CN2178026Y

CN2178026Y - All-system colour TV

Info

Publication number: CN2178026Y
Application number: CN93226068U
Authority: CN
Inventors: 谢同安
Original assignee: DONGJIE ELECTRICAL (CHINESE) Co Ltd
Current assignee: DONGJIE ELECTRICAL (CHINESE) Co Ltd
Priority date: 1993-07-22
Filing date: 1993-07-22
Publication date: 1994-09-21
Anticipated expiration: 2003-07-22

Abstract

The utility model relates to an all-system color TV, being capable of receiving a PAL system, an NTSC system and an SECAN system. The utility model is characterized in that a color machine core is formed by connecting an integrated circuit LA7680 comprising a picture medium frequency, a sound medium frequency, a luminance, a chrominance, a deflection and a field frequency automatic identification circuits, a CPU control voltage synthesizing channel selecting system circuit M34300N4-012SP and a chrominance signal processing circuit. The utility model is also provided with an NTSC 3.58 system converting circuit. The utility model has the advantages that the cost is low, the used integrated blocks and components are fewer, the number of the stored programs reaches 44, the image is not interfered, and the utility model has multiple functions and is suitable to be made into various all-system color TV sets with the sizes of 4 inches to 21 inches.

Description

All-system colour TV

The utility model relates to a kind of Phase Alternation Line system that receives, the full system type pictorial color television set of TSC-system and SECAN system.

Similar color television set in the market adopts integrated circuit, peripheral component is many, and corresponding television system is few, for example the most of television sets on the market can not receive the NTSC3.58 vision signal, hope and the band source of present employed Laser disc machine about all be the NTSC3.58 standard more than 90%, No. two satellites in and for example inferior state also utilize NTSC3.58, so the NTSC3.58 standard has user market widely, Phase Alternation Line system has been arranged, the color television set of TSC-system still can not satisfy for example market demand of state such as Russia and Eastern Europe employing SECAN system, the multi-modulation scheme colour TV is arranged in the market, but the cost height, the components and parts of usefulness are many.

The purpose of this utility model provides a full system type pictorial color television set with less integrated circuit and components and parts.

This practical technical scheme is:

A, by the integrated circuit LA7681 that includes visual intermediate frequency, sound intermediate frequency, brightness, colourity, deflection, field frequency automatic identification circuit and CPU control and the synthetic station selector circuit N34300N of voltage ₄-012SP and chroma processin circuit AN5635N connect into the colour TV movement;

B, the NTSC3.58 standard switching circuit is set, be equipped with 3.58NHZ oscillator X901 and 4.43NHZ oscillator X201 in the circuit, its 5V power supply is through diode VD905 voltage stabilizing and capacitor C 902 filtering, two oscillators are connected to switching diode VD902 and VD901 separately, the anode of VD902 with after the negative terminal of VD901 is connected respectively through capacitor C 903, resistance R 903 is connected with the terminal KN3 and the inverter V901 collection utmost point, inverter output is connected with isolating diode VD904 anode through resistance R 907, with diode VD904, the negative terminal of the VD904 of capacitor C 904 series connection connects 3.58NHZ and absorbs LC901, the LC901 other end is connected with terminal KN2, and by R202 ground connection, the base stage of inverter V901 is connected with emitter follower V902 emitter-base bandgap grading and inverter V903 through resistance R 909, V903 collection utmost point output resistance R908 is connecting terminal KN1 respectively, and by capacitor C 271 ground connection, follower V902 base stage is connected with terminal KN6 through resistance R 904, connect the logical inverter of change chroma strip by KN6, its collection utmost point also passes through (40) pin and the coil of integrated circuit LA7681 through electric capacity, the non-ground-end of L251 connects, the inverter V901 collection utmost point is also through resistance R 914, and diode VD907 is connected with the colored control end of the NCP of terminal KN7 and N34300N4-012SP.

The utility model embodiment is further described in conjunction with the accompanying drawings.

