Optical sensing device and optical sensing method thereof

An optical sensing device, comprising:

• a first sensor, configured to sense light to generate a first sensing signal and including a first coating, wherein a spectrum of the first coating includes a first peak of an X spectrum;
• a second sensor, configured to sense the light to generate a second sensing signal and including a second coating, wherein a spectrum of the second coating includes a second peak of the X spectrum;
• a third sensor, configured to sense light to generate a third sensing signal and including a third coating, wherein a spectrum of the third coating includes a Y spectrum;
• a fourth sensor, configured to sense light to generate a fourth sensing signal and including a fourth coating, wherein a spectrum of the fourth coating includes a Z spectrum;
• and
• a processing circuit, coupled to the first sensor, the second sensor, the third sensor, and the fourth sensor, generating an X output value according to the first sensing signal and the second sensing signal, and respectively generating a Y output value and a Z output value according to the third sensing signal and the fourth sensing signal;
• wherein, the processing circuit comprises:
• a first transimpedance amplifier, coupled to the first sensor, configured to amplify and convert the first sensing signal to a first voltage;
• a second transimpedance amplifier, coupled to the second sensor, configured to amplify and convert the second sensing signal to a second voltage;
• a third transimpedance amplifier, coupled to the third sensor, configured to amplify and convert the third sensing signal to a third voltage;
• a fourth transimpedance amplifier, coupled to the fourth sensor, configured to amplify and convert the fourth sensing signal to a fourth voltage;
• a first analog-to-digital converter, coupled to the first transimpedance amplifier to convert the first voltage to a first digital signal;
• a second analog-to-digital converter, coupled to the second transimpedance amplifier to convert the second voltage to a second digital signal;
• a third analog-to-digital converter, coupled to the third transimpedance amplifier to convert the third voltage to a third digital signal;
• a fourth analog-to-digital converter, coupled to the fourth transimpedance amplifier to convert the fourth voltage to a fourth digital signal;
• and
• a color processing unit, coupled to the first analog-to-digital converter, the second analog-to-digital converter, the third analog-to-digital converter, and the fourth analog-to-digital converter, configured to determine the X output value according to the first digital signal and the second digital signal, determine the Y output value according to the third digital signal, and determine the Z output value according to the fourth digital signal;
• wherein, the color processing unit comprises:
• a register, configured to provide a first calibration coefficient, a second calibration coefficient, a third calibration coefficient and a fourth calibration coefficient;
• a first multiplier, coupled to the register and the first analog-to-digital converter, configured to multiply the first digital signal with the first calibration coefficient to generate a first sub-output value;
• a second multiplier, coupled to the register and the second analog-to-digital converter, configured to multiply the second digital signal with the second calibration coefficient to generate a second sub-output value;
• an adder, coupled to the first multiplier and the second multiplier, configured to generate the X output value by adding the first sub-output value to the second sub-output value;
• a third multiplier, coupled to the register and the third analog-to-digital converter, configured to multiply the third digital signal with the third calibration coefficient to generate the Y output value;
• and
• a fourth multiplier, coupled to the register and the fourth analog-to-digital converter, configured to multiply the fourth digital signal with the fourth calibration coefficient to generate the Z output value.

An optical sensing method, comprising the steps of:

• sensing light by a first sensor to generate a first sensing signal, wherein the first sensor includes a first coating, and a spectrum of the first coating includes a first peak of an X spectrum;
• sensing the light by a second sensor to generate a second sensing signal, wherein the second sensor includes a second coating, and a spectrum of the second coating includes a second peak of the X spectrum;
• sensing the light by a third sensor to generate a third sensing signal, wherein the third sensor includes a third coating, and a spectrum of the third coating includes a Y spectrum;
• sensing the light by a fourth sensor to generate a fourth sensing signal, wherein the fourth sensor includes a fourth coating, and a spectrum of the fourth coating includes a Z spectrum;
• and
• generating an X output value according to the first sensing signal and the second sensing signal, and generating a Y output value and a Z output value respectively according to the third sensing signal and the fourth sensing signal;
• wherein, the step of generating the X output value, the Y output value and the Z output value comprises the steps of:
• compensating the first sensing signal, the second sensing signal, the third sensing signal and the fourth sensing signal to generate a fifth sensing signal, a sixth sensing signal, a seventh sensing signal and an eighth sensing signal, respectively;
• converting the fifth sensing signal, the sixth sensing signal, the seventh sensing signal and the eighth sensing signal to a first voltage, a second voltage, a third voltage and a fourth voltage, respectively;
• converting the first voltage, the second voltage, the third voltage and the fourth voltage to a first digital signal, a second digital signal, a third digital signal and a fourth digital signal. respectively;
• determining the X output value according to the first digital signal and the second digital signal;
• determining the Y output value according to the third digital signal;
• and
• determining the Z output value according to the fourth digital signal;
• wherein, the step of determining the X output value, the Y output value and the Z output value comprise the steps of:
• multiplying the first digital signal with a first calibration coefficient to generate a first sub-output value;
• multiplying the second digital signal with a second calibration coefficient to generate a second sub-output value;
• generating the X output value by adding the first sub-output value to the second sub-output value;
• multiplying the third digital signal with a third calibration coefficient to generate the Y output value;
• and
• multiplying the fourth digital signal with a fourth calibration coefficient to generate the Z output value.

An optical sensing method, comprising the steps of:

• sensing light by a first sensor to generate a first sensing signal, wherein the first sensor includes a first coating, and a spectrum of the first coating includes a first peak of an X spectrum;
• sensing the light by a second sensor to generate a second sensing signal, wherein the second sensor includes a second coating, and a spectrum of the second coating includes a second peak of the X spectrum;
• sensing the light by a third sensor to generate a third sensing signal, wherein the third sensor includes a third coating, and a spectrum of the third coating includes a Y spectrum;
• sensing the light by a fourth sensor to generate a fourth sensing signal, wherein the fourth sensor includes a fourth coating, and a spectrum of the fourth coating includes a Z spectrum;
• and
• generating an X output value according to the first sensing signal and the second sensing signal, and generating a Y output value and a Z output value respectively according to the third sensing signal and the fourth sensing signal;
• wherein the step of generating the X output value, the Y output value and the Z output value comprises the steps of:
• amplifying and converting the first sensing signal, the second sensing signal, the third sensing signal and the fourth sensing signal to a first voltage, a second voltage, a third voltage and a fourth voltage, respectively;
• converting the first voltage, the second voltage, the third voltage and the fourth voltage to a first digital signal, a second digital signal, a third digital signal and a fourth digital signal, respectively;
• determining the X output value according to the first digital signal and the second digital signal;
• determining the Y output value according to the third digital signal;
• and
• determining the Z output value according to the fourth digital signal;
• wherein the step of determining the X output value, the Y output value and the Z output value comprise the steps of:
• multiplying the first digital signal with a first calibration coefficient to generate a first sub-output value;
• multiplying the second digital signal with a second calibration coefficient to generate a second sub-output value;
• generating the X output value by adding the first sub-output value to the second sub-output value;
• multiplying the third digital signal with a third calibration coefficient to generate the Y output value;
• and
• multiplying the fourth digital signal with a fourth calibration coefficient to generate the Z output value.