JPS5822172Y2 - Ichigan reflex camera Niokeru - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a memory fixing switch of a photometry circuit in an open photometry type eye reflex camera, which stores the photometry value immediately before the aperture is stopped.

Open metering system that measures the brightness of the subject using the light rays passing through the photographic lens - In an eye reflex camera, the metering circuit is designed to show accurate measured values when the lens is open, and for observing the depth of focus, When the lens is narrowed down by preview operation, mechanical EE, electronic EE
It is a well-known fact that erroneous light measurement occurs in either case.

Conventionally, in order to prevent such inconveniences, it is necessary to adjust the operating method so that the release operation is not performed while in preview mode, or to switch the metering circuit from open metering to closed-down metering in conjunction with the preview operation, or Methods have been taken, such as providing a release blocking member that is linked to the operation and making the release operation impossible during preview, but the first method often has the risk of causing an unintentional erroneous operation. The second method, regardless of whether the structure is mechanical or electrical, is extremely complex and may often cause failures, and it is difficult to match the characteristics of both.

The third method has the disadvantage of poor operability since it is necessary to cancel the preview every time a photograph is taken.

Therefore, in the present invention, the memory fixing switch of the photometry circuit is made detachable from the aperture interlocking lever that operates both during preview operation and release operation, and the memory fixing switch is also switched during aperture operation. By doing this, the photometric value immediately before the aperture is memorized, thereby solving the drawbacks of the conventional method.

Hereinafter, the present invention will be explained with reference to the embodiments shown in the accompanying drawings.

Referring to FIG. 1, reference numeral 1 denotes an aperture interlocking lever that is rotatably mounted on a shaft 2 of a fixing part of the camera body, and a bending part 1a at one end engages with a lens-side aperture lever 3, and in the state shown, the spring 4, the lever 3 is moved to the right and held in the open state.

5 is pivotally supported on the same shaft 2 as the aperture interlocking lever 1;
A spring 6 is fixed between the pin 7 and the pin 7, which is implanted at one end, engages the aperture interlocking lever 1, and 8 is a common shaft 2.
A diaphragm spring 9 is connected between the diaphragm drive lever 1 and a diaphragm release spring 10 is engaged between the diaphragm drive lever 1, and a pin 11 that can be engaged with the diaphragm drive lever 5 is implanted. A charge lever 12 stores the aperture spring 9 and the aperture opening spring 10 in conjunction with the operation, and a first locking lever 13 locks the aperture drive lever 5 and releases the lock in conjunction with the release operation. 14 is a second locking lever that locks the charge lever 8 in the charged state and releases the lock in conjunction with the completion of shutter operation; 14 is a second locking lever that can be freely connected to and detached from the aperture interlocking lever 1; The memory fixed switch 14 is turned off by turning the aperture interlocking lever 1 to the right.
is attached to the storage circuit described later.

Figure 2 shows a block diagram of the electric circuit when the present invention is applied to a set of electronic shutters - an eye reflex camera.
5 is a photoelectric element such as CDS, 16 is an analog calculation circuit for introducing the aperture value and film sensitivity, 17 is a memory circuit having the memory fixing switch 14, 18 is a voltage-to-hour conversion circuit, and 19 is connected to the circuit 18. a magnet that drives the second shutter curtain or shutter blade return locking member;
20 is a shutter speed display circuit provided branching off from the analog calculation circuit 16.

The present invention has the above-mentioned configuration, and the aperture interlocking lever 1 is operated from the outside from the state shown in FIG.
When the memory fixing switch 14 is turned to the right against
moves to the right following the aperture interlocking lever 1 by the spring 4, the aperture is narrowed down and enters the preview state, and when the operation of the aperture interlocking member 1 is stopped, the aperture interlocking lever 1 is moved by the spring 6.
The aperture lever 3 returns against the spring 4 and the aperture is opened again.

Also, during normal shooting, the first locking lever 5 releases the aperture drive lever 5 due to the release operation, so the lever 5 is moved to the right by the aperture spring 9 until its pin 7 comes into contact with the pin 11 together with the aperture interlocking lever 1. Rotating and aperture lever 3
follows this, the aperture is narrowed down, and when the shutter operation is completed, the pin 11 of the second locking lever 13 is rotated to the left by the aperture opening spring 10 together with the aperture drive lever 5, and the aperture is opened.

In the above embodiment, the memory fixing switch 14 is turned from on to off at the start of narrowing down, but it may be changed from off to on by changing the memory circuit 17.

As described above, according to the present invention, even when the aperture is narrowed down by the preview operation, the metering value is memorized and fixed before the lens is stopped down, just as in normal shooting, so the optimal exposure can be achieved by releasing the shutter release even during the preview operation. , the operability is extremely good, there is no risk of erroneous operation in any case, the structure is simple, and the operation is reliable.

[Brief explanation of drawings]

FIG. 1 is a front view of main parts showing the configuration of the present invention, and FIG. 2 is a block diagram of an electric circuit diagram. 1... Aperture interlocking lever, 3... Aperture lever 5... Aperture drive lever, 8...
・Charge lever 9... Squeezing spring, 10.
...Aperture opening spring, 14...Memory fixing switch, 17...Memory circuit.

Claims (1)

[Scope of utility model registration request] An aperture-linked lever that is displaced by an operation from outside the camera body to narrow down the lens during a preview operation, and an aperture drive that moves the aperture-linked lever in the aperture direction in conjunction with the release operation of the camera body, regardless of the external operation. an open metering type comprising a lever and a charge lever that stores energy in the aperture drive lever in the aperture direction in conjunction with the winding operation and returns with the aperture drive lever in conjunction with the completion of shutter operation; In a reflex camera,
A memory fixing switch of a photometry circuit, which is connected to and disengaged from the aperture interlocking lever, is always kept in an on or off state, and is switched to off or on before aperture is stopped by displacement of the aperture interlocking lever during a preview operation.