KR200154754Y1 - Saw filter converter in a vcr system capable of receiving pal/secam dual and nicam signal - Google Patents

Abstract

The present invention relates to a dual system capable of receiving a PAL / SECAM method, and selectively converts a multiple-saw filter capable of detecting a plurality of voice carriers according to a broadcasting method, thereby providing a NAL ( When the NICAM function is added, it is to increase satisfaction with various voice carrier frequencies in the VSI system.

To this end, the present invention includes a first saw filter unit for detecting and outputting only a video carrier frequency (VIF) of a desired band from an intermediate frequency (IF) signal from which an adjacent channel signal is removed through an adjacent channel trap unit; A VSI system capable of dual reception of a PAL / SECAM system having a second saw filter unit for detecting a desired PAL / SECAM audio carrier frequency from the intermediate frequency (IF) signal, wherein the intermediate frequency has passed through the adjacent channel trap unit. A third saw filter section for detecting an audio carrier frequency of a desired SECAM accent from the signal; And a saw filter switching unit configured to selectively drive the second saw filter unit and the third saw filter unit by a SECAM accent signal of a system driving microprocessor.

Description

SAW filter changers in VSI systems capable of receiving PAL / SECAM dual and NICAM signals

FIG. 1 is a block diagram showing a saw filter processing portion in a dual receive VSI system configured to receive a conventional PAL / SECAM broadcast signal.

2 is a schematic block diagram of a SAW filter switching device in a VSI system capable of receiving PAL / SECAM dual and NICAM signals according to the present invention.

* Explanation of symbols for main parts of the drawings

11 tuner and intermediate frequency detection unit 12 adjacent channel trap unit

13,14,16: SAW filter unit 15: demodulation unit

17: Sour filter switching unit Q1, Q2: switching transistor

D1, D2: Diode VIF: Video Carrier Signal

SIF, SIF1, SIF2: Audio Carrier Signal

The present invention relates to a VCR system for receiving a PAL (Phase Alternation by Line) / SECAM (Sequential Couleur a Memoire) broadcast signal, and more specifically, a dual capable of receiving a PAL / SECAM scheme. When the NAMAM function is added to the receiving system, a plurality of surface acoustic wave filters (hereinafter referred to as a sow filter) that can detect a plurality of voice carriers are selectively switched according to a broadcasting method. The present invention relates to a saw filter switching device in a PAL / SECAM dual and Nicam type receivable VSI system to satisfy various voice carrier frequencies in one VSI system.

The dual receiving VSI system configured to receive a conventional PAL / SECAM broadcast signal is tuned to a desired channel from a high frequency received signal received through an antenna ANT as shown in FIG. A tuner and an intermediate frequency detector 11 for detecting a signal; and an adjacent channel trap unit 12 for removing an adjacent channel signal included in an intermediate frequency (IF) signal selected through the tuner and the intermediate frequency detector. And a first saw filter unit 13 for detecting and outputting only a video carrier signal VIF of a desired band from the intermediate frequency signal passing through the adjacent channel trap unit, and a desired band from the intermediate frequency signal passing through the adjacent channel trap unit. A second saw filter section 14 for detecting only the audio carrier signal SIF, and a signal passed through the first saw filter section and the second saw filter section are changed. Demodulating the previous signal is to constitute a demodulator 15 to produce the original video signal (Video out) or the audio signal (Audio out) of.

When a high frequency signal is received over the air by the conventional dual-type broadcast receiving system, the tuner and the intermediate frequency detection unit 11 amplify the high frequency signal through a high frequency amplifier and amplify the high frequency signal using a local oscillator, a frequency synthesizer, or the like. The desired channel is tuned to detect the intermediate frequency signal of the channel. At this time, the tuner and the intermediate frequency detector output the audio signal of the desired channel as well as the signal of the adjacent channel.

Therefore, the adjacent channel trap unit 12 of the next stage removes the adjacent channel signal included in the intermediate frequency (IF) signal selected by the tuner intermediate frequency detector, and thus, the first saw filter unit 13 and the second saw filter unit 14, the first saw filter section 13 detects only a predetermined band of video signals (38.9 MHz; PAL video signal carrier frequency) and outputs the demodulation section 15 to the demodulator 15. In (1), an audio signal of 33.4MHz or 33.05MHz (33.4MHz is a PAL system mono sound signal carrier frequency and 33.05MHz SECAM system mono sound signal carrier frequency) is selectively detected.

In this case, the second saw filter unit 14 detects 33.4 MHz of mono sound in the PAL method and the SECAM method using the adjacent channel trap unit selectively operating according to the respective reception methods in the PAL method and the SECAM method. In the standard mode, 32.4MHz mono sound was detected. In the SECAM standard mode, 33.05MHz Nycam sound was detected.

Therefore, the demodulator 7 at the subsequent stage demodulates the signal which has passed through the two saw filters to the signal before being modulated to generate and output the original video out or audio out.

However, in the conventional PAL / SECAM simultaneous reception system as described above, when Nicam function is added, various audio carrier frequencies cannot be satisfied with one audio saw filter.

Therefore, the present invention has been devised to solve the above problems, and the present invention has a multiple saw filter capable of detecting a plurality of voice carriers in a dual system capable of receiving a PAL / SECAM method, and the SAW filter. By selectively switching according to the broadcasting method, PAL / SECAM dual and PAL / SECAM dual system can satisfy various voice carrier frequencies when NICAM is added to the dual system. An object of the present invention is to provide a SAW filter switching device in a NICAL receiving VSI system.

In order to achieve the above object, the present invention provides a first saw filter unit for detecting and outputting only a video carrier frequency (VIF) of a desired band from an intermediate frequency (IF) signal from which an adjacent channel signal is removed through an adjacent channel trap unit; A VSI system capable of dual reception of a PAL / SECAM system having a second saw filter unit for detecting a desired PAL / SECAM audio carrier frequency from the intermediate frequency (IF) signal, wherein the intermediate frequency has passed through the adjacent channel trap unit. A third saw filter section for detecting an audio carrier frequency of a desired SECAM accent from the signal; A PAL / SECAM dual and Nycam comprising a Saw filter switching unit configured to selectively drive the second and third Saw filter units by a SECAM accent signal of a system driving microprocessor. It provides a SAW filter switching device in a NICAM-receivable VSI system.

Hereinafter, an embodiment of a SAW filter switching device in a PAL / SECAM dual and NICAM receivable VSI system will be described in detail with reference to the accompanying drawings. .

FIG. 2 is a block diagram showing an embodiment of a SAW filter switching device in a PAL / SECAM dual and NICAM receivable VSI system according to the present invention.

In the drawing, a tuner and an intermediate frequency detector 11 which detects an intermediate frequency (IF) signal of a corresponding channel by tuning a desired channel from a high frequency received signal received through an antenna ANT, and through the tuner and the intermediate frequency detector A video output signal is demodulated by demodulating the adjacent channel trap unit 12 for removing the adjacent channel signal included in the selected intermediate frequency IF signal, the video carrier signal VIF, and the audio carrier signal SIF. And a demodulator 15 for generating an audio output signal Audio out, as in the conventional case.

The video carrier and audio carrier signal detection part, which is a main part of the present invention, includes a first saw filter part 13 for detecting and outputting only a video carrier signal VIF of a desired band from an intermediate frequency signal passing through the adjacent channel trap part. A second saw filter section 14 for detecting only a PAL / SECAM system audio carrier signal SIF1 of a desired band from the intermediate frequency signal passing through the adjacent channel trap section, and a desired frequency from the intermediate frequency signal passing through the adjacent channel trap section. The third saw filter section 16 detects the audio carrier signal SIF2 of the SECAM accent.

In addition, the second saw filter unit 14 and the third saw filter unit 16 for detecting the audio carrier signals SIF1 and SIF2 of the different bands may include a SECAM accent signal of a microprocessor used to drive a system. A saw filter switching unit 17 which can be selectively driven by SECAM ACCENT) is connected.

