JP2002318406A - Waist level finder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate influence of outside light to a photometric means of a waist level finder. SOLUTION: An opening shutter 4b of a shielding member and a plurality of photometric elements 4a around it are arranged in an opening of an ocular lens of the waist level finder 4 and a shielding member driving means 4c, the photometric elements 4a, a display part 4e of arithmetic results, a stopping means 4f of a photometric means and a signal transmitting means 4g to a camera main body 1 are connected with an exposure operation control circuit 4d to control the opening shutter, the photometric elements and an arithmetic operation of an optimal exposure value. When a shutter release button 1c of the camera main body 1 is half-depressed, the opening shutter 4b is driven by a solenoid and shields the opening by shutting a sector blade. Various kinds of information in relation to exposure are simultaneously inputted and a calculated photometric value is displayed on the display part 4e. Drive of the solenoid is released when half-depression of the shutter release button 1c is interrupted and shielding of the opening by the sector blade of the opening shutter 4 is released by a return spring.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waist level finder which is detachable from a single-lens reflex camera and has photometric means for measuring the finder surface, so that incident light from an eyepiece is shielded to prevent erroneous photometry. Waist level finder.

[0002]

2. Description of the Related Art Conventionally, a photometer for a waist-level finder capable of measuring the brightness of an image on a finder surface of a single-lens reflex camera has been designed to reduce the influence of incident light from an eyepiece at an opening just above a finder screen. It could not be avoided sufficiently, causing erroneous photometry. To avoid this,
As shown in FIG. 8, a part of the image forming portion of the finder screen 201 is guided to the light receiving element 203 disposed on the rear surface of the finder screen 201 by a half mirror 204 or the like.
A flexible hood 205 is attached to the eyepiece window, and photometry is performed with the face in contact. Alternatively, as shown in FIG. 9, the light receiving element 203 is disposed near the light receiving surface near the finder screen 201. The flexible hood 205 is attached so that the influence of the incident light from the eyepiece 202 is reduced as much as possible.

[0003]

However, in such a waist-level finder of a conventional single-lens reflex camera, it is necessary to perform photometry while keeping a face on a flexible hood attached to an eyepiece. If the manual exposure setting is sufficient, the automatic exposure control set at the time of the release is good, but if you use the automatic exposure control set at the time of release, you can shoot with the posture looking into the viewfinder, or put the cap on the eyepiece after compiling the composition This operation is inconvenient because it requires such operations. Even in the case of manual exposure setting, especially for photographers wearing glasses, it is not possible to completely eliminate the effect of incident light from the gap between the glasses and the face as stray light, and it is necessary to correct this by experience was there.

In the arrangement of the conventional photometric element as described above, partial light metering is performed in which the light flux of a part of the finder surface is measured by the photometric element. In the weighted light metering method, the reflected light of the incident light from the eyepiece lens by the finder screen is directly measured, which has a large influence and cannot be used.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and eliminates erroneous light measurement due to incident light from an eyepiece, allows a free choice of a light measurement method, and enables automatic exposure control. It aims to provide a level finder.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is detachable from a camera body of a single-lens reflex camera and can transmit various information signals to and from the camera body. A waist-level finder having an opening through which the finder surface of the main body can be seen and having a hermetically sealed periphery, and a photometric means capable of measuring the finder surface of the camera main body, and capable of blocking incident light from the opening. It is an object of the present invention to provide a waist level finder provided with a simple shielding member and driving means for opening and closing the shielding member.

The driving means closes the shielding member prior to the start of photometry by the photometry means in conjunction with the release operation of the camera body, and maintains the closed state at least until the end of photometry.

Further, in the waist level finder, a stop means for disabling the operation of the photometric means and the operation of the shielding member may be provided.

A waist-level finder, which is detachable from the camera body of the single-lens reflex camera and has an opening at an upper portion through which the finder surface of the camera body can be viewed, and is hermetically sealed around the periphery of the camera body, Photometric means capable of measuring the light in the finder surface, a shielding member capable of blocking incident light from the opening, an electric driving member for opening and closing the shielding member, and control means for controlling the operation of the electric driving member are provided. Also offers a waist level finder.

The waist level finder is provided with a manual photometric operation means, and an electric drive member for opening and closing the shielding member is operated in conjunction with the manual photometry means. The incident light from the lens is blocked, and the blocked state is maintained at least until the photometry is completed.

[0011]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a schematic structural view of an exposure control means of a camera equipped with a waist level finder according to the present invention, FIG. 2 is a perspective view of its appearance, and FIG.
4 (a) and 4 (b) are plan views showing the configuration of the opening shutter and its different operating states, and FIG. 5 is a perspective view showing an example of a storage method. .

