JP3449112B2 - Low power consumption device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low power consumption device for reducing power consumption of electronic equipment such as a video cassette recorder.

[0002]

2. Description of the Related Art In a conventional electronic device such as a video cassette recorder, even if the power is turned off by, for example, turning off the power switch on the operation panel surface, a memory is retained for time display, calibration, and timer reservation. , In order to detect the signal from the remote controller and the power-on input by operating the power switch on the panel, power is always supplied to the microcomputer and its associated circuits inside the equipment, and it is in the standby state. It was

FIG. 14 schematically shows an example of a power supply configuration of this conventional electronic device (video cassette recorder in this example). Note that in this figure, in order to avoid complication, audio / data not directly related to the description
Each signal line such as a video signal is omitted.

From the main power supply circuit 100 to the switch 101
Power is supplied to the tuner unit 102, the video processing unit 103, and the audio processing unit 104 via the. Similarly,
Power is supplied to the mechanical deck 106 and the microcomputer 107 via the switch 105. This microcomputer 10
The control unit 7 controls, for example, the tuner unit 102, the video processing unit 103, the audio processing unit 104, and the mechanical deck 106.

On the other hand, power is supplied from the main power supply circuit 100 directly to a remote control light receiving section 109 which receives control commands from the microcomputer 108 and the remote controller without passing through a switch or the like. The microcomputer 108 controls the switches 101 and 105 based on a user's instruction from a power switch (not shown) on the operation panel, and the tuner unit 102 and the image processing unit 1 are controlled.
03, the voice processing unit 104, the mechanical deck 106, and the microcomputer 107 are controlled to turn on / off the power supply from the main power supply circuit 100. Further, when the remote control light receiving unit 109 receives a command to turn on / off the power of the device, the remote control light receiving unit 109 sends a power on / off request to the microcomputer 108, and the microcomputer 108 follows the request. Switch 101
And 105 are controlled.

As described above, the on / off control of the power supply of the equipment is controlled by the microcomputer 108 by the switches 101 and 10.
It is performed under the control of No. 5. Therefore, for example, in order to change the power supply of the device from the off state to the on state, the microcomputer 108 and the remote control light receiving unit 10 can be operated even when the power is off.
The power is continuously supplied to 9. When the power is turned off, for example, in the case of a video cassette recorder, power is supplied to the microcomputer 108 for timer operation for reserved recording and memory retention. In this way, even when the power of the device is turned off, the microcomputer 108 and the remote control light receiving unit 1
Power is supplied to 09 to put it in a standby state.

[0007]

By the way, the main power supply circuit 100 is designed so that the maximum efficiency can be obtained at the load current during the operation of the video cassette recorder. Therefore, in the standby state where the load current is small (when the power is off), the power supply efficiency is extremely low, and the main power supply 100
However, there was a problem that power wasted in vain. For example, the microcomputer 108 and the remote control light receiver 1
Even if the original power consumption in 09 is about 0.5 W, the main power supply circuit 100 consumes about 2 W. Also, depending on the configuration, 5-6
The power of W may be consumed.

Further, such an electronic device is used only for several hours a day at home, for example. Therefore, there is a problem that this power is consumed even when the device is not used for other time.

As a means for suppressing such wasteful power consumption when the power is turned off, a sub-power supply circuit 110 for low current consumption is provided separately from the main power supply circuit 100 as shown in FIG. Circuit 110 to microcomputer 10
8 and the remote control light receiving unit 109 may be supplied with power. In this case, the microcomputer 108 controls the switch 111, which controls on / off of power supply to the main power supply circuit 100.
Further, the sub power supply circuit 110 constantly supplies power to the microcomputer 108 and the remote control light receiving unit 109,
It is placed in a standby state.

Since the sub power supply circuit 110 is designed for a small load current, the power supply efficiency is better than that of the method shown in FIG. 14, and when the power is off, the main power supply circuit 100 consumes no power. Therefore, low power consumption can be achieved. However, this method also has a problem that the power efficiency of the sub power supply circuit 110 cannot be extremely improved, and power consumption of about 1 W is consumed due to power consumption in the microcomputer 108. .

Therefore, an object of the present invention is to provide a low power consumption device for suppressing power consumption in electronic equipment such as a video cassette recorder.

[0012]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention controls the connection of a power source to a device.
However, when the power is turned off, the power connection to the above equipment is opened.
It is charged by the microcomputer and the power source, and the power source is turned on.
Circuit that requires operating power supply including the above microcomputer even when
In contrast, when the power is turned off,
Source supply means and monitored by the microcomputer when the power is turned off.
When the voltage of the operating power supply falls below the first voltage value
Connect the power source by the microcomputer and connect the power source.
The above-mentioned charging for the tier is performed and the completion of the above-mentioned charging is detected.
Then, open the power source by the microcomputer and charge the battery.
Low power consumption having control means of power supply means for terminating
External and internal events at the input device
The CPU operates normally when the microcomputer operates.
Normal operation mode operating at clock frequency and CP
The sleep mode in which U is not operating and the normal clock frequency above
The CPU is operating at a clock frequency lower than the wave number
Low clock operation mode including voltage detection operation of the above operating power supply
Low power consumption mode in which transitions with the
It consists of a production mode and the above external event or the above internal event.
Based on the event, the above low power consumption operating mode
Low power consumption characterized by transition to normal operation mode
It is a power consumption device.

[0013]

As described above, according to the present invention, the power is supplied to the circuit requiring the operating power by the chargeable power supply means when the power of the device is off. Further, by controlling the power source by the power source connecting unit, the power source supplying unit can be intermittently charged when the power source is turned off.
Therefore, it is possible to reduce power consumption when power is supplied to a circuit that requires an operating power when the power is turned off.

Further, the operation mode of the microcomputer can be transited from the normal operation mode to the low power consumption operation mode during the low power consumption operation, and the low power consumption operation mode can be transited to the normal operation mode by an external event or an internal event. The power consumption can be reduced.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below. This invention provides a main power supply with a backup element having a sufficiently large capacity and capable of being charged in a short time, and when the power is off in the standby state, charging / discharging the backup element is repeated at predetermined intervals. Power is supplied to a circuit such as a microcomputer that operates in a standby state. Further, in the present invention, in this standby state, the microcomputer operating in the standby state is operated at a low power consumption operation to reduce the power consumption.

