JP2008020809A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To cool the inside of a housing without causing the upsizing of the housing. <P>SOLUTION: A ventilation port 9B is provided on the upper surface 9A of a holding part 9 provided at the lower part of the side surface of the housing 3, and also a bridge part 9C extended in a direction nearly parallel with the side surface 3A of the housing 3 is provided thereon. Thus, it is unnecessary to provide a recessed part which is hollowed to the inner side of the housing 3 afresh in order to provide the ventilation port 9B, and it is unnecessary to consider interference with an electric motor and an electric substrate or the like provided in the housing 3 afresh. Since the ventilation port 9B is made open toward the lower side, noise or nasty smell or the like produced in a laser printer is hardly discharged to a user side, and also the ventilation port 9B is hardly viewed from the user. Therefore, a situation that an unpleasant feeling is given to the user is restrained, and a foreign matter is prevented from infiltrating into the housing 3 from the ventilation port 9B. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus, and is particularly effective when applied to an electrophotographic image forming apparatus.

Heat generating components such as a power supply board and an electric motor are housed in the housing of the image forming apparatus. In order to keep these heat generating components below the heat resistant temperature, for example, in the invention described in Patent Document 1, the housing ( A concave portion recessed inward is provided on a side surface of the image forming apparatus main body), and a ventilation vent is provided in the concave portion.
JP 2004-279747 A

  However, in recent years, in order to reduce the size of the image forming apparatus, each device provided in the housing (image forming apparatus main body) is mounted in a dense state so as not to interfere with each other. As in the invention described, if a recessed portion that is newly recessed on the inner side of the housing is provided in order to provide a vent, there is a risk that the recessed portion and the device provided in the housing may interfere with each other.

Therefore, in the invention described in Patent Document 1, there is a high possibility that the casing must be enlarged to such an extent that the recess and the built-in device do not interfere with each other.
For this, a means of providing a vent opening that opens in the horizontal direction on the side surface of the housing without providing a recess is conceivable. However, in this means, a portion of the side surface of the housing where the vent is provided. Since it is necessary to provide a space where air can flow between the device and other devices or walls, it becomes difficult to install the image forming device in a narrow place, and the installation of the image forming device is reduced. A malfunction occurs.

  In addition, when the vent hole is opened in the horizontal direction, noises, odors and the like generated in the image forming apparatus are easily emitted toward the user side. It is easy to generate.

  The present invention has been made in view of the above points, and an object of the present invention is to cool the inside of the housing without increasing the size of the housing while preventing the occurrence of the above-described problems.

  To achieve the above object, according to the present invention, an image forming unit (10) for forming an image on a recording medium and a housing (3) for housing the image forming unit (10) are provided. And a grip portion (9) provided at a lower portion of the side surface of the housing (3) and recessed inward of the housing (3), and an upper surface portion (9A) of the grip portion (9) A vent (9B) is provided that opens downward and communicates the inside and outside of the housing (3). Further, the air in the housing (3) is vented into the housing (3). A blower (120) for discharging from the opening (9B) to the outside of the housing (3) is provided.

  Accordingly, in the present invention, in the image forming apparatus, since the vent (9B) is normally provided in the grip portion (9) that is always provided, a new housing is provided to provide the vent (9B). There is no need to provide a recessed portion recessed inward of (3), and there is no need to newly consider interference with equipment provided in the housing (3).

  Further, since the air vent (9B) is opened downward, noises, odors and the like generated in the image forming apparatus are not easily emitted toward the user side, which causes discomfort to the user. This can be suppressed and foreign matter can be prevented from entering the housing (3) from the vent (9B).

Therefore, in the present invention, the inside of the housing (3) can be cooled without increasing the size of the housing (3) while preventing the occurrence of the above-described problems.
In the second aspect of the present invention, the vent (9B) extends in a direction substantially parallel to the side surface (3A) of the housing (3) and has one side and the other side of the edge of the vent (9B). The bridge part (9C) which connects is provided.

