JP2667989B2 - Camera system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a camera system provided with a lens shutter and a focal plane shutter.

(Prior art and its problems) Cameras equipped with a lens shutter (hereinafter referred to as LS) (hereinafter referred to as LS camera) and cameras equipped with a focal plane shutter (hereinafter referred to as FPS) (hereinafter referred to as FPS)
Cameras) are all well known.

The LS camera is effective for flash photography due to the feature of the shutter opening form, while the FPS camera is capable of exchanging the lens from the light shielding form and controlling the time at a high speed from the operation form.

In order to make use of the features of the above two types of cameras, there has been proposed an interchangeable lens of a type having an LS that operates independently in an interchangeable lens of an FPS camera.

However, since it is a shutter that operates independently as an interchangeable lens, and the control part is individually provided in the FPS and the LS, there are many useless parts.

By the way, the limit that can be controlled by LS is that the subject brightness is LV17.
It is about. That is, it is difficult for the LS to operate at a high speed, and the reduction of the aperture diameter also causes the diffraction phenomenon of the lens, and the above limit is set.

Particularly in the LS, the limit value is set so as not to perform an exposure operation of a pinhole or the like due to a manufacturing error. Therefore, an appropriate exposure value cannot be given to an object exceeding the above limit.

If you are using an LS and want to continue shooting at a brightness that exceeds the limit that can be controlled by the LS, re-install the interchangeable lens that has only the built-in aperture, and operate with high-speed FPS operation. Since the images are taken in combination, the operation is complicated.

(Object of the Invention) The present invention has been made in view of the above problems,
An object of the present invention is to provide a camera that includes an FPS and that automatically selects the FPS mode for an object that exceeds the operation limit in the LS mode and expands the shooting range.

(Means for Achieving Object) According to the present invention, in a camera including a lens shutter for performing a program exposure operation and an aperture adjustment operation, and a focal plane shutter, a lens shutter mode in which the lens shutter operates as a program shutter, Switching means for controlling a shutter speed by a focal plane shutter and setting a focal plane shutter mode for controlling an aperture by the lens shutter; first driving means for controlling a program exposure value and / or an aperture value of the lens shutter; When the exposure value to be controlled exceeds the program exposure value of the lens shutter, the second drive unit that controls the operation time of the focal plane shutter, the sequence control unit that controls the operation timing of the two drive units, and The above object is achieved by a camera system including a forced switching means for setting a focal plane shutter mode regardless of the setting of the switching means.

(Structure) Explaining in detail with reference to the drawings showing an embodiment of the present invention, in FIG. 1, a photographing lens 2 is attached to a camera body 1 while being supported by a mirror copper 3. The subject image passing through the lens 2 forms an image on a photosensitive material F (hereinafter, referred to as a film) stored behind a range limited by the photographing screen 4.

A finder 5 having a field frame at the top of the camera body;
There is provided a light-shielding tube 6 for blocking harmful light from a portion other than the taking lens to the film, and a release button 7 for operating the camera is provided on the upper surface of the camera.

A lens shutter (LS) 8 for opening and closing the lens opening is provided behind the taking lens 2, and the lens opening is normally opened and closed by shutter blades 8a.

The stepping motor 9 is a shutter blade that is disposed in the lens barrel 3 and also serves as an aperture according to an output signal of the first driving unit D1.
8a opens and closes.

An electronic circuit 10 for controlling the step motor 9 includes a first drive unit D1, a sequence control unit SC for controlling the differential timing of shutters, a photometric circuit including a light receiving element for photometrically measuring the subject brightness, and a second control unit described later. And the like.

The focal plane shutter (FPS) 11 has a structure in which a front curtain 13 and a rear curtain 14 are supported on a substrate 12 attached to the camera body 1, and two electromagnets (not shown) are driven by a second driving unit D2 of the electronic circuit 10. When is sequentially operated, the exposure time is controlled by operating at a desired time interval.

The FPS 11 is charged by a known method at the time of film feeding, and when performing a multiple exposure operation, the FPS 11 is separated from the film feeding and charged alone.

Switching means 15 is provided at the top of the camera to select whether to perform photographing using FPS11 or LS8.

FIG. 2 is a block diagram showing an operation system having the above configuration.

The calculating means 105 includes a photometric circuit 101 including a light receiving element for measuring the brightness of the subject, a distance measuring circuit 102 for measuring a distance to the subject, a means 20 for setting a focal length f of the photographing lens 2, and a film sensitivity setting. The signal is output to the switching means 15 and a sequence control means SC described later, using the signal of the means 104 for performing the input as an input.

The switching means 15 selects whether to perform the program exposure operation by the LS or the exposure time control by the FPS. In other words, once you press the part protruding above the camera, LS
Is set to the lens shutter mode in which is operated, and when pressed again, the focal plane shutter mode in which the FPS is operated is set, and when pressed again, the lens returns to the lens shutter mode.

When the lens shutter mode is set, the subject is extremely bright and the output Q1 of the arithmetic unit 105 exceeds a limit value (for example, LV17) that can be controlled by the LS program exposure operation (for example, LV17). Is set to

The output Q2 of the arithmetic means 105 outputs a signal corresponding to each mode to the sequence control means KC in order to set an exposure level according to the brightness of the subject.

