JP2564072B2 - Device for measuring layer thickness of liquid, especially layer thickness of dampening agent on plate surface of offset printing machine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring the layer thickness of a liquid, particularly the layer thickness of a dampening agent on the surface of a plate of an offset printing machine , and more particularly to the radiation absorbing band of the dampening agent. of
For devices equipped with a transmitter that radiates microwaves at frequencies
I do.

[0002]

2. Description of the Prior Art In order to obtain good print quality, it is important to adjust the amount of dampening agent on the plate surface of a printing machine to a completely defined amount. Depending on the amount of dampening agent supplied, a corresponding layer thickness of dampening agent is produced. If the dampening agent layer thickness was measured from various parameters such as temperature, printing speed, plate formation or its dependence on the plate surface, this was compared with the target value. In some cases, it can be corrected accordingly.

[0003]

SUMMARY OF THE INVENTION The basic object of the present invention is to provide a method as described above, in which the amount of liquid or the layer thickness, in particular the layer thickness of the dampening agent on the plate surface, can be measured easily. Form of equipment.

[0004]

According to the invention, according to the invention, an oscillator emitting microwaves having a wavelength in the absorption band of a liquid is mounted near the moistened surface of the printing plate and emits it. power consumption vessels are, depending on the absorbed microwave changed, further, the change is accomplished by being used as a measure of the layer thickness of the liquid on the printing plate.

In accordance with the present invention, between the transmitter frequency band and the liquid are combined, the operating state of the transmitter caused by the coupling is a measure for the measured value. In other words,
The transmitter also acts as a receiver at the same time. This is not in the electronic sense, as the amount of liquid or the layer thickness affects the transmitter.
Have a sound, and its influence, so to speak, outgoing by the receiving device
Means causing a reaction that can interpret as the receiving vessels signals. For the present invention, the effect is, outgoing energy from the transmitter is taken out depending on the amount or thickness of the liquid, resulting der the input power to the transmitter is determined
In particular , the power input to the transmission circuit is determined. If the amount or layer thickness of the liquid is increased, since many outgoing energy is consumed, the input of the power increase. However, this effect can only be fully measured if the output of the oscillator is not significantly greater than the energy absorbed by the liquid. Therefore, according to the present invention,
Energy absorbed by the liquid to the transmitter
The power input of the
The transmitter power must be low. Therefore, outgoing
The fuse is compared to a storage battery with a high internal resistance, which results in a correspondingly low voltage even at relatively small loads.

[0006] According to one embodiment, the electromagnetic wave radiated from the transmitter is Ri near the microwave band, further, since the injection force release is extremely small, it is guaranteed that no no or little warmed liquid .

Further, a transmitting antenna device provided with a slight gap in front of the printing plate on the rotating plate cylinder of the printing machine is transmitted.
It is advantageous to equip the vessel . With the device according to the invention, it is also possible to measure the amount of liquid or the layer thickness even in the rotating state of the plate cylinder .

According to another embodiment of the present invention, a call
Vessel is adapted to have a transmitting antenna apparatus that radiate multiple several locations spaced from one another on the printing plate surface. By doing so, the average value of the measured values at the respective points can be measured. If it is necessary to measure the measured values on the entire printing plate as an averaged value, it is useful to configure the transmitting antenna device as a strip antenna extending over the entire width of the printing plate.

[0009] In contrast to this, providing a few of the transmitter double, to those of the antenna is spaced apart from each other point of the surface of the printing plate
Obviously it is possible to apply microwaves . By doing so, the measurement value at each location is measured. It is thus possible to measure, for example, the local amount of dampening agent on the surface of the plate.

[0010]

Example of the Embodiment] The present invention has been shown in FIG.

FIG. 1 shows in a schematic diagram (block diagram) an apparatus 1 used for measuring the amount or layer thickness of dampening agent 2 or liquid 7 on the surface of a plate 4. The plate 4 is formed as a printing plate 5, which is stretched on a plate cylinder 6 of an offset printing machine (not shown in detail). The dampening agent consists mainly of water.

[0012] with the surface 3 and the liquid 7 at a small distance, the transmitting antenna 8 is provided which is connected to the oscillator 9. This this oscillator 9 is a microwave transmitter
And is desirable. Outgoing energy emitted from the transmitter 9, the power of transmitter 9 inputs, especially corresponding to the power input <br/> of the oscillation circuit. Order determining power input, the ammeter 10 is provided. This ammeter 10 corresponds to the power input ,
Display device 1 for displaying the layer thickness of the liquid 7 on the surface 3 of the plate cylinder 4.
Connected to 1. Further, the ammeter 10 is the adjustment device 1
Connected to 2. Therefore, the adjusting device 12 is supplied with the actual value. Furthermore, a setpoint 13 for the desired amount of dampening agent on the surface 3 of the plate cylinder 4 is supplied to the adjusting device 12. The output terminal of the adjusting device 12 is a dampening agent , that is,
It is connected to the operating elements 14 for measuring the liquid on the surface 3 of the plate cylinder 4.

