Display device

Abstract

A display device is provided, which includes: an optical image sensor; a pinhole array mask layer located on the optical image sensor; a display layer, which is arranged on the pinhole array mask layer and includes a plurality of pixels; and a transparent cover layer, which is arranged on the display layer, wherein a finger placement surface is arranged on the transparent cover layer, wherein each pixel is one of a red pixel, a green pixel and a blue pixel, and when a finger is adjacent to the finger placement surface, at least one of the green pixel and the blue pixel emits light, while the red pixel does not emit light.

Description

[0001] This application claims the priority benefit of Korean Patent Application No. 10-2018-0006149 filed on January 17, 2018, in the Korean Intellectual Property Office (KIPO), the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0002] Exemplary embodiments of the present invention relate to a display device, and more particularly, to a display device including an optical image sensor. Background Art

[0003] Biometric authentication is widely used in display devices such as mobile terminals. Fingerprint detection and matching is an example of biometric authentication adopted by mobile terminals.

[0004] However, the fingerprint recognition area of ​​the fingerprint recognition device may overlap the display area of ​​the display device. Summary of the invention

[0005] According to an exemplary embodiment of the present invention, a display device includes: an optical image sensor; a pinhole array mask layer located on the optical image sensor; a display layer disposed on the pinhole array mask layer and including a plurality of pixels; and a transparent cover layer disposed on the display layer, wherein a finger placement surface is disposed on the transparent cover layer. Each pixel is one of a red pixel, a green pixel, and a blue pixel, and when a finger is adjacent to the finger placement surface, at least one of the green pixel and the blue pixel emits light, while the red pixel does not emit light.

[0006] The display layer can display a fingerprint recognition area overlapping the optical image sensor.

[0007] Only red pixels located in the area of ​​the finger placement surface that is in contact with the finger may not emit light.

[0008] At least one of the green pixel and the blue pixel located in the area of ​​the finger placement surface in contact with the finger may emit light.

[0009] The display layer may further include a touch sensing layer for sensing a touch of a finger in contact with the finger placement surface.

[0010] The width of the pinholes of the pinhole array mask layer may be in the range from about 20 μm to about 80 μm.

[0011] When the distance between the pinhole array mask layer and the optical image sensor is greater than or equal to about 3.0 mm and less than or equal to about 4.0 mm, the width of the pinholes of the pinhole array mask layer may be about 65 μm or greater, when the distance between the pinhole array mask layer and the optical image sensor is greater than or equal to about 2.0 mm and less than or equal to about 3.0 mm, the width of the pinholes may be in the range from about 45 μm to about 75 μm, when the distance between the pinhole array mask layer and the optical image sensor is greater than or equal to about 1.0 mm and less than or equal to about 2.0 mm, the width of the pinholes may be in the range from about 25 μm to about 55 μm, and when the distance between the pinhole array mask layer and the optical image sensor is greater than or equal to about 0.5 mm and less than or equal to about 1.0 mm, the width of the pinholes may be in the range from about 25 μm to about 55 μm.

[0012] According to an exemplary embodiment of the present invention, a display device includes: an optical image sensor; a pinhole array mask layer disposed on the optical image sensor and including a plurality of pinholes; a display layer disposed on the pinhole array mask layer and including a plurality of pixels; and a transparent cover layer disposed on the display layer and having a finger placement surface. Adjacent pinholes of the plurality of pinholes are separated from each other by a distance of about 40 μm to about 127 μm.

[0013] Adjacent pinholes are separated from each other by a distance of about 40 μm to about 85 μm.

[0014] The pinhole array mask layer may be separated from the optical image sensor by a distance of about 0.25 mm to about 4.0 mm.

[0015] When the distance between the pinhole array mask layer and the optical image sensor is greater than or equal to approximately 3.0 mm and less than or equal to approximately 4.0 mm, the minimum value of the distance between adjacent pinholes may be approximately 80 μm, when the distance between the pinhole array mask layer and the optical image sensor is greater than or equal to approximately 2.0 mm and less than or equal to approximately 3.0 mm, the minimum value of the distance between adjacent pinholes may be approximately 70 μm, when the distance between the pinhole array mask layer and the optical image sensor is greater than or equal to approximately 1.0 mm and less than or equal to approximately 2.0 mm, the minimum value of the distance between adjacent pinholes may be approximately 55 μm, when the distance between the pinhole array mask layer and the optical image sensor is greater than or equal to approximately 0.5 mm and less than or equal to approximately 1.0 mm, the minimum value of the distance between adjacent pinholes may be approximately 45 μm, and when the distance between the pinhole array mask layer and the optical image sensor is greater than or equal to approximately 0.25 mm and less than or equal to approximately 0.5 mm, the minimum value of the distance between adjacent pinholes may be approximately 40 μm.

[0016] The pinhole array mask layer may be separated from the optical image sensor by approximately 1 mm or less.

[0017] A width of a first pinhole among the plurality of pinholes may be in a range from about 20 μm to about 80 μm.

[0018] When the distance between the pinhole array mask layer and the optical image sensor is greater than or equal to about 3.0 mm and less than or equal to about 4.0 mm, the width of the first pinhole can be about 65 μm or greater, when the distance between the pinhole array mask layer and the optical image sensor is greater than or equal to about 2.0 mm and less than or equal to about 3.0 mm, the width of the first pinhole can be in the range from about 45 μm to about 75 μm, when the distance between the pinhole array mask layer and the optical image sensor is greater than or equal to about 1.0 mm and less than or equal to about 2.0 mm, the width of the first pinhole can be in the range from about 25 μm to about 55 μm, and when the distance between the pinhole array mask layer and the optical image sensor is greater than or equal to about 0.5 mm and less than or equal to about 1.0 mm, the width of the first pinhole can be in the range from about 25 μm to about 55 μm.

[0019] A ratio of a thickness of the pinhole array mask layer to a width of a first pinhole among the plurality of pinholes may be in a range from about 5 to about 20.

[0020] According to an exemplary embodiment of the present invention, a display device includes: an optical image sensor; a pinhole array mask layer located on the optical image sensor; a display layer disposed on the pinhole array mask layer and including a plurality of pixels; a transparent cover layer disposed on the display layer and having a finger placement surface; and an anti-reflection layer located between the display layer and the pinhole array mask layer.

[0021] The anti-reflection layer may include a polarizing layer.

[0022] The anti-reflection layer may include a retardation layer.

[0023] The delay layer may be a quarter delay layer.

[0024] The anti-reflection layer may include a matte film.

[0025] The anti-reflection layer may include a matte-treated surface of the display layer.

[0026] The anti-reflection layer may include a matte-treated surface of the pinhole array mask layer.

[0027] The inner circumferential surface of the pinhole may be matte-finished.

[0028] The optical image sensor may further include a filter for blocking red light.

[0029] The filter may be a color filter that transmits green light or blue light.

[0030] The optical image sensor may further include a filter for blocking infrared rays.

[0031] According to an exemplary embodiment of the present invention, a display device includes: an optical image sensor including a plurality of sensing elements having a first pattern; a pinhole array mask layer disposed on the optical image sensor and including a plurality of pinholes having a second pattern; a display layer disposed on the pinhole array mask layer and including a plurality of pixels having a third pattern; and a transparent cover layer disposed on the display layer and having a finger placement surface. The first pattern and the second pattern are not parallel to each other.

[0032] Each of the first pattern and the second pattern may be in the form of a matrix having rows and columns, and the rows and columns of the first pattern may not be parallel to the rows and columns of the second pattern.

[0033] An angle between a row of the first pattern and a row of the second pattern may be greater than about 0 degrees and less than about 45 degrees.

[0034] An angle between rows of the first pattern and rows of the second pattern may be greater than about 15 degrees and less than about 30 degrees.

[0035] The second pattern and the third pattern may not be parallel to each other.

[0036] The third pattern may be in the form of a matrix having rows and columns, and the rows and columns of the third pattern may not be parallel to the rows and columns of the second pattern.

[0037] The first pattern, the second pattern, and the third pattern may not be parallel to each other.

[0038] According to an exemplary embodiment of the present invention, a display device includes: an optical image sensor including a plurality of sensing elements, wherein "n" sensing elements are arranged per predetermined length in a first direction; a pinhole array mask layer, disposed on the optical image sensor, and including a plurality of pinholes, wherein "m" pinholes are arranged per predetermined length in the first direction; a display layer, disposed on the pinhole array mask layer, and including a plurality of pixels; and a transparent cover layer, disposed on the display layer, and having a finger placement surface, wherein n and m are natural numbers that are mutually prime. The predetermined length may be substantially equal to or greater than the length of the optical image sensor in the first direction.