  Accordingly, in the invention according to claim 2, since the extending direction of the bridge portion (9C) is substantially orthogonal to the direction of inserting the hand when the hand is put on the grip portion (9), the bridge portion ( 9C) functions as an anti-slip, and can compensate for the mechanical strength of the grip portion (9), which is reduced by providing the vent portion (9B) in the grip portion (9) at the bridge portion (9C).

  Further, the invention according to claim 3 is characterized in that the bridge portion (9C) is provided with a guide surface (9E) for guiding the air flowing through the vent (9B) in a predetermined direction. The exhaust discharged from the vent (9B) can be discharged in a predetermined direction, and the exhaust flow can be rectified by the bridge portion (9C), so that noise due to turbulence of the airflow can be reduced. .

  In the third aspect, as in the fourth aspect, the guide surface (9E) is set so that the air flowing through the vent (9B) is turned and guided toward the outside of the housing (3). If it does, it can suppress reliably that noise, a strange odor, etc. will be discharge | released toward the user side.

  According to the fifth aspect of the present invention, the temperature detection means (131) for detecting the temperature in the housing (3) and the control for controlling the operation of the blower (120) based on the temperature detected by the temperature detection means (131). Means (130), and the control means (130) stops the blower (120) at least when the temperature detected by the temperature detection means (131) is equal to or lower than a predetermined temperature.

  As a result, even when the temperature of the image forming unit (10) is low and an image cannot be formed properly (during cold start), the temperature in the housing (3) is raised to an appropriate temperature at an early stage. be able to.

  That is, in the present invention, since the vent hole (9B) is provided at the lower part of the side surface of the housing (3), the temperature rises and the air accumulated in the upper side in the housing (3) ), The possibility of being discharged from the vent (9B) is low.

  Therefore, as in the fifth aspect of the invention, if the blower (120) is stopped when the detected temperature is equal to or lower than the predetermined temperature, it is possible to prevent the air whose temperature has been increased from being discharged from the vent (9B). Therefore, even during a cold start, the temperature in the housing (3) can be raised to an appropriate temperature at an early stage.

In addition, you may comprise an air blower (120) by having an axial fan like the invention of Claim 6.
Moreover, you may comprise an air blower (120) by having a centrifugal fan like the invention of Claim 7.

  Incidentally, the reference numerals in parentheses for each of the above means are examples showing the correspondence with the specific means described in the embodiments described later, and the present invention is indicated by the reference numerals in the parentheses of the above respective means. It is not limited to specific means.

In this embodiment, the image forming apparatus according to the present invention is applied to an electrophotographic image forming apparatus such as a laser printer. The present embodiment will be described below with reference to the drawings.
(First embodiment)
1. Configuration of Laser Printer FIG. 1 is an external perspective view of a laser printer 1 according to this embodiment, FIG. 2 is a schematic cross-sectional view of the laser printer 1 cut in the front-rear direction, and FIG. 3 shows the laser printer 1 in the left-right direction. FIG. 4A is a schematic view showing a part of a cut section, FIG. 4A is an enlarged view of a portion A in FIG. 3, FIG. 4B is a view taken in the direction of arrow B in FIG. FIG. 3 is a block diagram showing a control system of the blower 120.

Note that the laser printer 1 according to the present embodiment is installed with the upper side of the paper in FIG. 1 as the upper side in the direction of gravity, and is normally used with the right side of the paper as the front side.
The housing 3 of the laser printer 1 is formed in a substantially box shape (cubic shape), and on the upper surface side of the housing 3 is a sheet of paper, an OHP sheet, or the like that has finished printing and is discharged from the housing 3. A paper discharge tray 5 on which a recording medium (hereinafter simply referred to as paper) is placed, an operation panel 7 for performing a setting operation of the laser printer 1, and the like are provided. 3 is provided with a recessed gripping portion 9 on the inner side.

