Input sensing device and method of correcting an input sensing device

Abstract

An input sensing device and a correction method of the input sensing device are disclosed. The input sensing device includes a display panel that displays a fingerprint sensing pattern corresponding to an object. A sensor pixel senses light reflected by the object from the fingerprint sensing pattern to generate a sensing signal. A fingerprint detection section detects a fingerprint of the object based on the sensing signal. The fingerprint detection section changes an exposure time of the sensor pixel to the light based on a size of the fingerprint sensing pattern.

Description

Technical Field

[0001] This invention relates to an input sensing device and a method for calibrating the input sensing device. Background Technology

[0002] Recently, display devices such as smartphones and tablets have been used in various applications, leading to the widespread use of biometric authentication methods such as fingerprints. To provide fingerprint sensing functionality, fingerprint sensors can be provided either built into the display device or attached to the top and / or bottom of the display device.

[0003] As an example, a fingerprint sensor can be configured as a photosensitive sensor. A photosensitive fingerprint sensor uses light-emitting elements disposed within pixels as a light source and includes a photosensitive sensor array. This photosensitive sensor array can, for example, be implemented as a CMOS image sensor (CIS).

[0004] On the other hand, in order to correct the light intake deviation caused by the characteristic distribution and position of the sensor pixels in the light sensor array, calibration is performed for the fingerprint sensor under specific conditions. Summary of the Invention

[0005] As fingerprint sensors become more widespread, users may only use a portion of the sensor. When only a portion of the fingerprint sensor is activated, the conditions under which the user uses the sensor differ from the calibration conditions applied to the sensor (e.g., calibration conditions applied to the entire area of ​​the fingerprint sensor). Consequently, the calibration performance of the fingerprint sensor deteriorates, and fingerprints may not be accurately detected.

[0006] One object of the present invention is to provide an input sensing device that can accurately sense fingerprints even when only a portion of the area is used, and a method for calibrating the input sensing device.

[0007] However, the purpose of this invention is not limited to the above-described purpose, and various extensions can be made without departing from the concept and scope of this invention.

[0008] To achieve an objective of the present invention, an input sensing device according to an embodiment of the present invention includes: a display panel displaying a fingerprint sensing pattern corresponding to an object; a sensor pixel that senses light reflected by the object from the fingerprint sensing pattern to generate a sensing signal; and a fingerprint detection unit that detects a fingerprint of the object based on the sensing signal. The fingerprint detection unit changes the exposure time of the sensor pixel to the light based on the size of the fingerprint sensing pattern.

[0009] According to one embodiment, the size of the fingerprint sensing pattern may correspond to the area of ​​the object in contact with the display panel, and the fingerprint detection unit reduces the exposure time as the size of the fingerprint sensing pattern decreases.

[0010] According to one embodiment, the display panel may display the fingerprint sensing pattern based on the same grayscale value, and the brightness of the fingerprint sensing pattern increases as the size of the fingerprint sensing pattern decreases.

[0011] According to one embodiment, the fingerprint detection unit may include a gate driving unit for generating a scanning signal, and the sensor pixel may include: a photoelectric element for converting the light into charge; and a transistor for outputting an electrical signal corresponding to the charge in response to the scanning signal.

[0012] According to one embodiment, the fingerprint detection unit may control the gate driving unit to change the pulse width of the scanning signal based on the size of the fingerprint sensing pattern.

[0013] According to one embodiment, the fingerprint detection unit may reduce the pulse width of the scanning signal as the size of the fingerprint sensing pattern decreases.

[0014] According to one embodiment, the gate driving unit may output a clock signal as the scanning signal in response to a start signal, and the fingerprint detection unit may change the duty cycle of the clock signal based on the size of the fingerprint sensing pattern.

[0015] According to one embodiment, the sensor pixel may further include a capacitor storing the charge, the transistor responds to the scan signal by outputting an electrical signal corresponding to the charge charged in the capacitor, and the fingerprint detection unit adjusts the timing of applying the scan signal to the sensor pixel after the capacitor is reset.

[0016] According to one embodiment, the fingerprint detection unit may store information related to a first exposure time and a second exposure time corresponding to a first fingerprint sensing pattern and a second fingerprint sensing pattern having different sizes from each other, and the fingerprint detection unit determines the exposure time by interpolating the first exposure time and the second exposure time based on the size of the fingerprint sensing pattern.

[0017] According to one embodiment, the fingerprint detection unit may perform analog-to-digital conversion on the sensing signal to generate sensing data, correct the sensing data using pre-set correction data, and perform authentication for the object based on the corrected sensing data and pre-registered fingerprint data.

[0018] To achieve an objective of the present invention, the calibration method for an input sensing device according to an embodiment of the present invention may be performed on an input sensing device, the input sensing device comprising: a display panel displaying a fingerprint sensing pattern corresponding to an object; and sensor pixels sensing light reflected by the object from the fingerprint sensing pattern to generate a sensing signal. The calibration method for the input sensing device includes the step of setting the exposure time of the sensor pixels to the light using fingerprint sensing patterns having different sizes on a plane.

[0019] According to one embodiment, the step of setting the exposure time may include: setting a first exposure time of the sensor pixel based on a first fingerprint sensing pattern having a first size; and setting a second exposure time of the sensor pixel based on a second fingerprint sensing pattern having a second size.

[0020] According to one embodiment, the step of setting the exposure time may be based on the first exposure time and the second exposure time, modeling a mathematical expression related to the exposure time based on the size of the fingerprint sensing pattern.

[0021] According to one embodiment, the step of setting the first exposure time may include: determining whether the first sensing sensitivity of the sensor pixel for the first fingerprint sensing pattern is within a reference range; increasing or decreasing the exposure time until the first sensing sensitivity is within the reference range; and setting the exposure time as the first exposure time when the first sensing sensitivity is within the reference range.

[0022] According to one embodiment, the step of setting the second exposure time may include: determining whether the second sensing sensitivity of the sensor pixel for the second fingerprint sensing pattern is the same as the first sensing sensitivity; and setting the exposure time of the sensor pixel when the second sensing sensitivity is the same as the first sensing sensitivity as the second exposure time.

[0023] (Invention Effects)

[0024] According to embodiments of the present invention, the input sensing device and its calibration method change the exposure time of sensor pixels based on the size of the fingerprint sensing pattern (or display pattern) corresponding to the object displayed on the display panel. This allows the sensor pixels to be controlled to have the same sensing sensitivity as when generating calibration data (i.e., data used to compensate for light intake deviations based on sensor pixel positions) and to generate sensing data. Therefore, the input sensing device and its calibration method can accurately correct the sensing data based on the calibration data, enabling more accurate sensing of the user's fingerprint.

[0025] However, the effects of the present invention are not limited to those described above, and various extensions can be made without departing from the concept and scope of the present invention. Attached Figure Description

[0026] Figure 1a This is a block diagram that schematically illustrates a display device according to an embodiment of the present invention.

[0027] Figure 1b It is a summary. Figure 1a A block diagram of another example of a display device.

[0028] Figure 2 It is shown Figure 1a A cross-sectional view of an example of a display device.

[0029] Figure 3 It is shown that it includes Figure 1a A block diagram of an example of a fingerprint sensing device in a display device.

[0030] Figure 4 It is shown that it includes Figure 3 A circuit diagram of an example of a sensor pixel in an input sensing device.

[0031] Figure 5 This is an explanation Figure 4 The waveform diagram of the sensor pixel operation.

[0032] Figure 6 It is shown that it includes Figure 3 A block diagram of an example of a fingerprint detection unit in a fingerprint sensing device.

[0033] Figure 7 It is shown in the inclusion of Figure 1a An example of a fingerprint sensing pattern displayed on the display panel of a display device.

[0034] Figure 8 It shows based on Figure 7 A graph showing the area and brightness of the fingerprint sensing pattern.

[0035] Figure 9 This is a graph showing the sensing sensitivity based on the exposure time of the sensor pixels.

[0036] Figure 10 It shows based on Figure 7 A graph showing the area of ​​the fingerprint sensing pattern and the exposure time of the sensor pixels.

[0037] Figure 11a as well as Figure 11b This is a diagram illustrating an example of adjusting the exposure time of sensor pixels.

[0038] Figure 12 This is a flowchart illustrating a calibration method for an input sensing device according to an embodiment of the present invention.

[0039] Figure 13 This is a flowchart illustrating the process of setting the first exposure time.

[0040] Figure 14 This is a diagram illustrating an example of the process of setting the first exposure time.

[0041] Figure 15 This is another example illustrating the process of setting the first exposure time.

[0042] Figure 16 This is a flowchart illustrating the process of setting the second exposure time. Detailed Implementation

[0043] Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings, so that those skilled in the art to which this invention pertains can readily practice it. The present invention can be implemented in various different forms and is not limited to the embodiments described herein.

[0044] To clearly illustrate the invention, irrelevant details have been omitted, and the same reference numerals are used throughout the specification to refer to the same or similar constituent elements. Therefore, the reference numerals described above may also be used in other figures.

[0045] Furthermore, for ease of explanation, the size and thickness of the components shown in the accompanying drawings are arbitrarily depicted; therefore, the invention is not necessarily limited to the drawings. In the drawings, thicknesses may be exaggerated to clearly show the layers and regions.

[0046] Figure 1a This is a block diagram that schematically illustrates a display device according to an embodiment of the present invention. Figure 1b It is a summary. Figure 1a A block diagram of another example of a display device.

[0047] For convenience, in Figure 1a as well as Figure 1b In the illustration, the display panel 100 and the driving unit 200 are shown separately, but the present invention is not limited thereto. More specifically, all or part of the driving unit 200 may be integrally implemented on the display panel 100.

[0048] Reference Figure 1a as well as Figure 1b The display device 1000 (or input sensing device) may include a display panel 100 and a driving unit 200. The driving unit 200 may include a panel driving unit 210 and a fingerprint detection unit 220 (or input detection unit).

[0049] The display device 1000 as a whole or at least a part thereof may be flexible.

