# US 2014/0192035 A1 · Pixel circuit, active sensing array, sensing device and driving method thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0192035 A1 - Document ID: US20140192035A1 - Status: Published application - Kind: A1 - Application number: 13/913,521 - Filed: 2013-06-10 - Published: 2014-07-10 - Earliest claimed: 2013-01-04 - Assignees: Industrial Technology Research Institute - Applicants: Industrial Technology Research Institute - Inventors: Ya-Hsiang Tai; Bo-Cheng Chen; Lu-Sheng Chou; Bo-Wen Xiao; Heng-Yin Chen - Web page: https://patentgrep.com/patent/US20140192035A1 ## CPC - H10F 39/803: {Pixels having integrated switching, control, storage or amplification elements} - H04N 25/672: between adjacent sensors or output registers for reading a single image - H04N 25/78: Readout circuits for addressed sensors, e.g. output amplifiers or A/D converters - H10F 39/18: Complementary metal-oxide-semiconductor [CMOS] image sensors; Photodiode array image sensors - H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A pixel circuit, an active sensing array, a sensing device, and a driving method thereof are provided. The pixel circuit includes a sensing transistor, a reset transistor, and a storage capacitor. The sensing transistor is electrically connected to a sensing element and a data line. The reset transistor is electrically connected to a first scan line and the sensing transistor. The storage capacitor is electrically connected to the sensing transistor and a second scan line. During a compensation period, the reset transistor is turned on in response to a first scanning pulse from the first scan line, so that the sensing transistor is connected into a diode configuration, and the storage capacitor charges and discharges to a threshold voltage of the sensing transistor through the sensing transistor having the diode configuration in response to switching of a level of the data line. ## Claims ### Claim 1 A pixel circuit, electrically connected to a first scan line, a second scan line, and a data line, the pixel circuit comprising: a sensing transistor, electrically connected to a sensing element and the data line; a reset transistor, electrically connected to the first scan line and the sensing transistor; and a storage capacitor, electrically connected to the sensing transistor and the second scan line, wherein during a compensation period, the reset transistor is turned on in response to a first scanning pulse from the first scan line, so that the sensing transistor is connected into a diode configuration, and the storage capacitor charges and discharges to a threshold voltage of the sensing transistor through the sensing transistor having the diode configuration in response to switching of a level of the data line. ### Claim 2 (depends on 1) The pixel circuit according to claim 1, wherein during the compensation period, the data line is sequentially switched to a bias voltage and a floating state, wherein when the data line is switched to the bias voltage, the storage capacitor charges to the bias voltage through the sensing transistor having the diode configuration, and when the data line is switched to the floating state, the storage capacitor discharges to the threshold voltage of the sensing transistor through the sensing transistor having the diode configuration. ### Claim 3 (depends on 2) The pixel circuit according to claim 2, wherein the data line is electrically connected to a reading circuit through a switch, and during the compensation period, the switch is sequentially turned on and turned off, wherein when the switch is turned on, the data line is switched to the bias voltage, and when the switch is turned off, the data line is switched to the floating state. ### Claim 4 (depends on 1) The pixel circuit according to claim 1, wherein during a sensing period, the sensing transistor and the reset transistor are turned off, and the sensing element senses an incident energy and stores a sensing voltage into the storage capacitor. ### Claim 5 (depends on 1) The pixel circuit according to claim 1, wherein during a reading period, the reset transistor is turned off, and the sensing transistor generates a sensing current in response to a second scanning pulse from the second scan line and a voltage stored in the storage capacitor. ### Claim 6 (depends on 1) The pixel circuit according to claim 1, wherein the sensing transistor has a first terminal, a second terminal, and a control terminal, wherein the first terminal of the sensing transistor is electrically connected to the data line, the second terminal of the sensing transistor is electrically connected to a ground, the control terminal of the sensing transistor is electrically connected to the sensing element and a first end of the storage capacitor, and a second end of the storage capacitor is electrically connected to the second scan line. ### Claim 7 (depends on 6) The pixel circuit according to claim 6, wherein the reset transistor has a first terminal, a second terminal, and a control terminal, wherein the first terminal of the reset transistor is electrically connected to the first terminal of the sensing transistor, the second terminal of the reset transistor is electrically connected to the control terminal of the sensing transistor, and the control terminal of the reset transistor is electrically connected to the first scan line. ### Claim 8 (depends on 1) The pixel circuit according to claim 1, wherein the sensing element is disposed inside or outside the pixel circuit, or the sensing element is stacked on the pixel circuit. ### Claim 9 A driving method of a pixel circuit, wherein the pixel circuit comprises a sensing transistor, a reset transistor, and a storage capacitor, the driving method comprising: electrically connecting the pixel circuit through a data line, a first scan line, and a second scan line, wherein the sensing transistor is electrically connected to a sensing element and the data line, the reset transistor