JPS6067973A - Image processor - Google Patents

Abstract

PURPOSE:To discriminate on a copy easily by detecting an image processing condition with a pattern formed by using a reflection type liquid-crystal panel, and controlling image processing. CONSTITUTION:When copying operation starts after image display operation, an image displayed on liquid crystal is cleared temporarily, the potential on a photosensitive body 8 corresponding to a light part is measured by an electrometer 25, and the quantity of light of an exposure lamp 9 is increased until the light part potential reaches a specific potential. Then, the liquid-crystal is displayed entirely in black and the potential of a primary electrifier 7 is varied until the contrast between the light part and shade part potentials converges on a prescribed value. A reflecting plate 26 is attached to the reverse surface of a transmission type liquid-crystal display element 3. When said control is completed, the stored image is reproduced on the display screen 2 and copied to obtain a copy having clear contrast without any ground fogging.

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to an image processing device that can obtain a clear hard copy of images and text information by using the display device sound of images and text as originals in a copying machine, etc. . ′ [Prior Art] Conventional image processing devices, such as general copying machines.

A document table is placed on a document table made of a transparent material. Light is illuminated from below the document table, and the reflected light according to the density of the document is focused by an optical system made of gold such as a lens, and the image of the document is exposed. The image is configured to be imaged onto the drum.

On the other hand, liquid crystal display devices are known as image output devices for computers and the like. Therefore, the entire display screen of this liquid crystal display device is placed on the document table so that it is aligned with the top surface of the document table of the copier, the entire image is output on the display screen, and the copying operation of the copier is controlled. When executed, a hard copy of the image displayed on the liquid crystal display device can be made.

FIG. 1 shows a copying machine capable of making such hard copies. That is, it is a perspective view of an image processing apparatus that is a combination of a liquid crystal display device with a liquid crystal display screen attached to the cover of the copying machine and a copying machine.

In the figure, 1 is an electrophotographic direct paper copying machine, and 2 is a display device formed in the shape of a cover, the display screen 3 of which is constructed so as to cover the original 1° 4 copying machine 4. The display device 2 is connected to the keyboard via the cable 6. It is connected to computer 5.

With this configuration, the display screen of the computer 5 is used as a consortium output, all processing information is displayed on the display screen 3, and after checking the display contents, the cover-like display device 2 is folded over and copying is started. For example, you can easily obtain a hard copy of the displayed content. In particular, when the computer 5 is used as a word processor, the document output on the display screen 3 can be edited and checked, and then a hard copy can be obtained immediately, resulting in good operability and high copying efficiency. In addition, in a system that can be introduced into a local area network and can transfer information between multiple computers, for example, image information can be transferred between offices, the image information can be output on the display screen 3, and the entire content can be transferred between offices. It is extremely convenient as it allows you to check and easily save only the necessary information as a hard copy. Furthermore, if the display screen 3 is left blank, the copying machine 1 can be used for copying general documents, making it very useful as a multi-purpose office machine.

In fact, there are two types of liquid crystal display elements used as display screens: reflective type and transmissive type.Reflective type has a reflector placed on the back side of the liquid crystal display element, and transmissive type has a light source placed on the back side. However, both have the characteristic that they are difficult to see unless high contrast is obtained.

Even if the display has good contrast to the naked eye, if you try to copy the entire image on the liquid crystal display, the contrast will be insufficient and the copy will be very difficult to distinguish. There is a problem.

This is due to the low sensitivity of the photoreceptor of the copying machine.

[Purpose of the invention]

An object of the present invention is to completely prevent the copying from becoming difficult to distinguish when display copying is performed using display section sound.

Specifically, by using a reflective liquid crystal display element and changing the light leaf during copying or the primary position of the photosensitive drum between display copying and normal copying, we are able to achieve the optimum contrast level. The purpose is to make it possible to obtain a liquid crystal display.

Furthermore, when copying an image or text displayed on the display screen of a display device, since the sensitivity of the photosensitive drum is low, if the copy is made as is, the copy will have low contrast and become unclear.

It is an object of the present invention to prevent this occurrence of dots, as well as to completely prevent background fogging in copies and decreases in image density due to deterioration of the photoreceptor of the photoreceptor drum.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to FIG. FIG. 2 is a sectional view of the image processing device. Components that are the same as or equivalent to those in FIG.

The primary charger 7 places a charge of ->2 on the photosensitive drum 8, and the exposure lamp 9 and SELFOC lens array 10 charge it.
The image is exposed completely, and a latent image is completely formed on the photosensitive drum 8.

