JPS6368873A - Electrophotographic device - Google Patents

Abstract

PURPOSE:To obtain uniform irradiation and to perform excellent electrostatic discharging by providing two corrugated reflecting plates which are arranged in parallel to light sources across the light sources and reflect light emitted by the light sources to a photosensitive body, and converging the light on a position to which the reflecting surfaces of the reflecting plates correspond between the light sources. CONSTITUTION:The two corrugated reflecting plates 12 are arranged in parallel to the light sources 9 across the light sources 9 to reflect the light emitted by the light sources 9 to the photosensitive body 1, and the reflecting surfaces of the reflecting plates 12 are so constituted as to converge light on positions between light sources 9 and 9. The quantity of light projected on the photosensitive body 1 has its distribution smoothed by an electrostatic discharger 8 when the reflecting plates 12 are used, so even when the light is projected on the darkest part, the difference from the part where the light strikes most intensely is reduced to about +20%. Consequently, the electrostatic discharging is performed excellently.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to printing devices such as optical printers and laser printers, and electrophotographic devices used in copying machines and the like.

2. Description of the Related Art Conventionally, electrophotographic apparatuses have used static eliminators equipped with tungsten lamps or light emitting diodes. However, in recent years, as copying machines and the like have become popular in general households, devices have become smaller and cheaper, and static eliminators are also required to have lower power consumption and lower prices.

Conventionally used tungsten lamps emit a large amount of light, emitting 30 to 4. , Omm, it is possible to irradiate the photoconductor with the neutralizing light almost uniformly. However, while it is easy to secure a space of 30 to 40 mm within the apparatus in the case of a conventional large-sized copying machine, it is very difficult to secure this distance in a small model for general household use. Also, when a tungsten lamp is emitting light, it becomes hot and its resistance increases.
Although the drive current value is small, when the lamp is turned off, the temperature is low and the resistance of the windings inside the lamp is small, so the rush current at startup is large, so the capacity of the power supply must be large. For example, in a tungsten lamp with a driving voltage of 24 V, a current of about 250 mA flows during normal lighting, but the current value of the rush current is 2 A, and this current continues for about 2 seconds. Therefore, although the drive current is 250 mA, a drive power source of 2 A is required.

As explained above, since tungsten lamps are not suitable for small devices, the use of light emitting diodes has been considered.

Problems to be Solved by the Invention However, when using a light emitting diode, the amount of light emitted by the light emitting diode is 1/10 that of a tungsten lamp.
Since the light emitting diode is as small as about 0, the light emitting diode is about 10
It is necessary to arrange them close to each other on the order of mm. At this time, a large amount of light can be obtained in the area close to the light emitting diode, but
Only a small amount of light can be obtained at a position between the light emitting diodes. Generally, if you want to remove static electricity well, a light amount of about 15 to 20 μW/cm2 is required, so if you irradiate light at the darkest position, the light amount will be 45 to 50 μW at a position close to the light emitting diode.
/cm2, and the photoreceptor is irradiated with more light than necessary, causing optical fatigue and shortening the life of the photoreceptor.

One possible solution to this problem is to increase the number of light emitting diodes and make the distribution of light intensity uniform, but this poses the problem of making the device expensive.

Means for Solving the Problems The present invention provides two wavy reflecting plates that are arranged parallel to the light source so as to sandwich the light source and reflect the light generated by the light source onto the photoreceptor. The surface is configured to condense light to a position corresponding to between the light sources.

Effect: With the above configuration, light is reflected at a position where there is no light source, so dark areas are reduced and uniform irradiation can be obtained.

Embodiment Hereinafter, an electrophotographic apparatus according to an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 2 is a block diagram of the electrophotographic apparatus of this embodiment, in which 1 is a photoreceptor, 2 is a charger, 3 is a scanning means, 4 is a developing device, 5 is a transfer device, 6 is a fixing device, and 7 is a A cleaning blade 8 is a static eliminator.

FIG. 1 is a plan view of the static eliminator 8, in which 9 is a light emitting diode (hereinafter abbreviated as LED'D) arranged at regular intervals, 10 is an LED board that supports the LED 9, and the LED The LED 9 is fixed to the substrate 10 by soldering lead wires 11. Reference numeral 12 designates a reflector plate that is disposed on both sides of the LED 9 and includes side walls 12a that reflect light onto the photoconductor 1 and a bottom plate 12b that connects both side walls 12a. Reference numeral 13 designates a fixture that supports the reflector plate 12 and the LED board 10. A mounting hole 13a is formed in the fixing fitting 18.

Next, the reflection plate 12 will be explained in more detail.

