JP2001145051A - Signal recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a signal recorder that inhibits the supply of power to a signal processing circuit in a reservation standby state so as to realize power saving. SOLUTION: The signal recorder is provided with a detection means 28 that detects presence/absence of a video signal from an external tuner 11, a signal processing means 27 that applies required processing for recording to a video signal received from the external tuner 11, and a recording means 26 that records the video signal that is processed by the signal processing means 27 to a recording medium, and also provided with power supply control means 29, 23, 24 that inhibit the supply of power to the signal processing means 27 and the recording means 26 at least in the power saving mode, releases the power saving mode when the detection means 28 detects the video signal to permit the supply of power to the signal processing means 27 and the recording means 28.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal recording apparatus for recording a video signal reserved for a program by an external tuner, and more particularly to a signal recording apparatus capable of reducing power consumption during reservation standby. .

[0002]

2. Description of the Related Art Conventionally, there has been proposed an automatic recording system capable of, for example, making a reservation for receiving a CS digital broadcast program by a CS digital tuner and automatically recording the program by a VTR.

A conventional automatic recording system will be described with reference to FIG. The received program is converted into an EPG (Electrical Program Guid) through the operation unit 2 of the CS digital tuner 1.
e: hereinafter referred to as EPG) By making a reservation, the microcomputer 3 sends the program broadcast signal to the M at the desired program broadcast time.
After being demodulated by the PEG decoder 4 and the NTSC decoder 5, it is output as a video signal.

[0004] The VTR 6 is set to a pre-set recording standby state by setting automatic recording via the operation unit 7.
When a video signal is input from the external tuner 1, the synchronization determination circuit 8 determines whether or not a video signal has been input, and outputs the determination result to the video presence determination unit 9 a of the microcomputer 9.

[0005] The microcomputer 9 determines the presence of an image by
A control signal is output to the recording unit 10 in order to set the VTR 6 in the recording mode. The recording unit 10 records a video signal from the external tuner 1 on a recording medium (not shown) according to the control signal.

As described above, when the desired broadcast program is recorded and the broadcast of the reserved program ends, the external tuner 1 enters the power-off mode and the video signal is not output. VT
Since R6 continuously performs the video presence / absence determination by the above-described synchronization determination, when there is no video signal input from the external tuner 1, the recording mode is released and the power supply is turned off.

[0007]

However, in the above-mentioned conventional automatic recording system, the external tuner 1
Determination circuit 8 for detecting the presence or absence of a video signal from
Is normally included in a signal processing circuit, and in order to detect the presence or absence of a video signal and to set the VTR 6 to the recording mode, power must always be supplied to the signal processing circuit, thereby reducing power consumption. It is difficult to do this.

That is, the signal processing circuit of the video signal system performs AGC (automatic gain adjustment) on the normally input video signal, performs clamping for fixing the DC potential of the input video signal, A sync separation circuit is included to generate a burst gate pulse for extracting a burst signal of a color signal included in the signal.

However, the signal processing circuit is a one-chip LSI.
In order to operate only the synchronization separation circuit included in the LSI, it is not preferable from the viewpoint of power saving to supply power to the entire LSI.

Conversely, if the power is supplied to the signal processing circuit to operate the synchronization determination circuit 8, the VTR 6 cannot be set to the power saving mode for a long time in the reservation standby state. That is, there is a problem that it is not possible to achieve both the reservation recording of the CS digital broadcast and the power saving in the reservation standby state.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems. By providing video detecting means operable independently of a signal processing circuit, power supply to the signal processing circuit can be performed in a reservation standby state. It is an object of the present invention to provide a signal recording device that can inhibit power consumption and realize power saving.

[0012]

According to a first aspect of the present invention, there is provided a detecting means for detecting the presence or absence of a video signal from an external tuner, and a process required for recording the video signal input from the external tuner. A signal recording device comprising: a signal processing unit that performs the following, and a recording unit that records the video signal processed by the signal processing unit on a recording medium,
At least in the power saving mode, the power supply to the signal processing unit and the recording unit is prohibited, and when a video signal is detected by the detection unit, the power saving mode is released.
A power supply control means for permitting power supply to the signal processing means and the recording means is provided.

