KR19980041550A - Automatic fine tuning method of TV using voice noise signal - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fine adjustment method applied to a television having a voice noise detection unit (19) for detecting the level of noise signals contained in a voice signal applied to a speaker (18), in particular a power switch (23) of a television. When turned on, the first and second steps 101 to 103 for comparing the voice noise level measured by the voice noise detector 19 with a preset reference value and the voice noise level measured in the first step are greater than the preset reference value. If larger, the second step (104 to 105) of increasing the local oscillation frequency of the tuner 12 and observing the change of the voice noise level, and if the voice noise level is reduced in the second step, the measured voice noise level is preset. A third step (106) of increasing the local oscillation frequency until it is equal to the reference value; and if the voice noise level is increased in the second step, the local oscillation frequency is measured until the measured voice noise level is equal to the preset reference value. It comprises a fourth step (107 to 108) for reducing the frequency, it is possible to always maintain the optimum receiving condition of the television.

Description

Automatic fine tuning method of TV using voice noise signal

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for fine tuning a television, and in particular, a television using a voice noise signal which automatically performs fine adjustment according to a level of a noise signal included in a voice signal applied to a speaker to always maintain an optimal reception state. Of the automatic fine tuning method.

In general, a television tuner plays two roles of selecting a high frequency signal of a channel to be received from a plurality of high frequency signals emitted from an antenna and converting the selected signal into an intermediate frequency signal which is easy to amplify.

Figure 1 is a block diagram showing the configuration of a general tuner that performs the above role, and is largely composed of a UHF tuner 1 and a VHF tuner (2). The VHF tuner 2 is composed of an input circuit section 3, a high frequency amplification circuit section 4, a local oscillation circuit section 5, and a mixed circuit section 6, and the UHF tuner 1 has a high frequency amplification circuit section omitted. Except that, it has the same configuration as the VHF tuner 2.

The operation of each component of the VHF tuner 2 is as follows. First, the input circuit section 3 matches the input impedance of the feed line from the antenna ANT2 and the high frequency amplification circuit section 4 to effectively supply the signal induced by the VHF antenna ANT2 to the high frequency amplification circuit section 4. It removes unnecessary signals that interfere, and the high frequency amplification circuit section 4 improves the signal-to-noise ratio (SN ratio) by selecting and amplifying signals of a desired channel. On the other hand, the local oscillation circuit section 5 generates a local oscillation signal necessary for producing an intermediate frequency signal, and always generates a signal having a frequency higher than the frequency of the reception channel image carrier by the image intermediate frequency. For example, since the current image intermediate frequency is 58.75 MHz, when receiving the third channel (image carrier: 103.25 MHz), the local oscillation frequency is 103.25 + 58.75 = 162.00 MHz. In addition, the mixed circuit unit 6 generates an intermediate frequency signal IF by mixing the desired channel signal amplified by the high frequency amplification circuit unit 4 and the local oscillation signal.

When receiving the VHF broadcast, the VHF tuner (2) of the tuner configured as described above selects and amplifies a desired channel signal, and at the same time, an intermediate frequency of 58.74 MHz so as to easily amplify the amplified signal in the image intermediate frequency amplifier circuit of the next stage. Convert to a signal. When receiving a UHF broadcast, the UHF tuner 1 selects and amplifies a signal of a desired channel, converts it into an intermediate frequency signal of 58.74 MHz, and applies it to the high frequency amplification circuit section 4 of the VHF tuner 2, where the VHF The tuner 2 operates as part of the intermediate frequency amplifier circuit portion.

In order to obtain the best image through the tuner as described above, the local oscillation frequency must be accurately adjusted so that the image intermediate frequency obtained at the output side of the tuner is 58.75 MHz. However, since the local oscillation frequency can be changed due to the change of ambient temperature or the replacement of the channel, fine tuning (AFT) should be performed to maintain the correct local oscillation frequency.

In the conventional television, fine tuning is mainly performed by using an image carrier of 58.75MHZ extracted from a signal output from an image intermediate frequency amplifier. However, in the present invention, fine tuning is performed using a noise signal included in an audio signal applied to a speaker. Its purpose is to provide a way to do this.

In order to achieve the above object, the present invention provides a fine adjustment method applied to a television having a voice noise detector for detecting a level of a noise signal included in a voice signal applied to a speaker, wherein the power switch of the television is turned on. (on) When the voice noise level measured by the voice noise detector is compared with a preset reference value, and the voice noise level measured by the first step is larger than the preset reference value, the local oscillation frequency of the tuner is increased and the voice is increased. A second step of observing a change in the noise level, and a third step of increasing the local oscillation frequency until the measured voice noise level is equal to a predetermined reference value when the voice noise level is decreased in the second step; When the voice noise level increases in step 2, the local oscillation frequency is decreased until the measured voice noise level is equal to the preset reference value. The key is characterized by having a fourth step.

1 is a block diagram schematically showing a configuration of a general tuner;

2 is a block diagram schematically showing the configuration of a television to which the present invention is applied;

3 is a flowchart showing an automatic fine adjustment method of a television according to the present invention.

