JPS60200270A - Exposing device of image forming device - Google Patents

Abstract

PURPOSE:To perform exposure with high efficiency by forming an aperture which controls the transmission of image exposure light, the 2nd aperture which controls the transmission of uniform light from a light source, and an image formation lens which forms an image of the 2nd aperture in a no-image area of a photosensitive body surface perpendicular to the movement direction in one member. CONSTITUTION:The image exposure light A irradiates an image exposure area (a) while its optical path at the peripheral part is controlled by the 1st aperture 16 in the top surface of a member 15. Blank exposure light from the light source A is passed through the 2nd apertures 18 to irradiate a no-image area (b) on the photosensitive body 2 through a lens 20. The member which controls the optical path of the image exposure light A and the member which controls the optical path of sharp cut exposure are formed in one body, so as adjustment need not be made very time the device is assembled and the overlap of both exposure ranges is minimized.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an exposure device for an image forming apparatus, and particularly to an exposure device suitable for uniformly exposing areas of a photoreceptor that are not image exposed.

In an image forming device such as an electronic copying machine, a moving photoconductor surface is charged, a positive original image is projected onto it to form an electrostatic latent image, and the charged portion of the latent image is developed with developing toner to form a positive image. It is copied to. As shown in FIG. 3, if the width of the surface of the photoreceptor 2 where image exposure A is performed (image area a) is smaller than the charging width, the area that is not image exposed (non-image area b)
Because the electrical charge does not disappear, the developing toner also adheres to the non-image area, and during transfer, this developed toner sticks to the copy paper. , inside the device, especially on the belt that separates the copy paper from the photoreceptor surface. Furthermore, the developing toner is wasted.

To prevent this, during image exposure, uniform light is applied to the non-image areas at both ends in the direction perpendicular to the moving direction of the photoreceptor surface, so-called sharp cut a light B.
is being done. Sharp cut exposure B is slightly wider than the non-image area, and range C is just enough to enter the image area a.
is exposed. Δ is the overlap acid at that time.

It is almost impossible to expose two exposure areas so that they do not overlap or have any holes, due to the placement accuracy of the exposure equipment. There is a risk that black bands or streaks may appear on the copy paper at positions corresponding to the parts. Therefore, both exposure areas must be overlapped. However, conventionally, the member that regulates the exposure range of image exposure and the member that regulates the exposure range of sharp cut S light are separate, and effective means for minimizing the amount of overlap Δ have not been adopted. It wasn't. Therefore, there is a tendency to increase Δ in order to provide a margin. As a result, there is a drawback that images around the image exposure area C are not copied.

The present invention has been made in order to eliminate such drawbacks of conventional devices, and aims to provide a fog light device that minimizes the overlap between the image area and the sharp cut exposure area. This is the purpose.

The present invention, which achieves this object, has a device that forms an image by exposing the surface of a moving photoreceptor, in which the first seven perchas regulate the transmission of image exposure light and the transmission of uniform light from a light source. Exposure characterized in that the second seven pertiers are integrated into an integral member, and an imaging lens that forms an image of the second seven pertiers on a non-image area in a direction orthogonal to the moving direction of the photoreceptor surface. It is a device.

Examples of the present invention will be described in detail below.

FIG. 1 is a schematic diagram of main parts of an image forming apparatus to which the present invention can be applied.
It is the cause.

Inside the process cartridge 1, image forming process equipment such as a photoreceptor 2 rotating in the direction of the arrow, a corona charger 3, a developing device 5, and a cleaner 6 are installed either integrally or detachably. This cartridge l is attached to the main body of the apparatus so as to be removable. Below the photoreceptor 2, there is a transfer corona charger 7. Copy paper guide plates 8a and 8b are arranged.

Since the functions of each unit of 0 or more, where P is copy paper, are well known, detailed explanations will be omitted. Image exposure A is applied to the upper surface of the photoreceptor 2 from above through the upper opening 13 of the cartridge l. N light lamp 1o.

In order to remove the residual charge on the photoreceptor 2 after image formation is completed,
The photoreceptor 2 is illuminated through the window 11 of the cartridge 1.

Exposure lamp 10 also sends uniform light for sharp cut exposure B.

FIG. 2 is a perspective view of essential parts of an exposure apparatus according to the present invention. 15
is an integral member that regulates the optical path of image exposure A and also regulates the optical path of sharp cut exposure B. Image fog light A regulates the optical path of the peripheral area by the first seven perchers 16 on the top surface of the member 15. and irradiates the image exposure area a.

The blank exposure B emitted from the light source IO passes through the second seven pertiers 18 and is irradiated onto the non-image area of the photoreceptor 2 by the lens 20. The aperture 18 is formed so that the image of the aperture 18 is formed on the surface of the photoreceptor 2, and so that when the image is formed, the aperture width of the seven vertices 18 is slightly larger than the width of the non-image area. The size and position as well as the focal length and position of the lens 2o are determined.

At this time, since the member that regulates the optical path of image exposure A and the member that regulates the optical path of sharp cut exposure B are integrated, the exposure range of both can be easily adjusted without making special adjustments each time they are assembled. ＾＾＾＾＾ｲﾞﾞｲｯIn particular, since the sharp cut exposure is also image forming exposure using a lens, there is no need to overlap the image area a more than necessary.

FIG. 3 shows an example of an image forming apparatus in which the exposure apparatus of the present invention can be mounted, and shows the essential parts of a microfilm league printer. In the apparatus shown in the figure, a film illumination light source 30, a condenser lens 31, a field lens 32, a film F, and a projection lens 33 are provided in a projection area. A mirror 35 and a screen 36 are used to observe the original image on the film F in the league section. The image light from the projection section is guided by scanning mirrors 37 and 38 and is also projected onto the photoreceptor 2. When the image is being projected onto the screen 36, the scanning mirror 371138 moves the image from the projection lens 33 to the screen 36.
However, when a copy is to be made, it advances into the optical path and scans the original image on the film F while exposing the upper surface of the rotating photoreceptor 2 to an image. The scanning speed is the rotational speed of the photoreceptor 2. The scanning mirrors 37 and 38 are orthogonal to each other, and 0 is their intersection point.
It starts moving from s and scans the original image from OL to 02 at a constant speed.

In the embodiment described above, the photoreceptor 2 and the like are housed in the cartridge and can be inserted into and removed from the main body, but the present invention can also be implemented with an apparatus in which each process device is directly incorporated into the main body.

As described above, according to the exposure apparatus of the present invention, it is possible to suppress as much as possible the sharp cut exposure from overlapping the image area, and therefore it is possible to prevent the situation in which the periphery of the image is not copied. Furthermore, since sharp cut exposure is exposure using a lens, highly efficient exposure can be achieved and a low brightness light source can be used.

Therefore, there is an advantage that light source cooling is not required and the device is inexpensive.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an embodiment of an image forming apparatus equipped with an exposure device to which the present invention is applied, FIG. 2 is a perspective view of essential parts of the exposure device to which the present invention is applied, and FIG. 3 is a diagram illustrating an exposure area. , FIG. 4 is a diagram showing the main part of a microfilm league printer in which the exposure apparatus of the present invention can be mounted. 2 is a photoreceptor, IO is an exposure lamp, 15 is an exposure regulating member,
16 is the first 7 apertures, 18 is the second aperture, 2
0 is a lens.

Claims (1)

[Claims] (1) In an apparatus that forms an image by exposing a moving photoreceptor surface, a first aperture that regulates transmission of image exposure light, a second aperture that regulates transmission of uniform light from a light source, A second 7.
An exposure device characterized in that an imaging lens for forming a percha image is integrated into an integral member.