Patent Description:
Organic light emitting diode (OLED) display panels have merits of excellent luminance, driving voltage, and response rate characteristics and implementing color images, so they are being employed for various display devices.

Meanwhile, recently, display devices have increasingly implemented biometric recognition technologies via which certain biometric information or gesture information is extracted by one or more devices to authenticate a person in financial, health care, and mobile fields. Particularly, leading smartphone companies are focusing on adapting fingerprint and iris recognition technologies.

<CIT> discloses technologies of forming a near-infrared sensor for fingerprint recognition on the same plane as an OLED emitter. That is, a separate near-infrared emitter and near-infrared detector are utilized for fingerprint recognition.

Since the near-infrared emitter and the near-infrared detector are formed on the same plane as the OLED emitter in <CIT>, an aperture ratio of the OLED emitter including such near-infrared emitter and the near-infrared detector may be decreased compared with a conventional OLED emitter having no near-infrared emitter and near-infrared detector. The aperture ratio decrease of the OLED emitter may have a large influence on display characteristics of a mobile display device including the OLED emitter, particularly, a smart phone having a small display area.

<CIT> discloses a display panel comprising a substrate, OLED light emitting structures, and fingerprint recognitions units.

<CIT> discloses a biometric-recognition display panel comprising sensing circuits for sensing an intensity of light from an emitting device.

<CIT> discloses a sensing device including a light sensor located in at least one of an upper and a lower panel, as well as a backlight device including light emitting members.

<CIT> discloses a display device in an information device having a pen input function.

The invention is defined by the subject matter of the claims. Some example embodiments provide a visible light sensor embedded OLED display panel as defined by claim <NUM> (also referred to herein as simply an "OLED display panel") configured to implement biometric recognition without an effect on an aperture ratio of an OLED emitter or reducing or minimizing the effect, thereby improving performance of the OLED display panel, for example improving the display characteristics of a display device including the OLED display panel.

Some example embodiments provide a display device that includes a visible light sensor embedded OLED display panel as defined by claim <NUM> configured to implement biometric recognition without an effect on an aperture ratio of an OLED display part or reducing or minimizing the effect, thereby improving performance of the OLED display panel, for example improving the display characteristics of a display device including the OLED display panel.

An OLED display panel as defined in claim <NUM>, according to some example embodiments is configured to display images and to emit light for biometric recognition; and a visible light sensor configured to detect light reflected by a recognition target after being emitted by the OLED light emitter, wherein the visible light sensor is positioned under a non-light emitting region of the OLED light emitter.

By employing the OLED light emitter as a light source for the visible light sensor, the OLED display panel may be configured to perform biometric recognition without a separate light source other than the OLED light emitter, so as to prevent an aperture ratio decrease of the OLED light emitter.

The OLED display panel may maintain the aperture ratio of the OLED light emitter at about <NUM> % or may reduce or minimize the aperture ratio decrease by forming the visible light sensor in a non-light emitting region that does not affect the aperture ratio of the OLED light emitter based on the location of the visible light sensor, or by forming the visible light sensor in a stack structure under the non-light emitting region (e.g., between the non-light emitting region of the OLED light emitter and a substrate).

Accuracy or efficiency of biometric recognition provided by the aforementioned OLED display panels may be improved since the amount or intensity of the light emitted to perform biometric recognition is increased or maximized based on employing the biometric recognition sensor as a visible light sensor.

The visible light sensor may be formed of (e.g., may at least partially comprise) an organic material and thus may be bent or stretchable. Accordingly, the visible light sensor may contribute to easily realizing a flexible display device and thus improve portability and versatility of a display device that includes the OLED display panel.

According to an aspect of the invention, there is provided an OLED display according to claim <NUM>.

The visible light sensor may be configured to absorb light in an entirety of a wavelength spectrum of visible light.

The visible light sensor may include an organic photodiode including an organic material.

The visible light sensor may include an a-Si-based P-I-N photodiode, a poly-Si-based P-I-N photodiode, a CIGS (Cu-In-Ga-Se) photodiode, or a Cd-Te photodiode.

A display device may include the OLED display panel.

A method for performing biometric recognition of a user of a display device, the display device including the OLED display panel of claim <NUM>, includes driving the OLED light emitter to emit light and further driving the visible light sensor to detect at least a portion of the emitted light based on reflection of the portion of the emitted light from a recognition target that is a portion of the user, in response to a determination that the OLED light emitter is turned on, user access to the display device is disabled, and the recognition target is in a certain proximity to the OLED display panel. The method includes turning off the visible light sensor, granting user access to the display device, and driving the OLED light emitter to display an image, in response to a determination that recognition of the recognition target is completed via comparison of a reference recognition target image with an image of the recognition target generated based on an output signal of the visible light sensor in response to detecting the reflected portion of the emitted light.

The determination that the recognition target is in the certain proximity to the OLED display panel may be based on receiving a signal from a touch sensor of the OLED display panel.

The driving the OLED light emitter may include selectively driving a particular limited set of OLED light emitters of an array of OLED light emitters of the OLED display panel. The further driving the visible light sensor may include selectively driving a particular limited set of visible light sensors of an array of visible light sensors of the OLED display panel.

The determination that the recognition target is in the certain proximity to the OLED display panel may be based on receiving a signal from a touch sensor of the OLED display panel, the signal indicating a limited area, of a total area of a surface of the OLED display panel that is in contact with the recognition target. The driving the OLED light emitter may include selectively driving the particular limited set of OLED light emitters that are a limited portion of the array of OLED light emitters that vertically overlap with the limited area in response to a determination that the recognition target is in contact with the limited area. The further driving the visible light sensor may include selectively the particular limited set of visible light sensors that are a limited portion of the array of visible light sensors that vertically overlap with the limited area in response to the determination that the recognition target is in contact with the limited area.

The OLED display panel may further include an infrared light emitter on the substrate, the infrared light emitter configured to emit infrared light, and an infrared light sensor on the substrate, the infrared light sensor configured to detect at least a portion of the emitted infrared light based on reflection of the portion of the emitted infrared light from a recognition target. The infrared light sensor may be in a separate non-light emitting region adjacent to the OLED light emitter, or between the substrate and a separate non-light emitting region that is adjacent to the OLED light emitter.

The OLED display panel may further include an array of OLED light emitters on the substrate, the array of OLED light emitters including the OLED light emitter; and an array of visible light sensors on the substrate, the array of visible light sensors including the visible light sensor. The array of OLED light emitters may extend through a first region of the OLED display panel, and the array of visible light sensors extends through a second region of the OLED display panel, the second region being smaller than the first region, such that the array of visible light sensors do not extend through at least a third region of the OLED display panel that includes at least one OLED light emitter of the array of OLED light emitters, and no visible light sensors.

The first region may extend over a total area of the OLED display panel, the second region may extend over a limited area of the OLED display panel, and the third region may extend between at least one side of the second region and at least one edge of the OLED display panel.

The third region may completely surround the second region and may be between all sides of the second region and all edges of the OLED display panel.

The OLED display panel may further include an array of infrared light emitters on the substrate, the array of infrared light emitters configured to emit infrared light; and an array of infrared light sensors on the substrate, the array of infrared light sensors configured to detect at least a portion of the emitted infrared light based on reflection of the portion of the emitted infrared light from a recognition target. The array of infrared light emitters and the array of infrared light sensors may extend through at least a portion of the first region.

The array of infrared light emitters and the array of infrared light sensors may not extend through the second region.

The array of infrared light emitters and the array of infrared light sensors may not extend through the third region.

The OLED display panel includes a substrate, an OLED light emitter stack on the substrate, the OLED light emitter stack including a plurality of sub-pixels, including a red OLED sub-pixel, a green OLED sub-pixel, and a blue OLED sub-pixel, each of the red, green, and blue OLED sub-pixels configured to emit light; and a visible light sensor on the substrate, the visible light sensor configured to detect at least a portion of the emitted light based on reflection of the portion of the emitted light from a recognition target. The visible light sensor is between the substrate and a non-light emitting region of the OLED light emitter stack such that the visible light sensor is vertically aligned with the non-light emitting region of the OLED light emitter stack in a vertical direction extending perpendicular to the upper surface of the substrate.

The visible light sensor is partially overlapped with at least one OLED sub-pixel of the OLED light emitter stack in the vertical direction.

The visible light sensor may include an organic photodiode including a lower electrode, an upper electrode, and a visible light absorption layer between the lower and upper electrodes. The lower electrode may be a reflecting electrode. The upper electrode may be a transparent electrode.

The OLED display panel includes a substrate, a driver stack on the substrate, and an OLED light emitter stack on the driver stack. The OLED light emitter stack includes a plurality of sub-pixels configured to emit light and a visible light sensor, the plurality of sub-pixels including a red OLED sub-pixel, a green OLED sub-pixel, and a blue OLED sub-pixel, the visible light sensor configured to detect at least a portion of the emitted light based on reflection of the portion of the emitted light from a recognition target.

The visible light sensor may include an a-Si-based photodiode, a poly-Si-based P-I-N photodiode, a CIGS (Cu-In-Ga-Se) photodiode, or a Cd-Te photodiode.

The visible light sensor may include an organic photodiode including a lower electrode, an upper electrode, and a visible light absorption layer between the lower and upper electrodes. The lower electrode may be a reflecting electrode. The upper electrode may be a transflective electrode.

Hereinafter, example embodiments of the present inventive concepts will be described in detail so that a person skilled in the art would understand the same. This disclosure may, however, be embodied in many different forms and is not construed as limited to the example embodiments set forth herein.

Regarding the reference numerals assigned to the elements in the drawings, it should be noted that the same elements will be designated by the same reference numerals, wherever possible, even though they are shown in different drawings.

Hereinafter, visible light sensor embedded organic light emitting diode (OLED) display panels according to some example embodiments is described with reference to the drawings.

