JP2000098861A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the temp. rising of an image forming device which is apt to be affected by heat, while saving the energy of a heat source. SOLUTION: This image forming device is constituted so as to absorb heat of the first device 25 by a heat shifting element 35 arranged between the first device 25 which is apt to be affected by the heat in one hand, and to discharge the absorbed heat into the second device 27 provided with the heat source 30a, to cool the first device 25, while heat insulating the second device 27.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine and a printer, and more particularly, to an apparatus having a device susceptible to heat and a device having a heat source.
The present invention relates to a technique for preventing a device having a heat source from being unnecessarily cooled and preventing a temperature of a device susceptible to heat from rising.

[0002]

2. Description of the Related Art An image forming apparatus such as a copying machine using an electrophotographic process includes a device having a heat source and a device which is easily affected by heat. As the former, for example, a fixing device having a heat source such as a halogen lamp and fixing an unfixed image transferred to a sheet (recording material) to the sheet by heating with a heat source is known, while the latter is known as the latter. For example, a developing device that transfers, for example, toner as a developer to, for example, a photosensitive drum as an image carrier, thereby visualizing an electrostatic latent image on the photosensitive drum as an image, A cleaning device (developer collecting device) for collecting residual toner remaining on the body drum,
There are known a substrate on which electronic components are mounted, an ROS unit for writing data on a photosensitive drum by a laser, and the like.

[0003] In recent years, space saving and miniaturization of image forming apparatuses have been promoted, and apparatuses having a heat source and apparatuses which are easily affected by heat have come close to each other. For this reason, a device that is easily affected by heat will be greatly affected by exhaust heat from a device having a heat source. For example, when a developing device and a cleaning device are close to the device having a heat source, There is a problem that the toner of the developing device and the cleaning device hardens, and
For example, when the substrates are close to each other, there is a risk that the device malfunctions. For example, when the ROS units are close to each other, there is a problem that a frame forming the units is distorted and good writing cannot be performed.

For example, Japanese Patent Application Laid-Open No. 5-142911 discloses a device having a heat source as a fixing device and a device susceptible to heat as a cleaning device. There is disclosed a technique in which a ventilation line is formed on the front side and a cooling fan is efficiently cooled by a heat exhaust fan disposed in the ventilation line.

[0005] However, Japanese Patent Application Laid-Open No. HEI 5-142291 describes the above.
In the device described in No. 1, since a fan is used as a means for cooling the cleaning device, there is a problem that noise is generated when the fan rotates.

Therefore, for example, Japanese Patent Publication No. 2626031
No. 2 has an exhaust duct that passes near the cleaning device and the fixing device, and heats the portion of the exhaust duct near the fixing device by using the exhaust heat from the fixing device to promote natural convection in the exhaust duct. There is disclosed a technology in which the cleaning device is cooled to reduce the noise at least in a standby state by disabling the fan.

[0007]

However, in the apparatus described in Japanese Patent Publication No. 2626031, the waste heat from the heat source of the fixing device is used to promote natural convection in the exhaust duct. Therefore, it is necessary to constantly supply the heat source with the heat energy lost for promoting natural convection, and there is a problem from the viewpoint of energy saving (energy loss).

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide an image forming apparatus which achieves energy saving of a heat source and prevents a temperature rise of an apparatus which is easily affected by heat. I do.

[0009]

According to the present invention, there is provided an image forming apparatus comprising: a first apparatus which is easily affected by heat; and a second apparatus having a heat source.
A heat transfer element is provided between the first device and the second device, and the heat transfer element is arranged such that the heat absorption side is the first device side and the heat removal side is the second device side. It is characterized by:

[0010] According to the image forming apparatus of the present invention configured as described above, the heat of the first device is absorbed by the heat transfer element disposed between the first device and the second device. On the other hand, the absorbed heat is exhausted to the second device. Therefore, the first device is cooled and the second device is kept warm.

Here, it is preferable that a shielding member is provided so as to surround the heat transfer element and to shield the first device side and the second device side.

