JP3810189B2 - Strobe attachment / detachment identification device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a strobe attachment / detachment identifying device that can recognize attachment / detachment of a strobe attached to a hot shoe of a camera on the camera side.
[0002]
[Prior art]
Near the center of this type of hot shoe, there is a connection contact for electrically connecting the strobe trigger circuit and the X-contact of the camera-side shutter in a non-coded manner when a clip-on type strobe is installed. The shape of these hot shoes, the position of contact points for connection, etc. are defined in detail by JIS.
[0003]
As described above, when a clip-on type strobe is attached to a camera having a hot shoe having only a contact point for connection with the strobe to perform strobe photography, the camera is, for example, a medium format single-lens reflex camera having a focal plane shutter. As described above, when the shutter synchronization speed with the flash is lower than the usual shutter speed such as 1/30 second (6 × 7 size) or 1/60 second (semi size), the photographer manually releases the shutter. The speed must be switched to the strobe synchronization speed or slower, and if this is forgotten, the strobe light will reach only a part of the screen, resulting in a shooting failure.
[0004]
In order to solve such a problem, conventionally, a plurality of mutual control terminals unique to each camera are provided on the hot shoe separately from the contact point for connecting to the strobe, and dedicated strobes corresponding to these are used in pairs. As a result, the camera recognizes the attachment / detachment of the strobe, and accordingly, for example, the shutter speed is automatically set to the strobe synchronization speed, and the photometry method is automatically switched to the TTL metering mode that can measure the film surface illuminance. Even if there is no AF auxiliary light emission function on the strobe side, there is provided a device that emits AF-side light on the camera side for distance measurement prior to the strobe emission.
[0005]
In addition, by inserting a specific adapter between a specific strobe and various cameras, the camera recognizes the attachment / detachment of the strobe on the camera side in response to multiple types of cameras. Some of the functions that can be changed automatically have appeared.
[0006]
[Problems to be solved by the invention]
However, in such a conventional strobe attachment / detachment identification device, the strobe is attached only when a dedicated strobe paired with a specific camera is used or when a specific adapter is used for a specific camera and strobe. When using a general-purpose strobe with only one connection terminal that is generally available on the market, it is not possible to recognize the attachment / detachment automatically on the camera side. there were.
[0007]
In addition, when a dedicated switch or the like that can recognize the attachment / detachment of a commercially available strobe is provided near the hot shoe of the camera, a wireless remote control device that uses, for example, near infrared rays other than the strobe is mounted. There is a risk of erroneous recognition.
The present invention has been made in view of the above points, and an object thereof is to recognize whether a strobe is attached or detached with a simple configuration.
[0008]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the present invention is a strobe attachment / detachment identification device capable of recognizing attachment / detachment of a strobe to / from a camera's hot shoe on the camera side, and is provided at substantially the center of the hot shoe. The connection contact for electrically connecting the trigger circuit on the side and the X contact of the camera side shutter is divided into a first terminal and a second terminal that are normally insulated from each other and conductive when the strobe is mounted, A strobe attachment / detachment identifying device is provided in which the first terminal is connected to the X contact of the camera shutter and a continuity detection circuit is connected between the first and second terminals.
[0009]
By configuring the strobe attachment / detachment identification device according to the present invention as described above, when the strobe is mounted on the hot shoe of the camera, the first and second terminals are conducted. When this is detected by the continuity detection circuit, a continuity detection signal is output, which recognizes the attachment of the strobe, and if it is a focal plane shutter camera, the shutter speed can be automatically switched to the strobe tuning speed. Failure due to a mistake in setting the shutter speed at the time can be prevented in advance.
[0010]
Regardless of focal plane shutter lens or lens shutter camera, it is also possible to switch the metering method to TTL metering mode according to the function of the camera side and the flash side, or to emit AF auxiliary light prior to flash firing become.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be specifically described below with reference to the drawings.
FIG. 1 is an electric circuit diagram showing the configuration of an embodiment in which the present invention is implemented in a focal plane shutter camera equipped with a hot shoe, and FIG. 2 is a perspective view showing an example of the appearance of the hot shoe and strobe. 3 is a waveform diagram for explaining the operation of the embodiment shown in FIG.
[0012]
1 and 2, the hot shoe 1 includes a metal frame 11 for mounting the leg portion 21 of the strobe 2, and a frame 11 by an insulating material 13 at a predetermined position substantially in the center thereof. The frame 11 is fixed to the body of the camera 3 and grounded. The contact 11 is connected to the strobe 2 that is electrically insulated. The connection contact 12 corresponds to the connection contact 22 on the strobe 2 side and is divided into a first terminal 12a and a second terminal 12b which are insulated from each other.
