JP3990838B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus that transmits driving using a driving belt, and particularly relates to solving a problem caused by temperature rise in the apparatus.
[0002]
[Prior art]
As an example of an image forming apparatus having a driving belt for transmitting driving, an electrophotographic image forming apparatus will be described. In general, in an electrophotographic image forming apparatus, a sheet conveying unit that supplies and conveys a sheet from a sheet stacking unit, a photosensitive drum that carries an electrostatic latent image, a refeed unit that performs double-sided recording, and the like, It has a plurality of means that require driving. Of these, those that are driven at a constant speed usually have a common drive source in the drive belt to simplify the configuration.
[0003]
FIG. 11 is a schematic rear view of a conventional image forming apparatus, and FIG. 12 is a schematic side view of the image forming apparatus. The image forming apparatus shown in the figure has a drive transmission mechanism using a drive belt 102 between a main body rear frame 100 and a rear cover 101. That is, a drive pulley 104 is attached to the output shaft of the motor 103 that is a drive source, and the drive belt 102 is stretched between the drive pulley 104 and the drive input pulleys 105, 106, and 107 of each part. . The drive belt 102 is maintained at an appropriate tension by tensioners 108 and 109. When the image forming operation is started, the motor 103 rotationally drives the driving belt 102 in the direction of the arrow in the drawing, and transmits driving force to each part.
[0004]
[Problems to be solved by the invention]
In such an image forming apparatus, the number of components used in recent years is increasing with the increase in image quality and speed, and the heat sources that cause the temperature rise in the apparatus are scattered in each part as the number of electrical components increases. It is becoming. In particular, in the space between the main body rear frame 100 and the rear cover 101, many components such as each drive mechanism, electric board, and power source are mounted at high density, making it difficult to construct an overall cooling airflow. Yes. For this reason, even if a cooling mechanism is provided, the local cooling effect often remains, and efficient cooling of the entire apparatus is difficult.
[0005]
In addition, when an exhaust mechanism that exhausts the air inside the device to the outside of the device is provided as a cooling mechanism, various filters that need to be replaced are provided at the exhaust port so that the toner dust and ozone layer generated inside the device are not discharged outside the device. It is necessary to provide a large number of exhaust mechanisms, which is undesirable in terms of cost and maintenance load.
[0006]
SUMMARY OF THE INVENTION An object of the present invention is to enable efficient cooling or exhausting in a wide range in an image forming apparatus that transmits driving by a driving belt.
[0007]
[Means for Solving the Problems]
In order to solve the above-described problems, an image forming apparatus according to the present invention includes a case member that covers the entire drive system formed by the drive belt, and an internal part of the case member. The blower is configured to cool a part of the track of the drive belt.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
[First embodiment]
A first embodiment of an image forming apparatus according to the present invention will be described with reference to the drawings. 1 is an overall configuration diagram of an image forming apparatus according to the present embodiment, FIG. 2 is a schematic rear view of the image forming apparatus, FIG. 3 is a schematic side view of the image forming apparatus, and FIG. FIG. 5 is a side view for explaining the vicinity of the cooling means, and FIG. 6 is a rear view for explaining the cooling airflow.
[0009]
The image forming apparatus shown in FIG. 1 transmits to a plurality of means using a driving belt as will be described later, forms an electrostatic latent image on an image carrier made of a photosensitive member, and develops the latent image. An electrophotographic color image forming apparatus that forms a full-color image by transferring it to a sheet.
[0010]
An image reading unit 2 is provided on the upper part of the apparatus main body 1, and an original lamp S placed on the original platen glass 10 is exposed and scanned by an exposure lamp 11, thereby reflecting reflected light images from the original mirrors 12 a, 12 b, 12c, the light is condensed on the full color sensor 14 by the lens 13 to obtain a color separation image signal.
