JPH02287463A - Copying device - Google Patents

Abstract

PURPOSE:To prevent rising of temperature in the device by providing an air supplying fan in the copying device main body and lowering the ozone concentration in the device. CONSTITUTION:An ozone decomposing means 2 containing ozone decomposing agent is provided in an exhausting part of the copying device main body 1, the air containing ozone in the device is passed by an exhausting fan 3 through this ozone decomposing means 2, while passing through, the ozone is decomposed by contact of the ozone decomposing agent and the exhaust air, and is exhausted outside the device. Further, the air feeding fan 4 is provided near the exhausting fan 3 of the copying device main body 1, and the driving means 9 of the exhausting fan 4 is controlled by the controlling means 8. Thus, the ozone concentration in air in the device is lowered and the temperature in the device can also be lowered.

Description

[Detailed description of the invention] Industrial applications The present invention relates to an electrophotographic copying apparatus.

Conventional technology In conventional electrophotographic copying machines, a photoreceptor is uniformly charged by discharging from a charger, and then exposed to light to form a latent image, which is then transferred to a sheet of paper through the process of development, transfer, and fixing. Transcription is in progress.

In this process, a charger that uses corona discharge is used to uniformly charge the photoreceptor.
During discharge from the charger, the air reacts and generates ozone due to its high potential. If this ozone is left as it is, it may deteriorate the photoreceptor, so it must be discharged from the apparatus. However, if ozone is emitted in high concentrations, it may have an adverse effect on the human body, so an ozone decomposition means is installed in the exhaust section of the main body of the copying machine, and this decomposition means removes ozone from the air exhausted by the exhaust fan. It has become.

By the way, the ozone decomposition means mentioned above uses volatile synthetic decomposers called terpenoids, which have a fast decomposition rate. Correlation is the first
As shown in Figure 0, when the ozone concentration is high, the decomposition rate is fast, but as the ozone concentration becomes low, the decomposition rate becomes slow.

By the way, when the ozone-containing air is discharged outside the device, the ozone concentration is 0. It is desirable that it is less than lppm, but
As can be seen from the above, it takes a long time to accomplish this, and during continuous copying, it is difficult to maintain a decomposition rate that is equal to the increase in the amount of ozone.

In addition to this slow ozone decomposition rate.

Because the pressure loss in the ozone decomposition means is large.

If the amount of exhaust air inside the device is restricted and the temperature inside the device rises, and this temperature rises to 20 to 40 degrees Celsius, potential fluctuations in the photoreceptor and displacement of the optical system due to heat will occur. This will cause a problem.

Problems to be Solved by the Invention Therefore, it is necessary to reduce the concentration of such emitted ozone and prevent the temperature inside the device from rising.

To achieve this, the rotational speed of the exhaust fan should be increased to efficiently exhaust the air inside the device. However, if the ozone concentration inside the device is 0.1 ppm or less, there is no problem, but it is usually around 2 to 5 ppm, so if you increase the speed of the exhaust flow by increasing the rotation speed of the exhaust fan, the ozone decomposition will occur. Since the contact time with the agent or catalyst is shortened and the ozone removal rate is reduced, the rotation speed of the exhaust fan cannot be increased, thus reducing the ozone concentration in the exhaust air and reducing the temperature inside the device. There is a problem in that it is not possible to effectively prevent this from increasing.

SUMMARY OF THE INVENTION An object of the present invention is to provide a copying apparatus which can solve the problems of the conventional copying apparatus as described above, dilute the ozone concentration inside the apparatus, and prevent the temperature inside the apparatus from increasing.

Means for Solving the Problems In order to achieve the above-mentioned objects, the present invention provides an air supply fan or an air supply/exhaust fan in addition to the ozone decomposition means and exhaust fan as in the conventional copying apparatus. It is something that

The air supply fan or the supply/exhaust fan is provided so as to communicate with a space adjacent to the rear of the exhaust fan.

Further, the air supply fan or the supply/exhaust fan is selectively operated depending on the temperature or ozone concentration of the atmosphere within the main body of the copying apparatus, and furthermore, the number of revolutions thereof is adjusted.

Function: In the copying apparatus described above, the air supply fan or the air supply/exhaust fan is operated depending on the temperature or ozone concentration inside the apparatus, thereby lowering the ozone concentration and temperature inside the apparatus.

