JPS58176632A - Exposure lighting device of copying machine - Google Patents

Abstract

PURPOSE:To correct irregular illuminance easily and to save electric power by using plural lamps arrayed at intervals perpendicularly to a scanning direction. CONSTITUTION:An exposure scanner has lamps arrayed linearly at intervals to maximum original width perpendicularly to the scanning direction, i.e. in a direction parallel to a platen 3 and perpendicular to the moving direction of the scanner. A specific number of the lamps correspond to each original size (A, B, and C). Each lamp unit is provided with an individually controllable controller; all the lamps are turned on normally for a copy of size C, a lamp No.6 is turned on or dimmed for a copy of size B, and lamps No.4, No.5, and No.6 are turned off or dimmed for a copy of size A.

Description

[Detailed description of the invention] An exposure scanner scans the document surface by irradiating it with slit-shaped light to form an electrostatic latent image on the photoreceptor, which is visualized with developing toner, and the toner image is The present invention relates to an electrostatic copying machine that obtains a copy image by transferring the image to a transfer material, and particularly to an exposure illumination device thereof.

This type of exposure illumination device is required to be able to provide at least uniform illumination over the entire surface of a copy document. Conventionally,
For example, as shown in Figure 1, all the light emitters are integrally constructed,
There are known lighting devices that include an exposure scanner consisting of a bar-shaped halogen lamp 1' and a flutter 2', and lighting devices that have a plurality of lamps and are controlled by a single controller.

In conventional devices, the light emitting body and the control device are integrally combined, and the illuminance control is only for uniformly controlling the entire light emitting body. Therefore, with the conventional device, it has not been possible to correct uneven illuminance in the axial direction of the lamps or partial variations between lamps.

Also, for lighting. In terms of efficiency, it is common to utilize the reflected light from various reflectors 2' and focus the light on a predetermined slit. It is impossible to perform fine control, and manufacturing the light emitting element and reflector requires a great deal of labor.

Also, the lifespan of the light emitting body is short compared to the lifespan of the entire machine.
There was a need for replacement during operation, and during the replacement, there were cases where it was necessary to manually readjust variations in the light emitting body.

Furthermore, since power is supplied to all the light emitters regardless of the size of the original to be exposed, unnecessary power is eliminated.

Note that electrostatic copying machines are also capable of copying three-dimensional objects, but in this case, depending on the shape of the document cover, strong direct light often leaks to the operator.

In addition, photoreceptors are sensitive to even weak light, and repeated exposure to strong light in non-image areas may cause partial deterioration of the photoreceptor's physical properties. It cannot be overlooked that they had to take defensive measures.

It is an object of the present invention to easily correct the non-uniform illuminance, which was a drawback of the prior art, to save power, to cause no discomfort to the operator, and to reduce the effect on the photoreceptor, which is the core of the copying machine. The objective is to provide a lighting device with less impact.

According to the present invention, it is possible to perform partial exposure correction for a copying machine with automatic exposure adjustment, which is thought to become the mainstream of copying machines.

The present invention will be explained below according to the illustrated embodiments.

The copying machine shown in FIG. 2 scans the entire surface of a document 4 set on a document table 3 in the form of a slit using an exposure scanner configured with a lamp 1 and a reflector 2 and movable in the P direction. The optical image obtained here is transferred to the photoreceptor 9 using an optical device (mirror 5, 7°8, lens 6).
Project on top.

Charge is imaged on the photoreceptor in advance by a charger 11, and an electrostatic latent image corresponding to the original image is formed on the photoreceptor. Thereafter, the developing device 1o visualizes the image, and the transfer charger 13 transfers the image onto the transfer material 12.
A fixing device 14 fixes the image on the transfer material to obtain a copy image. After the transfer process is completed, the photoconductor is cleaned.
It is cleaned by the car device 15, charged again by the charger 11, and repeats the above steps.Since the configuration described above is the same as the conventional one, further explanation will be omitted.

In Figures 3 and 4, the lamp 1 of the exposure scanner
consists of a plurality of lamps arranged at intervals from each other in a straight line across the maximum document width in a direction perpendicular to the scanning direction, that is, parallel to the document table 3 and perpendicular to the movement direction P of the scanner. . In this example, &1″ to “
The lamps up to &6" are arranged at equal intervals as shown in Figure 4. In other words, the light source consists of a plurality of divided lamps, and each of these light sources can be used for various document sizes. (Column A, Column B, Column 6) with a predetermined number. Note that the document size here means the size corresponding to the transfer paper size. For example, the transfer paper size is A4. In this case, the lamps sufficient to expose and scan document size A are lamps 1, 2, and 3, and the lamps sufficient to expose and scan size B are lamps A1, 2, 3, 4, and 5, and so on. In this case, it should be noted that when exposing and scanning a document size A, there is no particular need for the lamp A4°5.6.