[0011]
The color-separated image signal is processed by a video processing unit through an amplifier circuit (not shown) and sent to an image forming unit. When an image formation start signal is input to the image forming unit, first, the photosensitive drum 15 as an image carrier is rotationally driven in the direction of arrow A by a driving unit (not shown). Around the photosensitive drum 15, there are a pre-exposure lamp 16, a corona charger 17, a laser exposure optical system 18 as an exposure means, a potential sensor 19, four developing devices 20y, 20c, 20m, 20Bk of different colors, and a light amount on the drum. A detecting means 21, a transfer device 3, and a cleaning device 22 are arranged.
[0012]
After the rotation of the photosensitive drum 15 is started, the transfer drum 23 of the transfer device 3 is pressed against the photosensitive drum 15 by the transfer drum pressurizing cam 34, and is driven by the photosensitive drum 15 to start driven rotation at a constant speed. . When the rotation of the photosensitive drum 15 is stabilized and preparations such as sheet conveyance are completed, an image forming operation for the photosensitive drum 15 is started.
[0013]
In the laser exposure optical system 18, the image signal from the image reading unit is converted into an optical signal by a laser output unit (not shown), and the converted laser beam is reflected by the rotary polygon mirror 18a and passes through the lens 18b and the mirror 18c. And projected onto the cylindrical surface of the photosensitive drum 15. At the time of image formation, the photosensitive drum 15 is rotated in the direction of arrow A, and the photosensitive drum 15 after being neutralized by the pre-exposure lamp 16 is uniformly charged by the corona charger 17, and an optical image is irradiated for each separated color. An electrostatic latent image is formed.
[0014]
Next, a predetermined developing device is operated to develop the latent image on the photosensitive drum 15, and a toner image using a resin as a base is formed on the photosensitive drum 15. The developing unit is configured to selectively approach the photosensitive drum 15 according to each separation color by the operation of the eccentric cams 25y, 25c, 25m, and 25Bk. The toner image formed on the photosensitive drum 15 in this way is transferred from the sheet cassette 4 to the sheet supplied to the position facing the photosensitive drum 15 via the conveyance system and the transfer drum 23.
[0015]
The transfer drum 23 has a transfer charger 26 inside, an adsorption charger 27 for electrostatically adsorbing the sheet, and an inner charge eliminating charger 28, and the whole is pressed against the photosensitive drum 15 as described above. ing. The transfer drum 23 electrostatically adsorbing the sheet transfers the toner image on the photosensitive drum 15 onto the sheet by the transfer charger 26 according to the rotation.
[0016]
In this way, a desired number of color images are transferred to the sheet sucked and conveyed to the transfer drum 23, and when the transfer of the four color toner images is completed, a full color image is formed. When the transfer is completed, the sheet is separated from the transfer drum 23 by the action of the separation claw 29 and the separation push-up roller 30, and after the toner is fixed via the heat roller fixing device 31, it is discharged to the discharge tray 32. When image formation is continuously performed on a plurality of sheets, the next sheet is continuously conveyed to the transfer drum 23, and the image forming operation to the photosensitive drum 15 and the transfer operation to the sheet are repeated.
[0017]
The transfer drum 23 is pressed and rotated by the photosensitive drum 15 as it is after the final sheet is separated, and the surface of the transfer drum 23 is cleaned by the transfer drum cleaner 33. The cleaning operation is performed for at least the time that the transfer drum 23 rotates once. When the cleaning is completed, the transfer drum pressurizing cam 34 rotates and the transfer drum 23 is separated from the photosensitive drum 15. The rotation of the photosensitive drum 15 is stopped after the transfer drum 23 is separated.
[0018]
As shown in FIGS. 2 and 3, on the back side of the apparatus, a drive transmission mechanism using a drive belt 36 is provided between the main body rear frame 1a and the rear cover 1b. That is, a drive pulley 37 is attached to the output shaft of the motor 35 that is a drive source, and the drive belt 36 is stretched between the drive pulley 37 and the drive input pulleys 38, 39, and 40 of each part. . The drive belt 36 is maintained at an appropriate tension by the tensioners 41 and 42.
