JPH01245210A - Range-finder for camera - Google Patents

Abstract

PURPOSE:To range-find in a wide range and to almost surely range-find even when an object is dislocated from the central part of a finder by disposing plural range-finding optical systems horizontally in a line and obliquing both the longitudinal direction of a projecting part in the range-finding optical system and detecting direction of the photodetector in a light receiving part. CONSTITUTION:The range-finding system constituted with projecting part 13 and light receiving part 14 is disposed horizontally in a line while pinching a finder 12 in the projecting part 13, a projecting element 13a is obliquely disposed so that the object is irradiated obliquely with the light; in the light receiving part 14, the photodetector 14a is disposed so that it receives the light reflected by the object and detecting direction is oblique. Thus, when the camera is held horizontally or perpendicularly, the light is obliquely projected to the object in the form of a slit or plural dots. Since the detecting direction of the light receiving part is oblique, the part receives surely the light which is obliquely projected to the object and reflected by it. The object is detected in a wide range of all directions; thus, information on range for accurate range-finding is obtained in photographing.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a distance measuring device for a camera that measures the distance to a subject during photographing.

[Conventional technology]

2. Description of the Related Art In order to conveniently take photographs, cameras have become popular that have an autofocus function that measures the distance to an object by pointing the camera at the object and automatically focuses based on this distance information.

In this type of autofocus function, light is emitted from a light emitter such as an infrared light emitting diode (infrared LED) attached to the camera, and the light reflected back to the subject is received by a light receiver and then connected to the emitter. There is an active method that measures the distance to the subject based on the angle it makes with the light receiving section. If the light from the light projector is concentrated on one point, for example, when two people are lined up, the light from the light projector will be concentrated between them, and in such a case, the light from the light projector will be concentrated between the two people. Because the light reflects off a certain object, it won't focus on the two people you're trying to photograph, and it will be out of focus.

Therefore, as ways to improve the light projecting section, it is possible to consider a method in which the light from the light projecting section is made into a plurality of pieces and is projected onto multiple locations, or the dazzling light is formed into a slit and the light is projected onto the subject. Regarding the arrangement of the light emitting and receiving parts, if the light emitting and receiving parts are arranged horizontally, there is a risk that the light will not be emitted to the subject if the subject is shifted vertically, so as shown in Fig. 4,
It is conceivable to arrange the distance measuring optical system to be oblique with the photographic lens 1 in between. That is, it is conceivable to provide the light projecting section 2 on the side of the finder 3 at the top of the camera, and to arrange the light receiving section 4 near a position that is approximately point symmetrical with the light projecting section 2 with respect to the photographing lens 1.

(Problems to be Solved by the Invention) However, if the distance measuring optical system, such as the light receiving section 4, is disposed diagonally below the photographic lens 1 as described above, people who are inexperienced in handling cameras, children, etc. If the camera is held during photographing, there is a risk that the light receiving section 2 will be covered with a finger, making distance measurement impossible.

It is desirable to be able to take photographs more easily and reliably without making mistakes even if users are inexperienced in handling cameras.

Therefore, the present invention provides a distance measuring device for a camera that has a distance measuring optical system installed in a position that will not be covered by fingers or the like, and that can measure the distance to the subject in the vertical and horizontal directions. It is intended to provide.

[Means for solving problems]

In order to achieve the above object, the distance measuring device according to the present invention is a distance measuring optical system that emits light from a light projecting part during photographing, receives the light reflected by the subject in a light receiving part, and measures the distance to the subject. In a camera equipped with.

In the part that is not covered by fingers when holding the camera,
The distance measuring optical system is arranged in a line on the horizontal line, and the longitudinal direction of the light projecting section of the distance measuring optical system is oblique to the detection direction of the light receiving element of the light receiving section.

[For production]

Since the longitudinal direction of the light projecting section is oblique, when the camera is held horizontally or vertically, light is projected obliquely onto the subject in the form of a slit or in the form of a plurality of dots. therefore,
For example, when the subjects are two people, even if the two people are close together, some of the light emitted from the light projecting section will be projected onto some part of the two people. and,
Since the detection direction of the light receiving section is oblique, the light that is obliquely projected onto the subject and reflected is reliably received. Therefore, since the subject is detected in a wide range in the vertical and horizontal directions, accurate distance measurement can be performed as distance information at the time of photographing.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The distance measuring device according to the present invention will be specifically explained below based on the preferred embodiment shown in FIGS. 1 to 3.