[0013]
The first terminal 12a is a normally open X contact 6 that is turned on when the focal plane shutter on the camera 3 side is fully opened, which incorporates a microcomputer (hereinafter abbreviated as "CPU") 4 comprising a CPU, ROM, RAM, and the like. The other terminal 6 b of the X contact is connected to the frame 11 of the hot shoe 1 through the body of the camera 3. The second terminal 12b is connected to the continuity detection circuit 7 together with the first terminal 12a.
[0014]
The continuity detection circuit 7 includes a transformer T and a photocoupler 8. One end of the primary winding L1 of the transformer T is grounded, and the pulse signal P1 generated by the pulse oscillator 5 is applied to the other end. One end of the secondary winding L2 of the transformer T is connected to the second terminal 12b of the connecting contact 12, and the other end is connected to the anode of the light emitting element (light emitting diode) 8a of the photocoupler 8 via the diode D1 and the resistor R1. And its cathode is connected to the first terminal 12a.
[0015]
A capacitor C is connected between the first terminal 12a, the cathode of the diode D1, and the connection point of the resistor R1. A positive voltage is applied from a DC power source (battery) E to the collector of the light receiving element (phototransistor) 8b of the photocoupler 8, and the emitter is grounded via a resistor R2.
[0016]
Then, when the strobe 2 shown in FIG. 2 is mounted, a continuity detection signal Sa is output from the output terminal a, which is a connection point between the emitter of the light receiving element 8b and the resistor R2, and is input to the CPU 4. The CPU 4 is also connected to the first and second release contacts S1 and S2. On the output side, the TTL photometric circuit 9, the AF auxiliary light emitting circuit 10, the transistor TR1 for controlling the shutter magnet SM, and the release magnet LM. The bases of the transistors TR2 for controlling are connected via resistors R5 and R6, respectively.
[0017]
Next, the operation of this embodiment configured as described above will be described.
When the leg portion 21 of the strobe 2 shown in FIG. 2 is inserted into the hot shoe 1 of the camera 3, the connecting contact 22 on the strobe 2 side conducts between the first and second terminals 12 a and 12 b of the hot shoe 1.
[0018]
In this state, when a release button (not shown) on the camera 3 side is pressed for flash photography, the first release contact S1 shown in FIG. 1 is turned on in the first stroke, that is, when the release button is half-pressed, and the pulse oscillator 5 is grounded via the diode D2 and the release contact S1, and this pulse oscillator 5 is supplied with power from a power supply circuit (not shown) to start an oscillation operation, and outputs a pulse signal P1 as shown in FIG. To do.
[0019]
This pulse signal P1 is applied to the primary winding L1 of the transformer T of the conduction detecting circuit 7, thereby inducing a pulse voltage in the secondary winding L2. At this time, if the first terminal 12a and the second terminal 12b of the connection contact 12 are conductive, a closed circuit including the secondary winding L2 and the light emitting element 8a of the photocoupler 8 is formed. Current flows in the closed circuit. Therefore, a current flows through the light emitting element 8a of the photocoupler 8 to emit light. The diode D1 and the capacitor C rectify and smooth the direction of the flowing current in the forward direction with respect to the light emitting element 8a, and cause the light emitting element 8a to emit light stably.
[0020]
As a result, the light receiving element 8b of the photocoupler 8 becomes conductive, a current flows from the DC power source E to the resistor R2, a positive voltage is generated at the output terminal a, and the continuity detection signal Sa is shown in FIG. To become high level. The CPU 4 identifies the attachment of the strobe by the change in the continuity detection signal Sa.
[0021]
When the first release contact S1 is turned on, the signal Sb, which has been high level via the resistor R3 by the power supply voltage Vcc, is grounded via the diode D3, and as shown in FIG. become. Thereby, the CPU 4 sets the output O1 to the high level, turns on the transistor TR1, excites the shutter magnet SM, and locks the shutter closing member (not shown) in the charged state.
[0022]
At this time, when the strobe 2 is not attached to the hot shoe 1, the first and second terminals 12a and 12b are insulated from each other, so that the secondary winding of the transformer T constituting the conduction detecting circuit 7 is used. Since a closed circuit including L2 and the light emitting element 8a of the photocoupler 8 is not formed, no current flows through the light emitting element 8a, and the light receiving element 8b of the photocoupler 8 remains in a non-conductive state. As shown in (c) of 3, the low level is maintained.
[0023]
When the strobe 2 is attached to the hot shoe 1, the continuity detection signal Sa becomes high level as described above, and the CPU 4 identifies the attachment of the strobe, so that the set shutter speed is when the focal plane shutter is fully open. For example, when it is faster than 1/60 seconds, it automatically switches to 1/60 seconds.
[0024]
When the release button is further pressed in this state, the second release contact S2 shown in FIG. 1 is turned on, and the signal Sc that has been set to the high level via the resistor R4 by the power supply voltage Vcc passes through the release contact S2. Is grounded and low level. As a result, the CPU 4 sets the output O2 to the high level to turn on the transistor TR2, energizes the release magnet LM to release the shutter, the shutter front curtain runs, and the shutter starts to open.
