JPH04249267A - Temperature controller for photosensitive drum - Google Patents

Abstract

PURPOSE:To effectively utilize heat generated in a device without using a heat generating body such as a heater and to raise the temperature of the photosensitive drum speedily when the temperature is low by controlling the admittance of hot air to the photosensitive drum according to the temperature detection result of the photosensitive drum. CONSTITUTION:A heat sensing element such as a thermistor is used as a temperature sensor 5 for detecting the temperature of the photosensitive drum 1. A control means 6 controls the admittance of the hot air and external air to the photosensitive drum 1 according to the temperature detection result of the temperature sensor 5. The temperature sensor 5 monitors the temperature of the photosensitive drum 1 and a fan 3 is put in operation when the temperature is lower than specific temperature to guide the hot air in the device into the photosensitive drum 1, whose temperature is raised.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a temperature control device for a photosensitive drum in an image forming apparatus such as a copying machine.

0002

2. Description of the Related Art Conventional image forming apparatuses, such as copying machines, have heat generating means such as coil heaters and pattern heaters and temperature detection devices installed in the rotating shaft that supports the photoreceptor drum or on the inner wall of the cavity of the photoreceptor drum. The heater is controlled on and off based on the temperature detection result of the photoreceptor drum by the temperature detection means. These conventional temperature control devices for photoreceptor drums are described in detail in, for example, Japanese Patent Application Laid-Open No. 53-47838 and Japanese Patent Application Laid-Open No. 54-30047.

0003

[Problems to be Solved by the Invention] However, although it is possible to increase the temperature of the photoreceptor drum at low temperatures with the above-mentioned conventional photoreceptor drum temperature control device, it is difficult to increase the temperature of the photoreceptor drum at high temperatures. I couldn't bring it down quickly.

Furthermore, since the heater is provided within the rotating photosensitive drum or within the drum rotation shaft, the wiring for supplying power to the heater has become complicated and troublesome.

[0005]

[Means for Solving the Problems] The present invention has been made to solve the above-mentioned conventional drawbacks, and is characterized by having the following means.

A first means is a temperature control device for a photosensitive drum 1 of an image forming apparatus having a photosensitive drum 1 and a heat-generating structure 2, etc., in which hot air generated by the structure 2, etc. in the image forming apparatus is heated. a temperature detecting means 5 for detecting the temperature of the photoreceptor drum 1; It is characterized by comprising a control means 6 for controlling the introduction of hot air.

A second means is to direct the hot air to the photosensitive drum 1.
Outside air is introduced into the photoreceptor drum 1 along with hot air introducing means 3
It is characterized by being provided with outside air introduction means 3 for guiding the air inside.

The third means is characterized in that a duct 7 for guiding hot air into the photosensitive drum 1 is provided between the heat generating member 2 and the photosensitive drum 1.

A fourth means is that in a temperature control device for a photosensitive drum 1 of an image forming apparatus having a photosensitive drum 1, a heat generating component 2, etc., at least a component that determines the air blowing direction is made of a shape memory member. The present invention is characterized in that a fan 13 formed by the above method is disposed in a hollow portion of the photoreceptor drum 1.

A fifth means is characterized in that the fan 13 formed of the shape memory member is provided on the rotation shaft of the photosensitive drum so as to be rotatable with the rotation of the rotation shaft. .

[0011]

[Operation] According to the first and second means described above, it is possible to effectively utilize the heat inside the device to control the temperature of the photoreceptor drum without using a heating element such as a heater. The temperature of the photoreceptor drum can be quickly raised, and when the temperature is high, the temperature of the photoreceptor drum can be quickly lowered by effectively utilizing outside air.

According to the third means, in addition to the above effects, hot air can be guided to the photosensitive drum more reliably and quickly.

According to the fourth means, the temperature can be controlled using the heat inside the device and the outside air with a simple configuration that reduces the number of parts without providing not only a heating element such as a heater but also a temperature detection means. It can be performed.

[0014] According to the fifth means, it is possible to provide a temperature control device with a simpler configuration that does not require a driving means for rotating the fan or wiring for supplying power.

[0015]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of a first embodiment of a photosensitive drum temperature control device according to the present invention.

In FIG. 1, reference numeral 1 denotes a photoreceptor drum, which is configured to rotate together with the photoreceptor drum 1 when a rotating shaft (not shown) of the photoreceptor drum 1 is rotationally driven by a drum drive motor 4. The inside is hollow. Reference numeral 2 denotes a fixing unit, which is one of the components that generate heat within the image forming apparatus. Reference numeral 3 denotes a fan for guiding heat generated by components within the apparatus into the photoreceptor drum 1, and is capable of guiding hot air into the photoreceptor drum 1 or near the drum 1. It is installed in a suitable position. Another fan is provided near the photoreceptor drum 1 to guide air from outside the apparatus into the photoreceptor drum 1. The fan for introducing outside air may also be used as the fan for introducing hot air. That is, by providing the hot air introduction path and the outside air introduction path so as to be switchable, and switching the introduction path as necessary, the hot air introduction and the outside air introduction can be controlled. Further, by devising the shape of the blades of the fan 3, it may be configured such that hot air introduction and outside air introduction can be switched simply by changing the rotation direction of the fan.

Reference numeral 5 denotes a temperature sensor for detecting the temperature of the photosensitive drum 1, and a heat-sensitive element such as a thermistor is used. Reference numeral 6 denotes a control means for controlling the introduction of hot air and outside air into the photoreceptor drum according to the temperature detection result of the temperature sensor 5. Reference numeral 7 denotes an air duct provided between the fixing unit, which is the heat generating member, and the photosensitive drum 1.

