JPS58134664A - Exposing method for photoreceptor - Google Patents

Abstract

PURPOSE:To easily adjust exposure at a fixed position, by arranging a screening member having a slit-like opening part to adjust exposure at a place close to a position where is unvariably irradiated by exposed light flux during the exposure through the slit. CONSTITUTION:The screening member 6 having the slit-like opening part is used for cutting out stray light or uniforming the quantity of exposure at an image formation part. Since a position P on which exposed light flux from a slit scanning starting position A is intersected with the exposed light flux from a scanning end position B is unvariably irradiated by the exposed light flux during the exposure through the slit, the screening member 6 is placed on the position P. Thus the exposure can be easily adjusted at the fixed position and proper exposure to the photoreceptor is attained without using a driving device.

Description

[Detailed description of the invention] The present invention relates to a photoreceptor exposure method.

The applicant previously proposed a photoreceptor exposure method in which a stationary original is scanned by a slit using an exposure optical system including a movable part, and a slit-shaped optical image of the original is projected onto a photoreceptor that moves in a specific direction. A method was proposed in which the photoreceptor was exposed to slit light while the projection position was moved in the opposite direction to the moving direction of the photoreceptor in the apparatus space (Japanese Patent Application No. 84182/1982).

Since the present invention relates to a photoreceptor exposure method that is an improved exposure method, the above exposure method will first be briefly explained below.

In Fig. 1, 0 is a document placed in a fixed position, 1 is a lens, 2tri photoreceptor, and 3 is a lamp.
It shows. The photoreceptor 2 is in the form of a sheet or a belt and is fed in the direction of the arrow, that is, to the left in the drawing, at a speed of one foot.

A lens 1 and a lamp 3 constitute an exposure optical system, both of which are movable in this example. That is, the robot can reciprocate between the position shown by the solid line and the position shown by the broken line, and when exposing the photoreceptor 2 to slit exposure, the VC is in the one position shown by the solid line. The robot moves at a constant speed from the position shown by the broken line to the position shown by the broken line, and when the dew point ends, returns to the position shown by the solid line.

When the slit exposure of the photoreceptor 2 is started, the lamp 3 and the lens 1 are in the position shown by the solid line, and the image at point A at the slit scanning start portion on the side of one document O is focused on point A'. This A'
This point is called the exposure start position. When the slit exposure is completed, the lamp 3 and the lens lfl occupy the position shown by the broken line, and an image is formed at point B' in the image of point B at the slit scanning end position. This point B' is called the exposure end position. The feature of this exposure method is that the start position and end position of slit exposure are separated, and the start position A' is on the downstream side with respect to the moving direction of the photoreceptor 2, and the end position B' is on the upstream side. , during slit exposure,
The projection position of the slit-shaped optical image of document 0 is at the point where it moves from the start position A' to the end position B' at the same speed, that is, in the opposite direction to the moving direction of the photoreceptor.

Now, if the slit scanning length is l as shown in the figure, the distance between the exposure start position A' and the end position B' is L, and the magnification of the exposure source is m, then the speed of the lamp 3 during slit exposure is If the speed of the lens 1 and the speed S of the photoreceptor 2 are satisfied, slit exposure as described above can be performed.

At the end of the slit exposure, the rear end of the formed latent image is at point B', so until the rear end advances to point A', the lamp 3 and lens 1 are moved along the solid line. If the latent image is returned to the position, a new slit exposure can be performed immediately following the rear end of the latent image, and latent images can be formed one after another on the photoreceptor 2 without any interval.

By the way, when performing lit exposure, generally '1
In order to cut 1° stray light and furthermore to equalize the amount of exposure light at the imaging section, exposure adjustment is performed using a light-shielding plate with a slit-shaped opening.03- Exposure method as shown in Figure 1 In this case, if you want to perform such exposure adjustment, you can either install a light shielding plate 4 in the document scanning section as shown in FIG. Ran. However, regardless of whether the light shielding plate 4 or the light shielding plate 5 is used, these are movable,
It must be movable in synchronization with slit scanning or slit exposure, and a driving device for that purpose is required, leading to complexity of the device.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a photoreceptor exposure method that enables the above-mentioned exposure adjustment, that is, exposure amount adjustment for uniformizing the exposure light amount and shielding of stray light, without complicating the apparatus. It is.

The present invention will be explained below.

The exposure method of the present invention is the same as that described above for the N era method. In other words, an original placed on a foot is scanned by a slit using an exposure optical system including a movable part, and a slit-shaped optical image of the original is directed toward the foot. In this method, the image is projected onto a moving photoreceptor, and the projection position is moved in the apparatus space in a direction opposite to the direction of the moving blade 4 of the photoreceptor, thereby exposing the photoreceptor to slits.

The main feature of the present invention lies in the selection of the position where the light shielding member is placed.

That is, in order to adjust the exposure, a light shielding member having a slit-shaped opening is provided in communication with the slit during exposure and in the vicinity of a position that is permanently occupied by the exposure light flux.