FIG. 1 schematically shows an example of the configuration of an electronic apparatus (video cassette recorder in this example) to which the present invention is applied. In this figure, in order to avoid complication, signal lines such as audio / video signals which are not directly related to the contents of the present invention are omitted.

Power is supplied to this electronic device from the plug 1 connected to the outlet of the commercial power supply. This power is supplied to the main power supply circuit 3 via the switch 2. The supplied power is rectified and stabilized with a predetermined voltage by the main power supply circuit 3 including, for example, a switching power supply.

The power source stabilized by the main power source circuit 3 is
It is supplied to the tuner unit 5, the video processing unit 6, and the audio processing unit 7 via the switch 4. Further, the power from the main power supply circuit 3 is transmitted via the switch 8 to the mechanical deck 9
And supplied to the microcomputer 10. Further, the power from the main power supply circuit 3 is supplied to the backup element 12, the microcomputer 13, and the remote control light receiving unit 14 via the diode 11 connected in the forward direction from the main power supply circuit 3.

The microcomputer 10, which is, for example, a microprocessor, controls the system of the video cassette recorder such as tape running and signal processing.

The remote control light receiving unit 14 receives a control command transmitted from, for example, infrared rays from a remote controller (not shown), and receives the received signal from the microcomputer 1
Convert to a format suitable for processing in 3
Send to 3. The microcomputer 13 includes, for example, a microprocessor, and further includes an interface between the microcomputer 13 and the outside, various timing generation circuits, and an oscillation circuit that generates a clock for operating these circuits included in the microcomputer 13. included. Microcomputer 13
Controls the switch 2 based on the operation of a power switch (not shown) arranged on the operation panel of the device, decodes the control command sent from the remote control light-receiving unit 14, and controls based on this command. The microcomputer 13 also controls reserved recording and manages the internal clock of this device.

The main power supply circuit 3, the backup element 12, the microcomputer 13, and the switch 2 controlled by the microcomputer 13 constitute a low power consumption device according to the present invention.

While the switch 2 is in the conducting state, that is, while the power is on and the device is operating, power is supplied from the main power supply circuit 3 to the backup element 12 via the diode 11 to charge the backup element 12. To be done. When the power switch on the operation panel described above is turned off, that is, in the standby state, the switches 2, 4, and 8 are opened by the control of the microcomputer 13. Then, the power supply to the backup element 12 is stopped and the backup element 12 starts discharging.

The electric charge discharged from the backup element 12 is supplied to the microcomputer 13 and the remote control light receiving section 14, and the microcomputer 13 and the remote control light receiving section 14 are supplied.
It is used as a power source. Since the diode 11 is connected in the opposite direction to the backup element 12, the electric charge discharged from the backup element 12 is not supplied to the main power supply circuit 3.

The electric potentials at both ends of the backup element 12 are monitored by the microcomputer 13. Backup element 12
Discharge continues and the discharge potential drops below the specified value,
The switch 2 is turned on by the control of the microcomputer 13. Then, power is supplied to the backup element 12 and charging of the backup element 12 is started. When the backup element 12 is sufficiently charged, the switch 2 is opened again under the control of the microcomputer 13.

At this time, the power required to charge the backup element 12 is, for example, about 6 W, and the region of the main power supply circuit 3 having a high power supply efficiency can be used. Further, as will be described later in detail, the operation of the microcomputer 13 in the standby state is, for example, an operation in which the clock frequency is lowered, or in a stop mode or a sleep mode, and is a low power consumption operation. As a result, the microcomputer 13 in the standby state
Power consumption is suppressed.

Therefore, in the standby state, the microcomputer 1
The power supply from the backup element 12 to the remote controller 3 and the remote control light receiver 14 may be extremely small. For example,
The duty at the time of charging / discharging in the backup element 12 is 1/60, that is, 6 for 1 minute of charging time.
Electric power is supplied to the microcomputer 13 and the remote control light receiving unit 14 at a rate such as 0 minute discharge.

In this standby state, the switch 4
Since and 8 remain open, no power is supplied to the following circuits.

FIG. 2 shows an example of the configuration of the low power consumption device according to the present invention in more detail. In addition, in this figure,
The same parts as those in FIG. 1 described above are designated by the same reference numerals, and detailed description thereof will be omitted. When an electronic device (video cassette recorder in this example) to which this device is applied operates, the switch 2 is in a conductive state, and commercial power is supplied from the plug 1 to the main power circuit 3 through the switch 2.

The commercial power source is made a stable DC power source by the main power source circuit 3, and is supplied to the charging control circuit 20. This charge control circuit 20 is for preventing an excessive current generated when the switch 2 is brought into the conductive state from the open state and the main power supply circuit 3 is started up, to flow to the subsequent circuit. The power output from the charge control circuit 20 is
Diode 1 connected in the forward direction to this circuit 20
1 is supplied to the backup element 12, the microcomputer 13, and the DC-DC converter 21. The backup element 12 is charged. Also, D
The output of the C-DC converter 21 is supplied to the remote control light receiving unit 14 as a constant power supply voltage.

The backup element 12 used in this embodiment is, for example, a supercapacitor, which is a high-capacity capacitor filled with activated carbon and having a high density. For example, it is about 10 F (farad). Has a capacity of. Since the backup element 12 using this supercapacitor has a small internal impedance of, for example, about 1Ω or 10Ω, it can be charged in about 1 minute, which usually takes about 1 hour. Therefore, the charging of the backup element 12 can be completed in an extremely short time. Furthermore, since this backup element 12 has a small internal impedance, it has a DC-D
The current flowing to the C converter 21 can be increased.

In the above description, the supercapacitor is used as the backup element 12 for supplying power when the power is off, but this is not limited to this example. For example, a rechargeable secondary battery can be used for this backup element.

