JPH06165005A - Video light turning on/off control method and video camera with light - Google Patents

Abstract

PURPOSE:To supply power to a video light without increasing the ability of a power source and to stably operate the system of an entire video camera, as well. CONSTITUTION:When a video light 36 is turned on and the capstan motor 14 of the video camera is started, a large current flows but attending on the start of this motor 14, the turned-on video light 36 is turned off by the period when current consumption is increased, and the video light 36 is turned on again after lapse this period. Thus, the reduction of a power supply voltage is prevented by controlling the maximum value of current consumption, and the system down of the entire video camera is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video light on / off control method and a video camera with a light applied to a video camera with a light having a common power source for supplying power to the video camera and the video light.

[0002]

2. Description of the Related Art Conventionally, a video light mounted on a video camera has a power source separately from the video camera, but in recent years, a video camera having a built-in video light or an integrated type, only the light part can be attached and detached. There is a semi-built-in one that looks like this. Also, in this type of video camera, a video light is automatically turned on when the camera detects a low light condition (Japanese Utility Model Publication No. 62-57478), and the video light is attached to the shoe of the camera. There is a device that can supply power to the video light via the shoe when this happens (Japanese Utility Model Publication No. 61-100078).

[0003]

However, in the case of each of the above video cameras, the video light uses the same power source (battery, AC adapter, etc.) as the video camera, and thus a large current flows from the power source. And
When a large current flows, the output impedance of the power supply lowers the power supply voltage, causing the system of the entire video camera to go down. In particular, a large current flows when the motor of the camera unit is started with the video light turned on, and the above problem becomes prominent.

The present invention has been made in view of the above circumstances, and it is possible to supply power to a video light without increasing the power supply capacity, and to stably operate the entire system of the video camera. An object of the present invention is to provide a video light on / off control method and a video camera with a light.

[0005]

In order to achieve the above object, the present invention provides a method for controlling turning on / off of a video light in a video camera with a light having a common power source for supplying power to the video camera and the video light. When the motor of the video camera is started while the video light is turned on, the video light is turned off during a period in which current consumption increases with the start of the motor, and the video light is turned on again after the period has elapsed. Is characterized by.

[0006]

The present invention focuses on the fact that a large current flows when the video light is turned on and the motor of the video camera is started, and the video is turned on only during the period when the consumption current increases with the start of the motor. The light is turned off, and the video light is turned on again after the period. As a result, the maximum value of current consumption is suppressed to prevent the power supply voltage from dropping, and the system of the entire video camera is prevented from going down.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of a video light on / off control method and a video camera with a light according to the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a block diagram of essential parts showing an embodiment of a video camera with a light according to the present invention. As shown in the figure, the video camera with a light mainly includes a mechanical block 10, a mechanical controller 20, a mode controller 28, a power supply unit 30, and a video light 36. It should be noted that the image pickup unit and the signal processing unit are omitted in FIG.

The mechanical block 10 is a drum motor 12,
Capstan motor 14 and loading motor 1
6, a drum motor 12 drives a rotary head drum for magnetically recording and reproducing a video signal on a video tape, a capstan motor 14 drives a capstan or the like for feeding a tape, and a loading motor 16 defines a tape cassette. It drives the loading mechanism to set the position and wind the tape in the tape cassette around the rotary head drum.

The mechanical controller 20 controls the operation of the mechanical block 10, and includes drivers 22, 24 and 2
The drum motor 12, the capstan motor 14, and the loading motor 16 are controlled via the control unit 6.
The drum motor 12 and the capstan motor 14
In addition, known drum FG pulse, drum PG pulse, and capstan FG pulse necessary for servo control at the time of recording and reproducing are added.

The mode controller 28 controls the functions and specifications of the entire camera-integrated VTR.
Communicate closely with each other via the communication bus 27 and exchange information with each other. In addition, from the mechanical control 20 to the mode control 2
The information transmitted to 8 includes timing information immediately before the various motors managed by the mechanical controller 20 are turned on, as will be described later.

The power supply unit 30 includes a battery 34 and DC-DC.
It has a converter 32, etc., and a DC-DC converter 3
Reference numeral 2 converts the input voltage from the battery 34 into a predetermined voltage required in each circuit to which power is supplied, and outputs the voltage. The video light 36 is a DC-D of the power supply unit 30.
Power is supplied from the C converter 32, and lighting / extinguishing is controlled by the DC-DC converter 32 which receives a control signal from the mode converter 28.

Next, turning on / off control of the video light 36 according to the present invention will be described. Generally, the current consumption of the motor becomes extremely large at the moment when the motor starts from a stopped state. FIG. 2A shows a current waveform of the capstan motor. As shown in the figure, the current value at the time of starting the motor is much larger than that during steady operation.

According to the present invention, the video light 36 that is turned on is turned off only during a predetermined period when the current consumption of the motor is particularly high, and the maximum value of the current consumption is suppressed to prevent the power supply voltage from being lowered, so that the entire video camera is protected. I try to prevent the system from going down. CAP_ON shown in FIG. 2B indicates a flag of the timing when the capstan motor 14 is turned on. When the mode controller 28 determines that the flag has become "H" (to "H" immediately before the motor is turned on) based on the information from the mechanical controller 20, immediately turns on the software timer inside the mode controller (( In the same figure (C)), a control signal for turning off the video light 36 is output to the DC-DC converter 32, and the video light 36 is turned off (the same figure (D)).

