JPH08201912A - Imaging device - Google Patents

Abstract

(57) [Summary] [Purpose] In a shooting device that has an optical system that forms an image on the photoconductor surface such as a silver salt film or a shooting device, eliminates the viewfinder parallax and allows you to shoot the subject image as you see it. To be [Arrangement] A semi-transmissive concave mirror 3d is arranged so as to face the subject, and a photographing system for guiding the light flux reflected by the concave mirror out of the light flux of the subject onto the photosensitive surface 10 and the concave mirror 3d. It has a finder system for observing the subject image with this luminous flux.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photographing device, and more particularly to a photographing device for forming an image on a recording medium such as a silver salt film or a photographing element by a photographing system.

[0002]

2. Description of the Related Art In a so-called lens shutter camera that prioritizes compactness, which is the first conventional example of this type of photographing apparatus, the back focus of the photographing lens is such that the photosensitive surface (image forming surface) and the final lens surface are in contact with each other. Since it only needs to have a length not to do so, it is advantageous for downsizing of the entire photographing optical system.

In a so-called single-lens reflex camera having a TTL finder device, which is a second conventional example, since the optical axes of the photographing optical system and the finder optical system are coincident with each other, there is no finder parallax, and the object distance and focal length. It has the feature that the viewfinder field can be photographed as it is on the photosensitive surface (image forming surface) regardless of the value of.

[0004]

However, in the above-described first conventional example, a finder parallax exists because a finder optical system having an optical axis different from that of the taking optical system is provided separately. In particular, in the case of a taking lens having a long focal length and a close-up taking a short taking distance, there is a problem that the parallax amount becomes extremely large.

In the second conventional example, since a mirror for bending the optical path such as a quick return mirror for guiding the optical path to the finder optical system is provided between the photographing optical system and the image forming surface, a space with the quick return mirror is provided. No photographic optical system can be placed inside. This space is usually required to be about 40 mm in a camera system using a 35 mm film, for example. As a result, the taking lens must be designed so as to secure the back focus, and there is a problem that the entire camera including the taking lens becomes large.

The present invention has been made to solve the problems of the conventional example as described above, and the invention according to the present application eliminates the finder parallax, and the subject image as seen by the eye can be photographed as it is. It is an object of the present invention to provide an image pickup apparatus in which the entire configuration including the image pickup lens is reduced.

It is another object of the present invention to provide a thin and compact photographing device having good portability, which has a thin and compact simple shape for the photographing optical system and the viewfinder optical system and which prevents extreme deterioration of optical performance. .

[0008]

According to the invention of the present application, a semi-transmissive concave mirror is arranged so as to face a subject, and a light flux of the light flux of the subject reflected by the concave mirror is guided to a photosensitive surface. The finder system for observing a subject image with the light flux that has passed through the concave mirror eliminates the finder parallax, and the photographic optical system and the finder optical system have the same angle of view. Therefore, it is possible to obtain the effect that it is possible to shoot the subject image as it is viewed. Moreover, since the photographic optical system and the finder optical system are configured by one optical block, it has a very simple and simple shape similar to a rectangular parallelepiped, has high strength, and is easy to cost.
The high-power viewfinder can be thinly and compactly integrated with the shooting optical system.

[0009]

【Example】

First Embodiment FIGS. 1 to 11 show an image pickup apparatus according to a first embodiment of the present invention. In particular, FIG. 1 is a perspective view in a photographable state, and FIG. 2 is a central longitudinal section of a camera in a finder observation state. FIG. 3 is a view showing a viewfinder screen, FIG. 4 is a central longitudinal sectional view of the camera in a photographing exposure state, FIG. 5 is a perspective view of a film surface position changing mechanism, and FIG. 6 is a line AA of FIG. FIG.

In these figures, reference numeral 1 denotes a camera body as a photographing apparatus body, and the camera body 1 is sandwiched between a film cartridge side block 1a, a film spool side block 1b, a cartridge side block and a spool side block. Photographic optical storage block 1c, exposure opening 1
have d.

Reference numeral 2 is a photographic optical block, and 3 is a photographic optical member assembled by engaging the convex portion of the prism block 3b with the concave portion of the prism block 3a, and a semi-transmissive concave surface formed on the concave and convex engaging surface. The mirror 3d is arranged so that the concave surface faces the subject, and the photographing system that guides the light flux reflected by the concave mirror out of the light flux of the subject onto the photosensitive surface, and the light flux that has passed through the concave mirror forms a subject image. It has a viewfinder system for observation.

Reference numeral 4 denotes a field frame LCD comprising an LCD section 4a forming a field frame and an illumination optical system 4b, which is transmitted through the LCD section 4a when observing the viewfinder, and external light or a beam collimated by the illumination optical system 4b is used. It is backlit and the field frame looks bright. The viewfinder screen at that time is shown in FIG. Further, at the time of photographing exposure, the LCD section 4a becomes non-transmissive as shown in FIG. 4, and the entire surface of the field frame LCD 4 is shielded.

The field frame LCD 4 is constructed so as to face forward and obliquely upward so that the backlight illumination can be efficiently performed by external light.

Reference numeral 5 denotes an eyepiece LCD that is in close contact with an exit surface 3f that guides the light beam that has passed through the concave mirror 3d to the photographer. The eyepiece LCD is entirely transmitted during finder observation (when no current is applied) and is emitted from the exit surface 3f. The subject image and field frame can be observed. On the other hand, during photographing exposure (when energized), the entire surface is non-transmissive (light-shielded state) as shown in FIG.
Prevents back light from entering d.

