Indication device

Abstract

To provide a display device that can suppress a decline in display quality. [Solution] According to the embodiment, the display device comprises a display panel and a light source unit arranged along the edge of the display panel, the display panel comprising a first transparent substrate, a second transparent substrate facing the first transparent substrate, a liquid crystal layer sealed between the first transparent substrate and the second transparent substrate and comprising a polymer-dispersed liquid crystal containing polymers and liquid crystal molecules, a third transparent substrate facing the first transparent substrate, and a selective reflective layer located between the first transparent substrate and the third transparent substrate, the selective reflective layer being configured to transmit light in the blue wavelength range and light in the green wavelength range, and to reflect light in the red wavelength range, at a predetermined incident angle with respect to its normal.

Description

Technical Field

[0001] Embodiments of the present invention relate to a display device.

Background Art

[0002] Various display devices using a polymer-dispersed liquid crystal capable of switching between a scattered state that scatters incident light and a transparent state that transmits incident light have been proposed. In a display device using a polymer-dispersed liquid crystal, an edge-lighting method in which a light-emitting module is arranged at an edge of a display panel is used. In such a display device, it is desired to suppress a decrease in display quality.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of an embodiment is to provide a display device capable of suppressing a decrease in display quality.

Means for Solving the Problems

[0005] According to one embodiment, a display device includes a display panel, and a light source unit arranged along an edge of the display panel, wherein the display panel includes a first transparent substrate, a second transparent substrate facing the first transparent substrate, a liquid crystal layer sealed between the first transparent substrate and the second transparent substrate and including a polymer-dispersed liquid crystal containing a polymer and liquid crystal molecules, a third transparent substrate facing the first transparent substrate, and a selective reflection layer located between the first transparent substrate and the third transparent substrate, and the selective reflection layer is configured to transmit light in a blue wavelength range and light in a green wavelength range and reflect light in a red wavelength range at a predetermined incident angle with respect to its normal. [Brief explanation of the drawing]

[0006] [Figure 1] Figure 1 shows an example configuration of the display device 1. [Figure 2] Figure 2 is a cross-sectional view of the display device 1 along line A and B in Figure 1. [Figure 3] Figure 3 shows an example of the wiring layout included in the display panel 100. [Figure 4] Figure 4 is a cross-sectional view of the display panel 100 along the CD line shown in Figure 3. [Figure 5A] Figure 5A is a diagram illustrating one of the characteristics required for the selective reflective layer 300. [Figure 5B] Figure 5B is a diagram illustrating other characteristics required of the selective reflective layer 300. [Figure 6A] Figure 6A is a diagram illustrating the reflection characteristics of the selective reflection layer 300. [Figure 6B] Figure 6B is a diagram illustrating the transmission characteristics of the selective reflective layer 300. [Figure 7] Figure 7 is a diagram illustrating the function of the selective reflective layer 300 in the display panel 100. [Figure 8] Figure 8 shows an example of application of the display device 1. [Figure 9] Figure 9 shows an example of application of the display device 1, part 2. [Modes for carrying out the invention]

[0007] One embodiment will be described with reference to the drawings. The disclosure is merely an example, and any modifications that a person skilled in the art could easily conceive of while maintaining the spirit of the invention are naturally included within the scope of the present invention. Furthermore, the drawings may schematically represent the width, thickness, shape, etc., of each part in order to clarify the explanation, but these are merely examples and do not limit the interpretation of the present invention. In addition, in this specification and each drawing, the same reference numerals are used for components that perform the same or similar functions as those described above with respect to previously shown drawings, and redundant detailed explanations may be omitted as appropriate.

[0008] Furthermore, the drawings will include mutually orthogonal X, Y, and Z axes as needed to facilitate understanding. The direction along the X-axis will be referred to as the first direction X, the direction along the Y-axis as the second direction Y, and the direction along the Z-axis as the third direction Z. Viewing various elements parallel to the third direction Z is called a plan view. In addition, terms referring to the positional relationship between two or more constituent elements, such as above, above, between, and opposite, include not only cases where the two or more constituent elements of the object are in direct contact, but also cases where they are separated from each other by gaps or other constituent elements.

