This application is based on and claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2020-0183610, filed on Dec. 24, 2020 in the Korean Intellectual Property Office, the disclosure of which is incorporated by reference herein in its entirety.
Example embodiments of the present disclosure relate to a thermal infrared detector.
Thermal infrared devices convert heat generated within a device into an electrical signal by absorbing far-infrared (LWIR) energy emitted from an object to be measured. Thermal imaging cameras or thermography may convert signals of a plurality of thermal infrared devices arranged in a two-dimensional array into a thermal image, so that a temperature difference of an object to be measured or a whole scene may be seen with the naked eye. Typical thermal infrared detection devices operating at room temperature may include a bolometric device, a thermopile, and a pyroelectric device. These devices are used in various small or portable applications because they do not need a cryogenic cooling system.
One or more example embodiments provide a thermal infrared detector, a thermal infrared sensor array, and a driving method thereof.
Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of example embodiments.
According to an aspect of an example embodiment, there is provided a thermal infrared detector including a thermal infrared sensor array including a plurality of resistive infrared devices that are provided in a plurality of rows and a plurality of columns, and a driving circuit configured to drive the thermal infrared sensor array, wherein at least two resistive infrared devices among the plurality of resistive infrared devices adjacent to each other in a row direction or a column direction are grouped together, wherein at least one resistive infrared device among the plurality of resistive infrared devices is shared by at least two groups, and wherein at least two resistive infrared devices among the plurality of resistive infrared devices that are included in each of the at least two groups are connected in series.
The thermal infrared detector may further include a connection switch connected between the at least two resistive infrared devices included in each of the at least two groups.
A number of the plurality of rows may be M, a number of the plurality of columns may be N, where M and N may be each a natural number greater than or equal to 3.
Each pixel among a plurality of pixels including each of the plurality of resistive infrared devices may include a first switch having a first end connected to a row direction line and a second end connected to a first end of the each of the plurality of resistive infrared devices, and a second switch having a first end connected to a column direction line and a second end connected to a second end of the each of the plurality of resistive infrared devices.
Each pixel among a plurality of pixels including each of the plurality of resistive infrared devices may include a first switch switching from a row direction line based on a row selection signal, and having a first end connected to a first end of the each of the plurality of resistive infrared devices and a second end connected to a column direction line, and a second switch having a first end connected to a second end of the each of the plurality of resistive infrared devices and a second end that is grounded.
The driving circuit may be further configured to sequentially drive pixel groups including adjacent pixels among a plurality of pixels provided in the plurality of rows and the plurality of columns, and turn on the connection switch to measure series resistance of the at least two resistive infrared devices in each pixel group.
The driving circuit may be further configured to output a connection signal to turn the connection switch on, and output a first row selection signal to select a first row among the plurality of rows.
The driving circuit may be further configured to output a first connection signal to turn on the connection switch that connects a first resistive infrared device in a first row among the plurality of rows to a grouped first resistive device in a second row, output a first row selection signal to select the first resistive infrared device in the first row, such that the first switch connected to a first end of the first resistive infrared device in the first row is turned on based on the first row selection signal, and output a first column selection signal to select a first column among the plurality of columns, such that the second switch connected to a second end of the first resistive infrared device in the second row is turned on based on the first column selection signal.
The driving circuit may be further configured to output a second connection signal to turn on the connection switch that connects a second resistive infrared device in the first row to a grouped second resistive device in the second row, output a first-second row selection signal to select the second resistive infrared device in the first row, such hat the first switch connected to a first end of the second resistive infrared device in the first row is turned on based on the first row selection signal, and output a second column selection signal to select a second column among the plurality of columns, such that the second switch connected to a second end of the second resistive infrared device in the second row is turned on based on the second column selection signal.
The driving circuit may be further configured to output a first connection signal to turn on the connection switch that connects a first resistive infrared device in a first row among the plurality of rows to a grouped second resistive infrared device in the first row, output a first row selection signal to select the first resistive infrared device in the first row among the plurality of rows, such that the first switch connected to a first end of the first resistive infrared device in the first row is turned on based on the first row selection signal, and output a second column selection signal to select a second column among the plurality of columns, such that the second switch connected to a second end of a second resistive infrared device in the first row is turned on based on the second column selection signal.