5? The entire image is copied using the charger 12. 13 is a cleaner, and 14 is a pre-exposure unit.

The blank paper is fed from the top of the manual feed tray 15 to the paper feed row 216.1.
7 into the copying machine 1. Register roller 18
．． At step 19, the toner image is transferred onto the copy paper by the transfer charger 12, which charges the toner image from the back side in time with the image. After that, the conveyor belt 20, the fixing roller 21.2
The image is fixed once and is ejected onto a paper tray 24 by a paper ejection roller 23.

25 is an electrometer that measures the potential on the photosensitive drum 8, and is connected to a circuit (not shown) that controls the α position on the photosensitive drum 8 to a specified level. A reflective plate 26 is provided on the back side of the display screen 3, that is, the transmissive liquid crystal display element 3, and is necessary to enhance the contrast of the liquid crystal.

With this configuration, when the screen display ends and copying begins, the characters and images displayed on the LCD will temporarily disappear, and the photosensitive drum corresponding to the black ground (bright area) will disappear. The potential on B is determined 611j by the electrometer 25. Then, the exposure lamp 9 is raised until the ground potential reaches a specified potential (potential at which the parafuge 2 rounds do not overlap on the copy).

Next, the potential of the primary charger 7 on the photosensitive drum 8 is changed so that the entire surface of the liquid crystal display is heated and the dark potential is specified, and this is repeated several times to create a gap between the light potential and the dark potential. Control is performed until the contrast converges to the specified value.

During this time, the document table 4 may be stationary or moving.

When this control is finished, the stored image 'c ll'
i.

By performing the copying operation 4 on the crystal display screen 3, a copy with sharp contrast and no background fog can be obtained.

After copying is completed, when using the copier again as a normal copier, the amount of light and the voltage applied to the primary charger 7 are returned to their original values. In addition, in the case of input without image memory, the dark or light potential is controlled using the leading or trailing edge of the image while the pressure plate, that is, the display device 2, is stopped (outside the image area). It's okay.

FIG. 3 shows a basic conceptual diagram of the display copy system according to the present invention.

This consists of a reflective liquid crystal panel 27 and a Sesef Ogg lens 2.
8. In combination with the light source 29, an image is formed on the photosensitive drum. The feature of this invention is that by using such a reflective liquid crystal display, the displayed image is temporarily erased to obtain the optimum image quality before copying the display part. Measure the potential (VL) ffi on the photoreceptor drum 30 corresponding to (bright area), and change the light fftk of the light source 29 (10G/V or fluorescent lamp) until the specified potential is reached. Na V r,
The bias potential and frequency are also changed at the same time until the value of is obtained.

Next, the entire surface of the liquid crystal display is heated, and the potential of the dark area (V l
The charger 31 (C, C
) changes the potential of This process is performed one after another to determine the appropriate charge amount, exposure amount, and negative bias value. 32 is a potential set. Note that the above control may be performed by forming both black and white patterns on the same surface. FIG. 4 shows an example of a reflective liquid crystal screw 27, which is characterized in that it also serves as a document holding plate for normal copying.

FIG. 5 shows a conceptual diagram of the control system according to the present invention.

In order to change the process conditions when switching between display copy and normal copy, light (fluorescent lamp or halogen lamp), high-voltage electric lamp, and frequency sound (hereinafter These controls are performed centrally using the MCU (called MCU).This is basically a PWM (curse width modulation) method,
The control of the number of pulses and the number of pulses rIJ is performed by a combination of internal pulses and programs in the MCU.The basic generation method for these is as shown in Fig. (referred to as tC)), and as shown in Figure 9, 0N(i
There is a method that completely changes the ratio (duty ratio) between n) and 0FF(tf). The former is mainly used to control light sources such as fluorescent lights.
The latter is used for controlling φ11 of the high voltage power supply and bias power supply. In FIG. 5, a fluorescent lamp is used as an example of a light source. Fluorescent lamps use a high frequency oscillation method to stabilize the amount of light and ensure linearity, and the basic oscillation of 20K14z is 211.
(Used as a chop cycle of Hz. High frequency output stabilized by PWM control oscillated by the MCU is generated on the secondary side of transformers H and T to emit light from the fluorescent lamp. Control the number of pulses during the chop cycle. It is possible to linearly vary the amount of emitted light.

The high-voltage power supplies C and C are similar to the principle of the fluorescent lamp described above.
M control, further rectifying the high frequency transformer, high voltage 't-;q
It is a DC-DC converter that generates energy. This is also PWM
The generated voltage can be increased or decreased by control.