First, referring to FIG. 1, a schematic configuration of a waist level finder embodying the present invention and an exposure control means of a single-lens reflex camera to which the waist level finder can be attached and detached will be described. Central processing unit (hereinafter referred to as “CPU”) on the camera body 1 side
1a, a first release switch S1, a second release switch S2, a finder interface 1b, and a lens shutter 2d having an aperture information member 2a, an open aperture information member 2b, and a shutter speed information member 2c on the lens 2 side. A film sensitivity information member 3a is provided on the film back 3 side. On the other hand, on the side of the waist level finder 4, a photometric element 4a, which is a photometric information member, an opening shutter 4b, which is a shielding member, a shielding member driving means 4c, an exposure calculation control for controlling a shielding member driving means and calculating an appropriate exposure value. Circuit 4
d, a display unit 4e for displaying the calculated proper exposure value, a stopping unit 4f for disabling the operation of the photometric unit, and a signal transmitting unit 4g for the camera body 1, respectively.
By connecting the film back 3 and the waist level finder 4 to the camera body 1, respective circuits can be connected.

As shown in FIG. 3, an eyepiece 4k is provided in an opening 4n provided in an upper part of a housing 4h of the waist level finder 4, and a cover glass 4m and an opening shutter 4b are provided immediately below the opening 4n. Also, eyepiece 4k
, The condenser lens 4a 'and the incident angle regulating tube 4
A pair of right and left photometric elements 4a, 4a having an a "are disposed toward the center of the finder focus surface 1d of the camera body 1. Further, as shown in FIG. A light measuring element 4a and a display unit 4 shown in FIG.
e, the respective circuits of the shielding member driving means 4c and the stopping means 4f are connected to the exposure calculation control circuit 4d, and the input / output circuit of the exposure calculation control circuit 4d is arranged so as to be able to contact a contact receiver (not shown) on the camera body 1 side. Signal transmission means 4 installed
Connect to g.

As shown in FIG. 4, the opening shutter 4b includes a rotating shaft 42 implanted on a substrate 41 having an aperture 41a at the center, and a sector ring 43 rotatably provided around the aperture 41a of the substrate 41. Pin 44 planted in
, Five sector blades 45, a solenoid 46 for driving the sector ring 43, and a return spring 47.

Next, the operation when the waist level finder 4 shown in this embodiment is mounted on the camera body 1 of an electronically controlled single-lens reflex camera and used will be described. FIG.
When the shutter release button 1c of the camera body 1 shown in FIG. 1 is half-pressed, the release first-stage switch S1 in FIG. 1 is turned on and the sleep of the power is released, the CPU 1a sets the solenoid 46 of the waist level finder 4 (FIG. 4). Is driven in the suction direction. The sector ring 43 connected to the solenoid 46 resists the urging force of the return spring 47 as shown in FIG.
5, the five sector blades 45 shield the aperture 41a (see FIG. 4B).

At the same time, the waist level finder 4
The photometry element 4a (FIG. 3) of the camera body 1 is turned on, and the exposure calculation control circuit 4d operates the finder interface 1 of the camera body 1.
In the case of aperture priority metering via b, aperture value A of lens 2
Lens shutter 2 of lens 2 for V, speed priority metering
d speed value TV, film back 3 film sensitivity SV
And the photometric value BV of the photometric element 4a are input and calculated, and the set film sensitivity SV and aperture value AV or speed value TV are set.
And the calculated speed value TV or aperture value AV are displayed on the display unit 4e shown in FIG.

In this state, when the shutter release button 1c of the camera body 1 is released, the first-stage release switch S1 is turned off, the suction force of the solenoid 46 of the waist level finder 4 is extinguished, and the sector ring 43 is returned by a return spring. 4 (b), the five sector blades 45 retreat from the shielding position and open the aperture 41a (see FIG. 4 (a)).

If the CPU 1a of the camera body 1 is compatible with automatic exposure, the shutter release button 1c is further pressed to turn on the release second-stage switch S2.
The speed value TV or the aperture value AV calculated at that time is stored, and the photometry ends. When the photometry is completed, the waist level finder 4 turns off the circuit of the solenoid 46 by the signal, the sector ring 43 rotates counterclockwise by the urging force of the return spring 47, and the five sector blades 45
The aperture 41a is opened by retracting from the shielding position of n.

Further, the mirror (not shown) of the camera body 1 starts to rise at the same time when the release second-stage switch S2 is turned on, and the lens 2 stops down the aperture to a set value or a stored aperture value AV. The shutter blade is opened at the position where the raising of the mirror is completed, and is held in the open state. CPU
1a starts counting the time from the time when the trigger switch is turned off, and when a set value or the stored speed value TV is counted, the shutter drive circuit is turned on to release the holding of the shutter blade and close the shutter blade. Exposure is complete.