<FIG> and <FIG> show a pixel layout of visible light sensors embedded OLED display panel <NUM> according to some example embodiments and a cross-sectional view thereof, respectively. The cross-sectional view shown in <FIG> may be a cross-sectional view of the OLED display panel <NUM> shown in <FIG> along view line II-II'.

Referring to <FIG> and <FIG>, a visible light sensor embedded OLED display panel <NUM> according to some example embodiments is a stack-type display panel that includes a visible light sensor stack <NUM> that is stacked under an OLED light emitter stack <NUM>. Accordingly, as shown in <FIG> and <FIG>, and as further shown in at least <FIG> and <FIG>, an OLED display panel <NUM> includes a substrate <NUM>, an OLED light emitter stack <NUM> on the substrate <NUM>, and at least one visible light sensor <NUM> on the substrate <NUM>. The OLED light emitter stack <NUM> includes OLEDs <NUM> configured to emit light <NUM>. Each OLED <NUM> may be referred to herein as simply an OLED light emitter that is configured to emit light <NUM>. The visible light sensor <NUM> is configured to detect at least a portion of the emitted light <NUM> (e.g., light <NUM>) based on reflection of the portion of the emitted light <NUM> from a recognition target.

In the OLED light emitter stack <NUM>, sub-pixels 310R, <NUM>, and 310B are grouped to provide a unit pixel (Px), where a unit pixel (Px) as described herein may be referred to as simply a pixel (Px), and the unit pixel (Px) is repeated and arranged in a pattern, also referred to herein as a matrix. The sub-pixels 310R, <NUM>, and 310B include or are defined by separate OLEDS <NUM> that are configured to emit light of different wavelength spectra, such that the sub-pixels 310R, <NUM>, and 310B may be understood to be configured to emit light of different wavelength spectra. Sub-pixel 310R is defined by an OLED <NUM> that is configured to emit light <NUM> in a red wavelength spectrum ("red light"), sub-pixel <NUM> is defined by an OLED <NUM> that is configured to emit light <NUM> in a green wavelength spectrum ("green light"), and sub-pixel 310B is defined by an OLED <NUM> that is configured to emit light <NUM> in a blue wavelength spectrum ("blue light").

<FIG> shows a pentile matrix type layout in which one pixel (Px) comprises two green sub-pixels <NUM>, one red sub-pixel 310R, and one blue sub-pixel 310B (e.g., RGBG). As described herein, sub-pixel 310R may be referred to as a red OLED sub-pixel, sub-pixel <NUM> may be referred to as a green OLED sub-pixel, and sub-pixel 310B may be referred to as a blue OLED sub-pixel.

In the array shown in <FIG>, the pixel array of the OLED display panel <NUM> includes an array of red sub-pixels 310R, an array of blue sub-pixels 310B, and an array of green sub-pixels <NUM>. As shown, each array defines a separate pattern of the respective sub-pixels 310R, 310B, <NUM>, where some or all of the sub-pixels in a given pattern of sub-pixels may include a particular type of sub-pixel 310R, 310B, <NUM>. It will be understood that a given sub-pixel 310R, <NUM>, 310B that is defined by a pattern of respective OLEDs may not include an OLED <NUM> that corresponds to the sub-pixel. For example, as described further below with reference to <FIG>, a visible light sensor <NUM> may replace an OLED <NUM> in a given sub-pixel that corresponds to a pattern of OLEDS <NUM> (e.g., the visible light sensor <NUM> may be in a position at which an OLED <NUM> should otherwise be located based on a pattern of other OLEDs configured to emit the same wavelength spectrum of light) such that the visible light sensor <NUM> may be referred to as being "in" the given sub-pixel, provided that it is arranged as defined in claim <NUM>.

As further shown in <FIG> and <FIG>, the OLEDs <NUM> are spaced apart from each other in a horizontal direction that is parallel to the upper surface 110u of the substrate <NUM> (e.g., an x-direction and/or a y-direction). The regions adjacent to the OLEDs <NUM> in the OLED light emitter stack <NUM> may be referred to as non-light emitting regions <NUM> of the OLED light emitter stack <NUM>, and thus each unit pixel (Px) includes OLEDs <NUM> and a non-light emitting region <NUM> adjacent to the one or more OLEDs <NUM>. As shown, the non-light-emitting region of a unit pixel (Px) may be a continuous region that surrounds the OLEDs <NUM> of the pixels (Px) of the OLED display panel <NUM> in the pixel array of the OLED display panel <NUM>. As shown, the non-light emitting region(s) of the OLED display panel <NUM> may include insulating layers <NUM> and <NUM>, which may be at least partially transparent to light <NUM> that may be emitted by the OLEDs <NUM> and reflected back into and through the OLED light emitter stack <NUM> from a recognition target. Accordingly, reflected light <NUM> may pass through the OLED light emitter stack <NUM> via the non-light emitting region(s) of the unit pixels (Px) of the OLED display panel <NUM>.

It will be understood that, because the unit pixels (Px) of the OLED display panel <NUM> may have the same horizontal boundaries (e.g., in the x and y directions) as the corresponding unit pixels (Px) of the OLED light emitter stack <NUM>, where the unit pixels (Px) of the OLED light emitter stack <NUM> are defined by a particular grouping of the sub-pixels 310R, <NUM>, 310B of the OLED light emitter stack <NUM>, the unit pixels (Px) of the OLED display panel <NUM> and the corresponding unit pixels (Px) of the OLED light emitter stack <NUM> may be collectively referred to herein as simply unit pixels (Px) or simply pixels (Px).

It will be understood that, in some example embodiments, some or all of the pixels (Px) and/or sub-pixels in the OLED display panel <NUM> and/or OLED light emitter stack <NUM> may be arranged according to one or more other patterns, or matrices, including a strip structure pattern.

It will be understood that the OLED display panel <NUM> may be described as including an array of pixels (Px), where each pixel (Px) of the OLED display panel <NUM> may be considered to correspond to a separate pixel (Px) of the OLED light emitter stack <NUM>. Additionally, each pixel (Px) of the OLED display panel <NUM> includes sub-pixels (Sub-Px), where each sub-pixel (Sub-Px) of a pixel (Px) of the OLED display panel <NUM> is considered to correspond to a separate sub-pixel 310R, <NUM>, 310B of the OLED light emitter stack <NUM>. For example, as shown in <FIG>, a given pixel (Px) of the OLED light emitter stack <NUM> includes a certain set of sub-pixels 310R, <NUM>, and 310B that are configured to emit light having different wavelength spectra ( one red sub-pixel 310R, one blue sub-pixel 310B, and two green sub-pixels <NUM> may define a pixel (Px) of the OLED light emitter stack <NUM>), and a given pixel (Px) of the OLED display panel <NUM> encompasses (and is defined by) the given pixel (Px) of the OLED light emitter stack <NUM>, such that the given pixel (Px) of the OLED display panel includes (and is defined by) the given pixel of the OLED light emitter stack <NUM> and the portions of the visible light sensor stack <NUM>, driver <NUM>, substrate <NUM>, and cover glass <NUM> that overlap the pixel (Px) of the OLED light emitter stack <NUM>. Similarly, as shown in <FIG>, each separate sub-pixel (Sub-Px) of the given pixel (Px) of the OLED display panel <NUM> includes (and is defined by) a separate sub-pixel 310R, 310B, <NUM> of the pixel (Px) of the OLED light emitter stack <NUM> and further includes the portions of the visible light sensor stack <NUM>, driver <NUM>, substrate <NUM>, and cover glass <NUM> that overlap the respective sub-pixel of the OLED light emitter stack <NUM>.

As further shown, the boundaries of the sub-pixels (Sub-Px) and pixels (Px) of the OLED display panel <NUM>, while defined by the respective sub-pixels 310R, <NUM>, 310B and pixels (Px) of the OLED light emitter stack <NUM>, may not exactly be the same as the boundaries of the respective sub-pixels 310R, <NUM>, 310B and pixels (Px) of the OLED light emitter stack <NUM>. For example, as shown in <FIG>, each sub-pixel of the OLED display panel <NUM> includes a respective sub-pixel of the OLED light emitter stack <NUM> and also includes a portion (e.g., half) of the non-light emitting region <NUM> extending between the respective sub-pixel of the OLED light emitter stack <NUM> and one or more adjacent sub-pixels of the OLED light emitter stack <NUM>. OLED display panel <NUM> includes a given pixel (Px) of the OLED light emitting stack.

Herein, where OLED sub-pixels are referenced, it will be understood that said OLED sub-pixels are referring to sub-pixels of the OLED light emitter stack <NUM> (e.g., 310R, <NUM>, 310B), instead of sub-pixels of the OLED display panel <NUM>.

In <FIG> and <FIG>, a visible light sensor <NUM> is disposed under the non-light emitting region <NUM> to implement the detection of the visible light <NUM> received at the visible light sensor <NUM> through the non-light emitting region <NUM> between respective OLED sub-pixels (Sub-Px). <FIG> shows one example that the sub-pixels 310R, <NUM>, and 310B and the visible light sensor <NUM> are partially overlapped in the vertical direction (z-direction). Accordingly, as shown in <FIG>, a visible light sensor <NUM> is between a non-light emitting region <NUM> of the OLED light emitter stack <NUM> and the substrate <NUM> so as to be vertically aligned with the non-light emitting region <NUM> of the OLED light emitter stack <NUM> in a vertical direction (e.g., Z-direction) extending perpendicular to the upper surface 110u of the substrate <NUM>.

It will be understood that, as described herein, an element that is "above" or "below" another element may be referred to as being "on" the other element. Similarly, an element that is described herein to be "on" another element may be "above" or "below" the other element. Furthermore, an element that is described to be "between" two other elements may be separately "on" each of the two other elements. It will be understood that an element that is "on" another element may be "directly" on the other element so as to be in direct contact with the other element or may be "indirectly" on the other element so as to be isolated from direct contact with the other element by one or more interposing spaces and/or structures.

