JP2000013700A - Field strength optimization circuit at every channel of television receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve receiving performance of a television receiver in a signal state which the RF-AGC of a tuner can not control in an area where a channel of weak electric field and a channel of strong electric field exist at the same time. SOLUTION: A circuit 3 which switches its gain with voltage control is attached to a booster 2, the gain control terminal of the circuit 3 is connected to a microcomputer 7 for channel selection control and a memory 8 which stores control voltage for each channel. And, gain control voltage of the booster which is stored in the memory 8 and is suitable for a channel is supplied to the booster 2 the moment the channel is switched.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a television receiver equipped with one terrestrial antenna input, a booster and a distributor, and two terrestrial tuners. Electric field strength appropriate for each channel of the television receiver which can ensure good reception state on all reception channels by preventing booster or tuner from causing cross modulation in strong electric field by booster equipped for S / N improvement The present invention relates to a conversion circuit.

[0002]

2. Description of the Related Art Conventional television receivers equipped with a single terrestrial antenna input, a distributor, and two terrestrial tuners do not have a booster inserted or have a gain even if a booster is equipped. The switch SW was only installed, and the user could not set it for each channel, but could only turn on or off the booster uniformly on any channel. When a channel having a weak electric field intensity and a channel having a strong electric field exist, one of the channels is deteriorated in the reception state and cannot be avoided.

[0003]

Many current television receivers are equipped with one terrestrial antenna input and distributed to connect two terrestrial tuners. In this state, the S / N deteriorates due to the loss of the electric field, so that a booster may be provided. However, since the electric field intensity differs for each channel, a good reception state is not necessarily obtained in all the channels. In other words, in a channel with a weak electric field strength, the reception state is improved by the booster. However, when a channel with a strong electric field strength exists in the channel, the reception state may be deteriorated by over-input in the booster section or the tuner section. . In other words, the tuner RF-
A signal state that cannot be controlled by AGC occurs. In order to solve such a phenomenon, it is necessary to switch the gain of the booster for each channel.

[0004]

In order to solve this problem, the present invention provides a booster equipped with a circuit capable of switching its gain by voltage control, and connecting this gain control terminal to a microcomputer for channel selection control. It is equipped with a memory that can store the control voltage every time, and is configured so that the gain control voltage of the booster suitable for the channel stored in the memory is supplied to the booster at the same time as changing the channel. is there.

According to the present invention, the gain of the booster can be set for each channel. Therefore, even in an area where a channel of a weak electric field and a channel of a strong electric field are present at the same time, it is possible to perform good reception on any channel. It is possible to provide an electric field strength optimization circuit for each channel of the machine.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the first aspect of the present invention, in a channel having a weak electric field intensity, a reception state is improved by a booster. In a channel having a strong electric field intensity, the gain of the booster is switched to increase a booster section or a tuner. The input over can be avoided in the section, and these can be set for each channel, so that there is an effect that a good reception state can be obtained in all the channels.

According to a second aspect of the present invention, in addition to the first aspect, when setting a channel at the time of installing a television, the operation status of the tuner is monitored by the RF-AGC and the automatic operation is performed. The gain switching of the booster can be set for each channel and can be stored in the memory, and has an effect that a good reception state can be obtained in all the channels.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. (Embodiment 1) FIG. 1 shows a circuit for optimizing the electric field strength for each channel of the television receiver of the first embodiment.

FIG. 1 shows a terrestrial TV antenna 1, a booster 2, a booster gain switching circuit 3 and a distributor 4, and two output terminals of the distributor 4 are terrestrial tuners (a). 5 and a terrestrial tuner (b) 6 are connected. Further, the microcomputer 7 for tuning control is a booster gain switching circuit 3 for the booster 2.
And a circuit that can switch the gain of the booster at the time of channel selection based on information for each channel of the memory 8 through this signal line.

(Embodiment 2) FIG. 2 shows a circuit for optimizing the electric field strength for each channel of the television receiver of the second embodiment.

FIG. 2 shows a terrestrial television antenna 1, a booster 2, a booster gain switching circuit 3 and a distributor 4. The two output terminals of the distributor 4 are terrestrial tuners (a). 5 and a terrestrial tuner (b) 6 are connected. Further, the microcomputer 7 for tuning control is a booster gain switching circuit 3 for the booster 2.
, And is configured so that the gain of the booster can be switched at the time of channel selection based on the information of each channel of the memory 8 through this signal line, and furthermore, a terrestrial tuner (a) 5 (or a terrestrial wave). The RF-AGC terminal of the tuner (b) 6) is connected to the microcomputer 7 for tuning control.
Here, the operating state of the tuner is monitored at the time of channel setting, and how the gain switching circuit 3 of the booster is set is determined. It is composed of a circuit for storing settings.

[0012]

As described above, according to the electric field intensity optimizing circuit for each channel of the television receiver of the present invention, the RF-tuning of the tuner is performed in an area where a weak electric field channel and a strong electric field channel exist simultaneously. In a signal state that cannot be controlled by AGC, the reception performance of the television receiver can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram of an electric field strength optimization circuit for each channel according to a first embodiment of the present invention;

FIG. 2 is a block diagram of an electric field strength optimization circuit for each channel according to a second embodiment of the present invention;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 terrestrial TV antenna 2 booster 3 booster gain switching circuit 4 distributor 5 terrestrial tuner (a) 6 terrestrial tuner (b) 7 microcomputer for channel selection control 8 memory

Claims (2)

[Claims] 1. A terrestrial antenna input is equipped with one system, a booster and a distributor are equipped, and two terrestrial tuners connected to the distributor are equipped. The gain of the booster is switched by voltage control. This gain control terminal is connected to a microcomputer for channel selection control.Equipped with a memory that can store the control voltage for each channel, the channel is changed and the memory is stored at the same time. An electric field strength optimization circuit for each channel of a television receiver, wherein the gain control voltage of the booster is supplied to the booster. 2. A configuration in which the voltage of the RF-AGC of the terrestrial tuner can be monitored by the tuning control microcomputer when the first channel is set, and the terrestrial tuner operates with the minimum gain. 2. The television receiver as claimed in claim 1, wherein the channel is stored in a memory so as to reduce the gain of the booster, and vice versa. Electric field strength optimization circuit for each machine channel.