JPS595235A - Automatic printing control device in diazo type copying machine - Google Patents

Abstract

PURPOSE:To improve the accuracy in control with less constituting parts by detecting the transmittance of an original as an analogical change in voltage, holding the peak voltage of said voltage and selecting the speed characteristics of a driving motor with respect to the transmittance of the original. CONSTITUTION:When an original is inserted in a conveying path 3 for the original, the transmittance of the original is continuously detected with a detection circuit 23 and is converted to an analogical voltage. The voltage is higher as the transmittance of the original is higher; the highest peak voltage thereof is held in a peak holding circuit 24. A changeover circuit 26 for the speed control side of a driving motor changes over a driving motor 15, which is kept run at a constant speed by the timing of a timing circuit 25, to the speed control side for the driving motor. The peak voltage held therein is fed to a control circuit 27 for the speed of the driving motor as a control signal thereof, by which the motor 15 is controlled of speed automatically and a copying machine 1 is operated under the automatic printing control. The photosensitive paper and original conveyed in a conveying path 8 for the original are conveyed superposedly in tight contact with each other and the paper is printed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic printing control device for a diazo copying machine that detects the degree of transparency of a document and controls the drive motor speed or amount of printing light corresponding to the degree of transparency.

Generally, when a copying machine detects the transparency of the original and uses an automatic printing control device, this transparency is digitally divided and detected, and automatic printing is controlled. There is a method to do this. However, although the digital method produces less noise and stabilizes control results, it is complex and expensive. On the other hand, the analog method has the disadvantage that it tends to contain noise (and it is difficult to stabilize the control results).

In view of these conventional problems, the present invention effectively solves the problems, and provides an automatic printing control device for a diazo copying machine that has fewer component parts (is easier to manufacture, and has improved control accuracy). The purpose is to provide.

According to the present invention, this purpose is achieved by: a document transparency detection section that detects the transparency of an inserted document; a document transparency detection circuit that detects the transparency as an analog voltage change; A peak hold circuit that detects and holds the highest peak voltage among voltage changes, and a speed characteristic of a drive motor for transporting the original and the photosensitive paper that is brought into close contact with the original to the printing unit are determined by the transmission of the original. This is achieved by adjusting the drive motor speed control circuit and selecting the drive motor speed control circuit to obtain the optimum copy density depending on the printing density.

According to another embodiment, a document transparency detection section that detects the transparency of the inserted document, a document transparency detection circuit that detects the transparency as an analog voltage change, and a document transparency detection section that detects the transparency of the inserted document; A peak hold circuit detects and holds the highest peak voltage among voltage changes, and the printing light amount characteristics that are printed on the photosensitive paper that overlaps and adheres to the original document can be used to obtain the optimum copy density according to the transparency of the original document. and a printing light amount control circuit that selects the amount of light as shown in FIG.

Next, one embodiment of the present invention will be described in detail based on the drawings.

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

In the figure, the diazo copying machine 1 mainly includes a printing material section 2, a document insertion roller 4 installed in a document conveyance path 3, a document insertion detection sensor 5, a document transparency detection section 6, and a document feeding section 90-7.
, a photosensitive paper feed roller 9 provided in the photosensitive paper conveyance path 8, a VA+Ji feed roller'' 110, a conveyor belt 11, a printing material end detection sensor 12, a photosensitive paper feed roller 13,
Original photosensitive paper separation belt 14 and these rollers 5, 7
, 9, 10, 13, and a drive motor 15 that drives the bell) 11, 14'. The baking section 2 includes a baking drum 16 and a light source lamp 1 built into this baking material tram 16.
7, a reflecting plate 18, etc. Further, the original insertion detection sensor 5 and the printing completion detection sensor 12 are, for example, microswitches or photosensors. Original transparency detection section 6 Fi Optical fiber 19 Parallel Original transparency detection sensor, for example, a photo sensor 2 degree The photo sensor 20 faces the photo sensor 2o through the photo sensor 2o, and the amount of light from the surface of the printing drum 16 is irradiated onto the photo sensor 2o.

Therefore, even though the light intensity of the -C1 light source lamp 17 changes due to changes over time, the transmittance of the original is measured in accordance with this change.
Appropriate automatic burn control is always possible.

The conveyor belt 11 is provided to rotate the printing drum 16 so that the original and the photosensitive paper pass through the printing section 2 smoothly. Note that the photosensitive paper feed roller 13 is connected to the printing section 2.
After passing through the document/photosensitive paper separating belt 14, the photosensitive paper is separated and sent to a developing section (not shown).

Further, the automatic burn-in control device is the drive motor speed control device 21 in this embodiment. This speed control device 21 includes a document insertion detection circuit 22, a document transparency detection circuit 23, a peak hold circuit 24, a timing circuit 25, a drive motor speed control side switching circuit 26, a drive motor speed control circuit 27, a printing end detection circuit 28, It is comprised of a peak hold release circuit 29, a drive motor speed constant speed side switching circuit 30, and a drive motor constant speed rotation circuit 31.

The functions and functions of the present invention configured as described above will be explained.