Reference numeral 6 denotes a photographing optical block cover made of a light-shielding material for covering and holding the photographing optical member 3, the field frame LCD 4, the eyepiece LCD 5 and the like, and 7 an openable and closable eyepiece slide cover for covering and protecting the eyepiece LCD 5. Reference numeral 8 denotes a photographing ready state in which the photographing optical member 3 is positioned perpendicular to the film surface 10 as shown in FIG. 1 so that the light beam reflected by the concave mirror 3d is emitted from the first emission surface 3h to the film surface 10. 2 is a light-shielding plate for keeping a space between the photographing optical block 2 and the film storage portion in a dark box state, and forms a spigot with the groove 1e of the camera body 1. Then, in the above-mentioned image-capable state, it becomes possible to slide upward.

Similarly, 9 is a light-shielding flexible member for keeping the space between the photographic optical block 2 and the film accommodating portion in a dark box state, which is adhered and held to the end faces of the camera body 1 and the photographic optical block cover 6, and the photographic optical block 2 is provided. It can be transformed and moved freely even when folded. Also, both sides of the photographing optical block 2 are located on the lower end surface of the photographing optical block cover and the side walls 1 of the photographing optical block housing portion of the camera body.
An inlay (not shown) is formed between f and 1g, and a dark box state is formed between the front and rear light shielding members 8 and 9 and between the photographing optical block 2 and the film storage portion. The photographic optical block 2 is fixed to the photographic enabled state shown in FIG. 1 by a lock mechanism (not shown) so as to reliably hold such a dark box state.

Reference numeral 10 is a photographic film as a light-sensitive material located on the image plane, 11 is a front curtain of a focal plane shutter composed of a plurality of divided plates, and 12 is a rear curtain of the shutter. The film is shielded from light by the front curtain 11. Reference numeral 13 is a release button, 14 is an AE photometric window, 15 is an active autofocus light projecting window, 16 is an active autofocus light receiving window, and 17 is a speedlight.

Reference numeral 18 denotes a first emission surface 3h of the photographing optical member 3 for emitting the light beam reflected by the concave mirror 3d to the film surface.
It is a physical property diaphragm that is in close contact with, and changes the arrangement of the enclosed liquid crystal or the like according to the applied voltage value, controls the transmittance of light rays, and functions as an ND filter with variable density. When the finder is observed (non-energized), the transmittance is smallest (dark), which enhances the light shielding property of the film.

FIGS. 5 and 6 are views showing a film surface position varying mechanism. In FIGS. 5 and 6, 19 is a film cartridge and 20 is a spool for winding the film, which is driven by a film winding mechanism (not shown). To be done. Reference numeral 21 denotes a rotatable guide roller which is located immediately outside the exposure opening and which guides and holds the film while constantly applying tension to the film from the film emulsion surface side. Reference numeral 21a denotes a rotation shaft of the guide roller 21, which is a guide roller support frame. 22 rotatably supported,
A girder-shaped frame is formed. 23 is a film pressure plate,
After the film is loaded, it is integrated with the guide roller support frame 22 to form an extremely narrow film passage.

Reference numerals 24 are guide bars for guiding the guide roller support frame 22 so as to be slidable up and down, and are provided at three places. Reference numeral 25 is a compression coil spring provided with each guide bar 22 as a guide rod, and generates a biasing force to push the guide roller support frame 22 downward. 26
Is a drive lever for moving the film surface position in the photographing optical axis direction, is supported rotatably about the axis P as a central axis, and has one end by a projection 23a and a pivot Q provided on the back side of the center of the film pressure plate 23. It is rotatably connected and has a spherical projection 26a for receiving a cam at the other end.

Reference numeral 27 denotes an AF motor which is a DC motor, and 28
Is a pinion gear and a pulse generating plate provided integrally therewith, 29 is a reduction gear train, and 30 is a cam gear having a lift for changing the film surface position.
By a, the ball projection 26a is contacted and pressed. Reference numeral 31 is a photo interrupter, which counts the pulses generated by the light-shielding portion and the light-transmitting portion of the pulse generation plate 28, and the AF
The amount of rotation of the motor 27 is detected.

The photographic optical block 2 will be described in detail below. The part centering on the prism block 3a that forms the finder optical system adopts a prism type virtual image type system with a view angle of 135 film equivalent and a focal length angle of view of about 50 mm for the purpose of thinning. This is an application of a type that performs both total reflection and transmission depending on the difference in the incident angle of light rays.

As shown in FIG. 2, the light from the field frame LCD 4 passes through the prism entrance surface 3g and enters the second exit surface 3f at an incident angle equal to or greater than the critical angle for total reflection, and the concave mirror 3d reflects the light. Reflecting portion 3c provided in a region corresponding to the peripheral portion
The light is reflected by (100% reflection back surface reflection prevention), again enters the exit surface 3f at a critical angle or less, is transmitted, and is guided to the eyeball of the photographer. In this way, since one emission surface 3f performs total reflection and transmission, it is equivalent to the existence of a surface having two curvatures, and the concave mirror 3d having a curvature has a power of three surfaces. become.

Further, in superimposing the field frame image on the outside landscape image, the respective incident surfaces 3e having substantially the same surface shape as the exit surface 3f are arranged so as to vertically cross the optical axis of the eyeball. Are arranged in parallel, and the prism as a whole in which the prism blocks 3a and 3b are combined is substantially the same as a non-power meniscus lens.

Next, FIG. 7 shows a specific example of the structure of the finder optical system.

FIG. 7 shows a vertical fold type finder system with good optical performance, which uses a toric aspherical surface or an anamorphic aspherical surface for the concave mirror 3d and the exit surface 3f.

In the present invention, all reflecting (including total reflection) surfaces have a curvature. Therefore, it is possible to reduce the focal length of the reflection optical system by giving power to a portion that has been reflected by a flat surface in the past, and to reduce the size.

By using a surface (a toric aspherical surface or an anamorphic aspherical surface) having a different power depending on the difference in azimuth angle as these reflecting surfaces, decentering aberration is suppressed to a small level and good optical performance is obtained.