The potential sensor 35 is obtained by amplifying the electrostatic potential by mechanically chopping the electric field using a ceramic vibrator. In recent years, a small electrostatic field chopper type potential sensor with good linearity has appeared and is now in practical use. This output is A/D converted and input to the MCU as a serial output.

The bias potential is controlled to an appropriate value by monitoring the values of the surface potentials V H and V L. Figure 6 is a curve showing the relationship between surface potential and image density during development (total thickness (UL)). Curve a tends to produce a hard-toned image, while curve b tends to produce a soft-toned image. This can be achieved by increasing or decreasing the resistance of the photosensitive drum 36 during image formation.

Another gradation switching method can be achieved by changing the thickness of the toner 37 coated on the developing surface.For example, when display copying, butterflies,
The bias voltage is set at 1600 VKt to make the coating thicker for high contrast development, and when copying normally, the bias voltage is lowered to 45 ov to make the toner coating thinner for soft contrast development (1);

In addition, in the case of the Jambi/G development method, high contrast development (800
~1600Hz), and soft expression 1M! (200~600H
z) can be selected.

In this example, as mentioned earlier, the internal counter of the MCU 34 is combined with the program data to perform PWM modulation.
It is characterized by switching bias voltage and frequency. Note that DgV varies by δ in the developing device.

FIG. 7 conceptually shows the structure of this invention.

It is connected to other computers and image processing equipment via a LAN (Local Area Network). In FIG. 7, a LAN interface is placed. The image memory is a memory that temporarily stores transmitted images. The printer controller and image scanner, as shown in the figure, are controllers for an electrostatographic imaging system. It is of course possible to copy with a normal copying machine (7). As mentioned above, in the present invention, the display uses a reflective liquid crystal, and in the case of normal copying, the background is illuminated. The color tone is matched to white so that it reflects and is used as a document holding plate, and in the case of display copying, the bias, amount of light, and amount of charge are controlled to achieve the optimal process conditions.This method was described earlier. .

In FIG. 7, a schematic diagram of the photoreceptor 38 is shown, and DI! JLI is developer, C,
C is a charging corona, T, C is a transfer corona, D.

C is a separation corona, 39 is a potential sensor, 40 is a self-oggling lens, and 41 is a cassette.

In this way, the present invention can adjust the amount of light for display copying and normal copying, and adjust the charging potential.

The development characteristics are switched by one frequency of the bias potential to control the gradation. This makes it possible to prevent fogging and the like and obtain an appropriate image.

〔Effect of the invention〕

As explained above, according to the present invention, the display screen is composed of several reflective types, and the image processing process, such as the light of the optical system or the primary potential of the photosensitive drum, is displayed on the entire liquid crystal display. Since the contrast can be changed from one moment to the next, a liquid crystal display with optimum contrast can be obtained during copying, and deterioration in image quality due to deterioration of the photosensitive drum can be avoided.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a conventional image processing device, FIG. 2 is a sectional view of an image processing device according to the present invention, FIG. 3 is a conceptual diagram of a display covey system A (D) according to the present invention, and FIG. 4 is a reflective liquid crystal A perspective view of the panel, FIG. 5 is a conceptual diagram of the control system of the present invention, FIG. 6 is a diagram showing the relationship between the surface potential of the photoreceptor drum and image density, and FIG. 7 is a detailed diagram of the configuration of the present invention. The illustrated figures, FIGS. 8 and 9, are diagrams for fully explaining the pulse modulation method. 1. Copying machine 2. Display screen 5. ......Computer T...Primary charger 8...Photosensitive drum 25...Potential potential I. Fig. 8 Figure 9

Claims (5)

[Claims] (1) Display copy 1 using a reflective liquid crystal panel
In the apparatus, the reflective liquid crystal panel forms at least a white or black pattern, detects an image processing condition based on the pattern, and controls an image processing process according to the detection output. Characteristic image processing device. (2) A patent characterized in that for a white pattern, the entire potential of the bright area corresponding to the background is measured, and at least the amount of flashing light or the developing bias is controlled in order to perform optimal image processing. An image processing apparatus according to claim 1''f14. (3) The black pattern is used to measure the potential of dark areas and control the high-voltage power supply in order to perform optimal image processing. Image processing device. (4) The image processing process includes at least the amount of light from the lamp, the developing bias, or the high-voltage power supply, which is controlled using an internal counter of the microcomputer/computer. The image processing device according to any one of Items 1 to 3. (5) The image processing device according to any one of claims 1 to 4, wherein the image processing device is capable of normal copying. .