At this time, the saw filter switching unit 17 is alternately operated by the logic value of the SECAM accent signal (SECAM ACCENT) of the microprocessor to switch the two switches connecting the input terminals of the two saw filters 14 and 16 to ground, respectively. Transistors Q1 and Q2 and diodes D1 and D2 which are connected in reverse directions to the two saw filters, respectively, for introducing or blocking a signal flowing into each saw filter unit according to the operation of the two switching transistors. Doing.

When the IF signal of the desired channel is detected by the tuner and the IF detector 11, the present invention configured as described above has an intermediate frequency (IF) selected by the tuner and the intermediate frequency detector by the adjacent channel trap unit 12 of the next stage. The adjacent channel signal included in the) signal is removed and simultaneously output to the first saw filter unit 13, the second saw filter unit 14, and the third saw filter unit 16.

At this time, the first saw filter unit 13 detects only a predetermined band of video signals (38.9 MHz; PAL video signal carrier frequency) and outputs the demodulated unit 15 to the demodulator 15.

However, when the NICAM function is added in the PAL / SECAM dual reception system, the various voice carrier frequencies cannot be satisfied with one saw filter. Therefore, according to the PAL / SECAM method, the second saw filter unit ( By switching the 14 and the third saw filter unit 16, it is possible to receive a signal of a desired frequency band.

That is, when the Secam accent L signal is input from the microprocessor, the first switching transistor Q1 of the saw filter switching unit 17 is turned off (at this time, the diode D1 is cut off). (16) is turned off, on the contrary, the second switching transistor Q2 of the saw filter switching section 17 is turned on (the diode D2 remains in the conducting state) and the second saw filter section 14 is usable. In this state, the second saw filter unit 14 can receive PAL mono sound (33.4 MHz), Secam standard mono sound (32.4 MHz), and Secam standard Nycam sound (33.05 MHz) signals.

On the contrary, when the Secam accent H signal is input from the microprocessor, the first switching transistor Q1 of the saw filter switching unit 17 is turned on so that the third saw filter unit 16 is in a usable state. The second switching transistor Q2 of (17) is turned off so that the second saw filter portion 14 is turned off, so that the Secam accent mono sound (40.4 MHz) and the Sekam accent Nycam sound (3) through the third saw filter portion 16 are obtained. 39.75 MHz) signal can be received.

According to the SAW filter switching device of the PAL / SECAM dual and NICAM receiving system of the present invention as described above, the dual system capable of receiving the PAL / SECAM system By selectively switching the multiple saw filters that can detect multiple voice carriers according to the broadcasting method, the VISA system can control various voice carrier frequencies when the NICAM function is added to the PAL / SECAM dual system. It is useful to be able to improve the audio carrier frequency reception capability in VSI system by making it satisfactory.

Claims (2)

A first saw filter unit for detecting and outputting only a video carrier frequency VIF of a desired band from an intermediate frequency (IF) signal from which adjacent channel signals are removed through an inlet channel trap unit; A VSI system capable of dual reception of a PAL / SECAM system having a second saw filter unit for detecting a desired PAL / SECAM system audio carrier frequency from the intermediate frequency (IF) signal, A third saw filter section (16) for detecting an audio carrier frequency of a desired SECAM accent from the intermediate frequency signal passing through the adjacent channel trap section; PAL / SECAM comprising a saw filter switching unit 17 for selectively driving the second saw filter unit and the third saw filter unit according to a SECAM accent signal of a system driving microprocessor. SAW filter changer in dual and NICAM receivable VSI systems. The method of claim 1 The saw filter switching unit 17 is alternately operated by the logic value of the SECAM accent signal (SECAM ACCENT) of the microprocessor, so that the two switching transistors respectively connect the input terminals of the two saw filters 14 and 16 to ground. (Q1) (Q2); Arm / Secam, which is connected to the two saw filters in the reverse direction and constitutes diodes D1 and D2 for introducing or blocking a signal flowing into each saw filter unit according to the operation of the two switching transistors. PAL / SECAM) SAW filter changer in dual and NICAM receiving VSI systems.