JPH1115052A - Flash synchronization timing detection system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the reliability of a flash synchronization signal, to reduce the number of parts and man-hour for generating the synchronization signal and to reduce cost by providing a shutter blade traveling detection means detecting the traveling state of a shutter front blade and a control means calculating timing to emit flash light from the time when the traveling of the shutter front blade is detected. SOLUTION: A CPU 11 performs arithmetic operation based on signals supplied from a light emitting part combined with a light receiving part 1, a setting input dial 14, a flash light emitting mode setting and selecting button 15, a shutter button 30 and an external release signal terminal 31; and controls a display part 16, a memory 13, a flashing device 20, a front curtain magnet 43 and a rear curtain magnet 44 through a driver 12. The part 1 is a non-contact sensor for detecting the traveling of the shutter blade and detects whether or not a light beam emitted from the part 1 is reflected by a reflection mirror 2 and reaches the part 1 so as to decide whether or not a front curtain passes through the center of an image plane.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a system for detecting a flash synchronization timing of a camera.

[0002]

2. Description of the Related Art At the time of flash photography of a camera, a flash is emitted in synchronism with the moment when a shutter is opened. Therefore, in a conventional camera, a mechanical member included in a shutter mechanism portion is energized or de-energized by a mechanical contact or non-contact state in conjunction with an operation of a shutter driving member at the time of shutter operation. By forming the state, the moment when the shutter is opened is detected. That is, an energization signal from a mechanical switch that is interlocked with the operation of the shutter is used to detect the flash synchronization timing for the shutter.

[0003]

However, the above-mentioned mechanical energizing switch has a plurality of problems described below. First, there is a possibility that contact points and mechanical members that come into contact with each other are deteriorated or destroyed due to wear or the like due to repeated mechanical contact or non-contact operations. Secondly, in the above-described switch for turning on and off mechanically, the contact surface changes (electrical resistance increases) due to electric spark generated at every operation at the contact portion, and the function of the signal switch is performed. There is a possibility that you can not fulfill. Third, precise adjustment of the position of the mechanical member is required, and a switch member and a member supporting the switch member are also required. Therefore, the presence and adjustment of these members is a factor of cost increase.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and aims to improve the reliability of a flash tuning signal and reduce costs by reducing the number of components for generating a flash tuning signal and the number of steps. With the goal.

[0005]

In order to achieve this object, a first invention is a shutter blade travel detecting means (1) for detecting at least a traveling state of a shutter leading blade, and a shutter blade travel detecting means (1). Comprises a control means (11) for calculating a timing for emitting a flash from a time at which the travel of the shutter leading blade is detected.

According to a second aspect of the present invention, in the first aspect, the shutter blade travel detecting means (1) is arranged so as to detect travel of the shutter leading blade at a position before the shutter is fully opened, and a control means (11). Calculates the time at which a predetermined time has elapsed from the time at which the shutter blade travel detection means (1) detects the passage of the shutter leading blade as a predicted value for fully opening the shutter leading curtain, and emits a flash at the calculated time. It is characterized by the following.

A third invention according to claim 1, further comprising a control magnet (43) for starting travel of the shutter leading blade by turning off the power, wherein the shutter blade travel detecting means (1) is adapted to detect the travel of the shutter leading blade. It is arranged to detect at the position before the shutter is fully opened, and the control means (1
1) The time when the shutter front curtain is fully opened based on the time from the time when the power supply to the control magnet (43) is turned off to the time when the shutter blade travel detecting means (1) detects the passage of the shutter leading blade. Is calculated as a predicted value, and a flash is emitted at the calculated time.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Before describing the embodiments of the present invention, the outline of the present invention will be briefly described.

In order to emit a signal of the flash synchronization timing, it is sufficient that the position of the shutter blade member or the shutter driving member can be detected. JP-A-6-208157 and JP-A-6-2586 filed by the present applicant.
As described in Japanese Patent Publication No. 90, a shutter monitor system provided with a non-contact sensor to detect the operation of the shutter blade measures the timing of the flash synchronization signal without any hardware modification. It can also be used as a means for performing.

In the above-mentioned shutter monitor system, a non-contact sensor is provided in a portion outside the screen where a shutter blade is actually traveled and outside a screen where an image is actually taken. The edge passing time is measured. In this way, both the shutter speed and the curtain speed up to the half screen position of the shutter blades can be measured. The gist of the present invention is to use this shutter monitor system as a flash synchronization signal timing measurement means without any modification in hardware, and the following three embodiments are conceivable.

First, in the case of front curtain synchronization in which flash emission starts at the moment when the shutter is fully opened, the time from when the shutter front curtain edge passes through the sensor portion (for example, the center position of the screen) to when the aperture is fully opened. Is set in the software in anticipation of.

