JP2006196979A - Image reading apparatus and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the effect of heat generation from a heat source installed in an image reading apparatus without a cost increase or without the need for excess power (energy). <P>SOLUTION: A lamp power source 20 with a high heating value is located to a corner in an outer frame 19 of an image reading apparatus main body remotest from a lens block stay 10 and the lamp power supply 20 is located at a remotest position from the lens block stay 10. Thus, the effect of heat on the lens block stay 10 to which a lens 8 and a CCD 9 are adhered and fixed can be suppressed, and occurrence of a positional deviation or the like of the lens 8 and the CCD 9 due to thermal deterioration of the adhered parts can be prevented. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image reading apparatus that optically reads an original image by an image sensor, and an image forming apparatus such as a copying machine, a facsimile machine, and a scanner equipped with the image reading apparatus.

In an image reading apparatus having an optical configuration as described in Patent Documents 1 and 2, as described in Patent Document 3, the position of the image sensor (CCD) is adjusted according to various characteristics of the optical lens. A lens block that is bonded and fixed to a predetermined portion is disclosed as an inexpensive and highly accurate lens block.
Japanese Patent No. 3005112 JP 2001-245098 A Japanese Patent No. 3545493

  However, in the configuration of the conventional lens block, for example, a fine range is adjusted and adhered by using a photo-curing type adhesive, so that the adhesive (adhesive layer) is thermally deformed due to a temperature change around the lens block, and is adjusted. The position and the fixed position will change.

  On the other hand, inside the image reading apparatus, there are a lamp as a light source for illuminating the document, a power supply for the lamp that supplies power to the lamp, a drive motor for driving a carriage that holds the lamp and the mirror, and this drive motor. There is a heat source such as a control board provided with a motor driver IC for driving and controlling.

  In the image reading apparatus equipped with the lens block adjusted and adhered by the adhesive as described above, the focus changes or the magnification changes due to the ambient temperature change of the lens block due to the internal heat source, which causes image degradation. This causes a malfunction.

  In order to avoid the occurrence of such problems, a cooling fan is provided inside the image reading apparatus, and measures are taken such as cooling by circulating the heat inside the apparatus or discharging the heat outside the apparatus. However, this method requires parts such as a fan or an airflow duct, which increases costs and requires power to rotate the fan, leading to the consumption of excess energy. It was.

  An object of the present invention is to solve the above-described conventional problems and obtain a good image by suppressing the influence of a heat source generated in the image reading apparatus without increasing the cost or using extra power (energy). An object of the present invention is to provide an image reading apparatus and an image forming apparatus.

  In order to achieve the object, an invention according to claim 1 is directed to a light source for exposing a document, a carriage holding a mirror for turning back the light source and reflected light from the document, and reflected light from the mirror. In an image reading apparatus comprising: an optical lens that forms an image on an imaging sensor; and the position of the imaging sensor is adjusted by a combination with the optical lens in accordance with the characteristics of the optical lens, and the adhesive is fixed to a predetermined part. A light source power supply unit, which is a heat generation source for supplying power to the light source, is arranged in a part in the image reading apparatus main body that is farthest from the imaging sensor. With this configuration, power is supplied to the light source. Since the light source power source, which is a heat generation source, is separated from the image sensor, the temperature rise in the vicinity of the image sensor can be kept low, and the adverse effect due to the heat of the bonding part in the image sensor It can be suppressed.

  According to a second aspect of the present invention, a light source for exposing a document, a carriage for holding a mirror for turning back the light reflected from the light source and the document, and the reflected light from the mirror are imaged on an image sensor. In an image reading apparatus comprising an optical lens, and adjusting the position of the imaging sensor in combination with the optical lens in accordance with the characteristics of the optical lens and bonding and fixing the image sensor to a predetermined part, power is supplied to the light source. A light source power supply unit, a drive motor for driving the carriage, and a control board including a motor driver of the drive motor, the light source power supply part that is a heat source, the drive motor, and the control board. It is characterized in that it is arranged in a part in the image reading apparatus body that is far from the imaging sensor in descending order of calorific value, and with this configuration, than the invention according to claim 1, It is possible to suppress the temperature rise in the vicinity of the image sensor even lower, it is possible to suppress the adverse effect of heat of the bonding portion in the image sensor.