[0050] Display panel 100 includes a display area AA and a non-display area NA. The display area AA is an area provided with a plurality of pixels PXL (or may be named sub-pixels), and may be named the active area. In various embodiments, each pixel PXL may include at least one light-emitting element. Display device 1000 drives the pixels PXL in response to image data input from the outside, thereby displaying an image in the display area AA.

[0051] In one embodiment, the display area AA may include a fingerprint sensing area FSA (or an input sensing area). The fingerprint sensing area FSA may include at least a portion of pixels PXL provided in the display area AA.

[0052] In one embodiment, such as Figure 1a As shown, at least a portion of the display area AA can be designated as the fingerprint sensing area FSA. In another embodiment, as... Figure 1b As shown, the entire display area AA can also be set as the fingerprint sensing area FSA. When performing fingerprint sensing, the fingerprint sensing operation can be performed only on the area that actually forms the user's touch.

[0053] On the other hand, Figure 1a The illustration shows an example where only one fingerprint sensing area (FSA) is formed on the display area AA, but the invention is not limited thereto. For example, multiple fingerprint sensing areas (FSAs) arranged regularly or irregularly can be formed on the display area AA.

[0054] In addition, Figure 1a as well as Figure 1b The illustration shows an example where the fingerprint sensing area FSA is formed in at least a portion of the display area AA, but the invention is not limited thereto. That is, in various embodiments, the display area AA and the fingerprint sensing area FSA may also be arranged to overlap only in at least a portion of the area.

[0055] The non-display area NA is the area surrounding the display area AA, and can be named the non-active area. For example, the non-display area NA can include wiring areas, pad areas, and various dummy areas.

[0056] In one embodiment, the display device 1000 may further include a plurality of sensor pixels SPXL provided in the fingerprint sensing area FSA. The sensor pixels SPXL may be composed of light sensors PS for sensing light. In one embodiment, when light emitted from a light source (or pixel PXL) arranged in the display device 1000 is reflected by an object (e.g., a user's finger), the sensor pixels SPXL can sense the reflected light and output a corresponding electrical signal (e.g., a voltage signal). The electrical signal can be transmitted to the driving unit 200 (e.g., the fingerprint detection unit 220) for fingerprint sensing. Hereinafter, the invention will be described using the sensor pixels SPXL for fingerprint sensing as an example, but the sensor pixels SPXL can be used for various functions, such as touch sensors or scanners.

[0057] On a planar surface, when sensor pixel SPXL is disposed within the fingerprint sensing area FSA, sensor pixel SPXL may overlap with pixel PXL or be disposed around pixel PXL. For example, some or all of sensor pixel SPXL may overlap with pixel PXL or be disposed between pixels PXL. In various embodiments, sensor pixel SPXL and pixel PXL may have the same or different sizes. The relative size and arrangement between sensor pixel SPXL and pixel PXL are not particularly limited.

[0058] When sensor pixel SPXL and pixel PXL are arranged adjacent to each other or at least partially overlap, sensor pixel SPXL can use the light-emitting element disposed in pixel PXL as a light source. In such an embodiment, sensor pixel SPXL, together with the light-emitting element disposed in pixel PXL, can constitute a photosensitive fingerprint sensor (or, a light sensor PS). Thus, when a fingerprint sensor-integrated display device is constructed by using pixel PXL as a light source without an additional external light source, the thickness of the photosensitive fingerprint sensor (i.e., the light sensor PS) and the module of the display device 1000 incorporating it is reduced, thereby reducing manufacturing costs.

[0059] In various embodiments, the sensor pixels SPXL may be configured on one side of the display panel 100 opposite to the side displaying the image (e.g., the front side). However, the invention is not limited thereto.

[0060] The driving unit 200 can drive the display panel 100. For example, the driving unit 200 can output a data signal DS corresponding to image data to the display panel 100. In addition, the driving unit 200 can output a driving signal for the sensor pixel SPXL and receive electrical signals (e.g., sensing signals SS) received from the sensor pixel SPXL. The driving unit 200 can use the electrical signals to detect the shape of a user's fingerprint and detect forged fingerprints.

[0061] In various embodiments, the driving unit 200 may include a panel driving unit 210 and a fingerprint detection unit 220. For convenience, in Figure 1a as well as Figure 1b The panel driving unit 210 and the fingerprint detection unit 220 are shown separately, but the present invention is not limited thereto. For example, at least a portion of the fingerprint detection unit 220 may be integrated with the panel driving unit 210, or may operate in conjunction with the panel driving unit 210.

[0062] The panel driving unit 210 can sequentially scan the pixels PXL of the display area AA and supply the pixels PXL with data signals DS corresponding to the image data. Then, the display panel 100 can display an image corresponding to the image data.

[0063] In one embodiment, the panel driving unit 210 may supply a driving signal for fingerprint sensing to the pixel PXL. This driving signal may be provided to function as a light source for the sensor pixel SPXL, enabling the pixel PXL to emit light. In such an embodiment, the driving signal for fingerprint sensing may be provided to pixels PXL arranged in a specific area within the display panel 100 (e.g., pixels PXL arranged in the fingerprint sensing area FSA, or pixels PXL corresponding to the portion forming a user's touch). In this case, the display panel 100 may display a fingerprint sensing pattern (or a display pattern, image pattern, such as a white image pattern with maximum brightness) in at least a portion of the fingerprint sensing area FSA (e.g., the portion forming a user's touch).

[0064] In one embodiment, the panel driving unit 210 may provide fingerprint sensing pattern information I_DP to the fingerprint detection unit 220. Here, the fingerprint sensing pattern information I_DP may include area information (or size information) related to the size of the area in the display panel 100 where the fingerprint sensing pattern is displayed. According to an embodiment, if the display device 1000 is equipped with a touch sensor that senses the user's touch input, the panel driving unit 210 (or the touch detection unit that drives the touch sensor) may also provide fingerprint sensing pattern information I_DP, which includes area information (or size information) related to the area where the user's touch is formed, to the fingerprint detection unit 220.

[0065] The fingerprint detection unit 220 can transmit a driving signal (e.g., a driving voltage) to the sensor pixel SPXL and detect the user's fingerprint based on the electrical signal received from the sensor pixel SPXL. For example, the fingerprint detection unit 220 can perform fingerprint authentication based on the sensing signal SS supplied from the sensor pixel SPXL (e.g., a light sensor PS). The light sensor PS including the sensor pixel SPXL and the fingerprint detection unit 220 can constitute a fingerprint sensing device FDD (or a fingerprint sensor).

[0066] In this embodiment, the fingerprint detection unit 220 can change the driving conditions of the sensor pixel SPXL based on the fingerprint sensing pattern information I_DP. For example, the fingerprint detection unit 220 can change the exposure time of the sensor pixel SPXL based on the fingerprint sensing pattern information I_DP. Here, the exposure time can refer not only to the time for the sensor pixel SPXL to receive reflected light, but also to the time for the sensor pixel SPXL to output an electrical signal corresponding to the reflected light. Depending on the exposure time, the magnitude of the electrical signal received by the fingerprint detection unit 220 from the sensor pixel SPXL can be different.

[0067] Although referencing Figure 7 as well as Figure 8 As will be described later, the brightness of the fingerprint sensing pattern may vary depending on the area (or size) of the fingerprint sensing pattern (or the area where touch input is generated) displayed on the display panel 100. Consequently, the amount of reflected light sensed by the sensor pixel SPXL (or the responsiveness to reflected light from the sensor pixel SPXL, i.e., the sensing sensitivity) may differ, and the correction value set for the sensor pixel SPXL under specific conditions (e.g., based on a specific amount of light) may be ineffective. Here, the correction value is a value preset to correct for light intake deviations caused by the dispersion and position of the sensor pixel SPXL in the manufacturing process, and may be a value used to correct sensing data generated based on the sensing signal SS of the sensor pixel SPXL. Therefore, the fingerprint detection unit 220 can adjust the amount of reflected light sensed by the sensor pixel SPXL (or the sensing sensitivity of the sensor pixel SPXL) to a condition where the correction value can be effectively applied, i.e., the same as the specific amount of light, by changing the exposure time of the sensor pixel SPXL based on the fingerprint sensing pattern information I_DP.

[0068] Reference Figures 6 to 11b The fingerprint detection unit 220 will be described in more detail later.

[0069] As described above, the display device 1000 (or input sensing device) may include a fingerprint sensing device FDD. The fingerprint sensing device FDD includes a light sensor PS disposed on one side of the display panel 100 and a fingerprint detection unit 220, using a pixel PXL disposed on the display panel 100 as a light source. Furthermore, the fingerprint detection unit 220 may change the driving conditions (e.g., exposure time) of the sensor pixel SPXL based on fingerprint sensing pattern information I_DP (i.e., area information or size information of the area displaying the fingerprint sensing pattern or where touch input occurs) provided from the panel driving unit 210 (or touch detection unit). As a result, the sensing signal SS supplied from the sensor pixel SPXL becomes a state where a correction value can be effectively applied to correct for light reception deviations based on the position of the sensor pixel SPXL, enabling more accurate correction of the sensing signal SS (or its corresponding sensing data), and allowing for more accurate sensing of the user's fingerprint.

[0070] Figure 2 It is shown Figure 1a A cross-sectional view of an example of a display device. Specifically, Figure 2 Show Figure 1a as well as Figure 1b An example of a cross-section in the fingerprint sensing area FSA of the display device 1000 shown in the figure.

[0071] Reference Figures 1a to 2 The display device 1000 may include a display panel 100 and a light sensor PS disposed on one side of the display panel 100 in the fingerprint sensing area FSA. Additionally, the display device 1000 may include a substrate SUB, a circuit element layer BPL, a light-emitting element layer LDL, a first protective layer PTL1, a first adhesive layer ADL1, and a window WIN, sequentially disposed on one side (e.g., the upper side) of the substrate SUB. Furthermore, the display device 1000 may include a second adhesive layer ADL2 and a second protective layer PTL2 sequentially disposed on the other side (e.g., the lower side) of the substrate SUB in the sensing area SA.

