JPS58186737A - Automatic exposure quantity controlling device of copying machine - Google Patents

Abstract

PURPOSE:To simplify the constitution and also to easily execute proper control of an exposure quantity, by photodetecting an exposure quantity of an exposure transmission drum by an original drawing paper transmittivity detecting sensor through an optical fiber, detecting the exposure transmissivity of original drawing paper, and operating a light shielding plate. CONSTITUTION:An original drawing paper insertion detecting circuit 17 converts a detecting signal for detecting the insertion of original drawing paper 1 by a photosensor 2, and uses it as a start signal. By this start signal, an original drawing paper exposure transmissivity detecting circuit 18 detects transmissivity by an exposure transmission degree of the original drawing paper 1 detected by a photosensor 4, and its signal is converted to a control signal through an amplifying circuit 19, a peak voltage detecting circuit 20, a holding circuit 21, a timing circuit 22 and a converting circuit 23. A main control part 15 transmits a forward or reverse pulse signal to a step-motor 6 in accordance with a deviation of the control signal, to a light shielding plate operating motor driving circuit 16, drives the step-motor 6 in the forward or reverse direction, and controls an exposure quantity of an exposure transmission drum 13 properly in accordance with the exposure transmittivity of the original drawing paper 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic exposure amount adjustment device for a copying machine that can automatically perform optimal printing on copy paper according to the exposure transparency of the original paper.

Conventionally, automatic exposure amount adjustment devices have been developed using methods such as detecting the light transmittance of the original paper and adjusting the copying speed of a copying machine by controlling the motor speed, or adjusting the light amount of an exposure lamp by voltage control. However, all of them had complicated configurations and were expensive.

In view of the above points, it is an object of the present invention to provide an automatic exposure amount adjustment device for a copying machine that eliminates the drawbacks of the prior art, has a simple mechanism, and easily achieves optimal control. .

According to the present invention, this purpose is achieved by: an original paper insertion detection sensor which is provided close to the original paper insertion slot of the copying machine and detects the insertion of the original paper; an optical fiber whose end is provided close to the rear of the original paper insertion detection sensor and near the original paper transport path and transmits exposure light from an exposure lamp built in the exposure transmission drum; an original paper exposure transmittance detection sensor that is provided opposite to the other end of the optical fiber and detects the transmittance of exposure light that passes through the inserted original paper; A control signal is transmitted to the light shielding plate operation motor in response to a detection signal from the light shielding plate operation 1 for rotatably operating the light shielding plate, and the exposure transmittance detection 7 to 7 for the original paper exposure transmittance detection, thereby exposing the exposure transmitting drum. and a regulating circuit for regulating the quantity.

Further, according to a preferred embodiment of the invention, the regulation circuit comprises:
It has one peak voltage detection circuit that detects the maximum transmittance of the exposure transmittance of the original paper as a peak voltage.

According to another preferred embodiment of the present invention, the adjustment circuit includes a timing circuit that calculates the timing from insertion to printing based on the detection signal of the original paper insertion detection sensor.

Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a schematic configuration diagram of an embodiment of the present invention.

In the figure, the original drawing paper l is carried in by an original drawing paper carrying rotary roller 8 provided near an original drawing paper insertion opening (not shown). Furthermore, this original paper l passes through an original paper transport path 11 in which rotating rollers 9 and 10 are arranged, and then passes through an exposure transmission drum 1.
Transported to 3. At this time, the original drawing paper 1 is
The photosensitive material is polymerized with copy paper (not shown) carried in through the exposure and transmission drum 13, and is printed on the copy paper. This exposure transmission drum 13 has an exposure lamp 7 and a light shielding plate 5 built therein. The light shielding plate operation motor 6 is a drive motor connected to the light shielding plate 5 and rotatably operating the light shielding plate 5, and is a step motor in this embodiment.

In addition, the original drawing paper insertion detection sensor, in this embodiment the photo sensor 2, is connected to the original drawing paper loading rotating roller 8 which is close to the original drawing paper insertion slot.
It detects that the original drawing sheet 1 has been inserted. The optical fiber 3 is made up of a large number of glass fibers, one end of which is installed close to the outer peripheral surface of the exposure-transmitting drum 13, and the other end is installed close to the rear of the photosensor 2 and near the original paper transport path 11. (The exposure lamp provided in the exposure transmitting drum 13 is installed in the exposure lamp 13 to effectively transmit the light) from one end of the fiber 3 to the other end. Furthermore, the original paper exposure transmittance detection sensor, in this embodiment the photo sensor 4, is connected to the original paper transport path 1.
1, opposite the other end of the original fiber 3,
The transmittance of exposure light passing through the original paper 1 passing between the other end of the optical fiber 3 and the photosensor 4 is detected.

The automatic exposure amount adjustment circuit 100 includes a human power signal section 14, a main control section 15, and a light shielding plate operation motor drive circuit 16. Human input signal section 14ilL, original paper insertion detection circuit 1
7. Consists of an original paper exposure transmittance detection circuit 18, an amplifier circuit 19, a peak voltage detection circuit 20, a hold circuit 21, a timing circuit 22, a conversion circuit 23, and ρ. this house,
The original drawing sheet insertion detection circuit 7 is a detection signal converter for detecting that the original drawing sheet 1 has been inserted into the photosensor 2.
This is used as a starting signal to the original paper malt light transmittance detection circuit 18.

