JP2000321659A - Single lens reflex camera and single lens reflex monitoring camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain appropriate exposure with simple constitution by directly detecting the rotating speed of a normally/reversely rotating motor constituting a reciprocating sliding mechanism for reciprocating a mirror slit body and controlling the rotating speed in accordance with the luminance of a subject. SOLUTION: The moving speed of a mirror unit body 30 at the time of photographing is detected by a rotary slit disk gear 46 and a photocoupler 47. Namely, when the normally/reversely rotating motor 45 is driven, the gear 46 meshed with a pinion 45a is also driven to be rotated simultaneously, and the passage of a slit 46a is detected as a pulse by the photocoupler 47. A photographing control circuit 50 detects the speed of the motor 45, that is, the moving speed of the mirror unit body 30 according to the number of pulses per unit time, and feeds back obtained information to the circuit 50. The circuit 50 moves the motor 45 through a motor driving circuit 51 at speed that the appropriate exposure is obtained in accordance with the luminance of the subject and the F value information of a photographing lens.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a single-lens reflex camera and a single-lens reflex type surveillance camera.

[0002]

2. Description of the Related Art The present applicant has disclosed a single-lens reflex camera which does not require a focal plane shutter, and a single-lens reflex camera which not only does not require a focal plane shutter but also completely eliminates a viewfinder image even during photographing. (Japanese Unexamined Patent Publication No. 8-62720). This camera is provided with a mirror slit body having a pair of mirrors and a slit located between the pair of mirrors, and at the time of shooting, the mirror slit body is moved to cross the shooting screen by the slit, while the slit is used for shooting. Before and after traversing the screen, the pair of mirrors gives the subject light flux to the finder system, and the mirror slit body provides the functions of a mirror and a shutter.

In this camera, since the slit width is basically fixed and the moving speed of the mirror slit body is constant, the only way to obtain proper exposure is to change the aperture of the taking lens in accordance with the luminance of the subject. . The moving speed of the mirror slit body may be changed, but no specific mechanism has been proposed.

[0004]

SUMMARY OF THE INVENTION Accordingly, the present invention is directed to Japanese Patent Application Laid-Open No. 8-62720.
SUMMARY OF THE INVENTION It is an object of the present invention to provide a single-lens reflex camera or a single-lens reflex monitoring camera which does not require a focal plane shutter proposed by the present applicant in Japanese Patent Application Laid-Open Publication No. H10-209,041 and which can obtain proper exposure with a simple configuration.

[0005]

SUMMARY OF THE INVENTION According to the present invention, if the rotation speed of a forward / reverse rotation motor constituting a reciprocating slide mechanism for reciprocatingly driving a mirror slit body is directly detected and the rotation speed is controlled in accordance with the luminance of the subject, exposure can be easily performed. The focus is on the fact that control can be performed.

According to a first aspect of the present invention, there is provided a single-lens reflex camera according to a first aspect, wherein a mirror slit provided between a photographic lens and a photographic recording medium; and light of the photographic lens provided in the mirror slit is provided. A pair of mirrors located on the same plane, and a slit located between the pair of mirrors, for providing a finder system with a light beam transmitted through the photographing lens, which is alternatively positioned on the axis; A reciprocating slide mechanism for reciprocally moving the slit in a plane direction of the pair of mirrors and in which the slit crosses the photographing screen of the photographing recording medium; and for observation, an optical axis of the photographing lens by selecting a pair of mirrors of the mirror slit body. A photographing control mechanism for controlling a reciprocating slide mechanism of a mirror slit body so as to be positioned at an upper position and to provide a subject light to a photographing recording medium across a photographing screen when photographing; In a single-lens reflex camera having the same, a forward / reverse rotation motor constituting a reciprocating slide mechanism; a speed detector for detecting a rotation speed of the forward / reverse rotation motor; and a speed detector according to a subject luminance detected by a light receiving element. A photographing control circuit for controlling the rotation speed of the forward / reverse rotation motor.