Therefore, in the present invention, a control device that can control each lamp individually is prepared, and when copying size C, all the lamps are turned on normally, and when copying size B, lamp A6 is turned on.
Turn off the light or reduce the pressure, and when copying size A, turn on lamp 4.
4, 5.6 to be able to turn off the lights or reduce the pressure.

Figure 5 shows a specific example of the control device, in which individual lamps A
1 to A6 respectively have dedicated light control units 21 to 26. These dimming units are of a type that can manually adjust the light amount output of the lamp 1 depending on the input amount, such as the magnitude of voltage. Reference numeral 17 denotes a determination unit for determining the transfer paper or original size and copy mode (copy magnification conversion, etc.). The control unit 18 receives the document size and copy mode signals from the determination section 17, processes the signals, and controls the light control unit of the lamps belonging to the area outside the predetermined minimum document size (A size in this example), i.e. In this example, 44.5.6 dimming units 24 to 26. This is the main control unit that issues control commands to the The main control unit 18 is 1, for example, when the original is A.
When receiving a signal indicating the size, the light control unit 24~
The output voltage to 26 is reduced to zero, and lamp A4-b6 is turned off. When the document is B size, the lamp lamp 6 is turned off, and when the document is C size, the output voltage is controlled so that all the lamps are allowed to turn on.

Reference numeral 19 denotes a determination unit that determines the image condition (density, background density, etc.) for all sides of the original 4 and outputs it as a dual-time image check signal or as an image condition storage program signal once stored in the memory. . The control unit 20 receives an image check signal or an image state storage program signal from the determination unit 19, and is a sub-controller that converts this into a voltage of a corresponding magnitude for each of the areas to which the individual lamp shops 1 to A6 belong. Department. This sub-control unit 2
0 and 1 receive a video output signal from, for example, a television camera, create a potential corresponding to each small section to which each lamp belongs, and apply this to each dimming unit 21-26. As a result, for example, background stains on the document are automatically compensated for.

In addition, among the light control units 21 to 26, lamp shops 4 to A6
The light control units 24 to 26 belonging to the above are preferentially controlled by the main control section 18.

As described above, the exposure illumination device of the present invention uses a plurality of lamps arranged at intervals from each other across the maximum document width in the direction perpendicular to the scanning direction as the light source of the exposure scanner, and adjusts each of these lamps. The apparatus is provided with a light unit and a control unit that turns off or depressurizes a light control unit belonging to a lamp located outside the minimum document width among these light control units depending on the document size. Therefore, according to the present invention, it is possible to control the amount of illumination light locally by individually controlling the light control units.

It is possible to save power by turning off lights or reducing the pressure in unnecessary areas, to solve uneven image quality caused by uneven illuminance, to reduce direct light leakage when copying three-dimensional objects, and to reduce partial light leakage when copying three-dimensional objects. It becomes possible to adjust image quality, etc. Furthermore, since the light reflected by the document cover in the non-image area can be controlled, deterioration of one part of the photoreceptor can be minimized.

[Brief explanation of the drawing]

Fig. 1 is a diagram illustrating a conventional exposure scanner, Fig. 2 is a schematic diagram of a copying machine equipped with an exposure illumination device of the present invention, Fig. 3 is a perspective view of the exposure scanner, and Fig. 4 is each lamp of the exposure scanner. A diagram showing the relationship between and manuscript size, and the fifth
The figure is a diagram showing a control section of the exposure lighting device. 1: Lamp 2: Reflector - 3 = Original table 4: Original 17: Judgment section 18: Main control unit 19: Judgment section 20: Sub-control units 21 to 26: Lamp Fig. 5

Claims (1)

[Claims] An exposure scanner that has a light source and moves relative to the document illuminates the surface of the document with slit-shaped light and performs exposure scanning.
In a copying machine that forms an electrostatic latent image on a photoreceptor, visualizes it with developing toner, and transfers the toner image to a transfer material to obtain a copy, the light source of the exposure scanner has a light source that is perpendicular to the scanning direction. A dimming unit for each of these lamps, and a dimming unit for the lamps that are outside the minimum document width, using a plurality of lamps arranged at intervals from each other across the maximum document width in the direction. 1. An exposure illumination device for a copying machine, comprising a control unit that turns off or depressurizes the unit depending on the document size.