[0009] Figure 1 shows an example configuration of the display device 1.

[0010] The display device 1 comprises a display panel 100 configured to display an image, and a light source unit 200 configured to illuminate the display panel 100.

[0011] The display panel 100 comprises a transparent substrate 110, a transparent substrate 120, a liquid crystal layer LC, and a seal SE. Each of the transparent substrates 110 and 120 is formed in a flat plate shape parallel to the XY plane defined by a first direction X and a second direction Y. The transparent substrates 110 and 120 overlap each other in a plan view. The transparent substrate 110 extends further along the second direction Y than the transparent substrate 120. In the illustrated example, both the transparent substrates 110 and 120 are formed as rectangles extending in the first direction X, but are not limited to this. For example, the transparent substrates 110 and 120 may be squares, or they may be polygons other than quadrilaterals, circles, ellipses, semicircles, or any other shape.

[0012] The liquid crystal layer LC is located between the transparent substrate 110 and the transparent substrate 120, extends across the display area DA where the image is displayed, and is sealed by a seal SE. The orientation processing direction D1 of the alignment film AL1 located between the transparent substrate 110 and the liquid crystal layer LC, and the orientation processing direction D2 of the alignment film AL2 located between the transparent substrate 120 and the liquid crystal layer LC1 are parallel to each other and opposite in direction. In the illustrated example, both the orientation processing direction D1 and the orientation processing direction D2 are parallel to the first direction X. The orientation processing applied to the alignment film AL1 and the alignment film AL2 may be rubbing processing or optical alignment processing.

[0013] As schematically shown in the magnified figure, the liquid crystal layer LC comprises a polymer-dispersed liquid crystal containing a polymer PL and liquid crystal molecules LM. In one example, the polymer PL is a liquid crystalline polymer. Both the polymer PL and the liquid crystal molecules LM have optical anisotropy or refractive index anisotropy. The response of the polymer PL to the electric field is lower than the response of the liquid crystal molecules LM to the electric field.

[0014] As described above, since the alignment processing directions D1 and D2 are parallel to the first direction X, the polymer PL is formed in a streak shape extending along the first direction X. The liquid crystal molecules LM are dispersed in the gaps of the polymer PL and are aligned so that their major axes are along the first direction X. That is, the initial alignment direction of the liquid crystal molecules LM is set to the first direction X.

[0015] The alignment direction of the polymer PL hardly changes regardless of the presence or absence of an electric field. On the other hand, the alignment direction of the liquid crystal molecules LM changes in response to the electric field when a voltage higher than the threshold value is applied to the liquid crystal layer LC. When no voltage is applied to the liquid crystal layer LC, the optical axes of the polymer PL and the liquid crystal molecules LM are parallel to each other, and the light incident on the liquid crystal layer LC is transmitted through the liquid crystal layer LC almost without being scattered (transparent state). When a voltage is applied to the liquid crystal layer LC, the optical axes of the polymer PL and the liquid crystal molecules LM intersect each other, and the light incident on the liquid crystal layer LC is scattered within the liquid crystal layer LC (scattering state).

[0016] Note that the configuration of the polymer-dispersed liquid crystal including the polymer PL and the liquid crystal molecules LM is not limited to the above example.

[0017] The display area DA includes a plurality of pixels PX arranged in a matrix in the first direction X and the second direction Y.

[0018] As shown enlarged in the figure, each pixel PX includes a switching element SW, a pixel electrode PE, a common electrode CE, a liquid crystal layer LC, etc. The switching element SW is constituted by, for example, a thin film transistor (TFT) and is electrically connected to the scanning line G and the signal line S.

[0019] The scanning line G extends in the first direction X and is electrically connected to the switching element SW in each of the pixels PX arranged in the first direction X. That is, the alignment processing directions D1 and D2 are parallel to the scanning line G. Also, the streak-shaped polymer PL extends along the scanning line G.

[0020] The signal line S extends in the second direction Y, intersects with the scan line G, and is electrically connected to the switching element SW in each of the pixels PX aligned in the second direction Y. In other words, the orientation processing direction D1 and orientation processing direction D2 intersect or are perpendicular to the signal line S. Furthermore, the striated polymer PL extends so as to intersect with the signal line S.