According to another expression, the single-lens reflex camera of the present invention is a single-lens reflex camera in which subject light transmitted through a photographing lens is guided to a finder system via a mirror, and a photographing recording medium is arranged behind the mirror. A mirror slit body provided with a pair of mirrors on the same plane and provided with a slit between the pair of mirrors; and a mirror slit body arranged in a plane direction of the mirror and in a direction in which the slit crosses a photographing screen of a photographing recording medium. A reciprocating slide mechanism for reciprocating; a pair of mirrors of a mirror slit body is selected and positioned on the optical axis of the photographing lens during observation, and the slit crosses the photographing screen during photographing, and the subject light is transferred to the photographing recording medium. To give,
A photographing control mechanism for controlling a reciprocating slide mechanism of the mirror slit body; a forward / reverse rotation motor constituting the reciprocal slide mechanism; a speed detector for detecting a rotation speed of the forward / reverse rotation motor; Depending on the brightness,
A photographing control circuit for controlling the rotation speed of the forward / reverse rotation motor via a speed detector.

According to the present invention, in an aspect of a single-lens reflex monitoring camera, a mirror slit member disposed between a photographing lens and a film; and a mirror slit member provided on the mirror slit member, which is selected on an optical axis of the photographing lens. A pair of mirrors located on the same plane, and a slit located between the pair of mirrors, and a solid-state imaging device that captures an image of the finder system. A camera used; a reciprocating slide mechanism for reciprocating the mirror slit body in a plane direction of the pair of mirrors and a direction in which the slit crosses the photographing screen of the film; and selecting a pair of mirrors of the mirror slit body for observation. At the same time, it is positioned on the optical axis of the photographic lens. A single-lens reflex camera having a photographing control mechanism for controlling a ride mechanism; a forward / reverse rotation motor constituting a reciprocating slide mechanism; a speed detector for detecting a rotation speed of the forward / reverse rotation motor; An imaging control circuit for controlling the rotation speed of the forward / reverse rotation motor via a speed detector in accordance with the subject brightness to be performed;
It is characterized by having provided.

The speed detector has a simple structure, for example, when it is composed of a slit disk that rotates in conjunction with the rotation of the forward / reverse rotation motor and a photocoupler that forms a pair with the slit of the slit disk. If the photographing lens does not have a fixed F-number, a means for providing F-number information to the photographing control circuit is provided.

[0010]

1 to 4 show an embodiment in which the present invention is applied to a single-lens reflex type surveillance camera. The camera body 20 has a photographic lens 1 before and after it.
1 and a photographing opening 22 located on the optical axis O of the photographing lens 11. This shooting aperture 2
2 defines the size of the shooting screen. A pair of upper and lower inner rails 23 and outer rails 2 which are well-known
4, a back cover 25 abuts against the outer rail 24, and a film tunnel 26 is formed between the inner rail 23 and the back cover 25. In a normal single-lens reflex camera, a focal plane shutter is provided in front of the film tunnel 26. However, the single-lens reflex monitoring camera of the present invention does not include the focal plane shutter.

A detachable mount 21 is attached to the camera body 20.
A mirror slit body (frame body) 30 is provided between the mirror slit body 30 and the photographing opening 22. The mirror slit body 30 has a single angle of approximately 45 ° with respect to the optical axis O of the photographing lens 11. Mirror member 32 is supported. The single mirror member 32 is made of a transparent plane-parallel plate,
On this single mirror member 32, a pair of mirrors 32L, 3L
2R, and a slit 33 located between the pair of mirrors 32L, 32R are formed.

FIG. 2 shows an example in which the mirrors 32L and 32R and the slit 33 are formed on the single mirror member 32. FIG. 2A shows a case where a slit region 33A is set at the center of the rear surface of a single horizontally long mirror member 32, and the slit region 3A is formed.
This is an example in which a reflective film 34 is formed except for 3A. The slit region 33 </ b> A is a portion where the reflection film is not formed, and forms the slit 33. (B) is an example in which a semi-transmissive (half mirror) film 34X is formed in the central slit region 33A of the single horizontally long single mirror member 32. In this example, the translucent film 34X forms the slit 33. FIG. 2C shows an example in which a through hole 33B is formed in the center of a horizontally long single mirror member 32, and a reflection film 34 is formed on the entire surface of the single mirror member 32. In this example, the through hole 33B is
Is configured.