  Note that the gripping portion 9 is a gripping means for placing the user's hand when the user lifts the laser printer 1 or the like, and the gripping portion 9 according to the present embodiment is shown in FIGS. As shown to a), a part of lower part of the side surface of the housing | casing 3 is dented in step shape. For this reason, as for the holding part 9 which concerns on this embodiment, the height dimension H (refer FIG. 4 (a)) is set to about 15 mm-40 mm, and the depth dimension D (refer FIG. 4 (a)) is about 15 mm-40 mm. Is set to

  Further, as shown in FIG. 2, an image forming unit 10, a feeder unit 20, a transport mechanism 30 and the like are housed in the housing 3. The image forming unit 10 is an image forming unit that forms an image on a sheet. The feeder unit 20 forms a part of a conveying unit that supplies the sheet to the image forming unit 10, and removes the sheet from the sheet feeding tray 21. The conveyance mechanism 30 is a conveyance unit that conveys the sheet to the four developing toner cartridges 70K, 70Y, 70M, and 70C constituting the image forming unit 10 one by one.

  The feeder unit 20 feeds a sheet placed on the sheet feeding tray 21 placed above the front end of the sheet feeding tray 21 stored in the lowermost part of the housing 3 to the image forming unit 10. The paper feed roller 21 is configured to be (conveyed), and the paper feed tray 21 is assembled to the housing 3 so as to be detachable in a direction parallel to the paper transport direction.

  The transport mechanism 30 includes a transport belt 31 that is rotationally driven in conjunction with the operation of the image forming unit 10, and the transport belt 31 rotates from the paper feed tray 21 by rotating with the paper loaded thereon. The conveyed sheet is sequentially conveyed to the four developing toner cartridges 70K, 70Y, 70M, and 70C.

  The image forming unit 10 includes a scanner unit 60, a developing toner cartridge 70, a fixing unit 80, and the like. The image forming unit 10 according to the present embodiment is a so-called direct tandem type capable of color printing, and toners (developer) of four colors of black, yellow, magenta, and cyan from the upstream side in the paper transport direction. The four developing toner cartridges 70K, 70Y, 70M, and 70C corresponding to the above are arranged in series along the sheet conveyance direction.

  The four developing toner cartridges 70K, 70Y, 70M, and 70C are the same except for the toner color. Therefore, the four developing toner cartridges 70K, 70Y, 70M, and 70C are collectively referred to as a developing toner cartridge 70.

  The scanner unit 60 is provided on the upper part of the housing 3 and irradiates the surface of the photosensitive drum 71 provided in each of the four developing toner cartridges 70K, 70Y, 70M, and 70C with laser light, thereby causing the scanner unit 60 to move on the photosensitive drum 71. Forming an electrostatic latent image.

  The developing toner cartridge 70 is detachably disposed in the housing 3 below the scanner unit 60. The developing toner cartridge 70 houses a photosensitive drum 71, a charger 72, a toner container 74, and the like. The casing 75 is configured. The transfer roller 73 is rotatably supported by the frame member on the opposite side to the photosensitive drum 71 with the conveyance belt 31 interposed therebetween.

  The fixing unit 80 is a fixing unit that heats and melts the toner transferred onto the paper and fixes the toner. The fixing unit 80 is disposed on the printing surface side of the paper and applies a conveying force to the paper while heating the toner. And a pressure roller 82 which is disposed on the opposite side of the heating roller 81 and presses the sheet toward the heating roller 81.

  Further, the image forming unit 10, that is, the scanner unit 60, the developing toner cartridge 70, the fixing unit 80, and the like are assembled in a substantially plate-like frame 100 provided inside the housing 3, as shown in FIG. The frame 100 is assembled with driving means such as an electric motor 110 for rotating rollers such as the photosensitive drum 71 and the transfer roller 73, and an electric board 111 such as a control board and a power board for controlling the electric motor 110. Yes.

