JPS5929844B2 - Automatic exposure control camera for motor drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention generates a signal (hereinafter referred to as an end signal) indicating that one cycle of shutter operation has ended in a camera, and transmits this signal to a motor drive mechanism to enable continuous shooting using the motor drive. This invention relates to an automatic exposure control camera.

The film is automatically advanced by the motor drive (including shutter charge).

), and in order to enable the photographer to take continuous shots by continuously pressing or holding down the shutter button, it is necessary to confirm that the series of shutter operations has finished, that is, that the reflecting mirror has returned to its original position. It is necessary to detect that the trailing curtain has finished traveling. In most conventional cameras, such detection of the end of the shutter operation was performed by mechanical means.

However, if mechanical means are used, the structure inside the camera becomes complicated, which not only increases the size of the camera but also causes an increase in cost. Some conventional cameras used electrical signals to detect the end of the shutter operation, but in conventional cameras, this electrical signal was generated in conjunction with the pressing of the shutter button, and After a period of time allowing for the shutter speed, an end signal is generated and the next film advance is started.

Therefore, even with the shortest shutter speed, the same amount of time is required before the next shot can be taken as with the longest shutter speed, making it unsuitable for high-speed continuous shooting. Ta. Furthermore, in the case of subjects that require the shutter to be released at the shortest shutter speed, it is necessary to shoot continuously at a higher speed, so a camera that can shoot continuously at higher speeds without such delay is desired. There is. In view of these circumstances, it is an object of the present invention to provide an automatic exposure control camera that has a simple structure and generates an end signal with extremely little time delay. The automatic exposure control camera of the present invention extracts the trailing curtain travel start signal as an electrical signal, and delays that signal by the time required for the remaining shutter operations (travel completion of trailing curtain, mirror return, etc.) through a delay circuit. This is characterized in that it is generated as an end signal.

Since the automatic exposure control camera of the present invention electrically transmits the end signal indicating that it is OK to proceed to the next photographing cycle, the structure is extremely simple compared to mechanical methods.

Furthermore, in the case of a focal plane shutter, even if the shutter speed varies, the time required for the remaining shutter operation is the same, so the camera of the present invention does not waste any time at all, and the following You can move on to shooting.

Therefore, if the camera of the present invention is motor-driven, it is particularly suitable for high-speed continuous photography of a subject moving at high speed, which requires a high-speed shutter. Further, the camera of the present invention may have a built-in motor drive mechanism, or may be motor driven by attaching a motor drive attachment.

Embodiments of the present invention will be described in detail below with reference to the drawings.

The drawing is a block diagram showing an example of an end signal generation circuit used in a camera according to an embodiment of the present invention.

In the drawing, reference numeral 1 denotes an automatic exposure control circuit, which generates a signal to run a front curtain (not shown) according to exposure conditions, and then generates a rear curtain start signal 1a after a certain period of time corresponding to a desired shutter speed has elapsed. However, for example, the trailing curtain locking magnet 3 is driven to cause the trailing curtain to travel.

Reference numeral 2 denotes a delay circuit, which branches and extracts the trailing curtain start signal, and outputs the trailing curtain start signal as an end signal 2a after a certain period of time required for the remaining shutter operation after the trailing curtain starts running. ing.

In this embodiment, the trailing curtain start signal 1a generated from the automatic exposure control circuit 1 is branched and taken out, and the operation of the trailing curtain locking magnet 3, which is driven by the signal, is taken out as an electrical signal. , this may be output as an end signal via the delay circuit 2, and in this specification, including such a case, it will be referred to as a trailing curtain start signal.

Furthermore, the camera of the present invention can be applied to any type of automatic exposure control camera, such as an aperture priority type, a shutter speed priority type, or a programming type.

As explained in detail above, since the end signal generated by the camera of the present invention is generated by extracting the trailing curtain start signal, there is no wastage of time at all. Moreover, since the signal is transmitted electrically, the structure is simple.

[Brief explanation of the drawing]

The drawing is a block diagram showing an example of an end signal generating circuit used in the camera of the present invention. 1...Slide exposure control circuit, 1a...2nd curtain start signal, 2...Delay circuit, 2a...
... End signal, 3... Rear curtain locking magnet.

Claims (1)

[Claims] 1. In a camera in which a trailing curtain locking magnet is driven by a trailing curtain start signal from an automatic exposure control circuit, and the trailing curtain travel is completed after a certain period of time and the shutter operation is terminated, the trailing curtain start signal is driven by the trailing curtain start signal for the specified period of time. An automatic exposure control camera for a motor drive equipped with a delay circuit configured to output an end signal after the elapsed time and transmit this end signal to a motor drive mechanism.