[0039] The predetermined length may be at least twice or more the length of the optical image sensor in the first direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The above and other features of the present invention will become more apparent by describing in detail exemplary embodiments of the present invention with reference to the accompanying drawings, in which:

[0041] Figure 1 is a perspective view showing a display device according to an exemplary embodiment of the present invention;

[0042] Figure 2 is a block diagram showing a display device according to an exemplary embodiment of the present invention;

[0043] Figure 3A is a schematic diagram showing an exemplary embodiment of the present invention. Figure 1 An exploded perspective view of a display device;

[0044] Figure 3B According to an exemplary embodiment of the present invention Figure 1 A cross-sectional view taken along line II';

[0045] Figure 4 and Figure 5 are a plan view and a cross-sectional view showing a display panel according to an exemplary embodiment of the present invention;

[0046] Figure 6 and Figure 7 shows a pinhole array mask layer and an enlarged pinhole according to an exemplary embodiment of the present invention;

[0047] Figure 8 is a diagram illustrating a display device in which a fingerprint recognition area is displayed according to an exemplary embodiment of the present invention;

[0048] Fig. 9 is a flow chart showing a method for a display device to capture a fingerprint image according to an exemplary embodiment of the present invention;

[0049] Fig. 10A , Fig. 10B , Fig. 10C , Fig. 10D , Fig.11A , Fig. 11B , Fig. 11C and Fig.11D It is an image captured using a pinhole of predetermined width and a light source;

[0050] Fig.12 is a schematic cross-sectional view showing a display device according to an exemplary embodiment of the present invention;

[0051] Fig.13A is a graph showing a value of a pitch of pinholes according to a distance between a pinhole array mask layer and an optical image sensor according to an exemplary embodiment of the present invention;

[0052] Fig. 13Bis a graph showing the intensity of diffracted light for each position according to a distance between a pinhole array mask layer and an optical image sensor and according to a diameter of a pinhole according to an exemplary embodiment of the present invention;

[0053] Fig.14A , Fig. 14B , Fig. 14C and Fig.14D is a simulation diagram showing diffraction propagation of the optical image sensor according to the diameter of the pinholes for each given distance between the pinhole array mask layer and the optical image sensor;

[0054] Fig.15 is a cross-sectional view for explaining light reflection between a display layer and a pinhole array mask layer according to an exemplary embodiment of the present invention;

[0055] Fig.16A , Fig. 16B and Fig. 16C is a cross-sectional view schematically showing a display device for preventing light reflection between a pinhole array mask layer and a display layer according to an exemplary embodiment of the present invention;

[0056] Fig.17A , Fig. 17B and Fig. 17C are plan views respectively showing arrangements of pixels of a display layer of a display panel, pinholes of a pinhole array mask layer, and sensing elements of an optical image sensor according to an exemplary embodiment of the present invention;

[0057] Fig.18A , Fig.18B , Fig.18C , Fig.18D and Fig.18E are images captured by different display devices according to an exemplary embodiment of the present invention, the different display devices having different angles between an arrangement direction of the pinholes of the pinhole array mask layer and an arrangement direction of the sensing elements of the optical image sensor;

[0058] Fig.19A , Fig.19B and Fig.19C An exemplary embodiment according to the present invention shows that moire (or moirés) appear depending on the angle between two arrays; and

[0059] Fig. 20A and Fig. 20B An exemplary embodiment according to the present invention shows the moire produced according to the resolution of two arrays. DETAILED DESCRIPTION

[0060] Exemplary embodiments of the present invention will now be described more fully hereinafter with reference to the accompanying drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein.

[0061] In the accompanying drawings, the thickness of multiple layers and regions may be shown in an exaggerated manner to make it clear and convenient to describe. When a layer, region, or plate is referred to as being "located on" another layer, region, or plate, the layer, region, or plate may be directly located on the other layer, region, or plate, or there may be an intermediate layer, region, or plate therebetween. In the accompanying drawings, the same reference numerals may represent the same elements.

[0062] Throughout this specification, when an element is referred to as being “connected” to another element, the element may be “directly connected” to the other element or “electrically connected” to the other element with one or more intervening elements interposed therebetween.

[0063] As used herein, "about" or "approximately" may include the stated value and mean within an acceptable range of deviation of the particular value as determined by one of ordinary skill in the art, taking into account the measurements being discussed and the errors associated with the measurement of the particular quantity (e.g., limitations of the measurement system). For example, "about" may mean within one or more standard deviations, or within ±30%, ±20%, ±10%, ±5% of the stated value.

[0064] In the following, reference will be made to Figures 1 to 20B to describe exemplary embodiments of the present invention.

[0065] Figure 1 is a perspective view showing a display device 10 according to an exemplary embodiment of the present invention, Figure 2 is a block diagram illustrating a display device 10 according to an exemplary embodiment of the present invention.

[0066] Reference Figure 1 and Figure 2 The display device 10 includes a housing 20 such as a portable housing and a controller 60 in the housing 20. The display device 10 may be a mobile wireless communication device, such as a cellular phone. The display device 10 may be another type of electronic device, such as a tablet computer, a laptop computer, or a wearable computer.

[0067] A wireless transceiver 80 is also included in the housing 20 and coupled to the controller 60. The wireless transceiver 80 cooperates with the controller 60 to perform at least one wireless communication function such as voice and / or data. In an exemplary embodiment of the present invention, the display device 10 may not include a wireless transceiver 80 or other wireless communication circuitry.

[0068] The display panel 100 (also referred to as a display layer or display area) is included in the housing 20 and coupled to the controller 60. The display panel 100 may be, for example, a light emitting diode (LED) display panel. The display panel 100 may include additional circuits to provide a touch display function.

[0069] The memory 70 is included in the housing 20 and is coupled to the controller 60. The memory 70 stores, for example, finger matching biometric template data. The memory 70 may store other or additional types of data.

[0070] The display panel 100 is in the form of a touch display that serves as both an input device and a display. In addition, the display panel 100 can cooperate with the controller 60 in response to an input to perform one or more functions. For example, the display panel 100 can perform a menu function based on powering on or off the display device 10, initiation of communication through the wireless transceiver 80, and / or input to the touch display.

[0071] For example, regarding a menu function, the controller 60 may display a menu of available applications on the display panel 100 based on an input or a tap to the touch display. In addition, an input unit 50 such as a button switch may be included in the housing 20.

[0072] Figure 3A is a schematic diagram showing an exemplary embodiment of the present invention. Figure 1 An exploded perspective view of a display device, Figure 3B According to an exemplary embodiment of the present invention Figure 1 The cross-sectional view taken along the line II' of FIG. Figure 3A and Figure 3B The display device 10 will be described in more detail.

[0073] Reference Figure 3A , the display device 10 includes a transparent cover layer 330, a touch sensing layer 310, a display panel 100, a pinhole array mask layer 400, an optical image sensor 200, a bracket 21, a printed circuit board 24, a housing 20, and a back surface cover 22. According to an exemplary embodiment of the present invention, the components of the display device 10 may be stacked in close contact with each other or partially separated from each other.

[0074] The transparent cover layer 330 may form the appearance of the front surface of the display device 10, which defines a finger placement surface 331 capable of accommodating an adjacent finger 40. According to an exemplary embodiment of the inventive concept, the transparent cover layer 330 may include a transparent material such as glass so that the content output through the display panel 100 may be exposed to the outside. According to an exemplary embodiment of the present invention, a portion of an edge portion of the front cover may be bent backward from the finger placement surface 331 to form a curved surface. Figure 3AIt is shown in FIG. 3 that the side surface area of ​​the transparent cover layer 330 forms a curved surface.

[0075] The display panel 100 is disposed below the transparent cover layer 330 and can display various contents. The display panel 100 may include a substrate, a plurality of pixels PX disposed on one surface of the substrate, and at least one wire electrically connected to the pixel PX. The substrate may include a flexible material so that at least a portion of the substrate (e.g., the curved portion 23) can be bent in the back surface direction of the substrate. The wire may include at least one gate line or at least one data line. According to an exemplary embodiment of the present invention, a plurality of gate lines and a plurality of data lines may be arranged in a matrix, and a plurality of pixels PX may be aligned near a point where the gate lines and the data lines intersect each other to be electrically connected to the point.

