JP2002271715A - Av(audio-video) unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an AV unit that can stop supply of power to a video signal processing section when a player reproduces a disk on which only an audio signal is recorded. SOLUTION: A video input selection circuit 3 selects a video signal from a video input terminal 1, and outputs the video signal to a video output terminal 12 through an amplifier 9, a character synthesis section 10 and an output amplifier 11. An audio input selection circuit 4 selects an audio signal from an audio input terminal 2 and an output amplifier 6 amplifies the audio signal. Furthermore, a video signal detection section 16 receives the selected video signal to discriminate whether the input signal is a still image signal or a moving image signal. When no video signal exists, supply of power to the amplifier 9, the character synthesis section 10 and the output amplifier 11 is stopped.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an audio-visual (AV) apparatus having an audio amplifier circuit and a video amplifier circuit for audio equipment or the like.

[0002]

2. Description of the Related Art AV (Audio Visual) devices are various disc reproducing devices, for example, CD (Co
mpact Disc player, VD (Video
Disc) player, DVD-Video (Digit)
al Versatile Disc-VIDEO) player, DVD-AUDIO (Digital Ver.)
(satellite Disc-AUDIO) player, video tape recorder, television / satellite broadcast tuner, etc., an audio signal input from each device, or an audio signal and a video signal are amplified and processed to convert the video signal into a television or the like. It is configured to output an image to a display to display an image, and output an audio signal to a speaker or a speaker built in a television to output sound.

[0003] In a disk reproducing apparatus, a VD player can reproduce a VD and a CD.
Many VIDEO players can play CDs and DVD-VIDEOs. In addition, D
VD-AIDIO player is CD, DVD-VIDE
O and DVD-AUDIO can be played, and various media are supported.

FIG. 6 is a block diagram for explaining an example of a conventional audio video amplifier. In the figure, 1 is a video input terminal, 2 is an audio input terminal, 3 is a video input selection circuit, 4 is an audio input selection circuit, 5 is an output amplifier, 6 is an audio output terminal, 7 is a DA converter, 8
Denotes a microprocessor, 9 denotes an amplifier, 10 denotes a character synthesizing unit, 11 denotes an output amplifier, 12 denotes a video output terminal, 13 denotes an operation unit, 15 denotes an output control switch, and 17 denotes an optical input terminal.

A video input terminal 1 is connected to a DVD player (DVD-VIDEO player or DVD-AUD
Connection terminals for connecting video signal outputs from an IO player), a VDP (LD player), and a VCR (video tape recorder) are provided. The audio input terminal 2 has a PHONO, CD player, DVD player, VD
Connection terminals for connecting audio signal outputs from the P and VCR are provided. An optical cable from a CD player or the like having a digital optical output can be connected to the optical input terminal 17.

A DVD connection terminal of the video input terminal 1, a DVD connection terminal of the audio input terminal 2, and a video input terminal 1
Synchronized signals are connected to the VDP connection terminal of the audio input terminal 2 and the VDP connection terminal of the video input terminal 1 and the VCR connection terminal of the audio input terminal 2 respectively.

A video input signal from each connection terminal of the video input terminal 1 is selected by a video input selection circuit 3. An input signal is instructed to be selected by a selection operation through a key input or the like of the operation unit 13, a control signal is output by the microprocessor 8, and an input signal is selected by the video input selection circuit 3.

The video input signal selected by the video input selection circuit 3 is amplified by, for example, 6 dB by the amplifier 9 and character information such as the channel name selected by the character synthesis circuit 10 is added to the input video signal. The signal is amplified by the output amplifier 11 and output from the video output terminal 12.

[0009] Output signals from PHONO, CD, DVD, VDP, and VCR are input to respective connection terminals of the audio input terminal 2. The input audio signals are input to the audio input selection circuit 4 respectively. The digital audio signal input to the optical input terminal 17 is subjected to digital / analog conversion by the DA converter 7 controlled by the microprocessor 8 and input to the audio input selection circuit 4. Each of the input audio signals is instructed by a selection operation by a key input or the like of the operation unit 13, and is controlled and switched by the microprocessor 8.

The audio input signal selected by the audio input selection circuit 4 is power-amplified by the output amplifier 5, passes through the output control switch 15, and is output from the audio output terminal 6. The output control switch 15 is controlled by the microprocessor 8, and turns on and off the output signal so as not to output switching noise at the time of input switching.
Is made.

