JPH04348Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a camera, and more particularly, to a strobe-mountable camera incorporating a device for removing noise emitted by a strobe.

(Background of the invention) In recent years, the functions of strobes attached to cameras have been improved by not only being able to control the amount of light by themselves, but also by exchanging various signals with the camera. An example of this will be explained based on FIGS. 1 and 2. FIG. 1 is a perspective view showing the external appearance of the camera, and FIG. 2 is a block diagram showing the internal circuits of the camera Ca and strobe S.

In FIG. 2, the electric circuit inside the camera Ca will be explained. The electric circuit of the camera consists of a light receiving element 1 that converts the amount of exposure through the photographic lens into an electrical signal.
0. A photometering circuit 12 that measures light using the output from the light-receiving element 10, an arithmetic circuit 14 that performs predetermined calculations based on the output from the photometering circuit 12, and at the same time when switching the camera to strobe photography mode when a strobe is attached.
A circuit 16 that tells the strobe side that the camera is capable of TTL dimming, a light intensity integration circuit 18 that integrates the light intensity based on the output from the arithmetic circuit 14, and an output from the light intensity integration circuit 18 that stops the strobe light emission at the appropriate amount. A circuit 20 for generating a stop signal for the shutter to open, a so-called X contact switch 25 that turns on in synchronization with the opening operation of the shutter, a ready light LED 24 that can be checked in the viewfinder, and circuits 12 to 20.
It is composed of circuits 22 that perform other functions. The hot show 26 includes contacts a _, b, c and
Grounded through C ₂ and C ₃ .

The electric circuit of Strobe S is a discharge tube 3 that emits a flash.
2. a trigger circuit 34 for discharging the discharge tube 32; a light emitting discharge circuit 36 for stopping the discharge of the discharge tube 32;
Boost circuit 38, camera interface circuit 4
Consists of 0. The strobe contact section 42 connectable to the camera's hot show 26 includes contacts 44a,
44b, 44c, 46, etc. Camera Ca
When the strobe contact section 42 of the strobe S is connected to the hot shoe 26 of the strobe S, the two electric circuits are connected to each other: the contact a and the contact 44a, the contact b and the contact 44b, the contact c and the contact 44c, and the contact X and the contact 46. exchange electrical signals.

As is clear from FIG. 1, the photometric circuit 1
2. Arithmetic circuit 14, circuit 16, light amount integration circuit 1
8. The stop signal generation circuit 20, etc. is an integrated circuit IC 5 mounted on a flexible printed board (hereinafter referred to as "FPC") 52 placed on the side of the pentaprism.
Consists of 0. Capacitors C ₁ , C ₂ and C ₃ are also attached to the FPC 52, and lead wires A ₁ , A ₂ and A ₃ are connected to the hot shoe 26.
connected with. Further, light receiving elements 54 and 56 for normal photometry are attached to the lower surface of an FPC 58 fixed below the hot show 26 and connected to a predetermined circuit (not shown).

In this conventional example, the strobe S is connected to the camera Ca.
When the camera is attached to the hot shoe 26 of the camera, a strobe attachment signal is input to the switching circuit of the camera through the b contact, and the camera enters the strobe photography mode. Furthermore, when the strobe S is charged, a charging completion signal is input to the camera Ca through the a contact, and the LED in the viewfinder
24 lights up. Then, when the shutter is released, the switch 25 is closed and the strobe S emits light. At this time, the shutter is fully open, and the light receiving element 10 receives the light reflected from the film.

When the light emitted from the strobe S is received by the light receiving element 10, the amount of received light is measured by the photometry circuit 12, and calculated and integrated by the calculation circuit 14 and the light amount integration circuit 18. Then, when the appropriate amount of light is reached, a light emission stop signal is transmitted from the stop signal generation circuit 16 to the strobe S through the c contact.

By the way, since a very high voltage is applied to the discharge tube 32, quite a large amount of noise is generated as the discharge tube 32 emits light. When such noise occurs, the noise is superimposed on the electric signal on the strobe S side and the camera
Since it is input to the electrical circuit on the Ca side, the operation of this electrical circuit will be disrupted and correct processing will not be possible. To this end, capacitors C ₁ , C ₂ , and C ₃ are connected between contacts a, b, and c in the hot shoe 26 and the camera's electrical circuit to remove noise from the capacitor C _{1 .}
By absorbing it with ~ _C3 , the camera's electrical circuit was able to operate normally.

However, as shown in Figure 1, the camera
Capacitors C ₁ , C ₂ and C ₃ placed on the FPC 52 having an electrical circuit of
Lead wires A ₁ and A ₂ from contacts a, b, and c, respectively.
and _A3 , and noise is not removed from these lead wires _A1 to _A3 . Therefore, as shown in Figure 1, the lead wire
A ₁ to A ₃ crawl around on FPC52 and capacitor C ₁
~ _C3 , for example, if the leads _A1 and _A2 approach the IC50, the electric circuits 12~2
There is a risk that it will have a negative impact on 2. In addition, the current in the photometry circuit system is weak and susceptible to noise, but since the light receiving elements 54 and 56 for photometry are normally provided directly below the hot show 26, if the lead wire A ₂ approaches them, The noise generated during light emission also has an adverse effect on the system, interfering with its normal operation.