  According to a third aspect of the present invention, in the image reading apparatus according to the second aspect of the present invention, the image reading apparatus includes a power supply unit that supplies power to the control board. It is characterized in that it is arranged in a part in the main body of the image reading device that is far from the image sensor in order, and with this configuration, the temperature rise in the vicinity of the image sensor can be kept low, and the adverse effect due to the heat of the adhesive part in the image sensor is suppressed. Can do.

  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 part where the heat source is arranged and the part where the imaging sensor is arranged are partitioned by a partition member. Characteristically, with this configuration, the heat source is partitioned from the image sensor by the partition member, so that heat is not easily transmitted and temperature rise in the vicinity of the image sensor can be suppressed.

  According to a fifth aspect of the present invention, in the image reading apparatus according to any one of the first to fourth aspects, each of the portions where the plurality of heat sources are arranged is partitioned by a partition member. Since each heat generation source is partitioned by the partition member, it becomes difficult to transfer heat from a space where heat is generated to a low space, and finally a temperature rise near the imaging sensor can be further suppressed.

  According to a sixth aspect of the present invention, in the image reading apparatus according to the fourth or fifth aspect, the partition member is a frame that also serves as a structure of the main body of the image reading apparatus. Because it also serves as a body, the amount of heat released to the outside and other structural members is large, making it difficult for heat to be transmitted to the vicinity of the imaging sensor, and the partition member also serves as a structure and a frame, creating a new partition member structure Is not added, the cost is not increased, and the weight is not increased.

  According to a seventh aspect of the present invention, in the image reading apparatus according to any one of the fourth to sixth aspects, the partition member is made of a material having a lower thermal conductivity than the structure of the main body of the image reading apparatus. This structure makes it difficult to transfer heat from the heat source to the vicinity of the image sensor, and the heat of the partition member heated over time is higher in the thermal conductivity of the contacting structure. It is easy to transfer heat to the structure, increasing the heat dissipation effect.

  According to an eighth aspect of the present invention, in the image reading apparatus according to any one of the first to seventh aspects, at least three surfaces of the corner portion of the cover member of the image reading apparatus main body on which the heat source is arranged are provided for ventilation. An opening is provided. With this configuration, heat exchange is performed by air circulation, and the heat source can be efficiently cooled.

  According to a ninth aspect of the present invention, in the image forming apparatus provided with the image reading device for optically reading an image, the image reading device according to any one of the first to eighth aspects is mounted as the image reading device. With this configuration, the focus, the change in magnification, and the like due to the heat change of the adhesion portion in the image sensor are suppressed, the image reading is performed well, and the image quality of the formed image can be maintained.

  According to the present invention, heat can be prevented from being transmitted to the image sensor from the light source power source, drive motor, control board, and the like, which are heat sources. It is possible to reduce the adverse effect due to heat of the bonded portion in the sensor, improve the reliability of image reading, and prevent image deterioration. In addition, since cooling fans can be reduced or eliminated as compared with the conventional apparatus, it is possible to take measures against heat without cost.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of an image reading apparatus for explaining an embodiment of the present invention.

  In FIG. 1, a contact glass 1 that is a document supporting portion made of transparent glass, a lamp 2 that is a light source that irradiates a document D placed on the contact glass 1, and a second image that deflects a reflected image of the document D. 1 mirror 3, 2nd mirror 4, 3rd mirror 5, lens 8 which condenses the light reflected by each mirror 3, 4 and 5, and CCD9 which photoelectrically converts the condensed light, and lamp The second carriage 7 having the second mirror 4 and the third mirror 5 advances by L / 2 while the first carriage 6 having the second mirror 3 and the first mirror 3 advances by the distance L in the direction of arrow A. The optical path length of the lens 8 is kept constant, and the entire document D is scanned by the irradiation of the lamp 2.

  The lens 8 is fixed by a lens block stay 10, and the CCD 9 is bonded to the tip of the protrusion 10 a of the lens block stay 10 with an adhesive 11. As a matter of course, the positions of the lens 8 and the CCD 9 are adjusted so as to satisfy various lens characteristics such as the distance of the entrance surface of the lens 8 from the contact glass 1 and the distance from the exit surface of the lens 8 to the light receiving surface of the CCD 9. After that, the lens 8 and the CCD 9 are fixed and bonded.

  FIG. 2 is a perspective view showing an outline of a drive system for explaining carriage drive in the image reading apparatus of the present embodiment.

