JPS5834817B2 - Exposure adjustment device - Google Patents

Description

[Detailed description of the invention] The present invention relates to an exposure adjustment device.

Generally, when photographing a high-brightness subject, it is necessary to use a small aperture aperture and a high-speed shutter.
When using a high-sensitivity film, the aperture aperture must be further narrowed down to a very small aperture when the shutter speed is kept constant.

Using a film with a film speed of ASAl 00,
If you use a F1, 4 lens, and the minimum aperture of the lens is 16, when shooting under the same conditions using a film with a film sensitivity of ASA 400, the aperture needs to be F32, but you can set an ultra-small aperture of F32 to the photographic lens. It is difficult to obtain the aperture accuracy of the diaphragm device of the photographing lens as in the case of apertures Fl, 4 to 16 due to the limit of mechanical accuracy, and it is impossible to obtain the accuracy of the ultra-small aperture of F32.

Furthermore, in the case of an extremely small aperture, the contact area between the plurality of aperture blades of the aperture device becomes large, making it difficult to obtain durability.

Furthermore, an ultra-small aperture has the disadvantage that a good photographed image cannot be obtained due to blurring due to the influence of optical diffraction.

The present invention was made in view of the above circumstances, and its purpose is to reduce the optical path by reducing the aperture aperture of the aperture device to an ultra-small aperture when photographing using high-sensitivity film or photographing high-brightness objects. By intervening a filter that corresponds to the aperture of an ultra-small aperture within the aperture, the actual aperture aperture is set within a range that is not affected by mechanical precision or optical diffraction, and an effect similar to that achieved by narrowing the aperture to an ultra-small aperture can be obtained. It is in.

Furthermore, the object of the present invention is that when the subject luminance is in a high luminance region, the illuminance-photocurrent characteristic of the light receiving element that measures the subject luminance loses linearity and it becomes difficult to obtain a photocurrent corresponding to the subject luminance. In order to avoid limiting the photometry range to a range where the illuminance-photocurrent characteristic of the element shows linearity, a filter is inserted in front of the photodetector to shift the illuminance on the photodetector surface to within the photometry range. It's about doing.

Next, embodiments of the present invention will be illustrated and explained.

In Fig. 1, 1 is a photographic lens, 1a is an aperture ring with aperture setting scales 1.4, 2, 2.8, etc. on the surface.
8°11, 16, and 22 are engraved.

1a' is a cam for setting the minimum aperture (F22) which is interlocked with the aperture ring 1a.

1b is a distance ring, and 1c is a minimum aperture setting member, which is slidably supported on the camera housing 2' and is always applied with a force in the direction of the photographing lens by a spring 1c'.

1d indicates an aperture.

1e is a fixed index provided on the lens barrel of the photographic lens.

The minimum aperture setting member 1c slides on the end face of the aperture ring 1a as the aperture ring 1a rotates, and when the aperture scale 22 of the aperture ring 1a matches the fixed index, it slides onto the top of the minimum aperture setting cam 1a'; Slide the minimum aperture setting member 1c to the left.

2 indicates the camera body.

3 is a total reflection mirror held in a mirror holding frame 20, 5 is a focusing glass, and 6 is a condenser lens, which is a half mirror.
8 are installed.

A pentaprism 10 and an eyepiece lens 12 form a finder optical system of a well-known single-lens reflex camera.

14 is a shutter curtain, 16 is a photographic film, and 18 is a part of an aperture.

Reference numeral 20 denotes a holding frame for the total reflection mirror 3, which is rotatable about a shaft 24.

The mirror holding frame 20 includes pins 20a, 20b and a rising portion 20.
It has C.

A filter holding frame 26 forms the outer frame of the filter 28 and holds the filter 28 inside.

26a and 26b are pins installed in the filter holding frame.

Reference numeral 30 denotes an interlocking lever, which is rotatably supported by a shaft 32 on a rising portion 20c of the mirror holding frame, and is given a clockwise rotational force by a spring 34 installed between the rising portion 20c and the pin 26a. engage.

36 is an intermediate lever that can be rotated around a shaft 38 and has a spring 40.
One end of the connecting rod 42 connects with the minimum aperture setting member 1c, and the other end of the connecting rod 42 contacts the interlocking lever 30.