When the stop button 4p (FIG. 2), which is an operation member of the stopping means 4f, is pressed, the operation of the exposure calculation control circuit 4d is stopped, and the opening shutter 4 by the shielding member driving means 4c.
The operation of b becomes inoperative, and the aperture 41a keeps the open state. When the stop button 4p is pressed again, the operation of the exposure calculation control circuit 4d is restored, and photometry can be performed.

Next, as another embodiment of the present invention, a schematic configuration of a waist level finder having a photometry function which is detachable from a single-lens reflex camera having no electronic exposure control means will be described. 6 and 7 are the same as those of the previous embodiment shown in FIGS.
Are commonly used, and the same reference numerals are given in FIGS. 6 and 7. Referring to FIG. 6, the waist level finder 104 controls the photometric element 4a, which is a photometric information member, the opening shutter 4b, which is a shielding member, the shielding member driving means 4c, and the driving means of the shielding member, and calculates an appropriate exposure value. Exposure calculation control circuit 104d, film sensitivity input means 104g,
Mode selection means 104h for selecting aperture-priority metering or speed-priority metering, setting switch 104k for setting a set aperture value AV or a set speed value TV of lens 102 according to the selected mode, and a display for displaying the calculated proper exposure value Section 4e, photometric switch 104f of photometric means and circuit power supply 1
04n respectively.

Also in this embodiment, as shown in FIG. 3, an eyepiece 4k is provided in an opening 4n provided in an upper portion of a housing 4h of the waist level finder 4, and an eyepiece 4k is provided immediately below the opening 4n.
A cover glass 4m and an opening shutter 4b are provided. Further, a pair of left and right photometric elements 4a, 4a each having a condenser lens 4a 'and an incident angle restricting tube 4a "are disposed with the eyepiece lens 4k interposed therebetween, facing the center of the finder focus surface of the camera body 101. I do.

As shown in FIG. 6, a display unit 4e is provided at the front of the housing 4h, and the photometric element 4a, the display unit 4e, the shielding member driving unit 4c, the film sensitivity input unit 104g, Mode selection means 104h, setting switch 10
The respective circuits of 4k and the photometric switch 104f are connected to the exposure calculation control circuit 104d.

As shown in FIG. 4, the opening shutter 4b includes a rotating shaft 42 implanted on a substrate 41 having an aperture 41a in the center, and a sector ring 43 rotatably provided around the aperture 41a of the substrate 41. Pin 44 planted in
, Five sector blades 45, a solenoid 46 for driving the sector ring 43, and a return spring 47.

Next, an operation when the waist level finder 4 shown in this embodiment is mounted on the camera body 101 of a single-lens reflex camera having no electric finder interface will be described. First, the film sensitivity SV is set by the film sensitivity input means 104g of the film back 103 shown in FIG.
04, the aperture priority metering or the speed priority metering is selected by the mode selection means 104h, and the aperture value A is set by the setting switch 104k.
V or set speed value TV is set.

When the photometry button 104p (FIG. 7), which is the operation member of the photometry switch 104f, is pressed, the exposure calculation control circuit 1
04d operates to drive the solenoid 46 (FIG. 4) of the waist level finder 104 in the suction direction. The sector ring 43 connected to the solenoid 46 rotates clockwise from the state of FIG. 4A against the urging force of the return spring 47,
The five sector blades 45 shield the aperture 41a (see FIG. 4B).

At the same time, the waist level finder 1
The photometry element 4a of FIG. 4 (FIG. 3) is turned on, and the exposure calculation control circuit 104d determines the set aperture value AV or the set speed value TV, the film sensitivity SV and the photometry value B of the photometry element 4a.
The calculated film speed SV, aperture value AV or speed value TV, and the calculated speed value TV
Alternatively, the aperture value AV is displayed on the display unit 4e shown in FIG.

When the photometry button 104p is released, the photometry switch 104f is turned off, the suction force of the solenoid 46 is extinguished, and the sector ring 43 is rotated counterclockwise by the urging force of the return spring 47 to rotate five sectors. The blade 45 retracts from the shielding position of the opening 4n to open the aperture 41a.

Conventionally, the waist-level finder is characterized in that the height of the camera when it is carried can be reduced by a foldable structure, but it is difficult to maintain the light density due to its structure, so it is adopted in a finder having a photometric function. could not. As shown in FIG. 5, the housing 4h has a multiplex box structure,
As shown by the imaginary line, the inner casing 4h 'is pulled out at the time of photographing, and is pushed down as shown by the solid line at the time of storage to reduce the overall height, and is positioned by a locking member (not shown), thereby providing a waist having a photometric function. It is possible to improve the portability of the camera when the level finder is attached.

