JPS58187080A - Video system - Google Patents

Abstract

PURPOSE:To reduce the power consumption without losing the copying speed performance, by applying the power supply to circuits in the order of longer rising time after the power supply of each means required for video recording is applied sequentially. CONSTITUTION:In depressing a power switch 18, the power supply from a battery 19 is impressed to timers 25-27, an oscillator 16, a motor control circuit 11, an electronic view finder 17, and a display 31. Further, the oscillator 16, the motor control circuit 11, and the electronic view finder 17 are driven immediately. The timers 25-27 go to high level after the respective set time to turn on switches 28, 29 and the display 31 and to drive an AF control circuit 21, a lens drive circuit 22, a video signal processing circuit 7 and a driver circuit 8.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a video system that converts a subject (elephant) into an electrical signal and records the electrical signal on a recording medium.

As such a video system, a system consisting of a video camera and a VTR for recording moving images has been well known. Such systems have a standby mode in which the tape is loaded onto the drum and the head and capstan are kept rotating. In this standby mode, the actual recording operation is executed at the same time as the trigger switch is operated.

However, if the waiting time in this standby mode is long, there is a problem in terms of battery life.

Furthermore, if the actual recording operation is started before the image pickup tube for imaging or the capstor/motor for recording has been started up sufficiently, the video will not be accurately recorded during the time from the start of the operation until the start up. The occurrence of such a situation becomes a particularly serious problem especially when recording still images.

In view of the above-mentioned points, the present invention aims to provide a video system capable of achieving power saving and accurately recording video signals.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

In this embodiment, a video system 9 made by Seiichi using a magnetic disk as a medium will be described, but the present invention is not limited to this.

FIG. 1 is a block diagram showing one embodiment of the configuration of a still video camera.

Reference numeral 1 in the figure indicates an optical system for photographing one image. 2 is a squeezing means,
It may be physical or mechanical.

3ii Shutter is one means, and it may be physical or mechanical.

Further, it may also be used as the aperture 2. 5 is, for example, a CCD (Charge coupled device).
e) is a charging conversion element.

Reference numeral 4 denotes a color filter disposed in front of the imaging means 5, which may be of a strife type, a mosaic type, or the like.

Further, this filter may be omitted in order to obtain only the black and white image i1M. 6 is the shutter speed setting circuit, 7 is the imager l
ft A signal processing circuit that converts the image information obtained from the conversion element 5 into an appropriate signal form. A driver circuit 8 controls scanning, transfer, etc. of the conversion element 5. 9
1 is a shutter control circuit which controls the opening and closing of the shutter means 3 according to the setting value of the setting circuit 6. Reference numeral 10 denotes a sequence control circuit which controls the sequence of the entire still video camera of this embodiment.

Reference numeral 11 denotes a motor control circuit, which is controlled by a sequence control circuit when the power switch is turned on. 12 is a motor synchronously controlled by the cough control circuit 11; 13#i;
A magnetic disk is rotationally driven by a motor, 14 is a magnetic head, and 15 is a PG head, and the rotational phase of the motor is fed back to the motor control circuit 11 (Vr). Terminal F is a terminal for outputting a servo lock signal, 16 is a clock oscillator, 17 is an electronic viewfinder device for displaying one object, 18 is a power switch, and 19 is a battery. 20 is a detector that detects the distance #11 to the subject, and 21 is an autofocus control circuit (hereinafter referred to as AP control circuit) that controls a lens drive device 22 that moves the lens according to the distance detected by the detector 20.

FIG. 2 shows a detailed circuit diagram of the sequence control circuit 10 of FIG. 1, and FIG. 3 shows a timing chart of each part of FIG. 2.

In Figure 2, 25, 26, and 27 are delay times τ, respectively.
1. τ2τ3 timer, 28. 29. 32 is a switch, 30 is a release button, 31 is a Hareliz aT.
This is a display device that displays. Hereinafter, explanation will be given based on the timing chart of FIG.

When the power switch 1B is pressed, the power from the power switch 19 is switched to the timer 25, 26, 27, and oscillator 16.
, motor side control circuit 11. The signal is applied to the electronic viewfinder 17 and the display 31.

The motor control circuit 11 rotates the motor at the same time as power is applied, and starts control to rotate the magnetic disk at a predetermined speed using a synchronizing signal from the oscillator 16 and an output pulse from the PG head 15.

