JPS6283773A - Image forming method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image forming method, and more particularly to an image forming method for an electrophotographic apparatus or the like that can faithfully reproduce a document containing text, printed photographs, and printed photographs.

It is known that when reproducing a conventional U4 direct print photograph by electrophotography, a latent image is formed in the form of halftone dots to improve the reproducibility of halftones.

Since printed photographs and the like are mixed with text in a document, depending on the state of the latent image mesh that is formed, the characters may appear jagged or the printed photographs may exhibit a moire phenomenon.

Therefore, when characters, printed photographs, etc. are formed on the same document surface, it is necessary to copy the characters and printed photographs separately and then combine them together by cutting and pasting.

An object of the present invention is to solve the conventional problems and provide an image forming method that has good reproducibility regardless of the type of image on the original.

(2) In order to achieve the above object, the present invention is characterized in that an area corresponding to a designated area of a document on a latent image carrier is erased in a halftone dot pattern.

The structure and operation of the present invention will be explained in detail based on embodiments shown in the drawings.

FIG. 1 shows a case where a document 1 is formed with a text area 2, a printed photo area 3, and a printed photo area 4. In this example, the printed photograph area 3 is the area to be erased in the form of halftone dots.

The X coordinates X1 to X2 and the Y coordinates Y1 to Y2 of the printed photograph area 3 are input in advance to an image forming apparatus, for example, an electrophotographic apparatus, as designated areas.

In FIG. 2, in a known electrophotographic copying machine having a latent image carrier 5, a charger 6, an exposure position 7, a developing device 8, a transfer charger 9, a cleaning device 10, and a static elimination lamp 11, the exposure position 7 and the developing device are shown. A random erase device 12 is placed between 8 and 8.

The random erase device 12 includes a random erase light source 1
3, and a halftone screen film 14, for example, a cylindrical screen film, which runs between the random erase light source 13 and the latent image carrier 5. The halftone screen film 14 is formed to move at the same speed as the latent image carrier.

The electrostatic latent image of the document is charged by the charger 6 and exposed at the exposure position 7 to be formed on the latent image carrier 5 (the image is a FW-defined area by the random erase device 12, for example, in FIG. X1-X2, Y.

The range surrounded by Y2 is erased.

As shown in FIG. 3, the random erase light source 13 can be composed of a large number of LEDs that are arranged in the axial direction (width direction) of the latent image carrier 5 and emit light separately. many L
For example, if only those EDs corresponding to the specified range Y1 to Y2 in FIG. 1 emit light, it is suitable for halftone dot erasing of the original document in FIG.

As the screen film 14, for example, a film having a halftone dot pattern as shown in FIG. 4 is used, and when enlarged, as shown in FIG. are arranged in an appropriate array shape.

The latent image formed by image exposure is screen film 1
4 and is re-exposed by the random erase light source 13.

Through the above process, the latent image of only the printed photographic part of the copied image of the original is corrected into a halftone dot pattern, and the other parts are developed as normal latent images in the next developing step.

According to the present invention, it has become possible to perform halftone correction on an arbitrary portion of an image of a document.

According to the present invention, a latent image can be erased in a halftone pattern only in a designated area of a document, so it is possible to cut and paste documents containing various types of images, such as text, printed photographs, printed photographs, etc. Good copies can now be obtained for all images without unnecessary procedures such as

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an example of an image arrangement of a document, FIG. 2 is an explanatory diagram of a copying apparatus according to the present invention, FIG. 3 is an explanatory perspective view of a light source of an erase device, and FIG. 4 is a screen of an erase device. FIG. 5 is a partial plan view for explaining an example of the film, and FIG. 5 is an enlarged view of a part of FIG. 4.

Claims (1)

[Claims] An image forming method in which an electrostatic latent image is formed by charging and exposing an image on a document onto a latent image carrier, and then random erasing is performed by irradiating light onto an area on the latent image carrier that corresponds to a pre-specified designated area on the document. An image forming method characterized in that the specified area on the latent image carrier is erased in a halftone dot pattern.