The single mirror member 32 described above is supported by the mirror slit body 30 so that the back surface except the peripheral edge is open. According to the single mirror member 32, the pair of mirrors 32L and 32R can always be formed on the same plane. When the mirror slit body 30 moves, one of the mirror slit bodies 30 is selectively located on the optical axis O of the photographing lens 11. And, in the state located on the optical axis O,
Each of the mirrors 32L and 32R is approximately 4 with respect to the optical axis O.
Make 5 °. When the mirror slit body 30 moves, the slit 33 functions as a shutter that traverses the photographing screen 27I of the film 27 located in the film tunnel 26 and gives the subject light transmitted through the photographing lens 11 to the photographing screen 27I. In this embodiment, the shooting screen 27I is 3
It is a half size of 5 mm size, and the slit 33 is
The shooting screen 27I faces in a direction parallel to the long side.
As the film 27, a long film is used.

A detachable mount 21 is attached to the camera body 20.
A light-shielding tube 28 is provided to make the space between the camera and the photographing opening 22 light-shielded, and the mirror slit body 30 is provided through light-shielding moving holes 29 formed in the left and right light-shielding tubes 28, respectively.
It is movably guided in a light-shielded state. As is clear from FIG. 4, the mirrors 32L, 3
When one of the 2Rs is located inside the light-shielding tube 28, the other is located outside the light-shielding tube 28, and the slit 33 is also located outside the light-shielding tube 28.

A mirror 32L or 32R is positioned on the camera body 20 above the optical axis O of the taking lens 11.
A fixed mirror 35 and a relay lens 36, which make a pair with the lens, are supported. The fixed mirror 35 and the relay lens 36
An image on a focus glass 37 provided at a position optically equivalent to the film 27 is formed on a CCD camera 38.

An endless belt 41 is connected to the upper and lower sides of the mirror slit body 30, and the endless belt 41 is wound around a pair of pulley bodies 42. A gear 43 is provided coaxially and integral with one pulley body 42, and this gear 43 meshes with a small gear 44 a of a relay gear 44. The relay gear 44 has a large gear 44b coaxially and integrally, and this large gear 44b meshes with a pinion 45a of the forward / reverse rotation motor 45. The pinion 45a is meshed with the rotary slit disk gear 46 at the same time, and a photo coupler 47 is combined with the rotary slit disk gear 46. On the rotating slit disk gear 46, slits 46a are formed at a fine pitch in the circumferential direction,
The photocoupler 47 generates a pulse when detecting the passage of the slit 46a. This pulse is applied to the imaging control circuit 50.
The imaging control circuit 50 detects the rotation speed of the forward / reverse rotation motor 45 from the number of pulses per unit time, and controls the forward / reverse rotation motor 45 via the motor control circuit 51.

The photographing control circuit 50 receives a signal from a light receiving element 52 for detecting the luminance of the subject. Further, both ends of the mirror slit body 30 are detected by a pair of end detectors 53, and the detection signals are also input to the imaging control circuit 50.

When the photographing lens 11 has a fixed aperture, the F-number information is recorded in the photographing control circuit 50 in advance. On the other hand, when a variable aperture is provided,
1 itself has F value information 54, and this F value information 54
Is input to the photographing control circuit 50 via the information contact 55 between the photographing lens 11 and the camera body 20. The feed motor 56 of the take-up spool 27S for the film 27 is controlled by the photographing control circuit 50.

The single-lens reflex surveillance camera having the above configuration operates as follows. In a normal monitoring state, the photographing control circuit 5
0 is the mirror 32 of the mirror slit body 30 according to the mirror slit body detection signal from the end detector 53.
One of L and 32R (referred to as mirror 32R) is located on the optical axis O of the taking lens 11. Therefore, the subject light transmitted through the photographing lens 11 is reflected by the mirror 32R, and a subject image is formed on the focus glass 37.
This subject image is displayed on the fixed mirror 35 and the relay lens 3.
The image is picked up by the CCD camera 38 via 6. The image captured by the CCD camera 38 is observed on a monitor screen, and is further recorded by a VTR. At this time, the slit 33
Since it is located outside the photographing screen 27I, the film 27 is not exposed through the slit 33.