When the copier NC power is turned on and a document is inserted, 111
The document insertion roller 4 transports the document to the document insertion detection sensor 5, and the document insertion detection circuit 22Fi detects that the document has been inserted. Next, the document is conveyed to the document transparency detection section 6, and the document transparency detection circuit 23 continuously detects the transparency of the document passing through the document transparency detection section 6 and converts it into an analog voltage.

This voltage is higher as the transparency of the original is higher, and as the original advances, it is sent to the peak hold circuit 24 as needed to detect and hold the voltage at the point where the transparency of the original is the best. The timing circuit 25 calculates the timing until the leading edge of the document detected by the document insertion detection sensor 5 enters the printing section 2 . Drive motor speed control side switching circuit 26
According to the timing of the timing circuit 25, the drive motor I5, which was rotating at a constant speed, is switched to the drive motor speed control side. Here, the held peak voltage is used as a control signal for the drive motor speed control circuit 270 to automatically control the speed of the drive motor 15. Due to this automatic speed control pressure, the copying machine 1 enters the automatic printing control state, and the original is brought into close contact with the photosensitive paper conveyed by the photosensitive paper conveyance roller 9 via the multi-photosensitive paper conveyance path 8, and then transferred to the printing conveyance roller 210g and conveyed. It is conveyed to the printing section 2 through the bell) 11, where it is printed.

Note that when the printing is completed and the trailing edge of the photosensitive paper passes the printing completion detection sensor 12, the printing completion detection circuit 2
8 works. Due to the operation of the burn-in end detection circuit 28, the peak hold release circuit 29 is activated by the peak bold circuit 2.
The bold capacitor No. 4 is discharged to release the hold state. At the same time, the drive motor speed constant speed side switching circuit 30
1) The drive motor speed control circuit 27 is switched to the drive motor foot speed rotation circuit 31 pressure, the drive motor 15 which had been under automatic speed control is returned to constant speed rotation, and the automatic seizure control state is canceled.

Next, FIG. 2 shows a drive motor speed characteristic diagram with respect to the transparency of the original. In the figure, in order to ensure that the printing density of the photosensitive paper, that is, the copy density is always correct, the relationship between the transparency of the original, that is, the transparency voltage detected by the original transparency detection circuit 23, and the drive motor speed is selected. do. Normally, this relationship is not a linear proportional relationship, but a quadratic relationship, and varies depending on the photosensitive wavelength of the original transparency detection sensor 20, the method of the original transparency detection circuit 23, and other characteristics. Based on this selection, the drive motor speed control circuit 27 is configured to control the speed of the drive motor 15 based on the drive motor speed characteristic depending on the transparency of the document.

As described above, according to the present invention, there is provided a document transparency detection circuit that detects the transparency of the document as an analog voltage change, and a document transparency detection circuit that detects and holds the highest peak voltage among the analog voltage changes. A peak hold circuit to
The speed characteristics of the drive motor are optimized according to the transparency of the original7.
．． C copy density obtained) 7. By providing a drive motor speed control circuit selected so that 1) The speed is controlled by selecting the speed characteristic of the drive motor.The voltage is detected with high sensitivity and the voltage of the electric circuit is
When the Ft structure is used, the number of parts used is reduced, and the accuracy of automatic baking fbi control is further improved compared to the digital method, providing stable speed control.

/:1: An embodiment of the present invention is an automatic firing control device based on the speed control of a drive motor, which will be described below.
．． For those limited to 7e (, printing f for the transparency of the original:
A similar effect can be obtained by selecting the characteristics of the J light and creating an automatic printing material control device that automatically controls the amount of printing light.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention, and FIG. 2 is a drive motor speed characteristic line 1 with respect to the transparency of an original. l: Copying machine, 2: Baking ladle section, 5: Original insertion detection sensor, 6
: Original transparency detection section, 12: Burning completion detection sensor, 22
: Original insertion detection circuit, 23 2 Original transparency detection circuit, 24
: Peak hold circuit, 26: Drive motor speed control side switching circuit, 27: Drive motor speed control circuit, 30: Drive motor speed constant speed side switching circuit, 31: Drive motor constant speed rotation circuit. Patent applicant: Copia Co., Ltd. No. 2

Claims (2)

[Claims] (1) A document transparency detection section that detects the transparency of the inserted document, a document transparency detection circuit that detects the transparency as an analog voltage change, and the highest peak of the analog voltage changes. The speed characteristics of a peak hold circuit that detects and holds the voltage, and a drive motor for conveying the original and the photosensitive paper with which the original is in close contact with each other to the printing section are optimized according to the transparency of the original. What is claimed is: 1. An automatic printing control device for a diazo type photographing machine, characterized by comprising a drive motor speed control circuit selected so as to obtain a copy density. (2) A document transparency detection unit that detects the transparency of the inserted document, a document transparency detection circuit that detects the transparency t as an analog voltage change, and the highest peak of the analog voltage change. A peak hold circuit that detects and holds the voltage, and a printing light amount characteristic that prints on the photosensitive paper that is superimposed and adhered to the original are selected to be 5 to obtain the optimum copy density corresponding to the transparency of the original. An automatic printing control device for a diazo copying machine, characterized by comprising a light amount control circuit.