JPS6026963A - Image processing device - Google Patents

Abstract

PURPOSE:To enable image processing in proper density by providing a changeover means between the case of an ordinary original and a reflective type display, and even in the case of a reflective type original, providing a means for controlling image processing density in a scale same as in the case of an ordinary original. CONSTITUTION:A photosensitive drum 1 is rotated in the direction of an arrow 2, and a light source 3 and mirrors 4, 5 are moved in the direction of an arrow 6 to expose the drum 1 to the light image of an original 8. On the other hand, the drum 1 is destaticized with a destaticization charger 11 and the surface is electrostatically charged with a primary charger 13. The drum 1 is reversely charged with a secondary charger 14 and at the same time, said exposure is made by illuminating the surface of the drum 1 with a lamp 15 to form an electrostatic latent image on the surface. It is developed to form a toner image with a developing device 16, and it is transferred to a paper with a transfer charger 17 when it passes between the drum 1 and charger 17. The transferred toner image is fixed to the paper when it passes through a fixing device 18. Image density of a copoied image can be controlled by moving a lever 19 to a proper position in accordance with original density on an operational panel.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an image processing apparatus having an adjusting means for processing an image on a document at an appropriate density.

Related to conventional electrophotographic copying machines, not only general originals but also images displayed on a display device, etc., such as the output of a computer, etc., can be displayed by placing the display surface of the display device on the document table. A device capable of copying has been proposed. However, for example, when attempting to copy by placing the display surface of the liquid crystal display device against the document table, only a completely black copy is obtained because there is little reflected light from the liquid crystal display device. Even if you increase the density by moving the density adjustment lever, you will still only be able to obtain copies that are entirely black. To deal with this, we moved the density adjustment lever so that when the density was increased, the image on the LCD display could be copied clearly, but the width of the lever movement when adjusting the density of ordinary originals became smaller. . Further, when the lever is continuously movable and adjustable using a volume control, etc., there is a drawback that the variable range of the variable portion for density adjustment in the density adjustment mechanism must be made very large. Further, even if the document is a normal document, a similar drawback occurs when the document has a very high reflectance or is dark.

Purpose In view of the above points, it is an object of the present invention to eliminate the above-mentioned drawbacks and to provide an image processing apparatus capable of always processing images at appropriate density.

Embodiments Next, embodiments to which the present invention is applied will be described with reference to the drawings. FIG. 1 is a diagram showing the configuration of an electrostatic photocopying machine.

During the copying operation, the photosensitive drum 1 rotates in the direction of the arrow 2, and in synchronization with this rotational speed, the light sources 3, 20, and the first
Mirror 4 and second mirror 5 move in the direction of arrow 6. At this time, the speed of the second mirror 5 is moved at half the speed of the first mirror 4, so that the optical path length from the document 8 to the lens 1o of the optical path 9 from the document 8 on the document table 7 to the photosensitive drum is are always equal. However, in Figure 1,
Since the state before the original is copied is shown, the optical path 9 does not connect the original 8 and the photosensitive drum 1. In this way, the optical image of the original 8 is exposed onto the photosensitive drum 1. - The photosensitive drum is equipped with a pre-static charger 11. The charge is removed by the pre-exposure rung 12, and the surface is uniformly charged by the negative charger 13. Next, the secondary charger 14 performs the above-mentioned exposure at the same time as charging in the opposite direction, and then the drum surface is uniformly illuminated by the entire surface exposure lamp 15, so that an electrostatic latent image is formed on the surface of the photosensitive drum 1. It is formed.

In order to ensure accurate focus during exposure, when using the liquid crystal display as an original, an optical system for focus correction (
For example, a glass plate may be inserted into the exposure path).

Next, development is performed in the developing device 16, and the toner adheres to the latent image portion corresponding to the black portion of the document 8 to form a visible image.The toner is applied to the paper passing between this and the photosensitive drum 1 by the transfer charger 17. When the visible image is transferred and the paper passes through fuser 18, the image is fused to the paper. Note that toner remaining on the photosensitive drum 1 without being completely transferred is scraped off by a cleaner 119. The above is an example of the copying operation of one of the well-known electrostatographic methods.