[0076] According to an exemplary embodiment of the present invention, the display panel 100 may be connected to a driving circuit (or display driving circuit). According to an exemplary embodiment of the present invention, the display driving circuit may be connected to the curved portion 23 of the display panel 100. The display driving circuit may be electrically connected to the wire. The display driving circuit may include a driving integrated circuit ("IC") for providing a driving signal and an image signal to the display panel 100 or a timing controller ("T-con") for controlling the driving signal and the image signal. The driving IC may include a gate driving IC for sequentially selecting a gate line of the display panel 100 and applying a scan signal (or a driving signal) and a data driving IC (or a source driving IC) for applying an image signal to a data line of the display panel 100. According to an exemplary embodiment of the present invention, when the gate driving IC selects a gate line and applies a scan signal to make a specific pixel PX become an activated state, the data driving IC may apply an image signal to the specific pixel PX through the data line. The timing controller may adjust the transmission time of the signal to be transmitted to the driving IC, and therefore, the display time difference that may occur during the process of outputting on the display panel 100 may be prevented.

[0077] The pinhole array mask layer 400 is disposed on at least a portion of the back surface of the display panel 100 (for example, disposed at a lower center portion of the display panel 100), and the optical image sensor 200 is disposed on at least a portion of the back surface of the pinhole array mask layer 400. Details of the pinhole array mask layer 400 and the optical image sensor 200 will be described below.

[0078] The bracket 21 may have a size substantially the same as or similar to that of the transparent cover layer 330, and may support the display panel 100 located therein. According to an exemplary embodiment of the present invention, the bracket 21 may be at least partially covered by the curved portion 23 of the display panel 100. For example, a portion of the display panel 100 other than the curved portion 23 is placed on the front surface of the bracket 21, and the curved portion 23 of the display panel 100 may be bent to cover a portion of one side surface and a back surface of the bracket 21. According to an exemplary embodiment of the present invention, the bracket 21 may be coated with an adhesive material or may include an adhesive layer in at least a portion of its area contacting the display panel 100, so that the display panel 100 may be fixed to the bracket 21. In addition, the bracket 21 may fix and support the optical image sensor 200. The bracket 21 may have a groove 25 corresponding to the step difference between the optical image sensor 200 and the display panel 100.

[0079] The printed circuit board 24 may be disposed below the bracket 21, and various electronic components may be mounted on the printed circuit board 24. For example, at least one electronic element or circuit line, etc. may be disposed on the printed circuit board 24, and at least some of these electronic components may be electrically connected to each other. The electronic components may include, for example, a controller 60, a memory 70, and a wireless transceiver 80, etc. According to an exemplary embodiment of the present invention, a display driving circuit may be electrically connected to the printed circuit board 24 or disposed on the printed circuit board 24. In addition, a driving circuit for driving the optical image sensor 200 or a circuit for processing image data output from the optical image sensor 200, etc. may be electrically connected to the printed circuit board 24, or may be disposed on the printed circuit board 24. According to an exemplary embodiment of the present invention, the printed circuit board 24 may include a plurality of printed circuit boards 24, and at least some of the plurality of printed circuit boards 24 may be electrically connected to each other.

[0080] The housing 20 may fix and support internal components of the display device 10. According to an exemplary embodiment of the present invention, the display panel 100, the pinhole array mask layer 400, the optical image sensor 200, the bracket 21 and the printed circuit board 24 may be sequentially stacked to be mounted on the housing 20.

[0081] According to an exemplary embodiment of the present invention, at least one surface of the housing 20 may include a metal material. According to an exemplary embodiment of the present invention, a side surface of the housing 20 may include a metal frame. According to an exemplary embodiment of the present invention, a transparent cover layer 330 may be detachably attached to the housing 20. According to an exemplary embodiment of the present invention, the transparent cover layer 330 may cover the front surface of the housing 20 and may be fixed at the side surface of the housing 20.

[0082] The back surface cover 22 may define the appearance of the back surface of the display device 10. According to an exemplary embodiment of the present invention, the back surface cover 22 may be detachable from the housing 20. According to an exemplary embodiment of the present invention, the back surface cover 22 may cover the back surface of the housing 20 and may be fixed at a side surface of the housing 20.

[0083] According to an exemplary embodiment of the present invention, the display device 10 may omit at least one of the above components, or may further include at least one other component. According to an exemplary embodiment of the present invention, the display device 10 may further include a touch sensing layer 310. The touch sensing layer 310 may be stacked between the transparent cover layer 330 and the display panel 100. The touch sensing layer 310 may include a touch sensor capable of sensing a touch or proximity of a touch object such as a part of a user's body or an electronic pen. In addition, the display device 10 may further include a battery capable of supplying power to the display device 10.

[0084] In the following, reference will be made to Figure 3B Each component of the display device 10 according to an exemplary embodiment of the present invention will be described in more detail.

[0085] Reference Figure 3B , for example, an optical image sensor 200 for detecting a fingerprint pattern of a user's finger 40 is disposed below the display panel 100. For example, the optical image sensor 200 includes an IC substrate and an image sensing circuit carried by the IC substrate. The optical image sensor 200 may be bonded to a circuit board 220, for example, a flexible substrate. The optical image sensor 200 may be a backlight sensor or a backlight illumination (BSI) image sensor. The optical image sensor 200 may include, for example, a complementary metal oxide semiconductor (CMOS) or a charge coupled device (CCD), etc.

[0086] The optical image sensor 200 may include various filters, for example, a red filter, a green filter, or a blue filter, etc. In addition, the optical image sensor 200 may include a filter that blocks red light, for example, a filter that transmits green light or blue light. In addition, the optical image sensor 200 may include a filter for blocking infrared rays.

[0087] Light emitted from the display panel 100 may be directed toward the user's finger 40, and light reflected from the finger 40 may be directed toward the optical image sensor 200. In other words, the pixels PX included in the display panel 100 serve as a light source for capturing an image of a fingerprint pattern.

[0088] For example, the pixel PX may include, for example, a red pixel R, a green pixel G, and a blue pixel B. The red pixel R, the green pixel G, and the blue pixel B may have a red color filter, a green color filter, and a blue color filter, respectively. The pixel PX may also include a white pixel W. The white pixel W may have a white color filter or may not have a separate filter. However, exemplary embodiments of the present invention are not limited thereto, and the display panel 100 may use various color pixels, invisible light sources (e.g., infrared (IR) or ultraviolet (UV)) and / or other types of light sources. The pixel PX of the display panel 100 may be synchronized with the signal acquisition of the optical image sensor 200. The detailed structure of the display panel 100 will be described below.

[0089] The protective film 300 may be disposed below the display layer of the display panel 100, for example, between the display layer and the pinhole array mask layer 400. The protective film 300 may be attached to the lower portion of the display layer, for example, to the lower portion of the substrate, using an adhesive. The protective film 300 may improve the strength of the display panel 100 and prevent the display panel 100 from being damaged. The protective film 300 may include a flexible plastic material. In addition, the protective film 300 may have various thicknesses according to the Young's modulus.

[0090] The optically transparent support member 210 may be disposed on the optical image sensor 200. The optically transparent support member 210 may be referred to as "support member 210" hereinafter. The support member 210 separates the pinhole array mask layer 400 and the optical image sensor 200 so that they are spaced apart from each other. In other words, the support member 210 is disposed between the optical image sensor 200 and the pinhole array mask layer 400. In addition, the support member 210 may be a cover layer for protecting the sensing element CE of the optical image sensor 200. An optically transparent adhesive layer may be disposed above and / or below the support member 210.

[0091] The pinhole array mask layer 400 is disposed on the optical image sensor 200 and is separated from the optical image sensor 200 by a distance, for example, in the range from about 0.25 mm to about 4.0 mm. For example, the optical image sensor 200 may be separated from the pinhole array mask layer 400 by about 1 mm or less. For example, the pinhole array mask layer 400 is disposed on the upper surface of the support member 210. The upper surface of the support member 210 may be a surface of the support member 210 that is not in contact with the optical image sensor 200. The pinhole array mask layer 400 is an opaque mask and has a plurality of pinholes PH through which light can pass. The pinholes PH may be spaced apart from each other uniformly or, for example, in a honeycomb pattern. The spacing of the intervals of the pinholes PH may be, for example, in the range from about 40 μm to about 127 μm. More specifically, the spacing of the intervals of the pinholes PH may be in the range from about 40 μm to about 85 μm. In addition, the width (eg, diameter) of each pinhole PH may be, for example, in the range from about 20 μm to about 80 μm. Specific numerical values ​​related to the pinhole array mask layer 400 will be described below.

[0092] The pinhole array mask layer 400 is opaque and thus does not allow light to pass through. The pinhole array mask layer 400 may include chrome (eg, a chrome layer) to provide opacity. The opacity of the pinhole array mask layer 400 may be provided by using a layer form or using a material in addition to a layer form.

[0093] The display panel 100, or more specifically, a display layer as a part of the display panel 100, is located on the pinhole array mask layer 400. As described above, for example, the display layer includes a plurality of pixels PX for displaying an image. Specifically, the display layer may be a part of an organic light emitting diode ("OLED") display panel. The pixels PX may be spaced apart from each other so that light reflected by the finger 40 may pass through the pixels PX and may be aligned with the pinholes PH.