The running power applied to the electronic viewfinder 17 starts heating the cathode of the finder 17 .

After a time .tau.1 after the power switch 18 is turned on, the output of the timer 25 goes to the high level, and the switch 28 is turned on. Then, power is supplied to the AP control circuit 21 and the lens drive circuit 22, and the focus is automatically adjusted.

Furthermore, after a time τ2 from turning on the power switch 18, the timer 26
The output becomes high level, the switch 29 is turned on, and power is supplied to the image signal processing circuit 7 and the driver circuit 8.

Then, after a time τ3 from turning on the power switch 18, the timer 2
7 output is at high level, the display 311 lights up,
Inform the photographer that the release is possible (filming Mue Noh).

When the photographer presses the release button 30 at this point, the switch 32 closes and the shutter control circuit 9 operates. Then, the shutter opens and closes, and the signal from the conversion element 5 is applied to the recording head 14 via the video signal processing circuit 7, and is recorded on the normally rotating magnetic disk 13. Here, even if the release button 30 is pressed before the time τ1 has elapsed since the power switch 18 was turned on, the output of the timer 27 is at a low level, so the switch 32 will not close. Therefore, the photographing and recording operations are not performed.

Here, the rise characteristics of the motor control circuit 11 and the electronic viewfinder 17 are shown in FIG. 384K.

The start-up characteristics of the AP control circuit 21 and the lens driving circuit 22 are shown in FIG. 3, 85K, and the start-up characteristics of the video signal processing circuit 7 and the driver circuit are shown in FIG. 3, 86. As shown in the figure, time τ3 is the time required from when power is supplied to the motor control circuit 11 until the magnetic disk actually rotates at a normal speed. Electronic viewfinder 17vcII
The time from when the L source is supplied until the finder becomes visible also approximately coincides with time τ3.

Further, the maximum value of the time required for the lens to reach the autofocus position after power is supplied to the AP control circuit 21 and the lens drive circuit 22 is time (τ1-τl).

The time required for signal readout from the conversion element 5 to become possible after the IN signal processing circuit 7 and driver 11 path 89 power is supplied is time (τ3-τ2). As is obvious, τ1 × τ2〈τ3.(τ
3-τ2)<(T3-τ1)<τ3.

As described above, in the present embodiment, during the time τ3 from turning on the power switch until it becomes possible to take an image, the K'IIt sources are turned on in descending order of the rising time of the VC.

With this configuration, power consumption can be kept extremely low. In particular, power consumption can be minimized by finally aligning the start-up timings of all the means necessary for photographing.

In addition, after the means necessary for filming and recording are operating normally,
Since filming is permitted, there will be no recording errors or inappropriate recordings.

Next, a second embodiment of the sequence control circuit 10 shown in FIG. 1 will be described with reference to FIGS. 4 and 5. In the figure, items with the same functions as in Figure 2 are marked with "'".
It is shown with . In the figure, 5θ, 51 is a voltage dividing resistor, 52 is a comparator, 53.55ri switch, and 54 is a timer.

56 is a phase comparator, and 57 is a speed controller.

Moreover, the signal 8m is the ON signal of the power switch 18'.

8b is the phase error signal, the output signal of the Sc#i comparator 52, 8d is the output signal of the timer 54, and Se is the diagonal IO1 of the signal processing circuit 7' and the driver circuit 8'.
This is a signal indicating.

When the power switch 18' is turned on, a synchronizing signal from the oscillator 16' is applied to the motor control circuit 11', and power is simultaneously supplied to the motor control circuit 11'. The motor control circuit 11' includes a phase comparator 55 as shown in detail in FIG. 9B.
6. FG pulses from the motor 12' are fed back to the speed controller 57, and DG pulses are fed back to the phase comparator. The phase comparator 56 is the oscillator 16
The synchronizing signal from ' is compared with the phase error of the PG pulse, and a phase error indicating the phase error is output to the speed control a57. This phase error signal sb is input to the -h input terminal of the comparator 52. A voltage at level LE is input to the other input terminal of the comparator 52. error signal s
The level of b becomes smaller to some extent, and the level LBt-lower m
Ru. ! -, the output 8c#i of the comparator 52 becomes high level, closes the switch 53, and supplies the video signal processing circuit 7' and the driver circuit s'ct*.

