JPH0258627B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an exposure optical device such as a copying machine,
In particular, the present invention relates to an exposure light source for a copying machine having an exposure device that is compact and has excellent light source reflection efficiency.

Generally, in a copying machine, such as an electrophotographic copying machine, light from a light source is irradiated onto the surface of a document placed on a document table, and this reflected light is guided to the surface of a photoreceptor while being reflected by an optical system including a reflecting mirror. Image recording is performed by forming a light image on the surface of a photoreceptor.

The image recording method described above usually requires
There are two known methods: one in which the document table is fixed and the optical system moves, and the other in which the optical system is fixed and the document table is moved.

FIG. 1 is a conceptual diagram of an exposure apparatus in which an optical system moves. In the figure, 1 is a document placed with the print side facing down on the transparent glass of the document table. When the document is reflected and irradiated by the illumination lamp 3, the light reflected from the print surface is reflected by the reflection mirrors 4, 5, and 6. and 7 to the surface of the photoreceptor 9. 8 is a lens for imaging. Next, the operation of the optical system configured as described above will be explained. First, when the light source 3 is turned on, the first reflecting mirror 4, which is configured to move integrally with the light source 3, moves parallel to the document at a speed υ in the direction of the arrow, and the first reflecting mirror Simultaneously with the movement of the mirror 4, the second reflecting mirror 5 and the third reflecting mirror 6 follow and move parallel to the document, but the speed at this time is 1/2υ in order to keep the optical path length constant. In this way,
The entire surface of the document is optically scanned, and the reflected light from this image area is guided to the surface of the photoreceptor 9 as described above, but at this time, the surface of the photoreceptor 9 also moves at the same speed υ as the first reflecting mirror 4 described above. The reflected light is projected onto the surface of the photoreceptor 9 as an image of the document, thereby accurately forming an optical image.

In the moving optical system described above, both the second reflecting mirror 5 and the third reflecting mirror 6 are connected to the first reflecting mirror 4.
Since the two reflecting mirrors move together at half the speed of be pulled and move.

With the spread of copying machines with optical systems such as those described above, such as electrophotographic copying machines, there is a demand for more compact and lightweight equipment, and as a result, making the exposure equipment more compact and lightweight has become an important issue. It is becoming. SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a light source device for exposure such as a copying machine that is compact and lightweight without reducing the luminous efficiency of the light source.

As a result of various studies to address the above-mentioned problems, the inventor of the present invention has developed a document table for placing a document to be copied, and a device for focusing reflected light disposed below the document table for exposing the document. a reflective umbrella having a curved reflective surface;
An optical device for a copying machine including an exposure light source lamp installed in the reflector, the coupling structure capable of dividing the reflector into two parts at a portion where the curved reflective surface wraps around the back side of the light source lamp. At the same time, one of the two divided reflective umbrellas is integrally formed with a flat reflective surface at the tip of the curved reflective surface, and the reflected light from below the document is reflected at the tip of the flat reflective surface. a mirror holder is integrally formed, and the reflection umbrella is oriented so that the opening of the curved reflection surface is oriented in a direction substantially parallel to the document table, and the reflection is reflected by the curved reflection surface of the other divided reflection umbrella. An optical device for a copying machine, characterized in that the optical device is arranged so that the light is reflected by the flat reflective surface and is focused on the lower surface of the document together with the light reflected by the curved reflective surface of the one split reflective umbrella. It has been found that the above object can be achieved by the following method.

That is, the present invention relates to an improvement of the exposure optical device in the optical system shown in FIG.

Hereinafter, the present invention will be specifically explained with reference to embodiments shown in the drawings. FIG. 2 is a side view showing the main parts of the exposure optical device of the copying machine of the present invention. In the figure, explanations of the same symbols as in the previous figure will be omitted. Reference numeral 11 denotes a frame for the entire illumination portion of the optical device, a part of which is configured as a reflector 10, and a reflective surface 10A of the reflector 10 is formed in an elliptic curve. The opening of the reflector is oriented substantially parallel to the glass plate 2 for placing an original. 3 is a light source lamp for exposure, and a reflecting surface 10A formed in an elliptic curve.
It is placed in a position where it can be reflected in a concentrated manner. The reflective umbrella 10 has an elliptic curved reflective surface 10A on its inner surface.
is divided into two equal parts, and the reflective umbrella 10 is formed separately from the part that becomes the non-reflective surface 10B when arranged by the exposure light source lamp 3, and the connecting screw 13 is connected and fixed at the non-reflective surface 10B part. and configure it so that it is integrated. Reference numeral 14 is formed at the tip of one of the reflectors and is formed flat to reflect the reflected light from the exposure light source lamp 3 reflected by the reflective surface 10A toward the document surface, thereby efficiently exposing the document 1, etc. This is the second reflective surface. 4 is the first reflecting mirror shown in FIG.
It is held by a mirror holding part formed at the tip of the second reflecting surface. The reflective surface 14 and the holding portion of the mirror 4 are formed on an extension of the frame 11. Therefore, for example, when polishing the inner surface of the reflector 10, the connecting screw 13 can be loosened to separate the upper and lower reflectors 10 for polishing. It becomes possible to perform the cloth polishing process, which is impossible with other methods, extremely easily.

Furthermore, after the polishing process, the upper and lower reflective umbrellas 10
The shape of the entire reflective umbrella when the non-reflective surface portions 10B of the mirrors are overlapped and joined with the connecting screws 13 is made such that the opening is narrow and the inside of the reflective umbrella is wide in an elliptical curve to make it easier for the light flux to concentrate on one point. Since the mirror surface can have a high reflectance, the illumination efficiency of the illumination lamp 3 is high, and it is also possible to use a low-intensity illumination lamp. It goes without saying that the frame 11 may be formed of metal such as aluminum.

Further, the reflector 10 according to the present invention has its frame 11 without directing the opening toward the document surface as in the conventional case.
Since the reflector 10 can also hold the first mirror 4 integrally, the height of the optical device can be made low, making it compact as a lighting device. It was also possible to reduce the weight. Furthermore, since the original is illuminated by reflecting the light from the illumination lamp 3, uneven illumination can be completely prevented.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram of the optical system of a copying machine, and FIG. 2 is a side view of the main parts of the optical system of the copying machine according to the present invention. 3...Illumination lamp, 4...First mirror, 5...
Second mirror, 6...Third mirror, 10...Reflector, 11...Frame, 10B...Non-reflective surface portion of reflector, 13...Connection screw.

Claims (1)

[Scope of Claims] 1. A document table for placing a document to be copied; a reflective umbrella having a curved reflective surface for converging reflected light, disposed below the document table for exposing the document;
An optical device for a copying machine including an exposure light source lamp installed in the reflector, the coupling structure capable of dividing the reflector into two parts at a portion where the curved reflective surface wraps around the back side of the light source lamp. In addition, one of the two divided reflective umbrellas is integrally formed with a flat reflective surface at the tip of the curved reflective surface, and furthermore, the reflected light from the bottom surface of the document is reflected at the tip of the flat reflective surface. A holding part of the mirror is integrally formed, and the reflectance is reflected by the curved reflective surface of the other divided reflective umbrella with the opening of the curved reflective surface facing in a direction substantially parallel to the document table. An optical device for a copying machine, characterized in that the optical device is arranged so that the light is reflected by the flat reflective surface and is focused on the lower surface of the document together with the light reflected by the curved reflective surface of the one split reflective umbrella.