* Description of the symbols for the main parts of the drawings *

11: antenna 12: tuner

13 image processor 14 image amplifier

15: water pipe (CRT) 16: voice processing unit

17: voice amplifier 18: speaker

19: voice noise detection unit 20: micom

21 control unit 22 operation unit

23: power switch

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram schematically showing the configuration of a television to which the present invention is applied, and selectively receives and amplifies a broadcast signal desired by a viewer among broadcast signals output from a plurality of broadcast stations, thereby obtaining stable amplification and necessary selectivity characteristics. A tuner 12 for converting an intermediate frequency signal, that is, 58.75 MHz for a video signal and 54.25 MHz for an audio signal, is connected to the reception antenna 11. Among the intermediate frequency signals converted by the tuner 12, the image intermediate frequency signal is applied to the image processor 13. The image processor 13 amplifies and detects the input image intermediate frequency signal to detect the image from the image intermediate frequency signal. Extract the signal. The extracted video signal is amplified by the video amplifier 14 and provided to the water pipe 15. On the other hand, the intermediate frequency signal of the intermediate frequency signal converted by the tuner 12 is applied to the speech processing unit 16. The speech processor 16 extracts and amplifies the 4.5 MHz speech middle frequency signal from the input 54.25 MHz speech middle frequency signal, and FM-detects the amplified 4.5 MHz speech middle frequency signal to extract the speech signal. The extracted voice signal is amplified by the voice amplifier 17 and provided to the speaker 18 and the voice noise detector 19. The voice noise detector 19 measures the level of the noise signal included in the voice signal output from the voice amplifier 17 and applies it to the microcomputer 20.

The microcomputer 20 for controlling each component of the television system includes a control unit 21 and a calculating unit 22. The calculating unit 22 compares the noise signal level measured by the voice noise detector 19 with a preset reference value. Perform the role of comparison.

Meanwhile, when the power switch 24 of the television is turned on, the controller 21 provides the noise signal level measured by the voice noise detector 19 to the calculator 22, and according to the output result of the calculator 22. The local oscillation frequency of the tuner 12 is finely adjusted to obtain the best image.

2 is a flowchart illustrating an automatic fine tuning method of a television according to the present invention applied to a television configured as described above, wherein a voice noise detector 19 detects a level of a noise signal included in an audio signal applied to a speaker 18. In the fine adjustment method applied to a television having a), a first step of comparing the sound noise level measured by the sound noise detection unit 19 with a preset reference value when the power switch 23 of the television is turned on; A second step of increasing the local oscillation frequency of the tuner 12 and observing a change in the voice noise level if the voice noise level measured in the first step is larger than a preset reference value; and in the second step, the voice noise level is increased. Is reduced, the third step of increasing the local oscillation frequency until the measured voice noise level is equal to the preset reference value, and if the voice noise level is increased in the second step, A fourth step of reducing the local oscillation frequency equal to the reference value until the specified voice noise rebael predetermined showing a switch works.

According to the present invention configured as described above, when the viewer turns on the power switch 23 to watch television, the controller 20 transfers the voice noise level measured by the voice noise detector 19 to the calculator 22. Provide 102. Accordingly, the calculator 22 compares the measured voice noise level with a preset reference value to obtain an optimal image (103).

Since the optimal image cannot be obtained when the measured voice noise level is larger than the preset reference value, the controller 21 increases the local oscillation frequency of the tuner 12 and observes the change of the voice noise level (104 to 105). When the voice noise level is decreased, the controller 21 increases the local oscillation frequency until the measured voice noise level is equal to the preset reference value (106), and when the measured voice noise level is equal to the preset reference value, the current channel After storing the data in the internal memory (109), the video and audio signals are output through the water pipe 15 and the speaker 18, respectively (110).

Meanwhile, when the voice noise level increases despite the increase in the local oscillation frequency, the controller 21 decreases the local oscillation frequency of the tuner 12 until the measured voice noise level is equal to the preset reference value (107 to 107). 108). When the measured sound noise level is equal to the preset reference value, the controller 21 stores the current channel data in the internal memory (109), and outputs the video and audio signals through the water pipe (15) and the speaker (18), respectively. (110).

As described above, the present invention automatically maintains an optimum television reception state because the fine adjustment is automatically performed according to the level of the noise signal included in the voice signal applied to the speaker.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention should be defined only by the appended claims.

Claims (2)

In the fine adjustment method applied to a television having a voice noise detector (19) for detecting the level of a noise signal included in a voice signal applied to a speaker (18), A first step (101 to 103) for comparing the sound noise level measured by the sound noise detection unit 19 with a preset reference value when the power switch 23 of the television is turned on; A second step (104 to 105) of increasing the local oscillation frequency of the tuner 12 and observing a change of the voice noise level when the voice noise level measured in the first step is larger than a preset reference value; A third step (106) of increasing the local oscillation frequency until the measured voice noise level is equal to a preset reference value when the voice noise level is decreased in the second step; And a fourth step (107 to 108) for reducing the local oscillation frequency until the measured voice noise level is equal to a preset reference value when the voice noise level is increased in the second step. Automatic fine tuning method of used TV. The method of claim 1, further comprising storing the unadjusted channel data in a memory when the fine adjustment is completed.