As shown in FIG. 4A, the upper surface portion 9A of the grip portion 9 is provided with a vent 9B that opens downward and communicates the inside and outside of the housing 3. 4B, as shown in FIG. 4B, the edge of the vent 9B extending in a direction substantially parallel to the side surface 3A of the housing 3 (in the front-rear direction in this embodiment) and formed in a substantially rectangular shape. A plurality of bridge portions 9C that connect one side (front side) and the other side (rear side) of the unit are provided. That is, in the present embodiment, a plurality of bridge portions that extend in a direction substantially parallel to the side surface 3A of the housing 3 are provided. A plurality of vents 9B are formed by the strip-shaped opening of the book, and a bridge portion 9C is provided between the plurality of vents 9B.

  The reinforcing bridge 9D is a reinforcing member that reinforces the flexural rigidity of the bridge portion 9C. The reinforcing bridge 9D extends in a direction perpendicular to the bridge portion 9C and extends to one side (right side) of the edge of the vent 9B. The other side (left side) is connected to form the vents 9B in a substantially lattice shape.

  Incidentally, in the present embodiment, the housing 3 is made of a resin having excellent mechanical strength such as high impact polystyrene, and the plurality of bridge portions 9C, the vents 9B, and the reinforcing bridge 9D are integrated when the housing 3 is molded. Molded.

  Moreover, since the lower end side of the bridge portion 9C protrudes downward from the lower end portion of the vent 9B as shown in FIG. 4A, the upper surface portion 9A of the grip portion 9 is provided with the bridge portion 9C. The concave portion is convex and the portion provided with the vent 9B is concave.

  As shown in FIG. 3, a blower 120 for discharging the air in the housing 3 from the air vent 9B to the outside of the housing 3 is disposed in the housing 3 above the vent 9B. In this embodiment, the blower 120 includes an axial fan (see JIS B 0132 number 1012 or the like).

  An electric board 111 is disposed on the suction side (upstream side of the air flow) of the blower 120, and the ambient temperature in the housing 3 is detected in the vicinity of the electric board 111, the electric motor 110, and the like. A temperature sensor 131 is disposed.

  As shown in FIG. 5, the output of the temperature sensor 131 is input to the control device 130, and the control device 130 operates the blower 120 according to a program set in advance based on the temperature detected by the temperature sensor 131. Control. Incidentally, the control device 130 is a well-known microcomputer composed of a CPU, a RAM, a ROM, and the like, and the program is stored in the ROM.

  Further, as shown in the flowchart of FIG. 6, when the power switch (not shown) of the laser printer 1 is turned on, the control device 130 reads the detected temperature of the temperature sensor 131 (S1), and the read detection. It is determined whether the temperature is equal to or higher than a predetermined temperature (for example, 10 ° C.) (S3).

  Next, when it is determined that the detected temperature is equal to or lower than the predetermined temperature, the control device 130 stops or maintains the blower 120 (S5), whereas when it is determined that the detected temperature is higher than the predetermined temperature. Then, the air blower 120 is operated to discharge the air in the housing 3 to the outside of the housing 3 from the vent 9B, thereby cooling the heating elements such as the electric motor 110 and the electric board 111.

  7 is an explanatory diagram showing the flow of air entering and exiting the inside and outside of the housing 3. As shown in FIG. 7, the air in the housing 3 is directed downward from the vent 9B (gripping portion 9). Fresh air (outside air) is sucked into the housing 3 through the gap between the housing 3 and the front cover 3B that opens and closes the paper outlet 3A and the outlet of the developing toner cartridge 70.

2. Features of the Laser Printer According to the Present Embodiment In the present embodiment, in the laser printer 1, since the vent 9B is normally provided in the grip portion 9 that is always provided, a new housing is provided to provide the vent 9B. There is no need to provide a recessed portion that is recessed inward of the body 3, and there is no need to newly consider interference with the electric motor 110, the electric substrate 111, and the like provided in the housing 3.

  Further, since the air vent 9B is opened downward, it is difficult for noise, odor and the like generated in the laser printer 1 to be emitted toward the user side, and the air vent 9B is difficult to see from the user. For this reason, it is possible to prevent the user from feeling uncomfortable and to prevent foreign matter from entering the housing 3 from the vent 9B.