[0025]
The trigger contact (not shown) is turned off at the beginning of the opening of the shutter, the timer in the CPU 4 starts counting the shutter time, and the X contact 6 is turned on when the shutter front curtain is finished and the shutter is fully opened. Then, when the strobe 2 emits light and the count value at the shutter speed reaches a predetermined value calculated or calculated, the output O1 is set to low level to turn off the transistor TR1 and demagnetize the shutter magnet SM. As a result, the shutter rear curtain travels and the shutter closes.
[0026]
At this time, even if the strobe 2 mounted on the hot shoe 1 is of a type in which a high pressure acts on the connection contact 12 on the camera 3 side via the connection contact 22, the continuity detection circuit 7 is connected to the photocoupler. Since it is insulated by 8, there is no fear of electric shock.
[0027]
When the strobe 2 is pulled out from the hot shoe 1, the first and second terminals 12a and 12b are insulated and the continuity detection circuit 7 is opened. Therefore, even if the release button of the camera 3 is half-pressed and the first release contact S1 is closed, the continuity detection signal Sa from the continuity detection circuit 7 remains at a low level, and the shutter speed in the CPU 4 is arbitrary. It is set at the set second and the normal shooting state is set.
[0028]
In the above embodiment, the example in which the flash speed of the focal plane shutter is automatically changed when the shutter is fully open by inserting the strobe 2 into the hot shoe 1 has been described. When the strobe 2 is inserted, the TTL metering circuit 9 on the camera 3 side is operated to automatically switch the metering method to the TTL metering mode. The AF auxiliary light emitting circuit 10 on the camera 3 side can be operated by pushing to emit AF auxiliary light.
[0029]
In the above-described embodiment, the case where the present invention is applied to a camera equipped with a focal plane shutter has been described. However, when the present invention is applied to a lens shutter camera capable of full-speed shutter speed recognition, it is recognized that the strobe is mounted. Thus, it is possible to switch and operate various functions on the camera side described above other than the shutter speed switching.
[0030]
In addition, even when a specific flash equipped with various control terminals other than the trigger contact or a flash with a specific adapter is attached to a hot shoe of a camera having the flash attachment / detachment identification device according to the present invention, Since the terminal corresponding to the control terminal is not provided, these control terminals remain in an inoperative state and can be used without any trouble.
Furthermore, when a remote control device or the like other than the strobe is attached to the hot shoe 1, the first and second terminals are not conducted, so there is no possibility of erroneous recognition.
[0031]
【The invention's effect】
As described above, the strobe attachment / detachment identifying device according to the present invention divides the connection contact with the strobe provided on the camera-side hot shoe into the first and second terminals that are insulated from each other and conducted when the strobe is mounted. Since the first terminal is connected to the X contact of the shutter and the continuity detection circuit is connected between the first and second terminals, the first and second terminals can be used when the strobe is mounted, regardless of which strobe is used. By detecting that the terminal is conductive, it is possible to identify the attachment of the strobe on the camera side based on the detection signal.
[0032]
By identifying the strobe attachment, for example, the shutter speed of the focal plane shutter can be automatically switched to the strobe tuning speed, and failure due to a shutter speed setting error can be eliminated. Regardless of the focal plane shutter lens or lens shutter camera, when the flash is attached, the camera side metering method is switched to TTL metering mode according to the function of the camera, and the metering accuracy by the strobe light is improved. Even without an AF auxiliary light emission function, it is possible to measure the distance of a low-luminance subject by emitting AF auxiliary light on the camera side prior to flash emission.
[Brief description of the drawings]
FIG. 1 is an electric circuit diagram showing a configuration of an embodiment of the present invention.
FIG. 2 is a perspective view showing an example of the appearance of the hot shoe and the strobe.
FIG. 3 is a waveform diagram for explaining the operation of the embodiment shown in FIG. 1;
[Explanation of symbols]
1: Hot shoe 2: Strobe 3: Camera 4: Microcomputer (CPU)
5: Pulse oscillator 6: X contact 7: Conduction detection circuit 8: Photocoupler 9: TTL photometry circuit 10: AF auxiliary light emission circuit 11: Frame body 12: Contact for connection (camera side)
12a: First terminal 12b: Second terminal 21: Strobe leg 22: Contact for connection (strobe side)

Claims (1)

A strobe attachment / detachment recognition device that can recognize attachment / detachment of a strobe to / from a camera hot shoe on the camera side,
Connected to the strobe-side trigger circuit and the camera-side shutter's X contact at the center of the hot shoe, which is normally insulated from each other and electrically connected when the strobe is installed. The first terminal is divided into a second terminal, the first terminal is connected to the X contact of the camera-side shutter, and a continuity detection circuit is connected between the first and second terminals. A strobe attachment / detachment identification device.

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