When such a configuration is adopted, the first device side and the second device side are blocked by the shielding member, and the heat transfer from the second device side to the first device side is suppressed. For,
The exhaust heat of the heat source of the second device is prevented from affecting the first device. Therefore, it is preferable that the shielding member is a heat shielding plate made of, for example, a resin having a low thermal conductivity.

Further, it is preferable that the heat transfer element is supported by a shielding member.

When such a configuration is adopted, the member supporting the heat transfer element is also used as a shielding member, so that the number of parts is reduced.

A first shielding member interposed between the first device and the heat absorbing side of the heat transfer element for blocking the first device side and the second device side; A second element interposed between the moving element and the exhaust heat side and intercepting the first apparatus side and the second apparatus side;
It is preferable to provide a configuration in which the space defined by the first and second shielding members communicates with the outside of the machine.

When such a configuration is employed, the space defined by the first and second shielding members is communicated with the outside of the machine, and this space is formed by the exhaust heat of the heat source of the second device. Since the space is warmed, the space between the first and second shielding members becomes an air flow path of natural convection, and the air in this space is discharged outside the machine. Since the heat in the first device side and the second device side is transmitted to the air in this space via the first and second shielding members, respectively, the first device is transmitted from the second device side to the first device. The heat transfer to the side is suppressed, and the exhaust heat of the heat source of the second device is prevented from affecting the first device. Therefore, it is preferable that the first and second shield members are shield plates made of, for example, metal having good thermal conductivity.

Further, a first shielding member interposed between the first device and the heat absorbing side of the heat transfer element for blocking the first device side and the second device side; A second element interposed between the moving element and the exhaust heat side and intercepting the first apparatus side and the second apparatus side;
And a heat insulating material filled in a space defined by the first and second shielding members.

When such a configuration is employed, the first device side and the second device side are insulated from each other by the heat insulating material filled in the space defined by the first and second shielding members. Since the heat transfer from the second device side to the first device side is suppressed, the exhaust heat of the heat source of the second device is prevented from affecting the first device.

Various devices can be employed as the first device and the second device. Specifically, as the first device, for example, a developing device containing a developer to be used for image formation or a developing device A developer collecting device that collects the residual developer used for image formation is employed. As the second device, for example, a fixing device that fixes an unfixed image formed on a recording material to the recording material is employed.

When such a configuration is adopted, unused developer in the developing device and waste developer in the developer collecting device are prevented from being solidified by heat from the fixing device.

Further, as the heat transfer element, specifically,
Peltier elements are employed.

[0022]

Embodiments of the present invention will be described below with reference to the drawings. In each of the drawings, the same elements are denoted by the same reference numerals, and redundant description will be omitted. FIG. 1 is an overall configuration diagram showing a copying machine (image forming apparatus) according to a first embodiment of the present invention. The copying machine generally includes a copying machine main body 1 and an automatic document feeder 2 provided so as to freely open and close a copy glass 3 provided on an upper surface of the copying machine main body 1.

An image of a moving document conveyed on the copy glass 3 by the automatic document feeder 2 or a fixed document placed on the copy glass 3 is read into an image signal inside the copying machine body 1. A document reading unit 4 to be converted and a sheet (recording material) based on an image signal from the document reading unit 4
An image forming unit 5 that forms a visible image thereon, and a paper feeding unit 6 that supplies a sheet to the image forming unit 5 are provided.

The original reading section 4 is provided with an image sensor 19 such as a CCD for receiving reflected light of a moving or fixed original illuminated by a light source 7 such as a halogen lamp via lenses 8 to 10, and the image sensor 19. And an image processing processor unit 20 for performing predetermined image processing on the obtained information.

The paper feed section 6 is provided at a lower portion of the copying machine main body 1 and includes a plurality of paper feed trays 29. The paper feed tray 29 is for stacking and storing sheets by size or type. The paper feed tray 29 is removably mounted on the copying machine main body 1 in a line up and down. Will be sent out. The paper P is sent out one by one to the registration roll 11 via the paper transport path 14 by the pickup roll 13.

