JPS5934893Y2 - Camera tuning contact circuit - Google Patents

Description

[Detailed explanation of the invention] This invention consists of a camera tuning contact circuit, specifically a direct hot shoe dedicated to the X contact, a synchro socket, and an X contact circuit.
The present invention relates to a tuning contact circuit for a camera having a -FP contact changeover switch, particularly a -eye reflex camera.

Conventionally, in high-end cameras such as -eye reflex cameras,
Built-in tuning contact circuit with a direct hot shoe dedicated to the X contact, a synchro socket, and an X-FP contact switching switch so that it can be used with both an FP class tuned light bulb and a strobe device that is a flash synchronized light emitter. has been done.

As is well known, the direct hot shoe mentioned above has an electrical contact for connecting an electric circuit inside the accessory shoe of the camera, and when a strobe device with a corresponding electrical contact is attached, the strobe device automatically connects to the hot shoe. The X contact inside the camera is connected cordlessly to the electric circuit inside the camera.

Next, before explaining the present invention, an example of the conventional tuning contact circuit will be explained with reference to FIG.

In the same figure, electrical contact 1 of direct hot shoe 1
A is connected to an internal connection terminal 2a of the synchro socket 2, and an external connection terminal 2b of the socket 2 and a shoe fitting 1b of the hot shoe 1 are each grounded to the body.

The connection point between the electrical contact 1a and the connection terminal 2a is X-
Switching movable contact terminal S1a of FP contact switching switch S1
is connected to one fixed terminal S of the switch S1.
1b is connected to the fixed terminal of the X timing switch S2, the other fixed terminal Sac is connected to the fixed terminal of the FP timing switch S3, and both switches S2. S
Each movable contact piece terminal No. 3 is grounded.

When using a strobe device that does not have an electrical contact connected to the electrical contact 1a of the hot shoe 1 or a light emitting device of an FP class luminous bulb, the synchro socket 2 is used to insert the synchro plug into the strobe device. Alternatively, it serves to connect the X timing switch S2 or the FP timing switch S3 in the camera to the electric circuit in the light emitter via the changeover switch S1.

In addition, in a single-lens reflex camera having a focal plane shutter, the X timing switch S2 is
It is turned on when the shutter is fully opened when the leading curtain ends, and turned off when the trailing curtain ends or in connection with film winding.

The FP timing switch S3 is turned on before the front curtain travels, for example, 10 m5 before the front curtain travels, and operates so that the amount of light emitted from the FP luminescent bulb reaches its maximum when the shutter is fully opened.

In the conventional tuning contact circuit configured in this way,
When using a strobe device that has electrical contacts that correspond to hot shoe 1, attach the strobe device to hot shoe 1, and set the changeover switch S1 to the X timing switch S.
When the shutter button is pressed after switching to 2, the X timing switch S2 is turned on when the shutter is fully open, and synchronized flash light emission is performed.

In addition, when using a strobe device that does not have an electrical contact corresponding to the hot shoe 1 or an FP light emitter, insert the synchro plug into the synchro socket 2 and turn the switch S1. All you have to do is to switch the X timing switch S2 to alligator and, when using the FP bulb light emitter, to the FP timing switch S3, and then press the shutter button.

Then, the X timing switch S2 or the FP timing switch S3 is turned on, and synchronized light emission is performed when the shutter is fully open.

The above is an example of a conventional tuning contact circuit.
1 to the optimum state, it is not possible to obtain completely synchronized light emission.

That is, in the case of a strobe device that uses the real shoe 1, if the FP timing switch S3 is switched to the wrong side by erroneously operating the changeover switch S1, the strobe device will flash before the shutter is fully opened. When using an FP bulb light emitting device, if the X timing switch S2 is switched to the wrong side by erroneously operating the changeover switch S1, the FP bulb will start emitting light when the shutter is fully opened, making it impossible to obtain synchronized light emission. This results in an underexposed photo.

On the other hand, in the tuning contact circuit configured as described above, since the synchro socket 2 and the electrical contact 1a of the hot shoe 1 are always connected, the synchro socket 2
When the synchro plug of the strobe device is inserted into the strobe device, the relatively high charging voltage of the trigger capacitor in the strobe device is also applied to the electrical contact 1a.

Therefore, without attaching a strobe device to hot shoe 1,
When a strobe device is attached using a camera's tripod hole or the like, there is a risk of electric shock if the photographer accidentally touches the electrical contact 1a.

Therefore, as a measure to prevent electric shock, a diode is inserted in the connection between the electrical contact 1a of the hot shoe 1 and the synchro socket 2 (Utility Model Publication No. 52-15225, Utility Model Application No. 4).
No. 9-21039 and Japanese Utility Model Application Publication No. 49-137535) have already been proposed.

However, in this conventional electric shock prevention device, the anode of the diode is connected to the electrical contact 1a of the hot shoe 1, and the cathode is connected to the synchro socket 2, so that a positive voltage is applied to the electrical contact 1a, and a negative voltage is applied to the shoe fitting 1b. It is effective for devices in which a negative voltage is applied to the electrical contact 1a and a positive voltage is applied to the shoe fitting 1b, as seen in some foreign-made strobe devices. has no effect.

