CN1148057C - TV set compatible with VGA display - Google Patents

Abstract

The present invention relates to a television set compatible with VGA display, which adopts a high frequency scan television set or a progressive scan television set. The present invention is characterized in that a controlling and processing circuit of the original system is utilized, and the VGA signal and the ordinary TV signal can be processed by one processing circuit. Thus, the present invention has the advantages that the circuit design is simple; the function which is completed by a plurality of complex components in the prior art can be completed by two pieces of integrated circuits and small amount of discrete components; the integral quality of the product is enhanced; the production process is simple; the cost of a complete machine is lower; the reliability of the complete machine in work is enhanced.

Description

The television set that compatible with VGA shows

Technical field

The design that compatible with VGA shows in various times of field frequencies scanning that the invention belongs to that line frequency doubles or the progressive-scan tv machine.

Background technology

At present, along with developing rapidly of digital television techniques and internet, the requirement of the VGA signal that computer is exported occurred on screen of TV set, showing,, just necessarily required television set that the VGA signal of computer is carried out particular processing in order to satisfy this demand.In as products such as multimedia television, PC-TV, TV-PC, the technology that adopts is that the VGA signal transition is become the PAL of common simulation or the shows signal that TSC-system is shown, show through television system again, this processing method greatly reduces the definition of VGA signal, original looks that can not true reappearance VGA signal.Another kind method is that the treatment system of TV signal is separated with VGA Signal Processing system, handle separately at unlike signal, though the original looks that this processing method can true reappearance VGA signal, complex circuit designs, system's control difficulty, cost is higher.

Summary of the invention

The objective of the invention is, provide a kind of and adopting high frequency sweep television set or progressive-scan tv machine for addressing the above problem, compatible demonstration to the VGA signal, the circuit global design, simple in structure, control the television set that compatible with VGA easily shows.

For achieving the above object, the present invention realizes like this, the television set that a kind of compatible with VGA shows, comprise high line frequency scanning television set or progressive-scan tv machine, it is characterized in that: described television set is provided with the VGA signal input part, and the VGA three primary colors input of this input is connected R, B, the G input of television display respectively with capacitance by impedance matching resistance; The line synchronizing signal input of described input and field sync signal input are connected the capable signal input part and the field signal input of Synchronization Control and row-field scanning signal processing chip respectively; The resolution identification output of this Synchronization Control and row-field scanning signal processing chip is connected the master control chip of television set, and same polarity row, the field signal output of this Synchronization Control and row-field scanning signal processing chip is connected row, the field signal input that the VGA signal is selected chip respectively; The VGA signal that this VGA signal selects the selection signal input part of chip to connect television set master control chip is selected output, this VGA signal selects the capable signal output of chip to connect original Video processing of television set and synchronous processing circuit, and this VGA signal selects the field signal output of chip directly to connect the field sync signal of television set.

The model of above-mentioned Synchronization Control and row-field scanning signal processing chip is WT8041 (a multiple frequency synchronous processor Taiwan Weitu Electrons Stock Co., Ltd product), its row signal input part is that its 1 pin and field signal input are its 2 pin, same polarity row signal output part is its 4 pin, and same polarity field signal output is its 5 pin; Its resolution identification output is its 10～14 pin, and by connecting television set master control chip after the resistance parallel connection, by capacity earth ,+5V power supply also connects television set master control chip jointly by resistance simultaneously respectively for they.

It is 74HC126 (tristate buffer, the generic logic integrated circuit is as company's products such as Philip, Motorolas) that above-mentioned VGA signal is selected the model of chip, and its row signal input part is its 9 pin, and its field signal input is its 5 pin; Its row signal output part is its 8 pin, and its field signal output is its 6 pin; It selects signal input part is its 4 pin.

Advantage of the present invention and good effect are, because existing high line frequency scanning television set scans the line frequency of a television set, progressive-scan tv machine etc. all at 31.5KHZ as times field frequency, identical with the line frequency of the VGA signal of standard, therefore in such treatment system, can realize the requirement of true reappearance VGA signal easily by improvement of the present invention.The present invention has utilized the control processing circuit in the original system cleverly, thereby can adopt same set of treatment circuit to the VGA Signal Processing and to the processing of normal tv signal, so circuit design is simple, two integrated circuits and a small amount of discrete component have only been used, just finished the function that has needed the large amount of complex components and parts just can finish in the past, improved the overall quality of product, production technology is simple, reduce the cost of complete machine, improved the complete machine reliability during operation.

Description of drawings

Below in conjunction with accompanying drawing the present invention is described in further detail.

Fig. 1 is the circuit diagram of one embodiment of the invention.

Embodiment

As shown in the figure, the television set that a kind of compatible with VGA shows comprises high line frequency scanning television set all devices as times field frequency scanning television set or progressive-scan tv machine.

