JPH08220419A - Camera distance specifying device - Google Patents

Abstract

PURPOSE: To provide an excellent camera distance specifying device capable of easily, quickly and precisely obtaining a subject distance and depth of field, even if a photographer does not have a special knowledge of a camera. CONSTITUTION: The camera distance specifying device is provided with a subject distance deciding part 14 deciding the subject distance (s) by a zooming position fixed by a zooming position detecting circuit 11 and a focusing position fixed by a focusing position detecting circuit 12 and a depth of field deciding part 15 deciding the depth of field by an F-number set by an F-value detecting circuit 13, the zooming position fixed by the zooming position detecting circuit 11 and the subject distance (s), so that the subject distance and the depth of field can be easily, quickly and precisely obtained by specifying them on a display device 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention determines and displays a subject distance and a depth of field at the time of shooting in a video camera or a camera-integrated video tape recorder (hereinafter referred to as a camera-integrated VTR) and an electronic still camera. The present invention relates to a photographing distance specifying device.

[0002]

2. Description of the Related Art In recent years, the widespread use of video cameras, VTRs with built-in cameras, and electronic still cameras has increased the opportunity to enjoy camera photography in earnest. Further, along with the miniaturization and weight reduction of the video camera or the VTR with a built-in camera, it is required to reduce the size and weight of the zoom lens, and an inner focus type zoom lens having a small number of lens components is generally adopted. In addition, a convenient automatic focusing (hereinafter abbreviated as AF) function when shooting with a camera,
The number of apertures that can set the F number (hereinafter, abbreviated as FNo) is increasing.

A conventional photographing distance specifying device will be described below. FIG. 4 is a block diagram of a conventional photographing distance specifying device. In FIG. 4, reference numeral 6 denotes a lens system, which is composed of four lens groups, a first group lens 1, a second group lens 2, a third group lens 3, and a fourth group lens 4, and a diaphragm 5 from the objective side. In particular, the second group lens 2 is a variable magnification lens group for zooming, the fourth group lens 4 is a focusing lens group for focusing on the image sensor 7, and the second group lens 2, the fourth group lens 4 are each The drive means (not shown) separately moves in the optical axis direction, and the movement positions are detected by the zoom encoder 8 and the focus encoder 9, respectively. A zoom position detection circuit 11 detects the position of the second lens group 2 in the optical axis direction from the information of the zoom encoder 8. A focus position detection circuit 12 detects the position of the fourth group lens 4 in the optical axis direction from the information of the focus encoder 9. Further, 13 is an F-number detection circuit unit, which inputs information of the aperture sensor 10 that detects the aperture of the aperture 5 and detects FNo. Reference numeral 17 denotes a display device which inputs information about the position of the second lens group 2 and information about the opening of the diaphragm 5 from the zoom position detection circuit 11 and the F value detection circuit 13 and clearly indicates the information.

The operation of the photographing distance specifying device configured as described above will be described below. First, when zooming to a wide angle or a telephoto, the position of the second lens group 2 is determined by the zoom position detection circuit 1 according to the information of the zoom encoder 8.
Detected in 1. Further, at the time of automatic shooting, the position of the fourth lens group 4 is controlled by using the signal detected by the focus position detection circuit 12 based on the information of the focus encoder 9 so that the image sensor 7 is in focus. The opening / closing of the diaphragm 5 is controlled by using the signal detected by the F-number detection circuit unit 13 based on the information of the diaphragm sensor 10 so that the amount of light entering 7 becomes appropriate. Then, the signal detected by the zoom position detection circuit 11 at that time and the F value detection circuit 13
The signal detected by the display device 17 is used by the display device 17 in FIG.
As shown in, the zoom position and FNo are clearly indicated in the viewfinder, for example.

