JP2007172725A - Image pick-up signal recording and reproducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image pick-up signal recording and reproducing device capable of long time recording by reducing power consumption in battery driving and prolonging duration of battery. <P>SOLUTION: The image pick-up signal recording and reproducing device comprises: an average power consumption measuring means for continuously measuring an average power consumption of a power source in a unit time; and a test signal recording and reproducing means which records a predetermined test signal by changing recording laser drive current for each recording double speed and also storing the average power consumption corresponding to the recording laser drive for each recording double speed, acquiring an optimum laser drive current value for each recording double speed by reproducing the recorded test signal while comparing the average power consumption corresponding to the optimum laser drive current value at each recording double speed, and selecting a recording double speed showing a minimum power consumption, and the device records an information signal from the video camera at the selected recording double speed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an imaging signal recording / reproducing apparatus that uses an optical disk as an information recording medium, and more particularly, to an imaging signal recording / reproducing apparatus capable of reducing power consumption when a battery is driven and recording for a long time.

In recent years, many video camera apparatuses using an optical disk as an information recording medium in place of a conventional magnetic tape have been proposed (for example, see Patent Document 1 below).
In general, a video camera device using an optical disk takes advantage of the advantages born by changing the information recording medium to an optical disk, such as a simple mechanism and improved accessibility.

  On the other hand, as is well known, optical disks are easy to control the rotational speed and perform recording and playback with digital signals. Easy. For example, playback can be performed in a short time at twice or four times the speed during recording, or during recording, the time axis of the recording signal can be compressed to ¼, and recording can be performed in ¼ time. is there. Patent Document 2 below discloses a technique for selecting the rotation speed of an optical disc according to conditions during reproduction.

  However, in a video camera device using an optical disk as an information recording medium, recording and reproduction are generally performed in real time, that is, at a predetermined standard speed for the purpose of imaging and recording a subject.

JP 2001-111877 A JP-A-10-261255

Usually, the power source is driven by a battery so that the video camera device can be used outdoors, but in such a video camera device, the duration of the battery is an important performance factor. Therefore, conventionally, video camera apparatuses have been designed with low power consumption everywhere, such as reducing the circuit current or selecting a motor with low power consumption in order to extend the battery duration as much as possible.
However, in the case of a video camera device using a conventional optical disk as an information recording medium, the power consumption can be reduced by utilizing the characteristic that the above-described optical disk can perform recording and reproduction even if various low power consumption designs are made. Since no measures have been taken, there has been a drawback that further reduction in power consumption has not been achieved.

The spindle drive part that rotates the optical disk at high speed and the laser drive part that emits the laser beam that records the signal consume the most power during the recording / reproducing process of the optical disk. When recording is performed in such a combination, the power consumption of the entire apparatus is minimized.
That is, when the optical disk is rotated at a high speed, the power consumption for that purpose increases, but conversely, the laser light only needs to be emitted intermittently, so that the power consumption is reduced.
Therefore, the present invention has been made paying attention to this point, and it is possible to reduce power consumption by optimally selecting the rotation speed of the optical disc during recording in a video camera device using the optical disc. Accordingly, it is an object of the present invention to provide an imaging signal recording / reproducing apparatus capable of extending the battery duration and recording for a long time.

The present invention includes the following configurations (1) and (2) as means for solving the above-described problems. That is,
(1) In an imaging signal recording / reproducing apparatus integrated with a video camera using an optical disk capable of recording at a plurality of recording speeds,
An average power consumption measuring means for continuously measuring the average power consumption per unit time of the power supply;
Recording a predetermined test signal by changing a recording laser driving current for each of the plurality of recording speeds, storing the average power consumption corresponding to the changing recording laser driving current value, and reproducing the recorded test signal A test signal for obtaining the optimum laser driving current value for each recording speed and comparing the stored average power consumption corresponding to the optimum laser driving current value for each recording speed and selecting the recording speed at which the power consumption is minimum. Recording and reproducing means;
And an imaging signal recording / reproducing apparatus for recording an imaging signal from the video camera at the selected recording speed.
(2) In a video camera integrated imaging signal recording / reproducing apparatus using an optical disk capable of recording at a plurality of recording speeds,
An average power consumption measuring means for continuously measuring the average power consumption per unit time of the power supply;
Recording a predetermined test signal by changing a recording laser driving current for each of the plurality of recording speeds, storing the average power consumption corresponding to the changing recording laser driving current value, and reproducing the recorded test signal To obtain the optimum laser driving current value for each recording speed and measure the jitter or error rate value of the reproduction signal, and when the power source is a built-in battery, the stored average corresponding to the optimum laser driving current value for each recording speed Compare the power consumption and select the recording speed that shows the minimum power consumption. When using an external power supply, compare the jitter or error rate value at the optimum laser drive current value for each recording speed and minimize the value. Test signal recording / reproducing means for selecting a recording double speed to be indicated;
And an imaging signal recording / reproducing apparatus for recording an imaging signal from the video camera at the selected recording speed.