[0021] The pixel electrodes PE are electrically connected to the switching element SW. Each pixel electrode PE faces a common electrode CE, and the electric field generated between the pixel electrode PE and the common electrode CE drives the liquid crystal layer LC (particularly the liquid crystal molecules LM). Capacitance CS is formed, for example, between an electrode at the same potential as the common electrode CE and an electrode at the same potential as the pixel electrode PE.

[0022] The scan line G, signal line S, switching element SW, and pixel electrode PE are located between the transparent substrate 110 and the liquid crystal layer LC1. The common electrode CE is located between the transparent substrate 120 and the liquid crystal layer LC.

[0023] IC chips (CP) and flexible printed circuit boards (FP) are mounted on the transparent substrate (110).

[0024] The light source unit 200 is positioned along the edge of the display panel 100 that extends in a first direction X. The light source unit 200 is configured to emit illumination light for illuminating the liquid crystal layer LC. The light source unit 200 comprises a plurality of light-emitting elements LDs arranged at intervals in the first direction X. Each of the plurality of light-emitting elements LDs comprises a red light-emitting element LDR, a green light-emitting element LDG, and a blue light-emitting element LDB as light-emitting parts. The red light-emitting unit (LDR) is configured to emit red light with a dominant wavelength of λr. The green light-emitting unit (LDG) is configured to emit green light with a dominant wavelength of λg. The blue light-emitting unit (LDB) is configured to emit blue light with a dominant wavelength of λb. These red light-emitting unit (LDR), green light-emitting unit (LDG), and blue light-emitting unit (LDB) are configured to light up sequentially. However, the red light-emitting unit (LDR), green light-emitting unit (LDG), and blue light-emitting unit (LDB) may all light up simultaneously.

[0025] Figure 2 is a cross-sectional view of the display device 1 along line A and B in Figure 1.

[0026] In the display panel 100, the scan lines, signal lines, switching elements, insulating films, etc., are omitted from the illustration, and only the main parts necessary for explanation are shown.

[0027] Transparent substrates 110 and 120 face each other in the third direction Z. The liquid crystal layer LC is located between transparent substrates 110 and 120. Each pixel electrode PE of a pixel PX is located between transparent substrate 110 and liquid crystal layer LC and is covered with alignment film AL1. A common electrode CE facing multiple pixel electrodes PE is located between transparent substrate 120 and liquid crystal layer LC and is covered with alignment film AL2. The liquid crystal layer LC is in contact with alignment films AL1 and AL2. The pixel electrodes PE and common electrode CE are transparent electrodes formed from a transparent conductive material such as indium tin oxide (ITO).

[0028] In the illustrated example, the display panel 100 further comprises a transparent substrate 130, a transparent substrate 140, and a selective reflective layer 300. The transparent substrates 130 and 140 face each other in a third direction Z. The transparent substrates 110 and 120, and the liquid crystal layer LC are located between the transparent substrates 130 and 140 in the third direction Z. The selective reflective layer 300 is located between the transparent substrates 110 and 130. The selective reflective layer 300 is arranged to overlap at least the entire display area DA, and in the illustrated example, has an edge portion 300E that overlaps with the side surface 120E of the transparent substrate 120.

[0029] When a sheet-like selective reflective layer 300 is placed between a transparent substrate 110 and a transparent substrate 130, it is desirable that the selective reflective layer 300 be bonded to either the transparent substrate 110 or the transparent substrate 130, and even more preferably to both the transparent substrate 110 and the transparent substrate 130. When the selective reflective layer 300 is formed directly on the transparent substrate 110, it is desirable that the selective reflective layer 300 be bonded to the transparent substrate 130. Alternatively, when the selective reflective layer 300 is formed directly on the transparent substrate 130, it is desirable that the selective reflective layer 300 be bonded to the transparent substrate 110. The adhesive layer for bonding the selective reflective layer 300 is preferably transparent and has a refractive index approximately the same as that of the transparent substrates 110 and 130. Undesirable interfacial reflection is suppressed by eliminating the presence of air layers between the selective reflective layer 300 and the transparent substrate 110, and between the selective reflective layer 300 and the transparent substrate 130.

