JP2008199239A - Signal processing device, and signal playback device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To speedily select a desired input system in a signal playback device which has a plurality of input systems and switches the input systems in a sequential switching manner. <P>SOLUTION: The signal playback device is provided with a comparator 31 and a signal detecting circuit 30a having a diode 33 and a capacitor 34, between an input system 12a and a controller 14. A video signal input terminal of the input system 12a is connected to an inverting input terminal (+) of the comparator 31, a reference voltage Vref is connected to a noninverting input terminal (-), and the anode of the diode 33 is connected to an output terminal. One end of the capacitor 34 and the controller 41 are connected to the cathode of the diode 33, the other end of the capacitor 34 is grounded, and the rectifier 32 is composed of the diode 33 and the capacitor 34. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a signal processing apparatus and a signal reproduction apparatus that include a plurality of signal input terminals and that can be switched sequentially.

  A signal reproducing device such as a CRT (Cathode Ray Tube) or a liquid crystal display device or a television equipped with such a signal reproducing device is provided with a plurality of audio / video signal input terminals, such as a video deck or a DVD player. Some AV (Audio Visual) devices can be connected. In such a display device or the like, a changeover switch such as a button for selecting a desired terminal or display is provided on the main body or the remote control, and a user selects and outputs an input from the desired terminal. Become.

  As the selection method, for example, the applicant of the present application has proposed a method using a screen display of OSD (On Screen Display) (Patent Document 1). In this method, the terminal and the connection status of the device to the terminal are displayed on the screen as the OSD, and it becomes easy to select a desired terminal.

  Patent Document 1 proposes a method of displaying a terminal and the connection status of the device to the terminal on an screen as an OSD (On Screen Display), and facilitating selection of a desired terminal.

  However, even if the method of Patent Document 1 is used, when the change-over switch is of a sequentially switchable type, it is unlikely to be selected like a terminal to which no device is connected or a terminal to which no signal is input. Switching is possible including terminals. For this reason, the number of times the changeover switch is pressed increases until a terminal to which a device for reproducing desired images and sounds is connected is selected. Therefore, a method of skipping a terminal to which no device is connected (Patent Document 2) and a method of skipping a terminal to which no video signal is input (Patent Document 3) have been proposed.

Furthermore, even if a device is connected, a terminal that does not receive a signal from the device because it is not turned on is unlikely to be selected. A method has been proposed in which a terminal to which no video signal is input is skipped at the time of switching by detecting a synchronized signal.
JP 2006-03356 A Japanese Patent Laid-Open No. 10-262190 Japanese Patent Laid-Open No. 5-207386

  However, in the method proposed in Patent Document 3, the synchronization signal must be detected from the video signal, and a special circuit needs to be provided.

  Therefore, the present invention provides a sequential switching type change-over switch that can quickly select a desired input system by skipping an input system to which no signal is input when selecting an input system by simply providing a simple circuit. It is an object of the present invention to provide a signal processing apparatus having the above and a signal reproducing apparatus including the same.

  To achieve the above object, the present invention outputs any of a plurality of input systems, a signal processing unit that receives signals input to each of the input systems, and a signal that is input to the signal processing unit. A reproduction output unit; an input switching unit that sequentially switches the input system of the signal output to the reproduction output unit; an operation unit that outputs a switching signal that is operated by a user to switch the input system; and And a control device that causes the input switching unit to switch the input system in response to the switching signal from the input unit, the input system is connected to the non-inverting input between the input system and the control device. A comparator connected to a reference voltage at the inverting input, a diode connected to the output of the comparator and a cathode connected to the controller, and one end of the diode A signal detection circuit including a capacitor connected to the node and grounded at the other end, and when the voltage output from the signal detection circuit is less than a predetermined voltage, the corresponding input system is switched to the input system. It is characterized by skipping.