The driving circuit may be further configured to output a second connection signal to turn on the connection switch that connects the second resistive infrared device in the first row to a grouped third resistive infrared device in the first row, output a first-second row selection signal to select the second resistive infrared device in the first row among the plurality of rows, such that the first switch connected to a first end of the second resistive infrared device in the first row is turned on based on the first row selection signal, and output a third column selection signal to select a third column among the plurality of columns, such that the second switch connected to a second end of a third resistive infrared device in the first row is turned on based on the third column selection signal.
Each of the plurality of resistive infrared devices may include a bolometer.
According to another aspect of an example embodiment, there is provided a thermal infrared sensor array including a plurality of resistive infrared devices connected to M row electrodes and N column electrodes, a plurality of first switches, each of the plurality of first switches being connected between a first end of each of the plurality of resistive infrared devices and a corresponding row electrode line, a plurality of second switches, each of the plurality second switches being connected between a second end of each of the plurality of resistive infrared devices and a corresponding column electrode line, and a plurality of connection switches connected in series between adjacent resistive infrared devices among the plurality of resistive infrared devices, respectively, to group at least two adjacent resistive infrared devices in a row direction or a column direction.
Each of M and N may be a natural number greater than or equal to 3, a size of a group may be m in the row direction and n in the column direction, where m is a natural number less than M, n is a natural number less than N, and both m and n are not 1.
At least two groups may share at least one resistive infrared device.
Each of the plurality of connection switches may be provided at a first pixel including one of the plurality of resistive infrared devices, one of the plurality of first switches, and one of the plurality of second switches or a second pixel that is grouped with the first pixel that is adjacent to the second pixel in the row direction or the column direction.
Each of the plurality of resistive infrared devices may include a bolometer.
The method may include turning a connection switch among the plurality of connection switches on based on a connection signal, the connection switch being provided between one of the plurality of resistive infrared devices in an m-th row and one of the plurality of resistive infrared devices in an (m+1)th row, the one of the plurality of resistive infrared devices in the (m+1)th row being grouped with the one of the plurality of resistive infrared devices in the m-th row, turning one of the plurality of first switches on based on an m-th row selection signal, the one of the plurality of first switches being connected to a first end of an resistive infrared device in the m-th row and an n-th column, turning one of the plurality of second switches on based on an n-th column selection signal, the one of the plurality of second switches being connected to a second end of the resistive infrared device in the (m+1)th row and the n-th column, and obtaining series resistance of the resistive infrared device in the m-th row and the n-th column and the resistive device in the m-th row and the (n+1)th column, where m is a natural number less than M and n is a natural number less than N.
The method may include turning a connection switch among the plurality of connection switches on based on a connection signal, the connection switch being provided between one of the plurality of resistive infrared devices in an m-th row and an n-th column and one of the plurality of resistive infrared devices in the m-th row and an (n+1)th column, the one of the plurality of resistive infrared devices in the m-th row and the n-th column being grouped with the one of the plurality of resistive infrared devices in the m-th row and the (n+1)th column, turning one of the plurality of first switches on based on an m-th row selection signal, the one of the plurality of first switches being connected to a first end of an resistive infrared device in the m-th row and the n-th column, turning one of the plurality of second switches on based on an (n+1)th column selection signal, the one of the plurality of second switches being connected to a second end of the resistive infrared device in the m-th row and the (n+1)th column, and obtaining series resistance of the resistive infrared device in the m-th row and the n-th column and the resistive device in the m-th row and the (n+1)th column, where m is a natural number less than M and n is a natural number less than N.