[0005]

However, in the above-mentioned conventional configuration, the zoom position or the focal length and the F of the diaphragm are set.
Only the No can be known independently, and the subject distance or the depth of field cannot be displayed. Therefore, with a video camera equipped with an AF function, if there is another subject before and after the subject you want to shoot, another subject will be focused due to incorrect recognition of the AF function, and the subject you want to shoot will be recorded without out-of-focus. It is difficult to understand whether or not it is necessary to judge whether there is an image in the viewfinder. Also, in manual shooting, when shooting while waiting for the subject to appear (standby shooting), if you do not decide the subject distance you will miss the shooting opportunity that was in focus, and when setting the depth of field, Without specialized knowledge of the camera, the FNo of the aperture cannot be set, and there is a problem that the enjoyment of taking a picture such as background blur cannot be fully enjoyed.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, and provides a photographing distance specifying device which can easily, quickly, and clearly identify the subject distance and the depth of field without the expert knowledge of the camera. With the goal.

[0007]

In order to achieve this object, a photographing distance specifying device of the present invention comprises a zoom lens group for zooming a subject image, a focusing lens group for focusing a subject image, and a light amount. A diaphragm for adjusting the position, a light receiving element for converting light information into electric information, a zoom position detecting means for detecting the position of the variable power lens group, and a position of the focusing lens group. Focus position detecting means for detecting the F number of the diaphragm, and F number detecting means for detecting the F number of the diaphragm.
From the information of the zoom position detecting means and the information of the focus position detecting means, the subject distance determining means for determining the subject distance, the information of the zoom position detecting means, the information of the F number detecting means, and the information of the subject distance determining means. It has a configuration including depth-of-field determination means for determining the depth of field, and display means for displaying the determined subject distance and depth of field.

[0008]

With this configuration, the subject distance determining means and the depth of field determining means automatically determine the subject distance and the depth of field from the focus position information, the zoom position information, and the F number, and display them on the display means. Therefore, the subject distance and the depth of field can be easily and quickly and clearly understood and the user can concentrate on shooting even if the user does not have specialized knowledge of the camera.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a photographing distance specifying device according to the present invention. In FIG. 1, reference numeral 6 denotes a lens system, and like the conventional example, four lens groups of a first group lens 1, a second group lens 2, a third group lens 3 and a fourth group lens 4 and a diaphragm 5 are provided.
It consists of. The second lens group 2 is a variable power lens group for zooming, the fourth lens group 4 is a focusing lens group for focusing on the image sensor 7, and the second lens group 2 and the fourth lens group 4 are respectively The driving means (not shown) separately moves in the optical axis direction. A zoom position detection circuit 11 is configured as a zoom position detection unit together with the zoom encoder 8 and detects the position of the second group lens 2 in the optical axis direction from the information of the zoom encoder 8. Reference numeral 12 denotes a focus position detection circuit, which is configured as focus position detection means together with the focus encoder 9 and detects the position of the fourth lens group 4 in the optical axis direction from the information of the focus encoder 9. Further, 13 is an F value detection circuit, which is configured as an F number detecting means together with the aperture sensor 10 and detects FNo from the information of the aperture sensor 10.
Reference numeral 14 denotes a subject distance determination unit, which is a zoom position detection circuit 1
Information on the position of the first to second lens group 2 is input, and information on the position of the fourth lens group 4 is input from the focus position detection circuit 12 to determine the distance to the subject. Reference numeral 15 is a depth-of-field determination unit that receives information on the shooting distance from the subject distance determination unit 14,
Information on the position of the second lens group 2 is input from the zoom position detection circuit 11 and FNo is input from the F value detection circuit 13 to determine the depth of field. Reference numeral 16 denotes a display device, which is a subject distance determination unit 1
The information of the shooting distance is input from 4 and the information of the depth of field is input from the depth of field determination unit 15 and is specified.

The operation of the photographing distance specifying device configured as described above will be described with reference to FIGS. 2 and 3.

FIG. 2 is an example of a relationship between the 4th lens group position and the object distance in an embodiment of the photographing distance specifying device of the present invention, wherein the 2nd lens group 2 for zooming is used as a parameter.
The position of the fourth group lens 4 (horizontal axis) and the subject distance (vertical axis) when the position of is set to the wide angle (W), the standard (N), the telephoto (T) and their intermediate positions (WN, TN) ) Is shown.

As is well known, in the AF function, the signal of the image pickup device 7 is passed through a focus signal detection section (not shown), and the fourth group lens 4 is installed so that the focus signal becomes maximum, thereby making the subject An image can be formed on the image sensor 7.