[0072] The substrate SUB serves as the base material for the display panel 100 and can be a substantially transparent light-transmitting substrate. The substrate SUB can be a rigid substrate, including glass or tempered glass, or a flexible substrate made of plastic. However, the material of the substrate SUB is not limited to these; it can be made of various materials.

[0073] The circuit element layer BPL can be disposed on one side of the substrate SUB and includes at least one conductive layer. For example, the circuit element layer BPL may include multiple circuit elements constituting the pixel circuitry of the pixel PXL, and wiring for supplying various power supplies and signals for driving the pixel PXL. In this case, the circuit element layer BPL may include at least one transistor and various circuit elements such as capacitors, and multiple conductive layers for forming wiring for connection thereto. In addition, the circuit element layer BPL may include at least one insulating layer provided between the multiple conductive layers.

[0074] The light-emitting element layer (LDL) can be disposed on one side of the circuit element layer (BPL). The LDL can include multiple light-emitting elements (LDs) connected to the circuit elements and / or wiring of the BPL via contact holes or the like. In one embodiment, at least one of the multiple LDs can be configured for each pixel (PXL). For example, the LD can be composed of an organic light-emitting diode (OLED), a micro-LED, a quantum dot LED, or other inorganic OLED. Alternatively, the LD can be a composite of organic and inorganic materials. Furthermore, each pixel (PXL) may include a single LD, or in another embodiment, each pixel (PXL) may include multiple LDs connected in series, parallel, or a series-parallel connection.

[0075] Each pixel PXL can be composed of a circuit element disposed on the circuit element layer BPL and at least one light-emitting element LD disposed on the light-emitting element layer LDL above the circuit element layer BPL.

[0076] The first protective layer PTL1 can be configured above the light-emitting element layer LDL to cover the display area AA. The first protective layer PTL1 may include sealing components such as a thin film encapsulation (TFE) layer or a sealing substrate, and may additionally include a protective film in addition to the sealing components.

[0077] The first adhesive layer ADL1 is disposed between the first protective layer PTL1 and the window WIN, thereby bonding the first protective layer PTL1 and the window WIN. The first adhesive layer ADL1 may contain a transparent adhesive such as OCA (optically clear adhesive), or various other adhesive substances.

[0078] The window WIN, serving as a protective component disposed at the top of the module of the display device 1000 including the display panel 100, can be a substantially transparent light-transmitting substrate. Such a window WIN can have a multi-layer structure selected from glass substrates, plastic films, and other plastic substrates. The window WIN can include rigid or flexible materials, and the constituent materials of the window WIN are not particularly limited.

[0079] In various embodiments, the display device 1000 may also include a polarizing plate (not shown), an anti-reflective layer, and / or a touch sensor layer (touch electrode layer), etc. For example, the display device 1000 may also include a polarizing plate and / or a touch sensor layer disposed between the first protective layer PTL1 and the window WIN.

[0080] The touch sensor layer may include multiple sensing electrodes (or sensing units). In this case, refer to... Figure 1a The driving unit 200 described above can sense the presence or absence of touch input and the position (or coordinates, area) of touch input based on the change in capacitance between sensing electrodes.

[0081] The second protective layer PTL2 can be disposed on the other side of the substrate SUB. The second protective layer PTL2 can be bonded to the substrate SUB via the second adhesive layer ADL2.

[0082] The second adhesive layer ADL2 can firmly bond (or attach) the substrate SUB and the second protective layer PTL2. The second adhesive layer ADL2 may contain a transparent adhesive such as OCA. The second adhesive layer ADL2 may contain a pressure-sensitive adhesive (PSA) that functions when pressure is applied to bond the surfaces together.

[0083] The second protective layer PTL2 can prevent the inflow of oxygen and moisture from the outside and can be provided in single or multiple layers. The second protective layer PTL2 can be formed in the form of a film to further ensure the flexibility of the display panel 100. The second protective layer PTL2 can be bonded to the light sensor PS through other adhesive layers (not shown) containing transparent adhesives such as OCA.

[0084] The light sensor PS is attached to the reverse side (e.g., the back side) of the display panel 100 by an adhesive or the like to overlap with at least one area of ​​the display panel 100. The light sensor PS may, for example, be configured to overlap with the display panel 100 in the fingerprint sensing area FSA. The light sensor PS may include a plurality of sensor pixels SPXL dispersed at a predetermined resolution and / or spacing.

[0085] In one embodiment, although not illustrated, an optical system can be provided on the photosensitive sensor PS to focus light directed toward the photosensitive sensor PS to provide a light path. In this optical system, the width of the light-transmitting portion of the light guide can be determined taking into account sensing precision and light conversion efficiency. Such an optical system can improve the focusing efficiency of light incident on the photosensitive sensor PS. According to an embodiment, the optical system can be formed from optical fibers, silicon, or the like.

[0086] The sensor pixels SPXL can have an appropriate number, size, and arrangement to generate a fingerprint image of a identifiable degree based on the electrical signals output by the sensor pixels SPXL. The spacing between the sensor pixels SPXL can be densely configured such that reflected light from an object (e.g., a fingerprint) can be incident on at least two adjacent sensor pixels SPXL.

[0087] Sensor pixels SPXL can sense external light and output corresponding electrical signals, such as voltage signals. The reflected light received by each sensor pixel SPXL can have optical characteristics (for example, frequency, wavelength, size, etc.) based on the valleys and ridges of a fingerprint formed on a user's finger (or a palm pattern formed on the palm, or a dermatoglyphic pattern formed on the skin). Therefore, each sensor pixel SPXL can output sensing signals SS with different electrical characteristics corresponding to the optical characteristics of the reflected light.

[0088] In one embodiment, the display device 1000 (or display panel 100) may further include a light-shielding layer PHL.

[0089] The light-shielding layer PHL can be disposed inside the display panel 100 or between the display panel 100 and the sensor pixel SPXL, cutting off a portion of the light incident on the sensor pixel SPXL. For example, a portion of the light incident on the light-shielding layer PHL can be cut off, with the remaining portion passing through the pinhole PIH to reach the sensor pixel SPXL below the light-shielding layer PHL. The pinhole PIH functions as an optical system and can also be used in conjunction with other optical systems.

[0090] A pinhole PIH can refer to an optical hole, which can be a type of light-transmitting hole. For example, a pinhole PIH can be a light-transmitting hole with the smallest size (or area) among the light-transmitting holes in which the layers of the display device 1000 are arranged to overlap each other, on the path where reflected light passes through the display panel 100 in an oblique or vertical direction and enters the sensor pixel SPXL.

[0091] The pinhole PIH can have a predetermined width, for example, a width (w) ranging from 5 μm to 20 μm. In this way, the width of the optical opening area to be ensured in each layer of the display device 1000 can be gradually increased as it moves away from the light-shielding layer PHL (i.e., as it moves towards the top and bottom of the light-shielding layer PHL).

[0092] The width (or diameter) of the pinhole PIH can be set to approximately 10 times or more the wavelength of the reflected light, for example, approximately 4 μm or 5 μm or more, to prevent light diffraction. Additionally, the width of the pinhole PIH can be set to prevent image blur and to more clearly sense the shape of the fingerprint. For example, the width of the pinhole PIH can be set to approximately 15 μm or less. However, the invention is not limited to this; the width of the pinhole PIH can also vary depending on the wavelength band of the reflected light and / or the thickness of each layer of the module.

[0093] Only the reflected light passing through the pinhole PIH can reach the sensor pixel SPXL of the optical sensor PS. The phase of the light reflected from the fingerprint through the very narrow pinhole PIH and the phase of the image formed on the optical sensor PS can have a 180-degree difference.

[0094] The sensor pixel SPXL can output a sensing signal SS corresponding to the received reflected light, such as a voltage signal.

[0095] Although not illustrated, an infrared cutoff filter may also be configured between the optical system (e.g., the light-shielding layer PHL) and the light sensor PS, or between the display panel 100 and the optical system.

[0096] On the other hand, Figure 2 The illustration shows an example of using a light-shielding layer PHL including a pinhole PIH as an optical system, but it is not limited to this. For example, microlens type, collimator type optical systems (or, light sensors) can also be used.

[0097] Figure 3 It is shown that it includes Figure 1a A block diagram illustrating an example of a fingerprint sensing device in a display device. Specifically, Figure 3 Showing includes Figure 1a as well as Figure 1b An example of a fingerprint sensing device FDD in a display device 1000.

[0098] Reference Figures 1a to 3 The fingerprint sensing device FDD may include a light sensor PS and a fingerprint detection unit 220.

[0099] The light sensor PS may include an array of sensor pixels SPXL. In one embodiment, the sensor pixels SPXL may be arranged in a two-dimensional array, but are not limited thereto. Each sensor pixel SPXL may include a photoelectric element that converts incident light into electrical charge according to its intensity.

[0100] The fingerprint detection unit 220 may include a gate driving unit 221 (or a horizontal driving unit), a sensing driving unit 222 (or a vertical driving unit), and a control unit 223. The gate driving unit 221 may be formed together with the photosensitive sensor PS on a substrate, and the sensing driving unit 222 and the control unit 223 may be implemented as an integrated circuit and connected to the photosensitive sensor PS, etc., via a flexible circuit board. However, it is not limited to this.

[0101] The gate driving unit 221 can be connected to the sensor pixel SPXL via reset lines RSL1 to RSLn (where n is a positive integer). The gate driving unit 221 can be configured using a shift register or an address decoder, etc. In various embodiments, the gate driving unit 221 can apply a reset signal to at least a portion of the sensor pixel SPXL via reset lines RSL1 to RSLn to initialize the sensor pixel SPXL (e.g., to initialize or discharge the photoelectric conversion charge charging the sensor pixel SPXL).

[0102] In one embodiment, the gate driving unit 221 may supply a reset signal to at least a portion of the reset lines RSL1 to RSLn based on the start signal FLM and the clock signal CLKS (e.g., a reset start signal and a reset clock signal) provided from the control unit 223. For example, the gate driving unit 221 may include multiple stages respectively connected to the reset lines RSL1 to RSLn, each stage outputting a portion of the clock signal CLKS as a reset signal in response to the start signal FLM or the output of a previous stage.