is electrically connected to the first scan line and the sensing transistor, and the storage capacitor is electrically connected to the sensing transistor and the second scan line; during a compensation period, providing a first scanning pulse to the first scan line to turn on the reset transistor; connecting the sensing transistor into a diode configuration through the turned-on reset transistor; and switching a level of the data line, so that the storage capacitor charges and discharges to a threshold voltage of the sensing transistor through the sensing transistor having the diode configuration. ### Claim 10 (depends on 9) The driving method according to claim 9, wherein the step of electrically connecting the pixel circuit through the data line, the first scan line, and the second scan line comprises: electrically connecting a first terminal of the sensing transistor and a first terminal of the reset transistor through the data line, wherein a second terminal of the sensing transistor is electrically connected to a ground, and a second terminal of the reset transistor is electrically connected to a control terminal of the sensing transistor, a first end of the storage capacitor, and the sensing element; electrically connecting a control terminal of the reset transistor through the first scan line; and electrically connecting a second end of the storage capacitor through the second scan line. ### Claim 11 (depends on 9) The driving method according to claim 9, wherein the step of switching the level of the data line so that the storage capacitor charges and discharges to the threshold voltage of the sensing transistor through the sensing transistor having the diode configuration comprises: during the compensation period, sequentially switching the data line to a bias voltage and a floating state, wherein when the data line is switched to the bias voltage, the storage capacitor charges to the bias voltage through the sensing transistor having the diode configuration, and when the data line is switched to the floating state, the storage capacitor discharges to the threshold voltage of the sensing transistor through the sensing transistor having the diode configuration. ### Claim 12 (depends on 11) The driving method according to claim 11, wherein the step of sequentially switching the data line to the bias voltage and the floating state during the compensation period comprises: disposing a switch between the data line and a reading circuit; and during the compensation period, sequentially turning on and off the switch, wherein when the switch is turned on, the data line is switched to the bias voltage, and when the switch is turned off, the data line is switched to the floating state. ### Claim 13 (depends on 9) The driving method according to claim 9 further comprising: during a sensing period, turning off the sensing transistor and the reset transistor, sensing an incident energy through the sensing element, and storing a sensing voltage into the storage capacitor. ### Claim 14 (depends on 9) The driving method according to claim 9 further comprising: during a reading period, turning off the reset transistor, and providing a second scanning pulse to the second scan line, so that the sensing transistor generates a sensing current in response to the second scanning pulse and a voltage stored in the storage capacitor. ### Claim 15 An active sensing array, comprising: M pixel rows, corresponding to M first scan lines, M second scan lines, and a plurality of data lines, wherein an ith pixel row is electrically connected to an ith first scan line, an ith second scan line, and the data lines, M is a positive integer, i is an integer, 1≦i≦M, the ith pixel row comprises a plurality of pixel circuits, and each of the pixel circuits of the ith pixel row comprises: a sensing transistor, electrically connected to a sensing element and one of the data lines; a reset transistor, electrically connected to the ith first scan line and the sensing transistor; and a storage capacitor, electrically connected to the sensing transistor and the ith second scan line, wherein during a compensation period, the reset transistors of the 1st to the Nth pixel rows are turned on in response to N first scanning pulses from the 1st to the Nth first scan lines, so that the sensing transistors of the 1st to the Nth pixel rows are respectively connected into a diode configuration, wherein N is an integer not greater than M, and during the compensation period, the storage capacitors of the 1st to the Nth pixel rows charge and discharge to threshold voltages of the sensing transistors having the diode configuration of the 1st to the Nth pixel rows through the sensing transistors having the diode configuration in response to switching of levels of the data lines. ### Claim 16 (depends on 15) The active sensing array according to claim 15, wherein during the compensation period, the data lines are sequentially switched to a bias voltage and a floating state, wherein when the data lines are switched to the bias voltage, the storage capacitors of the 1st to the Nth pixel rows respectively charge to the bias voltage through the sensing transistors having the diode configuration, and when the data lines are switched to the floating state, the storage capacitors of the 1st to the Nth pixel rows discharge to the threshold voltages of the sensing transistors having the diode configuration through the sensing transistors having the diode configuration. ### Claim 17 (depends on 16) The active sensing array according to claim 16, wherein the data lines are electrically connected to a plurality of reading circuits through a plurality of switches, and during the compensation period, the switches are sequentially turned on and off, wherein when the switches are turned on, the data lines are switched to the bias voltage, and when the switches are turned off, the data lines are switched to the floating state. ### Claim 18 (depends on 15) The active sensing