By the way, recent strobe devices are configured to have an electrical contact connected to the electrical contact 1a, based on the fact that most camera accessory shoes are composed of direct hot shoes.

An object of the present invention is to provide a tuning contact circuit for a camera that overcomes the above-mentioned conventional drawbacks by paying attention to these points.

The present invention will be explained below with reference to illustrated embodiments.

FIG. 2 is a camera tuning contact circuit showing an embodiment of the present invention.

In FIG. 2, the electric contact 4a of the direct hot shoe 4 is connected to the cathode of a diode D, and the anode of the diode D is connected to the switching movable contact terminal S4a of the X-FP contact switching switch S4. ing.

This changeover switch S4 is a switch that can be changed manually.When using an FP bulb light emitter, the movable contact piece is switched to one of the fixed terminals for FP S4b, and when a strobe device is used, the movable contact piece is switched to one of the fixed terminals S4b for FP. The contact piece is switched to the other X fixed terminal S4c, the FP fixed terminal S4b is connected to ground, and the X fixed terminal S4c is a loose terminal.

The movable contact terminal S4a of the switch S4 is FP
It is connected to the movable contact terminal of the timing switch S6, the fixed terminal of the switch S6 is connected to the internal connection terminal 5a of the synchro socket 5, and the external connection terminal 5b of the socket 5 is grounded.

The FP timing switch S6 is turned on when the movable reflector of the -eye reflex camera moves upward.

Further, the electric contact 4a is connected to a fixed terminal of an X timing switch S5, and a movable contact terminal of the switch S5 is grounded.

In the above embodiment configured in this way, when using a strobe device connected to the electrical contact 4a of the hot shoe 4, the strobe device is attached to the hot shoe 4, and the switch S4 is connected to the fixed terminal for X. All you have to do is switch to S4c and press the shutter button.

When the shutter is pressed, the movable reflector rises, thereby closing the FP timing switch S6, but since the synchro socket 5 is not used, this operation is unrelated to closing or light emission.

Then, when the shutter is fully open, the X timing switch S
5 is closed, a trigger current flows from the electrical contact 4a to the ground through the switch S5, and the strobe device emits flash synchronized light.

At this time, the diode D connects the electrical contact 4a to the switch S4. Current flowing towards S6 is blocked.

In the present invention, when using the above-mentioned strobe device, the changeover switch S4 is accidentally turned off by the FP fixed terminal S4b.
Even if the switch S4 is
Since the trigger current is blocked by diode D and does not flow, the strobe device will not flash before the shutter is fully opened, and even if the switch S4 is switched incorrectly, the strobe device will not fire in sync. I can do it.

Therefore, this type of conventional drawback is eliminated.

Furthermore, when using a strobe device that does not have electrical contacts, it is sufficient to insert the synchro plug into the synchro socket 5 and then switch the switch S4 to the X fixed terminal S4c.

In this way, the FP timing switch S6 is closed by the rise of the movable reflector, and then the X timing switch S5 is closed when the shutter is fully opened, so that the trigger current is transferred to the FP timing unlatched S6 diode D,
The signal flows through the X timing switch S5, and synchronized flash light emission is performed.

Furthermore, when using an FP bulb light emitter, it is sufficient to insert a synchro plug into the synchro socket 5 and switch the switch S4 to the FP fixed terminal S4b.

Then, as the movable reflector rises, the FP timing switch S6 closes, so that the trigger current FP timing switch S6 and the movable contact terminal S4 of the switch S4
a, flows to the FP fixed terminal S4b and emits synchronized light.

FIG. 3 is a camera tuning contact circuit showing another embodiment of the present invention.

In this embodiment, the X-FP contact changeover switch is configured with a one-circuit two-contact disconnection switch S7 without using a diode.
It skillfully eliminates the drawbacks of the previous model.

In FIG. 3, the electric contact 6a of the direct hot shoe 6 is connected to one X fixed terminal S7c of a changeover switch S7 configured with two contacts in one circuit.

Then, the other FP fixed terminal S7 of this switch S7
b is connected to ground, and the switching movable contact terminal S7a of the switch S7 is connected to the FP timing switch S9.
Connected to the movable contact terminal.

The fixed terminal of this switch S9 is connected to the internal connection terminal 7a of the synchro socket 7, and the external connection terminal 7b of the socket 7 is grounded.

Further, the electric contact 6a is connected to a fixed terminal of an X timing switch S8, and a movable contact terminal of the switch S8 is connected to ground.

In the above-described embodiment configured in this way, when using a strobe device having electrical contacts, the strobe device is attached to the hot shoe 6, and the switch S7 is connected to the X fixed terminal S7.
All you have to do is switch to C and press the shutter button.