The image forming section 5 includes a laser exposure section (ROS unit) 21 for emitting a laser beam modulated by an image signal from the image processing processor section 20 and a charging device 22 such as a charging trocolon. A photosensitive drum (electrostatic latent image carrier) 23 exposed by the laser beam from the exposure unit 21 and a developer such as toner contained in a cartridge 24a (hereinafter simply referred to as toner)
And a developing device 24 that visualizes or develops the electrostatic latent image formed on the photosensitive drum 23 by the exposure as an image by carrying The image developed above is sent out from the paper feeding unit 6 and is transferred to the registration roll 11.
A transfer device 26 composed of a transfer roll or the like for transferring the paper P sent between the photosensitive drums 23 with the paper posture and the transport timing being matched by the printer, and transferring the image transferred to the paper P by the transfer device 26 to the paper P The fixing device 27 includes a fixing device 27 for fixing to the P and a cleaning device 25 for collecting the toner remaining on the photoconductor 23 after the transfer. The sheet P on which the image is fixed by the fixing device 27 is
The paper is discharged onto the paper discharge tray 28 by the paper discharge roll 12.

As shown in FIGS. 1 and 2, the cleaning device 25 includes a brush cleaner 25a for removing the residual toner on the photoreceptor 23, and a collection unit 25b for collecting the removed residual toner. Is done. As described above, the cleaning device 25 accommodates the toner that solidifies when affected by heat, and thus corresponds to a device (first device) that is easily affected by heat.

As shown in FIGS. 1 and 2, the fixing device 27 includes a fixing device cover 27a and a pair of rolls 33 disposed inside the fixing device cover 27a. The heating roll 30 constituting one roll of the roll pair 33 includes a heat source 30a such as a halogen lamp therein,
The pressure roll 31 constituting the other roll is disposed so as to be pressed against the heating roll 30 with an appropriate pressure.
Therefore, the fixing device 27 corresponds to a device having a heat source (a second device). A nip portion having a predetermined nip width is formed between these rolls 30 and 31. The paper P is heated and pressurized by passing the paper P through the nip portion, and the unfixed image transferred to the paper P is fixed.

The cleaning device 25 and the fixing device 27 are arranged close to each other as shown in FIGS. 1 and 2 in order to reduce the size of the device. That is, the cleaning device 25 is in an arrangement relationship that is greatly affected by the heat source 30a of the fixing device 27.

Here, in the present embodiment, a Peltier device 35 as a heat transfer device is disposed between the cleaning device 25 and the fixing device 27. As shown in FIG. 2, the Peltier element 35 is disposed so that the heat absorbing side 35a is in contact with the cleaning device 25 and the heat exhaust side 35b is in contact with the fixing device 27. A heat shield (shielding member) 36 is arranged so as to shield the device 25 side and the fixing device 27 side. The heat shield plate 36 is made of, for example, resin or the like having a low thermal conductivity in order to suppress heat transfer from the fixing device 27 side to the cleaning device 25 side.
Fixed to The Peltier device 35 is supported by the heat shield plate 36. A dedicated cooling fan (not shown) for assisting the cooling of the cleaning device 25 is provided on the cleaning device 25 side, and is driven at a predetermined time.

As described above, the Peltier element 35 is arranged in the above-described positional relationship between the cleaning device 25 and the fixing device 27, so that the heat of the cleaning device 25 is absorbed by the Peltier device 35, The absorbed heat is discharged to the fixing device 35. Therefore, the cleaning device 25 is cooled and the fixing device 27 is kept warm without using the exhaust heat of the heat source 30a of the fixing device 27 and driving the dedicated cooling fan.

Here, when the copying machine is on standby (at a time other than the time of image formation), the heat is not taken away by the sheet P, so that the halogen lamp (heat source) 30a is
It is turned on only when 0 is raised to a predetermined temperature, and is turned off at other times. For this reason, the cleaning device 25
The temperature of the fixing device 27 and the temperature of the fixing device 27 are set to desired temperatures only by the operation of the Peltier element 35 described above, that is, only by cooling the cleaning device 25 and keeping the fixing device 27 warm. Therefore, there is no need to drive a dedicated cooling fan, and the fan noise is reduced to zero.

