Display device and method of driving a display device

Abstract

A display device and a method of driving the display device, the display device including a first display panel for displaying a first image, a fingerprint sensor disposed on one surface of the first display panel and detecting light passing through the first display panel, and a first light transmission control unit disposed between the first display panel and the fingerprint sensor, the first light transmission control unit for controlling transmission of light.

Description

Technical Field

[0001] The present invention relates to a display device and a method for driving the display device. Background Technology

[0002] With the development of information technology, the demand for display devices for displaying images has increased in various forms. For example, display devices are used in various mobile devices, computers, and home appliances, such as smartphones, smartwatches, digital cameras, tablet computers, laptop computers, navigators, and smart TVs.

[0003] Recently, flexible, foldable or bendable display devices have been applied to small electronic devices such as smartphones and tablet PCs to improve portability. A foldable display device may include a first display panel that displays an image forward when folded and a second display panel that displays an image backward when unfolded. Therefore, a foldable display device can be a double-sided display device that displays images in both directions.

[0004] The foldable display device may also include a fingerprint sensor for authenticating a user's fingerprint as biometric information to protect privacy. It is anticipated that the foldable display device will be able to detect fingerprints of fingers touching the first display panel and also fingerprints of fingers touching the second display panel. In this case, manufacturing costs increase when the fingerprint sensor is attached to each of the first and second display panels of the foldable display device. Summary of the Invention

[0005] One aspect of the present invention is to provide a display device that can reduce manufacturing costs by using a fingerprint sensor to identify fingerprints touching a first display panel and fingerprints touching a second display panel, the fingerprint sensor being disposed between the first display panel that displays an image forward and the second display panel that displays an image backward.

[0006] Another aspect of the present invention is to provide a method for driving a display device that can reduce manufacturing costs by attaching a fingerprint sensor between a first display panel and a second display panel, wherein the first display panel displays an image in a frontal direction and the second display panel displays an image in a rearal direction.

[0007] A display device includes: a first display panel for displaying a first image; a fingerprint sensor disposed on a surface of the first display panel, the fingerprint sensor detecting light passing through the first display panel; and a first light transmission control unit disposed between the first display panel and the fingerprint sensor, the first light transmission control unit being used to control the transmission of light.

[0008] The first light transmission control unit may include: a first substrate and a second substrate facing each other; a first electrode disposed on a surface of the first substrate; a second electrode disposed on a surface of the second substrate facing the first substrate; and a light transmission control layer disposed between the first electrode and the second electrode.

[0009] The light transmission control layer may include: an electrochromic layer disposed on a surface of the second electrode facing the first electrode, and the electrochromic layer being configured to change color according to a redox reaction by applying a first driving voltage to the first electrode and a second driving voltage to the second electrode; an anti-reduction layer disposed on a surface of the first electrode facing the second electrode and positioned between the first electrode and the electrochromic layer, the anti-reduction layer being used to assist the redox reaction of the electrochromic layer; and an electrolyte layer disposed between the electrochromic layer and the anti-reduction layer, the electrolyte layer being used to provide cations and anions to induce the redox reaction in the electrochromic layer and the anti-reduction layer.

[0010] When the first driving voltage is positive and the second driving voltage is negative, the electrochromic layer can be in a light-blocking mode, in which light passing through the first display panel and incident on the fingerprint sensor is blocked.

[0011] When the first driving voltage is negative and the second driving voltage is positive, the electrochromic layer can be in a light transmission mode, in which light passing through the first display panel and incident on the fingerprint sensor is transmitted.

[0012] The light transmission control layer may include a liquid crystal layer containing liquid crystal molecules.

[0013] When an electric field is applied to the first electrode and the second electrode, the liquid crystal layer can be in a light-blocking mode, in which light passing through the first display panel and incident on the fingerprint sensor is blocked.

[0014] When no electric field is applied to the first electrode and the second electrode, the liquid crystal layer can be in a light transmission mode, in which light passing through the first display panel and incident on the fingerprint sensor is transmitted.

[0015] The display device may further include: a second display panel for displaying a second image; and a second light transmission control unit disposed between the second display panel and the fingerprint sensor, wherein the second light transmission control unit is used to control the transmission of light.

[0016] When a touch event occurs on the first display panel, the first light transmission control unit can be in a light transmission mode for transmitting light, so that light passing through the first display panel is incident on the fingerprint sensor, and the second light transmission control unit can be in a light blocking mode for blocking light.

[0017] When a touch event occurs on the second display panel, the second light transmission control unit can be in a light transmission mode for transmitting light, so that light passing through the second display panel is incident on the fingerprint sensor, and the first light transmission control unit can be in a light blocking mode for blocking light.

[0018] The display device may further include: a first light guide unit disposed between the first display panel and the first light transmission control unit, the first light guide unit being used to provide light passing through the first display panel to the light sensing element of the fingerprint sensor; and a second light guide unit disposed between the second display panel and the second light transmission control unit, the second light guide unit being used to provide light passing through the second display panel to the light sensing element of the fingerprint sensor.

[0019] The display device may further include: a first light guide unit disposed between the first light transmission control unit and the fingerprint sensor, the first light guide unit being used to provide light passing through the first display panel to the photosensitive element of the fingerprint sensor; and a second light guide unit disposed between the second light transmission control unit and the fingerprint sensor, the second light guide unit being used to provide light passing through the second display panel to the photosensitive element of the fingerprint sensor.

[0020] A display device includes: a first display panel; a second display panel disposed on one surface of the first display panel; a fingerprint sensor disposed between the first display panel and the second display panel; a first light guide unit disposed between the first display panel and the fingerprint sensor, and the first light guide unit provides light passing through the first display panel to a photosensitive element of the fingerprint sensor; and a second light guide unit disposed between the second display panel and the fingerprint sensor, and the second light guide unit provides light passing through the second display panel to the photosensitive element of the fingerprint sensor.

[0021] Each of the first light guiding unit and the second light guiding unit may include any one of a lens array, a collimator, and a light blocking layer. The lens array includes multiple lenses, the collimator includes a light transmission portion that transmits light and a light blocking portion that blocks light, and the light blocking layer includes a light transmission pin hole.

[0022] The first light guiding unit may include a lens array, the lens array including multiple lenses, and the second light guiding unit may include a collimator or a light blocking layer, the collimator including a light transmission portion that transmits light and a light blocking portion that blocks light, and the light blocking layer including a pinhole for transmitting light.

[0023] The first light guiding unit may include a collimator, which includes a light transmission portion that transmits light and a light blocking portion that blocks light. The second light guiding unit may include a lens array or a light blocking layer, where the lens array includes multiple lenses and the light blocking layer includes pinholes that transmit light.

[0024] The first light guiding unit may include a light blocking layer, the light blocking layer including a light-transmitting pin hole, and the second light guiding unit may include a lens array or a collimator, the lens array including a plurality of lenses, and the collimator including a light-transmitting portion that transmits light and a light-blocking portion that blocks light.

[0025] The display device may further include: a first light transmission control unit disposed between the first display panel and the fingerprint sensor and controlling the transmission of light; and a second light transmission control unit disposed between the second display panel and the fingerprint sensor and controlling the transmission of light.

[0026] A method for driving a display device may include: determining whether a touch event occurs in a first display panel and a second display panel disposed on a surface of the first display panel; when the touch event occurs in the first display panel, configuring a first light transmission control unit disposed between the first display panel and a fingerprint sensor in a light transmission mode for transmitting light, such that light passing through the first display panel is incident on the fingerprint sensor; when the touch event occurs in the first display panel, configuring a second light transmission control unit disposed between the second display panel and the fingerprint sensor in a light blocking mode for blocking light; when the touch event occurs in the second display panel, configuring the second light transmission control unit in a light transmission mode for transmitting light, such that light passing through the second display panel is incident on the fingerprint sensor; and when the touch event occurs in the second display panel, configuring the first light transmission control unit in a light blocking mode for blocking light.

[0027] A display device may include: a first display panel that is not bent or folded, the first display panel being used to display a first image in the front direction of the display device; a second display panel that is bent or foldable, the second display panel being attached to the first display panel and displaying a second image in the rear direction of the display device; and a fingerprint sensor disposed between the first display panel and the second display panel, the fingerprint sensor detecting light passing through the first display panel or light passing through the second display panel.

[0028] The display device may further include: a first light transmission control unit disposed between the first display panel and the fingerprint sensor; and a second light transmission control unit disposed between the second display panel and the fingerprint sensor, wherein, when a touch event occurs in the first display panel, the first light transmission control unit is in a light transmission mode for transmitting light, such that light passing through the first display panel is incident on the fingerprint sensor, and the second light transmission control unit is in a light blocking mode for blocking light; and when a touch event occurs in the second display panel, the second light transmission control unit is in a light transmission mode for transmitting light, such that light passing through the second display panel is incident on the fingerprint sensor, and the first light transmission control unit is in a light blocking mode for blocking light. Attached Figure Description

[0029] The above and other features of the present invention will become more apparent from the detailed description of embodiments of the invention with reference to the accompanying drawings, in which:

[0030] Figure 1 This is a perspective view showing the folded state of a display device according to an embodiment of the concept of the present invention;

[0031] Figure 2 This is a perspective view showing the unfolded state of a display device according to an embodiment of the concept of the present invention;

[0032] Figure 3 This is a cross-sectional view showing the folded state of a display device according to an embodiment of the present invention;

[0033] Figure 4 This is a cross-sectional view showing the unfolded state of a display device according to an embodiment of the concept of the present invention;

[0034] Figure 5 It is shown Figure 3 and Figure 4 A cross-sectional view of an example of the first display area of ​​the display panel;

[0035] Figure 6 It is shown Figure 3 and Figure 4A cross-sectional view of an example of a first light transmission control unit, a second light transmission control unit, and a fingerprint sensor;

[0036] Figure 7 It is shown Figure 6 A cross-sectional view of an example of the first optical transmission control unit;

[0037] Figure 8 It is shown Figure 6 A cross-sectional view of another example of the first optical transmission control unit;

[0038] Figure 9 It is shown Figure 3 and Figure 4 A cross-sectional view of another example of the first light transmission control unit, the second light transmission control unit, and the fingerprint sensor;

[0039] Figure 10 It is shown Figure 3 and Figure 4 A cross-sectional view of another example of the first light transmission control unit, the second light transmission control unit, and the fingerprint sensor;

[0040] Figure 11 It is shown Figure 3 and Figure 4 A cross-sectional view of another example of the first light transmission control unit, the second light transmission control unit, and the fingerprint sensor;

[0041] Figure 12 It is shown Figure 3 and Figure 4 A cross-sectional view of another example of the first light transmission control unit, the second light transmission control unit, and the fingerprint sensor;

[0042] Figure 13 It is shown Figure 3 and Figure 4 A cross-sectional view of another example of the first light transmission control unit, the second light transmission control unit, and the fingerprint sensor;

[0043] Figure 14 It is shown Figure 3 and Figure 4 A cross-sectional view of another example of the first light transmission control unit, the second light transmission control unit, and the fingerprint sensor;

[0044] Figure 15 It is shown Figure 3 and Figure 4 A cross-sectional view of another example of the first light transmission control unit, the second light transmission control unit, and the fingerprint sensor;

[0045] Figure 16 It is shown Figure 3 and Figure 4A cross-sectional view of another example of the first light transmission control unit, the second light transmission control unit, and the fingerprint sensor;

[0046] Figure 17 It is shown Figure 3 and Figure 4 A cross-sectional view of another example of the first light transmission control unit, the second light transmission control unit, and the fingerprint sensor;

[0047] Figure 18 It is shown Figure 3 and Figure 4 A cross-sectional view of another example of the first light transmission control unit, the second light transmission control unit, and the fingerprint sensor;

[0048] Figure 19 It is shown Figure 3 and Figure 4 A cross-sectional view of another example of the first light transmission control unit, the second light transmission control unit, and the fingerprint sensor;

[0049] Figure 20 and Figure 21 This is a perspective view illustrating a display device according to an embodiment of the concept of the present invention;

[0050] Figure 22A and Figure 22B This is a cross-sectional view illustrating an embodiment of a display device according to the present invention; and

[0051] Figure 23 This is a flowchart illustrating a method for driving a display device according to an embodiment of the present invention.

[0052] because Figures 1 to 23 The accompanying drawings are for illustrative purposes only, and therefore the elements in the drawings are not necessarily drawn to scale. For example, some elements may be enlarged or exaggerated for clarity. Detailed Implementation

[0053] In the following description, embodiments of the inventive concept will be described more fully with reference to the accompanying drawings. Throughout the specification and drawings, the same reference numerals may denote the same elements.

[0054] It will be understood that when a component, such as a membrane, region, layer, or element, is referred to as being "on," "connected to," "coupled to," or "adjacent to" another component, the component may be directly on, directly connected to, directly coupled to, or directly adjacent to the other component, or there may be intermediary components. It will also be understood that when a component is referred to as being "between" two components, the component may be the only component between the two components, or there may be one or more intermediary components. It will also be understood that when a component is referred to as "covering" another component, the component may be the only component covering the other component, or one or more intermediary components may also cover the other component. Other terms used to describe relationships between elements can be interpreted in the same way.

[0055] It will be further understood that, unless the context explicitly indicates otherwise, the description of a feature or aspect within each embodiment can be used for other similar features or aspects in other embodiments. Therefore, it is anticipated that all features and structures described herein can be mixed and matched in any desired manner.

[0056] As used herein, unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” are also intended to include the plural forms.