The microprocessor 8 receives the selection information input and instructed by the operation unit 13, and controls the audio input selection circuit 4, the character synthesizing circuit 10, and the video input selection circuit 3 according to the contents of the instruction. The video circuit system always operates in the input standby state. However, when amplifying only an audio signal, a video circuit that amplifies and processes a video signal generates high-frequency noise.

However, in the above-mentioned conventional technology, when the audio-video amplifying device provided with the input switching of the video signal amplifies only the audio signal, a video circuit which does not need to amplify the video signal operates. An amplifier 9 for amplifying and processing a video signal and a character synthesizing unit 1
0, a video circuit composed of the output amplifier 11 and the like generates high-frequency noise and deteriorates the S / N of the audio signal. There is also a disadvantage that unnecessary power is consumed by the video circuit during reproduction of only the audio signal.

As an apparatus for solving such a disadvantage, there is an audio-video amplifying apparatus disclosed in Japanese Patent Application Laid-Open No. H11-149775. However, JP-A-11-14
In the audio-video amplifying device disclosed in Japanese Patent No. 9557, when a CD is reproduced by a DVD-VIDEO player connected to the video input terminal DVD and the audio input terminal DVD, the video input terminal DVD and the audio input terminal When a DVD-AUDIO player connected to a DVD reproduces a CD, a DVD-AUDIO disk in which only an audio signal is recorded, or a DVD-AUDIO disk in which a still image is recorded, a video signal is also input to a video input terminal. Therefore, power supply to the video circuit of the audio-video amplifier is not stopped.

A DVD-VIDEO player is a DVD-Video player.
When a VIDEO disc is reproduced, a video signal is output from a video output terminal and an audio signal is output from an audio output terminal. Also, when playing a CD,
A video signal for displaying a playback track number on a television is output from a video output terminal, and an audio signal is output from an audio output terminal. Therefore, a video signal and an audio signal are input to the video input terminal and the audio input terminal of the audio / video amplifying device, respectively.
It cannot be determined whether the player is playing a CD or a DVD-Video disk.

A DVD-AUDIO player is a DVD-AUDIO player.
VIDEO disk or DVD with still image recorded
When playing back an AUDIO disc, a video signal is output from a video output terminal and an audio signal is output from an audio output terminal. Even when a DVD-AUDIO disc in which only a CD or an audio signal is recorded is reproduced, a video signal for displaying a reproduction track number on a television is output from a video output terminal in the same manner as a DVD-VIDEO player. Output audio signal from the terminal. Therefore, a video signal and an audio signal are input to the video input terminal and the audio input terminal of the audio video amplifier, respectively.
The audio-video amplifying device is a DVD-AUDIO player that uses a CD or a DV in which only an audio signal is recorded.
Are you playing a D-AUDIO disc DVD-VI
DVD-AU with DEO disk or still image recorded
It cannot be determined whether the DIO disc is being played.

When playing back VD, the VD player outputs a video signal from a video output terminal and outputs an audio signal from an audio output terminal. Even when a CD is played, a video signal for displaying a playback track number on a television is output from a video output terminal, and an audio signal is output from an audio output terminal. Therefore, a video signal and an audio signal are input to the video input terminal and the audio input terminal of the audio / video amplifier, respectively.
D-VIDEO player is playing CD or DVD
-It cannot be determined whether a VIDEO disc is being reproduced.

As described above, when a player capable of outputting a video signal and an audio signal is connected, the audio-video amplifying device disclosed in the above-mentioned Japanese Patent Application Laid-Open No. H11-149775 discloses that the player It is not possible to determine whether a disc on which only signals are recorded or a disc on which video signals and audio signals are recorded is being reproduced. For this reason, high frequency noise is mixed into the conventional audio circuit, causing a deterioration in the S / N ratio of the audio signal, and the video circuit consumes unnecessary power during reproduction of only the audio signal.

[0018]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has been described in connection with the case where a player is playing a disc on which only audio signals are recorded.
It is an object of the present invention to provide an AV device that stops supply of power to a video signal processing unit, prevents high frequency noise from being mixed into an audio circuit, and prevents unnecessary power consumption. .