According to the present invention, since there is a special configuration described in claim 1, it is possible to record a video camera signal with an optimum laser driving current and a minimum power consumption according to the loaded optical disk. Thereby, there is an effect that the duration of the battery can be increased as compared with the conventional case.
Further, according to the special configuration of the second aspect, it is possible to select either the recording that prioritizes the power consumption or the recording that prioritizes the recording quality according to the type of the power source to be used. It will be a highly convenient product.

  Hereinafter, an imaging signal recording / reproducing apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of an imaging signal recording / reproducing apparatus according to the present invention. FIG. 2 is a diagram showing the relationship between the recording speed and the power consumption due to the spindle driver and the laser drive current. FIG. 3 is a diagram showing the relationship between laser drive current and output power. FIG. 4 is a diagram showing the recording speed, power consumption, and recording quality.

First, the configuration of the imaging signal recording / reproducing apparatus according to the present invention will be described with reference to FIG.
As shown in FIG. 1, the imaging signal recording / reproducing apparatus of the present embodiment is roughly composed of an optical disk recording / reproducing unit 10, an imaging unit 23, and power sources 11 to 14.
The optical disk recording / reproducing unit 10 includes an optical disk 19 that is detachable inside, a spindle driver 20 that rotationally drives the optical disk 19, and an optical pickup 15 that irradiates the optical disk 19 with laser light to record pits. The intensity of the laser beam irradiated by the driver 16 is controlled.

At the time of recording, the video / audio signal input from the imaging unit 23 enters the signal processing circuit 21 of the optical disc recording / reproducing unit 10, where predetermined signal processing is performed, and an optical disc recording signal is supplied to the laser driver 16. The
At the time of reproduction, the reflected light of the laser beam irradiated on the optical disk 19 is received by the optical pickup 15, converted into an electrical signal here, and input to the signal processing circuit 21 via the amplifier in the laser driver 16. The signal processing circuit 21 restores the input reproduction signal to a video / audio signal. At this time, the reproduction signal input to the signal processing circuit 21 is also supplied to the jitter / error rate measuring unit 22 where the jitter or error rate of the reproduction signal is measured. The measured jitter or error rate is input to the system controller 17.

  The system controller 17 is composed of a microcomputer, and functions to control the operation by supplying a control signal to each circuit. Further, an OPC program 18 is connected to the system controller 17, and a procedure program for OPC (Optimum write Power Control) operation is supplied from this, and an OPC operation according to the procedure is performed. Details of the OPC operation will be described later.

  On the other hand, in the power supply part, the internal battery 11 and the external power input unit 12 are connected to the power detection switching circuit 13 and normally the power of the internal battery 11 is used, but external power is supplied to the external power input unit 12. Then, the power supply detection switching circuit 13 detects it, switches to an external power supply, and supplies it to the optical disc recording / reproducing unit 10 and the imaging unit 23. At this time, the average power consumption measurement unit 14 always measures the average power consumption per predetermined unit time, and outputs the value of the average power consumption measured together with the type of power source used to the system controller 17. Note that the average power consumption can be calculated by, for example, inserting a low resistance into the power supply circuit and measuring the voltage across the resistance.

Next, an operation for reducing the power consumption of the imaging signal recording / reproducing apparatus of the present embodiment will be described. First, an outline of the operation will be described.
The image pickup signal recording / reproducing apparatus of the present embodiment is laser-driven for each speed of a plurality of recording speeds when an optical disk having a plurality of recording speed specifications with respect to a standard recording speed is newly loaded. The test signal is recorded by varying the current sequentially, and the optimum laser drive current is determined for each speed from the reproduction signal of that portion, so that test recording / reproduction by so-called OPC operation is performed. At the same time, by sequentially measuring the power consumption of the entire device, compare the power consumption at the optimum laser drive current for each speed, select the recording speed with the lowest power consumption, and record the information signal at this recording speed To do.

Next, the above operation will be specifically described with reference to FIG.
First, when the optical disk 19 is newly loaded, the system controller 17 enters an operation for performing the test recording / reproduction described above. The test recording is performed according to the procedure of the OPC program 18 connected to the system controller 17.

