JPH05300523A - Color system switching device - Google Patents

Abstract

PURPOSE:To provide a faithful automatic switching device for TV systems of a SECAM system, a PAL system, etc. CONSTITUTION:The system switch data (a), the tuning voltage data (b), the band data (c), and the channel display data are stored in an E<2>PROM 10 as the channel preset data. When a channel is selected, a CPU 11 fetches the data (b) and (c) out of the E<2>PROM 10 and applies them to a tuner 12 via a D/A converter 13. Meanwhile the data (a) are sent to an IF circuit 14 and a voice IF is switched. At the same time, the data (a) are sent to a video circuit 15 and a color demodulating circuit is switched.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television color system (SECAM system / PAL system / NTSC system, etc.) switching device, and more particularly to a system automatic switching system.

[0002]

2. Description of the Related Art Recently, the TV broadcasting system of the former Eastern European countries is S.
Although the ECAM system (line-sequential transmission method in which color signals are FM-modulated) was broadcast, the PAL system (N
With the improved TSC system, it becomes possible to receive broadcasts of quadrature phase modulation system for color signals. SECAM system / PAL
A television capable of receiving both types of systems is required. In Hungary, for example, CATV (cable T
According to V), it is confirmed that both types of broadcasting are being performed.

FIG. 7 is a block diagram of a system switching device in a conventional television receiver. The channel selection circuit shown in FIG. 7 is a voltage (voltage) synthesized tuning system, and when it is used in each home, the channel preset is performed first.

The channel preset is to first determine whether the receiving channel is a VHF low band, a high band, or a UHF band.
The band data C represented by a digital signal of 2 to 3 bits is stored in a storage device (hereinafter referred to as E ² PROM) (electrically erasable and writable ROM) 101.

Next, a tuning voltage (analog voltage 0 to 30 V) d applied to determine the tuning frequency of the tuner circuit 12 is converted into a 14-bit digital signal, and E ² PR is obtained as tuning voltage data b.
Stored in OM101. The above setting is repeated for the number of reception channels, and the channel preset is completed.

When a channel key is pressed to select a channel, the microcomputer 102 outputs the channel preset data corresponding to the selected channel to the E ² PROM.
101, the band data C and the tuning voltage data b are converted into an analog tuning voltage d by the D / A converter 13 and sent to the tuner circuit 12.
The tuner circuit 12 tunes to the band (frequency band) selected by the applied signal c and voltage d and the channel frequency within the band, and outputs the converted intermediate frequency IF. The IF amplifier circuit 103 also demodulates the audio signal. In this case, the SECAM method 6.5 MHz, the PAL method 5.
Demodulation processing is performed for both audio intermediate frequencies of 5 MHz.

The demodulated audio signal is reproduced by the speaker 18 via the audio circuit 16. On the other hand, the video circuit 104 uses the signal format such as the modulation type of the color signal in the SECAM.
CRT 1
A color image is displayed on 7.

[0008]

However, in the method of discriminating between the conventional SECAM system and PAL system broadcast signals shown in FIG. 7 and automatically switching the color system, the format of the transmitted radio signal is always correct. However, there is a problem in that there is a possibility of malfunction such as the screen not being colored due to a misjudgment.

Further, in order to avoid the malfunction of the automatic discrimination system, the SECAM system / PAL system / (AUTO) is forcibly switched by a slide switch or a remote controller.
When the methods / PAL methods coexist, there is a problem in that it is necessary to operate the switch (or remote controller) one by one, which is complicated.

The present invention has been made in view of the above circumstances. By storing the television system for each channel and setting the color system at the same time when performing channel presetting, the television is automatically switched every time the channel is switched. An object of the present invention is to provide a color system switching device in which the system faithfully switches.

[0011]

[Means for Solving the Problems]
Therefore, according to the present invention, the preset channel preset data
To Store in storage device and switch TV system for each channel
Channel selection for the selected system.
Tuning voltage of tuning circuit for voltage synthesizer
Data and channel display data and TV system automatically
System switching data for switching and channel pre-setting
A storage device to store as set data and the
And the band data stored in the storage device and the tu
The voltage synthesizer that takes in the learning voltage data
Sends to the tuning circuit and captures the system switching data
When the frequency is switched by sending it to the audio intermediate frequency amplifier circuit
At the same time, it is sent to the video circuit to switch the color demodulation circuit.
Equipped with means.

[0012]

With the above configuration, band data for selecting the channel frequency band at the time of channel presetting, tuning voltage data of the voltage synthesizer for tuning and tuning to the channel frequency of the band selected by the band data, and tuning channel In addition to the channel display data for the selected channel, system switching data for automatically switching the television system is also set and stored as preset data for that channel in the storage device, and control is performed when the channel is actually selected. The means selects the band data and tuning voltage data of the selected channel from the storage device and sends it to the tuning circuit to perform the channel selection, and the system switching data of the channel is acquired from the storage device to obtain the audio intermediate frequency. The TV channel for sending and receiving channels to the amplifier circuit Switching frequency in accordance with mat switch according to the color demodulation circuit also format of the video circuit at the same time, and displayed as an image, so also it receives channel displayed by the channel display data, loyal automatic switching system it is possible for each channel switching.

