JPH08328454A - Image forming device - Google Patents

Abstract

PURPOSE: To provide an image forming device capable of preventing compound becoming the cause of an irregularly of discharge from being generated and capable of definitely adjusting the temp. in the device. CONSTITUTION: The first circulation path of air flow in which a first circulation path member 32 arranged in the outside of a case and provided with a heat radiation plate is made one part of airflow and a second circulation path in which a second circulation path member 33 in which a member arranged in the circulation path is shared with the first circulation member and which is arranged in the case is made one part of airflow are provided, either the first circulation path or the second circulation path is selected by changeover drivings of fan 14 to 17 and a temp. adjustment is executed by airflow of the selected circulation path with respect to the member in the selected circulation path. In this case, when the temp. in the case is lower than a target time., the second circulation path is selected by the detection signal of a temp. sensor and the temp. in the case is controlled to be raised by airflow whose temp. is raised with a closed-circulation and when the temp. in the case is higher than the target temp., the first circulation path is selected and the temp. in the case is controlled to be lowered by airflow whose heat is radiated to the outside of the case with the closed-circulation.

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, and more particularly to an image forming apparatus having a temperature adjusting function inside a housing.

[0002]

2. Description of the Related Art In an image forming apparatus such as an electronic copying machine, a surface of a photosensitive member is charged by a charging charger when an image is formed. A corona discharge wire used for the charging charger has a diameter of 60 to 100 μm. A tungsten wire is used, and a high voltage is applied to this tungsten wire to cause discharge. In this case, if uneven discharge occurs,
Since the image quality is deteriorated, it is required to perform discharge without uneven discharge.

This discharge unevenness occurs when dust in the air, floating toner, or various compounds generated during discharge adhere to the surface of the corona discharge wire. In particular, the influence of the attachment of the compound is great, and this compound is often generated by the substance contained in the air taken in for cooling the inside of the machine being oxidized by ozone.

It is known that this discharge unevenness is likely to occur especially when the apparatus is driven in a room where the humidifier is used in the winter, and the discharge unevenness depends on environmental conditions such as temperature and humidity. There is.

On the other hand, in the image forming apparatus, the resistance value of the transfer roller for transferring the toner image on the photoconductor onto the transfer paper has a high temperature dependence, and the data storage means such as a magneto-optical disk is used. It is known that it is necessary to use in an atmosphere of a temperature within a predetermined range for normal operation of.

Therefore, in the image forming apparatus, the fixing device,
Under the heat generation conditions from the heat generation unit such as the power supply unit and copy lamp, without generating compounds that cause uneven discharge,
It is necessary to maintain the resistance value of the transfer roller at a predetermined value and operate the data storage means at the ambient temperature at which the data storage means operates normally.

On the other hand, for example, JP-A-62-215
In Japanese Patent No. 138, a thermoelectric refrigeration element is arranged between a photoconductor drum and a fixing device which is a heat source, and an airflow blows down cool air between the photoconductor drum and the fixing device by the thermoelectric refrigeration device to blow air from a fan. There is disclosed a cooling device for an image forming apparatus that exchanges heat by convection circulation in the housing by the action.

[0008]

In the conventional cooling device for an image forming apparatus according to the disclosure, since the cooling is performed by the circulating air flow, it is possible to generate the compound that causes the uneven discharge by taking in the dust of the outside air. It is possible to prevent the photosensitive drum from being shielded from the heat from the fixing device to some extent by the cold air blown down from the thermoelectric refrigeration element. However, it is difficult to cool the air circulating in the housing, and the temperature inside the machine gradually rises, so that the circulating air cannot set the transfer roller, the data storage means, and the like to a desired temperature atmosphere.
In order to suppress this temperature rise, it is necessary to dispose a heat exchanger inside the machine, and the size of the apparatus becomes large, which causes a problem in manufacturing cost.

The present invention has been made in view of the current state of circulating temperature adjustment inside the image forming apparatus as described above.
It is an object of the present invention to provide an image forming apparatus capable of preventing the generation of a compound that causes uneven discharge and capable of appropriately adjusting the temperature inside the apparatus.

