JPH0291664A - Copying machine - Google Patents

Abstract

PURPOSE:To enable a sure setting of an user's desired density level by making the copying action stop once when EE mode is released and changed to manual mode, during continuous copying in the EE mode. CONSTITUTION:In an EE mode, the density of a document D is read by a sensor 1, in the vicinity of the main lens 15, and based on this result, a bias circuit 4 is controlled by CPU 3, and developing bias voltage, by which the copy is made an appropriate density, is pressed on a developing sleeve 18. Then, when the EE mode is changed to the manual mode by traveling the selection knob 6 during a continuous copying, the copying action is stopped once. Therefore, the copying action is started again by pushing the copying button after selecting the desired density level.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrophotographic apparatus having a copy density selection section capable of switching between a manual density selection mode and an automatic density selection mode using one slide volume. The present invention relates to a type of copying apparatus.

[Conventional technology]

Conventionally, in an electrophotographic copying apparatus having a copy density selection section that can switch between a manual density selection mode and an automatic density selection mode by adjusting the slide volume of 1111, the slide volume provided on the operation panel is When the selection knob fixed to the volume slider is positioned at the lower end of its movement range, automatic density selection mode (hereinafter referred to as EE) is activated.
mode), and by moving it upward from the lower end, it can be switched to a manual density selection mode (hereinafter referred to as manual mode).

When copying is performed in EE mode, the automatic density selection function works and automatically selects the appropriate density level, and the development bias voltage or exposure amount of the scanning optical system corresponding to that density level is adjusted continuously or stepwise. It was controlled to maintain an appropriate copy density (toner image density). In the manual mode, the voltage taken out changes depending on the position of the slide volume selection knob, and that voltage is input to the analog port of the CPU in the copying machine to set the density level of the copy, and the density level corresponding to that density level is set. The developing bias voltage, the exposure amount of the scanning optical system, etc. are controlled and determined.

FIG. 3 is a diagram showing an example of the arrangement of copy density selection sections on the operation panel of a conventional copying apparatus.

In the figure, 6 is a selection knob fixed to the slider of the slide volume, 6a is an index provided on the top surface of the selection knob 6, and 7 is, for example, seven density level marks 7a and an EE mark 7b indicating the EE mode. But, select knob 6
The density display sections 9 are arranged in parallel along the movement path, and 9 is a hole in the operation panel 8 so that the connecting section between the selection knob 6 and the slider of the slide volume can be moved through the operation panel 8. It is a long time.

When the selection knob 6 is at the lowest position, it is EE mode.
When the selection knob 6 is slightly raised, the mode becomes manual mode. The density level in manual mode is normal when the index 6a is located at the center of the manual mode range, and at the lowest end of the manual mode range, for example, the developing bias voltage is low and the copy density is high (high density). ), and at the top end, for example, the developing bias voltage is high and the copy density becomes light (density is small).

Further, in the conventional method, even if the density selection mode is changed during continuous copying, the copying operation continues without interruption.

[Problem to be solved by the invention]

As mentioned above, in conventional copying machines, when the selection knob 6 is moved during continuous copying in the EE mode to change the mode from the EE mode to the manual mode by 4, the density level is changed to the darkest level and copying is not continued. Ta.

Therefore, if you change to manual mode in order to slightly change the copy density while a large number of copies are being made continuously in the EE mode, for example with a level near the normal level selected, the density level will be different from the previous one. transition to widely separated maximum concentration levels. The problem is that copying continues without interruption even while the operator selects an appropriate density level, resulting in defective copies with inappropriate density levels being made until the appropriate density level is set. There was a point. The same problem occurs even when the order of the density levels determined by the position of the selection knob 6 is reversed and the EE mode is switched to the minimum density of the manual mode.

In the EE mode, the density of the document is detected and set to an average appropriate density level, so the density is frequently changed slightly depending on the user's preference, and this problem is important.

SUMMARY OF THE INVENTION An object of the present invention is to provide a copying apparatus that solves these problems and prevents defective copies from occurring.

[Means to solve the problem]

The above object is to provide an EE mode in a copying apparatus having a copy density selection unit that can switch between manual mode and EE mode using one slide volume, while continuous copying is being performed in the EE mode. This is achieved by a copying apparatus characterized in that when the mode is released, the copying operation is stopped without continuing the subsequent copying.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of essential parts showing the configuration of an embodiment of the present invention.

First, an overview of the copying operation of the copying apparatus of the present invention will be explained with reference to FIG.

At the top of the main body of the copying machine, there is a document tray 31 made of a transparent glass plate or the like, and a scale plate 32 for specifying the placement position according to the size of the document tray. A cover 33 is provided. An exposure lamp 1 is located below the document table 31 and inside the main body of the copying machine.
1 and the first mirror 12.
A second mirror unit 26 consisting of a second mirror 13 and a third mirror 14 is provided. The first mirror unit 25 is mounted parallel to the document tray 31 and movable in a straight line in the horizontal direction in the drawing, and scans the entire surface of the document tray while illuminating it with the exposure lamp 11. The second mirror unit 26 moves linearly parallel to the document table 31 and in the horizontal direction of the drawing at 1/2 the speed of the first mirror unit 25, so that the optical path length from the document surface to the main lens 15 is a constant length. It is designed to be held in The reflected light from the document tray on the document table 31 is reflected by the first mirror 12 , the second mirror 13 , and the third mirror 14 , and further passes through the main lens 15 and the fourth mirror 16 and onto the photosensitive drum 10 through the slit 17 .
is projected through. When the scanning is finished, the first mirror unit 25 and the second mirror unit 26 return to their original positions.
Wait until next copy.

