JPH01118859A - Image forming device - Google Patents

Abstract

PURPOSE:To correct deviation from a real density value by setting a proper density obtained from a set density value in case of performing copying in a past manual exposing state as a density at the time of switching to the manual exposing state. CONSTITUTION:The title device is provided with a storage means 53 for storing the set density value in case of finally forming an image with copying density set by a manual exposing function and a control means 51 which obtains the proper density from the set density value stored in the storage means 53 so as to set the density with the obtained proper density at the time of switching from an automatic exposing state to a manual exposing state. The proper density is obtained from the set density value at the time when copying is performed in the past manual exposing state and the obtained proper density is set as the density in case of switching to the manual exposing state. Thus, the deviation from the real density value can be corrected.

Description

[Detailed Description of the Invention] [Objective of the Invention] (Industrial Application Field) This invention provides an automatic exposure function that automatically sets the copy density according to the density of the original, and an automatic exposure function that automatically sets the copy density according to the density of the original. It has a manual exposure function that allows you to manually set the density.
The present invention relates to an image forming apparatus such as an electronic copying machine that includes an exposure means that automatically sets a predetermined copy density when switching from an automatic exposure state to a manual exposure state.

(Prior Art) Generally, electronic copying machines have an automatic exposure function that automatically sets the copy density according to the density of the original, and an automatic exposure function that manually sets the copy density according to the density of the original. An exposure device having an exposure (manual exposure) function is provided.

In this type of copying machine, for example, as shown in FIG. 6, the automatic exposure mode (automatic exposure state) is set by operating the automatic exposure button A, and the automatic exposure display A1
is now lit. In addition, if the top or bottom of manual exposure button B ("Ting" or "Dark" key) is operated in this automatic exposure mode, automatic exposure will be canceled and the mode will automatically switch to standard manual exposure mode (predetermined copy density). It is now set to . That is, when switching from automatic exposure mode to manual exposure mode (manual exposure state), the manual exposure mode is automatically set to "4" and the manual exposure indicator B4 is lit. There is something.

When copying in manual exposure mode in a copying machine equipped with such an exposure device, when switching from automatic exposure mode to manual exposure mode, the predetermined copy density (standard manual exposure mode - "4" in manual exposure mode) is always maintained. Therefore, exposure adjustment and other settings often deviate from the actual density value, resulting in the resulting copied image being either light or dark. Therefore, it is necessary to search for the appropriate density while repeating copying, such as by operating the manual exposure button B, resetting the copying density, and redoing the copying. Therefore, there are disadvantages in that many unnecessary copies are made and the operation is time consuming.

(Problems to be Solved by the Invention) In this invention, when switching from automatic exposure mode to manual exposure mode, a predetermined copy density is always set, so copying is repeated until the appropriate density is achieved. This was done to eliminate the disadvantages of having to manually expose a large number of unnecessary duplicated images and taking a long time to operate.It is possible to reduce unnecessary duplicated images caused by copying under manual exposure conditions. Another object of the present invention is to provide an image forming apparatus that can shorten operation time by preventing unnecessary operations.

[Structure of the Invention] (Means for Solving the Problems) The image forming apparatus of the present invention has an automatic exposure function that automatically sets the copy density according to the density of the original, and an automatic exposure function that automatically sets the copy density according to the density of the original. an image forming apparatus that has a manual exposure function for manually setting the copy density using an exposure means that automatically sets the copy density to a predetermined copy density when the automatic exposure state is switched to the manual exposure state. , a storage means for storing a set density value when an image is finally formed according to the copy density set by the manual exposure function; The control means determines an appropriate density from the set density values stored in the memory, and sets the density based on the determined appropriate density.

(Operation) This invention calculates the appropriate density from the setting density value when copying was performed in the past manual exposure state, and sets the density using the determined appropriate density when switching to the manual exposure state. By doing so, the deviation from the actual density value is corrected.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIGS. 2 and 3 schematically show an image forming apparatus of the present invention, such as an electronic copying machine. That is, 1 is a main body of a copying machine, and a document table (transparent glass) 2 is fixed to the upper surface of the main body 1 to support a document. This document table 2 is provided with a fixed scale 21 that serves as a reference for setting the document, and furthermore, a document cover 1 that can be opened and closed is provided near the document table 2.

