Image forming device

Abstract

To improve the detection accuracy of a sensor.SOLUTION: An image forming apparatus comprises: an image forming unit 140 that forms an image on a medium P; a fixing unit 150 that fixes the image to the medium P; a housing 30 that accommodates the image forming unit 140 and the fixing unit 150 and has an intake port 41; an intake duct 51 that communicates with the intake port 41; an intake fan 61 that is arranged in the intake duct 51; and a sensor 20 that is arranged between the intake port 41 and the intake fan 61 inside the intake duct 51 and detects at least either one of temperature or humidity.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to an image forming apparatus that forms an image on a medium. [Background technology]

[0002] The image forming apparatus is provided with a sensor for detecting the temperature and humidity of the environment in order to form an image according to the temperature and humidity of the environment in which the image forming apparatus is placed. For example, Patent Document 1 proposes placing a sensor near the air intake of the image forming apparatus. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2004-20683 A (see Figs. 1 and 2) Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, as image forming devices become smaller, components such as the fixing unit tend to be arranged closer together, which may cause the temperature and humidity detection results obtained by the sensor to be affected by heat from the fixing unit, etc.

[0005] The present disclosure has been made to solve the above problems, and aims to improve the accuracy of temperature and other detection by a sensor. [Means for solving the problem]

[0006] The image forming apparatus according to the present disclosure includes an image forming unit that forms an image on a medium, a fixing unit that fixes the image on the medium, and a fixing unit that accommodates the image forming unit and the fixing unit. 1. Air intake and a second intake A housing having 1. Air intake and a second intake A duct connected to the duct, an intake fan installed in the duct, and inside the duct 1.a sensor disposed between the intake port and the intake fan, the sensor detecting at least one of temperature and humidity; 、 Equipped with The first air intake and the second air intake are formed on surfaces of the housing that face in different directions. do. Effect of the Invention

[0007] According to the present disclosure, the sensor is positioned inside the duct between the intake port and the intake fan, thereby suppressing the effects of heat from other components and enabling the sensor to detect the temperature, etc. of the environment in which the image forming device is placed with high accuracy. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 illustrates a configuration of an image forming apparatus according to a first embodiment. [Diagram 2] FIG. 2 is a block diagram showing a control system of the image forming apparatus according to the first embodiment. [Diagram 3] 1 is a perspective view showing an external appearance of an image forming apparatus according to a first embodiment. [Figure 4] 1 is a perspective view showing an image forming apparatus according to a first embodiment with a left side cover removed; [Diagram 5] FIG. 2 is a diagram illustrating a duct structure of the image forming apparatus according to the first embodiment. [Figure 6] 1A is a diagram showing the arrangement of an environmental sensor in the first embodiment, and FIGS. 1B and 1C are diagrams showing a support structure for the environmental sensor. [Figure 7] 2 is a diagram illustrating an arrangement of an air intake, an air intake duct, a fan, and a sensor in the first embodiment. FIG. [Figure 8] FIG. 2 is a perspective view showing an image forming apparatus of a comparative example with a left side cover removed. [Figure 9] FIG. 4 is a diagram showing an internal air passage of an image forming apparatus of a comparative example. [Figure 10] 11 is a diagram showing the air flow in the intake duct when a shield is placed on one side of the image forming apparatus. FIG. [Figure 11] 13A and 13B are diagrams illustrating a duct structure of a modified image forming apparatus. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] First embodiment <Configuration of Image Forming Apparatus> 1 is a diagram showing an image forming apparatus 1 according to a first embodiment. The image forming apparatus 1 is a printer that forms an image using electrophotography. The image forming apparatus 1 includes a medium tray 110, a medium supply unit 120, a medium transport unit 130, an image forming unit 140, a fixing unit 150, and a medium discharge unit 170. These components are housed in a housing 30.

[0010] The medium tray 110 stores medium P such as printing paper, and is removably attached to the lower part of the housing 30. Inside the medium tray 110, a medium placement plate 111 on which the medium P is placed is provided rotatably about a support shaft 112 extending in the width direction of the medium P.

[0011] A lift-up lever 113 rotatably supported by a rotating shaft 114 is provided below the medium placement plate 111. The rotating shaft 114 is configured to be connectable to a motor 115 provided inside the housing 30. When the medium tray 110 is attached to the housing 30, the rotating shaft 114 is connected to the motor 115. The lift-up lever 113 rotates due to the driving force of the motor 115, and the medium placement plate 111 biased by the lift-up lever 113 rotates about the support shaft 112.

[0012] A rise detector 116 is provided within the housing 30 to detect when the medium P on the medium placement plate 111 has risen to a predetermined height. When the rise detector 116 detects the medium P, the rotation of the motor 115 is stopped, thereby stopping the rise of the medium placement plate 111. The medium tray 110 is also provided with a guide member (not shown) that regulates the loading position of the medium P.

[0013] Also provided within the housing 30 are a medium presence / absence detection unit 117 that detects the presence or absence of medium P on the medium placement plate 111, and a medium remaining amount detection unit 118 that detects the remaining amount of medium P.

[0014] The medium supply unit 120 sends out the media P stored in the medium tray 110 one by one to the transport path 101. The medium supply unit 120 has a pickup roller 121 provided so as to be in pressure contact with the upper surface of the medium P on the medium placement plate 111, and a feed roller 122 and a retard roller 123 provided adjacent to the pickup roller 121.

[0015] Pickup roller 121 is rotated in the direction indicated by the arrow in FIG. 2 by transport motor 222, and sends medium P on medium placement plate 111 to transport path 101. Retard roller 123 generates torque in the direction indicated by the arrow in FIG. 2 by a torque generating mechanism, and prevents double feeding of medium P. Pickup roller 121 and feed roller 122 each have a built-in one-way clutch, and can rotate freely in the direction indicated by the arrow in FIG. 2 even when the rotational drive is stopped.