The photosensitive drum IO rotates clockwise as shown by the arrow at the same time when copying is started by pressing a copy button (not shown), and is uniformly charged by the charging electrode 23, so that the optical image from the scanning optical system is According to the projection, an electrostatic latent image corresponding to the original is formed on the photoreceptor drum IO. This electrostatic latent image is developed into a visible toner image by a developing sleeve 18 of a developing device 19 supplied with a developing bias voltage determined by the control of the CPU 3 via a bias circuit 4.

From a cassette 24 that accommodates a large number of recording papers P, the recording papers P are fed out one by one by a first paper feed roller 41. This fed-out recording paper P is sent onto the photoreceptor drum IO by the second paper feed roller 42 which operates in synchronization with the toner image on the photoreceptor drum IO. and transfer pole 27
The recording paper P onto which the toner image on the photoreceptor drum 10 has been transferred is further transferred to the photoreceptor drum 10 by the separation pole 28.
After the paper is separated from the paper, it is sent to the fixing device 29 by a conveyance means, where it is fixed and discharged as a copy. Meanwhile, the photosensitive drum 10 continues to rotate, is cleaned by the cleaning device 30, and is prepared for the next copy.

The above cycle is repeated to perform continuous copying.

Next, the selection and setting of the copy density level upon copying as described above will be explained.

In FIG. 1, reference numeral 5 denotes a copy density selection section consisting of a slide volume VR and a selection knob 6 connected to its slider. The arrangement of the copy density selection section 5 on the operation panel 8 is the same as that of the conventional example shown in FIG. 3, so a detailed explanation will be omitted.

A voltage of 5V is applied to one terminal of the slide volume VR from a DC constant voltage device, and the other terminals are grounded, so as the selection knob 6 is moved, the voltage changes from 0 to 5V.
voltage can be input to the analog port of the CPU 3. Depending on the magnitude of this input voltage, the CPU 3 switches between the EE mode and the manual mode, and sets the copy density in the manual mode.

FIG. 2 is a graph showing an example of the relationship between the input voltage, mode selection, and developing bias voltage.

As shown in Figure 2, when the input voltage is 0 to 0.5V, the CPU
3 is the EE mode state, and when the input voltage exceeds 0.5V, the CPU 3 is switched to the manual mode state.

In the case of the EE mode where the input voltage is 0.5V or less, the density of the document is read by a sensor l provided near the main lens 15, for example, and compared with the reference voltage by the judgment circuit 2, and based on the result. CPU3 is bias circuit 4
A developing bias voltage is applied to the developing sleeve 18 so that the copy has an appropriate density.

If you move the selection knob 6 so that the input voltage exceeds 0.5V, the state will switch from EE mode to manual mode, and if you move the selection knob 6 further to the desired density level, the input voltage will change according to that position. Occurred C
Input to PU3. Then, CPU3 uses bias circuit 4
is controlled by $, and a developing bias voltage corresponding to the input voltage shown in FIG. 82 is applied to the developing sleeve 18 to perform copying.

The copying apparatus of the present invention is configured such that when switching from the HE mode to the manual mode by moving the selection knob 6 during continuous copying, the copying operation is temporarily stopped. Therefore, the copying operation will not resume unless the copy button is pressed again after selecting the desired density level.

In the embodiment described above, when the selection knob 6 moves in the vertical direction in the figure and is located at the lowest end, the selection knob 6 is in the EE mode;
Although the case has been described in which the lightest density level is set in manual mode when it is located at the top end, the moving direction of the selection knob 6, the mode switching point, and the order of selected density levels are not limited to this. do not have.

The density display section 7 shown in FIG. 3 is made of a transparent or semi-transparent plate material with a mark printed thereon, and is configured to have a light emitting element on the back surface, so that the density level in the selected manual mode can be adjusted. It goes without saying that the mark and the mark corresponding to the density level automatically selected in the EE mode can be illuminated and displayed by lighting the light emitting element behind it.

〔Effect of the invention〕

As explained above, in the present invention, if the EE mode is canceled during continuous copying in the EE mode and the mode is changed to the manual mode, the copying operation is temporarily stopped, so the user can make sure to set the desired density level before copying. will be able to resume.

Therefore, it is possible to provide a copying apparatus that does not wastefully make defective copies.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of essential parts showing the configuration of an embodiment of the present invention, and 2vlJ shows the relationship between the input voltage from the copy density selection section to the CPU, mode selection, and developing bias voltage in the copying apparatus of the present invention. A graph showing an example, and FIG. 3 is a diagram showing an example of the arrangement of copy density selection sections on the operation panel of a conventional copying apparatus. l...Sensor 2...Judgment circuit 3.
...CPU 4...Bias circuit 5
...Copy density selection section 6...Selection knob 6a
...Indicator 7...Concentration display section 7a.
...Density level mark 7b...EE mark 8...
・Operation panel 9...Long lO...Photoconductor drum 15...Main lens 18...Developing sleeve 19...Developing device 25...First
Mirror unit 26...Second mirror unit 27...Transfer pole 2
8...Separation pole 29...Fixing device 3
0...Cleaning device 31...Original table D.
・・Manuscript P・Recording paper VR・・Slide volume 2nd figure

Claims (1)

[Claims] In a copying apparatus having a copy density selection section capable of switching between a manual density selection mode and an automatic density selection mode using one slide volume, when continuous copying is being performed in the automatic density selection mode,
A copying apparatus characterized in that when an automatic density selection mode is canceled, the copying operation is stopped without continuing the subsequent copying.