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
Low drop-out regulator providing constant current and maximum voltage limit
System and method for stranded file opens during disk compression utility requests
Multi-function wrench for a power tool
Rotation angle detecting device
Fuel cell system, and electric vehicle equipped with the fuel cell system
Edge alphas for image translation
Ionic compound, anti-static pressure-sensitive adhesive and polarizer comprising the same
  Randomly Featured Patents
Apparatus for manipulating droplets
Transseptal puncture needles and needle assemblies
Push-button type sprayer
Imaging system with a diamine charge transport material in a polycarbonate resin
Control system for internal combustion engines
Ballistic tolerant dual load path ballscrew and ballscrew actuator
Tube expander
Multiple saw blade adjustable dado cutter assembly including a cam assembly and nestable dado blades
Compressible blanket assembly