[0010]

In order to achieve the above object, the invention according to claim 1 is a member in which a circulation passage for an air flow is formed in an apparatus, and the member arranged in the circulation passage by the air flow. Is an image forming apparatus for adjusting the temperature of the first circulation path and the first circulation path and a member arranged in the circulation path are formed in common, and the first circulation path is temperature-adjusted. A second circulation path that operates differently; and a switching unit that selects one of the first circulation path and the second circulation path as the circulation path in which the member is arranged. To do.

Similarly, in order to achieve the above object, the invention according to claim 2 is the image forming apparatus according to claim 1, wherein the first circulation path is used to cool the air flow in the circulation path. An air cooling unit is provided.

[0012] Similarly, in order to achieve the above-mentioned object, the invention according to claim 3 is the invention according to claim 1 or 2, wherein a part of the first circulation path is provided outside the housing of the apparatus. In addition, the second circulation path is disposed inside the housing.

Similarly, in order to achieve the above object, the invention according to claim 4 is the image forming apparatus according to any one of claims 1 to 3, wherein the temperature in the vicinity of the member inside the housing is set. Temperature detecting means for detecting the temperature is detected, and the switching means switches between the first circulation path and the second circulation path based on a detection signal of the temperature detection means. Is.

[0014]

According to the first aspect of the present invention, the first air flow is applied to the device.
And a second circulation path for the air flow having a common temperature sharing operation with the first circulation path and having a temperature adjusting operation different from that of the first circulation path. Therefore, either the first circulation path or the second circulation path is selected by the switching means. Then, the temperature adjustment is performed on the members arranged in the selected circulation path by the airflow flowing through the selected circulation path, and the case where the first circulation path is selected and the second circulation path is selected. When the path is selected, different temperature adjusting operations are performed on the members arranged in the circulation path.

According to the second aspect of the invention, in addition to the effect of the first aspect of the invention, when the first circulation path is selected by the switching means, the first circulation path is arranged in the first circulation path. The air cooling unit cools the air flow circulating in the first circulation path, and the cooled air flow adjusts the temperature of the member arranged in the first circulation path to be lowered.

According to the invention of claim 3, in the operation of the invention of claim 1 or claim 2, when the first circulation path is selected by the switching means, a part of it is outside the housing. The air flow circulating through the first circulation path provided is brought into contact with a member inside the circulation path in a state where heat is dissipated due to a temperature difference from the outside air, and a temperature adjusting operation is performed. When the second circulation path arranged in the housing is selected, the air flow circulating in the second circulation path contacts the members in the circulation path as it is and the temperature adjustment operation is performed. Be seen.

According to the invention described in claim 4, in addition to the operation of the invention described in any one of claims 1 to 3, based on the temperature in the vicinity of the member arranged in the circulation path detected by the temperature detecting means. Thus, the switching means switches between the first circulation path and the second circulation path.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 is an exploded perspective view showing the structure of the present embodiment, FIG. 2 is an explanatory view of the first circulation path and the second circulation path of FIG. 1, and FIG. 3 is a structure of the first circulation path of FIG. It is an explanatory view shown.

In this embodiment, as shown in FIG.
An optical reading unit 10 for optically reading a document image is provided on the top of the optical reading unit 10. The optical reading unit 10 is provided at a substantially central position in the housing C.
The photoconductor 2 on which the electrostatic latent image of the original image read in is formed is rotatably arranged around the rotation shaft 2a.

A charging charger 1 facing the peripheral surface of the photoconductor 2 to uniformly charge the photoconductor 2 in a clockwise direction, a developing unit 3 for developing an electrostatic latent image of the photoconductor 2 into a toner image, and a transfer A registration roller 4 for feeding the paper, a transfer separation charger 5 for transferring the toner image onto the transfer paper, and a cleaning unit 8 for cleaning the residual toner on the photoconductor 2 are arranged in this order.

Further, adjacent to the transfer separation charger 5,
A conveyor belt 6 that conveys the transfer sheet onto which the toner image has been transferred is provided, and a fixing unit 9 that fixes the toner image onto the transfer sheet is provided at an end position of the conveyance of the conveyor belt 6.
Further, a power supply unit 7 of the apparatus is disposed near the fixing unit 9, and a housing C is disposed near the charging charger 1.
A temperature sensor 35 for detecting the internal temperature is provided.