  The present invention also includes a plurality of input systems, a signal processing unit that receives signals input to each of the input systems, and an input switching unit that sequentially switches the input system of signals output from the signal processing unit in a switching manner. And a control unit that outputs a switching signal that is operated by a user to switch the input system, and a control device that receives the switching signal from the operation unit and causes the input switching unit to switch the input system. In the processing device, between the input system and the control device, a comparator in which the input system is connected to a non-inverting input and a reference voltage is connected to an inverting input, and an anode is connected to an output of the comparator and a cathode Comprises a signal detection circuit comprising a diode connected to the control device, and a capacitor having one end connected to the anode of the diode and the other end grounded. If the voltage output from the circuit output is less than the predetermined voltage, characterized in that skips over the input lines corresponding to the time of switching of the input system.

  According to the present invention, in the signal processing device configured as described above, the input system has at least one of a video signal input terminal and an audio signal input terminal, and at least one of the video signal input terminal and the audio signal input terminal is the above It is connected to a signal detection circuit.

  A signal processing apparatus according to the present invention includes the signal processing apparatus having the above-described configuration and a reproduction output unit that outputs any of the signals input to the signal processing unit.

  According to the present invention, it is possible to detect that a signal is input to the input system only by providing a simple circuit composed of a comparator, a diode, and a capacitor in a signal reproducing device having a conventional configuration. Since an input system to which no AV device is connected or an input system to which a signal from the AV device is not input can be skipped, a desired input system can be quickly selected.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a display device which is a signal reproducing device according to the present invention, and FIG. 2 is a circuit diagram of a signal detection circuit.

  As shown in FIG. 1, the display device 10 can be connected to a playback output unit 11 composed of a device for displaying images such as a liquid crystal panel or a CRT, or a device for outputting sound such as a speaker, or an AV device such as a video deck or a DVD player. A signal processing unit 13 that receives signals input from the input systems 12a, 12b, 12c, and 12d and the input systems 12a, 12b, 12c, and 12d and outputs a signal based on any of the signals to the reproduction output unit 11, A control device 14 that controls the overall operation of the display device 10, an operation unit 15 for a user to directly operate the display device 10 such as volume adjustment, and a signal based on the signal received from the remote controller 20, and the control device 14 Remote control signal control unit 17 for transmitting to

  The operation unit 15 and the remote controller 20 are provided with input system switching buttons 15a and 20a for selecting an input system to be output from the reproduction output unit 11 by the user from any of the input systems 12a, 12b, 12c, and 12d. The signal processing unit 13 is provided with an input switching unit 13a that switches the output from the reproduction output unit 11 to any one of the input systems 12a, 12b, 12c, and 12d based on the operation of the input system switching buttons 15a and 20a. It has been.

  Each input system 12a, 12b, 12c, 12d is provided with a video signal input terminal to which a video signal is input and an audio signal input terminal to which an audio signal is input. The video signal input terminal is an S terminal, a CVBS (Composite Video Burst Signal) terminal, or the like, and each of the input systems 12a, 12b, 12c, and 12d may include a plurality of these terminals.

  The input system switching of the display device 10 is a sequential switching type. Each time the input system switching buttons 15a and 20a are pressed, the control device 14 receives the signal and switches the input system to the input switching unit 13a of the signal processing unit 13. The input switching unit 13a switches the input system in the order of the input system 12a, the input system 12b, the input system 12c, the input system 12d, and the input system 12a.

  In the present embodiment, signal detection circuits 30a, 30b, 30c, and 30d are provided between the video signal input terminals of the input systems 12a, 12b, 12c, and 12d and the control device 14, respectively. The signal detection circuits 30a, 30b, 30c, and 30d include a comparator 31, a diode 33, and a capacitor 34 as shown in FIG. FIG. 2 shows only the input system 12a, and the input system 12a will be described below as an example, but the same applies to other input systems.

  The video signal input terminal of the input system 12a is connected to the inverting input terminal (+) of the comparator 31, the reference voltage Vref is connected to the non-inverting input terminal (−), and the anode of the diode 33 is connected to the output terminal. Yes. The cathode of the diode 33 is connected to one end of the capacitor 34 and the control device 14, and the other end of the capacitor 34 is grounded. The diode 33 and the capacitor 34 constitute a rectifier 32.

