JPS6366546A - Camera - Google Patents

Abstract

PURPOSE:To considerably simplify the constitution and to contrive to improve the precision of exposure detection by using one photometric element for pre- photometry before photographing as well as direct photometry at the time of photographing. CONSTITUTION:A mirror plate 14 turned by a rotary solenoid 15 is arranged in front of a solid-state image pickup element 3 of an electronic still camera and is provided with a total reflection mirror 21 and a semitransparent mirror 22. In the normal state, the mirror 21 is arranged in the optical path and the light reflected on the mirror 21 is made incident on a photometric element 29 to perform pre-photometry. At the time of photographing, power is supplied to the solenoid 15 to turn the mirror plate 14 clockwise and the semitransparent mirror 22 is inserted to the optical path, and an image is picked up by the image pickup element 3 and photometry is performed in real time with 10% of the incident light by the element 29. Thus, the constitution is simplified and the precision of exposure detection is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a photographing device such as an electronic still camera, and more particularly to a photographing device with improved photometry means.

[Prior art] An all-J optical element for so-called pre-photometering, which API determines the reflected light from the subject prior to the shooting operation, and a direct photometry element for detecting the amount of exposure during the shooting operation. Separate imaging devices are known in the art.

Furthermore, an apparatus is also known in which the photometric element for brilliance photometry and the element for direct photometry described above are configured by a common element.

[Problems to be Solved by the Invention] However, in a device in which a photometric element for pre-photometry and a photometric element for direct photometry are provided separately, the optical conditions for photometry are different between pre-photometry and direct photometry. It will be different. On the other hand, a device in which a common photometric element is used for both the flash metering element and the direct metering element is conventionally realized with a still camera using a silver halide film, and when using a single direct meter, a film of the incident light is used. Normally, photometry is performed on light reflected from a surface, but the mechanical configuration is 'fMN'. Furthermore, in devices such as electronic still cameras where the reflectance of the imaging surface of the imaging cable is low, sufficient reflected light for 1 PI light cannot be obtained from the imaging surface with the same configuration as a normal multi-electrode still camera. Therefore, direct 1iIII light becomes virtually impossible. Generally, the dynamic range of an imaging probe is narrower than the latitude of a comparable silver halide film, so it is especially desirable for electronic still cameras to perform highly accurate direct photometry.

Therefore, the inability to perform direct photometry is a serious problem in electronic still cameras.

This invention was made in view of these points,
By using a common element as the photometric element for bristle photometry and the ΔPI optical element for direct photometry, the optical photometry conditions for both types of photometry are made equal, while the mechanical configuration is extremely simple. It is an object of the present invention to provide a photographing device capable of performing direct 71111 light with sufficiently high precision.

[Means for Solving the Problems] The photographing device of the present invention includes a photometric element for detecting the exposure amount by receiving the light emitted from the photographic lens system, and a photometric element for directing the emitted light from the photographic lens system to the photometric element. A reflecting mirror is provided in a photographing optical path so as to be movable forward and backward in order to reflect the light in a photographic manner, and when the reflecting mirror is retreated from the photographing optical path, a part of the light emitted from the photographing lens system is transmitted so as to be directed toward the photographing surface. It consists of a semi-transparent mirror provided to reflect the other part toward the 71PI optical element.

[Function] Before starting photography, the reflector enters the photographing optical path and directs the light emitted from the photographic lens system to the photometric element to perform blur metering, and during photography it takes the place of the reflector and measures 1".

A transparent mirror enters the photographing optical path and directs the light emitted from the photographing lens system to the photometric element to perform direct photometry.

[Embodiment] Fig. 1 is a longitudinal sectional side view of one embodiment of an electronic still camera which is a photographing device of the present invention, and Fig. 2 shows
It is a longitudinal sectional front view along the line -■.

The state of this electronic still camera shown in FIGS. 1 and 2 is the state at the time of photographing.

In FIGS. 1 and 2, a support member 2 is fixed to the inner wall of the back plate in the main body 1 of the electronic still camera, and a solid-state imaging device 3 such as a CCD (charge coupled device) is attached to the support member 2.
A printed circuit board 4 on which is arranged is attached with screws 5. A low-pass filter 6 for moire prevention is fixed on the imaging surface of the solid-state imaging probe 3.

The photographing lens system 7 in the lens barrel includes a focus lens [
8. Variator lens group 9. Convencator lens group 1
0. It is composed of an aperture 11, a relay lens 8112, etc., and a photographing optical axis 13 passing through this photographing lens system passes through the above-mentioned low-pass filter 6, and passes through the imaging surface 3 of the solid-state image sensor 3.
It is incident perpendicularly to a.