Here, using the zoom position determined by the zoom position detection circuit 11 and the focus position determined by the focus position detection circuit 12, the relationship between the focus position and the subject distance shown in FIG. Distance determination unit 1
4 determines the subject distance s. Further, the F value detection circuit 13
By inputting the F value determined by, the zoom position determined by the zoom position detection circuit 11, and the subject distance s output from the subject distance determination unit 14, the depth of field determination unit 15 determines the depth of field, Front depth of field a, rear depth of field b
To decide. Then, as shown in FIG. 3, the display device 16 displays a combination of the subject distance s, the front depth of field a, and the rear depth of field b in the viewfinder, for example.

As described above, according to the present embodiment, in the camera device having the zoom lens barrel, the object distance determining unit is inputted with the information of the zoom position of the zoom position detecting circuit and the information of the focus position of the focus position detecting circuit. Determines the subject distance, inputs the information of the zoom position, the subject position information of the subject distance determination unit, and the FNo information of the F value detection circuit, and the depth of field determination unit determines the depth of field. By displaying the depth of field on the display device, the subject distance and the depth of field can be easily, quickly, and clearly known even if the user does not have camera expertise.
In addition to preventing out-of-focus of the subject due to erroneous recognition, it is possible to easily perform standby shooting of the subject, effective shooting in which the background is blurred and only the subject is focused.

In the present embodiment, both the subject distance and the depth of field are displayed on the display means, but a focusable range in which both are combined (that is, subject distance-front side depth of field, subject distance + back) The range between the side depths of field) may be displayed. Further, although the display means is provided in the finder, it is not limited to this.

[0017]

As described above, according to the present invention, a zoom lens group for zooming a subject image, a focusing lens group for focusing a subject image, a diaphragm for adjusting the light amount, and light information are provided. A light receiving element for converting into electric information, a zoom position detecting means for detecting the position of the variable power lens group, a focus position detecting means for detecting the position of the focusing lens group,
F number detecting means for detecting the F number of the diaphragm, subject distance determining means for determining the subject distance based on the information of the zoom position detecting means and the information of the focus position detecting means, and the information of the zoom position detecting means. Providing a depth of field determining means for determining the depth of field based on the information of the F number detecting means and the information of the subject distance determining means, and a display means for displaying the determined subject distance and depth of field. According to this, the subject distance determining means and the depth of field determining means automatically determine the subject distance and the depth of field from the focus position information and the zoom position information, and the F number, and are displayed on the display means. Even if a person has no camera expertise, he / she can easily and quickly understand the subject distance and depth of field, and can easily achieve advanced shooting effects. There is provided a can better shooting distance explicitly device.

[Brief description of drawings]

FIG. 1 is a block diagram of a photographing distance specifying device according to an embodiment of the present invention.

FIG. 2 is a diagram showing the relationship between the fourth lens group position and the subject distance

FIG. 3 is a schematic diagram of the display of the subject distance and the depth of field on the display unit.

FIG. 4 is a block diagram of a conventional photographing distance specifying device.

FIG. 5 is a schematic diagram of the display means.

[Explanation of symbols]

 1 1st group lens 2 2nd group lens 3 3rd group lens 4 4th group lens 5 Aperture 6 Lens system 7 Image sensor 8 Zoom encoder 9 Focus encoder 10 Aperture sensor 11 Zoom position detection circuit 12 Focus position detection circuit 13 F value detection circuit 14 Subject Distance determination unit 15 Depth of field determination unit 16 Display device

Claims (1)

[Claims] 1. A camera device having a zoom lens barrel, comprising a zoom lens group for zooming a subject image, a focusing lens group for focusing a subject image, and a diaphragm for adjusting the amount of light.
A light receiving element for converting light information into electrical information, a zoom position detecting means for detecting the position of the variable power lens group, and a focus position detecting means for detecting the position of the focusing lens group. An F-number detecting means for detecting the F-number of the aperture, a subject distance determining means for determining a subject distance based on the information of the zoom position detecting means and the information of the focus position detecting means, and the zoom. The depth of field determining means for determining the depth of field based on the information of the position detecting means, the information of the F number detecting means, and the information of the subject distance determining means, and the determined subject distance and depth of field A photographing distance specifying device comprising: a display unit for displaying.