Abstract: Provided is optical waveguide sheet for a keypad having a light guiding portion 21 positioned below an indicating portion 11a of a keytop part 11, and a light introducing portion 22 positioned above a light source 13 to guide the light emitted from the light source 13 to the light guiding portion 21 so as to be guided toward the indicating portion 11a. The light introducing portion 22 includes a through hole 24 formed therein, a light introducing flap 23 of a barrel shape formed around the edge of the through hole 24 so as to connect with the light introducing portion 22 and protrude toward the light source 13, and a light introducing section 23a provided on an end of the light introducing flap 23 for the light emitted from the light source 13 to be introduced.

Abstract: Disclosed is a push switch device. Since a push button is pressed to relatively rotate first and second pressing members in opposite directions and a push direction conversion unit converts the relative rotation of the first and second pressing members into a push movement in a switching direction, a pressing projection of the first pressing member can accurately vertically press an apex of a movable terminal. Therefore, a sense of click when the movable terminal is resiliently deformed and recovered can be maintained well, and a slide friction generated between the movable terminal and the pressing projection of the first pressing member can be minimized, preventing decrease in sense of operation and reduction in lifespan of parts due to the friction. In addition, an operation sense of the push button can be improved because straightness of the push button can be improved and there is no additional repulsion, except the repulsion by the resilient deformation of the movable terminal.

Abstract: Disclosed is a metal dome switch for a keypad capable of maintaining click sensitivity in an optimal state upon a push operation of a key button by forming a large height of an uplift part while maintaining structural strength of the uplift part, and increasing a height of a pressure concentration projection projecting upward from an apex of a dome-shaped metal plate while minimizing deformation in outer appearance and dimension of the metal dome switch, when the pressure concentration projection is press formed through a press forming process such as a bending process or a half-blanking process.

Abstract: Disclosed is a push switch device. Since a push button is pressed to relatively rotate first and second pressing members in opposite directions and a push direction conversion unit converts the relative rotation of the first and second pressing members into a push movement in a switching direction, a pressing projection of the first pressing member can accurately vertically press an apex of a movable terminal. Therefore, a sense of click when the movable terminal is resiliently deformed and recovered can be maintained well, and a slide friction generated between the movable terminal and the pressing projection of the first pressing member can be minimized, preventing decrease in sense of operation and reduction in lifespan of parts due to the friction. In addition, an operation sense of the push button can be improved because straightness of the push button can be improved and there is no additional repulsion, except the repulsion by the resilient deformation of the movable terminal.

Abstract: Disclosed is a metal dome switch for a keypad capable of maintaining click sensitivity in an optimal state upon a push operation of a key button by forming a large height of an uplift part while maintaining structural strength of the uplift part, and increasing a height of a pressure concentration projection projecting upward from an apex of a dome-shaped metal plate while minimizing deformation in outer appearance and dimension of the metal dome switch, when the pressure concentration projection is press formed through a press forming process such as a bending process or a half-blanking process.