FIG. 2 is a front view of a compact camera, particularly a 35 mm lens shutter camera equipped with a variable focus function, in which a photographic lens 11 is disposed in the center of the frame, and a finder 12 is disposed above it. On the right side of this finder 12 is a light projecting section 13 that is made up of a light projecting element such as an infrared LED and emits light onto the subject, and on the left side is a light projecting section 13 that is made up of a position sensing device (PSD) or other position detecting device that emits light reflected by the subject. A light receiving section 14 is provided to receive the light. That is, as shown in FIG. 1, a distance measuring optical system consisting of a light projecting section 13 and a light receiving section 14 is arranged in a straight line on the horizon with the finder 12 in between.

Note that a focus changeover switch 1 is provided on the side of the photographic lens 11.
5 and a sensor I6 for automatic exposure are provided. Further, a strobe light emitting window 17 is provided at the upper right end, and a release button 18 is provided on the left side of the upper surface.

Figure 1 shows a finder 12, a light emitter 13, and a light receiver 1.
4 is a front view of the vehicle. In the light projecting section 13, a light projecting element 13a is disposed diagonally so as to project light obliquely to the subject, and in the light receiving section 14, a light receiving element 13a is arranged so as to receive light reflected by the subject so that the detection direction thereof is oblique. An element 14a is provided.

Figure 3 shows subjects 19a and 19b taken from the finder 12.
When photographing, the subjects 19a and 19b should be placed approximately in the center of the field of view frame 12a.

The operation of the embodiment of the distance measuring device according to the present invention constructed as described above will be explained.

Aim the camera at the subjects 19a and 19b, and move the field of view frame 12
Confirm with the finder 12 that the subjects 19a and 19b are placed approximately in the center of the area a. Subject 19a, 1
FIG. 3 shows two people 9b positioned approximately in the center of the field of view frame 12a.

When the release button 8 is slightly pressed in this state, light is projected from the light projecting section 13 onto the subjects 19a and 19b. Since the light projecting section 13 is arranged diagonally, the light emitted from the light projecting section 13 is directed toward the subject 19a as shown by the broken line in the figure.

The light is projected obliquely to 19b. Further, the detection direction of the light receiving element 14a of the light receiving section 14 is oblique, and the light reflected at the broken line is received obliquely as shown by the broken line in FIG. Since the range indicated by the broken line in the upper part of FIG. 3 extends from the head of the subject 19a to the waist of the subject 19b,
Either of the lights emitted from the object 19a or 19b
reflect. Since the detection direction of the light receiving section 14 is oblique,
This reflected light can be received by the subject 19a,
The distance to 19b can be measured.

In this embodiment, the light emitting part 13 and the light receiving part 14 are arranged on the left and right sides of the finder 12, but these parts are not likely to be covered by the photographer's fingers when holding the camera for taking pictures. If so, it may be placed in another position. Furthermore, the light projecting section 13 and the light receiving section 14 may be inclined in opposite directions as long as they are oblique.

Further, although a 35 mm lens shutter camera has been shown as an example, the present invention can be applied to instant cameras and other cameras.

〔Effect of the invention〕

As explained above, according to the distance measuring device according to the present invention, since the longitudinal direction of the light emitting part and the detection direction of the light receiving part are arranged diagonally, distance measurement can be performed over a wide range, and the object can be measured in the center of the viewfinder. Even if you position it off-center, you can still measure the distance reliably.

In addition to being able to measure a wide range of distances, the distance-measuring optical system is placed in an area that is not covered by the photographer's fingers when taking pictures, so even users who are not familiar with using cameras can use it easily.
This prevents distance measurement from becoming impossible and failures in shooting. Therefore, photography can be made easier.

[Brief explanation of the drawing]

1 to 3 show a preferred embodiment of the distance measuring device according to the present invention, and FIG. 1 is a front view of the main part. FIG. 2 is a front view of a camera equipped with this distance measuring device, and FIG. 3 is a view of the field of view when looking at a subject through the finder. FIG. 4 is a front view of a camera equipped with a subordinate axis distance measuring device capable of measuring a wide range. 11...Photographing lens 12...Finder 1
2a... Viewing frame 13... Light projecting section 13a...
・Light projecting element 14... Light receiving part 14a... Light receiving element 19a, 19b... Subject patent applicant Fuji Photo Photoki Co., Ltd. Figure 1 Figure 2

Claims (1)

[Scope of Claims] A camera equipped with a distance measuring optical system that emits light from a light emitting part during photographing and measures the distance to the subject by receiving the light reflected by the subject at the light receiving part, when the camera is held. In areas that are not covered by fingers,
The distance measuring optical system is arranged in a row on the horizontal line, and the longitudinal direction of the light emitting part of the distance measuring optical system is oblique to the detection direction of the light receiving element of the light receiving part. range device.