Hereinafter, description will be given based on specific examples.

FIG. 3 shows an example in which the present invention is applied to the exposure mode shown in FIG. 1.

The position where the exposure light beam from the slit scan start position point A and the exposure light beam from the slit scan end position B point intersect during exposure, ie, point P in FIG.

This is the position that is unchangeably occupied by the exposure light flux throughout the slit exposure.

By disposing a light shielding member 6 near this point P to perform exposure adjustment such as cutting off stray light, it is possible to easily perform exposure adjustment at a fixed position and properly expose the photoreceptor.

FIG. 4 shows an example in which the present invention is applied to another exposure mode.

In order to avoid confusion, the same reference numerals as in FIG. 1 are used for the confusion. In this exposure mode, the lens has a 1% color of 7.8.9.

10 constitutes an exposure optical system together with a lamp (not shown), and the lamp, mirrors 7.8, 9.10fi, and movable parts of the exposure optical system are constituted.

The slit exposure of the photoreceptor 2 is ``X'', which is the mirror 7.8, 9.1.
This is done by moving at a constant speed from the position shown by the solid line to the position shown by the broken line. The lamp (not shown) is moved integrally with the mirror 7.

In this exposure position, the position between the mirrors 8 and 9 shown by the solid line is a position that is unchangeably occupied by the exposure light flux throughout the exposure. Therefore, by providing a light shielding member 6 near such a position, it is possible to adjust the exposure at a fixed position. If something changes, it will change with time. Therefore, when switching the exposure magnification is possible, changing the position of the light shielding member 6 according to the switching of the magnification,
Needless to say.

-4, since the lens 1 has a cosine fourth power law, in the case of slit exposure, when illuminating the document side in a slit shape, even if the illumination is uniform in the longitudinal direction of the slit, the illuminance at the exposed part will vary. The illuminance is not uniform in the longitudinal direction of the slit (the direction perpendicular to the drawings in FIGS. 3 and 4), and the illuminance is lower at both ends in the longitudinal direction than at the center. In such a case, in order to make the exposure amount of the photoreceptor uniform in the longitudinal direction of the slit, if the exposure mode is as shown in FIG.
As shown in the figure, the shape of the light shielding member 6 may be such that the width of the opening 6A is widened at both ends in the longitudinal direction to cut off stray light and adjust exposure.

Furthermore, since the adjustments are made in detail, a pair of light shielding plates 61 and 62 as shown in Figure 6) are used as light shielding members in Figure 7''.
11, and the size of the opening of the slit can be adjusted by moving the slits in the left and right directions either interconnected or independently using wires or the like.

In the case of the exposure mode as shown in Fig. 1, as shown in Fig. 8,
The angle θ of the light beam incident on the lens 1 changes continuously during one exposure. This change in angle θ can also cause non-uniform exposure in the direction in which the photoreceptor 2 travels.

Therefore, Σ1K is used to remove such non-uniformity of the exposure meter.
For example, as shown in FIG. 9, a light shielding member 6'' is used in which a pair of light shielding plates 61' and 62' are mounted on shafts 63 and 64 so that they can swing around the shafts 63 and 64. nf: 10th
As shown in the figure, the incident angle θ(
According to the change in FIG. 8), the light shielding member 61'.

Exposure adjustment may be performed by oscillatingly displacing 62' and changing the size of the opening.

[Brief explanation of the drawing]

1 and 2 are diagrams for explaining the photoreceptor exposure method to be improved by the present invention, FIG. 3 is a front view explanatory diagram showing one embodiment of the present invention, and FIG. Front view explanatory diagrams showing another embodiment of the present invention, FIGS. 8-5 to 1O are diagrams for explaining exposure amount adjustment,
...Original placed on foot, l...Lens, 2...Photoreceptor 6.6/, 6//...Light blocking member, 61, 62, 61
', 62'... Light shielding plate, 7, 8° 9.10... Mirror 0

Claims (1)

[Claims] 1. A fixed original is scanned by a slit using an exposure element system including a movable part, and a slit-shaped optical image of the original is projected onto a photoreceptor that moves in a fixed direction. In a method of exposing a photoconductor to slit exposure while moving the position in the device space in the opposite direction to the direction of movement of the photoconductor, the method of exposing the photoconductor to a slit in the vicinity of the position invariably occupied by the nine-element bundle of exposure throughout the slit exposure. A method for exposing a photoreceptor, comprising: providing a light-shielding member having a slit-shaped opening; and adjusting the exposure amount of the photoreceptor and blocking stray light with the light-shielding member. 2. In claim 1: A method for exposing a photoconductor, characterized in that the position of the light shielding member is variable, and the position is displaced in accordance with switching of exposure magnification. 3. A method for exposing a photoreceptor according to claim 1 or 2, characterized in that the size of the opening in the light shielding member is variable.