[0030] The transparent substrate 140 is bonded to the transparent substrate 120. In the illustrated example, the side surface 120E of the transparent substrate 120 and the side surface 140E of the transparent substrate 140 overlap in the third direction Z. Both side surfaces 120E and 140E extend in the first direction X. The transparent substrate 140 may extend further along the second direction Y than the transparent substrate 120. In this case, the side surface 120E of the transparent substrate 120 is located between the side surface 140E of the transparent substrate 140 and the display area DA in the second direction Y.

[0031] The main surface 130A of the transparent substrate 130 and the main surface 140A of the transparent substrate 140 are both parallel to the XY plane and are in contact with the air.

[0032] The light source unit 200 faces the side surface 140E of the transparent substrate 140 in the second direction Y. In this case, the side surface 140E corresponds to the edge of the display panel 100. The light source unit 200 may also face both the side surface 120E and the side surface 140E. The light source unit 200 comprises a light-emitting element LD and a light guide LG. The light guide LG is located between the light-emitting element LD and the transparent substrate 140 in the second direction Y.

[0033] Transparent substrates 110 and 120 are colorless, transparent glass substrates formed from the same material. In one example, transparent substrates 110 and 120 are made of alkali-free glass or optical glass.

[0034] The transparent substrate 130 is a glass substrate made of a different material from the transparent substrates 110 and 120. In one example, the transparent substrate 130 is made of soda-lime glass (blue glass). Such a transparent substrate 130 is used as window glass or automotive glass.

[0035] The transparent substrate 140 is made of a different material than the transparent substrate 130. In one example, the transparent substrate 140 is a glass substrate made of the same material as the transparent substrate 120. The transparent substrate 140 may also be a resin substrate.

[0036] The transparent substrates 130 and 140 function as cover members. The transparent substrate 140 also functions as a light guide plate that propagates the illumination light L emitted from the light source unit 200 along the second direction Y.

[0037] In one example, the transparent substrate 130 is thicker than the transparent substrate 110, and the transparent substrate 140 is thicker than the transparent substrate 120. Note that the transparent substrate 140 may be omitted. If the transparent substrate 140 is omitted, the light source unit 200 is positioned so as to face the side surface 120E of the transparent substrate 120 in the second direction Y.

[0038] Such a display panel 100 is driven in synchronization with the light source unit 200. For example, in the display panel 100, each pixel PX is driven based on the red video signal, and the red light-emitting part LDR of the light source unit 200 lights up during the period when a potential is maintained in all pixels PX. Next, in the display panel 100, each pixel PX is driven based on the green video signal, and the green light-emitting part LDG of the light source unit 200 lights up during the period when a potential is maintained in all pixels PX. Subsequently, in the display panel 100, each pixel PX is driven based on the blue video signal, and the blue light-emitting part LDB of the light source unit 200 lights up during the period when a potential is maintained in all pixels PX.

[0039] When a voltage exceeding a threshold is applied to the liquid crystal layer LC of each pixel PX, the liquid crystal layer LC enters a scattering state. The illumination light L emitted from the light source unit 200 is scattered by the liquid crystal layer LC of each pixel PX, becoming display light, and a color image is displayed in the display area DA. The display light emitted from the display panel 100 is linearly polarized and parallel to the first direction X.

[0040] When the liquid crystal layer LC is transparent, the background can be observed through the display panel 100 when the display panel 100 is viewed from the main surface 130A side, and similarly, the background can be observed through the display panel 100 when the display panel 100 is viewed from the main surface 140A side.

[0041] Figure 3 shows an example of the wiring layout included in the display panel 100.

[0042] Multiple scan lines G each extend in a first direction X and are aligned in a second direction Y. Multiple signal lines S each extend in a second direction Y and are aligned in the first direction X. The switching element SW, shown in a simplified diagram here, is located at the intersection of the scan lines G and the signal lines S.

[0043] The insulating layer IL, shown by the dashed line, is formed in a grid pattern. The insulating layer IL has a first portion ILX extending in the first direction X and a second portion ILY extending in the second direction Y. The first portion ILX mainly overlaps the scan lines G. The second portion ILY mainly overlaps the signal lines S.