Reference numeral 44 denotes a mirror up lever rotatably supported by a shaft 46 fixed to the camera housing, one end of which abuts the pin 20a, and the other end of which is implanted with a pin 44a.

Reference numeral 48 denotes a driving member which is rotatably supported by a shaft 50 fixed to the camera housing, and is applied with a clockwise rotational force by a spring 52.

54 is a quick return lever that connects the drive member 48 and the shaft 50.
A counterclockwise rotational force is applied by a spring 56.

Reference numeral 58 denotes a retaining lever with a shaft 6 implanted at one end of the drive member 48.
0, and is rotatably supported by a spring 62, and a counterclockwise rotational force is applied by a spring 62, so that one end 60b can be engaged with the quick return lever 54.

The illustrated state in FIG. 1 shows a state in which film loading is completed, and at this time, the quick return lever 54 is in contact with the pin 44a of the mirror up lever 44 at one end, and is engaged with the engagement lever 58 at the other end.

Further, the mirror drive member 48 is held against the spring force of the spring 52 by a locking member 64 that interlocks with a release member (not shown).

Reference numerals 66 and 68 are stoppers that determine the locking positions when the total reflection mirror 22 and the filter 28 are on the optical path.

A spring 69 applies a clockwise rotational force to the filter holding frame 26 to push the filter holding frame 26 against the stoppers 66 and 68 to determine the position of the filter.

70 is a stop member for the mirror drive member 48.

12 is a drum on which a light-shielding curtain 14 is wound around by a spring member 13.

Reference numeral 76 and 78 refer to rollers disposed on the camera housing, and a "string" 80 is disposed through the rollers between one end of the light shielding curtain 14 and the pin 26b planted in the filter holding frame 26 to hold the filter. When the frame 26 moves out of the optical path in conjunction with the mirror-up operation of the total reflection mirror 72, a light-shielding curtain is pulled out from the drum 72 against the spring force of a spring member 73 to prevent reflection of incident light by the filter.

FIG. 2 shows a plan view of section A in FIG. 1 viewed from direction B.

Reference numeral 82 denotes a switching member which is slidably supported by the main body of the camera, and has one end in contact with the connecting rod 42 and the other end in contact with one end of the light-receiving bare hand filter holding member 84 .

The light-receiving element filter holding member 84 holds the light-receiving element filter 86 at one end, is rotatably supported by a shaft 88, and is given a counterclockwise rotational force by a spring member 90.

Reference numeral 92 denotes a light-receiving element disposed within the condenser lens 6. A portion of the finder light beam guided by the mirror 8 irradiates the light-receiving element and performs photometry.

1 and 2, when the aperture scale 22 of the aperture ring 1a is aligned with the fixed index 1e, the minimum aperture setting member 1c is placed on the top of the minimum aperture setting cam 1a', and the connecting rod 42 is slid to the left. .

As the connecting rod slides to the left, the cam portion 42a of the connecting rod that fixes the connecting rod 42 slides upward on the switching member 82.

By sliding the switching member 82 upward, the light-receiving element filter holding member 84 rotates clockwise about the shaft 88 against the spring force of the spring 90, thereby covering the light-receiving element 92 with the light-receiving element filter 86.

FIG. 3 is a view of the total reflection mirror 3 and the filter holder 26 viewed from an oblique angle upward in the direction in which the photographic lens is attached.

75 is pin 1 which is attached to the main plate of the camera (not shown) by a spring.
1 and the mirror holding frame 20, and the mirror 3 is placed on the shaft 2.
Rotating force is applied clockwise around point 4.

Next, the operation of this embodiment shown in FIGS. 1 to 3 will be explained.

The aperture scale shown on the aperture ring of the photographic lens shown in Figure 1 is F2.
The aperture device of the photographic lens is configured so that it can only stop down to the aperture aperture of F16 and cannot stop down any further.

In the state shown in FIG. 1, the aperture value is set to be larger than the minimum aperture value F16 of the aperture device.

(For example, set to F8) When the shutter of the camera is released in the state shown in FIG.
The driving member 48 is rotated by the spring force of the spring 52 until it abuts and locks the locking member 70.

