Hot Shoe System for Camera

The present invention relates to cameras having an internal strobe, and more specifically, to devices for disabling the internal strobe when an external strobe unit is attached to the camera.

Modern cameras may be built with a pop-up internal strobe unit. Such an internal strobe unit typically has a limited range, and a camera may have some provision for attaching a generic or dedicated external strobe unit. Frequently, a hot shoe is provided to the camera body for mounting and controlling the external strobe. The hot shoe is conventionally provided close to the pop-up strobe.

However, modern cameras may also be constructed with a contoured body and a recessed hot shoe, and have a hot shoe cover for protecting the hot shoe and for preserving the contour of the camera body. The hot shoe cover is mounted to the hot shoe in a like manner to an external strobe coupling mount.

When a camera has a pop-up strobe located next to the hot shoe, if the strobe is popped-up when the external strobe is mounted, the pop-up and external strobes interfere with each other. A camera may suppress the pop-up of an internal strobe when an external strobe is mounted. However, such a camera, unable to discriminate between the hot shoe cover and an external strobe unit, is not able to control the pop-up of the internal strobe according to the mounted part. If such provision is not included, the internal strobe may be disabled inappropriately if a hot shoe cover is mounted in the hot shoe.

It is therefore an object of the present invention to provide a camera having a hot shoe system able to discriminate between the mounting of a hot shoe cover and of an external strobe, and which can selectively disable an internal strobe unit based upon which of the cover or external strobe is mounted thereon.

According to one aspect of the present invention, a hot shoe system for a camera having a pop-up internal strobe unit positioned on the camera proximate to a hot shoe for mounting an external strobe may include a device for determining if a hot shoe cover or an external strobe unit is inserted in a hot shoe and a device for suppressing at least one operation of the internal strobe unit when a coupling base of the external strobe unit is inserted in the hot shoe and for enabling the at least one operation of the internal strobe unit when the hot shoe cover is inserted in the hot shoe. Preferably, the operation is a pop-up operation of an internal strobe. Further preferably, the device for suppressing and for enabling at least one operation of the internal strobe unit further enables said at least one operation of the internal strobe unit when the hot shoe is empty. Still further preferably, the means for suppressing and for enabling at least one operation of the internal strobe may include a controller and a pop-up actuator controlled by the controller, the pop-up operation being actuated by the pop-up actuator, the controller may enable the pop-up actuator to actuate the pop-up operation when the hot shoe cover is inserted in the hot shoe or the hot shoe is empty, and the controller may disable the pop-up actuator from actuating the pop-up operation when the external strobe is inserted in the hot shoe. The means for suppressing and for enabling at least one operation of the internal strobe preferably includes a detection switch provided to said hot shoe, and the detection switch may include a pin extending into the hot shoe and a resilient contact switch actuatable by moving the pin from a neutral position. The hot shoe cover is preferably shaped to avoid the pin when the hot shoe cover is inserted into the hot shoe.

According to another aspect of the present invention, a hot shoe system for a camera having a pop-up internal strobe unit positioned on the camera proximate to a hot shoe for mounting an external strobe may include a switch provided to the hot shoe, a hot shoe cover, insertable into the hot shoe, having a recess, an external strobe unit having a coupling base, insertable into the hot shoe; and a device for activating the internal strobe responsive to the switch. The switch may be arranged such that the switch maybe not actuated when the hot shoe cover is inserted into the hot shoe, the switch maybe arranged such that the switch may be actuated when the coupling base of the external strobe unit is inserted into the hot shoe, and the activating means may deactivate the internal strobe when the switch is actuated, and may activate the internal strobe when the switch is unactuated. Preferably, the means for activating the internal strobe extends the internal strobe away from a body of the camera when the internal strobe is activated. Further preferably, the switch may include a pin extending into the hot shoe; a resilient contact switch actuatable by moving the pin from a neutral position, and the device for activating maybe enabled when the pin is in the neutral position and maybe disabled when the pin is moved from the neutral position.

FIG. 1 is a perspective view of a camera and external strobe unit to which the present invention is applied;

FIG. 2 is an internal view of a first embodiment of a hot shoe system, showing a first state;

FIG. 3 is an internal view of an internal strobe portion of the first embodiment of the hot shoe system, showing a second state;

FIG. 4 is a perspective view of a hot shoe portion of the first embodiment of the hot shoe system;

FIG. 5 is a plan view of the hot shoe portion of the first embodiment of the hot shoe system, showing a hot shoe cover mounted in the hot shoe;

FIG. 6 is a plan view of the hot shoe portion of the first embodiment of a hot shoe system, showing an external strobe coupling mounted in the hot shoe;

FIG. 7 is a block diagram of a controller for the embodiments of the hot shoe system; and

FIG. 8 is a plan view of the hot shoe portion of a second embodiment of the hot shoe system, showing a hot shoe cover mounted in the hot shoe.

