TFT optical sensor apparatus and system with enhanced dynamic range
AssigneeJapan Display Inc.
InventorsXingle Wang, Chungkai Chen, Naoki Takada
Life of this patent
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Abstract
An optical sensor system includes a thin-film transistor (TFT) optical panel including an array of TFT pixels, a charge amplifier configured to temporarily store a charge received from a TFT pixel in the array of TFT pixels and generate a voltage based on the temporarily stored charge, an analog-to-digital converter to generate a digitized value based on the voltage, an accumulator configured to store the digitized value, and a controller circuit configured to cause the temporarily stored charge in the charge amplifier to be reset based on one of the voltage and the digitized value.
Claims14
An optical sensor system comprising:
- a thin-film transistor (TFT) optical panel including an array of TFT pixels;
- a charge amplifier configured to temporarily store a charge received from a TFT pixel in the array of TFT pixels and generate a voltage based on the temporarily stored charge;
- an analog-to-digital converter to generate a digitized value based on the voltage;
- an accumulator configured to store the digitized value;
- and
- a controller circuit configured to cause the temporarily stored charge in the charge amplifier to be reset based on one of the voltage and the digitized value, wherein
- the charge amplifier includes
- an operational amplifier, and
- a reset transistor having a first controlled terminal connected to an inverting input of the operational amplifier, a second controlled terminal connected to an output of the operational amplifier, and a reset control terminal that controls current flow in the first controlled terminal and the second controlled terminal;
- and
- the controller circuit is configured to send a reset signal pulse to the reset control terminal to cause the temporarily stored charge in the charge amplifier to be reset.
A method of operating an optical sensor system, the method comprising:
- receiving light on a thin-film transistor (TFT) optical panel including an array of TFT pixels;
- temporarily storing, in a charge amplifier, a charge received from a TFT pixel in the array of TFT pixels;
- generating a voltage based on the temporarily stored charge;
- generating, in an analog-to-digital converter, a digitized value based on the voltage;
- storing the digitized value in an accumulator;
- causing, by a controller circuit, the temporarily stored charge in the charge amplifier to be reset based on one of the voltage and the digitized value;
- and
- sending, from the controller circuit, a reset signal to cause the temporarily stored charge in the charge amplifier to be reset, when the voltage exceeds a predetermined threshold.
A non-transitory computer readable medium storing instructions, which when executed by a computer in an optical sensor system including a thin-film transistor (TFT) optical panel including an array of TFT pixels, a charge amplifier configured to temporarily store a charge received from a TFT pixel in the array of TFT pixels and generate a voltage based on the temporarily stored charge, and an analog-to-digital converter to generate a digitized value based on the voltage, cause the computer to perform steps comprising:
- storing the digitized value in an accumulator;
- and
- causing the temporarily stored charge in the charge amplifier to be reset based on one of the voltage and the digitized value, wherein
- the computer is further cause to perform steps further comprising:
- sending a reset signal to cause the temporarily stored charge in the charge amplifier to be reset when the digitized value based on the voltage exceeds a predetermined threshold.
Dependencies are inferred from the claim text.