Abstract: A push button device in which convex portions are provided on the lower surface of a button positioned to turn a switch mounted on a substrate ON and OFF. The convex portions are provided at a position symmetrical with a center axis of the button, and a resilient member is provided in contact with the lower surface of the button and placed in pressure contact with the convex portions. A smooth restoring force when the resilient member is restored from being and compression deformation is obtained through the joint use of an action of the convex portions of the button to bend the resilient member and a compression action caused by a small area. As a result, the switch can be turned ON and OFF without much pressure, and the button is always reliably returned to its original position when pressure is removed. Also, the convex portions engage the resilient member to prevent play.

Abstract: A surface lighting apparatus for backlighting a liquid crystal display panel(LCD) (4) has a light guide (11) for evenly illuminating back face of the LCD, the light guide comprising: an incidence plane wherefrom light beams from light source come in; a front face disposed vertical to the incidence plane wherefrom the light beams are out; and a curved back face whereon light reflecting layer is formed for reflecting the light beams to the front face.

Abstract: In a liquid crystal display, a shade frame (9) is provided between a light source (1) and a filter (41) in order to shade heat coming from the light source (1) toward the filter (41).

Abstract: A planar luminescent device comprising a light source whose luminance distribution exhibits varied luminous intensity from a high level to a low level, a light transmitting plate having a light transmitting property and shaped in a planar form, and a reflecting frame for enclosing the light source in cooperation with the surface of a printed board to which the light source is attached and the end face of the light transmitting plate and also holding the light transmitting plate having its end faces on which the light from the light source does not impinge in close contact therewith, in which a portion on an end face of the light transmitting plate is disposed closest to the position where the luminance of the light source is at the low level and incident light on the end face is adapted to be scatteringly reflected by a scattering reflection layer disposed on the back face of the light transmitting plate and radiated from the surface of the same.

Abstract: A rotating drum device, of a tape that a magnetic head scans recording tracks which are formed obliquely with respect to a travelling direction of a magnetic tape at any speed of the magnetic tape, comprises a driving part attached to a rotating drum, a supporting member supporting a magnetic head, a coil mounted on the supporting member and a magnetic unit. A control electric current is supplied to the coil depending on the travelling speed of the magnetic tape to produce a magnetic force, whereby the magnetic head is vertically moved along the axis of rotation of the rotating drum.