[0019]

According to a first aspect of the present invention, there is provided an audio signal processing unit having an audio signal amplifying circuit for amplifying an audio signal, and a video signal processing unit having a video signal amplifying circuit for amplifying a video signal. And an input signal selection unit for selecting an input signal, a video signal determination unit, and a control unit, wherein the video signal determination unit determines whether the input signal to the video signal processing unit is a still image signal or Determine whether or not the video signal, the control unit, based on the determination result of the video signal determination unit,
When the input signal is other than a still image signal or a moving image signal, the supply of power to at least the video signal amplifier circuit in the video signal processing unit is stopped.

According to a second aspect of the present invention, in the AV apparatus according to the first aspect, the video signal determining section performs the determination based on temporal difference information and luminance information of the video signal. is there.

According to a third aspect of the present invention, in the AV apparatus according to the second aspect, the determination based on the temporal difference information is performed based on a difference between a luminance signal and a color signal or a color difference signal. Things.

According to a fourth aspect of the present invention, in the AV apparatus according to the second or third aspect, the determination based on the luminance information is performed based on an average luminance of a predetermined screen range.

[0023]

FIG. 1 is a block diagram for explaining an example of an embodiment of an AV apparatus according to the present invention.
In the figure, 1 is a video input terminal, 2 is an audio input terminal,
3 is a video input selection circuit, 4 is an audio input selection circuit, 5 is an output amplifier, 6 is an audio output terminal, 7 is D
A converter, 8 is a microprocessor, 9 is an amplifier, 10
Is a character synthesizing unit, 11 is an output amplifier, 12 is a video output terminal, 13 is an operation unit, 14 is a power switch, 15
Is an output control switch, 16 is a video signal detection unit, and 17 is an optical input terminal.

The video input terminal 1 is connected to a DVD player (DVD-VIDEO player or DVD-AUD
Connection terminals for connecting video signal outputs from an IO player), a VDP (LD player), and a VCR (video tape recorder) are provided. The audio input terminal 2 has a PHONO, CD player, DVD player, VD
Connection terminals for connecting audio signal outputs from the P and VCR are provided. An optical cable from a CD player or the like having a digital optical output can be connected to the optical input terminal 17.

The DVD connection terminal of the video input terminal 1, the DVD connection terminal of the audio input terminal 2, and the video input terminal 1
Synchronized signals are connected to the VDP connection terminal of the audio input terminal 2 and the VDP connection terminal of the video input terminal 1 and the VCR connection terminal of the audio input terminal 2 respectively.

A video input signal from each connection terminal of the video input terminal 1 is selected by a video input selection circuit 3. An input signal is instructed to be selected by a selection operation through a key input or the like of the operation unit 13, a control signal is output by the microprocessor 8, and an input signal is selected by the video input selection circuit 3.

The video input signal selected by the video input selection circuit 3 is amplified by, for example, 6 dB in the amplifier 9 and character information such as a channel name selected by the character synthesis circuit 10 is added to the input video signal. The signal is amplified by the output amplifier 11 and output from the video output terminal 12.

Each output signal from PHONO, CD, DVD, VDP and VCR is input to each connection terminal of the audio input terminal 2. The input audio signals are input to the audio input selection circuit 4 respectively. The digital audio signal input to the optical input terminal 17 is subjected to digital / analog conversion by the DA converter 7 controlled by the microprocessor 8 and input to the audio input selection circuit 4. Each of the input audio signals is instructed by a selection operation by a key input or the like of the operation unit 13, and is controlled and switched by the microprocessor 8.

The audio input signal selected by the audio input selection circuit 4 is power-amplified by the output amplifier 5 and subjected to signal processing such as adjustment of frequency characteristics by a sound quality adjustment circuit (not shown). Street,
Output from the audio output terminal 6. As the signal processing, there are some which generate a surround signal or add an echo. The output control switch 15 is controlled by the microprocessor 8 and turns on and off the output signal so as not to output switching noise at the time of input switching.
F is made.

The microprocessor 8 receives the selection information input by the operation unit 13 and controls the audio input selection circuit 4, the character synthesizing circuit 10, and the video input selection circuit 3 according to the content of the instruction.

Although the video input signal selected by the video input selection circuit 3 is selected as described above, the input signal selected by the video input selection circuit 3 Is determined.

In a video circuit, in this example, a video input selection circuit 3, an amplifier 9, a character synthesizing section 10, an output amplifier 11, and a power supply circuit to the video signal detecting section 16, a power supply changeover switch 14 is interposed. I have. The operation of the power switch 14 is controlled by the microprocessor 8.