When the shutter is pressed, the movable reflector rises and closes the FP timing switch S9, but as mentioned above, this is an unrelated operation, and then when the shutter is fully opened,
When the timing switch S8 is closed, a trigger current flows from the electrical contact 6a to the ground through the switch S8, and the strobe device emits flash synchronized light.

In this invention, when this strobe device is used,
Even if the selector switch S7 is accidentally switched to the FP fixed terminal S7b, the switching mode of this switch S7 and the F
Regardless of the operation of the P timing switch S9, when the X timing switch S8 is closed, a trigger current flows from the electrical contact 6a to the X timing switch S8 to perform flash synchronized light emission.

Therefore, the conventional drawbacks can be overcome.

Furthermore, in the case of a strobe device that does not have electrical contacts, a synchro plug may be inserted into the synchro socket 7, and the switch S7 may be switched to the X fixed terminal S7c.

In this way, the FP timing switch S9 is closed by the bounce of the movable reflector, and the X timing switch S8 is closed when the shutter is fully opened, so that the trigger current is transferred to the FP timing switch S9. Since the current flows through the fixed terminal S7c for the movable contact terminal 57aX of the switch S7 and the X timing switch S8, synchronized flash light emission is performed.

When using an FP light emitter, a synchro plug is inserted into the synchro socket 7, and the switch S7 is switched to the FP fixed terminal S7b.

Then, the FP timing switch S9 closes due to the rise of the movable reflector, and the trigger current flows through the FP timing switch S9 and the movable contact terminal S7 of the switch S7.
a, flows to the FP fixed terminal S7b to perform synchronized light emission.

According to the present invention, when using a strobe device having electrical contacts that contact the electrical contacts 4a and 6a of the hot shoes 4 and 6, the X-FP contact switching switch S4. S7
Due to incorrect operation, the FP fixed terminals S4 b and S7
Even if the flash is switched to "b", the strobe device performs flash synchronized light emission completely, so the drawbacks of this type of conventional technology are eliminated.

Furthermore, according to the present invention, the FR timing switches S6 and S9, whose bottoms open when the movable reflector flips up, are connected between the synchro sockets 5 and 7 and the switching movable contact terminal of the X-FP contact switching switch. Since the electrical contacts of the hot shoe and the synchro socket are open, the charging pressure of the trigger capacitor is not applied to the electrical contacts of the hot shoe through the synchro socket, completely preventing electric shock. will be done.

Also, the FP timing switch S6. When the S9 is turned on, the charging voltage of the trigger capacitor is applied to the electrical contacts 4a and 6a, but at this time, the camera is being photographed and the camera is normally held with both hands, so the camera cannot be used in this state. There is no need to touch the hot shoe with your fingers, and electric shock is completely prevented.

In addition, this electric shock prevention means does not use diodes like conventional ones, so it is carried out regardless of the directionality of the diode. Even in a flash device of the type in which a negative voltage is applied to the terminal, electric shock can be effectively prevented by switching the X-FP contact changeover switch to the X fixed terminal.

Furthermore, when a strobe device is attached to the direct hot shoe and a data imprinting device is connected to the synchro socket, even if the strobe device fires a test light, the FP timing switch is in the OFF state, so the data imprinting device does not work. Since no activation signal is applied and the device does not work, double copying of data can be completely prevented.

As described above, according to the present invention, it is possible to provide a camera tuning contact circuit which eliminates the conventional drawbacks, has a simple circuit configuration, has fewer failures, and is highly practical.

[Brief explanation of drawings]

Fig. 1 is an electrical circuit diagram showing an example of a conventional camera tuning contact circuit, Fig. 2 is an electrical circuit diagram of a camera tuning contact circuit showing an example of the present invention, and Fig. 3 is an electrical circuit diagram showing an example of a camera tuning contact circuit used conventionally. FIG. 2 is an electrical circuit diagram of a tuning contact circuit of a camera showing another embodiment of the present invention. 1.4,6...Direct hot shoe 2°5.7...Synchro socket, Sl, S4. S
7...X-FP contact changeover switch, S2. S
5. S8...X timing switch, S3. S
6. S9...FP timing switch, D...
····diode.

Claims (1)

[Claim for Utility Model Registration] A shoe fitting for attaching a strobe device is body-grounded to the camera body, and has a built-in electrical contact that connects directly to the electric circuit of the attached strobe device without a cord. The direct hot shoe has one end connected to the electrical contact mentioned above, the other end connected to body ground, and an It consists of a synchro socket that is grounded and has an FP timing switch connected to its internal connection terminal, and a selector switch, and when the synchro socket is used as an X contact, the switchable movable contact terminal is open. an X-FP contact switching switch that can switch the movable contact terminal to the body ground when the synchro socket is used as an FP contact, and a switch for switching the X-FP contact switching switch to the body ground. An FP timing switch whose one end is connected to the movable contact terminal and the other end is connected to the internal connection terminal of the synchro socket and is closed before the shutter is fully opened, and the X-FP contact changeover switch. A camera tuning contact circuit comprising: an electric shock prevention diode having an anode connected to a movable contact terminal and a cathode connected to a built-in electric contact of the direct hot shoe.