The air supply fan or supply/exhaust fan for this purpose supplies air outside the equipment to the space adjacent to the rear of the exhaust fan, thereby reducing the ozone concentration inside the equipment and preventing a rise in temperature. Temperature rise is prevented.

At this time, depending on the ozone concentration or the temperature inside the device, the rotation speed of the air supply fan or the supply/exhaust fan is adjusted to adapt to the situation inside the device.

Embodiment In the first embodiment shown in FIG. 1, an ozone decomposition means 2 having an ozone decomposition agent is provided in the exhaust section of the main body 1 of the copying apparatus, and an exhaust fan 3 is used to remove ozone contained in the apparatus. Air is passed through the device, and during this passage, the ozone decomposer comes into contact with the exhaust gas, whereby ozone is decomposed and discharged outside the device.

An air supply fan 4 is provided near the exhaust fan 3 of the copying apparatus main body 1, 5 is a photoreceptor drum, 6 is a temperature measuring element provided in front of the photoreceptor drum 5, 7 is an ozone sensor, and 8 is a photoreceptor drum. A control means inputs detection signals from the temperature measuring element 6 and the ozone sensor 7, and 9 is a drive means for the air supply fan 4, which is controlled by the control means 8.

FIG. 2 is a control block diagram for the control means 7 using the temperature detection element 6, in which 10 is an A/D converter, 11 is an input interface, 12 is a CPU, 13 is an output interface, 1
4 indicates display elements, respectively.

FIG. 3 shows an example of the ozone sensor 7, in which a semiconductor thin film 17 kept at a constant high temperature (400°C) by a platinum thin film heater 16 is provided on an alumina substrate 18, and the semiconductor thin film 17 is oxidized. The resistance value changes due to the decomposition (decomposition into 02.0) and adsorption of ozone. A platinum thin film electrode 19 reads changes in the resistance value of the semiconductor thin film 17.

This change in resistance value is detected as a voltage change using a constant current measurement method using a circuit as shown in FIG.

The operation of the first embodiment will be explained with reference to FIG.

When the copying machine starts operating, the exhaust fan 3 operates in synchronization with it, and when the temperature inside the machine is less than 30°C and the ozone concentration is less than 0.5 ppm, the ozone decomposition means 2 decomposes the ozone as in the conventional copying machine. As a result of continuous operation in this way to remove ozone, for example, if the temperature inside the device reaches 30°C or the ozone concentration reaches o, spp, the temperature detection element 6 or ozone sensor 7 detects this. The output signal is inputted to the control means 8 through each circuit 10 to 13, and the drive means 9 operates the air supply fan 4. In this way, the temperature inside the device is 30°C or less or the ozone concentration is 0.5pp.
On the other hand, when it becomes less than +m, the air supply fan 4 is stopped.

When the temperature or ozone concentration inside the device increases in this way, the air supply fan 4 sucks outside air into the device, thereby lowering the temperature or ozone concentration inside the device.

FIG. 6 shows a second embodiment of the present invention, which is completely the same except that the air supply fan 4 of the first embodiment is replaced by an air supply/exhaust fan 4'. be.

In this embodiment, as shown in FIG. 7, (1) In region (1) where the temperature inside the device is below 30°C and the ozone concentration is below 0.5 ppm, only the exhaust fan 3 operates as in the conventional system; The air supply/exhaust fan 4' is stopped.

(2) While operating in this way, the temperature exceeded 30℃ as shown in area (■), but the ozone concentration was 0.5ppm.
If the temperature does not exceed , only the temperature detection element 6 outputs a signal,
The drive means 9 causes the air supply/exhaust fan 4' to operate as an exhaust fan to exhaust air within the apparatus. In conventional copying machines, this can be dealt with by increasing the number of rotations of the exhaust fan 3 to increase the exhaust volume.
This shortens the contact time between the ozone-containing exhaust gas and the ozone decomposition means, resulting in a decrease in ozone decomposition ability and a high concentration of ozone being discharged.

On the other hand, in this embodiment, as the air inside the device is discharged, outside air is sucked into the device from other parts of the device to prevent the temperature from rising. Since the amount of ozone is below the specified value, no problem arises due to external release of ozone.

(3) Contrary to the above, when the temperature does not exceed 30°C but the ozone concentration exceeds 0.5 pp- as in region (3), only the ozone sensor 7 outputs a signal and the driving means 9 As a result, the supply/exhaust fan 4' operates as an air supply fan, sucking outside air into the apparatus and reducing the ozone concentration within the apparatus.