Secondly, in the case of a shutter of a type in which a blade drive member or a blade drive member locking member that is attracted and held by an electromagnet in response to a release signal, the shutter curtain is caused to run by stopping the energization of the electromagnet. The time from when the shutter curtain traveled to the center position until the shutter was fully opened was calculated by a predetermined program before the front curtain travel was completed, based on the power-off time to the front curtain attraction and holding magnet. At the timing, a shutter fully open signal is output.

With this configuration, the hardware of the shutter monitor system (particularly, the non-contact sensor for detecting the movement of the shutter blades) which has already existed for the shutter control remains in the conventional shutter mechanical part. The flash tuning signal contact member, which also required the adjustment operation, can be omitted only by improving the software.

An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 are a block diagram and a perspective view showing an embodiment of a flash tuning timing detecting system according to the present invention.

1 and 2, power is supplied to a CPU 11 and a driver 12 from a power supply 50.
The CPU 11 includes a light emitting unit and light receiving unit 1, a setting input dial 1,
4. Operation is performed based on signals supplied from the flash light emission mode setting / selection button 15, the shutter button 30, and the external release signal terminal 31, and the display unit 16, the memory 13, the flash device 2
0, the first curtain magnet 43 and the second curtain magnet 44 are controlled. The light-emitting unit and light-receiving unit 1 is a non-contact sensor for detecting the movement of the shutter blades. The light emitted from the light-emitting unit and light-receiving unit 1 is reflected by the reflecting mirror 2 and reaches the light-emitting unit and light-receiving unit 1. It is determined whether or not the front curtain 41 has passed through the center of the screen.

Next, a method for detecting the movement of the shutter blades by the non-contact sensor for detecting the movement of the shutter blades according to the present embodiment will be described with reference to FIGS.

FIGS. 3 to 5 are sectional views of a focal plane shutter having a non-contact sensor for detecting the movement of the shutter blades in this embodiment.

This cross-section is a cross-sectional view outside the photographing screen including a non-contact sensor for detecting the movement of the shutter blade in relation to the shutter blade as shown in FIG.

FIG. 3 shows a situation where the shutter is charged and not released. The front curtain 41 covers the shooting screen, and the rear curtain 42 is out of the screen by folding each blade.

In the state shown in FIG. 3, the light beam emitted from the light emitting / photodetecting unit 1 is blocked by the front curtain 41 and cannot reach the reflecting mirror 2, and the reflection of the surface of the front curtain 41 is the light emitting / photoreceiving unit. The output from the light-emitting / light-receiving unit 1 to the CPU 11 indicates a dark state because the light-emitting unit 1 does not have a reflectivity enough to be photosensitive.

FIG. 4 shows a state in which the front curtain 41 of the shutter has completed traveling and the rear curtain 42 has not yet started traveling.

In the state shown in FIG. 4, since there is nothing obstructing the optical path between the light emitting / photoreceptor 1 and the reflecting mirror 2, the light emitted from the light emitting / photoreceiver 1 is reflected by the reflecting mirror 2 before the light emitting Since the operation returns to the light receiving / light receiving unit 1, the output from the light emitting / light receiving unit 1 to the CPU 11 is clear.

That is, the energization of the front curtain magnet 43 is turned off to open the front curtain 41, and then the slit side of the front curtain 41 passes between the light emitting / photoreceiving unit 1 and the reflecting mirror 2 to emit light / light. At the moment when the output from the unit 1 to the CPU 11 changes from dark to bright, the CPU 11 recognizes that the front curtain has passed.

FIG. 5 shows a state immediately after the photographing in which the rear curtain 42 of the shutter has completed the traveling and covered the photographing screen.

In the state shown in FIG. 5, light rays emitted from the light-emitting / light-receiving section 1 are blocked by the rear curtain 42 and cannot reach the reflecting mirror 2, and the reflection of the surface of the rear curtain 42 is a light-emitting / light-receiving section. The output from the light-emitting / light-receiving unit 1 to the CPU 11 indicates a dark state because the light-emitting unit 1 does not have a reflectivity enough to be photosensitive.

That is, after the energization of the rear curtain magnet 44 is turned off and the rear curtain 42 is opened, the slit side of the rear curtain 42 passes between the light emitting unit / light receiving unit 1 and the reflecting mirror 2 to emit light. The moment the output from the unit 1 to the CPU 11 changes from light to dark, the CPU 11 recognizes the passage of the rear curtain.

FIG. 6 is a flowchart for explaining the operation of the CPU 11 (FIG. 1). When the shooting operation starts, it is determined in step S101 whether or not the flash synchronization method is set to the second curtain synchronization. If it is determined that the rear curtain sync mode has been set, the process proceeds to step S111. If it is determined that the rear curtain sync mode has not been set, the process proceeds to step S102.