According to yet another aspect of an example embodiment, there is provided a method of driving a thermal infrared sensor, the method including turning a first switch on based on receiving an m-th row selection signal, the first switch being connected to a first end of a resistive infrared device among a plurality of resistive infrared devices in an m-th row and an n-th column, selectively turning a switch on based on a connection signal, the switch being connected between the plurality of resistive infrared devices, to electrically serially connect P×Q resistive infrared devices included from the m-th row to a (m+P−1)th row and from the n-th column to an (n+Q−1)th column, turning a second switch on based on an (n+Q−1)th column selection signal, the second switch being connected to a second end of one of the plurality of resistive infrared devices in the (n+Q−1)th column and from the m-th row to an (m+P−1)th row, and obtaining series resistance of the P×Q resistive infrared devices, where m is a natural number less than M, n is a natural number less than N, P is a natural number less than M, Q is a natural number less than N, and both P and Q are not 1.
According to yet another aspect of an example embodiment, there is provided a thermal infrared detector including a pixel array including a plurality of pixels provided in a plurality of rows and a plurality of columns, the plurality of pixels including a plurality of resistive infrared devices, respectively, and a driving circuit configured to drive the pixel array, wherein the pixel array includes a plurality of groups of pixels respectively including at least two resistive infrared devices among the plurality of resistive infrared devices adjacent to each other in a row direction or a column direction, wherein the plurality of groups of pixels overlap with each other such that at least two resistive infrared devices are shared by at least two groups of pixels, and wherein the at least two resistive infrared devices that shared by the at least two groups of pixels are connected in series.
The above and/or other aspects, features, and advantages of example embodiments will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:
Reference will now be made in detail to example embodiments of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. In this regard, the example embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the example embodiments are merely described below, by referring to the figures, to explain aspects. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list. For example, the expression, “at least one of a, b, and c,” should be understood as including only a, only b, only c, both a and b, both a and c, both b and c, or all of a, b, and c.
The terms used in the disclosure have been selected from currently widely used general terms in consideration of the functions in the disclosure. However, the terms may vary according to the intention of one of ordinary skill in the art, case precedents, and the advent of new technologies. Also, for special cases, meanings of the terms selected by the applicant are described in detail in the description section. Accordingly, the terms used in the disclosure are defined based on their meanings in relation to the contents discussed throughout the specification, not by their simple meanings.
Terms such as “first” and “second” are used herein merely to describe a variety of constituent elements, but the constituent elements are not limited by the terms. Such terms are used only for the purpose of distinguishing one constituent element from another constituent element.
The terminology used herein is not intended to limit embodiments. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Furthermore, in example embodiments, when a layer, region, or component is referred to as being electrically connected to another layer, region, or component, it can be directly electrically connected to the other layer, region, or component or indirectly electrically connected to the other layer, region, or component via intervening layers, regions, or components Furthermore, it will be further understood that the terms “comprises” and/or “comprising” used herein specify the presence of stated features or components, but do not preclude the presence or addition of one or more other features or components.
The use of the terms “a” and “an” and “the” and similar referents in the context of describing the disclosure (especially in the context of the following claims) are to be construed to cover both the singular and the plural. Furthermore, the steps of all methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The disclosure is not limited to the described order of the steps.
The disclosure may be described in terms of functional block components and various processing steps. Such functional blocks may be realized by any number of hardware and/or software components configured to perform the specified functions. For example, the functional blocks related to embodiments may be implemented by one or more microprocessors or other circuit configurations for a predetermined function. Furthermore, functional blocks may be implemented with any programming or scripting language. Furthermore, functional blocks may be implemented by algorithm executed in one or more processors. An embodiment may employ conventional technologies for electronic environment settings, signal processing, and/or data processing, and the like.
The connecting lines or connectors shown in the various figures presented are intended to represent functional relationships and/or physical or logical couplings between the various elements. It should be noted that many alternative or additional functional relationships, physical connections or logical connections may be present in a practical device.
The disclosure will now be described more fully with reference to the accompanying drawings, in which example embodiments of the disclosure are shown. The disclosure may, however, be embodied in many different forms and should not be construed as being limited to the example embodiments set forth herein
In an example embodiment, a thermal infrared detector may be applied to a read-out circuit IC and a signal detection control circuit of a thermal imaging system.