[0016] The medium transport unit 130 transports the medium P sent from the medium tray 110 to the transport path 101 to the image forming unit 140. The medium transport unit 130 includes two pairs of transport rollers 131, 132 along the transport path 101. The transport rollers 131, 132 are rotated by a transport motor 222 in the direction indicated by the arrow in the figure, and transport the medium P along the transport path 101.

[0017] Further, a paper feed sensor 133 that detects the passage of the medium P is provided upstream of the transport roller 131 along the transport path 101. The transport roller 131 corrects skew of the medium P by starting to rotate a predetermined time after the transport sensor 133 detects the passage of the medium P.

[0018] A paper feed sensor 134 that detects the passage of the medium P is provided upstream of the transport rollers 132. The transport rollers 132 immediately start rotating after the paper feed sensor 134 detects the passage of the medium P, and feed the medium P without stopping.

[0019] A writing sensor 135 that detects the passage of the medium P is provided downstream of the transport rollers 132. The writing sensor 135 is used to determine the exposure timing of the exposure head 143, which will be described later.

[0020] The image forming unit 140 has a photoconductor drum 141 as an image carrier. The photoconductor drum 141 is a cylindrical member having a photosensitive layer, which is made of a charge generating layer and a charge transport layer laminated on the surface of a conductive substrate, and is rotated clockwise in the figure by a drum motor 220.

[0021] An exposure head 143 serving as an exposure device is disposed opposite the photosensitive drum 141. The exposure head 143 has an LED array in which LEDs (light emitting diodes) serving as light emitting elements are arranged, and a lens array, and forms an electrostatic latent image by irradiating the surface of the photosensitive drum 141 with light. The exposure head 143 is suspended and supported by a top cover 36, which will be described later.

[0022] In addition to the photosensitive drum 141, the image forming unit 140 has a charging roller 142 as a charging member, a developing roller 144 as a developer carrier, a supply roller 145 as a supply member, a toner container 146 as a developer container, and a cleaning member 147.

[0023] A charging voltage is applied to the charging roller 142 by the voltage application unit 211 (FIG. 2), and the charging roller 142 uniformly charges the surface of the photoconductor drum 141. A developing voltage is applied to the developing roller 144 by the voltage application unit 211, and the developing roller 144 develops the electrostatic latent image on the surface of the photoconductor drum 141 with black toner (developer).

[0024] Supply roller 145 receives a supply voltage from voltage application unit 211 and supplies black toner to development roller 144. Toner container 146 is, for example, a removable toner cartridge, and supplies toner to development roller 144 and supply roller 145. Cleaning member 147 scrapes off toner remaining on the surface of photoconductor drum 141.

[0025] A transfer roller 148 serving as a transfer body is disposed so as to come into contact with the surface of the photosensitive drum 141. The transfer roller 148 has a roller portion formed of conductive sponge or rubber. A transfer nip is formed between the photosensitive drum 141 and the transfer roller 148, and the medium P from the medium conveying unit 130 passes through the transfer nip. A transfer voltage is applied to the transfer roller 148 by a voltage application unit 211, and the toner image on the surface of the photosensitive drum 141 is transferred to the medium P by this transfer voltage.

[0026] 1 is configured to form a monochrome image in black by the image forming unit 140, but is not limited to such a configuration example. For example, a plurality of image forming units for yellow, magenta, cyan, black, etc. may be arranged in the transport direction of the medium P to form a color image.

[0027] Fixing section (fixing device) 150 fixes the toner image onto medium P onto which the toner image has been transferred by image forming section 140. Fixing section 150 has fixing roller 151 incorporating heater 153, and pressure roller 152 incorporating heater 154. Heaters 153 and 154 are, for example, halogen lamps. A fixing nip is formed between fixing roller 151 and pressure roller 152. Fixing roller 151 is rotationally driven by fixing motor 221.

[0028] The fixing roller 151 and the pressure roller 152 apply heat and pressure to the medium P passing through the fixing nip to melt and fix the toner image on the medium P. Adjacent to the downstream side of the fixing unit 150, a discharge sensor 156 that detects the passage of the medium P is disposed.

[0029] The medium discharge section 170 discharges the medium P on which the toner image has been fixed by the fixing section 150 to the outside of the housing 30. The medium discharge section 170 has three pairs of discharge rollers 171, 172, and 173 along the discharge path 102 leading to the discharge opening.

[0030] The discharge rollers 171, 172, and 173 are rotated by a transport motor 222 to transport the medium P and discharge it from the discharge port. The rotation timing of the discharge rollers 171, 172, and 173 is determined by the detection of the passage of the medium P by the discharge sensor 156. The medium P discharged by the medium discharge unit 170 is placed on a stacker 36a provided in the top cover 36.

[0031] Furthermore, an MPT (Multi Purpose) tray 160 is provided on one side (the right side in the figure) of the housing 30. The MPT tray 160 is attached to an MPT cover 37 (FIG. 3) described below. The MPT tray 160 has a tray section 161 on which the medium P is placed, and a pickup roller 162 that feeds the medium P on the tray section 161 one by one into the housing 30. A transport roller 163 is provided inside the housing 30 to transport the medium P supplied from the MPT tray 160 toward the transport roller 132. Note that the image forming apparatus 1 does not necessarily have to include the MPT tray 160.

[0032] Furthermore, for double-sided printing, the image forming apparatus 1 is provided with a reversing conveying mechanism 180 that reverses the medium P having a toner image fixed on its surface and conveys it to the conveying rollers 131. The reversing conveying mechanism 180 has a switching guide 181 that selectively guides the medium P sent out from the fixing unit 150 to the discharge path 102 or the evacuation path 103.

