JP6982797B2 - Image forming device - Google Patents

Description

The present invention relates to an image forming apparatus.

Conventionally, a fixing device, which is a heating device that heats an image on a conveyed recording medium and fixes the image on the recording medium, and an image detecting means for detecting a fixed image on the recording medium that has passed through the fixing device. An image forming apparatus is known that is arranged between a recording medium and an image detecting means and includes a protective member such as a protective glass that protects the image detecting means.

Patent Document 1 describes the image forming apparatus, in which the recording medium that has passed through the fixing apparatus is cooled by the cooling device, and then the image fixed on the recording medium is detected by the image detecting means. .. By cooling the recording medium with a cooling device and then detecting the image fixed on the recording medium with the image detection means, the temperature of the image detection means rises due to the recording medium heated by the fixing device, which is a heating device. It is stated that it can be suppressed.

However, in the above-mentioned Patent Document 1, there is a possibility that the image forming apparatus becomes large.

In order to solve the above problems, the present invention presents a transport path for transporting a recording medium, an image forming unit for forming an image on the recording medium, a heating device for heating the recording medium, an image pickup element, and the image pickup element. Detects an image on a recording medium that has a substrate on which an image is arranged, an image forming lens for forming an image on the image pickup element, and a holder for holding the image forming lens, and has passed through the heating device. An image forming apparatus including an image detection sensor and a protective member projecting from the lower end of the image detection sensor to the transport path. The protective member is held by a heat conductive member and has heat. It is characterized by providing an auxiliary heat dissipation member that assists the heat dissipation of the conductive member.

According to the present invention, it is possible to suppress the increase in size of the apparatus and the temperature rise of the image detecting means.

The schematic block diagram of the printer which concerns on this embodiment. Schematic block diagram of the image detection device. The figure explaining the attachment to the heat dissipation member of an image detection sensor. Schematic configuration diagram showing an auxiliary heat dissipation member and a heat dissipation member holding an image detection sensor. The figure explaining the positioning of an image detection sensor. An enlarged cross-sectional view of the vicinity of D surrounded by the chain line in FIG. Perspective view of the image detection device. Schematic diagram of an image detection device in which an auxiliary heat dissipation member is provided on the outer wall of the heat dissipation member. The schematic perspective view of the image detection apparatus which provided the auxiliary heat dissipation member on the outer wall of the heat dissipation member. Schematic diagram of an image detection device in which a heat conductive sheet is provided between a guide member and a heat dissipation member.

Hereinafter, an embodiment in which the present invention is applied to an electrophotographic printer (hereinafter, simply referred to as “printer”) which is an image forming apparatus will be described.
FIG. 1 is a schematic configuration diagram of a printer 100 according to this embodiment. Reference numerals “C”, “M”, “Y”, and “K” in the figure indicate that the members are members for each color of cyan, magenta, yellow, and black, respectively.

As shown in FIG. 1, the printer 100 includes four toner image forming portions 101 (C, M, Y, K) for generating cyan, magenta, yellow, and black square toner images, respectively. The four toner image forming portions 101 (C, M, Y, K) use C, M, Y, K toners of different colors as the image forming substance, but other than that, they have the same configuration. , Hereinafter, reference numerals (C, M, Y, K) indicating the color of the toner to be used will be omitted as appropriate.

As shown in FIG. 1, the printer 100 includes an intermediate transfer belt 107, which is an intermediate transfer body, below the four toner image forming portions 101. The intermediate transfer unit 120, which is a transfer means, moves the intermediate transfer belt 107 endlessly while being stretched by a plurality of tension rollers. Below the intermediate transfer unit 120, a fixing device 108 which is a heating device and a fixing means is provided, and below the fixing device 108, paper feed trays 105a and 105b for accommodating the transfer paper P which is a recording medium are provided. A paper portion 105 is provided. The transfer paper P is fed from the paper feed unit 105 to the transport path S for transporting the transfer paper P. The transfer paper fed to the transport path S is conveyed toward the resist roller pair 116 as shown by the arrow A.

Each toner image forming unit 101 includes a drum-shaped photoconductor 112 which is a latent image carrier, a charging device 111 which is a charging means, a developing device 113 which is a developing means, an exposure device 110 which is a latent image forming means, and the like. ing. The charging device 111 uniformly charges the surface of the photoconductor 112 rotated in the counterclockwise direction in FIG. 1 by the driving means. The surface of the uniformly charged photoconductor 112 is exposed and scanned by a laser beam emitted from an exposure device 110 which is a latent image forming means based on image information, and an electrostatic latent image corresponding to the image information of each color is formed. Will be done. The electrostatic latent image on the surface of the photoconductor 112 of each color is developed into the toner image of each color by the developing apparatus 113 using the toner of each color. The toner image on the surface of each photoconductor 112 is sequentially intermediately transferred onto the intermediate transfer belt 107.

The intermediate transfer unit 120 includes four primary transfer bias rollers 114 (C, M, Y, K), a secondary transfer backup roller 103, and the like, in addition to the intermediate transfer belt 107. The intermediate transfer belt 107 is endlessly moved in the clockwise direction in FIG. 1 (direction of the arrow “B” in FIG. 1). The four primary transfer bias rollers 114 (C, M, Y, K) sandwich the intermediate transfer belt 107 thus endlessly moved between the four photoconductors 112 (C, M, Y, K). Each of them forms a primary transfer nip. The four primary transfer bias rollers 114 are of a type in which a transfer bias having the opposite polarity (for example, plus) to the toner is applied to the back surface (loop inner peripheral surface) of the intermediate transfer belt 107.

Of the plurality of rollers on which the intermediate transfer belt 107 is stretched, all the rollers except the primary transfer bias roller 114 are electrically grounded. The intermediate transfer belt 107 sequentially passes through the primary transfer nips for C, M, Y, and K as it moves endlessly, and the C on the surface of the photoconductor 112 (C, M, Y, K). , M, Y and K toner images are superimposed and primary transferred. As a result, a four-color superimposed toner image (hereinafter referred to as “four-color toner image”) is formed on the intermediate transfer belt 107.