Based on this activation signal, the original paper exposure/transmission single detection circuit 18 detects the transmittance based on the exposure transmittance of the original paper 1 detected by the photosensor 4, amplifies it in the amplifier circuit 19, and transmits it to the peak voltage detection circuit 20. do. Peak voltage detection circuit 2
0 detects the highest transmittance as a peak voltage among the transmittances of the original paper 1 while it is passing, and transmits it to the hold circuit 21.

The hold circuit 21it holds this peak voltage. The timing circuit 22 uses the held peak voltage to measure the timing from the insertion of the original paper 1 to the printing, and the conversion circuit 23 converts the human input signal into a control signal.

The main control unit 15 sends a necessary operation signal, in this embodiment, to the step motor 6, in accordance with the deviation of the control signal of the conversion circuit 23, which is the exposure transmittance of the original paper 1, with respect to the exposure of the fog light transmitting drum 1. The forward and reverse pulse signals of the light-shielding plate operation motor drive circuit 1
Send to 6. The light-shielding plate operation motor drive circuit 16 drives the step motor 6 forward and reverse within a required rotation range using forward and reverse pulse signals, and adjusts the appropriate exposure amount of the exposure transmitting drum 13 according to the exposure transmittance of the original drawing paper 1. However, proper printing on copy paper is effective. In this way, the exposure lamp 7
Since the optical fiber 3 that transmits the exposure amount of the exposure transmitting drum 13, including changes over time, is provided close to the original paper insertion detection sensor 2, the time from when the original paper 1 is inserted until it reaches the exposure transmitting drum 13 is It is possible to appropriately adjust the amount of exposure on the exposure-transmitting drum 13 using the light-shielding plate 5 within the time.

Furthermore, once the baking is completed, the timing circuit 22Fi,
It is turned off and the hold of the hold circuit 210 is released. The main control section 15 rotates the light shielding plate 5 in the direction of the exposure amount of the exposure transmission drum 13, stops it, and waits until the insertion of the first original paper 1.

Next, FIG. 2 shows a schematic configuration diagram of a light shielding plate operating motor.

In the diagram? The parts having the same functions as those in FIG. 1 are given the same reference numerals. The light-shielding plate operation motor (step motor) 6 has a rotation axis of this motor 6 and a light-shielding plate 50 rotation axis 2.
4 are connected by a joint 25 so as to be rotatable. In addition,
The step motor 6 is fixed to the main body of the copying machine by a fixing fitting 26.

As described above, according to the present invention, the exposure amount of the exposure transmission drum is transmitted through an optical fiber, and is received by the original paper exposure transmittance detection sensor provided near the original paper insertion slot. The structure is such that the exposure transmittance of the original paper passing between the fiber and the original paper exposure transmittance detection sensor is detected, and the light shielding plate is operated in consideration of the timing from inserting the original paper to printing. Although this is simple, it has the effect that appropriate adjustment of the amount of exposure falling on the exposure transmission drum can be easily achieved.

(7)

[Brief explanation of drawings]

(Main symbols shown in the figure) 1: Original paper, 2: Original paper insertion detection sensor, 3: Optical fiber, 4: Original paper exposure transmittance detection sensor, 5: Shield if, 6
: Step motor, 14: Input section, 15, Main control section, 1
6: Shade plate operation motor drive circuit, 20; Peak voltage detection circuit, 21: Hold circuit, 22: Timing circuit, 1
00: Automatic exposure adjustment circuit. Patent applicant Copia Co., Ltd. (8) Figure 1

Claims (1)

[Scope of Claims] (1) An original paper insertion detection sensor that is provided close to the original paper insertion slot of the copying machine and detects the insertion of the original paper; an optical fiber that is provided close to the rear of the original paper insertion detection sensor and near the original paper transport path and is capable of transmitting the amount of exposure on the exposure transmission drum; and the other end of the optical fiber that is connected through the original paper transport path. an original paper exposure transmittance detection sensor that is provided opposite to the original paper and detects the transmittance of exposure light that passes through the original paper; and a sensor that is connected to a light shielding plate built in the exposure transmission drum and that allows the light shielding plate to freely rotate. a control circuit for adjusting the amount of exposure on the exposure transmitting drum by transmitting a control signal to the light shielding plate operating motor according to a detection signal of the operating axis and the original paper exposure transmittance detection sensor; An automatic exposure amount adjustment device for a copying machine characterized by the following features: (2. In the description of claim 1, the adjustment circuit includes a peak voltage detection $1 circuit that detects the maximum transmittance of the exposure transmittance of the original paper as a peak voltage. (3) In the description of claim 1, it is stated that the adjustment circuit has a timing circuit that calculates the timing from insertion to printing based on the detection signal of the original paper insertion detection sensor. Features: Automatic exposure adjustment device for copying machines.