In an example embodiment, a thermal infrared sensor array may include a plurality of thermal infrared devices that are configured in a two-dimensional array, which may convert output signals from the thermal infrared devices to a thermal image so that a temperature difference of an object to be measured or the whole scene is displayed.
In an example embodiment, although a thermal infrared device may be described as a bolometric resistive device, embodiments are not limited thereto, and the thermal infrared device may include a thermopile or a pyroelectric device.
In an example embodiment, a group or grouping may be combining a plurality of devices arranged a sensor array in a row direction and/or a column direction.
In an example embodiment, a pixel may be a device implemented in a pixel array, and one pixel may include a thermal infrared device, a row selection switch, a column selection switch, and the like.
Referring to
The thermal infrared detector 100 may be implemented by a non-cooling type thermal imaging camera. The non-cooling type thermal imaging camera may include an optical system, a focal plane array, a signal processor, a signal controller, a temperature stabilizer, and a display. In the optical system, infrared light radiated from an object or scene is projected onto a focal plane array through infrared lenses. The infrared radiation energy projected onto the focal plane array is converted to electrical signals by the focal plane array sensor and the signal processor and then changed to digital signals through analog-digital conversion. To reduce heat conduction to ambient atmosphere, the focal plane array may be arranged in vacuum packaging and an infrared window may be arranged in front of the focal plane array. The data converted to digital signals is converted to image data through offset correction, amplification correction, and other signal processing in the signal processor, and displayed on a screen. The offset and amplification correction may be performed by additionally adding a reference device in units of rows or in units of columns. The temperature stabilizer may allow sensors of the focal plane array to operate under a constant temperature condition.
Referring back to
The driving circuit 120 may include a readout integrated circuit (ROIC) to detect a change of the characteristics of each detection device. The driving circuit 120 may sequentially drive all pixels of the pixel array 110 to read out data from the infrared detection device or resistive infrared device and detect the temperature of an object to be measured.
The driving circuit 120 may further include a bias circuit for generating a bias signal, a row selection circuit for optionally activating a detection device, a column selection circuit, column channel amplification circuits, a sample and hold circuit, a column multiplexer, an output buffer circuit, and the like.
A signal path from one pixel to an output is as follows. An active bolometer Ra is biased via a switch Sa. A reference bolometer Rb that is blinded may be connected to an end of each column. To integrate a difference of a current flowing in the active bolometer Ra and the blind bolometer Rb, an amplification (trans-impedance amplifier) circuit is used. The output voltage of an amplifier is accumulated in a capacitor Csh by an operation of a switch Sh, and then sent to an output voltage Vout by an operation of a switch Ss.
One end of an active bolometer resistance R1 is connected to a bias voltage. The other end of the active bolometer resistance R1 is connected to a first column line col1 via a first switch S01. A switching control line of the switch S1 is connected to a first row line rows. An end of the first column line col1 is connected to a blind resistance Rb1 and an input port of an amplifier to be connected to a reference voltage. Time interleaving driving measures resistance of the devices arranged at a certain interval to obtain and display a thermal image. A timing control circuit is configured to control timing of a row selection circuit and a column selection circuit. The row selection circuit, in response to a signal from the timing control circuit, optionally activates one of row lines. The row selection circuit may be implemented by a multiplexer or other type of component/device.
The pixel array 110 may include a plurality of resistive infrared devices 111 to 117 connected to M row electrodes and N column electrodes. M denotes the number of electrodes in a row direction, and N denotes the number of electrodes in a column direction. A plurality of resistive infrared devices are grouped in a row direction or a column direction. For example, in the row direction, the resistive infrared device 111 and the resistive infrared device 112 are grouped into one, the resistive infrared device 112 and the resistive infrared device 113 are grouped into one, and the resistive infrared device 113 and the resistive infrared device 114 are grouped into one, thereby grouping all pixels. In the column direction, the resistive infrared device 111 and the resistive infrared device 115 are grouped into one. In an example embodiment, M and N are natural numbers greater than or equal to 3.
