JPH01269950A - Image forming device - Google Patents

Abstract

PURPOSE:To prevent copies taken by mistake by grasping image density information which is set automatically even at the time of automatic density mode by carrying out a density display of a manual density mode, equivalent to that density, even at the time of the automatic density mode selection. CONSTITUTION:The density of an original to be copied is read by an original density detecting means, concerning copying actions where the automatic density mode is set. Then based on the read original density, the most suitable image density for that original density is automatically judged from a ROM table, and the exposure condition and the developing condition are changed to change the image density. Even when the automatic density mode is selected here, a display of density judged based on the original density is displayed by a density display of a manual density mode equivalent to that density, that is the notch display by an LED 77 of a density display part 76. Thus a finished density can be assumed and grasped before the actual image formation, even at the time of the automatic density mode, preventing mistakenly taken copies.

Description

[Detailed description of the invention] Technical field The present invention relates to an image forming apparatus such as a copying machine.

2. Description of the Related Art Conventionally, some copying machines and the like are capable of freely selecting between an automatic density mode and a manual density mode for image density adjustment. That is, in the automatic density mode, the density of the document is read, an appropriate image density is determined from the density, and an image with the appropriate density is automatically obtained by varying exposure conditions, developing bias, etc. On the other hand, in the manual density mode, the operator specifies the desired density by operating the density selection keys (dark key and light key) on the operation panel as appropriate.Normally, there are seven notches, and the number of notches is selected. By operating each notch under preset image forming conditions, an image with a specified density is obtained.

However, in the conventional method, when the automatic density mode is selected, the image density can only be known from the image actually obtained by copying, and cannot be known before or during copying.

Furthermore, when the automatic density mode is selected, all notch displays and the like for manual density adjustment are also erased. In this way, although the automatic density mode copies copies at the automatic appropriate density corresponding to the density of the original, it does not necessarily result in copies with the density desired by the user, and may end up being too dark or too light. , I often copy again using manual density mode. In any case, there is no image density information in the automatic density mode, which is inconvenient.

Purpose The present invention has been made in view of the above points, and provides an image forming apparatus that can grasp automatically set image density information even in automatic density mode, and can prevent copy mistakes and the like. The purpose is to obtain.

Structure In order to achieve the above object, the present invention includes means for selecting and setting automatic density mode and manual density mode, image density changing means, original density reading means, and means for selecting original density reading means when automatic density mode is selected. A means for determining the image 11 degrees based on the density of the read document, and a density display means for displaying the density specified when the manual density mode is selected, are provided,
Further, the present invention is characterized in that a display control means is provided for displaying the concentration of the pro-eutectinized concentration when the automatic concentration mode is selected by displaying a concentration corresponding to the concentration when the manual concentration mode is selected.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

First, the general structure and operation of the copying machine will be explained with reference to FIG. The original 2 set on the contact glass 1 is exposed to light by the exposure lamp 3, and the reflected light from the original 2 is
An image is formed on the photoreceptor 12 via the three mirrors 4, 5, and 6, the imaging lens 7, the fourth to sixth lenses 8, 9, and 10, and the dustproof glass 11.

Second, the exposure lamp 3 and the first mirror 4 constitute a first scanner, which reciprocates in the left-right direction on the lower surface of the contact glass 1 at a predetermined speed. On the other hand, the second and third mirrors 5
, 6 constitute a second scanner, which moves in the same direction at half the speed of the first scanner. Further, these mirrors or imaging lenses 7 are moved to predetermined magnification positions by a magnification stepping motor 13 in accordance with the reduction/enlargement magnification.

Here, the photoreceptor 12 is uniformly charged by the charger 14, and an electrostatic latent image is formed on the photoreceptor 12 by being irradiated with the original image as described above. This electrostatic latent image is developed by a developing device 15 to become a visible image.

On the other hand, the transfer paper 16 is fed by paper feed rollers 18 or 19 from one of the lower cassettes 7 and 16, and is conveyed to the registration roller 21 jn via the conveyance roller 20. The photoreceptor 12 is transported toward the transfer position. At the transfer position, the visible image on the photoreceptor 12 is transferred to the transfer paper 16 by the action of the charger 22.
-Transferred to L. After the transfer, the transfer paper 16 is separated from the photoreceptor 12 by a separation claw 23 and is conveyed to a fixing roller 25 via a conveyance means 24. The transfer paper 16 fixed by the fixing roller 25 passes through a conveyance roller 26 and heads to an ejection system such as an ejection roller 27 . On the other hand, the surface of the photoreceptor 12 after the transfer is cleaned by a cleaning device 28.

Here, the copying machine of this embodiment is capable of double-sided copying and composite copying in which images are superimposed on the same transfer paper 16, and the transfer paper 16 on which one image has been formed is transferred to the image forming unit centered on the photoreceptor 12. Circulation path 29 for reintroducing conveyance to
is formed.