It will be understood that an element and/or direction that is described herein as being parallel with a reference surface may be substantially parallel with the reference surface such that the element and/or direction is parallel with the reference surface within manufacturing tolerances and/or material tolerances. It will be understood that an element and/or direction that is described herein as being perpendicular with a reference surface may be substantially perpendicular with the reference surface such that the element and/or direction is perpendicular with the reference surface within manufacturing tolerances and/or material tolerances.

The OLED display panel <NUM> shown in <FIG> and <FIG> may be suitable for a high resolution display panel having a display resolution of greater than or equal to about 2960X1440 (WQHD) and an aperture ratio between sub-pixels (Sub-Px) of about <NUM> %. But the present disclosure is not necessarily limited to the resolution and the aperture ratio.

When the terms "about" or "substantially" are used in this specification in connection with a numerical value, it is intended that the associated numerical value include a tolerance of ±<NUM>% around the stated numerical value. When ranges are specified, the range includes all values therebetween such as increments of <NUM>%.

The OLED light emitter stack <NUM> is a region configured to emit light, and therefore is configured to emit light to display an image and also to emit light for biometric recognition, simultaneously or separately. The OLED light emitter stack <NUM> includes OLEDs <NUM> (also referred to herein as OLED light emitters), each OLED <NUM> including an organic emission layer <NUM>, and a first electrode <NUM> and a second electrode <NUM> formed under and on the organic emission layer <NUM>. As shown, the OLED light emitter stack <NUM> includes insulation layers <NUM> and <NUM>, where portions of the OLEDs <NUM> may be formed on insulation layer <NUM>, in gaps in the insulation layer <NUM>, and/or between separate instances of insulation layer <NUM>, and insulation layer <NUM> may be formed on both insulation layer <NUM> and the OLEDs <NUM> to cover the OLEDs <NUM>.

The organic emission layer <NUM> may be formed of (may at least partially comprise) various organic materials inherently configured to emit light <NUM> of any one of red R, green G, and blue B colors (wavelength spectra) away from an upper surface 110u of the substrate <NUM>, that is, in an opposite direction from the visible light sensor stack <NUM>. Accordingly, and as shown in <FIG>, each separate OLED <NUM> in a unit pixel (Px) of the OLED light emitter stack <NUM> (and thus a unit pixel (Px) of the OLED display panel <NUM>) may be considered to be, and thus may define, a separate sub-pixel 310R, 310B, <NUM> of the OLED light emitter stack <NUM> (OLED sub-pixel).

Either one of the first electrode <NUM> and the second electrode <NUM> is connected to a driving voltage line (Vdd) and an output terminal (Out Put) to function as an anode, and the other is connected to a common voltage (Vss) to function as a cathode. In order to well express light emitted from the organic emission layer <NUM>, the second electrode <NUM> may be formed as a light-transmitting electrode with a thickness of less than or equal to about <NUM>. For example, the second electrode <NUM> may be formed of MgAg, Ag, Mg, Al, Mo, Ti, TiN, Ni, ITO, IZO, AlZO, AlTO, or the like. The first electrode <NUM> may be formed with a reflecting electrode. As described above, luminous efficiency of the OLED <NUM> may be improved based on the first electrode <NUM> being a reflecting electrode. For example, the first electrode <NUM> may be formed of Al, Ag. Mo, AlNd, Mo/Al/Mo, TiN, ITO/Ag/ITO, ITO/Al/ITO, ITO/Mo/ITO, or the like. It may be formed with a light transmitting electrode to fluently enter light toward the lower visible light sensor stack <NUM>. The light-transmitting electrode may have a transmittance of greater than or equal to about <NUM>%. For example, the first electrode <NUM> may be formed of ITO, IZO, AlZO, AlTO, or the like.

The visible light sensor stack <NUM> may include a visible light sensor <NUM> that is an organic photodiode including a visible light absorption layer <NUM>, a lower first electrode <NUM> and an upper second electrode <NUM>. Particularly, the visible light absorption layer <NUM> may be formed with (may at least partially comprise) an organic material which may absorb visible light through the whole region of visible light (e.g., may absorb visible light at any wavelength within the entire wavelength spectrum of visible light, for example between about <NUM> to about <NUM>). For example, it may include any material suitable for absorbing visible light, for example, squaraine based, D-π-A based, Bodipy based, phthalocyanine based materials, and the like. For example, the visible light absorption layer <NUM> may include any well-known OLED material configured to emit visible light of any wavelength spectrum, including, for example, any one of phosphorescent materials, fluorescent materials, and TADF. Well-known materials that may at least partially comprise one or more visible light absorption layers <NUM> of the one or more visible light sensors <NUM> may include metal complexes such as Ir complex, Pt complex, Os complex, and Pd complex, anthracene (blue), Alq3 (green), DCM (red), any combination thereof, or the like. It will be understood that, in some example embodiments, a visible light sensor <NUM> may be other than an organic photodiode, for example the visible light sensor <NUM> may be a silicon photodiode, a quantum dot photodiode, or the like.

As shown, the visible light sensor stack <NUM> includes insulation layers <NUM> and <NUM>, where portions of the visible light sensors <NUM> may be formed on insulation layer <NUM>, in gaps in the insulation layer <NUM>, and/or between separate instances of insulation layer <NUM>, and insulation layer <NUM> may be formed on both insulation layer <NUM> and the visible light sensors <NUM> to cover the visible light sensors <NUM>.

As shown in <FIG>, a given unit pixel (Px) may include multiple visible light sensors that are vertically aligned with separate non-light emitting regions <NUM> of the OLED light emitter stack <NUM> or separate portions of a same non-light emitting region of the OLED light emitter stack <NUM>.

Referring to <FIG>, in some example embodiments a visible light sensor stack <NUM> may include an individual visible light sensor <NUM> that extends continuously in vertical alignment with ("vertically overlapping") a continuous non-light emitting region <NUM> that extends continuously between adjacent OLEDs <NUM> of the OLED light emitter stack <NUM> of the unit pixel (Px). As shown in <FIG>, where the OLEDs <NUM> are arranged in a pentile matrix in the OLED display panel <NUM>, the non-light emitting region <NUM> of the unit pixel (Px) may have a hatch shape (#), and the visible light sensor stack <NUM> may include an individual visible light sensor <NUM> that has a hatch shape (#) so as to be vertically aligned with (e.g., overlap in the Z-direction) the hatch-shaped non-light emitting region <NUM>.

Separate unit pixels (Px) may include separate visible light sensors <NUM>, such that visible light sensors <NUM> of adjacent unit pixels (Px) are isolated from direct contact with each other in a horizontal direction. As shown, a hatch-shaped visible light sensor <NUM> may include gaps that vertically overlap with at least a portion of one or more OLEDs <NUM>. Referring to <FIG>, which shows two separate visible light sensors <NUM> under a given unit pixel (Px) of the OLED light emitter stack <NUM>, in some example embodiments, a unit pixel (Px) of the OLED display panel <NUM> may include an individual visible light sensor <NUM> instead of multiple visible light sensors <NUM> under the unit pixel (Px) of the OLED light emitter stack <NUM>. At least a portion of one or more visible light sensors <NUM> may extend horizontally, beyond vertically overlapping with one or more non-light emitting regions <NUM>, such that the one or more visible light sensors <NUM> at least partially vertically overlap with (e.g., overlap in the Z-direction with) one or more OLEDs <NUM> of the OLED light emitter stack <NUM>.

In some example embodiments, a visible light sensor <NUM> in a given unit pixel (Px) (e.g., under a given unit pixel (Px) of the OLED light emitter stack <NUM> and within a corresponding given unit pixel (Px) of the OLED display panel <NUM>) may have a shape with no internal horizontal gap spaces such that the visible light sensor <NUM> may extend continuously under, and thus vertically overlap with, both some or all of the one or more OLEDs <NUM> and the one or more non-light emitting regions <NUM> of the OLED light emitter stack <NUM>. For example, while the cross-sectional view of <FIG> provides the appearance of a unit pixel (Px) that includes two separate visible light sensors <NUM>, or an individual visible light sensor <NUM> that includes a gap space under the sub-pixel 310R and extending continuously out of plane of the cross-sectional view (e.g., in the Y-direction), in some example embodiments, the cross-sectional view of the unit pixel (Px) of <FIG> may show an individual visible light sensor <NUM> that extends continuously under at least the sub-pixel 310R and under at least a portion of the non-light emitting regions <NUM> at opposite sides of the sub-pixel 310R.

While a greater quantity of visible light sensors <NUM> in a unit pixel (Px) and/or a visible light sensor <NUM> that has reduced or no vertical overlap with the one or more OLEDs <NUM> of the unit pixel (Px) may provide improved resolution of images generated by the visible light sensors <NUM> of the OLED display panel <NUM>, larger visible light sensors <NUM> that extend continuously under some or all of the OLEDs in a unit pixel (Px), in addition to the non-light emitting region(s) in the unit pixel (Px), may be fabricated more easily and with reduced cost due to reduced complexity of the shape of the visible light sensor <NUM>.

