JPH0193779A - Image forming device - Google Patents

Abstract

PURPOSE:To prevent the occurrence of blocking of waste toner recovered in a cleaning device by detecting the temperature in the vicinity of the device to pen or close the aperture of a wind path formed in the vicinity of the device. CONSTITUTION:A fan 9 is provided in a wind path D, and an aperture is formed in the end part of the wind path D to cover a primary charger 2. An aperture is formed in the vicinity of a cleaning device 7 also, and a cover body 10 consisting of a shape memory alloy, which changes the shape at the time of a prescribed temperature in such direction that this aperture is opened, is attached to this aperture. The cover body 10 consists of the shape memorizable alloy, which is deformed as shown by a dotted line to open the aperture at the temperature at which blocking of the used toner is apt to occur, to open the aperture in the state where the temperature rise in the device has an influence upon toner. The cover body 10 is closed when the ambient temperature falls to a prescribed value and blocking of toner does not occur.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Object of the Invention (Field of Industrial Application) The present invention relates to an image forming apparatus using an electrostatic transfer process, such as an electrostatic copying machine and a printer thereof.

(Prior art and problems to be solved) A transferable toner image is formed on the surface of an image carrier, and then a sheet-shaped transfer material such as paper is brought into contact with the toner image to transfer the toner image to the transfer material. 2. Description of the Related Art Image forming apparatuses are conventionally known in which a transfer material is fed to a fixing site and residual toner remaining on the surface of an image carrier is removed by a cleaning means.

FIG. 4 is a schematic side view showing the configuration of a typical image forming apparatus of this type, in which a photosensitive layer on the surface of an image carrier l formed in a rotating cylindrical shape is uniformly charged by a primary charger 2. After that, a light image is applied to this by an image signal applying means from the direction of arrow 3, and an electrostatic latent image is formed on the photosensitive layer.

Next, toner is supplied to this latent image by the developing device 4 and electrostatically adheres to the latent image portion to form a toner image.

This toner image is transferred to the image carrier 1 at the same timing.
The image is transferred to the transfer material P brought to the position where it contacts the image carrier by the action of the transfer charger 5. After the transfer, the transfer material is separated from the image carrier by the separation charger 6 and conveyed to the fixing device 8. Ru.

On the other hand, residual toner that does not contribute to transfer at the transfer site and remains on the surface of the image carrier arrives at the cleaning device 7 as the image carrier rotates, and is thereby removed from the image carrier. It is assumed that the image forming apparatus 2 reaches the position of the charger 2 again in a state in which the next image forming operation can be performed.

In such an image forming apparatus, electric parts such as a drive motor, a heater that heats the image carrier to prevent image quality from deteriorating due to adhesion of moisture, and furthermore, when using heat fixing, Since there are many elements such as heaters that promote temperature rise within the apparatus, this inevitably has various effects on various parts within the apparatus.

Regarding the cleaning device, the waste toner collected once solidifies (blows, kings) due to the temperature rise inside the device, which becomes an obstacle to conveying the toner from the cleaning device to the waste toner storage section, damaging the cleaning function. There is a risk.

In order to avoid such a situation, it has already been proposed to dispose a fan 9 near the cleaning device to prevent toner blocking, as shown in the figure. Since it is difficult to maintain this in a completely sealed state, there is a risk that the collected toner may flow into the original image forming device and contaminate various parts due to the pressure difference between the inside and outside of the cleaning device due to the airflow generated by the fan. .

In addition, since the heating element in the inner part of the image forming apparatus has a large difference in the amount of heat generated depending on its operating condition, the above-mentioned
In the arrangement of the cooling fan, the balance between the amount of heat generated and the amount of waste heat is not kept constant, and the temperature of the image carrier fluctuates greatly, making it difficult to obtain a stable image.

In order to avoid the above-mentioned difficulties, for example, it is possible to detect the temperature of the cleaning device or image carrier and control the fan on and off based on this information, or to adjust the speed of the fan. It is easy to understand that this method complicates the device, requires space inside the device, and is not preferable from a cost standpoint.

Furthermore, as schematically illustrated in FIG. It has been proposed that a 148K fan is used to provide an air flow for cooling the cleaning device 7 (it is well known that the discharge is stabilized), and that a 148K fan is used to cool the cleaning device 7. However, it is impossible to generate airflow for an optimal amount of time at a time that corresponds to the purpose of each part.

The present invention has been developed in order to deal with such a situation, and it is possible to minimize the flow of toner from a cleaning device, etc., prevent blocking from occurring, and furthermore prevent the leakage of toner from other parts. It is an object of the present invention to provide an image forming apparatus that can perform cooling simultaneously and in a state appropriate to each member, and that can cool the inside of the image forming apparatus as a whole in accordance with the requirements of each member. It is.