Fig. 1 is the utility model schematic block circuit diagram;

Fig. 2 is integrated circuit LA7681 circuit catenation principle figure;

Fig. 3 is integrated circuit N34300N4-012SP circuit catenation principle figure;

Fig. 4 is integrated circuit AN5635N circuit catenation principle figure;

Fig. 5 is a NTSC3.58 standard switching circuit schematic diagram

By shown in Figure 1, movement of the present utility model is by LA7681, N34300N4-012SP and AN5635N are formed by connecting, these three integrated circuits are finished PAL, SECAN system conversion, include the setting of the NTSC3.58 standard switching circuit of 3.58NHZ and 4.43NHZ two oscillators, realized the technical scheme of full system type pictorial color television set, other still are connected to the picture tube seat board, field deflection, 0.5NHZ oscillator, the video amplifier, tuner, SAW (Surface Acoustic Wave) filter, audio frequency one is looked switching circuit and power supply etc., and LA7681 is connected with N34300N4-012SP and is described as follows, and (3) pin of N34300N4-012SP send a blanking pulse through V ₇₄₁, V ₇₄₂, VD ₇₄₁(24) pin to LA7681; N34300N ₄-012 ^SP(11) pin send a pulse width modulating signal through V ₇₆₂, R ₇₇₁And conversion such as C764 and (40) pin of being filtering to LA7681 carry out adjustment of color; N34300N ₄(12) pin of-012SP send a pulse width modulating signal send through filtering such as R778 and C764 put LA7681(35) pin carries out brightness regulation; (13) pin of N34300N4-012SP send a pulse width modulating signal after filtering such as R783, C234, L211 to LA7681(12) pin degree of comparing regulates; (31) pin of N34300N4-012SP is sent one and is subjected to the level of commands for controlling to carry out the switch switching of AFT to (43) pin of LA7681 through the V751 paraphase; (36) pin of N34300N4-012SP is sent a level that is subjected to commands for controlling through V731, V810 removes to control the switching integrated circuit (IC) 8010LC4066B of AV on the one hand, on the other hand through VD801 to LA7681 (10) pin, make machine works when looking the audio frequency input state, (10) pin of LA7681 is placed low level, thereby the signal of sending into from high-frequency tuner is cut off by putting agc circuit among the LA7681, not influence sending into of vision signal, but having made such cooperation and original LA7681 compares function and increases the programs stored number and be increased to 44 from 32 with the cooperation of N34300N4-624SP, increased time clock feature, the timing start-up function, improve more serious picture annoyance level, reached essentially no interference.

In order to receive the NTSC3.58 vision signal, be provided with the NTSC3.58 standard switching circuit, by shown in Figure 5, described in its connected mode such as the scheme, be equipped with chroma processin circuit AN5635N in order to receive the SECAN vision signal, these three kinds of system conversion operation principles are described as follows: by Fig. 2, Fig. 3, shown in Figure 5, (31) pin of LA7681 is sent the variation voltage of 50Hz/60Hz, field frequency is 50Hz when input signal is the PALD/K system, (31) pin is sent a low level, when input signal is that NTSC358 system field frequency is 60Hz, (31) pin is sent a high level, at PALD/K system or SECAND/K, system (when comprising the B/G system) field frequency is 50Hz, LA7681(31) pin send the KN6 terminal that low level is added to standard switching circuit, V902 ends, V903 also ends, and (15) pin of LA7681 is only through C271 ground connection, the PAL-switch work among the LA7681, V901 also ends simultaneously, the collection of V901 very high voltage makes the VD901 conducting, so KN3 end is through C903 and 4.4NHz crystal oscillator X201 ground connection, and this moment, VD904 also ended, therefore, 3.58NHz absorb also place in circuit not of LC901, thereby this moment, colour TV was operated in the PAL4.43NHz state.

When receiving the NTSC3.58NHz program, field frequency is 60Hz, (31) pin of LA7681 is sent the high flat KN6 that is added to, make the V902 conducting, at this moment, the V902 emitter-base bandgap grading is that high level makes the V903 conducting, (15) pin of LA7681 is through R908 ground connection, make PAL-switch stop upset, LA7681 works in NTSC Jie sign indicating number state, also conducting of V901 this moment, the V901 collection is low level very, VD901 ends, the VD902 conducting, and the 3.58NHz crystal oscillator has replaced the 4.43NHz crystal oscillator to receive (16) pin of LA7681, pay a section wave frequency and just be transformed into 3.58NHz automatically, at this moment, the VD904 conducting, LC901 3.58NHz absorbs place in circuit, make and the 3.58NHz colour signal is absorbed in the Y passage, VD907 is conducting also, makes the R914 equivalent resistance be parallel to C764 electric capacity two ends, automatic like this NTSC colour amplitude being reduced to and PAL colour amplitude basically identical.