[0019]
Here, the drive input pulley 38 is a waste toner conveying mechanism of the cleaning device 22, the drive input pulley 39 is a developing sleep rotating mechanism of the developing device 20, and the drive input pulley 40 is opposed to the lower right of the transfer drum 23. The driving force is transmitted to each rotating mechanism. As described above, when the image forming operation is started, the motor 35 is rotated, the driving belt 36 is driven in the direction of arrow B in the figure, and the driving force is transmitted to each part.
[0020]
The entire drive system by the drive belt 36 is substantially covered with a case member 43 formed of a metal plate. As shown in FIGS. 4 and 5, the case member 43 is provided with an intake port 43a at a position corresponding to the track of the drive belt 36, and a blower fan 44, which is a cooling means, is provided in correspondence with the intake port 43a. A duct 45 is supported. The back side of the duct 45 is engaged with the opening louver 1c of the rear cover 1b via a seal member 46 (see FIG. 5), and is vented to the outside of the apparatus.
[0021]
When the drive belt 36 is driven, the cooling air supplied from the outside of the apparatus by the blower fan 44 is sent into the case member 43 from the intake port 43a as shown by the broken line arrow C in FIG. Be transported. This cooling air is conveyed to each part in the case member 43 along the track of the driving belt while clinging to the driving belt 36 as shown by an arrow D in FIG. 6, and is used for cooling each part.
[0022]
With this configuration, in the image forming apparatus according to the present invention, a wide range can be efficiently cooled with a very simple configuration, and problems due to temperature rise in the apparatus can be prevented.
[0023]
[Second Embodiment]
Next, a second embodiment of the image forming apparatus according to the present invention will be described with reference to the drawings. 7 is a schematic rear view of the image forming apparatus according to the present embodiment, FIG. 8 is a schematic side view of the image forming apparatus, FIG. 9 is a side view for explaining the vicinity of the cooling means, and FIG. 10 is a rear view for explaining the cooling airflow. is there.
[0024]
Similarly to the first embodiment, the present embodiment also has a drive transmission mechanism by a drive belt 36 between the main body rear frame 1a and the rear cover 1b on the back of the apparatus, and each part from a drive pulley 37 attached to the motor 35. Drive is transmitted to the drive input pulleys 38, 39, 40 by the drive belt 36.
[0025]
The entire drive system by the drive belt 36 is substantially covered with a case member 47 formed of a metal plate. As shown in FIG. 9, a duct 48 is provided at a position corresponding to the track of the drive belt 36 as a part of the case member 47. The duct 48 is provided with an intake port 48a and an exhaust port 48b. . The intake port 48a and the exhaust port 48b are respectively engaged with the louvers of the rear cover 1b via a seal member 46 and open to the outside of the apparatus (see FIG. 9), and a blower fan 44 is attached to the duct 48. The air flow is generated in the duct. The inside of the duct 48 is sealed from the other space in the apparatus so that air outside the apparatus is sucked and exhausted to the outside as it is.
[0026]
When the drive belt 36 is driven, the air heated from each part in a form tangled by the drive belt 36 as shown in FIGS. 9 and 10 is conveyed to the position of the duct 48. While the heated air passes through the position of the duct 48, it radiates heat into the duct 48 through the case member 47, which is a metal plate, is cooled, and is directly conveyed to each part by the drive belt 36. On the other hand, the airflow in the duct 48 rises due to heat radiation from the case member 47, but is quickly discharged out of the apparatus by the function of the blower fan 44. Here, the case member 47 is made of metal in order to improve the thermal conductivity. As a result, not only the heat can be smoothly transferred from the inside of the apparatus into the duct 48, but also a function as a heat sink can be achieved.
[0027]
For this reason, the airflow in the duct 48 is always kept in a cooled form, and the efficiency of heat radiation from the case member 47 can always be kept good. In addition, since the air exhausted from the duct 48 is cut off from the inside of the apparatus and only obtains heat, there is no risk of toner dust, ozone, etc. being released to the outside, and it can be exhausted without using a filter or the like. it can.