[0033] The reversing conveying mechanism 180 has two pairs of reversing rollers 182, 183 along the retreat path 103, and three pairs of conveying rollers 184, 185, 186 along the return conveying path 104. The reversing rollers 182, 183 are rotated in both forward and reverse directions by a reversing motor 224 (FIG. 2), and after pulling the medium P into the retreat path 103, they are reversed and sent out to the return conveying path 104.

[0034] The conveying rollers 184, 185, and 186 are rotated by a conveying motor 222 (FIG. 2) to convey the medium P along the return conveying path 104. The return conveying path 104 merges with the conveying path 101 upstream of the conveying roller 131. Note that if the image forming apparatus 1 does not have a double-sided printing function, the reversing conveying mechanism 180 may not be provided.

[0035] Image forming apparatus 1 also includes an intake duct 51 that takes in air from outside housing 30, between image forming unit 140 and fixing unit 150. Also, an exhaust duct 52 that exhausts the air taken in by intake duct 51 is disposed between fixing unit 150 and medium discharge unit 170. The intake duct 51 and exhaust duct 52 will be described later.

[0036] In Fig. 1, the axial direction of the photoconductor drum 141 is the X direction. The X direction is the width direction of the medium P being transported, and is also the axial direction of each roller in the image forming apparatus 1. The movement direction of the medium P when the medium P passes through the image forming unit 140 is the Y direction. The direction perpendicular to the X direction and the Y direction is the Z direction. Here, the Z direction is the up-down direction.

[0037] Regarding the Y direction, the transport direction when the medium P passes through the image forming unit 140 is the +Y direction, and the opposite direction is the -Y direction. Regarding the X direction, the right hand direction when facing the +Y direction is the +X direction, and the left hand direction is the -X direction. Regarding the Z direction, the upward direction in FIG. 1 is the +Z direction, and the downward direction is the -Z direction.

[0038] <Image forming device control system> 2 is a block diagram showing a control system of the image forming apparatus 1. The image forming apparatus 1 has a main control unit 201, an I / F (interface) control unit 230, a receiving memory 231, an image data editing memory 232, a voltage control unit 202, an exposure control unit 203, a drive control unit 204, a fixing control unit 205, a fixing motor control unit 206, a conveying motor control unit 207, an electromagnetic clutch control unit 208, a reversing motor control unit 209, and a fan motor control unit 210.

[0039] The main control unit 201 includes a microprocessor, a ROM (Read Only Memory), a RAM (Random Access Memory), an input / output port, a timer, etc. The main control unit 201 receives print data and control commands from a higher-level device via the I / F control unit 230, and executes the print operation of the image forming apparatus 1.

[0040] The main control unit 201 receives detection signals of the medium P from the above-mentioned paper feed sensors 133, 134, writing sensor 135, and discharge sensor 156. The main control unit 201 also receives detection signals of temperature and humidity from an environment sensor 20, which will be described later, and an operation signal from an operation panel 39.

[0041] The receiving memory 231 temporarily stores print data input from a higher-level device via the I / F control unit 230. The image data editing memory 232 receives the print data stored in the receiving memory 231 and records image data formed by editing the print data, i.e., image data.

[0042] The voltage control unit 202 controls the bias voltages (charging voltage, developing voltage, supply voltage, and transfer voltage) applied from the voltage application unit 211 to the charging roller 142, the developing roller 144, the supply roller 145, and the transfer roller 148.

[0043] The exposure control unit 203 sends the image data recorded in the image data editing memory 232 to the exposure head 143 and controls the light emission of the exposure head 143 .

[0044] A drive control unit 204 controls the rotation of a drum motor 220 that drives and rotates the photosensitive drum 141, the developing roller 144, the supply roller 145, and the like.

[0045] The fixing control unit 205 has a temperature adjustment circuit and supplies current to the heaters 153 and 154 based on an output signal of a temperature sensor (not shown) of the fixing unit 150. The fixing motor control unit 206 controls the rotation of the fixing motor 221 that drives the fixing roller 151 to rotate.

[0046] The conveying motor control unit 207 controls the rotation of a conveying motor 222 which drives the pickup rollers 121 and 162, the feed roller 122, the conveying rollers 131, 132 and 163, the discharge rollers 171, 172 and 173, and the conveying rollers 184, 185 and 186 to rotate.

[0047] The electromagnetic clutch control unit 208 controls the operation of an electromagnetic clutch 223 that controls the transmission of rotation from the transport motor 222 to the pickup rollers 121 and 162, the feed roller 122, the transport rollers 131, 132 and 163, the discharge rollers 171, 172 and 173, and the transport rollers 184, 185 and 186.

[0048] The inversion motor control unit 209 controls the rotation of an inversion motor 224 that drives the inversion rollers 182 and 183 of the inversion transport mechanism 180 to rotate.

[0049] The fan motor control unit 210 controls the rotation of a fan motor 225 that drives the intake fans 61 and 62, the blower fan 63, and the exhaust fan 64, which will be described later. Each motor shown in Fig. 2 can be configured by a two-phase excitation pulse motor, a DC motor, or the like.

[0050] <Duct structure of image forming device> 3 is a perspective view showing the appearance of the image forming apparatus 1. A housing 30 of the image forming apparatus 1 has a left side cover 31 as a side portion, a right side cover 32 as another side portion, a front cover 33 as a front portion, a rear cover 34 as a back portion, and an upper cover 35 as a top portion.

[0051] The left side cover 31 and the right side cover 32 are formed on the -X side (left side) and +X side (right side), respectively, of the housing 30. The front cover 33 and the rear cover 34 are formed on the -Y side (front side) and +Y side (rear side), respectively, of the housing 30.