Further, not only the reflecting surface but also the transmitting surface (incident surface, at the time of total reflection transmission) using a curved surface will further improve the optical performance.

(1) The folding direction of light rays is defined as the generatrix direction (y
Direction), a z direction orthogonal to the y direction, and a direction (x direction) perpendicular thereto (x direction) are defined as sagittal directions, the present invention often uses different powers due to the difference in azimuth angle. Nevertheless, when the focal length in the generatrix direction is f _y and the focal length in the sagittal direction is f _x , the condition of 0.9 <| f _y / f _x | <1.1 (1) is satisfied. At any azimuth angle, the focal length of the catoptric system is almost constant.

(2) Concave mirror 3d or total reflection surface 3f
When the paraxial radius of curvature in the generatrix direction is r _y and the paraxial radius of curvature in the sagittal direction is r _x on the surface having different powers due to the difference in azimuth angle of | r _x | <| r _y | (2) is satisfied. Since the generatrix direction is the folding direction of light rays, the concave mirror 3d must be largely tilted. Then, decentration aberrations are significantly generated. On the other hand, since there are few decentering points in the sagittal direction, decentration aberrations are less likely to occur. In other words, r _y in the generatrix direction is replaced by r _{x in the} sagittal direction
By making it larger, the power in the generatrix direction is made weaker than the power in the sagittal direction, and the eccentric aberration in the generatrix direction is reduced.

(3) Further, in the above (2), it is characterized in that: | r _x / r _y | <0.85 (3) is satisfied, and if this value is exceeded,
Correction of eccentric aberration becomes difficult.

(4) When a surface with different power is inserted in the incident surface 3e due to the difference in azimuth angle, conversely, if | r _x |> | r _y | In the generatrix direction of the surface 3e, it is possible to relatively reduce the occurrence of eccentric aberration. Therefore, the power of the concave mirror 3d and the total reflection surface 3f in the generatrix direction is weak,
The power of the incident surface 3e in the generatrix direction is strengthened to cover the power in the generatrix direction so that the focal length is constant at any azimuth angle.

(5) The power in the sagittal direction of the surface in front of the eyeball is negative (when the total reflection surface 3f is transmitted), the power in the sagittal direction of the concave mirror 3d is positive, and the total reflection surface of the total reflection surface 3f is the child. By making the power in the line direction negative, the effect (good correction of aberrations with a wide field angle in the sagittal direction) becomes more remarkable. In addition, the incident surface 3e
If the bus has a positive power in the bus direction, the power in the bus direction can be supplemented as described in (4) above.

(6) Even if the total reflection surface 3f in the generatrix direction has negative power and the concave mirror surface 3d in the generatrix direction has positive power, the optical performance is good in the generatrix direction, and when the incident surface 3e has power. By providing positive power in the sagittal direction, the four-plane aberration cancellation in the sagittal direction becomes good, and the aberration in the sagittal direction can be reduced.

[0036] (7) above in (5), the focal length of the sagittal direction f _x, the radius of curvature r _x2 of the total reflection surface, -2.0 <2f when the radius of curvature of the concave mirror and the r _{x3 x} / r _x2 <-0.1 meet the _{··· (5) -2.5 <2f x} / r x3 <-0.5 ··· (6). The lower limit of the equations (5) and (6) is that the powers of r _x2 and r _x3 become stronger, and the ratio becomes looser.
When the value goes below the lower limit of the expression (5), the curvature (negative power) of the sagittal direction total reflection surface becomes tight, and the distortion correction becomes difficult. At the lower limit of the expression (6), the curvature (positive power) of the sagittal concave mirror becomes so tight that it is difficult to correct astigmatism. At the upper limit of the equation (5), the curvature of the sagittal direction total reflection surface is in the direction having a positive power, so that it becomes difficult to satisfy the total reflection condition. The upper limit of the expression (6) is in the direction in which the positive power of the sagittal direction concave mirror is weakened, so that the thickness in the direction parallel to the optical axis of the eyeball is increased.

(8) In (6), when the total focal length in the generatrix direction is f _y , the radius of curvature of the total reflection surface is r _y2 , and the radius of curvature of the concave mirror is r _y3 , -1.0 < _{2f y / r y2 <0 ···} (7) meet the _{-2.5 <2f y / r y2 <} -0.2 ··· (8). If the lower limit of expression (7) is exceeded, the negative power of the generatrix direction total reflection surface becomes strong, and it becomes difficult to correct the eccentric distortion. As for the lower limit of the equation (8), the convex power of the concave mirror in the generatrix direction becomes strong, and the decentration astigmatism is increased. Since the upper limit of the equation (7) is included in the total reflection condition in the generatrix direction, if it exceeds this, the total reflection condition cannot be satisfied.
The upper limit of the expression (8) relates to the power of the concave mirrors in the generatrix / sagittal direction. When the upper limit is exceeded, the power becomes weak, so that the total length increases in the generatrix direction and the size becomes large.

(9) Further, the reflecting surface immediately in front of the eyeball is decentered parallel to the image side (+) in the generatrix direction (Y direction) from the optical axis of the eyeball. By doing so, the eccentric distortion in the generatrix direction is kept small.

Next, as described in the finder optical system, the portion centering on the prism block 3b forming the photographing optical system has a focal length angle of view of about 50 mm in terms of 135 film, a thin, finder optical system. The prism system is integral with the prism block 3a to be formed, and, like the finder optical system described above, one surface performs both total reflection and transmission depending on the difference in the incident angle of the light beam.