The charge control circuit 20 has a current limiter for preventing an excessive current generated due to the low internal impedance of the backup element 12 from flowing to the subsequent stage when the power source starts up. The current limiter is composed of, for example, a resistor, and when the voltage across the backup element 12 exceeds a predetermined voltage value, the resistor can be switched to increase the current flowing to the subsequent stage. Details of the charge control circuit 20 will be described later.

FIG. 3 shows an example of power consumption in the standby state of an electronic device to which this low power consumption device is applied. First, under the control of the microcomputer 13, the switch 2 is opened at the timing shown in FIG. 3C. As a result, when viewed from the outside of the video cassette recorder, the power consumption of this video cassette recorder becomes zero, as shown at timing A in FIG. 3A. At this time,
The charge of the backup element 12 is
It is supplied to the C-DC converter 21.

Then, as shown in FIG. 3B, the voltage across the backup element 12 gradually decreases due to the discharge. At this time, the remote control light receiving unit 14 is supplied with power whose voltage is constant by the DC-DC converter 21 as described above.

The potential across the backup element 12 is constantly monitored by the microcomputer 13. Then, as indicated by B in FIG. 3B, when the voltage across the both ends becomes equal to or lower than a predetermined voltage, the switch 2 is controlled by the microcomputer 13.
Are brought into conduction. Then, power is supplied from the commercial power supply to the main power supply circuit 3, and the backup element 12
Will start charging. Then, as indicated by C in FIG. 3B, when the voltage across the backup element 12 exceeds a predetermined voltage value, as indicated by D in FIG. 3C,
The switch 2 is opened under the control of the microcomputer 13. This operation is repeated in the standby state.

In this operation, the power consumption by the commercial power source by the device is regarded as the power consumption in the conduction period shown in FIG. 3, and the power consumption is 0 in the open period. Therefore, as shown in FIG. 3A, the consumption of the commercial power supply of the device in the standby state is the average power of the whole. For example, 6 W of power is consumed in the conductive state for 1 minute, and the average power consumption is 0.1 W / h when the open state continues for 60 minutes.

FIG. 4 shows an example of the configuration of the charge control circuit 20 described above. In this example, the charging control circuit 20 is
It is composed of a switch 60, charging control circuits 61 and 62, and a voltage detector 63. The switch 60 is controlled by the detection result of the voltage detector 63 so that the charging control circuit 61 is controlled.
And the connections to 62 are switched.

When it is determined that the voltage across the backup element 12 is equal to or lower than a predetermined voltage at the timing B shown in FIG. 3 in the standby state of the device, the switch 2 is turned on by the control of the microcomputer 13, and the main switch is turned on. Power supply circuit 3
The backup element 12 is charged through the switch 60 , the charge control circuit 61, and the diode 11. When the voltage detector 63 determines that the voltage across the backup element 12 exceeds a predetermined voltage, the voltage detector 63 supplies a switching signal to the switch 60 to switch the connection of the switch 60. .

The power supply voltage from the main power supply circuit 3 is supplied to the charging control circuit 62 via the switched switch 60, and further supplied to the backup element 12 via the diode 11 to charge the backup element 12. Then, at the timing C shown in FIG. 3, that is, when it is determined that the voltage across the backup element 12 exceeds a predetermined voltage, the switch 13 is opened by the control of the microcomputer 13.

In charging control circuit 20 shown in FIG. 4, charging control circuit 61 is set to have a larger current limit than charging control circuit 62. The charge control circuit 61 whose current limit is increased is used to limit the overcurrent of the initial charge of the backup element 12. Compared with the charge control circuit 61, the charge control circuit 62 has a smaller current limit and is configured to generate a larger charge current, so that positive charge can be performed. These two charging control circuits 6
By controlling 1 and 62 efficiently, the backup element 12 can be efficiently charged in a short time. Further, it is possible to further improve the charging efficiency by increasing the number of voltage detection steps by using a large number of such charge control circuits.

FIG. 5 shows another example of the configuration of the charge control circuit 20. The charge control circuit 20 shown in FIG. 5 includes a charge control circuit 70 and an A / D converter circuit 71. It becomes the timing B shown in FIG.
When it is determined that the voltage across both ends of 2 is less than or equal to the predetermined voltage,
The switch 2 is turned on under the control of the microcomputer 13, and the backup element 12 is charged from the main power supply circuit 3 via the switch 21, the charge control circuit 61, and the diode 11. At this time, the voltage across the backup element 12 is supplied to the A / D converter circuit 71, and this voltage value is converted from an analog value to a digital value.

The voltage value between both ends converted to a digital value is
The charge control circuit 70 is supplied from the A / D converter circuit 71. The charge control circuit 70 is composed of an electronic volume and is set to an impedance (resistance) corresponding to the digital value supplied from the A / D converter circuit 71. That is, the charge control circuit 70 controls the electronic volume (charge control) according to the voltage across the backup element 12. Specifically, the backup element 1
When the voltage at both ends of 2 is low, the impedance of the electronic volume is high, and as charging progresses and the voltage at both ends becomes higher, the impedance becomes lower. From these controls, more efficient charging can be performed.

6 and 7 show an example of a method of controlling the switch 2 by the microcomputer 13. FIG. 6 is an example in which the switch 2 is configured by the relay 30. FIG. 6A is an example in which power is supplied from a commercial power source as a DC power source via a DC adapter. FIG. 6B is an example in which the power is directly supplied to the device from the outlet of the commercial power, and the AC power transformed by the transformer 31 is rectified by the diode bridge 31 and smoothed by the capacitor 32 to be the DC power. Further, FIG. 6C is an example in which the switching power source 33 stabilizes the direct current of the power source directly supplied from the commercial power source and uses it as the power source. In any of these examples, a relay 30 that is driven and controlled by a control signal from the microcomputer 13 to be opened and closed.
The ON / OFF control of the power source is performed by.

FIG. 7 shows an example in which the switch 2 is constructed by electronic means. In the method shown in FIG. 7A, the commercial power supply supplied to the equipment is DC-stabilized by the switching power supply 34. By shorting the base-emitter of the control transistor 35 of the switching power supply 34, the operation of the switching power supply can be stopped and the supply of the power supply can be stopped.

