Abstract:
A photosensing transistor (100) for optical touch screens includes a gate layer (110), a gate insulation layer (120) on the gate layer, a channel layer (130) on the gate insulation layer, an etch stop layer (140) on a partial area of the channel layer (130), a source (150) and a drain (160) on the channel layer (130) and separated from each other with the etch stop layer (140) being interposed between the source (150) and the drain (160), and a passivation layer (170) covering the source(150), the drain (160), and the etch stop layer (140), wherein the source (150) is separated from the etch stop layer (140). The disclosed transistor structure has an improved efficiency in sensing incident light and increases an area of the channel layer (130) to be exposed to the incident light. A manufacturing method for the photosensing transistor (100) is also disclosed.
Abstract:
An apparatus comprises a transparent substrate (3), at least one sensor (5) for the detection of electromagnetic radiation (31), and for each sensor a corresponding mirror having a reflective surface (11). The reflective surface (11) is shaped so that electromagnetic radiation (31) incident on the transparent substrate (3) at a specific angle, passing through the transparent substrate (3) and being reflected by the reflective surface (11) is directed towards the sensor (5). The sensor (5) comprises a two dimensional material like graphene and may be a quantum dot functionalised graphene field effect transistor. The present invention enables the incident electromagnetic radiation (31) to be focussed onto the at least one sensor (5) without the use of additional optical components like lenses or microlenses. This may enable focussed images to be obtained by the apparatus.
Abstract:
A photosensing transistor (100) for optical touch screens includes a gate layer (110), a gate insulation layer (120) on the gate layer, a channel layer (130) on the gate insulation layer, an etch stop layer (140) on a partial area of the channel layer (130), a source (150) and a drain (160) on the channel layer (130) and separated from each other with the etch stop layer (140) being interposed between the source (150) and the drain (160), and a passivation layer (170) covering the source(150), the drain (160), and the etch stop layer (140), wherein the source (150) is separated from the etch stop layer (140). The disclosed transistor structure has an improved efficiency in sensing incident light and increases an area of the channel layer (130) to be exposed to the incident light. A manufacturing method for the photosensing transistor (100) is also disclosed.
Abstract:
The invention relates to a photoarray(1), comprising: a plurality of cells (10), wherein each of said cells (10) comprises a means (20)that is configured to generate a photocurrent (I) being proportional to the intensity (L) of the light impinging on the respective cell(10), and wherein each of said cells (10) comprises a change detection circuit(100) connected to the respective means (20) for generating the photocurrent (I), which change detection circuit (100) is configured to generate an output signal merely in case a change event occurs at which said intensity (L) changes by a threshold amount (T, T') since the preceding change event from the respective cell (10). According to the invention said means (20) for generating said photocurrent (I) is additionally also used to estimate the magnitude of the said photocurrent (I) being a measure of the brightness of the light at the respective cell (10).
Abstract:
A photoelectric conversion device includes a pixel cell including a phototransistor, a reference cell including a reference transistor having a temperature characteristic identical to that of the phototransistor and having a fixed electrical state, an analog-to-digital converter that converts an analog output of the pixel cell into a digital output, a correction amount computation unit that computes a correction amount for the digital output of the analog-to-digital converter based on an output of the reference cell and a reference value, and a correction unit that corrects the digital output of the analog-to-digital converter based on the correction amount.
Abstract:
The invention relates to a photoarray(1), comprising: a plurality of cells (10), wherein each of said cells (10) comprises a means (20)that is configured to generate a photocurrent (I) being proportional to the intensity (L) of the light impinging on the respective cell(10), and wherein each of said cells (10) comprises a change detection circuit(100) connected to the respective means (20) for generating the photocurrent (I), which change detection circuit (100) is configured to generate an output signal merely in case a change event occurs at which said intensity (L) changes by a threshold amount (T, T') since the preceding change event from the respective cell (10). According to the invention said means (20) for generating said photocurrent (I) is additionally also used to estimate the magnitude of the said photocurrent (I) being a measure of the brightness of the light at the respective cell (10).
Abstract:
An apparatus configured to alternate, at a predetermined frequency, the application of first and second gate voltages (311) to a gate electrode (304) of a photodetector during exposure of a plurality of quantum dots (306) of the photodetector to incident electromagnetic radiation to produce a signal comprising respective first and second changes in electrical current substantially at the predetermined frequency, wherein the first change in electrical current is relative to a predetermined measurement of electrical current taken at the first gate voltage in the absence of the incident electromagnetic radiation, and the second change in electrical current is relative to a predetermined measurement of electrical current taken at the second gate voltage in the absence of the incident electromagnetic radiation, the photodetector comprising a channel (303), and source and drain electrodes configured to enable a flow of electrical current through the channel (303) between the source and drain electrodes, the quantum dots (306) configured to generate charge carriers on exposure to the incident electromagnetic radiation to cause a detectable change in the electrical current flowing through the channel (303), the gate electrode configured to generate an electric field upon the application of a gate voltage thereto to tune the detectable change in electrical current. The apparatus is further configured to process the signal to at least partially remove any changes in electrical current which are attributed to noise such that the resulting processed signal is indicative of one or more of the presence and magnitude of the incident electromagnetic radiation.