JPH0287173A - Copying device - Google Patents

Abstract

PURPOSE:To prevent the occurrence of defective copies by not continuing successive copying but temporarily stopping a coping action when an EE mode where continuous copying is performed is released. CONSTITUTION:When density selection buttons 8 and 9 are depressed during continuous copying in the automatic density selection mode (EE mode) to release the EE mode, a manual density selection mode is set. Then, a CPU 3 temporarily stops the copying action. After an operator sets his desired density level, he depresses a copying button to resume the copying action. To set the EE mode, an EE mode button 5 is depressed. Thus, since copying can be resumed after an appropriate density level is set, defective copying is not performed uselessly.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrophotographic copying apparatus having a manual density setting section and an automatic density selection mode.

(Prior Art) Conventionally, in an electrophotographic copying apparatus having a manual density selection mode and an automatic density selection mode, when copying is performed in the automatic density selection mode, the automatic density selection function operates and the development bias is The voltage, the exposure amount of the scanning optical system, etc. are controlled continuously or stepwise to maintain an appropriate copy density (toner image density).

In the manual density selection mode, for example, seven density selection levels from 1 to 7 are provided, and the developing bias voltage or exposure amount of the scanning optical system corresponding to each level is set. I'm trying to choose one.

In any of the above cases, the set density level is generally displayed on the density level display section of the operation panel.

FIG. 2 is a diagram showing an example of a density level display section and a density selection button, which are the manual density setting section of the operation panel of a conventional copying machine, and FIG. 3 is an example of the relationship between the density selection level and the developing bias voltage. This is a graph showing.

In the figure, 7 is a density level display section in which seven marks are arranged side by side, and a light emitting element provided on the back side of the mark at a position corresponding to the selected density level lights up to display the selected density level. It looks like this. Reference numeral 8.9 is a density selection button, and by pressing density selection button 8 or 9, the automatic density selection mode is switched to manual. Furthermore, each time the density selection button 8 is pressed, the density level can be shifted to a lighter level by one step, and each time the density selection button 9 is pressed, the density level can be shifted to a darker direction by one step. It looks like this.

As for the density selection level, level 4 is normal (standard), levels 5 to 7 have high developing bias voltage and copy density is light (low density), and levels 1 to 3 have low developing bias voltage and copy density is low. The concentration is increased (density hole).

FIG. 4 is a plan view showing changes in the density level display section in a conventional copying apparatus when automatic density selection mode (hereinafter referred to as EE mode) is canceled and changed to manual density selection mode.

In conventional copying machines, when the density selection button 8 or 9 is pressed to cancel the EE mode and change to the manual density selection mode, the density selection level is generally changed to normal level 4, and continuous copying is performed. In general, even if the EE mode is canceled during copying, copying continues without interruption.

[Problem to be solved by the invention]

In the conventional copying apparatus, when changing from the EE mode to the manual density selection mode as described above, the density level shifts to the normal level as shown in FIG.

Therefore, in the middle of continuous copying of a large number of sheets when a level of 1 or near 7 is selected in the EE mode (level 7 in FIG. 4), density selection is performed to slightly change the copy density. When button 8 or 9 is pressed to change to manual density selection mode, the density level shifts to normal level 4, which is far different from the previous EE mode (level 7 in this example). Since copies are made continuously while the operator selects an appropriate density level, there is a problem in that defective copies are made until the appropriate density level is set.

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 purpose is to provide a copying apparatus having a manual density setting section and an automatic density selection mode, in which when the EE mode is canceled during continuous copying in the EE mode, the copying machine does not continue copying and performs -H copying. This is achieved by a copying machine that is characterized by stopping its operation.

〔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.

An overview of the copying operation of the copying apparatus will be explained with reference to FIG.