While <FIG> may illustrate that each unit pixel (Px) of the OLED display panel <NUM> may include one or more visible light sensors <NUM>, and may in some example embodiments include multiple visible light sensors <NUM> such that the quantity of visible light sensors <NUM> in an OLED display panel <NUM> is greater than the quantity of unit pixels (Px) of the OLED display panel <NUM> (and thus greater than the quantity of corresponding unit pixels (Px) of the OLED light emitter stack <NUM>), it will be understood that, in some example embodiments, an OLED display panel <NUM> may include a visible light sensor stack <NUM> that includes one or more visible light sensors <NUM> that extend between multiple (e.g., adjacent) unit pixels (Px) (e.g., under multiple unit pixels of the OLED light emitter stack <NUM>) such that one or more visible light sensors may be "shared" by multiple (e.g., two or more) unit pixels (Px). In some example embodiments, the ratio of the quantity of unit pixels (Px) (which may be either of the unit pixels of the OLED display panel <NUM> or the corresponding unit pixels of the OLED light emitter stack <NUM>) to visible light sensors <NUM> in an OLED display panel may be between about <NUM>:<NUM> to about <NUM>:<NUM>. In some example embodiments, the pixel density (e.g., density of unit pixels (Px)) in an OLED display panel <NUM> may be about <NUM> pixels per inch (ppi) and the sensor density (e.g., density of visible light sensors <NUM>) in the OLED display panel <NUM> may be about <NUM> dots per inch (dpi).

Referring back to <FIG>, in some example embodiments an OLED display panel <NUM> may include one or more visible light sensors <NUM> that are not arranged in a pattern or position that is based on the patterns of OLEDs/sub-pixels of the OLED light emitter stack <NUM> but is instead are located at one or more particular positions in the OLED display panel <NUM>, for example at an edge of the OLED display panel <NUM> as shown in <FIG>. Such visible light sensors <NUM> may be repeatedly arranged in or under one or more non-light emitting regions <NUM> in the OLED display panel <NUM>.

At least one of the first electrode <NUM> and the second electrode <NUM> is connected to a driving voltage line (Vdd) and an output terminal (Out Put) and functions as an anode, and the other is connected to a common voltage (Vss) and functions as a cathode. As the first electrode (lower electrode, <NUM>) is formed with the reflecting electrode, it may further improve sensing efficiency of the visible light sensor <NUM>. For example, the first electrode (lower electrode, <NUM>) may be formed of Al, Ag. Mo, AlNd, Mo/Al/Mo, TiN, ITO/Ag/ITO, ITO/Al/ITO, ITO/Mo/ITO, and the like. The second electrode (upper electrode, <NUM>) may be formed with the transparent electrode, so that incident light may be absorbed into the visible light absorption layer <NUM> as much as possible. For example, the second electrode (upper electrode, <NUM>) may be formed of ITO, IZO, AlZO, Ag nanowire, graphene, CNT, and the like.

The driver <NUM>, also referred to herein as simply a "driver stack," is disposed between the substrate <NUM> and the visible light sensor stack <NUM> not to deteriorate light-emitting function and light-receiving function of the OLED light emitter stack <NUM> and the visible light sensor stack <NUM>.

The driver <NUM> is formed on the substrate <NUM> and includes various transistor arrays 120a, 120b, and 120c (see <FIG>) configured to input (receive) and output (transmit) electrical signals from/to the visible light sensor stack <NUM> and the OLED light emitter stack <NUM> which are on the upper part and an interlayer insulating layer <NUM> in which a multi-layered wire layer <NUM> is formed.

The OLED transistor array 120a and a visible light sensor transistor array 120b may be formed on the same plane. While <FIG> only illustrates an OLED transistor array 120a and wire extending between the OLED transistor array 120a and a single OLED <NUM> of the OLEDs <NUM> of sub-pixels 310R, 310B, and <NUM> in the cross-sectional view of <FIG>, it will be understood that the driver <NUM> includes additional transistor arrays 120a that are each separately connected to a separate one of the OLEDs <NUM> of sub-pixels 310R and <NUM>, and said additional transistor arrays 120a are positioned out of plane of the cross-sectional view of <FIG> (e.g., in the Y-direction). When the transistor arrays 120a, 120b, 120c are formed on the same plane, each process of forming the OLED transistor array 120a and a visible light sensor transistor array 120b may be simultaneously carried out so it is not needed to prepare an additional process mask, compared to the case of forming them on different planes, so the number of process steps may be reduced. In addition, the thickness of the display panel may be thinner than the case of forming the transistor arrays in different planes, so it may be more suitable for embodying a flexible display panel.

The substrate <NUM> may be formed with various materials such as glass or plastic. In a case of plastic, it may be formed with a transparent and flexible material.

A cover glass <NUM> attached by an adhesive (not shown) is disposed on the OLED light emitter stack <NUM> and may protect the lower structure to provide a display surface and a biometric recognition surface.

While not shown in <FIG>, it will be understood, for example as shown in <FIG>, that the OLED display panel <NUM> may include a touch sensor <NUM>.

In some example embodiments, the OLED display panel <NUM> may have reduced thickness, and thus reduced device volume, improved flexibility, or any combination thereof due to the visible light sensors <NUM> being included "in-cell" as shown in <FIG> (and further as shown in <FIG> as described below). As a result, the amount of light transmission by the OLEDs <NUM> of the OLED light emitter stack <NUM> may be improved, which may improve sensitivity of the visible light sensors <NUM> when the OLEDs <NUM> are used to emit light and the visible light sensors <NUM> are used to detect reflections of the emitted light from a recognition target to perform biometric recognition operations. Accordingly, the OLED display panel <NUM> may be configured to enable improved biometric recognition accuracy. In addition, because the visible light sensors <NUM> are included "in-cell" with the OLEDs <NUM> as shown in <FIG> (and further as shown in <FIG> as described below), fabrication of the OLED display panel <NUM> may be simplified (e.g., by omitting bonding of separate stacks that include a separate element of the visible light sensors <NUM> and the OLEDs <NUM> and include separate, respective substrates on which separate elements are formed prior to the bonding). Additionally, power consumption in a display device that includes the OLED display panel <NUM> may be improved based on reducing or omitting separate light sources for biometric recognition operations beyond the OLEDs <NUM> that are already included in the OLED display panel <NUM> and can be used as light sources for the visible light sensors <NUM> during a biometric recognition operation.

<FIG> is a flowchart illustrating an operation algorithm of a display panel <NUM> embedded with the visible light sensor <NUM>; <FIG> is a schematic view showing operations of biometric recognition, specifically, fingerprint recognition by using of the visible light sensor embedded organic light emitting diode (OLED) display panel according to some example embodiments; <FIG> shows a read out circuit of each sub-pixel 310R, <NUM>, and 310B and a visible light sensor <NUM>; and <FIG> is a timing diagram for expressing a fingerprint recognition operation and a display signal. <FIG> exemplifies an organic visible light sensor (Vis OPD) as a visible light sensor. It will be understood that the operation algorithm shown in <FIG> may be partially or entirely implemented by processing circuitry as described herein with reference to <FIG> and may be implemented with regard to any of the example embodiments of the OLED display panel <NUM>, including example embodiments illustrated in <FIG>. The cross-sectional view shown in <FIG> may be a cross-sectional view of the OLED display panel <NUM> shown in <FIG> along view line II-II'.

As shown in <FIG>, a method for performing biometric recognition with regard to a portion of a user of a display device, such portion being referred to as a recognition target (e.g., face, hand, iris, fingerprint, etc.,) where the display device includes any of the example embodiments of OLED display panels <NUM>, may include driving an OLED <NUM> to emit light <NUM> and further driving a visible light sensor <NUM> to detect at least a portion <NUM> of the emitted light <NUM> based on reflection of the portion <NUM> of the emitted light <NUM> from a recognition target, in response to a determination that the OLED <NUM> is turned on, user access to the display device is disabled, and a recognition target that is a portion of the user is in a certain proximity to the OLED display panel; and turning off the visible light sensor <NUM>, granting user access to the display device, and driving the OLED <NUM> to cause the OLED display panel <NUM> to display an image, in response to a determination that recognition of the recognition target is completed via comparison of a reference recognition target image with an image of the recognition target generated based on an output signal of the visible light sensor <NUM> in response to detecting the reflected portion <NUM> of the emitted light <NUM>.

First, it is determined whether R/G/B OLEDs (e.g., the OLEDs <NUM> of sub-pixels 310R, <NUM>, and 310B) are turned on (S1001). The turning on of the R/G/B OLEDs <NUM> means a state of screen mode transition after switching a start power (e.g., initializing the supply of electrical power to the OLEDs <NUM> of the OLED display panel <NUM>). If the R/G/B OLEDs (e.g., the OLEDs <NUM> of sub-pixels 310R, <NUM>, and 310B) are turned off (e.g., power is not being supplied to the OLEDs <NUM>), a visible light sensor <NUM> (Vis OPD) and R/G/B OLEDs <NUM> (Vis-OLEDs) are not driven (S1002). Restated, if the OLEDs <NUM> are turned off at S1001, then signals are not supplied to the OLEDs <NUM> and/or the visible light sensors <NUM> to drive same and/or cause same to generate output signals. In the case when R/G/B OLEDs (e.g., the OLEDs <NUM> of sub-pixels 310R, <NUM>, and 310B) are determined to be turned on (e.g., electrical power is being supplied to the OLEDs <NUM>), it is determined whether a locking device is turned on or off (S1003).