FIG. 2 is a block diagram for explaining an example of the video signal detecting section 16 of FIG. In the figure, 21 is an AD converter, 22 is a buffer memory, 23 is a difference detector, 24
Denotes a luminance detecting unit.

The AD converter 21 extracts a luminance signal and a chrominance signal or a chrominance signal from the input video signal (when the video signal is a component signal, extracts a luminance signal and a chrominance signal, and converts the video signal into a composite video signal). In the case of, the luminance signal and the chrominance signal are extracted using a band-pass filter or the like), the voltage values of the luminance signal (analog signal) and the color signal (analog signal) or the color difference signal (analog signal) are set to 256 levels ( 0 to 255) and output as a digital signal. The buffer memory 22 stores the video signal for one frame or one field.

The difference detecting section 23 determines a predetermined time T (s) after the video signal is stored in the buffer memory 22.
(E.g., 5 seconds), the difference between the newly input video signal (luminance signal and color signal or color difference signal) and the video signal (luminance signal and color signal or color difference signal) stored in the buffer memory 22 And outputs the result of the difference detection to the microprocessor 8 as a difference detection signal.

The predetermined time T (s) will be described. DVD-VIDEO player and DVD-AU
When a DIO player plays a disk on which a moving image or a still image is recorded, the playback of the disk is started after the player's play button is pressed, and the video (video or music recorded on the disk is produced). Mark etc.)
Is about 2-3 seconds until it is displayed on the television. If the video signal of a moving image or a still image is not input from the player even after the time has elapsed,
It is determined that no moving image or still image is recorded on the disc being played by the player. Therefore, the predetermined time T (s) is set to about 5 seconds.

The difference detecting section 23 calculates the value of the luminance signal (digital signal) stored in the buffer memory 22 and the luminance signal (digital signal) of the newly input video signal after a predetermined time T (s) has elapsed. Is detected for each pixel. Further, the difference detection unit 23 compares the value of the color signal or the color difference signal (digital signal) stored in the buffer memory 22 with the color signal or the color difference of the newly input video signal after a predetermined time T (s) has elapsed. The difference from the value of the signal (digital signal) is detected for each pixel.

The difference detector 23 has a predetermined difference range for determining the presence or absence of a difference, and the difference between the luminance signal and the color signal or the color difference signal at each pixel is within the predetermined difference range. Is detected.

The predetermined difference range will be described. The difference range predetermined for the difference is ± 5 (256
This corresponds to about 2% of the step level. ). Video quality required by US Lucasfilm for DVD-Video players and audio-video amplifiers,
THXUlt that specifies audio quality and operability
In the ra standard, a video signal is defined such that a luminance level of a signal output when a signal having a white level of 100% (maximum value) is input is within a range of ± 2%. The predetermined range is THX Ultra standard ± 2.
Use% values.

Thus, for example, the value of a certain pixel of the luminance signal stored in the buffer memory 22 is 100, and the value of the same pixel in a newly input video signal after a predetermined time T (s) has elapsed. Is 103, the difference is 100−103 = 13. Since this difference is within the predetermined difference range (± 5), it is determined that there is no difference in luminance at this pixel. The same operation is performed for the color signal or the color difference signal, and the presence or absence of the color signal or the color difference signal difference is determined for the pixel based on whether the difference is within a predetermined difference range.

The determination of the presence or absence of a difference by the difference detector 23 will be described. The difference detection unit 23 determines that the pixel has a difference when one or both of the difference between the luminance signal and the difference between the color signal and the color difference signal is outside a predetermined difference range, and determines the difference between the pixels. If both the difference between the pixel and the color signal or the color difference signal are within a predetermined difference range, it is determined that the pixel has no difference. The color signal or the color difference signal may change in color due to the signal amplitude, and the difference may change. In order to reduce the influence of the signal amplitude change on the difference, the difference between the luminance signal and the difference between the color signal or the color difference signal. Only when both values are within the predetermined difference range, it is determined that the pixel has no difference. FIG. 3 is shown in FIG. 3 in order to make it easy to determine whether there is a difference between the luminance signal and the color signal or the color difference signal.