[0057] For ease of description, spatial relative terms such as “below,” “lower,” “above,” and “upper” may be used herein to describe the relationship between one element or feature and another element (or feature) or feature (or feature) as shown in the accompanying drawings. It will be understood that, in addition to the orientation depicted in the drawings, the spatial relative terms are also intended to cover different orientations of the device during use or operation. For example, if the device is flipped in the drawings, an element described as “below” other elements or features would subsequently be oriented “above” other elements or features. Thus, the exemplary term “below” can encompass both above and below orientations.

[0058] Given the measurements discussed and the errors associated with the measurement of a particular quantity (i.e., the limitations of the measurement system), the term “approximately” as used herein includes stated values ​​and means within an acceptable range of deviation from a particular value as determined by one of ordinary skill in the art. For example, “approximately” may mean within one or more standard deviations, or within ±30%, ±20%, ±10%, or ±5% of the stated value.

[0059] Figure 1 This is a perspective view showing the folded state of a display device according to an embodiment of the present invention, and Figure 2 This is a perspective view showing the unfolded state of a display device according to an embodiment of the present invention.

[0060] Reference Figure 1 and Figure 2 According to an embodiment of the present invention, the display device 10 includes a first display panel 110 having a first display area DA1 and a second display panel 120 having a second display area DA2. While the first display panel 110 is not bent or folded, the second display panel 120 can be bent or folded. That is, the display device 10 can be a foldable display device. Figure 1 As shown, the first display area DA1 of the first display panel 110 faces the front of the display device 10, but as... Figure 2 As shown, the second display area DA2 of the second display panel 120 can face the rear of the display device 10 in the unfolded state.

[0061] The first display panel 110 may have a rectangular shape and may have a short side in a first direction (X-axis direction) and a long side in a second direction (Y-axis direction). The angle where the short side in the first direction (X-axis direction) intersects the long side in the second direction (Y-axis direction) may be formed into a rounded shape with a predetermined curvature or a right angle shape. In addition to a rectangular shape, the planar shape of the first display panel 110 may also be formed into another polygonal shape (e.g., a square shape, a triangular shape, or other shapes with more than four sides), a circular shape, or an elliptical shape.

[0062] The first display panel 110 includes a first display area DA1 and a first non-display area NDA1. The first display area DA1 is an area in which pixels are arranged to display an image. The first non-display area NDA1 is an area in which no image is displayed because no pixels are arranged. The first non-display area NDA1 may be disposed around the first display area DA1. For example, the first non-display area NDA1 may be disposed around the first display area DA1.

[0063] The second display panel 120 may include a first non-foldable region NFA1, a second non-foldable region NFA2, and a foldable region FA. The first non-foldable region NFA1 may extend from one side of the foldable region FA, and the second non-foldable region NFA2 may extend from the other side of the foldable region FA. For example, the surface of the second display region DA2, together with the surface of the second non-display region NDA2, may include the display surfaces of the first non-foldable region NFA1, the foldable region FA, and the second non-foldable region NFA2. The second display panel 120 may not be bent or folded in the first non-foldable region NFA1 and the second non-foldable region NFA2. The areas of the first non-foldable region NFA1 and the second non-foldable region NFA2 may be substantially the same, but the inventive concept is not limited thereto.

[0064] The second display panel 120 can be bent or folded within the folding region FA. To facilitate bending or folding of the second display panel 120 within the folding region FA, a hinge can be provided on the lower surface of the second display panel 120 within the folding region FA. For example, the first non-folding region NFA1 and the second non-folding region NFA2 can each have a flat surface and can remain unfolded or bent, while the folding region FA can have a flat surface positioned on the same plane as the surfaces of the first non-folding region NFA1 and the second non-folding region NFA2 in their unfolded state. However, the folding region FA can also be folded or bent to have a curved surface. The area of ​​the folding region FA can be smaller than the area of ​​the first non-folding region NFA1 or the area of ​​the second non-folding region NFA2, but the inventive concept is not limited thereto.

[0065] The second display panel 120 includes a second display area DA2 and a second non-display area NDA2. The second display area DA2 is an area in which pixels are arranged to display an image. The second non-display area NDA2 is an area where no image is displayed because no pixels are arranged. The second non-display area NDA2 may be disposed around the second display area DA2. For example, the second non-display area NDA2 may be disposed around the second display area DA2. The second display panel 120 is folded inward such that the second display area DA2 of the first non-folded area NFA1 and the second display area DA2 of the second non-folded area NFA2 face each other. Figure 2 The diagram illustrates a folded region FA, but the inventive concept is not limited thereto. For example, in embodiments of the inventive concept, the display device 10 may be a multi-fold display device comprising multiple folded regions. Some of the folded regions may fold inward, and other folded regions may fold outward.

[0066] In both the folded and unfolded states, the second display panel 120 can have a rectangular planar shape. For example, in the folded state, the second display panel 120 can have a rectangular planar shape having a short side in a first direction (X-axis direction) and a long side in a second direction (Y-axis direction). Furthermore, in the unfolded state, the second display panel 120 can have a rectangular planar shape having a long side in the first direction (X-axis direction) and a short side in the second direction (Y-axis direction). In both the folded and unfolded states, the planar shape of the second display panel 120 is not limited to a rectangle, and the second display panel 120 can be formed into a polygon other than a rectangle (e.g., a square, triangle, or other shape with more than four sides), a circle, or an ellipse.

[0067] When the second display panel 120 is folded, the first display area DA1 of the first display panel 110 includes a first fingerprint sensing area FSA1. The first fingerprint sensing area FSA1 indicates that a fingerprint sensor is disposed therein. Figure 3 The region of 400 (in the example). Figure 1 As shown, the first fingerprint sensing area FSA1 may be a portion of the first display area DA1. Alternatively, the first fingerprint sensing area FSA1 may be the entire area of ​​the first display area DA1, and in this case, the first fingerprint sensing area FSA1 may be substantially the same as or substantially overlap with the first display area DA1. Additionally, in this case, as indicated by the first fingerprint sensing area FSA1, the fingerprint sensor 400 (see...) Figure 3 It can be set in the entire area of ​​the first display area DA1.

[0068] When the second display panel 120 is unfolded, the second display area DA2 of the second display panel 120 includes a second fingerprint sensing area FSA2. The second fingerprint sensing area FSA2 indicates that a fingerprint sensor is disposed therein. Figure 4 The region of 400 (in the example). Figure 2 As shown, the second fingerprint sensing area FSA2 may be a portion of the second display area DA2. Alternatively, the second fingerprint sensing area FSA2 may be the entire area of ​​the second display area DA2, and in this case, the second fingerprint sensing area FSA2 may be substantially the same as or substantially overlap with the second display area DA2. Additionally, in this case, as indicated by the second fingerprint sensing area FSA2, the fingerprint sensor 400 (see...) Figure 4 It can be set in the entire area of ​​the second display area DA2.

[0069] like Figure 1 and Figure 2 As shown, when the second display panel 120 is folded, the display device 10 can display a first image in the front direction using the first display panel 110. Furthermore, when the second display panel 120 is unfolded, the display device 10 can display a second image in the rear direction using the second display panel 120. When the second display panel 120 is unfolded, the first display panel 110 can display the first image in the front direction, or it can display no image. For example, the display device 10 can display one or more images on its front and rear surfaces (i.e., both surfaces of the display device 10).

[0070] Figure 3 This is a cross-sectional view showing the folded state of a display device according to an embodiment of the present invention, and Figure 4 This is a cross-sectional view showing the unfolded state of a display device according to an embodiment of the present invention. Figure 3 It is along Figure 1 The cross-sectional view taken by line I-I', and Figure 4 It is along Figure 2 The cross-sectional view taken from line II-II'. For ease of explanation, Figure 4 The configuration is shown above in an inverted top-bottom arrangement.

[0071] Reference Figure 3 and Figure 4 In addition to the first display panel 110 and the second display panel 120, the display device 10 also includes a first cover window 130, a second cover window 140, an adhesive member 150, a first light transmission control unit 200, a second light transmission control unit 300, and a fingerprint sensor 400.

[0072] A first cover window 130 may be disposed on the first display panel 110 to cover the front surface of the first display panel 110. Therefore, the first cover window 130 can protect the front surface of the first display panel 110. The front surface of the first display panel 110 refers to the display surface on which images are displayed.

[0073] The second cover window 140 can be disposed below the second display panel 120 to cover the rear surface of the second display panel 120. Therefore, the second cover window 140 can protect the rear surface of the second display panel 120. The rear surface of the second display panel 120 refers to the display surface on which images are displayed.

[0074] The second cover window 140 can be bent or folded. Therefore, in the folded area FA, the second cover window 140 can be folded together with the second display panel 120.

[0075] Each of the first cover window 130 and the second cover window 140 may be made of a transparent insulating material and may be glass, quartz, or plastic. For example, each of the first cover window 130 and the second cover window 140 may be ultra-thin glass (UTG) having a thickness of about 0.1 mm or less. Alternatively, each of the first cover window 130 and the second cover window 140 may be a transparent polyimide film.

[0076] An adhesive member 150 may be disposed between the first display panel 110 and the second display panel 120, for example, between the first non-folded area NFA1 of the first display panel 110 and the second display panel 120. The adhesive member 150 may be disposed at the edge of the first display panel 110 and the edge of the first non-folded area NFA1. For example, the adhesive member 150 may overlap with the first non-display area NDA1 of the first display panel 110 in the third direction (Z-axis direction). Additionally, the adhesive member 150 may overlap with the second non-display area NDA2 (see...). Figure 2A portion of the first non-folded region NFA1 and the second display region DA2 (see Figure 2 The first display panel 110 overlaps with a portion of the first non-folded region NFA1 adjacent to the folded region FA of the second display panel 120. The front surface of the adhesive member 150 may be attached to the rear surface of the first display panel 110, and the rear surface of the adhesive member 150 may be attached to the front surface of the second display panel 120. The first display panel 110 and the second display panel 120 may be attached to each other via the adhesive member 150. The adhesive member 150 may be a pressure-sensitive adhesive. Alternatively, the adhesive member 150 may comprise a thermosetting resin or a photocurable resin.

[0077] A fingerprint sensor 400 can be disposed between a first display panel 110 and a second display panel 120, and can sense light reflected from the fingerprint of a finger located in a first fingerprint sensing area FSA1 of the first display panel 110. For example, when finger F touches the first fingerprint sensing area FSA1 of the first display panel 110, the first display panel 110 can output predetermined light. The light output from the first display panel 110 can be reflected from the ridges and valleys of the fingerprint of finger F. In this case, the amount of light reflected from the ridges of the fingerprint of finger F may be different from the amount of light reflected from the valleys of the fingerprint of finger F. A fingerprint driving circuit electrically connected to the fingerprint sensor 400 can determine whether the light reflected from the fingerprint of finger F is reflected from the ridges or valleys of the fingerprint of finger F based on the amount of light incident on the sensor pixels of the fingerprint sensor 400. For example, the fingerprint sensor 400 disposed between the first display panel 110 and the second display panel 120 can detect light passing through the first display panel 110, which may contain fingerprint information. Therefore, the display device 10 can sense the fingerprint of the finger F that touches the first fingerprint sensing area FSA1 of the first display panel 110.

[0078] The fingerprint sensor 400 can also sense light reflected from the fingerprint of finger F located in the second fingerprint sensing area FSA2 of the second display panel 120. For example, when finger F touches the second fingerprint sensing area FSA2 of the second display panel 120, the second display panel 120 can output predetermined light. The light output from the second display panel 120 can be reflected from the ridges and valleys of the fingerprint of finger F. In this case, the amount of light reflected from the ridges of the fingerprint of finger F may be different from the amount of light reflected from the valleys of the fingerprint of finger F. The fingerprint driving circuit electrically connected to the fingerprint sensor 400 can determine whether the light reflected from the fingerprint of finger F is reflected from the ridges or the valleys of the fingerprint of finger F based on the amount of light incident on the sensor pixels of the fingerprint sensor 400. For example, the fingerprint sensor 400 disposed between the first display panel 110 and the second display panel 120 can detect light passing through the second display panel 120, which may contain fingerprint information. Therefore, the display device 10 can sense the fingerprint of finger F that touches the second fingerprint sensing area FSA2 of the second display panel 120. Therefore, when finger F touches the first fingerprint sensing area FSA1 of the first display panel 110, the fingerprint sensor 400 disposed between the first display panel 110 and the second display panel 120 can detect the light passing through the first display panel 110, and when finger F touches the second fingerprint sensing area FSA2 of the second display panel 120, the same fingerprint sensor 400 disposed between the first display panel 110 and the second display panel 120 can detect the light passing through the second display panel 120.

[0079] A first light transmission control unit 200 may be disposed between the first display panel 110 and the fingerprint sensor 400. The first light transmission control unit 200 controls the light passing through the first display panel 110 and incident on the fingerprint sensor 400, and can transmit most of the incident light in light transmission mode. For example, the transmittance of the first light transmission control unit 200 in light transmission mode may be approximately 60% or greater. Furthermore, the first light transmission control unit 200 can block most of the incident light in light blocking mode. For example, the transmittance of the first light transmission control unit 200 in light blocking mode may be approximately 40% or less.

[0080] The second light transmission control unit 300 can be disposed between the second display panel 120 and the fingerprint sensor 400. The second light transmission control unit 300 controls the light passing through the second display panel 120 and incident on the fingerprint sensor 400, and can transmit most of the incident light in light transmission mode. For example, the transmittance of the second light transmission control unit 300 in light transmission mode can be approximately 60% or greater. Furthermore, the second light transmission control unit 300 can block most of the incident light in light blocking mode. For example, the transmittance of the second light transmission control unit 300 in light blocking mode can be approximately 40% or less.