The locking device may be a functionality that is implemented by processing circuitry as described with reference to <FIG> to enable ("grant") or disable ("deny") user access to the display device and/or functionality of the display device, for example by selectively enabling or disabling functionality to display images to the user via the OLED display panel <NUM>. Restated, a determination is made whether user access to a display device that includes the OLED display panel <NUM> is enabled ("unlocked"). Such user access may be enabled based on user interaction with one or more interfaces of the display device (e.g., contact of a fingerprint with a particular portion of the OLED display panel <NUM>, user interaction with a button of the display device that is separate from the OLED display panel <NUM>, any combination thereof, or the like). In some example embodiments, user access may be enabled/disabled separately from the operational algorithm of <FIG>, such that the display device may grant unrestricted access to any user interacting with the display device via the OLED display panel <NUM>; in such cases the user access functionality of the display device (e.g., the "locking device") may be considered to be turned off, such that biometric recognition of a user may not be necessary. If the locking device is determined to be turned off at S1003 (e.g., user access is enabled), the visible light sensor <NUM> (Vis OPD) and R/G/B OLEDs (Vis-OLEDs, e.g., the OLEDs <NUM> of sub-pixels 310R, <NUM>, and 310B), which are one of the locking devices, are not driven (S1004), similarly to at S1002. In the case when the locking device is turned on (e.g., user access to the display device via the OLED display panel <NUM> is presently disabled), it is determined whether a recognition target is in a certain proximity to the OLED display panel <NUM> (S1005). As described below with reference to <FIG>, an OLED display panel <NUM> may include one or more touch sensors <NUM> that may generate output signals based on contact between a recognition target that is a portion of the user (e.g., a fingerprint) with at least a portion of the OLED display panel <NUM>. A touch sensor of the OLED display panel <NUM> may be considered to be turned on when the touch sensor generates an output signal that indicates that a recognition target is in contact with at least a portion of the OLED display panel <NUM>. A recognition target may be determined to be within a certain proximity of the OLED display panel <NUM> (S1005=yes) if an output signal is received from the touch sensor in response to the recognition target being in contact with the OLED display panel.

If the recognition target is not in the certain proximity to the OLED display panel (e.g., no signal is received from the touch sensor), the visible light sensor <NUM> (Vis OPD) and R/G/B OLEDs (Vis-OLEDs, e.g., the OLEDs <NUM> of sub-pixels 310R, <NUM>, and 310B) are not driven (S1006), similarly to S1002 and S1004. In some example embodiments, where the biometric recognition operation of <FIG> involves performing biometric recognition of a recognition target that is not in contact with the OLED display panel (e.g., face recognition, iris recognition, or the like), the determination at S1005 may include driving one or more visible light sensors <NUM> (e.g., a particular limited selection of the visible light sensors <NUM> of the OLED display panel <NUM>) to generate output signals that may be processed to generate an image of a field of view of the OLED display panel <NUM> to determine whether a recognition target (e.g., user iris, user face, or the like) is within the field of view and thus is in proximity to the OLED display panel. Thereby, power consumption more than required for biometric recognition operations may be reduced or prevented by inhibiting the use of power to drive the OLEDs <NUM> and visible light sensors <NUM> except in response to a determination that the OLEDs <NUM> are turned on (and thus the OLED light emitter stack <NUM> is turned on), user access to the display device is disabled, and a recognition target is in a proximity to the OLED display panel (e.g., in contact with the OLED display panel <NUM> and/or within the field of view of the OLED display panel <NUM>). In the case when the touch sensor is turned on and the locking device is turned on, it is determined whether a finger <NUM> is contacted on the surface of the display panel <NUM> for a threshold period of time or longer (e.g., greater than or equal to about <NUM> second) as shown in <FIG> (S1007), or whether a recognition target within the field of view of the OLED display panel <NUM> is within the field of view for at least a threshold period of time (e.g., greater than or equal to about <NUM> second).

One or more visible light sensor <NUM> (Vis OPD) and R/G/B OLEDs (Vis-OLEDs, e.g., the OLEDs <NUM> of sub-pixels 310R, <NUM>, and 310B) are selectively operated (driven) in the case when the recognition target is determined to be in the proximity to the OLED display panel for at least the threshold period of time or longer (S1008). In other words, as shown in <FIG> and <FIG>, driving the OLEDs <NUM> may include turning on the gate lines (Gate n+<NUM>, Gate n+<NUM>, Gate n+<NUM>) connected to red OLED sub-pixel 310R, blue OLED sub-pixel 310B, green OLED sub-pixel <NUM> which causes red OLED sub-pixel 310R, blue OLED sub-pixel 310B, green OLED sub-pixel <NUM> to emit light <NUM>, so that visible detecting light <NUM> may be reflected or scattered on a surface of a recognition target (e.g., the finger <NUM> surface , also referred to as a fingerprint <NUM>, as shown in <FIG>).

It will be understood that, in some example embodiments, operation S1008 includes driving a particular limited set of the visible light sensors <NUM> and OLEDs <NUM> of the OLED display panel <NUM>. For example, where the recognition target is a fingerprint in contact with a particular limited area of the total area of a surface 1000a of the OLED display panel <NUM>, as indicated by one or more touch sensors of the OLED display panel <NUM>, operation S1008 may include selectively driving only a limited portion of visible light sensors <NUM> that are in a limited portion of an array of visible light sensors <NUM> and OLEDs <NUM> that are in a limited portion of an array of OLEDs <NUM> that vertically overlap with the limited area.

As shown in <FIG> and <FIG>, when the reflected or scattered light is received (detected, absorbed, or the like) by a visible light sensor <NUM> (Vis sensing OPD), the gate line (Gate n) connected to the visible light sensor <NUM> (Vis sensing OPD) turns on (e.g., the visible light sensor <NUM> is driven), and a output line turns on, the signal accumulated in the visible light sensor <NUM> (Vis sensing OPD) is output through the output line (Output) as an output signal. The output signals generated by an array of visible light sensors <NUM> in some or all of the OLED display panel <NUM> may be processed to generate an image of the recognition target (e.g., a fingerprint image of the finger <NUM>) through an image generation process, which may include any well-known process for image generation based on output signals generated by an array of visible light sensors <NUM>, thereby performing fingerprint recognition. A light emitter (e.g., OLEDs <NUM>) emits each of red, green and blue light <NUM>, but the visible light sensor <NUM> (Vis sensing OPD) may be configured to absorb light in an entire visible light wavelength spectrum (e.g., may absorb visible light at any wavelength within the entire wavelength spectrum of visible light), such that the output signal does not specifically indicate the specific wavelength of the incident light <NUM> within the visible wavelength spectrum. Accordingly, output signals by an array of visible light sensors <NUM> in the OLED display panel <NUM> may be processed to generate a monochromatic image. Even if carrying out Fourier transform at a low frequency, an OLED display panel <NUM> that includes visible light sensors <NUM> that are each configured to absorb the same wavelength spectrum of light, and that extends over some or all of the entire visible wavelength spectrum, may provide merits of producing clearer digital image process results than the case of absorbing each of red, green, and blue. Restated, an OLED display panel <NUM> that includes unit pixels (Px) with one or more (or sharing one or more) visible light sensors <NUM> that are each configured to absorb the same wavelength spectrum of light <NUM>, where the wavelength spectrum extends over some or all of the entire visible wavelength spectrum, may be configured to generate a monochromatic image (based on output signals generated by the visible light sensors <NUM> in response to incident light <NUM>) that has greater resolution than a color image generated based on output signals generated by an array of RGB light sensors having similar size, sensor quantity, and pattern properties. This may be because a visible light sensor <NUM> that absorbs light across the entire visible wavelength spectrum may have more photocurrent than a visible light sensor <NUM> that only absorbs one of red, blue, or green light during rising time and fall time for generation of each frame (e.g., image).

It will be understood that the gate lines shown in <FIG> and <FIG> may be turned on based on certain visible light sensors <NUM> and OLEDs <NUM> being driven according to signals generated and/or transmitted by one or more instances of processing circuitry as described herein to supply power to the respective gate lines. As shown in <FIG> and <FIG>, such signals may be supplied to the gate lines via the "data" line; such signals may be referred to herein as "data" signals.

Subsequently, it is determined whether the biometric recognition is complete (S1009), and when the fingerprint recognition is completed, the driving of the visible light sensor <NUM> (Vis OPD) and R/G/B OLEDs (Vis-OLEDs, e.g., the OLEDs <NUM> of sub-pixels 310R, <NUM>, and 310B) that are driven starting at S1008 is ended (S1010), and the locking device is also turned off (i.e., user access to the display device is granted) (S1011). It will be understood that biometric recognition may include comparing the generated image of the recognition target with one or more stored reference images of recognition targets that are associated with authorized users for which access to the display device is pre-granted, and where recognition may be determined to be completed if the image generated based on processing output signals from the one or more visible light sensors <NUM> matches a stored reference recognition target image within at least a threshold confidence level (e.g., at least <NUM>% confidence match). Where the recognition target is a fingerprint, the reference recognition target images may be stored fingerprint images of fingerprints of authorized users. Similarly, where the recognition target is a face or iris, the reference images may be stored face images or iris images, respectively.

In some example embodiments, an OLED display panel <NUM> may include one or more infrared light emitters 310IR and one or more infrared light sensors 210IR, and where the recognition target is not in contact with the OLED display panel <NUM> (e.g., an iris or face), the driving at S1008 may include selectively driving at least one or more infrared light emitters 310IR and at least one or more infrared light sensors 210IR to cause an image of the recognition target to be generated based at least in part on reflected infrared light being received by the one or more infrared light sensors 210IR.

Then gate lines (Gate n+<NUM>, Gate n+<NUM>, Gate n+<NUM>) connected to red OLED sub-pixel 310R, blue OLED sub-pixel 310B, green OLED sub-pixel <NUM> are turned on and a general display is performed through the driving of a display signal part (S1012) that turns on red OLED sub-pixel 310R, blue OLED sub-pixel 310B, green OLED sub-pixel <NUM> (S1012). Restated, at S1012, the OLED light emitter stack <NUM> is driven to emit light to display one or more images. Unless and until the biometric recognition is completed at S1009, the locking device is turned on again or maintained on (S1013) and Step (S1005) is operated again.

Although <FIG> exemplifies a fingerprint of a finger <NUM> as a biometric subject, it may be applied for various biometric subjects ("recognition targets") such as a palm print, an iris, a retina, and a face.

The visible light sensor embedded OLED display panel illustrated referring to <FIG> employs the OLEDs <NUM> as a light source as it is with no additional light source for the biometric recognition, so that it may prevent an aperture ratio decrease of the OLED(s) <NUM> In the array of OLEDs <NUM> in the OLED display panel <NUM>. Accordingly, the utilization of the OLEDs <NUM> as a light source for the visible light sensors <NUM> during a biometric recognition operation enables the OLED display panel <NUM> to be configured to enable performance of the biometric recognition operation without any reduction in the quantity, spacing, or emission power of the OLEDs, thereby preventing a reduction in the cumulative light transmission area of the OLED display panel (e.g., the "aperture ratio" of the OLED display panel <NUM>).

