JPH01241577A - Voiding device in copying machine - Google Patents

Abstract

PURPOSE:To produce a flawless void free of shadow and density unevenness, to simplify structure and to reduce its cost by providing a void producing part whose side at an optical system side is an upward reflecting plane with a fixed width and whose rear surface is white. CONSTITUTION:The void producing part 9 is composed of a reflecting member 10 and a white board 11. When an optical system 4 moves below an original leading edge 3a, light from a sub-reflecting mirror 7 irradiates the white plane 11a to generate reflected light for producing void on a slit side. At this time, a shadow area due to the lack of light quantity arises on the surface of an original in proportion to the height of the reflecting member 10, because the light from the sub-reflecting mirror is blocked by the white plane 11a. However, the shadow area is auxiliary irradiated with indirect irradiation light reflected from a main reflecting mirror 6 through an upward reflecting plane 10a, and is corrected. Thus, a clear, void image free of density unevenness can be produced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to an improvement in a whitening device in a copying machine that creates a whitening area at the leading edge of copy paper.

[Conventional technology]

When setting an original on the original table glass of a copying machine, the leading edge of the original is pressed against a scale plate. This is to eliminate the inclination of the original and to set the original at a predetermined position according to its size. However, if the original has text or pictures printed all the way to the leading edge, such as a newspaper clipping, if you copy with the leading edge of the original against the scale plate, the toner will get onto the leading edge of the copy paper during development. It will be listed up to. When this toner melts during fixing, it acts like an adhesive that adheres the copy paper to the surface of the roller, so that the toner cannot be peeled off by the peeling claw, resulting in a paper jam. Therefore, various types of whitening devices have been proposed in the past for preventing paper jams by creating a whitening area of a certain width at the leading edge of a document.

That is, (1) the electrostatic latent image at the leading edge of the image is erased with a timed charge erasing light source;

■The lower surface of the document table glass at the leading edge of the document that is in contact with the scale plate is painted white, and the reflected light is used to erase the electrostatic latent image at the leading edge of the image.

Install a white board below in the same position as ■■. (Figure 3)
.

Such devices are known.

[Problem that the invention seeks to solve]

In the above-mentioned white-out device, points 1 and 2 require a dedicated light source separate from the main light source for copying, which increases the complexity and cost of the device.

(2) There is a possibility that unevenness in the white paint may cause density unevenness in the copied image.

Method (2) is widely used in practice, but because a plate is interposed between the optical system and the document surface, a shadow area proportional to the thickness of the plate is created on the document surface.

There were some problems.

The present invention is intended to solve these problems, and it is an object of the present invention to provide a whitening device that can create perfect white spots without shadows or density unevenness, and that is simple in construction and inexpensive.

[Means for solving problems]

In order to achieve the above object, the present invention provides a copying machine in which the optical system side surface is an upward reflecting surface of a constant width and the bottom surface is a white surface on the lower surface of the document table glass at the leading edge of the document that is in contact with the scale plate. A section is provided to create blank areas, which hides the leading edge of the document with a white surface, and uses the reflected light from the upward reflective surface to correct shadow areas where there is insufficient light when the light from the auxiliary reflective mirror is blocked by the white surface. It is composed of

〔Example〕

The present invention will be described below with reference to an embodiment shown in the accompanying drawings.

Fig. 1 is a sectional view showing the outline device of the present invention, Fig. 2 is an explanatory diagram showing the functions of the white surface and the reflective surface, and Fig. 3 is an explanatory diagram showing the relationship between the conventional outline device and shadow generation. be.

In the figure, reference numeral 1 denotes a scale plate, and the scale plate 1 is provided at the upper end of the document table glass 2 of the copying machine main body A.
The placement position can be determined by abutting the tip end 3a of the.

4 is an optical system, and the optical system 4 includes a light source 5 and a main reflection mirror 6.
, an auxiliary reflection mirror 7, a slit S, a first mirror 8, etc., are the main components, and is provided so as to be movable and scannable along the lower surface of the document table glass 2.

