Abstract: An optical switch of the push button type for producing a variable control signal which is proportional to the position of the push button includes a housing, having a first interior wall and a second interior wall, and a push button which extends into the interior of the housing from the exterior thereof. The push button includes a body portion disposed within the housing for movement though each of a plurality of positions, whereby changes in the position of the push button cause proportional changes in an output voltage produced by the switch. A stationary light shield is fixedly disposed within the housing between the body portion of the push button and the first interior wall of the housing, where the shield also includes a plurality of apertures. Light emitting means are disposed within the housing and between the stationary light shield and the first interior wall. Light responsive means are fixedly disposed between the stationary light shield and the body portion of the push button.

Abstract: A magnetic three-dimensional analysis system for use as a tool in the demonstration of hairdressing techniques by an instructor and to aid a student in learning and practicing such techniques. In one form, the system includes four magnetic grid head forms: a left profile grid head form, a right profile grid head form, a front section grid head form, and back section grid head form. The grid head forms have flat backs which are magnetized so they can be attached to a magnetic blackboard or metal sheet. The system also includes numerous flat magnetic or adhesive strips with pointed ends. The strips are cut to certain lengths and color coded to represent different hairdressing techniques. In a preferred embodiment, a grid head form is attached to a magnetic board and the flat magnetic strips are then attached to the board around the grid head form to both define cutting lines and show proper hair length for a plurality of prescribed hair styles.