JPS59226572A - Printer for television signal - Google Patents

Abstract

PURPOSE:To print out an image of a television picture correctly without being affected by noise even in receiving under weak electric field by applying automatic frequency control to a horizontal synchronizing signal. CONSTITUTION:Horizontal and vertical synchronizing signals s1, s2 are extracted from a composite video signal v1 given from a television receiving set by a synchronizing separator circuit 7 and become a video signal v2 and inputted and an A/D converter, and a gradation density signal d1 is outputted. When noises are superposed on the signal v1 due to receiving under a weak electric field, the noise is included also in s1, s2. So, AFC is applied to s1 by an AFC circuit 8. Accordingly, a writing controlling circuit 3 makes address counting by using s1 to which AFC is applied. Therefore, the signal d1 is written in normal address in the image memory 2 as in the case of normal state which is not receiving under a weak electric field. Thus, a normal picture can be printed out without being affected by the noise.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printer device for television signals.

Generally speaking, when a cooking program is being broadcast on a television receiver, for example, you may want to write down the menu list and ingredients displayed on both sides. This was extremely inconvenient as the person had to take notes on the menu list, ingredients, etc. while looking at the screen each time. Furthermore, if the cooking program is recorded on a VTR, it can be played back again, but even in that case, it is necessary to search for the necessary screen and play it back, which is a cumbersome operation.

Therefore, the inventor of the present invention has determined that the gradation density signal of the image on the television screen is R.
A printer device for a television receiver has already been developed which is capable of automatically copying images on a television screen by writing to AM and then not reading it.

The printer device of this television receiver is integrated with the television receiver body, but if this printer device is separated from the television receiver body and becomes an independent video printer, it will be possible to use other manufacturer's TVs. This means that the system will also be compatible with John receivers, which is considered to be very convenient for users.

However, in such a printer device that is independent from the television receiver body, when the television receiver performs reception under a weak electric field, noise is superimposed on the synchronization signal output to the printer device. This poses a problem in that the image on the television screen cannot be printed out correctly.

This invention was made in view of the above-mentioned problems, and by applying automatic frequency control to the horizontal synchronizing signal supplied from the television receiver body, it is possible to prevent the reception from being affected by noise even under weak electric fields. To provide a television signal printer device that can correctly print out images on a television screen without any problems.

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

The drawing shows a television signal printer apparatus according to an embodiment of the present invention, in which 7 is a synchronization separation circuit for separating horizontal and vertical synchronization signals sl and S2 from a composite video signal V1 from a television receiver; 1 is an AFC circuit that applies automatic frequency control (hereinafter referred to as AFC) to the horizontal synchronization signal sl, and 1 is an A/D converter for the video signal v2 from the synchronization separation circuit 7, and outputs, for example, a 4-bit gradation density signal di. 2 is a video memory for storing the gradation density signal d1; 3 is a video memory for storing the gradation density signal d1; 3 is for writing to the video memory 2 in response to a write command c2 using the AFC circuit 8 output sl' and the vertical synchronization signal S2; A write control circuit performs control; 4 is a copy command cl from a copy key 6;
In response to this, a write command C2 is given to the write control circuit 3, and a read address a is output to the video memory 2.
Read data d2 from video memory 2 is converted to print data d3
5 is the read print data d3
This is a printer that prints out.

Reference numeral 9 denotes a clock pulse generation circuit that supplies clock pulses p to the A/D converter 1 and the write control circuit 3.

Next, the operation will be explained. A composite video signal v1 from a television receiver has horizontal and vertical synchronizing signals sl and s2 extracted by a synchronization separation circuit 7, and is inputted to an A/D converter 1 as a video signal v2. The A/D
The converter l samples the video signal v2 using the clock pulse p of the clock pulse generating circuit 9 and outputs the gradation density signal d1. Write control circuit 3 receives write command C2
The gradation density signal d1 is converted to the black pulse p by
It is written to the video memory 2 at the timing of .

This write control circuit 3 performs control so that gradation density signals for 280 pixels in the horizontal direction and 234 lines in the vertical direction are written to the correct address of the video memo IJ2.

The write command C2 of the write control circuit 3 is issued from the CPU 4 when the viewer operates the copy key 6.

When the writing to the video memory 2 is completed, the CPU 4 gives the read address a to the video memory 2, and reads the gradation density signal d2.
Read out. This gradation density signal d2 is output as print data d3 to the printer 5, and as a result, the printer 5 prints out the image on the television screen.

By the way, when noise is superimposed on the composite video signal v1 due to reception under a weak electric field, this noise is also included in the horizontal and vertical synchronizing signals sl and s2. Therefore, if this device does not have the AFC circuit 8, the write control circuit 3 will count the noise as a horizontal synchronizing signal, which will cause a shift in the address count value and cause the gradation density signal di to be corrected in the video memory 2. It becomes impossible to write to the address, and as a result, there will be a shift in the printed image. However, in this embodiment, the AFC circuit 8 applies AFC to the horizontal synchronizing signal sl, and the write control circuit 3 performs address counting using the horizontal synchronizing signal sl' applied with this AFC.
In this case, the gradation density signal dl is written to the normal address as in the normal state where reception is not performed under a weak electric field.
A normal screen can be printed out without being affected by noise.

Furthermore, in this embodiment, the composite video signal is supplied from the television receiver body, and is synchronously separated within the printer to obtain the video signal and horizontal and vertical synchronization signals. It can be connected with just one cable to the video output terminal that is often installed on John receivers these days.

As described above, according to the television signal printer device according to the present invention, automatic frequency control is applied to the horizontal synchronizing signal supplied from the television receiver body, so that it can be applied to any television receiver. compatible with
Furthermore, even when receiving signals under weak electric fields, the image on the television screen can be printed out correctly without being affected by noise.

[Brief explanation of the drawing]

The drawing is a block diagram showing a television signal printer apparatus according to an embodiment of the present invention. 1...A/D converter, 2...video memory, 8...
AFC circuit, 3...Write control circuit, 4...CPU
(continued output control circuit), 5... printer. Agent Masuo Oiwa

Claims (1)

[Claims] +11 A printer device that prints out a composite video signal from a television receiver that is input from the outside, including an A/D converter that converts the video signal of the composite video signal from A/D to digital, and an A/D converter that converts the video signal of the composite video signal from A/D converter to Store the gradation density signal of -
an automatic frequency control circuit that applies automatic frequency control to the horizontal synchronization signal of the composite video signal; and an automatic frequency control circuit that applies automatic frequency control to the horizontal synchronization signal of the composite video signal; A television signal comprising: a write control circuit that performs write control; a read control circuit that reads out the gradation density signal from the video memory; and a printer that prints out the read gradation density signal. printer device.