The quick return lever 54 is rotated by the rotation of the drive member 48.
rotates clockwise around the shaft 50 while being engaged with the engagement lever 58, and rotates the mirror up lever 44, which contacts one end of the quick return lever 54 via the pin 44a, clockwise around the shaft 46. move.

By rotating the mirror up lever 44 in the clockwise direction, the mirror holding frame 20 is rotated counterclockwise about the shaft 24 via the pin 20a implanted in the mirror holding frame 20, and the mirror 3 is rotated in the counterclockwise direction.
is raised against the spring force of spring 15 and spring 29.

At this time, the interlocking lever 30, which is supported by a shaft 32 implanted in the rising portion 20c of the mirror holding frame 20, remains engaged with the pin 26a implanted in the filter frame 26. The frame 26 also rises integrally.

As the filter frame 26 rises, the light-shielding curtain 74 tied to the pin 26b planted in the filter frame 26 is pulled.
The string 80 is pulled, and the light-shielding curtain 74 wound around the drum 72 is pulled out to the right against the force of the spring 73.

Once the mirror 22 and filter holding frame 26 have been raised, the lower surface of the filter 28 can be covered with a light-shielding curtain to prevent light from being reflected by the filter.

This state is shown in FIG.

Once the mirror 22 and filter holding frame 26 have been raised, the aperture device of the photographic lens 1 is moved to the aperture ring 1 by a conventionally well-known method.
The aperture value is narrowed down to the aperture value set at a, the shutter 14 of the shutter device (not shown) is operated, and the photographic film 16 is exposed.The shutter operation completion member 65 moves to the left in response to the shutter operation completion signal, and engages the engagement lever 58. Upon contact, the engagement lever 58 is rotated clockwise about the shaft 60 against the spring force of the spring 62, and is disengaged from the quick return lever 54.

When the quick return lever 54 is disengaged from the engagement lever 58, it is rotated counterclockwise by the spring 56 and disengaged from the pin 44a implanted in the mirror up lever. , the mirror holding frame 20, the filter 28, and the filter holding frame 26 are returned to their original states as shown in FIG. 1 by the spring force of the spring 75.

That is, in this embodiment, the aperture scale of the aperture ring is F1.4.
From F16 to F16, the filter 28 moves integrally with the total reflection mirror 3.

Next, a case will be described in which photographing is performed using an aperture value (F22) of the photographic lens 1 that is smaller than the minimum aperture value (F16) narrowed down by the aperture device.

In FIGS. 5 and 6, when the aperture value F22 of the aperture ring matches the fixed index 1e, the minimum aperture setting member 1c is pushed to the left at the top of the minimum aperture setting cam 1a', pushing the connecting rod 42 to the left. .

As the connecting rod 42 slides to the left, the intermediate lever 36 rotates counterclockwise about the shaft 38 against the force of the spring 40, causing the interlocking lever 30 to rotate counterclockwise against the force of the spring 34. direction to disengage the interlocking lever 30 from the pin 26a implanted in the filter holding frame 26.

Furthermore, by moving the connecting rod 42 in the left direction, the cam portion 4 of the connecting rod
2 a to push up the switching member 82 and rotate the light-receiving element filter holding member 84 clockwise against the spring force of the spring 90 to install the light-receiving element filter 86 in front of the light-receiving element 92 .

When the shutter release is operated in this state, the locking member 64 that interlocks with the shutter release member (not shown) moves in the direction C shown in the drawing, rotates the drive member 48 clockwise, and the quick return lever 54 moves the locking member 64 in conjunction with the shutter release member (not shown). The up lever 44 is rotated clockwise to raise the mirror 3, but since the mirror 3 and the filter holding frame 26 are disengaged, the filter 28 is maintained on the optical path.

After the shutter release = after a certain period of time, the mirror 3 is returned by moving the shutter operation completion member 65 to the left, the interlocking lever 30 and the pin 26a are engaged, and the mirror and the filter holding frame are engaged at their original positions.

In this case, the aperture aperture of the aperture device of the photographic lens is F16, but by setting the transmittance of the filter 28 to a value equivalent to F22, the ultra-small aperture (
This can solve the problem of not being able to set F22).

By using the present invention, any ultra-small aperture can be obtained by arbitrarily selecting and setting the transmittance of the filter 28.