As shown in FIG. 2, the light beam from the subject enters the prism block 3b through the incident surface 3e and is reflected by the concave mirror 3d (half mirror) provided corresponding to the screen. The light is incident on the incident surface 3e at an incident angle equal to or greater than the critical angle to be totally reflected, and is emitted from the first exit surface 3h to form an image at the position of the film 10. Like this one
Since total reflection and transmission are performed by the one incident surface 3e, it is equivalent to the fact that there are surfaces having two curvatures, and the concave mirror 3d having the curvature has a power of three surfaces. The principle is that the finder optical system described above is traced from an almost reverse optical path.

As is apparent from FIG. 2, by aligning the optical axis of the object side of the photographing optical system with the optical axis of the finder optical system, and by matching the focal length angle of view of both, the photographed optical block 2 takes a photographed image. The same effect as that of a so-called TTL finder that can capture an image as it is seen without parallax between the observed image and the observed image is realized.

The concave mirror 3c serving as a reflecting portion provided in a region corresponding to the peripheral portion of the concave mirror 3d may be a continuous curve having an inflection point even if the boundary portion shown in the sectional view is discontinuous.

FIG. 8 is a block diagram showing an electric circuit according to the first embodiment of the present invention. In FIG. 8, 41 is a camera microcomputer (hereinafter referred to as camera microcomputer), 42 is a switch (SW1), and 43 is a switch (S).
W2), 42a, 43a are pull-up resistors, 42b, 4
3b is an inverter that outputs a high-level signal when the switches 42 and 43 are turned on, Pa is a port of the camera microcomputer that transmits the signal of the switch 42, Pb is a port of the camera microcomputer that transmits the signal of the switch 43, 4
Reference numeral 4 designates a photometric means composed of a photometric lens (not shown) provided in the back of the AE photometric window 14 and a light receiving sensor such as an SPC, which outputs an output signal corresponding to the brightness of the subject.
1 to port Pc.

Reference numeral 45 is a distance measuring means including a known active autofocus light emitting / receiving section and a focus detection circuit, and exchanges signals with the port Pd of the camera microcomputer 41. Reference numeral 46 is an LCD drive circuit for drivingly changing the field frame LCD 4 and the eyepiece LCD 5 to be transparent or non-transparent (light-shielding), and a driving signal is transmitted from the port Pe of the camera microcomputer 41. Reference numeral 47 is a drive circuit for the AF motor 27,
A drive signal is transmitted from the port Pf of the camera microcomputer 41. Pg is a port of the camera microcomputer 41 that transmits a signal from the photo interrupter 31 that detects the rotation amount of the AF motor.

Reference numeral 48 is a physical property diaphragm drive circuit for changing the light transmittance of the physical property diaphragm 18, and a drive signal is transmitted from the port Ph of the camera microcomputer. Reference numeral 49 is a shutter drive circuit, and a second control signal is transmitted from a port Pi of the camera microcomputer 41 at a timing of a predetermined second to energize the front curtain control magnet 50 and the rear curtain control magnet 51.

FIG. 9 is a perspective view of a portable state in which the photographing optical block 2 of the photographing apparatus according to the first embodiment of the present invention is stored in the storage portion 1c, and FIG. 10 is a central longitudinal sectional view of FIG.

In order to store the photographic optical block 2 from the photographic state shown in FIGS. 1 and 2, the lock mechanism (not shown) is released, and the interlock between the photographic optical block 2 and the film section in the dark box state is released. The light blocking member 8 may be slid upward until the front surface 3e of the prism block is covered so as to remove 1e (other not shown), and the photographing optical block 2 may be slightly lifted upward and then the photographing optical block may be tilted forward. At that time as well, a lock mechanism (not shown) can reliably hold the storage state. Further, by covering the eyepiece LCD 5 with the eyepiece slide cover 7, the eyepiece can be protected from dust and fingerprints. As a result, the camera body 1 has a flat box shape with few irregularities, which improves portability.

Next, the operation of the first embodiment will be described based on the program flow chart shown in FIG. In addition,
This program is the RO built in the camera microcomputer 41.
The number is stored in M, and each number added with # indicates a program step.

# 1: As shown in FIGS. 1 and 2, the photographing optical block 2 rises up to a predetermined position, the eyepiece slide cover 7 retracts to expose the viewfinder eyepiece, and the light shielding plate 8 is attached to the camera body 1. Slide to the side to expose the objective part of the photographic optical block 2 and set it so as to keep the state immediately before the film part in the dark box, the power supply (not shown) is turned on, the power is supplied to the camera microcomputer 41, and the power is turned on. After being up-cleared, the operation is performed in the following order of steps.

# 2: When the input state of the signal of the switch 42 is detected at the port Pa of the camera microcomputer 41, the release button 13 is pressed, and the ON signal is input, # 3.
Proceed to, otherwise wait for input.

# 3: An output signal corresponding to the brightness of the subject is transmitted to the port Pc of the camera microcomputer 41 by the photometric means 44, and the camera microcomputer 41 performs a photometric calculation based on the output signal so that the subject is properly exposed. Then, the aperture and shutter speed, or whether to control the light emission of the speedlight 17 as necessary (when it is darker than a predetermined brightness) is determined. At the same time, the object distance is measured by the distance measuring means 45, and an output signal corresponding to the distance is transmitted to the port Pd of the camera microcomputer 41. Based on the output signal, the camera microcomputer 41 calculates a distance so that the object is in focus. The
The drive amount of the AF motor 27 (the rotation amount of the AF motor 27 replaced with the number of detection pulses of the photo interrupter 31) is determined.

