JPH10228763A - Switching regulator power supply device, picture recording and reproducing device, and information recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable switching a mode in which a switching noise is desired to reduce and a economizing electric power mode as necessary and to suppress enlarging parts by varying a switching frequency of a switching regulator in accordance with an operation state of an image pickup device or a recording and reproducing device. SOLUTION: When output voltage (e) of a SW and rectifier circuit 6 decided by a pulse width of a switching signal (c) is deviated from target voltage, a supply voltage value from voltage (e) to a voltage comparator 8 through a voltage divider 7 is different from the reference voltage value. Then, output voltage (a) of the voltage comparator 8 is varied so that a pulse width of the switching signal (c) is widened to make them coincident, a pulse width of the switching signal (c) is widened, inputted to the SW and rectifier circuit 6, and outputted as voltage targeting DC voltage supplied from a battery 1. And switching for a economizing electric power mode and a switching noise suppressing mode can be performed by the operation of an input section 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switching regulator suitable for use in, for example, an imaging device.

[0002]

2. Description of the Related Art Conventionally, switching regulators have been used for imaging equipment, television receivers and other video equipment.
Widely used for power supply of electronic equipment. This switching regulator obtains a required DC voltage by, for example, switching an input voltage at a predetermined frequency, oscillating a pulse waveform signal, and rectifying the pulse signal.

In such a switching regulator, the frequency of the switching signal that determines the frequency of the pulse waveform signal is constant.

[0004]

Such a conventional switching regulator has the following problems.

In an image pickup apparatus such as a video camera using a magnetic tape or the like as a recording medium, power consumption during a recording operation is generally much larger than power consumption during image reproduction. Also, the reproduced signal handled by the head amplifier during image reproduction is smaller than the signal handled during recording (generally about -60 dB of the recorded signal), so that the influence of noise cannot be ignored.

FIG. 3 is a diagram showing the relationship between the switching frequency of the switching regulator and the power supply efficiency, and FIG. 4 is a diagram showing the relationship between the switching frequency and the power consumption when the load is constant. is there.

According to these figures, as the switching frequency increases, the power consumption in the oscillation circuit increases accordingly, so that the power consumption of the entire device increases,
The supply efficiency of the power supplied to the entire imaging device has been reduced.

On the other hand, if the switching frequency of the switching regulator is set low in order to suppress power consumption, the cutoff frequency of a filter composed of L and C for removing the switching frequency becomes low. The constant increases, the size of the coil and capacitor parts increases, which is disadvantageous in terms of space and cost.

FIG. 5 is a characteristic diagram showing the relationship between the switching frequency and the switching noise level. The horizontal axis represents the switching frequency, and the vertical axis represents the switching noise level. It can be seen that when the switching frequency is set to 1/2 of the switching frequency f (frequency f / 2), the switching noise is increased by 12 dB. Therefore, in order to suppress the switching frequency at the switching frequency f / 2, it is understood that a switching elimination filter having a larger time constant must be used.

In view of the above, the present invention changes the switching frequency of the switching regulator in accordance with the operation state of the apparatus, the operation state of the image pickup apparatus or the recording / reproducing apparatus, and increases the size and cost of components. It is an object of the present invention to provide a device capable of realizing power saving without mimicking the above.

[0011]

In order to achieve the above object, according to the first aspect of the present invention, a recording means for recording an image, and an image recorded by the recording means are reproduced. A power supply unit for supplying power to the image recording / reproducing device, an oscillating unit for oscillating a switching signal, and the power supply unit in synchronization with a frequency of the switching signal. A switching regulator that generates a pulse signal based on the power from the switching device and outputs a predetermined voltage based on the pulse signal, and the switching signal that is oscillated by the oscillating means according to an operation state of the image recording / reproducing apparatus. And control means for controlling the frequency of the control signal.

According to a second aspect of the present invention, in the first aspect, the control unit is configured to control a frequency of the switching signal when an image is recorded by the recording unit, and to control an image by the reproduction unit. The frequency of the switching signal in the case of reproduction is different from each other.

According to a third aspect of the present invention, in the second aspect, the control means controls the frequency of the switching signal when the image is reproduced by the reproducing means by the reproducing means. The frequency of the switching signal when an image is being reproduced is increased.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the power supply unit is a battery.

According to a fifth aspect of the present invention, in the fourth aspect, the switching regulator has a low-pass filter.

According to a sixth aspect of the present invention, in any one of the first to fifth aspects, the image recording / reproducing apparatus further comprises an image pickup means.

