JPH0820795B2 - Side eraser of copier for zooming - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a side erase device of a copying machine which performs zooming.

(Prior Art) As a side erase method for completely coping with the change of the copy width due to the magnification at the time of zoom magnification / reduction, as shown in FIG. 13, there are a shutter plate interlocking method and a small pitch LED eraser. The former has a single motor which has an electric interlocking means and a mechanically variable magnification mechanism and interlocking means, but both of them complicate the device and increase the cost. The latter has high cost of LED itself,
Wiring control becomes complicated.

As shown in Fig.14, a method that is usually used in practice is to combine a split LED and a white original cover, and cover the outside of the maximum original width with a white sheet of the pressure plate or a white belt of ADF to prevent the reflected light from the white area. It is exposed through the lens and side erased by a predetermined width (A) outside the image, and in combination with an LED eraser with a relatively rough pitch, the black frame is erased during zoom magnification (erasing in the scanning direction is the eraser lighting timing. Is easy).

However, since the eraser (LED) pitch is gradual (cost is high if the pitch is small), it is premised that the side erase width (A dimension) outside the image is increased.
The width of the white part of the ADF becomes large and the device becomes large.

If the white section of the pressure plate and ADF is insufficient (dimension A), the erase by the erase lamp bites into the image (section B),
White gaps occur depending on the magnification.

The area indicated by C is an area in which an image is captured, but since it is outside the effective image, the illuminance is insufficient and scumming occurs.

There was a problem.

Further, as shown in JP-A-55-142365, a reflector is installed at the end of the slit in the longitudinal direction between the light source and the document surface.
It is also known that the direct light of the light source is reflected by a reflector to form a white gap at the end of the photoconductor through the image forming element, but the side erase function at the time of end face reference equal magnification is also provided There is a problem that it does not have a side erase function for copying or center standard copying.

(Purpose) In a copying machine that performs zoom magnification, the present invention automatically erases the black frame by erasing the outside of the effective copy area in synchronism with changes in each magnification, and pressing the original. A device that can reduce the width of the white member at the edge of the plate to reduce the width of the contact glass, the pressure plate, the document feeder, and the like to downsize the entire device, and perform accurate black frame erasing with simple means. It is intended to be provided at low cost.

(Structure) The present invention is intended to solve the above-mentioned problems, and provides step-by-step variable magnification copying ((eg, 1% to 0.1
In a slit-exposure copying machine capable of performing an image forming operation, an image forming member that forms an original image, an image forming unit that projects the original image on the image forming member, an illuminating unit that illuminates the original, and a black frame outside the image. And an erasing means capable of divided lighting for erasing the light source. The illuminating means encloses the light source and directly condenses the light from the light source onto the document surface, and a part of the light source. A reflecting member that has a second reflecting surface that reflects light and is inclined so that the reflected light from the second reflecting surface is applied to the image forming member through the image forming means is provided at the end of the slit longitudinal direction at the lower part of the document surface. It is a shape covering the slit, the inner end surface of which is matched with the effective image forming light beam, and the reflected light from the second reflecting surface can be sufficiently received at a position where the reflected light from the first reflecting surface is not blocked. And the light receiving surface of the end reflection plate is formed of a diffuse reflection surface, Inevitably interlocked with a change in magnification between doubling and reducing, irradiating a predetermined range outside the effective copy area at each magnification and erasing the black frame together with the erase means. Is.

Hereinafter, a specific description will be given based on the illustrated embodiment.
FIG. 1 shows a known original moving type copying machine embodying the present invention. The document table 2 is driven by a single servo motor, and the speed is variable during zooming. At the time of zooming, the lens 1 and the third mirror 5 are moved in parallel in the horizontal direction. The lens and the third drive during zooming
Zooming is performed by driving a single stepping motor in which the mirrors are linked by a cam (the stepping motors for the lens and the third mirror can also be used). During zooming, the third mirror 5 moves so that the image formation point on the surface of the photoconductor is A during zooming.
Move from point B to point C. The photoconductor is a belt photoconductor
10 is used, and an erase lamp 16 is installed behind (or may be in front of) the exposed portion to perform front and rear end erase (scan direction) and side erase. Since the image formation point on the photoconductor moves due to the magnification change, the timing of the front and rear end erase is changed according to the magnification change.

As shown in FIG. 2, the light reflected by the reflection surface I 7A of the reflection plate 7 directly illuminates the document surface, and the light reflected by the reflection surface II 7B is reflected by the auxiliary reflection plate 9 and illuminates the document surface. There is. Reflective surface I, II
It has a co-elliptical shape and is focused on the original surface. The slit is formed by the end portion 7C of the reflection plate 7 and the slit regulation plate 17. The light source uses a rod-shaped halogen lamp.