In an example embodiment, a signal is detected from pixel groups including neighboring m×n pixels, where m and n are natural numbers, but both m and n are not 1. In this state, there are pixels included in two or more pixel groups. The pixels included in the same pixel group are electrically connected to each other to operate as one bolometer resistance. Individual pixels are included in at least one pixel group. The grouping is described below with reference to
Referring to
In an example embodiment, a pixel group of 2×3 include six pixels. Six pixels pbb, pbc, pbd, pcb, pcc, and pcd included in a pixel group G are electrically connected to each other and operate as one bolometer resistance. As more infrared light is absorbed in a relatively large area compared to an individual pixel, a signal change amount is increased. Likewise, six pixels pcc, pcd, pce, pdc, pdd, and pde included in a pixel group G are electrically connected to each other and operate as one bolometer resistance. Six pixels pcd, pce, pcf, pdd, pde, and pdf included in a pixel group Gk are electrically connected to each other and operate as one bolometer resistance. The pixel pcc is included in both of the pixel group Gi and the pixel group Gj. The pixel pcd is included in all of the pixel groups Gi, Gj, and Gk. The pixels pce, pdd, and pde are included in both of the pixel groups Gj and Gk. As illustrated in
Referring to
A pixel of the second row line row2 and the first column line col1 may include a resistive bolometer resistance R21 and fifteenth to eighteenth switches S15 to S18. A pixel of the second row line row2 and the second column col2 may include a resistive infrared device R22 and nineteenth to twenty-third switches S19 to S23. Similarly, the other pixels may be arranged by using resistive devices and switches.
When grouping 2×2 pixels, the third switch S03 connecting in series the resistive bolometer resistance R11 to the resistive bolometer resistance R21, the twenty-first switch S21 connecting in series the resistive bolometer resistance R21 to the resistive infrared device R22, and the eighth switch S08 connecting in series the resistive infrared device R22 to the resistive infrared device R12, are included.
When the first pixel group is driven, to connect in series the resistive infrared devices R11, R21, R22 and R12 of the 2×2 group, the third switch S03, the twenty-first switch S21, and the eighth switch S05 are turned on. Then, when a first row selection signal is applied to the first pixel group, the first switch S01 is turned on. When a second column selection signal is applied thereto, the sixth switch S06 is turned on. An output signal according to a change in the series resistances R11, R21, R22, and R12 is output through the second column line col2. As described above, a reference resistance value, for example, a value of a current flowing in the blind bolometer, is input to an amplification circuit.
Similarly to the above, when a second pixel group is driven, to connect in series the resistive infrared devices R12, R22, R23, and R13 of the next 2×2 group, the eighth switch S08, the twenty-sixth switch S26, and the thirteenth switch S13 are turned on. According to a signal to select a pixel in the first row and the second column, the fifth switch Sos is turned on. When a third column selection signal is applied to the second pixel group, the eleventh switch S11 is turned on. An output signal according to a change in the series resistances R12, R22, R23, and R13 is output through the third column line col3.
The temperature of an object to be measured is detected from the output signal with respect to all pixel groups by sequentially driving all pixel groups in the above-described method.
In an example embodiment, although the connection switches belonging to the first pixel group are turned on, the row or column selection signal is output, and the serially connected resistance values are measured, the disclosure is not limited thereto, and the row or column selection signal is first output and the connection switches belonging to the corresponding pixel group may be turned on.
In an example embodiment, a thermal infrared sensor array for measuring an electrical properties change of a plurality of resistive infrared devices arranged in a row direction or a column direction according to an infrared incidence amount is implemented. In this state, signals are measured by spatially grouping a plurality of neighboring devices, and the thermal infrared sensor array is implemented such that at least one device is simultaneously included in the spatially neighboring groups. Furthermore, the infrared resistive devices are connected in series within each group. Accordingly, problems according to the miniaturization of a pixel, for example, a decrease in the sensitivity due to an infrared absorption area decrease and a thermal conductivity increase, an increase in the noise equivalent temperature difference (NETD), or an increase of NETD 1/f due to a volume decrease of a bolometer material, may be solved.
