JPS58223143A - Electrostatic copying machine - Google Patents

Abstract

PURPOSE:To enable partial erasion and insertion of an image in either the moving direction of a photoreceptor or the direction at right angles thereto, by shielding partially an imaging luminous flux by an image exposing means with a slit shielding means and writing the shielded part of the photoreceptor with light. CONSTITUTION:A button array 24 for assigning the position where an image is cut off in a scanning direction, a button array 25 for assigning the position where the image in the direction at right angles thereto, that is, the axial direction of a photoreceptor is cut off, an input keyboard 26 for writing with light, and a monitor display plate 27 for checking the content thereof are provided around an original glass plate 11. The operator operates the buttons 24, 25 to shield a slit 20 with the blade 21 of a shutter 13 and to shield partially the imaging luminous flux to the photoreceptor. The image assigned from the keyboard 26 is written thereon through an optical writing device 5.

Description

[Detailed description of the invention] The present invention relates to an electrostatic copying machine equipped with an editing function.

A copier with editing capabilities is a copier that can automatically combine different images onto a single copy. The simplest conventional image compositing method is to copy a composite original that has been manually cut and pasted in advance using an ordinary copying machine.

Not only is this time-consuming, but the cut and pasted edges often appear as black lines, which does not look good.

Therefore, several attempts have been made to have copying machines automatically perform image composition.

In order to have an electrostatic copying machine perform image composition automatically,
First of all, it is necessary to erase unnecessary image parts of the original. As is well known, in electrostatic copying machines,
A light image is irradiated onto the surface of a pre-charged photoreceptor to create an electrostatic latent image, which is developed with colored fine particles called toner to reproduce the image. Therefore, in order to erase an image, it is sufficient to either not create an electrostatic latent image in that area or to erase it, and this can be easily done by irradiating it with light.

For example, if you line up a large number of erase lamps in a direction perpendicular to the direction of movement of the photoreceptor and turn on the lamps in the areas where you want to erase the image, the latent image will disappear or will not be formed, making it possible to erase parts of the image. Become.

However, although this method can easily erase unnecessary image parts, in order to create another image in the erased part, it is necessary to charge it again or to make a -H copy and then make a similar copy to that copy. It is necessary to transfer another image part by operation to obtain a composite image, which has the disadvantage of increasing the number of steps.

In addition, erasing using a lamp requires a certain amount of time after turning on until a certain amount of light is reached and after turning off until the amount of light reaches zero, so it has a slope relative to the moving speed of the photoreceptor. This has the disadvantage that half-tone shadow areas are created in the cut-off parts of the image.

Other methods for automatically synthesizing images in a copying machine include image exposure using a normal original and laser light, as described in Japanese Patent Laid-Open No. 57-6865. A method of performing this in combination with optical writing is known. In order to perform optical writing using a laser beam, it is necessary to maintain electrical charges on the photoreceptor in that area without performing image exposure using a document.

This is because the laser light used in optical writing devices is usually modulated by a negative image signal, that is, it stops emitting light for image areas such as characters, and emits light for background areas. As a result, only the electrical charges in the image area remain, to which toner adheres and development is performed. Therefore, for writing with laser light, it is essential that charges remain on the photoreceptor, and loss of charges due to the image capacitor C must be avoided. For this reason, only one of image exposure and optical writing is performed selectively, and it has conventionally been impossible to perform both at the same time.

Conventionally, when the position of the photoconductor where optical writing is desired is reached, the light beam for image exposure is shielded from the entire row by a shutter in order to conserve the charge. Although it is possible to erase a line, it is not possible to partially erase an image in a direction perpendicular to this, that is, to erase a line partially.

It is an object of the present invention to provide an electrostatic copying machine that combines image exposure and optical writing to synthesize images, in which partial erasure and insertion of images can be performed both in the direction of movement of a photoreceptor and in the direction perpendicular thereto. An object of the present invention is to provide an improved electrostatic copying machine capable of carrying out the following operations.

The electrostatic copying machine according to the present invention includes: an image exposure means for irradiating a light image of a document to be copied onto a photoreceptor; a slit shielding means capable of partially blocking the imaging light flux produced by the image exposure means; The photoreceptor includes an optical writing means capable of optically writing onto a portion of the photoreceptor that is shielded from light by the shielding means.