That is, the collector and the emitter of the transistor 37 are connected to both ends of the resistor 36 connected between the base and the emitter of the control transistor 35, respectively. When the base of the transistor 37 has no input and is in an open state, the resistance between the collector and the emitter of the transistor 37 is very high, and the switching power supply 3
4 works. On the other hand, by supplying a signal based on a control signal for the switch 2 from the microcomputer 13 to the base of the transistor 37, the transistor 37
It is possible to make the collector-emitter conductive state. As a result, the operation of the switching power supply 34 can be stopped and the power on / off can be controlled.

FIG. 7B shows an example in which the switch 2 is composed of a switching element, for example, a triac 38. In this case, the microcomputer 1 is connected to the gate 39 of the triac 38.
By supplying a signal based on the control signal from the switch 3 to the switch 2, the power supply can be controlled.

Next, the low power consumption operation of the microcomputer 13, which can reduce the power consumption of the apparatus by using it together with the control of the power source, will be described. The low power consumption operation of the microcomputer 13 is more effective when used in the standby state where the switch 2 is in the open state.

In order to operate the microcomputer 13 with low power consumption, the sleep mode, the stop mode, the main clock division operation mode, and the sub clock operation mode are selected.
Different operating modes are possible. Which of these modes the microcomputer 13 operates in can be set by software. FIG. 8 shows the internal configuration of the microcomputer 13 and the operation of the microcomputer 13 in each of these modes. The microcomputer 13 uses, for example, a main clock having a clock frequency of 16 MHz and a clock that is later than the main clock, for example, 3
With a sub clock having a clock frequency of 2 KHz,
It can operate with two clocks.

The 16 MHz main clock is generated by the oscillation circuit 41 with reference to the natural vibration of the crystal oscillator 40, for example. The generated main clock is supplied to the peripheral hardware 42 of the microcomputer 13 and the timing generator 43. The timing generator 43 uses the clock supplied to the CPU.
It is converted into a CPU clock for operating 44. The main clock supplied to the timing generator 43 is converted into a CPU clock and supplied to the CPU 44.

Similarly, the sub clock of 32 KHz is oscillated by the oscillation circuit 46 based on the natural vibration of the crystal oscillator 45, for example.
And is supplied to both the peripheral hardware 42 and the timing generator 43. The sub clock supplied to the timing generator is converted into a CPU clock and supplied to the CPU 44. This sub clock is a clock for the clock in the microcomputer 13.

The peripheral hardware 42 has an interface to the outside of the microcomputer 13, and for example, key inputs from the operation panel of the device or control commands of the remote controller received by the remote control light receiving unit are supplied to the peripheral hardware 42. To be done. Further, the peripheral device 42 includes the backup device 1 described above.
An I / O port for supplying the detection result of the discharge voltage in 2 is also provided.

The operation state of each of the parts constituting the microcomputer 13 differs depending on the above-mentioned operation modes. In the sleep mode shown in FIG. 8A, the oscillation circuit 46 that generates the sub clock is operating, and the CPU clock of the microcomputer 13 and the peripheral hardware 42 are operated.
The clock for is derived from the slower subclock. On the other hand, the oscillator circuit 4 that generates the main clock
1 is stopped, and the timing generator 4
3 and the CPU 44 are both stopped. Further, the peripheral hardware 42 has only a part of its function activated.

In the stop mode shown in FIG. 8B, both the main clock and the sub clock are stopped. Therefore, the timing generator 43
Both the CPU 44 and the CPU 44 are in a stopped state. The peripheral hardware 42 has only a part of its functions activated.

In the main clock division operation mode shown in FIG. 8C, both the main clock and the sub clock are generated, and these clocks are supplied to the peripheral hardware 42 and the timing generator 43. Then, the main clock supplied to the timing generator 43 is divided into, for example, 1 MHz in the timing generator 43, is supplied as a slower clock to the CPU 44.

In the subclock operation mode shown in FIG. 8D, the main clock is stopped and only the subclock is generated. This sub clock is supplied to the CPU 44 via the peripheral hardware 42 and the timing generator 43. Therefore, the microcomputer 13 operates based on this sub clock.

In each of the above-described modes of operation of the microcomputer 13, when they are arranged in ascending order of power consumption, there are the stop mode <sleep mode <sub clock operation mode <main clock frequency division operation mode. Of these modes, the CPU 44 can be operated in the main clock division mode and the sub clock operation mode. Further, in the sleep mode, the operation of the CPU 44 is stopped, so that event processing and the like cannot be performed, but the sub clock is generated.

The low power consumption operation of the microcomputer 13 in this embodiment is performed by alternately performing a sleep mode and a subclock operation mode among these modes at predetermined intervals. For example, after the sleep mode is continued for 100 msec, the sub clock operation mode is continued for 900 msec. This cycle of 1 sec is repeated in the standby state.

FIG. 9 shows an example of the operation state inside the microcomputer 13 in the sleep mode. In the sleep mode, as described above, the oscillation circuit 41 for generating the main clock, the timing generator 43, and the CPU are stopped, and a part of the peripheral hardware 42 is operated.

Among the circuits constituting the peripheral hardware 42, the I / O port and the remote control receiver are interfaces for interrupt input. Of these, an external input such as a key input is supplied to the I / O port. Further, the remote control receiving unit receives the signal from the remote control light receiving unit 14. Further, although not shown, the peripheral hardware 42 includes a power supply detection port for detecting the power supply voltage and a power supply control port for controlling the switch 2. These ports are included in I / O ports. By setting the power control port to'H 'and'L',
The switch 2 is brought into a conductive state and an open state, respectively. The sub clock generated by the oscillation circuit 46 is supplied to these circuits, and they are brought into an operating state in this sleep mode.

On the other hand, this peripheral hardware 42
Other circuits included in, for example, A / D converter, serial I / O, timer counter, time base counter,
PPG (Programable Pattern Generator), RTG (real
Circuits such as Time Generator) and PWM (Pulse Width Modulator) that are not related to interrupt processing are stopped.