# 4: The AF motor drive signal is transmitted from the port Pf of the camera microcomputer 41 to the AF motor drive circuit 47, and the AF motor 27 in the initial position is driven.
For example, the initial position is a position corresponding to the subject distance ∞, and in the film surface position varying mechanism shown in FIG. 6, the film surface position is set to the position closest to the prism exit surface 3h. Then, as the subject distance gets closer, the rotation of the AF motor 27 causes the cam gear 30 to pass through the reduction gear train 29.
Rotates in the direction in which the cam lift 30a decreases and the drive lever 26 rotates clockwise around the axis P by the urging force of the compression coil spring 25, and the film pressure plate 23, the guide roller support frame 22, and the guide roller 21 are filmed. At the same time, the film surface position is changed by moving downward in the figure so as to move away from the prism exit surface 3h.

# 5: The detection pulse signal of the photo interrupter 31 is transmitted to the port Pg of the camera microcomputer 41,
The camera microcomputer 41 counts the number of detection pulses,
It is determined whether or not the number of detection pulses determined in # 3 matches. If they match, the process proceeds to # 6. If not, # 4 is repeated again and the AF motor 27 continues to be driven until they match.

# 6: When the AF motor stop signal is transmitted from the port Pf of the camera microcomputer 41 to the AF motor drive circuit 47, the AF motor 27 stops.

# 7: When the input state of the signal of the switch 43 is detected at the port Pb of the camera microcomputer 41, the release button 13 is pressed to the second stroke, and the ON signal is input, the process proceeds to # 8. If not, the process proceeds to # 2.

# 8: The drive signals for the field frame LCD 4 and the eyepiece LCD 5 are transmitted from the port Pe of the camera microcomputer 41 to the LCD drive circuit 46, and as shown in FIG. The LCD part 4a and the eyepiece part LCD5 that are formed are non-transparent (as a result, both LCDs are non-transparent on the front surface), and prevent the finder back light from entering. Along with that
Show the photographer the disappearance of the viewfinder image and let the photographer know that the film will be exposed.

# 9: A drive signal for the physical property diaphragm 18 is transmitted from the port Ph of the camera microcomputer 41 to the physical property diaphragm driving circuit 48, and the physical property diaphragm 18 is driven so as to have a density corresponding to the diaphragm value determined in # 3. (In FIG. 4, the density of the physical property diaphragm 18 is lower than that in the observation state of FIG. 2, which indicates that the light reaching the film is increased).

# 10: Port Pi of camera microcomputer 41
The shutter drive circuit 49 transmits a shutter drive signal from the shutter drive circuit 49 to energize the front curtain control magnet 50 and the rear curtain control magnet 51 so that the shutter speed determined in # 3 is achieved. Thereby, the film 10 is exposed.

# 11: Port Ph of camera microcomputer 41
The drive signal of the physical property diaphragm 18 is transmitted from the physical property diaphragm drive circuit 48 to the maximum density (the minimum transmittance) for the observation state again, and the light shielding property to the film is enhanced.

# 12: Port Pe of camera microcomputer 41
To LCD drive circuit 46 from field frame LCD 4 and eyepiece L
The drive signal of the CD 5 is transmitted, and as shown in FIG. 2, the LCD unit 4a and the eyepiece LCD 5 that form the field frame are made transparent again, and finder observation is possible.

# 13: Port Pf of camera microcomputer 41
An AF motor drive signal is transmitted from the AF motor drive circuit 47 to the AF motor drive circuit 47, and the AF motor 27 is driven toward the initial position before exposure. As a result, the film surface position varying mechanism starts a movement opposite to that described in # 4, and moves the film surface position toward the position corresponding to the subject distance ∞ which is the initial position.

# 14: Port Pg of camera microcomputer 41
The detection pulse signal of the photo interrupter 31 is transmitted to the camera microcomputer 41, and the camera microcomputer 41 counts the number of detection pulses, decides at # 3, and moves the AF motor 27 at # 4 to # 6.
It is determined whether or not the number of detection pulses for return matches the number of pulses of. If they match, the process proceeds to # 15. If not, # 13 is repeated again and the AF motor 27 is continuously driven until they match. Here, although the initial position of the film surface position is detected by replacing the rotation of the AF motor 27 with a pulse, an initial position switch (not shown) interlocked with a movable member such as the drive lever 26 is provided. Good.

# 15: Same as # 6 # 16: A film feeding signal is transmitted from the camera microcomputer 41 to a film feeding circuit (not shown), and the film feeding mechanism (not shown) feeds the film one frame, and the shutter, etc. Is also charged.

# 17: It is determined whether the photographing is continued after exposure or the power is turned off and the photographing is finished. When the power is not turned off and the shooting is continued, the process proceeds to # 2.

When the power is turned off, the process proceeds to # 18. # 18: The (photographing) operation ends.

In the first embodiment, focusing is performed by changing the position of the film surface, but the photographic optical block 2 is moved with respect to the camera body 1 in the optical axis direction perpendicular to the film surface for focusing. You may do it.

Further, as a modification, although it is not a TTL finder, the finder optical system observation optical axis and the photographic optical system objective side optical axis are separated, and the finder optical system and the photographic optical system are connected (it is an optical block. However, it can be provided independently.

In that case, the concave mirror 3 of the finder system is used.
c also forms the broken line portion in FIG. 2, covers the entire viewfinder screen, and serves as a half mirror. The concave mirror 3d of the photographing system is located below the concave mirror 3c in FIG.
It is arranged as a 00% reflection mirror so that the optical paths of both the finder optical system and the photographing optical system do not interfere with each other.

Second Embodiment FIGS. 12 and 13 show a second embodiment of the present invention.
Is a central longitudinal sectional view of the camera in the viewfinder observation state (first
2) of the first embodiment), and FIG. 13 is a central longitudinal sectional view of the camera in a photographing exposure state (a view corresponding to FIG. 4 of the first embodiment), which is the same as the first embodiment. The part of is represented by a number obtained by adding 200 to the number.