An embodiment of the present invention will be described below with reference to the accompanying drawings. In FIG. 1, the photosensitive drum 1 is surrounded by a charging charger 2, an erase lamp 5, an image exposure device 4, an optical writing device 5, a developing device 6, a transfer charger 7, a separation charger 8, a cleaning device 9, and a static elimination charger. 1
0 etc. are arranged. The outline of the copying process of this copying machine will be explained in advance. First, the surface of the photoreceptor 10 rotating in the clockwise direction is uniformly charged by the charger 2, and then the erase lamp 5 is used to uniformly charge the surface of the photoreceptor 10.
Charges on portions of the upper original 12 other than the image area are erased, and the image of the image area is projected onto the surface of the photoreceptor by the image exposure device 4. As a result, the charges on the surface of the photoreceptor are selectively erased according to the brightness of the image, and an electrostatic latent image corresponding to the image is formed thereon. At this time, if necessary, a part of the imaging light flux is blocked by the shutter device 1 to create a part where no latent image is created by image exposure.
Light is applied thereto from the optical writing device 5 to create another electrostatic latent image. When these electrostatic latent images are developed by receiving toner from the developing device 6, a transfer paper 14 is superimposed on the developed image, and the image is transferred onto the transfer paper 14 by the charger 7. Ru. After the transfer, when the transfer paper 14 is separated from the photoreceptor surface by the separation charger 8, the toner remaining on the photoreceptor surface is removed by the cleaning device 9.
The residual potential is removed by the charger.

Next, the image exposure device 4, shutter device 15, and optical writing device @5, which are the main parts of the present invention, will be explained in more detail. The image exposure device 4 includes an exposure lamp 15 and a first mirror 16, which are disposed below the document platen glass 11 and move integrally in the direction of the arrow at the same speed V as the circumferential speed of the photoreceptor 1, and a first mirror 16 at a speed V in the same direction. 2nd mirror 17 moving at /2
, a stationary in-mirror lens 18, and a fifth mirror 19.

The original 12 on the original table glass ++-11 is exposed to the exposure lamp 15.
The light is illuminated in a slit shape parallel to the axial direction of the photoreceptor 1, and is scanned by the moving first and second mirrors 16 and 17. The entire optical system is shielded from light except for the slit-shaped optical path. Although this optical system is referred to as a mirror scanning type, other types of slit exposure optical systems can be used for this invention.

For example, as shown in FIG. It has an opening 20, which is opened and closed by vanes 21 which are divided into a number of parts and each can operate independently. Each blade 21 is driven by mechanical means, and its opening/closing speed is set to be, for example, approximately 5 to 10 times faster than the circumferential speed V of the photoreceptor 1. For example, if the opening/closing speed of the blade 21 is 2, the circumferential speed of the photoconductor is 4v, and the width of the slit 200 is t, then the cutting width on the image caused by the time lag due to the opening/closing of the slit is determined by the blade 21 moving in the same direction as the photoconductor 1. When opening the slit 20, l-' v (V4 v)
Or -Vv (v<v), and in the opposite case, Z +
v v.

Therefore, when the slit 20 moves in the opposite direction relative to the photoreceptor, the cutting width becomes larger than the slit width. For this reason, both the slits are made to operate in the same direction as the photoreceptor during opening and closing operations. For example, when the slit width t is 4M, by increasing the moving speed of the blades 21 by 5 times or more, the cutting width on the image can be made 1lar1 or less, and a satisfactory cut can be made.

In addition to such a mechanical means, the shutter device 15 is constructed such that each segment 22 is composed of a liquid crystal or a magneto-optical element 22, as shown in FIG. It is also possible to configure it so that it can be independently controlled on and off. As shown in FIG. 6, each segment 22 has a deflection surface rotation element 51 such as a TN type liquid crystal or a magneto-optical element arranged between two deflection plates 29 and 50, and this element 51 allows light to be emitted. It may be configured to control whether or not to transmit the light through the deflection plate 50, but in this case, it is necessary to align the deflection planes of the transmitted light.
If the deflection plane is rotated as shown by the arrow 52 to prevent light from passing through, the amount of light will be reduced by half or more due to the deflection plate 50, so instead of using such a deflection plate, the guest Host type liquid crystal 55 (arrow 54.5
5 indicates a deflection surface that can be used for shuttering. ) to configure each segment 22 is more suitable for implementing the present invention. The size of each blade 21 or segment 22 of such a shutter device 15 is preferably approximately equal to the character spacing of a normal document, but may be coarser.