FIG. 10 schematically shows the state transition in the microcomputer 13 between the low power consumption operating state and the normal operating state in which the main clock is operating. When the power is off, which is the standby state of the device, the microcomputer 13 is in the low power consumption operation state of step S10. At this time, as described above, in the peripheral hardware 42,
The I / O port and the remote control reception circuit are in operation.

In this standby state, when a power-on instruction is given to the I / O port of the peripheral hardware 42 or the remote control receiving circuit by a key operation on the panel of the device or a control command from the remote controller, for example, the microcomputer 13 The interrupt generation state of step S11 is set. Then, in the microcomputer 13, the oscillation circuit 4
In 1, the generation of the main clock is started, and the microcomputer 13 switches to the operation by the main clock in step S12.

FIG. 11 and FIG. 12 are flowcharts of the processing in the low power consumption operation state when the microcomputer 13 is applied to a video cassette recorder.
The processes shown in these figures are executed during the power-off of the video cassette recorder and are included in the overall process flow of the operation of the video cassette recorder.

From the main routine for processing the entire operation of the equipment, the process proceeds to step S20 which is the first processing in this low power consumption operation state. In step S20,
It is determined whether the device has been powered on. If it is determined that it has been turned on, the process proceeds to step S2.
Move to 1. In this step S21, the wait timer is set. The wait timer is included in the microcomputer 13 (not shown) and is a timer for setting the charging time of the backup element 12. The wait timer is constantly powered by, for example, a battery. When the power is first turned on to the device, the backup element 12 is kept for the time set by this wait timer.
The charging time for is secured. This charging time is set to 5 minutes, for example.

For example, when the backup device 12 is not charged immediately after factory shipment and the device is turned on and immediately turned off, normal operation of the device cannot be expected. If the wait timer is set as described above, the charging time for the backup element 12 can be secured even in such a case.

In this way, when the wait timer is set in step S21, the process proceeds to the next step S22, the timer value of the wait timer is decremented, and the microcomputer 13 controls the switch 2 to the conductive state. , Charging of the backup element 12 is started. Then, the process proceeds to step S23, and it is determined whether or not the content of the command by the remote controller or the key input is an instruction to turn on the power. Then, in step S23, if the command is not the instruction to turn on the power, the process is returned to the main routine. Also, during this period, the decrement of the wait timer is continued, and the backup element 12 is continuously charged until the wait timer times out.

If it is determined in step S23 that the content of the command is an instruction to turn on the power, the process proceeds to step S24. This step S
At 24, according to this instruction, first, the settings of various ports included in the peripheral hardware 42 of the microcomputer 13, such as the power detection port and the power control port, are set to normal settings. Then, the switch 2 is turned on by the control of the microcomputer 13, and the power of the device is turned on. The setting of various ports set by the microcomputer 13 will be described later.

On the other hand, if it is determined in step S20 that the power is not turned on, that is, the power is off, the process proceeds to step S25. In this step S25, it is determined whether or not the decrement of the timer value in the wait timer has ended and a time-out has occurred. If it is determined that the wait timer has not timed out, the process proceeds to step S22,
The wait timer is decremented.

If it is determined in step S25 that the wait timer has timed out, the process proceeds to step S26. From this step S26,
The power is turned off and the operation of discharging the backup element 12 is started. First, in step S26, unnecessary display on the operation panel arranged on the front surface of the device is erased. For example, only the time display is left and all other displays are erased. Alternatively, the display brightness may be halved when the power is turned on.

In the next step S27, among the ports included in the peripheral hardware 42, ports which are not used in the power-off state, such as serial I / O ports, are input and set. This is done by setting no current to the unused ports. Then, in the next step S28, the timer for the charging time for the backup element 12 is set. This charge time timer is included in the peripheral hardware 42 of the microcomputer 13, for example. This charging time timer sets the conduction time of power consumption in the standby state shown in FIG. 3 described above. Since the charging of the backup element 12 is actually ended when both ends reach a predetermined voltage value, the setting of this charging time is auxiliary.

Then, in the next step S29, 3
The 2 KHz timer counter is set to count up in about 1 sec. This 32 KHz timer / counter is included in the peripheral hardware 42 of the microcomputer 13, and counts based on the sub clock generated by the oscillation circuit 46. The cycle of the transition to the sleep mode and the sub clock mode described above is 32 KHz.
It is set to approximately 1 sec by the timer counter.

At the next step S30, the microcomputer 1
3 transits to the sleep mode and the subclock operation mode. FIG. 12 shows details of the processing in step S30. The symbols A, B, and C in FIG.
It corresponds to the symbols A, B, and C in FIG. 12, respectively.

When the processing shifts to the sleep mode and the sub clock operation mode in step S30, first, in the first step S40, the operation mode of the microcomputer 13 shifts to the sleep mode. This is an oscillating circuit 4 for oscillating a 16 MHz Mayclock in the microcomputer 13.
1 is stopped and only the oscillation circuit 46 that oscillates the 32 KHz sub clock operates.

As described above, in the low power consumption operation state of the microcomputer 13, the sleep mode and the subclock operation mode are alternately changed in units of 1 sec set in step S29 described above. Is executed intermittently. The timing of this transition is such that the sub-clock operation mode is transited after the sleep mode period of 100 msec, for example, and the sleep mode is returned again after the sub-clock operation mode of 900 msec.

In this way, after 100 msec has elapsed from the transition to the sleep mode in step S40, the operation mode of the microcomputer 13 transits to the subclock operation mode, and the processing shifts to step S41. In the sub clock mode, as described above, the microcomputer 13
CPU 44 and timing generator 43 in
Operate on the basis of a sub clock having a frequency of 32 KHz. Therefore, in this sub-clock operation mode, the trigger for the CPU 44 is valid. In step S41, the CPU 44 updates the internal clock of the video cassette recorder incorporating the microcomputer 13.

This internal clock is calibrated by a system called a just clock, which calibrates the time by receiving a time signal at a predetermined broadcast channel and time, for example. For example, 7:00 and 15:00
When the time is calibrated by the time signal, the power of the video cassette recorder is turned on 1 minute before these times based on the time information of the internal clock, and the internal clock is calibrated when these time signals are received. In the video cassette recorder, an operation such as reserved recording for starting recording of the broadcast of the designated channel at the designated time reserved by the user is performed based on the time information of the internal clock.