As shown in FIG. 1, a camera 100 having an internal strobe 102 is a single lens reflex (SLR) camera. The internal strobe 102 is actuated to pop up by a pop-up button 109 (shown in FIG. 7, but not depicted in FIG. 1) on the camera body. A hot shoe 106 is provided to the camera 100 for mounting and controlling either a generic or a dedicated external strobe 104. The external strobe 104 has a light-emitting portion 104a, and a mounting base 105 for coupling to the hot shoe 106. When coupled via the hot shoe 106 and mounting base 105, the camera 100 may control the external strobe unit 104 by means of matching electrical contacts (not shown) provided to both the hot shoe 106 and the strobe mounting base 105. To couple the external strobe unit 104 to the hot shoe 106, the mounting base 105 of the strobe 104 slides into the hot shoe 106 from the rear of the camera 100, in the direction shown by the arrow A.

FIGS. 2 and 3 are internal views of the internal strobe portion of the hot shoe system of the camera 100, showing a pop-up mechanism in detail in two states.

As shown in FIG. 2, a strobe head 140 has cam follower pins 146a and 146b on its respective left and right sides 142a and 142b. Guide grooves 144a and 144b for guiding the cam follower pins 146a and 146b, respectively, are provided to an upper cover 115 of the camera 100. An L-shaped connecting arm 124 is attached to a pivotable mount 148 at an end of one leg of the L shape, and the pivotable mount 148 is pivotable about pivot 152 provided to the upper cover 115. The pivotable mount 148 and connecting arm 124 are biased to rotate in a counterclockwise direction by a torsion spring 6 provided to the axis 152 and having a connection to the upper cover 115. The L-shaped connecting arm 124 is further rotatably attached, at an end of the remaining leg of the L shape, to a pin 126 provided on the left side 142a of the strobe head 140.

A lock recess portion 147 is provided to the cam follower pin 146a on the left side 142a of the strobe head 140. As shown in FIG. 2, the lock recess portion 147 mates with a catch 128a of a catch lever 128 when the strobe head 140 is in a "down" position. The catch lever 128 is pivotable about an axis 154, and is biased to rotate in a clockwise direction by a torsion spring end 14b of a torsion spring 14 provided to the axis 154. The remaining end 14a of the torsion spring 14a engages a support frame 16, and the support frame 16 supports the axes 154 and 156. The catch lever 128 further comprises a connecting tab 128b at an opposite end to the catch 128a, and the connecting tab engages an engaging portion 132b of a link lever 132 in such a manner that the link lever 132 may push the catch lever 128 counterclockwise.

The link lever 132 is also pivotable about the axis 154, and is linked to a solenoid-like electromagnet 130 by means of a plunger 130a inserted in a chamber through the coils (not shown) of the electromagnet. The electromagnet has a permanent magnet (not shown) attached therewith at one end of the chamber. The plunger 130a can be pushed away from the permanent magnet when the electromagnet 130 is energized, and pulled towards the permanent magnet when the electromagnet 130 is de-energized. When the plunger 130a of the electromagnet 130 is extended (FIG. 3), it pushes the link lever 132 counterclockwise, and when the plunger 130a returns (FIG. 2), the link lever 132 is moved clockwise and then held in place by the attraction between the permanent magnet and the plunger 130a. As previously described, an engaging portion 132b of the link lever 132 is arranged such that the engaging portion 132b can push the catch lever 128 counterclockwise. The link lever 132 further comprises a bent tab 132a, which engages a torsion spring end 15a of a torsion spring 15 provided to the axis 154.

The torsion spring 15 can be "charged" (deflected under load) in a counterclockwise direction at a remaining end 15b by a tab portion 134b of a pusher arm 134. However, the end 15b of the torsion spring 15 is only charged by the bent tab 134a (as end 15a is held at tab portion 132b) when the internal strobe 102 is in a "down" position as shown in FIG. 2. In an "up" position, the pusher arm 134 and link arm 132 are rotated such that the torsion spring 15 is not under load from either the bent tab 132a or tab portion 134b.

The pusher arm 134 is rotatably provided to the axis 156, and comprising a stopper portion 134a, a tab portion 134b, and a pusher portion 134c. The stopper portion 134a limits the rotational range of the pusher arm 134 by stopping the pusher arm 134 against the support frame 16 when the internal strobe is in the "up" position as shown in FIG. 3. The tab portion 134b contacts the end 15b of the torsion spring 15 (FIG. 2), and the torsion spring is pushed and charged by the pusher arm 134 in a counterclockwise direction, but only when the internal strobe 102 is in a "down" position as previously described. The pusher portion 134c follows the strobe head 140 (FIG. 2), with a slight pushing force from the bias of the torsion spring 15, when the strobe head 140 is moved to an "up" position by the torsion spring 6.

