Image reading device and image forming system
Patent Information
- Application Number
- JP2022202440
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2022-12-19
- Publication Date
- 2025-12-25
AI Technical Summary
Existing image reading devices face issues with temperature unevenness across the reading sensor, leading to decreased reading accuracy due to the circulation of air within a closed space.
The device incorporates a transport unit, reading unit, and a blower section with a vent hole, where the blower is positioned to face the vent hole, and the sensor unit is supported by a housing with an opening on the sheet conveyance side, allowing airflow distribution from the center to both ends, reducing temperature unevenness.
This configuration enhances reading accuracy by evenly cooling the sensor, reducing temperature gradients and minimizing dust accumulation, thereby improving overall reading performance.
Smart Images
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Abstract
Description
[Technical field]
[0001] The present invention relates to an image reading device that reads an image on a sheet, and an image forming apparatus to which the image reading device is applied. [Background technology]
[0002] Conventionally, there is known an image forming system equipped with an image reading device that reads an image on a sheet formed by an image forming device. For example, a reading unit in which the reading sensor is covered with glass or a housing so that the reading result by the reading sensor inside the reading unit used to read the image is not affected by foreign matter such as dust or dirt is widely used (see Patent Document 1). When the reading unit has a substantially sealed structure like this, the temperature of the light source of the reading sensor and its surroundings is likely to become very high. However, if an opening is provided in the reading unit to suppress the temperature rise, dust or dirt will adhere to the reading unit, leading to a deterioration in reading quality.
[0003] To solve this problem, a configuration has been developed in which a fan is placed inside the reading unit and the air inside is stirred for cooling (see Patent Document 2). Because outside air is not taken into the sealed space housing the reading sensor, it is possible to reduce the risk of reading errors caused by dust and dirt, while suppressing the temperature rise of the reading sensor by stirring the air. [Prior art documents] [Patent documents]
[0004] [Patent Document 1] JP 2020-6628 A [Patent Document 2] JP 2021-158440 A Summary of the Invention [Problem to be solved by the invention]
[0005] However, the reading unit described in Patent Document 2 mentioned above simply stirs the air inside the reading unit, which is an enclosed space, which can result in a large temperature difference between both longitudinal ends of the reading sensor, which can lead to a decrease in reading accuracy.
[0006] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide an image reading device and an image forming apparatus that can improve reading accuracy. [Means for solving the problem]
[0007] One aspect of the present invention is an image reading device comprising: a conveying section which receives a sheet from an image forming section which forms an image on the sheet and conveys the sheet in a sheet conveying direction; and a reading unit which reads image information of the sheet, wherein the reading unit has a substrate to which an image reading element is connected, a sensor unit which reads an image of the sheet being conveyed in the conveying direction, an air blowing section which blows air, a support member which is provided between the sensor unit and the air blowing section and supports the sensor unit, a housing which houses the sensor unit, the air blowing section, and the support member and has an opening which opens to the side to which the sheet is conveyed, and a transparent member which is provided in the opening, wherein the sensor unit is arranged to form a flow path between itself and the support member, the support member has an air vent formed at a position opposite to the outer surface of the sensor unit on the side where the substrate is provided, and the air blowing section is arranged opposite to the air vent.