[0081] like Figure 6 and Figures 9 to 19 As shown, a first light guide unit 510 can be disposed on one surface of the first light transmission control unit 200, and a second light guide unit 520 can be disposed on one surface of the second light transmission control unit 300. Therefore, the first light guide unit 510 can be disposed between the first display panel 110 and the fingerprint sensor 400, and the second light guide unit 520 can be disposed between the second display panel 120 and the fingerprint sensor 400. (See below for further details.) Figure 6 and Figures 9 to 19 Details of the first light guide unit 510 and the second light guide unit 520 are described below.

[0082] like Figure 3 and Figure 4As shown, a fingerprint sensor 400 is disposed between a first display panel 110 displaying a first image in the front direction and a second display panel 120 displaying a second image in the back direction. Furthermore, a first light transmission control unit 200 is disposed between the first display panel 110 and the fingerprint sensor 400 to control the light passing through the first display panel 110 incident on the fingerprint sensor 400. For example, the first light transmission control unit 200 can switch between a light transmission mode and a light blocking mode to control the light passing through the first display panel 110. Furthermore, a second light transmission control unit 300 is disposed between the second display panel 120 and the fingerprint sensor 400 to control the light passing through the second display panel 120 incident on the fingerprint sensor 400. For example, the second light transmission control unit 300 can switch between a light transmission mode and a light blocking mode to control the light passing through the second display panel 120. Therefore, when a user's finger F touches the first display panel 110, the first light transmission control unit 200 can be implemented in light transmission mode, and the second light transmission control unit 300 can be implemented in light blocking mode, thereby sensing the light reflected from the fingerprint of finger F. Furthermore, when a user's finger F touches the second display panel 120, the first light transmission control unit 200 can be configured in a light-blocking mode, and the second light transmission control unit 300 can be configured in a light-transmitting mode, thereby sensing the light reflected from the fingerprint of finger F. Therefore, the display device 10 can use a single fingerprint sensor 400 to sense the fingerprints of both the finger F touching the first display panel 110 and the finger F touching the second display panel 120. Thus, since it is not necessary to attach a fingerprint sensor to each display panel, the manufacturing cost of the display device 10 can be reduced. In other words, using one fingerprint sensor instead of two reduces manufacturing costs.

[0083] Although Figure 3 and Figure 4 The diagram shows the first light transmission control unit 200 and the fingerprint sensor 400 in direct contact with each other, the second light transmission control unit 300 and the fingerprint sensor 400 in direct contact with each other, the first display panel 110 and the first light transmission control unit 200 in direct contact with each other, and the second display panel 120 and the second light transmission control unit 300 in direct contact with each other. However, the inventive concept is not limited to this. For example, adhesive members can be disposed between the first light transmission control unit 200 and the fingerprint sensor 400, between the second light transmission control unit 300 and the fingerprint sensor 400, between the first display panel 110 and the first light transmission control unit 200, and between the second display panel 120 and the second light transmission control unit 300. In addition to adhesive members, other components can also be disposed. The adhesive members can be transparent.

[0084] Figure 5 It is shown Figure 3 and Figure 4 A cross-sectional view of an example of the first display area of ​​the display panel.

[0085] Although Figure 5 The illustration shows a first display panel 110 as an organic light-emitting display panel that includes organic light-emitting diodes (OLEDs) as light-emitting elements; however, the invention is not limited to this. For example, the first display panel 110 may be a quantum dot light-emitting display panel that includes a quantum dot layer as a light-emitting layer, an inorganic light-emitting display panel that includes inorganic semiconductor elements as light-emitting elements, or a micron or nanon light-emitting display panel that includes micron or nano LEDs (micron LEDs or nano LEDs) as light-emitting elements. The quantum dot layer of the quantum dot light-emitting display panel may include quantum dots and quantum rods, etc. Quantum dots and quantum rods may be small semiconductor particles with a size of a few nanometers.

[0086] The first display panel 110 includes a first substrate SUB1 and a thin film transistor layer (TFTL), a light-emitting element layer (EML), an encapsulation layer (TFEL), and a touch sensing layer (SENL) sequentially disposed on the first substrate SUB1.

[0087] The thin-film transistor layer (TFTL) includes a first transistor ST1 formed as a thin-film transistor, a capacitor electrode CAE, a first anode connection electrode ANDE1, a second anode connection electrode ANDE2, a first buffer layer BF1, a first gate insulating layer GI1, a first interlayer insulating layer 141, a second interlayer insulating layer 142, a first planarization layer 160, and a second planarization layer 180.

[0088] The first substrate SUB1 can be made of an insulating material such as glass or polymer resin. For example, when the first substrate SUB1 is a flexible substrate that can be bent, folded or rolled, the first substrate SUB1 can be made of polyimide.

[0089] The first buffer layer BF1 protects the first transistor ST1 of the thin-film transistor layer (TFTL) and the light-emitting layer 172 of the light-emitting element layer (EML) from moisture permeating from the first substrate (SUB1), which is susceptible to moisture permeation. The first buffer layer BF1 may comprise inorganic materials such as oxides or nitrides, organic materials, or a combination of organic and inorganic materials, and may have a single-layer or multi-layer structure comprising both inorganic and organic materials. For example, the first buffer layer BF1 may be formed from an inorganic layer such as a silicon nitride (Si3N4) layer, a silicon oxynitride (SiON) layer, a silicon oxide (SiO2) layer, a titanium oxide (TiO2) layer, a tantalum oxide (Ta2O5) layer, a hafnium oxide (HfO2) layer, or an aluminum oxide (Al2O3) layer.

[0090] The first transistor ST1 may be disposed on the first buffer layer BF1, and may include a first active layer ACT1, a first gate electrode G1, a first source electrode S1, and a first drain electrode D1.

[0091] The first active layer ACT1, the first source electrode S1, and the first drain electrode D1 of the first transistor ST1 can be disposed on the first buffer layer BF1. The first active layer ACT1 of the first transistor ST1 includes polycrystalline silicon (p-Si), single-crystal silicon (Si), low-temperature polycrystalline silicon (p-Si), amorphous silicon (a-Si:H), or oxide semiconductor. In embodiments of the present invention, the first active layer ACT1 of the first transistor ST1 may include an oxide of at least one material selected from, for example, indium (In), gallium (Ga), tin (Sn), zirconium (Zr), vanadium (V), hafnium (Hf), cadmium (Cd), germanium (Ge), chromium (Cr), titanium (Ti), and zinc (Zn). The first active layer ACT1, which overlaps with the first gate electrode G1 in a third direction (Z-axis direction) that is the thickness direction of the first substrate SUB1, can be defined as a channel region. The first source electrode S1 and the first drain electrode D1 are regions that do not overlap with the first gate electrode G1 in the third direction (Z-axis direction), and may include silicon (Si) semiconductor or oxide semiconductor doped with ions or impurities to be conductive.

[0092] A first gate insulating layer GI1 may be disposed on the first active layer ACT1, the first source electrode S1, and the first drain electrode D1 of the first transistor ST1. The first gate insulating layer GI1 may be formed of an inorganic layer, such as a silicon nitride (Si3N4) layer, a silicon oxynitride (SiON) layer, a silicon oxide (SiO2) layer, a titanium oxide (TiO2) layer, a tantalum oxide (Ta2O5) layer, a hafnium oxide (HfO2) layer, or an aluminum oxide (Al2O3) layer. The first gate insulating layer GI1 may have a single-layer or multi-layer structure comprising one or more of the aforementioned inorganic insulating materials.

[0093] The first gate electrode G1 of the first transistor ST1 may be disposed on the first gate insulating layer GI1 and may overlap with the first active layer ACT1 in the third direction (Z-axis direction). The first gate electrode G1 may be formed as a single layer or multiple layers including any one of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), tungsten (W) and copper (Cu) or alloys thereof.

[0094] The first interlayer insulating layer 141 can be disposed on the first gate electrode G1 of the first transistor ST1. The first interlayer insulating layer 141 can be formed of an inorganic layer, such as a silicon nitride (Si3N4) layer, a silicon oxynitride (SiON) layer, a silicon oxide (SiO2) layer, a titanium oxide (TiO2) layer, a tantalum oxide (Ta2O5) layer, a hafnium oxide (HfO2) layer, or an aluminum oxide (Al2O3) layer.

[0095] The capacitor electrode CAE can be disposed on the first interlayer insulating layer 141 and can overlap with the first gate electrode G1 of the first transistor ST1 in the third direction (Z-axis direction). Since the first interlayer insulating layer 141 has a predetermined dielectric constant, the capacitor can be formed by the capacitor electrode CAE, the first gate electrode G1, and the first interlayer insulating layer 141 disposed between the capacitor electrode CAE and the first gate electrode G1. The capacitor electrode CAE can be formed as a single layer or multiple layers including any one of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), tungsten (W), and copper (Cu), or alloys thereof.

[0096] For ease of description, Figure 5 The illustration shows a first gate electrode G1 of a first transistor ST1 overlapping with a capacitor electrode CAE to form a capacitor, but the inventive concept is not limited thereto. For example, in addition to overlapping the first gate electrode G1 of the first transistor ST1 with the capacitor electrode CAE, a capacitor can also be formed by overlapping a separate electrode with the capacitor electrode CAE. For example, the capacitor may not overlap with the first transistor ST1, and therefore, the capacitor electrode CAE can be overlapped with a separate electrode instead of the first gate electrode G1 to form a capacitor. For example, a capacitor can be formed by overlapping the gate electrodes of transistors other than the first transistor ST1 with the capacitor electrode CAE.

[0097] The second interlayer insulating layer 142 can be disposed on the capacitor electrode CAE. The second interlayer insulating layer 142 can be formed of an inorganic layer, such as a silicon nitride (Si3N4) layer, a silicon oxynitride (SiON) layer, a silicon oxide (SiO2) layer, a titanium oxide (TiO2) layer, a tantalum oxide (Ta2O5) layer, a hafnium oxide (HfO2) layer, or an aluminum oxide (Al2O3) layer.

[0098] The first anode connection electrode ANDE1 can be disposed on the second interlayer insulating layer 142, and can be connected to the first drain electrode D1 of the first transistor ST1 through a first connection contact hole ANCT1 penetrating the first gate insulating layer GI1, the first interlayer insulating layer 141, and the second interlayer insulating layer 142. The first anode connection electrode ANDE1 can be formed as a single layer or multiple layers including any one of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), tungsten (W), and copper (Cu) or alloys thereof. In embodiments of the present invention, the first anode connection electrode ANDE1 can have a multilayer structure, for example, including a Ti / Al / Ti three-layer structure.

[0099] A first planarization layer 160 for planarizing the step caused by the first transistor ST1 can be disposed on the first anode connection electrode ANDE1. For example, the first planarization layer 160 can have a flat top. When the first planarization layer 160 is to be formed, a layer can be formed, and then a chemical mechanical polishing (CMP) process can be performed on the top surface of the layer to provide a flat top surface. When the first planarization layer 160 is formed by a spin coating process, a flat top surface can be obtained by a coating and baking process without performing a chemical mechanical polishing (CMP) process. The first planarization layer 160 can be formed of an organic layer including, for example, acrylic resin, epoxy resin, phenolic resin, polyamide resin, or polyimide resin.

[0100] The second anode connection electrode ANDE2 can be disposed on the first planarization layer 160 and can be connected to the first anode connection electrode ANDE1 through the second connection contact hole ANCT2 penetrating the first planarization layer 160. The second anode connection electrode ANDE2 can be formed as a single layer or multiple layers including any one of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), tungsten (W) and copper (Cu) or alloys thereof.

[0101] The second planarization layer 180 may be disposed on the second anode connection electrode ANDE2. The second planarization layer 180 may be formed of an organic layer including, for example, acrylic resin, epoxy resin, phenolic resin, polyamide resin or polyimide resin.

[0102] Light-emitting elements (LELs) and a dam 190 can be disposed on the second planarization layer 180. Each of the light-emitting elements (LELs) includes a pixel electrode 171, a light-emitting layer 172, and a common electrode 173.

[0103] The pixel electrode 171 can be disposed on the second planarization layer 180 and can be connected to the second anode connection electrode ANDE2 through the third connection contact hole ANCT3 penetrating the second planarization layer 180.

[0104] In the top-emitting structure where light is emitted from the light-emitting layer 172 toward the common electrode 173, the pixel electrode 171 may include a metallic material with high reflectivity, such as a stacked structure of aluminum (Al) and titanium (Ti) (Ti / Al / Ti), a stacked structure of aluminum (Al) and indium tin oxide (ITO) (ITO / Al / ITO), a stacked structure of silver (Ag) and ITO (ITO / Ag / ITO), an APC alloy, or a stacked structure of APC alloy and ITO (ITO / APC / ITO). An APC alloy refers to an alloy of silver (Ag), palladium (Pd), and copper (Cu). Alternatively, the pixel electrode 171 may include a transparent conductive oxide such as indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium oxide (In2O3), indium gallium oxide (IGO), or aluminum zinc oxide (AZO).

[0105] The dam 190 can be formed on the second planarization layer 180 to divide pixel electrodes 171, thereby defining a first light-emitting region EA1, a second light-emitting region EA2, and a third light-emitting region EA3. The dam 190 can prevent arcing or similar phenomena between the pixel electrode 171 and the common electrode 173 positioned above the pixel electrode 171 by increasing the distance between their edges. The dam 190 can be formed from an organic layer including, for example, acrylic resin, epoxy resin, phenolic resin, polyamide resin, or polyimide resin.