In this embodiment, the mounting opening 3 is provided on the rear surface of the housing C.
0 is formed, and a circulation path member 31 is fixed to the mounting opening 30, as shown in FIG. In this circulation path member 31, a first circulation path member 32 having a substantially rectangular parallelepiped shape and a second circulation path member 33 having a substantially cylindrical shape are arranged in parallel with each other, and both ends thereof are First circulation path member 32 and second
Of substantially rectangular parallelepiped connecting member 34 perpendicular to the circulation path member 33
It is a structure connected by. The fans 16 and 17 are attached to the boundary portion between the first circulation path member 32 and the second circulation path member 33 of the connection body 34, and the fans 14 and 15 are attached to the end portions of the connection body 34. ing.

Further, as shown in FIG. 3, a plurality of ribs 22 are provided in parallel with each other in the first circulation path member 32, and the first circulation path member 32 is provided on the first circulation path member 32. Three
The heat radiation plates 21 that radiate the heat in 2 are provided in parallel with each other. The heat dissipation plate 21 and the rib 22 have an integrated structure, and heat of the air flowing through the first circulation path member 32 is easily conducted. The rib 22 and the heat dissipation plate 21 are made of a material having good thermal conductivity such as aluminum.

In the present embodiment, the circulation path member 31 having such a structure has the first circulation path member 32 located outside the housing C and the second circulation path member 33 in the housing as shown in FIG. It is located in C and is attached to the housing C.

The operation of this embodiment having such a configuration will be described. In the image forming apparatus according to this embodiment, the optical reading unit 10
The image of the original is optically read by, and based on the read signal of the optical reading unit 10, the electrostatic latent image of the original image is formed on the uniformly charged photoconductor 2 by corona discharge of the charging charger 1 and is developed. The electrostatic latent image is visualized as a toner image by the unit 3. Then, the toner image on the photoconductor 2 is transferred by the transfer separation charger 5 to the transfer paper fed by the registration roller 4, and the transfer paper on which the toner image is transferred is fixed by the transport belt 6 to the fixing unit 9 Then, the transfer paper is fixed by the fixing unit 9.

Through such an image forming operation, heat is mainly radiated from the fixing unit 9 and the power supply unit 7 into the housing C, and the temperature inside the housing C rises. The temperature Tk in the housing C is detected by the temperature sensor 35,
If Tk <Ts with respect to the target set temperature Ts in
As shown in FIG. 2A, the fans 14 and 15 are driven and the fans 16 and 17 are stopped.

In this state, the second circulation passage having the second circulation passage member 33 as a part of the circulation passage is arranged in the casing C and the first circulation passage arranged in the casing C as shown by an arrow in FIG. The temperature inside the housing C is adjusted by the air flow that is formed over the two circulation path members 33 and flows through the second circulation path. In this case, since the closed second circulation path is formed in the housing C, the temperature in the housing C gradually increases and Tk = Ts.
The temperature is controlled so that

On the other hand, the housing C detected by the temperature sensor 35
When the internal temperature Tk is Tk> Ts with respect to the target set temperature Ts in the housing C, the fans 14 and 15 are stopped and the fans 16 and 17 are driven, as shown in FIG. 2B. It In this state, the first circulation path having the first circulation path member 32 as a part of the circulation path is, as shown by an arrow in FIG.
First circulation path member 3 disposed inside the housing C and outside the housing C
The temperature inside the housing C is adjusted by the air flow formed over two and flowing through the first circulation path.

In this case, since the heat radiation plate 21 of the first circulation path member 32 radiates heat and the temperature of the air flowing through the first circulation path 32 is lowered, the temperature of the air flow flowing into the housing C is reduced. Is decreased, and the temperature in the housing C is gradually decreased to control Tk = Ts.

As described above, according to the present embodiment, when the temperature Tk in the housing C detected by the temperature sensor 35 is lower than the target set temperature Ts, the second circulation path member 33 including the second circulation path member 33 is provided. A circulation path is formed inside the housing C, and the air flow is
The temperature inside the housing C is controlled to rise by circulating through the circulation path.