[0094] In an exemplary embodiment of the present invention, the touch sensing layer 310 may be disposed on the display layer. For example, the display layer may include a first substrate 110 (see Figure 5 ) and a thin film encapsulation layer 160 (see Figure 5 In such an embodiment, the touch sensing layer 310 may be located on the thin film encapsulation layer 160 of the display layer. For example, the touch sensing layer 310 may be disposed between the thin film encapsulation layer 160 of the display layer and the transparent cover layer 330.

[0095] In an exemplary embodiment of the present invention, the touch sensing layer 310 may be disposed within the display layer, for example, between the first substrate 110 and the thin film encapsulation layer 160 .

[0096] In an exemplary embodiment of the present invention, the touch sensing layer 310 may be a touch panel separated from the display panel 100. The touch sensing layer 310 may include a metal touch electrode for sensing touch and an insulating layer, an adhesive layer, or a protective film above or below the touch electrode.

[0097] The transparent cover layer 330 is disposed on the touch sensing layer 310. The optically transparent adhesive layer 320 may be disposed between the touch sensing layer 310 and the transparent cover layer 330. The transparent cover layer 330 including onyx or the like is located on the display layer and defines a finger placement surface 331 capable of accommodating a user's finger. For example, the transparent cover layer 330 is fixed by the optically transparent adhesive layer 320, and the upper surface of the transparent cover layer 330 defines a finger placement surface 331 accommodating a user's finger 40.

[0098] The optical image sensor 200, more specifically, the image sensing circuit senses an image of the user's finger 40 or an object disposed adjacent to the finger placement surface 331, and based on this, one or more biometric functions such as user authentication (e.g., matching operation), biometric recognition function, and counterfeit detection function can be performed. In addition, in the case where the display device 10 is a touch display (e.g., the display device 10 includes a touch sensing layer 310), when the user touches the touch display, for example, in a navigation function or other touch display input, data from the user's finger 40 can be sensed or obtained by the optical image sensor 200 for finger matching and / or counterfeit detection.

[0099] Light from the pixel PX of the display layer is scattered based on the user's finger 40 that contacts the finger placement surface 331 or is located away from the finger placement surface 331. When the light is scattered, the scattered light passes through the transparent portion of the display layer and the pinholes PH of the pinhole array mask layer 400 to be captured by the optical image sensor 200.

[0100] Figure 4 and Figure 5 are a plan view and a cross-sectional view illustrating a display panel according to an exemplary embodiment of the present invention. Figure 5 is along Figure 4 A cross-sectional view taken along line II-II'.

[0101] Reference Figure 4 and Figure 5 , a display panel 100 according to an exemplary embodiment of the present invention includes a gate line 101 arranged in one direction, a data line 102 insulated from and crossing the gate line 101, a common power line 103, a switching thin film transistor (“TFT”) 104, a driving TFT 105 and a capacitor 106.

[0102] In other words, one pixel of the display device according to the exemplary embodiment of the present invention has a 2TFT-1CAP structure including two TFTs and one capacitor 106. However, the exemplary embodiment of the present invention is not limited thereto, and one pixel may include three or more TFTs and two or more capacitors.

[0103] The switching TFT 104 selects a pixel to emit light and includes a switching gate electrode 104a connected to the gate line 101, a switching source electrode 104b connected to the data line 102, a switching drain electrode 104c connected to the first capacitor plate 106a, and a switching semiconductor layer 104d.

[0104] The driving TFT 105 applies driving power that causes the organic light emitting layer 130 in the pixel selected by the switching TFT 104 to emit light. The driving TFT 105 includes a driving gate electrode 105a connected to the first capacitor plate 106a, a driving source electrode 105b connected to the common power line 103, a driving drain electrode 105c connected to the first electrode 120, and a driving semiconductor layer 105d.

[0105] The capacitor 106 includes a first capacitor plate 106a and a second capacitor plate 106b. The first capacitor plate 106a is connected to the switch drain electrode 104c and the drive gate electrode 105a, and the second capacitor plate 106b is connected to the common power line 103. The capacitance of the capacitor 106 is determined by the charge accumulated in the capacitor 106 and the voltage across the first capacitor plate 106a and the second capacitor plate 106b.

[0106] A voltage equal to the difference between the common voltage applied to the driving TFT 105 from the common power line 103 and the data voltage transmitted by (or from) the switching TFT 104 is stored in the capacitor 106, and a current corresponding to the voltage stored in the capacitor 106 flows to the organic light-emitting layer 130 through the driving TFT 105, so that the organic light-emitting layer 130 can emit light.

[0107] The first substrate 110 may include an insulating material including glass, quartz, ceramic, or plastic. However, exemplary embodiments of the present invention are not limited thereto, and the first substrate 110 may include a metal material such as stainless steel.

[0108] The first substrate 110 includes a red pixel area PA r , green pixel area PA g and blue pixel area PA b . Red pixel area PA r , green pixel area PA g and blue pixel area PA bDefined by the pixel defining layer 180 described below, the red pixel area PA r , green pixel area PA g and blue pixel area PA b The pixels may be sequentially disposed on the first substrate 110. In addition, the first substrate 110 may include a white pixel region.

[0109] The buffer layer 107 is disposed on the first substrate 110. The buffer layer 107 may prevent moisture or impurities from penetrating through the first substrate 110 and planarize the surface of the first substrate 110. The buffer layer 107 may include an inorganic insulating layer or an organic insulating layer, and may use SiO 2 or SiN x The buffer layer 107 is deposited on the first substrate 110 using various deposition methods such as a plasma enhanced chemical vapor deposition (PECVD) method, an atmospheric pressure chemical vapor deposition (APCVD) method, or a low pressure chemical vapor deposition (LPCVD) method. However, the exemplary embodiment of the present invention is not limited thereto, and the buffer layer 107 may be omitted.

[0110] The driving semiconductor layer 105 d is disposed on the buffer layer 107 , and includes a source region, a drain region, and a channel region between the source region and the drain region.

[0111] The gate insulating layer 108 is disposed on the buffer layer 107 to cover the driving semiconductor layer 105d, and the gate insulating layer 108 prevents moisture or impurities from penetrating through the first substrate 110. The gate insulating layer 108 includes an insulating material and may be silicon nitride (SiN x ) or silicon oxide (SiO x However, exemplary embodiments of the inventive concept are not limited thereto, and the gate insulating layer 108 may include various insulating materials.

[0112] The driving gate electrode 105 a is disposed on the gate insulating layer 108 , and the insulating interlayer 109 a is disposed on the gate insulating layer 108 to cover the driving gate electrode 105 a .

[0113] The driving source electrode 105b and the driving drain electrode 105c are disposed on the insulating interlayer 109a and are separated from each other, and the driving source electrode 105b and the driving drain electrode 105c contact the source region and the drain region of the driving semiconductor layer 105d through the openings in the gate insulating layer 108 and the insulating interlayer 109a, respectively.

[0114] The protective layer 109b is disposed on the insulating interlayer 109a to cover the driving source electrode 105b and the driving drain electrode 105c. The protective layer 109b protects the driving TFT 105, and may include an inorganic insulating layer or an organic insulating layer.

[0115] The first electrode 120, the organic light emitting layer 130, and the second electrode 140 are sequentially disposed on the protective layer 109b. The first electrode 120 may be an anode for injecting holes, and the second electrode 140 may be a cathode for injecting electrons. However, the exemplary embodiment of the present invention is not limited thereto, and the first electrode 120 may be a cathode, and the second electrode 140 may be an anode.

[0116] The organic light emitting layer 130 may include a low molecular weight organic material or a high molecular weight organic material. The organic light emitting layer 130 may include a red organic light emitting layer, a green organic light emitting layer and a blue organic light emitting layer. r , green organic light emitting layer 130 g and a blue organic light emitting layer 130 b Can be set in the red pixel area PA r , green pixel area PA g and blue pixel area PA b In such an embodiment, there may be no color filter to be described below. In addition, the organic light emitting layer 130 may include a single-color organic light emitting layer.

[0117] The display panel 100 according to an exemplary embodiment of the present invention has a top emission type structure, and thus, the first electrode 120 includes a reflective film, and the second electrode 140 includes a semi-transmissive reflective film.