The original placed on the document table 2 is moved back and forth by an optical system consisting of an exposure lamp 4, mirrors 5, 6.7 reciprocating along the lower surface of the document table 2 in the direction of arrow a. It is designed to be exposed and scanned at times. In this case, mirror 6.7 moves at half the speed of mirror 5 so as to maintain the optical path length. After the light reflected from the original by the scanning of the optical system, that is, the light reflected from the original by the light irradiation of the exposure lamp 4 is reflected by the mirrors 5, 6.7,
It passes through the variable magnification lens block 8 and then the mirror 9. ．． 9
2.93 and guided to the photoreceptor drum 10, and an image of the document is formed on the surface of the photoreceptor drum 10.

The photosensitive drum 10 rotates in the direction indicated by the arrow in the figure, and the surface is first charged by the charging device 11, and then,
By subjecting the image to slit exposure at the exposure portion ph, an electrostatic latent image is formed on the surface.

This electrostatic latent image is made visible by applying toner by the developing device 12.

On the other hand, sheets of paper (material to be transferred) are taken out one by one from the selected upper paper feed cassette 130 or lower paper feed cassette 132 by the feed rollers 141, 142 and the roller pair 15z, 152, and are taken out one by one by the paper guide path 16. ．． 162, and is guided to a pair of registration rollers 17, and guided to a transfer section by this pair of registration rollers 17.

Here, the paper feed cassette 13. ．． 132 is removably provided at the lower right end of the main body 1, and either one can be selected on the operation panel described later. Further, the cassette size of each of the paper feed cassettes 131 and 132 is detected by cassette size detection switches 601 and 602, respectively. The cassette size detection switches 601 and 602 are composed of a plurality of microswitches that are turned on and off according to the insertion of cassettes of different sizes.

Furthermore, a manual feed guide 13a is provided on the upper surface of the paper feed cassette 131.
The paper manually inserted through the feed roller 14a
According to the roller pair 15. After that, the paper feed cassette 13. It is designed to be conveyed in the same way as paper that is fed from scratch.

The paper sent to the transfer section comes into close contact with the surface of the photoreceptor drum 10 at the transfer charger 18, and the toner image on the photoreceptor drum 1° is transferred by the action of the charger 18. The transferred paper P is electrostatically peeled off from the photoreceptor drum 10 by the action of the peeling charger 19 and conveyed by the conveyor belt 2o, and then transferred to the fixing roller 21 as a fixing device provided at the end of the conveyor belt 2o. The transferred image is fixed by passing through this area. After fixing, the paper is discharged to a tray 25 outside the main body 1 by a pair of delivery rollers 22.

Further, the residual toner on the surface of the photosensitive drum 10 after the transfer is removed by a cleaner 26, and the residual image is erased by a static elimination lamp 27, so that the photosensitive drum 10 returns to its initial state. Note that 29 is a cooling fan for preventing the temperature inside the main body 1 from rising. Further, the exposure lamp 4,
The mirror 5 is provided on the first carriage 411, and the mirror 6
．． 7 is provided in the second carriage 412.

FIG. 4 shows the main body 11 of the copying machine; the operation panel 30 provided thereon. The operation panel 30 includes a copy key 3081 for commanding the start of copying, a numeric keypad 30b for setting the number of copies, a display section 30c1 for displaying the operating status of each section, paper jams, etc., and a density setting section 30d1 for setting the copy density. A magnification setting key 30e1 for setting the copy magnification in a predetermined relationship; a zoom key 30f for steplessly setting the copy magnification;
, an upper magnification display section 30g1 that displays the set magnification.

Lower paper feed cassette 13. ．． Paper feed selection key 3 to be operated when selecting paper feeding from 132 or manual feeding
0h etc. are provided.

The density setting section 30d includes an automatic exposure button 30t for automatically setting the copy density to an appropriate value, and an automatic exposure display 30j for displaying automatic exposure settings.

This manual exposure button 3 is operated when you want to increase or decrease the copy density.
7 levels (the thinnest manual exposure mode "1")
” to the darkest manual exposure mode “7”).
1 to 307 are provided.

