JPH02311863A - Image recorder - Google Patents

Abstract

PURPOSE:To noiselessly operate the image recorder by providing a control means which switches a cooling fan from a flow speed to high speed ventilating operation when a detected temperature of a temperature sensor comes to an alarm temperature at which the properties of a photosensitive body are damaged. CONSTITUTION:The temperature sensor 21 which detects the temperature of the photosensitive body and which is composed of thermister, etc., is arranged; temperature data detected by the temperature sensor 21 is taken in a control part 22, which is composed of a microcomputer; the data is compared with the previously set alarm temperature, and the cooling fan 12 is switched between the low speed and high speed ventilating operations. That is, when a power source is turned on, the cooling fan 12 starts ventilating at a low speed, and comes to normal idling operation; consequently, normal ventilation is carried out in an image recorder housing. Regardless of whether copying starts or not after that, the temperature Ta detected by the temperature sensor 21 is compared with the alarm temperature Tr; when the result is Ta>Tr, the cooling fan 12 is switched from the low speed to high speed ventilating operation. Thus, the photosensitive image recorder can be noiselessly operated.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an electrostatic recording type image recording device having a heat generating part, and in particular improves drive control of a cooling fan so as to be as quiet as possible. The present invention relates to an image recording device.

[Conventional technology]

In an electrostatic recording type copying apparatus, the recording section thereof is constructed as shown in FIG. That is, when a photoconductive photoreceptor 2 whose surface is charged with a high-voltage charge by a charging electrode 1 is rotated in the direction of arrow a and an image light 3 carrying image information is incident thereon, the charges on the surface of the photoreceptor 2 are transferred to the image light 3. , an electrostatic latent image is formed thereon, and this latent image is developed by the developing device 4 into a toner image. On the other hand, the transfer paper 8, which had been previously fed from the paper feed section 5 to the registration roller 7 by the paper feed roller 6, is re-fed from the registration roller 7 at a timing that matches the leading edge of the toner image and is transferred to the registration roller 7. When the toner image is conveyed to the pole 9, the toner image is transferred to the transfer paper 8. This transfer is performed by applying a potential of the same polarity higher than the potential of the photoreceptor 2 to the transfer pole 9. Then, the transfer paper 8 on which the toner image has been transferred is separated from the photoreceptor 2 by a separation pole 10 that generates an alternating current electric field, and is conveyed to a thermal fixing device 11. The heat fixing device 11 includes a heating roller IIA made of an aluminum cylinder having a heater inside and a pressure roller made of a rubber roller.

Therefore, an image recording apparatus incorporating such a thermal fixing device 11 is provided with a cooling (exhaust) fan 12 to prevent heat from becoming trapped inside and causing various problems.

Conventionally, the operation of the cooling fan 12 was controlled at the timing shown in FIG. That is, operation is performed in a cycle in which low-speed exhaust (idling) starts when the power is turned on, then switches to high-speed exhaust when copying starts, and then returns to low-speed exhaust once the copying is completed.

[Problem to be solved by the invention]

Therefore, in the past, when copying started, the exhaust operation always started at high speed, which increased the noise level and hindered the quietness of the office.

SUMMARY OF THE INVENTION An object of the present invention is to provide an image recording apparatus in which the cooling fan is not operated at a low speed or is operated at a low speed except when necessary, so as not to interfere with quietness as much as possible.

[Means to solve the problem]

To this end, the present invention provides an electrostatic recording type image recording apparatus equipped with a cooling fan, which includes a temperature sensor that detects the temperature of a photoconductor, and a temperature sensor that detects a temperature at which the temperature detected by the temperature sensor reaches an alarm temperature that impairs the characteristics of the photoconductor. The cooling fan is configured to include a control means for switching the cooling fan from low-speed exhaust operation to high-speed exhaust operation when the exhaust operation occurs.