At the same time, the timer 54 also starts timing. timer 54
The measured time is τ4, which is set to be approximately the same as the time required for the video signal processing circuit 7' and the driver circuit 8' to rise. When the timer 54 finishes counting, its output becomes high level, and the display 31' indicates that it is possible to take an image. Then, shooting is performed by operating the release button 30'. Further, the level of the phase error signal sb is O at the time when the timer 54 finishes counting.

By actually detecting the amount of phase error of the motor as in this embodiment, it is ensured that the magnetic disk is rotating normally when the release button is operated, and video signals can be accurately recorded.

A third embodiment of the sequence control circuit 10 is shown in FIG. In Figure 5, those with the same functions as those in Figures 2 and 4 are marked with a row.

61, 66 are switches, 62. 63 is a resistor, 6
4 is a comparator.

After the power switch is' is turned on, the comparator 52' detects that the phase error signal has fallen below a certain level, and the switch 61 is closed to put the AP control circuit 21' and the lens drive circuit 22'i into an operating state. Then, the lens drive control signal level indicating the amount of deviation from the focal position of the lens drive circuit zz' of the λF control circuit 21' becomes below a predetermined level (!: t'' 7 It is detected by the halo taro 4. The comparator 64 and When both the outputs of 52' reach the level..., the switch 66 is closed and the image signal processing circuit 7
'.

And the driver circuit 8' is turned on. The following actions are the fourth
This is similar to the embodiment shown in the figure.

FIG. 7 shows signal waveforms at various parts in FIG. 6.

8A is the turn-on signal of the power switch 18, SB is the phase error signal, SC is the output signal of the comparator 52, 8
D is a lens drive control signal, SR is an output signal of the comparator 64, 8F is an output signal of the timer 54', 8G is an image signal processing circuit 71. and the rising shape d of the driver circuit 81
It is a figure showing k.

As shown in FIG. 7, at time T3 when the level of the phase error signal 8B becomes zero, the level of the lens drive control signal SD becomes zero, and at the same time the level of the video signal processing circuit 71. The reference voltages of the comparators 52 and 64 are set so that the driver circuit 8' also rises.

In this manner, release is possible only when the magnetic disk rotates normally, the focus position is accurately aligned, and the signal processing circuit is turned on.

Therefore, it is possible to perform accurate magnetic recording without defocusing.

Similarly, in the above embodiments, the power switch and the release button are provided separately, but the power switch may be turned on with the first stroke, and the release button may be operated with the second stroke.

As described in detail above, the present invention has a control means that sequentially supplies power to the means necessary for recording in order of the time required for starting up after being supplied with power. Current consumption can be reduced. 11! Furthermore, since the recording operation is started after the recorder and camera have completed preparations for recording and photographing, inappropriate recording can be completely prevented.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an example of the configuration of a still/video camera. FIG. 2 is a circuit diagram of an embodiment of the 7-can control circuit of FIG. FIG. 3 is a signal waveform diagram of each part in FIG. 2. FIG. 4(A) is a circuit diagram of an embodiment of the sequence control circuit of FIG. FIG. 4(B) is a diagram showing details of the motor control circuit of FIG. 4 (person). FIG. 5 is a signal waveform diagram of each part in FIG. 4(A). FIG. 6 is a circuit diagram of still another embodiment of the sequence control circuit of FIG. 1. FIG. 7 is a signal waveform diagram of each part of FIG. 6. In the figure, 1 is the photographing optical system. 2 is the aperture means. One way to use 3Fi shutter. 5 is a charging conversion element. 7 is a video signal processing circuit. 5t-i shutter control circuit. 10 is a sequence control circuit. 11 is a motor control circuit. 12 is a motor. 13 is a magnetic disk. 18 is the power switch. 25, 26, and 27 are timers. 3G indicates a release button. Applicant Canon Co., Ltd.

Claims (1)

[Claims] a photographing means for converting a subject into an electrical signal; a recording means for recording the electrical signal on a recording medium; a driving means for moving the recording means relative to the recording medium; a power switch for supplying a power source to the means for driving the driving means and the photographing means; and a control means for supplying all the power to the driving means and the photographing means in order from the time it takes to start up after the power is supplied. A video system comprising: