SU113366A1 - The method of controlling the thickness of the ink layer on prints in printing and the device for implementing this method - Google Patents

Description

The printing process in modern printing industry is carried out at high speeds, at which it is not possible to visually control the thickness of the ink layer on prints in a visual way. At the same time, objective methods and devices for semi-automatic or automatic control of the amount of ink on the printing of monochrome and multicolor printed products are not known.

Thus, the thickness of the ink layer on the prints during printing is practically not controlled, which reduces the quality of the prints.

The proposed method eliminates this drawback and allows automatic control of the thickness of the paint layer on the prints and thus increase the quality of the products.

The essence of the method is that the thickness of the ink layer is determined by measuring the amount of light reflected from the marks on the prints and the light transmitted, in order to increase

Accuracy of control, through the light filter in color, complementary to the color of the paint.

To implement this method, a photovoltaic device is proposed which is made by a bridge circuit with a photocell included in the shoulder. A three-position polarized relay is included in the diagonal of the device circuit, when the thickness of the paint layer deviates from the specified one of the two available relays with an open time delay proportional to the magnitude of the mismatch that the warning lamps (green or red) switch on for a sufficiently long time to observe, indicating insufficient or excessive thickness of the atom paint.

To increase the duration of flashes of signal lamps, a polarized relay coil is shunted by capacitance.

A diagram of the device, explaining its construction and operation, is shown in the drawing.

On the rotating printing cylinder / there is an impression, the check mark 2 of which (or the place of the pattern chosen by the printer) is illuminated by the light source 3. The reflected light beam from the mark passes through the light filter in color, in addition to the color of the ink, and gets on the photocell 4, the photocurrent of which is enhanced using a bridge amplifying circuit. The amplified photocurrent is directed to the winding 5 of the three-position polarized relay 6.

The amplifier circuit is adjusted in such a way that with a normal amount of ink on the mark 2, the current in the winding 5 is equal to n) and the relay does not work. When the thickness of the paint layer deviates from the predetermined amount of reflected light, it also changes (increases or decreases), which causes the relay to operate and contacts 7 or 8 close. As a result, the red warning light 9 lights up indicating an excess of ink on the print, or green 10 signaling insufficient paint.

Since the viewing time of mark 2 is very insignificant, for a longer glow of signal lamps, relays 11–12 s are used. circuits A and B, which provide the necessary time for visual observation of the lamp burning time.

In order to increase the duration of flashes of signal lamps, another form of embodiment of the device can be used. The winding of the relay 6 is shunted by a large capacitance. The time delay of the flashes of the lamps is provided directly by the relay 6. In this case, the signal lamps 9 and 10 are directly connected to the circuit of contacts 7 and 8.

To turn the device on and off, use pattern 13 and pins 14 and J5. During the passage

marks 2 under the photocell 4, when the printing cylinder 1 rotates, contacts 14 and 15, which slide along the pattern 13 (having a length equal to the length of mark 2), turn on the device and turn it off when the mark leaves the photo field.

The described device can be included in an automatic adjustment scheme that automatically maintains the required thickness of the ink layer on the print.

The device can be used to control one-color and multi-color printing.

Subject invention

Claims (3)

1. A method of controlling the thickness of the ink layer on prints when printing, in that the thickness of the ink layer is determined by measuring the amount of light reflected from the marks on the prints and passed through to improve the accuracy of control through the light filter to the color of the ink. 2. A photoelectric device for carrying out the method according to claim I, made according to a bridge circuit with a photocell included in the arm, characterized in that the diagonal of the circuit includes a three-position polarized relay that, when the thickness of the paint layer deviates from the given one, one of the two relays in the device time delay for opening, proportional to the magnitude of the error, respectively, including the warning lamps (green or red) long enough for visual observation, marking edostatochnuyu or excess paint layer thickness. 3. The form of the device according to claim 2, characterized in that, in order to increase the duration of the flashes of signal lamps, the winding of the polarized relay is shunted by the capacitance.