  Therefore, in the present invention, the installation of the laser printer 1 is deteriorated, and noises and odors generated in the housing 3 are emitted toward the user side, which causes discomfort to the user. The inside of the housing 3 can be cooled without increasing the size of the housing 3.

  Further, as described above, the heating elements such as the electric motor 110 and the electric substrate 111 are disposed on one side or both sides in the horizontal direction with the image forming unit 10 interposed therebetween, and the grip unit 9 is also provided on the side surface of the housing 3. In this embodiment, the air vent 9B is provided in the vicinity of a heating element such as the electric motor 110 and the electric board 111. Therefore, heating elements such as the electric motor 110 and the electric board 111 can be efficiently cooled.

  In addition, as described above, in the ordinary laser printer 1, the grip portion 9 is always provided, and the grip portion 9 is recessed inside the housing 3. Therefore, as shown in FIG. If the blower 120 is disposed in the vicinity of the grip portion 9 recessed inside 3, the blower 120 can be easily disposed without considering interference between the blower 120 and other devices.

  In addition, since the bridge portion 9C extending in a direction substantially parallel to the side surface 3A of the housing 3 is provided in the vent hole 9B, the extending direction of the bridge portion 9C is a hand when the grip portion 9 is put on the hand. The upper surface portion 9 </ b> A of the grip portion 9 has a concavo-convex shape substantially orthogonal to the charging direction. Therefore, the bridge portion 9C functions as a non-slip, and the mechanical strength of the grip portion 9 that is lowered by providing the vent portion 9B in the grip portion 9 at the bridge portion 9C can be compensated.

  Further, in the present embodiment, since the vent 9B is provided at the lower side of the casing 3, the air that has risen in temperature and accumulated on the upper side in the casing 3 is not forcibly discharged by the blower 120. As far as possible, the possibility of being discharged from the vent 9B is low.

  Therefore, as in this embodiment, if the blower 120 is stopped when the temperature detected by the temperature sensor 131 is equal to or lower than the predetermined temperature, it is possible to prevent the air whose temperature has increased from being discharged from the vent 9B. Even in the cold start when the temperature in the body 3 (particularly the temperature of the fixing unit 80) is low, the temperature in the housing 3 can be raised to an appropriate temperature at an early stage.

  Further, the color laser printer has a larger number of electric motors 110 than the monochrome laser printer, and the amount of heat generated in the housing 3 is larger than that of the monochrome laser printer. Therefore, the present invention is particularly effective when applied to a color laser printer. is there.

3. Correspondence Relationship between Invention Specific Items and Embodiments In this embodiment, the temperature sensor 131 corresponds to the temperature detection means described in the claims.

(Second Embodiment)
In the present embodiment, as shown in FIG. 8, a guide surface 9E for guiding the air flowing through the vent 9B in a predetermined direction is provided in each bridge portion 9C, and the bridge portion 9C is formed in a so-called louver shape. .

  In addition, the guide surface 9E has a predetermined angle θ (about 3 ° to about 30 in the present embodiment) with respect to the vertical direction so as to turn and guide the air flowing through the vent 9B toward the outside of the housing 3. °) tilted.

  As described above, in this embodiment, since the guide surface 9E is provided in the bridge portion 9C, the exhaust discharged from the vent 9B can be discharged in a predetermined direction, and at the bridge portion 9C. Since the exhaust flow can be rectified, noise due to turbulence of the airflow can be reduced.

  In addition, since the guide surface 9E is set so as to turn and guide the air flowing through the vent 9B toward the outside of the housing 3, noise and off-flavors are released toward the user side. It can be reliably suppressed.

(Other embodiments)
In the above-described embodiment, the gripping portions 9 are provided on both sides in the horizontal direction (left and right sides) orthogonal to the paper conveyance direction of the laser printer 1, and the vent hole 9B is provided only on the left side. However, the present invention is not limited to this. For example, the air vent 9B may be provided in the grip portions 9 on both the left and right sides.

