JPH05344397A - Camcorder - Google Patents

Abstract

PURPOSE:To prevent the operation of the camcorder from being unstable and to improve the operability of the camcorder. CONSTITUTION:The illuminance of an object is measured by an iris control circuit 2 and inputted to an iris detection circuit 6. The iris detection circuit 6 generates a DC voltage corresponding to the illuminance of the object to be inputted to a voltage comparator circuit 7. The voltage comparator circuit 7 controls a switching circuit 8 corresponding to the input DC voltage and lights an incorporated light. At this time, time delay is provided in the rising characteristic of the voltage to be supplied to the incorporated light by a time constant circuit 9 and the rush current of the incorporated light is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to voltage control of a built-in light of a VTR integrated camera.

[0002]

2. Description of the Related Art In a conventional apparatus, when the built-in light of a VTR-integrated camera is turned on, the voltage inside the VTR-integrated camera drops for a moment due to the rush current of the built-in light.

A control system for a built-in light of a VTR integrated camera is known as disclosed in Japanese Patent Laid-Open No. 235482/1990.

[0004]

In the prior art, when the built-in light of the VTR-integrated camera is turned on, the voltage inside the VTR-integrated camera momentarily drops due to the rush current of the built-in light. In particular, in the case of a VTR integrated camera that has a system that automatically turns on the built-in light according to the brightness of the subject, if the built-in light automatically lights during shooting, the rush current of the built-in light causes the inside of the VTR integrated camera No consideration was given to the fact that the voltage of the device may drop for a moment, causing a problem such as the screen being disturbed during shooting.

The present invention reduces the rush current when the built-in light is lit by delaying the rising characteristic of the voltage supplied to the built-in light to prevent the operation of the VTR integrated camera from becoming unstable. It is intended to further improve the usability of the VTR integrated camera.

[0006]

In order to achieve the above object, the present invention provides a rising characteristic of a voltage supplied to a built-in light of a VTR integrated camera with a time delay.

Further, it is achieved by constructing a system in which the rising characteristic of the voltage supplied to the built-in light is delayed.

[0008]

[Operation] The illuminance of the subject being photographed is detected, and the built-in light is turned on or off according to the illuminance. At this time, the rising characteristic of the voltage supplied to the built-in light is delayed so that the rush current when the built-in light is turned on is reduced. This makes it possible to prevent a voltage drop inside the VTR-integrated camera due to the rush current, stabilize the operation of the VTR-integrated camera, and provide a VTR-integrated camera that is easier to use. ..

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a block system diagram.

The optical signal collected through the lens 1 is input to the iris control circuit 2. Iris control circuit 2
Controls the input level of the image pickup circuit 3 by measuring the illuminance of the subject being photographed, and iris the iris when it is bright and opening the iris when it is dark. The output of the image pickup circuit 3 is input to the video signal processing circuit 4, becomes a camera video signal output, and is input to the VTR.

On the other hand, the output of the iris control circuit 2 is input to the iris detection circuit 6. The iris detection circuit 6 is
Generates a high DC voltage when the illuminance of the subject is high,
Conversely, when the illuminance is low, a low DC voltage is generated and input to the voltage comparison circuit 7.

The voltage comparison circuit 7 compares the output voltage of the iris detection circuit 6 with a preset voltage, and when the voltage of the iris detection circuit 4 is lower, H
Conversely, when the voltage of the iris detection circuit 4 is higher than the i output, the Lo output is output and input to the switch circuit 8.

The switch circuit 8 turns on the switch when the input is Hi and supplies a voltage to the time constant circuit 9. When the input is Lo, the switch is turned off to stop the voltage supply to the time constant circuit 9.

The time constant circuit 9 delays the rising characteristic of the output voltage of the switch circuit 8 with a time delay in order to prevent a rush current when the internal light is turned on. The time delay of the rising characteristic can be freely set by changing R and C.

The output voltage of the time constant circuit 9 is the power supply circuit.
Input to 10. The power supply circuit 10 acts so as to gradually increase the voltage supplied to the built-in light 5 according to the increase in the input voltage.

[0016]

According to the present invention, it is possible to prevent a decrease in the internal voltage of the VTR-integrated camera due to the rush current of the built-in light, so that it is possible to provide a VTR-integrated camera that is easier to use.

[Brief description of drawings]

FIG. 1 is a circuit block system diagram showing an embodiment of the present invention.

[Explanation of symbols]

1 ... Lens, 2 ... Iris control circuit, 3 ... Imaging circuit, 4
... video signal processing circuit, 5 ... built-in light, 6 ... iris detection circuit, 7 ... voltage comparison circuit, 8 ... switch circuit 9 ... time constant circuit, 10 ... power supply circuit.

Claims (1)

[Claims] 1. A VTR-integrated camera having a built-in light, wherein a rising characteristic of a voltage supplied to the built-in light is delayed by about 100 milliseconds.