A method for adjusting an optical switch keyboard and an optical switch keyboard using the adjusting method are provided. The optical switch keyboard has a number of key units. The method includes the following steps. A scan signal is applied to one of a number of scan lines by a control unit at a first scan time point. A light is emitted by a light source according to the scan signal. A light emitted by the light source is detected by a detecting element to generate a detecting electric signal. The detecting electric signal is read by the control unit to obtain a first read signal voltage. When the first read signal voltage is outside the voltage range of the pressed state of the key unit, the period of the scan signal is increased by a first predetermined amount by the control unit to obtain an adjusted scan signal.

A method for adjusting an optical switch keyboard and an optical switch keyboard using the adjusting method are provided. The optical switch keyboard has a number of key units. The method includes the following steps. A scan signal is applied to one of a number of scan lines by a control unit at a first scan time point. A light is emitted by a light source according to the scan signal. A light emitted by the light source is detected by a detecting element to generate a detecting electric signal. The detecting electric signal is read by the control unit to obtain a first read signal voltage. When the first read signal voltage is outside the voltage range of the pressed state of the key unit, the period of the scan signal is increased by a first predetermined amount by the control unit to obtain an adjusted scan signal.

A light control type key switch assembly includes multiple key switch units each including a key switch holder and a key switch mounted in the key switch holder, multiple light receivers respectively mounted around one respective key switch holder, and a light-emitting unit including a light source and a light guide facing toward the light source and neighbored to each key switch holder for guiding the emitted light from the light source along a light path toward each light receiver. When the key switch is not pressed, the plunger of the respective key switch is kept away from the light path, and thus no electrical signal will be generated. When the key switch is pressed, the plunger of the respective key switch enters the light path, causing an electrical signal output.