The parts different from the first embodiment will be described below. Reference numeral 261 denotes a curved LCD closely attached to the back of the concave mirror 203d (half mirror) at the same index as that of the photographing optical member 203, and is in a finder observation state (see FIG. 1).
In 2), the light becomes transparent, and the subject light that has passed through the concave mirror 203d, which is a half mirror, is guided to the photographer's eyes.

On the other hand, in the photographing exposure state (FIG. 13), the curved surface L
The CD 261 becomes non-transparent. In the first embodiment, a part of the subject light that has passed through the concave mirror 3d, is incident on the prism block 3a, and is diffusely reflected, reversely passes through the concave mirror 3d and enters the prism block 3b. Although there was a risk of flare, this can be prevented in the second embodiment.

Reference numeral 262 denotes an AF lens provided between the prism exit surface 203h and the film 210, which is held slidably in the optical axis direction perpendicular to the film surface by a guide bar (not shown), and a drive mechanism (not shown). By the (composed of a motor, a gear train, a cam gear, etc.), focusing is performed by driving in the optical axis direction perpendicular to the film surface according to the distance measurement result.

The operation is basically the same as that of the first embodiment, and the curved LCD 26 is shown in # 8 of the program flow chart.
The non-transmission of the entire surface of No. 1 is that the operation of the curved LCD 261 is added to # 12, and the operation of the film surface position changing mechanism of the first embodiment is replaced with the operation of the AF lens 262 as the AF operation.

Third Embodiment FIGS. 14 to 17 show a third embodiment of the present invention, and its application to an electronic image camera (especially still video camera) will be described. 14 is a central longitudinal sectional view of the image pickup apparatus in the viewfinder shooting state (a view corresponding to FIG. 2 of the first embodiment), and FIG. 15 is a sectional view of the image pickup element position changing mechanism (FIG. 6 of the first embodiment). (Corresponding to FIG. 3), and the same or similar parts as those in the first embodiment are represented by numerals with 300 added to them, and duplicate explanations are omitted. The photographic optics block 302 has the same configuration as that of the first embodiment and is a TTL finder.

The parts different from the first embodiment will be described below. Reference numeral 363 denotes an image pickup device such as a CCD placed at a substantially focal position of the image pickup optical system of the image pickup optical block 2, and is held together with the mounting portion 322 on the image pickup device position changing plate 323. The image pickup device position changing plate 323 is movable in the photographing optical axis direction like the film surface position changing mechanism of the first embodiment, and moves according to the subject distance.
Focusing can be performed on the surface of the image sensor.

FIG. 16 is a block diagram showing an electric circuit according to the third embodiment of the present invention. In FIG. 16, 361 is a color measuring means for determining the white balance, which is a color measuring port Pj of the camera microcomputer 341. Convey a signal. Reference numeral 362 denotes a drive circuit for generating a gate pulse of a solid-state image sensor (hereinafter, referred to as an image sensor) 363, and a drive control signal is transmitted from the port Pk of the camera microcomputer 341. Reference numeral 364 denotes a color difference signal (RY and BY) from the output signal of the image sensor 363, a luminance signal + a synchronization signal (Y + S).
and an image pickup signal processing circuit for producing
A drive control signal is transmitted from the port Pl of the camera microcomputer 341.

Reference numeral 365 is a modulation circuit for FM-modulating the signal from the image pickup signal processing circuit 364, and a drive control signal is transmitted from the port Pm of the camera microcomputer 341.
366 is a recording amplifier for amplifying the signal from the modulation circuit 365, and a drive signal is transmitted from the port Pn of the camera microcomputer 341. 367 is a magnetic head for electromagnetically converting the signal from the recording amplifier 366, 368 is a magnetic sheet for recording the magnetic signal from the magnetic head 367, 369 is a magnetic sheet drive motor for rotating the magnetic sheet 368, 370. Is a servo circuit for controlling the rotation of the motor 369, and is a camera microcomputer 341
The drive signal is transmitted from the port Pq.

Next, the operation of the third embodiment will be described based on the program flow chart shown in FIG. The program is stored in the ROM incorporated in the camera microcomputer 341, and each number with # indicates a program step.

# 301: As shown in FIG. 14, the photographing optical block 302 rises to a predetermined position, the eyepiece slide cover 307 retracts to expose the viewfinder eyepiece, and the light shielding plate 308 slides to the camera body 301 side. Then, when the objective part of the photographing optical block 302 is exposed and the film part is set so as to be kept in a dark box immediately in front of the film part, a power source (not shown) is turned on to power on the camera microcomputer 341 to clear the power-up. After that, the operation is performed in the following order of steps.

# 302: When the input state of the SW1 signal is detected at the port Pa of the camera microcomputer 341, the release button is pressed, and the ON signal is input, the process proceeds to # 303, otherwise the input is waited.

# 303: An output signal according to the brightness of the subject is output from the photometry means 344 to the port P of the camera microcomputer 341.
Based on the output, the camera microcomputer 341 performs a photometric calculation so that the subject is properly exposed, and determines whether the aperture and shutter speed or the speedlight emission control is necessary (when it is darker than a predetermined brightness). decide. The colorimetric means 361 detects whether the subject illumination light is natural light, tungsten light or fluorescent light, and the camera microcomputer 341
The color measurement signal is transmitted to the port Pj of the camera microcomputer 3
Reference numeral 41 determines a color correction value at the time of image signal processing so that an appropriate white balance can be obtained based on the signal. At the same time, the distance measuring means 345 measures the subject distance, and an output signal corresponding to the distance is transmitted to the port Pd of the camera microcomputer 341. Based on the output signal, the camera microcomputer 341 performs distance measurement calculation so that the subject is in focus. Then, the drive amount of the AF motor (the rotation amount of the AF motor 327 is replaced by the number of detection pulses of the photo interrupter 331) is determined.