[0008] Another aspect of the present invention is an image forming apparatus comprising an image forming unit that forms an image on a sheet, and the above-mentioned image reading device that reads the image on the sheet on which an image has been formed in the image forming unit. Effect of the Invention
[0009] According to the present invention, reading accuracy can be improved. [Brief description of the drawings]
[0010] [Figure 1]1 is a cross-sectional view showing an image forming apparatus according to a first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view showing an adjustment device according to the first embodiment. [Diagram 3] FIG. 2 is a cross-sectional view showing a reading section according to the first embodiment. [Figure 4] FIG. 2 is an exploded perspective view showing a reading unit according to the first embodiment. [Diagram 5] 1A and 1B are cross-sectional views showing a reading unit according to a first embodiment, in which (a) shows a case where a heat dissipation surface is located at the bottom, and (b) shows a case where a heat dissipation surface is located at the side. [Figure 6] FIG. 2 is a vertical cross-sectional view showing the reading unit according to the first embodiment. [Figure 7] 4 is a table showing the relationship between the installation position of the axial flow fan in the reading unit according to the first embodiment and the air volume difference. [Figure 8] FIG. 11 is a vertical cross-sectional view showing a reading unit according to a second embodiment. [Figure 9] FIG. 11 is an exploded perspective view showing a reading unit according to a third embodiment. [Figure 10] FIG. 11 is a cross-sectional view showing a reading unit according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0011] <First embodiment> A first embodiment of the present invention (disclosure) will be described in detail below with reference to Figs. 1 to 7. First, a schematic configuration of an image forming apparatus 1 according to this embodiment will be described with reference to Fig. 1. Fig. 1 is a cross-sectional view showing an image forming apparatus 1 according to this embodiment. Note that this embodiment is applied to a full-color copying machine having a plurality of photosensitive drums. However, the present invention is not limited to this, and can also be applied to monochrome or mono-color copying machines and printers having one photosensitive drum. Furthermore, the present invention is not limited to electrophotographic systems, and can also be applied to inkjet printers, dye-sublimation printers, and the like.
[0012] [Image forming device] The image forming apparatus 1 transports the sheet S conveyed from the sheet cassette 113 to the image forming unit, and forms a toner image on the sheet S. The image forming apparatus 1 transports the sheet S, on which the toner image has been formed in the image forming unit 102, to fixing devices 150, 160, and applies heat and pressure to fix the unfixed toner on the sheet S to the sheet S. Examples of the sheet S include paper such as thin paper and thick paper, plastic films such as overhead projector sheets (OHP), surface-treated papers such as coated paper, sheets of special shapes such as envelopes, and cloth.
[0013] The image forming unit 102 has stations 120, 121, 122, and 123, and forms an image on a sheet transported by the sheet transport unit 10. The image forming apparatus 1 includes an intermediate transfer belt 106 and a secondary transfer outer roller 114. The stations 120, 121, 122, and 123 form yellow, magenta, cyan, and black toner images on the intermediate transfer belt 106, respectively. The configurations of the stations 120, 121, 122, and 123 are the same except for the toner colors. Therefore, the configuration of the station 120 will be described as an example here, and descriptions of the configurations of the other stations 121, 122, and 123 will be omitted.
[0014] The photosensitive drum 105 as an image carrier rotates counterclockwise in FIG. 1. The primary charger 111 charges the surface of the photosensitive drum 105 to a uniform surface potential. The laser unit 108 has a light source that outputs laser light and forms an electrostatic latent image on the photosensitive drum 105. The developer 112 develops the electrostatic latent image formed on the photosensitive drum 105 using a developer containing toner to form a toner image. The toner images formed by the stations 120, 121, 122, and 123 are transferred onto the intermediate transfer belt 106. The secondary transfer outer roller 114 transfers the toner image on the intermediate transfer belt 106 to the sheet S transported from the sheet cassette 113.
[0015] Meanwhile, the sheet S fed from the sheet cassette 113 is conveyed to the secondary transfer outer roller 114 via the sheet conveying unit 10. The secondary transfer outer roller 114 presses the sheet S against the intermediate transfer belt 106, and simultaneously applies a bias having an opposite characteristic to that of the toner to the secondary transfer outer roller 114. As a result, the visible image formed on the intermediate transfer belt 106 is secondarily transferred to the sheet S fed in synchronization with the sub-scanning direction by the feeding process mechanism. Around the intermediate transfer belt 106, a start position detection sensor 115 for determining the print start position when forming an image, a feeding timing sensor 116 for timing the feeding of the sheet S, and a density sensor 117 for measuring the density of a patch during density control are arranged. When density control is performed, the density sensor 117 measures the density of each patch.