[0044] Figure 4 is a cross-sectional view of the display panel 100 along the CD line shown in Figure 3.

[0045] The insulating layer 111 is placed on the transparent substrate 110. The insulating layer 112 is placed on top of the insulating layer 111. These insulating layers 111 and 112 are inorganic insulating layers formed from, for example, silicon oxide, silicon nitride, or silicon oxynitride.

[0046] The scan line G shown in Figure 3 is located between insulating layer 111 and insulating layer 112. The signal line S is located on insulating layer 112. Insulating layer IL is located on insulating layer 112. In the illustrated cross-section, insulating layer IL covers the signal line S. Insulating layer IL is an organic insulating layer.

[0047] The transparent electrode TE covers the insulating layer IL. The transparent electrode TE is made of a transparent conductive material such as ITO. The insulating layer 113 is placed on top of the insulating layer 112 and covers the transparent electrode TE. The pixel electrode PE is placed on top of the insulating layer 113. The insulating layer 113 is an inorganic insulating layer located between the transparent electrode TE and the pixel electrode PE. The alignment film AL1 covers the pixel electrode PE and the insulating layer 113 and is in contact with the liquid crystal layer LC.

[0048] The light-shielding layer BM is positioned between the transparent substrate 120 and the liquid crystal layer LC. Furthermore, the light-shielding layer BM is located directly above the signal line S and directly above the insulating layer IL. Although not shown in the diagram, the light-shielding layer BM is also located directly above the scan line G and the switching element SW.

[0049] The common electrode CE faces the pixel electrode PE in the third direction Z and covers the light-shielding layer BM. The alignment layer AL2 covers the common electrode CE and is in contact with the liquid crystal layer LC.

[0050] Next, a selective reflective layer 300 applicable to this embodiment will be described.

[0051] Figure 5A is a diagram illustrating one of the characteristics required for the selective reflective layer 300.

[0052] The horizontal axis of the figure represents the angle of incidence θi (deg) of light incident on the selective reflective layer 300, and the vertical axis represents the reflectance R (%). When light in the red wavelength range is incident on the selective reflective layer 300, the reflectance R reaches its maximum value Rp at an incident angle θi greater than or equal to the critical angle θc at which total internal reflection occurs.

[0053] Figure 5B is a diagram illustrating other characteristics required of the selective reflective layer 300.

[0054] The horizontal axis of the figure represents the wavelength λ (nm) of light incident on the selective reflective layer 300, and the vertical axis represents the reflectance R (%). The incident angle θi of light incident on the selective reflective layer 300 is assumed to be greater than the critical angle θc of light in the red wavelength range shown in Figure 5A.

[0055] In the selective reflective layer 300, light in the blue wavelength range and light in the green wavelength range are almost completely transmitted. Therefore, the reflectance in the blue wavelength range and green wavelength range of the selective reflective layer 300 is extremely small. On the other hand, light in the red wavelength range is almost completely reflected in the selective reflective layer 300. Furthermore, in the selective reflective layer 300, the wavelength range in which the reflectance R is at its maximum value Rp includes the main wavelength λr of the red light-emitting part LDR of the light-emitting element LD.

[0056] Figure 6A is a diagram illustrating the reflection characteristics of the selective reflection layer 300.

[0057] The light incident on the selective reflective layer 300 includes red light with a dominant wavelength λr emitted from the red light-emitting section LDR, green light with a dominant wavelength λg emitted from the green light-emitting section LDG, and blue light with a dominant wavelength λb emitted from the blue light-emitting section LDB. The incident angle θi with respect to the normal of the selective reflective layer 300 is assumed to be a predetermined incident angle θp that is greater than the critical angle θc shown in Figure 5A. The selective reflective layer 300 is configured to transmit blue light with a dominant wavelength λb and green light with a dominant wavelength λg at an incident angle θp, and to reflect red light with a dominant wavelength λr.

[0058] Figure 6B is a diagram illustrating the transmission characteristics of the selective reflective layer 300.

[0059] The selective reflective layer 300 is configured to transmit blue light with a dominant wavelength λb, green light with a dominant wavelength λg, and red light with a dominant wavelength λr when light is incident from its normal direction, that is, at an incident angle θi of 0°.