[0030]

As described above, according to the waist level finder according to the first aspect of the present invention, since the shielding member and the driving means for opening and closing the shielding member are provided, the opening level of the eyepiece can be reduced. , It is possible to perform accurate photometry by completely blocking the incident light. In addition, it is possible to install multiple photometric elements at positions away from the viewfinder surface around the opening of the eyepiece, and select and use a highly practical photometric method such as center-weighted, average, or evaluative photometry. It becomes possible.

According to the waist level finder according to the second aspect, since the opening and closing of the shielding member is interlocked with the release operation of the camera body, there is no need to perform an extra manual operation, which is not much different from a general quick return single-lens reflex camera. Automatic exposure shooting without discomfort due to the time lag becomes possible.

According to the waist level finder of the present invention, the stop means for disabling the operation of the photometric means and the operation of the shielding member does not cause a time lag due to the opening and closing of the shielding member during manual photographing without using the photometric operation. Also, power is saved because the exposure calculation control circuit and the solenoid are not energized.

According to the waist-level finder of the present invention, even in a camera having no electric finder interface, the finder surface of the camera body can be measured, and the incident light from the opening of the eyepiece can be completely removed. It can be used as a viewfinder with an exposure meter that can select center-weighted, averaged, and evaluative metering for accurate metering by shielding.

According to the waist level finder of the present invention, since the electric drive member for opening and closing the shielding member is interlocked with the manual photometric means, there is no need to perform an extra operation for opening and closing the opening.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of exposure control means of a camera equipped with a waist level finder according to the present invention.

FIG. 2 is an external perspective view of the same.

FIG. 3 is a cross-sectional view along the line AA of FIG. 2;

FIG. 4 is a plan view showing a configuration and an operating state of an opening shutter of the waist level finder according to the present invention.

FIG. 5 is a perspective view showing an example of the storing method.

FIG. 6 is a schematic configuration diagram of a photometric unit of a waist level finder according to another embodiment of the present invention.

FIG. 7 is an external perspective view of the same.

FIG. 8 is an explanatory diagram showing an example of a conventional photometric means of a waist level finder.

FIG. 9 is an explanatory diagram showing another example of the photometric means of the conventional waist level finder.

[Explanation of symbols]

 1: Camera body 2, 102: Lens 3, 103: Film back 4, 104: Waist level finder 4a: Photometric element 4a ': Condenser lens 4a ": Incident angle regulating tube 4b: Opening shutter 4c: Shielding member driving means 4d, 104d: exposure calculation control circuit 4e: display unit 4f: stop means 4g: signal transmission means 4h: housing 4k: eyepiece 4m: cover glass 4n: opening 4p: stop button 41: substrate 41a: aperture 42: rotation Axis 43: Sector ring 44: Pin 45: Sector blade 46: Solenoid 47: Return spring 104g: Film sensitivity input means 104h: Mode selection means 104k: Setting switch 104f: Photometry switch 104n: Circuit power supply 104p: Photometry button

Claims (5)

[Claims] 1. An opening which is detachable from a camera body of a single-lens reflex camera, can transmit various information signals to and from the camera body, and has an opening at an upper portion through which a finder surface of the camera body can be viewed. A waist-level finder having a closed periphery, a photometric device capable of measuring the finder surface of the camera body, and a shielding member capable of blocking incident light from the opening,
A waist level finder provided with driving means for opening and closing the shielding member. 2. The method according to claim 1, wherein the driving means closes the shielding member prior to the start of photometry by the photometric means in conjunction with a release operation of the camera body, and maintains the closed state at least until the photometry is completed. The waist level finder according to claim 1. 3. The waist level finder according to claim 1, further comprising a stop means for disabling an operation of said photometric means and an operation of said shielding member. Level finder. 4. A waist-level finder, which is detachable from a camera body of a single-lens reflex camera and has an opening at an upper portion through which a finder surface of the camera body can be viewed, and is hermetically sealed around the waist-level finder. A photometric means capable of photometrically measuring the viewfinder surface, and a shielding member capable of blocking incident light from the opening,
A waist level finder, comprising: an electric drive member for opening and closing the shielding member; and control means for controlling the operation of the electric drive member. 5. The waist-level finder according to claim 4, further comprising a manual light metering operation means, wherein an electric driving member for opening and closing the shielding member operates in conjunction with the manual light metering means, and the shielding member is operated immediately before the light metering means is operated. A waist-level finder, which is closed to block incident light from an eyepiece, and maintains the blocked state at least until the photometry is completed.