The hot shoe 106 is visible in profile in FIGS. 2 and 3. A contact switch 108 is provided in the camera 100, adjacent to and in front of the hot shoe 106, and a switch pin 136 extends from the contact switch 108 into the hot shoe 106. The switch pin 136 is supported by the camera 100 body and is slidable in the direction of its axis to depress the contacts of the contact switch 108. FIG. 4 shows the hot shoe arrangement in perspective. A hot shoe cover 110 is formed having a recess 110a, positioned, such that when the hot shoe cover 110 is inserted in direction x into the hot shoe 106, the switch pin 136 fits into the recess 110a, and is therefore not moved and does not actuate the contact switch 108.

The hot shoe 106 is shown in a plan view in FIG. 5, with the hot shoe cover 110 inserted into the hot shoe 106 in direction X. As shown in FIG. 5, the switch pin 136 fits into the recess 110a, and is not actuated by the hot shoe cover 110. Conversely, FIG. 6 shows the hot shoe 106, in plan view, but with the mounting base 105 of the external strobe unit 104 in direction X instead. In this case, the side 105c of the mounting base 105 presses on the switch pin 136, and actuated the contact switch 108, turning the contact switch OFF.

As shown in FIG. 7, a controller 138 is connected to the internal strobe 102, the external strobe (contacts) 104, the electromagnet 130, the pop-up button 109, and the contact switch 108. The controller 138 does not allow the internal strobe 102 to be moved to an "up" position when the contact switch 108 is OFF (external strobe 104 is inserted in the hot shoe 106) by controlling the electromagnet 130. Even if the pop-up button 109 is pressed, the controller 138 keeps the internal strobe 102 in a "down" position.

When the internal strobe 102 is to be moved to the "up" position of FIG. 3 from the "down" position of FIG. 2, the pop-up button 109 is actuated. If the hot shoe cover 110 is inserted in the hot shoe 106, or the hot shoe 106 is empty, the contact switch 108 is not turned OFF by the switch pin 136, and the electromagnet 130 may be operated.

From the position shown in FIG. 2, the next stage of the pop-up operation is shown in FIG. 3. The controller 138 briefly energizes the electromagnet 130, which pushes the plunger 130a away from the electromagnet 130 (and permanent magnet), and the torsion spring 15 carries the link arm 132 in a counterclockwise direction. The catch arm 128 is also moved by the link arm 132 counterclockwise by virtue of the engagement at the engagement portion 132b. The catch 128a of the catch arm releases the lock recess portion 147 of the cam follower pin 146a, and the strobe head 140 "pops" up to the position shown in FIG. 3 as the torsion spring 6 pushes the connecting arm 124 counterclockwise, making the cam follower pins 146a and 146b proceed along the respective cam grooves 144a and 144b. The electromagnet 130 is then de-energized, and the catch arm 128 and link arm 132 then return to the positions shown in FIG. 2, as the permanent magnet of the plunger 130a is attracted to the ferromagnetic portions of the de-energized electromagnet 130, while the pusher arm 134 remains in the position shown in FIG. 3, no longer charging the torsion spring 15. The position of the pusher arm 134 in FIG. 3 defines a standby position where the strobe head 140 maybe re-locked when pushed down as the back of the strobe head is pushed against pusher portion 134c of the pusher arm 134 and the torsion spring 15 is charged and lock recess portion 147 may re-engage the catch 128a of the catch arm 128.

As previously described, if an external strobe 104 is present in the hot shoe 106, then the contact switch 108 is turned OFF by the switch pin 136, and the controller 138 will not energize the electromagnet 130. In this case, the internal strobe 102 will not move to the "up" position, and may not be operated. In such a case, the controller 138 further inhibits the charging of a strobe circuit and capacitor (not shown) associated with the internal strobe 102.

A second embodiment is shown in FIG. 8. In this embodiment, the contact switch 108 is placed at the side of the hot shoe 106, and a tapered switch pin 166 is used. In this case, a recess (dotted line) is provided at the side of a hot shoe cover 170. The recess is positioned such that the hot shoe cover does not press on the tapered switch pin 166 when inserted, but an external strobe unit 104 will press on the taper of the tapered switch pin 166 and turn the contact switch 108 OFF. Otherwise, the operation of the second embodiment is identical to that of the first.

Thus, the embodiments of a hot shoe system as described are able to allow the camera 100 to determine whether an internal strobe 102 is to be activated or suppressed. Furthermore, the popping-up operation of a pop-up internal strobe 102 is suppressed when an external strobe is mounted, even when a pop-up button is depressed.

The present disclosure relates to subject matter contained in Japanese Utility Model Application No. HEI 05-074665, filed on Dec. 29, 1993, which is expressly incorporated herein by reference in its entirety.