[0013] With this, the presence or absence of the video signal from the external tuner can be constantly monitored by the detection means operably provided independently of the signal processing means, so that the recording apparatus can be omitted during the standby state. The power mode is set, and power supply to the signal processing unit is prohibited, so that power consumption can be reduced. Further, when a video signal from the external tuner is detected by the detection means, the recording device can be returned from the power saving mode, and the video signal from the external tuner can be automatically recorded.

According to a second aspect of the present invention, there is provided a detecting means for detecting the presence or absence of a video signal from an external tuner, a process for recording a video signal input from the external tuner, and a process for recording the video signal. A signal processing means for detecting the presence or absence of a video signal subjected to the processing, and a recording means for recording the video signal processed by the signal processing means on a recording medium, wherein at least In the power mode, power supply to the signal processing means and the recording means is prohibited, and when a video signal is detected by the detection means, the power saving mode is released and power supply to the signal processing means is permitted. And a power control means for permitting power supply to the recording means when a video signal is detected by the signal processing means.

Thus, the presence or absence of a video signal from an external tuner is constantly monitored by the detection means operably provided independently of the signal processing means, and when a video signal is detected by this detection means, By returning the recording device from the power saving mode and detecting a high-precision video signal in the signal processing circuit, a detection unit operable independently of the signal processing unit can be easily operated with low power consumption. It is possible to use a power supply, and the standby power can be further reduced.

When returning from the power saving mode,
The highly accurate video signal is detected again by the signal processing means, and the recording apparatus is set to the recording mode based on the detection result, so that more accurate scheduled recording can be performed.

According to a third aspect of the present invention, the power supply control means includes a normal operation mode in which the CPU operates at a normal clock frequency, and a low clock operation mode in which the CPU operates at a lower frequency than the normal clock frequency. A microcomputer having an intermittent operation mode in which transitions between a normal clock frequency and a low clock operation mode are intermittently repeated, or a low power consumption mode such as a sleep mode in which the CPU is not operated, at least In the power saving mode, the microcomputer is set to the low power consumption mode.

In this manner, during the reservation standby state, the microcomputer itself used as the power control means also operates in the sleep mode,
By using a low power consumption mode such as a low clock operation mode or an intermittent operation mode, power consumption can be further reduced.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of the present invention will be described.
FIG. 1 shows a case where a VTR is used as a signal recording device.
And FIG. Here, FIG. 1 is a block diagram showing a schematic configuration in the present embodiment, and FIG. 2 is a flowchart showing a timer reservation recording operation in the present embodiment.

In FIG. 1, a tuner 11 for receiving a digital broadcast or the like comprises an operation unit 12, a microcomputer 13, an antenna 14, a reception unit 15, an MPEG decoder 16, and an NTSC encoder 17.

A VTR 21 connected to the external tuner 11 via an AV cable includes a power supply circuit 22 and a switch 2.
3, switch 24, mechanical deck 25, recording / reproducing unit (recording unit) 26, signal processing unit (signal processing unit) 27, synchronization determination circuit (detection unit) 28, microcomputer (power control unit) 2
9, and an operation unit 30.

In the tuner 11, the user operates the operation unit 1.
The microcomputer 13 receives these input and setting information when inputting and setting the EPG reservation via the communication unit 2, and the receiving unit 15,
It controls the MPEG decoder 16 and the NTSC encoder 17. That is, immediately before the time when the EPG reservation is set, the broadcast wave input from the antenna 14 is received by the receiving unit 1.
5, and when the broadcast is a digital broadcast, the MPEG decoder 16 decodes the MPEG-compressed video signal, audio signal, and the like.

The signal decoded by the MPEG decoder 16 is output by the NTSC encoder 17 to the NTSC of a normal broadcast.
The video signal and the audio signal converted into the SC signal and converted by the NTSC encoder 17 are supplied to the VTR 21 through an AV cable or the like.

On the other hand, the basic operation of the VTR 21 is as follows. When the user performs an operation input such as power-on, reproduction, recording, etc., via the operation unit 30, the microcomputer 29 which controls the entire VTR 21 switches the switch 23, The switch 24, the mechanical deck 25, the recording / reproducing unit 26, the signal processing unit 27, and the like are controlled.