Referring to
Referring to
Referring to
Referring to
For a first pixel group 710, the second switch S02 is turned on, and the first switch S01 and the twelfth switch S12 are turned on. An output value 715 is obtained through the first column line coll. Although, in the above description, the second switch S02 is turned on, and then the first switch S01 and the twelfth switch S12 are turned on, the first switch S01 and the twelfth switch S12 may be turned on, and then the second switch S02 may be turned on, or three switches may be simultaneously turned on.
For a second pixel group 720, the fifth switch S05 is turned on, and then the fourth switch S04 and the fifteenth switch S15 are turned on. An output value 725 is obtained through the second column line col3.
For a third pixel group 730, the eighth switch S11 is tuned on, and then the seventh switch S10 and the eighteenth switch S18 are turned on. An output value 735 is obtained through the third column line col3.
For a fourth pixel group 740, the eleventh switch S11 is tuned on, and then the tenth switch S10 and the twentieth switch S20 are turned on. An output value 745 is obtained through the first column line col1.
For a fifth pixel group 750, the fourteenth switch S14 is tuned on, and then the thirteenth switch S13 and the twenty-second switch S22 are turned on. An output value 755 is obtained through the second column line col2.
For a sixth pixel group 760, the seventeenth switch S17 is tuned on, and then the sixteenth switch S16 and the twenty-fourth switch S24 are turned on. An output value 765 is obtained through the third column line col3.
After driving the six pixel groups, a temperature value of an object to be measured may be obtained from the output values 715 to 765 and displayed.
In an example embodiment, although the first to sixth pixel groups 710 to 760 are described to be sequentially driven, embodiments are not limited thereto, and the first to sixth pixel groups 710 to 760 may be simultaneously driven. Furthermore, the first to third pixel groups 710 to 730 that do not overlap each other may be driven simultaneously, and then the fourth to sixth pixel groups 740 to 760 may be driven simultaneously.
Referring to
For a first pixel group 910, the fourth switch S04 is tuned on, and then the first switch S01 and the fifth switch S05 are turned on. An output value is obtained through the second column line col2.
For a second pixel group 920, the seventh switch S07 is tuned on, and then the third switch S03 and the eighth switch S08 are turned on. An output value is obtained through the third column line col3.
For a third pixel group 930, the twelfth switch S12 is tuned on, and then the ninth switch S09 and the thirteenth switch S13 are turned on. An output value is obtained through the second column line col2.
For a fourth pixel group 940, the fifteenth switch S15 is tuned on, and then the eleventh switch S11 and the sixteenth switch S16 are turned on. An output value is obtained through the third column line col3.
For a fifth pixel group 950, the twentieth switch S20 is tuned on, and then the seventeenth switch S17 and the twenty-first switch S21 are turned on. An output value is obtained through the second column line col2.
For a sixth pixel group 960, the twenty-third switch S23 is tuned on, and then the nineteenth switch S19 and the twenty-fourth switch S24 are turned on. An output value is obtained through the third column line col3.
For a first pixel group 1110, to connect the bolometer resistances R11, R21, R22, and R12 to each other, the fourth switch S04, the twenty-third switch S23, and the ninth switch S09 are tuned on, and then the first switch S01 and the seventh switch S07 are turned on. An output value is obtained through the third column line col3.
For a second pixel group 1120, to connect the bolometer resistances R12, R22, R23, and R13 to each other, the ninth switch S09, the twenty-eighth switch S28, and the fourteenth switch S14 are tuned on, and then the sixth switch S06 and the twelfth switch S12 are turned on. An output value is obtained through the fourth column line col4.
For a third pixel group 1130, to connect the bolometer resistances R21, R31, R32, and R22 to each other, the nineteenth switch S19, the thirty-eighth switch S38, the twenty-fourth switch S24 are tuned on, and then the sixteenth switch S16 and the twenty-second switch S22 are turned on. An output value is obtained through the third column line col3.
For a fourth pixel group 1140, to connect the bolometer resistances R22, R32, R33, and R23 to each other, the twenty-fourth switch S24, the forty-third switch S43, and the twenty-ninth switch S29 are tuned on, and then the twenty-first switch S21 and the twenty-seventh switch S27 are turned on. An output value is obtained through the fourth column line col4.