[0013]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of a color system switching device according to an embodiment of the present invention.

In FIG. 1, a storage device (hereinafter referred to as E ² PR
OM) 10 as channel preset data,
In addition to system switching data a, tuning voltage data b, band data c, channel display data are also stored.

At the time of channel selection, the CPU (microcomputer) 11 fetches the band data c from the E ² PROM 10 and sends it to the tuner circuit 12 to select a band, fetch the tuning voltage data b, and use the D / A converter 13 to select an analog signal. The tuning voltage d is converted and sent to the tuner circuit 12 for channel selection and IF conversion.

Further, the system switching data a is fetched, the audio intermediate frequency of the IF circuit 14 is switched and demodulated to the frequency of the television system format of the receiving channel,
It is reproduced by the speaker 18 via the audio circuit 16. On the other hand, the color demodulation circuit of the video circuit 15 is set to SECAM system / PA.
An image reproduced by switching the color by the L system and reproducing the color
To display.

FIG. 2 is a diagram showing an example of the contents of the E ² PROM shown in FIG.

In FIG. 2, positions 1 to 5 indicate the position numbers of the channel selection keys, and the band data c
Is a 2-bit signal,

[00] is VHF-L, [01]
Is VHF-H, [10] is UHF, position 1
The band selected in VHF-H, UH in position 2
It shows that it is F. Tuning voltage data b is 14
Represented by a bit signal, [00 ... 0] represents the voltage OV, [1
1 ... 1] represents up to 30 OV, and the channel at position 1 shows that [0110 ...] Has a tuner applied voltage of 1V.

The channel display data e of the selected actual channel is represented by an 8-bit signal and [00 ... 0] is 0.
ch (channel), [00 ... 1] indicates 1ch.

The system switching data a is represented by a 2-bit signal,

[00] is the PAL system and [01] is the SECAM
In the system, [10] indicates AUTO, and the selection of position 1 indicates that it is a SECAM system television signal.

FIG. 3 is a block diagram of input / output terminals of the CPU shown in FIG.

In FIG. 3, the E ² PROM of the CPU 11
10 The system switching signal a is sent from the input / output terminal 20 and the terminal 21, and is set to "L".

In the case of [00], the audio intermediate frequency of the PAL system is 5.5 MHz, and "H" is set to [0].
In the case of 1], SECAM audio intermediate frequency 6.5 MH
Switch to z. A channel display signal of the OSD circuit (display signal circuit) 50 is sent from the terminal 22 to synthesize and display the channel number on the display screen.

The terminal 30 is VHF-L of the band data c,
Reference numeral 31 sends a selection signal of VHF-H and 32HUHF to the tuner 3. The V _T of the tuning voltage data b is input to the D / A converter 13 from the terminal 33. A remote control input f is detected and input from the terminal 34, and a key input g such as a position number is input from the terminal 35.

FIG. 4 is an operation panel diagram of a television receiver incorporating the apparatus of the embodiment shown in FIG.

In FIG. 4, 1, 6 and 7 are channel setting buttons, 2 is a band switching button, and 3 is a channel button (key) for selecting a channel. 4 _A is a channel matching button, 4 _B is a color system button that is selected according to the receiving channel system, and 5 is a tuning button.

FIG. 5 is an explanatory diagram of a channel preset operation procedure on the operation panel of FIG. A to H in the drawing are the preset operation order, and the numbers 1 to 7 correspond to the respective button numbers on the operation panel in FIG.

FIG. 6 is an operation flowchart of the embodiment shown in FIG.

Next, the operation will be described. Figure 5
The first channel preset is shown in the order of setting. First, when the channel setting button 1 on the panel is pressed to enter the preset state, the display screen on the cathode ray tube 17 shows the selection band VHF-L at the center position and the left side. The channel number is displayed on the right side, and the channel indicating the actual broadcast channel number is displayed on the right side. The current display is 1 for the channel number and 01 for the broadcast channel (A).

In the following, taking as an example the case of presetting the channel number 5 (direct channel selection button number when operating from the remote control) with the UAL19 channel of the PAL system, the band switching button 2 is pressed and "VHF-
"UH" from the display of "L", "VHF-H", "UHF"
If "F" is selected, the band display is VHF-L on the display screen.
To UHF (B).

When the channel button 3 is pressed to search in the Δ ▽ direction and the channel number "5" is selected, the screen display shows channel number 5, broadcast channel 05, band UH.
It becomes F (C).