[0052] A top cover 36 serving as an opening / closing cover is provided above the housing 30. The top cover 36 can be opened and closed around an X-direction support shaft (not shown) provided at the rear of the housing 30. The top cover 36 is provided with the above-mentioned stacker 36a.

[0053] The upper cover 35 is formed above the housing 30 and on both sides in the X direction of the top cover 36. An operation panel 39 is provided on the upper cover 35. The operation panel 39 includes a display for displaying the state of the image forming apparatus 1, and an operation unit such as keys and switches for an operator to input instructions.

[0054] In addition to the front cover 33, an openable / closable MPT cover 37 and a removable tray cover 38 are provided on the -Y side of the housing 30. The above-mentioned MPT tray 160 (FIG. 1) is attached to the MPT cover 37. The above-mentioned media tray (FIG. 1) is attached to the tray cover 38.

[0055] The left side cover 31 is formed with an intake port 41 as a first intake port, an exhaust port 45, and a vent port 46. The intake port 41 is formed in approximately the center in the Y direction of the left side cover 31. The exhaust port 45 and the vent port 46 are formed in the vicinity of the end of the left side cover 31 in the +Y direction.

[0056] 3, an air intake port 43 (FIG. 5) serving as a third air intake port is formed in the right side cover 32. The air intake port 43 is formed in approximately the center of the right side cover 32 in the Y direction.

[0057] An intake port 42 serving as a second intake port is formed at the end of upper cover 35 in the -X direction. Also, an intake port 44 serving as a fourth intake port is formed at the end of upper cover 35 in the +X direction. Both intake ports 42 and 44 are formed in approximately the center of upper cover 35 in the Y direction.

[0058] In order to prevent foreign matter from entering the housing 30, it is desirable that the intake ports 41 to 44, the exhaust port 45 and the ventilation port 46 are formed in a lattice shape (grid shape) or a slit shape.

[0059] Fig. 4 is a perspective view showing the image forming apparatus 1 with the left side cover 31 removed. As shown in Fig. 4, an intake duct 51 for taking in outside air is formed inside the housing 30. The intake duct 51 communicates with both the intake port 41 (Fig. 3) provided in the left side cover 31 and the intake port 42 provided in the upper cover 35.

[0060] A high-voltage board 90 mounting the voltage control unit 202 of Fig. 2 is disposed on the -X side of the housing 30 (a position covered by the left side cover 31). On the other hand, a control board mounting the main control unit 201 of Fig. 2 is disposed on the +X side of the housing 30 (a position covered by the right side cover 32).

[0061] Moreover, on the -X side of the housing 30, a blower fan 65 is disposed in the +Y direction (rearward) of the high-voltage board 90. The blower fan 65 blows air to the voltage application unit 211 (hidden in FIG. 4) in FIG. 2. The ventilation hole 46 shown in FIG. 3 is provided at a position corresponding to the ventilation fan 65. Note that the ventilation hole 46 and the ventilation fan 65 do not necessarily have to be provided.

[0062] Fig. 5 is a diagram showing a duct structure of the image forming apparatus 1. As shown in Fig. 5, the intake duct 51 extends linearly in the X direction so as to connect the intake port 41 provided in the left side cover 31 and the intake port 43 provided in the right side cover 32.

[0063] The intake duct 51 is disposed between the image forming unit 140 and the fixing unit 150 in the Y direction. The intake duct 51 is, for example, a rectangular cylindrical member made of plastic. The intake duct 51 also communicates with the intake ports 42 and 44 (FIG. 4).

[0064] Intake fans 61, 62 and a blower fan 63 are provided in intake duct 51. Intake fan 61 is disposed closer to intake port 41 than the center of intake duct 51 in the X direction, and intake fan 62 is disposed closer to intake port 43 than the center of intake duct 51 in the X direction. Blower fan 63 is disposed in the center of intake duct 51 in the X direction.

[0065] Intake fan 61 is fitted into an opening formed in intake duct 51 on the image forming unit 140 side. The rotation axis direction of the impeller of intake fan 61 is the Y direction, and the air blowing direction is the -Y direction. When intake fan 61 rotates, air flows into intake duct 51 from intake port 41, and then toward image forming unit 140.

[0066] Intake fan 62 is fitted into an opening formed in intake duct 51 on the image forming unit 140 side. The rotation axis direction of the impeller of intake fan 62 is the Y direction, and the air blowing direction is the -Y direction. By the rotation of intake fan 62, air flows into intake duct 51 from intake port 43, and then toward image forming unit 140.

[0067] The blower fan 63 faces the image forming unit 140 through an opening 51a formed in the intake duct 51, and faces the fixing unit 150 through an opening 51b. The rotation axis direction of the impeller of the blower fan 63 is the Y direction, and the blowing direction is the +Y direction. The blower fan 63 blows the air blown by the intake fans 61 and 62 to the image forming unit 140 in the +Y direction, i.e., toward the fixing unit 150.

[0068] An exhaust duct 52 is disposed in the +Y direction (i.e., on the rear cover 34 side) of the fixing unit 150. The exhaust duct 52 communicates with an exhaust port 45 formed in the left side cover 31 and extends in the X direction. The exhaust duct 52 is, for example, a rectangular tubular member made of plastic.

[0069] Exhaust duct 52 has an opening 52a on the intake duct 51 side (i.e., on the fixing unit 150 side). Air sent from intake duct 51 by blower fan 63 passes through fixing unit 150 and enters exhaust duct 52 from opening 52a.

[0070] An exhaust fan 64 is provided at the exhaust port 45. The rotation axis direction of the impeller of the exhaust fan 64 is the X direction, and the air blowing direction is the −X direction. The exhaust fan 64 exhausts the air in the exhaust duct 52 from the exhaust port 45 to the outside.