[0118] The reflective film and the semi-transparent reflective film may include one or more metals of titanium (Ti), magnesium (Mg), silver (Ag), gold (Au), calcium (Ca), lithium (Li), chromium (Cr) and aluminum (Al) or their alloys. In such an embodiment, whether the electrode is a semi-transparent reflective type or a reflective type depends on the thickness of the electrode. For example, the semi-transparent reflective film has a thickness of about 200nm or less. In addition, the reflective film and the semi-transparent reflective film may have a multilayer structure including a metal layer having a metal or an alloy of a metal and a transparent conductive oxide (TCO) layer stacked on the metal layer.

[0119] The first electrode 120 may further include a transparent conductive layer, which may include a transparent conductive oxide ("TCO") such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), or indium oxide (In 2 O 3 ).

[0120] The first electrode 120 may have a structure including only a reflective film, a double-layer structure including a reflective film and a transparent conductive film, or a triple-layer structure including a transparent conductive layer, a reflective layer, and a transparent conductive layer in sequence. However, the exemplary embodiments of the present invention are not limited thereto, and the first electrode 120 may have a structure including only a transparent conductive film.

[0121] The second electrode 140 may have a structure including a transparent conductive film. When the second electrode 140 includes a transparent conductive film, the second electrode 140 may be an anode for injecting holes, and the first electrode 120 may be a cathode including a reflective layer.

[0122] In an exemplary embodiment of the present invention, the pixel defining layer 180 is disposed on the first electrode 120 to cover the edge of the first electrode 120 and expose the central portion of the first electrode 120. In other words, the first electrode 120, the organic light emitting layer 130, and the second electrode 140 are sequentially stacked in the opening of the pixel defining layer 180. The organic light emitting layer 130 and the second electrode 140 may also be formed on the pixel defining layer 180.

[0123] The capping layer 150 may be disposed on the second electrode 140. The capping layer 150 protects the first electrode 120, the organic light emitting layer 130, and the second electrode 140, and allows light generated in the organic light emitting layer 130 to be effectively emitted to the outside.

[0124] The thin film encapsulation layer 160 is formed on the capping layer 150. The thin film encapsulation layer 160 seals the first electrode 120, the organic light emitting layer 130, the second electrode 140, and the capping layer 150 to protect them from the penetration of moisture or oxygen.

[0125] The thin film encapsulation layer 160 may have a structure in which at least one organic layer and at least one inorganic layer are alternately disposed. However, exemplary embodiments of the present invention are not limited thereto, and the thin film encapsulation layer 160 may include a single layer of an organic layer or an inorganic layer.

[0126] The red color filter 170R, the green color filter 170G, and the blue color filter 170B may be disposed on the thin film encapsulation layer 160, respectively, at the red pixel area PA r , green pixel area PA g and blue pixel area PA b superior.

[0127] In addition, as mentioned above Figure 3B As described above, the protective film 300 may be disposed under the first substrate 110, and the touch sensing layer 310 may be disposed over the color filters 170R, 170G, and 170B. In an exemplary embodiment of the present invention, a planarization layer 190 may be disposed between the color filters 170R, 170G, and 170B and the touch sensing layer 310. The planarization layer 190 flattens the layer on which the color filter 170 is disposed by removing the height difference of the color filter 170. The planarization layer 190 may include one or more of the following materials: polyacrylate resin, epoxy resin, phenolic resin, polyamide resin, polyimide resin, unsaturated polyester resin, polyphenylene ether resin, polyphenylene sulfide resin, and benzocyclobutene (BCB).

[0128] In an exemplary embodiment of the present invention, the touch sensing layer 310 may be disposed on the thin film encapsulation layer 160 , and the color filters 170R, 170G, and 170B and the planarization layer 190 may be disposed on the touch sensing layer 310 .

[0129] Figure 6 and Figure 7 A pinhole array mask layer 400 and an enlarged pinhole PH according to an exemplary embodiment of the present invention are shown.

[0130] The pinhole array mask layer 400 includes regularly arranged openings, for example, pinholes PH. Each pinhole PH has a width W (for example, a diameter) and a height H (for example, a thickness of the pinhole array mask layer 400). The pinholes PH may be arranged at a predetermined pitch P (for example, an interval). The pinholes PH may be openings that pass through the opaque pinhole array mask layer 400. The pinholes PH may be filled with a transparent material.

[0131] Among the light scattered by the finger 40, only the light 431 and 432 incident to the pinhole array mask layer 400 at a predetermined angle or greater (for example, the light 431 substantially perpendicular to the pinhole array mask layer 400) can pass through the pinhole PH. Figure 7 , the light 431 and 432 may be scattered light that does not contact the inner wall 420 of the pinhole PH. The light 433 obliquely incident on the pinhole array mask layer 400 at an angle less than a predetermined angle is blocked. Figure 7 , the light 433 may be scattered light contacting the inner wall 420 of the pinhole PH. The angle of light that may pass through the pinhole PH may be determined according to the ratio of the height H to the width W of the pinhole PH. According to an exemplary embodiment of the present invention, the ratio of the height H to the width W of the pinhole PH may be very large, so that light scattered at one point of the finger 40 may pass through only one pinhole PH (e.g., a pinhole PH vertically below the one point of the finger 40), and may not pass through other adjacent pinholes PH. For example, the ratio may be in the range from about 5 to about 20. However, exemplary embodiments of the present invention are not limited thereto, and the ratio may be in the range from about 1 to about 100.

[0132] In an example, light obliquely incident to the pinhole PH at an angle less than a predetermined angle may be totally reflected on the inner circumferential surface of the pinhole PH to be captured by the optical image sensor 200. However, this may deteriorate the image quality and resolution of the captured fingerprint. Therefore, according to an exemplary embodiment of the present invention, the inner circumferential surface of the pinhole PH may be matte-treated to reduce the total reflection of light.

[0133] Matt treatment may include plasma treatment, physical treatment such as sandblasting or chemical treatment, etc. Examples of matte treatment may also include a vacuum etching method, a surface buff polishing method, a sandpaper polishing method, or a method of forming a black composite by a chemical agent, etc.

[0134] Figure 8 is a diagram showing a display device in which a fingerprint recognition area is displayed according to an exemplary embodiment of the present invention, Fig. 9 is a flowchart illustrating a method of capturing a fingerprint image by a display device according to an exemplary embodiment of the present invention.

[0135] Reference Figure 8 and Fig. 9 , when fingerprint recognition is required, for example, when an application requiring user authentication is activated, the controller 60 displays an image 500 indicating a fingerprint recognition area on the display area of ​​the display panel 100 (S100). The fingerprint recognition area may correspond to an area in which the optical image sensor 200 is disposed, in other words, a fingerprint recognizable area. The fingerprint recognizable area may overlap with a portion or all of the display area. The image 500 may overlap with a portion or all of the fingerprint recognition area. However, exemplary embodiments of the present invention are not limited thereto, and the image 500 may not be displayed.

[0136] The touch sensing layer 310 senses a touch of the finger 40 input in the fingerprint recognition area ( S200 ).

[0137] When a touch input is detected, the controller 60 determines a touch input area (S300). The touch sensing layer 310 may sense the shape of the area 510 where the touch is input. Figure 8 As shown in FIG. 5 , a touch input area 510 and a touch non-input area 520 are recognized in the fingerprint recognition area.

[0138] The controller 60 stops the emission of the red pixel R in the area 510 where the touch is input, and only allows the green pixel G and / or the blue pixel B to emit light, for example, at maximum brightness (S400). At this time, the area 520 where the touch is not input can continue to display an image, for example, an image displayed before the touch is recognized. Therefore, the light source used for fingerprint recognition emits light only in the area 510 where the touch is input (for example, the area covered by the finger 40), and therefore, such a light source will not be viewed by the user. Therefore, although the red pixel R does not emit light, the user will not notice the change in the displayed image.

[0139] The optical image sensor 200 captures a fingerprint image (S500) in synchronization with light emission of the green pixel G and / or the blue pixel B. In this case, only green light and / or blue light is incident on the optical image sensor 200, and red light is not incident on the optical image sensor 200.

[0140] The controller 60 may perform user authentication based on the captured image (S600). For example, the controller 60 may perform a predetermined authentication function.

[0141] Therefore, in an exemplary embodiment of the present invention, the resolution of the fingerprint image captured by the optical image sensor 200 can be increased by excluding the red light source (see FIG. 10A to FIG. 11D ). In addition, in an embodiment of the present invention, because the light source emits light only in the area 510 where the touch is input (e.g., the area covered by the finger 40), the light source used for fingerprint recognition may not be visible to the user. Therefore, although the red pixel does not emit light, the user will not notice the change in the displayed image.

[0142] FIG. 10A to FIG. 11D It is an image captured using a pinhole PH of a predetermined width and a light source.