When an emergency occurs and the photographing switch 57 is turned on, the photographing control circuit 50 responds to the subject luminance information from the light receiving element 52 and the F value information of the photographing lens 11 from the F value information 54. The normal / reverse rotation motor 45 is driven via the motor control circuit 51. Then, the pulley body 42 rotates via the pinion 45a, the relay gear 44 and the gear 43, and the mirror slit body 30 moves via the endless belt 41. That is, the slit 33 crosses the photographing screen 27I and the subject light transmitted through the photographing lens 11 is
7, the still picture is taken. The operation itself in which the slit moves and the photographing is performed is the same as that of the focal plane shutter. When the slit 33 goes out of the photographing screen 27I, the mirror 32R is positioned on the optical axis O of the photographing lens 11 this time. , And returns to the monitoring state again. When the moving end of the mirror slit body 30 is detected by the end detector 53, the imaging control circuit 50 stops driving the forward / reverse rotation motor 45.

The moving speed of the mirror slit body 30 at the time of photographing is determined by the rotation slit disc gear 46 and the photo coupler 47.
Is detected by That is, when the forward / reverse rotation motor 45 is driven, the rotating slit disk gear 46 meshing with the pinion 45a is also driven to rotate at the same time, and the passage of the slit 46a is detected as a pulse by the photocoupler 47. The photographing control circuit 50 detects the speed of the forward / reverse rotation motor 45, that is, the moving speed of the mirror slit body 33, based on the number of pulses per unit time, and feeds back the information to the photographing control circuit 50. The photographing control circuit 50 uses the feedback loop to perform the forward / reverse rotation motor 45 (the mirror slit body 30) at a speed at which an appropriate exposure is obtained according to the subject luminance and the F-number information of the photographing lens 11 via the motor control circuit 51. Move).

In the case of continuous photographing, continuous photographing can be performed only by reciprocating the mirror slit body 30 in synchronization with the operation of the feed motor 56 for feeding the film 27. The feed amount of the film 27 is detected by the number of rotations (amount) of a known sprocket that rotates in conjunction with the film 27.

In the case where the slit 33 of the single mirror member 32 is formed in the non-formed portion of the reflection film or the through hole 33B (FIGS. 2A and 2C), the slit 33 is formed on the photographing screen 27I. When passing above, the subject light transmitted through the photographing lens 11 is not given to the fixed mirror 35, so that the image partially disappears (black stripes appear). However, if the slit 33 is formed by the semi-transmissive film 34X, If the image is partially darkened, it will not disappear.

In the above embodiment, the present invention is applied to a surveillance camera, but the present invention can also be applied to a more general single-lens reflex camera. FIG. 5 shows an embodiment of the present invention. On a focus glass 37, a finder optical system 62 including a normal pentaprism or pentamirror 60 and an eyepiece 61 is provided.

In the above embodiment, for convenience of explanation, the focusing glass 37 is disposed on a surface equivalent to the film surface of the finder system.
When imaging with, instead of the focus glass 37,
A condenser lens or a Fresnel lens can be provided.

[0026]

According to the present invention, there is no need for a focal plane shutter or a quick return mirror, and it is possible to switch between an observation state and a photographing state simply by reciprocating the mirror slit body. In a single-lens reflex monitoring camera, an appropriate exposure can be provided with a simple configuration.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a main part showing an embodiment of a single-lens reflex monitoring camera according to the present invention.

FIG. 2 is a longitudinal sectional view of the assembled state.

FIG. 3 is a vertical sectional view of the assembled state.

FIG. 4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a longitudinal sectional view showing an embodiment in which the present invention is applied to a more general single-lens reflex camera.

