JPH05304637A - Television receiver - Google Patents

Abstract

PURPOSE: To make it unnecessary for a user to store the connection of a VCR to an auxiliary input and manually select an auxiliary input in order to observe a signal from the VCR by automatically selecting an input suitable for observing a VCR signal in a TV receiver. CONSTITUTION: A remote control unit 32 has keys for controlling the TV receiver and an external signal source such as UP, DN, ANT, and VCR. When a VCR controlling key is depressed, its corresponding control instruction is sent to the VCR. The TV receiver is provided with a video switch 18 driven by a controller 30 for selecting an antenna S1 or auxiliary input S2 video signal for display. When the energization of a VCR controlling remote control key is sensed, the controller 30 in the TV receiver selects and displays a signal from the auxiliary input S2.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to televisions of the type having a radio frequency (RF) video input, a baseband video input, and a switch for selecting which of the input signals from these inputs to be displayed. It concerns John receivers.

[0002]

BACKGROUND OF THE INVENTION Television receivers having multiple inputs for RF modulated video signals and baseband video input signals are well known and are commonly referred to as "receivers / monitors". In such a receiver, a normal broadcast or cable signal is applied to the RF input and the tuner selects the required channel for display of that signal. In addition, a baseband video input is provided for a signal source such as a video cassette recorder (VCR) or computer having a baseband video output, which allows remodulation of the video signal at the signal source and subsequent reception in the receiver. The demodulation at 1 is unnecessary, and as a result, an excellent image is obtained when such a signal source is used.

In order to be compatible with conventional televisions and newer receivers / monitors, it is common for videocassette recorders to have both RF and baseband outputs. Therefore, there are more than one way to connect a VCR to a television receiver / monitor. For example, the VCR RF output can be connected to the receiver RF input. To make this connection, the receiver is tuned to one of the two television channels (eg, 3 or 4 channels) normally provided in the VCR for output channel selection.

Another method is to connect the baseband audio and video outputs of the VCR to the baseband audio and video inputs of the receiver. This method is usually preferred. This is because, as described above, this method can eliminate the possibility of signal distortion due to modulation and demodulation of audio and video signals. However, in some cases it may be desirable to connect a VCR that has only RF output to the receiver / monitor. In this case, there is no choice and the RF output of the VCR must be connected to the RF (tuner) input of the receiver.

[0005]

SUMMARY OF THE INVENTION In one aspect, the present invention provides for operation with a receiver / monitor with a signal source that has only RF output and a signal source that has both baseband and RF output. , It was made because it was found that a problem would occur. For example, when an external person who does not know how the VCR and the television receiver / monitor are connected plays a video tape, the VCR is connected to the baseband input of the receiver / monitor. However, there is a possibility that the receiver / monitor will be set to the RF mode. Alternatively, conversely, the baseband (auxiliary input) mode may be selected when the RF mode is used.

In this way, if the first selection is wrong,
You will be confused. Sometimes the owner of the device also forgets how the device was configured and has to follow the wiring to know which mode of VCR to select, or the receiver / monitor. It can be time consuming to manually adjust and look for the VCR signal. The present invention is intended to solve such a problem.

A television receiver embodying the invention provides tuner means for providing a first video signal when tuned to a television broadcast channel and a second video signal when energized. It includes auxiliary input means for connecting to an external signal source and display means. Switch means is provided having a tuner position for coupling the first signal to the display means and an auxiliary position for coupling the second signal to the display means.

Detecting means detect the presence of a valid video component of the combined signal and generate an indicator signal. There is provided control means coupled to the keyboard means and having a first mode of operation for placing the switch means in the tuner position in response to operation of the first key. The control means takes the second operation mode in response to the operation of the second key, and first places the switch means in the auxiliary position, and thereafter,
If no valid video indication signal is present, then
Place the switch means in the tuner position.

In yet another aspect of the invention, the receiver includes tuning voltage generator means for providing tuning voltage to the tuner means in response to the control means, the control means comprising the second operation. In mode, after placing the switch means in the tuner position, a control signal is provided to the tuning voltage generator means to cause the tuner to tune to a given channel.

In a further aspect of the invention, the control means is responsive to the second operating mode in response to the absence of a valid video display signal when the tuner means is tuned to the first predetermined channel. Second tuner means
Retune to the desired channel of.

In yet another aspect of the invention, the receiver comprises memory means for recording the channel number the tuner means was previously tuned to during the first mode of operation of the control means. And the control means, in the second mode of operation, causes the tuning voltage generator means to operate in response to the absence of a valid video indication signal when the tuner means is tuned to the second predetermined channel. The means is adapted to be retuned to the channel number stored in the memory means.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENT The receiver shown in FIG. 1 is for connection to a television antenna, cable system, or other suitable source of RF modulated video signals, such as the RF output of a video cassette recorder (VCR). It includes a tuner 10 having an antenna input terminal 12.