[0071] Intake fans 61, 62, blower fan 63 and exhaust fan 64 are, for example, axial fans (propeller fans) and are rotated by fan motor 225 shown in Fig. 2. When intake fans 61, 62, blower fan 63 and exhaust fan 64 rotate, air is taken into intake duct 51 from intake ports 41, 42 and intake ports 43, 44 (Fig. 3), as shown by arrow F in Fig. 5.

[0072] The air taken in by intake duct 51 is directed toward image forming unit 140 by intake fans 61 and 62, and is further directed toward fixing unit 150 by blower fan 63. The air that has passed through fixing unit 150 is sent into exhaust duct 52, and is exhausted outside housing 30 from exhaust port 45 by exhaust fan 64.

[0073] An environmental sensor 20 is disposed in the intake duct 51 between the intake port 41 and the intake fan 61. The environmental sensor 20 detects the temperature and humidity of the environment in which the image forming apparatus 1 is placed. Note that although the environmental sensor 20 detects both the temperature and humidity here, it is sufficient that the environmental sensor detects at least one of the temperature and humidity.

[0074] Fig. 6(A) is a diagram for explaining the arrangement of environmental sensor 20 in intake duct 51. As shown in Fig. 6(A), environmental sensor 20 is mounted on substrate 23, and is disposed in the air passage of intake duct 51. In particular, environmental sensor 20 is located in the +X direction with respect to intake port 41 (Fig. 3), and in the -Z direction with respect to intake port 42.

[0075] Fig. 6(B) is a perspective view showing a support structure for the environment sensor 20. As shown in Fig. 6(B), the environment sensor 20 is an element including a temperature detection section and a humidity detection section, and is mounted on a substrate 23. The substrate 23 is disposed so that its plate surface is perpendicular to the Y direction.

[0076] The board 23 on which the environmental sensor 20 is mounted is held by a pair of upper and lower support levers 21, 22 protruding from the wall portion 51c of the intake duct 51. In addition to the environmental sensor 20, the board 23 is also mounted with a connector 24a for connection to the main control unit 201, a chip 24b, etc.

[0077] Fig. 6(C) is a schematic diagram showing the support levers 21 and 22. As shown in Fig. 6(C), the support lever 21 has a claw portion 21a that engages with the upper end of the substrate 23. The support lever 22 has a claw portion 22a that engages with the lower end of the substrate 23. The support levers 21 and 22, which serve as sensor support members, support both ends of the substrate 23 in the Z direction with the respective claw portions 21a and 22a.

[0078] In this manner, the substrate 23 on which the environmental sensor 20 is mounted is held at a position away from the wall portion 51c of the intake duct 51 by the support levers 21 and 22. Therefore, the temperatures of the other components are not easily transmitted to the environmental sensor 20 via the wall portion 51c of the intake duct 51.

[0079] 7 is a diagram showing the positional relationship in a plane perpendicular to the Y direction between the intake duct 51, the intake ports 41, 42, and the environment sensor 20. The intake port 41 formed in the left side cover 31 and the intake port 42 formed in the upper cover 35 are located at approximately the same position in the Y direction.

[0080] As described above, the environment sensor 20 is located in the +X direction of the intake port 41 and in the -Z direction of the intake port 42. In other words, the environment sensor 20 is disposed on the flow path of air that has passed through the intake port 41 and on the flow path of air that has passed through the intake port 42.

[0081] In addition, a drip-proof wall 25 serving as a cover is disposed between the intake port 42 and the environment sensor 20. The drip-proof wall 25 is provided to prevent liquid droplets falling from the intake port 42 from splashing on the environment sensor 20 when a user spills liquid on the housing 30.

[0082] Here, upper and lower lattice sections 47, 48 are formed in the air intake 42 of the upper cover 35, and the drip-proof wall 25 is attached to the lower (-Z side) lattice section 48. However, the drip-proof wall 25 may be attached in any manner as long as it is disposed between the air intake 42 and the environment sensor 20.

[0083] Incidentally, an inclined surface 51e is provided in a portion of bottom 51d of intake duct 51 located on the -Z side of intake port 42. Inclined surface 51e is displaced in the -Z direction as it approaches intake port 41. Inclined surface 51e is provided in order to maximize the area of ​​intake port 41 and to facilitate discharging droplets that have fallen from intake port 42 to the outside from intake port 41.

[0084] The environment sensor 20 outputs detection signals of temperature and humidity to the main control unit 201 shown in Fig. 2. The main control unit 201 outputs a control signal to the voltage control unit 202 based on the detection signals of the environment sensor 20.

[0085] <Operation of the image forming device> Next, a basic operation of image forming apparatus 1 will be described with reference to Figures 1 and 2. Here, a case where an image is formed on medium P accommodated in medium tray 110 will be described.

[0086] When the main control unit 201 of the image forming apparatus 1 receives a print command and print data from a host device via the I / F control unit 230, it starts an image forming (printing) operation.

[0087] The main control unit 201 temporarily records print data received from a higher-level device in a reception memory 231 , edits the recorded print data to generate image data, and records the image data in an image data editing memory 232 .

[0088] Furthermore, in response to an instruction from main control unit 201, fan motor control unit 210 rotates fan motor 225, and intake fans 61, 62, blower fan 63, and exhaust fan 64 rotate. As a result, air is taken in from intake ports 41 to 44 into intake duct 51, and the air flows through image forming unit 140 and fixing unit 150. The air that has flowed through image forming unit 140 and fixing unit 150 is exhausted from exhaust port 45 via exhaust duct 52.

[0089] Furthermore, the fixing motor control unit 206 rotates the fixing motor 221, which starts rotating the fixing roller 151 and the pressure roller 152. Furthermore, the fixing control unit 205 energizes the heaters 153 and 154, which heat the fixing roller 151 and the pressure roller 152 to a predetermined fixing temperature.

