Resources Contact Us Home
Photographic camera

Image Number 3 for United States Patent #4440481.

A photographic camera of a type utilizing a roll of film comprises a camera back lid, a take-up spool for taking up the film therearound, and a plurality of switches incorporated in the take-up spool. The switches built in the take-up spool are all closed, when the film is turned around the spool, to generate a signal inidcative of the fact that the film has no doubt been secured to the spool. An electric circuit is also provided for disabling the film wind-up so long as the camera back lid has not yet been closed even though the film has already loaded in the camera.

  Recently Added Patents
Flexible lighting devices
Target trading system and method
Haloalky -substituted amides as insecticides and acaricides
Wild card auto completion
Nanogap device for field enhancement and a system for nanoparticle detection using the same
Isolation rings for blocking the interface between package components and the respective molding compound
  Randomly Featured Patents
Optical wavelength tunable filter
Transverse pressurization contour slider
Steering lock apparatus
Template-directed assembly of receptor signaling complexes
Controlled deflection roll
Spray nozzle
Convertible fiber-optic plug
Method of implementing authentication of high-rate packet data services
Portion of power module for power inverter
Apparatus for pulling arrows from surfaces in which they are embedded