[0016] The image forming apparatus 1 has a first fixing device 150 and a second fixing device 160 for fixing the toner image transferred to the sheet S by heat and pressure. The first fixing device 150 has a fixing roller 151 for applying heat to the sheet S, a pressure belt 152 for pressing the sheet S against the fixing roller 151, and a post-fixing sensor 153 for detecting the completion of fixing. The fixing roller 151 is a hollow roller having an internal heater, and conveys the sheet S while being driven to rotate. The second fixing device 160 is located downstream of the conveying path of the sheet S from the first fixing device 150, and is arranged for the purpose of adding gloss to the toner image on the sheet S fixed by the first fixing device 150 and ensuring fixability. The second fixing device 160 also has a fixing roller 161, a pressure roller 162, and a post-fixing sensor 163, like the first fixing device 150.
[0017] Some types of sheets S do not need to pass through the second fixing device 160. In this case, in order to reduce energy consumption, a conveying path 130 is provided for discharging the sheet S without passing through the second fixing device 160. The sheet S can be guided to the conveying path 130 by a switching member 131.
[0018] The switching member 132 switches whether the sheet S, which has been transported through the image forming unit 102 and the fixing devices 150 and 160, is guided to the outside of the image forming apparatus 1 or to the transport path 135. In the case of single-sided printing, the sheet S passes through the image forming unit 102 and the fixing devices 150 and 160 and image formation is completed, and then the switching member 132 guides the sheet S to a discharge path 139 and discharges it to the outside.
[0019] In the case of double-sided printing, the sheet S is inverted after one side has been printed, and is transported again to the image forming unit 102. Specifically, the switching member 132 guides the sheet S after fixing to a transport path 135, and transports it to an inverting unit 136. When an inversion sensor 137 detects the rear end of the sheet S, a switching member 133 switches the transport direction of the sheet S to a transport path 138. The inverted sheet S is transported again to the image forming unit 102 via the transport path 138, and further to the fixing devices 150 and 160. The sheet S after double-sided printing is guided by the switching member 132 to a discharge path 139, and is discharged to the outside.
[0020] [Adjustment device] An adjustment device 40, which is an example of an image reading device shown in FIG. 2, is disposed downstream of the image forming device 1. The adjustment device 40 includes an entrance conveying roller 401 that receives and conveys the sheet S from the image forming device 1, and a reading unit 700, which are disposed in this order, and a switching unit 412 is disposed downstream of the adjustment device 40. The switching unit 412 is configured to be able to switch the conveying path between a through path 430 that passes the sheet S to a device 60 further downstream of the adjustment device 40, and a discharge path 432 that discharges the sheet S to a fixed tray 423 on the upper surface. When the sheet S is passed through the through path 430, the switching unit 412 moves to an upper position, and the sheet S is passed to the downstream device 60 via an exit conveying roller 405 disposed downstream. When the sheet S is passed through the discharge path 432, the switching unit 412 moves to a lower position, and the sheet S is discharged to the fixed tray 423 via pairs of conveying rollers 415, 416, 417, and 418 disposed downstream.
[0021] The configuration of the reading unit 700 will be described with reference to FIG. 3. The reading unit 700 measures the shape and positional relationship of the image pattern printed on the sheet S and feeds back the results to the image forming apparatus 1. To obtain highly accurate measurement results, it is necessary to average out the shape variations and print position variations for each sheet, so multiple sheets S are measured. To shorten the adjustment time, while the sheet S is being conveyed, a reading unit 700a for the back side and a reading unit 700b for the front side, which are disposed opposite each other, are used to read the measurement test patterns formed on the front and back sides of the sheet S. In addition, since it is desirable for the size of the device to be as small as possible, a contact image sensor (hereinafter, referred to as CIS) is used as the reading means in this embodiment.
