JPS5829457B2 - Insatsubutsuno Kensasouchi - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses a television camera to convert the image of a printed matter into an image electrical signal (hereinafter referred to as an image signal), and this image signal is stored in a signal conversion type storage tube (hereinafter referred to as a storage tube) as a standard image signal. By comparing the image signal of printed matter and processing it electrically,
This invention relates to a device that inspects printed matter for density unevenness, dirt, deprinting, etc.

Conventionally, such printed matter has been inspected by an operator measuring the density of a plurality of patterns to check whether the density is appropriate.

For this reason, (1) performing a complete inspection requires a lot of manpower and a lot of time.

(2) It is easy to make mistakes in determining whether it is good or bad.

(3) Inspection requires skill.

There were other drawbacks. The present invention was invented in view of the above-mentioned circumstances, and an object thereof is to provide a printed matter inspection device that can accurately and quickly inspect printed matter without using human hands.

An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, a standard printed matter 2' is placed on a printed matter placement board 1 by a standard printed matter feeding mechanism 11.

When the standard printed matter 2' is placed in a fixed position relative to the television camera 4, the photosensors 3, 3' detect the eye mark on the side of the printed matter and send this signal to the controller 10.

Upon receiving the signals from the photosensors 3 and 3', the controller 10 opens the gate of the analog switch 5 and sends a synchronizing signal to the television camera 4 and storage tube 9.

The picture on the standard printed matter 2' is converted into an image signal by the television camera 4 and input to the positive/negative converter 7.

Here, the image signal of the standard printed matter is converted into a negative image signal.

This converted negative image signal is sent to the controller 10.
The data is stored in the storage tube 9 according to a write command from the storage tube 9.

When the writing to the storage tube 9 is completed, the controller 10 issues a command to the standard printed matter feeding mechanism 11 to transport the standard printed matter from the printed matter placement board 1.

When this operation is completed, a command is then issued to the inspected printed matter feeding mechanism 12 to place the inspected printed matter 2 at a fixed position on the printed matter placement board 1.

When the printed matter 2 to be inspected is placed in a fixed position relative to the television camera 4, the photosensors 3, 3' detect the eye mark on the side of the printed matter and send this signal to the controller 10.

Upon receiving the signals from the photosensors 3 and 3', the controller 10 opens the gate of the analog switch 6 and sends a synchronizing signal to the television camera 4 and storage tube 9.

The image of the printed matter 2 to be inspected is converted into an image signal by the television camera 4 and input to the phase compensation circuit 8 .

Here, the image signal of the printed matter to be inspected is compensated by the phase overlap of the image stored in the storage tube 9.

The image signal of the printed matter to be inspected and the negative image signal of the standard printed matter read out by the read command from the controller 10 to the storage tube 9 are synchronized by the synchronization signal from the controller 10, and are sent to the mixing amplification circuit 14. to go into.

In this circuit, for example, as shown in FIG. 2, a negative image signal A of a standard printed material and an image signal B of a printed material to be inspected are mixed and amplified to obtain an output signal C from the mixing amplification circuit 14.

A synchronization signal removal circuit 15 removes the synchronization signal from this output signal, leaving only the image signal.

If there is no difference in pattern, density, etc. between the standard printed matter and the inspected printed matter, the output signal C of the mixing amplification circuit will be at a constant level.

If there is a difference in pattern, density, etc. between the standard printed matter and the inspected printed matter, as shown in Figure 2C, the mixing amplification circuit 1
In the output signal No. 4, an abnormal signal portion E appears in which the level increases or decreases with respect to a constant level.

This is detected by the level determination circuit 16, and differences in pattern, density, etc. between the standard printed matter and the inspected printed matter are detected.

A negative image signal of the standard printed matter and a positive image signal of the inspected printed material are input to this mixing amplification circuit 14, but there is a possibility that the phases of the two are shifted when they pass through each circuit.

Therefore, the phase of the image signal of the printed matter to be inspected is advanced.

Alternatively, a delay circuit is provided as the phase compensation circuit 8.

When the level determination circuit 16 detects the abnormal signal E, this signal enters the controller 10.
issues a command to the defective product rejection mechanism 13 to reject the printed material to be inspected at this time.

When the inspection of one printed matter to be inspected is completed, the controller 10
In response to this command, the printed material to be inspected is removed from the printed material placement board 1, and at the same time, the next printed material to be inspected is placed again on the printed material placement board 1, and the above-described operations are repeated.

Since there is a limit to the amount of time that the storage tube 9 can store the negative image signal of the standard print 2', first input the negative image signal of the standard print into the storage tube 9, and then after a certain period of time, store the negative image signal of the standard print again. It is necessary to convert the picture into an image signal using the television camera 4 and store it through the positive/negative conversion circuit 7.

Since the present invention has the above-described configuration, it does not require manpower or time to inspect printed matter, and it is possible to perform a complete inspection of printed matter, and it is possible to inspect printed matter without making false judgments within the performance of the device. can.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a block diagram of an inspection machine for printed matter, and FIG. 2 is an explanatory diagram of image signals. 1...Printed material installation board, 2...Printed material to be inspected, 2...Standard printed material, 3,3'-...
・Photo sensor, 7...Positive/negative converter, 8
...Phase compensation circuit, 9...Storage tube, 1
0...Controller, 14...Mixing amplification circuit, 16...Level judgment circuit.

Claims (1)

[Claims] 1 A television camera converts the image of the standard printed matter into an image electrical signal, this image signal is phase-inverted and stored in a signal conversion type storage tube, and this accumulated image signal and the television camera are used to convert the image of the inspected printed matter into an electrical image signal. A print inspection device that performs comparative inspection between standard prints and inspected prints by mixing and amplifying the converted image signals and determining the level with a comparator.