At the top of the main body of the copying apparatus, there is a document table 31 made of a transparent glass plate or the like. ! : There is a scale plate 32 for specifying the placement position according to the size of the document tray, and a document cover 33 that covers the document tray placed on the document table 31 is also provided. A first mirror unit 25 consisting of an exposure lamp lf and a first mirror 12, and a second mirror unit 26 consisting of a second mirror 13 and a third mirror 14 are provided below the document table 31 and within the main body of the copying apparatus. It is being The first mirror unit 25 is mounted parallel to the original platen 31 and movable in a straight line in the horizontal direction in the drawing, and scans the entire surface of the original plate 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 a speed of 172 times that of the first mirror unit 25, and maintains the optical path length from the document surface to the main lens 15 at a constant length. It is supposed to be done. 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 then passes through the main lens 15 and the fourth mirror 16 to the slit 17 onto the photoreceptor drum IO. is projected through. When scanning is completed, the first mirror unit 25 and the second mirror unit 26 return to their original positions and wait until the next copy.

The photoreceptor drum IO rotates clockwise as shown by the arrow at the same time as copying starts, and is charged by the charging electrode 23, so the original is printed on the photoreceptor drum IO according to the light image projected from the scanning optical system. An electrostatic latent image corresponding to the image is formed. 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 fed onto the photosensitive drum 10 by a second paper feed roller 42 that operates in synchronization with the toner image on the photosensitive drum 10. 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.

During the above copying, the copy density is set as follows. - As an example, a case will be described with reference to FIG. 1 in which seven density levels from 1 to 7 (4 in the center is the normal level) can be selected.

The density level display section and the density selection button are the same as those shown in FIG. 2, so a description thereof will be omitted.

In FIG. 1, numeral 5 is an EE mode button (not provided in some cases) provided on the operation panel, and numeral 8.9 is the density selection button shown in FIG. If you press the EE mode button 5 or do not press the concentration selection buttons 8 and 9, the CP
The EE mode selection signal is input to U3, and the CPU 3 enters the EE mode state.

When the manual density selection button 8.9 is pressed, a manual density selection signal is input to the CPU 3, and the CPU 3 enters the manual density selection state.

In the case of the EE mode, for example, the density of the document is read by a sensor l provided near the main lens 15, and the judgment circuit 2 compares and judges the density with a reference voltage.Based on the result, the CPU 3 controls the bias circuit 4. Then, a developing bias voltage of an appropriate density level is applied to the developing sleeve 18, and a mark at a position corresponding to the selected level on the density level display section 7 is lit up to perform copying.

When the density selection button 8 or 9 is pressed to enter the manual density selection mode, first, normal level 4 is selected and the mark in the center of the density level display section 4 is displayed lit. Next, when the density selection button 8 or 9' is pressed to move the display to a desired level, the CPU 3 controls the bias circuit 4 to apply a developing bias to the developing sleeve 18 corresponding to the selected density level. Apply voltage.

In the present invention, when the density selection button 8 or 9 is pressed during continuous copying in the EE mode to cancel the EE mode and enter the manual density selection mode, the CPU 3 temporarily stops the copying operation. The copying operation is resumed only after the operator sets the desired density level and presses the copy button.

Note that even if the EE mode is configured to be set by pressing the EE mode button 5, unless the EE mode button 5 is omitted and the density selection button 8 or 9 is pressed, the EE mode will not be set.
There is no problem even if the configuration is such that the E mode is maintained.

〔Effect of the invention〕

As explained above, in the present invention, when the EE mode is canceled and the manual density selection mode is entered during continuous copying in the EE mode, the copying operation is temporarily stopped, so the density level is changed during the stop. You can choose.

Therefore, since copying can be restarted after setting an appropriate density level, 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 main parts showing the configuration of an embodiment of the present invention, and FIG. 2 is a diagram illustrating the density level display section and density selection button, which are the manual density setting section of the operating paddle, in a conventional copying machine. FIG. 3 is a graph showing an example of the relationship between density selection level and developing bias voltage. FIG. 4 is a graph showing an example of the relationship between density selection level and developing bias voltage. FIG. 6 is a diagram showing changes in a density level display section. l...Sensor 2...Judgment circuit 3...
・CPU 4...Bias circuit 5...
・EE mode button 7... Density level display section 8.9... Density selection button 10... Photosensitive drum 15... Main lens 1
8...Developing sleeve 19...Developing device 25
...First mirror unit

Claims (1)

[Claims] In a copying apparatus having a manual density setting section and an automatic density selection mode, if the automatic density selection mode is canceled during continuous copying in the automatic density selection mode, subsequent copies are continued. A copying apparatus characterized in that a copying operation is temporarily stopped without stopping.