[0022] The reading units 700a and 700b are provided to read the image information of the sheet, and include a CIS 702, a conveying guide member 701 made of glass for stabilizing the position of the CIS in the focal depth direction, and a housing 703 that contains the CIS 702. The CIS 702 is accommodated in a substantially sealed space formed by the conveying guide member 701 made of glass and the housing 703. That is, the housing 703 has an opening 703a that opens to the side where the sheet S is conveyed, and the conveying guide member 701, which is an example of a transparent member, is provided in the opening 703a. In addition, the sheet conveying roller pairs 402, 403, and 404 for reading at a stable sheet conveying speed and the conveying guide member 750 are also similarly arranged opposite to each other. The conveying guide member 750 has a black backing to clarify the contrast with the sheet end. The sheet conveying roller pairs 402, 403, and 404 are an example of a conveying unit that conveys the sheet in the sheet conveying direction, and are driven by a driving means using a motor or the like (not shown).
[0023] [Reading unit] Next, the internal configuration of the reading units 700a and 700b will be described with reference to Figures 4 and 5(a). Note that the reading units 700a and 700b are arranged upside down with roughly the same shape, so the internal configuration will be described only for the reading unit 700a for the back side. In the following description, the X direction indicates the main scanning direction (longitudinal direction), the Y direction indicates the sheet transport direction (shortitudinal direction), and the Z direction indicates the up-down direction.
[0024] The reading unit 700a has a CIS 702 capable of reading the entire area of the maximum paper passable size in the X direction. The CIS 702 is an example of a sensor unit that reads an image of the sheet S transported in the transport direction. This CIS 702 can read the entire area of a 13-inch sheet, for example. The CIS 702 of this embodiment has an image reading element 702a on the transport guide member 701 side, and a substrate 702b on the rear side of the image reading element 702a. The CIS 702 is packaged, and the surface that covers and faces the substrate 702b is a heat dissipation surface 702c. The heat dissipation surface 702c is the outer surface of the CIS 702 on the side where the substrate 702b is provided. Note that when the substrate 702b is exposed to the outside of the CIS 702, the heat dissipation surface 702c is the rear surface of the substrate 702b. The board 702b is equipped with many heat-generating components, such as an analog front end (AFE), which is an analog circuit that connects a signal detection device and a digital signal processing device. That is, the CIS 702 has a board 702b to which an image reading element 702a is connected, and the heat dissipation surface 702c is the surface on which the board 702b is attached.
[0025] The CIS 702 is supported by the CIS holder 704 at both ends in the X direction via a biasing spring 705 that biases the CIS 702 against the conveying guide member 701. That is, the CIS holder 704 holds the CIS 702 via the biasing spring 705. The biasing spring 705 is an example of a pair of elastic bodies that elastically supports both ends of the heat dissipation surface 702c of the CIS 702 against the CIS holder 704, and the ventilation hole 704a is disposed between the biasing springs 705. The CIS holder 704 is an example of a support member that is provided between the CIS 702 and the axial flow fan 707 and supports the CIS 702. At both ends in the X direction of the housing 703, a holding shaft 706 is provided that supports the CIS holder 704 slidably in the sheet conveying direction (Y direction). The CIS holder 704 is moved by a slide drive unit (not shown). The holding shaft 706 and the slide drive unit are an example of a moving unit that allows the CIS holder 704 to move in the sheet conveying direction inside the housing 703 to a reading position P1 (described later) and a shading position P2 different from the reading position P1. The reading unit 700a also has an axial fan 707 that is disposed approximately in the center of the CIS 702 in the X direction and directly below the substrate 702b, and a fan support plate 708 that supports the axial fan 707 and is fixed to the housing 703. The axial fan 707 is an example of a blower that blows air, and in this embodiment, it blows air toward the ventilation opening 704a.
[0026] The biasing spring 705 biases the CIS 702 against the transport guide member 701, thereby stabilizing the focal depth of the CIS 702.
