JPS58221838A - Method and device for displaying printing level of controller for automatic printing of diazo copying machine - Google Patents

Abstract

PURPOSE:To make the deflection of an indication meter constant, by prohibiting lighting or operation of a display means for the transmittance of light through an original while the transmittance of the light through the original is under detection and lighting all of the lighting elements under the lighting element corresponding to a printing level when the printing stage after the detection of the transmittance of the light through the original is attained. CONSTITUTION:The analog signals outputted from the comparators C1-CN of a detection circuit 40 for the transmittance of light through an original are applied to an analog/digital converter and a holding circuit 54 in the next stage. The digital signal corresponding to the optimum transmittance of the light through the original held in the 2nd circuit 54 is applied to a control circuit 64 for a display level and an encoder 56. The encoder 56 outputs the signal corresponding to the input signal. The circuit 64 which receives the control signal from a timing circuit 60 controls a display means for automatic printing level having plural lighting elements for displaying different levels respectively in accordance with the digital signal corresponding to the optimum transmittance of the light through the original applied from the 2nd circuit 54 and lights all of the lighting elements under the lighting element below the printing level. None of the lighting elements of the level display means 68 are thus not lighted while the transmittance of the light through the original is under detection.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printing level display method and apparatus for an automatic printing control device for a diazo copying machine.

Diazo copiers having automatic printing control functions as well as manual printing functions have been known for some time. As is well known, automatic printing control is effective for printing the "base" (the blank area) of the original.
The system detects the light transmittance of the document, controls the printing speed (conveying speed of the document and photosensitive paper) or the amount of light from the copying machine's light source, and automatically performs printing control corresponding to the document.

By the way, conventional diazo copiers with an automatic printing function are equipped with display means (such as a lamp) to indicate that automatic printing control has been switched to, as well as a meter to display the automatic printing level. is normal. The automatic printing level display means (level meter) is provided in consideration of convenience when manually copying the same type of original.

However, in the above-mentioned conventional example, an indicator meter with a pointer is used as the automatic printing level display means, so when the light transmittance of the document is being detected, the pointer of the meter is violently moved by the letters or pictures written on the document. In addition to the problem of being unsightly as it oscillates, there is also the drawback that even after switching to automatic burn-in control, the pointer of the meter that displays the burn-in level does not swing uniformly. Furthermore, since a separate display means is provided to indicate that the automatic printing control has been switched, there are problems such as design restrictions, complication of the manufacturing process, and an increase in the number of maintenance points.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a diazo copying machine having an automatic printing control function, in which an automatic printing level display means (i.e., a level meter for automatic printing level display) having a plurality of lighting elements is used to detect the light transmittance of an original. By turning on all the lighting elements below the lighting element corresponding to the burn-in level at the printing stage after detecting the light transmittance of the original, without turning on the light inside the original, the conventional drawback that the indicator meter fluctuation is not constant is solved. A method for displaying a burn level in an automatic burn control device for a diazo copying machine which does not have the drawbacks of the above-mentioned conventional example by removing the conventional display means and replacing the conventional display means that operates when automatic burn control is activated with an automatic burn level display means. and a display device.

Hereinafter, one embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a diagram showing parts of a general diazo copying machine related to the present invention, and FIG. 2 is a circuit diagram for explaining the present invention in detail. In FIG. 1, lO is the light source for exposure, 12
is a rotating cylinder glass (with a light source 10 inside)
As is well known, the conveyor belt rotates in contact with the cylinder glass 12, and the stacked document and photosensitive paper are transferred to the cylinder glass 12 by the conveyor belt.
The photosensitive paper is exposed to light while the photosensitive paper is transported along the outer surface of the paper. One end of the optical fiber 14, which is a light guiding means, is connected to a light source lO
It is provided on the outside or inside of the cylinder glass 12 in order to take in light from the cylinder glass 12, and the other end is provided on the photosensor 16 side. Reference numeral 18 denotes a document feed roller, 20 a document insertion detection sensor such as a microswitch or a photo sensor, 24 a photosensitive paper feed roller, 26 a printing section conveyance roller, 28 a driving motor of the copying machine, and 30 a part of a printing belt.

Next, the present invention will be explained in detail with reference to FIGS. 1 and 2. When the power switch of the copying machine is turned on, the light source 10 lights up and the drive motor 28 starts rotating at a predetermined speed.

When the light source reaches a steady state, when the original is inserted into the original insertion slot of the copying machine, the original insertion detection sensor 20 detects that the original has been inserted and outputs an insertion detection signal, and the original introduction roller 18 Transport the original into the copier.

When the leading edge of the document reaches between the optical fiber 14 and the photosensor 16, the document light transmittance detection circuit 40 (first circuit)
The light transmittance of the "ground" portion of the document is detected.

The original light transmittance detection circuit 40 includes, in addition to the photosensor 16,
An amplification transistor 42, an N (arbitrary integer) bond comparator Cl-CN, resistors RIA and RIB that apply a reference voltage to the inverting input terminal of the comparator C1, and a reference voltage to the inverting input terminal of the comparator C2. Applying resistors R2A, R2B11.11
6. Resistors R(N-1)A, R(N-1)B, and comparator C that apply a reference voltage to the inverting input terminal of comparator C(N-1).
Resistors RNA and R that apply a reference voltage to the inverting input terminal of N
NB, a resistor 50 provided between the photosensor 16 and the base of the transistor 42, and a resistor 52 provided between the collector of the transistor 42 and ground. and a resistor (no reference number) connected between each output terminal of the comparators 01 to CN and the positive voltage source element B. Note that the reference voltages applied to the inverting input terminals of the comparators 01 to CN are made to differ little by little in order to detect the light transmittance of the document based on the outputs of the comparators.