In an example embodiment, as several neighboring pixels are operated by being electrically connected to each other, an infrared radiation energy absorption amount may be increased as an effective area is increased, and as bolometer resistances in several pixels are connected in series to operate as one resistance, a resistance change amount according to a change of temperature may be increased. Accordingly, as an output signal from a thermal infrared sensor array increases, sensitivity and signal-to-noise ratio (SNR) may be improved, and a temperature resolution may be reduced.
Referring to
A first column selection signal is output (S1208). In response to the first column selection signal, a second switch is turned on (S1210). In this state, the second switch is connected between a first column line and a grouped resistive infrared device of a pixel in the next row.
Series resistance of the resistive infrared device in the first row and the resistive infrared device in the second row is measured (S1212).
In an example embodiment, for an M×N pixel array, an output signal is detected by an m×n group or grouping. In this state, M and N each are natural numbers, M and N each are greater than or equal to 3, m is a natural number less than M, and n is a natural number less than N. In this state, both m and n are not 1. In the example embodiment described with reference to
Referring to
A first row selection signal is output (1304). In response to the first row selection signal, a first switch is turned on (S1306). In this state, the first switch is connected between a first row line and one end of the resistive infrared device of the first pixel.
A second column selection signal is output (S1308). In response to the second column selection signal, a second switch is turned on (S1310). In this state, the second switch is connected between a second column line and a resistive infrared device of a pixel in the first row and the second column that are grouped.
Series resistance of the resistive infrared device in the first row and the resistive infrared device in the second column is measured (S1312).
In an example embodiment, for an M×N pixel array, an output signal is detected by an m×n group or grouping. In this state, M and N each are natural numbers, M and N each are greater than or equal to 3, m is a natural number less than M, and n is a natural number less than N. In this state, both m and n are not 1. In the example embodiment described with reference to
Referring to
Next, signals are detected from groups consisting of pixels in 2 to 9 columns from t5 to t8. Likewise, signals are simultaneously detected from four pixel groups that do not overlap each other and are included in 1-2 rows at t5, 3-4 rows at t6, 5-6 rows at t7, and 7-8 rows at t8.
Next, signals are detected from a group consisting of pixels in 1-8 columns from t9 to t12. Signals are simultaneously detected from four pixel groups that do not overlap each other and are included in 2-3 rows at t9, 4-5 rows at t10, 6-7 rows at t11, and 8-9 rows at t12.
Finally, signals are detected from a group consisting of pixels in 2 to 9 columns from t13 to t16. Signals are simultaneously detected from four pixel groups that do not overlap each other and are included in 2-3 rows at t13, 4-5 rows at t14, 6-7 rows at t15, and 8-9 rows at t16. Data of 64 group pixels in an 8×8 array may be measured in the above method.
Referring to
The example embodiments may be written as computer programs and may be implemented in general-use digital computers that execute the programs using a computer readable recording medium. Furthermore, the structure of data used in the above-described example embodiments may be recorded in a computer-readable recording medium through various means. Examples of the computer readable recording medium include magnetic storage media (e.g., ROM, floppy disks, hard disks, etc.), optical recording media (e.g., CD-ROMs, or DVDs), etc.
As the thermal infrared detector according to an example embodiment is operated as several neighboring pixels are electrically connected to each other, a far-infrared radiation energy absorption amount may be increased as an effective area is increased.
Furthermore, as bolometer resistances in several pixels are connected in series to operate as one resistance, a resistance change amount according to a temperature change is increased and an output signal is increased so that sensitivity and SNR may be improved and a minimum temperature resolution may be further decreased.
Furthermore, as a pixel group area in which several neighboring pixels are electrically connected to each other is selected by moving in unit of one pixel, a resolution equivalent to a pixel pitch may be obtained.
It should be understood that example embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each example embodiment should typically be considered as available for other similar features or aspects in other embodiments. While example embodiments have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims.
Number | Date | Country | Kind |
---|---|---|---|
10-2020-0183610 | Dec 2020 | KR | national |