The secondary transfer backup roller 103 sandwiches an intermediate transfer belt 107 with the secondary transfer roller 115 to form a secondary transfer nip. The transfer papers P accommodated in the paper feed trays 105a and 105b are fed one by one to the transport path S by the paper feed rollers, and are conveyed toward the secondary transfer nip by the resist roller pair 116 at a predetermined timing.

The four-color toner image formed on the intermediate transfer belt 107 is transferred to the transfer paper P by the secondary transfer nip. In the secondary transfer nip, the transfer paper P is sandwiched between the intermediate transfer belt 107 and the secondary transfer roller 115, which move on the surface in the forward direction of each other, and is conveyed. When the transfer paper P sent out from the secondary transfer nip passes between the rollers of the fixing device 108, the four-color toner image transferred to the surface is fixed by heat and pressure.
The transfer paper P that has passed through the fixing device 108 is cooled by the cooling roller 109 and then discharged from the transport path S onto the output tray 117 outside the housing of the printer 100.

An operation unit 104 having a display unit and an operation panel is provided on the upper surface of the apparatus main body. Further, a reverse retransmission section may be provided to enable double-sided printing. When double-sided printing is performed, the fixed transfer paper is conveyed to the reverse retransmission section, the transfer paper P is inverted and re-fed to the resist roller pair 116, and the toner image is transferred from the intermediate transfer belt 107 to the back surface of the paper. Toner. After that, the paper is fixed by the fixing device 108 in the same manner as in the case of single-sided printing, and then the paper is discharged onto the output tray 117 outside the housing of the printer 100.

Further, an image detection device 201, which is an image detection means for detecting an image fixed on the transfer paper P, is provided between the fixing device 108 and the cooling roller 109. The image detection device 201 includes an image detection sensor such as a contact image sensor, and can detect image information two-dimensionally.

In the present embodiment, the position of the fixed image of the transfer paper P passing through the image detection device 201 and the image density (color tint) are detected, and the image formation conditions are corrected based on the detection result. When the image position detected by the image detection device 201 deviates from the specified position, the image is imaged by adjusting the latent image writing timing of the exposure device 110 or adjusting the drive start timing of the resist roller pair 116. The position is adjusted. If the image density (color) detected by the image detection device 201 deviates from the specified value, the image density (color) can be increased by adjusting the development bias, charge bias, exposure amount of the exposure device 110, and the like. It will be adjusted.

When printing a large number of images continuously, the image detection device 201 detects the image position and image density (color) of each image fixed on the transfer paper and feeds it back to subsequent printing. do. As a result, when a large number of images are continuously printed, it is possible to suppress the occurrence of image quality unevenness such that the quality of the first image and the quality of the last image are different.

The image detection sensor consists of a substrate in which a plurality of light emitting elements and a plurality of image pickup elements are arranged in a straight line in the width direction of the transfer paper, and SLA (Selfoc), which is an image pickup lens for forming an image on the image pickup element. (Registered trademark) lens array).

The image detection sensor is sensitive to heat. For example, when the temperature of the SLA rises, the components are deposited on the surface, and the components deposited on the surface react with the water vapor in the air to make the surface of the SLA cloudy, and the optical performance is deteriorated. I will let you. As a result, good image detection cannot be performed. In addition, there is a possibility that good image detection may not be performed because the position of the image pickup element deviates from the specified position due to thermal expansion of the substrate due to heat. Therefore, in order to perform good image detection, it is preferable that the image detection sensor is kept at 50 ° C. or lower.

On the other hand, in order to accurately detect the fixed image of the transfer paper, there is a restriction that the distance between the image detection sensor and the transfer paper P must be maintained at several millimeters, and it is heated by the heat of the fixing device. It is necessary to place the image detection sensor at a close distance to the transfer paper. The temperature of the transfer paper heated by the heat of the fixing device exceeds 100 ° C., and when the transfer paper heated by the fixing device passes through the image detection position of the image detection sensor, the image detection sensor is heated to generate an image. The temperature of the detection sensor rises. When a large number of images are continuously printed, the temperature of the image detection sensor may exceed 50 ° C., and there is a possibility that good image detection cannot be performed.

A protective glass, which is a protective member that protects the image detection sensor, is arranged between the image detection sensor and the transferred transfer paper, and the heat of the transfer paper is transmitted to the image detection sensor through the protective glass. Then, the temperature of the image detection sensor is raised. Therefore, in the present embodiment, the protective glass is held by the heat radiating member, and the heat of the protective glass is radiated by the heat radiating member to reduce the heat transferred from the protective glass to the image detection sensor, and the temperature of the image detection sensor. I tried to suppress the rise. Hereinafter, a specific description will be given with reference to the drawings.

FIG. 2 is a schematic configuration diagram of the image detection device 201.
As shown in FIG. 2, the image detection device 201 has an image detection sensor 1. The image detection sensor 1 includes a plurality of image pickup elements 3 such as photodiodes, a plurality of light emitting elements 4 such as LEDs, and an SLA (selfock lens array) 2 which is an imaging lens for forming an image on the image pickup element. ing. The plurality of image pickup elements 3 and the plurality of light emitting elements 4 are arranged on the substrate 5 side by side in the width direction of the transfer paper (direction orthogonal to the paper surface). The SLA 2 is held in the holder 6.

A protective glass 7 which is a transparent protective member for protecting the image detection sensor 1 is arranged between the image detection sensor 1 and the transferred transfer paper. The protective glass 7 is held by the heat radiating member 10, and the image detection sensor 1 is housed in the heat radiating member 10. The heat radiating member 10 has a sensor holding unit 11 that holds the image detection sensor 1, and the image detection sensor 1 is held by the sensor holding unit 11. Further, the heat radiating member 10 has a substantially box-shaped shape with an open upper portion in the drawing, and a cover member 31 is attached to the upper portion thereof.