[0090] In addition, the conveying motor control unit 207 rotates the conveying motor 222, and the electromagnetic clutch control unit 208 operates the electromagnetic clutch 223, whereby the pickup roller 121 and the feed roller 122 rotate to send the medium P in the medium tray 110 one by one to the conveying path 101. In addition, the conveying rollers 131 and 132 rotate to convey the medium P to the image forming unit 140.

[0091] For image formation in the image forming unit 140, the voltage control unit 202 applies a charging voltage, a developing voltage, and a supply voltage from a voltage application unit 211 to the charging roller 142, the developing roller 144, and the supply roller 145. The developing voltage and the supply voltage are adjusted based on a detection signal from the environment sensor 20.

[0092] In addition, drive control unit 204 rotates drum motor 220 to rotate photoconductor drum 141. As photoconductor drum 141 rotates, charging roller 142, developing roller 144, and supply roller 145 also rotate. Charging roller 142 charges the surface of photoconductor drum 141 uniformly.

[0093] When the leading edge of the medium P reaches the writing sensor 135, the exposure control unit 203 causes the exposure head 143 to emit light based on the image data recorded in the image data editing memory 232. An electrostatic latent image is formed on the surface of the photoconductor drum 141 by the light irradiation.

[0094] The electrostatic latent image formed on the surface of the photoconductor drum 141 is developed by the toner of the developing roller 144, and a toner image is formed on the surface of the photoconductor drum 141. The voltage control unit 202 applies a transfer voltage from the voltage application unit 211 to the transfer roller 148. At this time, the transfer voltage is adjusted based on a detection signal from the environment sensor 20.

[0095] The toner image formed on the surface of the photoconductor drum 141 is transferred to the medium P passing through the transfer nip between the photoconductor drum 141 and the transfer roller 148. The toner that has not been transferred to the medium P is scraped off by the cleaning member 147.

[0096] In the fixing unit 150, as described above, the fixing roller 151 and the pressure roller 152 rotate and reach a predetermined fixing temperature. Heat and pressure are applied to the medium P conveyed to the fixing nip between the fixing roller 151 and the pressure roller 152, thereby fixing the toner image to the medium P.

[0097] When the leading edge of the medium P reaches the discharge sensor 156, the transport motor control unit 207 rotates the transport motor 222, and the electromagnetic clutch control unit 208 activates the electromagnetic clutch 223, causing the discharge rollers 171, 172, and 173 to rotate and transport the medium P, and discharge it outside the housing 30. The discharged medium P is stacked on the stacker 36a. This completes the formation of an image on the medium P.

[0098] When continuous printing is performed, the medium P, on whose surface the toner image has been fixed by the fixing unit 150, is guided to the evacuation path 103 by the switching guide 181. Then, the reversing motor control unit 209 rotates the reversing motor 224 in the forward direction to pull the medium P into the evacuation path 103, and then reverses the reversing motor 224 to send the medium P out of the evacuation path 103.

[0099] Furthermore, the conveying motor control unit 207 rotates the conveying motor 222 and operates the electromagnetic clutch control unit 208, whereby the conveying rollers 184, 185, and 186 rotate to convey the medium P along the return conveying path 104. The medium P conveyed along the return conveying path 104 reaches the conveying roller 131, and then a toner image is formed on the back surface of the medium P.

[0100] <effect> The operation of the image forming apparatus 1 of the present embodiment will be described in comparison with a comparative example. Fig. 8 is a perspective view showing the image forming apparatus 1B of the comparative example with the left side cover 31 removed. Fig. 9 is a schematic diagram showing the internal structure of the image forming apparatus 1B of the comparative example.

[0101] As shown in Fig. 8, image forming apparatus 1B of the comparative example does not have intake duct 51 and exhaust duct 52. As shown in Fig. 9, an intake port 43 is formed in right side cover 32 of housing 30 of image forming apparatus 1B. An exhaust port 45 is formed in left side cover 31 of housing 30. An exhaust fan 64 is attached to exhaust port 45.

[0102] The intake port 43 is formed in the center of the housing 30 in the Y direction. The exhaust port 45 is disposed in approximately the same position in the Y direction as the fixing unit 150. When the exhaust fan 64 rotates, as shown by the arrow F in FIG. 9, air flows from the intake port 43 toward the exhaust port 45 and passes through the fixing unit 150. This causes heat from the fixing unit 150 to be released to the outside of the housing 30. The arrow F indicates an ideal air flow, but in reality, the air flowing in from the intake port 43 spreads and flows inside the housing 30.

[0103] The environment sensor 20 is disposed in the vicinity of the end (front end) of the high voltage board 90 in the -Y direction in order to be disposed at a position as far away from the fixing unit 150 as possible.

[0104] In the comparative example, the exhaust fan 64 generates a flow of air passing through the fixing unit 150, but it is difficult to prevent the heat of the fixing unit 150 from reaching the periphery of the environment sensor 20.

[0105] In addition to the heat from the fixing unit 150, heat generated by friction between the photoconductor drum 141 and the developing roller 144 of the image forming unit 140, or heat generated when the fixed medium P is transported by the reversing transport mechanism 180 during double-sided printing, also reaches the surroundings of the environment sensor 20. Due to the influence of the heat from the fixing unit 150, the image forming unit 140, and the reversing transport mechanism 180, the temperature around the environment sensor 20 rises by several degrees Celsius.

[0106] When the temperature around the environment sensor 20 rises, the temperature and humidity of the environment in which the image forming apparatus 1B is placed cannot be detected with high accuracy. As a result, the bias voltage cannot be controlled with high accuracy according to the temperature and humidity of the environment, which may result in a deterioration of image quality.

