JPS61174891A - Image pick-up device - Google Patents

Abstract

PURPOSE:To prevent the erroneous operation of a photographing device by giving a warning to a photographer when a color temperature converting filter is changed over while the white balance is adjusted. CONSTITUTION:The white balance is executed by changing over a color temperature converting filter 2 and by an automatic white balance circuit 11. At such a time, the condition of the filter 2 is detected by a change-over detecting circuit 15, and the signal in accordance with the condition of the filter 2 at that time is sent to a warning control circuit 16. On the other hand, the signal concerning whether the white balance is adjusted or not also enters the circuit 16 from the circuit 11. When the filter 2 is changed over carelessly while the white balance is being adjusted, the circuit 16 light-emits an LED 18 and gives the warning to the photographer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an imaging apparatus that warns a photographer when switching of color temperature conversion filters is necessary.

[Prior Art] In a color television camera (hereinafter referred to as a CTV camera), the so-called "white balance" is one of the important elements. The ratio of the three components of red, blue, and green (hereinafter referred to as R, B, and G, respectively), which are the three primary colors of CTV cameras, is:
For example, when lighting with an incandescent light bulb, R:B:G is approximately 2 colors.
: It is about 0.5, but it changes greatly to about 1:l:2 in daylight. On the other hand, T
When viewing with a V receiver, R and G are applied to the white part of the subject.
, B color signals are not L:1:1, the entire image becomes reddish or bluish, and the reproducibility of one color deteriorates. By correcting the ratio of R, G, and H of the illumination light source for this object, the ratio of R, G, and H color signals for a white object is adjusted.
:1:1 correction is commonly known as "white balance."

Traditionally, the method of performing this white balance is
A method of correcting using a color temperature conversion filter in an optical system and a method of electrically correcting in a signal processing system have been proposed.

For example, in home TV cameras, in order to obtain good operability and accurate color reproduction, the optical system switches between indoor and outdoor shooting by attaching and detaching a color temperature conversion filter, and the signal processing system includes a switch. Many cameras are equipped with an auto white balance function that allows you to accurately adjust the white balance simply by pressing Alternatively, you can automatically control the white balance by wearing a white lens cap, photographing the light source, and pressing the white balance switch.

In such conventional examples, if the above-described operations are performed reliably, accurate white balance can be achieved without requiring special skill. However, in reality, erroneous operations, particularly erroneous operations such as inadvertently switching the color temperature conversion filter during photographing, have occurred. For example, if you temporarily store the camera after taking an image with an appropriate white balance, you may inadvertently switch the color temperature conversion filter, and when you start shooting again, the image will be taken with an incorrect white balance. Something happened. As a result, images that are not worth viewing are sometimes taken, giving the average user the impression that CTV cameras are difficult to take pictures of and that they often fail.

Conventionally, as a method to prevent this type of erroneous operation, a method has been adopted in which when auto white balance is performed and the white balance cannot be achieved, a warning is issued to the user by lighting up a light bulb, etc. No warning was given regarding the erroneous operation of switching the temperature conversion filter carelessly. For this reason, especially when using a CT'V camera, it is rarely monitored on a color monitor TV.1Usually, people take pictures without noticing the erroneous operation, and only when looking at it later do they see it. There was a problem in that it was common for users to notice incorrect operations.

〔the purpose〕

The present invention has been made to solve these conventional problems, and it is an object of the present invention to provide an imaging device that is free from the risk of erroneous operation.

〔Example〕

A first embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a block circuit diagram of a CTV camera.

First, the configuration will be explained.

In the figure, 1 is an optical system including a lens and an aperture, 2 is a plurality of color temperature conversion filters, 3 is a changeover switch for attaching/detaching or switching each filter 2, 4 is an imaging unit including an image pickup tube, a preamplifier, etc., 5 6 is a brightness process, 6 is a color separation circuit, 7.9 is a variable gain circuit, 8 and 10 are color thread processes, 11 is an auto white balance circuit, 12
is a color difference matrix, and 13 is a video signal encoder 9.
14 is an electrical contact provided on the changeover switch 3 of the color temperature conversion filter 2; 15 is a switching detection circuit that detects switching of the color temperature conversion filter 2; 16 is a warning control circuit;
17 is a buffer amplifier, and 18 is an LED for displaying a warning to replace the color temperature conversion filter, which is usually installed in the viewfinder or the like. 19 is a white balance setting switch.