In the above-described embodiment, the bridge portion 9C is provided in the vent 9B. However, the present invention is not limited to this, and the bridge portion 9C may be eliminated.
In the above-described embodiment, the blower 120 is configured by an axial fan. However, the present invention is not limited to this, and a centrifugal fan (see JIS B 0132 number 1004 or the like) or a cross-flow fan (JIS B 0132). The blower 120 may be configured by other fans such as the number 1017).

  In the above-described embodiment, the present invention is applied to a direct tandem color printer. However, the present invention is not limited to this, and may be applied to a monochrome printer, a 4-cycle color printer, or the like. it can.

  Further, the present invention is not limited to the above-described embodiment as long as it matches the gist of the invention described in the claims.

1 is an external perspective view of a laser printer 1 according to an embodiment of the present invention. It is the schematic diagram of the cross section which cut | disconnected the laser printer 1 which concerns on embodiment of this invention in the front-back direction. It is the schematic diagram of the cross section which cut | disconnected the laser printer 1 which concerns on 1st Embodiment of this invention in the left-right direction. (a) is the A section enlarged view of FIG. 3, (b) is a B arrow view of FIG. 4 (a). It is a block diagram which shows the control system of the air blower. It is a flowchart which shows the control flow of the air blower. It is explanatory drawing which shows the flow of the air which goes in and out of the housing | casing 3 in the laser printer 1 which concerns on embodiment of this invention. It is the schematic diagram of the cross section which cut | disconnected the laser printer 1 which concerns on 2nd Embodiment of this invention in the left-right direction.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Laser printer, 3 ... Housing | casing, 3A ... Side surface, 3A ... Discharge port,
3B ... Front cover, 5 ... Paper discharge tray, 9 ... Gripping part, 9A ... Upper surface part,
9B ... Vent, 9C ... Bridge part, 9D ... Reinforcement bridge, 9E ... Guide surface,
DESCRIPTION OF SYMBOLS 10 ... Image formation part, 20 ... Feeder part, 21 ... Paper feed tray, 30 ... Conveyance mechanism,
31 ... Conveying belt, 60 ... Scanner unit, 70 ... Developing toner cartridge,
71 ... photosensitive drum, 72 ... charger, 73 ... transfer roller, 75 ... casing,
80: fixing unit, 81: heating roller, 100: frame, 110: electric motor,
DESCRIPTION OF SYMBOLS 111 ... Electric board, 120 ... Blower, 130 ... Control apparatus, 131 ... Temperature sensor.

Claims (7)

An image forming unit for forming an image on a recording medium;
A housing for housing the image forming unit;
A grip portion provided at a lower portion of the side surface of the housing and recessed inward of the housing;
The upper surface of the gripping portion is provided with a vent opening that opens downward and communicates the inside and outside of the housing.
The image forming apparatus according to claim 1, further comprising a blower for discharging the air in the housing from the vent to the outside of the housing.   2. The bridge according to claim 1, wherein the vent is provided with a bridge portion that extends in a direction substantially parallel to a side surface of the housing and connects one side of the vent to the other side. Image forming apparatus.   The image forming apparatus according to claim 2, wherein the bridge portion is provided with a guide surface that guides air flowing through the vent hole in a predetermined direction.   The image forming apparatus according to claim 3, wherein the guide surface turns and guides the air flowing through the vent toward the outside of the housing. Temperature detecting means for detecting the temperature in the housing;
Control means for controlling the operation of the blower based on the detected temperature of the temperature detecting means,
5. The image forming apparatus according to claim 1, wherein the control unit stops the blower at least when a temperature detected by the temperature detection unit is equal to or lower than a predetermined temperature. 6.   The image forming apparatus according to claim 1, wherein the blower includes an axial fan.   The image forming apparatus according to claim 1, wherein the blower includes a centrifugal fan.

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