Manual or automatic camera and electronic flash for use therewith

Abstract

A camera has an electrical exposure-time determining structure as well as a manually adjustable electrical structure and a light-responsive electrical structure both of which are connected to the exposure-time determining structure by way of a selecting circuit which can be set to operate the exposure-time determining structure either by way of the manually adjustable electrical structure or by way of the light-responsive electrical structure. An electronic flash assembly can be connected to the camera to provide additional flash illumination if necessary. The electronic flash assembly is connected with the camera in such a way that the exposure-time determining structure thereof will be operated by way of the light-responsive electrical structure irrespective of whether the selector circuit structure is set for operating the exposure-time determining structure by way of the manually adjustable electrical structure or by way of the light-responsive electrical structure.

What is claimed is: 
     
       1. In a camera, electrical exposure-time determining means, light-responsive electrical means, manually adjustable electrical means, and selector circuit means electrically connecting said light-responsive electrical means and said manually adjustable electrical means to said exposure-time determining means for selectively controlling the latter either by way of said light-responsive electrical means for automatically determining the exposure time in accordance with lighting conditions or by way of said manually adjustable electrical means for providing a manually determined exposure time, electronic flash means for providing, if necessary, additional flash illumination to be utilized for exposure, and electrical connecting means connecting said electronic flash means to said selector circuit means for rendering the latter operable to control said exposure-time determining means by way of said light-responsive electrical means irrespective of whether said selector circuit means is set for controlling said exposure-time determining means by way of said light-responsive electrical means or said manually adjustable electrical means when additional flash illumination is required from said electronic flash means. 
     
     
       2. The combination of claim 1 and wherein said electronic flash means includes a control means for preventing operation of said electronic flash means in the event that the latter has not yet operated to produce flash illumination and for terminating operation of said electronic flash means after the latter has started to provide flash illumination, said exposure-time determining means being electrically connected with said control means for operating the latter upon termination of an exposure either to prevent operation of said electronic flash means in the event that the latter has not yet provided any flash illumination or to terminate operation of said electronic flash means in the event that the latter has started to provide flash illumination. 
     
     
       3. The combination of claim 2 and wherein a means is operatively connected with said electronic flash means for selectively disconnecting said control means thereof from said exposure-time determining means and for selectively disconnecting said electronic flash means from said selector circuit means by way of said electrical connecting means, so that if desired the electronic flash means can be operated independently of the camera while said exposure-time determining means can be selectively operated either by way of said light-responsive means or by way of said manually adjustable means. 
     
     
       4. The combination of claim 2 and wherein said electronic flash means includes a signal-generating means for generating a signal indicating that said electronic flash means is ready for operation, said electrical connecting means connecting said signal-generating means to said selector circuit means for rendering said exposure-time determining means operable only by way of said light-responsive means irrespective of whether said selector circuit means is set for operation by said light-responsive means or by said manually adjustable means, only when said signal is generated by said signal-generating means, whereby after said signal is generated if sufficient light is available for exposure without flash illumination said exposure-time determining means will operate said control means to prevent operation of said electronic flash means while if additional flash illumination is required, said additional flash illumination will be detected by said light-responsive means and said exposure-time determining means will operate said control means to terminate operation of said electronic flash means when the light from the latter and the available light are sufficient for exposure. 
     
     
       5. The combination of claim 4 and wherein said selector circuit means includes a selecting switch capable of being manually placed in open or closed positions and connecting said light-responsive means to said exposure-time determining means in one of said positions and said manually adjustable means to said exposure-time determining means in the other of said positions, said electrical connecting means including a transistor connected in parallel across said switch and rendered operable upon receiving said signal for connecting said light-responsive means to said exposure-time determining means irrespective of the position of said switch. 
     
     
       6. The combination of claim 4 and wherein said electronic flash means includes a flash lamp and a trigger circuit electrically connected therewith for rendering said lamp operable to provide flash illumination, said trigger circuit including a trigger capacitor and a thyristor connected in series therewith and having a gate, said signal generating means being electrically connected with said gate to prevent charging of said trigger capacitor unless said signal is generated, so that without generation of said signal said electronic flash means cannot operate and said exposure-time determining means will be operated either by said light-responsive means or by said manually adjustable means in accordance with the condition of said selector circuit means. 
     
     
       7. The combination of claim 4 and wherein said light-responsive electrical means includes a timing switch adapted to be .[.closed.]. .Iadd.opened .Iaddend.in synchronism with opening of a shutter of a camera for rendering said light-responsive electrical means operative, and said electronic flash means including an X-contact switch adapted to close subsequent to the .[.closing.]. .Iadd.opening .Iaddend.of said timing switch for rendering said electronic flash means operative, whereby if said light-responsive electrical means receives an amount of light sufficient for exposure prior to closing of said X-contact switch said exposure-time determining means will terminate the exposure and will operate said control means to prevent operation of said electronic flash means even if said X-contact switch should subsequently close. .Iadd. 8. Electronic flash apparatus for a camera having a shutter, electrical exposure-time determining means, light-responsive means for supplying information on light intensity to said electrical exposure-time determining means, a timing switch in said camera included in said light-responsive means and adapted to be opened in synchronism with opening of said shutter for rendering said light-responsive means operative and an X-contact switch coupled to said timing switch by means for closing said X-contact switch subsequent to the opening of said timing switch, said flash apparatus comprising: flash means for illumination; and   control means electrically connected to said flash means and adapted to be electrically connected to said X-contact switch and to said electrical exposure-time determining means of the camera when said camera and flash apparatus are connected for preventing operation of said flash means when said flash means has not yet operated to provide flash illumination and for terminating operation of said flash means after said flash means has started to provide flash illumination. .Iaddend. .Iadd. 9. Electronic flash apparatus as claimed in claim 8, further comprising a souce of voltage electrically connected to said flash means and signal generating means electrically connected to said source of voltage and connectable to said electrical exposure-time determining means of said camera for generating a signal indicating that said flash means is ready for operation. .Iaddend..Iadd. 10. Electronic flash apparatus as claimed in claim 9, wherein said camera has manually adjustable electrical means and settable selector circuit means electrically connecting said light-responsive means in said flash manually adjustable means to said exposure-time determining means, said apparatus further comprising electrical connecting means electrically connecting said signal-generating means to the selector circuit means of the camera for rendering said exposure-time determining means operable only by way of said light-responsive means irrespective of the setting of said selector circuit means for operation by said light-responsive means or by said manually adjustable means, only when said signal is generated by said signal-generating means, whereby after said signal is generated if sufficient light is available for exposure without flash illumination said exposure-time determining means will operate said control means to prevent operation of said flash means while if additional flash illumination is required, said additional flash illumination will be detected by said light-responsive means and said exposure-time determining means will operate said control means to terminate operation of said flash means when the light from the latter and the available light are sufficient for exposure. .Iaddend..Iadd. 11. Electronic flash apparatus as claimed in claim 10, wherein said flash means consists of a flash lamp and said electronic flash apparatus further comprises a trigger circuit electrically connected to said flash lamp for rendering said lamp operable to provide flash illumination, said trigger circuit including a trigger capacitor and a thyristor connected in series therewith and having a gate, said signal-generating means being electrically connected to said gate to prevent charging of said trigger capacitor unless said signal is generated, so that without generation of said signal said electronic flash apparatus cannot operate and said exposure-time determining means of said camera will be operated either by said light-responsive means or by said manually adjustable means in accordance with the condition of said selector circuit means. .Iaddend. .Iadd. 12. Electronic flash apparatus as claimed in claim 10, wherein if said light-responsive means receives an amount of light sufficient for exposure prior to closing of said X-contact switch, said exposure-time determining means of said camera will terminate the exposure and will operate said control means to prevent operation of said electronic flash apparatus even if said X-contact switch should subsequently close. .Iaddend. .Iadd. 13. Electronic flash apparatus as claimed in claim 8, further comprising switch means electrically connected to said flash means for selectively disconnecting said control means from said exposure-time determining means of said camera, to permit said flash means to be operated independently of said camera. .Iaddend. .Iadd. 14. Electronic flash apparatus for a camera having a shutter, electrical exposure-time determining means, light-responsive means for supplying information on light intensity to said electrical exposure-time determining means, a timing switch in said camera included in said light-responsive means adapted to be opened in synchronism with opening of said shutter for rendering said light-responsive means operative and an X-contact switch coupled to said timing switch by means for closing said X-contact switch subsequent to the opening of said timing switch, said flash apparatus comprising:   a source of potential;   a main capacitor electrically connected to said source of potential;   flash means for providing flash illumination; and   flash control means adapted to be electrically connected to said X-contact switch and to said electrical exposure-time determining means of said camera when said camera and flash apparatus are connected, said control means including,   a first trigger circuit including a first trigger transformer for triggering said flash means and a first thyristor electrically connecting said first transformer to said source of potential and which becomes conductive in response to a signal representing completion of charging of said main capacitor;   quenching means electrically connected in parallel with said flash means for terminating energization thereof; and   a second trigger circuit including a second trigger transformer for triggering said quenching means and a second thyristor electrically coupled to said second transformer and electrically connected to said source of potential, said second thyristor becoming conductive in response to exposure-time information from said electrical exposure-time determining means of the camera, said second trigger transformer being electrically connected to said source of potential through said first thyristor, said second trigger circuit being caused to operate before said first trigger circuit to prevent said flash means from flashing when the exposure-time information from said electrical exposure-time determining means indicates that flash illumination from said flash means is not required and when said exposure-time information indicates a requirement for flash illumination and exposure-time information turning on said second thyristor upon reaching a proper exposure value after said flash means has started providing flash illumination thereby automatically adjusting the duration of said flash illumination. .Iaddend.