The difference detection unit 23 determines that there is no difference between the two video signals when the number of pixels having no difference is equal to or greater than a predetermined ratio (for example, 90%) with respect to the total number of pixels. Is output to the microprocessor 8, indicating that there is a difference between the two video signals if the number of pixels having no difference is lower than a predetermined ratio with respect to the total number of pixels. A difference detection signal “1” indicating the presence of an input is output to the microprocessor 8.

The luminance detecting section 24 calculates the predetermined time T
(S) The video signal input after the elapse (the difference detection unit 2
A video signal input through the video signal 3), a luminance detection signal indicating a video signal other than a moving image or a still image when the average luminance is a predetermined luminance. “0” is output to the microprocessor 8, and when the luminance is other than the predetermined luminance, a luminance detection signal “1” indicating a video signal of a moving image or a still image is output to the microprocessor 8.

DVD-VIDEO Player and DVD
-When playing back a disc in an AUDIO player, generally, a blue image (blue background) is displayed on a screen of a television or the like before the playback of the disc is started, and the screen of the television or the like is displayed when the playback of the disc is started. Displays a moving image or still image. When a DVD or a DVD-AUDIO disc on which only an audio signal is recorded is reproduced, a screen of a television or the like has a gray background and a part of the screen (in most cases, displayed on the upper left of the screen). The playback track number is displayed in parentheses. When playing back a DVD-VIDEO disc or a DVD-AUDIO disc on which a still picture is recorded, a moving image or a still picture is displayed on a screen of a television or the like after a mark of a video production company of the disc is displayed. Is done.

When the difference is detected during the above-mentioned predetermined time T (s), the difference may not be detected from the video signal of the still image in some cases. In order to distinguish between a video signal of a still image and a video signal for displaying a playback track, an AV
The apparatus also detects the average luminance by the luminance detection unit 24 in addition to the difference detection by the difference detection unit 23. By the difference detection and the luminance detection, the AV device can use the DVD, VIDEO player and DVD-AUDIO player to record the CD,
It is possible to determine which of the DVD-VIDEO disk, the DVD-AUDIO disk in which only the audio signal is recorded, and the DVD-AUDIO disk in which the still image is recorded is being reproduced.

Next, the predetermined screen range will be described. The luminance detector 24 detects the average luminance of a video signal of one frame or one field in a predetermined screen range. DVD-VIDEO player and DVD-AUD
When an IO player plays back a DVD or a DVD-AUDIO disc on which only an audio signal is recorded, the playback track number is often displayed at the upper left of a screen of a television or the like. The character portion of the number is excluded from the luminance detection, and luminance detection is performed in a predetermined screen range including the center of the screen.
The playback track number is rarely displayed at the center of the screen. If the playback track number is displayed at the center of the screen, it is determined as a still image by luminance detection described later.

The predetermined screen area is a rectangular area including the center of one screen (one frame or one field). For example, the number of pixels in one screen is 480 pixels vertically and 720 pixels horizontally.
In the case of pixels (the number of pixels of a general television), the 120th pixel and the 120th pixel are centered on the 240th pixel and the 360th pixel.
The range is 360th, 180th to 540th.
The predetermined screen range is a range including the center of one screen (one frame or one field).
When the screen has 525 scanning lines, the range from the 230th scanning line to the 290th scanning line around the 262nd scanning line may be used.

The following describes the predetermined luminance. V
D player, DVD-VIDEO player or DVD
When the AUDIO player outputs a video signal other than a still image or a moving image, a blue (blue back) or gray screen is displayed on the television screen. VD player, DVD-VIDEO player or DVD-AU
In a DIO player, a black screen may be displayed at the start of disc playback. In the AD-converted video signal, when black is set to “0” without luminance and white is set to the maximum luminance “255”, the luminance of blue is “93” and the luminance of gray is “165”. The brightness of white, blue, gray, and black is not specified in the standards, etc.
The luminance value may be different from the above-mentioned value depending on the specification of the IC of the D conversion unit and the like. Therefore, each brightness range,
For example, ± 5 (corresponding to about 2% of 256 levels) is provided, and the predetermined luminance is set to 0 to 5 (black), 8
8-98 (blue), 160-170 (gray), 250-
255 (white).

The microprocessor 8 controls the video input selection circuit 3 and controls the video signal to be stored in the buffer memory 22 of the video signal detector 16. The video signal is stored in the buffer memory 22 at every predetermined time (for example, one minute), when the function switch is switched, and the audio input selection circuit 4 is monitored. This is performed when the input of the audio signal is interrupted (when the disc is replaced or when the playback track changes).