  In FIG. 2, the drive wire 12 is attached to the first carriage 6, and the drive wire 12 is wound around the pulley 13 in the second carriage 7. The drive wire 12 is wound around a pair of wire pulleys 14 connected to the drive shaft, and the drive force from the carriage drive motor 17 is transmitted by the timing pulley 15 and the timing belt 16. A position where a certain distance is returned after one end of the first carriage 6 crosses the home position sensor 18 is defined as a home position.

  FIG. 3 is a perspective view illustrating an installation configuration of main parts inside the image reading apparatus according to the first embodiment.

  In FIG. 3, reference numeral 19 denotes an outer frame of the structure in the main body of the image reading apparatus, on which the lamp 2, the lens 8, the CCD 9, the lens block stay 10, and the carriage drive motor 17 described with reference to FIGS. Yes.

  Reference numeral 20 denotes a lamp power source which is a light source power source for supplying power to the lamp 2, reference numeral 22 denotes a motor control board on which a motor driver for driving and controlling the carriage drive motor 17, resistors, capacitors and the like are mounted; This is an image processing control board for controlling the processing of the output.

  As described above, the lamp 2 is mounted on the first carriage 6 and reciprocates during image reading, and the lens block stay 10 is disposed at an optical distance from the document surface through the mirrors 3 to 5. Since there is a position to be, neither can be placed in other parts. On the other hand, the lamp power supply 20, the carriage drive motor 17, the motor control board 22, the image processing control board 23, and the like are installed at the installation positions unless there is a layout restriction such as the height does not match or the width does not match. It is possible to move.

  The lamp power source 20 generates a large amount of heat in the heat source, but is conventionally disposed near the lens block stay 10, that is, the CCD 9. For this reason, the temperature is changed by the heat generated during image reading, and the atmosphere in the vicinity of the CCD 9 is raised. Therefore, in the lens block stay 10, the layer of the adhesive 11 is thermally expanded to change its shape, and the position of the CCD 9 adjusted at the optimum position may be displaced. Such changes are greater the higher the temperature rise.

  Therefore, in the first embodiment, as illustrated in FIG. 3, the lamp power supply 20 is disposed at the corner of the outer frame 19 of the image reading apparatus main body that is farthest from the lens block stay 10. As a result, the lamp power supply 20 is disposed at a position far from the lens block stay 10, so that the influence of heat on the lens block stay 10 is very small. Further, according to the first embodiment, the cooling effect on the main part is enhanced, and the number of exhaust heat fans 25 can be reduced as compared with the conventional case.

  Although not shown, a rail for traveling the first carriage 6 and the second carriage 7 is installed (position indicated by a two-dot chain line) in the main body of the image reading apparatus. The arrangement position of the power source 20 needs to be a position that does not interfere with the power supply 20. In the first embodiment, the arrangement position is outside the rail arrangement position shown by the two-dot chain line in FIG. Is set.

  4A and 4B are perspective views illustrating an installation configuration of main parts inside the image reading apparatus according to the second embodiment. In the following description, members corresponding to those described in FIGS. 1 to 3 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the case of the second embodiment, the arrangement positions of the carriage drive motor 17, the lamp power source 20, the motor control board 22, and the image processing control board 23 are considered as heat sources. Among the four members, the heat source is ranked in the order of the lamp power source 20, the carriage drive motor 17, the motor control board 22, and the image processing control board 23.

  Therefore, in the second embodiment, first, the lamp power source 20 is disposed at the disposition position A-1 farthest from the lens block stay 10 shown in FIG. 4A, and then the outer frame 19 far from the lens block stay 10. The carriage drive motor 17 is arranged at the position A-2 on the side of the motor, and then the motor control board 22 and the image processing control board 23 are sequentially arranged at positions A-3 and A-4. With this arrangement, the influence of heat on the lens block stay 10 can be minimized.

  Further, as shown in the modification of the second embodiment shown in FIG. 4B, depending on the size, for example, the motor control board 22 or the image processing control board 23 has an electrical element with a very high element height. / Because there are few cases where electronic elements are mounted, the motor control board 22 or the image processing control board 23 as a whole is high enough not to contact the first carriage 6 and the second carriage 7 in the travel region. 4, the motor control board 22 or the image processing control board 23 can be arranged at the positions B-3 and B-4 shown in FIG. 4B. Compared to the example shown in FIG. 5A, the lens block stay 10 can be arranged at a farther position, which is advantageous in terms of thermal influence.