Further, the housing C detected by the temperature sensor 35
When the internal temperature Tk is higher than the target set temperature Ts, the first circulation path is formed across the inside of the housing C and the first circulation path member 32 arranged outside the housing C, and the air flow The temperature is lowered by the heat radiation from the heat dissipation plate 21 of the first circulation path member 32, and the temperature inside the housing C is controlled to be lowered. In any case, high-quality image formation is performed on the members inside the housing C. Accurate temperature control for performing

In this case, switching between the first circulation path and the second circulation path is carried out by switching between the fans 1 and 15 and the fans 16 and 17.
The N-OFF control is performed easily and appropriately, and the circulation path member 31 having a simple structure is assembled to the housing C. The structure is suitable in the housing C of the image forming apparatus without a problem in manufacturing cost. Temperature control becomes possible.

The first circulation path member 3 outside the housing C
It is also possible to easily process 2 to have a structure in which ozone generated in the transfer / separation charger 5 is discharged to the outside of the machine so as to have a function of discharging ozone.

[0034]

According to the first aspect of the present invention, the first circulation passage for the air flow and the members arranged in the first circulation passage and the circulation passage are made common to the device by the switching means. Either one of the first circulation path and the second circulation path of the air flow having a different temperature adjusting operation is selected, and the selected circulation path is set to the member arranged in the selected circulation path. Since the temperature is adjusted by the flowing air flow, different temperatures are applied to the members arranged in the circulation path depending on whether the first circulation path is selected or the second circulation path is selected. The adjustment can be performed with a simple structure and operation.

According to the invention described in claim 2, in addition to the effect obtained in the invention described in claim 1, by selecting the first circulation path, the air cooling section disposed in the first circulation path is selected. As a result, the air flow circulating in the first circulation path is cooled, and the temperature of the member arranged in the first circulation path is adjusted by the cooled air flow. It becomes possible to cool the member.

According to the invention of claim 3, in addition to the effect obtained by the invention of claim 1 or 2,
When the circulation path is selected, the air flow that circulates through the first circulation path, which is partially disposed outside the housing, is radiated by the temperature difference from the outside air, and Since it comes into contact with the member, the member in the first circulation path is provided with a cooling effect by the radiated airflow, and when the second circulation path disposed in the housing is selected, the second circulation path is selected. The air flow circulating in the circulation path is
Since the member in the circulation path contacts with the member in the circulation path in a state where the temperature is raised in the housing, it is possible to heat the member in the second circulation path.

According to the invention described in claim 4, in addition to the effect obtained by the invention described in any one of claims 1 to 3, in the vicinity of the member arranged in the circulation path detected by the temperature detecting means. Since the switching circuit switches between the first circulation path and the second circulation path based on the temperature, the temperature of the member in the circulation path can be appropriately set within a desired temperature range.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing the configuration of an embodiment of the present invention.

2 is an explanatory view of the first circulation path and the second circulation path in FIG. 1. FIG.

FIG. 3 is an explanatory diagram showing a configuration of a first circulation path of FIG.

[Explanation of symbols]

 1 Charging Charger 2 Photoreceptor 3 Developing Unit 4 Registration Roller 5 Transfer Separation Charger 9 Fixing Unit 14 to 17 Fan 21 Heat Sink 22 Rib 31 Circulation Passage Member 32 First Circulation Passage Member 33 Second Circulation Passage Member 35 Temperature Sensor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiyuki Uchida 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd.

Claims (4)

[Claims] 1. An image forming apparatus in which a circulation path for an air flow is formed in the apparatus, and the temperature of a member disposed in the circulation path is adjusted by the air flow, the first circulation path and the first circulation path. A second circulation path which is formed in common with a first circulation path and a member arranged in the circulation path, and has a temperature adjustment operation different from that of the first circulation path; and a circulation path in which the member is arranged. As an image forming apparatus, the image forming apparatus includes: a switching unit that selects one of the first circulation path and the second circulation path. 2. The image forming apparatus according to claim 1, wherein
An image forming apparatus, wherein the first circulation path is provided with an air cooling unit that cools an air flow in the circulation path. 3. The method according to claim 1, wherein a part of the first circulation path is arranged outside the housing of the device, and the second circulation path is arranged inside the housing. Item 2. The image forming apparatus according to item 2. 4. The image forming apparatus according to claim 1, further comprising temperature detecting means for detecting a temperature in the vicinity of the member inside the housing, and the switching means, Based on the detection signal of the temperature detecting means, the first
An image forming apparatus, characterized in that the switching between the second circulation path and the second circulation path is performed.