If the process has proceeded to step S111, it is determined whether or not the photographing action has been stopped. If it has been determined that the shooting has been stopped, the program is immediately terminated. If it is determined that the operation has not been stopped, the process proceeds to step S112. It should be noted that it is determined that the photographing action has been stopped when the shutter button 30 shown in FIGS. 1 and 2 is not pressed from the outside, or when the external release signal terminal 31 shown in FIGS.
If there is no input of a release signal or a standby signal for, it is determined that the photographing action has been stopped. The method of determining whether to stop the photographing action is described in step S10.
2, Step S211 and Step S202 in FIG.
But the same is true.

In step S112, it is determined whether the energization of the rear curtain magnet 44 of the shutter is stopped and the rear curtain 42 is released. If it is determined that it has been released, the process proceeds to step S113, and if it is determined that it has not been released, the process returns to step S111.

In step S113, the CPU 11 transmits a flash tuning signal. In step S114, the flash device 20 (FIGS. 1 and 2) emits light, and the program ends.

On the other hand, from step S101 to step S1
If the process has proceeded to 02, it is determined in step S102 whether or not the photographing action has been stopped. If it is determined that the processing has been stopped, the program is immediately terminated. If it is determined that the processing has not been stopped, the process proceeds to step S103.

In step S103, it is determined whether or not the power to the front curtain magnet 43 of the shutter is stopped and the front curtain 41 is released. If it is determined that the release has been made, the process proceeds to step S104, and if it is determined that the release has not been made, the process returns to step S102.

In step S104, the light-emitting unit and light-receiving unit 1
The light rays from FIGS. 3 to 5 are reflected by the reflecting mirror 2 and reach the light-emitting and light-receiving section 1 depending on whether or not the first curtain 4 is used.
It is determined whether or not 1 has passed the center of the screen. When it is determined that the vehicle has passed, the process proceeds to step S105, and when it is determined that the vehicle has not passed, the process remains at step S104.

When the passage of the front curtain 41 is recognized in step S104, the process proceeds to step S105, and the time at which the front curtain 41 does not completely cover the shooting screen, that is, the flash synchronization time is calculated, and then the process proceeds to step S106. The calculation of the flash synchronization time is calculated from the time from the time when the front curtain magnet 43 is turned off to the time when the front curtain 41 passes through the light emitting unit / light receiving unit 1.

In step S106, the flash synchronization time calculated in step S105 is stored in the memory 13 shown in FIG. 1, and then the process proceeds to step S107. In step S107, it is determined whether or not time has elapsed until the above-described flash synchronization time. If it is determined that the time has elapsed, the process proceeds to step S108. If it is determined that the time has not elapsed, the process remains at step S107.

In step S108, a flash tuning signal is transmitted, and then the process proceeds to step S109. In step S109, the flash 20 emits light by the CPU 11 transmitting the flash tuning signal. Since the flash 20 has fired in step S109, this program ends.

Next, a second embodiment of the present invention will be described with reference to FIG. In the first embodiment, step S10 in FIG.
In 5, the flash synchronization time is calculated from the off time of the front curtain magnet 43 and the passing time of the front curtain 41, and the flash 20 is emitted at the calculated flash synchronization time. The time difference from the time to the flash synchronizing time is defined in advance, and the flash 20 is caused to emit light after a lapse of a predetermined period from the time when the passage of the front curtain is recognized.

Hereinafter, a second embodiment will be described.

In FIG. 7, when the photographing operation is started, it is determined in step S201 whether or not the flash tuning mode is set to the rear curtain sync mode. If it is determined that it has been set, the process proceeds to step S211 and
If it is determined that it has not been set, step S202
Proceed to.

When the process proceeds to step S211, it is determined whether or not the photographing action has been stopped. If it is determined that the processing has been stopped, the program is immediately terminated. If it is determined that the processing has not been stopped, the process proceeds to step S212.

When the process proceeds to step S212, it is determined whether or not the energization of the rear curtain magnet 44 has been turned off. If it is determined that the switch has not been turned off, step S2
Returning to step S11, if it is determined that the switch has been turned off, step S
Proceed to 213.

In step S213, the CPU 11 transmits a flash tuning signal, and then proceeds to step S214. In step S214, the flash 20 emits light by the CPU 11 transmitting the flash tuning signal. Since the flash emission was performed in step S214, the program ends.

On the other hand, from step S201 to step S2
When proceeding to 02, it is determined whether or not the photographing action has been stopped. If it is determined that the processing has been stopped, the program is immediately terminated. If it is determined that the processing has not been stopped, the process proceeds to step S203.

In step S203, the first curtain magnet 4
Then, it is determined whether or not the power supply to No. 3 is turned off. If it is determined that the switch is turned off, the process proceeds to step S204. If it is determined that the switch is not turned off, the process returns to step S202.