[0027] In this embodiment, the axial fan 707 is disposed on the back surface of the substrate 702b as shown in FIG. 5(a), but when the substrate 702b is disposed on the side surface of the CIS 702 as shown in FIG. 5(b), it is preferable to dispose the axial fan 707 on the side surface.
[0028] While the image forming apparatus 1 is in operation, the CIS 702 and the CIS holder 704 slide in the Y direction at predetermined intervals from a reading position P1 shown by a solid line in Fig. 5(a) and are capable of moving to a shading position P2 shown by a two-dot chain line in Fig. 5(a). At the shading position P2, a white reference plate (not shown) is read and calibration is performed to maintain reading accuracy.
[0029] In this embodiment, the axial fan 707 is disposed on the reading position P1 (first position) side of the CIS 702 as shown in Fig. 5(a). This is because the time that the CIS 702 is at the reading position P1 side is longer than the time that it is at the shading position P2 (second position), and therefore a higher cooling effect can be obtained. If the time that the CIS 702 is at the shading position P2 is longer than the reading position P1, the axial fan 707 may be disposed on the shading position P2 side. The axial fan 707 is disposed opposite the ventilation hole 704a when the CIS 702 is located at the reading position P1 or the shading position P2, whichever position it stays at for a longer period of time.
[0030] The CIS holder 704 has a U-shaped cross section as shown in Fig. 5(a) and Fig. 6, and a conveying guide member 701 is disposed on the opening side to form a duct having the CIS 702 therein. The CIS holder 704 has a bottom surface 704b facing the heat dissipation surface 702c, and a side surface 704c that is perpendicular to the bottom surface 704b and protrudes toward the CIS 702. In this embodiment, the side surfaces 704c are provided on both sides of the CIS 702 in the Y direction. The CIS 702 is provided so that at least a portion of the CIS 702 overlaps with the side surface 704c when viewed from the sheet conveying direction (Y direction).
[0031] A gap is provided at the contact portion between the transport guide member 701 and the CIS holder 704 for the above-mentioned shading operation. Furthermore, the CIS holder 704 is provided with an air vent 704a for taking in air at the portion facing the axial fan 707. The air of the axial fan 707 that flows in from the air vent 704a is dispersed to the front and rear sides, passes through the gaps K1, K2, and K3 between the CIS holder 704 and the CIS 702, and flows to both ends in the X direction while exchanging heat with the CIS 702. The air that reaches both ends forms an airflow that passes outside the CIS holder 704 and returns to the axial fan 707 at the approximate center. That is, the CIS 702 is disposed so that the heat dissipation surface 702c faces the CIS holder 704 and forms a flow path between the CIS holder 704 and the CIS holder 704, and the gaps K1, K2, and K3 are examples of the flow path. In addition, in this embodiment, the CIS holder 704 has an air vent 704a formed at a position opposite the heat dissipation surface 702c on the side of the CIS 702 on which the substrate 702b is provided, and the axial fan 707 is positioned opposite the air vent 704a.
[0032] Moreover, the CIS 702 has a short side direction along the Y direction, and a long side direction along the X direction perpendicular to the short side direction and the Z direction, which is the optical axis direction of the CIS 702. The heat dissipation surface 702c has a first region located at both ends in the long side direction and a second region located closer to the center than the first region, and the vent 704a is arranged opposite the second region of the heat dissipation surface 702c. In particular, in this embodiment, the vent 704a is arranged opposite the center of the heat dissipation surface 702c in the long side direction. Also, for example, even if the vent 704a is arranged at the end of the second region, the air that passes through the vent 704a abuts against the heat dissipation surface 702c and branches to both sides in the X direction. Therefore, it is possible to reduce temperature unevenness compared to the case where air is blown in from the end and flows in only one direction.