Next, FIGS. 2 and 4 will be described. As shown in FIG. 3, the end reflection plates 18 are installed at both ends of the illumination unit,
The reflected light from the reflection surface II 7B of the reflection plate 7 is received, diffused and reflected by the minute unevenness of this portion, and the light is received so that it enters the effective image forming light beam and directly forms an image on the photoconductor through the lens 1. Surface 18A is sloped. Further, the front end portion 18B is set at a position where it does not block the light irradiating the original surface of the reflecting surface I 7A, yet sufficiently receives the reflected light from the reflecting surface II 7B, and further covers the slit width.

If the light from the reflective surface I 7A is blocked, the illuminance at the edge of the image will be insufficient, and the light reception from the reflective surface II 7B will be insufficient, or if the width of the edge light receiving surface 18A is narrower than the slit width, the erase light will be insufficient. To do. The light receiving surface 18A of the end reflection plate 18 is formed of a white diffuse reflection surface. This is because the light source is a halogen lamp (point light source). In the case of a mirror surface, specular reflection causes the light to bleed and a predetermined range cannot be illuminated. In the case of a fluorescent lamp, it may be a mirror surface.

As shown in FIG. 3, the end reflection plate is arranged so that the upper part thereof is in contact with the light flux at the same magnification. With the above-described configuration, it is possible to always irradiate the outside of the image with a sufficient amount of light accurately and to erase the predetermined range. Since the light reflected by the end reflectors is applied to the photoconductor through the lens, it is possible to automatically erase a certain width (C to D) outside the image when changing the magnification (reduction) as shown in Fig. 4. Therefore, if the width of the white member 20 that covers the document surface is made slightly larger than the maximum document width (A = 1 to 2 mm), the cover can be sufficiently covered (the width of the white member can be reduced).

The width D of the end reflected light at the time of reduction is a value obtained by multiplying the width C at the same magnification by the magnification m.

D = m × C (m = magnification) The erase lamp 16 is provided with a partition 16A, and the lighting is controlled according to the change of the magnification. For example, when the magnification is 0.5 to 0.6, the block B + C + D is turned on. Since the irradiation width of the end reflected light can be sufficiently secured, the erasing lamp 16 can be divided relatively roughly. Since the installation position of the edge reflection plate is close to the document surface and passes through the lens, it is possible to accurately erase outside the image even if there is a magnification error, so there is a problem due to misalignment between the erase and the image (white blank, black belt). ) Does not exist. In Figure 9
An example of black band generation due to erasure and image shift when copying on A3 transfer paper with a reduction of A3 → A4 is shown.

As shown in FIG. 5, when the thickness of the end reflection plate is large, a shadow is generated at the border between the erase irradiation light of the end reflection plate 18 and the image, and a thin (about 0.5 mm) black stripe is formed on the image. The thickness is as thin as possible (0.05-0.1mm).

Further, as shown in FIG. 6, as a method for preventing the above-mentioned shadow, the erase irradiation light by the end reflection plate may be inclined (B = 1 mm, B dimension in FIG. 3 is also about 1 mm) with respect to the exposure slit to erase. it can.

The reflected light from the reflecting surface II 7B of the reflecting plate 7 shown in FIG. 2 is used as the reflected light at the end. That is, since a part of the light that illuminates the document is blocked, a decrease in illuminance (about 10%) may occur at the edge of the image as shown in FIG.

The lowering of the illuminance at the end can be improved depending on the installation conditions of the end reflector, and a method for further improvement will be described below.

In FIG. 7A, the light from the light emitting point 8A at the end of the illumination lamp 8 is blocked by the end reflection plate 18, and the area A on the document surface is shaded.

In FIG. 7B, the light emitting point 8B at the end of the illumination lamp 8 is moved inward, and the end 9A of the auxiliary reflector 9 is bent to move the shadow of the end reflector 18 to the outside of the end of the document. It is possible to prevent a decrease in illuminance at the inner edge of the effective image.

It should be noted that it is possible to prevent a decrease in illuminance at the inner edge of the image by a method of making the end reflection plate semi-transparent or a method of partially transmitting light. Dirt is generated due to reduced illuminance.

When the auxiliary reflection plate 9 of FIG. 2 is removed, as shown in FIG. 10, since there is no document illumination light by the auxiliary reflection plate, the illumination efficiency is deteriorated by about 10 to 20%, but the reflection surface I 7A of the main reflection plate 7 is reduced. Since the light is not shielded by the end reflection plate 18, the end of the document surface can be sufficiently illuminated and no shadow is generated.

As shown in FIG. 11, due to the change in the angle of view at equal magnification and reduction at the center reference, the amount A of penetration into the light flux at the time of reduction of the end reflector is the magnification, the lens focal length, and the original surface. It depends on the distance, but it is usually less than 1 mm without any problem.