  When the voltage of the signal input to the video signal input terminal of the input system 12a exceeds the reference voltage Vref (for example, 0.2V), a voltage equal to or higher than a predetermined voltage V1 (for example, 2.0V) is output from the output terminal of the comparator 31. If the voltage of the signal input to the video signal input terminal is equal to or lower than the reference voltage Vref, no voltage is output from the output terminal of the comparator 31. A signal composed of the voltage output from the output terminal of the comparator 31 is smoothed by the rectifier 32 and input to the control device 14. In the control device 14, when a voltage equal to or higher than a predetermined voltage V2 (for example, 0.5 V) is input from the signal detection circuit 30a, it is recognized that a signal is input to the video signal input terminal of the corresponding input system.

  The signal input to the video signal input terminal is a video signal, and periodically has a blanking period and an effective period for scanning when output to the reproduction output unit 11. The video signal is equal to or higher than the reference voltage Vref in the effective period, and is lower than the reference voltage Vref in the blanking period. Since a signal obtained by smoothing the video signal is input to the control device 14 by the signal detection circuits 30a, 30b, 30c, and 30d having a simple configuration including the comparator 31, the diode 33, and the capacitor 34 as described above. During the period when the signal is input to the video signal input terminal, the control device 14 reliably detects that the signal is input to the video signal input terminal even if the video signal includes a blanking period where the voltage is low. be able to.

  With this configuration, when the input system switching buttons 15a and 20a are pressed to switch the input system, it is possible to skip the input system in which no video signal is input by the control device 14.

 For example, it is assumed that the input system 12c is currently selected, the video signals are input to the input systems 12b and 12c, and no video signal is input to the input systems 12a and 12d. In this case, assuming that the input system 12b is desired, conventionally, the input system switching buttons 15a and 20a have to be pressed a total of three times to switch from the input system 12c to the input systems 12d, 12a and 12b. However, according to the present invention, since the input systems 12a and 12d to which no video signal is input are skipped, the input system 12b can be quickly selected by simply pressing one of the input system switching buttons 15a and 20a. it can.

  Further, in the present embodiment, when image playback is started on a device connected to any of the input systems 12a, 12b, 12c, and 12d, the control device 14 of the display device 10 detects a signal from the device and You may make it select the input system to which the apparatus was connected. Thereby, even if it does not operate input system change button 15a, 20a, the input system to which the apparatus was connected can be selected automatically only by operating a desired apparatus. In this case, another input system may already be selected and a signal may be input through a plurality of input systems, and the input system in which input was last started may be selected with priority.

  In the present embodiment, when the display device 10 is in a standby state, when playback of an image is started with a device connected to any of the input systems 12a, 12b, 12c, and 12d, the control device 14 starts from the device. May be detected to turn on the main power of the display device 10 and select an input system to which the device is connected. Thereby, even if it does not operate the display apparatus 10, the main power supply of the display apparatus 10 can be turned on only by operating a desired apparatus, and the input system | strain to which the apparatus was connected can be selected automatically.

  In any of the above cases, the control device 14 may display an OSD to indicate which of the input systems 12a, 12b, 12c, and 12d is input.

  The signal detection circuits 30a, 30b, 30c, and 30d are not limited to the video signal input terminals of the input systems 12a, 12b, 12c, and 12d, but may be audio signal input terminals or video Both a signal input terminal and an audio signal input terminal may be used. When the audio signal input terminal is connected, detect that at least one of the video signal and the audio signal is input when both the audio signal, the video signal input terminal and the audio signal input terminal are connected. In any case, the above-described operation can be performed in the display device 10.