[0033] Here, in the conventional configuration in which the axial fan 707 is disposed at one end, the airflow travels back and forth between the ends of the CIS 702, so the circulation path becomes long. As a result, the air temperature rises and the heat exchange efficiency with the CIS 702 gradually decreases, so that the temperature on the side farther from the axial fan 707 is difficult to lower, and temperature unevenness occurs in the longitudinal direction of the CIS 702. In contrast, in this embodiment, the axial fan 707 is disposed approximately at the center of the CIS 702, so that the airflow is dispersed from approximately the center of the CIS 702 to the front and rear sides, and the cooling efficiency at the front and rear sides becomes equal, and the longitudinal temperature unevenness can be eliminated. In addition, by disposing the axial fan 707 approximately at the center of the CIS 702, the circulation path can be shortened, and efficient cooling can be achieved by suppressing the rise in air temperature.
[0034] Fig. 7 shows the difference in wind speed between the front and rear sides when the axial fan 707 is moved toward the rear side from the center position of the CIS 702. The movement ratio is the amount of movement of the axial fan 707 relative to the overall length (X direction) of the CIS 702. Fig. 7 confirms that an effect can be obtained by positioning the axial fan 707 within ±40% of the overall length (X direction) of the CIS 702, and that an especially high effect can be obtained by positioning it within ±20%.
[0035] As described above, according to the reading unit 700 of this embodiment, the CIS holder 704 has the ventilation hole 704a facing the center of the heat dissipation surface 702c, and the axial fan 707 is disposed facing the ventilation hole 704a. Therefore, the airflow is distributed from approximately the center of the CIS 702 to the front and rear sides, so that the cooling efficiency at the front and rear sides is equalized, and the temperature unevenness in the longitudinal direction can be eliminated, and the decrease in reading accuracy caused by the temperature unevenness can be suppressed, and the reading accuracy can be improved.
[0036] Furthermore, according to the reading unit 700 of this embodiment, the axial flow fan 707 is disposed approximately in the center of the CIS 702, thereby shortening the circulation path and enabling efficient cooling by suppressing the rise in air temperature. In this way, the temperature gradient in the longitudinal direction that occurs when the image reading element 702a or the substrate 702b of the CIS 702 generates heat can be averaged, so that the temperature rise of the CIS 702 can be effectively suppressed while suppressing deterioration of reading accuracy due to dust and dirt.
[0037] In the above embodiment, the axial fan 707 has been described as blowing air toward the vent 704a, but the present invention is not limited to this, and the axial fan 707 may be configured to blow air in a direction in which air is sucked from the vent 704a. In this case, the air flows from both ends of the CIS 702 toward the center. In this case, the cooling efficiency is the same at the front and back sides of the CIS 702, and temperature unevenness in the longitudinal direction can be eliminated, and the decrease in reading accuracy caused by temperature unevenness can be suppressed, thereby improving reading accuracy.
[0038] <Second embodiment> Next, a second embodiment of the present invention will be described in detail with reference to Fig. 8. This embodiment differs from the first embodiment in that a cooling duct 722 is provided outside the housing 703. However, other configurations are the same as those of the first embodiment, so the same reference numerals are used and detailed description will be omitted.
[0039] In this embodiment, a duct 722, which is an example of a duct portion, is provided on the outer surface of the bottom of the housing 703. In the duct 722, an upstream fan 720 is provided on the upstream side and a downstream fan 721 is provided on the downstream side as an example of an airflow generating portion that ventilates the duct 722 and assists the cooling effect of the axial flow fan 707. The upstream fan 720 is provided in communication with one end of the duct 722 in the flow direction, and supplies air to the duct 722. The downstream fan 721 is provided in communication with the other end of the duct 722 in the flow direction, and sucks air from the duct 722. Note that, although two fans are used as the airflow generating portion in this embodiment, the present invention is not limited thereto, and one or three or more fans may be used.