[0106] Each of the first light-emitting region EA1, the second light-emitting region EA2, and the third light-emitting region EA3 is a region in which a pixel electrode 171, a light-emitting layer 172, and a common electrode 173 are sequentially stacked, and holes from the pixel electrode 171 and electrons from the common electrode 173 combine at the light-emitting layer 172 to emit light. The first light-emitting region EA1 can emit light of a first color, the second light-emitting region EA2 can emit light of a second color, and the third light-emitting region EA3 can emit light of a third color. Each of the first light-emitting region EA1, the second light-emitting region EA2, and the third light-emitting region EA3 can emit, for example, red light, green light, blue light, or white light.

[0107] A light-emitting layer 172 is formed on the pixel electrode 171 and the dam 190, and may include organic materials to emit light of a predetermined color. In embodiments of the present invention, the light-emitting layer 172 may include fluorescent or phosphorescent materials. For example, the light-emitting layer 172 may include a hole transport layer, an organic material layer, and an electron transport layer. Furthermore, the light-emitting layer 172 may also include a hole injection layer and an electron injection layer.

[0108] A common electrode 173 is formed on the light-emitting layer 172 and can be formed to cover the light-emitting layer 172. The common electrode 173 can be a common layer formed in the first light-emitting region EA1, the second light-emitting region EA2, and the third light-emitting region EA3. A cover layer can be formed on the common electrode 173.

[0109] In the top-emitting structure, the common electrode 173 may include a transparent conductive material (TCO) capable of transmitting light, such as indium tin oxide (ITO), zinc oxide (ZnO), indium oxide (In2O3), or indium zinc oxide (IZO), or a semi-transmissive conductive material, such as magnesium (Mg), silver (Ag), or an alloy of magnesium (Mg) and silver (Ag). When the common electrode 173 includes a semi-transmissive conductive material, the luminous efficiency can be improved through the microcavity.

[0110] The encapsulation layer TFEL can be formed on the common electrode 173 and can include at least one inorganic film to prevent oxygen or moisture from penetrating into the light-emitting element layer EML. Furthermore, the encapsulation layer TFEL can include at least one organic layer to protect the light-emitting element layer EML from foreign matter such as dust. For example, the encapsulation layer TFEL includes a first encapsulation inorganic layer TFE1, an encapsulation organic layer TFE2, and a second encapsulation inorganic layer TFE3.

[0111] A first encapsulating inorganic layer TFE1 can be disposed on the common electrode 173, an encapsulating organic layer TFE2 can be disposed on the first encapsulating inorganic layer TFE1, and a second encapsulating inorganic layer TFE3 can be disposed on the encapsulating organic layer TFE2. In embodiments of the present invention, the number of encapsulating organic layers and the number of encapsulating inorganic layers, as well as the order in which the encapsulating organic and inorganic layers are stacked, can be varied. Each of the first encapsulating inorganic layer TFE1 and the second encapsulating inorganic layer TFE3 can be formed as a plurality of layers in which one or more inorganic layers are alternately stacked, such as silicon nitride (Si3N4) layers, silicon oxynitride (SiON) layers, silicon oxide (SiO2) layers, titanium oxide (TiO2) layers, tantalum oxide (Ta2O5) layers, hafnium oxide (HfO2) layers, and aluminum oxide (Al2O3) layers. The encapsulating organic layer TFE2 can be formed of an organic material including, for example, acrylic resin, epoxy resin, phenolic resin, polyamide resin, or polyimide resin. The encapsulation organic layer TFE2 can provide a flat surface on the first encapsulation inorganic layer TFE1 and can reduce stress between contact layers.

[0112] The touch sensing layer SENL can be disposed on the encapsulation layer TFEL, and the touch sensing layer SENL can be driven by a mutual capacitance method, in which, after a driving signal is applied to the driving electrode TE, the voltage charged by the mutual capacitance is sensed by the sensing electrode RE. Since the first display panel 110 includes the touch sensing layer SENL, the display device 10 can detect touch events of a user touching the first display panel 110.

[0113] The touch sensing layer SENL includes a second buffer layer BF2, a connection electrode BE1, a first touch insulating layer TINS1, a driving electrode TE, a sensing electrode RE, and a second touch insulating layer TINS2.

[0114] The second buffer layer BF2 can be formed from an inorganic layer, such as a silicon nitride (Si3N4) layer, a silicon oxynitride (SiON) layer, a silicon oxide (SiO2) layer, a titanium oxide (TiO2) layer, a tantalum oxide (Ta2O5) layer, a hafnium oxide (HfO2) layer, or an aluminum oxide (Al2O3) layer.

[0115] The connecting electrode BE1 can be disposed on the second buffer layer BF2. The connecting electrode BE1 can be formed of, for example, a laminated structure of aluminum (Al) and titanium (Ti) (Ti / Al / Ti), a laminated structure of aluminum (Al) and ITO (ITO / Al / ITO), a laminated structure of silver (Ag) and ITO (ITO / Ag / ITO), an APC alloy, and a laminated structure of APC alloy and ITO (ITO / APC / ITO).

[0116] A first touch insulating layer TINS1 is disposed on the connecting electrode BE1. The first touch insulating layer TINS1 can be formed of an inorganic layer, such as a silicon nitride (Si3N4) layer, a silicon oxynitride (SiON) layer, a silicon oxide (SiO2) layer, a titanium oxide (TiO2) layer, a tantalum oxide (Ta2O5) layer, a hafnium oxide (HfO2) layer, or an aluminum oxide (Al2O3) layer. Alternatively, the first touch insulating layer TINS1 can be formed of an organic layer including, for example, acrylic resin, epoxy resin, phenolic resin, polyamide resin, or polyimide resin.

[0117] The driving electrode TE and the sensing electrode RE can be disposed on the first touch insulating layer TINS1. In addition to the driving electrode TE and the sensing electrode RE, dummy patterns, a first driving line, a second driving line, and a sensing line can also be arranged on the first touch insulating layer TINS1.

[0118] The driving electrode TE and the sensing electrode RE can overlap with the connecting electrode BE1 in the third direction (Z-axis direction). The driving electrode TE can be connected to the connecting electrode BE1 through a touch contact hole TCNT1 that penetrates the first touch insulating layer TINS1. Therefore, due to the connecting electrode BE1, the driving electrode TE and the sensing electrode RE can be electrically isolated at their intersection, and mutual capacitance can be formed between the driving electrode TE and the sensing electrode RE. Each of the driving electrode TE and the sensing electrode RE can be formed by, for example, a laminate of aluminum (Al) and titanium (Ti) (Ti / Al / Ti), a laminate of aluminum (Al) and ITO (ITO / Al / ITO), a laminate of silver (Ag) and ITO (ITO / Ag / ITO), an APC alloy, and a laminate of APC alloy and ITO (ITO / APC / ITO). In embodiments of the inventive concept, to prevent the user from seeing the driving electrode TE and the sensing electrode RE including the metal layer, the driving electrode TE and the sensing electrode RE including the metal layer can have a grid shape.

[0119] The second touch insulating layer TINS2 is formed on the driving electrode TE and the sensing electrode RE, and can flatten the step formed by the driving electrode TE, the sensing electrode RE and the connecting electrode BE1. The second touch insulating layer TINS2 can be formed of an organic layer including, for example, acrylic resin, epoxy resin, phenolic resin, polyamide resin or polyimide resin.

[0120] Reference Figure 1 and Figure 2 Since the second display area DA2 of the second display panel 120 can be substantially the same as the first display area DA1 of the first display panel 110, the description of the second display area DA2 of the second display panel 120 will be omitted.

[0121] Figure 6 It is shown Figure 3 and Figure 4 A cross-sectional view of an example of a first light transmission control unit, a second light transmission control unit, and a fingerprint sensor.

[0122] Reference Figure 6 The fingerprint sensor 400 may be an optical fingerprint sensor comprising a second substrate SUB2 and a light-sensing layer LDL. The light-sensing layer LDL includes sensor pixels SEPs that sense light. Each of the sensor pixels SEPs includes a second transistor ST2, a light-sensing element PD, a second gate insulating layer GI2, a first insulating layer INS1, a second insulating layer INS2, and a planarization layer PLA. For example, in an embodiment, each of the sensor pixels SEPs primarily includes a second transistor ST2 and a light-sensing element PD.

[0123] The second substrate SUB2 can be made of an insulating material such as glass or polymer resin. For example, when the second substrate SUB2 is a flexible substrate that can be bent, folded or rolled up, the second substrate SUB2 can be made of polyimide.

[0124] The second transistor ST2 can be disposed on the second substrate SUB2, and can include a second active layer ACT2, a second gate electrode G2, a second source electrode S2, and a second drain electrode D2.

[0125] The second gate electrode G2 of the second transistor ST2 can be disposed on the second substrate SUB2. The second gate electrode G2 can be formed as a single layer or multiple layers of any one of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), tungsten (W) and copper (Cu) or alloys thereof.

[0126] The second gate insulating layer GI2 can be disposed on the second gate electrode G2. The second gate insulating layer GI2 can be formed of an inorganic layer, such as a silicon nitride (Si3N4) layer, a silicon oxynitride (SiON) layer, a silicon oxide (SiO2) layer, a titanium oxide (TiO2) layer, a tantalum oxide (Ta2O5) layer, a hafnium oxide (HfO2) layer, or an aluminum oxide (Al2O3) layer.

[0127] The second active layer ACT2 of the second transistor ST2 can be disposed on the second gate insulating layer GI2. The second active layer ACT2 includes polycrystalline silicon (p-Si), single-crystal silicon (Si), low-temperature polycrystalline silicon (p-Si), amorphous silicon (a-Si:H), or an oxide semiconductor. In embodiments of the present invention, the second active layer ACT2 of the second transistor ST2 can include an oxide of at least one material selected from, for example, indium (In), gallium (Ga), tin (Sn), zirconium (Zr), vanadium (V), hafnium (Hf), cadmium (Cd), germanium (Ge), chromium (Cr), titanium (Ti), and zinc (Zn). The second active layer ACT2 can overlap with the second gate electrode G2 in a third direction (Z-axis direction) of the thickness direction of the second substrate SUB2.

[0128] The second source electrode S2 and the second drain electrode D2 of the second transistor ST2 can be disposed on the second active layer ACT2. The second source electrode S2 can be disposed on one side of the second active layer ACT2, and the second drain electrode D2 can be disposed on the other side of the second active layer ACT2.

[0129] The first insulating layer INS1 can be disposed on the second active layer ACT2, the second source electrode S2, and the second drain electrode D2. The first insulating layer INS1 can be formed of an inorganic layer, such as a silicon nitride (Si3N4) layer, a silicon oxynitride (SiON) layer, a silicon oxide (SiO2) layer, a titanium oxide (TiO2) layer, a tantalum oxide (Ta2O5) layer, a hafnium oxide (HfO2) layer, or an aluminum oxide (Al2O3) layer.

[0130] The photosensitive element PD can be disposed on the second gate insulating layer GI2. The photosensitive element PD can be as follows: Figure 6 The photodiode shown is not limited to this invention. For example, the photosensitive element PD can be formed as a phototransistor. When the photosensitive element PD is a photodiode, the photosensitive element PD may include a cathode electrode CAT, a semiconductor layer PSEM, and an anode electrode AND.

[0131] The cathode electrode CAT can be disposed on the second gate insulating layer GI2. The cathode electrode CAT can be formed of a transparent conductive material capable of transmitting light, such as indium tin oxide (ITO), zinc oxide (ZnO), indium oxide (In2O3), or indium zinc oxide (IZO).

[0132] A semiconductor layer PSEM, in which an N-type semiconductor layer NL, an I-type semiconductor layer IL, and a P-type semiconductor layer PL are sequentially stacked, can be disposed on the cathode electrode CAT. In this case, the photodiode is a PIN photodiode. When the semiconductor layer PSEM is formed as a PIN structure, the I-type semiconductor layer IL is depleted by the P-type semiconductor layer PL and the N-type semiconductor layer NL to generate an electric field in the I-type semiconductor layer IL, and holes and electrons generated by sunlight are drifted by the electric field. Therefore, holes can be collected to the anode electrode AND through the P-type semiconductor layer PL, and electrons can be collected to the cathode electrode CAT through the N-type semiconductor layer NL. For example, holes move to the anode electrode AND and electrons move to the cathode electrode CAT to generate a photocurrent.

[0133] An N-type semiconductor layer NL can be disposed on the cathode electrode CAT, an I-type semiconductor layer IL can be disposed on the N-type semiconductor layer NL, and a P-type semiconductor layer PL can be disposed on the I-type semiconductor layer IL. For example, the I-type semiconductor layer IL can be located between the N-type semiconductor layer NL and the P-type semiconductor layer PL. In this case, the P-type semiconductor layer PL can be formed by doping amorphous silicon (a-Si:H) with a P-type dopant. The I-type semiconductor layer IL can be formed from amorphous silicon germanium (a-SiGe:H) or amorphous silicon carbide (a-SiC:H). The N-type semiconductor layer NL can be formed by doping amorphous silicon germanium (a-SiGe:H) or amorphous silicon carbide (a-SiC:H) with an N-type dopant. Each of the P-type semiconductor layer PL and the N-type semiconductor layer NL can be formed to have approximately The thickness, and the type I semiconductor layer IL can be formed to have approximately up to approximately The thickness.