For example, as shown in FIG. 4, the optical writing device 5 includes light emitting diodes 25 arranged in a matrix, and is connected to a microcomputer to selectively emit light in the form of predetermined characters, figures, etc. This optical writing device@5 can also be an optical scanning type laser device that performs scanning using a deflection device such as a rotating polygon mirror used in a normal laser printer.

Images are synthesized using the image exposure device 4, shutter device 15, and optical writing device 5, and an example of the operation will be explained with reference to FIG.

FIG. 5 shows the top of the copying machine, with the original glass table 11
Around 0, there is a button row 24 for specifying the image deletion position in the scanning direction, a button row 25 for specifying the image deletion position in the direction perpendicular to this, that is, the axial direction of the photoreceptor, and an input for optical writing. A keyboard 26 and a monitor display board 27 for checking the contents are provided in addition to the usual operation section. The pitch of each button in the button row 24 is approximately equal to the line spacing of the document normally used.
The button pitch of 5 is equal to the pitch of the blades 21 or segments 22 of the shutter device 15.

The deletion position can be specified using these position specification buttons, for example, buttons 24a to 24b in the button row 24, buttons 24b in the button row 24, etc.
When the buttons 25a to 25b of No. 5 are pressed, the processing is performed for the area 2B surrounded by the coordinates designated by these buttons. That is, by using the buttons 24a and 24b, the microcomputer issues a command to cover the slit 20 with the blade 21 or the segment 22 of the shutter 15 for a certain number of seconds after the start of scanning the document. At the same time, out of the many blades 21 or segments 22 of the shutter 15, operate only the blades 21 or segments 22 corresponding to the range from the button 25a to the button 25b using the buttons 25& and 25h to cover the slit 20'4i. , is similarly issued from Mykuro Computer. As a result, the shutter 15 is closed only in a portion corresponding to the region 2B, thereby avoiding dissipation of the photoreceptor charge in that region, and the image specified by the input keyboard 26 is written there through the optical writing device 5. The other portions of the rows or lines that do not include the area 28 are not closed by the shutter 15, so that image exposure from the original is performed as is.

In this way, image exposure from the original and optical writing from the optical writing device are performed simultaneously, but the button row 2
When a row is designated by 4 and all buttons in the button row 25 are pressed, images in all parts of the designated row are deleted, and optical writing becomes possible in those parts.

Also, if you press all buttons in button rows 24 and 25,
Image formation using only optical writing becomes possible, and vice versa.
Image formation is performed only by image exposure. Furthermore, it goes without saying that by setting an appropriate program in the microconbeater, various forms of image deletion and image composition can be performed. As described above, the image composition according to the present invention can take various forms and produce a good quality composite copy.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an embodiment of the invention, FIG. 2 is a diagram showing an example of a shutter device according to the invention together with a photoreceptor, and FIG. 5 is a diagram showing another example of a shutter device. FIG. 4 is a diagram showing an example of the optical writing device according to the invention, FIG. 5 is a diagram showing an example of the top surface of the electrostatic copying machine according to the invention, and FIGS. FIG. 3 is a diagram showing the configuration of each segment of the shutter device shown in FIG. 1... Photosensitive drum, 2... Charger, 5...
...Erase lamp, 4...Image exposure device, 5...
Optical writing device, 6...Developing device, 15...Shutter device, 20...Slit, 21...Blade, 22
...Liquid crystal segment, 25...Light emitting diode matrix. Work 1 M 12 Ka 5 M 1'; cgc

Claims (1)

[Scope of Claims] 1. An image exposure means for irradiating a light image of a document to be copied onto a photoreceptor; and a gutter shielding means capable of partially blocking the imaging light beam produced by the image exposure means. . An electrostatic copying machine comprising: an optical writing means capable of optically writing onto a portion of the photoreceptor shielded from light by the slit shielding means. 2. Claim 1, wherein the slit shielding means is a shutter device having a large number of independently openable and closable shielding members arranged in a direction perpendicular to the moving direction of the photoreceptor.
Electrostatic copying machine described in Section 1. 6. The static device according to claim 1, wherein the slit shielding means is a shutter device having a large number of liquid crystal elements or magneto-optical elements that are arranged in the moving direction of the photoreceptor and can be turned on and off independently. Electric copying machine. 4. The electrostatic copying machine according to claim 1, wherein the optical writing device is an optical scanning laser device. 5. The electrostatic copying machine according to claim 1, wherein the optical writing device includes a large number of semiconductor lasers or light emitting diodes arranged in a matrix.