In the next step S42, reservation information such as reservation recording is checked based on the updated time information of the internal clock. The reservation information is stored in advance in the memory (not shown) of the video cassette recorder by the user, and is made by the CPU 44 accessing the memory. When the reservation information is checked, the process is step S43.
Move to.

In step S43, the power supply detection port included in the peripheral hardware 42 is checked. The power supply voltage is detected by this power supply detection port, and the discharge state of the backup element 12 can be known by checking this power supply detection port by the CPU 44. For example, when the voltage value of the power supply voltage is supplied to this power supply detection port and this voltage value indicates a value lower than a preset threshold value,
The CPU 44 makes a determination such as "L" and "H" when the value is high.

If it is determined that the detected value is'L ', it is determined that the backup element 12 needs to be charged, and the process proceeds to step S44. In this step S44, the timer for the charging time of the backup element 12 is set. Then, the process proceeds to the next step S45.
Then, the power supply control port is set to "H" to bring the switch 2 into a conductive state, and the backup element 12 is charged. This charging is ended when the above-mentioned charging time timer expires. Further, the charging state of the backup element 12 may be monitored, and the charging may be terminated when it is determined that the charging is completed.

When the power supply control port is set to "H" in step S45, the process proceeds to step S49 which causes an interrupt process for the CPU 44.
The description of step S49 will be given later.

On the other hand, if it is determined in the above step S43 that the detected value of the power supply voltage is'H ', the process proceeds to step S46, and the charging time timer is decremented. Then, the process proceeds to the next step S47, and it is determined whether or not the charging time timer has become 0. If it is judged that the timer is not 0,
It is determined that the backup element 12 should be charged, and the process proceeds to step S45. And
The power supply control port is set to "H" and charging is started.

If it is determined in step S47 that the timer is 0, the process proceeds to the next step S48, the power supply control port is set to "L", and the backup element 12 is not charged. Will be terminated. Then, the process proceeds to step S49.

The following steps S49, S50,
And step S51 is a step of performing an interrupt process for the CPU 44 in the sub clock operation mode. In step S49, it is checked whether or not a command has been input by the keys arranged on the operation panel of the device. This is done, for example, by detecting the edges of the signals from these input means.
If there is a command input from the key, it is considered that an interrupt due to an external event has occurred, and the processing shifts from the flow of C in the figure to the flow chart of FIG.

The input in step S49 is not limited to the key input. For example, a sensor may be provided in the eject mechanism of the tape in the video cassette recorder, and the edge of the signal when detecting the insertion of the tape may be used as this input.

On the other hand, if there is no key input in step S49, the process proceeds to step S50, and it is checked whether or not there is a control command input of the remote controller. If the remote controller receiving circuit of the peripheral hardware 42 of the microcomputer 13 is instructed to turn on the power, for example, an interrupt due to an external event is generated, and the process is changed from the flow of C in the drawing to the flowchart of FIG. Move.

On the other hand, if there is no instruction to the remote control receiving circuit in step S50, the process proceeds to step S5.
The process shifts to 1 and it is determined by referring to the time information of the internal clock of the video cassette recorder whether it is a predetermined time, for example, 1 minute before the execution time of the reservation event. The reserved event includes, for example, execution of the reserved recording described above and calibration of the internal clock with the just clock described above. Also, in the United States and other countries, there is a service that inserts and transmits television program information during the vertical blanking period of a television signal, but automatic reception of this program information can also be defined by this reservation event. it can.

If the execution time of the reservation event is, for example, 1
If it is determined that it is not before, the process returns to step S40, and the operation mode of the microcomputer 13 transits to the sleep mode again.

On the other hand, if it is determined in step S51 that it is, for example, one minute before the start time of the reservation event, it is determined that an interrupt due to an internal event has occurred, and the processing returns from B in the drawing to the flowchart in FIG. Step S31
Move to. In this step S31, the microcomputer 1
The operation of No. 3 is returned to the normal operation state. That is, the oscillating circuit 41 is activated and a main clock with a frequency of 16 MHz is generated. The operation of the CPU 44 is the main clock operation based on this main clock.

In the next step S24, as described above, the settings of various ports included in the peripheral hardware 42 of the microcomputer 13 such as the power supply detection port and the power supply control port are set to normal settings. Then, the switch 2 is turned on by the control of the microcomputer 13, and the power of the device is turned on. Then, the process returns to the main routine of the device process.

On the other hand, in step S51, if there is an interrupt due to a key input or an input to the remote control receiving circuit,
The process returns from C in the figure to the flowchart in FIG. 11 and proceeds to step S32. In this step S32, the oscillation circuit 41 is brought into the operating state, and the microcomputer 13 is returned to the normal operating state based on the main clock having a frequency of 16 MHz, similarly to the above-mentioned step S31.

Then, in the next step S33, the wait timer is set, and the process proceeds to step S23. In this step S23, the above-mentioned step S
It is determined whether the content of the command by the remote controller or the key input in step S50 or 49 is a command to turn on the power. Then, if it is determined that the content of this command is an instruction to turn on the power, the process proceeds to step S24, the port is set, and the power of the device is turned on by the control of the switch 2. If it is determined that the command does not indicate power-on, the process directly returns to the main routine of the device process.

The processing from step S41 to step S51 described above is performed in the sub clock operation mode. In the above description, the sub clock operation mode and the sleep mode are each 900 ms in the unit of 1 sec in the setting of the above 32 KHz counter.
ec, 100 msec, but it is not limited to this example. For example, the transition between the sub clock operation mode and the sleep mode may allocate the extra time required for the sub clock operation mode to the sleep mode.

The order of steps S49, S50 and S51 for performing the interrupt process for the CPU 44 can be arbitrarily changed based on the priority order of these processes set for the device.

In the above description, in the low power consumption operation mode, the CPU operation is combined with the sleep mode and the subclock operation mode.
This is not limited to this example. For example, in a device having no internal clock, the sub clock operation mode may be combined with the stop mode shown in FIG. 6B. Further, the main clock frequency division operation mode shown in FIG. 6C may be combined with the sleep mode or the stop mode.

