KR19990013324U - Demodulation circuit of tuner for VCR - Google Patents

Abstract

The present invention relates to a demodulation circuit of a tuner for a VCR, comprising: a demodulator for detecting and demodulating an intermediate frequency signal of a tuner unit, and a parallel connection to the demodulator unit for removing unnecessary noise signals included in the intermediate frequency signal of the tuner unit; In the demodulation circuit of the tuner for VCR comprising a filter unit consisting of an inductor and a capacitor, the inductor and capacitor of the filter unit are modularized and connected in parallel so as to be detachable from the demodulator, that is, the intermediate frequency of the tuner unit. By demodulating and connecting a filter part consisting of an inductor and a capacitor to remove and remove a noise signal that may appear during a demodulation part demodulating the signal, the module is detachably connected to the demodulation part, thereby providing durability against external impact and contact, and a defective part. It is an excellent effect that can be replaced easily.

Description

Demodulation circuit of tuner for VCR

The present invention relates to a demodulation circuit of a tuner for VCR, and more particularly, to a filter unit consisting of an inductor and a capacitor, which is modularized to be detachably attached to the demodulation unit, so that the VCR tuner has durability against external shock and contact. It relates to a demodulation circuit.

In general, the tuner selects a desired high frequency signal from among a plurality of high frequency signals induced from an antenna and converts the desired high frequency signal into an intermediate frequency signal. In this case, the demodulation circuit of the VCR tuner according to the prior art including the tuner performing a function of converting a plurality of high frequency signals induced from the antenna into an intermediate frequency signal will be described with reference to FIG. 1.

1 is a block diagram showing a demodulation circuit of a VCR tuner according to the prior art.

As shown in FIG. 1, the demodulation circuit of the VCR tuner according to the related art includes a tuner unit 10 for selecting a desired high frequency signal from a plurality of high frequency signals derived from an antenna ANT and converting the desired high frequency signal into an intermediate frequency signal. And a demodulator 20 for detecting and demodulating the intermediate frequency signal output through the tuner 10.

In this case, the tuner unit 10 includes a high frequency input unit 11 for removing a signal other than a desired channel from a plurality of high frequency signals induced from a feed line of the antenna ANT and selecting only a predetermined desired high frequency signal, and the high frequency input unit. An intermediate frequency signal by mixing the high frequency amplification unit 12 for amplifying the high frequency signal of the desired channel output from the (11), the high frequency signal output from the high frequency amplification unit 12 and the oscillation signal of the local oscillation unit 14; And a mixing unit 13 for converting to and an intermediate frequency amplifying unit 15 for amplifying and outputting the intermediate frequency signal output from the mixing unit 13.

In addition, the demodulator 20 which detects and demodulates the intermediate frequency signal of the intermediate frequency amplifier 15, inductor L to remove unnecessary noise signals included in the intermediate frequency signal of the tuner 10. And filter units 21 constituted by capacitors C are connected in parallel.

Referring to the operation of the demodulation circuit of the VCR tuner according to the prior art having the above configuration as follows.

First, when a plurality of high frequency signals are induced from the feed line of the antenna ANT, the high frequency input unit 11 selects only the high frequency signals of the desired channel and supplies them to the high frequency amplifier 12.

At this time, the high frequency amplifying unit 12 amplifies a desired high frequency signal applied from the high frequency input unit 11 and supplies it to the mixing unit 13 to be mixed with the oscillation signal of the local oscillating unit 14.

Thereafter, the mixing unit 13 mixes the high frequency signal of the high frequency amplifier 12 and the oscillation signal of the local oscillator 14 to output the intermediate frequency signal, and the intermediate frequency signal is an intermediate frequency amplifier ( Amplified again in 15) and applied to the demodulator 20.

Meanwhile, the demodulator 20 demodulates and outputs an intermediate frequency signal of the mixing unit 13 amplified by the intermediate frequency amplifier 15 at this time. In this case, the demodulation process of the demodulator 20 is performed. The noise signal that may appear is removed by the filter unit 21 composed of the inductor L and the capacitor C so that the final demodulated signal can be output through the output unit (not shown).