The microprocessor 8 operates at a predetermined time T after the video signal is stored in the buffer memory 22.
After (s) (one minute in the above example) has elapsed, the difference detection unit 23 and the luminance detection unit 24 are controlled, and the difference detection unit 23 controls the video signal stored in the buffer memory 22 and the predetermined time T (s). ) The presence or absence of a difference from the video signal input after the elapse is detected, and the luminance
(S) Control is performed to detect the average luminance of a predetermined screen range in the video signal input after the elapse.

The microprocessor 8 includes a difference detection unit 23
It is determined whether the input video signal is a video signal of a moving image or a still image or a video signal for displaying a track number on the basis of the difference detection signal from the luminance detection unit 24 and the luminance detection signal from the luminance detection unit 24.

Returning to FIG. 1, the description will be continued. From the above-described determination result, if the disc being played by the player is a disc on which a moving image or a still image is recorded, and a video signal of a moving image or a still image is input from the player to a video input terminal, the video circuit (video The power being supplied to the input selection circuit 3, the amplifier 9, the character synthesizing unit 10, and the output amplifier 11) is not stopped, and the disk being reproduced by the player is a disk on which only audio signals are recorded. When a video signal for displaying a playback track number is input to the terminal, the power supply switch 14 is turned off, and the supply of power to the video circuit is stopped.

DVD-VIDEO player, DVD-A
DVD-AUDI in which only a CD or audio signal is recorded in a UDP player or VD player
When the O disk is reproduced, the background of the television is blue or gray, and the reproduction track number is displayed at the upper left of the screen. In this case, the luminance of the video signal is “88 to 98”.
(Blue), “160-170” (gray), and the microprocessor 8 stops supplying power to the video circuit. In the AV device, even if the supply of power to the video circuit is stopped and the video is no longer displayed on the television, the playback track number is displayed on the display of the player, so that the user is displayed on the display of the player. The reproduction track can be recognized from the reproduction track number.

The character synthesizing circuit 10 synthesizes a character (OSD (On Screen Demind) screen) superimposed on the video signal and displayed on the video signal. The OSD screen is
For example, it is a setting screen for selecting a type of surround and setting parameters in the audio video amplifier circuit. When the surround parameters are changed using the operation keys of the operation unit 13 or the like, the microprocessor 8 turns on the power switch 14 and supplies power to the video circuit. While the key operation is being performed, the OSD screen is displayed on the television. If the key operation is not performed for a few seconds (for example, 10 seconds), the power supply switch 14 is turned off to supply power to the video circuit. Stop supply.

As described above, the power supply changeover switch 14
Are controlled by the microprocessor 8, and are controlled by the video input selection circuit 3, the amplifier 9, the character synthesizing circuit 10, and the output amplifier 1.
A power supply of a video circuit system such as 1 is turned on and off.

A DVD-AU is added to the AV apparatus described with reference to FIG.
The operation of the AV apparatus according to the embodiment of the present invention will be described with reference to FIGS. 1 and 2 using the flowchart of FIG. 4 by taking a case where a DIO player is connected as an example.

When the power is first turned on (S31), the power of the video circuit is turned on (S32). A video output terminal of the DVD-AUDIO player is connected to the DVD of the video input terminal 1, and a video signal input from the player is transmitted from the video input selection circuit 3 to the video signal detection unit 16.
Is input to Difference detection unit 23 of video signal detection unit 16
Performs the difference detection of the video signal and sends the detection result to the microprocessor 8 (S33).

The difference detecting section 23 receives the video signal stored in the buffer memory 22 and the video signal input after a predetermined time T (s) (5 seconds in the above example) has elapsed since the video signal was recorded. And outputs a "1" difference detection signal to the microprocessor 8 when there is a difference, and outputs a "0" detection signal to the microprocessor 8 when there is no difference.

If there is no difference in S33, the luminance detecting section 24 of the video signal detecting section 16 detects the average luminance of the video signal, and sends the detection result to the microprocessor 8 (S34). The luminance detection unit 24 detects the average luminance of the video signal in a predetermined screen range, and determines that the average luminance is a predetermined luminance (for example, 0 to 5, 88 to 98, 160 to 170,
In the case of 250 to 255), a luminance detection signal of “0” is output to the microprocessor 8 and the average luminance is a predetermined luminance (for example, 0 to 5, 88 to 98, 160 to 170,
In the cases other than 250 to 255), a luminance detection signal of “1” is output to the microprocessor 8.