array according to claim 15, wherein during a sensing period, the sensing transistors and the reset transistors of the M pixel rows are all turned off, and the sensing elements of the M pixel rows respectively sense an incident energy and store a plurality of sensing voltages into the storage capacitors of the M pixel rows. ### Claim 19 (depends on 15) The active sensing array according to claim 15, wherein during a reading period, the reset transistors of the M pixel rows are turned off, and the M pixel rows sequentially receive M second scanning pulses from the M second scan lines, wherein the sensing transistors of the ith pixel row generate a plurality of sensing currents in response to the second scanning pulse from the ith second scan line and voltages stored in the storage capacitors of the ith pixel row. ### Claim 20 (depends on 15) The active sensing array according to claim 15, wherein the sensing transistor has a first terminal, a second terminal, and a control terminal, wherein the first terminal of the sensing transistor is electrically connected to the one of the data lines, the second terminal of the sensing transistor is electrically connected to a ground, the control terminal of the sensing transistor is electrically connected to the sensing element and a first end of the storage capacitor, and a second end of the storage capacitor is electrically connected to the ith second scan line. ### Claim 21 (depends on 20) The active sensing array according to claim 20, wherein the reset transistor has a first terminal, a second terminal, and a control terminal, wherein the first terminal of the reset transistor is electrically connected to the first terminal of the sensing transistor, the second terminal of the reset transistor is electrically connected to the control terminal of the sensing transistor, and the control terminal of the reset transistor is electrically connected to the ith first scan line. ### Claim 22 (depends on 15) The active sensing array according to claim 15, wherein the sensing element is disposed inside or outside the corresponding pixel circuit, or the sensing element is stacked on the corresponding pixel circuit. ### Claim 23 A driving method of an active sensing array, wherein the active sensing array comprises M pixel rows, an ith pixel row comprises a plurality of pixel circuits, and each of the pixel circuits comprises a sensing transistor, a reset transistor, and a storage capacitor, M is a positive integer, i is an integer, and 1≦i≦M, the driving method comprising: electrically connecting the M pixel rows through M first scan lines, M second scan lines, and a plurality of data lines, wherein the ith pixel row is electrically connected to an ith first scan line, an ith second scan line, and the data lines; during a compensation period, providing N first scanning pulses to the 1st to the Nth first scan lines to turn on the reset transistors of the 1st to the Nth pixel rows, wherein N is an integer not greater than M; respectively connecting the sensing transistors of the 1st to the Nth pixel rows into a diode configuration through the turned-on reset transistors of the 1st to the Nth pixel rows; and switching levels of the data lines, so that the storage capacitors of the 1st to the Nth pixel rows charge and discharge to threshold voltages of the sensing transistors having the diode configuration through the sensing transistors having the diode configuration. ### Claim 24 (depends on 23) The driving method according to claim 23, wherein the step of switching the levels of the data lines so that the storage capacitors of the 1st to the Nth pixel rows charge and discharge to the threshold voltages of the sensing transistors having the diode configuration through the sensing transistors having the diode configuration comprises: during the compensation period, sequentially switching the data lines to a bias voltage and a floating state, wherein when the data lines are switched to the bias voltage, the storage capacitors of the 1st to the Nth pixel rows charge to the bias voltage through the sensing transistors having the diode configuration, and when the data lines are switched to the floating state, the storage capacitors of the 1st to the Nth pixel rows discharge to the threshold voltages of the sensing transistors having the diode configuration through the sensing transistors having the diode configuration. ### Claim 25 (depends on 24) The driving method according to claim 24, wherein the step of sequentially switching the data lines to the bias voltage and the floating state during the compensation period comprises: disposing a plurality of switches between the data lines and a plurality of reading circuits; and during the compensation period, sequentially turning on and off the switches, wherein when the switches are turned on, the data lines are switched to the bias voltage, and when the switches are turned off, the data lines are switched to the floating state. ### Claim 26 (depends on 23) The driving method according to claim 23 further comprising: during a sensing period, turning off the sensing transistors and the reset transistors of the M pixel rows, sensing an incident energy through the sensing elements of the M pixel rows and storing a plurality of sensing voltages into the storage capacitors of the M pixel rows. ### Claim 27 (depends on 23) The driving method according to claim 23 further comprising: during a reading period, turning off the reset transistors of the M pixel rows, and sequentially providing M second scanning pulses to the M second scan lines, so that the sensing transistors of the ith pixel row generate a plurality of sensing currents in response to the second scanning pulse from the ith second scan line and voltages stored in the storage capacitors of the ith pixel row. ### Claim 28 A sensing device, comprising: at least one sensing element; and an active sensing array, comprising at least one pixel circuit, wherein the at least one pixel circuit