[0143] FIG. 10A to FIG. 10D is a captured image when the pinhole PH has a width W of about 50 μm or less, FIG. 11A to FIG. 11D It is a captured image when the pinhole PH has a width W of about 40 μm or less. Fig. 10A and Fig.11A is an image captured when the blue pixel B of the display layer is used as a light source for fingerprint image capture, Fig. 10B and Fig. 11B is the image captured when the green pixel G is used as the light source for fingerprint image capture, Fig. 10C and Fig. 11C is the image captured when the red pixel R is used as the light source for fingerprint image capture, Fig. 10D and Fig.11D is an image captured when white pixels W are used as the light source for fingerprint image capture.

[0144] FIG. 10A to FIG. 10D The images are compared FIG. 11A to FIG. 11D The image is clear. This is because if the width W of the pinhole PH becomes smaller than a predetermined value, the diffraction becomes even greater and the resolution of the image decreases. In addition, when FIG. 10A to FIG. 10D When images of the same image are compared with each other, the image becomes blurred as the wavelength of the light source becomes longer (in other words, in the order of blue light, green light, and red light). This is because as the wavelength of the light source becomes longer, more diffraction occurs, thereby reducing the resolution.

[0145] like Fig. 10C and Fig. 11C As shown in FIG. , a captured image in the case where only green pixels G or blue pixels B are emitted for fingerprint recognition according to an exemplary embodiment of the present invention is compared with a captured image when pixels of all colors are emitted for fingerprint recognition (e.g., Fig. 10D and Fig.11D The image is clearer than the one in the figure.

[0146] Fig.12 is a schematic cross-sectional view illustrating a display device according to an exemplary embodiment of the present invention. Fig.12 1 is a diagram for explaining the arrangement of the optical image sensor 200, the pinhole array mask layer 400, the display layer of the display panel 100, and the transparent cover layer 330. Therefore, other components are omitted.

[0147] The resolution of the image captured by the optical image sensor 200 depends on the pitch P of the pinholes PH, the diameter W of the pinholes PH, and the distance D between the pinhole array mask layer 400 and the optical image sensor 200. The distance between the pinhole array mask layer 400 and the finger placement surface 331 and the thickness H of the pinhole array mask layer 400 also affect the resolution of the image.

[0148] According to an exemplary embodiment of the present invention, the pitch P has a value of about 127 um or less. For example, the pitch P may have a value of about 85 um or less. Fig.12 As shown in , only light substantially perpendicular to the pinhole array mask layer 400 among the light scattered by the finger 40 is incident on the optical image sensor 200. Therefore, in order to provide a fingerprint image with sufficient resolution, the resolution (in other words, 1 / P) of the pinhole array mask layer 400 should be large enough. When the pitch P is about 127 μm, a resolution or separation capability of about 200 ppi or more can be obtained, and when the pitch P is about 85 μm, a resolution or separation capability of about 300 ppi or more can be obtained.

[0149] Fig.13A 4 is a graph showing a value of a pitch P of the pinholes PH according to a distance D between the pinhole array mask layer 400 and the optical image sensor 200 according to an embodiment of the present invention. Fig. 13B PH is a graph showing the intensity of diffracted light for each position according to the distance D between the pinhole array mask layer 400 and the optical image sensor 200 and according to the diameter W of the pinhole PH.

[0150] According to an exemplary embodiment of the present invention, Fig.13A The minimum value of the pitch P of the pinholes PH that prevents interference of light passing through adjacent pinholes PH is shown in FIG.

[0151] exist Fig.13A, the horizontal axis represents the distance D (unit: mm) between the pinhole array mask layer 400 and the optical image sensor 200, and the vertical axis represents the pitch P (unit: μm) of the pinholes PH. In the case of green light (e.g., 530 nm), the pitch P is about 40 μm or more when the distance D is about 0.25 mm, the pitch P is about 45 μm or more when the distance D is about 0.50 mm, the pitch P is about 55 μm or more when the distance D is about 1.0 mm, the pitch P is about 70 μm or more when the distance D is about 2.0 mm, and the pitch P is about 80 μm or more when the distance D is about 3.0 mm.

[0152] like Fig.13A As shown in , because red light (e.g., 760 nm) diffracts more, the value of the pitch P is about 5 μm to about 20 μm larger than that of the case using a green light source. In addition, because blue light (e.g., 380 nm) diffracts less, the value of the pitch P is about 5 μm to about 10 μm smaller than that of the case using a green light source.

[0153] Specifically, the case where a green light source is used in an embodiment of the present invention will be described below. When the distance D is greater than or equal to approximately 3.0 mm and less than or equal to approximately 4.0 mm, the minimum value of the spacing P may be approximately 80 μm. When the distance D is greater than or equal to approximately 2.0 mm and less than or equal to approximately 3.0 mm, the minimum value of the spacing P may be approximately 70 μm. When the distance D is greater than or equal to approximately 1.0 mm and less than or equal to approximately 2.0 mm, the minimum value of the spacing P may be approximately 55 μm. When the distance D is greater than or equal to approximately 0.5 mm and less than or equal to approximately 1.0 mm, the minimum value of the spacing P may be approximately 45 μm. When the distance D is greater than or equal to approximately 0.25 mm and less than or equal to approximately 0.5 mm, the minimum value of the spacing P may be approximately 40 μm.

[0154] exist Fig. 13B In the graph, the horizontal axis represents the distance from the center of the pinhole PH (e.g., the diffraction position [μm]), and the vertical axis represents the intensity of the light incident on the corresponding position (normalized amplitude [N / A], i.e., normalized Amp [N / A], Normalized Amp [N / A]).

[0155] like Fig. 13B As shown in , light that has passed through one pinhole PH may be diffracted and incident on the optical image sensor 200 at an area corresponding to another pinhole PH adjacent to the one pinhole PH. Therefore, this may have an adverse effect on the resolution of the image. In addition, as the distance D between the pinhole array mask layer 400 and the optical image sensor 200 increases from about 0.5 mm to about 3 mm, the light diffracts more, and as the diameter W of the pinhole PH increases from about 30 μm to about 70 μm, the light diffracts more. Therefore, as shown in reference Fig.13A As described above, as the distance D becomes larger and the diameter W becomes smaller, the pitch P of the pinholes PH should be increased.

[0156] FIG. 14A to FIG. 14D 4 is a simulation diagram showing the diffraction spread of the optical image sensor 200 according to the diameter W of the pinholes PH for each given distance D between the pinhole array mask layer 400 and the optical image sensor 200 .

[0157] exist FIG. 14A to FIG. 14D In , the vertical axis represents diffraction spread or resolution (um), and the horizontal axis represents the diameter W (μm) of the pinhole PH. The dotted line corresponds to the blur caused by diffraction due to, for example, the pinhole PH, and the solid line corresponds to the sum of the blur caused by diffraction and the blur caused by the diameter W of the pinhole PH. In addition, three solid lines of different thicknesses respectively show the simulation results using a red light source, a green light source, and a blue light source, and three dotted lines of different thicknesses (i.e., Spread-R, Spread-G, and Spread-B) respectively show the simulation results using a red light source, a green light source, and a blue light source. In Fig.14A , Fig. 14B , Fig. 14C and Fig.14D The quadrilateral column in each graph in represents the optimum value of the diameter W (μm) of the pinhole PH.

[0158] The distance D between the pinhole array mask layer 400 and the optical image sensor 200 is Fig.14A The middle is about 3.0mm, Fig. 14B The middle is about 2.0mm, Fig. 14C is about 1.0 mm, and Fig.14D The diameter is about 0.5 mm. FIG. 14A to FIG. 14D As shown in , the larger the distance D, the worse the resolution.

[0159] According to an exemplary embodiment of the present invention, the optimal value of the diameter W at each distance D is as follows. For example, considering the signal-to-noise ratio (SNR), the diameter W of the pinhole PH is selected to be slightly larger than the optimally determined resolution. The diameter W of the pinhole PH is in the range of about 65 μm to about 75 μm when the distance D is about 3.0 mm, the diameter W of the pinhole PH is in the range of about 45 μm to about 55 μm when the distance D is about 2.0 mm, the diameter W of the pinhole PH is in the range of about 25 μm to about 55 μm or less when the distance D is about 1.0 mm, and the diameter W of the pinhole PH is in the range of about 25 μm to about 55 μm when the distance D is about 0.5 mm.

[0160] Therefore, in an embodiment of the present invention, the width W of the pinhole PH is about 65 μm or more when the distance D is greater than or equal to about 3.0 mm and less than or equal to about 4.0 mm, the width W of the pinhole PH is in the range from about 45 μm to about 75 μm when the distance D is greater than or equal to about 2.0 mm and less than or equal to about 3.0 mm, the width W of the pinhole PH is in the range from about 25 μm to about 55 μm when the distance D is greater than or equal to about 1.0 mm and less than or equal to about 2.0 mm, and the width W of the pinhole PH is in the range from about 25 μm to about 55 μm when the distance D is greater than or equal to about 0.5 mm and less than or equal to about 1.0 mm.