Next, press the combined button 4 _A to the channel, select the broadcast channel "19", the search direction of channel alignment button 4 _A is, △ button + of position (0
9), the ▽ button becomes the minus position (0 to 9). The screen display in this case is channel number 5, band UHF, and broadcast channel 19 (D).

Press the color system button 4 _B and press A (auto) → P (PAL) → S (SECAM) to P (PA
When L) is selected, the screen display is channel number 5, band UHF, and broadcast channel 19P, and P indicates the PAL system (E).

The UHF 19-channel image is searched by the tuning button 5, the screen is adjusted, and the screen display turns yellow during the search, and when the tuning button 5 is pressed, it shows green (F).

When the channel setting button 6 is pressed again, the signal of the receiving channel 19 is displayed on the screen for several seconds and the display 19P is displayed.
Is preset to the channel number 5 and the adjustment is completed (G), the screen returns to the normal screen (H). CPU1
The channel preset setting operation by 1 is completed, and each preset data is stored in the E ² PROM 10 as position 5.

FIG. 6 is a flow chart of the procedure for selecting the position 5 of the E ² PROM 10, which is actually set as the channel number 5. Channel selection button (CP
Position 5 is selected with the U key (f input of terminal 34) or the panel key (g input of terminal 35) (step S
-60). The CPU 11 determines the address of the contents of position 5 to be stored in the E ² PROM 10 (step S-
61).

The band data C, the tuning voltage data b, the system switching data a, and the channel display data e held as the contents of the position 5 are sent from the E ² PROM 10 to the CPU 11 from the terminal 20 (step S-62).

CPU which has received the data of position 5
11 switches the state of the output port according to each data, outputs UHF [10] of the band data C from the terminal 32 to the tuner circuit 3, and switches the reception band (step S).
-63).

The tuning voltage data 6 is output as V _T, the duty ratio of PWM (pulse width modulation) is changed, and it is sent to the D / A converter 13 from the terminal 33, and the D / A converter 1 is supplied.
In step 3, the analog tuning voltage d is applied to the tuner circuit 3 to select channel number 5 (broadcast channel 19P) (step S-64).

The channel display data e is sent to the OSD circuit 50 and 19P is displayed on the screen from the terminal 22 (step S
-65).

The signal "L" is sent from the terminal 21 to the system switching data a for switching the audio intermediate frequency.

Send [00] to PAL
It is switched to 5.5MHz for the system, and by switching the color system of the video circuit 15, "L"

A color demodulation circuit of the PAL system is switched by [00] (step S-66).

In this embodiment as described above, the system switching data is simultaneously set to E ² PRO at the time of channel presetting.
Since the IF circuit 14 and the video circuit 15 are stored in the memory M10 and the CPU 11 switches the IF circuit 14 and the video circuit 15 each time the channel is selected, faithful automatic system switching without malfunction can be performed.

The above embodiment can be used not only as a channel switching device but also as a system switching device for one or more AV inputs such as an audio device, a VTR, and a video disk recording input.

[0043]

As described above, according to the present invention, in addition to the preset data for channel selection to the voltage synthesizer tuner section, system switching data for automatically switching the television system is stored in the E ² PROM. Then, the system switching data is changed to E ² every time the channel is selected.
Since it is configured so that the audio intermediate frequency and the color demodulation circuit are switched by taking in from the PROM and sending it to the IF circuit and the video circuit, there is no malfunction of the color system like the conventional automatic discrimination method, and automatic faithful system switching is possible. This makes it possible to eliminate complications such as compulsory switching operations by mechanism switches.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a color system switching device according to an exemplary embodiment of the present invention.

FIG. 2 is a diagram showing an example of contents of an E ² PROM shown in FIG.

3 is a block diagram of input / output terminals of the CPU shown in FIG.

FIG. 4 is an operation panel diagram of a television receiver incorporating the device of the embodiment of FIG.

5 is an explanatory diagram of a channel preset operation procedure of the operation panel shown in FIG.

FIG. 6 is an operation flowchart of the embodiment shown in FIG.

FIG. 7 is a configuration diagram of a system switching device in a conventional television receiver.

[Explanation of symbols]

10 E ² PROM 11 CPU 12 Tuner 13 D / A Converter 14 IF Circuit 15 Video Circuit 16 Audio Circuit 17 CRT 18 Speaker

Claims (1)

[Claims] 1. Channel preset data set in advance
To Store in storage device and switch TV system for each channel
Channel selection for the selected system.
Tuning voltage of tuning circuit for voltage synthesizer
Data and channel display data and TV system automatically
System switching data for switching and channel pre-setting
A storage device to store as set data and the
And the band data stored in the storage device and the tu
The voltage synthesizer that takes in the learning voltage data
Sends to the tuning circuit and captures the system switching data
When the frequency is switched by sending it to the audio intermediate frequency amplifier circuit
At the same time, it is sent to the video circuit to switch the color demodulation circuit.
Switching of color system characterized by having control means
apparatus.