(Purpose of the invention) The present invention aims to eliminate the drawbacks of the prior art, that is, to provide an improved camera that can prevent noise generated when flashing a strobe from entering the camera and adversely affecting the electric circuit. The purpose is to

(Example) Hereinafter, an example of the present invention will be described based on the drawings.

In this embodiment, the block diagram showing the control system inside the camera Ca and the strobe S is shown in the second block diagram.
Since there are no differences from the figures, illustration and explanation will be omitted, and the explanation will be focused on the different parts based on FIGS. 3 and 4. Further, in this case, members corresponding to the conventional example are given the same reference numerals and detailed explanations are omitted.

The biggest difference between the first embodiment and the conventional example is
Another feature is that another FPC 60 is interposed between the FPCs 52 and 58 and the hot show 26, and capacitors C ₁ , C ₂ and C ₃ are placed thereon to act as noise removal means. To elaborate, the fourth
As shown in the figure, three pairs of electrodes M ₁ and N ₁ , M ₂ and N ₂ , and N ₃ and M ₃ are arranged in close opposition to each other on the conductor pattern on the FPC 60, and there is a space between each electrode. Capacitors C ₁ , C ₂ and C ₃ are arranged. An electrode _N4 for body grounding is also provided on the pattern of the FPC 60 on which the electrodes _N1 to _N3 are formed. Further, each of the electrodes M ₁ to _{M 3} is formed on a land L ₁ to _{L 3} , respectively, and is electrically connected to the electrodes P ₁ to _{P 3} on the land. Electrodes P ₁ to P ₃ on lands L ₁ to L ₃ are connected to contacts a, b, and c of the hot shoe 26 (see FIG. 2) by lead wires (not shown).
Also, the electrodes P ₁ to _{P 3} are connected to the lead wires B ₁ to
The electrical circuit on the _FPC52 (IC50
etc.). Therefore, the electric signals from the strobe S and the camera Ca are sent to the hot show 26 and
Can be exchanged via FPC60. Here, the lead wire through which the electric signal containing noise is passed when the discharge tube of the strobe S emits light is only the lead wire (not shown) that connects the hot show 26 and the FPC 60 mentioned above, and the lead wire that connects the FPC 60 and the FPC 52 is The electrical signals from which noise has been removed by the capacitors _C1 to _C3 pass through the lead wires _B1 to _B3 that connect them. In addition,
The portion of the FPC 60 other than the portion where the capacitors C ₁ to _{C 3} are mounted is insulated with a cover film or a resistor, thereby insulating the electronic components inside the camera.

In this example, the capacitor
Connect C ₁ to C ₃ to the FPC 60 near the hot shoe 26.
and connect the contacts a to c of the hot shoe 26 and the capacitors C ₁ to _{C 3} with lead wires (not shown).
The lands L ₁ to _{L 3} of the FPC 60 are electrically connected through the electrodes P ₁ to P ₃ . The lead wires (not shown) connecting the contacts a to c of the hot shoe 26 and the capacitors C1 _{to C3} remain in the same position with respect to the camera's electric circuit on the FPC 52 and the FPC 58, and they hang down to the IC 50, etc. There is no contact with
Noise existing near the hot shoe 26 does not adversely affect the operation of the electric circuits 12-22. In addition, each capacitor C ₁ to _{C 3} is on the FPC60,
The capacitors C ₁ ~
The fact that C ₃ is body grounded from one point (electrode L ₄ ) is also effective in preventing the adverse effects of noise.

Therefore, by placing the noise canceling capacitors C ₁ to _{C 3} on the FPC 60 near the hot shoe 26, the contact point a of the hot shoe 26
The lead wires (not shown), which pass electrical signals carrying noise from ~c to capacitors _C1 to _C3 , are much shorter than before (lead wires _B1 to _B3 are free of noise, so It may be a little longer)
Since the lead wire (not shown) does not come into contact with the electric circuit of the camera as in the conventional case, the operation of the electric circuit of the camera is not adversely affected. In addition, since the land L on the FPC 60 is surrounded by a conductor pattern with the ground electrode _N4 , the shielding effect prevents noise signals from having a negative effect on the electrical circuits on other FPCs. .

Next, a second embodiment of the present invention will be described with reference to FIGS. 5 and 6. This embodiment differs from the previous embodiment in the method of connecting the contacts a to c of the hot shoe 26 and the lands _L1 to _L3 on the FPC 60.

That is, from the hot show 26, contacts a, b, c
and four legs 62a, 6 to form an
2b, 62c, and 62d (only two are shown) protrude downward, while on the FPC 70 there are leaf springs for forming corresponding four contacts Q ₁ , Q ₂ , Q ₃ , and Q ₄ . 72, 74, 76 and 78 are arranged. Leaf springs 72 to 78 are FPC70
Fixed parts 82, 84, 86 and 88 fixed on an insulating base 80 placed on the FPC
Leg portions 92, 94, 96 and 98 are soldered to predetermined pattern portions of 70 for electrical conduction, and contact portions Q ₁ , Q ₂ , Q ₃ that rise from the fixed portions 82 to 88 and are elastically deformable in the vertical direction and Q ₄ . The FPC 70 has almost the same configuration as the FPC 60 of the first embodiment.
Land L ₄ for contact X is provided at 0, and screw hole 5
5 is not empty. And for FPC70,
As in the first embodiment, a capacitor for noise cancellation
C ₁ to C ₃ are placed. As shown in Figure 6,
A base 80 is fixed on this FPC 70, and a leaf spring 7
2 to 78, and the legs 92 to 98, respectively.
Solder to lands _L1 to _L4 of FPC70.

In this way, the legs 62a, 62b, etc. come into contact with the contact portions _Q1 to _Q4 , and conduction is easily and reliably established by simply assembling the hot shoe 26 as shown in FIG. Also, hot show 26 and FPC52,
Since the FPC 70 as an insulating material is interposed between the FPC 58 and the FPC 58, as in the first embodiment, the adverse effects of noise on the camera's electric circuit, etc. can be better prevented. Furthermore, in the conventional case, the base 80
Although the spring members 72 to 78 are integrated and fixed to predetermined locations with insulating tape or the like, in this embodiment, the spring members 72 to 78, the base 80 and the FPC 7 are integrated.
Since it is possible to prepare in advance a device with 0 integrated therein and to incorporate it into the camera, there is an advantage that the installation work is easier and more reliable than in the past.

Note that the present invention should not be construed as being limited to the above embodiments; for example, the first substrate
FPC52, FPC58 and the second board FPC6
0 (FPC70) as one FPC, and in that case, the lead wire
B ₁ to _{B 3} can be formed using FPC conductor patterns, eliminating the need for soldering.

(Effects of the invention) As described above, the invention of the present application forms a connecting member extending directly below the external contact of the hot shoe, and mounts the contact piece member that comes into contact with the connecting member on the second board. Therefore, despite the narrow distance between the hot shoe and the second substrate, assembly is easy and the external contact of the hot shoe and the noise removal member on the second substrate can be easily electrically connected.
In addition, by forming a ground conductor pattern on the second board so as to surround the entire area facing the hot show, the external contacts of the hot show, which are a source of noise, can be protected against the electronic components of the first board, which are susceptible to noise. Since the connecting members do not come into contact with each other or face each other, it is possible to completely prevent the electrical circuit of the first board from being adversely affected by noise signals transmitted through the air (shielding effect). Furthermore, the noise removal member removes the noise component riding on the signal from the external contact of the hot shoe, and the signal from the contact of the hot shoe from which noise has been completely removed is transmitted to the electrical circuit of the first board. play.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a strobe attachment part of a conventional camera, FIG. 2 is a block diagram showing a control system for the strobe and camera, and FIG. 3 is a first embodiment of the present invention. FIG. 4 is a perspective view corresponding to FIG. 3, a plan view of the main board of FIG.
The figures each show the second embodiment; FIG. 5 is a front view of the main part of the pentameter part of the camera, and FIG. 6 is a perspective view of the main part board of FIG. 5. Explanation of symbols of main parts, strobe...S, camera...Ca, capacitor (noise removal means)...C ₁ ,
C ₂ , C ₃ , Hot show...26, Hot show contact...a, b, c, X, Discharge tube...32, IC
...50, FPC (first board) ...52,56,
FPC (second board)...60, 70, light receiving element...
...54,56.

Claims (1)

[Claims for Utility Model Registration] A camera having a hot shoe installed on the top of a pentaprism cover to which a strobe can be attached, and equipped with a noise removal member for removing noise generated when the strobe emits light, comprising: A connecting member that is electrically connected to an external contact of the connectable hot show and extends directly below the external contact, and an electronic component or lead for configuring an electric circuit of the camera that is electrically connected to the external contact. A first board provided with a pattern, and a contact member disposed directly below and in the vicinity of the hot show between the hot show and the first board and in contact with the connecting member is mounted. a second board on which the noise removing member is mounted, which is connected to the contact piece member and removes the noise riding on the signal from the connecting member;
In order to prevent the transmission of the noise signal that propagates through the air and adversely affects the first board, a ground potential is applied to surround the area facing the hot shoe including the mounting area of the contact piece member and the noise removal member. a second board on which a ground conductor pattern is arranged, the second board transmits a signal from an external contact of the hot show to the noise removing member from the connecting member and the contact piece member. A strobe-mountable camera, wherein the strobe is transmitted to the first substrate via the strobe.