JPH07287320A - Electrophotographic recording device - Google Patents

Abstract

PURPOSE:To provide an electrophotographic recording device where the surface of a dustproof member is surely cleaned by a simple constitution without providing a special cleaning tool. CONSTITUTION:This device is provided with a reflection mirror 12 reflecting a light beam B for image forming, a photoreceptor 1 where an electrostatic latent image is formed on an outer surface by scanning of the light beam B reflected by the reflection mirror 12, a frame body 7 housing and supporting the photoreceptor 1 and a light transmissible plate-like dustproof member 6 disposed between the reflection mirror 12 and the photoreceptor 1 and supported by the frame body 7; and an ultrasonic vibrator assembly 10 as a vibrating means vibrating the plate-like dustproof member 6 is arranged at a part of the plate-like dustproof member 6 and also the plate-like dustproof member 6 is arranged at the frame body 7 through a surrounding elastic member 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic recording device, and more particularly to an electrophotographic recording device having a light beam scanning means and a photoconductor such as a copying machine or a laser printer.

[0002]

2. Description of the Related Art FIG. 6 shows a conventional example. In FIG. 6, reference numeral 100 indicates a photoconductor. Around the photosensitive member 100, a primary charger 101, a developing device 102, a transfer charger 1
03, the cleaning device 104 is equipped. Also,
A reflection mirror 105 as a light beam scanning device is provided above the photoconductor 100. Further, a dustproof glass 107 held by the frame body 106 is provided between the photoconductor 100 and the reflection mirror 105.

In this conventional example, first, an image forming scanning beam (hereinafter referred to as "image beam") B is projected on the photosensitive member 100 via the reflecting mirror 105 to form an electrostatic latent image. It This electrostatic latent image moves toward the developing device 102 with the rotation of the photoconductor 100, is developed by the developer in the developing device 102, and is visualized. Then, the visible image is transferred via the transfer charger 103 onto the transfer paper P conveyed from a paper feed system (not shown).

Next, the transfer paper P is sent to a fixing device (not shown), and this visible image is fixed on the transfer paper P as a permanent image, and the photoconductor 100 after the transfer is cleaned by the cleaning device 104. The residual developer is cleaned.
After that, the same operation is repeated to sequentially form a predetermined image on the transfer paper B.

In this case, during the above process, the developer, oil mist and the like are scattered around the photoconductor 100,
The reflection mirror 10 is shielded by the dust-proof glass 107.
These impurities do not adhere to 5. Therefore, the electrostatic latent image formed on the photoconductor 100 is stable. Therefore, it is necessary to frequently clean the dustproof glass 107 at the time of regular maintenance.

[0006]

However, in the above-mentioned conventional example, since the cleaning tool is separately prepared in advance and the dustproof glass 107 is cleaned using this cleaning tool, the cleaning work is very troublesome. Therefore, a method has been adopted in which cleaning is performed at the time of maintenance of the entire apparatus.

As a result, in an electrophotographic recording apparatus (such as a high-speed machine for copying a large number of sheets) in which the dustproof glass 107 is frequently soiled, the sensitivity of the image beam B is lowered and the electrostatic latent image formed on the photoreceptor 100. However, there is an inconvenience that the deterioration of the quality occurs.

On the other hand, with respect to the above problems, a technique provided with a cleaning means and capable of performing cleaning at an arbitrary timing is disclosed in, for example, Japanese Patent Laid-Open No. 4-172440.

However, this Japanese Patent Laid-Open No. 4-17244
The cleaning means in Japanese Patent Laid-Open No. 0 has a motor as its power source, a cleaning member is slidably arranged in the longitudinal direction of the dustproof glass by a pulley, and cleaning is performed by reciprocating the cleaning means. Has become. For this reason,
The one disclosed in Japanese Unexamined Patent Publication No. 4-172440 has a complicated structure and a large number of parts, and is therefore expensive. Further, if foreign matter is caught between the cleaning member provided in the cleaning means and the dustproof glass, the dustproof glass is damaged and it is difficult to obtain a stable image.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to improve an inconvenience of the conventional example, and to provide an electrophotographic recording apparatus capable of reliably cleaning the surface of the dustproof member with a simple structure without preparing a special cleaning tool. The purpose is to provide.

[0011]

SUMMARY OF THE INVENTION In the present invention, a reflecting mirror for reflecting a light beam for image formation, and a photoconductor on which an electrostatic latent image is formed on the outer surface by scanning the light beam reflected by the reflecting mirror. And a frame for accommodating and supporting the photoconductor, and a light-transmissive plate-shaped dustproof member disposed between the reflecting mirror and the photoconductor and supported by the frame.

