JPH0210544Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a linear illumination device for removing charges remaining on a photosensitive drum of a copying machine such as an electrostatic copying machine.

For example, in an electrostatic copying machine, as shown in FIG. 1, a document 1 is irradiated with light from a light source 2, and the reflected light is guided onto a photoreceptor drum 3.
A charged pattern in the form of the image on the original 1 is formed on the drum 3, and then a powder toner 5 is attached to the charged portion by a magnetic brush 4, and transfer paper 7 is sequentially transferred from the paper feed tray 6. After being sent out and charged, it is run close to the photosensitive drum 3, and at this time, transfer from the drum 3 to the transfer paper 7 is performed. In order to obtain a clear transfer, after the above-mentioned transfer is performed, the drum is generally first irradiated with light from an illumination device 8.
The residual charge on the top is removed, and then the rotating brush 9
By wiping the surface of the drum 3 with the toner, the toner remaining on the photosensitive drum 3 is removed.

However, as an example of this kind of linear lighting device for static elimination that uses tungsten bulbs as a light source, for example, the one described in Japanese Patent Application Laid-Open No. 56-51769 uses a large number of small bulbs, resulting in large illumination unevenness. There was a problem. Furthermore, due to space constraints in the static eliminator of a copying machine, it is difficult to place a light bulb close to the photoreceptor drum, resulting in poor utilization of light source light and low illuminance. There was a problem. Furthermore, for the same reason, the light bulb itself was too large and difficult to install.

In view of the above-mentioned problems, the present invention aims to provide a linear illumination device for static elimination that has less uneven illumination, has high illuminance, and is easy to install.

The linear illumination device for static elimination according to the present invention consists of an elongated output end surface that can be placed close to the surface of a photoreceptor drum of a copying machine, and a plurality of continuous chevrons located on the opposite side of the output end surface. a light guide plate having a lamp housing hole and an incident side end surface having a roughened surface other than the lamp housing hole;
a reflection case that covers both side surfaces and the entire left and right end surfaces of the light guide plate, the light path from the bottom of the lamp storage hole toward the output end surface enters at least one of the both sides of the light guide plate, and one side of the bottom is connected to the output end surface. A triangular pyramid-shaped recess parallel to the edge of the end face is provided to equalize the light distribution between the high-brightness part of the lamp and other parts, so that even if the light source is far from the photoreceptor drum, attenuation of the light source light is small. The output end of the light guide plate is made thinner.

Hereinafter, the present invention will be described in detail based on an embodiment shown in FIGS. 2 and 3. Reference numeral 11 refers to an elongated inclined emission end surface 11c that can be disposed close to the surface of the photoreceptor drum, and the emission end surface 11c. A lamp storage hole 11 is located on the opposite side of the lamp housing hole 11, which is formed of a plurality of continuous chevrons and has a spherical bottom surface 11a' at the top of each hole.
a, and an incident-side end surface 11b whose surface other than the lamp storage hole 11a is roughened by hairline processing, satin surface processing, or white coating processing, and the entire width is the width of the photoreceptor drum. The light guide plate is made of acrylic resin or the like and has a length corresponding to the length of the light guide plate.
Correspondingly, a triangular pyramid-shaped recess 11d is provided on one side of the bottom surface and parallel to the edge of the emission end surface, and enters the optical path from the bottom surface 11a' of each lamp storage hole 11a toward the emission end surface 11c. The shape of the recess 11d is basically desirably such that the inverse square of the length along the optical path is proportional to the luminance distribution of the lamp, and if so, various shapes can be selected.

Here, the function of the recessed portion 11d will be explained.

That is, depending on the directivity of the light source lamp 13, the brightness at the output end face 11c increases the closer it is to the lamp, but as the light passes through the recess 11d, that is, through the air, the brightness increases in proportion to the inverse square of the distance. Since a part of the light is absorbed, the light is attenuated, and the distance the light travels in the air is longer the closer it is to the lamp, so the brightness at the output end surface becomes uniform.
In addition, since the concave portion 11d has a triangular pyramid shape, a portion of the light is reflected at the interface between the concave portion 11d and the light guide plate 11 and is directed toward the portion of the output end surface corresponding to between the light source lamps 13, 13. and increases the brightness of that part. Therefore, the luminance distribution in the longitudinal direction of the entire emission end face is made uniform. Note that this kind of linear illumination device for static elimination is designed to provide linear illumination along the generatrix of the photoreceptor drum, so it is important that the luminance distribution in the longitudinal direction of the output end surface be uniform. The brightness distribution in the short direction of the output end face is not very important. Further, the recessed portion 11d may be provided on the opposite side surface of the light guide plate 11. 12 covers and fixes both sides and the entire left and right end surfaces of the light guide plate 11, and is made of synthetic resin, non-magnetic metal, non-conductive metal, etc. whose inner surface is treated to have a high degree of light reflection and light-shielding properties. This is a reflective case. 13 is a light source lamp consisting of a tungsten bulb housed in each lamp storage hole 11a; 14 is a printed circuit board that holds the light source lamp 13, covers the top surface 11b, and has both ends fixed to the reflective case 12; It has printed wiring for supplying power to each light source lamp 13.