(4) Next, when the temperature exceeds 30°C and the ozone concentration exceeds 0.5 ppm as in region (■), the temperature detection element 6 and the ozone sensor 7 output signals, and these signals cause the control means 8 to As shown in FIG. 8, the air supply/exhaust fan 4' is caused to repeat the air supply/exhaust action at regular intervals via the drive means 9, thereby reducing the temperature rise inside the device and the ozone concentration. It has been found that this is extremely effective in preventing air pollution compared to a method that only unilaterally performs air and exhaust.

Furthermore, in this case, it has been found that changing the rotational speed of the air supply/exhaust fan 4' depending on the temperature or ozone concentration works more effectively, as shown in FIG.

In both of the above two embodiments, the fans 4゜4' are automatically activated by the signals from the temperature measuring element 6 and the ozone sensor 7, but instead of this, the temperature measuring element 6 and the ozone sensor 7 The temperature or concentration may be detected using a device such as the above, and the operator may manually operate the fans 4, 4' based on the detected temperature or concentration.

Effects of the Invention The present invention is as described above, and since an air supply fan or an air supply/exhaust fan is provided in the main body of the copying apparatus in addition to the ozone removal exhaust fan, the temperature or ozone concentration of the atmosphere inside the apparatus is lower than that of the exhaust fan. If the ozone concentration exceeds the set conditions, the ozone concentration in the air inside the equipment is diluted and the ozone concentration in the equipment is Ozone removal is possible by reducing the internal temperature and eliminating the need to increase the rotation of the exhaust fan to lower the temperature and shorten the contact time of the exhaust air with the ozone decomposition means as in conventional copying machines. carried out reliably over a long period of time,
Furthermore, there is an effect that it is possible to prevent problems caused by a rise in temperature inside the device.

Moreover, since the air supply fan or supply/exhaust fan communicates with the space near the exhaust fan, it is possible to supply air directly to the air inside the equipment, which has a high ozone concentration, effectively reducing the ozone concentration. This has the effect that high-temperature air can also be reliably discharged to the outside of the device.

The air supply fan or supply/exhaust fan is controlled depending on the temperature or ozone concentration of the atmosphere inside the equipment, and its rotational speed is increased or decreased depending on the amount of ozone, so it is always adjusted according to the actual situation. Appropriate air supply and exhaust will be performed.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view of a first embodiment of the present invention, FIG. 2 is a control block diagram of the same as above, FIG. 3 is a perspective view of an example of an ozone sensor, and FIG. 4 is a diagram of a control circuit using an ozone sensor. Example circuit diagram, Figure 5 is a graph showing the operation of the first embodiment, Figure 6 is a graph showing the operation of the first embodiment.
The figure is a schematic sectional view of the second embodiment of the invention, and FIG.
A graph similar to FIG. 5 of the example, FIG. 8 is a graph showing the fan rotation state in the region (■) of the second example, and FIG. 9 is a graph showing the fan rotation speed, temperature, and ozone concentration of the second example. Figure 1θ is a graph showing the relationship between ozone concentration and decomposition time in a copying machine. l... Copying device main body, 2... ozone decomposition means, 3.
...Exhaust fan, 4...Air supply fan, 6...Temperature detection element. 7... Ozone sensor, 8... Control means, 9... Drive means. Figure 3 ￥4 Figure 5 Figure 6 Figure 7 Figure 5 twice (C

Claims (1)

[Claims] 1. In a copying machine in which ozone decomposition means is provided in the exhaust section of the copying machine main body, and ozone is removed from the air discharged by the exhaust fan by the decomposition means, the supply of ozone to the copying machine main body is A copying device characterized by being equipped with an air fan. 2. In a copying machine in which an ozone decomposition means is provided in the exhaust section of the copying machine main body, and the decomposition means removes ozone from the air discharged by the exhaust fan, an air supply/exhaust fan is provided in the copying machine main body. A copying device characterized by: 3. The copying apparatus according to claim 1 or 2, wherein the air supply fan or the supply/exhaust fan is arranged to communicate with a space adjacent to the rear of the exhaust fan. 4. The copying apparatus according to claim 1, wherein the air supply fan or the supply/exhaust fan is selectively operated depending on the temperature or ozone concentration of the atmosphere within the main body of the copying apparatus. 5. The copying apparatus according to claim 4, wherein the air supply fan or the supply/exhaust fan has its rotational speed adjusted depending on the temperature of the atmosphere inside the copying apparatus main body or the temperature.