[0107] Furthermore, as described in Patent Document 1, even if the environment sensor 20 is disposed near the air intake 43, it is difficult to prevent the heat of the fixing unit 150, etc. from reaching the environment sensor. Therefore, as in the comparative example, the temperature and humidity of the environment cannot be detected with high accuracy.

[0108] 5, in the present embodiment, the environment sensor 20 is disposed inside the intake duct 51 and between the intake ports 41, 42 and the intake fan 61. Therefore, fresh air that has flowed into the intake duct 51 from the intake ports 41, 42 flows around the environment sensor 20.

[0109] Therefore, the influence of heat from the fixing unit 150, the image forming unit 140, the reverse transport mechanism 180, etc. can be suppressed, and the temperature and humidity of the environment in which the image forming apparatus 1 is placed can be detected by the environmental sensor 20 with high accuracy.

[0110] 6(B), since the environment sensor 20 is supported by the support levers 21 and 22 at a position away from the wall 51c of the intake duct 51, the temperature of other components is less likely to be transmitted to the environment sensor 20 via the wall 51c of the intake duct 51. This makes it possible to further improve the detection accuracy of the environment sensor 20.

[0111] 7, both air intake port 41 and air intake port 42 are connected to air intake duct 51, and environmental sensor 20 is disposed on the flow path of air that has passed through air intake port 41 and on the flow path of air that has passed through air intake port 42. This makes it possible to increase the amount of air that flows into air intake duct 51 and passes through environmental sensor 20, thereby improving the detection accuracy of environmental sensor 20.

[0112] Furthermore, since the drip-proof wall 25 is disposed between the intake port 42 and the environmental sensor 20 in the Z direction, even if liquid enters the intake duct 51 from the intake port 42, the drip-proof wall 25 can protect the environmental sensor 20. Therefore, even if a user tips a plastic bottle, cup, or the like over the upper cover 35 and liquid enters through the intake port 42, the drip-proof wall 25 protects the environmental sensor 20, and normal operation of the environmental sensor 20 can be maintained.

[0113] 10 is a diagram showing the positional relationship between the intake duct 51, the environment sensor 20, and the intake ports 41 and 42 when a blocking object B, such as a bookshelf, is placed on the left side cover 31 side of the image forming apparatus 1. When the blocking object B is placed on the left side cover 31 side as shown in FIG. 10, the inflow of air from the intake port 41 is blocked.

[0114] However, in this embodiment, the air intake 41 and the air intake 42 formed on differently oriented surfaces of the housing 30 (the left side cover 31 and the top cover 35) are connected to the air intake duct 51, so that even if the air intake 41 is closed, air flows from the air intake 42 into the air intake duct 51 and passes through the environmental sensor 20.

[0115] Therefore, even if the image forming device 1 is placed in a small space such as an office, a store's back yard, or a reception counter, and the air intake 41 is blocked by an obstruction B, the temperature and humidity of the environment in which the image forming device 1 is placed can be detected with high accuracy by the environmental sensor 20.

[0116] In addition, even if books or the like are placed on the upper cover 35 and the air intake 42 is closed, air flows from the air intake 41 into the air intake duct 51 and passes through the environmental sensor 20, so that the environmental temperature and humidity can be detected with high accuracy by the environmental sensor 20.

[0117] Although an example has been described here in which the intake port 41 is formed in the left side cover 31 and the intake port 42 is formed in the top cover 35, the intake ports 41, 42 may be formed on surfaces of the housing 30 that face in different directions. For example, the intake port 41 may be formed in the right side cover 32 and the intake port 42 may be formed in the front cover 33.

[0118] <Effects of the embodiment> As described above, image forming apparatus 1 of the present embodiment includes image forming section 140 and fixing section 150, housing 30 accommodating them, intake duct 51 connected to intake port 41 of housing 30, and intake fan 61 arranged in intake duct 51, and environmental sensor 20 is arranged inside intake duct 51 between intake port 41 and intake fan 61. This suppresses the influence of heat on the components within image forming apparatus 1, and allows environmental sensor 20 to detect the temperature or humidity of the environment in which image forming apparatus 1 is placed with high accuracy.

[0119] Furthermore, since the intake duct 51 is connected to the multiple intake ports 41, 42, the amount of air passing through the environmental sensor 20 can be increased, improving the detection accuracy of the environmental sensor 20. In addition, since the intake ports 41, 42 are formed on surfaces of the housing 30 facing different directions (the left side cover 31 and the upper cover 35), even if one of the intake ports 41, 42 is blocked by an obstruction, air flows in from the other intake port and passes through the environmental sensor 20, thereby enabling the environmental sensor 20 to detect the environmental temperature or humidity with high accuracy.

[0120] In addition, since the intake duct 51 extends between the intake port 41 of the left side cover 31 and the intake port 43 of the right side cover 32, the air volume of the intake duct 51 can be increased. Therefore, the heat dissipation efficiency of the image forming unit 140 and the fixing unit 150 can be improved, and the detection accuracy of the environment sensor 20 can be improved.

[0121] Furthermore, since the exhaust fan 64 is provided, the air that has been drawn into the intake duct 51 from the intake ports 41 to 44 by the intake fans 61 and 62 can be exhausted from the exhaust fan 64. This makes it possible to form a passage for air that passes through the components that are targets of heat dissipation (such as the image forming unit 140 and the fixing unit 150) within the housing 30, thereby improving the heat dissipation efficiency.

[0122] In addition, intake duct 51 is disposed between image forming unit 140 and fixing unit 150, and intake fans 61, 62 blow air onto image forming unit 140, and blow air onto fixing unit 150 with blower fan 63. Therefore, by disposing ducts 51, 52 in the empty space within housing 30, heat from image forming unit 140 and fixing unit 150 can be released to the outside.