When the copying machine is operating (at the time of image formation), the halogen lamp 30 is applied to the sheet P via the nip portion.
In this case, since the heat of the halogen lamp 30a is removed and the lighting state of the halogen lamp 30a is substantially maintained, a dedicated cooling fan needs to be driven in some cases. Thus, even when the dedicated cooling fan needs to be driven, the cleaning device 25 is cooled by the action of the Peltier element 35, so that the dedicated cooling fan can be rotated at a low speed. According to the experiment of the inventor, the fan noise which was about 40 to 45 dB in the past is about 30 to 35 dB.
B.

Further, in both the standby mode and the operation mode of the copying machine, the heat energy deprived for promoting natural convection as described in the related art is continuously supplied to the heat source 30a. On the contrary, since the fixing device 27 is kept warm by the action of the Peltier device 35, energy saving of the heat source 30a is achieved.

That is, according to the present embodiment, the provision of the Peltier element 35 achieves energy saving of the heat source 30a and reduces fan noise (at least zero when the copying machine is on standby) to increase the temperature of the cleaning device 25. Is prevented. Since the temperature rise of the cleaning device 25 is prevented in this way, the toner collected in the cleaning device 25 is prevented from being solidified by the heat from the fixing device 27.

Further, the heat shield plate 36 blocks the cleaning device 25 and the fixing device 27 from each other, so that the heat transfer from the fixing device 27 to the cleaning device 25 is suppressed. Exhausted heat is prevented from affecting the cleaning device 25. For this reason, the temperature rise of the cleaning device 25 is further prevented.

Further, since the Peltier element 35 is supported by the heat shield plate 36 and the member supporting the Peltier element 35 is also used as the heat shield plate 36, the number of components is reduced, and the cost of the apparatus is reduced. Have been.

Further, since the Peltier element 35 has a thin thickness of, for example, about 4 mm, the cleaning device 25
And the fixing device 27 can be arranged closer to each other, and the size of the device can be further reduced.

FIG. 3 is a structural view similar to FIG. 2 showing a main part of a copying machine according to a second embodiment of the present invention. The difference between the copying machine of the second embodiment and that of the first embodiment is that the structure for suppressing the heat transfer from the fixing device 27 to the cleaning device 25 is changed.

That is, in the second embodiment,
An exhaust duct 41 that passes between the cleaning device 25 and the fixing device 27 and blocks the cleaning device 25 and the fixing device 27 is disposed. This exhaust duct 41
Is a plate member (first shielding member) on the side of the cleaning device 25 which forms a hollow rectangular column shape and forms the hollow rectangular column shape.
37 and a plate member (second shielding member) 38 on the fixing device 27 side
Are configured to come into face-to-face contact with the cleaning device 25 and the fixing device 27, respectively. These plate members 37, 38
Is made of a metal having good thermal conductivity, such as aluminum, so that the heat of the cleaning device 25 and the fixing device 27 can be easily transmitted to the space 39 defined in the exhaust duct 41.

The Peltier device 35 described in the first embodiment is disposed between the cleaning device 25 and the fixing device 27 in the exhaust duct 41. This Peltier device 3
5 is arranged such that the heat absorption side 35a is in face-to-face contact with the plate material 37 and the heat discharge side 35b is in face-to-face contact with the plate material 38.

The exhaust duct 41 has open ends at both ends, and one open end is connected to the frame 1a of the copying machine body 1.
And is connected to an exhaust port 1b communicating with the outside of the machine, and the other open end is installed at a predetermined position in the copying machine body 1.

The cleaning device 25 and the fixing device 2
7, the thickness of the Peltier element 35 is about 4 mm +
Since the thickness of the plate 37 is about 2 mm + the thickness of the plate 38 is about 2 mm, it is about 8 mm, so that the cleaning device 25 and the fixing device 27 can be arranged close to each other.