  Here, in FIG. 3, the signal detection circuit 30a in the case where a video signal having a period of 63.5 μsec (frequency: 15.75 kHz), an effective period of 52.7 μsec, and a blanking period of 10.8 μsec is input to the video signal input terminal. The graph of the change of the voltage of the signal input into the control apparatus 14 from FIG. In the graph of FIG. 3, the horizontal axis represents time, and the vertical axis represents voltage. In addition to the signal input to the control device 14 indicated by the solid line, the signal input to the video signal input terminal is indicated by the broken line. Similar results were obtained with the signal detection circuits 30b, 30c, and 30d.

  When signal input to the video signal input terminal is started at time 0, the voltage of the signal input from the signal detection circuit 30a to the control device 14 starts to rise as shown in FIG. It reaches 2.3 V in 130 μsec and becomes almost stable. The control device 14 recognizes that a signal is input to the video signal input terminal when a voltage equal to or higher than a predetermined voltage V2 (for example, 0.5 V) is input. For this reason, the input voltage is 0.5 V or more, and the controller 14 does not skip when switching by the control device 14 after 45 μsec from the start of input of the video signal, that is, after the 0.8th cycle of the video signal. This can reduce the possibility of skipping the input system to which the video signal is input.

  The display device 10 may include a television signal receiving unit, or may reproduce and output only audio. When the television signal receiving unit is provided, the television signal receiving unit may be handled as one of the input systems.

  The present invention can be used for an electronic apparatus having an input system that is switched by a sequential changeover type changeover switch.

The block diagram of the display apparatus which is the signal reproducing | regenerating apparatus concerning this invention Circuit diagram of a signal detection circuit according to the present invention Graph of change in voltage of signal input to control device from signal detection circuit

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Display apparatus 11 Reproduction | regeneration output part 12a Input system 12b Input system 12c Input system 12d Input system 13 Signal processing part 13a Input switching part 14 Controller 15 Operation part 15a Input system switching button 17 Remote control signal control part 20 Remote control 20a Input system switching button 30a Signal detection circuit 30b Signal detection circuit 30c Signal detection circuit 30d Signal detection circuit 31 Comparator 32 Rectifier 33 Diode 34 Capacitor

Claims (4)

A plurality of input systems, a signal processing unit that receives signals input to each of the input systems, a reproduction output unit that outputs any of the signals input to the signal processing unit, and an output to the reproduction output unit An input switching unit that sequentially switches the input system of the signal to be switched, an operation unit that outputs a switching signal that is operated by a user to switch the input system, and the input that receives the switching signal from the operation unit In a signal reproduction device comprising a control device that causes the switching unit to switch the input system,
A comparator in which the input system is connected to a non-inverting input and a reference voltage is connected to an inverting input between the input system and the control device; an anode is connected to an output of the comparator; and a cathode is the control device A signal detection circuit comprising a diode connected to the capacitor and a capacitor having one end connected to the anode of the diode and the other end grounded;
When the voltage output from the signal detection circuit is less than a predetermined voltage, the corresponding input system is skipped when the input system is switched. A plurality of input systems, a signal processing unit that receives signals input to each of the input systems, an input switching unit that sequentially switches the input system of signals output from the signal processing unit, and a user In a signal processing device comprising: an operation unit that operates to output a switching signal for switching the input system; and a control device that receives the switching signal from the operation unit and causes the input switching unit to switch the input system.
A comparator in which the input system is connected to a non-inverting input and a reference voltage is connected to an inverting input between the input system and the control device; an anode is connected to an output of the comparator; and a cathode is the control device A signal detection circuit comprising a diode connected to the capacitor and a capacitor having one end connected to the anode of the diode and the other end grounded;
When the voltage output from the signal detection circuit is less than a predetermined voltage, the corresponding input system is skipped when the input system is switched.   The input system includes at least one of a video signal input terminal and an audio signal input terminal, and at least one of the video signal input terminal and the audio signal input terminal is connected to the signal detection circuit. Item 3. The signal processing device according to Item 2.   A signal reproduction device comprising: the signal processing device according to claim 2 or 3; and a reproduction output unit that outputs any of the signals input to the signal processing unit.

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