FIG. 3 is a perspective view of the main parts of the static eliminator 8. The reflector plate 12 is made of a reflective glossy stainless steel plate with a thickness of 0.5 mm, the width d of the bottom plate 12b is 5 nm, the height 1 of the side wall 12a is 8 mm, and the angle between the side wall 1.2 a and the bottom part 12b is θ is 120 degrees.

FIG. 4 shows a cross section of the static eliminator 8 taken parallel to the bottom plate 12b at the height of the top surface of the light emitting element of the LED 9 (omitted in the figure. The shape is a rectangular parallelepiped of approximately 0.3XO, 3X0°2 mm). It shows. As shown in FIG. 4, the side wall 12a has a wavy shape, and the inner surfaces of the concave portion and the convex portion toward the LIED 9 are respectively displaced by fl from the non-wavy portion at the end of the side wall 12a. =4mm, f2
= 1mm, and each part has a radius rl =
It is formed by a circular arc of 6 mm, r2 = 1 mm, and the discontinuous portions of the line are smoothed. The LED 9 is arranged between the convex portions on both sides.

FIG. 5 shows the distribution of the amount of light irradiated onto the photoreceptor 1 by the static eliminator 8, the solid line is the distribution of the amount of light by the reflector 12 of this embodiment, and the broken line is the wavelength of 630 nm±50 nm.
For comparison, the light intensity distribution when two flat reflecting plates are placed on both sides of the LBI is shown. As shown in the figure, when the reflector 12 of this embodiment is used, the distribution of light amount is smoothed, so even if the light is irradiated at the darkest part, the difference from the part that is strongly illuminated is +20 %, the photoreceptor does not suffer from optical fatigue and can maintain a long lifespan.

In this embodiment, the angle between the bottom plate 12a and the side wall 12b is set to 120 degrees, but even if the angle is set to 110 to 150 degrees, the smoothness of the distribution of the amount of light can be maintained and good static elimination can be performed. Further, in this embodiment, the reflecting plate 12 is provided with a continuous circular arc in the cross section parallel to the bottom plate 12a, but within this circular arc,
The convex portion toward the LED 9 may have any radius as long as it is 3 mm or less, and as shown in FIG. Good static elimination can be performed.

Effects of the Invention The present invention provides two wavy reflecting plates that are arranged parallel to the light source so as to sandwich the light source and reflect the light generated by the light source onto the photoreceptor, and the reflective surfaces of the reflecting plates are arranged parallel to the light source and the light source. Since the light is focused on the position where there is no light source, the dark areas are reduced, uniform irradiation is obtained, and good static electricity removal is possible. Even if the light is irradiated in accordance with the area where the photoreceptor is exposed, the difference between the area and the area that is strongly illuminated is small, so the photoreceptor does not suffer from optical fatigue and its lifespan can be maintained for a long time.

[Brief explanation of the drawing]

FIG. 1(a) is a plan view of a static eliminator for an electrophotographic apparatus according to an embodiment of the present invention, FIG. 1(b) is a sectional view of the same static eliminator,
Fig. 2 is a block diagram of the same, Fig. 3 is a perspective view of the same static eliminator, Fig. 4 is a sectional view of the main part of the same static eliminator, Fig. 5 is a graph showing the distribution of the same light amount, and Fig. 6 is a diagram of other static eliminators. It is a top view of the static eliminator in an Example. 1... Photoreceptor, 2... Charger, 3... Scanning means,
4...Developer, 5...Transfer device, 6...Fixer, 7
...Cleaning blade, 8...Static eliminator, 9...
・LED, 10...LIED board, 12...Reflector, 18...Fixing metal fittings, 14...Flat plate

Claims (4)

[Claims] (1) a photoreceptor; a charging means for charging the photoreceptor;
a scanning device that irradiates the photoreceptor with light to form a latent image, a developing device that attaches a developing material to the latent image, a transfer device that transfers the developer material that has adhered to the photoreceptor onto a printing medium, and printing. a fixing means for fixing the developer material on the medium to the printing medium; a cleaning means for removing the developer material remaining on the photoreceptor; and a light source disposed discretely parallel to the surface of the photoreceptor; It is equipped with a static eliminator that irradiates light onto the body surface and removes the charge remaining on the photoreceptor, and has a wavy shape in which the distance between adjacent peaks is equal to the distance between the positions of the light source, and the light source is connected to the light source on both sides of the light source. An electrophotographic apparatus characterized in that two reflecting plates are arranged parallel to each other and arranged between the light sources on the surface of the photoreceptor so as to condense light to corresponding positions. (2) The electrophotographic apparatus according to claim 1, wherein the angle formed by the reflecting surfaces of the two reflecting plates is in the range of 40 degrees to 120 degrees. (3) The electrophotographic apparatus according to claim 1, wherein the reflective surface has an arcuate cross section. (4) The electrophotographic apparatus according to claim 1, wherein the reflective surface is a flat surface.