[0040] The upstream fan 720 generates an airflow in a duct 722 formed at the bottom of the housing 703, thereby indirectly lowering the temperature in the accommodation space of the CIS 702. Similarly to the upstream fan 720, the downstream fan 721 indirectly lowers the temperature in the accommodation space of the CIS 702 and exhausts heat from the entire adjustment device 40.
[0041] As described above, according to the reading unit 700 of this embodiment, the duct 722 is provided on the outer surface of the housing 703, and the temperature inside the space housing the CIS 702 can be lowered, so that the cooling efficiency of the CIS 702 can be improved.
[0042] <Third embodiment> Next, a third embodiment of the present invention will be described in detail with reference to Figures 9 and 10. This embodiment differs from the first embodiment in that the housing 703 has two chambers with different functions. However, other configurations are the same as those of the first embodiment, so the same reference numerals are used and detailed description is omitted.
[0043] 9 is a diagram showing the internal configuration of the back side reading unit 710a in this embodiment. The housing 703 has a partition wall 711 that divides the inside into a first chamber C1 and a second chamber C1. The first chamber C1 houses a CIS 702 and a CIS holder 704. The partition wall 711 has communication holes 711a and 711b that communicate between the first chamber C1 and the second chamber C2. The two communication holes 711a and 711b are respectively disposed near both ends of the axial flow fan 707 in the Y direction. The axial flow fan 707 is provided penetrating the partition wall 711 and blows air between the first chamber C1 and the second chamber C2. The housing 703 forms a substantially sealed space by the transport guide member 701.
[0044] As shown in Fig. 10, the axial fan 707 takes in air from the second chamber C2 and generates an airflow in the Y direction. In this embodiment, the downstream side of the axial fan 707 in the transport direction is inclined toward the CIS 702 side about the X axis, so that air that does not enter the ventilation hole 704a can easily flow toward the communication hole 711a. That is, the axial fan 707 is arranged to blow air in a direction inclined with respect to the center line of the ventilation hole 704a. However, the inclination of the axial fan 707 is not limited to this, and it may be oriented in the Z direction, or the upstream side in the transport direction may be inclined to easily flow toward the communication hole 711b.
[0045] The generated airflow flows from the ventilation hole 704a to the end portion through the gaps K1, K2, and K3 between the CIS holder 704 and the CIS 702. The air that does not enter the ventilation hole 704a forms an airflow that passes through the communication holes 711a and 711b and returns to the axial fan 707 in the first chamber C1 via the second chamber C2, thereby reducing the pressure loss on the intake side of the axial fan 707 and improving the cooling efficiency.
[0046] As described above, according to the reading unit 700 of this embodiment, it is possible to circulate air efficiently by providing two communication holes 711a, 711b and the second chamber C2 near both ends of the axial flow fan 707. This makes it possible to more effectively suppress the occurrence of temperature unevenness in the longitudinal direction of the image reading element 702a and the substrate 702b of the CIS 702. [Explanation of symbols]
[0047] 1...image forming apparatus, 40...adjustment device (image reading device), 102...image forming section, 402...sheet conveying roller pair (conveying section), 403...sheet conveying roller pair (conveying section), 404...sheet conveying roller pair (conveying section), 700a...reading unit, 700b...reading unit, 701...conveying guide member (transparent member), 702...CIS (sensor unit), 702a...image reading element, 702b...substrate, 702c...heat dissipation surface (outer surface), 703...housing, 704...CIS holder (support supporting member), 704a...ventilation port, 704b...bottom surface, 704c...side surface, 705...biasing spring (elastic body), 706...support shaft (moving portion), 707...axial flow fan (blowing portion), 711...partition wall, 711a, 711b...communicating holes, 720...upstream fan (airflow generating portion), 721...downstream fan (airflow generating portion), 722...duct (duct portion), C1...first chamber, C2...second chamber, K1, K2, K3...gaps (flow passages), P1...moving position (first position), P2...shading position (second position)
Claims
1. a conveying section that receives a sheet from an image forming section that forms an image on the sheet and conveys the sheet in a sheet conveying direction; a reading unit that reads image information from the sheet, The reading unit includes: A transparent member; a sensor unit having a substrate to which an image reading element is connected, and reading an image on the sheet through the transparent member; a blower that blows air; a support member having an opening formed at a position facing the sensor unit and supporting the sensor unit; a housing that houses the sensor unit, the blower, and the support member; and the air blower is disposed opposite the opening of the support member on a side opposite to the sensor unit with respect to the opening, the sensor unit and the support member are arranged such that a flow path for air that has passed through the opening of the support member is formed between the sensor unit and the support member. An image reading device characterized by:
2. an outer surface of the sensor unit has first regions located at both ends of the sensor unit in a longitudinal direction and second regions located between the first regions in the longitudinal direction; the opening is disposed opposite the second region of the outer surface.