However, the demodulation circuit of the VCR tuner according to the related art having the above configuration includes an inductor for removing a noise signal that may appear in the demodulation process of the demodulator 20 demodulating the intermediate frequency signal of the tuner 10 ( Since the filter unit 21 composed of L) and the capacitor C are connected in parallel in a state exposed to the outside of the demodulation unit 20, the filter unit 21 is easily broken by external contact or impact and loses a predetermined filter function. Or, because it is made of a structure that is fixedly connected to the demodulator 20, there was a big disadvantage that the complexity of the replacement of the parts.

Accordingly, the present invention has been made to solve the above-mentioned problems, and the object of the present invention is to modularize and connect the filter unit detachably attached to the demodulator to remove the noise signal that may appear during the demodulation process. The present invention provides a demodulation circuit for a VCR tuner that is durable against external shocks and contacts and can be easily replaced in case of a defective component.

1 is a block diagram showing a demodulation circuit of a tuner for a VCR according to the prior art.

2 is a block diagram showing a demodulation circuit of a tuner for a VCR according to the present invention.

Explanation of symbols on the main parts of the drawings

10: tuner unit 11: high frequency input unit

12: high frequency amplification unit 13: mixing unit

14: local oscillation unit 15: intermediate frequency amplification unit

20: demodulation unit 100: filter unit

ANT: Antenna C: Capacitor

L: Inductor

Therefore, the demodulation circuit of the VCR tuner according to the present invention for achieving the above object, the demodulation unit for detecting and demodulating the intermediate frequency signal of the tuner unit, and removing unnecessary noise signals included in the intermediate frequency signal of the tuner unit In the demodulation circuit of the VCR tuner comprising a filter unit consisting of an inductor and a capacitor connected in parallel to the demodulator, the inductor and capacitor of the filter unit are modularized and connected in parallel so as to be detachable from the demodulator.

Hereinafter, a preferred embodiment of a demodulation circuit of a VCR tuner according to the present invention will be described with reference to FIG. 2.

Figure 2 is a block diagram showing a demodulation circuit of a VCR tuner according to the present invention, the same name and the same reference numerals will be used for the configuration having the same operation as the conventional configuration.

As shown in FIG. 2, the demodulation circuit of the VCR tuner according to the present invention selects a desired high frequency signal from a plurality of high frequency signals derived from the antenna ANT and converts it into an intermediate frequency signal 10. And a demodulator 20 for detecting and demodulating the intermediate frequency signal of the tuner unit 10 and the demodulator 20 to remove unnecessary noise signals included in the intermediate frequency signal of the tuner unit 10. It consists of a filter unit 100 composed of an inductor (L) and a capacitor (C) connected in parallel.

In this case, the inductor L and the capacitor C of the filter unit 100 are modularized and connected in parallel to be detachable from the demodulator 20.

The operation of the demodulation circuit of the VCR tuner according to the present invention having the above configuration is the same as in the prior art, but in the working surface thereof, the demodulation process of the demodulator 20 demodulating the intermediate frequency signal of the tuner 10 may appear. Filter unit 100 composed of an inductor (L) and a capacitor (C) for removing a noise signal is modularized and connected to the demodulation unit 20 so as to be detachable, it has durability against external shock and contact, defective parts It can be seen that it can be replaced more easily at the same time.

As described above, in the demodulation circuit of the VCR tuner according to the present invention, a filter part including an inductor and a capacitor which removes a noise signal that may appear during a demodulation process of demodulating the tuner's intermediate frequency signal is detached from the demodulator. By making the connection as modular as possible, it has durability against external impact and contact, and has an excellent effect of simply replacing the defective part.

Claims (1)

A demodulator for detecting and demodulating an intermediate frequency signal of a tuner unit, and a filter unit comprising an inductor and a capacitor connected in parallel to the demodulator to remove unnecessary noise signals included in the intermediate frequency signal of the tuner unit. In the demodulation circuit of And an inductor and a capacitor of the filter unit are modularized and connected in parallel to be detachable from the demodulator.