In addition, as the visible light sensor <NUM> is formed in a stack structure under the non-light emitting region which does not have an effect on the aperture ratio of the OLED(s) <NUM>, it may maintain the aperture ratio of the OLED light emitter(s) <NUM> as it is. In addition, the biometric recognition sensor is used as a visible light sensor to maximize the incident light dose, so that it may improve accuracy and efficiency of biometric recognition.

The visible light sensor <NUM> is formed of an organic material and thus may be bent or stretchable. Accordingly, the visible light sensor <NUM> may contribute to easily realizing a flexible display device and thus improve portability and versatility of a display device.

<FIG> is a schematic view showing a pixel layout of a light emitter of a visible light sensor embedded organic light emitting diode (OLED) display panel according to some example embodiments, and <FIG> is a cross-sectional view of a visible light sensor embedded OLED display panel according to some example embodiments. The cross-sectional view shown in <FIG> may be a cross-sectional view of the OLED display panel <NUM> shown in <FIG> along view line VIII-VIII'.

A visible light sensor embedded OLED display panel <NUM> according to some non-inventive embodiments illustrated in <FIG> and <FIG> includes an OLED light emitter stack <NUM> and a visible light sensor <NUM> disposed on the same plane as the OLED light emitter stack <NUM>, such that the visible light sensor <NUM> is in the non-light emitting region <NUM> of the OLED light emitter stack <NUM> (e.g., the non-light emitting region <NUM> that is adjacent to one or more OLEDs <NUM> of the OLED light emitter stack <NUM>) and is aligned with at least one adjacent OLED <NUM> (e.g., at least one OLED <NUM> of the OLED sub-pixels 310R, <NUM>, or 310B) of the OLED light emitter stack <NUM> in a horizontal direction extending in parallel to an upper surface 110u of the substrate <NUM> (e.g., an x-direction). It will be understood that the visible light sensor <NUM> shown in <FIG>, horizontally aligned with at least one adjacent OLED light emitter (e.g., sub-pixel 310B) may be understood to be included in the OLED light emitter stack <NUM> along with the sub-pixels 310R, <NUM>, and 310B. As shown in non-invention example of <FIG>, the visible light sensor <NUM> in the non-light emitting region <NUM> of the OLED light emitter stack <NUM> may have a shape and size so as to extend continuously along and around one or more OLEDS <NUM> of a unit pixel (Px) and/or between two or more adjacent OLEDs <NUM> of a unit pixel (Px), or may simply occupy a portion of the non-light emitting region <NUM> that is bounded by proximate OLEDs <NUM>.

The OLED display panel <NUM> is a structure in which the OLED light emitter stack <NUM> and the driver <NUM> are stacked. In the OLED light emitter stack <NUM>, one unit pixel (Px) is formed with sub-pixels 310R, <NUM>, and 310B emitting lights R, G, B having different wavelengths from each other, and the unit pixels (Px) are repeated and arranged in a matrix. Thus, in a non-inventive example the visible light sensor <NUM> may be formed in a non-light emitting region <NUM> between each OLED sub-pixels or a part of green OLED region <NUM>.

In a non-inventive example, where a OLED display panel <NUM> includes a pattern of red OLED sub-pixels 310R, a pattern of green OLED sub-pixels <NUM>, and a pattern of blue OLED sub-pixels 310B, one or more of the green OLEDs <NUM> in the pattern of green sub-pixels <NUM> may be replaced ("substituted") with one or more visible light sensors <NUM>, such that the one or more visible light sensors <NUM> occupy a location in the OLED light emitter stack <NUM> that corresponds to a location of a green OLED sub-pixel <NUM> in the pattern of green OLED sub-pixels <NUM> in the OLED display panel <NUM>. The visible light sensor <NUM> that replaces a green OLED <NUM> in the OLED display panel may be referred to as being "in" a green sub-pixel <NUM> of the OLED display panel <NUM>/OLED light emitter stack <NUM>. It will be understood that one or more visible light sensors <NUM> may, in addition or in alternative to being "in" a green sub-pixel <NUM>, be "in" a red sub-pixel 310R and/or a blue sub-pixel 310B.

The OLED display panel <NUM> illustrated in non-inventive examples of <FIG> and <FIG> is a display panel having a display resolution of less than or equal to about 2220X1080 (FHD), which is appropriate in the case of an aperture ratio between sub-pixels (Sub-Px) of less than or equal to about <NUM> %. But the present disclosure is not necessarily limited to the resolution and the aperture ratio.

The OLED light emitter stack <NUM> is a region for displaying an image and also a region for emitting light for biometric recognition, simultaneously. The visible light sensor <NUM> may include an organic photodiode as in the OLED <NUM> for the OLED light emitter stack <NUM>. In this case, the upper electrode of the OLED <NUM> and the upper electrode of the visible light sensor <NUM> may be formed with a transflective electrode, and the lower electrode of the OLED <NUM> and the lower electrode of the visible light sensor <NUM> may be formed with a reflective electrode. For example, the upper electrode of the OLED <NUM> and the upper electrode of the visible light sensor <NUM> may be formed of MgAg, Ag, Mg, Al, and the like. The lower electrode of the OLED <NUM> and the lower electrode of the visible light sensor <NUM> may be formed of Al, Ag, Mo, AlNd, Mo/Al/Mo, TiN, ITO/Ag/ITO, ITO/Al/ITO, ITO/Mo/ITO, and the like.

In addition, the visible light absorption layer for the visible light sensor <NUM> may be formed of an organic material configured to absorb visible light through the whole region of the visible light, as in some example embodiments. For example, it may include any materials suitable for absorbing visible light such as squaraine based, D-π-A based, Bodipy based, phthalocyanine based materials, and the like.

The fingerprint recognition of the OLED display panel <NUM> illustrated in non-inventive examples of <FIG> and <FIG> is performed according to the same process as described with references to <FIG>, so the descriptions thereof are omitted.

In the visible light sensors <NUM>/<NUM> illustrated in <FIG>, an organic photodiode configured to absorb visible light is exemplified, but the visible light sensors <NUM>/<NUM> may be embodied by ("may include") a-Si based P-I-N photodiode, a poly-Si based P-I-N photodiode, a CIGS (Cu, In, Ga, Se) photodiode (III-V photodiode), or a Cd-Te photodiode (II-VI photodiode).

<FIG> are schematic views of smart phones <NUM> including the visible light sensor embedded OLED display panel <NUM>.

<FIG> shows that the visible light sensor embedded OLED display panel <NUM> recognizes a fingerprint <NUM>, <FIG> shows the case of recognizing an iris <NUM>, and <FIG> shows the case of recognizing a face <NUM>. As shown in <FIG>, the OLED display panel <NUM> may display an image of the recognition target (e.g., iris) and may further display an icon that highlights and/or overlays the image of the recognition target, for example to provide an observable indication of the recognition target for which a biometric recognition operation is being performed.

<FIG> show a smart phone <NUM> as one example of the display device, but it may be applied to a screen such as a TV as well as for a multi-media player, a tablet PC, or the like that are capable of employing the visible light sensor embedded OLED display panel <NUM>, in addition to the smart phone <NUM>.

<FIG> is a cross-sectional view showing a visible light sensor embedded OLED display panel that includes a touch sensor according to some example embodiments. The cross-sectional view shown in <FIG> may be a cross-sectional view of the OLED display panel <NUM> shown in <FIG> along view line II-II'.

Referring to <FIG>, in some example embodiments, an OLED display panel <NUM> may include a touch sensor <NUM>. As shown in the cross-sectional view of <FIG>, the touch sensor <NUM> may extend between the cover glass <NUM> and the OLED light emitter stack <NUM>, but example embodiments are not limited thereto. For example, in some example embodiments, the cover glass <NUM> may be between the touch sensor <NUM> and the OLED light emitter stack <NUM>, the OLED light emitter stack <NUM> may be between the cover glass <NUM> and the touch sensor <NUM>, or the like.

A touch sensor <NUM> may include one or more sensor electrodes in a mold layer and may be electrically connected, via one or more electrical wire with a device (e.g., a transistor) in the driver <NUM>. The one or more sensor electrodes may be, for example, a transparent electrode, which may be formed of or include indium tin oxide (ITO), zinc oxide (ZnO), indium zinc oxide (IZO), cadmium tin oxide (CTO), graphene, carbon nanotube (CNT), and so forth, an opaque electrode, which may be formed of or include a metal (e.g., copper (Cu), silver (Ag), and aluminum (Al)), or any combination thereof.

In some example embodiments, the touch sensor <NUM> is configured to generate one or more signals based on a recognition target (e.g., finger <NUM>) contacting a particular pixel (Px) of the OLED display panel <NUM>, where separate signals may be generated for different pixels (Px) contacted by the recognition target. Accordingly, particular pixels (Px) in contact with the recognition target may be determined based on processing of said one or more signals generated by the touch sensor <NUM>. Such processing and determination may be implemented by processing circuitry as described further herein with reference to <FIG>.

While <FIG> illustrates example embodiments of the touch sensor <NUM> being included in an OLED display panel <NUM> featuring a visible light sensor stack <NUM> between the OLED light emitter stack <NUM> and the substrate <NUM>, it will be understood that in a non-inventive example the touch sensor <NUM> may be included in any of the example embodiments of OLED display panels, including OLED display panels that include a visible light sensor in a non-light emitting region of the OLED light emitter stack, as described herein with reference to at least the non-inventive examples of <FIG>.