The heat radiating member 10 is a heat conductive member, and the heat conductive member means a member having a thermal conductivity of 60 [W / (m · K)] or more. In the present embodiment, it is preferable to use a heat conductive member having a thermal conductivity of 200 [W / (m · K)] or more, and a heat conductive member having a thermal conductivity of 400 [W / (m · K)] or more is used. Is more preferable. In the present embodiment, the heat radiating member is made of aluminum (thermal conductivity of 200 [W / (m · K)] or more).

The heat of the transfer paper P heated by the fixing device first moves to the protective glass 7 when passing through the image detection position of the image detection sensor 1. The heat transferred to the protective glass 7 is transferred to the heat radiating member 10 composed of the heat conductive member holding the protective glass, so that the temperature of the protective glass 7 can be suppressed from rising. The heat radiating member 10 has a substantially box shape and has side walls extending in all directions perpendicular to the paper surface of the transfer paper. The atmosphere temperature is high in the vicinity of the transfer paper on the lower side in the figure because the transfer paper heated by the fixing device passes through, but the atmosphere temperature on the upper side in the figure is relative to the lower side in the figure. It's low enough. As described above, the heat radiating member 10 is composed of the heat conductive member, so that the heat transferred from the protective glass 7 quickly moves to the upper side in the figure in which the atmospheric temperature is low and dissipates heat. As a result, even during continuous printing of a large amount of images, the heat of the protective glass 7 heated by the transfer paper P can be satisfactorily transferred to the heat radiating member 10, and the temperature rise of the protective glass 7 can be suppressed. Therefore, it is possible to suppress the transfer of heat from the protective glass 7 to the image detection sensor 1, and it is possible to suppress the temperature rise of the image detection sensor 1. As a result, it is possible to suppress thermal deformation such as the SLA of the image detection sensor 1 becoming cloudy or the substrate 5 holding the light emitting element 4 and the image pickup element 3 thermally expanding, resulting in good image detection. It can be carried out.

The heat radiating member 10 is provided with guide members 41 and 42 for guiding the transferred transfer paper P. The guide surface for guiding the transfer paper of the guide members 41 and 42 projects toward the transfer paper transport side from the protective glass 7, and guides the transfer paper P so as not to come into contact with the protective glass. As a result, it is possible to prevent the protective glass 7 from rubbing against the transfer paper P during transportation to damage the surface and to prevent stains adhering to the transfer paper from adhering to the protective glass. As a result, the image fixed on the transfer paper can be satisfactorily detected by the image detection sensor over time.

Further, by guiding the transfer paper P so as not to come into contact with the protective glass 7, it is possible to suppress the transfer of heat directly from the transfer paper to the protective glass 7, and to suppress the temperature rise of the protective glass 7. Can be done.

Further, by providing the guide members on the front side in the transport direction and the rear side in the transport direction with respect to the protective glass 7, it is possible to suppress the transfer paper entering the image detection position from coming into contact with the protective glass 7, and the image. It is possible to prevent the transfer paper that has passed the detection position from coming into contact with the protective glass 7.

In this embodiment, the guide members 41 and 42 are made of SUS. By forming with SUS, it is possible to prevent the surface from being damaged by the fixed image on the transfer paper. Further, since the guide members 41 and 42 come into contact with the transfer paper, heat is directly transferred from the transfer paper, and the temperature of the guide members 41 and 42 rises. The heat transferred to the guide members 41 and 42 is transferred from the portion of the guide members 41 and 42 in contact with the heat radiating member 10 to the heat radiating member 10, and the temperature around the heat radiating member 10 holding the protective glass 7 rises. As a result, the amount of heat transferred from the protective glass 7 to the heat radiating member 10 is reduced, and there is a possibility that the temperature rise of the protective glass cannot be sufficiently suppressed. Therefore, it is preferable that the guide members 41 and 42 are not in contact with the heat radiating member 10 except for the mounting portion attached to the heat radiating member 10. As a result, it is possible to suppress the transfer of heat from the guide members 41 and 42 to the heat radiating member 10, and it is possible to suppress the decrease in the amount of heat transfer from the protective glass 7 to the heat radiating member 10.

Further, the guide members 41 can be made of a material having a low thermal conductivity, or the guide members 41 and 42 can be attached to the heat radiating member 10 via a material having a low thermal conductivity. It is preferable that the heat of, 42 is difficult to transfer to the heat radiating member.

Further, in the present embodiment, the guide members 41 and 42 are attached to the side wall portions provided at both ends in the width direction of the transfer paper, and the attachment position where the guide members 41 and 42 are attached to the heat dissipation member is set to the heat dissipation member. The position is set away from the place where the protective glass 7 is held. As a result, it is possible to suppress the temperature rise in the vicinity of the heat radiating member 10 holding the protective glass 7 due to the heat transferred from the guide member.

Further, by attaching the guide members 41 and 42 to members other than the heat radiating member 10, the heat of the guide members 41 and 42 can be satisfactorily suppressed from being transferred to the heat radiating member 10. However, if the guide members 41 and 42 are attached to other than the heat radiating member 10 that holds the protective glass 7, the positional accuracy between the guide members 41 and 42 and the protective glass 7 deteriorates due to the stacking of component tolerances and the like. As a result, the transfer paper may not be able to be guided so that the transfer paper does not come into contact with the protective glass 7. Therefore, it is preferable that the guide members 41 and 42 are attached to the heat radiating member 10.

Further, inside the heat radiating member 10, an auxiliary heat radiating member 21 for assisting the heat radiating of the heat radiating member 10 is provided. Like the heat radiating member, the auxiliary heat radiating member 21 is made of aluminum, has a heat receiving portion 25 on the left side in the drawing, and the heat receiving portion 25 is a heat radiating member via the first heat conductive sheet 12. It is thermally connected to 10. A mounting portion 24 is provided on the right side of the drawing, and is mounted to the mounted portion 18 of the heat radiating member 10 with screws. The auxiliary heat radiating member 21 is formed with a heat radiating portion 21a composed of a plurality of fins extending in the width direction of the transfer paper (direction orthogonal to the paper surface). A part of the heat of the heat radiating member 10 moves to the auxiliary heat radiating member 21 via the first heat conductive sheet 12, and is radiated from the heat radiating portion 21a of the auxiliary heat radiating member 21. As a result, the heat dissipation efficiency can be improved and the temperature rise of the heat dissipation member 10 can be suppressed as compared with the one that dissipates heat only by the heat dissipation member 10. As a result, the heat of the protective glass can be satisfactorily transferred to the heat radiating member 10, and the temperature rise of the protective glass can be suppressed. As a result, the heat transferred from the protective glass 7 to the image detection sensor 1 can be reduced, and the temperature rise of the image detection sensor 1 can be suppressed.

Further, the auxiliary heat dissipation member 21 is thermally connected to the substrate 5 of the image detection sensor 1 via the second heat conduction sheet 22. The substrate 5 of the image detection sensor 1 has an image processing chip 5a (see FIG. 3) that processes an image captured by the image pickup element 3, and the image processing chip emits heat. Further, since the light emitting element 4 such as the LED held by the substrate 5 also emits heat, the temperature of the substrate 5 rises, and the substrate 5 may undergo thermal deformation such as thermal expansion. When the substrate 5 is thermally deformed, the position of the image pickup element held on the substrate may deviate from the specified position, and the focal position may change. As a result, the image captured by the image pickup device 3 may be out of focus, and the image detection accuracy may decrease. Further, the heat of the substrate 5 may be transferred to the SLA2 to raise the temperature of the SLA2, and the surface of the SLA2 may become cloudy.

In the present embodiment, the heat of the substrate 5 is transferred to the auxiliary heat dissipation member 21 via the second heat conductive sheet 22. Then, the heat of the substrate 5 that has moved to the auxiliary heat dissipation member 21 is dissipated by the heat dissipation unit 21a. As a result, the temperature rise of the substrate 5 can be suppressed, the substrate 5 can be suppressed from being deformed by heat, and the deterioration of the image detection accuracy can be suppressed. Further, it is possible to suppress the temperature rise of SLA2 due to the heat of the substrate 5, and it is possible to suppress the surface of SLA2 from becoming cloudy.

Further, since the auxiliary heat radiating member 21 is made of aluminum and is conductive, it is preferable that the second heat conductive sheet 22 is insulating. By making the second heat conductive sheet 22 insulating, it is possible to prevent the current flowing through the substrate 5 from flowing to the auxiliary heat radiating member 21 through the second heat conductive sheet.

FIG. 3 is a diagram illustrating attachment of the image detection sensor 1 to the heat dissipation member 10.
As shown in FIG. 3, the heat radiating member 10 is provided with sensor holding portions 11 for holding the box-shaped image detection sensor 1 at two locations in the width direction (left-right direction in the figure) of the transfer paper. Positioning units 15 for positioning the image detection sensor 1 in a direction orthogonal to the image forming surface of the transfer paper (direction orthogonal to the paper surface) are provided at both ends of the sensor holding unit 11 in the width direction of the transfer paper. Then, the two image detection sensors 1 are fitted into the corresponding sensor holding portions 11, and are held by the heat radiating member 10 side by side in the width direction of the transfer paper.

Images captured by the image sensor are processed at two locations in the width direction of the transfer paper on the surface of the substrate 5 of the image detection sensor 1 opposite to the surface on which the image sensor and light emitting element are mounted (hereinafter referred to as the back surface of the substrate). The image processing chip 5a is mounted.

FIG. 4 is a schematic configuration diagram showing an auxiliary heat radiating member 21 and a heat radiating member 10 holding the image detection sensor 1.
As shown in FIG. 4, leaf springs 23 are attached at four locations on the facing surface of the auxiliary heat dissipation member 21 facing the substrate 5 of the image detection sensor 1. As shown by the chain line X in the figure, each leaf spring 23 is provided on the facing surface of the auxiliary heat dissipation member 21 facing the substrate 5 of the image detection sensor so as to abut on the end portion of the substrate 5 in the width direction of the transfer paper. .. Further, a second heat conductive sheet 22 is attached to the facing surface of the auxiliary heat radiating member 21 facing the substrate 5. In FIG. 4, the second heat conductive sheet 22 is provided so that the second heat conductive sheet 22 is in close contact with almost the entire back surface of the substrate 5, but the second heat conductive sheet 22 is brought into close contact only with the image processing chip 5a, which generates a large amount of heat. The heat of the image processing chip 5a may be transferred to the auxiliary heat dissipation member.

Further, a first heat conductive sheet 12 is attached to the lower side wall of the heat radiating member 10 in the drawing. The first heat conductive sheet 12 is made of an elastic body such as acrylic rubber or silicone rubber, and is crushed by the auxiliary heat radiating member 21 to be in close contact with the heat receiving portion 25 of the auxiliary heat radiating member 21 to dissipate the heat of the heat radiating member 10. It is intended to transfer heat to the member 21 satisfactorily. While crushing the first heat conductive sheet 12 with the heat receiving portion 25, the heat receiving portion 25 is slid with the surface of the first heat conductive sheet 12 to assemble the auxiliary heat radiating member 21. However, since the first heat conductive sheet 12 is made of an elastic body such as acrylic rubber or silicone rubber and has poor slidability, the heat receiving portion 25 does not smoothly slide on the surface of the first heat conductive sheet 12, and the first heat conductive sheet 12 does not slide smoothly. 1 The heat conductive sheet 12 may be peeled off from the heat radiating member 10.

Therefore, in the present embodiment, the sliding sheet 13 is attached to the surface of the first heat conductive sheet 12. The sliding sheet 13 is a member having a lower coefficient of friction with the heat receiving portion 25 than the first heat conductive sheet, and in this embodiment, a PET film is attached. This makes it possible to prevent the first heat conductive sheet 12 from peeling off from the heat radiating member 10 when the auxiliary heat radiating member 21 is assembled to the heat radiating member 10.

The auxiliary heat radiating member 21 is attached to the heat radiating member 10 by passing a screw through the through hole 24a provided in the mounting portion 24 of the auxiliary heat radiating member 21 and screwing the screw into the screw hole of the mounted portion 18 of the heat radiating member 10. Be done. When the auxiliary heat radiating member 21 is attached to the heat radiating member 10, the second heat conductive sheet 22 is crushed and comes into close contact with the back surface of the substrate 5.

Reference numeral 16 in FIG. 4 is a communication hole for passing a duct for passing air into the heat radiating member 10 described later.

FIG. 5 is a diagram illustrating the positioning of the image detection sensor 1, and FIG. 6 is an enlarged cross-sectional view of the vicinity of D surrounded by the chain line of FIG.
When the auxiliary heat radiating member 21 is attached to the heat radiating member 10, the leaf spring 23 presses both ends of the substrate 5 in the width direction of the transfer paper toward the protective glass side. As a result, the holder 6 of the image detection sensor 1 abuts on the positioning portion 15 of the heat dissipation member 10, and the image detection sensor 1 is positioned in a direction orthogonal to the image forming surface of the transfer paper. As a result, the focus of the image pickup device 3 can be adjusted to the transport region of the transfer paper, and the image of the transfer paper can be detected with high accuracy.

Further, when the heat radiated by the heat radiating portion 21a of the auxiliary heat radiating member 21 is stored inside the heat radiating member 10, the temperature of the heat radiating member 10 rises, the heat radiating efficiency of the protective glass 7 decreases, and the heat radiated from the auxiliary heat radiating member 21. Efficiency also drops. Therefore, it is preferable to allow air to flow inside the heat radiating member 10 to exhaust the warmed air inside the heat radiating member 10 and to air-cool the auxiliary heat radiating member 21.

FIG. 7 is a perspective view of the image detection device 201.
As shown in FIG. 7, at one end of the heat radiating member 10 in the width direction of the transfer paper, a communication hole 16 for passing the duct 52 is provided in the heat radiating member 10, and the duct 52 is inserted into the communication hole 16 to form a duct. The air ejection port of 52 is provided so as to face the heat radiating portion 21a of the auxiliary heat radiating member. An air outlet of the sirocco fan 51 is attached to the air intake port of the duct 52. On the other hand, an exhaust lid 32 provided with a plurality of exhaust ports 32a is attached to the other end of the heat radiating member 10 in the width direction of the transfer paper.

The air taken in by the sirocco fan 51 moves through the duct 52 into the heat radiating member 10, and is ejected from the air ejection port of the duct 52. Then, as shown by the arrow A in the figure, the heat flows toward the other end side in the width direction of the transfer paper, and the heat radiating portion 21a of the auxiliary heat radiating member 21 is air-cooled. The air that has taken heat from the heat radiating portion 21a and whose temperature has risen is exhausted from the plurality of exhaust ports 32a of the exhaust lid 32 provided at the other end of the heat radiating member 10 in the width direction of the transfer paper. As a result, the temperature rise of the auxiliary heat radiating member 21 can be suppressed, and the heat of the substrate and the heat radiating member 10 can be satisfactorily dissipated.

Further, since the temperature inside the image forming apparatus is higher than that of the outside air due to heat generated from various apparatus, the outside air is preferable as the air taken in by the sirocco fan 51. Therefore, it is preferable to provide an intake port in the housing of the image forming apparatus and connect the intake port with the air intake port of the sirocco fan 51 to take in outside air.

For example, when the transfer paper is thick paper or when the image has a high image area ratio, the amount of heat required for fixing increases, so that the temperature of the fixing device is raised. As a result, the temperature of the transfer paper that has passed through the fixing device becomes high, and the temperature of the image detection sensor tends to rise. Therefore, in such a case, it is preferable to increase the flow rate of the air flowing into the heat radiating member 10. On the other hand, in the case of forming a single image of only one image, the image detection sensor 1 is not heated to 50 ° C. or higher without air-cooling the auxiliary heat dissipation member. Therefore, in such a case, it is preferable to stop driving the sirocco fan 51, for example.

Therefore, in the present embodiment, the sirocco fan 51 is connected to the control unit 90, which is a control means, and the control unit 90 controls the flow rate of the air flowing to the heat radiating member 10. Thereby, the sirocco fan 51 can be controlled by the control unit 90 based on the thickness of the transfer paper, the image area ratio, and the number of sheets to be printed, and the flow rate of the air flowing to the heat radiating member 10 can be controlled. This makes it possible to suppress a good temperature rise of the image detection sensor 1 and reduce noise such as wind noise generated from the sirocco fan and power supply to the sirocco fan.

Further, in the present embodiment, the auxiliary heat radiating member 21 is provided with a fin-shaped heat radiating portion 21a, and the auxiliary heat radiating member 21 is cooled by air-cooling the radiating portion 21a. It may be cooled. Further, the auxiliary heat radiating member 21 may be eliminated and the heat radiating member 10 may be cooled by a liquid cooling device to improve the heat radiating efficiency of the heat radiating member 10.

FIG. 8 is a schematic configuration diagram of an image detection device in which the auxiliary heat dissipation member 21 is provided on the outer wall of the heat dissipation member 10, and FIG. 9 is an image detection device in which the auxiliary heat dissipation member 21 is provided on the outer wall of the heat dissipation member 10. It is a schematic perspective view which shows.
As shown in FIGS. 8 and 9, the auxiliary heat radiating member 21 may be provided on the outer wall of the heat radiating member 10. Even with such a configuration, the heat of the heat radiating member 10 can be transferred to the auxiliary heat radiating member and radiated by the heat radiating portion 21a of the auxiliary heat radiating member 21. As a result, the temperature rise of the heat radiating member 10 can be suppressed, and the heat of the protective glass can be satisfactorily transferred to the heat radiating member 10. Further, even in such a configuration, it is preferable to air-cool the heat-dissipating portion to cool the heat-dissipating portion.

Further, in the above description, by suppressing the transfer of heat from the guide members 41 and 42 to the heat radiating member 10, it is possible to suppress the decrease in the amount of heat transfer from the protective glass 7 to the heat radiating member 10, and the protective glass 7 is used. The temperature rise of the glass is suppressed. However, depending on the configuration of the device, it is better to positively release heat from the guide members 41 and 42 to the heat radiating member 10 and positively remove the heat of the transfer paper by the guide members 41 and 42 to protect the glass from the transfer paper. In some cases, the heat transferred to the 7 is suppressed, and the temperature rise of the protective glass 7 can be suppressed.

FIG. 10 is a schematic configuration diagram of an image detection device in which a heat conductive sheet is provided between the guide members 41 and 42 and the heat radiating member 10 so that the heat of the guide members 41 and 42 is positively released to the heat radiating member 10. Is.
As shown in FIG. 10, the guide member 41 and the heat radiating member 10 are in close contact with each other, and the third heat conductive sheet 43 that transfers the heat of the guide member 41 to the heat radiating member 10 is in close contact with the guide member 42 and the heat radiating member 10. It has a fourth heat conductive sheet 44 that transfers the heat of the guide member 42 to the heat radiating member 10. As a result, a part of the heat of the guide member 41 is transferred to the heat radiating member 10 via the third heat conductive sheet 43, and is radiated from the heat radiating member 10. Further, a part of the heat of the guide member 42 is transferred to the heat radiating member 10 via the fourth heat conductive sheet 44, and is radiated from the heat radiating member 10. Further, a part of the heat of the guide members 41 and 42 transferred to the heat radiating member 10 is transferred to the auxiliary heat radiating member 21 via the first heat conductive sheet 12 and radiated from the auxiliary heat radiating member. As a result, the temperature rise of the guide members 41 and 42 can be suppressed, and the heat of the transfer paper can be satisfactorily taken away by the guide members 41 and 42. Therefore, the transfer paper can be cooled, and the amount of heat transferred from the transfer paper to the protective glass 7 can be reduced. As a result, the temperature rise of the protective glass 7 can be suppressed, the heat transferred from the protective glass 7 to the image detection sensor 1 can be reduced, and the temperature rise of the image detection sensor 1 can be suppressed.

In the above description, the fixing device is used as the heating device, but the present invention is not limited to this, and any device that heats the recording medium may be used. For example, as a heating device, in an inkjet recording device which is an image forming device, a drying device that heats a recording medium and dries the ink ejected on the recording medium can be mentioned.

The above description is an example, and the effect peculiar to each of the following aspects is exhibited.
(Aspect 1)
A transport path for transporting a recording medium such as transfer paper P, an image forming unit for forming an image on the recording medium (in this embodiment, composed of four toner image forming units 101, an intermediate transfer unit 120, and the like), and the recording. A heating device such as a fixing device 108 that heats the medium, an image detection means such as an image detection sensor 1 that detects an image on the recording medium that has passed through the heating device, and a transport path from the lower end of the image detection means. It is an image forming apparatus provided with a protective member such as a protective glass 7 protruding from the image forming apparatus, and the protective member is held by a heat conductive member such as a heat radiating member 10.
According to this, as described in the embodiment, the protective member such as the protective glass 7 arranged between the image detection means such as the image detection sensor 1 and the recording medium such as the transfer paper P is replaced with the heat radiation member 10. By holding the heat conductive member, when the recording medium heated by the fixing device 108 passes through the image detection position of the image detecting means, the heat transferred from the recording medium to the protective member is dissipated by the heat conductive member. be able to. As a result, it is possible to suppress the heating of the image detection means by the heat of the recording medium, and it is possible to suppress the temperature rise of the image detection means without providing a cooling device for cooling the recording medium. It is possible to suppress the increase in size.

(Aspect 2)
In the first aspect, the auxiliary heat dissipation member 21 that assists the heat dissipation of the heat conductive member such as the heat dissipation member 10 is provided.
According to this, as described in the embodiment, the heat conductive member such as the heat radiating member 10 and the auxiliary heat radiating member 21 can dissipate heat from the protective member such as the protective glass 7, and the heat conductive member protects the heat conductive member. The heat dissipation efficiency can be improved as compared with the one that dissipates heat from the member. As a result, the temperature rise of the heat conductive member can be suppressed, and the heat of the protective member such as the protective glass 7 can be satisfactorily transferred to the heat conductive member. As a result, it is possible to satisfactorily suppress the heating of the image detecting means by the heat of the recording medium, and it is possible to suppress the temperature rise of the image detecting means.

(Aspect 3)
In the second aspect, the auxiliary heat dissipation member 21 receives heat from the substrate 5 of the image detection means such as the image detection sensor 1 and dissipates heat.
According to this, as described in the embodiment, it is possible to suppress the temperature rise of the substrate 5 due to the heat generated by the substrate 5 of the image detection means such as the image detection sensor 1, and the substrate 5 thermally expands. Can be suppressed. As a result, it is possible to prevent the image sensor provided on the substrate 5 from being displaced from the specified position and causing problems such as out-of-focus of the fixed image on a recording medium such as transfer paper imaged by the image sensor. .. Further, it is possible to suppress the temperature rise of the imaging lens such as SLA2 of the image detecting means due to the heat of the substrate 5. As a result, it is possible to prevent a situation in which a component is deposited on the surface of the imaging lens and the precipitated component reacts with water vapor to cause the lens surface to become cloudy. Therefore, good image detection can be performed.

(Aspect 4)
In aspect 3, the auxiliary heat dissipation member 21 includes a pressing means such as a leaf spring 23 that presses against a positioning portion 15 that positions an image detecting means such as an image detection sensor 1.
According to this, the auxiliary heat dissipation member 21 can also be used as a pressing mechanism for pressing the positioning unit 15 for positioning the image detection means such as the image detection sensor 1, and the auxiliary heat dissipation member 21 and the pressing mechanism are provided respectively. Compared to the ones, the number of parts can be reduced and the cost of the device can be reduced.

(Aspect 5)
In the third or fourth aspect, the second heat conduction sheet 22 that is in close contact with the substrate 5 of the image detection means such as the image detection sensor 1 and the auxiliary heat dissipation member 21 and transfers the heat of the substrate 5 to the auxiliary heat dissipation member 21. It has a substrate heat conductive member such as.
Since the substrate 5 and the auxiliary heat radiating member 21 are rigid bodies and are not completely smooth surfaces, the entire surface of the substrate cannot be in close contact with the auxiliary heat radiating member 21, and a gap (air layer) is inevitably created from the substrate 5. Efficient heat transfer to the auxiliary heat dissipation member 21 may not be possible.
However, in the fifth aspect, since the substrate heat conductive member such as the substrate 5 of the image detecting means and the second heat conductive sheet 22 which is in close contact with the auxiliary heat radiating member 21, is provided, either the substrate 5 of the image detecting means or the auxiliary heat radiating member 21 Efficient heat transfer from the substrate 5 to the auxiliary heat radiating member 21 can be performed via the heat conductive member that is also in close contact with the substrate 5. As a result, the temperature rise of the substrate can be satisfactorily suppressed.

(Aspect 6)
In the fifth aspect, the substrate heat conductive member such as the second heat conductive sheet 22 is insulating.
According to this, as described in the embodiment, it is possible to prevent the current flowing through the substrate 5 from flowing to the auxiliary heat radiating member 21 via the heat conductive member such as the second heat conductive sheet 22.

(Aspect 7)
In any of aspects 2 to 6, the first heat conductive sheet 12 or the like that is in close contact with the heat conductive member such as the heat radiating member 10 and the auxiliary heat radiating member 21 and transfers the heat of the heat radiating member 10 to the auxiliary heat radiating member 21. It has a second heat conductive member.
Since the heat conductive member such as the heat radiating member 10 and the auxiliary heat radiating member 21 are rigid bodies and are not completely smooth surfaces, the heat conductive member and the auxiliary heat radiating member 21 cannot be brought into close contact with each other, and a gap (a gap (inevitably) is inevitable. An air layer) is formed, and efficient heat transfer from the heat conductive member to the auxiliary heat dissipation member 21 is not possible.
Therefore, in aspect 7, since the heat conductive member such as the heat radiation member 10 and the second heat conductive member such as the first heat conductive sheet 12 that is in close contact with the auxiliary heat radiation member 21, the heat conductive member and the auxiliary heat radiation are provided. Efficient heat transfer from the heat conductive member to the auxiliary heat dissipation member 21 can be performed via the second heat conductive member that is in close contact with any of the members 21. As a result, the temperature rise of the heat conductive member can be suppressed, and the heat of the protective member such as the protective glass 7 can be satisfactorily transferred to the heat radiating member 10.

(Aspect 8)
In the seventh aspect, the second heat conductive member such as the first heat conductive sheet 12 is one of the heat conductive members such as the auxiliary heat radiation member 21 and the heat radiation member 10 (in this embodiment, the heat radiation member 10). ), And the contact portion in contact with the other member is composed of a sheet-like member such as a sliding sheet 13 having a lower friction coefficient with the other member than the second thermally conductive member.
According to this, when the other member (in the present embodiment, the auxiliary heat dissipation member 21) is attached so as to slide with the second heat conductive member such as the first heat conductive sheet 12, the second member is attached. It is possible to smoothly slide on the surface of the heat conductive member of No. 1 and prevent the second heat conductive member from peeling off from one member (heat dissipation member 10 in this embodiment).

(Aspect 9)
In any of aspects 2 to 8, a cooling means (in this embodiment, composed of a sirocco fan 51, a duct 52, etc.) for cooling the auxiliary heat radiating member 21 is provided.
According to this, as described with reference to FIG. 7, the temperature rise of the auxiliary heat radiating member 21 can be suppressed, and the heat transferred from the heat radiating member 10 can be satisfactorily dissipated.

(Aspect 10)
In the ninth aspect, a control means such as a control unit 90 for controlling the cooling means (in this embodiment, composed of a sirocco fan 51, a duct 52, etc.) is provided.
According to this, as described with reference to FIG. 7, the cooling means can be controlled based on the temperature of the transfer paper conveyed to the image detection position where the image detection means detects the image, and the cooling means can be controlled satisfactorily. The temperature rise of the image detecting means can be suppressed, the cooling can be suppressed to the minimum necessary, and the power consumption of the device can be suppressed.

(Aspect 11)
In any one of aspects 1 to 10, the recording medium is placed so that the recording medium such as transfer paper passing through the image detection position of the image detection means such as the image detection sensor 1 does not come into contact with the protective member such as the protective glass 7. It has guide members 41 and 42 to be guided, and the guide member is attached to the heat conductive member.
According to this, as described in the embodiment, by attaching the guide member to the heat conductive member such as the heat radiating member 10 that holds the protective member, the stacking of component tolerances and the like is minimized, and the protective member and the guide member are used. It is possible to prevent the relationship with and from deviating from the prescribed relationship. As a result, a good recording medium can be guided so as not to come into contact with the protective member, and dirt and temperature rise of the protective member can be suppressed.

(Aspect 12)
In the eleventh aspect, except for the attachment portion attached to the heat conductive member such as the heat radiating member 10 of the guide members 41 and 42, the heat radiating member 10 is not in contact with the heat radiating member 10.
According to this, as described in the embodiment, the heat that heats the guide members 41 and 42 when the transfer paper comes into contact with the guide members 41 and 42 is transferred to the heat conductive member such as the heat radiating member 10. Can be suppressed. As a result, it is possible to suppress the temperature rise of the heat conductive member, the heat of the protective member such as the protective glass 7 can be satisfactorily transferred to the heat conductive member, and the temperature rise of the protective member is suppressed. be able to.

(Aspect 13)
In the eleventh aspect, the third heat conductive sheet 43 and the third heat conductive sheet 43 and the third which are in close contact with the guide members 41 and 42 and the heat conductive member such as the heat radiation member 10 and transfer the heat of the guide members 41 and 42 to the heat conductive member. 4 It has a guide heat conductive member such as a heat conductive sheet 44.
According to this, as described in the embodiment, the heat of the guide members 41 and 42 can be transferred to the heat conductive member such as the heat radiating member 10 via the guide heat conductive member, and the guide members 41 and 42 can be transferred. It is possible to suppress the temperature rise of. As a result, the heat of the recording medium such as transfer paper can be satisfactorily taken by the guide members 41 and 42, and the recording medium can be satisfactorily cooled by the guide members 41 and 42. As a result, the amount of heat transferred from the recording medium to the protective member such as the protective glass 7 can be reduced, and the temperature rise of the protective member can be suppressed.

(Aspect 14)
In any of aspects 11 to 13, the guide member is provided before and after the protective member such as the protective glass 7 in the transport direction of the recording medium such as the transfer paper P.
According to this, as described in the embodiment, a recording medium such as a transfer paper that enters an image detection position where an image detection means such as an image detection sensor 1 detects an image comes into contact with a protective member such as a protective glass 7. It is possible to suppress the contact of the recording medium that has passed the image detection position with the protective member.

(Aspect 15)
In any one of embodiments 1 to 14, the heat conductive member is a metal.
According to this, the heat of the protective member such as the protective glass 7 can be satisfactorily transferred to the heat conductive member such as the heat radiating member 10, and the heat can be radiated by the heat conductive member.

1: Image detection sensor 2: SLA
3: Image pickup element 4: Light emitting element 5: Substrate 5a: Image processing chip 6: Holder 7: Protective glass 10: Heat dissipation member 11: Sensor holding part 12: First heat conduction sheet 13: Sliding sheet 15: Positioning part 16: Communication hole 18: Attached part 21: Auxiliary heat dissipation member 21a: Heat dissipation part 22: Second heat conduction sheet 23: Leaf spring 24: Mounting part 24a: Through hole 25: Heat receiving part 31: Cover member 32: Exhaust lid 32a: Exhaust Ports 41, 42: Guide member 43: Third heat conductive sheet 44: Fourth heat conductive sheet 51: Sirocco fan 52: Duct 90: Control unit 100: Printer 108: Fixing device P: Transfer paper S: Conveyance path

Japanese Patent No. 4983813

Claims (16)

A transport path for transporting recording media and
An image forming unit that forms an image on the recording medium,
A heating device that heats the recording medium,
The recording medium having an image pickup element, a substrate on which the image pickup element is arranged, an image pickup lens for forming an image on the image pickup element, and a holder for holding the image pickup lens, and having passed through the heating device. An image detection sensor that detects the above image and
An image forming apparatus including a protective member projecting from the lower end of the image detection sensor to the transport path.
The protective member is held by a heat conductive member and is held by a heat conductive member .
An image forming apparatus characterized in that an auxiliary heat dissipation member is provided to assist heat dissipation of the heat conductive member. In the image forming apparatus according to claim 1,
The auxiliary heat dissipation member is an image forming apparatus characterized in that it receives heat from the substrate of the image detection sensor and dissipates heat. In the image forming apparatus according to claim 2,
The heat conductive member has a positioning portion that the image detection sensor comes into contact with and positions the image detection sensor in a direction orthogonal to the image forming surface of the recording medium.
The auxiliary heat dissipation member is an image forming apparatus including a pressing means for pressing the image detection sensor against the positioning portion. In the image forming apparatus according to claim 2 or 3.
An image forming apparatus comprising a substrate heat conductive member that is in close contact with the substrate of the image detection sensor and the auxiliary heat radiating member and transfers heat of the substrate to the auxiliary heat radiating member. In the image forming apparatus according to claim 4,
The substrate heat conductive member is an image forming apparatus characterized by being insulating. In the image forming apparatus according to any one of claims 1 to 5.
An image forming apparatus comprising a second heat conductive member that is in close contact with the heat conductive member and the auxiliary heat radiating member and transfers heat of the heat conductive member to the auxiliary heat radiating member. In the image forming apparatus according to claim 6,
The second heat conductive member is attached to one of the auxiliary heat dissipation member and the heat conductive member, and the contact portion in contact with the other member is a contact portion of the second heat conductive member. An image forming apparatus characterized in that it is composed of a sheet-like member having a lower coefficient of friction with the other member. In the image forming apparatus according to any one of claims 1 to 7.
An image forming apparatus characterized in that a cooling means for cooling the auxiliary heat radiating member is provided. In the image forming apparatus according to claim 8,
An image forming apparatus including a control means for controlling the cooling means. In the image forming apparatus according to claim 8 or 9.
The heat conductive member has a substantially box-shaped shape with an open upper portion for accommodating the image detection sensor and the auxiliary heat dissipation member.
A cover member that covers the opening of the heat conductive member is attached to the heat conductive member.
The cooling means includes a duct that is inserted into a communication hole of the heat conductive member and is provided so that an air ejection port faces the auxiliary heat dissipation member, and a fan that blows air to the duct.
An image forming apparatus characterized in that the auxiliary heat radiating member is air-cooled by blowing air from the duct into the heat conductive member and exhausting the air from the exhaust port of the heat conductive member. In the image forming apparatus according to any one of claims 1 to 10.
It has a guide member that guides the recording medium so that the recording medium passing through the image detection position of the image detection sensor does not come into contact with the protective member.
An image forming apparatus characterized in that the guide member is attached to the heat conductive member. In the image forming apparatus according to claim 11,
An image forming apparatus characterized in that the guide member is not in contact with the heat conductive member except for a mounting portion attached to the heat conductive member. In the image forming apparatus according to claim 12,
The heat conductive member has a facing wall portion that holds the protective member and faces the recording medium, and a side wall portion that is orthogonal to the facing wall portion.
The image forming apparatus, characterized in that the guide member is attached to the side wall portion. In the image forming apparatus according to claim 13,
An image forming apparatus comprising a guide heat conductive member that is in close contact with the guide member and the heat conductive member and transfers heat of the guide member to the heat conductive member. The image forming apparatus according to any one of claims 11 to 14.
An image forming apparatus characterized in that the guide member is provided in front of and behind the transport direction of the recording medium with respect to the protective member. The image forming apparatus according to any one of claims 1 to 15.
The image forming apparatus, wherein the heat conductive member is made of metal.

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