[0103] In one embodiment, the gate driving unit 221 can output the reset signal sequentially in units of sensor pixel rows. However, the gate driving unit 221 is not limited to this; in another embodiment, the gate driving unit 221 can also output at least a portion of the reset signal to the sensor pixel SPXL simultaneously.

[0104] Additionally, the gate driving unit 221 can be connected to the sensor pixel SPXL via scan lines SCL1 to SCLn. The gate driving unit 221 can be configured using a shift register or an address decoder, etc. In various embodiments, the gate driving unit 221 can apply a scan signal to drive a selected portion of the sensor pixel SPXL. The gate driving unit 221 can apply the scan signal on a row-by-row basis.

[0105] In one embodiment, the gate driving unit 221 may supply a scan signal to at least a portion of the scan lines SCL1 to SCLn based on a start signal FLM and a clock signal CLKS (e.g., a scan start signal and a scan clock signal) provided from the control unit 223. For example, the gate driving unit 221 may include multiple stages respectively connected to the scan lines SCL1 to SCLn, each stage outputting a portion of the clock signal CLKS as a scan signal in response to the start signal FLM or the output of a previous stage.

[0106] The sensor pixel SPXL, selected and driven by the gate driving unit 221, senses light using photoelectric elements arranged inside and outputs an electrical signal (sensing signal SS) corresponding to the sensed light (see reference). Figure 1a as well as Figure 1b For example, a voltage signal in analog form. For example, when the sensor pixel SPXL is connected to the i-th reset line RSLi (where i is a positive integer less than or equal to n) and the i-th scan line SCLi, the sensor pixel SPXL can be initialized in response to the reset signal provided through the i-th reset line RSLi (e.g., the charge generated by the photoelectric element is initialized), and output an electrical signal in response to the scan signal provided through the i-th scan line SCLi.

[0107] For a more detailed explanation of the structure and operation of the SPXL sensor pixel, please refer to [reference needed]. Figure 4 as well as Figure 5 This will be discussed later.

[0108] The sensor drive unit 222 can be connected to the sensor pixel SPXL via readout lines RL1 to RLm (where m is a positive integer). For example... Figure 3 As shown, when the sensor pixel SPXL is connected to the j-th readout line RLj (where j is a positive integer less than or equal to m), the sensing drive unit 222 can receive the electrical signal output from the sensor pixel SPXL through the j-th readout line RLj.

[0109] The sensing drive unit 222 can perform processing on the signal output from the sensor pixel SPXL. For example, the sensing drive unit 222 can perform CDS (Correlated Double Sampling) processing to eliminate noise from the received electrical signal. Additionally, the sensing drive unit 222 can convert the analog signal received from the sensor pixel SPXL into a digital signal. In one embodiment, the analog-to-digital converter can be arranged separately for each sensor pixel column, and the analog signals received from the sensor pixel columns can be processed in parallel.

[0110] The control unit 223 can control the gate drive unit 221 and the sensing drive unit 222.

[0111] In one embodiment, the control unit 223 may generate a start signal FLM and a clock signal CLKS. For example, the control unit 223 may generate a start signal FLM (e.g., a reset start signal) and a clock signal CLKS (e.g., a reset clock signal) for generating a reset signal. As another example, the control unit 223 may generate a start signal FLM (e.g., a scan start signal) and a clock signal CLKS (e.g., a scan clock signal) for generating a scan signal.

[0112] In this embodiment, the control unit 223 can change the exposure time of the sensor pixel SPXL based on the fingerprint sensing pattern information I_DP. Here, the fingerprint sensing pattern information I_DP can be provided from the panel driving unit 210, but is not limited thereto.

[0113] In one embodiment, the control unit 223 can control the gate driving unit 221 to change the pulse width of the scan signal (or, the scan signal having a range of on-state voltage levels that turn on the transistors) based on the fingerprint sensing pattern information I_DP. For example, the control unit 223 can change the pulse width of the clock signal CLKS (or, the start signal FLM) that forms the basis of the scan signal (or, the ratio of the range of on-state voltage levels that turn on the transistors, i.e., the duty cycle). For example, as the fingerprint sensing pattern information I_DP is applied to the display panel 100 (see reference 100), the control unit 223 can control the gate driving unit 221 to change the pulse width of the scan signal (or, the ratio of the range of on-state voltage levels that turn on the transistors, i.e., the duty cycle). Figure 1a as well as Figure 1b As the area of ​​the fingerprint sensing pattern displayed in the image becomes smaller, the control unit 223 can reduce the pulse width of the clock signal CLKS. For the operation of the control unit 223 that changes the pulse width of the clock signal CLKS, refer to... Figure 11a This will be discussed later.

[0114] In one embodiment, the control unit 223 can generate image data corresponding to the sensing signal received from the sensing drive unit 222, and perform processing on the generated image data. Alternatively, in one embodiment, the control unit 223 can detect fingerprints based on the processed image data, or authenticate and / or transmit the detected fingerprints to an external device. However, this is merely an example; the generation of image data and fingerprint detection can be performed externally, such as by a main processor, instead of by the control unit 223.

[0115] As described above, the fingerprint sensing device FDD (or fingerprint detection unit 220) can change the exposure time of the sensor pixel SPXL by changing the pulse width of the clock signal CLKS, which is the basis of the scanning signal, based on the fingerprint sensing pattern information I_DP.

[0116] Figure 4 It is shown that it includes Figure 3A circuit diagram of an example sensor pixel in an input sensing device. The reset line RSL may be one of reset lines RSL1 to RSLn, the scan line SCL may be one of scan lines SCL1 to SCLn, and the readout line RL may be one of readout lines RL1 to RLm. Figure 5 This is an explanation Figure 4 The waveform diagram of the sensor pixel operation.

[0117] Reference Figure 3 as well as Figure 4 The sensor pixel SPXL may include a first transistor T1, a second transistor T2, a third transistor T3, a photodiode PD, and a capacitor C_PD.

[0118] Alternatively, the anode electrode of the photodiode PD can be connected to the second power supply line PL2, and the cathode electrode of the photodiode PD can be connected to the gate electrode of the first transistor T1. A bias voltage VBIAS for driving the photodiode PD can be applied to the second power supply line PL2.

[0119] A capacitor C_PD can be formed between the gate electrode of the first transistor T1 and the second power line PL2, and connected in parallel to the photodiode PD. The capacitor C_PD can store the charge converted from photoelectric activity in the photodiode PD. According to an embodiment, the capacitor C_PD can also be omitted.

[0120] Alternatively, the first electrode of the third transistor T3 can be connected to the first power supply line PL1, the second electrode of the third transistor T3 can be connected to the gate electrode of the first transistor T1, and the gate electrode of the third transistor T3 can be connected to the reset line RSL. Here, a reset voltage VRST can be applied to the first power supply line PL1. The third transistor T3 can electrically connect the first power supply line PL1 and the gate electrode of the first transistor T1 in response to a reset signal RST applied to the reset line RSL. In this case, the voltage applied to the gate electrode of the first transistor T1 (or the voltage stored in the capacitor C_PD) can be initialized or reset by the reset voltage VRST.

[0121] like Figure 5 As shown, depending on the operation of the gate drive unit 221, the reset signal RST corresponds to one pulse of the clock signal CLKS (e.g., the reset clock signal CLK_RST).

[0122] Alternatively, the first electrode of the first transistor T1 can be connected to the third power line PL3, the second electrode of the first transistor T1 can be connected to the first electrode of the second transistor T2, and the gate electrode of the first transistor T1 can be connected to the cathode electrode of the photodiode PD. A common voltage VCOM can be applied to the third power line PL3. The first transistor T1 can control the amount of current flowing from the third power line PL3 to the second transistor T2 in response to the voltage stored in the capacitor C_PD (i.e., the charge converted by photoelectric conversion in the photodiode PD). The first transistor T1 can operate as an amplifier that amplifies and outputs the voltage stored in the capacitor C_PD.

[0123] Alternatively, the first electrode of the second transistor T2 can be connected to the second electrode of the first transistor T1, the second electrode of the second transistor T2 can be connected to the readout line RL, and the gate electrode of the second transistor T2 can be connected to the scan line SCL. The second transistor T2 can form a current flow path between the first transistor T1 (or, the third power supply line PL3) and the readout line RL in response to the scan signal HDS applied to the scan line SCL. Figure 5 As shown, depending on the operation of the gate drive unit 221, the scan signal HDS corresponds to one pulse of the clock signal CLKS (e.g., the scan clock signal CLK_HDS). The scan signal HDS with the turn-on voltage level is applied to the scan line SCL after a specific time P_C from the time when the reset signal RST with the turn-on voltage level is applied.

[0124] For example, in response to a scan signal HDS at a conduction voltage level, the second transistor T2 turns on, and the second electrode of the first transistor T1 is electrically connected to the readout line RL. In this case, an electrical signal corresponding to the voltage of the charge converted in the photodiode PD (or the voltage stored in the capacitor C_PD during a specific time P_C) can be output to the outside (e.g., the induction drive unit 222) via the readout line RL (see reference). Figure 3 ).

[0125] On the other hand, Figure 4 The transistors T1, T2, and T3 shown are examples of P-type transistors, but in various embodiments, at least some of the transistors can be configured as N-type, and correspondingly, the circuit structure of the sensor pixel SPXL can be modified in various ways.

[0126] Figure 6 It is shown that it includes Figure 3 A block diagram of an example of the fingerprint detection unit in a fingerprint sensing device.

[0127] Reference Figure 3 as well as Figure 6The fingerprint detection unit 220 may include a control unit 223, an analog-to-digital converter 224, a memory 226, and a fingerprint analysis unit 228.

[0128] The fingerprint detection unit 220 can perform fingerprint authentication in response to fingerprint sensing commands provided from the outside.

[0129] The analog-to-digital converter 224 can convert the analog sensing signal SS into the digital sensing data SD.