[0161] Fig.15 is a cross-sectional view for explaining light reflection between a display layer of a display panel 100 and a pinhole array mask layer 400 according to an exemplary embodiment of the present invention.

[0162] like Fig.15 As shown in FIG. 1 , light that has passed through the display layer of the display panel 100 and has been obliquely incident on the pinhole array mask layer 400 may be repeatedly reflected between the upper surface of the pinhole array mask layer 400 and the lower surface of the display layer to pass through adjacent pinholes PH. Therefore, the quality of the image captured by the optical image sensor 200 may be deteriorated.

[0163] FIG. 16A to FIG. 16C is a cross-sectional view schematically illustrating a display device for preventing light reflection between a pinhole array mask layer 400 and a display layer of a display panel 100 according to an exemplary embodiment of the present invention.

[0164] First, refer to Fig.16A , the anti-reflection layer 600 is disposed between the pinhole array mask layer 400 and the display layer of the display panel 100. The anti-reflection layer 600 transmits most of the light that has passed through the display layer and blocks at least a portion of the light that has been reflected from the pinhole array mask layer 400. In addition, the anti-reflection layer 600 may also block at least a portion of the light that has passed through the anti-reflection layer 600 and reflected from the display layer.

[0165] In an exemplary embodiment of the present invention, the anti-reflection layer 600 is a polarization layer that blocks reflected light. In an exemplary embodiment of the present invention, the polarization layer may include a retardation layer (eg, a phase retardation layer), and the retardation layer may be a quarter retardation layer.

[0166] In an exemplary embodiment of the present invention, the anti-reflection layer 600 is a matte treated film. Examples of matte treatment may include plasma treatment, physical treatment such as sandblasting, chemical treatment, etc. For example, the matte treatment may be performed by a vacuum etching method, a surface buff polishing method, a sandpaper polishing method, or a method of forming a black composite by a chemical reagent, etc.

[0167] Next, refer to Fig. 16B , an anti-reflection layer is formed on the back surface 301 of the display layer of the display panel 100. For example, the back surface 301 of the first substrate 110 or the protective film 300 may be matte-treated. Therefore, at least a portion of the light reflected from the pinhole array mask layer 400 is not reflected again from the back surface 301 of the display layer. The matte treatment method is as described above.

[0168] Next, refer to Fig. 16C , an anti-reflection layer is formed on the upper surface 410 of the pinhole array mask layer 400. For example, the upper surface 410 of the pinhole array mask layer 400 may be matte-treated. Therefore, at least a portion of the light incident on the upper surface 410 of the pinhole array mask layer 400 is not reflected. The matte-treatment method is as described above.

[0169] Based on the above, light may be repeatedly reflected between the upper surface 410 of the pinhole array mask layer 400 and the lower surface 301 of the display layer of the display panel 100 to pass through adjacent pinholes PH, thereby deteriorating the quality of an image captured by the optical image sensor 200 .

[0170] However, according to the present embodiment, light that is repeatedly reflected between the upper surface 410 of the pinhole array mask layer 400 and the lower surface 301 of the display layer of the display panel 100 and passes through adjacent pinholes PH can be reduced, thereby improving the quality of the image captured by the optical image sensor 200.

[0171] Fig.17A , Fig. 17B and Fig. 17C 1 and 2 are plan views respectively illustrating arrangements of pixels of a display layer of a display panel 100 , pinholes PH of a pinhole array mask layer 400 , and sensing elements CE of an optical image sensor 200 according to an exemplary embodiment of the present invention.

[0172] Each of the pixels PX of the display layer of the display panel 100, the pinholes PH of the pinhole array mask layer 400, and the sensing elements CE of the optical image sensor 200 has a pattern that repeats in at least one direction. For example, when the pixels PX are regularly arranged in the horizontal direction, the vertical direction, and the diagonal direction, the direction of the pattern of the pixels PX may be the direction in which the distance between adjacent pixels PX is the shortest. In other words, when the distance between the pixels PX in the horizontal direction is the shortest, the pattern has a horizontal direction.

[0173] In an exemplary embodiment of the present invention, the pattern direction of the pixel PX and the pattern direction of the pinhole PH may be different from each other. In other words, the pattern of the pixel PX and the pattern of the pinhole PH are not parallel to each other. In addition, in an exemplary embodiment of the present invention, the pattern of the sensing element CE and the pattern of the pinhole PH are not parallel to each other. In addition, in an exemplary embodiment of the present invention, the pattern of the sensing element CE, the pattern of the pinhole PH, and the pattern of the pixel PX may not be parallel to each other.

[0174] Reference Fig.17A , the pixels PX of the display layer of the display panel 100 have a matrix shape or a lattice shape, and have rows in the X-axis direction and columns in the Y-axis direction. Fig. 17B , the pinholes PH of the pinhole array mask layer 400 also have a matrix shape or a lattice shape, and have rows in the X1-axis direction and columns in the Y1-axis direction. Fig. 17C , the sensing elements CE of the optical image sensor 200 have a matrix shape or a lattice shape, and have rows in the X2-axis direction and columns in the Y2-axis direction.

[0175] In an exemplary embodiment of the present invention, the X1 axis and the X2 axis are not parallel to each other. In other words, the row of pinholes PH and the row of sensing elements CE are not parallel to each other. In addition, the X axis may not be parallel to the X1 axis and / or the X2 axis.

[0176] In an exemplary embodiment of the present invention, each row and each column are perpendicular to each other. Alternatively, each row and each column may not be perpendicular to each other, and the angles between each row and each column may be different from each other. In addition, in an exemplary embodiment of the present invention, the pixel PX, the pinhole PH, and the sensing element CE may have different resolutions (for example, the number per unit distance may be different from each other).

[0177] 18A to 18E , are images captured by different display devices having different angles between an arrangement direction of the pinholes PH of the pinhole array mask layer 400 and an arrangement direction of the sensing elements CE of the optical image sensor 200 according to an exemplary embodiment of the present invention.

[0178] 18A to 18EImages captured as the angle between the arrangement direction (or pattern direction) of the pinholes PH and the arrangement direction (or pattern direction) of the sensing elements CE (in other words, the angle between the X1 axis and the X2 axis (or the angle between the Y1 axis and the Y2 axis)) increases by approximately 15 degrees each time are shown.

[0179] like 18A to 18E As shown in , moire (or moiré fringes, interference fringes, moirés) appear in the captured image due to the difference in resolution and / or the difference in pattern direction between the pinhole PH and the sensing element CE. In addition, the angle difference of about 45 degrees Fig.18A and Fig.18D (or Fig.18B and Fig.18E ) shows moire patterns with similar shapes but different directions. Fig.18C There is hardly any moire visible.

[0180] FIG. 19A to FIG. 19C An exemplary embodiment according to the present invention shows the occurrence of moire depending on the angle variation between two arrays.

[0181] Fig.19A A case is shown in which the pattern direction X1 of the pinholes PH and the pattern direction X2 of the sensing elements CE (in other words, each row) are parallel to each other. Fig.19B A case where the pattern direction X1 of the pinholes PH and the pattern direction X2 of the sensing elements CE (in other words, each row) have an angle difference of about 22.5 degrees is shown. Fig.19C The case of an angular difference of approximately 45 degrees is shown. Fig.19A and Fig.19C The moire pattern appears regularly, but Fig.19B Moire not shown.

[0182] Therefore, according to an exemplary embodiment of the present invention, the angle between the row of pinholes PH and the row of sensing elements CE is greater than about 0 degrees and less than about 45 degrees. For example, the angle between the row of pinholes PH and the row of sensing elements CE may be in the range from about 15 degrees to about 30 degrees. However, the exemplary embodiment is not limited thereto, and the angle between the row of pinholes PH and the row of sensing elements CE may be determined according to the resolution of the pinholes PH and the sensing elements CE in the row direction and the column direction and the angle between the pinholes PH and the sensing elements CE in the row direction and the column direction.

[0183] Fig. 20A and Fig. 20B An exemplary embodiment according to the present invention shows the moire produced according to the resolution of two arrays.