Then, a vibration means for vibrating the plate-shaped dustproof member is provided in a part of the plate-shaped dustproof member, and the periphery of the plate-shaped dustproof member is mounted on the frame body through an elastic member. I am collecting. This aims to achieve the above-mentioned object.

[0013]

[Operation] The cleaning operation is started when the operator issues a dust-proof glass cleaning command from a predetermined operation panel when the power is turned on or at an arbitrary timing. That is, when a drive command is externally sent to the vibrator excitation circuit 42, the vibrator excitation circuit 42 causes the electrode 30 of the ultrasonic vibrator assembly 10 to move.
An alternating electric field in the Z-axis direction or an electric field close thereto is applied between a and 30b. Thereby, the ultrasonic transducer assembly 10
Expands and contracts in the Z-axis direction, and vibrates the dustproof glass 6 as a plate-shaped dustproof member in the same thickness direction. The dust-proof glass 6 is held by the elastic support body 11, and the whole of the held dust-proof glass 6 is easily excited repeatedly at high speed.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a view showing the positional relationship of the respective constituent members arranged around the photosensitive drum 1. In FIG. 1, a primary charging device 2 and a developing device 3 are arranged around the photosensitive drum 1. Reference numeral 4 denotes a blank exposure lamp that removes electric charges on unnecessary portions of the photosensitive drum 1 such as paper intervals after the electrostatic latent image, and reference numeral 5 denotes a pre-exposure lamp that uniformly removes charges on the photosensitive drum 1 after cleaning. Indicates.

When an image beam B, which will be described later, is exposed on the photosensitive drum 1 which is primarily charged by the primary charger 2, an electrostatic latent image is formed on the photosensitive drum 1 according to the image beam B. This electrostatic latent image moves toward the developing device 3 as the photosensitive drum 1 rotates, is developed by the developer in the developing device 3, and is visualized. Then, this visible image is transferred onto a transfer paper conveyed from a paper supply system (not shown) through a transfer charger (not shown). Next, the transfer paper carrying the visible image is sent to a fixing device (not shown) and fixed as a permanent image on the transfer paper, and the photosensitive drum 1 after transfer is cleaned by a cleaning device (not shown). The residual developer is cleaned, and thereafter the same steps are repeated to sequentially form images on the transfer paper.

A lens (not shown) as an optical means and a reflecting mirror 12 for reflecting the laser beam light B from this lens are provided above the photosensitive drum 1 in FIG. Further, a plate-shaped dustproof glass 6 is disposed as a light-transmitting plate-shaped dustproof member between the reflection mirror 12 and the photosensitive drum 1. The dustproof glass 6 is for preventing the developer, oil mist, dust, or the like scattered around the photosensitive drum 1 from adhering to the reflection mirror 12 or a lens (not shown).

As shown in FIG. 2, the dustproof glass 6 is a long glass provided along the axial direction of the photosensitive drum 1.
The elastic support 11 provided on the frame 7 is fitted and held on the rail 13. The elastic support 11 is made of elastic rubber or the like which holds the dust-proof glass 6 so that it can be easily vibrated and prevents the vibration from being transmitted to the frame 7. There is.

The end of the dustproof glass 6 is provided with a stopper 8
It is pressed down (see FIG. 1) so that it does not easily fall off the rail 13. Then, the ultrasonic transducer assembly 10 which is a vibrating means (cleaning means) is provided with the reflection mirror 12.
Is installed on the facing surface side of the dust-proof glass 6 installed so as to face.

This ultrasonic transducer assembly 10 has one surface pressed by an insulating pressing plate 9 and the other surface pressed and fixed so as to come into close contact with the dustproof glass 6, whereby the dustproof glass 6 is fixed. It does not fall off easily.

The developer, oil mist, dust, etc., which are generated during the operation of the electrophotographic recording apparatus and are scattered around the photosensitive drum 1, are shielded by the dust-proof glass 6.
It does not adhere to optical means such as the reflecting mirror 12.

On the other hand, in an electrophotographic recording apparatus for copying a large number of sheets, a cleaning means will be described when the above-mentioned developer, oil mist, dust or the like adheres to the surface (upper and lower surfaces) of the dustproof glass 6.

FIG. 2 is a front view of the dustproof glass 6 seen from above, that is, a front view seen from the reflection mirror 12 side of FIG. The area surrounded by the virtual line B'is the image beam B in FIG.
Indicates a scannable area. For this reason, even when the above-mentioned developer, oil mist, dust, etc. adhere to the dust-proof glass 6 especially on the B ', the image beam is blocked or polarized, and a printing defect occurs.

