CN1053343A

CN1053343A - Circuit for inserting characters on screen in the television receiver

Info

Publication number: CN1053343A
Application number: CN 90110327
Authority: CN
Inventors: 戴维·R·格雷; 约翰·P·麦喀逖
Original assignee: Deutsche Thomson Brandt GmbH
Current assignee: Deutsche Thomson Brandt GmbH
Priority date: 1989-12-09
Filing date: 1990-12-08
Publication date: 1991-07-24
Also published as: DE3940812A1; AU6888491A; EP0504193A1; WO1991009497A1

Abstract

Be used on the phosphor screen of television receiver, inserting the circuit of character.Microprocessor (8) in the television receiver produces the rgb signal that is used for additional character.Its objective is at television receiver does not have under the situation of RGB input, for above-mentioned signal provides a simple control circuit.Each output of microprocessor (8) is always walked around video processing circuit (3) and is connected to the negative electrode of picture tube (4), especially for having at the television receiver that inserts additional character (OSD means on phosphor screen and shows) on the phosphor screen.

Description

Circuit for inserting characters on screen in the television receiver

The present invention relates to a kind of by the circuit for inserting characters on screen in the television receiver that claim 1 limited.

This television receiver comprises a video processing circuit, and this circuit produces color difference signal and luminance signal from the TV signal of the TV station of reception, be used to control picture tube.An additional microprocessor is provided on picture tube inserting the rgb signal of character on its output.These characters may be, for example, describe a users' guidebook by a procedures sheet, and nationality helps its operation to constitute about using the dialogue of television receiver, contains the information of teletext content, and perhaps the indication with other appends on the operation image of frequent description.This insertion is also referred to as OSD(and is showing on the screen) or OSP(on screen, programme).

From the rgb signal of microprocessor output, preferably be transported to the RGB input of television receiver simultaneously.Yet, just there is not such RGB input for television receiver simple in structure.After this, for this signal conveys in video processing circuit, rgb signal must be encoded or handle by any alternate manner.Yet this is always not possible immediately, especially when video processing circuit be that integral restrictor circuit by complexity is when constituting.

The present invention is based on such task: when television receiver does not provide the RGB input, utilize the rgb signal of microprocessor output by a simple circuit, realize the control to picture tube.

The invention solves above-mentioned task by given in claim 1.Provided useful further formation of the present invention in the dependent claims.

Therefore, in situation of the present invention, walked around known video processing circuit.Rgb signal from the microprocessor output is transported to such place, and the matrix circuit at this place by existing color difference signal and luminance signal constitutes rgb signal.Preferable is that each output of processor is connected on the transistor level.The output signal that transistorized operating voltage provides with processor is sent on the RGB terminating stage on the picture tube.This processor can provide, and in the rgb signal for example only is provided, and for example only provides the G signal in order to produce green insertion character.When the character insertion should be various color,, preferably be three all rgb signals to be sent on the picture tube by microprocessor according to method of the present invention.

Below explain one embodiment of the present of invention with reference to the accompanying drawings.In the drawings, receive the radio broadcasting TV signal and pass the signal to tuner 2 with antenna 1.In addition, tuner 2 offers video processing circuit 3 with signal, and this treatment circuit provides color difference signal (R-Y), (G-Y) and (B-Y) and brightness signal Y, is used to control picture tube 4.Signal (R-Y) and Y are supplied with transistor level and provided a colour signal R by it for picture tube 4.Signal (B-Y) and Y are supplied with transistor level 7 and provide for picture tube 4 by it colour signal B during in, signal (G-Y) and Y supply transistor level 6 also provide a colour signal G by it for picture tube.So far, described circuit is used for controlling picture tube 4, with to switch off the TV-radio signals receives image and is illustrated.

This television receiver comprises additional microprocessor 8.In addition, this microprocessor produces colour signal-R at its output 22,23,24 ,-B, and-G is used for producing as diacritics such as character, data, indications on the phosphor screen of picture tube 4.By three colour signal-R of processor 8 output ,-G ,-B are placed in three transistor T R, TG, on the base stage of TB, transistorized each collector electrode and affiliated transistor 5,6,7, each transmitter be connected.Therefore, character display signal R, G, B just are inserted in transistor level 5,6,7 in the signal from circuit 3, and produce corresponding character on the phosphor screen of picture tube 4.Microprocessor 8 and transistor level TR, TG, TB is connected, and keeps not having the state of operating voltage on its position that links to each other, but transistor level 5,6, the fixing direct voltage on each emitter of 7 is as operating voltage.Therefore, flow to terminating stage 5,6 at character control signal RGB from microprocessor 8, during 7 direction, operating voltage then by opposite direction from transistor 5,6,7 flow to transistor T R, TG, TB.Therefore, in described example, character has three all colour signal RGB.Especially, these signals are divalence, so be not that amplitude peak is exactly zero amplitude.Utilize three signal RGB just can comprise that the colour of the character of black and white developing describes.And show that for the character of a monochrome then only handle also is possible from a signal conveys among three colour signal RGB of microprocessor 8 to picture tube 4.Especially only with signal G that character is shown in green.Equally, it also is possible being made up by only two signals among three colour signal RGB.

Circuit 3 comprises, for example, and an integrated circuit, model is M51407ASP(PAL).Microprocessor 8 models are, for example μ P474634N.

Claims

1, the circuit for inserting characters on screen in a kind of television receiver, comprise a video processing circuit (3), a picture tube (4) and a microprocessor (8), output at this microprocessor provides the rgb signal that character shows, it is characterized in that, each output of processor (8) (22,23,24) is walked around video processing circuit (3) and is connected with the negative electrode of picture tube (4).

According to the circuit of claim 1, it is characterized in that 2, each output of processor (8) is connected to transistor (TR, TG, base stage TB), the negative electrode connection under the same picture tube of transistorized collector electrode (4).

3, according to the circuit of claim 2, it is characterized in that, have picture tube (4) separately each control electrode of negative electrode collector electrode with control RGB transistor terminal level (5,6,7) be connected.

According to the circuit of claim 1, it is characterized in that 4,, collector electrode each transistorized emitter with RGB terminating stage (5,6,7) linked to each other that (R-Y, G-Y B-Y) import base stage, and luminance signal is input to emitter color difference signal.

According to the circuit of claim 3 or 4, it is characterized in that 5, terminating stage (5,6,7) is gone up transistor (TR, TG, operating voltage TB) on the output that additional fixedly direct voltage is used as processor (8).