[0130] Memory 226 can store calibration data CAL_DATA and registered fingerprint data RFD. The calibration data CAL_DATA is used for calibrating sensor pixels SPXL (see reference). Figure 3 Data such as light reception deviation caused by the position of the sensor (SPXL) may include correction values ​​corresponding to at least a portion of the sensor pixels (SPXL). For example, the correction data CAL_DATA can be displayed in the fingerprint sensing device FDD (or, the display device 1000 (see reference)). Figure 1a The fingerprint data RFD is generated during the manufacturing process and stored in memory 226. The registered fingerprint data RFD can be generated based on the sensing data SD provided from analog-to-digital converter 224 during a separate fingerprint registration period and stored in memory 226.

[0131] Additionally, memory 226 may store a lookup table (LUT). As described later, the lookup table LUT may include information related to the exposure time of the sensor pixel SPXL corresponding to the fingerprint sensing pattern information I_DP. For example, the lookup table LUT may include information relating to the area information related to the region displaying the fingerprint sensing pattern (or the area generating touch input) and the time at which the sensor pixel SPXL senses reflected light (or the time at which it outputs an electrical signal corresponding to the sensed reflected light). As described later, the lookup table LUT may include multiple exposure time information corresponding to multiple areas, or information relating to a mathematical expression (or model) that models the relationship between area information and exposure time.

[0132] The fingerprint analysis unit 228 can receive sensing data SD from the analog-to-digital converter 224. Additionally, the fingerprint analysis unit 228 can receive correction data CAL_DATA from the memory 226. The fingerprint analysis unit 228 can use the correction data CAL_DATA to correct the sensing data SD. That is, the fingerprint analysis unit 228 can use the correction data CAL_DATA to correct deviations in the data values ​​within the sensing data SD (i.e., deviations caused by light intake deviations in the sensor pixel SPXL). For example, the fingerprint analysis unit 228 can correct the sensing data SD by adding the correction value corresponding to the sensor pixel SPXL from the correction value in the correction data CAL_DATA to the data value corresponding to the specific sensor pixel SPXL within the data values ​​of the sensing data SD.

[0133] For reference, the registered fingerprint data RFD can also be generated by correcting the sensing data SD acquired during the fingerprint registration period using the correction data CAL_DATA in the fingerprint analysis unit 228.

[0134] The fingerprint analysis unit 228 can receive registered fingerprint data RFD from the memory 226. The fingerprint analysis unit 228 can perform fingerprint authentication by comparing the calibrated sensing data (i.e., the data generated by calibrating the sensing data SD using calibration data CAL_DATA) and the registered fingerprint data RFD.

[0135] The fingerprint analysis unit 228 can calculate the consistency rate between the corrected sensing data and the registered fingerprint data RFD. In one embodiment, the fingerprint analysis unit 228 can generate a fingerprint image corresponding to the corrected sensing data and compare it with the fingerprint image of the registered fingerprint data RFD to perform fingerprint authentication. For example, the fingerprint analysis unit 228 can extract feature points from the fingerprint image and compare the extracted feature points with feature points included in the registered fingerprint data RFD to perform fingerprint authentication. However, this is exemplary, and the fingerprint authentication can be performed using various known fingerprint recognition methods. The fingerprint analysis unit 228 may include hardware and / or software structures for this purpose.

[0136] When the consistency rate is above a preset threshold, the fingerprint analysis unit 228 can determine that the sensed fingerprint matches the registered fingerprint data RFD. When the consistency rate is below the threshold, the fingerprint analysis unit 228 can determine that the sensed fingerprint does not match the registered fingerprint data RFD.

[0137] When the sensed fingerprint is determined to match the registered fingerprint data RFD, the fingerprint analysis unit 228 can output an acceptance signal ASS. Conversely, when the sensed fingerprint is determined to be inconsistent with the registered fingerprint data RFD, the fingerprint analysis unit 228 can output a rejection signal RS. The acceptance signal ASS or the rejection signal RS can be output to an external source (e.g., a main processor). The operation of the display device 1000 or a corresponding application can be approved based on the acceptance signal ASS or the rejection signal RS.

[0138] The control unit 223 can generate a start signal FLM and a clock signal CLKS.

[0139] In this embodiment, the control unit 223 can change the sensor pixel SPXL (refer to) based on the fingerprint sensing pattern information I_DP and the lookup table LUT. Figure 3 Exposure time.

[0140] For example, the control unit 223 can change the pulse width of the clock signal CLKS (or the duty cycle of the clock signal CLKS) or the pulse width of the start signal FLM based on the fingerprint sensing pattern information I_DP and the lookup table LUT.

[0141] To explain the structure of the control unit 223 that changes the exposure time, please refer to... Figures 7 to 10 , Figure 11a as well as Figure 11b .

[0142] Figure 7 It is shown in the inclusion of Figure 1a An example of a fingerprint sensing pattern displayed on a display panel in a display device. Specifically, Figure 7 Shown in Figure 1a as well as Figure 1b An example of a fingerprint sensing pattern displayed in the fingerprint sensing area FSA of the display device 1000 shown. Figure 8 It shows based on Figure 7 A graph showing the area and brightness of the fingerprint sensing pattern. Figure 9 This is a graph showing the sensing sensitivity based on the exposure time of the sensor pixels. Figure 10 It shows based on Figure 7 A graph showing the area of ​​the fingerprint sensing pattern and the exposure time of the sensor pixels. Figure 11a as well as Figure 11b This is a diagram illustrating an example of adjusting the exposure time of sensor pixels.

[0143] First, refer to Figure 1a , Figure 1b , Figure 6 as well as Figure 7The display panel 100 may display a fingerprint sensing pattern (or display pattern) for fingerprint sensing in at least a portion of the fingerprint sensing area FSA. Here, the fingerprint sensing pattern may be an image or image pattern with brightness corresponding to a specific grayscale value. For example, the fingerprint sensing pattern may be a white image pattern with maximum brightness corresponding to the maximum grayscale value. For example, the display panel 100 may display a white image pattern corresponding to the maximum grayscale value in the area where the user touches the fingerprint. As another example, the fingerprint sensing pattern may also include a pattern that mimics a specific color of a fingerprint on a white background (e.g., a pattern with black, gray, or other colors).

[0144] For example, when a user touches the fingerprint sensing area FSA with one finger, the display panel 100 can display a first fingerprint sensing pattern DP1 with maximum brightness corresponding to the maximum grayscale value in the area where the user's finger is touching. The display panel 100 may not display an image or may display an image pattern corresponding to minimum brightness (e.g., a black image) in the remaining areas other than the area where the user's finger is touching, but is not limited thereto.

[0145] As another example, when a user's two fingers touch the fingerprint sensing area FSA, the display panel 100 can display a second fingerprint sensing pattern DP2 with maximum brightness corresponding to the maximum grayscale value in the area where the user's two fingers are touching. As yet another example, when a user's palm touches the entire fingerprint sensing area FSA, the display panel 100 can display a third fingerprint sensing pattern DP3 with maximum brightness corresponding to the maximum grayscale value in the entire fingerprint sensing area FSA.

[0146] Reference Figure 7 as well as Figure 8 The brightness of the fingerprint sensing pattern can vary depending on the area of ​​the fingerprint sensing pattern. For example... Figure 8 As shown, the brightness of the fingerprint sensing pattern decreases as the area of ​​the fingerprint sensing pattern increases. For reference, as the area of ​​the fingerprint sensing pattern increases, the sensor pixel SPXL (reference) that emits light at maximum brightness corresponding to the maximum grayscale value also increases. Figure 3 As the number of fingerprint sensors increases, the total current supplied to or flowing to the sensor pixels SPXL (or display panel 100) increases. Due to the resistive components in the current movement path and the increased total current, the voltage drop of the driving voltage (or power supply voltage) applied to the sensor pixels SPXL becomes larger. As a result, the brightness of the fingerprint sensing pattern (i.e., the brightness displayed or measured in the display panel 100 corresponding to a specific target brightness to be displayed) can be relatively reduced. In other words, even if the target brightness is constant, the brightness of the fingerprint sensing pattern (i.e., the actual measured brightness) can increase as the area of ​​the fingerprint sensing pattern decreases.

[0147] Reference Figure 7 as well as Figure 8 For example, when the second area A_DP2 of the second fingerprint sensing pattern DP2 is greater than the first area A_DP1 of the first fingerprint sensing pattern DP1, the brightness of the second fingerprint sensing pattern DP2 can be lower than the brightness of the first fingerprint sensing pattern DP1. Similarly, when the third area A_DP3 of the third fingerprint sensing pattern DP3 is greater than the second area A_DP2 of the second fingerprint sensing pattern DP2, the brightness of the third fingerprint sensing pattern DP3 can be lower than the brightness of the second fingerprint sensing pattern DP2. On the other hand, as the brightness of the fingerprint sensing pattern increases, the amount of reflected light (or the amount of light received) sensed by the sensor pixel SPXL increases, or the responsiveness of the sensor pixel SPXL to reflected light, i.e., its sensing sensitivity, becomes higher. That is, due to the change in the area of ​​the fingerprint sensing pattern, the amount of light received or the sensing sensitivity of the sensor pixel SPXL can change.

[0148] Therefore, differences may arise between the brightness conditions of the display panel 100 (i.e., correction conditions) during the generation of correction data CAL_DATA for correcting light reception deviations based on the position of sensor pixel SPXL, and the brightness conditions of the display panel 100 (i.e., user conditions) during the sensing of the user's fingerprint. For example, a third fingerprint sensing pattern DP3 may be used during the generation of correction data CAL_DATA to compensate for the overall sensor pixel SPXL within the fingerprint sensing area FSA, while a first fingerprint sensing pattern DP1 may be used during the sensing of the user's fingerprint corresponding to the user's finger. The area of ​​the third fingerprint sensing pattern DP3 (and its brightness) may differ from the area of ​​the first fingerprint sensing pattern DP1. Therefore, in sensor pixels SPXL operating under the same driving conditions (e.g., the same exposure time), the sensing sensitivity and brightness deviation for the third fingerprint sensing pattern DP3 exhibit different characteristics than those for the first fingerprint sensing pattern DP1. Directly applying the correction data CAL_DATA generated based on the third fingerprint sensing pattern DP3 may not accurately correct the sensing data generated based on the first fingerprint sensing pattern DP1 (i.e., sensing data reflecting the sensing sensitivity and deviation of sensor pixels SPXL under different brightness conditions).