The ultrasonic transducer assembly 10 is fixed by pressure contact with one surface of the insulating pressing plate 9, and the other surface of the insulating pressing plate 9 is directly fixed to the frame body 7 by the set screw 20 and easily detached. Not configured.

FIG. 3 shows a specific mounting structure of the ultrasonic transducer assembly 10. In FIG. 3, the insulating presser plate 9 is formed by bending twice in different directions at a right angle, and the ultrasonic transducer assembly 10 is press-contacted and fixed by one of the flat surface portions, and the other flat surface portion is fixed. It is fixed to the frame body 7 directly with the set screw 20 so that it does not easily fall off.
Ultrasonic transducer 1 forming the main part of ultrasonic transducer assembly 10
OA is a plate-shaped insulator 31 on the lower surface in FIG.
An electrode 30b is provided on the upper surface and an electrode 30a is provided on the upper surface.

Of these, the electrode 30b on the lower surface side is provided in direct contact with the dustproof glass 6, and the electrode 30a on the upper surface side is provided.
Is grounded. Here, when an alternating electric field in the Z-axis direction or an electric field close thereto is applied between the electrodes 30a and 30b from the vibrator excitation circuit 42 (see FIG. 4), the ultrasonic vibrator 10A moves in the arrow direction (Z-axis direction). Stretching motion is induced on the dustproof glass 6, vibrates the dustproof glass 6 in the same direction, and removes the developer, oil mist, dust, etc. adhering to the dustproof glass 6 by shaking off.

In the present embodiment, the ultrasonic vibrator 10A is, for example, barium titanate (B) of ferroelectric ceramics.
Materials having piezoelectric characteristics such as aTiO ₃ ) and zircon / lead titanate (PZT) are used. In this case, not only one type of piezoelectric element but also two or more types of piezoelectric elements having different expansion and contraction rates may be bonded together.

In the above embodiment, the cleaning operation is performed when the operator issues a dustproof glass cleaning command from a predetermined operation panel at power-on or at an arbitrary timing, or the total number of printed sheets of the electrophotographic recording apparatus. It is programmed in the CPU 40 in advance so that it is performed every time a certain specified value is exceeded.

FIG. 4 shows a circuit block for driving the ultrasonic transducer assembly 10 by excitation. In FIG. 4, the CPU 40, which has received a dustproof glass cleaning command from the outside, outputs a drive command to the vibrator excitation circuit 42 via the I / O port 41. The oscillator excitation circuit 42 is used for the ultrasonic oscillator assembly 10
An alternating electric field in the Z-axis direction or an electric field close thereto is applied between the electrodes 30a and 30b. As a result, the ultrasonic transducer assembly 10 is induced to expand and contract in the Z-axis direction of the arrow shown in FIG. 4, causing the dust-proof glass 6 to vibrate in the same direction. The dustproof glass 6 is fitted and held in the rails 13 of the elastic support 11 and has a structure that can be easily vibrated by the elasticity of the elastic support 11.

It is desirable to apply a wavelength (resonance frequency) satisfying the resonance condition to the alternating electric field based on the combined impedance of the impedance of the ultrasonic transducer assembly 10 and the impedance of the dustproof glass 6 in contact therewith. The oscillator excitation circuit 42, when there is no change in the combined impedance,
It suffices to apply an alternating electric field having a resonance frequency obtained by calculation and experiment in advance to the ultrasonic transducer assembly 10. On the other hand, when the above-mentioned combined impedance fluctuates due to the load and the resonance frequency cannot be fixed, a detection circuit for detecting the change in the combined impedance and a frequency for outputting the resonance frequency satisfying the resonance condition to the vibrator excitation circuit 42 based on the detection circuit You may make it equip with the feedback circuit provided with the variable circuit.

1 to 4, the ultrasonic transducer 10 is applied by applying an alternating electric field in the Z-axis direction between the electrodes 30a and 30b from the transducer excitation circuit 42.
Although the structure in which A is expanded and contracted in the Z-axis direction to vibrate the dust-proof glass 6 in the same direction, another method may be adopted for the vibration direction in which the dust-proof glass 6 is vibrated.

FIGS. 5A and 5B show another example of the vibration direction in which the dustproof glass 6 is vibrated. Of these, in FIG. 5A, in order to vibrate the dustproof glass 6 in the Z-axis direction as in the above-described embodiment, the ultrasonic vibrator assembly 10 is provided on the other surface of the dustproof glass 6, that is, in FIG. The feature is that it is provided on the lower surface side facing the photosensitive drum 1.