  The system controller 17 first sets the first recording speed. Next, a test signal prepared in advance is supplied to the laser driver 16, and the level of the test signal is sequentially varied. The laser driver 16 supplies a laser drive current to the optical pickup 15, irradiates the optical disk 19 with the laser light emitted from the optical pickup 15, and sequentially records test signals in a predetermined test recording area. The test signal is recorded with the time axis shortened to 1/2 when the recording speed is the standard speed and to 1/4 when the recording speed is the quadruple speed. Therefore, the laser drive current is cut off during the surplus period caused by the shortening of the signal, and recording is stopped.

  Simultaneously with the recording of the test signal, the power consumption of the apparatus with respect to the variable laser drive current value is sequentially measured by the average power consumption measuring unit 14, and the system controller 17 stores this measured value. The power consumption is an average power consumption for a predetermined unit time including a period during which the laser drive current is supplied and a period when the supply is stopped.

When the recording of the preset variable range of the laser drive current is completed, the system controller 17 then switches to the second recording speed and performs the same test recording and power consumption measurement again.
When the test recording at the second recording speed is finished, the test recording is then switched to the third recording speed, and the same test recording and power consumption measurement are repeated.
In this way, test recording and power consumption measurement are performed for all the multiple recording speeds that can be recorded on the optical disc 19.

Next, the process proceeds to test recording reproduction. For playback, test recorded parts are played back sequentially at standard speed. The reproduction signal generated by the optical pickup 15 is input to the system controller 17 via an amplifier in the laser driver 16. The system controller 17 evaluates the input reproduction signal by a predetermined evaluation method, and selects an optimum reproduction signal for each recording speed. Then, the corresponding laser drive current when the selected optimum reproduction signal is recorded and the power consumption when recorded with this laser drive current are read out.
The reproduction signal evaluation method includes, for example, a method of calculating and evaluating the amplitude ratio of two types of long and short pulse signals included in the recorded test signal, and the center value of two types of pulses. There are methods for measuring and evaluating the deviation. The operation of performing such test recording to evaluate the reproduction signal and obtain the optimum laser drive current is called an OPC operation.
Further, as described above, in this embodiment, the reproduction speed is performed at the standard speed. However, the present invention is not limited to this, and for example, all reproduction may be performed at double speed or quadruple speed. Further, it may be played back by switching to the same speed as during recording.

  Next, the power consumption at each of the read recording speeds is compared, and the minimum power consumption is selected. At this time, the recording speed and the laser drive current value are set as the recording set values of the optical disk 19 loaded. And By recording the information signal at the recording speed and the laser drive current value set in this way, the optical disc can be recorded with the optimum laser drive current and used with the minimum power consumption.

Here, the relationship between the recording speed and the power consumption will be described with reference to FIGS.
FIG. 2 shows an example of the relationship between the recording speed and the power consumption due to the spindle driver and laser drive current. This characteristic varies depending on the difference between the spindle motor and the optical disk.
As described above, the power consumption of the apparatus depends on the driving state of the spindle drive portion and the laser drive portion. As shown in FIG. 2, the power consumption at 1 × speed (standard speed) and 2 × speed increases because the spindle drive portion becomes high speed at 2 × speed, and the laser drive portion is intermittently driven as will be described later. Therefore, the average power consumption becomes small. The total power consumption of the two varies depending on the degree of change, but generally tends to be smaller at 2 × speed than at 1 × speed. However, when the speed is 4 ×, 8 ×, or 16 ×, the speed varies depending on the characteristics of the spindle motor and the optical disk.

FIG. 3 is a diagram for explaining a change in power consumption of the laser drive portion, showing a relationship between the laser drive current and the output power.
The power of the recording laser light requires a high power corresponding to the speed as the recording speed increases. However, the relationship between the laser drive current and the output power is not a straight line, but a non-linear relationship as shown in FIG. is there. That is, even if the light emission power is doubled from P1 to P2, the laser drive current changes from I1 to I2, and does not need to be doubled.

Therefore, when recording at double speed, even if the laser light power needs to be doubled, the laser drive current can be less than doubled, and since it is driven for half a period, the average consumption at this time The electric power is smaller than that at the time of 1 × speed.
As a result, a state occurs in which the total power consumption of the spindle drive portion and the laser drive portion is smaller than double speed than double speed.

Next, selection of a recording speed in a state where an external power source is connected to the power source will be described.
In this case, the recording speed prioritizing the recording quality is selected instead of the recording speed at which the power consumption is minimized.