Since the linear illumination device for static elimination according to the present invention is configured as described above, part of the light in the high-intensity portion directly below the light source lamp 13 is reflected by the side surface (boundary surface) of the recessed portion 11d. The light is emitted from a position away from directly below the high-intensity portion of the emitting end surface 11c.
Furthermore, the light b emitted from the peripheral part of the lamp 13 is reflected in the recess 1.
The light is reflected by the side surface 1d and reaches the end face 11b, where it is diffusely reflected and emitted from a position away from directly below the high-brightness portion of the output end face 11c. Note that the light passing only through the light guide plate 11 is attenuated by absorption by the light guide plate 11 very little, and is not attenuated in proportion to the inverse square of the distance. On the other hand, another part of the light in the high-intensity part (light emitted from the center of the lamp 13) is transmitted through the side surface of the recessed part 11d, and is transmitted at a distance R (the third
As shown in Figures B and C, it is attenuated by being absorbed by the air in proportion to the inverse square of the optical path (distance along the optical path from the bottom surface 11a' of the lamp storage hole 11a to the output end surface 11c), and the recess 11d is attenuated again. After entering the light guide plate 11 from the bottom surface, the light is emitted from a position directly below the high-brightness portion of the output end surface 11c. In this way, the output end face 11c of the light emitted from the output end face 11c
Since the intensity in the longitudinal direction is made uniform, uneven illumination is reduced. Moreover, as mentioned above, the light source lamp 13
Since the light is guided to the surface of the photoreceptor drum through the light guide plate 11, even if the light source lamp 13 is far from the photoreceptor drum, attenuation of the light source light can be reduced, thereby improving the utilization efficiency of the light source light. improves and the illuminance increases. Further, since both side surfaces and left and right end surfaces of the light guide plate 11 are covered with the reflective case having high reflection efficiency as described above, the illuminance is further increased and uniformity is promoted. Further, as described above, since the light emitting end portion of the light guide plate 11 is made thin, it can be arranged without difficulty even if there is a space restriction in the light removal section of a copying machine.

Note that a fluorescent lamp may be used as the light source, and in that case, the recessed portion needs to have a shape corresponding to the luminance distribution of the fluorescent lamp. Furthermore, the linear illumination device for static elimination according to the present invention can also be applied to facsimiles.

As described above, the linear illumination device for static elimination according to the present invention has important practical advantages of less uneven illumination, high illuminance, and easy installation.

[Brief explanation of the drawing]

FIG. 1 is a schematic sectional view showing an example of an electrostatic copying machine;
Figures 2A, B, and C are a partially cutaway plan view, front view, and side view of an embodiment of the linear illumination device for static elimination according to the present invention, and Figures 3A, B, and C are respectively the above-described embodiments. FIG. 2 is a plan view, a front view, and a longitudinal cross-sectional view of essential parts of an example light guide plate. 11...Light guide plate, 11a...Lamp storage hole, 1
1b...Top surface, 11c...Emission end surface, 11d...
Recessed portion, 12...Reflection case, 13...Light source lamp, 14...Printed circuit board.

Claims (1)

[Scope of utility model registration request] The lamp comprises an elongated output end face that can be placed close to the surface of a photoreceptor drum of a copying machine, and a plurality of continuous chevrons located on the opposite side of the output end face, each having a lamp housing hole at the top thereof. A light guide plate having an end surface on the incident side that is roughened except for the storage hole, and a reflective case that covers both side surfaces and the entire left and right end surfaces of the light guide plate, and the lamp is disposed on at least one of both sides of the light guide plate. A linear illumination device for neutralizing static electricity in a copying machine, comprising a triangular pyramid-shaped recess that enters the optical path from the bottom of the storage hole toward the output end surface and has one side of the bottom parallel to the edge of the output end surface.