That is, the ultrasonic transducer 10 formed into a prismatic shape.
An electrode 30b is provided on the upper surface of A via an insulator 31 and an electrode 30a is directly provided on the lower surface. The electrode 30b is brought into contact with the dustproof glass 6 and the electrode 30a is grounded. With this configuration, when an alternating electric field is applied between the electrodes 30a and 30b of the ultrasonic oscillator assembly 10, the ultrasonic oscillator 10 is
A expands and contracts in the arrow direction (Z-axis direction), and vibrates the dustproof glass 6 in the Z-axis direction.

FIG. 5B is a diagram showing a structure in which the dustproof glass 6 is vibrated in the X-axis direction by mounting the ultrasonic vibrator assembly 10 of FIG. 5A in the X-axis direction.
Further, FIG. 5C is a diagram showing a configuration in which the dustproof glass 6 is vibrated in the Y-axis direction by mounting the ultrasonic transducer assembly 10 in the Y-axis direction. As described above, the direction in which the dustproof glass 6 is vibrated is not limited, and may be any of the vertical direction, the parallel direction, and the oblique direction as long as the dustproof glass 6 is vibrated. In each of FIGS. 5B and 5C, the periphery of the ultrasonic transducer assembly 10 is hermetically mounted on the frame body 7 by the same member as the elastic support body 11 described above. I shall.

Here, in the above-mentioned embodiment, a vibrating means is used to vibrate by using a voltage element that generates displacement or force by applying a voltage. However, for example, deformation of expansion or contraction by applying a magnetic field is adopted. A vibrating means, which is composed of a magnetostrictive element or a coil or a magnet that causes (magnetostriction phenomenon) and vibrates the dustproof member by applying an electromagnetic force, may be used as the cleaning means.

[0036]

Since the present invention is constructed and functions as described above, according to the present invention, the surface of the dustproof member can be removed only by inputting a drive command from the outside without preparing a special cleaning tool as in maintenance. Immediate and reliable cleaning is possible. Therefore, even when cleaning, it is possible to transmit a good-quality image beam onto the photoconductor for a long period of time without damaging the dustproof member. It is possible to provide an unprecedented excellent electrophotographic recording device capable of obtaining an image and a visible image.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of the present invention.

FIG. 2 is a front view showing an example of the configuration around the dustproof glass disclosed in FIG.

FIG. 3 is an explanatory diagram showing an example of a mounting structure of the ultrasonic transducer assembly disclosed in FIG.

FIG. 4 is an explanatory diagram showing an example of a drive circuit portion of the ultrasonic transducer assembly disclosed in FIG.

FIG. 5 is a diagram showing an attachment position of an ultrasonic transducer assembly, FIG. 5 (A) is an explanatory view showing an example in which it is attached to the back surface of the dustproof glass, and FIG. 5 (B) is attached to a side surface of the dustproof glass. FIG. 5C is an explanatory diagram showing an example in the case of being attached, and FIG. 5C is an explanatory diagram showing an example in the case of being attached to the end face in the longitudinal direction of the dustproof glass.

FIG. 6 is an explanatory diagram showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photosensitive drum 6 Dust-proof glass as a plate-shaped dust-proof member 7 Frame 10 Ultrasonic oscillator assembly 10A Ultrasonic oscillator 11 Elastic member 12 Reflector 30a, 30b Electrode 42 Transducer excitation circuit B Light beam

Claims (4)

[Claims] 1. A reflection mirror for reflecting a light beam for image formation, a photoconductor on which an electrostatic latent image is formed on the outer surface by scanning the light beam reflected by the reflection mirror, and the photoconductor. An electrophotographic recording apparatus comprising: a supporting frame body; and a light-transmissive plate-like dustproof member disposed between the reflecting mirror and the photoconductor and supported by the frame body. Part is equipped with a vibration means for vibrating the plate-shaped dustproof member, and the plate-shaped dustproof member is
An electrophotographic recording apparatus, characterized in that the frame is equipped with an elastic member provided around the frame. 2. The vibrating means comprises an ultrasonic transducer assembly, and the frame body is equipped with a transducer excitation circuit for applying an excitation signal of a predetermined frequency to the ultrasonic transducer assembly. The electrophotographic recording apparatus according to claim 1, which is characterized in that. 3. The electrophotographic recording apparatus according to claim 2, wherein the ultrasonic transducer assembly is configured based on a piezoelectric ultrasonic transducer. 4. The electrophotographic recording apparatus according to claim 2, wherein the ultrasonic vibrator assembly is configured based on a magnetostrictive ultrasonic vibrator.