  Returning to FIG. 1, during reproduction of the test recording portion, the reproduction signal generated by the optical pickup 15 and obtained via the amplifier in the laser driver 16 is transferred to the jitter / error rate via the signal processing circuit 21. Although supplied to the measurement unit 22, the jitter or error rate measured here is connected to the system controller 17. As described above, the system controller 17 evaluates the reproduction signal for each recording speed and obtains the optimum reproduction signal. The jitter or error rate at this time is stored, and the optimum reproduction for each recording speed is stored. The jitter or error rate when the signal is obtained is compared, and the recording speed showing the best value is selected.

FIG. 4 is an example showing the recording speed, power consumption, and recording quality.
This figure shows a state in which the power consumption is low at double speed but the recording quality is better at single speed than double speed.
By recording the information signal with the selected recording speed and laser drive current value as set values, the optical disc can be recorded with the optimum laser drive current and used with the best recording quality.

Further, based on an identification signal from the power detection switching circuit 13 that identifies and switches whether the power source is the built-in battery 11 or an external power source connected to the external power input unit 12, the system controller 17 has a built-in power source. In the case of a battery, a recording speed that minimizes power consumption is selected. In the case of an external power supply, a recording speed that provides the best recording quality is selected.
By this operation, the imaging signal recording / reproducing apparatus of the present embodiment can be used properly according to the purpose, which is convenient.

  As described above in detail, the imaging signal recording / reproducing apparatus according to the present invention examines the characteristics of the loaded optical disk and can set the optimum laser driving current at the time of recording, and at the same time, the recording speed and recording that minimize power consumption. Since it is possible to select the recording speed at which the quality is the best, it is possible to perform recording for a longer time when the battery is driven and high quality recording when the external power source is driven.

  In the present embodiment, the timing for performing the test recording / reproduction is set when the optical disk is loaded. However, the present invention is not limited to this, for example, immediately before starting the recording of information or when the user starts at an arbitrary time. It is clear that you can do it. In addition, the recording speed selection operation that minimizes the power consumption and the recording speed that prioritizes the recording quality are automatically switched by detecting the type of the power supply. However, the user may be able to select this. It is also obvious. Further, depending on the specifications of the apparatus, the recording speed selection operation prioritizing the recording quality and the accompanying circuit portion may be omitted.

It is a block diagram which shows one Example of the imaging signal recording / reproducing apparatus which concerns on this invention. It is a figure which shows the relationship between the recording speed and the power consumption by a spindle driver and a laser drive current. It is a figure which shows the relationship between the drive current of a laser, and output power. It is a figure which shows the state of recording speed, power consumption, and recording quality.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Optical disk recording / reproducing part 11 ... Built-in battery 12 ... External power supply 13 ... Power supply detection switching circuit 14 ... Average power consumption measuring part 15 ... Optical pick-up 16 ... Laser driver 17 ... System controller 18 ... OPC (Optimum write Power Control) program 19 Optical disk 20 Spindle driver 21 Signal processing circuit 22 Jitter / error rate measuring unit 22 Imaging unit

Claims (2)

In an imaging signal recording / reproducing apparatus integrated with a video camera using an optical disk capable of recording at a plurality of recording speeds,
An average power consumption measuring means for continuously measuring the average power consumption per unit time of the power supply;
Recording a predetermined test signal by changing a recording laser driving current for each of the plurality of recording speeds, storing the average power consumption corresponding to the changing recording laser driving current value, and reproducing the recorded test signal A test signal for obtaining the optimum laser driving current value for each recording speed and comparing the stored average power consumption corresponding to the optimum laser driving current value for each recording speed and selecting the recording speed at which the power consumption is minimum. Recording and reproducing means;
And an image signal from the video camera is recorded at the selected recording speed. In an imaging signal recording / reproducing apparatus integrated with a video camera using an optical disk capable of recording at a plurality of recording speeds,
An average power consumption measuring means for continuously measuring the average power consumption per unit time of the power supply;
Recording a predetermined test signal by changing a recording laser driving current for each of the plurality of recording speeds, storing the average power consumption corresponding to the changing recording laser driving current value, and reproducing the recorded test signal To obtain the optimum laser driving current value for each recording speed and measure the jitter or error rate value of the reproduction signal, and when the power source is a built-in battery, the stored average corresponding to the optimum laser driving current value for each recording speed Compare the power consumption and select the recording speed that shows the minimum power consumption. When using an external power supply, compare the jitter or error rate value at the optimum laser drive current value for each recording speed and minimize the value. Test signal recording / reproducing means for selecting a recording double speed to be indicated;
And an image signal from the video camera is recorded at the selected recording speed.

Images