Next, the operation will be explained.

Light from the subject passes through an optical system 1 and a color temperature conversion filter 2, and is converted into an electrical signal by an imaging unit 4. Of this signal, the luminance component is processed by a luminance process 5 to become a luminance signal Y and a low-range luminance signal YL. In addition, the color components are
The color separation circuit 6 separates it into a red component R and a blue component B.
Variable gain circuits 7, 9, respectively. After passing through processes 8 and 10, the dye matrix 12 synthesizes the dye signal R-Y.
, B-Y, which are added to the luminance signal Y and the synchronization signal by the encoder 13 to become a standard television signal. on the other hand,
The red component R2, the blue component B, and the low-range luminance signal YL are compared by the auto white balance circuit 11, and R:B:
While the switch 19 is ON, the variable gain circuits 7 and 9 are adjusted so that YL=1:1.

White balance is performed by switching the color temperature conversion filter 2 and using the auto white balance circuit 11.

At this time, the state of the color temperature conversion filter 2 is detected by the switching detection circuit 15 via the changeover switch 3 and the electrical contact 14, and a signal corresponding to the state of the color temperature conversion filter 2 at that time is sent to the warning control circuit 16. On the other hand, a signal indicating whether or not the white balance has been adjusted also enters the warning control circuit 16 from the auto white balance circuit 11. If the color temperature conversion filter 2 is switched inadvertently while the white balance is being adjusted, the warning control circuit 1
6 causes the LED I 8 to emit light via the buffer amplifier 17 to give a warning to the photographer.

Note that the auto white balance circuit 11 adjusts the white/
If the Herans 3i switch 19 is turned off after adjustment to save the previous state, the warning control circuit 16 can also be configured to memorize the state of the color temperature conversion filter 2. Even if the temperature conversion filter 2 is switched, a warning can be given in the same way as described above.

FIG. 2 shows a second embodiment of the invention, in which 20 is a flip-flop and 21 is a transistor.

The flip-flop 20 is set when the switch 19 turns ON, and is reset when the switch 14 turns ON. Further, when the output Q of the flip-flop 20 is at a high level, the transistor 21 is turned on and the LE018 emits light.

Therefore, whenever the filter is changed, a warning is issued, and the LED emits light until the switch 19 is turned on and the white balance is adjusted. It may be configured like this.

As mentioned above, in this embodiment, the warning control circuit 16
Signal corresponding to the state of color temperature conversion filter 2 and white balance! ! ! If the color temperature conversion filter 2 is inadvertently switched while the white balance is properly adjusted or has been adjusted, the LED 18 will alert the photographer. Since the camera is configured to issue a warning, even if you accidentally make a mistake in operation, you can check this in advance.Therefore, there is no risk of erroneous operation and there will be no chance of a failure in shooting.

That is, for example, even if the photographer accidentally switches the color temperature conversion filter when storing the camera temporarily after taking a picture after adjusting the white balance, the photographer will receive a warning from the LED 18, so when he or she starts shooting again, There is no need to worry about taking a picture without adjusting the white balance.

〔effect〕

As explained above, according to the present invention, since the configuration is configured such that a warning is issued to the photographer when the color temperature conversion filter is switched with the white balance adjusted, it is possible to obtain an imaging device that is free from the risk of erroneous operation. I can do it.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a CTV camera according to a first embodiment of the invention, and FIG. 2 is a circuit diagram of a second embodiment. In the figure, 1 is an optical system, 2 is a color temperature conversion filter, 3 is a changeover switch, 14 is an electrical contact, 15 is a switching detection circuit, 16
is a warning control circuit, 17 is a buffer amplifier, and 18 is an LED.
It is. 7th prisoner

Claims (1)

[Claims] An imaging device that is equipped with a means to issue a warning if the color temperature conversion filter is switched with the white balance properly adjusted.