By setting the aperture value scale of the aperture ring 1a to F22, the filter 86 can be covered by the light receiving element 92, and the filter 86 can be used when the subject brightness is high and is out of the photometry range of the light receiving element.
By this, the amount of incident light on the light receiving element can be moved to the photometry range, thereby making it possible to photometer a high brightness area.

When photographing using the light-receiving element filter shown in this embodiment, that is, when the aperture value is set to F22, the subject brightness information input to the camera's exposure control circuit via the light-receiving element is provided by the photographing lens. Minimum aperture value (F16)
and the aperture value of the light-receiving element filter 86,
By setting other shooting conditions (shutter speed conditions, film sensitivity conditions, etc.) to information compatible with F22, the camera's exposure control circuit can output appropriate shutter speed information, and when the camera's shutter release is released, the Since the filter 28 is installed on the photographing optical path, the phase of the minimum aperture value of the aperture device provided in the photographic lens and the aperture value by the filter 28 is the same as the minimum aperture value provided in the photographic lens and the light receiving element filter 86. The aperture value is equal to the sum of the aperture values, and proper exposure can be obtained for the photographic film.

This embodiment has been described above as a so-called aperture-priority shutter time control exposure control system in which aperture information is input and the shutter time is controlled according to that information. The same can be applied to a shutter speed-priority aperture control exposure control system that controls the value.

That is, when the shutter time setting member is set to ultra-high speed, the filter 28 is interposed in the photographing optical path, and the light receiving element 92
What is necessary is just to arrange so that the filter 86 for light receiving elements may be interposed before.

In the description of this embodiment, the filter 86 is provided in front of the light receiving element 92 to adjust the amount of light incident on the light receiving element, but the same effect can be obtained by providing a diaphragm instead of the filter.

Further, by intervening a filter in front of the light receiving element of the light control strobe, the same effect as described above can be obtained by applying it to the light control type strobe.

As described above, the present invention provides a mechanical diaphragm device using aperture blades that can be improved by adding simple components to a mechanical diaphragm device using aperture blades when there are mechanical precision or mechanical limitations in the mechanical diaphragm device using aperture blades. It is possible to easily obtain an aperture value that is difficult to obtain with a mechanical aperture device using a It is possible to obtain an ultra-small aperture that is more accurate than the aperture value obtained with the mechanical aperture device used.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an embodiment in which an exposure adjustment device according to the present invention is used in a single-lens reflex camera. FIG. 2 is a plan view of part A of the exposure adjustment device shown in FIG. 1. FIG. 3 is a perspective view of a filter holding section of the exposure adjustment device shown in FIG. 1. 4, 5, and 6 are explanatory diagrams of the operation of the first embodiment shown in FIG. 1, and FIG. 4 is a diagram showing the raised state of the filter holding frame. FIG. 5 shows a state in which the filter holding frame is attached and removed, and FIG. 6 shows a state in which a part of the mirror has been raised. 1...Photographing lens, 20...Mirror holding frame, 26-...Filter holding frame, 28...
... Filter 36 ... Intermediate lever, 42.
...Connecting rod, 48... Drive member, 54.
...Quick return lever, 72...
Drum, 74... Light shielding curtain, 86... Filter for light receiving element 92... Aiko element.

Claims (1)

[Claims] 1. A reflecting mirror that reflects object light from a photographic lens and guides the object light to a finder optical system;
a mirror-up mechanism for raising the reflecting mirror so as to guide the subject light into the photographing optical path of the camera; and a mirror raising mechanism that holds a filter disposed in the photographing optical path of the camera and is capable of being raised integrally with the reflecting mirror. The reflection mirror is rotatably supported by a filter holding frame that is supported as shown in FIG. When the interlocking lever that links the filter to the rising of the mirror and the aperture setting ring of the photographic lens are set to a value smaller than the minimum aperture that can be formed by the aperture blades of the photographic lens, the aperture setting ring An exposure adjustment device for a single-lens reflex camera, comprising a release mechanism that releases the engagement between the interlocking lever and the retaining piece in accordance with a setting operation. 2. Claims characterized in that a photometric filter is positioned in a photometric optical path of a light-receiving element that measures the subject light reflected by the reflecting mirror in conjunction with the release operation of the release mechanism. 2. The exposure adjustment device for a single-lens reflex camera according to item 1.