A mirror plate 14 is arranged between the rear end of the relay lens group 12 and the low-pass filter 6 so as to block the photographing optical axis 13 and to be inclined. A rotary solenoid 15 for rotating the mirror plate 14 is disposed at the bottom of the camera body 1 with a drive shaft 15a inclined, and a screw 1 is connected to the rotary solenoid body via a support 16.
The camera body 1 is fixed by attaching the mounting plate 18 fixed by the screws 19 to the camera body 1 with screws 19. The drive shaft 15a is attached to the tip of the drive shaft 15a of the rotary linenoid 15.
A flange 15b having two bottles 15c protruding in a direction parallel to is integrally provided. These two pins 15c are located at symmetrical positions on flange +5b 180'.

As is clear from FIGS. 2 to 4, the mirror plate 14 is
A fan-shaped flange 14b having two elongated holes 14c is integrally provided at the rear end of the rotating shaft 14H that projects toward the rotary solenoid 15 (see FIG. 3). These two elongated holes 14c have two holes in the drive shaft 15a.
The two bins 15C are always fitted together so that the rotational force of the drive shaft 15a is transmitted to the rotation shaft 14a. The reason why the drive shaft 15a and the rotation shaft 14a are connected by the axial fitting between the pin 15c and the elongated hole 14c is that the drive shaft 15a moves slightly in the axial direction when the rotary renoid 15 is energized. This is because the rotating shaft 14a is rotated while the rotating shaft 14a is rotated. Therefore, flanges 14b and 15b are usually
The pin 15c is engaged with the elongated hole 14c while being separated by at least the axial movement of the drive shaft 15a.
(See Figure 1).

Further, as shown in FIG. 3, a spiral return spring 20 is provided in tension between the drive shaft 15a of the rotary solenoid 15 and the rotary solenoid body. 14 is given a habit of rotating in the direction opposite to the direction in which the rotary solenoid 15 is always energized.

A total reflection mirror 21 is provided on a part of the front surface of the mirror plate 14, and a through hole is formed on the mirror plate 14 at a position approximately 90@ apart from the total reflection mirror 21 around the rotation axis 14a. A pellicle mirror 22 is provided to cover the through hole. Pellicle mirror 22 is 1/100 ~ 2/
It is a semi-transparent mirror made of a thin film of about 100mm, which reflects about 90mm of the incident light.
% is transmitted and the remaining approximately 10% is reflected.

In the electronic still camera, the rotary solenoid 15 is not energized under normal conditions, and therefore, the mirror plate 14 is moved to the third position by the rotational behavior of the drive shaft 15a by the return spring 20.
As shown in the figure, it has completely rotated counterclockwise and is stopped by being positioned by a stopper (not shown). When the mirror plate 14 is fully rotated counterclockwise, the total reflection mirror 21 is in a position that blocks the photographing optical path including the photographing optical axis 13, and directs the light that has passed through the photographing lens system toward the finder section above. It's reflecting. The light reflected by the total reflection mirror 21 and directed toward the finder section passes through a pentaprism 23, a magnifying lens 24, an eyepiece 25, and an eyecup 26, and enters the photographer's eye. A half mirror 28 is formed at the center of the upper surface of the pentaprism 23, and the light transmitted through the half mirror 28 is made to enter a photometric element 29 disposed above the pentaprism 23.

As will be described later, this photometering cable 29 serves both as a blur metering device that measures the light reflected from the subject before shooting starts, and a direct metering device that measures the reflected light from the subject during shooting in real time. It is a photometric element.

Here, the photographer points the electronic still camera toward the subject.
When the M & shadow start button (not shown) is pressed, first, prior to starting photography, the subject light reflected by the total reflection mirror 21 is received and measured. The photometric value at this time is used, for example, to control the aperture 11, or for control prior to photographing, such as calculating the subject distance when using a strobe for daytime synchronized photography.

After diaphragm control is performed, for example, by the output of the photometer 29, the rotary lens 15 is energized, and the mirror plate 14 is rotated approximately 90 degrees clockwise in FIG. 3 against the rotational behavior of the return spring 20. Rotate. As shown in FIG. 1.2.4, when the pellicle mirror 22 of the mirror plate 14 reaches the rotational position where the photographing optical path is transmitted, the mirror plate 14 is positioned by a stopper (not shown) and stopped.

In this state, a mechanical shutter or an electronic shutter (not shown) is opened and photographing by the solid-state image sensor 3 is started.