# 304: An AF motor drive signal is transmitted from the port Pf of the camera microcomputer 341 to the AF motor drive circuit 347, and the AF motor 327 in the initial position is driven. For example, the initial position is a position corresponding to the subject distance ∞, and in the image sensor position varying mechanism shown in FIG. 15, the image sensor position is set to the position closest to the prism exit surface 303h. Then, as the subject distance approaches, the rotation of the AF motor 327 causes the cam gear 330 to rotate in the direction in which the cam lift is reduced via the reduction gear train 329, and the driving lever 326 is centered on the axis R by the urging force of the compression coil spring 325. The image pickup element position changing plate 323 is rotated in the clockwise direction and is moved downward together with the image pickup element in the downward direction of the drawing so as to be away from the prism exit surface 303h, thereby changing the image pickup element position.

# 305: The detection pulse signal of the photo interrupter 331 is transmitted to the port Pg of the camera microcomputer 341, and the camera microcomputer 341 counts the number of detection pulses and determines whether or not it matches the number of detection pulses determined in # 303. Determine.

If they match, the process proceeds to step # 306,
Otherwise, # 304 is repeated again, and the AF motor 32
Continue driving 7 until they match.

# 306: An AF motor stop signal is transmitted from the port Pf of the camera microcomputer 341 to the AF motor drive circuit 347, and the AF motor 327 stops.

# 307: When the input state of the SW2 signal is detected at the port Pb of the camera microcomputer 341, the release button is pressed to the second stroke, and the ON signal is input, the process proceeds to # 308, otherwise # Move to 302. # 308: Perform a clear operation for discharging charges accumulated in the storage element of the solid-state imaging device 363, emptying the storage element, converting an optical signal corresponding to the subject into an electric signal and preparing for storage. Camera microcomputer 34
A drive signal is sent from the first port Pk to the image sensor drive circuit 362, and a clear operation is performed.

# 309: View frame LCD 304 from the port Pe of the camera microcomputer 341 to the LCD drive circuit 346.
And the driving signal of the eyepiece LCD 305 is transmitted, and the LCD unit 304a and the eyepiece LCD 305 which form the field frame which has been transparent until now become non-transparent (as a result, both LCDs
(Non-transparent on the front) Prevents back light from entering the viewfinder. Along with that
Show the disappearance of the viewfinder image to the photographer and let him / her know that the image sensor is exposed.

# 310: A drive signal for the physical property diaphragm 318 is transmitted from the port Ph of the camera microcomputer 341 to the physical property diaphragm drive circuit 348, and the physical property diaphragm 318 is driven so as to have a density corresponding to the diaphragm value determined in # 303. To do.

# 311: A shutter drive signal is transmitted from the port Pi of the camera microcomputer 341 to the shutter drive circuit 349, and the front curtain control magnet 350 and the rear curtain control magnet 351 are controlled so that the shutter speed determined in # 303 is achieved. Drive electricity. Thereby, the solid-state image sensor 3
Exposure to 63 is performed.

# 312: A read command is transmitted from the port Pk of the camera microcomputer 341 to the image pickup device drive circuit 362, and the signal stored in the storage element of the solid-state image pickup device 363 is read out.

# 313: The drive signal of the physical property diaphragm 318 is transmitted from the port Ph of the camera microcomputer 341 to the physical property diaphragm drive circuit 348, and the maximum density (minimum transmittance) for the observation state is reached again, and the light shielding property to the film. Raises.

# 314: The drive signals for the field-of-view frame LCD 304 and the eyepiece LCD 305 are transmitted from the port Pe of the camera microcomputer 341 to the LCD drive circuit 346, and the LCD section 304a and the eyepiece LCD 305 forming the field-of-view frame are made transparent again. , Finder observation becomes possible.

# 315: A drive control signal is transmitted from the port Pl of the camera microcomputer 341 to the image pickup signal processing circuit 364, and the color difference signals (RY and BY) are output from the output signal of the image pickup element 363 read in # 312. And luminance signal + synchronization signal (Y + Sync).

# 316: A drive control signal is transmitted from the port Pm of the camera microcomputer 341 to the modulation circuit 365, and the color difference signal and the luminance signal + from the image pickup signal processing circuit 364.
The synchronization signal is FM-modulated.

# 317: A drive signal is transmitted from the port Pn of the camera microcomputer 341 to the recording amplifier 366, and the FM circuit modulates the FM modulated signal.

# 318: The color difference signal and the luminance signal + synchronization signal amplified in # 317 are electromagnetically converted by the magnetic head 367. The servo circuit 370 to which the drive signal from the port Po of the camera microcomputer 341 is transmitted is
The magnetic sheet 368 is rotated via 69, and recording is performed on the magnetic sheet 368 by the magnetic head 367.

# 319: An AF motor drive signal is transmitted from the port Pf of the camera microcomputer 341 to the AF motor drive circuit 347, and the AF motor 327 is driven toward the initial position before exposure. As a result, the image sensor position varying mechanism starts a movement opposite to that described in # 304, and moves the image sensor position toward the position corresponding to the subject distance ∞ which is the initial position.

# 320: The detection pulse signal of the photo interrupter 331 is transmitted to the port Pg of the camera microcomputer 341, and the camera microcomputer 341 counts the number of detection pulses, determines in # 303, and moves in AF in # 304 to # 306. It is determined whether or not the number of pulses for detection of return matches the number of pulses for the motor 327.

If they match, the process proceeds to # 321. If not, # 319 is repeated again and the AF motor 327 is continuously driven until they match.

Here, the initial position of the film surface position is detected by replacing the rotation of the AF motor 327 with a pulse, but an initial position switch (not shown) interlocked with a movable member such as the drive lever 326 is provided. You may do it.

# 321: Same as # 306. # 322: A mechanical charge signal is transmitted from the camera microcomputer 341 to a mechanical charge circuit (not shown), and mechanical charging at the time of shutter operation is performed by a charging mechanism (not shown).