(2) Structure of the invention (technical means for solving the problem, its operation) In order to achieve the above object, the present invention provides a -order charger, an image signal applying means, a developing device, In an image forming apparatus that is equipped with members necessary for image formation such as a transfer charger, a separation means, and a cleaning device, the cooled section including the cleaning device is faced to the opening of an air passage in which a fan is installed, and at least the cleaning device is installed. The device is characterized in that a lid member is disposed in the opening corresponding to the device to detect the temperature and open and close the opening accordingly.

With this configuration, members having different cooling conditions can be cooled in a state suitable for each member, and each member can be operated in an optimal state at all times.

(Explanation of Embodiments) FIG. 1 shows the application of the present invention to a copying machine equipped with a rotating cylindrical image carrier (hereinafter referred to as photoreceptor), similar to those shown in FIGS. 4 and 5 above. FIG. 2 is a side view showing the configuration of an embodiment.

In the photoreceptor 1, parts corresponding to those shown in FIGS. 4 and 5 are designated by the same reference numerals, and their structures and functions will be omitted unless particularly necessary. do.

In the illustrated apparatus, an air passage is provided in the upper part of the figure, and a fan 9 is provided inside the air passage.

An opening D1 formed at the end of the air path is formed to cover the primary charger 2, and an opening D2 is also formed near the cleaning device 7. A lid lO made of a shape memory alloy is attached, which has a shape that closes the opening at room temperature and changes its shape to open the opening D2 at a predetermined temperature.

Therefore, by constructing the lid body 10 with a shape memory alloy that deforms as shown by the dotted line in the figure and opens the opening D2 at a temperature at which the toner to be used tends to block if left for a long time, the fan 9 is constantly operated while the primary charger 2 is discharging, the discharge characteristics of the negative charger 2 are maintained, and the opening D2 is opened when the rising temperature inside the device is in a state that affects the toner. However, it is possible to create an air flow near the cleaning device to cool it, and to close the lid 10 when the environment reaches a predetermined temperature and no blocking of toner occurs.

FIG. 2 is a sectional view showing only the air passage portion showing another embodiment of the present invention, in which two shape memory alloys are arranged so as to block the air passage by deformation. It is easy to understand that even with such a configuration, the same effect as that described above can be obtained.

FIG. 3 shows yet another embodiment of the invention.

In the illustrated apparatus, parts corresponding to those in the first, fourth, and fifth figures described above are designated by the same reference numerals, and a description thereof will be omitted.

In this device, a rigid lid 12, a solenoid 14 for operating the lid, and a plunger 1 are used to open and close an opening that generates an airflow for cooling the cleaning device.
It has 5.

The opening D2 is closed at the position indicated by the solid line in the figure at room temperature, and the temperature of the cleaning device is detected by the temperature sensor 11 disposed at an appropriate location in the cleaning device 7, and this signal is sent to the control power source 13 for driving the plunger. It is assumed that the lid body 12 is opened and closed by applying the voltage.

Although the configuration of this device is more complicated than that of the above-mentioned embodiment, the temperature sensor can be placed as close as possible to the toner in the cleaning device. It is less affected by temperature differences between heat sources and airflow.

In the above embodiments, the charger and the cleaning device are cooled, but the present invention is not limited thereto. Share a part of the wind path,
It goes without saying that it can be configured to open and close as needed.

(3) Effects of the Invention As explained above, the present invention includes an image carrier, a primary charger, an image signal applying means, a developing means, a transfer means,
In an image forming apparatus equipped with members necessary for image formation, including a cleaning means, the opening of the air passage formed near the cleaning device is opened and closed by detecting the temperature near the cleaning device. It effectively prevents the waste toner collected in the device from causing blocking and maintains its function over a long period of time, and also provides a cooling means and purpose for other components whose cooling conditions are different from that of the cleaning device. ventilation means for other parts that differ;
Since the cooling means can be easily shared with that used for the cleaning device, it is possible to simplify the configuration and shorten the length of the air path in the image forming device, thereby reducing the output of the fan. Since the amount can be reduced, it is extremely advantageous in terms of cost.

[Brief explanation of the drawing]

FIG. 1 is a side view of a main part showing an embodiment in which the present invention is applied to a copying machine, FIG. 2 is a cross-sectional view of a part of another embodiment, and FIG. 3 is a main part showing another embodiment. The side view, FIGS. 4 and 5 are schematic side views of essential parts of an image forming apparatus, illustrating the configuration of a known cooling means. DESCRIPTION OF SYMBOLS 1...Photoreceptor, 2...-forming charger, 3...Image signal applying means, 4...Developer, 511φ/transfer charger,
7...Cleaning device, 9...Fan, 10.1
2...Lid body, 11.e.Temperature sensor, 1411...Solenoid. Akira 4. Review 5rg! 4

Claims (1)

[Claims] In the vicinity of the image carrier, a primary charger, an image signal applying means,
In an image forming apparatus comprising members necessary for image formation including a developing means, a transfer means, a separating means, and a cleaning means, the temperature near the cleaning means is detected, and only when the temperature exceeds a predetermined temperature, the temperature near the cleaning means is removed. An image forming apparatus characterized in that a means for generating an air flow is provided in the image forming apparatus.