FIG. 2 is an example of an operation panel of a copying machine. Lever 19
1 is an original density adjustment lever, which moves the lever 19 to an appropriate position according to the density of the original to adjust the density of the image when copied. For example, for an original that is completely dark, such as a blueprint, move the lever 19 in the direction of number 1, and for an original written in pencil on high-quality paper, move the lever 19 in the direction of number 9 to obtain a proper copy. .

21 is a normal original density adjustment button, and 22 is a low reflectance original density adjustment button. The brightness of the central source 3 in FIG. 1 can be changed according to the position of the lever 19. This method can be realized using a well-known technique such as the ignition angle control method for a four-gun lamp. In addition, the light source 20 is a low reflectance original density adjustment button 2.
When 2 is pressed, the light is turned on during the copying operation, and when the normal original density adjustment button 21 is pressed, the light remains off even during the copying operation.

Further, 50 is a numeric keypad and a clear key for setting the number of sheets. Reference numeral 51 denotes various display sections, 52 a copy start key, 53 a cassette size display section, and 54 a variable magnification setting section for setting and displaying a variable magnification mode.

FIG. 3 shows the concentration control circuit.

The output boat PA of the microcomputer 23 is the light source 3
When turned on, it becomes ``'1'' level. The output of the hammer driver 24 is connected to the drive terminal L of the lamp regulator 25.
Connected to RD 1. When the output power (PA) is at the 11" level, the drive terminal (2) becomes the "0" level, an average current corresponding to the voltage value of the dimming terminal LINT at that time flows to the light source 3, and the light source 3 is turned on. Note that the output from the volume 19A that is linked to the lever 19 is connected to the dimming terminal LINT, so move the lever 19 to adjust the volume 19A.
By changing the value of L, the average current value flowing through the light source 3 can be controlled and the amount of light can be changed. The above technique is a well-known technique. Now, connect the switch 22A linked to the low reflectance original density adjustment button 22 to the set terminal S of the RS flip-flop 26, connect the switch 21A linked to the normal original density adjustment button 21 to the reset terminal 100, and connect this output and the output cap. -) The hammer driver 27 is driven by the AND of PA, and the rung driver 28 is driven by the hammer driver 27. If 0, the low reflectance original density adjustment button 22 is pressed, and then the normal original density adjustment button 21 is pressed. Until is pressed, the rung driver 28 is driven and the light sources 20 are simultaneously turned on at the timing when the light source 6 is turned on, that is, when the boat PA becomes '1''.The light intensity of the light source 20 is controlled by the lever 19. You can do it like this.

The above example shows an example in which another light source is additionally turned on in response to the density adjustment button in a copying machine that adjusts the copy density by adjusting the light intensity of the light source. A similar method can be applied to copying machines that change the aperture.

It is also possible to use a combination of these, such as using aperture adjustment as coarse adjustment and light amount adjustment as fine adjustment.

Further, as a rough adjustment, a method may be adopted in which the process speed and the moving speed of the snubber drum and optical system are changed. This method takes advantage of the fact that the amount of exposure per unit time increases when the speed of the drum is slowed down.Although the density adjustment is performed in two stages as an example of the present invention, it is possible to adjust the density in any number of stages.

In addition, we have shown an example in which the density is adjusted by resetting the RSS free lag flop set based on the state of the switch linked to the density adjustment button.
Alternatively, it may be determined whether or not to drive 7.

Effects As described above, according to the present invention, it is possible to provide an image processing apparatus that can always perform image processing at an appropriate density regardless of the type of document.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a structural diagram of a copying machine. Fig. 2 is a diagram showing an example of the operation panel of a copying machine.0 Fig. 6 is a diagram showing a density control circuit.023 is a microcomputer, s, 20tj is a light source, 19 is a density adjustment lever, and 22 is a low Reflectance original density adjustment button, 21 is normal original density adjustment button, 52 is copy start key 0 Applicant: Canon Co., Ltd., 3-30-2 Shimomaruko, Ota-ku, Tokyo, Canon Co., Ltd.

Claims (1)

[Claims] An image processing apparatus that can use a reflective display as an original includes a switching means for switching between a normal original and a reflective display as an original; An image processing apparatus comprising a density adjustment means for adjusting image processing density on a scale similar to that of an original.