According to a seventh aspect of the present invention, in any one of the first to sixth aspects, the recording means is configured to perform magnetic recording.

Further, according to the invention according to claim 8, a power supply unit, an oscillating means for oscillating a switching signal, and an oscillating frequency of the switching signal oscillated by the oscillating means are controlled in accordance with an operation state of a load. Control means for generating a pulse signal based on the power from the power supply unit in synchronization with the frequency of the switching signal, and a predetermined signal by smoothing the pulse signal generated by the generation means. Voltage output means for outputting a voltage.

According to a ninth aspect of the present invention, in the information recording / reproducing apparatus, comprising: recording means for recording information; and reproducing means for reproducing the information recorded by the recording means. A power supply unit for supplying power to the information recording / reproducing apparatus, an oscillating unit for oscillating a switching signal, and synchronizing with a frequency of the switching signal, generating a pulse signal based on power from the power supply unit, A switching regulator that outputs a predetermined voltage based on a signal; and a control unit that controls a frequency of the switching signal that is oscillated by the oscillating unit in accordance with an operation state of the information recording / reproducing device. .

According to a tenth aspect of the present invention, in the ninth aspect, the control means is configured to control the frequency of the switching signal when the information is recorded by the recording means and the information by the reproduction means. The frequency of the switching signal in the case of reproduction is different from each other.

According to an eleventh aspect of the present invention, in the tenth aspect, the control means controls the frequency of the switching signal when the information is reproduced by the reproducing means by the reproducing means. The frequency of the switching signal when information is reproduced is increased.

According to a twelfth aspect of the present invention, in any one of the ninth to eleventh aspects, the power supply unit is a battery.

According to a thirteenth aspect, in the twelfth aspect, the switching regulator comprises:
It has a low-pass filter.

According to a fourteenth aspect of the present invention, in any one of the ninth to thirteenth aspects, the recording means is configured to perform magnetic recording.

[0025]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

(First Embodiment) FIG. 1 is a diagram schematically showing the configuration of a switching regulator and its surroundings.

Referring to FIG. 1, reference numeral 1 denotes a battery (battery) serving as a power supply unit, and 2 denotes a microcomputer (hereinafter, referred to as a microcomputer) having a function as control means for supplying power to a load circuit or controlling a switching frequency. The oscillation circuit 3 functions as an oscillating means for controlling the frequency of a triangular wave which is a switching signal by a control signal from the microcomputer 2.

Reference numeral 4 denotes a reference voltage. The SW drive circuit 5 performs switching based on the triangular wave (FIG. 2B) supplied from the oscillation circuit 3 and the output voltage of the voltage comparator 8 (FIG. 2A). Generate a signal (FIG. 2c).

The SW & rectifier circuit 6 has a function as voltage output means for converting a DC voltage supplied from the battery 1 into a target DC voltage by a switching signal c. The voltage divider 7 outputs the output voltage e of the SW & rectifier 6.
Is equal to the reference voltage 4 when the target voltage is equal to the target voltage.
The voltage value fed back from the & rectifier circuit 6 is compared with the reference voltage 4 to determine a voltage value to be output to the SW drive circuit 5. Reference numeral 9 denotes the configuration of one channel of the switching regulator.

In the configuration shown in FIG. 1, as shown in FIG. 2, the pulse width of the switching signal c generated by the SW drive circuit 5 is the same as that of the triangular wave b supplied from the oscillation circuit 3.
And the voltage comparator 8 determines the output voltage e of the SW & rectifier circuit 6 according to the pulse width of the switching signal c.
Is determined.

When the output voltage e is deviated from the target voltage, the voltage supplied from the output voltage e to the comparator 8 via the voltage dividing circuit 7 is different from the reference voltage. So that the pulse width of the switching signal c is increased (duty ratio is increased)
The voltage comparator 8 changes its output voltage from a to a '. The switching signal c ′ having the increased pulse width is represented by S
It is input to the W & rectifier circuit 6, which outputs the DC voltage supplied from the battery 1 as a target voltage.

When the voltage value output from the SW & rectifier circuit 6 still does not match the target value, the above operation is repeated.

In the switching regulator that performs such an operation, in the present embodiment, switching between the power saving mode and the switching noise suppression mode can be performed by operating the input unit 10.

When the mode is switched to the power saving mode by operating the input unit 10, the microcomputer 2 controls the oscillation circuit 3 to lower the oscillation frequency of the triangular wave b, thereby lowering the frequency c of the switching signal. As a result, power consumption in the oscillation circuit 3 can be suppressed, and overall power consumption can be suppressed.