First, a conveying roller 30 is sunk in front of the ejecting roller 27, and a reversing guide 31 for reversing the transfer paper 16 during single-sided copying is provided. Switching between the discharge side and the reversal side or circulation side is performed by a branch pawl that is switched by a branch solenoid. The circulation path 29 is provided with a relay roller 33, a discharge roller 34, and -
The transfer paper 16 is first discharged onto the relay tray 35. This relay tray 35 is equipped with a jogger fence 36 that moves in the tray left and right directions (front and back of the paper surface), and the left and right widths of the ejected transfer sheets 16 are aligned. or,
A roller 37 made of a sponge or the like that can move vertically is provided on the relay tray 35, and is configured to align the leading edge of the ejected transfer paper 16 by abutting it against a leading edge aligning surface 38. This leading edge alignment surface 38 is set to be upwardly displaced by a tray lift solenoid (not shown) during paper refeeding. Refeeding of paper from the relay tray 35 is performed by a refeeding roller 39. The re-fed transfer paper 16 passes through the front of the cassette 17 and is conveyed to the registration rollers 21 by the conveyance rollers 20. Then, the registration rollers 21 convey the sheet to the transfer position again at a predetermined timing, and the sheet is used for double-sided copying or overlapping copying.

Here, in the circulation path 29, sensors for detecting and outputting signals for timing control etc. are provided, specifically, a fixing sheet discharge sensor 40, a discharge sensor 41, a relay sensor 42, a registration sensor 43, etc. . 44 is a main motor.

Next, FIG. 3 shows a control system block diagram of the copying machine of this embodiment. First, a main control section 50 that controls the entire system is provided. This main control section 50 includes a RAM 51 as a storage means, various solenoids 52 and various sensors 53.
is connected.

Also connected to the main control section 50 is an optical system control section 57 that exchanges data and controls the stepping motor 13, the scanner motor 54, a sensor 55 for detecting document density, which will be described later, and the like.

Furthermore, the exposure lamp 3, the fixing heater 58, the main motor 44. An AC control section 62 that controls the developing motor 59, the conveyance motor 60, the paper ejection motor 61, etc. is connected to the main control section 50. On the other hand, a display section 63 composed of an LED or an LCD and a switch section 64 composed of keys are connected to the main control section 50 via an operation control section 65.

Here, the operation panel 70 including the display section 63 and the switch section 64 is provided with switches, keys, etc. as shown in FIG. 1, a part of which is extracted.

First, the switch section 64 includes, in addition to the numeric keypad 71, an automatic density key 72 as a mode selection setting means, and a dark key 7.
3 and a light key 74 are provided.

In addition to the copy number display section 75-, the display section 63 is provided with a density display section 76 with seven notches from 1 to 7 in the manual density mode. This concentration display section 76
is provided with an LED 77 in each of the numerically corresponding parts of the notch display.

Here, the developing bias voltage VB and the exposure lamp voltage vL (the reference voltage is VO) for each notch 1 to 7 in the manual density mode are set in advance as shown in Table 1, and the ROM table etc. is stored in.

Next, the document density detection method required in this embodiment will be explained with reference to FIGS. 4 to 7. The copying machine of this embodiment is provided with document density reading means 80 for detecting the density of the document 2 in order to perform copying in automatic density mode (ADS mode). As shown in FIG. 4, this document density reading means 80 also uses the exposure lamp 3 for exposing the document as a light source, and introduces reflected light information from the document 2 through an inlet 81a of an optical fiber 81. The signal is output to a detection circuit including a sensor 55 using a phototransistor or the like.

More specifically, the optical fiber 81 receives the light reflected from the original 2 by the light irradiated onto the original 2 from the exposure lamp 3, and the light is received at the leading edge of the original (as shown in FIGS. 4 and 5).
Detect the position of distance Q, = mm from the original scale 82). This position is the home position of the optical fiber 81), and as the scanner moves from this position, the distance Q, = 38 m.
The concentration detection operation is performed for m minutes. The circle in FIG. 5 indicates a concentration detection spot, which has a diameter of about 10M.

The detected amount of received light is sent to the main control unit 50 side through the optical fiber 81, converted into voltage, and the maximum voltage value is read by the CPU. In other words, the voltage VDE (=
ADS data value) is used to correctly correct the developing bias (automatic density correction) to obtain a clear copy of the background area.

FIG. 6 is an explanatory diagram of the voltage VDH, and shows how the ADS input voltage changes as the detection time changes. Also,
The relationship between the reading voltage VDE by the CPU, the developing bias reference setting value vB, and the document density ○D is set as shown in FIG. This is the relationship with VoE & VB as shown in Table 2 (input voltage 3.07 hours), and also shows the corresponding notch in manual density mode. RO shown in this table 2
The contents of the M table are the main body of the means for automatically setting and determining the image density based on the original density.

In such a configuration, operation control centered on automatic density/manual density adjustment and its display according to this embodiment will be explained with reference to flowcharts shown in FIGS. 8 to 10.