# 323: It is determined whether the photographing is continued after exposure or the power is turned off and the photographing is finished. If the power is not turned off and the shooting is continued, the process proceeds to # 302. When the power is turned off, the process proceeds to # 324.

# 324: (Photographing) operation ends.

It is a matter of course that the photographic optical block 2 of the present invention can be made compact by using a solid-state image pickup device such as a CCD, which is much smaller than the silver salt film, to form a camera. For example, the screen size in the silver salt film 35 format is 24 mm in height and 36 mm in width, while the screen size in 1/2 "CCD (total pixel 410,000 pixels) is 7 mm in length and 10.6 mm in width, which is an optical path. The magnetic sheet such as a floppy disk is extremely thin compared to the film cartridge, and the size of the above-mentioned photographing optical block 2 can be made smaller (thinner).
Together with this, it can be a camera with a thin design that is more portable.

Further, the concave mirror 3 is used as in the second embodiment.
A curved LCD closely attached to the back of the 03d (half mirror) may be provided, or an AF lens driving mechanism may be provided instead of the image pickup device position changing mechanism. Focusing may be performed by moving in the vertical optical axis direction.

[0106]

As described above, according to the invention of the present application, the semi-transmissive concave mirror is arranged so as to face the subject, and the light flux reflected by the concave mirror out of the light flux of the subject is formed on the photosensitive surface. Since it has a finder system for observing a subject image with a light beam that has passed through the concave mirror, the finder parallax is eliminated,
The angle of view of the photographing optical system and the viewfinder optical system can be made the same, and the effect that the subject image viewed by the eye can be photographed as it is. Also, since the photographic optical system and the viewfinder optical system are configured with one optical block, it has a very simple and simple shape similar to a rectangular parallelepiped, has high strength, is low in cost, and has a high-magnification viewfinder and a thin optical system. The effect that it can be compactly obtained is obtained.

[Brief description of drawings]

FIG. 1 is a perspective view showing a photographing enabled state of a photographing apparatus according to a first embodiment of the present invention.

FIG. 2 is a central longitudinal sectional view showing a finder observation state of the image pickup apparatus according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a finder screen of the image capturing apparatus according to the first embodiment of the present invention.

FIG. 4 is a central vertical cross-sectional view showing a photographing exposure state of the photographing apparatus according to the first embodiment of the present invention.

FIG. 5 is a perspective view of a film surface position varying mechanism in the image capturing apparatus according to the first embodiment of the present invention.

6 is a sectional view taken along the line AA in FIG.

FIG. 7 is a configuration diagram of a finder optical system of the image capturing apparatus according to the first embodiment of the present invention.

FIG. 8 is a block diagram showing an electric circuit of the image capturing apparatus according to the first embodiment of the present invention.

FIG. 9 is a perspective view showing a portable state in which the optical system of the image capturing apparatus according to the first embodiment of the present invention is housed.

FIG. 10 is a central longitudinal sectional view of the camera in the state of FIG.

FIG. 11 is a program flowchart showing the operation of the image capturing apparatus according to the first embodiment of the present invention.

FIG. 12 is a central longitudinal sectional view showing a finder observation state of an image pickup apparatus according to a second embodiment of the present invention.

FIG. 13 is a central longitudinal sectional view showing a photographing exposure state of a photographing device according to a second embodiment of the present invention.

FIG. 14 is a central longitudinal sectional view showing a finder observation state of an image pickup apparatus according to a third embodiment of the present invention.

FIG. 15 is a sectional view of an image pickup element position changing mechanism of an image pickup apparatus according to a third embodiment of the present invention.

FIG. 16 is a block diagram showing an electric circuit of a photographing apparatus according to a third embodiment of the present invention.

FIG. 17 is a program flowchart showing the operation of the image capturing apparatus according to the third embodiment of the present invention.

[Explanation of symbols]

1, 201, 301 Camera body 2, 202, 302 Photographing optical block 3 Photographing gloss member (photographing optical system, finder optical system) 3a, 3b, 203a, 203b, 303a, 303b
Prism block 3d, 203d, 303d Concave mirror 3e, 203e, 303e Incident surface 3c, 203c, 303c Reflector 3f, 203f, 303f Emission surface (second emission surface) 3h, 203h, 303h Emission surface (first emission surface) ) 10,210 Film (photosensitive surface) 363 Solid-state imaging device (photosensitive surface)

Claims (5)

[Claims] 1. An imaging system in which a semi-transmissive concave mirror is arranged so that the concave surface faces a subject, and a light flux reflected by the concave mirror among the light flux of the subject is guided to a photosensitive surface, and the concave mirror. An image pickup apparatus having a finder system for observing a subject image with a light beam that has passed through. 2. A light flux from a subject is incident from an incident surface, a semi-transmissive concave surface of the light flux from the incident surface is decentered toward the subject side, reflected by a concave mirror, and reflected by the concave mirror. 1. An imaging system that directs the light flux from the first exit surface to guide the light flux from the exit surface onto the photosensitive surface, and a light flux that has passed through the entrance surface and the concave mirror from the second exit surface and guides it to the photographer. An imaging device having a finder system that emits light. 3. The finder system has a finder field frame adapted to irradiate with illuminating light, and a light flux from the finder field frame is reflected by a reflecting portion provided in a region corresponding to a peripheral portion of the concave mirror. 3. The photographing apparatus according to claim 2, wherein the photographing light is emitted from the second emission surface and guided to a photographer. 4. The light flux from a part of the finder system is totally reflected by the second exit surface, and then is reflected by the reflection portion to be exited from the exit surface.
The imaging device described. 5. The photographing apparatus according to claim 2, wherein the light flux reflected by the concave mirror is reflected by the incident surface and then emitted from the first exit surface.