performed on a circuit board on which an image processing circuit is mounted. Tone processing, scaling processing, editing processing, etc. are performed. After the reading of the document is completed, the first carriage 102 and the second carriage 103 return to the home position.

  FIG. 2 is a plan view showing the image sensor substrate 110 on which the image sensor is mounted. In the figure, the image pickup device substrate 110 has an image pickup device 109 mounted in the vicinity of the center, and a connector 201 for connecting a harness for transmitting an image signal or the like to the peripheral portion. As described above, the image pickup device substrate 110 is fixed to the lens holding member 107. However, in order to increase the mounting position accuracy and to reduce the position variation due to the distortion of the substrate, the image pickup device substrate 110 is bonded or adjacent to the vicinity 202 of the image pickup device 109. It is fixed by screw fastening. For this reason, the peripheral portion of the image sensor substrate 110 on which the connector 201 is disposed is in a cantilevered support state that is a free end with respect to the support member.

  FIG. 3 is a perspective view showing a main part of the lens block unit 104 having a receiving member according to an embodiment of the present invention. As shown in the figure, in the embodiment of the present invention, a receiving member 301 is installed in the lens block unit 104. The receiving member 301 is fixed to the frame of the lens block unit 104 (not shown here), and the receiving surface 301a is just on the back side of the peripheral portion of the image sensor substrate 110 where the connector 201 is installed. Has been placed. The receiving surface 301 a of the receiving member 301 is in light contact with the back surface of the image sensor substrate 110. In a preferred embodiment, the receiving member 301 is an elastic member having a relatively small linear expansion coefficient such as resin.

  In this state, a harness (not shown) is connected to the connector 201 from the direction of the arrow in the figure. At this time, a certain load is applied to the image pickup device substrate 110, and the periphery thereof is bent to bend backward. A moment is generated. However, when the peripheral portion of the image pickup device substrate 110 tries to bend backward, the receiving member 301 supports the image pickup device substrate 110 against this force, whereby the bending of the image pickup device substrate 110 is minimized. As a result, the load on the image sensor substrate 110 and the image sensor mounted thereon is reduced.

  FIG. 4 is a perspective view showing a receiving member in another embodiment. In the figure, only a part of the image sensor substrate 110 including the receiving member 401 and the connector 201 according to this embodiment is shown. In the drawing, the receiving member 401 in the present embodiment is disposed on the back surface of the image sensor substrate 110 provided with the connector 201 in the same manner as the receiving member 301 in the previous embodiment, but the receiving surface 401a has a rib shape or It has a corrugated shape. In addition, the receiving surface 401a of the receiving member 401 is a distance of about 1 mm from the image pickup device substrate 110 in a state before and after installation (hereinafter referred to as normal time) where the pressing force of the harness is not applied to the image pickup device substrate 110. It is arranged at a non-contact position separated by d. By keeping the receiving member 401 in non-contact with the image pickup device substrate 110 in this way, it is possible to prevent an accident in which the receiving surface 401a damages the image pickup device substrate 110 due to an unexpected impact or the like at normal times. . Further, since the receiving surface 401a has a rib shape, even when the imaging element substrate 110 comes into contact with the receiving surface 401a due to the pressing force of the harness, the contact area is minimized, The friction at the time of contact can be reduced, and the influence on the substrate can be minimized.

  5 and 6 are a side view and a plan view showing a receiving member in still another embodiment. In the figure, the receiving member 501 according to the present embodiment has a curved arm portion 501b, and one end of the arm portion 501b is fixed to the lens holding member 107 with a screw 502 and formed at the other end. The receiving surface 501a is configured to come to a position facing the back side of the image sensor substrate 110. The receiving surface 501a of the receiving member 501 is arranged away from the back surface of the image sensor substrate 110 by a slight distance d, as in the previous embodiment. As shown in FIG. 6, a long hole 501c is formed at the end on the mounting side of the receiving member 501, and the receiving member 501 is screwed through the long hole 501c to adjust its mounting position. Thus, the distance d can be adjusted. As described above, by fixing the receiving member 501 to the lens holding member 107 to which the image pickup device substrate 110 is fixed, it is possible to improve the mounting position accuracy of the receiving member 501 with respect to the image pickup device substrate 110, and the distance d. Management becomes easy. In addition, when adjusting the position of the imaging element 109 with respect to the imaging lens 105, the attachment position of the receiving member 501 can be adjusted at the same time.

  Here, when the distance from the mounting position of the receiving member 501 to the lens holding member 107 to the receiving surface 501a is L, and the linear expansion coefficient of the receiving member 501 is α, the distance d satisfies the relationship αL <d. Installed. Due to this relationship, even when the receiving member 501 contracts due to a temperature change in the lens block unit 104 at normal times, the receiving surface 501a is prevented from coming into contact with the image sensor substrate 110.

1A and 1B are diagrams illustrating a schematic configuration of an image reading apparatus in which the present invention is employed, in which FIG. 1A is a schematic side view illustrating an internal optical system thereof, and FIG. 1B is a plan view illustrating a mounting state of an internal lens block unit. is there. It is a top view which shows the image pick-up element board | substrate which mounts an image pick-up element. It is a perspective view which shows the principal part of the lens block unit provided with the receiving member concerning one Example of this invention. It is the perspective view which showed the receiving member in another Example. It is a side view which shows the receiving member in another Example. FIG. 6 is a plan view of FIG. 5.

Explanation of symbols

Reference Signs List 101 optical unit 102 first carriage 103 second carriage 104 lens block unit 105 imaging lens 106 lens fixing member 107 lens holding member 108 lens support member 109 imaging element 110 imaging element substrate 201 connector 301 receiving member 301a receiving surface 401 receiving member 401a Receiving surface 501 Receiving member 501a Receiving surface 501b Arm portion 501c Long hole 502 Screw

Claims (8)

In an image reading apparatus including a lens block unit configured by fixing a substrate on which an imaging element is fixed to a holding member on which an imaging lens is fixed,
The substrate to which the image sensor is fixed includes a connector for connecting a harness for transmitting a signal from the image sensor on the substrate surface, and the lens block unit includes a back surface of the substrate surface including the connector. An image reading apparatus comprising a substrate receiving member on the side. The image reading apparatus according to claim 1, wherein the receiving member is disposed in a non-contact state with respect to the substrate surface. The image reading apparatus according to claim 1, wherein the receiving member has a rib shape on a surface that receives the substrate. 4. The image reading apparatus according to claim 1, wherein the receiving member is attached to a holding member to which the imaging lens is fixed. The image reading apparatus according to claim 4, wherein the receiving member is attached to a holding member to which the imaging lens is fixed so as to be positionally adjustable. The receiving member is disposed in a non-contact state with respect to the substrate surface, the distance between the surface of the receiving member that receives the substrate and the substrate surface is d, and the receiving member is mounted from the attachment position of the receiving member with respect to the holding member. 6. The image reading apparatus according to claim 5, wherein a relationship of αL <d is satisfied, where L is a distance to a surface of the member receiving the substrate and α is a linear expansion coefficient of the receiving member. 7. The image reading apparatus according to claim 1, wherein the receiving member is made of resin. An image forming apparatus comprising the image reading device according to claim 1.

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