Approximately 90% of the subject light that passes through the photographing optical axis 13 and enters the pellicle mirror 22 passes through the pellicle mirror 22 as photographing light, further passes through the low-pass filter 6 and enters the imaging surface 3a of the solid-state imaging probe 3. . Pellicle mirror 2
Approximately 10% of the subject light that reached 2 is the Berikuru mirror.
22 and reaches the light receiving surface of the photometric cable 29. Therefore,
The light from the subject during shooting is adjusted to 1p by the photometering cable 29.
1 light is emitted, and 71111 light values corresponding to the exposure amount of the imaging surface 3a of the solid-state imaging element 3 are obtained in real time from the 1-light element 29. When the photometric value of the photometric cable 29 reaches a predetermined value that provides proper exposure to the imaging surface 3a of the solid-state image sensor 3, the shutter closes and the photographing ends. When the photographing is completed, the power to the rotary solenoid 15 is cut off, and the mirror plate 14 is rotated 90 degrees counterclockwise again due to the rotational behavior of the return spring 20, and the pellicle mirror 22
Instead, the total reflection mirror 21 reaches a position where it blocks the photographing optical path including the photographing optical axis 13 and stops (see FIG. 3).

In this embodiment, the switching of the incident light for the same 7111j optical element 29 during blur photometry and direct photometry is performed by switching and moving the total reflection mirror 21 and the pellicle mirror 22 on the same plane. Therefore, even if this switching movement is performed at a very high speed, there is very little risk that the pellicle mirror 22 will be damaged due to air resistance or the like.

FIG. 5 is a longitudinal sectional side view of another embodiment of the electronic still camera, and FIG. 6 is a longitudinal sectional front view taken along the line ■-■ in FIG. The state of this electronic still camera shown in FIGS. 5 and 6 is the normal state.

In FIGS. 5 and 6, the same parts as in the embodiment shown in FIG. 1 are given the same reference numerals, and redundant explanation thereof will be omitted. A mounting plate 48 is fixed to the inner wall of the rear panel of the camera body 41 at a position above the mounting portion of the printed circuit board 4 with screws 49. The mounting plate 48 is a vertically elongated rectangular plate, which is bent at the lower end of the portion that contacts the inner wall of the back plate, and has a shape in which the lower portion thereof is inclined forward. The mounting plate 4 is located between the relay lens group 12 and the low-pass filter 6.
A through hole is formed in 8, and this mounting plate 48 covers the through hole.
A pellicle mirror 52 is provided in front of the.

A mirror plate 44 is arranged above the mounting plate 48 in the vicinity of the mounting plate 48 and in an inclined state substantially parallel to the mounting plate 48. It is rotatably attached to the upper end of the slanted portion of the shaft by means of a support shaft 43. The mirror plate 44 is formed in a vertically elongated manner with a width that completely covers the pellicle mirror 52, and at least a portion of the front surface thereof corresponding to the pellicle mirror 52 is formed of a total reflection mirror.

The mirror plate 44 has one side cut out near the support shaft 43 to have a slightly narrow constricted shape, and a plunger for rotating the mirror plate 44 is inserted into a long hole 44a formed in the same part. The plunger 45a of the solenoid 45 is connected by being fitted with a connecting pin 46 implanted at the tip thereof. The main body of the plunger solenoid 45 is the mounting plate 4
It is fixed to the bent part formed on the side surface of 8 with a screw 47 (see Fig. 6.7). Plunger solenoid 45
As shown in Fig. 8, the main body is a solenoid coil 45c.
A shield member 45b is provided around the periphery.

Further, as shown in FIG. 7, a coil-shaped return spring 50 is stretched between a portion of the mirror plate 44 near the support shaft 43 and a stationary member (not shown). It is given the habit of constantly rotating clockwise around the center.

When the plunger solenoid 45 is not energized, the mirror plate 44 completely rotates clockwise due to the rotational behavior and is stopped by a stopper (not shown), as shown in FIGS.
in the position shown in the figure.

That is, in the states shown in FIGS. 5 to 8, the mirror plate 44
covers the pellicle mirror 52, so when the photographer points the electronic still camera at the subject, the light from the subject passing through the photographing optical axis 13 is reflected by the total reflection mirror in front of the mirror plate 44. The light passes through the optical path 53 to the pentaprism 23 in the finder section, and from the pentaprism 23 to the magnifying lens 2.
4. Out of the light that enters the photographer's eye as observation light via the eyepiece 25 and eyecup 26 and also enters the pentaprism 23 from the mirror plate 44, the light that passes through the half mirror 28 integrated in the pentaprism 23. is incident on the photometric element 29.