On the other hand, when the mode is switched to the switching noise suppression mode by operating the input unit 10, the microcomputer 2 controls the oscillation circuit 3 to increase the oscillation frequency of the triangular wave b, thereby increasing the frequency c of the switching signal. And reduce the switching noise level. At this time, the SW & rectifier circuit 6 is configured to remove noise by, for example, including an integration circuit as shown in FIG. 6, but in this filter configuration, as shown in FIG. The relationship between the switching frequency and the switching noise is 12 dB / oct. At this time, the configuration of the integration circuit of the SW & rectifier circuit 6 smoothes the pulse signal generated by switching the input voltage. That is,
A pulse signal supplied from the battery 1 is generated according to a switching signal from the SW drive circuit 5.

As described above, when power saving is desired, the switching frequency is lowered, and when it is desired to suppress the switching noise, the switching frequency is increased. It is possible to perform processing suitable for each operation of the device for supplying power while suppressing cost increase and saving power.

(Second Embodiment) In this embodiment, the configuration of the switching regulator shown in the first embodiment is applied to an imaging apparatus for recording / reproducing a photographed image on a recording medium such as a magnetic tape. It is a form that did.

FIG. 7 is a diagram schematically showing the configuration of the imaging apparatus according to the present embodiment. 7 that are denoted by the same reference numerals as those in FIG. 1 indicate the same configuration, and a description thereof will be omitted.

20 is a lens, and 11 is a lens 20
An image sensor, such as a CCD, that converts light incident from the device into an electrical signal. Also, the video camera signal processing 12
The signal obtained from the image sensor 11 is separated into a luminance signal and a color difference signal. Also, the recorder signal processing 13
Represents the image signal obtained in the video camera signal processing 12,
The signal is converted into a recording signal for recording on a recording medium such as a magnetic tape, and at the time of reproduction, the recording signal is read from the recording medium and output to the monitor 21.

The head amplifier 14 amplifies a recording signal, and the magnetic head 15 converts the recording signal sent from the head amplifier 14 into a magnetic recording medium 16.
And the stored recording signal is read out from the magnetic recording medium 16. Reference numeral 16 denotes a magnetic recording medium such as a magnetic tape.

The monitor 21 comprises an LCD or the like, and displays an image photographed by the image pickup device 11 or an image stored by the magnetic recording medium 16. Input unit 22
Is provided with a trigger switch for recording a captured image and a reproduction switch for reproducing an image stored in the magnetic recording medium 16.

These components are controlled by a camera control circuit 23 constituted by a CPU or the like. In addition, each component is supplied with power from each switching regulator 9.

That is, since power is consumed by the image sensor 11, the video camera signal processor 12, the monitor 21 and the like during recording, the power consumption of the entire apparatus is larger than that during reproduction, and the power consumption is particularly large when the battery is used. It becomes a problem. On the other hand, the recording current flowing through the head during recording has a large signal level in order to perform saturated recording. Therefore, the S / N can be gained even if the switching noise is slightly mixed, so that the switching frequency is lowered by giving priority to the power consumption over the switching noise. Thereby, low power consumption can be realized.

When an image is recorded on the magnetic recording medium 16 (when the trigger switch of the input section 22 is ON), power is supplied to all components. Trigger switch O
When detecting N, the microcomputer 2 sets the switching regulator 9 to the power saving mode, lowers the frequency of the triangular wave (FIG. 2) oscillated from the oscillation circuit 3, and suppresses power consumption.
As a result, when recording an image that consumes a large amount of power, power saving can be achieved, and the life of the battery (battery) 1 can be extended. Note that the switching noise oscillated from the switching regulator is weaker than a recording signal when an image is recorded on the magnetic recording medium 16, and can be ignored.

On the other hand, when an image is reproduced from the magnetic recording medium 16 (when the reproduction switch is ON), power is supplied only to the head amplifier 14, the recorder signal processing 13, and the monitor 21. Further, when detecting the ON of the reproduction switch, the microcomputer 2 switches the switching regulator 9 to the switching noise suppression mode, and increases the frequency of the triangular wave oscillated from the oscillation circuit 3. In this way, as shown in FIG. 5, switching noise can be suppressed, so that a weak reproduction signal (generally, about -60 dB of a recording signal) handled by the head amplifier is affected by the noise. Can be read out without any error. Further, it is not necessary to provide a device for removing the noise, and the device can be reduced in size. In this case, the power consumption of the switching regulator itself is slightly increased, but since the imaging system is not operating during reproduction,
Power consumption increases as a whole.