This television set also is provided with the VGA signal input part, and the VGA tristimulus signals VGA-R of this input, VGA-G, VGA-B are connected R, B, the G input of television display CRT respectively by impedance matching resistance R 13, R14, R15 and capacitance C6, C7, C8; The line synchronizing signal VGA-HS of this input is connected Synchronization Control respectively with field sync signal VGA-VS and its model of row-field scanning signal processing chip IC1 is capable signal input part 1 pin and field signal input 2 pin of WT8041; The resolution of this Synchronization Control and row-field scanning signal processing chip IC1 identification output 10～14 pin are connected 18 pin of television set master control chip CPU after by resistance R 2, R3, R4, R5, R6 parallel connection, also by capacitor C 2 ground connection ,+5V power supply also connects 18 pin of television set master control chip CPU jointly by resistance R 1 simultaneously.The same polarity row of this Synchronization Control and row-field scanning signal processing chip IC1, field signal output 4 pin, 5 pin are connected row, field signal input 9 pin, 5 pin that the VGA signal is selected chip IC 2 respectively; It is 74HC126 that this VGA signal is selected chip IC 2 models, its VGA signal of selecting signal input part 4 pin to be connected television set master control chip CPU with 10 pin is selected outputting VGA-SWITH, this VGA signal selects the capable signal of chip IC 2 to export 8 pin connection original Video processing of television set and synchronous processing circuit, this circuit is isolated the line synchronizing signal HS-SYS that compliance with system requires, this VGA signal selects the field signal of chip IC 2 to export the field sync signal VS-SYS that 6 pin directly connect television set, and line synchronizing signal HS-SYS and field sync signal VS-SYS are transported to the respective input of display CRT through line-field sweep circuit generation row signal H-DEF and field signal V-DEF in the control system of original television set.

During this television set work, when selecting TV signal, the VGA-SWITH that CPU produces is a low level, and 6 pin and 8 pin of IC2 are output as high-impedance state, do not influence the work of original system; When under the VGA display mode, the R of VGA, G, the B signal is delivered directly to display, the VGA-SWITH that CPU produces is a high level, 6 pin of IC2 and 8 pin are output as its 5 pin and the 9 pin HS from the IC1 input, the VS signal, the HS signal is isolated the line synchronizing signal HS-SYS that compliance with system requires through the Video processing and the synchronous processing circuit of original system then, the VS signal is directly connected on the field sync signal VS-SYS of original system, and line synchronizing signal HS-SYS and field sync signal VS-SYS handle through line-field sweep circuit and produce H-DEF, the V-DEF signal conveys is to display.Under the VGA pattern, the requirement that had both met the VGA demonstration synchronously of system also meets former television system to synchronous requirement like this, and display can demonstrate high-quality VGA signal.

Claims (3)

1. the television set that shows of a compatible with VGA, comprise high line frequency scanning television set or progressive-scan tv machine, it is characterized in that: described television set is provided with the VGA signal input part, and the VGA three primary colors input (VGA-R, VGA-G, VGA-B) of this input is connected R, B, the G input of television display (CRT) respectively with capacitance (C6, C7, C8) by impedance matching resistance (R13, R14, R15); The line synchronizing signal input (VGA-HS) of described input and field sync signal input (VGA-VS) are connected the capable signal input part and the field signal input of Synchronization Control and row-field scanning signal processing chip (IC1) respectively; The resolution identification output of this Synchronization Control and row-field scanning signal processing chip (IC1) is connected the master control chip (CPU) of television set, and same polarity row, the field signal output of this Synchronization Control and row-field scanning signal processing chip (IC1) is connected row, the field signal input that the VGA signal is selected chip (IC2) respectively; The VGA signal that this VGA signal selects the selection signal input part of chip (IC2) to connect television set master control chip (CPU) is selected output, this VGA signal selects the capable signal output of chip (IC2) to connect original Video processing of television set and synchronous processing circuit, and this VGA signal selects the field signal output of chip (IC2) directly to connect the field sync signal (VS-SYS) of television set.

2. the television set that compatible with VGA according to claim 1 shows, it is characterized in that: the model of above-mentioned Synchronization Control and row-field scanning signal processing chip (IC1) is WT8041, its row signal input part is that its 1 pin and field signal input are its 2 pin, same polarity row signal output part is its 4 pin, and same polarity field signal output is its 5 pin; Its resolution identification output is its 10～14 pin, they connect television set master control chip (CPU) by resistance (R2, R3, R4, R5, R6) back in parallel respectively, by electric capacity (C2) ground connection ,+5V power supply also connects television set master control chip (CPU) jointly by resistance (R1) simultaneously.

3. the television set that compatible with VGA according to claim 1 and 2 shows is characterized in that: it is 74HC126 that above-mentioned VGA signal is selected the model of chip (IC2), and its row signal input part is its 9 pin, and its field signal input is its 5 pin; Its row signal output part is its 8 pin, and its field signal output is its 6 pin; It selects signal input part is its 4 pin and 10 pin.