Next, the operation of the photosensitive drum temperature control device configured as above will be explained. Photosensitive drum 1
The temperature of the device is monitored by a temperature sensor 5, and when the temperature is lower than a predetermined temperature, the fan 3 is operated to guide the hot air inside the device into the photoreceptor drum 1 via the air duct 7. increase the temperature.

On the other hand, the temperature detection result by the temperature sensor 5,
When the temperature of the photoreceptor drum 1 is higher than a predetermined temperature, the outside air introduction fan is driven to introduce cold outside air into the photoreceptor drum 1 to cool the drum 1.

Next, a second embodiment will be explained. Figure 2
FIG. 2 is a diagram showing a schematic configuration of a second embodiment. Figure 3, Figure 4
FIG. 2 is a diagram illustrating the direction of inclination of the fan blades of the second embodiment.

In the figures, the same components as in the first embodiment are denoted by the same reference numerals. In the fan 13, at least the sloped part of the blade that determines the direction of air flow is made of a shape memory material. This material is, for example, a nickel-titanium alloy, a copper-zinc-aluminum alloy, or the like. When a unidirectional shape memory material is used, it has a double structure in which a shape memory alloy part and a material having spring characteristics such as a phosphor bronze material are bonded together. By doing so, above a predetermined set temperature, the shape stored in the shape memory alloy appears, and conversely, below the set temperature, the shape due to the spring characteristics of the phosphor bronze material appears.

Furthermore, when a bidirectional shape memory material is used, the shape reversibly changes depending on the set temperature, so there is no need to use a spring material as in the case of a unidirectional shape memory material.

The fan 13 configured as described above is attached to the rotating shaft of the photosensitive drum 1 so as to rotate together with the rotating shaft. The fan 13 is provided in the internal cavity of the photosensitive drum 1 at a position where hot air or outside air can be introduced.

Next, the operation of the second embodiment will be explained. When the temperature is lower than a preset temperature, the blades of the fan 13 are bent and inclined in a direction to guide hot air into the photoreceptor drum 1 as shown in FIG. Heat generated by the fixing unit, etc. is introduced into the photoreceptor drum 1 via the air duct 7,
temperature increases. When the temperature reaches a preset temperature or higher, the blades of the fan 13 bend in the opposite direction from when the temperature is low. Therefore, although the introduction of hot air is stopped, the photosensitive drum 1 continues to rotate.
This time, cold outside air is introduced into the photoreceptor drum 1, thereby cooling the drum 1.

With the above configuration, it is possible to automatically switch between introducing hot air and introducing outside air into the photoreceptor drum depending on a preset temperature.
The temperature sensor 5 provided in the embodiment is no longer necessary.

[0026]

Effects of the Invention According to claim 1 of the present invention, the temperature of the photoreceptor drum can be quickly raised at low temperatures by effectively utilizing the heat generated within the apparatus without using a heating element such as a heater. can.

Furthermore, according to claim 2 of the present invention, the temperature of the photosensitive drum can be efficiently and quickly lowered by introducing outside air when the temperature is high.

According to claim 3 of the present invention, hot air within the apparatus can be guided to the photosensitive drum more reliably and quickly.

According to claim 4 of the present invention, there is no need to provide not only a heating element such as a heater but also a temperature detection means, so that the temperature of the photosensitive drum can be controlled with a simple configuration that reduces the number of parts. Can be done.

According to claim 5 of the present invention, it is possible to provide a temperature control device with a simpler configuration that does not require a driving means for rotating a fan or wiring for supplying power.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a schematic configuration of a first embodiment of a photoreceptor drum temperature control device according to the present invention.

FIG. 2 is a diagram showing a schematic configuration of a second embodiment of a photoreceptor drum temperature control device according to the present invention.

FIG. 3 is a diagram illustrating the bending direction of the fan blades and the air flow at low temperatures in the second embodiment.

FIG. 4 is a diagram illustrating the bending direction of the fan blades and the air flow at high temperatures in the second embodiment.

[Explanation of symbols]

3 Hot air introduction means 5 Temperature detection means 6 Control means 7 Duct 13 Fan

Claims (5)

[Claims] [Industrial application field] 1. A temperature control device for a photoreceptor drum of an image forming apparatus having a photoreceptor drum and a heat-generating member, etc., wherein hot air generated by the members within the image forming apparatus is guided into the photoreceptor drum. A hot air introduction means, a temperature detection means for detecting the temperature of the photoreceptor drum, and a control means for controlling the introduction of hot air into the photoreceptor drum according to the temperature detection result of the photoreceptor drum. A temperature control device for a photoreceptor drum characterized by: 2. The temperature control device for a photoreceptor drum according to claim 1, further comprising a hot air introduction means for introducing the hot air into the photoreceptor drum and an outside air introduction means for introducing outside air into the photoreceptor drum. 3. Temperature control of a photoreceptor drum according to claim 1, characterized in that a duct for guiding hot air into the photoreceptor drum is provided between the heat generating structure and the photoreceptor drum. Device. 4. In a temperature control device for a photoreceptor drum of an image forming apparatus having a photoreceptor drum and a component that generates heat, the fan in which at least a component that determines the air blowing direction is formed of a shape memory member is provided. A temperature control device for a photoconductor drum, characterized in that it is disposed in a cavity of the photoconductor drum. 5. Claim 4, wherein the fan formed of the shape memory member is provided on the rotating shaft of the photosensitive drum so as to be rotatable as the rotating shaft rotates.
The temperature control device for the photoreceptor drum described above.