In the present embodiment, the recording medium of the image pickup apparatus is described as a magnetic recording medium, but the present invention can be applied to a magneto-optical recording medium.

[0047]

As described above, since the switching frequency of the switching regulator can be switched as required, the switching between the mode in which the switching noise is to be reduced and the power saving mode is switched as required. This makes it possible to suppress an increase in the size of parts.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a switching regulator power supply device.

FIG. 2 is a diagram showing signals flowing to respective parts of a switching regulator;

FIG. 3 is a diagram showing a relationship between a switching frequency and power supply efficiency.

FIG. 4 is a diagram showing a relationship between a switching frequency and power consumption.

FIG. 5 is a diagram showing a relationship between switching frequency and switching noise.

FIG. 6 is a diagram showing an example of a SW & rectifier circuit.

FIG. 7 illustrates a configuration of an imaging device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Battery 2 Microcomputer 3 Oscillation circuit 4 Reference voltage 5 SW drive circuit 6 SW & rectifier circuit 7 Divider circuit 8 Voltage comparator 9 Switching regulator 10 Input unit 11 Image sensor 12 Video camera signal processing 13 Recorder signal processing 14 Head amplifier 15 Head 16 Magnetic recording medium 22 Input unit 23 Camera control circuit

Claims (14)

[Claims] An image recording / reproducing apparatus comprising: a recording unit for recording an image; and a reproducing unit for reproducing an image recorded by the recording unit. A power supply for supplying power to the image recording / reproducing device An oscillation unit for oscillating a switching signal; generating a pulse signal based on power from the power supply unit in synchronization with a frequency of the switching signal; and outputting a predetermined voltage based on the pulse signal. An image recording / reproducing apparatus comprising: a switching regulator; and control means for controlling a frequency of the switching signal oscillated by the oscillating means in accordance with an operation state of the image recording / reproducing apparatus. 2. The control device according to claim 1, wherein the control unit controls a frequency of the switching signal when the image is recorded by the recording unit and a frequency of the switching signal when the image is reproduced by the reproduction unit. An image recording / reproducing apparatus characterized in that frequencies are different from each other. 3. The switching device according to claim 2, wherein the control unit controls the switching of the frequency of the switching signal when the image is reproduced by the reproducing unit. An image recording / reproducing apparatus configured to increase a frequency of a signal. 4. The image recording / reproducing apparatus according to claim 1, wherein the power supply unit is a battery. 5. The apparatus according to claim 4, wherein the switching regulator has a low-pass filter. 6. The image recording / reproducing apparatus according to claim 1, wherein the image recording / reproducing apparatus further includes an imaging unit. 7. An image recording / reproducing apparatus according to claim 1, wherein said recording means is configured to perform magnetic recording. 8. A power supply unit, oscillating means for oscillating a switching signal, control means for controlling an oscillating frequency of the switching signal oscillated by the oscillating means in accordance with an operation state of a load, and a frequency of the switching signal Generating means for generating a pulse signal based on the power from the power supply section in synchronization with the power supply section; and voltage output means for smoothing the pulse signal generated by the generating means and outputting a predetermined voltage. A switching regulator power supply device characterized by the above-mentioned. 9. An information recording / reproducing apparatus comprising: recording means for recording information; and reproducing means for reproducing information recorded by the recording means, wherein a power supply for supplying power to the information recording / reproducing apparatus. An oscillation unit for oscillating a switching signal; generating a pulse signal based on power from the power supply unit in synchronization with a frequency of the switching signal; and outputting a predetermined voltage based on the pulse signal. An information recording / reproducing apparatus comprising: a switching regulator; and control means for controlling a frequency of the switching signal oscillated by the oscillating means in accordance with an operation state of the information recording / reproducing. 10. The control device according to claim 9, wherein:
The frequency of the switching signal when the information is recorded by the recording unit and the frequency of the switching signal when the information is reproduced by the reproducing unit are configured to be different from each other. Information recording and reproducing device. 11. The switching device according to claim 10, wherein the control unit controls the switching of the frequency of the switching signal when the information is being reproduced by the reproducing unit. An information recording / reproducing apparatus characterized by being configured to increase a frequency of a signal. 12. The information recording / reproducing apparatus according to claim 9, wherein the power supply unit is a battery. 13. The information recording / reproducing apparatus according to claim 12, wherein the switching regulator has a low-pass filter. 14. An information recording / reproducing apparatus according to claim 9, wherein said recording means is configured to perform magnetic recording.