[0149] Reference Figure 9 The first curve, CURVE1, can represent the sensing sensitivity (or light reception) of the sensor pixel SPXL during the generation of correction data CAL_DATA. For example, it could be used to correct for overall deviations in the sensor pixel SPXL within the fingerprint sensing area FSA. Figure 7The third fingerprint sensing pattern DP3 shown in the figure generates correction data CAL_DATA (refer to...). Figure 6 The first curve, CURVE1, represents the sensing sensitivity of the sensor pixel SPXL for the third fingerprint sensing pattern DP3.

[0150] The second curve CURVE2 can represent the sensing sensitivity (or light exposure) of the sensor pixel SPXL during the process of sensing a user's fingerprint. In actual fingerprint sensing, fingerprint sensing patterns of various sizes may be used, for example, using a first fingerprint sensing pattern DP1. The second curve CURVE2 represents the sensing sensitivity of the sensor pixel SPXL for the first fingerprint sensing pattern DP1.

[0151] During the generation of correction data CAL_DATA, according to the first curve CURVE1, the sensor pixel SPXL can have a first sensing value VALUE1 (or, a first sensing sensitivity) corresponding to the first exposure time T_CAL1. Here, the first exposure time T_CAL1 is a value preset during the manufacturing process of the fingerprint sensing device FDD. For example, it can be the exposure time of the sensor pixel SPXL where the difference in light received by the valleys and ridges of the fingerprint corresponds to the third fingerprint sensing pattern DP3 and is the largest.

[0152] On the other hand, during the process of sensing a user's fingerprint, according to the second curve CURVE2, the sensor pixel SPXL can have a second sensing value VALUE2 (or, a second sensing sensitivity) corresponding to the first exposure time T_CAL1. The second sensing value VALUE2 can be greater than or equal to the first sensing value VALUE1.

[0153] Therefore, the correction data CAL_DATA (i.e., the correction value set with the first value VALUE1 as a reference) may not be effective in correcting the sensing data generated during actual fingerprint sensing (i.e., the sensing data generated with the second value VALUE2 as a reference).

[0154] Therefore, during the process of sensing the user's fingerprint, the control unit 223 (refer to...) Figure 6The exposure time of sensor pixel SPXL can be changed to give sensor pixel SPXL a first sensing value VALUE1 (or, the sensing sensitivity of sensor pixel SPXL when generating correction data CAL_DATA). For example, according to the second curve CURVE2, control unit 223 can adjust the exposure time of sensor pixel SPXL from the first exposure time T_CAL1 to the second exposure time T_CAL2. In this case, the correction data CAL_DATA set with sensor pixel SPXL having the first sensing value VALUE1 (or, the first sensing sensitivity) as a reference can be effectively applied to sensing data SD (i.e., sensing data SD generated using sensor pixel SPXL having the first sensing sensitivity when adjusted for fingerprint sensing). Therefore, sensing data SD can be corrected more accurately, and the user's fingerprint can be sensed more accurately.

[0155] Reference Figure 10 The exposure time curve CURVE_E represents the exposure time of the sensor pixels SPXL based on the area of ​​the fingerprint sensing pattern.

[0156] In one embodiment, a first exposure time T_CAL1 may be preset corresponding to the third area A_DP3 of the third fingerprint sensing pattern DP3, and a second exposure time T_CAL2 may be preset corresponding to the first area A_DP1 of the first fingerprint sensing pattern DP1. For example, the first exposure time T_CAL1 and the second exposure time T_CAL2 can be determined during the manufacturing of the fingerprint sensing device FDD (see reference). Figure 3 The data is measured during the process and stored in a lookup table (LUT) (see reference). Figure 6 That is, the exposure time for at least two fingerprint sensing patterns with different areas can be pre-stored in a lookup table (LUT).

[0157] In this case, the control unit 223 can interpolate (or extrapolate) the first exposure time T_CAL1 and the second exposure time T_CAL2 based on the area of ​​the fingerprint sensing pattern acquired during fingerprint sensing, and determine the exposure time of the sensor pixel SPXL.

[0158] For example, during fingerprint sensing, when the second fingerprint sensing pattern DP2 is used, the control unit 223 can interpolate the first exposure time T_CAL1 and the second exposure time T_CAL2 based on the second area A_DP2 of the second fingerprint sensing pattern DP2 to determine the exposure time of the sensor pixel SPXL.

[0159] In another embodiment, the control unit 223 may also use a mathematical formula preset for the exposure time to calculate or determine the exposure time corresponding to the area of ​​the fingerprint sensing pattern acquired during fingerprint sensing. For example, it may be based on the fingerprint sensing device FDD (refer to...) manufactured during the manufacturing process. Figure 3 The first exposure time T_CAL1 and the second exposure time T_CAL2 were measured during the process, and the mathematical formula was modeled. In addition, the coefficients (or variables) of the mathematical formula were set.

[0160] For example, the control unit 223 can calculate the exposure time based on the following mathematical formula 1.

[0161] [Mathematical Expression 1]

[0162]

[0163]

[0164] Here, LUMI FullActive T is the brightness of the fingerprint sensing pattern corresponding to the entire fingerprint sensing area FSA. CAL1 It corresponds to LUMI FullActive The set exposure time of the sensor pixels, LUMI FingerActive This refers to the brightness of the fingerprint sensor pattern displayed for fingerprint sensing. CAL2 It is with LUMI FingerActive The corresponding exposure time of the sensor pixel, α is a coefficient or variable. LUMI FullActive T CAL1 And α can be pre-defined and stored in a lookup table (LUT). LUMI FingerActive The fingerprint sensing pattern information I_DP (i.e., the area of ​​the fingerprint sensing pattern) and the exposure time curve CURVE_E can be exported. The exposure time curve CURVE_E can be preset and stored in a lookup table LUT.

[0165] As another example, the control unit 223 can calculate the exposure time based on the following mathematical formula 2.

[0166] [Mathematical Expression 2]

[0167]

[0168] Here, T CAL2 Is it related to AREA FingerActive The corresponding exposure time of the sensor pixel, β is a coefficient or variable, T CAL1 It corresponds to AREA FullActive The set exposure time of the sensor pixels, AREA FingerActive It is the area of ​​the fingerprint sensing pattern displayed for fingerprint sensing, AREAFullActive It is the area of ​​the fingerprint sensing pattern corresponding to the entire fingerprint sensing area (FSA). FullActive T CAL1 And β can be pre-defined and stored in a lookup table (LUT).

[0169] As described above, the control unit 223 can determine or calculate the exposure time of the sensor pixel SPXL by using a preset exposure time for at least two fingerprint sensing patterns with different areas from each other or by using a pre-modeled mathematical formula.

[0170] In an embodiment, the control unit 223 may change the pulse width of the clock signal CLKS (or the start signal FLM) or change the application time of the start signal FLM in accordance with the exposure time of the sensor pixel SPXL.

[0171] Reference Figure 11a For example, when a third fingerprint sensing pattern DP3 is used for fingerprint sensing, the control unit 223 can generate a clock signal CLKS (e.g., a scan clock signal) having a first pulse width PW1. In this case, it can be as described in reference... Figure 5 As explained, a scan signal HDS with a first pulse width PW1 is generated, and the sensor pixel SPXL (refer to...) Figure 4 The control unit 223 outputs an electrical signal during a time corresponding to the first pulse width PW1 (e.g., the first exposure time T_CAL1). As another example, when a first fingerprint sensing pattern DP1 (or a second fingerprint sensing pattern DP2) is used for fingerprint sensing, the control unit 223 can generate a clock signal CLKS (e.g., a scan clock signal) having a second pulse width PW2. In this case, a scan signal HDS having a second pulse width PW2 can be generated, and the sensor pixel SPXL (refer to...) Figure 4 The output electrical signal is generated during the time corresponding to the second pulse width PW2 (e.g., the second exposure time T_CAL2).

[0172] On the other hand, Figure 11a The description states that, based on the premise that the exposure time is approximately the same as the period of the clock signal CLKS, the control unit 223 adjusts the pulse width of the clock signal CLKS, but is not limited to this. For example, when the exposure time is more than twice the length of the clock signal CLKS, the control unit 223 can also adjust the pulse width of the start signal FLM, which has a conduction voltage level. That is, in order to adjust the pulse width of the scan signal HDS, the control unit 223 can also adjust the pulse width of the start signal FLM corresponding to the scan signal HDS.

[0173] Reference Figure 11bFor example, when a third fingerprint sensing pattern DP3 is used for fingerprint sensing, the control unit 223 can generate a scan start signal FLM_HDS of the on-state voltage level after a first time P1 from the time of the reset start signal FLM_RST that outputs the on-state voltage level. A reference signal is generated corresponding to the reset start signal FLM_RST. Figure 4 The reset signal RST described herein, in addition, since a scan signal HDS is generated corresponding to the scan start signal FLM_HDS, can be output after a first time P1 starting from the time point of the reset signal RST at the output conduction voltage level. In this case, it may be that during the first time P1 (e.g., the first exposure time T_CAL1), the scan signal HDS at the photodiode PD (reference) Figure 4 The charge converted by photoelectric conversion in the photodiode PD is stored in the capacitor C_PD, and the sensor pixel SPXL outputs an electrical signal in response to the voltage stored in the capacitor C_PD. As another example, when using a first fingerprint sensing pattern DP1 (or a second fingerprint sensing pattern DP2) for fingerprint sensing, the control unit 223 can generate a scan start signal FLM_HDS with a conduction voltage level after a second time P2, starting from the time of the reset start signal FLM_RST that outputs the conduction voltage level. In this case, during the second time P2 (e.g., the second exposure time T_CAL2), the charge converted by photoelectric conversion in the photodiode PD is stored in the capacitor C_PD, and the sensor pixel SPXL outputs an electrical signal in response to the voltage stored in the capacitor C_PD. That is, the control unit 223 can also adjust the timing of applying the scan signal HDS to the sensor pixel SPXL after the capacitor C_PD of the sensor pixel SPXL is initialized (or reset).