If there is a difference between the two video signals from the difference detection signal of the video signal detecting section 16 in S33, the microprocessor 8 determines that the disk being played by the player is a DVD-VIDEO disk on which a moving image is recorded. to decide. The microprocessor 8 maintains the power supply switch 14 when the power supply switch 14 is on and supplying power to the video circuit.
Is off and the supply of power to the video circuit is stopped, the power supply switch 14 is turned on to supply power to the video circuit (S40). The AV device outputs a video signal from the video output terminal and outputs an audio signal from the audio output terminal (S41).

Further, even if there is no difference between the two video signals from the difference detection signal in S33, if the average brightness of the video signal is a brightness other than the predetermined brightness from the brightness detection signal in S34, The disc being played by the player is a DVD-AU on which a still image is recorded.
It is determined that the disc is a DIO disc. The microprocessor 8 maintains the state when the power supply changeover switch 14 is turned on and supplying power to the video circuit, and when the power supply changeover switch 14 is turned off and the supply of power to the video circuit is stopped. The power supply switch 14 is turned on to supply power to the video circuit (S
40).

The AV device outputs a video signal from the video output terminal, and outputs an audio signal from the audio output terminal (S41). The microprocessor 8 performs S42
While looping from S44 to S44, it is monitored whether or not the function switch is switched (S42). When the function switch is switched (for example, when the function switch switches from DVD to CD), the process of S33 is performed. Returning to the processing, difference detection is started.

If the function switch is not switched, the process loops from S42 to S44, but the audio input selection circuit 4 monitors whether the input of the audio signal is continued (S43), and the input of the audio signal is interrupted. In this case (when the playback track is shifted to the next track or another track, or when the disk is replaced), the process returns from S42 to S33 to start the difference detection.

If the input of the audio signal is continued (S43), it is detected whether or not the power-off operation has been performed (S44). If the power-off operation has not been performed, the processing from S42 is repeated to turn off the power. If the operation is performed, the power is turned off and the process ends.

In S33, there is no difference between the two video signals,
If the average luminance is the predetermined luminance in S34, the microprocessor 8 determines whether the disk being reproduced by the player is a CD or a DVD-A on which an audio signal is recorded.
It is determined to be a UDPIO disk. Microprocessor 8
Turns off the power switch 14 to stop supplying power to the video circuit (S35). The AV device outputs only the audio signal from the audio output terminal without outputting the video signal from the video output terminal (S36).

The microprocessor 8 determines from S37 to S3
While looping through step 9, it is monitored whether or not the function switch has been switched (S37). When the function switch has been switched (for example, when the DCD has been changed to VDP), the power switch 14 is switched.
Is turned on to supply power to the video circuit (S32), and difference detection (S33) is started.

If the function switch has not been switched, steps S37 to S39 are looped. The audio input selection circuit 4 monitors whether or not the input of the audio signal is continued (S38), and the input of the audio signal is interrupted. In this case (when the playback track has shifted to the next track or another track, or when the disk has been replaced), the process returns to S33 and difference detection is started. That is, in the DVD-AUDIO player, for example, when the disc being reproduced is changed from a DVD-AUDIO disc in which only a CD or an audio signal is recorded to a DVD-VIDEO disc or a DVD-AUDIO disc in which a still image is recorded. The difference detection and the luminance detection are performed again, and the DVD-
During playback of a VIDEO disc, power is supplied to the video circuit.

If the input of the audio signal is continued in S38, it is detected whether or not the power-off operation is performed (S38).
39) If no power-off operation has been performed, the processing from S37 is repeated. If a power-off operation has been performed, the power is turned off and the process ends.

In this flowchart, the case where a DVD-AUDIO player is connected to the video input terminal DVD has been described as an example.
When an IDEO player is connected and a VD player is connected to the video input terminal VDP, the same processing is performed to determine whether a CD or DVD-VIDEO disk is used, and to control on / off of power supply to the video circuit.