[0134] Instead of the PIN photodiode described above, the N-type semiconductor layer NL can be disposed on the cathode electrode CAT, the I-type semiconductor layer IL can be omitted, and the P-type semiconductor layer PL can be disposed on the N-type semiconductor layer NL. In this case, the photodiode is a PN junction photodiode, and the P-type semiconductor layer PL can be formed by doping amorphous silicon (a-Si:H) with a P-type dopant. The N-type semiconductor layer NL can be formed by doping amorphous silicon germanium (a-SiGe:H) or amorphous silicon carbide (a-SiC:H) with an N-type dopant. Each of the P-type semiconductor layer PL and the N-type semiconductor layer NL can be formed to have approximately The thickness.

[0135] The upper or lower surface of at least one of the cathode electrode CAT, the P-type semiconductor layer PL, the I-type semiconductor layer IL, and the N-type semiconductor layer NL can be textured to form a non-uniform structure, thereby improving the absorption rate of external light. Textured processing is a process of forming a non-uniform structure on the surface of a material; that is, processing the surface of the material to have the same shape as the surface of a fabric. Textured processing can be performed using photolithographic etching, anisotropic wet etching using chemical solutions, or groove formation using mechanical scribing.

[0136] The anode electrode AND can be disposed on the p-type semiconductor layer PL. The anode electrode AND can be formed of a transparent conductive material capable of transmitting light, such as indium tin oxide (ITO), zinc oxide (ZnO), indium oxide (In2O3), or indium zinc oxide (IZO). The anode electrode AND can be a common layer formed in the photosensitive layer LDL.

[0137] The planarization layer PLA can be disposed on the anode electrode AND. The planarization layer PLA can be formed from an organic layer including, for example, acrylic resin, epoxy resin, phenolic resin, polyamide resin or polyimide resin.

[0138] The first light transmission control unit 200 can be disposed on the planarization layer PLA. The second light transmission control unit 300 can be disposed below the second substrate SUB2. (See below for further details.) Figure 7 and Figure 8 The first optical transmission control unit 200 and the second optical transmission control unit 300 are described.

[0139] The first light guide unit 510 can be disposed on the first light transmission control unit 200, and can be disposed between the first light transmission control unit 200 and the first display panel 110 (see...). Figure 3 Between. The first light guide unit 510 can provide or guide light to each of the sensor pixels SEP, for example, to provide or guide light to the light sensing element PD of the fingerprint sensor 400. Figure 6 The diagram shows that the first light guiding unit 510 includes a first lens array LA1 having a plurality of first lenses LENS1.

[0140] Each of the first lenses LENS1 can be an upwardly convex lens. The first lenses LENS1 can form the upper surface of the first light guiding unit 510. The first lens array LA1 can be formed of a polymer resin or plastic capable of transmitting light.

[0141] The second light guide unit 520 can be disposed below the second light transmission control unit 300 and between the second light transmission control unit 300 and the second display panel 120. The second light guide unit 520 can provide or guide light to each of the sensor pixels SEP, for example, provide or guide light to the photosensitive element PD of the fingerprint sensor 400. Figure 6 The diagram shows that the second light guide unit 520 includes a second lens array LA2 having a plurality of second lenses LENS2.

[0142] Each of the second lenses LENS2 can be a downwardly convex lens. The second lenses LENS2 can form the lower surface of the second light guide unit 520 below the second light transmission control unit 300. The second lens array LA2 can be formed of a polymer resin or plastic capable of transmitting light.

[0143] The minimum distance between the first lens LENS1 and the photosensitive element PD can be different from the minimum distance between the second lens LENS2 and the photosensitive element PD. Therefore, the refractive index of the first lens LENS1 can be different from the refractive index of the second lens LENS2. Furthermore, the pitch PLE1 of the first lens LENS1 can be different from the pitch PLE2 of the second lens LENS2. For example, when the minimum distance between the first lens LENS1 and the photosensitive element PD is shorter than the minimum distance between the second lens LENS2 and the photosensitive element PD, the refractive index of the first lens LENS1 can be less than the refractive index of the second lens LENS2. Additionally, the pitch PLE1 of the first lens LENS1 can be less than the pitch PLE2 of the second lens LENS2. Alternatively, in embodiments of the present invention, the pitch PLE1 of the first lens LENS1 can be approximately the same as the pitch PLE2 of the second lens LENS2.

[0144] A transparent adhesive member can be disposed between the photosensitive layer LDL of the fingerprint sensor 400 and the first light transmission control unit 200, between the first light transmission control unit 200 and the first light guide unit 510, and between the first light guide unit 510 and the first display panel 110. For example, the first light guide unit 510 can be disposed on the first light transmission control unit 200, and the transparent adhesive member can be located between the first light guide unit 510 and the first light transmission control unit 200 to bond the first light guide unit 510 to the first light transmission control unit 200. Furthermore, the transparent adhesive member can be disposed between the second substrate SUB2 of the fingerprint sensor 400 and the second light transmission control unit 300, between the second light transmission control unit 300 and the second light guide unit 520, and between the second light guide unit 520 and the second display panel 120. The transparent adhesive member can be a transparent adhesive resin such as optically transparent resin (OCR) or a transparent adhesive film such as an optically transparent adhesive (OCA) film. For example, the transparent adhesive member can be a transparent adhesive film such as a pressure-sensitive adhesive (PSA) film. Figure 6 As shown, since both the cathode electrode CAT and the anode electrode AND of the photosensitive element PD are formed of transparent conductive material, the photosensitive element PD can detect both light incident from the upper part of the photosensitive layer LDL and light incident from the lower part of the photosensitive layer LDL.

[0145] The first light transmission control unit 200 is disposed on the fingerprint sensor 400, and the second light transmission control unit 300 is disposed below the fingerprint sensor 400. Therefore, in the display device 10, the first light transmission control unit 200 and the second light transmission control unit 300 can each be used to control only one of the light incident on the photosensitive element PD from the top of the photosensitive element PD and the light incident on the photosensitive element PD from the bottom of the photosensitive element PD.

[0146] Although Figure 6 The diagram shows a first light transmission control unit 200 disposed between the first light guide unit 510 and the fingerprint sensor 400, and a second light transmission control unit 300 disposed between the second light guide unit 520 and the fingerprint sensor 400; however, the inventive concept is not limited thereto. For example, as... Figure 14 As shown and will be further described later, since the first light transmission control unit 200 is disposed on the upper surface of the first light guide unit 510, the first light guide unit 510 can be disposed between the first light transmission control unit 200 and the fingerprint sensor 400. Furthermore, since the second light transmission control unit 300 is disposed on the lower surface of the second light guide unit 520, the second light guide unit 520 can be disposed between the second light transmission control unit 300 and the fingerprint sensor 400.

[0147] A light transmission filter that transmits or reflects long-wavelength light, such as infrared light, and transmits visible light can be disposed between the first light transmission control unit 200 and the fingerprint sensor 400, and between the second light transmission control unit 300 and the fingerprint sensor 400. Alternatively, the light transmission filter can be disposed between the first light transmission control unit 200 and the first light guide unit 510, and between the second light transmission control unit 300 and the second light guide unit 520. Since long-wavelength light, such as infrared light, is not reflected from the finger, it may be noisy light. Therefore, the light transmission filter can be used to prevent or reduce the incidence of long-wavelength light, such as infrared light, on the photosensitive element PD. By reducing noisy light, the performance of the photosensitive element PD can be enhanced.

[0148] Figure 7 It is shown Figure 6 A cross-sectional view of an example of the first optical transmission control unit.

[0149] Reference Figure 7 The first light transmission control unit 200 can transmit most of the incident light in light transmission mode and block most of the incident light in light blocking mode. For example, the transmittance of the first light transmission control unit 200 in light transmission mode can be about 60% or more, and the transmittance of the first light transmission control unit 200 in light blocking mode can be about 40% or less.

[0150] The first light transmission control unit 200 includes a first substrate 210, a second substrate 220, a first electrode 230, a second electrode 240, and a light transmission control layer 1200. The light transmission control layer 1200 includes an electrochromic layer 250, a counterlayer 260, and an electrolyte layer 270.

[0151] Each of the first substrate 210 and the second substrate 220 may be made of glass or plastic.

[0152] The first electrode 230 is disposed on a surface of the first substrate 210 facing the second substrate 220. The second electrode 240 is disposed on a surface of the second substrate 220 facing the first substrate 210, and thus, the second electrode 240 is positioned between the second substrate 220 and the first electrode 230. Each of the first electrode 230 and the second electrode 240 may be formed of a transparent conductive material capable of transmitting light, such as indium tin oxide (ITO), zinc oxide (ZnO), indium oxide (In2O3), or indium zinc oxide (IZO).

[0153] The reverse layer 260 can be disposed on the first electrode 230, the electrolyte layer 270 can be disposed on the reverse layer 260, and the electrochromic layer 250 can be disposed on the electrolyte layer 270. For example, the electrochromic layer 250 can be disposed on one surface of the second electrode 240 facing the first electrode 230, the reverse layer 260 can be disposed on one surface of the first electrode 230 facing the second electrode 240 and can be positioned between the first electrode 230 and the electrochromic layer 250, and the electrolyte layer 270 can be disposed between the electrochromic layer 250 and the reverse layer 260.

[0154] In the electrochromic layer 250, the reverse layer 260, and the electrolyte layer 270, when a voltage is applied to the first electrode 230 and the second electrode 240, an electrochemical redox reaction occurs, and thus the color of the electrochromic layer 250 may change.

[0155] When a first driving voltage applied to the first electrode 230 is positive and a second driving voltage applied to the second electrode 240 is negative, a reduction reaction occurs in the electrochromic layer 250, and an oxidation reaction occurs in the reverse layer 260. Since the electrochromic layer 250 is disposed on the second electrode 240, the negative voltage applied to the second electrode 240 is applied to the electrochromic layer 250. The negative voltage can be less than 0V, and the positive voltage can be greater than 0V. In this case, since the electrochromic layer 250 has a predetermined color such as black through the reduction reaction, it can block most of the incident light. Therefore, the first light transmission control unit 200 can realize a light-blocking mode for blocking light.

[0156] When the first driving voltage applied to the first electrode 230 is negative and the second driving voltage applied to the second electrode 240 is positive, an oxidation reaction occurs in the electrochromic layer 250, and a reduction reaction occurs in the reverse layer 260. In this case, because the electrochromic layer 250 becomes transparent due to the oxidation reaction, most of the incident light can be transmitted. Therefore, the first light transmission control unit 200 can realize a light transmission mode for transmitted light.

[0157] The electrochromic layer 250 includes an electrochromic material. When a reduction reaction occurs, the electrochromic material absorbs a predetermined color to acquire that color, and when an oxidation reaction occurs, the electrochromic material becomes transparent. For example, the electrochromic material may be viologen (1,1'-dibenzyl-4,4'-bispyridinium bis(tetrafluoroborate)). To enhance the light-blocking function of the electrochromic layer 250, it may include electrochromic materials that acquire various colors through a reduction reaction. For example, in addition to viologen compounds, terephthalic acid compounds and pyridine compounds may be used to form the electrochromic layer 250 for color development or decolorization at relatively low voltages and exhibiting good color values.

[0158] The reverse layer 260 corresponds to the auxiliary electrochromic layer 250 to facilitate redox reactions. The reverse layer 260 includes a counter material that acquires a predetermined color by absorbing a predetermined color during an oxidation reaction and becomes transparent through a reduction reaction. The counter material can be, for example, TMPD (N,N,N',N'-tetramethyl-1,4-phenylenediamine), TMB (3,3',5,5'-tetramethylbenzidine), NTMB (N,N,N',N'-tetramethylbenzidine), or DAB (3,3'-diaminobenzidine). The reverse layer 260 may be omitted.

[0159] Electrolyte layer 270 may include an electrolyte, a polymer, and a UV initiator. The electrolyte may be lithium perchlorate, tert-butylammonium perchlorate, tert-butylammonium-tert-fluoroborate, or tetrabutylammonium trifluoromethanesulfonate. The polymer may be an acrylate polymer, a polyester polymer, or an epoxy polymer. The UV initiator may be benzoin ether or an amine. Electrolyte layer 270 may be formed by UV curing after being applied in a viscous liquid state. In embodiments of the present invention, the viscous liquid may include polymerizable monomers or oligomers, and the polymerizable monomers or oligomers may be polymerized by UV curing. Electrolyte layer 270 provides cations and anions, causing electrochromic layer 250 and reverse layer 260 to perform redox reactions.

[0160] like Figure 7 As shown, since the first light transmission control unit 200 includes an electrochromic layer 250, the first light transmission control unit 200 can have a predetermined color or a transparent color through an oxidation-reduction reaction based on a first driving voltage applied to the first electrode 230 and a second driving voltage applied to the second electrode 240. Therefore, the first light transmission control unit 200 can be implemented as a light-blocking mode in which most incident light is blocked and a light-transmitting mode in which most incident light is transmitted.

[0161] Second optical transmission control unit 300 (refer to) Figure 6The second light transmission control unit 300 can be similar to the first light transmission control unit 200. (Refer to...) Figure 6 (can be compared with reference) Figure 7 The first optical transmission control unit 200 described is substantially the same, therefore the description of the second optical transmission control unit 300 (see reference) will be omitted. Figure 6 The description of ).

[0162] Figure 8 It is shown Figure 6 A cross-sectional view of another example of the first light transmission control unit.