For example, when the user inputs power on from the operation unit 30 using a remote controller or operation keys, the switch 2
3. Turn on the switch 24 to supply power from the power supply circuit 22 to the mechanical deck 25, the recording / reproducing unit 26, and the signal processing unit 27. When the recording key is pressed, the input video signal is subjected to predetermined signal processing by the signal processing unit 27, and then the cassette tape (shown in FIG. Record).

In the recording / reproducing section 26 and the signal processing section 27, the processing particularly necessary for recording a video signal is generally as follows.

The input video signal is subjected to AGC and DC clamping in the signal processing unit 27, and is separated into two systems of a luminance signal and a chrominance signal. The separated luminance signal is a low carrier FM modulated wave (for example, in the case of VHS (registered trademark) standard, a white peak is 4.4 MHz,
The sync tip is converted to 3.4 MHz. The separated chrominance signal (3.58 MHz ± 500 KHz) is converted to a lower frequency (629 KHz) than the luminance signal and is AM-modulated.

The signal processed by the signal processing unit 27 is
The data is supplied to a recording / reproducing unit 26 composed of a head amplifier and the like, and is recorded on a video tape (not shown) by a video head (not shown) attached to a rotating drum.
Therefore, the recording / reproducing unit 26, the signal processing unit 27, and the like do not need to operate because they do not perform signal recording / reproducing at the time of EPG reservation standby.

Although not shown in FIG. 1, the switch 2
In addition to the power supply switches 3 and 24, a power supply switch is provided. When the power supply is turned off or a standby state is reserved, the power supply switch is shut off to prohibit power supply such as a clock display. Needless to say, power consumption can be further reduced.

Further, in order to further reduce the power consumption when the power is turned off or when waiting for reservation, the operation clock frequency of the microcomputer 29 is reduced, or the microcomputer 29 is set to the intermittent operation mode or the sleep mode to set the low power consumption mode.

The CPU (Central Processi) of the microcomputer 29
ng Unit) in the low clock mode in which the operating clock frequency is lower than the normal operating clock frequency, for example, while the normal operating clock frequency is 14 MHz or the like,
32.768 KHz for a built-in clock count is used.

Thus, when an operation other than clock counting is not required, the power consumption of the microcomputer 29 itself can be greatly reduced by putting the microcomputer 29 into the low clock mode. In actual operation cases,
At a normal operation clock frequency, the current consumption of 50 mA is:
In the low clock mode, it can be reduced to 50 μA.

Depending on the system, the normal operation clock frequency and the low clock mode may be set to a mode in which the transition is intermittent. In this case, what cannot be processed in the low clock mode is processed at the normal operation clock frequency and returned to the low clock mode again, so that the power consumption is larger than in the low clock mode only.

A sleep mode in which the clock of the CPU of the microcomputer 29 is stopped may be used. In this mode, the power consumption of the microcomputer 29 can be minimized, but the clock count cannot be executed. Therefore, when the microcomputer 29 returns from the sleep mode, the current time information and the like transmitted by broadcast radio waves are obtained. , The internal clock count needs to be adjusted to the current time.

When recording a broadcast program reserved for EPG by the tuner 11, the user performs automatic recording setting from the operation unit 30 in the VTR 21. VT set for automatic recording
R21 turns off the switches 23 and 24 by the microcomputer 29, and cuts off the power supply to the mechanical deck 25, the recording / reproducing unit 26, and the signal processing unit 27.

At this time, the microcomputer 29 itself enters the low power consumption mode. The synchronization determination circuit 28 is operable by receiving power supply from the power supply circuit 22 independently of the signal processing unit 27.

Therefore, even when the switch 23 is turned off and the power supply to the signal processing unit 27 is prohibited, the synchronization determination circuit 28 receives the power supply and
1 is detected as the synchronization signal of the video signal.

Here, the power of the synchronization determination circuit 28 is always supplied. However, it is possible to control the power supply of the synchronization determination circuit 28 only when the automatic recording is set by the operation unit 30. good.

It is a necessary condition of the present invention that the power consumption of the synchronization determination circuit 28 is smaller than the power consumption of the recording / reproducing unit 26 and the signal processing unit 27. Recording / reproducing unit 26,
As the power consumption of the synchronization determination circuit 28 is smaller than the power consumption of the signal processing unit 27, the power saving effect of the present invention increases.