[0184] Fig. 20A It shows that every predetermined length Ph in the horizontal direction 1There are 40 units and every predetermined length Pv in the vertical direction 1 A grid having 40 cells and a predetermined length Ph in the horizontal direction 1 There are 39 units and each predetermined length Pv in the vertical direction 1 Lattice superposition with 39 cells. Fig. 20B It shows that every predetermined length Ph in the horizontal direction 2 There are 5 units and each predetermined length Pv in the vertical direction 2 A grid having 5 units with a predetermined length Ph in the horizontal direction 2 There are 4 units and each predetermined length Pv in the vertical direction 2 A grid with 4 cells is superimposed. The entire grid corresponds to the optical image sensor 200 or the fingerprint recognition area (510 and 520). Fig. 20A Repeating moire is not shown, but Fig. 20B Shown is a predetermined length Ph 2 and Pv 2 Repeating moire pattern.

[0185] According to an exemplary embodiment of the present invention, a number "n" (e.g., 40) of sensing elements CE are arranged per a predetermined length in one direction (e.g., in a column or row direction), and a number "m" (e.g., 39) of pinholes PH are arranged per the same length in substantially the same direction. Here, n and m are natural numbers that are mutually prime. In other words, the predetermined length (e.g., Ph 1 and Pv 1 ) may be the least common multiple of the distance (eg, pitch) between the pinholes PH and the distance (eg, pitch) between the sensing elements CE. 1 and Pv 1 ) (in other words, the least common multiple of the distance (e.g., pitch) between the pinholes PH and the distance (e.g., pitch) between the sensing elements CE) may be substantially equal to or greater than the length of the optical image sensor 200 in that direction or the length of the fingerprint recognition area (510 and 520) in that direction. For example, the predetermined length (e.g., Ph 1 or Pv 1 ) is twice or more the length of the optical image sensor 200.

[0186] Therefore, in the present embodiment, the moire that may be generated due to the resolution difference between the sensing element CE and the pinhole PH can be reduced. In addition, the present embodiment can be applied to the resolution of the pinhole PH and the pixel PX.

[0187] As explained above, according to exemplary embodiments of the present invention, the display device can obtain a fingerprint image with a higher resolution when, for example, the display area and the fingerprint recognition area overlap each other.

[0188] While the present invention has been shown and described with reference to exemplary embodiments thereof, it will be apparent to those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the claims.

Claims

1. A display device, comprising: Optical image sensor; A pinhole array mask layer, located on the optical image sensor, wherein adjacent pinholes of the pinhole array mask layer are separated from each other by a distance of 40 μm to 127 μm; a display layer, disposed on the pinhole array mask layer and comprising a plurality of pixels; and a transparent cover layer disposed on the display layer, wherein the finger placement surface is disposed on the transparent cover layer, Each of the plurality of pixels is a red pixel, a green pixel, and a blue pixel, and When a touch input is detected, the controller determines a touch input area, and the controller causes at least one of the green pixel and the blue pixel in the touch input area to emit light, while the red pixel in the touch input area does not emit light, and Wherein, when the distance between the pinhole array mask layer and the optical image sensor is greater than or equal to 3.0 mm and less than or equal to 4.0 mm, the minimum value of the distance between the adjacent pinholes is 80 μm.

2. The display device according to claim 1, wherein: The display layer displays a fingerprint recognition area overlapping the optical image sensor.

3. The display device according to claim 1, wherein: Only the red pixels located in the touch input area do not emit light.

4. The display device according to claim 1, wherein: The display layer further includes a touch sensing layer for sensing a shape of an area where a touch is input.

5. The display device according to claim 1, wherein: The width of the pinholes of the pinhole array mask layer is in the range from 20 μm to 80 μm.

6. The display device according to claim 1, wherein: When the distance between the pinhole array mask layer and the optical image sensor is greater than or equal to 3.0 mm and less than or equal to 4.0 mm, the width of the pinholes of the pinhole array mask layer is 65 μm or greater; when the distance between the pinhole array mask layer and the optical image sensor is greater than or equal to 2.0 mm and less than or equal to 3.0 mm, the width of the pinholes is in the range from 45 μm to 75 μm; when the distance between the pinhole array mask layer and the optical image sensor is greater than or equal to 1.0 mm and less than or equal to 2.0 mm, the width of the pinholes is in the range from 25 μm to 55 μm; when the distance between the pinhole array mask layer and the optical image sensor is greater than or equal to 0.5 mm and less than or equal to 1.0 mm, the width of the pinholes is in the range from 25 μm to 55 μm.

7. A display device, comprising: Optical image sensor; A pinhole array mask layer, disposed on the optical image sensor and comprising a plurality of pinholes; A display layer, disposed on the pinhole array mask layer and comprising a plurality of pixels; as well as a transparent cover layer, disposed on the display layer and having a finger placement surface, wherein adjacent pinholes in the plurality of pinholes are separated from each other by a distance of 40 μm to 127 μm, and Wherein, when the distance between the pinhole array mask layer and the optical image sensor is greater than or equal to 3.0 mm and less than or equal to 4.0 mm, the minimum value of the distance between the adjacent pinholes is 80 μm.

8. The display device according to claim 7, wherein: The adjacent pinholes are spaced apart from each other by a distance of 40 μm to 85 μm.

9. The display device according to claim 7, wherein: The pinhole array mask layer is separated from the optical image sensor by a distance of 0.25 mm to 4.0 mm.

10. The display device according to claim 9, wherein: When the distance between the pinhole array mask layer and the optical image sensor is greater than or equal to 2.0 mm and less than or equal to 3.0 mm, the minimum value of the distance between adjacent pinholes is 70 μm; when the distance between the pinhole array mask layer and the optical image sensor is greater than or equal to 1.0 mm and less than or equal to 2.0 mm, the minimum value of the distance between adjacent pinholes is 55 μm; when the distance between the pinhole array mask layer and the optical image sensor is greater than or equal to 0.5 mm and less than or equal to 1.0 mm, the minimum value of the distance between adjacent pinholes is 45 μm; when the distance between the pinhole array mask layer and the optical image sensor is greater than or equal to 0.25 mm and less than or equal to 0.5 mm, the minimum value of the distance between adjacent pinholes is 40 μm.

11. The display device according to claim 9, wherein: The pinhole array mask layer is separated from the optical image sensor by 1 mm or less.

12. The display device according to claim 9, wherein: A width of a first pinhole among the plurality of pinholes is in a range from 20 μm to 80 μm.

13. The display device according to claim 12, wherein: When the distance between the pinhole array mask layer and the optical image sensor is greater than or equal to 3.0 mm and less than or equal to 4.0 mm, the width of the first pinhole is 65 μm or greater; when the distance between the pinhole array mask layer and the optical image sensor is greater than or equal to 2.0 mm and less than or equal to 3.0 mm, the width of the first pinhole is in the range from 45 μm to 75 μm; when the distance between the pinhole array mask layer and the optical image sensor is greater than or equal to 1.0 mm and less than or equal to 2.0 mm, the width of the first pinhole is in the range from 25 μm to 55 μm; when the distance between the pinhole array mask layer and the optical image sensor is greater than or equal to 0.5 mm and less than or equal to 1.0 mm, the width of the first pinhole is in the range from 25 μm to 55 μm.

14. The display device according to claim 7, wherein: A ratio of a thickness of the pinhole array mask layer to a width of a first pinhole among the plurality of pinholes is in a range from 5 to 20.

15. A display device, comprising: Optical image sensor; A pinhole array mask layer, located on the optical image sensor, wherein adjacent pinholes of the pinhole array mask layer are separated from each other by a distance of 40 μm to 127 μm; A display layer, disposed on the pinhole array mask layer and comprising a plurality of pixels; a transparent cover layer disposed on the display layer and having a finger placement surface; and an anti-reflection layer, located between the display layer and the pinhole array mask layer, Wherein, when the distance between the pinhole array mask layer and the optical image sensor is greater than or equal to 3.0 mm and less than or equal to 4.0 mm, the minimum value of the distance between the adjacent pinholes is 80 μm.

16. The display device according to claim 15, wherein: The anti-reflection layer includes a polarizing layer.

17. The display device according to claim 16, wherein: The anti-reflection layer includes a retardation layer.

18. The display device according to claim 17, wherein: The retardation layer is a quarter retardation layer.

19. The display device according to claim 15, wherein: The anti-reflection layer includes a matte film.

20. The display device according to claim 15, wherein: The anti-reflection layer includes a matte-treated surface of the display layer.

21. The display device according to claim 15, wherein: The anti-reflection layer includes a matte-treated surface of the pinhole array mask layer.

22. The display device according to claim 15, wherein: The inner circumferential surfaces of the pinholes of the pinhole array mask layer are matte-finished.

23. The display device according to claim 15, wherein: The optical image sensor further includes a filter for blocking red light.

24. The display device according to claim 23, wherein: The filter is a color filter that transmits green light or blue light.

25. The display device according to claim 15, wherein: The optical image sensor further includes a filter for blocking infrared rays.

Images