JPS63312838A - Method and apparatus for preventing lack of ink in printing step - Google Patents

Abstract

PURPOSE:To prevent an improper product by providing a pressurized fluid supply device at a detection nozzle attached to the front face of a squeegee, and providing an alarm unit operated in response to the extension of the detected nozzle end from an ink reservoir, thereby generating an alarm before the ink lacks. CONSTITUTION:A detection nozzle 12 of a pneumatic sensor type fine level switch 10 is attached to the front face of a squeegee 3, pneumatic pressure of approx. 1-2mm of water column is acted at the end of the nozzle 12, and the end of the nozzle 12 is submerged several mm in an ink reservoir 4. Then, when the surface level of the reservoir 4 drops so that the end of the nozzle 12 is opened, the switch 10 is operated to actuate an alarm unit. A predetermined process is conducted by this alarm before the ink actually lacks.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for preventing ink running out in a screen printing process.

[Prior art J] As is well known, screen printing is a process in which a screen made of gauze or other material is stretched around a frame.1 Usually, it is a photographic method, and the image is printed by using a squeegee to pass the screen through the screen surface using a squeegee. This refers to a method of printing by extruding ink.

The squeegee used for screen printing is formed by sandwiching a long and thin rubber plate between wooden or metal holders, and by sliding it under pressure on the screen, the ink contained in the formwork is squeezed onto the screen in one print area. [Print by extruding from step 1 into the object to be printed.

The angle formed between the tip of the rubber plate and the screen, the hardness of the rubber, the sliding speed, the pressure, etc. affect the amount of ink extruded. In a steady printing state, an ink puddle with a height of, for example, about 20 mm is formed between the tip of the squeegee and the screen.

[The dark problem that IJJ is trying to solve] In the above-mentioned screen printing, if the ink supply is insufficient for the ink consumption, the ink pool in front of the squeegee will decrease and eventually reach zero. Ink runs out, resulting in defective printing.

Currently, the machine is stopped after running out of ink.
, increase the ink supply amount and start m4t.

However, this method produces large number of defective products.

An object of the present invention is to eliminate the above-mentioned drawbacks, provide a method and device for preventing ink running out in screen printing, and prevent ink running out before it actually occurs. The purpose is to generate f4i etc. and prevent the production of defective products.

[Means and operations for solving the problem] The outline of the present invention for achieving the object described in L is to detect the drop in the liquid level of the ink reservoir formed on the front surface of the squeegee, and to detect the actual ink shortage. An alarm system is activated when the ink is used to prevent defective products from being produced due to running out of ink.

According to an embodiment of the present invention, one to two
Apply air pressure equivalent to a water column, attach the detection nozzle to a squeegee, and place the tip into the ink reservoir to the required depth. When the liquid level in the ink reservoir drops and the detection nozzle tip opens, the switch is activated! ! Activate the alarm device.

This automatically activates the warning system when the level of the ink reservoir drops, making it possible to take necessary measures before ink exhaustion actually occurs.

[Example] Embodiments and drawings illustrating the present invention will be described.

FIG. 1 shows an outline of the present invention, and shows a frame 1 with a substrate (not shown).
A squeegee 3 moves the screen plate 2 of 1 by a sliding mechanism (not shown) to Ff! ! move. Slanted squeegee 3
In a steady state, an ink puddle 4 with a height of about 2 cm is formed at the lower front end of the ink tank.

According to the present invention, two detection nozzles 12 of the fine level switch 10 are attached to the front of the squeegee 3, and the tips of the detection nozzles 12 are buried several millimeters into the ink reservoir 4.
A required signal is generated when both detection nozzles 12 are inside the ink reservoir 4, and an alarm signal is generated when at least one detection nozzle 12 is outside the ink reservoir 4.

The fine level switch is the source of pressurized air or nitrogen 1
4 to 0.1 to 0.3 kg/c layer 2 pressure and fluid P, S
The P and I boats 18 are supplied to the boat 16 and detected by the nozzle 1.
2, the pressurized fluid of 1 to 3 layers of water is supplied to the nozzle 12.
Supply to the tip of the

FIG. 2 shows the pneumatic circuit of the fine level switch 10, from the pressurized air source 14 to the pressure regulator 20, air filter 22, and so on. The pressurized chamber % of the vagina 2 of 0.1 to 0.3 kg/c is supplied to the P and S boats 16 of the fine level switch 10 via the micro switch 24 and the precision pressure regulator 26.

Pressurized air is sent to the detection nozzle 12 from the conduit 18 in the form of about 1 to 3 μm water column. Since the ink is viscous, the moment when the tip of the detection nozzle 12 hits the ink reservoir 4 is accurately detected.

That is, when the tip of the detection nozzle 12 is in the ink, the microswitch COM of the fine level switch 10,
There is continuity between the No contacts. One or both detection nozzles 12
When the ink comes out of the ink reservoir 4, the micro switch COM
, NOJg points are closed.

This on/off is used to activate an alarm circuit to detect a drop in the level of the ink reservoir 4 and notify the operator that the ink supply amount should be increased before the ink runs out.

Although the configuration described above uses air pressure to detect a drop in the level of the ink reservoir 4, other means for detecting a drop in the level may also be used.

[Effects of the Invention] As clarified above, by detecting the drop in the level of the ink puddle formed in front of the squeegee in screen printing due to "Missing 1", an alarm signal can be issued before the ink actually runs out. 1. When receiving and running out of ink. (<
Solved the problem of defective products.

[Brief explanation of the drawing]

Figure 1 is a conceptual diagram of a device to prevent ink running out in the screen printing process according to an example of unreleased IJI.
FIG. 3 is a fluid circuit diagram of a fine level switch used in the device shown in the figure. l... Frame 2... Screen plate 3... Squeegee 4... Ink reservoir 10... Fine level switch 12... Detection nozzle 14... Pressurized air source 16... P, S Boat 18...P-I port 20...Pressure regulator 22...Air filter 24...Micro alessa 26...Precision pressure regulator Fig. 2

Claims (2)

[Claims] (1) In a printing process that forms an ink pool on the upstream side of a plate such as screen printing, a drop in the level of the ink pool is detected and an alarm is generated in response to the level drop. How to prevent cuts. (2) A screen printing machine is equipped with a screen that serves as a printing plate and a squeegee that slides on the screen, and when an ink pool is formed between the front surface of the squeegee and the plate during operation, a screen is installed on the front of the squeegee 3. at least one detection nozzle 12 and a device 1 for supplying pressurized fluid to the detection nozzle;
1. A device for preventing ink running out in a printing process, characterized in that it comprises: an alarm device which is activated in response to the tip of a detection nozzle 12 coming out of an ink well 4;