[0163] Reference Figure 8 The first light transmission control unit 200 includes a first substrate 310, a second substrate 320, a first electrode 330, a second electrode 340, a first alignment layer 350, a second alignment layer 360, a light transmission control layer 1200, a first polarizer 380, and a second polarizer 390. The light transmission control layer 1200 may be a liquid crystal layer 370.

[0164] Figure 8 The first substrate 310, the second substrate 320, the first electrode 330, and the second electrode 340 shown can be compared with those already referenced. Figure 7 The first substrate 210, the second substrate 220, the first electrode 230, and the second electrode 240 described are substantially the same. Therefore, details regarding... Figure 8 Description of the first substrate 310, the second substrate 320, the first electrode 330 and the second electrode 340 shown.

[0165] The first orientation layer 350 may be disposed on a surface of the first electrode 330 facing the second substrate 320. The second orientation layer 360 may be disposed on a surface of the second electrode 340 facing the first substrate 310, and therefore, the second orientation layer 360 may be positioned between the second electrode 340 and the first orientation layer 350.

[0166] The liquid crystal layer 370 may include liquid crystal. (Although reference...) Figure 8 The invention primarily describes a liquid crystal layer 370 comprising a twisted nematic (TN) liquid crystal that can have low voltage requirements and operate over a wide wavelength range; however, the inventive concept is not limited thereto. The twisted nematic (TN) liquid crystal is essentially a 90° liquid crystal polarization rotator.

[0167] The liquid crystal in liquid crystal layer 370 is pre-tilted by first alignment layer 350 and second alignment layer 360. When an electric field is not applied to liquid crystal layer 370 by first electrode 330 and second electrode 340, the liquid crystal in liquid crystal layer 370 can be arranged to rotate first polarized light by 90° to convert the first polarized light into second polarized light. The situation where the electric field is not applied to liquid crystal layer 370 by first electrode 330 and second electrode 340 includes not only the case where the voltage difference between the first driving voltage applied to first electrode 330 and the second driving voltage applied to second electrode 340 is less than a threshold voltage, but also the case where the first driving voltage is not applied to first electrode 330 and the second driving voltage is not applied to second electrode 340. Therefore, when no voltage is applied to first electrode 330 and second electrode 340, the first light transmission control unit 200 can operate in a light transmission mode in which most of the incident light is transmitted, and thus can achieve the light transmission mode without power consumption. For example, this could be a normally white mode, which has maximum transmission when zero voltage is applied, with a first polarizer 380 and a second polarizer 390 orthogonally mounted in a first light transmission control unit 200. The light can then attenuate as the voltage increases. This mode achieves high contrast by using a cross-polarizer configuration.

[0168] When an electric field is applied to the liquid crystal layer 370 by the first electrode 330 and the second electrode 340, the liquid crystal in the liquid crystal layer 370 can be arranged to allow the first polarized light to pass through as is. The case where the electric field is applied to the liquid crystal layer 370 by the first electrode 330 and the second electrode 340 refers to a situation where the voltage difference between the first driving voltage applied to the first electrode 330 and the second driving voltage applied to the second electrode 340 is greater than a threshold voltage.

[0169] The first polarizer 380 can be disposed on another surface of the first substrate 310, and the second polarizer 390 can be disposed on another surface of the second substrate 320. The other surface of the first substrate 310 can be a surface opposite to one surface of the first substrate 310, and can be a surface that does not face the second substrate 320. Similarly, the other surface of the second substrate 320 can be a surface opposite to one surface of the second substrate 320, and can be a surface that does not face the first substrate 310.

[0170] The first polarizer 380 may have a first optical transmission axis through which first polarized light is transmitted, and the second polarizer 390 may have a second optical transmission axis through which second polarized light is transmitted. The first and second optical transmission axes may be orthogonal to each other.

[0171] like Figure 8As shown, the first light transmission control unit 200 may include a liquid crystal layer 370 to control the polarization of incident light according to a first driving voltage applied to the first electrode 330 and a second driving voltage applied to the second electrode 340. For example, when an electric field is not applied to the liquid crystal layer 370 by the first electrode 330 and the second electrode 340, the liquid crystal in the liquid crystal layer 370 is arranged to rotate the first polarized light by 90° to convert the first polarized light into second polarized light, and therefore, light passing through the liquid crystal layer 370 can pass through the second polarizer 390. Because the first polarizer 380 and the second polarizer 390 are orthogonally mounted in the first light transmission control unit 200, the first polarized light rotated by 90° can pass through the second polarizer 390. That is, when an electric field is not applied to the liquid crystal layer 370 by the first electrode 330 and the second electrode 340, the first light transmission control unit 200 can achieve a light transmission mode in which most of the incident light is transmitted. Furthermore, when an electric field is applied to the liquid crystal layer 370 by the first electrode 330 and the second electrode 340, the liquid crystal in the liquid crystal layer 370 is arranged to allow the first polarized light to pass through as is, and therefore the light passing through the liquid crystal layer 370 cannot pass through the second polarizer 390. Because the first polarizer 380 and the second polarizer 390 are orthogonally mounted in the first light transmission control unit 200, the first polarized light, as is, may not be able to pass through the second polarizer 390. In other words, when an electric field is applied to the liquid crystal layer 370 by the first electrode 330 and the second electrode 340, the first light transmission control unit 200 can be implemented in a light-blocking mode in which most of the incident light is blocked.

[0172] Second optical transmission control unit 300 (refer to) Figure 6 The second light transmission control unit 300 can be similar to the first light transmission control unit 200. (Refer to...) Figure 6 (can be compared with reference) Figure 8 The first optical transmission control unit 200 described is essentially the same, therefore the description of the second optical transmission control unit 300 (see reference) will be omitted. Figure 6 The description of ).

[0173] Although Figure 7 and Figure 8 The diagram illustrates that each of the first light transmission control unit 200 and the second light transmission control unit 300 includes an electrochromic layer 250 or a liquid crystal layer 370 to control light transmission, but the inventive concept is not limited thereto. For example, in addition to the electrochromic layer 250 and the liquid crystal layer 370, it should be considered that if a certain configuration can control light transmission according to the applied driving voltage, that configuration can be applied to the first light transmission control unit 200 and / or the second light transmission control unit 300.

[0174] Figure 9 It is shown Figure 3 and Figure 4A cross-sectional view of another example of the first light transmission control unit, the second light transmission control unit, and the fingerprint sensor.

[0175] Figure 9 Implementation examples and Figure 6 The difference in the embodiments is that the first light guide unit 510 includes a first collimator COM1 instead of a first lens array LA1, and the second light guide unit 520 includes a second collimator COM2 instead of a second lens array LA2. Figure 9 In the middle, the main description will be related to Figure 6 The differences between the embodiments.

[0176] Reference Figure 9 The first collimator COM1 may include a first light-transmitting portion OA1 that transmits light and a first light-blocking portion LSA1 that blocks light. The first light-transmitting portion OA1 and the first light-blocking portion LSA1 may be disposed on the first light-transmitting control unit 200. The first light-blocking portion LSA1 may be disposed around each of the first light-transmitting portions OA1, and may be disposed between the first light-transmitting portions OA1 in one direction, which may be a direction perpendicular to a third direction (Z-axis direction). For example, the portions of the first light-transmitting portion OA1 and the first light-blocking portion LSA1 may be arranged alternately in said one direction.

[0177] The first light-transmitting portion OA1 can be the path through which light reflected from the fingerprint of finger F passes, and can be formed of a transparent organic layer including, for example, acrylic resin, epoxy resin, phenolic resin, polyamide resin, or polyimide resin. Therefore, the first collimator COM1 can convert divergent light or other radiation into a parallel beam.

[0178] The first light-blocking portion LSA1 can be formed of a photosensitive resin capable of blocking light. For example, the first light-blocking portion LSA1 may include an inorganic black pigment such as carbon black or an organic black pigment.

[0179] The second collimator COM2 may include a second light-transmitting portion OA2 that transmits light and a second light-blocking portion LSA2 that blocks light. The second light-transmitting portion OA2 and the second light-blocking portion LSA2 may be disposed on the second light-transmitting control unit 300. The second light-blocking portion LSA2 may be disposed around each of the second light-transmitting portions OA2, and may be disposed between the second light-transmitting portions OA2 in one direction, which may be a direction perpendicular to a third direction (Z-axis direction). For example, the portions of the second light-transmitting portion OA2 and the second light-blocking portion LSA2 may be arranged alternately in said one direction.

[0180] The second light-transmitting portion OA2 can be the path through which light reflected from the fingerprint of finger F passes, and can be formed of a transparent organic layer including, for example, acrylic resin, epoxy resin, phenolic resin, polyamide resin, or polyimide resin. Therefore, the second collimator COM2 can convert divergent light or other radiation into a parallel beam.

[0181] The second light-blocking portion LSA2 can be formed from a photosensitive resin capable of blocking light. For example, the second light-blocking portion LSA2 may include inorganic or organic black pigments such as carbon black.

[0182] The minimum distance between the first light guide unit 510 and the photosensitive element PD can be different from the minimum distance between the second light guide unit 520 and the photosensitive element PD. Therefore, the length OAL1 of the first light transmission portion OA1 in one direction can be different from the length OAL2 of the second light transmission portion OA2 in that same direction. For example, when the minimum distance between the first light guide unit 510 and the photosensitive element PD is shorter than the minimum distance between the second light guide unit 520 and the photosensitive element PD, the length OAL1 of the first light transmission portion OA1 in one direction can be longer than the length OAL2 of the second light transmission portion OA2 in that same direction. Alternatively, in embodiments of the present invention, the length OAL1 of the first light transmission portion OA1 in one direction can be approximately the same as the length OAL2 of the second light transmission portion OA2 in that same direction.

[0183] Figure 10 It is shown Figure 3 and Figure 4 A cross-sectional view of another example of the first light transmission control unit, the second light transmission control unit, and the fingerprint sensor.

[0184] Figure 10 Implementation examples and Figure 6 The difference in the embodiments is that the first light guide unit 510 includes a first light transmission layer LTL1 and a first light blocking layer LSL1 instead of a first lens array LA1, and the second light guide unit 520 includes a second light transmission layer LTL2 and a second light blocking layer LSL2 instead of a second lens array LA2. Figure 10 In the middle, it will mainly be aimed at and Figure 6 The differences between the embodiments will be described.

[0185] Reference Figure 10 The first light transmission layer LTL1 can be disposed on the first light transmission control unit 200, and the first light blocking layer LSL1 can be disposed on the first light transmission layer LTL1. The second light transmission layer LTL2 can be disposed below the second light transmission control unit 300, and the second light blocking layer LSL2 can be disposed below the second light transmission layer LTL2.

[0186] Each of the first light-transmitting layer LTL1 and the second light-transmitting layer LTL2 can be made of an insulating material that transmits light. For example, each of the first light-transmitting layer LTL1 and the second light-transmitting layer LTL2 can be formed of an organic layer including, for example, acrylic resin, epoxy resin, phenolic resin, polyamide resin or polyimide resin.

[0187] Each of the first light-blocking layer LSL1 and the second light-blocking layer LSL2 may comprise a light-transmitting photosensitive resin, which includes, for example, an inorganic black pigment or an organic black pigment, such as carbon black. Alternatively, each of the first light-blocking layer LSL1 and the second light-blocking layer LSL2 may comprise a metallic material that is opaque or has low light transmittance. For example, each of the first light-blocking layer LSL1 and the second light-blocking layer LSL2 may be formed as a single layer or multiple layers comprising, for example, any one of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), tungsten (W), and copper (Cu), or alloys thereof.

[0188] Each of the first pin holes PH1 may be defined by a first light-blocking layer LSL1, and may be the path through which light reflected from the fingerprint of finger F passes. In embodiments of the present invention, the first light-blocking layer LSL1 may be configured to surround each of the first pin holes PH1, and may be disposed between the first pin holes PH1 in one direction, said one direction being a direction perpendicular to a third direction (Z-axis direction). For example, portions of the first pin holes PH1 and the first light-blocking layer LSL1 may be arranged alternately in said one direction.

[0189] Each of the second pin holes PH2 can be defined by a second light-blocking layer LSL2, and can be the path through which light reflected from the fingerprint of finger F passes. In embodiments of the present invention, the second light-blocking layer LSL2 can be configured to surround each of the second pin holes PH2, and can be disposed between the second pin holes PH2 in one direction, said direction being a direction perpendicular to a third direction (Z-axis direction). For example, portions of the second pin holes PH2 and the second light-blocking layer LSL2 can be arranged alternately in said direction.

[0190] Although Figure 10 The diagram shows that the first pin hole PH1 is included as part of the first display panel 110 (see Figure 110). Figure 5 The first light guide unit 510 of the separated components is located therein, but the inventive concept is not limited thereto. The first pin hole PH1 may be located in the first display panel 110 (see...). Figure 5 The first base SUB1 (see) Figure 5) and the first buffer layer BF1 (see Figure 5 Between ) . Furthermore, although in Figure 10 The diagram shows that the second pin hole PH2 is included as part of the second display panel 120 (see Figure 120). Figure 1 The second light guide unit 520 of the separated components is located therein, but the inventive concept is not limited thereto. The second pin hole PH2 may be located in the second display panel 120 (see...). Figure 1 The first base SUB1 (see) Figure 5 ) and the first buffer layer BF1 (see Figure 5 )between.