  The carriage drive motor 17 can also be the same as described above. When the motor height is low, the rail arrangement position (the position indicated by the two-dot chain line) in the vicinity of the lamp power source 20 (right side in the figure) in FIG. The lens block stay 10 and the CCD 9 can be arranged at a position as far as the position B-1 of the lamp power supply 20 by arranging the lens block stay 10 and the CCD 9 at a position B-2 where the lamp power supply 20 is located. it can.

  Since the first and second embodiments have been described as the configuration of the image reading apparatus for the copying machine, the original power source (AC power source) that supplies power to the lamp power source 20, the motor control board 22, and the image processing control board 23 is described. ) Is mounted on the printer unit side, and power is supplied from the AC power source via a harness.

  On the other hand, an AC power source must be installed in the scanner itself in the scanner alone. For this reason, when AC power is loaded, although not shown, the AC power is disposed at a position farthest from the lens block stay 10, and then the lamp power 20, the carriage drive motor 17, and the motor control board, as described above. 22 and the image processing control board 23 are arranged in a position far from the lens block stay 10 in this order.

  FIG. 5 is a partial cross-sectional plan view showing the installation configuration of the main part inside the image reading apparatus of Embodiment 3, and FIG. 6 is a cross-sectional view of the apparatus shown in FIG.

  In the third embodiment, the lamp power source 20, which is a heat source, the carriage drive motor 17, the motor control board 22, and the image processing control board 23, these heat sources, and the first carriage 6 and the second carriage 7. The rail 26 that guides the traveling is partitioned by partition plates 27 and 28, respectively, and the partition plates 27 and 28 make it difficult for heat to be transmitted to the CCD 9 and the lens block stay 10 from the space where each heat source is arranged. Yes.

  As shown in FIG. 6, a part 28 of the partition plate is used as an outer frame (frame) 19 of the structure in the main body of the image reading apparatus, so that it is connected to the structure and the amount of heat released to the outside and other structural members. And the heat is not easily transmitted by the lens block stay 10. In addition, since the partition plates 27 and 28 have a frame shape, there is no need to newly add a dedicated partition member structurally, so that there is an advantage that the cost can be reduced and the weight can be reduced. .

  For example, the right frame 19a, the base frame 19b, and the left frame 19c constituting the outer frame 19 in FIG. 6 are part of the structure, but when these frames are made of an aluminum alloy, the thermal conductivity is generally The numerical value is 200 W / mk, and when the material of the frame portion constituting the partition plates 27 and 28 is a steel material, the thermal conductivity is 50 W / mk.

  As described above, the partition member is made of an aluminum alloy or the like that has a low thermal conductivity and makes it difficult to transfer the heat in the arrangement space of the heat generation source to the lens block arrangement space. As a result, it is easy to transfer the heat of the heat source arrangement space, and a cooling effect can be expected. Furthermore, since the heat of the partition member heated over time is higher in the thermal conductivity of the contacting structure body, the heat is easily transferred to the structure body, and the heat dissipation effect is enhanced.

  Further, in the third embodiment, as shown in FIG. 5, by arranging a partition plate 27 between the lamp power source 20, the carriage drive motor 17, the motor control board 22, and the image processing control board 23, Heat exchange between heat sources is difficult to occur. As a result, a boundary layer is formed between the heat generation sources, making it difficult to transfer heat from each heat generation source to another heat generation source. Therefore, heat transfer from each heat source 20, 17, 22, 23 to the lens block stay 10 is prevented.

  FIG. 7 is a perspective view showing a lamp power supply portion in the embodiment. As described above, in this embodiment, the lamp power supply 20 is a heat generation source with the largest amount of heat generation, and the lamp power supply 20 is an image reading device. In this case, the lamp power supply 20 is efficiently cooled by providing louver-shaped heat exchange ports 30 at the three corners on the upper side, the front side, and the rear side of the outer frame 19. can do. That is, as shown by the arrows in FIG. 7, the introduction of cold air and the discharge of heat naturally occur.