As shown in FIG. 12, in the case of the end face reference, the deviation of the light flux of the reference image is small, but on the side opposite to the reference side, the light flux changes greatly at equal magnification and reduction, and the bite amount C of the end reflector is It will be about 3-5 mm. Therefore, in the case of the end face reference, it is necessary to move at least the end reflection plate on the side opposite to the reference side stepwise in conjunction with the magnification.

The present invention may use an optical system moving type copying machine, end face reference, or a zoom lens.

(Effects) According to the present invention, an image forming member for forming a document image in a slit exposure copying machine capable of stepwise variable magnification copying (eg, 1% to 0.1%) between equal magnification and reduction. An image forming means for projecting an original image on the image forming member, an illuminating means for illuminating the original, and an erasing means capable of divided lighting for erasing a black frame outside the image. Hold the light source,
A first reflecting surface for directly collecting the light from the light source on the original surface,
A reflection member having a second reflection surface for reflecting a part of the light from the light source and tilted so that the reflection light from the second reflection surface is applied to the image forming member through the image forming means is provided at the lower part of the original surface. A slit is formed at the end in the longitudinal direction of the slit so that the inner end face thereof coincides with the effective image forming light beam, and the light reflected from the first reflecting surface is not blocked, and the light is reflected from the second reflecting surface. It is arranged so that it can sufficiently receive light, and the light receiving surface of the end reflection plate is formed of a diffuse reflection surface, which is inevitably linked to the change in magnification between equal magnification and reduction. In the above, the black frame is erased together with the erase means by irradiating a predetermined range outside the effective copy area, and as a side erase of the zoom magnification / reduction copying machine, an erase and an erase lamp by a reflection plate at the end are used. The original white material (AD
The width of the F-belt, etc. can be made smaller, and the width of the contact glass, the pressure plate, the document feeder, etc. can be made smaller, and the device can be made smaller, without using a complicated method (such as shutter plate interlocking). The black frame at the end can be erased with high precision, and the entire apparatus can be provided at low cost.

[Brief description of drawings]

FIG. 1 is an operation explanatory view of a well-known moving original copying machine embodying the present invention, FIG. 2 is a side sectional view of a first embodiment of an illuminating unit of the present invention, and FIG. 3 is a position of an end reflector of the present invention. 4 is a plan view showing the erasing action of the present invention, FIG. 5 is a front view of the erasing irradiation light of the end reflection plate, and FIG. 6 is a diagram showing the erasing irradiation light of the end reflection plate with respect to the exposure slit. Slanted figure,
FIG. 7A is a view showing that the light from the light emitting point of the illumination lamp is shielded by the end reflection plate and the area A on the document surface becomes a shadow, and FIG. 7B is the end reflection plate of FIG. 7A. Fig. 8 shows the image width position and illuminance, and Fig. 9 shows A3 →
Fig. 10 is a diagram showing a state in which a black band is generated in the reduced image of A4, Fig. 10 is a diagram in which the auxiliary reflection plate of Fig. 2 is removed, and Fig. 11 is a diagram showing the light flux of the end reflection plate at the center reference. FIG. 12 is a diagram showing the amount of bite, and FIG. 12 is a diagram showing the amount of bite into the light flux of the end reflector when the end face is a reference,
Fig. 13 is a diagram explaining the principle of the conventional shutter plate interlocking method, Fig. 14
The figure is a principle explanatory view of an erasing means using a combination of a conventional split LED and a white original cover. 1a …… Lens magnification position, 1b …… Lens reduction position, 1c ……
Lens magnifying position 2 ... Original plate, 3 ... First mirror, 4 ... Second mirror 5 ... Third mirror, 6 ... Fourth mirror, 7 ... Reflector 8 ... Illumination lamp, 10 ... Photoconductor belt, 16 ... Erase lamp 18 ... Edge reflector, 19 ... Original, 20 ... White member

Claims (1)

[Claims] 1. Step-by-step variable magnification copying between equal size and reduction (eg: 1%
In a slit exposure copying machine capable of about 0.1%), an image forming member for forming an original image, an image forming means for projecting the original image on the image forming member, an illuminating means for illuminating the original, and an outside image. And an erasing means capable of divided lighting for erasing the black frame of the illuminating means. The illuminating means encloses the light source and directly collects the light from the light source on the document surface; A reflecting member which has a second reflecting surface for reflecting the light of a certain portion and is inclined so that the reflected light from the second reflecting surface is irradiated to the image forming member through the image forming means. In the shape of covering a slit, the inner end face is made to coincide with the effective image forming light flux, and the reflected light from the first reflecting surface is not blocked, and the reflected light from the second reflecting surface is sufficiently received. And the light receiving surface of the end reflection plate is a diffuse reflection surface. , Irradiating a predetermined range outside the effective copy area at each magnification, inevitably interlocking with a change in magnification between equal magnification and reduction, and erasing the black frame together with the erase means. A side erase device for a copying machine that performs zooming.