The tuner output signal S1 is supplied to an IF signal processing and demodulation unit 14 which, in a conventional configuration, has intermediate frequency (IF) amplification and video signal demodulation functions and which produces a baseband video output signal S2. .. Also, an auxiliary input terminal 16 is provided for connection to an external signal source of the baseband video signal S3 supplied from, for example, a VCR having a baseband video output, a computer, or another appropriate signal source. There is. Video cassette recorders with both RF and baseband video outputs are commercially available.

The baseband signal S2 and the auxiliary video signal S3 selected by the tuner are selectively coupled to the display unit 20 via the normal video processing unit 22 to display the coupled signal S4. A video switch 18 for switching on is provided. The video processing unit 22 provides a combined signal S4, such as luma / chroma separation, hue and saturation control, peaking and contrast control, sweep signal generation, etc., to the unit 20 (e.g., direct view video tube, projection type device, Alternatively, it performs the functions to allow display on other suitable video display devices).

Channel selection and control of the switch 18 by the tuner 10 is provided by a microprocessor-based controller 30. The controller 30 includes up / down channel scan control keys (UP, DN),
Antenna / VCR mode selection keys (ANT, VCR) and a pair of channel storage and deletion keys (STORE, E)
RASE) is received from the keyboard 32.

Controller 30 is coupled via bus 34 to read only memory (ROM) 36, random access memory (RAM) 38 and electrically erasable programmable ROM (EEPROM) 40. RO
M36 stores the operation program of the control device, RAM3
8 constitutes a scratch pad memory, and EEPROM4
0 stores a list of channels selected by the user.

The controller 30 outputs a band select signal to the tuner 10 through bus 42 to select the band to be tuned (eg, low, medium, high band VHF, UHF, etc.), and a specific for the tuner 10. An output adapted to provide a control signal to a tuning voltage generator 44 which produces a channel tuning voltage. As the tuning voltage generator 44, for example, on September 20, 1983, Mr. J. Tults and Mr. M. Fr.
U.S. Pat. No. 4,405,94 issued to Mr.
The frequency synthesizing type described in No. 7 can be used. Another example is U.S. Pat. No. 4,485,4 issued to Mr. Taltz on Nov. 27, 1984.
No. 04 is shown.

An automatic fine tuning (AFT) unit 46 is coupled to the IF signal processing / demodulating unit 14, and
The T signal is provided to controller 30 to fine tune the tuning voltage generator to the channel selected by the user using the UP / DN channel select keys on keyboard unit 32. STORE and ERA on the keyboard unit 32
The SE key allows the user to write to EEPROM 40 a list of desired channels to which tuner 10 should be tuned in response to the UP / DN channel select keys.

The normal television receiver described above /
In the monitor, when the ANT key on the keyboard 32 is operated, the switch 18 is placed in the antenna (tuner) position, the tuner signal S2 is selected for display on the display unit 20, and when the VCR key is operated, it is normal. Means that the switch 18 is in the auxiliary position and the signal S3 is displayed on the display unit 20. According to the invention, the state of the switch 18 is, in VCR mode, the signal selected by the switch 18, that is,
It is intended to depend on whether the presence of a "valid" video signal in signal S4 is detected.

"Valid" means here that the signal S4 is in fact a video signal, for example when the tuner 10 is tuned to an empty channel or the auxiliary input 16
Means that signal S4 is clearly not noise, such as when is not coupled to the source or when the source to which auxiliary input 16 is coupled is not energized.

In accordance with the present invention, the receiver / monitor of FIG. 1 receives the sync signal component of signal S4 provided by video processing unit 22 and is "effective video" when signal S4 is an effective video signal. Video signal detector 4 coupled to supply an instruction signal S5 to the controller 30
Eight. The detector 48 can be realized by detecting the synchronization component of the signal S4 that matches the given broadcasting system.

In the NTSC system video signal, the vertical synchronizing signal is 59.94 Hz for color broadcasting and 6 for black and white.
It has a frequency of 0 Hz and the horizontal sync component is 1 in color.
It is 5.734 Hz, and black and white is 15.750 Hz. N
In a TSC type receiver, when a vertical synchronizing signal is used to detect an effective signal, the detection range is at least 5
It is necessary to set the frequency to 9.94 Hz to 60 Hz, and similarly, in the case of the horizontal synchronizing signal, the detection range is at least 15.7.
It is necessary to cover the range of 34 Hz to 15.750 Hz. If desired, both vertical and horizontal sync signals may be used to detect a valid video signal.

For PAL or SECAM receivers, the respective vertical and / or horizontal sync signal frequencies can be used to identify valid video signals. Another method for detecting sync signal timing to identify "valid" video signals (ie, those that are distinct from noise) is to measure the width or amplitude of the signal (up to the signal's tip or pouch). And confirm that the signal is actually a video signal and not just noise.

In the presently recommended application of the principles of the present invention, as shown in FIG. 2, the controller 30 activates the VCR key on the keyboard 32 and the presence or absence of a valid video instruction signal S5, as will be described. Is programmed to respond to. Initially, as with conventional receivers,
Controller 30 puts switch 18 in tuner mode when the ANTENNA key is energized. However, if the user scans the VCR key, the program of FIG. 2 will be launched.

