Optical sensor having current amplifier including at least one thin-film transistor, and display apparatus provided with the optical sensor

An optical sensor comprising:

• an optical sensor element to receive external light, and output a photocurrent signal according to the illuminance of the external light;
• and
• a current amplifier including thin-film transistors, to increase and decrease an output current in proportion to an increase and decrease in the photocurrent signal output from the optical sensor element,
• wherein the optical sensor element has the same layers lamination structure as each of the thin-film transistors included in the current amplifier.

An optical sensor comprising:

• an optical sensor element including a thin-film transistor, to output a photocurrent signal according to the illuminance of external light;
• a current-to-voltage converter including a thin-film transistor, to convert the photocurrent signal to a voltage signal;
• a voltage amplifier including an inverter circuit including two thin-film transistors connected in series, to amplify the voltage signal;
• and
• a current amplifier including at least one thin-film transistor, to output a current signal according to the voltage signal amplified by the voltage amplifier,
• wherein the thin-film transistors included in the optical sensor element, current-to-voltage converter, voltage amplifier, and current amplifier have the same layers lamination structures as each other.

A display apparatus comprising:

• a display unit having arrays of pixels, each having a thin-film transistor, which displays an image by controlling transmission of light input to the pixels;
• an illumination unit which emits an illumination light to illuminate the pixels;
• an optical sensor which comprises a photoelectric converter to receive external light and output a photocurrent signal according to the illuminance of the external light, a current-to-voltage converter to convert the photocurrent signal to a voltage signal, a voltage amplifier to amplify the voltage signal, and a current amplifier to output a current signal according to the voltage signal amplified by the voltage amplifier, wherein each of the photoelectric converter, current-to-voltage converter, voltage amplifier and current amplifier includes at least one thin-film transistor;
• and
• a control unit which controls the illuminance of the illumination light based on the current signal output from the optical sensor.

A display apparatus comprising:

• a display unit having arrays of pixels, each having a thin-film transistor, which displays an image by controlling transmission of light input to the pixels;
• an illumination unit which emits an illumination light to illuminate the pixels;
• an optical sensor which comprises an optical sensor element to receive external light, and output a photocurrent signal according to the illuminance of the external light, and a current amplifier including thin-film transistors, to increase and decrease an output current signal in proportion to an increase and decrease in the photocurrent signal output from the optical sensor element, wherein the optical sensor element and each of thin-film transistors included in the current amplifier have the same layers lamination structures as each other;
• and
• a control unit which controls the illuminance of the illumination light based on the current signal output from the optical sensor.

A display apparatus comprising:

• a display unit having arrays of pixels, each having a thin-film transistor, which displays an image by controlling transmission of light input to the pixels;
• an illumination unit which emits an illumination light to illuminate the pixels;
• an optical sensor which comprises an optical sensor element including a thin-film transistor, to receive external light and output a photocurrent signal according to the illuminance of the external light, a current-to-voltage converter including a thin-film transistor to convert the photocurrent signal to a voltage signal, a voltage amplifier including an inverter circuit including two thin-film transistors connected in series, to amplify the voltage signal, and a current amplifier including at least one thin-film transistor, to output a current signal according to the voltage signal amplified the voltage amplifier, wherein the thin-film transistors included in the optical sensor element, current-to-voltage converter, voltage amplifier, and current amplifier have the same layers lamination structures as each other;
• and
• a control unit which controls the illuminance of the illumination light based on the current signal output from the optical sensor.