Next, a modification of the embodiment of the present invention will be described with reference to FIG. The above-described embodiment is applied to the video cassette recorder in which the low power consumption device according to the present invention is controlled by a single microcomputer. On the other hand, this modification is an example in which the low power consumption device according to the present invention is applied to a device having a plurality of microcomputers. FIG. 13 schematically shows an example in which the low power consumption device according to the present invention is applied to the device having the plurality of microcomputers. It should be noted that, in this figure, only the low power consumption device and the microcomputer for operating the low power consumption operation state are shown, and other circuits controlled by these microcomputers are omitted.

This device includes one main microcomputer 50 and a plurality of (for example, N) sub-microcomputers 51 ₁ , 51 ₂ ,.
.., 51 _N , from the main power supply 52 to the main microcomputer 50 and the sub-microcomputers 51 ₁ , 51 ₂ ,
The power source V _dd is supplied to 51 _N. The main power supply 52 is connected to the main power supply 52 by the main microcomputer 50.
Power is supplied from the outside via a power switch whose open state is controlled. Further, the main microcomputer 50 can control the operation of each of the sub-microcomputers 51 ₁ , 51 ₂ , ..., 51 _N.

Main microcomputer 50 and sub microcomputer 5
1 ₁ , 51 ₂ , ..., 51 _N are usually 16M, for example.
Although it operates based on the main clock having a frequency of Hz, the operation based on a sub clock having a frequency lower than the main clock, for example, 32 KHz can be performed by setting software or the like. In addition, the main microcomputer 50 and the sub-microcomputers 51 ₁ , 51
By performing communication and port control for ₂ , ..., 51 _N , interrupt processing can be performed.

The main power supply 52 can supply power to the equipment without the supply of power from the outside.
It has a power backup means. For the power supply backup means, for example, a power supply using a backup element with a supercapacitor as described above can be used.

When the power switch is in the open state and the power of the equipment is off, the main microcomputer 50 and the sub-microcomputers 51 ₁ , 51 ₂ , ..., 51 _N sleep as in the above-described embodiment. The low power consumption operating state is set in which the mode and the subclock operation mode are repeated intermittently. When the power is off, the main microcomputer 50 and the sub-microcomputers 51 ₁ , 51 ₂ , ...
Power is supplied from the backup element to 51 _N.

The processing of the main microcomputer 50 when the power is off is the same as the processing in the above-described embodiment. That is, the power supply voltage supplied from the backup element is checked by the main microcomputer 50,
When the voltage value becomes equal to or lower than a predetermined threshold value, the power switch is turned on by the control of the microcomputer 50, and the backup element is charged. Then, when the charging is completed, the power switch is opened by the control of the microcomputer 50. When an interrupt process is performed on the main microcomputer 50 by external communication or port control, it is determined whether this process is a power-on instruction. If it is a power-on instruction, the power switch of the main power supply 52 is controlled so as to be in a conductive state, and the operation of the main microcomputer 50 and the sub-microcomputers 51 ₁ , 51 ₂ , ..., 51 _N is performed. Is returned from the low power consumption operating state by the sub clock operation to the normal operating state by the main clock operation.

On the other hand, it is not always necessary that all of the plurality of sub-microcomputers 51 ₁ , 51 ₂ , ..., 51 _N be operating when the power of this device is turned on. For example,
There is a case where only the sub-microcomputers 51 ₁ and 51 ₂ need to be operated, or when only the main microcomputer 50 operates and none of the sub-microcomputers 51 ₁ , 51 ₂ , ..., 51 _N need be operated. To be In such cases,
If the sub-microcomputer that does not need to operate is normally operated by the main clock, power will be consumed uselessly.

Therefore, in the modification of this embodiment,
Under the control of the main microcomputer 50, the sub-microcomputers that do not need to operate are put into a standby state by operating with low power consumption.
Then, when a request to make a transition to the normal operation state by the main clock is made to the sub-microcomputer placed in the standby state by communication or port control, the sub-microcomputer is changed to the main clock from the low power consumption operation state by the subclock. Return to normal operation.

As described above, in a device having a plurality of microcomputers, only the necessary microcomputers are put into the normal operating state by Mayclock, and the other microcomputers are put into the low power consumption operating state, so that the power consumption of the device as a whole is reduced. can do.

The sub-microcomputers 51 ₁ , 51 ₂ , ...
, 51 _N can be switched between the normal operation state and the low power consumption operation state by the control of the main microcomputer 50. Further, in the flowcharts shown in FIGS. 11 and 12, the respective judgment conditions are appropriately set according to the purpose of use of the sub-microcomputer, and when interrupt processing is entered by communication or port control,
The operations of the sub-microcomputers 51 ₁ , 51 ₂ , ..., 51 _N may be switched according to this processing. Furthermore, these methods can be combined.

In the above description, the present invention is applied to the video cassette recorder, but the present invention is not limited to this example. The present invention can be applied to other electronic devices as long as the device is in a standby state when the power is turned off, and a specific event is used as a trigger to recover from the standby state and turn on the power. For example, the present invention can be applied to a television receiver or an audio device in which a remote controller instructs to turn on / off the power. Further, when the present invention is applied to a telephone or a fax machine, a predetermined function in these devices can be activated by, for example, triggering a telephone call.

[0107]

As described above, according to the present invention, the AC power supply is completely disconnected during the time when the electronic device such as the video cassette recorder is in the standby state, and the microprocessor operates in the standby state. Since necessary circuits are operated by the power backed up by the backup element, there is an effect that the power consumption can be substantially 0 W when the video cassette recorder is viewed from the outside in this state.

Further, according to the present invention, the backup element is charged in a very short time with respect to the backup time. Therefore, the total power consumption of the video cassette recorder seen from the outside can be made close to 0 W, and the power consumption of the device can be significantly reduced.