At the EPG reservation time, the tuner 11 supplies the received video signal and audio signal to the VTR 21 through an AV cable or the like. At this time, since the switch 23 is still off, the power is not supplied to the signal processing unit 27 and the switch 23 does not operate.

Since the synchronization determining circuit 28 is constantly supplied with power, the presence or absence of a video signal is determined by detecting a synchronization signal in the video signal from the tuner 11.
When the synchronization determination circuit 28 determines that there is a synchronization signal, that is, that there is a video signal from the tuner 11, the microcomputer 29
From the low power consumption mode.

The microcomputer 2 recovered from the low power consumption mode
9 starts operation at the normal operation clock frequency, confirms the discrimination result of the synchronization discrimination circuit 28 again,
3. When the switch 24 is turned on, the recording / reproducing unit 2
6. By operating the signal processing unit 27 and setting the VTR 21 to the recording mode, the video signal and the audio signal of the desired program from the tuner 11 are recorded.

Here, the microcomputer 29 is set to the low power consumption mode at the time of waiting for reservation, but the microcomputer 29 may be operated in the normal mode without entering the low power consumption mode.

Next, the reservation recording operation of this embodiment will be described with reference to the flowchart of FIG. First, the EPG reservation setting is performed on the tuner 11 side (step 1), and the automatic recording setting is performed on the VTR 21 side (step 2).

In the VTR 21 for which automatic recording is set, the switches 23 and 24 of the power supply line are turned off (step 3), and the VTR 21 itself is set to the power saving mode (step 4). At this time, the power supply such as a clock display is also turned off.

As a result, the VTR 21 apparently has no power, and can be set to the power saving mode. Also, the microcomputer 29 enters a low power consumption mode such as a low clock mode (step 5).
G reservation waiting.

The tuner 11 waits until the reservation start time of the EPG comes (step 6). When the reservation time comes, the tuner 11 sends out the received and demodulated video signal (step 7). VTR2
On the first side, the synchronization determination circuit 28 operable even in the power saving mode detects the synchronization signal (step 8), and when it is determined that the synchronization signal is present, the microcomputer 29 is switched from the low power consumption mode. Return (step 9).

The microcomputer 29 which has returned to the normal mode turns on the switches 23 and 24 of the power supply line (step 10), and also returns the VTR 21 itself from the power saving mode (step 11). The recording mode is executed (Step 12).

Here, when the VTR 21 is a VTR capable of digital recording such as D-VHS, it is needless to say that not only video signals and audio signals but also data broadcasting contents can be recorded.

That is, even when the tuner 11 and the VTR 21 are coupled by a digital signal, if the analog video signal (NTSC signal) from the tuner 11 is determined by using the synchronization determination circuit 28 provided in D-VHS or the like, As in the case of the analog recorder described above, the EPG reservation of the tuner 11 can be executed in the power saving standby mode. D
In the case of a VTR capable of performing digital recording such as -VHS, power consumption is particularly large in the signal processing unit 27 and the like, and the power saving effect according to the present invention is large.

Further, regarding the second embodiment of the present invention,
3 and 4, the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. Here, FIG. 3 is a block diagram illustrating a schematic configuration according to the present embodiment, and FIG. 4 is a flowchart illustrating a timer reservation recording operation according to the present embodiment.

The VTR 31 according to the present embodiment includes a power supply circuit 22, a switch 23, a switch 24, and a mechanical deck 2.
5. Recording / reproducing unit 26, signal processing unit 37 having signal processing circuit 37a and synchronization separation circuit 37b, synchronization determination circuit 2
8, a microcomputer 39 and an operation unit 30.

At the time when the EPG is reserved by the tuner 11, the video signal and the audio signal received via the antenna 14 are supplied to the VTR 31. The supplied video signal is
Input to the synchronization determination circuit 28 and the signal processing unit 37,
At this time, since the switch 23 is off, the signal processing unit 37 does not operate.