[0123] Variations. The configuration of the image forming apparatus 1 described above is merely one example, and various modifications are possible. A modified image forming apparatus 1A is shown in Fig. 11. In this image forming apparatus 1A, the intake fans 61 and 62 in the intake duct 51 are arranged so that their respective air blowing directions are inclined with respect to the Y direction.

[0124] More specifically, intake fans 61, 62 are disposed so as to blow air that has flowed into intake duct 51 from intake ports 41-44 (intake ports 42, 44 are not shown) toward the center in the X direction of image forming unit 140. In addition, blower fan 63 is fitted into an opening formed in intake duct 51.

[0125] Even in this modified example, the air that flows into the intake duct 51 from the intake ports 41-44 by the intake fans 61, 62 is directed toward the image forming unit 140, and then passed through the fixing unit 150 by the blower fan 63, and then exhausted from the exhaust port 45 by the exhaust fan 64 via the exhaust duct 52.

[0126] The environmental sensor 20 is disposed in the intake duct 51 between the intake port 41 and the intake fan 61. Therefore, the influence of heat from the components of the image forming apparatus 1 is suppressed, and the temperature or humidity of the environment in which the image forming apparatus 1A is placed can be detected with high accuracy.

[0127] In the first embodiment and the modified example, the left side cover 31 of the housing 30 has the air intakes 41, 42, and the right side cover 32 has the air intakes 43, 44, but it is sufficient that the housing 30 has at least one air intake.

[0128] In the first embodiment and the modified example, intake duct 51 and exhaust duct 52 are provided, but exhaust duct 52 may not be provided. That is, air taken into intake duct 51 from intake ports 41 to 44 may be exhausted from exhaust port 45 by exhaust fan 64 (without using exhaust duct 52).

[0129] Furthermore, the intake duct 51 may be disposed at other positions, not limited to between the image forming unit 140 and the fixing unit 150. If there is free space inside the housing 30, the intake duct 51 may be disposed, for example, between the image forming unit 140 and the front cover 33.

[0130] The present disclosure can be used in image forming apparatuses, such as printers, copiers, facsimile machines, and MFPs (Multi Function Peripherals), that form images on media. [Explanation of symbols]

[0131] 1, 1A, 1B image forming apparatus, 20 environmental sensor (sensor), 21, 22 support lever, 23 board, 25 cover (water-proof wall), 30 housing, 31 left side cover (side portion), 32 right side cover (side portion), 33 front cover (front portion), 34 rear cover (rear portion), 35 upper cover (upper surface portion), 36 top cover, 39 operation panel, 41 intake port (first intake port), 42 intake port (second intake port), 43 intake port (third intake port), 44 intake port (fourth intake port), 45 exhaust port, 51 intake duct (duct), 51c wall portion, 51d bottom portion, 51e inclined surface, 52 exhaust duct, 61, 62 intake fan, 63 blower fan, 64 exhaust fan, 90 high voltage board, 110 media tray, 120 media supply section, 130 media transport section, 140 image forming section, 141 photosensitive drum (image carrier), 142 charging roller (charging member), 143 exposure head (exposure device), 144 developing roller (developer carrier), 145 supply roller (supply member), 146 toner container (developer container), 148 transfer roller (transfer body), 150 fixing section (fixing device), 170 media discharge section, 180 reversing transport mechanism, 201 main control section, 202 voltage control section, 211 voltage application section.

Claims

1. an image forming unit that forms an image on a medium; a fixing section for fixing an image onto the medium; a housing that houses the image forming unit and the fixing unit and has a first intake port and a second intake port; a duct connected to the first intake port and the second intake port; an intake fan disposed in the duct; a sensor disposed inside the duct between the first intake port and the intake fan, the sensor detecting at least one of temperature and humidity. The first intake port and the second intake port are formed on surfaces of the housing that face in different directions.

1. An image forming apparatus comprising:

2. The sensor is disposed at a position through which the air flowing in from the first intake port passes and through which the air flowing in from the second intake port also passes.

2. The image forming apparatus according to claim 1,

3. The first air intake port is formed in a side surface of the housing, The second intake port is formed in the upper surface of the housing.

3. The image forming apparatus according to claim 1, wherein the image forming apparatus is a multi-color image forming apparatus.

4. A cover is disposed between the second intake port and the sensor in the vertical direction.

4. The image forming apparatus according to claim 3.

5. the housing has a third air intake port on a side surface opposite to the side surface, The duct extends to connect the first air intake port and the third air intake port.

5. The image forming apparatus according to claim 3, wherein the image forming apparatus is a multi-color image forming apparatus.

6. A sensor support portion that supports the sensor at a position separated from the inner wall of the duct is provided inside the duct.

6. The image forming apparatus according to claim 1, wherein the image forming apparatus further comprises a first fixing unit.

7. The device further includes an exhaust port provided in the housing, and an exhaust fan that exhausts air from the exhaust port.

7. The image forming apparatus according to claim 1, wherein the image forming apparatus further comprises: a first fixing member;

8. the duct is an intake duct, Further, an exhaust duct connected to the exhaust port is provided. The air that flows into the intake duct from the first intake port and the second intake port passes through the exhaust duct and is exhausted from the exhaust port.

8. The image forming apparatus according to claim 7,

9. The air conditioner further includes a blower fan for blowing air from the intake duct to the exhaust duct.

9. The image forming apparatus according to claim 8,

10. The duct is disposed between the image forming unit and the fixing unit.

10. The image forming apparatus according to claim 1, wherein the image forming apparatus comprises:

11. The intake fan blows the air that has flowed into the duct from the first intake port and the second intake port toward the image forming unit.

11. The image forming apparatus according to claim 10.

Images