The mode display unit 106 displays which of the setting modes is set, and when the focal plane shutter mode is forcibly set, blinks repeatedly.

Based on the signal of the switching means 15, the sequence control circuit SC,
The FPS11 and the LS8 are operated at a preset timing of the operation order of the first driving means D1 and the second driving means D2.

Next, the operating method will be described with reference to FIGS. 3 and 4. In the figure, the horizontal axis indicates the elapsed time, and the vertical axis indicates the exposure amount or the screen position on the photographing screen 4.

FIG. 3 is an operation diagram when the switching means 15 is set to a lens shutter mode in which an exposure operation is performed by the LS8. When the release button 7 in FIG. 1 is pressed during photographing, the sequence control means SC first specifies the second driving means D2 to output a signal, and the front curtain 13 of the FPS 11 is moved to one end P of the screen.
The photographing screen 4 is opened by operating from 1 to the other end P2.

Next, the sequence control means SC designates the first drive means D1 to output a signal to open / close the LS8 to expose the film F with the light quantity corresponding to the area Q1. At this time, the LS 8 performs a program exposure operation combining the aperture and time depending on the brightness of the subject.

Then, the sequence control means SC designates the second drive means D2 to output a signal, operate the rear curtain 14 of the FPS 11 from one end P1 to the other end P2, and close the photographing screen 4.

When the operation of FPS11 ends, the sequence control means SC
A signal for winding the film F up to the new frame number is output, and a motor (not shown) is operated to charge the FPS 11.

With the above operation, the photographing in the lens shutter mode is completed.

FIG. 4 is an operation diagram when the switching means 15 is set to a focal plane shutter mode in which the FPS 11 performs an exposure operation.

When the release button 7 in FIG. 1 is pressed during photographing, the sequence control means SC first specifies the first driving means D1 to output a signal, and opens the LS8 to a predetermined aperture value d1, Open the lens opening.

Next, the sequence control means SC designates the second driving means D2 to output a signal, and sequentially operates the front curtain 13 and the rear curtain 14 of the FPS 11 to expose the film F. At this time, the front curtain 13 and the rear curtain 14 have an aperture value d of LS8 depending on the brightness of the subject.
It operates at a time interval t that gives an appropriate exposure amount in combination with 1.

Subsequently, the sequence control means SC designates the first drive means D1 to output a signal, and closes LS8.

When the operation of the LS8 is completed, the sequence control means SC outputs a signal for winding the film F to a new number of frames, and operates a motor (not shown) to charge the FPS11.

With the above operation, the photographing in the focal plane shutter mode is completed.

FIG. 5 shows that in the above embodiment, the program exposure operation is performed by the LS8, and when the operation limit value is exceeded, the FPS1
FIG. 3 is a program diagram showing a process of performing an exposure operation according to 1.

That is, the portion shown by the thick solid line is the operation of the LS8, and the portion shown by the thick broken line is the operation of the FPS11.

Also, a single-lens reflex camera can be configured based on the concept of the present invention.

(Effects) As is clear from the above description, whether one of the LS or FPS is operated by one switching means
Automatically even for bright subjects that exceed the operating limit of
By setting FPS, the sequence control circuit SC
By operating the LS and FPS at appropriate timing, the features of the two shutters can be used effectively according to the purpose of photographing.

[Brief description of the drawings]

1 shows an embodiment of the present invention. FIG. 1 is a sectional view of a camera, FIG. 2 is a block diagram showing an operation system of the camera, and FIG.
4 and 5 show an operation diagram, and FIG. 5 shows an operation program diagram. 1 camera body 2 photographic lens 5 viewfinder 7 release button 8 lens shutter 11 focal plane shutter 15 switching means 107 forced switching means SC sequence control means D1 First drive means D2 Second drive means

 ───────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Atsushi Takami 934-13 Shiwato, Yokkaido, Chiba Prefecture Inside Seikosha Chiba Office (72) Inventor Yoichi Nakano 934-13, Shikato, Yotsukaido City, Chiba Japan Seikosha Inside Chiba Works (72) Inventor Isamu Ishii 934-13 Kadawato, Yokkaido, Chiba Prefecture Inside Seikosha Chiba Works (72) Inventor Yoshiyuki Iwamatsu 934-13, Kadawato, Yotsukaido City, Chiba Inside Seikosha Chiba Works ( 56) References JP-A-47-37930 (JP, A) JP-A-55-40464 (JP, A) JP-A-52-98520 (JP, A) JP-A-52-148118 (JP, A) 1955-164622 (JP, U)

Claims (1)

(57) [Claims] 1. A camera provided with a lens shutter for performing a program exposure operation and an aperture adjustment operation and a focal plane shutter, wherein a lens shutter mode in which the lens shutter operates as a program shutter, and a shutter speed is controlled by the focal plane shutter. Switching means for setting a focal plane shutter mode for controlling an aperture by the lens shutter; first driving means for controlling a program exposure value and / or an aperture value of the lens shutter; and controlling an operation time of the focal plane shutter. A second drive unit for controlling the operation timing of the two drive units, and a control unit for controlling the switching timing when the exposure value to be controlled exceeds the program exposure value of the lens shutter. Camera system comprising a forced switching means, a to set regardless focal plane shutter mode.