It will be understood that the touch sensor <NUM> shown in <FIG> is an example: in some example embodiments, the touch sensor <NUM> may be any touch sensor known in the art.

<FIG> are cross-sectional views showing visible light sensor embedded OLED display panels that include an infrared light emitter and an infrared light sensor according to some example embodiments. The embodiment of <FIG> is not according to the invention.

Referring to <FIG>, in some example embodiments, an OLED display panel <NUM> may include, in addition to an OLED <NUM> and a visible light sensor <NUM>, an infrared photosensor embedded in the OLED display panel <NUM>, including an infrared light emitter 310IR and an infrared light sensor 210IR. It will be understood that an infrared light emitter 310IR may be a near infrared (NIR) light emitter, and an infrared light sensor 210IR may be an NIR light sensor. Accordingly, the OLED display panel <NUM> may include an infrared light emitter 310IR on the substrate <NUM>, where the infrared light emitter 310IR is configured to emit infrared light 330IR, and an infrared light sensor 210IR on the substrate, where the infrared light sensor 210IR is configured to detect at least a portion 245IR of the emitted infrared light 330IR based on reflection of the portion 245IR of the emitted infrared light 330IR from a recognition target. As shown in <FIG>, the infrared light emitter 310IR may be configured to emit infrared light 330IR out of the OLED display panel in a same direction as the light <NUM> emitted by the OLEDs <NUM>, and the infrared light sensor 210IR may be configured to detect light 245IR received at the infrared light sensor 210IR from the same direction (e.g., light 245IR is received at the infrared light sensor 210IR through a same surface through which both the OLEDs <NUM> and the infrared light emitter 310IR may emit light).

As shown in <FIG>, the infrared light emitter 310IR and the infrared light sensor 210IR may be embedded in the OLED display panel <NUM> according to the same configurations of OLEDs <NUM> and visible light sensors <NUM>/<NUM> as described herein with reference to at least <FIG>. For example, as shown in <FIG>, the infrared light emitter 310IR may be included in the OLED light emitter stack <NUM> in one or more particular pixels (Px) of the OLED display panel <NUM>, and the infrared light sensor 210IR may be between one or more non-light emitting regions <NUM> of the OLED light emitter stack <NUM> and the substrate <NUM> (<FIG>) and/or in a non-inventive example the one or more non-light emitting regions of the OLED light emitter stack <NUM> are adjacent to one or more OLEDs <NUM> of the OLED light emitter stack <NUM> (<FIG>).

It will be understood that, as shown in <FIG>, the infrared light emitter 310IR and/or infrared light sensor 210IR may be included in different pixels (Px) of the OLED display panel <NUM> from the one or more pixels (Px) that include one or more visible light sensors <NUM>, such that a given pixel (Px) and/or sub-pixel of the OLED display panel <NUM> that includes an infrared light sensor 210IR and/or infrared light emitter 310IR does not include a visible light sensor <NUM>. It will also be understood that, in some example embodiments, the infrared light emitter 310IR and/or infrared light sensor 210IR may be included in a same (common) pixel (Px) of the OLED display panel <NUM> as one or more pixels (Px) that include one or more visible light sensors <NUM>.

The infrared light emitter 310IR may include an organic emission layer 311IR that is configured to emit light in an infrared wavelength spectrum (e.g., one or more infrared wavelengths in a wavelength spectrum ranging from about <NUM> to about <NUM>) and a first electrode 313IR and a second electrode 315IR formed under and over the organic emission layer 311IR, respectively (e.g., on opposite surfaces of the organic emission layer 311IR, as shown in at least <FIG>). The organic emission layer 311IR may be formed of ("may at least partially comprise") any material that is well-known to be appropriate for emitting light in a desired infrared wavelength. The second electrode 315IR may be formed as ("may at least partially comprise") a transparent electrode in order to be configured to enable infrared light emitted from the infrared light emitter 310IR to exit the OLED display panel <NUM>. For example, the second electrode 315IR may be formed of ("may at least partially comprise) ITO, IZO, AlZO, AlTO, or the like. The first electrode 313IR may be formed as ("may at least partially comprise") a reflective electrode configured to enable the emitted infrared light to be emitted toward the second electrode 315IR through resonance, and the second electrode 315IR may be a transparent electrode. For example, the second electrode 315IR may be formed of ("may at least partially comprise") Al, Ag, Mo, AlNd, Mo / Al / Mo, TiN, ITO / Ag / ITO, ITO / Al / ITO, ITO / Mo / ITO, or the like.

The infrared light sensor 210IR may be an organic photodiode including an organic light-absorbing layer 211IR that is configured to absorb light in an infrared wavelength and a first electrode 213IR and a second electrode 215IR formed under and over the organic light-absorbing layer 211IR, respectively (e.g., on opposite surfaces of the organic light-absorbing layer 211IR, as shown in at least <FIG>). The organic light-absorbing layer 211IR may be formed of ("may at least partially comprise") any well-known material appropriate for absorbing ("configured to absorb") light of an infrared wavelength. In other words, the organic light-absorbing layer 211IR may be formed of ("may at least partially comprise") any well-known appropriate material for absorbing ("configured to absorb") light in a wavelength region ("wavelength spectrum") of about <NUM> to about <NUM>. The second electrode 215IR of the infrared light sensor 210IR may at least partially comprise a transparent electrode. In some example embodiments, the second electrode 215IR may be formed of ("may at least partially comprise") a transparent electrode having transmittance of about <NUM>% or greater (e.g., equal to or greater than about <NUM>%). For example, the second electrode 215IR may be formed of ("may at least partially comprise") ITO, IZO, AlTO, carbon nanotube (CNT), graphene, nanosilver (Nano Ag), or the like. The first electrode 213IR may be formed as ("may at least partially comprise") a reflective electrode so that the incident infrared light is not transmitted and lost. For example, the first electrode 213IR may be formed of ("may at least partially comprise") Al, Ag, Mo, AlNd, Mo / Al / Mo, TiN, ITO / Ag / ITO, ITO / Al / ITO, ITO / Mo / ITO or the like.

In some example embodiments, in a given pixel (Px) of the OLED display panel <NUM> that includes at least one infrared light emitter 310IR, the infrared light sensor 210IR, which may also define an infrared sub-pixel, may be included in a same (common) pixel (Px) of the OLED display panel <NUM> as red, green, and blue sub-pixels 310R, <NUM>, 310B. However, it will also be understood that, in some example embodiments, including the example embodiments shown in <FIG>, one or more pixels (Px) may include an infrared light emitter 310IR that is included in place of one of the red, green, or blue OLEDs <NUM> in one of the sub-pixels 310R, <NUM>, 310B, for example in a position that would otherwise be occupied by the one of the red, green, or blue OLEDS <NUM> in the one of the sub-pixels 310R, <NUM>, 310B in a pattern of said red, green, or blue sub-pixels 310R, <NUM>, 310B in the OLED display panel <NUM>. Such pixels (Px) that include an infrared light emitter 310IR in one of said red, green, or blue sub-pixels 310R, <NUM>, 310B may be a limited proportion of the total pixels (Px) of the OLED display panel <NUM> pixel array, and such pixels (Px) may be included in a limited region of the OLED display panel pixel array.

<FIG> is a schematic view showing various regions of a visible light sensor embedded OLED display panel having different light sensor configurations according to some example embodiments.

Referring to <FIG>, the OLED display panel <NUM> may include an array of unit pixels (Px) of the OLED display panel <NUM>, where each unit pixel (Px) includes at least one OLED light emitter. As shown, the array of unit pixels (Px) may extend through a total area TA of the OLED display panel <NUM>. Accordingly, the OLED display panel <NUM> may include an array of OLEDs <NUM> on the substrate <NUM> and an array of light sensors <NUM> and/or 210IR.

Still referring to <FIG>, the array of unit pixels (Px) of the OLED display panel <NUM> may extend through multiple regions <NUM>-<NUM> of the OLED display panel <NUM>. Each region <NUM>-<NUM> will be understood to be a portion or entirety of the total area of the OLED display panel <NUM>.

As shown, in <FIG>, the array of unit pixels (Px) may extend through a first region <NUM> of the OLED display panel <NUM>, where the first region <NUM> extends over a total area of the OLED display panel <NUM>. Each unit pixel (Px) that extends through the first region <NUM> may include at least one OLED <NUM> of the OLED light emitter stack <NUM>. Restated, the OLED light emitter stack <NUM> may be included in each of the pixels (Px) that extend through the first region <NUM> and the array of OLEDs <NUM> may extend throughout the entirety of the first region <NUM>.

Still referring to <FIG>, the array of unit pixels (Px) may extend through different regions <NUM>-<NUM> that are different from the first region <NUM> and may be entirely encompassed within the first region <NUM>, such that each region <NUM>-<NUM> is smaller than the first region <NUM> and regions <NUM>-<NUM> collectively define the first region <NUM>.