The synchronization determining circuit 28 determines the presence or absence of a video signal from the tuner 11, and returns the microcomputer 39 in the low power consumption mode from the low power consumption mode. The microcomputer 39 returning from the low power consumption mode uses the switch 2
3. Turn on the switch 24 to supply power to the mechanical deck 25, the recording / reproducing unit 26, and the signal processing unit 37.

The signal processing circuit 37a in the signal processing section 37 which has started operation processes the video signal and the like from the tuner 11 and supplies the microcomputer 39 with the synchronization signal separated from the video signal by the synchronization separation circuit 37b. . Microcomputer 3
9 starts operation at a normal operation clock frequency, and measures the synchronization signal supplied from the synchronization separation circuit 37b to determine the presence or absence of a video signal.

Normally, the microcomputer 39 in the low power consumption mode cannot operate at high speed, and therefore cannot determine the presence or absence of a synchronization signal. Here, the synchronization separation circuit 37
Although the video signal is detected by a combination of the microcomputer b and the microcomputer 39, a second synchronization discrimination circuit may be provided instead of the synchronization separation circuit 37b, and the result of the discrimination may be input to the microcomputer 39. Absent.

When the microcomputer 39 detects that there is a video signal input based on the synchronization signal from the synchronization separation circuit 37b, it turns on the switch 24 to supply power to the recording / reproducing unit 26 and set the VTR 31 in the recording mode. Then, the video signal and the audio signal of the desired program from the tuner 11 are recorded.

Next, the timer recording operation of this embodiment will be described with reference to the flowchart of FIG. FIG.
Are the same as those in the first embodiment shown in FIG. 2, and the description thereof will be omitted.

First, when a video signal is transmitted from the tuner 11 in step 7, the synchronization signal is discriminated by the synchronization discrimination circuit 28 which is operating even in the power saving mode (step 8), and it is determined that there is a synchronization signal. If so, the microcomputer 39 is returned from the low power consumption mode to the normal mode (step 9).

The restored microcomputer 39 turns on the switch 23 to supply power to the signal processing unit 37 (step 10). At this time, there is no need to turn on the switch 24. There is no need to supply power such as clock display.

The output from the synchronizing separation circuit 37b in the operating state is converted to the microcomputer 39 operating in the normal mode.
Measures the presence / absence of a synchronization signal (step 1).
1). If it is determined that there is no synchronization signal, the process returns to the low power consumption mode again (step 12). this is,
This corresponds to a case where the determination in step 8 is incorrect due to the influence of noise or the like.

When it is determined that a synchronizing signal is present, the switch 24 is turned on (step 13), and power is supplied to the mechanical deck 25 and the recording / reproducing unit 26, so that the VTR
31 itself returns from the power saving mode (step 14),
The recording mode is started (step 15).

As described above, if the synchronization separation circuit 37b is provided in the signal processing section 37, it is not necessary to require the synchronization determination circuit 28 to have a high-precision determination capability. That is, since the synchronization determination circuit 28 is used only to return the microcomputer 39 from the low power consumption mode and return the VTR 31 from the power saving mode, an inexpensive circuit having a low synchronization determination capability may be used as the synchronization determination circuit 28. it can.

In this case, even if the synchronization discriminating circuit 28 malfunctions due to noise or the like, it is possible to accurately determine the presence or absence of a video signal by the synchronization separating circuit 37b which starts the operation thereafter. It is possible to prevent occurrence.

Therefore, since a complicated circuit configuration is not required for the synchronization determination circuit 28, it is possible to adopt a circuit configuration in which current consumption is reduced as much as possible. The ability to reduce the power consumption of the synchronization determination circuit 28 further enhances the power saving effect of the present invention.

As described above, the synchronization determination circuit 28 in the present embodiment does not have the ability to determine the synchronization signal, and uses a circuit for simply detecting a change in the DC level of the video signal input and an increase in the AC component. Is also good.

The signal processing section 37, the synchronization discriminating circuit 28, and the like may be integrated into one chip as an LSI. In addition, a VTR equipped with a power saving mode often shuts off the power of a display circuit such as a fluorescent display tube when the power saving mode is entered. Since it is not known whether the power is on or not, the power saving mode such as an LED may be displayed when entering the power saving mode.