The control means may be replaced with means for switching the cooling fan from off to on when the detected temperature reaches the alarm temperature.

〔Example〕

Examples of the present invention will be described below. First, a photoreceptor made of an organic photoreceptor (OPC) is shown in Figure 3.
As the temperature increases, the surface potential decreases due to fatigue. In particular, when looking at the characteristics of the original (original) density and the copy image density, as shown in Figure 4, as the temperature rises, the surface potential decreases, the adhesion efficiency of potatoes deteriorates, and the copied image becomes thinner. There is a tendency to

Therefore, in this embodiment, the temperature of the photoreceptor is constantly monitored, and when the temperature reaches a point where there is a high risk of damaging the characteristics of the photoreceptor, the capacity of the cooling fan is increased, and the cooling fan is operated. We have tried to avoid causing a stir as much as possible.

FIG. 1 is a control circuit diagram of a cooling fan 12 in one embodiment,
FIG. 2 is a flowchart of a control program. In this embodiment, a temperature sensor 21 made of a thermistor or the like for detecting the temperature of the photoconductor 2 is arranged, and the temperature data detected by this temperature sensor 21 is sent to a microcomputer. The temperature is input to the control unit 22 and compared with a preset alarm temperature (for example, 30° C.), and the operation of the cooling fan 12 is switched between low-speed exhaust and high-speed exhaust. The specific location of the temperature sensor 21 may be any location where it can detect the temperature of the circumferential surface of the photoreceptor 2, for example, on the downstream side of the charging electrode 1, or on the developing device 4.
and the downstream side of the separation electrode 10.

Hereinafter, the operation control of the cooling fan will be explained according to the flowchart shown in FIG. First, when the power is turned on, the cooling fan 12 starts exhausting air at a low speed and enters normal idling operation. As a result, the inside of the image recording apparatus case is normally evacuated. Regardless of whether or not a copy is started thereafter, the temperature Ta detected by the temperature sensor 21 is compared with the alarm temperature Tr, and if Ta > Tr, the cooling fan 12 is switched from low-speed exhaust to high-speed exhaust. . This comparison control is then continuously performed.

In the above embodiment, a case has been described in which the cooling fan 12 performs two-stage exhaust switching of low-speed exhaust and high-speed exhaust, but it is also possible to control only the on/off of the cooling fan.
The invention is equally applicable.

In this case, turn off the cooling fan for the low-speed exhaust 1 mentioned above.
It is sufficient to replace r high-speed exhaust j with a cooling fan.

〔Effect of the invention〕

As described above, according to the image recording apparatus of the present invention, when the temperature of the photoreceptor reaches the alarm temperature, the cooling fan is switched to high-speed exhaust or turned on, so that the image recording apparatus can be made quieter. There is an advantage.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of cooling fan control according to an embodiment of the present invention;
Figure 2 is a flowchart of the control program, Figures 3 and 4 are characteristic diagrams of the photoreceptor, Figure 5 is a diagram showing the schematic configuration of the image recording device, and Figure 6 is a diagram of the conventional cooling fan control. This is a timing chart. Agent Patent Attorney Tsuneaki Nagao Figure 1 Figure 2 Ta: Detected temperature Tr: Alarm temperature Figure 3 Photoreceptor temperature → Figure 4 0 0.5 1.0 1.5 2.0 Original 1 degree → Figure 5 S1 =>$ Power off

Claims (2)

[Claims] (1) In an electrostatic recording type image recording device equipped with a cooling fan, there is a temperature sensor that detects the temperature of the photoreceptor, and the temperature detected by the temperature sensor becomes an alarm temperature that impairs the characteristics of the photoreceptor. An image recording apparatus comprising: a control means for switching the cooling fan from a low-speed exhaust operation to a high-speed exhaust operation. (2) The image recording apparatus according to claim 1, wherein the control means is replaced with means for switching the cooling fan from off to on when the detected temperature reaches the alarm temperature. .