[0060] Such a selective reflective layer 300 is formed, for example, as a dielectric multilayer film. As one example, PICASUS manufactured by Toray Industries, Inc. can be used as the selective reflective layer 300.

[0061] Figure 7 is a diagram illustrating the function of the selective reflective layer 300 in the display panel 100.

[0062] If the transparent substrate 130 is automotive glass with a bluish tint, the transparent substrate 130 has a higher absorption rate for light in the red wavelength range compared to the transparent substrate 110. Therefore, with respect to the red light of the dominant wavelength λr in the illumination light L, the absorption rate of the transparent substrate 130 is higher than that of the transparent substrate 110.

[0063] When illumination light L is incident on such a transparent substrate 130, the absorption rate of red light with a dominant wavelength λr on the transparent substrate 130 is higher than that of blue light with a dominant wavelength λb, and also higher than that of green light with a dominant wavelength λg. Therefore, when blue light with a dominant wavelength λb, green light with a dominant wavelength λg, and red light with a dominant wavelength λr, all contained in the illumination light L, are incident on the transparent substrate 130 in sequence, the red component of the illumination light L becomes insufficient, preventing the desired white color from being obtained, and causing the color of the illumination light L to shift towards a cyan-based color.

[0064] Therefore, in this embodiment, a selective reflective layer 300 having the above-described characteristics is placed between the transparent substrate 110 and the transparent substrate 130. The optical effect of the illumination light L will be described below.

[0065] The blue light with dominant wavelength λb, the green light with dominant wavelength λg, and the red light with dominant wavelength λr contained in the illumination light L propagate from the transparent substrate 140 toward the transparent substrate 120, pass through the liquid crystal layer LC and the transparent substrate 110, and then reach the selective reflective layer 300. In the selective reflective layer 300, the red light with dominant wavelength λr of the illumination light L becomes reflected light RL. Also in the selective reflective layer 300, the blue light with dominant wavelength λb and the green light with dominant wavelength λg of the illumination light L become transmitted light TL. The reflected light RL, after being reflected by the selective reflective layer 300, propagates toward the liquid crystal layer LC. The transmitted light TL, after being reflected at the interface between the transparent substrate 130 and the air, passes through the selective reflective layer 300 and propagates toward the liquid crystal layer LC.

[0066] Thus, the red light hardly reaches the transparent substrate 130. Therefore, unwanted absorption of red light by the transparent substrate 130 is suppressed. In addition, the red light reflected by the selective reflective layer 300, and the green and blue light transmitted through the transparent substrate 130, proceed again toward the liquid crystal layer LC. Therefore, the chromaticity of the illumination light L can be maintained at the desired white chromaticity.

[0067] The display light DL, obtained by scattering the illumination light L in the liquid crystal layer LC, contains blue light at the dominant wavelength λb, green light at the dominant wavelength λg, and red light at the dominant wavelength λr. The display light DL is transmitted through the transparent substrate 130 and the transparent substrate 140. In particular, a user facing the transparent substrate 140 can observe the display light DL of the desired chromaticity.

[0068] As described above, according to this embodiment, it is possible to suppress the deterioration of display quality caused by the optical properties of the transparent substrate 130.

[0069] Next, we will describe examples of applications for the display device 1.

[0070] Figure 8 shows an example of application of the display device 1.

[0071] Application Example 1 corresponds to the case where the display device 1 is installed at the front of the vehicle. The transparent substrate 130 of the display device 1 is the front windshield 410. The display area DA is superimposed on the front windshield 410. The light source unit 200, including the light-emitting element LD, is installed in the frame 420 surrounding the front windshield 410, or on the dashboard.

[0072] In this application example 1, the vehicle driver and passengers can see the area in front of the vehicle through the front windshield 410, and can also see the image displayed in the display area DA.

[0073] Figure 9 shows an example of application of the display device 1, part 2.

[0074] Application Example 2 corresponds to the case where the display device 1 is installed on the side of the vehicle. The transparent substrate 130 of the display device 1 is the side window 430. The display area DA is superimposed on the side window 430. The light source unit 200, including the light-emitting element LD, is installed on the door frame 440.