The first program step is "no-o
In p ', this means that no action is taken. The program simply gives a short delay (eg 200 ms). This configuration of the invention is a measure for the user with a so-called integrated remote control, in which one remote control unit controls both the VCR and the television receiver. Pressing the VCR key provided on such a remote control automatically turns on the VCR. The delay provided by the first no-op program step provides time for the VCR to power up and stabilize.

The second program step is switch 1
Sending a signal to switch 18 to put 8 into the auxiliary input selection mode. At this time, since the time sufficient for the VCR to receive power supply has elapsed, if the VCR is connected to the auxiliary input terminal 16, the VCR outputs the video signal to the terminal 1.
It supplies to 6.

The third step is again to give a 200 millisecond delay, during which no action is taken. The purpose of this delay is to give the video detector 48 time to check whether the signal S4 is a true valid video signal. In this case, it should be noted that the user can change the RF output of the VCR to the auxiliary input terminal 16
Instead, it may be connected to the antenna input terminal 12. In that case, the signal S4 becomes an invalid signal, that is, noise.

The fourth program step is the verification of signal S4 by examining the output of video detector 48. If a valid video signal is found, the program ends and switch 18 remains in the auxiliary input position.
The VCR baseband output signal (terminal 16) is coupled to the display unit 20. However, when the signal S5 indicates that the video signal is not valid, the controller 30
When the switch 18 is in the tuner position, the program ends.

The reason why the switch 18 is returned to the tuner position by the controller 30 when a valid video signal coupled by the switch 18 is not detected after the operation of the VCR key is that the VCR signal is fed to the auxiliary input terminal in the VCR mode. If not found, your system is VC
This is because there is a high possibility that R is connected to the tuner. Thus, the advantage of performing a signal search by operating the VCR key is that any user or anyone may know what configuration is used to operate in the system VCR mode. There is no need to stay.

That is, the system first assumes that a VCR baseband input is being used, checks to see if there is a valid video input signal, and if no valid video signal is present, automatically Switch to tuner input. These features of the invention increase the success rate of successfully finding and displaying the VCR signal when operating the system in VCR mode.

FIG. 3 is a development of the flow chart of FIG. 2 so that when the VCR key on the keyboard 32 is operated, the VCR signal is automatically found and displayed more effectively than in the case of FIG. It is equipped with another feature to enable the selection.

In addition to automatically switching to the tuner input when no valid video signal is found on the auxiliary input, controller 30 also performs a channel search for a valid video signal. That is, when the switch 18 is returned to the tuner position, the controller 30 first tunes the tuner 10 to channel 3. If channel 3 is valid (ie, "sync signal is valid"), the program ends. If channel 3 is not active, controller 30 tunes tuner 10 to channel 4. If channel 4 is valid, the program ends.

Finally, if channel 4 was also not active, controller 30 tunes tuner 10 to the channel that the receiver was tuned to before VCR mode was selected. The information of this last channel gives a command to the control unit 30 by the first step of the program of FIG.
It is obtained by storing the channel number that was synchronized with. The RAM 38 or the EEROM 40 can be used for the previous channel number storing function.

In the case of this embodiment, as explained previously,
The receiver automatically checks all possibilities of VCR connection (ie auxiliary input connection, tuner connection with channel 3 and tuner connection with channel 4), and in addition if VCR is not connected. And can also be checked if the VCR is not turned on. In this latter case, when no valid video signal is detected on the auxiliary input and channels 3 and 4, no further search is performed and the last tuned channel is returned.

[Brief description of drawings]

FIG. 1 is a block circuit diagram of a television receiver embodying the present invention.

FIG. 2 is a flowchart illustrating an operation of a control device used in the receiver of FIG.

FIG. 3 is a flowchart illustrating an operation of a control device used in the receiver of FIG.

[Explanation of symbols]

 10 Tuner Means 16 Auxiliary Input Means 18 Switch Means 20 Display Means 30 Control Means 32 Keyboard 48 Detecting Means

Claims (1)

[Claims] 1. A tuner means for providing a first video signal when tuned to a television broadcast channel and for connecting to an external signal source for providing a second video signal when energized. Switch means having auxiliary input means, display means, a tuner position for coupling the first video signal to the display means, and an auxiliary position for coupling the second video signal to the display means. Remote control means for generating a remote control signal for controlling the television receiver and the external signal source, and remote control signal reception for receiving the remote control signal. Means and a remote control signal receiving means for setting the switch means to the tuner position in response to actuation of a first one of the plurality of keys. Control means having an operation mode, the remote control means generating a remote control signal for controlling the external signal source in response to activation of a second one of the plurality of keys, The control means has a second operation mode for setting the switch means to the auxiliary position in response to detection of the bias of the second one of the plurality of keys.
Television receiver.