JPS58196554A - Variable power copying apparatus - Google Patents

Abstract

PURPOSE:To enable display of the region of an original to be copied, by illuminating an original placing glass or a place near it with the illumination light reflected from an image-nonforming area through a variable power image projection optical system. CONSTITUTION:A photosensitive drum illuminator 14 comprises a large number of light emitting diodes 141-14m. The diodes 141-14n are lighted, and they illuminate no image forming area I, but the image-nonforming area N and erase the charge on the area N, and toner is not attached to it. The illumination lights 141-14n are reflected with a reflective plate 15 and a mirror 13, passed through a lens 12, and reflected with mirrors 11, 10, 9 in succession, and projected on a screen 16 formed on a platen glass 8, and the images of the diodes 141-14n are formed on the screen 16. Therefore, the part of the original to be copied can be immediately discriminate even if copying magnification is changed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a variable magnification copying apparatus. In variable magnification subject fK, #i, which area of the IIA bucket is actually used for copy paper? It would be convenient to know whether the image is being transferred or not.1゜On the other hand, the area of the photoconductor where no image is uniformly formed, that is, the non-image area that is transferred to the photoconductor, is illuminated by a light source placed near the photoconductor. The electric charge in this area is erased to prevent toner from adhering to the area, thereby preventing wasted toner and dirt on the end of the copy paper shaft. The main object of the present invention is to provide a variable magnification copying apparatus with a simple structure, which utilizes the above-mentioned light source to display which area of a document will actually be copied.

The present invention will be explained in detail below with reference to the drawings. Figure 0m1 is an overall explanatory diagram of one embodiment of the present invention.

In FIG. 1c, a drum 1 has electrophotographic photoreceptors on both sides and rotates once in the direction of the arrow. This photosensitive drum 1Fi.

First, it is uniformly charged by the charger 2, and then the manuscript image is exposed to slit light. # image obtained by this exposure Fi developer 6
The toner image is obtained by developing the toner image.

This toner image is transferred to the copy paper 5 under the action of the transfer charger 40 to the copy paper 5Fi fixing roller pair 6, and this roller pair 6 fixes the toner onto the copy paper. The drum 1 is cleaned by a cleaning blade and used again for the above-mentioned image carver*.

The original 0 to be copied is placed on the glass B.

The glass 8 moves forward in the direction of the arrow from the position shown in the figure in synchronization with the rotation of the drum 1, thereby scanning the document 0, and its image is transferred to the drum 1. That is, the light from the original 0 is reflected in order from the mirrors 9, 10 and 11, passes through the lens 12, is then reflected from the mirror 16, and enters the drum 1. When the above original scanning is completed, the glass 8 is moved in the opposite direction to the arrow. Maneuver to 1i11 (home position>K
O! Cry.

In addition, the glass 80 forward speed and the wholesale m wheel running depth are drum 1.
The speed of the image is multiplied by the reciprocal of the magnification. In addition, the lens 12ti zoom lens is placed at the rear position 11 in the figure when the lens 12#i is used for 0-1s copying, in which the magnification of the subject can be changed virtually steplessly. For example, at position 12' when making small copies, and at U1 when making enlarged copies.
2' position. When changing the subject magnification, the lens 120 position is set to 4f! as selected above! t
*In addition to arranging the lens 12 in accordance with the selected magnification, the focal A distance of the lens 12 is also changed to a value corresponding to the selected magnification.
Since these methods are publicly known, 1is2 is used to avoid modesty.
@8#i omitted 0 direction, when using a fixed focal length lens as the lens 12, when changing the magnification, in addition to changing the position of the lens 12, for example, also change the position of the mirrors 10 and 11, Also change the optical path length.

Now, 14 is a photosensitive drum illumination device placed close to the drum 1.C] This device is located between the charger 2 and the dust collector 3, for example, as shown in the figure, at the same position as the corner of the original image. illuminating 11 non-forming areas of the photosensitive drum 1 at the position,
The light emitting device 2 applies λ7' to this area, and eliminates the L ridge load. As shown in FIG.
Now, it is assumed that the image forming area of the drum 1 (that is, the area where the copy paper 5 comes into contact at the transfer station) is I, and the non-forming area is N. The image formed in the area is transferred to copying paper 5. Then, the diodes 141 to 14n are turned on and the light illuminates the area N, so that the electric shock in this area N is eliminated. Therefore, toner does not adhere to area H. However, if the size of the copy paper 5 is changed, the area will naturally change.
1 The width of the castle structure also changes, and therefore the area N11) @ also changes.Then, the illumination system filt14 illuminates this area N by having A1 with the number of dies corresponding to kJ of the rings in area N. 3゜Figure 1 f ((P) C15 is a reflector.
The reflective plate 15 is selectively made by KIJJ between the position 111c (center center) between the drum 1 and the illumination device and the dotted line fill i 5'. μu
<l'' hum 1 Before starting 1 slit exposure, preferably when the glass 8 is stopped at the dome position, it is placed at the solid line position in the figure.
The plate 15 is: =iJ =d each main mirror 9, 10, 11.1
The image projection optical path constituted by the third lens 12 is shielded from the light flux guiding drum 1 that advances forward toward the drum 1.
The diodes 14t to 14n of the illumination device 1114 emit light, which is then reflected into the optical path). In other words, the diodes 141 to 14 deafen the synchrotron radiation ti reflecting plate 15.
q t, Next, reflect the C mirror 16, close the lens 12, reflect the mirror 11.1 (J, 9 in order, 0^Syb L-, which is projected onto the screen 16, as shown in FIG. tsi14t' of the diodes 141 to 14r.
14n' is imaged. (Incidentally, screen 16) 1
8H1 where t1 Mingsou 14 does not have a perfect optical conjugate relationship
Yo, ls! From 14t' to 14e, the image is slightly out of focus, but this does not pose a practical problem. ) and diode 1 night 1
The length N' of 41' to 1G is the number of light emitting diodes (1
Even if the width of N' is 4tt, the imaging magnification of the original image by the image projection optical system k changes as the magnification yc↓ changes. Part 1i (-f
* The original to be @ is projected onto drum 1, part 1 & 1
Since the region Ny of Nidrum will be projected, it will not be copied. , and 1' excluding the width part of N' in Figure 6
Since the image of the document in the ring part is projected onto the area (2) of the drum 1, this image is #1Ij4. Therefore, even if the copying magnification is changed, the portion of the original to be copied can be immediately identified.