At the novel PAL of this reality, in NTSC and the SECAN full system type pictorial machine, when being in the NTSC accepting state, VD906 is because of V902 conducting conducting, gives AN5635N(8) the pin (see figure 4) provides a voltage that is higher than 2V to guarantee the stable of NTSC operating state.LA7681(42) pin connects the SECAN composite colour television signal of output, through sound carrier filtering X121, behind the AV commutation circuit LC40668, enter AN5635N(14 through the bell filter that postemphasises again) pin, in AN5635N, carry out the processing of carrier chrominance signal then, finally in (1), (2), three color difference signals of (3) pin output.When the PAL colour signal from LA7681(14) pin delivers to AN5635(15) during pin, AN5635N can discern automatically according to the signal of sending into, inner circuit can automatically switch to PAL β-Y and PALR-Y operating state, LA7681(21 like this) the PAL B-Y signal that connects (23) pin output of the PAL R-Y signal of output and LA7681 is delivered to (22) pin and (4) pin of AN5635N respectively, produce the G-Y signal through the inner G-Y matrix circuit of AN5635N then, from (1), (2), (3) pin exports three road color difference signals.LA7681(23) variation of the level of pin is delivered to AN5635N(24 by V341) pin, like this when receiving the SECAN signal, control to the contrast power of LA7681Y signal, (23) pin by LA7681 is delivered to AN5635N(24) pin, AN5635N is the strong and weak control of colourity, and the interlock than degree and carrier chrominance signal when so just having guaranteed SECAN is controlled.

The utility model full system type pictorial colour television set, characteristics are that cost is low, and used integrated circuit and components and parts are few, and function is how noiseless to picture, and the movement of colour TV is to the various sizes television receiver applicable to 4 inches～21 inches.

Claims

1, a kind of full system type pictorial color television set, it comprises visual intermediate frequency, sound intermediate frequency, the colored sign indicating number that is situated between, luminance signal is handled, the line scanning vibration, control store and character take place, voltage synthesis system integrated circuit, it is characterized in that:

A, connect into the colour TV movement by synthetic station selector circuit N3430ON4-012SP of the integrated circuit LA7681 that includes visual intermediate frequency, sound intermediate frequency, brightness, colourity, deflection, field frequency automatic identification circuit and CPU control voltage and chroma processin circuit AN5635N;

B, the NTSC3.58 standard switching circuit is set, be equipped with 3.58NHZ oscillator X901 and 4.43NHZ oscillator X201 in the circuit, its 5V power supply is through diode VD905 voltage stabilizing and capacitor C 902 filtering, and oscillator is connected to separately switching diode VD902 and VD901, the anode of VD902 with after the negative terminal of VD901 is connected respectively through capacitor C 903, resistance R 903 is connected with the terminal KN3 and the inverter V901 collection utmost point, inverter output is connected with isolating diode VD904 anode through resistance R 907, with diode VD904, the negative terminal of the VD904 of capacitor C 904 series connection connects 3.58NHZ and absorbs LC901, the LC901 other end is connected with terminal KN2, and by R202 ground connection, the base stage of inverter V901 is connected with emitter follower V902 emitter-base bandgap grading inverter V903 through resistance R 909, the output of the V903 collection utmost point is through resistance R 908 difference connecting terminal KN1 and by capacitor C 271 ground connection, follower V902 base resistance R904 is connected with terminal KN6, connect the logical inverter of change chroma strip by KN6, its collection utmost point also is connected with the non-ground-end of coil L251 by (40) pin of integrated circuit LA7681 through electric capacity, and the inverter V901 collection utmost point is also through resistance R 914, diode VD907 is connected with the colored control end of the NCP of terminal KN7 and N34300N4-012SP.