[0191] The minimum distance between the first light guide unit 510 and the photosensitive element PD can be different from the minimum distance between the second light guide unit 520 and the photosensitive element PD. Therefore, the length PHL1 of the first pin hole PH1 in one direction can be different from the length PHL2 of the second pin hole PH2 in that same direction. For example, when the minimum distance between the first light guide unit 510 and the photosensitive element PD is shorter than the minimum distance between the second light guide unit 520 and the photosensitive element PD, the length PHL1 of the first pin hole PH1 in one direction can be longer than the length PHL2 of the second pin hole PH2 in that same direction. Alternatively, in embodiments of the present invention, the length PHL1 of the first pin hole PH1 in one direction can be approximately the same as the length PHL2 of the second pin hole PH2 in that same direction.

[0192] Figure 10 The first light-blocking layer LSL1 is used to form the first pin hole PH1, while Figure 9 The first light-blocking portion LSA1 is used to form the first collimator COM1. Therefore, Figure 10 The height of the first light-blocking layer LSL1 ( Figure 10 The length of the first light-blocking layer LSL1 in the third direction (Z-axis direction) can be less than Figure 9 The height of the first light-blocking part LSA1 ( Figure 9 The length of the first light-blocking portion LSA1 in the third direction (Z-axis direction).

[0193] Figure 10 The second light-blocking layer LSL2 is used to form the second pin hole PH2, while Figure 9 The second light-blocking portion LSA2 is used to form the second collimator COM2. Therefore, Figure 10 The height of the second light-blocking layer LSL2 ( Figure 10 The length of the second light-blocking layer LSL2 in the third direction (Z-axis direction) can be less than Figure 9 The height of the second light-blocking part LSA2 ( Figure 9The length of the second light-blocking portion LSA2 in the third direction (Z-axis direction).

[0194] Figure 11 It is shown Figure 3 and Figure 4 A cross-sectional view of another example of the first light transmission control unit, the second light transmission control unit, and the fingerprint sensor.

[0195] Figure 11 Implementation examples and Figure 6 The difference in this embodiment is that the second light guide unit 520 includes a second collimator COM2 instead of a second lens array LA2. Figure 11 In the middle, omission and Figure 6 The embodiments are described repeatedly.

[0196] Figure 11 The second collimator COM2 shown can be used with reference Figure 9 The second collimator COM2 described is essentially the same. Therefore, in Figure 11 The description of the second collimator COM2 will be omitted here.

[0197] and Figure 11 Unlike the embodiments described, where the first light guide unit 510 includes a first lens array LA1 and the second light guide unit 520 includes a second collimator COM2, in embodiments of the present invention, the first light guide unit 510 may include the first collimator COM1 instead of... Figure 11 The first lens array LA1, and the second light guide unit 520 may include a second lens array LA2 instead of Figure 11 The second collimator COM2.

[0198] Figure 12 It is shown Figure 3 and Figure 4 A cross-sectional view of another example of the first light transmission control unit, the second light transmission control unit, and the fingerprint sensor.

[0199] Figure 12 Implementation examples and Figure 6 The difference in this embodiment is that the second light guide unit 520 includes a second light transmission layer LTL2 and a second light blocking layer LSL2 instead of a second lens array LA2. Figure 12 In the middle, omission and Figure 6 The embodiments are described repeatedly.

[0200] Figure 12 The second light-transmitting layer LTL2 and the second light-blocking layer LSL2 shown can be compared with the reference layer. Figure 10 The second light-transmitting layer LTL2 and the second light-blocking layer LSL2 described are essentially the same. Therefore, in Figure 12The description of the second light transmission layer LTL2 and the second light blocking layer LSL2 will be omitted in the text.

[0201] and Figure 12 Unlike the embodiments described in the original text, where the first light guide unit 510 includes a first lens array LA1 and the second light guide unit 520 includes a second light transmission layer LTL2 and a second light blocking layer LSL2, in the embodiments of the present invention, the first light guide unit 510 may include the first light transmission layer LTL1 and the first light blocking layer LSL1 instead of... Figure 12 The first lens array LA1, and the second light guide unit 520 may include a second lens array LA2 instead of Figure 12 The second light-transmitting layer LTL2 and the second light-blocking layer LSL2.

[0202] Figure 13 It is shown Figure 3 and Figure 4 A cross-sectional view of another example of the first light transmission control unit, the second light transmission control unit, and the fingerprint sensor.

[0203] Figure 13 Implementation examples and Figure 9 The difference in this embodiment is that the second light guide unit 520 includes a second light transmission layer LTL2 and a second light blocking layer LSL2 instead of a second collimator COM2. Figure 13 In the middle, omission and Figure 9 The embodiments are described repeatedly.

[0204] Figure 13 The second light-transmitting layer LTL2 and the second light-blocking layer LSL2 shown can be compared with the reference layer. Figure 10 The second light-transmitting layer LTL2 and the second light-blocking layer LSL2 described are essentially the same. Therefore, in Figure 13 The description of the second light transmission layer LTL2 and the second light blocking layer LSL2 will be omitted in the text.

[0205] and Figure 13 Unlike the embodiments described in the original text, where the first light guide unit 510 includes a first collimator COM1 and the second light guide unit 520 includes a second light transmission layer LTL2 and a second light blocking layer LSL2, in the embodiments of the present invention, the first light guide unit 510 may include the first light transmission layer LTL1 and the first light blocking layer LSL1 instead of... Figure 13 The first collimator COM1, and the second light guide unit 520 may include a second collimator COM2 instead of Figure 13 The second light-transmitting layer LTL2 and the second light-blocking layer LSL2.

[0206] Figure 14 It is shown Figure 3 and Figure 4 A cross-sectional view of another example of the first light transmission control unit, the second light transmission control unit, and the fingerprint sensor.

[0207] Figure 14 Implementation examples and Figure 6 The difference in the embodiment is that the positions of the first light transmission control unit 200 and the first light guide unit 510 are interchanged, that is, the positions of the first light transmission control unit 200 and the first light guide unit 510 are exchanged, and the positions of the second light transmission control unit 300 and the second light guide unit 520 are interchanged, that is, the positions of the second light transmission control unit 300 and the second light guide unit 520 are exchanged. Figure 14 In the middle, omission and Figure 6 The embodiments are described repeatedly.

[0208] like Figure 14 As shown, the first light guide unit 510 can be disposed on the fingerprint sensor 400, and the first light transmission control unit 200 can be disposed on the first light guide unit 510. Furthermore, the second light guide unit 520 can be disposed below the fingerprint sensor 400, and the second light transmission control unit 300 can be disposed below the second light guide unit 520.

[0209] Figure 15 It is shown Figure 3 and Figure 4 A cross-sectional view of another example of the first light transmission control unit, the second light transmission control unit, and the fingerprint sensor.

[0210] Figure 15 Implementation examples and Figure 9 The difference in the embodiment is that the positions of the first light transmission control unit 200 and the first light guide unit 510 are interchanged, that is, the positions of the first light transmission control unit 200 and the first light guide unit 510 are exchanged, and the positions of the second light transmission control unit 300 and the second light guide unit 520 are interchanged, that is, the positions of the second light transmission control unit 300 and the second light guide unit 520 are exchanged. Figure 15 In the middle, omission and Figure 9 The embodiments are described repeatedly.

[0211] Figure 16 It is shown Figure 3 and Figure 4 A cross-sectional view of another example of the first light transmission control unit, the second light transmission control unit, and the fingerprint sensor.

[0212] Figure 16 Implementation examples and Figure 10The difference in the embodiment is that the positions of the first light transmission control unit 200 and the first light guide unit 510 are interchanged, that is, the positions of the first light transmission control unit 200 and the first light guide unit 510 are exchanged, and the positions of the second light transmission control unit 300 and the second light guide unit 520 are interchanged, that is, the positions of the second light transmission control unit 300 and the second light guide unit 520 are exchanged. Figure 16 In the middle, omission and Figure 10 The embodiments are described repeatedly.

[0213] Figure 17 It is shown Figure 3 and Figure 4 A cross-sectional view of another example of the first light transmission control unit, the second light transmission control unit, and the fingerprint sensor.

[0214] Figure 17 Implementation examples and Figure 11 The difference in the embodiment is that the positions of the first light transmission control unit 200 and the first light guide unit 510 are interchanged, that is, the positions of the first light transmission control unit 200 and the first light guide unit 510 are exchanged, and the positions of the second light transmission control unit 300 and the second light guide unit 520 are interchanged, that is, the positions of the second light transmission control unit 300 and the second light guide unit 520 are exchanged. Figure 17 In the middle, omission and Figure 11 The embodiments are described repeatedly.

[0215] Figure 18 It is shown Figure 3 and Figure 4 A cross-sectional view of another example of the first light transmission control unit, the second light transmission control unit, and the fingerprint sensor.

[0216] Figure 18 Implementation examples and Figure 12 The difference in the embodiment is that the positions of the first light transmission control unit 200 and the first light guide unit 510 are interchanged, that is, the positions of the first light transmission control unit 200 and the first light guide unit 510 are exchanged, and the positions of the second light transmission control unit 300 and the second light guide unit 520 are interchanged, that is, the positions of the second light transmission control unit 300 and the second light guide unit 520 are exchanged. Figure 18 In the middle, omission and Figure 12 The embodiments are described repeatedly.

[0217] Figure 19 It is shown Figure 3 and Figure 4 A cross-sectional view of another example of the first light transmission control unit, the second light transmission control unit, and the fingerprint sensor.

[0218] Figure 19Implementation examples and Figure 13 The difference in the embodiment is that the positions of the first light transmission control unit 200 and the first light guide unit 510 are interchanged, that is, the positions of the first light transmission control unit 200 and the first light guide unit 510 are exchanged, and the positions of the second light transmission control unit 300 and the second light guide unit 520 are interchanged, that is, the positions of the second light transmission control unit 300 and the second light guide unit 520 are exchanged. Figure 19 In the middle, omission and Figure 13 The embodiments are described repeatedly.

[0219] Figure 20 and Figure 21 This is a perspective view illustrating a display device according to an embodiment of the concept of the present invention. Figure 22A and Figure 22B This is a cross-sectional view illustrating a display device according to an embodiment of the concept of the present invention.

[0220] Figures 20 to 22B Implementation examples and Figures 1 to 4 The difference in this embodiment is that the second display panel 120 is not bent or folded. Figures 20 to 22B In the middle, the main description will be related to Figures 1 to 4 The differences between the embodiments.

[0221] Reference Figures 20 to 22B The second display panel 120 may have a rectangular planar shape. The second display panel 120 may have a short side in a first direction (X-axis direction) and a long side in a second direction (Y-axis direction). The angle where the short side in the first direction (X-axis direction) and the long side in the second direction (Y-axis direction) of the second display panel 120 intersect each other may be rounded or may be a right angle, the rounded shape having a predetermined curvature. The planar shape of the second display panel 120 is not limited to a rectangle, and the second display panel 120 may be formed as, for example, another polygon other than a rectangle (e.g., a square, triangle, or other shape with more than four sides), a circle, or an ellipse.

[0222] The second display panel 120 includes a second display area DA2 and a second non-display area NDA2. The second display area DA2 is an area in which pixels are arranged to display an image. The second non-display area NDA2 is an area where no pixels are arranged and no image is displayed, and can be disposed around the second display area DA2. For example, the second non-display area NDA2 can be disposed around the second display area DA2. The second display area DA2 of the second display panel 120 can be disposed on the rear surface of the display device 10 and facing the rear side.

[0223] The size or area of ​​the second display panel 120 may be substantially the same as that of the first display panel 110, but the concept of the present invention is not limited thereto.

[0224] The adhesive member 150 can be disposed at the edge of the first display panel 110 and the edge of the second display panel 120. For example, the adhesive member 150 can overlap with the first non-display area NDA1 of the first display panel 110 in the third direction (Z-axis direction). Additionally, the adhesive member 150 can overlap with the second non-display area NDA2 of the second display panel 120 in the third direction (Z-axis direction). The space between the first display panel 110 and the second display panel 120 can be sealed by the adhesive member 150.

[0225] like Figures 20 to 22B As shown, the display device 10 can display a first image in the front direction using a first display panel 110, and can display a second image in the rear direction using a second display panel 120. For example, the display device 10 can display images on the front and rear surfaces (i.e., the two surfaces of the display device 10).

[0226] Figure 23 This is a flowchart illustrating a method for driving a display device according to an embodiment of the present invention.

[0227] In the following text, reference will be made to Figure 23 Description-driven Figures 1 to 4 The method of the display device shown. However, driving Figure 20 , Figure 21 , Figure 22A and Figure 22B The method of the display device shown can be compared with the reference. Figure 23 The methods described are basically the same.

[0228] First, determine whether a touch event has occurred on the first display panel 110. Figure 23 (S100 in the middle).

[0229] Because the first display panel 110 includes, for example Figure 5The touch sensing layer SENL shown allows the display device 10 to detect touch events caused by a user touching the first display panel 110. For example, a touch driving circuit can be electrically connected to the driving electrode TE and the sensing electrode RE of the touch sensing layer SENL of the first display panel 110. The touch driving circuit can apply a driving signal to the driving electrode TE of the first display panel 110 and can detect a first mutual capacitance value formed between the driving electrode TE and the sensing electrode RE. The touch driving circuit can determine whether a touch event has occurred in the first display panel 110 based on the first mutual capacitance value. Touch events include situations where an object such as a user's finger or a pen directly contacts the front surface of the first display panel 110 disposed on the touch sensing layer SENL. Furthermore, touch events include situations where an object such as a user's finger or a pen is positioned (hovered) close to the front surface of the first display panel 110.

