US 12,293,883 B2
Backlight keyswitch and backlight module thereof
Heng-Yi Huang, Taoyuan (TW)
Assigned to DARFON ELECTRONICS CORP., Taoyuan (TW)
Filed by DARFON ELECTRONICS CORP., Taoyuan (TW)
Filed on Mar. 30, 2023, as Appl. No. 18/128,240.
Claims priority of provisional application 63/325,623, filed on Mar. 31, 2022.
Claims priority of application No. 112109798 (TW), filed on Mar. 16, 2023.
Prior Publication US 2023/0317386 A1, Oct. 5, 2023
Int. Cl. H01H 13/83 (2006.01)
CPC H01H 13/83 (2013.01) [H01H 2219/06 (2013.01); H01H 2219/062 (2013.01); H01H 2219/064 (2013.01)] 38 Claims
OG exemplary drawing
 
1. A backlight keyswitch comprising:
a keyswitch body;
a board disposed under the keyswitch body and connected to the keyswitch body to make the keyswitch body movable relative to the board, the board having at least one hole region corresponding to the keyswitch body;
a membrane circuit board disposed between the keyswitch body and the board; and
a backlight module disposed under the board, the backlight module comprising:
a light guide plate having a containing hole corresponding to the keyswitch body and having an optical microstructure corresponding to at least one hole region;
a backlight circuit board disposed under the light guide plate and having a backlight source disposed in the containing hole;
a light-blocking sheet disposed between the board and the light guide plate and having a light-permeable region corresponding to the keyswitch body;
a first reflecting ink layer formed on the light-blocking sheet and located above the backlight source, for reflecting at least partial light emitted upward by the backlight source back to the optical microstructure, such that light can pass through the light-permeable region, the at least one hole region, and the membrane circuit board sequentially via scattering of the optical microstructure to be incident to the keyswitch body; and
an opaque ink layer, wherein the opaque ink layer is formed on the first reflecting ink layer formed on an upper surface of the light-blocking sheet, or the opaque ink layer and the first reflecting ink layer are formed on the upper surface and the lower surface of the light-blocking sheet respectively, for preventing light passing through the first reflecting ink layer from being incident to the keyswitch body.