  The reason for arranging the louvers only at the corners of the image reading device main body is that when the louver portion (opening) is enlarged as a cooling louver, the strength of the outer frame 19 which is the structure of the image reading device main body is lowered. However, in order to compensate for the strength reduction, it is necessary to change the reinforcing member and the material, and this reinforcement increases the weight of the outer frame 19 or becomes expensive because a high-strength material is used. This is because a problem occurs.

  The image reading apparatus of each of the above embodiments is mounted on an image forming apparatus that is a copier, a facsimile machine, a scanner, or a combination of these, and is capable of reading excellent document information. Since the reading reliability is improved, the image quality of the formed image is improved, and the formed image can be maintained at high image quality.

  INDUSTRIAL APPLICABILITY The present invention is applied to an image reading apparatus that optically reads a document image with an image sensor, and an image forming apparatus such as a copying machine, a facsimile machine, a scanner, or a complex machine equipped with the image reading apparatus. In addition, the present invention is effective when applied to an image reading apparatus and an image forming apparatus that are required to eliminate the adverse effects of heat in the image reading apparatus without using excessive electric power (energy).

1 is a schematic configuration diagram of an image reading apparatus for describing an embodiment of the present invention. FIG. 3 is a perspective view schematically showing a drive system for explaining carriage drive in the image reading apparatus of the present embodiment. 1 is a perspective view illustrating an installation configuration of main parts inside an image reading apparatus according to a first embodiment of the present invention. (A), (b) is a perspective view which shows the installation structure of the principal part in the inside of the image reader of Embodiment 2 of this invention. Plane partial cross-sectional view showing an installation configuration of main parts inside an image reading apparatus according to Embodiment 3 of the present invention. Cross-sectional view of the image reading apparatus shown in FIG. The perspective view which shows the lamp power supply part in this embodiment

Explanation of symbols

2 Lamp 3, 4, 5 Mirror 6, 7 Carriage 8 Lens 9 CCD
DESCRIPTION OF SYMBOLS 10 Lens block stay 11 Adhesive 17 Carriage drive motor 19 Outer frame 20 Lamp power supply 21 Carriage drive motor 22 Motor control board 23 Image processing control boards 27 and 28 Partition plate 30 Heat exchange port

Claims (9)

A light source for exposing a document; a carriage that holds a mirror for turning back the light source and reflected light from the document; and an optical lens that focuses reflected light from the mirror on an image sensor; In an image reading apparatus in which the position is adjusted by a combination with the optical lens in accordance with the characteristics of the optical lens and the adhesive is fixed to a predetermined part.
An image reading apparatus, wherein a light source power supply unit, which is a heat generation source for supplying power to the light source, is disposed at a position in the main body of the image reading apparatus farthest from the imaging sensor. A light source for exposing a document; a carriage that holds a mirror for turning back the light source and reflected light from the document; and an optical lens that focuses reflected light from the mirror on an image sensor; In an image reading apparatus in which the position is adjusted by a combination with the optical lens in accordance with the characteristics of the optical lens and the adhesive is fixed to a predetermined part.
A light source power source for supplying power to the light source; a drive motor for driving the carriage; and a control board including a motor driver for the drive motor; An image reading apparatus, wherein the motor and the control board are arranged in a part in the main body of the image reading apparatus that is farther from the imaging sensor in descending order of heat generation.   A power supply unit that supplies power to the control board; and the light source power supply unit, the drive motor, the control board, and the power supply unit are arranged in a part in the image reading apparatus body that is farther from the imaging sensor in descending order of heat generation amount. The image reading apparatus according to claim 2, wherein the image reading apparatus is arranged.   The image reading apparatus according to claim 1, wherein a portion where the heat source is arranged and a portion where the imaging sensor is arranged are partitioned by a partition member.   5. The image reading apparatus according to claim 1, wherein a portion where the plurality of heat sources are arranged is partitioned by a partition member.   6. The image reading apparatus according to claim 4, wherein the partition member is a frame that also serves as a structure of the image reading apparatus main body.   The image reading apparatus according to claim 4, wherein the partition member is made of a material having a lower thermal conductivity than the structure of the image reading apparatus main body.   The image reading apparatus according to claim 1, wherein ventilation openings are provided on at least three surfaces of a corner portion of a cover member of the image reading apparatus main body in which the heat generation source is disposed. . In an image forming apparatus provided with an image reading apparatus for optically reading an image,
An image forming apparatus comprising the image reading apparatus according to claim 1 as the image reading apparatus.

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