[0028]
As described above, in the image forming apparatus according to the present embodiment, a wide range can be efficiently cooled with a simple configuration that does not use a filter or the like, and problems due to temperature rise in the apparatus can be prevented. it can.
[0029]
In each of the above embodiments, the blower fan 44, which is a cooling means, is configured to suck airflow into the apparatus, but this embodiment is not limited to this, and airflow is generated in the exhaust direction. Even if it is a thing to be made, the same effect can be acquired.
[0030]
【The invention's effect】
As described above, in the image forming apparatus according to the present invention, the driving belt driven in the case member conveys the surrounding air while entraining it, so that the vicinity of the image forming apparatus is efficiently cooled over a wide range with a simple configuration. Therefore, the problem caused by the temperature rise in the apparatus can be prevented.
[0031]
In addition, since the airflow in the vicinity of the drive belt is indirectly cooled through the case member, the cooled airflow can be circulated in a wide range in the apparatus, and toner dust and ozone generated in the apparatus can be circulated. And the like, and the configuration of a filter or the like can be omitted to simplify the configuration.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of an image forming apparatus according to a first embodiment.
FIG. 2 is a schematic rear view of the image forming apparatus.
FIG. 3 is a schematic side view of the image forming apparatus.
FIG. 4 is a rear view for explaining the vicinity of the cooling means.
FIG. 5 is a side view for explaining the vicinity of the cooling means.
FIG. 6 is a rear view illustrating a cooling airflow.
FIG. 7 is a schematic rear view of an image forming apparatus according to a second embodiment.
FIG. 8 is a schematic side view of the image forming apparatus.
FIG. 9 is a side view for explaining the vicinity of the cooling means.
FIG. 10 is a rear view illustrating a cooling airflow.
FIG. 11 is a schematic rear view of an image forming apparatus according to a conventional example.
FIG. 12 is a schematic side view of an image forming apparatus according to a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Apparatus main body 1a ... Main body rear frame 1b ... Rear cover 1c ... Opening louver 2 ... Image reading part 3 ... Transfer apparatus 4 ... Sheet cassette
10 ... Guide glass
11… Exposure lamp
12a ... mirror
13… Lens
14… Full color sensor
15… Photosensitive drum
16 Pre-exposure lamp
17… Corona charger
18 ... Laser exposure optics
18a ... rotating polygon mirror
18b ... Lens
18c ... mirror
19… Potential sensor
20… Developer
21… Drum light quantity detection means
22… Cleaning device
23 Transfer drum
25… Eccentric cam
26… Transfer charger
27… Adsorption charger
28… Internal static eliminating charger
29… Separation nail
30… Separate push-up roller
31… Heat roller fixing unit
32… discharge tray
33… Transfer drum cleaner
34… Transfer drum pressure cam
35… Motor
36… Drive belt
37… Drive pulley
38… Drive input pulley
39… Drive input pulley
40… Drive input pulley
41… Tensioner
42… Tensioner
43… Case material
43a ... Inlet
44… Blower fan
45… Duct
46… Seal member
47… Case material
48… Duct
48a ... Inlet
48b ... exhaust port

Claims (4)

In an image forming apparatus having a driving belt for transmitting driving,
A case member covering the entire drive system formed by the drive belt;
Air blowing means for blowing air toward the inside of the case member,
The image forming apparatus according to claim 1, wherein the blower is configured to cool a part of the track of the drive belt. In an image forming apparatus having a driving belt for transmitting driving,
A case member covering the entire drive system formed by the drive belt;
An image forming apparatus having a blowing unit for blowing air toward the case member,
The image forming apparatus according to claim 1, wherein the blower blows air toward a region of the case member facing the track of the drive belt . 3. The image forming apparatus according to claim 1, wherein the case member is formed of a material having a high thermal conductivity at least a portion applied to the blowing unit. 3. The image forming apparatus according to claim 2, wherein the blower unit is a duct provided at a position corresponding to a track of the drive belt of the case member.

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