First, Figure 8 shows the density adjustment keys (dark key 73, light key 74).
This shows the reception process for the manual density key. In this flow, the manual density set flag is used to check the fall of the density adjustment key. First, check whether the light key 74 or dark key 73 of the density adjustment keys has been pressed.
If any one is pressed, it is determined whether the mode is automatic density mode.

If it is in automatic density mode, cancel it and
Set to manual density mode. If the pressed key is the light key 74, each time the key 74 is pressed, the notch changes one step towards the lightest level, except when the lightest notch is 7.
Move them one by one to set and display. On the other hand, if the pressed key is the dark key 73, each time this key 73 is pressed, the notch is moved one by one to the darkest notch, unless the darkest notch is set to 1. Display (lighting display of the corresponding LED 77 of the vA degree display section 76).

In any case, in actual copying operations based on such manual density settings, the exposure lamp voltage VL and development bias voltage VB can be set to match the selected notch (
(See Table 1).

On the other hand, FIG. 9 shows the reception process of the automatic density key (ADS key) 72. In this flow, automatic concentration (AD
S) The set flag is for checking the fall of the automatic density key 72. First, it is checked whether the automatic density key 72 has been pressed. When this key 72 is pressed, the automatic density mode is set/cancelled alternately each time this key 72 is pressed, so first, if it is in the automatic density mode, cancel the automatic density mode. “
The message display 78 "Auto Density" is turned off), and the manual density is displayed in the center notch 4 on the density display section 76 (No, 4 LED 77 is turned on). If the automatic density mode is not selected, pressing this key 72 causes the automatic density mode to be set (turns on the message display 78 "Automatic density" shown in FIG. 1), and
The manual density on the density display section 76 is set as the display state of the center notch 4.

During a copy operation in which the automatic density mode is set, the density of the original 2 to be copied is read by the original density detection means 80, and based on the read original density, the main control unit 50 determines the optimum image density for the original density. is automatically determined from the ROM table as shown in Table 2, and the exposure conditions and development conditions are changed in order to change the image density. Specifically, based on the detected voltage VDH, the corresponding developing bias voltage VB is determined based on Table 2 or the like.

When copying in such an automatic density mode, conventionally, only a message 78 "Auto Density" is displayed on the operation panel 70, and the L on the density display section 76 is displayed.
All ED77s disappear. As a result, as mentioned above, when copying in automatic density mode, the density may not be adjusted properly and the result may be too dark or too light, and you may end up resetting to manual density mode and copying again. .

However, in this embodiment, even in the automatic density mode, the display of the density determined based on the original density is displayed as the density display in the manual density mode corresponding to the density, that is, the density display section 76. This is displayed as a notch display using the LED 77. The process for this is done in the first step.
This will be explained with reference to the flowchart shown in FIG. That is, in the automatic density mode, ADS data (voltage VDE data) is read, and the corresponding developing bias value vB and the manual density notch in the manual density mode corresponding to that density are determined. Based on

As a result, for example, in the case of VDE=1.50, the developing bias VB=44° is set, and it is equivalent to notch 6 in the manual density mode.
The LED 77 of the patient 6 in the concentration display section 76 lights up to display the concentration.

In this way, even in automatic density mode, the automatically set density is converted to the density in manual density mode and displayed, making it easier for the operator to estimate the final copy density before actually copying. can. As a result,
For example, if the notch is displayed as 7 and you think it is too light, you can reset it to a darker shade by operating the dark key 72. Conversely, the image density set in automatic density mode can be used as a factor in notch selection in manual density mode, reducing incorrect density settings.
Copy errors are reduced.

That is, in this embodiment, the processing shown in FIGS. 9 and 10 constitutes the content of the display control means.

Effect As described above, even when the automatic density mode is selected, the present invention provides
The density determined based on the original density is displayed using the density display in manual density mode that corresponds to that density, so even if the automatic density mode is set, the actual image formation will be difficult. It is possible to estimate the finished density in advance, and if it seems that the density is not appropriate, it is possible to take measures such as adjusting the density before actual image formation.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is a plan view of the operation panel, Fig. 2 is a side view showing the schematic configuration, Fig. 3 is a block diagram of the control system, and Fig. 4 is a document density detection mechanism. 5 is a plan view showing its detection area, FIG. 6 is a voltage characteristic diagram showing the original density detection operation, and FIG. 7 is a voltage characteristic diagram showing the voltage VDE-
Relationship diagram between voltage VB and original density OD, Figures 8 to 1
Figure 0 is a flowchart. 2... Original, 72, 73. 74... Mode selection setting means, 76... Density display means, 80... Original density reading means Applicant Ricoh Co., Ltd. -, ¥), L
J-Figure J35

Claims (1)

[Claims] means for selecting and setting automatic density mode and manual density mode; image density changing means; original density reading means; and means for determining image density from the original density read by the original density reading means when automatic density mode is selected. and a density display means for displaying the density specified when the manual density mode is selected, and a density display means for displaying the density determined when the automatic density mode is selected and corresponding to the density in the manual density mode. An image forming apparatus comprising a display control means for displaying density.