JP2572151Y2 - Automatic light control device for camera - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic light control device for a camera which divides an object field into a plurality of photometric areas, measures light reflected from each area, and performs dimming based on the output. Things.

[0002]

2. Description of the Related Art Conventionally, the main device has been disclosed in
No. 0-15626 is known. This is TTL
This method is called a dimming method.Preliminary light emission is performed prior to main light emission during flash photography. The main light emission is stopped when a determination is made and the total value of the outputs of the respective areas weighted with respect to the respective areas reaches a predetermined light control level.

[0003]

By the way, in this type of automatic light control device, the flash light emitted from the flash light emitter has a large amount of infrared components, and if the light is directly controlled, the exposure is not properly performed. A cut filter is arranged. In addition, if unrelated light due to stray light or the like enters the light receiving element, proper exposure cannot be obtained. Therefore, a light-shielding mask is arranged in front of the light receiving element so that stray light or the like does not enter. However, the work of arranging the two members, the infrared cut filter and the light shielding mask, in a narrow space in the camera is troublesome, requires time, and has a problem in that the assembling workability is poor.

Accordingly, the present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to integrate an infrared cut filter and a light shielding mask in a single step, thereby improving assembly workability. It is an object of the present invention to provide an automatic dimming control device for a camera in which the above and a condenser lens are unitized.

[0005]

Means for Solving the Problems To achieve the above object,
Therefore, the present invention is designed to collect light that has passed through the taking lens.
And the infrared component of the light flux transmitted through the optical member.
An infrared cut filter to be removed;
A light-blocking mask that blocks light beams other than the transmission area of the filter;
A receiver for receiving a light beam transmitted through the infrared cut filter.
And an optical element for dimming a light beam passing through the taking lens.
In the automatic light control device for a camera which, the infrared mosquito
That the light shielding mask is provided integrally with the cut filter.
Features. In addition, the present invention precedes the main flash during flash photography.
Because it has a flash device that pre-flashes at the subject
Based on the luminous flux of the preliminary light reflected by the object.
It is characterized in that light control is performed. In addition, the present invention includes an optical
Positioning for positioning the member and the infrared cut filter
Member, and the infrared cut filter and the
The optical member is provided integrally via the positioning member.
It is characterized by having been done . In addition, the present invention
Area where the light flux from the flash device reflected by the
Photoelectric conversion means for photometry every time, and the infrared component of the light flux
An infrared cut filter to be removed;
A light-blocking mask that blocks light beams other than the transmission area of the filter;
Automatically controls the amount of light emitted from the flash device during flash photography
In the automatic light control device for a camera,
That the light shielding mask is provided integrally with the cut filter.
Features .

[0006]

In the present invention, the infrared cut filter and the light shielding mask are provided integrally, and constitute one component.
In addition, prior to the main flash during flash photography,
If you have a flash device that emits light,
Dimming is performed based on the reflected preliminary light beam. Ma
The position of the optical member and the infrared cut filter
If you have a positioning member to determine the
The cut filter and the optical member are
Provided physically.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on an embodiment shown in the drawings. FIG. 1 is a perspective view showing an embodiment of an automatic light control device for a camera according to the present invention, FIG. 2 is a cross-sectional view of a camera incorporating the control device, FIG. FIG. 3 is a diagram illustrating an optical positional relationship between a cut filter and a condenser lens as viewed from the direction of arrow A in FIG. 2. In FIG. 2, 1 is a camera body of a single-lens reflex camera, 2 is a photographing lens, 3 is a flash light emitter, 4 is a shutter, 5 is a film surface, 6 is a main mirror, 7 is a pentaprism, 8 is an aperture,
9 is a screen, 10 is an eyepiece, and 11 is an automatic light control device. Light flux (stationary light) that has passed through the taking lens 2
Is reflected by the main mirror 6 in the mirror-down state indicated by the broken line, passes through the screen 9 and the pentaprism 7, and is guided to the eyepiece 10. When a release button (not shown) is operated during normal photographing, the main mirror 6 is rotated upward to an up position indicated by a solid line, and then the diaphragm 8 is stopped down and the shutter 4 is opened, thereby opening the photographing lens 2.
Is transmitted to the film surface 5 and is exposed. In flash photography, after the shutter 4 is opened, the flash emitter 3 emits light to irradiate the subject, and the reflected light from the subject reaches the film surface 5 via the photographing lens 2 and exposes it. Further, the camera according to the present embodiment can perform preliminary light emission for dimming the reflectance distribution of the object scene and determining an appropriate exposure value before the main light emission, and the preliminary light emission from the object scene due to the preliminary light emission is possible. The reflected light is reflected by the curtain before the shutter 4 opens, and is received by the automatic light control device 11. When the amount of light reaches a predetermined level, the preliminary light emission of the flash light emitter 3 is stopped to set an exposure time and an aperture value.

In FIGS. 1 and 2, the automatic light control device 11 includes a light receiving element (photoelectric conversion means) 12, an infrared cut filter 13, a condenser lens 14, and a T (not shown).
The camera body 1 includes a TL automatic light control circuit, and is disposed at a position on the inner bottom surface of the camera body 1 where the light reflected from the shutter 4 can be received.

The light-receiving element 12 has a divided light-receiving element 12a corresponding to a circular photometric area in the center of the object field and a divided light-receiving element 12a corresponding to a photometric area in which a rectangle around the object field is cut off by an arc. The light receiving elements 12b to 12e are arranged on the same plane. That is, in the present embodiment, the object field is divided into five photometric areas, and divided photometry is performed.

The infrared cut filter 13 is disposed between the condenser lens 14 and the light receiving element 12, and includes three transmitting portions 13a corresponding to the left, middle and right blocks of the divided light receiving elements 12a to 12e. 13c, and the other portions are formed with a light-shielding mask 15 by applying a light-shielding paint as shown by oblique lines. However, light shielding mask 1
5 is not limited to the application of the light-shielding paint, and
An opaque light-shielding film having three openings corresponding to 3c may be stuck to form a light-shielding mask.

The condenser lens 14 is integrally formed of a transparent resin, and is provided with the infrared cut filter 13.
Plate portion 14A having a size substantially the same as that of
And 3 projecting from the surface of the plate portion 14A corresponding to the left, middle and right blocks of the divided light receiving elements 12a to 12e.
It is composed of two convex lens portions 14a to 14c, and a pair of filter fixing portions 14B which extend integrally with the plate portion 14A and position and fix the infrared cut filter 13.
The filter fixing portion 14B is not limited to a pair of legs, and may be four or a frame. To position the condenser lens 14 and the light receiving element 12, a lead frame (not shown) is taken out of the light receiving element 12, a boss (not shown) is taken out of the condenser lens 14, and this is inserted into the lead frame. That is, the light receiving element 12, the infrared cut filter 13, and the condenser lens 14 are unitized and incorporated in the camera body.

In FIG. 3, an opening (exposure) area 17 for one frame on the film surface 5 has a circular circular area 17a located at the center and a rectangular area 17b divided into four parts, as in the field. The three left, middle and right blocks of the light receiving elements 12a to 12e shown in FIG. 1 are three convex lens portions 14a to 14e of the condenser lens, respectively.
It faces the left half, the center, and the right half of the exposure area 17 via 4c. Furthermore, since the five divisional elements 12a to 12e of the light receiving element 12 correspond in shape to the exposure area 17, the brightness of the five areas 17a to 17e is divided and measured.

In the automatic light control device for a camera having such a configuration, when the flash light emitter 3 is preliminarily illuminated, the light shines on the subject and is reflected by the divided light receiving elements 12a to 12e via the photographing lens 2. You. And
A luminance value, a luminance difference, a maximum luminance value, and the like of each of the light receiving elements 12a to 12e are compared and calculated by a TTL light control circuit built in the camera to determine an appropriate exposure value. Here, in the present invention, since the light-shielding mask 15 is provided integrally with the infrared cut filter 13, only one process is required compared to the conventional two processes, and the assembling work into the camera body is easy. It is. Further, since the light receiving element 12, the infrared cut filter 13 and the condenser lens 14 are unitized,
These assembling and positioning adjustment operations are also simple and easy. Further, since the condenser lens 14 integrally has the filter fixing portion 14B and positions and fixes the infrared cut filter 13, the work of assembling the infrared cut filter 13 to the condenser lens 14 is also easy.

[0014]

As described above, according to the automatic light control device for a camera according to the present invention, since the infrared cut filter and the light shielding mask are integrally provided, the number of parts is small and the assembling workability is improved. Can be done. Also,
Infrared cut filter and optical member are positioned via positioning member
So that it is integrated with the infrared cut filter
The positioning operation of the optical component is simple and easy, and the optical component can be securely fixed at a predetermined position.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of an automatic light control device for a camera according to the present invention.

FIG. 2 is a cross-sectional view of a camera incorporating the control device.

FIG. 3 is a diagram showing an optical positional relationship between an opening area on a film surface and a light receiving element, an infrared cut filter, and a condenser lens as viewed from the direction of arrow A in FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 3 flash light emitter 12 light receiving element 13 infrared cut filter 13 a to 13 c transmission part 14 condensing lens 14 B filter fixing part 15 light shielding mask

Claims (4)

(57) [Scope of request for utility model registration] 1. A light for condensing a light beam transmitted through a photographing lens.
And a red light for removing an infrared component of a light beam transmitted through the optical member.
Shields light flux outside the transmission area of the infrared cut filter and the infrared cut filter
A light-shielding mask for receiving the light beam transmitted through the infrared cut filter;
And an optical element for dimming a light beam passing through the taking lens.
An automatic light control device for a camera , wherein the light-shielding mask is provided integrally with the infrared cut filter . 2. The automatic light control device for a camera according to claim 1 , wherein a preliminary light emission toward the subject is performed prior to a main light emission during flash photography.
Before the light reflected from the subject
An automatic dimming control device for a camera, which performs dimming based on the luminous flux of the preliminary light emission . 3. The automatic camera according to claim 1 or 2,
In the dimming control device, a position for positioning the optical member and the infrared cut filter.
A positioning member, wherein the infrared cut filter and the optical member are in the position
It is characterized by being provided integrally via a determining member
Automatic dimming control device for camera. 4. A light beam from a flash device reflected by a subject.
Photoelectric conversion means for performing photometry for each of a plurality of divided areas, and an infrared cut filter for removing an infrared component of the light flux
And shields the light flux outside the transmission area of the infrared cut filter.
A light-shielding mask that automatically controls the light emission amount of the flash device during flash photography.
In the automatic light control device of the camera, the light shielding mask is integrated with the infrared cut filter.
An automatic light control device for a camera, characterized in that it is provided.