However, if the power consumption of the LED or the like is to be reduced, when the user installs the purchased VTR, the user immediately enters the power saving mode even if the AC power supply is connected. It is inevitable that you will be worried about whether it is working.

Therefore, while the clock is not set by the user, the clock display section is displayed in a flashing manner as before, so that the user is not put into the upper power mode. In addition, it is possible to further reduce power consumption. By adding such a mode, it is possible to further reduce the power consumption when the power is turned off or when waiting for a reservation according to the present invention.

[0070]

According to the first aspect of the present invention, the presence / absence of a video signal from an external tuner can be constantly monitored by the detection means operably provided independently of the signal processing means. During the standby state, the recording apparatus is set to the power saving mode, the power supply to the signal processing unit is prohibited, and the power consumption can be reduced. Further, when a video signal from the external tuner is detected by the detection means, the recording device can be returned from the power saving mode, and the video signal from the external tuner can be automatically recorded.

According to the second aspect of the present invention, the presence or absence of a video signal from an external tuner is constantly monitored by the detection means operably provided independently of the signal processing means.
When a video signal is detected by the detection means, the recording device is returned from the power saving mode, and a highly accurate video signal is detected in the signal processing circuit, thereby operating independently of the signal processing means. It is possible to use a simple detection means that can be provided with low power consumption, and it is possible to further reduce standby power.

When returning from the power saving mode,
The highly accurate video signal is detected again by the signal processing means, and the recording apparatus is set to the recording mode based on the detection result, so that more accurate scheduled recording can be performed.

According to the third aspect of the present invention, during the reservation standby state, the microcomputer itself used as the power supply control means is also in a low power consumption mode such as a sleep mode, a low clock operation mode, and an intermittent operation mode. As a result, power consumption can be further reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a signal recording device according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing timer timer recording operation in the first embodiment of the signal recording device of the present invention.

FIG. 3 is a block diagram showing a schematic configuration of a signal recording device according to a second embodiment of the present invention.

FIG. 4 is a flowchart showing a timer recording operation in a fifth embodiment of the signal recording apparatus of the present invention.

FIG. 5 is a block diagram showing a schematic configuration of a conventional signal recording device.

[Explanation of symbols]

 21, 31 VTR 22 power supply circuit 23 switch 24 switch 25 mechanical deck 26 recording / reproducing unit 27, 37 signal processing unit 37a signal processing circuit 37b synchronization separation circuit 28 synchronization determination circuit 29, 39 microcomputer 30 operation unit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5C018 HA10 HA12 5C025 AA25 BA13 BA22 BA26 DA01 DA08 5C053 FA21 GA11 GB10 JA26 KA24 LA06 5D102 AC01 AF06 HA06 HA12

Claims (3)

[Claims] A detecting means for detecting the presence or absence of a video signal from an external tuner; a signal processing means for performing processing required for recording on a video signal input from the external tuner; A signal recording device comprising: a recording unit that records the processed video signal on a recording medium, at least in a power saving mode, prohibiting power supply to the signal processing unit and the recording unit, When the video signal is detected by the detecting means, the power saving mode is released,
A signal recording apparatus, further comprising a power supply control unit for permitting power supply to the signal processing unit and the recording unit. 2. A detecting means for detecting the presence or absence of a video signal from an external tuner; and performing a process necessary for recording on the video signal input from the external tuner, and a video signal subjected to the processing. A signal processing means for detecting the presence or absence of the video signal, and a recording means for recording the video signal processed by the signal processing means on a recording medium, at least in the power saving mode, Prohibiting power supply to the processing means and the recording means, when the video signal is detected by the detection means, cancel the power saving mode,
A signal recording apparatus, comprising: a power supply control means for permitting power supply to the signal processing means and permitting power supply to the recording means when a video signal is detected by the signal processing means. . 3. The signal recording apparatus according to claim 1, wherein the power supply control means includes a normal operation mode in which the CPU operates at a normal clock frequency, and the CPU operates at a frequency lower than the normal clock frequency. A low clock operation mode, an intermittent operation mode in which transition between a normal clock frequency and a low clock operation mode is intermittently repeated, or a low power consumption mode such as a sleep mode in which the CPU is not operating. A signal recording device comprising: a microcomputer having at least a power saving mode in a power saving mode.