In some example embodiments, different regions <NUM>-<NUM> may include different configurations of light emitters and light sensors. For example, each unit pixel (Px) in the second region <NUM> of the OLED display panel <NUM>, encompassed within the first region <NUM>, include OLEDs <NUM> and further includes one or more visible light sensors <NUM>/<NUM>, for example as shown in any of the example embodiments described above with reference to <FIG>, and furthermore each unit pixel (Px) in the second region <NUM> may not include any infrared light emitters 310IR or infrared light sensors 210IR. In another example, each unit pixel (Px) in the third region <NUM> of the OLED display panel <NUM> may include one or more OLEDs <NUM>, similarly to the unit pixels (Px) in the second region <NUM>, and may further include one or more visible light sensors <NUM> and/or one or more infrared light sensors 210IR. In some example embodiments, the unit pixels (Px) in the third region <NUM> of the OLED display panel <NUM> may include a first pattern of pixels (Px) that include one or more OLEDs <NUM>, similarly to the unit pixels (Px) in the second region <NUM>, and further include one or more infrared light sensors 210IR and/or one or more infrared light emitters 310IR but no visible light sensors and a second pattern of pixels (Px) that include one or more OLEDs <NUM>, similarly to the unit pixels (Px) in the second region <NUM>, and further include one or more visible light sensors but not infrared light sensors 210IR or infrared light emitters 310IR. In some example embodiments, each unit pixel (Px) in the third region <NUM> of the OLED display panel <NUM> may include one or more OLEDs <NUM>, similarly to the unit pixels (Px) in the second region <NUM>, and may further include one or more infrared light sensors 210IR and/or one or more infrared light emitters 310IR but no visible light sensors <NUM>. In yet another example, each unit pixel (Px) in the fourth region <NUM> of the OLED display panel <NUM> may include one or more OLEDs <NUM>, similarly to the unit pixels (Px) in the second and third regions <NUM> and <NUM>, but may not include visible or infrared light sensors <NUM>/210IR. One or more unit pixels (Px) in the third and fourth regions <NUM> and <NUM> may include one or more infrared light emitters 310IR in addition to or in place of one or more OLED light emitters that are included in each pixel (Px) in the second region <NUM>.

Restating the above, while the array of OLEDs <NUM> may extend through the first region <NUM>, the array of visible light sensors <NUM> (which may consist of all of the visible light sensors of the OLED display panel <NUM>) may extend through the second region <NUM> but may not extend through any of the third and fourth regions <NUM>, <NUM>. Accordingly, at least the third region <NUM> may include at least one OLED <NUM> and no visible light sensors <NUM>. In addition, an array of infrared light emitters 310IR (which may consist of all of the infrared light emitters of the OLED display panel <NUM>) and an array of infrared light sensors 210IR (which may consist of all of the infrared light sensors of the OLED display panel <NUM>) may extend through at least a portion of the first region <NUM>, for example may not extend through the second region <NUM>, may not extend through the third region <NUM> and/or fourth region <NUM>, may only extend through the third region <NUM>, any combination thereof, or the like.

In some example embodiments, the light emitters and/or light sensors in different regions <NUM>-<NUM> of the OLED display panel <NUM> may be driven differently during a biometric recognition operation. For example, when a biometric recognition operation is performed at least partially based on a determination that a recognition target (e.g., a fingerprint) has contacted one or more pixels (Px) in the second region <NUM>, OLEDs <NUM> and visible light sensors <NUM> in one or more, or all, pixels (Px) in the second region <NUM> may be driven to emit light or detect incident light, respectively, and some or all of the light emitters and light sensors in the third and fourth regions <NUM> and <NUM> may be inactive (e.g., not driven), thereby conserving power consumption. In another example, when a biometric recognition operation is performed based on a determination that a recognition target (e.g., a face or iris) is in a proximity (e.g., field of view) of one or more light sensors of the OLED display panel <NUM>, the infrared light emitters and infrared light sensors 310IR and 210IR in the third region <NUM> may be driven to emit light or detect incident light, respectively, and some or all of the OLED light emitters and OLED light sensors in one or more of the second, third and fourth regions <NUM>, <NUM>, and <NUM> may be inactive (e.g., not driven), thereby conserving power consumption. It will be understood that example embodiments are not limited to the above examples.

In some example embodiments, one or more of the regions <NUM>-<NUM> may have various shapes and sizes. In <FIG>, for example, the second region <NUM> includes the center C of the area of the OLED display panel, which is also the center of the area of the first region <NUM>, but example embodiments are not limited thereto. Additionally, as shown in <FIG>, the second region <NUM> does not extend to any of the edges E of the OLED display panel <NUM>, but example embodiments are not limited thereto: in some example embodiments, the second region <NUM> may extend to one or more of the edges E of the OLED display panel <NUM> and/or may not extend through the center C of the OLED display panel <NUM>. In some example embodiments, including the example embodiments shown in <FIG>, the third region <NUM> may extend between at least one side of the second region <NUM> and at least one edge of the OLED display panel <NUM>. In some example embodiments, including the example embodiments shown in <FIG>, the third region <NUM> may completely surround the second region <NUM> and may be between all sides of the second region <NUM> and all edges E of the OLED display panel <NUM>, but example embodiments are not limited thereto.

As shown in <FIG>, the third and fourth regions <NUM> and <NUM> may have a same (common) ring shape and may concentrically surround the second region <NUM>, but example embodiments are not limited thereto. For example, the third and fourth regions may have different shapes and may partially surround different portions of the second region <NUM>.

It will be understood that the OLED display panel <NUM> may include different quantities of regions than what is shown in <FIG>. For example, the OLED display panel <NUM> may be limited to a single region <NUM> in which all pixels (Px) include identical configurations of OLED light emitters and visible light sensors. In another example, the OLED display panel <NUM> may include a greater quantity of separate regions, each having separate sets of pixels (Px) that include separate, respective configurations of light emitters and light sensors, than as shown in <FIG>. In another example, in some example embodiments, fourth region <NUM> may be absent as a separate region, and the third region <NUM> may extend entirely between the second region <NUM> as shown in <FIG> and the edges E of the OLED display panel <NUM>.

<FIG> is a diagram illustrating a display device that includes one or more visible light sensor embedded OLED display panels according to some example embodiments.

Referring to <FIG>, display device <NUM> includes a bus <NUM>, a processor <NUM>, a memory <NUM>, and one or more OLED display panels <NUM>. As shown, in some example embodiments, the display device <NUM> may further include one or more additional devices <NUM>. The processor <NUM>, a memory <NUM>, and one or more OLED display panels <NUM> (and where present, the one or more additional devices <NUM>) may communicate with one another through the bus <NUM>.

The one or more OLED display panels <NUM> may each be any of the visible light sensor embedded OLED display panels included in any of the example embodiments.

The processor <NUM> may include one or more instances of processing circuitry such as hardware including logic circuits; a hardware/software combination such as a processor executing software; or a combination thereof. For example, the processing circuitry more specifically may include, but is not limited to, a central processing unit (CPU), an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA), a System-on-Chip (SoC), a programmable logic unit, a microprocessor, application-specific integrated circuit (ASIC), etc. In some example embodiments, the processing circuitry may include a non-transitory computer readable storage device, for example a solid state drive (SSD), storing a program of instructions, and a processor configured to execute the program of instructions to implement the functionality of the processor <NUM> and/or one or more OLED display panels <NUM>.

Referring back to at least <FIG>, the processor <NUM> may partially or entirely implement the functionality of the OLED display panels <NUM> embedded with one or more visible light sensors <NUM> and/or <NUM>, including implementing some or all of the operations illustrated in the operation algorithm in the flowchart of <FIG>, implementing operations of biometric recognition, for example fingerprint recognition by using of the visible light sensor embedded organic light emitting diode (OLED) display panel according to some example embodiments as shown in <FIG>, and transmitting and/or receiving signals according to the timing diagram of <FIG>. Accordingly, the processor <NUM> may control display operations of the one or more OLED display panels <NUM> to display one or more images and/or may control biometric recognition operations implemented based at least in part upon at least one or more light sensors embedded in one or more OLED display panels <NUM>.

The one or more additional devices <NUM> may include one or more communication interfaces (e.g., wireless communication interface, wired interface), user interfaces (e.g., keypad, mouse, button, etc.), power supply and/or power supply interface, any combination thereof, or the like.

It will be understood that the memory <NUM> may store a program of instructions and the processor <NUM> may execute the stored program of instructions to implement functionality associated with the display device <NUM> and/or one or more OLED display panels <NUM>, including performing one or more biometric recognition operations.

The units and/or modules described herein may be implemented using hardware components and software components. For example, the hardware components may include microphones, amplifiers, band-pass filters, audio to digital convertors, and processing devices. A processing device may be implemented using one or more hardware device configured to carry out and/or execute program code by performing arithmetical, logical, and input/output operations. The processing device(s) may include a processor, a controller and an arithmetic logic unit, a digital signal processor, a microcomputer, a field programmable array, a programmable logic unit, a microprocessor or any other device capable of responding to and executing instructions in a defined manner. The processing device may run an operating system (OS) and one or more software applications that run on the OS. The processing device also may access, store, manipulate, process, and create data in response to execution of the software. For purpose of simplicity, the description of a processing device is used as singular; however, one skilled in the art will appreciated that a processing device may include multiple processing elements and multiple types of processing elements. For example, a processing device may include multiple processors or a processor and a controller. In addition, different processing configurations are possible, such a parallel processors.

While this disclosure has been described in connection with what is presently considered to be practical example embodiments, it is to be understood that the inventive concepts are not limited to the disclosed example embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claim 1:
An OLED display panel (<NUM>), comprising:
a substrate (<NUM>);
a driver stack (<NUM>) on the substrate, the driver stack (<NUM>) including transistor arrays (120a, 120b, 120c);
a visible light sensor stack (<NUM>), on the driver stack; and
an emitter stack (<NUM>) on the visible light sensor stack, the emitter stack comprising an OLED light emitter (<NUM>) on the substrate, the OLED light emitter configured to emit light;
wherein the visible light sensor stack (<NUM>) comprises a visible light sensor (<NUM>) on the substrate, the visible light sensor configured to detect at least a portion of the emitted light based on reflection of the portion of the emitted light from a recognition target,
wherein the visible light sensor is between the substrate and a non-light emitting region that is adjacent to the OLED light emitter such that the visible light sensor is vertically aligned with the non-light emitting region in a vertical direction extending perpendicular to the upper surface of the substrate, and
wherein the OLED light emitter includes a plurality of sub-pixels (<NUM>), including a red OLED sub-pixel (310R), a green OLED sub-pixel (<NUM>), and a blue OLED sub-pixel (310B),
and characterized in that visible light sensor is partially overlapped with at least one OLED sub-pixel in the vertical direction.