The main reflecting mirror 6 is for condensing the light from the light source 5 onto a slit on the lower surface of the original 3, and is made of an elliptical concave mirror. The auxiliary mirror 7 is a concave mirror that prevents the light irradiated from the main reflection mirror 6 alone from forming a shadow on the surface of the original 3 depending on its unevenness. It is provided so that the document surface can be irradiated from the opposite direction. A slit S provided between the main reflection mirror 6 and the auxiliary reflection mirror 7 is for guiding the reflected light from the original surface to a copying optical system (not shown).
Only the reflected light component substantially perpendicular to is allowed to pass to the first mirror 8 below.

The blank area 9 is the creation part, and the white area is the creation part 9 is the reflective member 1.
0 and a white plate 11. The reflecting member 10 is a shaped member having an inverted U-shape in cross section, and has an upward reflecting surface 10a of a constant width with the side surface on the optical system 4 side tilted upward by θ=3 to 20 degrees with respect to the vertical line. The light from the reflecting mirror 6 is reflected toward the original 3 side, so that the surface of the original 3 can be auxiliary irradiated instead of the light from the auxiliary reflecting mirror 7.

It goes without saying that the height of the side surface of the reflective member 10 (=width of the reflective surface 10a) and the inclination angle θ of the upward reflective surface 10a may be changed as appropriate depending on the thickness of the document table glass 2 and the configuration of the optical system 4. It is. Further, the upward reflecting surface 1 of the reflecting member 10
The mounting surface 10b facing 0a is the scale plate 1
It is screwed and fixed to the front surface of a holding member 12 provided below.

The upward reflecting surface 10a may be formed by forming the reflecting member 10 from a metal such as stainless steel and finishing the surface with a mirror finish, or may be formed by pasting a metal tape or a glass mirror.

The white plate 11 is used to create a blank area that hides the leading edge 3a of the document, and is made of a plate-like member having a white surface 11a with good light scattering property over a width of several centimeters on the lower surface of the leading edge of the plate. It is provided below the upward reflecting surface 10a.

The white surface 11a is coated with white paint on its lower surface, or
It is made white by pasting a white film, etc., so that a blank area can be created on the copy paper to hide the tip 3a during copying.

When the optical system 4 moves below the document leading edge 3a, the light from the auxiliary reflection mirror 7 irradiates the white surface 11a and generates reflected light on the pickpocket 7) S side that creates a white spot.

At this time, the light from the auxiliary reflection mirror is blocked by the white surface 11a, and a shadow area is generated on the surface of the document 3 due to an insufficient amount of light proportional to the height of the reflection member 10.
The indirect illumination light reflected from the main reflection mirror 6 via the upward reflection surface 10a is used to supplementally irradiate and correct the illumination.

Note that the white areas indicate the reflective member 10 and white plate 1 that constitute the creation section 9.
1. The three members of the holding member 12 may be configured separately and integrated, or two or three members may be configured as one member.

〔Effect of the invention〕

As described above, the whitening device of the present invention is used in a copying machine, on the bottom surface of the document table glass at the leading edge of the document abutted against the scale plate, with the optical system side surface being an upward reflecting surface of a constant width, and the bottom surface being a white surface. The constructed white areas are characterized by the provision of a creation section, so clear white areas with even density can be created without using a shadow erasing light source and without creating shadows due to the presence of white surfaces. can be created and paper jams can be prevented. In addition, by appropriately changing the width and inclination angle of the reflective surface according to the thickness of the document table glass and the structure of the optical system,
It can be easily applied to copying machines with different configuration conditions. Therefore, it has excellent effects of contributing to improved reliability and cost reduction of copying machines.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the whitening device of the present invention, FIG. 2 is an explanatory diagram showing the functions of the white surface and the reflective surface, and FIG. 3 is an explanatory diagram showing the relationship between the conventional whitening device and the shadow generating section. It is. A. - Copying machine main body H - White plate material 1 - Scale plate 2 - Original table glass 3 - Original 4 - Optical system 9 - White area is preparation section 10 - Reflective member 10a - Upward reflective surface 11 - White Face plate 11a - white surface patent applicant Konica Co., Ltd. Figure 1 Figure 2

Claims (1)

[Claims] A copying machine is characterized in that a white spot creating section is provided on the lower surface of the document table glass at the leading end of the document that abuts against the scale plate, with the side surface facing the optical system being an upward reflecting surface of a constant width and the lower surface being a white surface. A white outline device.