[0174] As described above, the control unit 223 can change the exposure time of the sensor pixel SPXL based on the area (or size) of the fingerprint sensing pattern included in the fingerprint sensing pattern information I_DP. Therefore, the correction data CAL_DATA set based on the sensor pixel SPXL with a specific sensing sensitivity can be effectively applied to the sensing data SD (i.e., the sensing data SD generated using the sensor pixel SPXL adjusted to have the same specific sensing sensitivity as when the correction data CAL_DATA was generated), the sensing data SD can be corrected more accurately, and the user's fingerprint can be sensed more accurately.

[0175] Figure 12 This is a flowchart illustrating a calibration method for an input sensing device according to an embodiment of the present invention. Figure 12 The method can be Figure 1a as well as Figure 1b The display device 1000 (or input sensing device) is executed as the object.

[0176] Reference Figure 1a , Figure 1b , Figure 3 , Figure 4 , Figure 6 as well as Figure 12 , Figure 12 The method can perform an electrical test (S100) on the display device 1000 (or the input sensing device).

[0177] For example, Figure 12 One method is to apply a driving voltage (or power supply voltage) to the display device 1000 to test whether the display device 1000 (e.g., the display panel 100 and the fingerprint sensing device FDD) is functioning correctly. For example, Figure 12 This method can be used to test whether the display panel 100 correctly displays the fingerprint sensing pattern in the fingerprint sensing area FSA. For example, Figure 12 The method can be tested Figure 4 Check whether the sensor pixel SPXL is working properly, for example, whether the photodiode PD is working properly, or whether the transistors T1 to T3 are working properly.

[0178] after, Figure 12 The method can utilize fingerprint sensing patterns (or display patterns) of different sizes on a plane to set the exposure time of the sensor pixels SPXL. For example, Figure 12 The method can utilize test patterns of different sizes on a plane (or test objects with different contact areas with the fingerprint sensing area FSA) to set the exposure time of the sensor pixel SPXL. As explained above, each exposure time refers to the time the sensor pixel SPXL receives reflected light or the time the sensor pixel SPXL outputs an electrical signal corresponding to the reflected light; the magnitude of the electrical signal received by the fingerprint detection unit 220 from the sensor pixel SPXL may vary depending on the exposure time. For example, Figure 12 The method can set or optimize the exposure time of the sensor pixel SPXL so that the difference in light received by the valleys and ridges of the fingerprint is maximized for a fingerprint sensing pattern of a specific size, or the sensor pixels SPXL have the same sensing sensitivity.

[0179] In an embodiment, Figure 12 The method can set the first exposure time of the sensor pixel SPXL using a first fingerprint sensing pattern (or a first display pattern) corresponding to the entire fingerprint sensing area FSA (S200), and set the second exposure time of the sensor pixel SPXL using a second fingerprint sensing pattern (or a second display pattern) smaller than the first fingerprint sensing pattern (S300).

[0180] The first exposure time and the second exposure time can be stored in a reference. Figure 6 The LUT (Lookup Table) described. According to an embodiment, Figure 12 The method can also utilize the first and second exposure times to set or model a mathematical formula related to the exposure time based on the area of ​​the fingerprint sensing pattern (e.g., refer to...). Figure 10 The mathematical formula 1 or mathematical formula 2 described.

[0181] For a more specific structure regarding the setting of the first and second exposure times, refer to... Figures 13 to 16 To be described later.

[0182] after, Figure 12 The method can correct for light intake deviations based on the position of sensor pixel SPXL (S400). For example, Figure 12 The method allows setting correction values ​​for each sensor pixel SPXL to improve the sensing sensitivity (or sensing value) of each sensor pixel SPXL (see reference). Figure 9 Uniform. For example, Figure 12 The method can acquire sensing data using a test object corresponding to the entire fingerprint sensing area FSA (e.g., a test object with a flat surface without valleys and ridges and a specific color such as white) and a first fingerprint sensing pattern corresponding to the entire fingerprint sensing area FSA, and set correction values ​​to correct deviations in the data values ​​within the sensing data respectively. For example, Figure 12 The method can set the offset value of the sensing sensitivity (or sensing value) of each sensor pixel SPXL as the correction value. However, this is exemplary, and the correction value is not limited to the offset value for sensing sensitivity. On the other hand, the correction value for each sensor pixel SPXL can be used to generate correction data CAL_DATA (see [reference]). Figure 6 ).

[0183] after, Figure 12 The method can perform optical testing on the display device 1000 (S500). For example, Figure 12 The method can utilize a pre-defined fingerprint (or a fingerprint that mimics the user's fingerprint) and its corresponding pre-defined registered fingerprint data RFD (see [reference]). Figure 6 The test displays whether the display device 1000 accurately senses the fingerprint. For example, a simulated fingerprint can be brought into contact with the display device 1000 to obtain sensing data. The sensing data is then corrected using a correction value (i.e., the correction value obtained in S400), and the corrected sensing data is compared with the registered fingerprint data (i.e., the registered fingerprint data corresponding to the simulated fingerprint).

[0184] When the optical test is not performed properly, that is, when the display device 1000 cannot accurately sense the fingerprint, the steps of performing correction for the sensor pixel SPXL (S400) and performing the optical test (S500) can be repeated.

[0185] When the optical test is performed normally Figure 12 The method can generate correction data CAL_DATA (see reference). Figure 6 (S600).

[0186] Right now, Figure 12 The method can generate correction data CAL_DATA based on the correction value set in the step of performing correction for sensor pixels SPXL. The correction data CAL_DATA can be stored in memory 226 (see reference). Figure 6 ).

[0187] On the other hand, Figure 12 The description indicates that calibration data CAL_DATA (S600) is generated after the optical testing step (S500), but is not limited to this. For example, Figure 12 The method can also generate or update the calibration data CAL_DATA after performing calibration for the sensor pixel SPXL (S400) and before performing optical testing (S500).

[0188] As mentioned above, Figure 12 The method can utilize fingerprint sensing patterns of varying sizes on a plane to set the exposure time of sensor pixels SPXL. Alternatively, the set exposure time can be used to set or model a mathematical formula related to the exposure time based on the area of ​​the fingerprint sensing pattern (e.g., refer to...). Figure 10 (as described in mathematical formula 1 or mathematical formula 2). Therefore, the display device 1000 can adjust the sensing sensitivity of the sensor pixel SPXL during fingerprint sensing to be the same as the sensing sensitivity of the sensor pixel SPXL when generating correction data CAL_DATA by using a set exposure time or mathematical formula. As a result, the sensing data SD can be corrected more accurately using the correction data CAL_DATA, and the fingerprint can be sensed more accurately.

[0189] Figure 13 This is a flowchart illustrating the process of setting the first exposure time. Figure 14 This is a diagram illustrating an example of the process for setting the first exposure time. In Figure 14 In order to illustrate the process of setting the first exposure time using a test pattern (or test object), a reference is shown. Figure 9 The first curve described is CURVE1. Figure 15 This is another diagram illustrating the process of setting the first exposure time. In Figure 15In order to illustrate the process of setting the first exposure time using multiple test patterns (or test objects), a diagram is shown with reference to... Figure 9 The curve corresponding to the first curve CURVE1 described.

[0190] Reference Figure 1a , Figure 1b , Figure 3 , Figure 4 , Figure 6 , Figure 12 , Figure 13 as well as Figure 14 , Figure 13 The method allows displaying a first fingerprint sensing pattern (or a first display pattern) in the fingerprint sensing area FSA of the display panel 100 (S210). For example, the first fingerprint sensing pattern can be compared with a reference... Figure 7 The third fingerprint sensing pattern DP3 described is the same.

[0191] after, Figure 13 The method can receive a first sensing signal generated in the sensor pixel SPXL (or, the light sensor PS) corresponding to the first fingerprint sensing pattern by the fingerprint detection unit 220 (S220).

[0192] after, Figure 13 The method can change the exposure time of the sensor pixel SPXL so that the first sensing signal is within the reference range.

[0193] In one embodiment, Figure 13 The method can determine whether the first sensing sensitivity of the sensor pixel SPXL based on the first sensing signal is greater than the first reference value VALUE_REF1 and less than the second reference value VALUE_REF2 (that is, whether the first sensing sensitivity of the sensor pixel SPXL is within the first reference range) (S230).

[0194] When the first sensing sensitivity of sensor pixel SPXL is less than the first reference value VALUE_REF1 or greater than the second reference value VALUE_REF2 (that is, when the first sensing sensitivity of sensor pixel SPXL exceeds the first reference range), Figure 13 The method can change the exposure time of the sensor pixel SPXL (S240). Additionally, Figure 13 The method can further determine whether the first sensing sensitivity of the sensor pixel SPXL is greater than the first reference value and less than the second reference value (i.e., whether the first sensing sensitivity of the sensor pixel SPXL is within the first reference range) (S230).

[0195] Reference Figure 14For example, when the exposure time of sensor pixel SPXL has a first time value t1, the first sensing sensitivity of sensor pixel SPXL may be less than the first reference value VALUE_REF1. In this case, Figure 13 This method can increase the exposure time of sensor pixel SPXL. Conversely, when the exposure time of sensor pixel SPXL has a second time value t2, the first sensing sensitivity of sensor pixel SPXL may be greater than the second reference value VALUE_REF2. In this case, Figure 13 This method can reduce the exposure time of the sensor pixel SPXL.

[0196] The process of increasing or decreasing the exposure time of sensor pixel SPXL can be repeated until the first sensing sensitivity of sensor pixel SPXL is greater than the first reference value VALUE_REF1 and less than the second reference value VALUE_REF2 (that is, until the first sensing sensitivity of sensor pixel SPXL is within the first reference range).