The device according to the invention operates as follows.

Depending on the amount of dampening agent on the surface 3 of the plate 4,
Outgoing energy amount was different Tsu is extraction from the transmitter 9, so that the corresponding power input occurs. The value of the power input is recorded by the current meter 10, this value represents the amount or amounts or the layer thickness of the liquid 7 in the outgoing energy. In that case, power of the transmitter 9, the liquid 7 in particular dampening agent 2
Is adjusted so that it is not much more than the energy absorbed by the molecules of (particularly water molecules). This ensures that on the one hand a sufficiently accurate measurement result is obtained and, on the other hand, that the dampening agent 2 is not heated at all or only slightly. The measurement value thus obtained is sent to the display device 11, and the adjustment device 1
Used as an actual value for 2. This actual value is compared with the target value 13, and if there is an adjustment deviation, the adjusting device 12 causes the adjusting device 12 to produce an amount of dampening agent or layer thickness on the surface 3 of the plate 4 corresponding to the predetermined target value 13. Control the operating element 14.

Furthermore, FIG. 2 shows a transmitter 9 connected to the antenna device 8 includes the antenna device 8 double several transmitter 15, thus, spaced apart from each other on the surface 3 of the plate 4 Radiation of electromagnetic waves is received at multiple positions . Thus, an overall averaged measurement value is obtained, in other words the amount of liquid 7 or the layer thickness is measured as the average of the irradiated points or layer thickness of the surface 3 of the plate 4. .

In FIG. 3, the transmitting antenna device 8 is constructed as a strip antenna 16, which extends over the entire width of the printing plate 5. By doing this, the averaged dampening agent amount of the whole printing plate 5 is measured.

[0017] Separately, in the embodiment, not shown, each of the one antenna to <br/> radiating microwaves to different points of the plate surface, comprising several transmitter 9 double each You can also do so. By doing so, the amount of each dampening agent or the layer thickness of the dampening agent at that location is measured in the stationary plate, and in the rotary printing plate each averaged local area of the dampening agent is measured. The amount of dampening agent or layer thickness is measured.

[Brief description of drawings]

FIG. 1 is a block connection diagram showing an embodiment of an apparatus for measuring the amount of dampening agent or the layer thickness on a plate surface according to the present invention.

FIG. 2 is an explanatory diagram showing a structure of a transmitting antenna device that constitutes the device shown in FIG.

FIG. 3 is an explanatory diagram showing another embodiment of the transmitting antenna device shown in FIG.

[Explanation of symbols]

1 device 2 dampening agent 3 surface 4 plate 5 printing plate 6 plate cylinder 7 liquid 8 transmitting antenna device 9 transmitter 10 ammeter 11 display device 12 adjusting device 13 target value 14 operating element 15 transmitter 16 strip antenna

Continuation of the front page (73) Patent holder 390009232 Kurfuersten-Anlage 52-60, Heidelberg, Federal General of Germany (56) References JP-A-57-18255 (JP, A) JP-A-61-148061 (JP, JP A)

Claims (6)

(57) [Claims] 1. A frequency band within the electromagnetic wave absorption band of a dampening agent.
A device for measuring the layer thickness of a liquid, particularly the layer thickness of a dampening agent on the plate surface of an offset printing machine , equipped with a transmitter for emitting a microwave, and measuring the wavelength of the absorption band of the dampening agent Radiates microwaves
Transmitter (9) is mounted near the printing plate (5) of the wet and agents given et surfaces, power output of the oscillator (9)
Can warm the dampening agent (2) at all or only slightly
Small, power consumption of the transmitter (9), absorbed my
It changes depending on the black wave , and this change is the ammeter (10).
A layer thickness of a liquid, characterized in that the layer thickness of the liquid is sent to a display device (11) and used as a measurement of the layer thickness of the dampening agent (2) on the printing plate (5). A device that measures the layer thickness of the dampening agent on the plate surface of an offset printing machine. 2. A transmitter (9) is a transmitting antenna device (8).
With a particularly rotating plate cylinder of the printing machine (6)
Device according to claim 1, provided at a small distance from the printing plate (5). 3. A transmitting antenna device (8) is a microwave on the plate (4) of the surface (3) double multiple locations that are spaced apart from each other on the
The device of claim 2 , which emits 4. Device according to claim 2 , wherein the transmitting antenna device (8) is configured as a strip antenna (16) and extends over the entire width of the printing plate (6). 5. The several transmitters double (9) is provided, that
The device according to claim 1, wherein an antenna provided for each emits microwaves at mutually spaced locations on the surface (3) of the printing plate (5). 6. A measurement is supplied as an actual value to the regulating device (12), the actual value is used to adjust the amount of damping solution on the surface of the plate (4), claims 1 5 The apparatus according to any one of 1.