In step S204, it is determined whether or not the slit side of the front curtain 41 has passed in front of the light emitting and light receiving unit 1. If it is determined that the vehicle has passed, the process proceeds to step S205. If it is determined that the vehicle has not passed, the process proceeds to step S204.
Stay in.

In step S205, step S204
Then, it is determined whether or not a predetermined time has elapsed from the time when the passage of the front curtain has been recognized. If you determine that it has passed,
Proceeding to step S206, if it is determined that the time has not elapsed, the process remains at step S205.

In step S206, the CPU 11 transmits a flash tuning signal, and then proceeds to step S207. In step S207, the flash 20 emits light by the CPU 11 transmitting the flash tuning signal. Since the flash 20 has fired in step S207, this program ends.

In this embodiment, the position of the non-contact sensor for detecting the movement of the shutter blades, which includes the light receiving unit 1 and the reflecting mirror 2, with respect to the photographing screen is set at the center of the screen. It can be placed anywhere as long as it can be detected. For example, the position may be the position of the light emitting unit / light receiving unit 1a and the reflecting mirror 2a indicated by the broken line in FIG.
Similarly, the position may be the position of the light emitting unit and light receiving unit 1b and the reflecting mirror 2b.

In this embodiment, a non-contact sensor for detecting shutter blade travel is used. However, a sensor for detecting shutter blade travel in a non-contact manner using a magnetic field or an electric field may be used.

[0051]

As described above, according to the flash synchronization timing detection system of the present invention, the shutter blade traveling detecting means (1) for detecting the traveling state of the shutter leading blade,
A control means (11) for calculating a timing for emitting a flash from a time at which the shutter blade travel detecting means (1) detects travel of the shutter leading blade is provided, and is used in a shutter monitor system for monitoring a shutter operation. The non-contact sensor for detecting shutter blade travel is also used as a flash synchronization timing detection sensor.
As a result, the reliability of the flash tuning signal can be improved, and the number of components for generating the flash tuning signal can be reduced, and the cost can be reduced by reducing the number of steps.

According to the third aspect of the present invention, the flash synchronization time is calculated for each release so that flash synchronization is performed. Therefore, even when the curtain speed of the shutter blade changes, the flash synchronization is performed. By making the tuning timing follow the change, it is possible to improve the reliability of the flash tuning signal.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a flash tuning timing detection system according to the present invention.

FIG. 2 is a perspective view showing one embodiment of a flash tuning timing detection system according to the present invention.

FIG. 3 is a cross-sectional view showing one embodiment of a flash tuning timing detection system according to the present invention.

FIG. 4 is a sectional view showing one embodiment of a flash tuning timing detection system according to the present invention.

FIG. 5 is a sectional view showing one embodiment of a flash tuning timing detection system according to the present invention.

FIG. 6 is a flowchart showing one embodiment of a flash tuning timing detection system according to the present invention.

FIG. 7 is a flowchart showing one embodiment of a flash tuning timing detection system according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Non-contact sensor light-emitting part and light-receiving part for shutter blade travel detection 2 Non-contact sensor reflector for shutter blade travel detection 10 Camera 11 Camera operation control CPU 12 Driver 13 Operation setting storage memory 14 Setting input dial 15 Flash emission mode setting・ Selection button 16 Display unit 20 Flash device 30 Shutter button 31 External release signal terminal 41 Front curtain 42 Rear curtain 43 Front curtain magnet 44 Rear curtain magnet 50 Power supply

Claims (3)

[Claims] 1. A shutter blade travel detecting means for detecting at least a traveling state of a shutter leading blade, and a control for calculating a flash emission timing from a time at which the shutter blade traveling detecting means detects the travel of the shutter leading blade. Means for detecting flash tuning timing. 2. The shutter blade travel detecting means is arranged to detect travel of the shutter leading blade at a position before the shutter is fully opened, and the control means comprises: 2. The flash memory according to claim 1, wherein a time at which a predetermined time has elapsed from the time when the passage of the leading blade has been detected is calculated as a predicted value for fully opening the shutter front curtain, and the flash is emitted at the calculated time. Flash tuning timing detection system. 3. The control apparatus according to claim 1, further comprising a control magnet for starting the travel of the shutter leading blade by turning off the power, wherein the shutter blade travel detecting means detects the travel of the shutter leading blade at a position before the shutter is fully opened. The control means is based on a time from a time when the power supply to the control magnet is turned off to a time when the shutter blade travel detecting means detects the passage of the shutter leading blade,
The flash synchronization timing detection system according to claim 1, wherein a time when the shutter front curtain is fully opened is calculated as a predicted value, and the flash is emitted at the calculated time.