is electrically connected to a first scan line, a second scan line, and a data line and comprises: a sensing transistor, electrically connected to the at least one sensing element and the data line; a reset transistor, electrically connected to the first scan line and the sensing transistor; and a storage capacitor, electrically connected to the sensing transistor and the second scan line, wherein during a compensation period, the reset transistor is turned on in response to a first scanning pulse from the first scan line, so that the sensing transistor is connected into a diode configuration, and the storage capacitor charges and discharges to a threshold voltage of the sensing transistor through the sensing transistor having the diode configuration in response to switching of a level of the data line. ### Claim 29 (depends on 28) The sensing device according to claim 28, wherein during the compensation period, the data line is sequentially switched to a bias voltage and a floating state, wherein when the data line is switched to the bias voltage, the storage capacitor charges to the bias voltage through the sensing transistor having the diode configuration, and when the data line is switched to the floating state, the storage capacitor discharges to the threshold voltage of the sensing transistor through the sensing transistor having the diode configuration. ### Claim 30 (depends on 28) The sensing device according to claim 28 further comprising: a reading circuit; and a switch, having a first terminal electrically connected to the reading circuit and a second terminal electrically connected to the data line, wherein during the compensation period, the sensing device sequentially turns on and off the switch so that the data line is sequentially switched to a bias voltage and a floating state. ### Claim 31 (depends on 30) The sensing device according to claim 30, wherein during a sensing period, the sensing device turns off the sensing transistor, the reset transistor, and the switch, and the at least one sensing element senses an incident energy and stores a sensing voltage into the storage capacitor. ### Claim 32 (depends on 30) The sensing device according to claim 30, wherein during a reading period, the sensing device turns off the reset transistor and turns on the switch, and the sensing transistor generates a sensing current in response to a second scanning pulse from the second scan line and a voltage stored in the storage capacitor. ### Claim 33 (depends on 30) The sensing device according to claim 30, wherein the reading circuit comprises: an operational amplifier, having a first input terminal electrically connected to the first terminal of the switch and a second input terminal for receiving the bias voltage; and a capacitor, having a first end electrically connected to the first input terminal of the operational amplifier and a second end electrically connected to an output terminal of the operational amplifier. ### Claim 34 (depends on 28) The sensing device according to claim 28, wherein the sensing transistor has a first terminal, a second terminal, and a control terminal, wherein the first terminal of the sensing transistor is electrically connected to the data line, the second terminal of the sensing transistor is electrically connected to a ground, the control terminal of the sensing transistor is electrically connected to the at least one sensing element and a first end of the storage capacitor, and a second end of the storage capacitor is electrically connected to the second scan line. ### Claim 35 (depends on 28) The sensing device according to claim 28, wherein the reset transistor has a first terminal, a second terminal, and a control terminal, wherein the first terminal of the reset transistor is electrically connected to the first terminal of the sensing transistor, the second terminal of the reset transistor is electrically connected to the control terminal of the sensing transistor, and the control terminal of the reset transistor is electrically connected to the first scan line. ### Claim 36 (depends on 28) The sensing device according to claim 28 further comprising: a scanning circuit; and a switching circuit, comprising a switching unit having a first terminal, a second terminal, a third terminal, and a fourth terminal, wherein the first terminal and the second terminal of the switching unit are electrically connected to a driving channel of the scanning circuit and a ground respectively, and the third terminal and the fourth terminal of the switching unit are electrically connected to the first scan line and the second scan line respectively, wherein during the compensation period, the scanning circuit generates the first scanning pulse, and the sensing device switches the switching circuit to a first state, so that the first terminal and the third terminal of the switching unit are electrically connected with each other, and the second terminal and the fourth terminal of the switching unit are electrically connected with each other. ### Claim 37 (depends on 36) The sensing device according to claim 36, wherein during a sensing period, the scanning circuit stops generating the first scanning pulse, and the sensing device maintains the switching circuit in the first state. ### Claim 38 (depends on 36) The sensing device according to claim 36, wherein during a reading period, the scanning circuit generates a second scanning pulse, and the sensing device switches the switching circuit to a second state, so that the first terminal and the fourth terminal of the switching unit are electrically connected with each other, and the second terminal and the third terminal of the switching unit are electrically connected with each other. ### Claim 39 (depends on 28) The sensing device according to claim 28, wherein the at least one sensing element is disposed inside or outside the at least one pixel circuit, or the at least one sensing element is stacked on the at least one pixel circuit.