The difference between the present invention in which the supply of power to the video signal processing unit is controlled by detecting a video signal and the prior art (Japanese Patent Application Laid-Open No. H11-149775) will be examined. In the prior art, by selecting a selection switch (function switch) on the operation unit,
Controls the supply of power to the video circuit. For this reason, for example, a DVD-AUDIO player
D-VIDEO disc or DV on which still images are recorded
It is not possible to discriminate between the case where D-AUDIO is reproduced and the case where a CD or DVD-AUDIO disc in which only audio signals are recorded is reproduced.
Even when the D-AUDIO player is playing back a CD or a DVD-AUDIO disc on which only an audio signal is recorded, power supply to the video signal processing unit is not stopped.

According to the present invention, it is determined whether or not the input signal is a still image signal or a moving image signal. For example, a DVD-AUDIO player uses a DVD-VIDEO
O-disk or DVD-AUDI with still images recorded
O is played back and a case where a DVD-AUDIO disc on which only a CD or an audio signal is recorded is played back. For example, the DVD-AUDIO player determines whether a DVD-VIDEO or a still image is recorded. Power supply to the video circuit is stopped when the DVD-AUDIO player is playing a CD or a DVD-AUDIO disk in which only audio signals are recorded. I do.

FIG. 5 shows the result of comparing the power supply to the video signal processing unit between the prior art and the embodiment of the present invention. It can be seen that the power supply can be effectively controlled.

In the above-described embodiment, the configuration in which all power supplied to the video circuit is cut off, that is, all power supply to the video signal processing unit is stopped, has been described. The power supply of the video signal amplifier circuit including the output amplifier 11 may be stopped, or the power supply of the character synthesizing unit 10 used for forming a display image may be stopped in addition to the video signal amplifier circuit. And the video input circuit 3
The power supply of the video signal detection unit 16 may not be stopped, and the input video signal may always be checked for a still image or a moving image.

In the above embodiment, the combination of the audio video amplifying device and the DVD player has been described. However, the present invention can be applied to a composite product such as a DVD player with a built-in AV amplifier.

[0075]

As is apparent from the above description, according to the present invention, when the input video signal is other than a still image and a moving image, the supply of power to the video system is stopped in the AV device. In addition, there is an effect that noise is not mixed into the audio circuit from the video circuit, and wasteful power consumption in the video circuit can be avoided.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an example of an embodiment of an AV apparatus according to the present invention.

FIG. 2 is a configuration diagram for explaining an example of a video signal detection unit 16 in FIG.

FIG. 3 is an explanatory diagram of an operation of a difference detection unit.

FIG. 4 is a flowchart for explaining the operation of the AV apparatus according to the embodiment of the present invention.

FIG. 5 is a diagram showing a result of comparing power supply to a video signal processing unit between a conventional technique and an example of an embodiment of the present invention.

FIG. 6 is a block diagram illustrating an example of a conventional audio-video amplifying device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Video input terminal, 2 ... Audio input terminal, 3 ... Video input selection circuit, 4 ... Audio input selection circuit, 5 ...
Output amplifier, 6: audio output terminal, 7: DA converter, 8: microprocessor, 9: amplifier, 10: character synthesizing unit, 11: output amplifier, 12: video output terminal, 1
Reference numeral 3 denotes an operation unit, 14 denotes a power switch, 15 denotes an output control switch, 16 denotes a video signal detection unit, 17 denotes an optical input terminal, 21 denotes an AD conversion unit, 22 denotes a buffer memory, and 23
... Difference detecting unit, 24. Luminance detecting unit.

Claims (4)

[Claims] An audio signal processing unit having an audio signal amplification circuit for amplifying an audio signal, a video signal processing unit having a video signal amplification circuit for amplifying a video signal, an input signal selection unit for selecting an input signal, An AV apparatus having a video signal determination unit and a control unit, wherein the video signal determination unit determines whether an input signal to the video signal processing unit is a still image signal or a moving image signal, The control unit, based on the determination result of the video signal determination unit, when the input signal is other than a still image signal or a moving image signal, stops supplying power to at least a video signal amplification circuit in the video signal processing unit. AV device characterized by the above-mentioned. 2. The AV apparatus according to claim 1, wherein the video signal discriminating section performs discrimination based on temporal difference information and luminance information of the video signal. 3. The AV apparatus according to claim 2, wherein the determination based on the temporal difference information is performed based on a difference between a luminance signal and a color signal or a color difference signal. 4. The AV apparatus according to claim 2, wherein the determination based on the luminance information is performed based on an average luminance in a predetermined screen range.