[Explanation of symbols]

 Reference Signs List 11 photographing lens 20 camera body 21 detachable mount 22 photographing aperture 26 film tunnel 27 film 27I photographing screen 29 light shielding moving hole 30 mirror slit body 32 single mirror member 32L 32R mirror 33 slit 33A slit area 33B through hole 34 reflective film 34X semi-transparent Film 35 Fixed mirror 36 Relay lens 37 Focus glass 38 CCD camera 41 Endless belt 42 Pulley body 45 Forward / reverse rotation motor 46 Rotating slit disc gear (speed detector) 46a Slit 47 Photocoupler (speed detector) 50 Photographing control circuit 51 Motor control circuit 52 Light receiving element

Claims (7)

[Claims] 1. A mirror slit member disposed between a photographing lens and a photographing recording medium; and a mirror slit member provided in the mirror slit member and selectively located on an optical axis of the photographing lens and transmitting through the photographing lens. A pair of mirrors located on the same plane, and a slit located between the pair of mirrors, for providing the illuminated light beam to the finder system; A reciprocating slide mechanism for reciprocating in a direction crossing a photographing screen of a medium; a pair of mirrors of the above-mentioned mirror slit body being selected and positioned on an optical axis of a photographing lens during observation; A photographing control mechanism for controlling a reciprocating slide mechanism of the mirror slit body so as to apply object light to the photographing recording medium across the camera. A forward and reverse rotation motor constituting the ride mechanism; a speed detector for detecting the rotational speed of the forward and reverse rotation motor;
A single-lens reflex camera, comprising: a photographing control circuit that controls a rotation speed of a forward / reverse rotation motor via the speed detector according to a subject luminance detected by a light receiving element. 2. A single-lens reflex camera in which object light transmitted through a photographing lens is guided to a finder system via a mirror, and a photographing recording medium is arranged behind the mirror. A mirror slit body provided with a slit between the mirrors; a reciprocating slide mechanism for reciprocating the mirror slit body in a plane direction of the mirror and in a direction in which the slit crosses the photographing screen of the photographing recording medium; Select a pair of mirrors of the mirror slit body and position them on the optical axis of the taking lens,
And a photographing control mechanism for controlling a reciprocating slide mechanism of the mirror slit body so that the slit gives a subject light to the photographing recording medium across the photographing screen at the time of photographing. A rotation motor; a speed detector for detecting a rotation speed of the forward / reverse rotation motor;
A single-lens reflex camera, comprising: a photographing control circuit that controls a rotation speed of a forward / reverse rotation motor via the speed detector according to a subject luminance detected by a light receiving element. 3. The single-lens reflex camera according to claim 1, wherein the speed detector includes a slit disk rotating in conjunction with rotation of the forward / reverse rotation motor, and a photo paired with the slit of the slit disk. A single-lens reflex camera consisting of a coupler. 4. A single-lens reflex camera according to claim 1, further comprising means for providing F-number information of the photographic lens to a photographic control circuit. 5. A mirror slit member disposed between a photographing lens and a film; and a light beam provided on the mirror slit member and selectively located on an optical axis of the photographing lens and transmitted through the photographing lens. To a finder system, a pair of mirrors located on the same plane, and a slit located between the pair of mirrors; a camera using a solid-state imaging device for capturing an image of the finder system; A reciprocating slide mechanism for reciprocating the slit in a plane direction of the pair of mirrors and in a direction in which the slit traverses the filming screen of the film; A shooting control mechanism for controlling the reciprocating slide mechanism of the mirror slit body so that the slit gives the subject light to the film across the shooting screen during shooting. A single-lens reflex monitoring camera comprising: a forward / reverse rotation motor constituting the reciprocating slide mechanism; a speed detector for detecting a rotation speed of the forward / reverse rotation motor;
A single-lens reflex surveillance camera, comprising: a photographing control circuit for controlling a rotation speed of a forward / reverse rotation motor via the speed detector according to a subject luminance detected by a light receiving element. 6. A single-lens reflex camera according to claim 5, wherein the speed detector comprises a slit disk rotating in conjunction with rotation of the forward / reverse rotation motor, and a photocoupler paired with the slit of the slit disk. A single-lens reflex surveillance camera consisting of 7. The single-lens reflex surveillance camera according to claim 5, further comprising means for providing F-number information of the photographing lens to a photographing control circuit.