FIG. 5 shows the main parts of the control circuit. That is,
The control section 51 performs overall control of the copying machine main body 1, and includes operation switches 52 such as various keys on the operation panel 30, the display section 30c1, the memory 53, and the exposure lamp 4. In addition to the lamp regulator 54 as an exposure lamp control circuit that controls the lighting and light amount of
7, a cleaner 26, a pair of fixing rollers 21, and the like are connected, as well as a motor control unit for controlling various motors (not shown), and by controlling these, the above-described copying operation is performed.

In the memory 53, density setting data (setting density value) when an image is finally formed in the manual exposure mode is stored for each copy.

Therefore, when automatic exposure is set by operating the automatic exposure button 30i of the density setting section 30d provided on the operation panel 30, the control section 51 controls the automatic exposure display 30j.
At the same time, during copying, the lamp regulator 54 is controlled to apply a voltage value to the exposure lamp 4 according to the amount of light reflected from the document.

Further, when manual exposure is set by operating the manual exposure button 30 of the density setting unit 30d, the control unit 51 reads past density setting data stored in the memory 53 to determine the appropriate density, and determines the appropriate density. The manual exposure indicators 301 to 307 corresponding to the density are lit, and at the time of copying, the lamp regulator 54 is controlled to apply a voltage value to the exposure lamp 4 according to the position of the lit manual exposure indicator. It has become. In this case, the control unit 51 selects the same data that is present the most from a data group excluding the darkest data and the lightest data among the data read from the memory 53, or averages the data groups. The appropriate concentration is determined through statistical processing.

As a result, for example, if copying is often done in manual exposure mode "2", when the manual exposure button 30k is operated, manual exposure mode "2" is used.
”, and the manual exposure display 302 is lit.

Note that storage in the memory 53 is performed by operating the copy key 30a on the operation panel 3°, and only the density setting data when an image is formed at the appropriate density is stored. . In this case, if only a predetermined number of data is stored by rewriting with the oldest data, a predetermined number of new data will always be stored in the memory 53. Therefore, memory 53
It is possible to reduce the capacity, reduce processing time, and obtain an appropriate concentration that approximates the actual concentration value.

Next, the operation of the above configuration will be explained with reference to the flowchart shown in FIG. For example, when the copying machine main body 1 is in a ready state (copyable state) and the control section 51 is in a state where it is possible to receive input from various operation switches 52 provided on the operation panel 30, the density setting section It is assumed that the manual exposure button 30k of the camera 30d is operated. Then, as shown in FIG. 1(a), the automatic exposure is canceled and the automatic exposure display 30j is turned off.
Manual exposure mode is set instead.

In this case, the control section 51 reads the density setting data stored in the memory 53 to determine the appropriate density, and lights up the manual exposure indicator corresponding to the determined appropriate density. In other words, manual exposure button 30k
When is operated, the density is automatically set to the density that was often set during past copying.

Further, when the manual exposure button 30k is not operated, the automatic exposure mode is set and the automatic exposure display 30j is turned on.

Further, after the magnification setting key 30e and the like on the operation panel 30 have been operated as necessary, it is determined whether the copy key 30a has been operated. If it is determined that the copy key 30a is not operated, the copying machine main body 1 is maintained in the ready state.

On the other hand, when it is determined that the copy key 30a on the operation panel 30 has been operated, the above-described copying operation is performed as shown in FIG. 1(b). In this case, the automatic exposure button 30
When automatic exposure is set by the operation i, the copying operation is performed at an appropriate density according to the amount of light reflected from the original. That is, in the case of automatic exposure, the lamp regulator 5
4, the exposure lamp 4 is turned on with an applied voltage value that corresponds to the amount of light reflected from the original, thereby forming an image with an appropriate density that corresponds to the density of the original.

Further, when manual exposure is set by operating the manual exposure button 30, the copying operation is performed according to the appropriate density value determined from the density setting data. That is, in the case of manual exposure, the appropriate density value (density setting data) determined from the density setting data is stored in the memory 53, and the exposure lamp 4 is turned on by the lamp regulator 54 at an applied voltage value corresponding to the above-mentioned appropriate density value. As a result, an image is formed with a density that corresponds to the position of the manual exposure indicator that is in the lit state. This allows smooth copying with proper exposure.