According to the second embodiment configured as described above, the operation of the Peltier element 35 is the same as that described in the first embodiment, and the same effect as that of the first embodiment can be obtained. . In addition, since the space 39 defined in the exhaust duct 41 is heated by the exhaust heat of the heat source 30a of the fixing device 27, the space 39 in the exhaust duct 41 becomes a natural convection air flow path, and this space ( The air in the air flow path 39 is discharged to the outside of the apparatus via the exhaust port 1b. This space 3
Since the heat of the cleaning device 25 side and the fixing device 27 side is transmitted to the air of No. 9 via the plate members 37 and 38, the heat transfer from the fixing device 27 side to the cleaning device 25 side is suppressed. And the heat source 3 of the fixing device 27
0a is prevented from affecting the cleaning device 25.

The other open end of the exhaust duct 41 is arranged at a position where it can receive the air from the dedicated cooling fan, so that airflow is generated by the dedicated cooling fan in addition to natural convection, and the cleaning device 25 is moved from the fixing device 27 side. The heat transfer to the side may be further suppressed. In this case, it is preferable to rotate the dedicated cooling fan at an extremely low speed so that fan noise does not become a problem.

Further, in the present embodiment, the structure for suppressing the heat transfer from the fixing device 27 side to the cleaning device 25 side is realized by the exhaust duct 41 as being more effective and preferable. The opposite side plates (plate members closing the plate members 37 and 38 and facing in the vertical direction in the drawing; not shown in FIG. 3) are eliminated, and the plate material 3 is removed.
An air flow path communicating outside the apparatus may be formed by only the elements 7 and 38. In the case of such a configuration, although the effect is somewhat reduced as compared with the exhaust duct 41, the fixing device 27
It is possible to suppress the heat transfer from the side to the cleaning device 25 side.

FIG. 4 is a configuration diagram similar to FIG. 2 showing a main part of a copying machine according to a third embodiment of the present invention. The difference of the copying machine of the third embodiment from that of the second embodiment is that the configuration for suppressing the heat transfer from the fixing device 27 to the cleaning device 25 is further changed.

That is, the space 39 is filled with the heat insulating material 40 and the exhaust port 1 communicating the space 39 outside the machine.
b is a closed point. Here, the heat insulating material 40 is made of a material having poor air permeability such as urethane foam, felt, and thinsulate.

According to the third embodiment configured as described above, the operation of the Peltier element 35 is the same as that described in the first embodiment, and the same effects as those of the first embodiment can be obtained. . In addition, the heat insulating material 40 filled in the space 39 allows the cleaning device 25 side and the fixing device 27
The side is insulated and the heat transfer from the fixing device 27 to the cleaning device 25 is suppressed, so that the exhaust heat of the heat source 30 a of the fixing device 27 is prevented from affecting the cleaning device 25. That is, the same effect as in the second embodiment can be obtained.

FIG. 5 is a block diagram showing a main part of a copying machine according to a fourth embodiment of the present invention. The difference between the copying machine of the fourth embodiment and that of the third embodiment is that the developing device 24 is arranged closer to the fixing device 27 with the change of the arrangement of the devices in the copying machine. The point is that the configuration of the third embodiment is adopted. In other words, a developing device 24 is provided instead of the cleaning device 25 of the third embodiment.

Here, as described above, since the developing device 24 contains the toner for transferring to the photosensitive drum 23 in the cartridge 24a, it corresponds to a device (first device) which is easily affected by heat. I do.

In the fourth embodiment configured as described above,
It goes without saying that the same operation and effect as in the third embodiment can be obtained. As a result, the toner accommodated in the cartridge 24 a of the developing device 24 is prevented from being solidified by the heat from the fixing device 27. The configuration of the first and second embodiments may be adopted for the developing device 24.

Although the present invention has been specifically described based on the embodiment, the present invention is not limited to the above embodiment. For example, in the above embodiment, the fixing device 27 is It is composed of a combination of the pressure rolls 31. For example, both rolls are made up of heated rolls as in a two-sided copying machine, those made up of a combination of a heated roll and a belt member, and a pair of rolls including at least the heated rolls are A plurality of units may be arranged in parallel along the transport direction.

In the above embodiment, the heat source is the halogen lamp 30a, but the heat source is not limited to the halogen lamp. Further, the device having a heat source is not limited to the fixing device 27, and other devices may be used as long as they have a heat source.

In the above embodiment, the cleaning device 25 and the developing device 24 are arranged near the device having a heat source and are easily affected by heat. However, the present invention is not limited to these devices. For example, a substrate on which electronic components are mounted, an RO for writing by laser exposure
The same applies to the S unit 21 and the like. Even if these devices are susceptible to heat, the Peltier device 35
In the case of a substrate on which electronic components are mounted, normal operation of the device can be ensured, and in the case of the ROS unit 21, distortion of the frame forming the unit is reduced. Prevention and good writing become possible.

The heat transfer element is not limited to the Peltier element 35, but may be another heat transfer element. Also, the developer is not limited to toner,
The same applies to the case where another developer is used.

Further, the above-described embodiment can be appropriately applied to an image forming apparatus such as a printer and a facsimile.

[0058]

According to the image forming apparatus of the present invention, while the heat of the first apparatus is absorbed by the heat transfer element disposed between the first apparatus and the second apparatus, the absorbed heat is removed. Second
Since the first device is configured to discharge heat, cool the first device, and keep the second device warm, it is possible to prevent a rise in the temperature of the first device while achieving energy saving of the heat source. It becomes possible.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing a copying machine according to a first embodiment of the present invention.

FIG. 2 is an enlarged configuration diagram illustrating a fixing device, a cleaning device, a Peltier element, and a peripheral portion thereof in FIG. 1;

FIG. 3 is a configuration diagram similar to FIG. 2, showing a main part of a copying machine according to a second embodiment of the present invention.

FIG. 4 is a configuration diagram similar to FIG. 2, showing a main part of a copying machine according to a third embodiment of the present invention.

FIG. 5 is a configuration diagram showing a main part of a copying machine according to a fourth embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Copy machine main body, 1a ... Copy machine main body frame, 1b ...
Exhaust port, 24 developing device (first device), 25 cleaning device (developer collecting device; first device), 27 fixing device (second device), 30a halogen lamp (heat source), 35 ... Peltier element (heat transfer element), 35a ... Heat absorbing side of Peltier element, 35b ... Heat discharging side of Peltier element,
36: heat shield plate (shielding member), 37: plate material (first shielding member), 38: plate material (second shielding member), 39: air flow path (space), 40: heat insulating material, 41: exhaust duct , P: paper (recording material).

Claims (7)

[Claims] 1. An image forming apparatus having a first device susceptible to heat and a second device having a heat source in an apparatus, wherein an image forming apparatus includes a first device and a second device. The image forming apparatus according to claim 1, further comprising a heat transfer element, wherein the heat transfer element is arranged such that a heat absorbing side is the first apparatus side and a heat exhaust side is the second apparatus side. 2. The image forming apparatus according to claim 1, further comprising a shielding member that surrounds the heat transfer element and is disposed so as to shield the first device side and the second device side. 3. The image forming apparatus according to claim 2, wherein the heat transfer element is supported by the shielding member. 4. A first shielding member interposed between the first device and a heat absorbing side of the heat transfer element, and configured to block the first device side and the second device side; A second device interposed between the first device side and the second device side, which is interposed between the second device and the heat transfer side of the heat transfer element.
The image forming apparatus according to claim 1, further comprising a shielding member, wherein a space defined by the first and second shielding members communicates with the outside of the machine. 5. A first shielding member that is interposed between the first device and a heat absorbing side of the heat transfer element, and blocks a first device side and a second device side; A second device interposed between the first device side and the second device side, which is interposed between the second device and the heat transfer side of the heat transfer element.
The image forming apparatus according to claim 1, further comprising: a shielding member, and a heat insulating material filled in a space defined by the first and second shielding members. 6. The image forming apparatus according to claim 1, wherein the first device is a developing device that stores a developer used for image formation or a developer collecting device that collects a residual developer used for image forming. The image forming apparatus according to claim 1, wherein the fixing device fixes an unfixed image formed on the recording material to the recording material. 7. The image forming apparatus according to claim 1, wherein the heat transfer device is a Peltier device.