Further, according to the present invention, in the standby state of the device, the operation of the microcomputer for controlling the ON / OFF of the power supply of the device is performed in the sleep mode in which the CPU is in a rest state.
A sub-clock operation mode in which the CPU operates at a lower clock frequency is intermittently repeated, and is performed by a low power consumption operation state. Therefore, there is an effect that the power consumption in the standby state can be reduced.

According to the modification of the present invention, in a device having a plurality of microcomputers, only the microcomputers that need to operate at that time are set to normal operation by the main clock having a high clock frequency, and the microcomputers that do not need to operate are It can be operated in a low power consumption operating state with a low clock frequency. Therefore, in the device having such a plurality of microcomputers, there is an effect that the power consumption can be reduced as a whole.

[Brief description of drawings]

FIG. 1 is a block diagram schematically showing an example of the configuration of a video cassette recorder to which the present invention is applied.

FIG. 2 is a schematic diagram showing an example of the configuration of a low power consumption device according to the present invention.

FIG. 3 is a schematic diagram illustrating an example of power consumption by a low power consumption device in a standby state.

FIG. 4 is a block diagram showing an example of a configuration of a charge control circuit.

FIG. 5 is a block diagram showing another example of the configuration of the charge control circuit.

FIG. 6 is a schematic diagram showing an example of a method of controlling a switch by a microcomputer.

FIG. 7 is a schematic diagram showing an example of a method of controlling a switch by a microcomputer.

FIG. 8 is a schematic diagram showing an internal configuration of a microcomputer and an operation in each mode.

FIG. 9 is a schematic diagram showing an example of an operating state of a microcomputer in a sleep mode.

FIG. 10 is a schematic diagram schematically showing a state transition of a microcomputer between a low power consumption operating state and a normal operating state.

FIG. 11 is a flowchart of processing in a low power consumption operation state when the present invention is applied to a video cassette recorder.

FIG. 12 is a flowchart of processing in a low power consumption operation state when the present invention is applied to a video cassette recorder.

FIG. 13 is a schematic diagram schematically showing an example in which the low power consumption device according to the present invention is applied to a device having a plurality of microcomputers.

FIG. 14 is a block diagram schematically showing an example of a power supply configuration of a conventional electronic device.

FIG. 15 is a block diagram schematically showing an example of a power supply configuration of a conventional electronic device.

[Explanation of symbols]

2 ... Switch, 3 ... Main power supply, 12 ... Backup element, 13 ... Microcomputer, 42 ... Peripheral hardware, 44 ... CPU

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hidenori Yamazaki Inventor Hidenori Yamazaki 6-735 Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (56) Reference JP-A-7-284225 (JP, A) JP-A 7-302133 (JP, A) JP-A 8-8681 (JP, A) JP-A 7-121259 (JP, A) JP-A 2-294712 (JP, A) JP-A 1-170515 (JP, A) A) Japanese Unexamined Patent Publication No. 4-328410 (JP, A) Actual Development Sho 61-77636 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H02J 1/00 G06F 1/26 G06F 1 / 32 H02J 7/00-7/10

Claims (11)

(57) [Claims] 1. A power source for controlling the connection of a power source to a device
When the power is off, open the power connection to the above devices
Even when the power is turned off,
For circuits that require operating power supply, including the above microcomputer
Power supply that supplies the operating power when the power is turned off.
And the means for monitoring by the microcomputer when the power is turned off.
If the operating power supply voltage drops below the first voltage value, the above
Connect the power source with an icon and connect it to the power supply means.
When the above charging is detected and the above charging is detected,
The above power supply is released by the microcomputer to end the above charging.
Low power consumption device having control means for power supply means
In a can accept external events and internal events
When the microcomputer operates, the CPU operates at the normal clock frequency.
The normal operation mode that operates in
No sleep mode and clocks below the normal clock frequency above.
The operating power supply for the CPU operating at the lock frequency
Between low clock operation mode including voltage detection operation
From low power consumption operation mode in which transfer is repeated intermittently
Based on the above external event or above internal event,
From the low power consumption operation mode to the normal operation mode
Low power consumption device characterized by transition. 2. The low power consumption device according to claim 1.
Update the clock in the above low clock operation mode.
Characteristic low power consumption device. 3. The low power consumption device according to claim 1.
Te, the transition between the sleep mode and the low-frequency clock operation mode
Low power consumption operation by performing 1 second as a cycle
Low power consumption characterized by updating the clock in mode
apparatus. 4. Claim 1 or claim 2 or claim 3.
In the low power consumption device described in (4), a timer that operates based on the time information from the above clock is added.
And the internal event is based on pre-reserved time information
It is generated by the timer operation, and the timer reservation
The low power consumption mode above is specified before the specified start time.
Mode to the above normal operation mode.
Low power consumption device characterized by 5. The low power consumption device according to claim 4.
Then, the above timer operation captures incoming external data.
Low power consumption device characterized by performing only 6. The low power consumption device according to claim 1.
The above external event is generated by the remote controller.
Of the received signal from the remote controller.
Generates an interrupt to the above microcomputer by
From the low power consumption operation mode,
After the transition to the normal operation mode, the received signal
Power consumption characterized by recognizing information based on
apparatus. 7. The low power consumption device according to claim 1.
Te, the external events, based on the key operation in the above-mentioned equipment
It is generated by a manual input, and the myco
Generate an interrupt for the
Transition from the low power consumption operation mode to the above normal operation mode
And then the signal based on the above key operation
A low power consumption device characterized by recognizing information. 8. The low power consumption device according to claim 1.
In the low power consumption operation mode,
Low power consumption device characterized by turning off the indicator light. 9. The low power consumption device according to claim 1.
The specified time has passed since the power to the above device was turned off.
It is characterized by transitioning to the low power consumption mode later
Low power consumption device. 10. The low consumption according to claim 6 or 7.
Based on the remote controller or the key operation in the power consumption device
The above low power consumption operation mode
Low power consumption device characterized by automatically transitioning to
Place 11. The low power consumption device according to claim 1.
In addition, a plurality of the above microcomputers are installed, and it is necessary to operate in the normal operation mode among the above multiple microcomputers.
For microcomputers that do not need to be switched to a low power consumption operation mode.
And a low power consumption device.