After that, when the timer measures a predetermined time (for example, several tens of ms), a control signal for turning on the video light 36 is output to the DC-DC converter 32 to turn on the video light 36 ((D) in the figure). As a result, the video light 36 is controlled to be extinguished only during a certain period in which the consumption current becomes particularly large with the activation of the capstan motor 14.

By the way, in order to reduce the current consumption, the mode in which the video light 36 is turned on is set to the recording pause (REC PA
USE) and recording (REC) only. FIG. 3 is a mode transition diagram of the video camera with a light, in which ◯ indicates a mode in which the video light is off and ∘ indicates a mode in which the video light is on. In the figure, the mode switching from the ejected state (EJECTED) to the shooting disabled state (STOP) is automatically performed by, for example, loading the cassette and inserting the cassette into the VTR unit to execute the loading operation and the loading operation. Incidentally, the loading operation is a cassette loading operation of pulling the cassette to a predetermined position of the VTR to set it, and the loading operation pulls out the tape from the cassette,
This is a tape loading operation to be wound around the rotary head drum.

Mode switching from STOP to REC PAUSE
This is done by turning on the power button. REC PAUS
When the mode is switched to E, the mode control 28
The video light 36 is automatically turned on by a control signal from the. In REC PAUSE, since the rotary head drum is rotated, the video light 36 is turned on after the drum motor 12 is activated.

In this REC PAUSE state, recording (REC) is started when the shooting start / stop button is pushed once, and when the shooting start / stop button is pushed once during recording, the state returns to the REC PAUSE state. Where REC PA
When the mode is switched from USE to REC, the video light 36 is temporarily turned off as described in the timing chart of FIG. Also, when the mode is switched from REC to REC PAUSE, the capstan motor is rotated in reverse for so-called joint shooting, and a certain amount of tape is wound. Let However, when switching the mode from REC PAUSE to REC, it is necessary to turn on the video light 36 as soon as possible before recording starts.
Is controlled to be turned on and off, but when switching from REC to REC PAUS, the video light 36 is turned off until it is confirmed that REC PAUSE is set.

When the eject button is operated in the REC PAUSE state, the eject operation is performed from the REC PAUSE via STOP, the eject operation is automatically performed, and the cassette is ejected. Become.
The eject operation is a tape unloading operation for returning the tape wound around the rotary head drum to the inside of the cassette, and the eject operation is a cassette loading operation for making the cassette at a predetermined position of the VTR section ready for removal. Also, in REC and REC PAUSE mode,
When the power is turned off, the tape end, the battery is exhausted, or various emergency situations occur, the mode can be switched to the STOP mode. Further, when the mode is switched to STOP, the video light 36 is automatically turned off by the control signal from the mode controller 28.

Although FIG. 1 shows the case where the battery 34 is used, it goes without saying that an AC adapter can be used instead of the battery 34.

[0020]

As described above, according to the present invention, the video light that is being turned on is turned off only during the period when the consumption current increases with the start of the motor, so that the maximum value of the consumption current is suppressed. Therefore, the system of the entire video camera can be stably operated without increasing the power supply capacity. Further, by reducing the load on the power supply, the DC-DC converter can be downsized, and a battery having a slightly large internal impedance can be used. Further, there is an advantage that it is not necessary to newly design an AC adapter for a video camera with a light.

[Brief description of drawings]

FIG. 1 is a block diagram of essential parts showing an embodiment of a video camera with a light according to the present invention.

2 (A) to 2 (D) are timing charts used to describe a method for controlling turning on / off of a video light according to the present invention.

FIG. 3 is a mode transition diagram of a video camera with a light according to the present invention.

[Explanation of symbols]

 10 ... Mechanical block 12 ... Drum motor 14 ... Capstan motor 16 ... Loading motor 20 ... Mechanical controller 22, 24, 26 ... Driver 27 ... Communication bus 28 ... Mode computer 30 ... Power supply section 32 ... DC-DC converter 34 ... Battery 36 ... Video light

Claims (4)

[Claims] 1. A method of controlling turning on / off of a video light in a video camera with a light having a common power source for supplying power to the video camera and the video light, wherein a motor of the video camera is started while the video light is turned on. Occasionally, the video light is turned off during a period in which current consumption increases with activation of the motor, and the video light is turned on again after the period has elapsed, and a method for controlling turning on / off of the video light. 2. A method for controlling turning on / off of a video light in a video camera with a light having a common power source for supplying power to the video camera and the video light, respectively. The video light is turned on, and then the video light is turned off when the capstan motor is started from the shooting standby state, and the video light is turned on again after a period in which the consumption current increases with the start of the capstan motor. A method for controlling turning on / off of a video light, characterized by: 3. A method for controlling turning on / off of a video light in a video camera with a light having a common power supply for supplying power to the video camera and the video light, respectively, wherein a period during which the video camera is switched from a shooting standby state to a shooting state and A method for controlling lighting / extinguishing of a video light, characterized by temporarily turning off a video light that is lit during a period of switching from a shooting state to a shooting standby state. 4. A video camera body, a video light,
In a video camera with a light having a common power source for supplying power to the video camera body and the video light, a detection unit for detecting information immediately before a motor of the video camera body is turned on, and lighting of the video light. A predetermined control means for controlling the on / off state, wherein at least the information immediately before the motor is turned on is detected by the detection means while the video light is on, the current consumption increases with the activation of the motor. A video camera with a light, comprising: a control means for turning off the video light for a period of time.