2. The image reading device according to claim 1, wherein:
3. The opening is disposed opposite to a central portion of the outer surface in the longitudinal direction.
3. The image reading device according to claim 2, wherein:
4. The blower blows air toward the opening.
3. The image reading device according to claim 1, wherein the image reading device is a scanning device.
5. The sensor unit has an opposing wall facing the substrate, the opening is formed at a position facing the opposing wall on the opposite side of the opposing wall from the sensor unit, 3. The image reading device according to claim 1, wherein the image reading device is a scanning device.
6. the support member is disposed between the blower and the sensor unit and has a bottom surface facing the sensor unit, and a side wall intersecting the bottom surface and protruding toward the sensor unit, the sensor unit at least partially overlaps the side wall when viewed from the sheet conveying direction; 3. The image reading device according to claim 1, wherein the image reading device is a scanning device.
7. A pair of elastic bodies that urge the sensor unit toward the transparent member, the opening is disposed between the pair of elastic bodies in the longitudinal direction of the sensor unit.
3. The image reading device according to claim 1, wherein the image reading device is a scanning device.
8. a moving unit configured to move the support member inside the housing between a first position where the sensor unit reads an image on a sheet and a second position different from the first position, the blower is disposed opposite the opening when the support member is located at the first position.
3. The image reading device according to claim 1, wherein the image reading device is a scanning device.
9. a duct portion provided on an outer surface of the bottom of the housing; an airflow generating unit that ventilates the duct portion, 3. The image reading device according to claim 1, wherein the image reading device is a scanning device.
10. The airflow generating unit is an upstream fan provided in communication with one end of the duct portion in a flow direction and configured to supply air to the duct portion; a downstream fan provided in communication with the other end of the duct portion in the flow path direction and configured to draw air from the duct portion; 10. The image reading device according to claim 9, wherein:
11. the housing has a partition wall that divides the interior into a first chamber and a second chamber, The first chamber accommodates the sensor unit and the support member, the partition wall has a communication hole that communicates the first chamber with the second chamber, The air blowing section is provided in the partition wall and blows air between the first chamber and the second chamber.
3. The image reading device according to claim 1, wherein the image reading device is a scanning device.
12. The air blowing unit is disposed so as to blow air in a direction inclined with respect to a surface of the support member on which the opening is formed.
12. The image reading device according to claim 11,
13. An image forming apparatus for forming an image on a sheet; an image reading device having a reading unit that reads an image on a sheet conveyed from the image forming device; Equipped with The reading unit includes: A transparent member; a sensor unit having a substrate to which an image reading element is connected, and reading an image on the sheet through the transparent member; a blower that blows air; a support member having an opening formed at a position facing the sensor unit and supporting the sensor unit; a housing that houses the sensor unit, the blower, and the support member; and the air blower is disposed opposite the opening of the support member on a side opposite to the sensor unit with respect to the opening, the sensor unit and the support member are arranged such that a flow path for air that has passed through the opening of the support member is formed between the sensor unit and the support member. An image forming system comprising: