KR900006436B1 - Multi-tuner system - Google Patents

Abstract

The multi-tuner sustem is for tuning European CCIR type broadcast signal including England M, East Germany Dk, France L,L', I types. The picture and sound makers in low freq. band of SECAM type are inversed in an inverter (2). The output of the CCIR tuner (1) is provided to a SAW filter (4) to form overall wave through a sound trap circuit (3) tuned for M type. The sound signal tuned by the CCIR tuner has different freq. bands according the broadcast type but a sound IF mixer (91) tunes it automatically.

Description

Multi tuner system

1 is a schematic block diagram of the present invention.

2 is a more detailed embodiment circuit diagram of FIG.

* Explanation of symbols for main parts of the drawings

1: CCIR tuner 2: Converter

3: voice trap device 4: saw filter

5: Image IF unit 6: Voice band pass filter

7: AM, FM audio circuit 8: QPT IC

9: FM demodulation IC 91: voice IF mixer

92,93: 1st, 2nd trap machine T ₁ , T ₂ : signal transformer

The present invention relates to a multi-tuner system designed to receive a broadcasting method according to various broadcasting systems with one receiver. In general, the television broadcasting method is known NTSC method of the United States, Japan, Korea, etc. and CCIR method of Arm and Sekam in Europe. Among the CCIR schemes in the European region, the UK's M scheme (video 38.9MHz and audio 34.4MHz), Eastern European DK (video 38.9MHz and audio 32.4MHz) and France's Secam L (video 38.9MHz and audio 32.4). MHz), and Secam L 'system (video 34.4MHz, audio 39.9MHz), and these video signals have almost no signal bend difference between them, but the bend width of audio signal is about 6MHz deviation. In addition, there is a difference in the FM or AM system of the voice modulation. However, in the related art, since there is no design designed to be received by one TV or VTR receiver according to the broadcasting method as described above, a restriction on trade in goods has been followed. In other words, since only one TV set can listen to a specific local broadcast, it is not preferable as a TV receiver or VTR in a state of active cultural and trade exchange, such as in an international era.

The present invention has been invented to improve these problems in the prior art, which is to provide a multi-tuner system associated with a CCIR-type tuner that can be used to share the local broadcasting system all in one receiver, especially to be universally used worldwide. It is still another object of the present invention to provide a multi-tuner system in which a CCIR-type multi-tuner and a multiple demodulation circuit are PIF packs mounted in one small pack, thereby providing compatibility thereof. This will be described in more detail below. That is, FIG. 1 shows a circuit diagram related to the multi-tuner system of the present invention. In this case, the output of the CCIR tuner 1, which allows tuning of all broadcast signals such as the arm BG, arm, and Secam, Sekam L, etc. The audio band pass filter 6 is divided into axes, and the output of the audio trap unit 3 is applied to the video IF unit 5 through the saw filter 4, and the video signal is output from the video IF unit 5. In the voice band pass filter 6 side, an AM and FM audio circuit 7 is connected to an output thereof, and an audio signal is output from the AM and FM audio circuit 7. In addition, the video IF unit 5 and the AM and FM audio circuits 7 are connected to the QPT ICs S through the signal transformers T1 and T2, and the outputs of the QPT ICs 8 are audio IF mixers 91. ) And the first demodulator 93 to the FM demodulation IC 9 and, on the other hand, to the FM demodulator 93, and to the first and second FM signals F1, It becomes the structure which produces | generates F2). In the present invention of this line, more detailed embodiments are shown as in FIG. Here, 1 is a CCIR tuner, 2 is a Seqam L low frequency converter 2, which is a mixer 21 and a 72.3 MHz oscillator 22. The output is passed through an amplifier, a saw filter 4, and an image IF unit ( 5) and the output thereof is connected to the video output via the second voice trapper 51 and the switch SW ₁ .

The output of the frequency converting section 2 is connected to the QPT IC 8 via an amplifier and a QPT filter, and to a saw filter, AM, and FM audio path 7 in another path. The output of the QPT IC 8 is connected to the AM and FM audio circuit 7 through the audio IF mixer 91, the first trap 92, and the FM demodulation IC 9, and the second trap ( 93) to the second FM audio output F2 side via the FM demodulation IC 9; Unexplained symbol, AFC is automatic frequency control stage. According to the present invention having such a configuration, the IF signal of the frequency bands of various broadcasting methods tuned by the CCIR tuner 1 is given only in the form of inverting the picture marker and the voice marker of the low band of the toxic secam L. Inverts the P and S frequencies via part (2). The output signal on the CCIR tuner 1 side is an overall waveform in the saw filter 4 through the audio trap 3 using the M method as a standard, and is converted into an image demodulation IC 5. Enter it. At this time, the image demodulation IC 5 inputs a part of its output so that the QPT IC can obtain the second IF frequency via the signal transformer T ₁ .

On the other hand, the audio end is demodulated and output from the AM and FM audio circuits 7 through the saw filter, which is a bend pass filter, via the amplifier, and the FM signal is input to the QPT IC 8 via the signal transformer T ₂ . Let's do it. In the QPT IC 8, when the video and audio carriers are received, the second audio IF frequency is generated, and in the case of the arm BG, the audio signals are inputted to the FM demodulation IC 9 as 5.5 MHz and 5.74 MHz as they are. In the case of the M, I, and DK systems, the oscillating outputs of 10.0 MHz, 11.5 MHz, and 12.0 MHz are variably oscillated as an oscillator of the voice IF mixer 91, and input to the mixer, and the QPT IC ( 8) Mix with the voice IF frequency on the side, and the output intermediate frequency makes 5.5MHz. Therefore, the signal tuned on the CCIR tuner 1 side usually has a video signal band of 38.9 MHz, but differs in the audio signal band. You will have one multi-tuner system.

The present invention mainly enables video and audio reception according to broadcasting methods such as M, Eastern Europe DK, Prassekam L, L ', and I in the UK on a CCIR tuner in Europe. There is an advantageous feature that expands the compatible functionality in the device and provides good economical and operational benefits.

Claims (1)

A system that leads to video output via a conversion unit 2, an audio trap unit 3, and an image IF unit 5 of the frequency band automatic inversion according to the Secam L input to a CCIR tuner 1, and the conversion unit ( The other path in 2) is a system leading to the AM, FM audio circuit 7 and the audio output 1 via the audio band pass filter 6, and the video IF unit 5 and the AM, FM audio circuit 7 The signal transformers (T1, T2) are connected to the QPT IC (8), and the output of the IC (8) is passed through the second trap (93) to the FM demodulation IC (9), AM, and FM audio circuit (8). A multi-tuner system characterized by a configuration that extends to one side or to an FM demodulation IC (9) and an FM audio output (F2) via a voice IF mixer (91) and a first trap (92) including a variable oscillator.

Images