JPH0473624A - Vtr with built-in camera - Google Patents

Abstract

PURPOSE:To recognize a distance to an object which is actually photographed by detecting the position of a focus ring moved by a motor, deducing the distance to the object which is photographed based on the detected position and displaying the distance. CONSTITUTION:Discrimination and driving circuits actuate an automatic focus motor 4 or the like and rotate the focus ring 5. Then, a lens on the inside is moved and finally brought in a focused state. Outputted information is outputted as the numeric value of the focusing distance previously set by a character generator 8. The image of the object under the focusing state is passed through an image pickup element 9, converted to a video signal by an encoder 10 and inputted to a VTR part 11 as the output of a camera. In the VTR part 11, the information of the distance at a focusing time outputted by the character generation circuit 8 is mixed with the video signal by a video output circuit 12 and outputted as the output of the video. Thus, the focusing distance is displayed on a monitor.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a system that uses the autofocus function of a VTR-integrated camera to determine and display the distance to a subject based on lens movement (position W). .

[Conventional technology]

Conventional VTR-integrated cameras only have an autofocus function that automatically focuses the object displayed on the sensor. This technique is already well known, as shown in "Color Video Cameras and How to Use Them" (written by Masakazu Hara, published by Japan Broadcast Publishing Association), pages 153 to 155. However, as in the present invention, this autofocus function is used to determine the distance to the subject to be photographed.
There has never been anything that has this function.

[Problem to be solved by the invention]

As mentioned above, the conventional technology does not take into consideration the function of knowing the distance to the object, which is inconvenient when, for example, you want to know the distance to the object that is actually being photographed.

An object of the present invention is to provide a VTR-integrated camera that calculates the distance to a subject from the position of a focus ring, outputs the value to a viewfinder (hereinafter referred to as EVF) or a TV monitor, and records it as necessary. .

[Means to solve the problem]

To achieve the above objective, we installed a variable resistor that moves in conjunction with the focus ring that is moved by the autofocus function, so that the resistance value changes depending on the position of the focus ring, and the distance to the subject corresponds to the resistance value. Set in advance.

In addition, the distance corresponding to the set resistance value was converted into a numerical value by a character generator (hereinafter referred to as gear radio energy), mixed with a video signal, and outputted and recorded together with the video shot on the EVF or monitor TV.

[Effect]

The autofocus function measures the distance to the subject using infrared rays and moves the focus lens back and forth to bring it into focus.

Further, the focus ring rotates until it reaches the focused point, and a variable resistor is provided that is linked to this focus ring, and the resistance value at the focused point is read out. Furthermore, the character generator circuit outputs the distance to the subject based on the resistance value at the focused point as a numerical value, mixes it with the video signal, and outputs it to a monitor, EVF, etc.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on FIGS. 1 and 2.

First, infrared rays (9KH
z pulse signal) toward the subject, and the reflected infrared rays reflected from the subject are detected by infrared elements 21 and 22 inside the autofocus circuit 2. Figure 2 shows focus circuit 2. The internal block diagram of the is shown.

The infrared signal A entering the infrared light receiving element 2I and the infrared signal B entering the infrared light receiving element 22 are set so that A=B when focusing is brought into focus. When A>B or A×B, preamplifier 2
3.24 and 9KHz bandpass filter 25.26
After removing components other than the signal, the signal is amplified by amplifiers 27 and 28, passed through addition/subtraction circuits 29 and 30, and further passed through a synchronous detector 3].

32 and manually input to the cosciparator 3:L 34 as A+B and A-B views.

Furthermore, A-B is used as main data for focus discrimination, and A+B is used as auxiliary data for discrimination.

Discrimination, drive circuit; 3. The autofocus motor 1
° etc., rotate the focus ring 5, move the internal lens, and finally bring the focus state of A = B.

A variable resistor is attached around the focus ring 5 so that the resistance value changes in conjunction with the focus ring 5. The resistance value is read by a resistance reader 6 and a resistance value detection circuit 7 outputs the resistance value at the focused point.

The output information is output as a numerical value of the focusing distance which has been pre-set by the character generator 8.

The image of the subject in focus passes through the image sensor 9, is converted into a video signal by the encoder 10, and is output as a camera output to VTRTi.
I1 is input.

The VTRTiI4 performs recording and playback using the same method as conventional methods, but the output distance information at the focused point is mixed with the video signal in the video output circuit 12 and output as video output. Ru. FIG. 3 shows the state actually output on the monitor screen.

The screen in FIG. 3 is focused on the subject, a stuffed toy bear, and the distance from the camera to the subject is displayed at 139 in the upper right corner of the screen as 3.8 meters.

〔Effect of the invention〕

According to the present invention, since the in-focus distance can be displayed on the monitor, there are new functions and added value effects not found in conventional VTR integrated cameras. Furthermore, there is less increase in the number of parts, resulting in higher cost performance.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention. Figure 2 is a block diagram of the autofocus circuit used in a VTR-integrated camera, including the resistance value detection device/character generator circuit, video output, and carradier mix circuit.

Claims (1)

[Claims] 1. It has an autofocus operation circuit, a motor operated by the autofocus operation circuit, and a lens block that can change rotational movement into forward and backward movement by the motor, detects the position of the focus ring moved by the motor, and detects the position of the focus ring moved by the motor. V characterized by having a function of determining the distance from to the object to be photographed and displaying the distance.
TR integrated camera.