US 12,333,086 B2
Composite function keyboard circuit
Yi-Liang Chen, Taipei (TW); Chih-Chen Chang, Taipei (TW); and Chien-Ming Li, Taipei (TW)
Assigned to Primax Electronics Ltd., Taipei (TW)
Filed by Primax Electronics Ltd., Taipei (TW)
Filed on May 4, 2023, as Appl. No. 18/143,552.
Claims priority of application No. 112110126 (TW), filed on Mar. 17, 2023.
Prior Publication US 2024/0310926 A1, Sep. 19, 2024
Int. Cl. G06F 3/023 (2006.01); H01H 13/703 (2006.01); H01H 13/785 (2006.01); H01H 13/79 (2006.01); H01H 13/80 (2006.01); H03K 17/96 (2006.01)
CPC G06F 3/0233 (2013.01) [G06F 3/0238 (2013.01); H01H 13/703 (2013.01); H01H 13/785 (2013.01); H01H 13/79 (2013.01); H01H 13/80 (2013.01); H03K 17/9625 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A composite function keyboard circuit, comprising:
a first matrix circuit comprising a first driving line group with plural first driving lines, a first sensing line group with plural first sensing lines and a first switch unit group with plural first switch units, wherein the plural first driving lines and the plural first sensing lines are arranged in a matrix, and each of the first switch units of the first switch unit group is electrically connected with a corresponding first sensing line and a corresponding first sensing line;
a first bias resistor group electrically connected with the first sensing line group and electrically connected with the first switch unit group in series, wherein the first bias resistor group comprises plural first bias resistors, a first terminal of each of the plural first bias resistors of the first bias resistor group is electrically connected with the first sensing line group and the first switch unit group, and a second terminal of each of the plural first bias resistors of the first bias resistor group is electrically connected with a ground terminal;
a second matrix circuit comprising a second driving line group with at least one second driving line, a second sensing line group with plural second sensing lines and a second switch unit group with plural second switch units, wherein the at least one second driving line and the plural second sensing lines are arranged in a matrix, and each of the second switch units of the second switch unit group is electrically connected with a corresponding second sensing line and a corresponding second sensing line;
a second bias resistor group electrically connected with the second sensing line group and electrically connected with the second switch unit group in series, wherein the second bias resistor group comprises plural second bias resistors, a first terminal of each of the plural second bias resistors of the second bias resistor group is electrically connected with the second sensing line group and the second switch unit group, and a second terminal of each of the plural second bias resistors of the second bias resistor group is electrically connected with the ground terminal; and
a controller electrically connected with the first driving line group, the first sensing line group, the first terminal of each of the first bias resistors of the first bias resistor group, the second driving line group, the second sensing line group and the first terminal of each of the second bias resistors of the second bias resistor group,
wherein each of the second switch units of the second switch unit group is an ink-type force sensing switch, a resistance of the ink-type force sensing switch is variable according to a pressing mode of a keypress action, and an electrical connection path is formed between the ink-type force sensing switch and a corresponding second bias resistor of the second bias resistor group, wherein when the ink-type force sensing switch is electrically conductive, a divided sensing voltage is generated by the electrical connection path, and the controller generates a corresponding key control instruction according to a level of the divided sensing voltage.