When light transmitted through the document conveyed between one end of the optical fiber 14 and the photosensor 16 reaches the photosensor 16, and a voltage proportional to the amount of light that has reached appears at the collector of the transistor 42, this collector voltage is applied to the comparator C1- applied to each non-inverting input of CN. Each of the comparators Cl-CN compares the voltages applied to the inverting and non-inverting input terminals, and if the voltage applied to the non-inverting input terminal is higher than the reference voltage applied to the inverting input terminal, r Outputs a "high" level signal. In other words, the output changes depending on the light transmittance of the original.
The number of comparators (CI-CN) that are at the "high" level is determined.

An analog signal output from the comparator C1-CN of the original light transmittance detection circuit 40 (the value of the analog signal is output from the comparator C1-CN)
(determined by how many "high" levels the output of CN reaches) is applied to the next stage analog/digital converter and holding circuit (second circuit) 54. The second circuit 54 receives the analog signal from the original light transmittance detection circuit 40, converts it into a corresponding digital signal, and holds the digital signal corresponding to the optimum original light transmittance. Here, the digital signal corresponding to the optimum original light transmittance is the highest signal among the outputs of the comparators C1 to CN (that is, the signal output corresponding to the part of the original with the highest light transmittance). This is a digital signal equivalent to . The digital signal corresponding to the optimum original light transmittance held in the second circuit 54 is transmitted to the display level control circuit 64.
and is applied to the encoder 56, and the encoder 56 outputs a signal corresponding to the input signal.

On the other hand, a signal output from the document insertion detection sensor 20 in response to the insertion of the document is applied to the document detection circuit 58, and the document detection circuit 58 detects that the document has been inserted. The output signals of the original detection circuit 58 are applied to the timing circuit 60, and the timing circuit 60 applies a control signal to the display level control circuit 64 and the latch circuit 62 after a predetermined period of time has elapsed. This refers to the time period from when the insertion of a document into the machine is detected until just before the drive motor 28 is controlled.

Note that the document insertion detection sensor 20, the document detection circuit 58, and the timing circuit 60 constitute a third circuit.

The display level control circuit 64 that receives the control signal from the timing circuit 60 controls a plurality of lighting elements that display different levels based on the digital signal applied from the second circuit 54 that corresponds to the optimum document light transmittance. control the automatic burn-in level display means having a burn-in level, and light up all the lighting elements below the lighting element corresponding to the burn-in level (in the illustrated example, the 8th and below). The number of lighting elements in the automatic burn level display means 68 is equal to the number of comparators in the original light transmittance detection circuit 40, and the burn level corresponds to the rotational speed of the controlled drive motor in this embodiment. do. It should be noted that during the detection of the light transmittance of the original, none of the lighting elements of the level display means 68 are turned on.On the other hand, the latch circuit 62 receiving the control signal from the timing circuit 60
The output signal of the encoder 56 is latched, and the latched signal is output to a D/A (digital/analog) conversion circuit 66.

The D/A conversion circuit 66 converts the digital signal from the latch circuit 62 into an analog signal and applies it to the drive motor speed control circuit 70. This control circuit 70 controls the rotational speed of the motor 28 based on the applied analog signal and performs automatic burning.

In the above explanation, automatic printing control is performed by controlling the rotational speed of the motor, but the present invention is of course not limited to this, and can also be applied to a method of controlling the amount of light from the light source 10. .

As described above, in the present invention, an automatic printing level display means is provided which has a plurality of lighting elements each displaying a different level, and this display means is not turned on or operated while the light transmittance of the original is being detected. At the printing stage after detecting the light transmittance of the original, all lighting elements below the lighting element corresponding to the burning level are lit, eliminating the drawback of inconsistent indicator meter fluctuation and eliminating the disadvantage of conventional automatic printing. By substituting the automatic printing level display means for the control changeover display means, it is possible to realize a diazo copying machine that is simple in construction and easy to operate.

[Brief explanation of the drawing]

FIG. 1 is a simple diagram of a diazo copying machine for explaining the present invention, and FIG. 2 is a circuit diagram showing an example of an NI control circuit used in the present invention. 40: Original light transmittance detection circuit (first circuit) 54: A
/D converter and holding circuit (second circuit) 62: Latch circuit 64: Display level control circuit 68: Automatic burn-in level display means Patent applicant Toshiaki Morisaki, agent of Copia Co., Ltd. Patent attorney Figure 1 4

Claims (2)

[Claims] (1) In a diazo copying machine with an automatic printing control function, the automatic printing level display means, which has a plurality of lighting elements each displaying a different level, is not turned on while the light transmittance of the original is being detected. A method for displaying a burn-in level in an automatic burn-in control device for a diazo copying machine, characterized in that at the burn-in stage after detection of burn-in level, all lighting elements below the lighting element corresponding to the burn-in level are lit. (2) In a diazo copying machine having an automatic printing control function, a first circuit outputs an analog signal corresponding to the light transmittance of the original, and a t! a display level control circuit connected to the display level control circuit; an automatic burn-in level display means connected to the display level control circuit and having a plurality of lighting elements each displaying a different level; and the first circuit connected to the first circuit. a second circuit that receives an analog signal from the second circuit, converts it into a digital signal, and holds the digital signal corresponding to the optimum original light transmittance; and a second circuit that receives the digital signal held by the second circuit and outputs a corresponding signal. an encoder, a third circuit that detects the insertion of a document into the copying machine and outputs a control signal when the printing stage is reached after detecting the light transmittance of the document; and a latch circuit for latching the output, and the display level control circuit operates all the lighting elements below the lighting element corresponding to the burn-in level when receiving the control signal. Burn-in level display device for burn-in control device.