Therefore, when the shooting start button is pressed after this, for example, aperture control is performed based on the light incident on the photometric element 29 prior to starting shooting. When the 7111J photometric control by the 7111J optical probe 29 is completed, the plunger solenoid 45 is energized and the plunger 45a is attracted into the solenoid coil 45c. As a result, the mirror plate 44 rotates counterclockwise against the rotational behavior of the return spring 50, and reaches a position 44A shown by a two-dot chain line in FIG.

Then, this mirror plate 44 retreats from the position in the photographing optical path where it covered the pellicle mirror 52 to a position outside the photographing optical path, and
The pellicle mirror 52 is exposed. In this state, a mechanical shutter (not shown) or an electronic shutter opens,
Photographing by the solid-state image sensor 3 is started.

After the mirror plate 44 is retracted out of the photographing optical path, the subject light that has passed through the photographing optical axis 13 is incident on the vertical mirror 52. Approximately 90% of the incident light is directly transmitted through the pellicle mirror 52 and directed to the imaging surface 3a of the solid-state image sensor 3 as photographing light, and the remaining approximately 10% of the light is directed to the pentaprism 23 through the optical path 54. This light passes through the half mirror 28 on the pentaprism 23 and enters the photometric element 29.

That is, the light from the object being photographed is directly metered by the photometering cable 29, and at this time the light value output from the DI optical element 29 is increased to /1-1 to perform exposure control. When the photometric value of the photometric element 29 reaches a predetermined value, the shutter closes and the photographing ends. When the photographing is completed, the power to the plunger solenoid 45 is cut off, so the mirror plate 44 rotates clockwise again due to the rotational behavior of the return spring 50, and the pellicle mirror 52
It reaches a position where it covers the photographic optical path and stops.

Incidentally, since the mirror plate 44 and the pellicle mirror 52 are disposed close to each other and parallel to each other, the reflected optical path 53 by the mirror plate 44 and the reflected optical path 54 by the pellicle mirror 52 are also close to and parallel to each other. The reflected light can be made incident on the light-receiving surface of one /1l11 optical element 29, but the mirror plate 44 or the mirror 52 are not necessarily parallel to each other, and one of the mirrors is not necessarily parallel to the other. By tilting, both of the reflected lights may be made to enter the same position on the light receiving surface of the photometric element 29.

In addition, in this embodiment, only the mirror plate 44 is movable, and the pellicle mirror 52 is provided on the mounting plate 48 and is immovable. Damage accidents can be prevented.

Further, in both of the above two embodiments, the mirror plate 14
．． 44 moves in the plane direction, it does not require much space and #14 formation is also easy.

Furthermore, the mirror plates 14 and 44 are moved by the rotary solenoid 15 in the first embodiment and by the plunger solenoid 45 in the second embodiment, but the plunger solenoid is used for the former, and the rotary solenoid is used for the latter. Alternatively, other drive means such as a motor may be used.

Furthermore, the present invention is applicable not only to imaging devices such as electronic still cameras, but also to single-lens reflex cameras using ordinary silver halide films.

[Effects of the Invention] As described above, according to the present invention, with a simple configuration, an all optical element for performing so-called blur metering before photographing and a photometric element for direct metering during photographing can be used in common. Therefore, it is possible to realize a system with high optical exposure detection accuracy.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional side view of an imaging device showing an embodiment of the present invention, FIG. 2 is a longitudinal sectional front view taken along the line ■-■ in FIG. FIG. 4 is a front view of the mirror plate in FIG. 1, FIG. 5 is a longitudinal sectional side view of an imaging device showing another embodiment of the present invention, and FIG. is a longitudinal sectional front view along the vt-vt line in FIG. 5 above, FIG. 7 is a front view of the mirror plate in FIG. 5 above, and FIG. 8 is a line ■-■ in FIG. 7 above. FIG. 7・・・・・・・・・・・・・・・Photographing lens system 14・・・・・・・・・・・・Mirror plate 21...
・・・・・・・・・・・・・Total reflection mirror (reflection m) 2
2.52...Pellicle mirror (semi-transparent mirror) 29.
.........Photometering element 44...
・・・・・・・・・Mirror plate (reflector) 1 Figure ■ ■ ・ Way 2 Figure False 3 % 4 Figure

Claims (1)

[Scope of Claims] A photographic lens system for forming an image of subject light; a photometric element for receiving the light emitted from the photographic lens system and detecting the exposure amount; A reflecting mirror is detachably installed in the photographing optical path to reflect the light toward the photometric element, and when the reflecting mirror leaves the photographing optical path, a part of the light emitted from the photographing lens system is directed toward the photographing surface. A photographing device comprising: a semi-transparent mirror provided for transmitting light toward the photometric element and reflecting the other part toward the photometric element.