[0197] When the first sensing sensitivity of sensor pixel SPXL is greater than the first reference value VALUE_REF1 and less than the second reference value VALUE_REF2 (that is, when the first sensing sensitivity of sensor pixel SPXL is within the first reference range), Figure 13 The method allows setting the corresponding exposure time to the first exposure time T_CAL1 (S250) of the sensor pixel SPXL.

[0198] According to an embodiment, Figure 13 The method can also utilize multiple test objects to set the first exposure time T_CAL1 of the sensor pixel SPXL. For example, in Figure 14 The test subjects used can have a specific skin tone and a specific reflectivity for the fingerprint sensing pattern. On the other hand, in Figure 15 The test objects used can be of the same size (e.g., the size that contacts the entire fingerprint sensing area FSA) and have different colors from each other. For example, the test objects can be white (or a relatively light color), black (or a relatively dark color), and light orange, respectively, and have different reflectivities for the fingerprint sensing pattern depending on their color. Each user has a different skin tone, and the reflectivity to light varies depending on the skin tone. Therefore, the first exposure time T_CAL1 of the sensor pixel SPXL can be set using test objects with different colors.

[0199] Reference Figure 15For example, when the first curve CURVE_S1 represents the sensitivity of sensor pixel SPXL to a white test object, and the exposure time of sensor pixel SPXL is the first exposure time T_CAL_S1, the sensitivity of sensor pixel SPXL can have a first value VALUE1 (i.e., referring to...). Figure 14 (The sensing value is within the first reference range described). When the second curve CURVE_S2 represents the sensing sensitivity of sensor pixel SPXL for a black test object, and the exposure time of sensor pixel SPXL is the second exposure time T_CAL_S2, the sensing sensitivity of sensor pixel SPXL can have a first value VALUE1. When the third curve CURVE_S3 represents the sensing sensitivity of sensor pixel SPXL for a light orange test object, and the exposure time of sensor pixel SPXL is the third exposure time T_CAL_S3, the sensing sensitivity of sensor pixel SPXL can have a first value VALUE1.

[0200] According to an embodiment, the first to third exposure times T_CAL_S1 to T_CAL_S3 can be included in the first exposure time T_CAL1. When the display device 1000 infers the color of an object (e.g., the user's skin tone), the display device 1000 can apply an exposure time more suitable for the object's color as the first exposure time. For example, when the user's skin tone is relatively bright, the display device 1000 can use the first exposure time T_CAL_S1 as the first exposure time T_CAL1 for fingerprint sensing of the corresponding user. As another example, when the user's skin tone is relatively dark, the display device 1000 can use the second exposure time T_CAL_S2 as the first exposure time T_CAL1 for fingerprint sensing of the corresponding user. That is, the control unit 223 can reduce the exposure time as the object's color becomes brighter. Therefore, a more optimized first exposure time T_CAL1 can be used for fingerprint sensing, enabling more accurate sensing of the user's fingerprint.

[0201] As described above, the first exposure time T_CAL1 of the sensor pixel SPXL for the first fingerprint sensing pattern can be set.

[0202] Figure 16 This is a flowchart illustrating the process of setting the second exposure time.

[0203] Reference Figure 1a , Figure 1b , Figure 3 , Figure 4 , Figure 6 , Figure 12 , Figures 13 to 16 The process of setting the second exposure time is essentially the same as or similar to the process of setting the first exposure time, so it will not be repeated.

[0204] Figure 16 The method allows a second fingerprint sensing pattern (or a second display pattern) to be displayed in the fingerprint sensing area FSA of the display panel 100 (S310). For example, the second fingerprint sensing pattern can be compared with a reference fingerprint sensor. Figure 7 The first fingerprint sensing pattern DP1 described is the same.

[0205] after, Figure 16 The method can receive a second sensing signal generated in the sensor pixel SPXL (or, the light sensor PS) corresponding to the second fingerprint sensing pattern by the fingerprint detection unit 220 (S320).

[0206] after, Figure 16 The method can change the exposure time of the sensor pixel SPXL so that the second sensing signal is within the reference range.

[0207] In one embodiment, Figure 16 The method can determine whether the second sensing sensitivity of the sensor pixel SPXL based on the second sensing signal is similar to the first sensing sensitivity (i.e., based on the reference signal). Figure 14 The sensor pixel SPXL has the same sensitivity during the first exposure time T_CAL1 (S330).

[0208] When the second sensing sensitivity of the sensor pixel SPXL is different from the first sensing sensitivity Figure 16 The method can change the exposure time of sensor pixel SPXL (S340), and then determine whether the second sensing sensitivity of sensor pixel SPXL is the same as the first sensing sensitivity (S330).

[0209] By repeating this process, the sensing sensitivity of the sensor pixel SPXL can be set to the same second exposure time T_CAL2 as the first sensing sensitivity.

[0210] That is, when the second sensing sensitivity of the sensor pixel SPXL becomes the same as the first sensing sensitivity, Figure 16 The method allows setting the corresponding exposure time to the second exposure time T_CAL2 (S350) of the sensor pixel SPXL.

[0211] According to the embodiments, as referred to Figure 15 As explained, the second exposure time T_CAL2 of the sensor pixel SPXL can also be set using test objects with different colors from each other.

[0212] As described above, the second exposure time T_CAL2 of the sensor pixel SPXL for the second fingerprint sensing pattern can be set.

[0213] The above description refers to preferred embodiments of the present invention. However, those skilled in the art or those with ordinary knowledge in the art will understand that various modifications and alterations can be made to the present invention without departing from the concept and scope of the invention as set forth in the claims.

[0214] Therefore, the technical scope of this invention is not limited to the contents described in the detailed description of the specification, but should be determined by the claims.

Claims

1. An input sensing device, wherein, include: The display panel shows a fingerprint sensing pattern corresponding to the object and used for fingerprint sensing; Sensor pixels generate a sensing signal by sensing light reflected by the object from the fingerprint sensing pattern; as well as The fingerprint detection unit detects fingerprints of the object based on the sensing signals. The fingerprint detection unit adjusts the exposure time of the sensor pixels to the light based on the size of the fingerprint sensing pattern. The size of the fingerprint sensing pattern corresponds to the area of ​​the object in contact with the display panel.

2. The input sensing device according to claim 1, wherein, The fingerprint detection unit reduces the exposure time as the size of the fingerprint sensing pattern decreases.

3. The input sensing device according to claim 2, wherein, The display panel displays the fingerprint sensing pattern based on the same grayscale values. As the size of the fingerprint sensing pattern decreases, the brightness of the fingerprint sensing pattern increases.

4. The input sensing device according to claim 2, wherein, The fingerprint detection unit includes a gate driving unit that generates a scanning signal. The sensor pixels include: Photoelectric element, which converts the light into electrical charge; and A transistor that outputs an electrical signal corresponding to the charge in response to the scan signal.

5. The input sensing device according to claim 4, wherein, The fingerprint detection unit controls the gate driving unit to change the pulse width of the scanning signal based on the size of the fingerprint sensing pattern.

6. The input sensing device according to claim 5, wherein, The fingerprint detection unit reduces the pulse width of the scanning signal as the size of the fingerprint sensing pattern decreases.

7. The input sensing device according to claim 5, wherein, The gate driving section outputs a clock signal as the scan signal in response to a start signal. The fingerprint detection unit changes the duty cycle of the clock signal based on the size of the fingerprint sensing pattern.

8. The input sensing device according to claim 4, wherein, The sensor pixel also includes a capacitor for storing the charge. The transistor responds to the scan signal by outputting an electrical signal corresponding to the charge in the capacitor. The fingerprint detection unit adjusts the timing of applying the scanning signal to the sensor pixel after the capacitor is reset.

9. The input sensing device according to claim 1, wherein, The fingerprint detection unit stores information related to a first exposure time and a second exposure time, the first exposure time and the second exposure time corresponding to a first fingerprint sensing pattern and a second fingerprint sensing pattern having different sizes from each other, respectively. The fingerprint detection unit determines the exposure time by interpolating the first exposure time and the second exposure time based on the size of the fingerprint sensing pattern.

10. The input sensing device according to claim 1, wherein, The fingerprint detection unit performs analog-to-digital conversion on the sensing signal to generate sensing data, corrects the sensing data using pre-set correction data, and performs authentication for the object based on the corrected sensing data and pre-registered fingerprint data.

11. A calibration method for an input sensing device, the input sensing device comprising: The display panel shows a fingerprint sensing pattern corresponding to the object and used for fingerprint sensing; and sensor pixels, which sense light reflected by the object from the fingerprint sensing pattern to generate a sensing signal, wherein, The calibration method for the input sensing device includes: The step of setting the exposure time of the sensor pixels for the light using fingerprint sensing patterns of different sizes on a plane. The size of the fingerprint sensing pattern corresponds to the area of ​​the object in contact with the display panel.

12. The calibration method for the input sensing device according to claim 11, wherein, The steps for setting the exposure time include: The step of setting the first exposure time of the sensor pixels based on a first fingerprint sensing pattern having a first size; and The step of setting the second exposure time of the sensor pixel based on a second fingerprint sensing pattern having a second size.

13. The calibration method for the input sensing device according to claim 12, wherein, The step of setting the exposure time is based on the first exposure time and the second exposure time, and models a mathematical expression related to the exposure time based on the size of the fingerprint sensing pattern.

14. The calibration method for the input sensing device according to claim 12, wherein, The steps for setting the first exposure time include: The step of determining whether the first sensing sensitivity of the sensor pixel for the first fingerprint sensing pattern is within a reference range; The step of increasing or decreasing the exposure time until the first sensing sensitivity is within the reference range; and The step of setting the exposure time to the first exposure time when the first sensing sensitivity is within the reference range.

15. The calibration method for the input sensing device according to claim 14, wherein, The steps for setting the second exposure time include: The step of determining whether the second sensing sensitivity of the sensor pixel for the second fingerprint sensing pattern is the same as the first sensing sensitivity; and The step of setting the exposure time of the sensor pixel when the second sensing sensitivity is the same as the first sensing sensitivity as the second exposure time.

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