[0230] Second, when a touch event occurs on the first display panel 110, the first light transmission control unit 200 is configured in light transmission mode, and the second light transmission control unit 300 is configured in light blocking mode. Then, the fingerprint sensor 400 detects the light passing through the first light transmission control unit 200 and identifies the fingerprint of finger F. Figure 23 (S200 and S300 in the text).

[0231] The first light transmission control unit 200 is disposed between the first display panel 110 and the fingerprint sensor 400. When the first light transmission control unit 200 is configured in a light transmission mode for transmitting light, light output from the first display panel 110 and reflected from the fingerprint of finger F can pass through the first display panel 110 and the first light transmission control unit 200, and can be incident on the photosensitive element PD of each of the sensor pixels SEP of the fingerprint sensor 400.

[0232] The amount of light reflected from the ridges of the fingerprint of finger F is different from the amount of light reflected from the valleys of the fingerprint of finger F. Therefore, the fingerprint driving circuit electrically connected to the fingerprint sensor 400 can determine whether the light is reflected from the ridges or valleys of the fingerprint of finger F based on the amount of light incident on the sensor pixels of the fingerprint sensor 400. For example, the fingerprint sensor 400 disposed between the first display panel 110 and the second display panel 120 can detect light passing through the first display panel 110, which may contain fingerprint information. Therefore, the display device 10 can detect the fingerprint of finger F that has touched the first display panel 110.

[0233] The second light transmission control unit 300 is disposed between the second display panel 120 and the fingerprint sensor 400. The second light transmission control unit 300 is implemented in a light-blocking mode to prevent noisy light passing through the second display panel 120 from incident on the fingerprint sensor 400. Therefore, the accuracy of fingerprint recognition can be prevented from being reduced by noisy light passing through the second display panel 120.

[0234] Third, if no touch event occurs in the first display panel 110, determine whether a touch event occurs in the second display panel 120. Figure 23 (S400 in the middle).

[0235] Because the second display panel 120 includes, for example Figure 5 The touch sensing layer SENL shown allows the display device 10 to detect touch events caused by a user touching the second display panel 120. For example, a touch driving circuit can be electrically connected to the driving electrode TE and the sensing electrode RE of the touch sensing layer SENL of the second display panel 120. The touch driving circuit can apply a driving signal to the driving electrode TE of the second display panel 120 and can detect a second mutual capacitance value formed between the driving electrode TE and the sensing electrode RE. The touch driving circuit can determine whether a touch event has occurred in the second display panel 120 based on the second mutual capacitance value. Touch events include situations where an object such as a user's finger or a pen directly contacts the front surface of the second display panel 120 disposed on the touch sensing layer SENL. Furthermore, touch events include situations where an object such as a user's finger or a pen is positioned (hovered) close to the front surface of the second display panel 120.

[0236] Fourth, when a touch event occurs on the second display panel 120, the first light transmission control unit 200 is configured in light-blocking mode, and the second light transmission control unit 300 is configured in light transmission mode. Then, the fingerprint sensor 400 detects light passing through the second light transmission control unit 300 and identifies the fingerprint of finger F. Figure 23 (S500, S600 in the example).

[0237] When the second light transmission control unit 300 is configured in a light transmission mode for transmitting light, light output from the second display panel 120 and reflected from the fingerprint of finger F can pass through the second display panel 120 and the second light transmission control unit 300, and can be incident on the light sensing element PD of each of the sensor pixels SEP of the fingerprint sensor 400.

[0238] The amount of light reflected from the ridges of the fingerprint of finger F and the amount of light reflected from the valleys of the fingerprint of finger F are different. Therefore, the fingerprint driving circuit electrically connected to the fingerprint sensor 400 can determine whether the light is reflected from the ridges or valleys of the fingerprint of finger F based on the amount of light incident on the sensor pixels of the fingerprint sensor 400. For example, the fingerprint sensor 400 disposed between the first display panel 110 and the second display panel 120 can detect light passing through the second display panel 120, which may contain fingerprint information. Therefore, the display device 10 can detect the fingerprint of finger F that has touched the second display panel 120.

[0239] The first light transmission control unit 200 is configured in a light-blocking mode to prevent noisy light passing through the first display panel 110 from incident on the fingerprint sensor 400. Therefore, the accuracy of fingerprint recognition can be prevented from being reduced by noisy light passing through the first display panel 110. Thus, when a touch event occurs in the first display panel 110, the fingerprint sensor 400 disposed between the first display panel 110 and the second display panel 120 can detect light passing through the first display panel 110, and when a touch event occurs in the second display panel 120, the same fingerprint sensor 400 disposed between the first display panel 110 and the second display panel 120 can detect light passing through the second display panel 120.

[0240] In a display device and a method for driving a display device according to an embodiment of the present invention, a fingerprint sensor is disposed between a first display panel that displays a first image forward and a second display panel that displays a second image backward. When a user's finger touches the first display panel, a first light transmission control unit disposed between the first display panel and the fingerprint sensor is configured in a light transmission mode, and a second light transmission control unit disposed between the second display panel and the fingerprint sensor is configured in a light blocking mode, thereby detecting light reflected from the fingerprint. Furthermore, when a user's finger touches the second display panel, the first light transmission control unit is configured in a light blocking mode, and the second light transmission control unit is configured in a light transmission mode, thereby detecting light reflected from the fingerprint. Therefore, the display device can detect the fingerprint of a finger touching the first display panel and the fingerprint of a finger touching the second display panel using only one fingerprint sensor. Therefore, since it is not necessary to attach a fingerprint sensor to each display panel, the manufacturing cost of the display device can be reduced.

[0241] While the inventive concept has been specifically shown and described with reference to embodiments thereof, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the inventive concept as defined in the appended claims.

Claims

1. A display device, wherein, The display device includes: A first display panel is used to display a first image; A second display panel is used to display a second image; A fingerprint sensor is disposed on one surface of the first display panel and between the first display panel and the second display panel, and the fingerprint sensor detects light passing through the first display panel or light passing through the second display panel; A first light transmission control unit is disposed between the first display panel and the fingerprint sensor. The first light transmission control unit is used to control the transmission of light passing through the first display panel; and A second light transmission control unit is disposed between the second display panel and the fingerprint sensor. The second light transmission control unit is used to control the transmission of light passing through the second display panel. When a touch event occurs on the first display panel, the first light transmission control unit is in a light transmission mode for transmitting light, so that light passing through the first display panel is incident on the fingerprint sensor, and the second light transmission control unit is in a light blocking mode for blocking light. When a touch event occurs on the second display panel, the second light transmission control unit is in a light transmission mode for transmitting light, so that light passing through the second display panel is incident on the fingerprint sensor, and the first light transmission control unit is in a light blocking mode for blocking light.

2. The display device according to claim 1, in, The first optical transmission control unit includes: The first and second substrates face each other; The first electrode is disposed on one surface of the first substrate. The second electrode is disposed on a surface of the second substrate facing the first substrate; and A light transmission control layer is disposed between the first electrode and the second electrode.

3. The display device according to claim 2, in, The light transmission control layer includes: An electrochromic layer is disposed on a surface of the second electrode facing the first electrode, and the electrochromic layer is configured to change color according to a redox reaction by a first driving voltage applied to the first electrode and a second driving voltage applied to the second electrode. An inverse layer is disposed on one surface of the first electrode facing the second electrode and positioned between the first electrode and the electrochromic layer, the inverse layer serving to assist the redox reaction of the electrochromic layer; and An electrolyte layer is disposed between the electrochromic layer and the reverse layer, the electrolyte layer being used to provide cations and anions to induce the redox reaction in the electrochromic layer and the reverse layer.

4. The display device according to claim 3, in, When the first driving voltage is positive and the second driving voltage is negative, the electrochromic layer is in a light-blocking mode, in which light passing through the first display panel and incident on the fingerprint sensor is blocked.

5. The display device according to claim 3, in, When the first driving voltage is negative and the second driving voltage is positive, the electrochromic layer is in a light transmission mode, in which light passing through the first display panel and incident on the fingerprint sensor is transmitted.

6. The display device according to claim 2, in, The light transmission control layer includes a liquid crystal layer containing liquid crystal molecules.

7. The display device according to claim 6, in, When an electric field is applied to the first electrode and the second electrode, the liquid crystal layer is in a light-blocking mode, in which light passing through the first display panel and incident on the fingerprint sensor is blocked.

8. The display device according to claim 6, in, When no electric field is applied to the first electrode and the second electrode, the liquid crystal layer is in a light transmission mode, in which light passing through the first display panel and incident on the fingerprint sensor is transmitted.

9. The display device according to claim 1, wherein, The display device further includes: A first light guide unit is disposed between the first display panel and the first light transmission control unit, and the first light guide unit is used to provide light passing through the first display panel to the light sensing element of the fingerprint sensor; and A second light guide unit is disposed between the second display panel and the second light transmission control unit. The second light guide unit is used to provide light passing through the second display panel to the light sensing element of the fingerprint sensor.

10. The display device according to claim 1, wherein, The display device further includes: A first light guide unit is disposed between the first light transmission control unit and the fingerprint sensor. The first light guide unit is used to provide light passing through the first display panel to the light sensing element of the fingerprint sensor. A second light guide unit is disposed between the second light transmission control unit and the fingerprint sensor. The second light guide unit is used to provide light passing through the second display panel to the light sensing element of the fingerprint sensor.

11. A display device, wherein, The display device includes: First display panel; The second display panel is disposed on one surface of the first display panel; A fingerprint sensor is disposed between the first display panel and the second display panel; A first light guide unit is disposed between the first display panel and the fingerprint sensor, and the first light guide unit provides light passing through the first display panel to the light sensing element of the fingerprint sensor; A second light guide unit is disposed between the second display panel and the fingerprint sensor, and the second light guide unit provides light passing through the second display panel to the photosensitive element of the fingerprint sensor; A first light transmission control unit is disposed between the first display panel and the fingerprint sensor. The first light transmission control unit is used to control the transmission of light passing through the first display panel; and A second light transmission control unit is disposed between the second display panel and the fingerprint sensor. The second light transmission control unit is used to control the transmission of light passing through the second display panel. When a touch event occurs on the first display panel, the first light transmission control unit is in a light transmission mode for transmitting light, so that light passing through the first display panel is incident on the fingerprint sensor, and the second light transmission control unit is in a light blocking mode for blocking light. When a touch event occurs on the second display panel, the second light transmission control unit is in a light transmission mode for transmitting light, so that light passing through the second display panel is incident on the fingerprint sensor, and the first light transmission control unit is in a light blocking mode for blocking light.

12. The display device according to claim 11, in, Each of the first light guiding unit and the second light guiding unit includes any one of a lens array, a collimator, and a light blocking layer. The lens array includes multiple lenses, the collimator includes a light transmission portion that transmits light and a light blocking portion that blocks light, and the light blocking layer includes a light transmission pin hole.

13. The display device according to claim 11, in, The first light guiding unit includes a lens array, which includes multiple lenses, and the second light guiding unit includes a collimator or a light blocking layer. The collimator includes a light transmission portion that transmits light and a light blocking portion that blocks light, and the light blocking layer includes a pinhole that transmits light.

14. The display device according to claim 11, in, The first light guiding unit includes a collimator, which includes a light transmission portion that transmits light and a light blocking portion that blocks light. The second light guiding unit includes a lens array or a light blocking layer, which includes a plurality of lenses and a light blocking layer that includes pin holes for transmitting light.

15. The display device according to claim 11, in, The first light guiding unit includes a light blocking layer, the light blocking layer includes a pin hole for transmitting light, and the second light guiding unit includes a lens array or a collimator, the lens array includes multiple lenses, and the collimator includes a light transmission portion for transmitting light and a light blocking portion for blocking light.

16. A method for driving a display device, wherein, The method includes: Determine whether a touch event occurs on a first display panel and a second display panel disposed on a surface of the first display panel; When the touch event occurs in the first display panel, the first light transmission control unit disposed between the first display panel and the fingerprint sensor is configured as a light transmission mode for transmitting light, so that light passing through the first display panel is incident on the fingerprint sensor. When the touch event occurs on the first display panel, the second light transmission control unit located between the second display panel and the fingerprint sensor is configured as a light blocking mode to block light. When the touch event occurs on the second display panel, the second light transmission control unit is configured in a light transmission mode for transmitting light, such that light passing through the second display panel is incident on the fingerprint sensor; and When the touch event occurs on the second display panel, the first light transmission control unit is configured in a light blocking mode to block light.

17. A display device, wherein, The display device includes: A first display panel is not bent or folded, and the first display panel is used to display a first image in the front direction of the display device; A second display panel is foldable or foldable, and the second display panel is attached to the first display panel and displays a second image in the rear direction of the display device; A fingerprint sensor is disposed between the first display panel and the second display panel, and the fingerprint sensor detects light passing through the first display panel or light passing through the second display panel; A first light transmission control unit is disposed between the first display panel and the fingerprint sensor. The first light transmission control unit is used to control the transmission of light passing through the first display panel; and A second light transmission control unit is disposed between the second display panel and the fingerprint sensor. The second light transmission control unit is used to control the transmission of light passing through the second display panel. When a touch event occurs on the first display panel, the first light transmission control unit is in a light transmission mode for transmitting light, so that light passing through the first display panel is incident on the fingerprint sensor, and the second light transmission control unit is in a light blocking mode for blocking light. When a touch event occurs on the second display panel, the second light transmission control unit is in a light transmission mode for transmitting light, so that light passing through the second display panel is incident on the fingerprint sensor, and the first light transmission control unit is in a light blocking mode for blocking light.

Images