In this way, when switching to manual exposure, the density that is likely to be set (density that is often copied)
By setting in advance, the possibility that the first copy in manual exposure will be made with appropriate density increases. Therefore, if, for example, it is not possible to obtain a copy image with the proper density by automatic exposure due to a deviation in exposure adjustment, dirt on the charger, deterioration of the photoreceptor drum, etc., or a copy image with the proper density cannot be obtained with automatic exposure. This is particularly effective when copying originals with a specific background color frequently.

As mentioned above, the appropriate density is calculated from the set density value when copying was performed in the past manual exposure state,
By setting the determined appropriate density when switching to the manual exposure state, the deviation from the actual density value is corrected.

In other words, the appropriate density (density setting data) when copying using manual exposure in the past is memorized, and the appropriate density (in this case, the density that is most likely to be set or the most frequently set) is stored. By determining the density that has been set, the appropriate density is automatically set when switching to manual exposure. As a result, for documents that are frequently copied, the first copy by manual exposure can be smoothly performed with a density close to the actual density value.

Therefore, it is possible to reduce unnecessary operations such as repeating copying until the appropriate density is achieved each time copying is performed by manual exposure or each time the operator changes. Therefore, it is possible to reduce unnecessary copies of images caused by copying operations associated with unnecessary operations, and to shorten operation time by preventing unnecessary operations.

Especially when it is not possible to obtain a copy image with the proper density with automatic exposure due to misalignment of exposure adjustment, dirt on the charging device, deterioration of the photoreceptor drum 10, etc., or when a copy image with the proper density cannot be obtained with automatic exposure. This is useful when you frequently copy originals with a background color of

In the above embodiment, the density was set by changing the exposure amount of the exposure lamp, but this is not limited to this, and there are other factors that affect the image density, such as the charging voltage of the charging device and the transfer voltage. It can also be applied to methods performed by changing the transfer voltage of a charger.

It goes without saying that various other modifications can be made without departing from the gist of the invention.

[Effects of the Invention] As described in detail above, according to the present invention, it is possible to reduce unnecessary copied images caused by copying in a state of manual exposure, and to shorten operation time by preventing unnecessary operations. It is possible to provide an image forming apparatus that can perform

[Brief explanation of the drawing]

Fig. 1 is a flow chart shown to explain the operation of an electronic copying machine which is an embodiment of the present invention, Fig. 2 is an external perspective view schematically showing the copying machine, and Fig. 3 shows the configuration of the copying machine. FIG. 4 is a side sectional view, FIG. 4 is a plan view showing the operation panel, FIG. 5 is a block diagram showing the main parts of the electric circuit, and FIG. 6 is a diagram for explaining the prior art and its problems. 1... Copying machine main body, 4... Exposure lamp, 10...
Photosensitive drum, 11...Charging device, 30...Operation panel, 30a...Copy key, 30d...Density setting section, 30i...Automatic exposure button, 30j...Automatic exposure display device, 30k...manual exposure button, 30
1-307...Manual exposure display, 51...Control unit, 53...Memory, 54...Lamp regulator. Applicant's agent Patent attorney Takehiko Suzue (a) Figure 1

Claims (2)

[Claims] (1) Equipped with an automatic exposure function that automatically sets the copy density according to the density of the original, and a manual exposure function that manually sets the copy density according to the density of the original, and allows manual exposure from the automatic exposure state. In an image forming apparatus equipped with an exposure means that automatically sets a predetermined copy density when the state is switched to the above state, the setting when an image is finally formed using the copy density set by the manual exposure function. A storage means for storing density values, and when the automatic exposure state is switched to the manual exposure state, an appropriate density is determined from the set density value stored in the storage means, and the density setting is determined based on the determined appropriate density. An image forming apparatus characterized by comprising a control means for controlling the image forming apparatus. (2) The image forming apparatus according to claim 1, wherein the control means sets the appropriate density to a copy density that is frequently used in a manual exposure state.