1.Reflector 15t; Broken before starting to scan original 0.
#1 *15' is forced to avoid -A. In this position, the anti-elbow plate 15 does not intercept the light beam from the original image, so the original gI
II#'i Drum 1 is slitted as described above.

In addition, in order to prevent 7-ray, it is important that the reflector plate 15 does not reflect the light from the illumination iron k14 at this position, or that it does not reflect the light so that it travels backwards in the optical path of the 4-h diagonal optical system. preferable.

In the above embodiment, when displaying the area to be copied in the 1A bucket, the diode 14 corresponding to the area N of the drum is
Guiodo 14, which corresponds to area engineering by turning off lights from 1 to 14.
a+1~14. In this case, a lighting diode image is formed in a portion of the screen 16 having a width of I'.

In the above example, the screen 16 is attached to the lower surface of the platen glass 8 at a position corresponding to the reference position for wrinkling the tip of the mho. It may be provided. In any case, in such a case, the image of the white screen 16 will be projected onto the photosensitive tip 1 instead of a small portion of the leading edge of the document. Therefore, no toner is deposited on the exposed drum part of the screen 160, and therefore, there is a blank space on the leading edge of the copy paper 5, which is conveyed so that its leading edge coincides with this drum part, where no toner is deposited. Therefore, the leading edge of the copy paper 5 is prevented from kicking the toner on the drum 1 and causing the paper to become smudged or sticking to the fixing roller pair 6. As shown at 16' in FIG. 1, the screen may be located at a separate location from, but adjacent to, the platen glass 8. In this case, the inclination of the screen reflector 15 at the solid line position is slightly changed to form an image of the swA device 14 on the screen 16'.

In the above embodiments, the illumination device 14 is constructed by arranging many small light emitting diodes in rows, but a illumination device as shown in Fig. wJ4 can also be used. In Fig. 4, 17 is a light-shielding box with an opening facing the drum 1 at the bottom, and a light-shielding partition plate 17' corresponding to the type of copy paper size that can be selected.
, 17', 17'' 5. This partition board divides each room into 9 rooms.
181 to 184 are accommodated. Then, depending on the size of the copy paper 5, the -non-image forming area N is set by a lamp (
In the figure, lights 18s and 18 are lit.When using the illumination device shown in Figure 4, it is recommended to use a diffuse reflector as the reflector 15.0-The lamp 181.18+ where the reflector 15 reflects diffusely The light travels backward through the optical path of the front 1 projection optical system and is irradiated onto the screen 16 or 16'.
The image of the illuminated part is clearly imaged (direction, i
(Similar to ml, this image is slightly out of focus, but it does not pose a problem for practical use).
Even when using &tIIL in the oM4 diagram where the area is displayed, when displaying the copy area of MA Yuzu, -yo, drum area I
The corresponding rung (#1181.184 in the figure) may be lit, and the lamp 181.18sB may disappear.

Moreover, when using the & position shown in FIG. 4, a mirror may of course be used as the reflecting plate 15.

Also, when using the apparatus shown in FIG. 2, a TI MIRA may be used as the reflecting plate 15, or a diffuse reflecting plate may be used.

In addition, the present inventor's Miff-9 and Mirror 10.11 are 1:
It can also be used in a copying device that scans an original by moving it at a speed ratio of 1/2. You can easily determine whether the @ area is photographed or not, and you can also display it by
Since the I-image non-formation area is illuminated using a device, there is no need to provide a display light source for each gender, and effects such as a simple configuration can be obtained.

[Brief explanation of the drawing]

Figure xi is an overall explanatory diagram of an embodiment of the present invention, Figure 2 is a clear view of the main part of an embodiment of the present invention, and the drum is seen from the front, Figure 3 is a diagram showing the upper part of the platen glass. FIG. 4 is a front view of the drum according to another embodiment of the present invention. 1 company electrophotographic photosensitive drum, 2a charger, 3a developer, 8
12 is a platen glass, 12 is a Hiro lens, 14 is a drum lighting device, 15 is a reflector, and 16 is a screen. T calendar 4z

Claims (1)

[Claims] The image of the original placed on the original barrel is projected onto the photoconductor K11l through the variable magnification projection optical system, while the variable magnification ridge K111 illuminates the non-image forming area of the photoconductor. In the 4-device, the illumination light of the above-mentioned IlliigI non-forming area is reflected and irradiated to the area where the original is placed or in the vicinity through the variable magnification image projection optical system to form a 41 image. Variable size copying device〇