[0075] In this application example 2, the driver or passenger of the vehicle can view the side of the vehicle through the side window 430 and also view the image displayed in the display area DA.

[0076] In the above embodiment, for example, transparent substrate 110 corresponds to the first transparent substrate, transparent substrate 120 corresponds to the second transparent substrate, transparent substrate 130 corresponds to the third transparent substrate, and transparent substrate 140 corresponds to the fourth transparent substrate.

[0077] As described above, this embodiment provides a display device that can suppress a decrease in display quality.

[0078] All display devices that a person skilled in the art can implement by appropriately modifying the design based on the display devices described above as embodiments of the present invention also fall within the scope of the present invention insofar as they encompass the gist of the present invention.

[0079] Within the scope of the spirit of the present invention, a person skilled in the art can conceive of various modifications, and such modifications are also understood to fall within the scope of the present invention. For example, modifications made by a person skilled in the art to the above-described embodiments, such as adding, deleting, or changing the design of components, or adding, omitting, or changing the conditions of processes, are also included within the scope of the present invention, as long as they retain the gist of the present invention.

[0080] Furthermore, any other effects and benefits brought about by the embodiments described above that are obvious from the description herein or that can be appropriately conceived by those skilled in the art are naturally considered to be brought about by the present invention. [Explanation of symbols]

[0081] 1...Display device 100...Display panel DA...Display area PX...Pixel 110...Transparent substrate 120...Transparent substrate LC...Liquid crystal layer AL1…Alignment layer AL2…Alignment layer G...Scan line S...Signal line SW...Switching element PE…Pixel electrode TE…Transparent electrode CE…Common electrode 200...Light source unit LD...Light-emitting element LDR...Red light-emitting part LDG...Green light-emitting part LDB...Blue light-emitting part LG…Light guide 300...Selective reflective layer

Claims

1. Display panel and The display panel comprises a light source unit arranged along the edge of the display panel, The aforementioned display panel is First transparent substrate and A second transparent substrate facing the first transparent substrate, A liquid crystal layer is sealed between the first transparent substrate and the second transparent substrate, and comprises a polymer-dispersed liquid crystal containing polymers and liquid crystal molecules. A third transparent substrate facing the first transparent substrate, The device comprises a selective reflective layer located between the first transparent substrate and the third transparent substrate, The selective reflection layer is configured to transmit light in the blue wavelength range and light in the green wavelength range, and to reflect light in the red wavelength range, at a predetermined incident angle with respect to its normal. Display device.

2. The selective reflective layer is configured to transmit light in the blue wavelength range, light in the green wavelength range, and light in the red wavelength range at an incident angle of 0°. The display device according to claim 1.

3. The light source unit includes a red light-emitting section configured to emit red light, The dominant wavelength of the red light emitted from the red light-emitting section is included in the wavelength range in which the reflectance of the selective reflection layer is at its maximum value. The display device according to claim 1.

4. The third transparent substrate is formed of a different material from the first transparent substrate and the second transparent substrate. The display device according to claim 1.

5. The light source unit includes a red light-emitting section configured to emit red light, In the main wavelength of the red light emitted from the red light-emitting portion, the absorption rate of the third transparent substrate is higher than that of the first transparent substrate. The display device according to claim 4.

6. The aforementioned light source unit is A red light-emitting section configured to emit red light, A green light-emitting unit configured to emit green light, It comprises a blue light-emitting section configured to emit blue light, The red light-emitting section, the green light-emitting section, and the blue light-emitting section are configured to light up sequentially. The display device according to claim 1.

7. The display panel further comprises a fourth transparent substrate that faces the second transparent substrate and is bonded to the second transparent substrate. The aforementioned light source unit is A light-emitting element configured to emit light, The system comprises a light guide positioned between the light-emitting element and the side surface of the fourth transparent substrate, The display device according to claim 1.

8. The fourth transparent substrate is made of a different material from the third transparent substrate and is formed of the same material as the second transparent substrate. The display device according to claim 7.

9. The third transparent substrate is made of soda-lime glass. The display device according to claim 1.

10. The third transparent substrate mentioned above is automotive glass. The display device according to claim 1.

11. The display panel further comprises the first transparent substrate and the liquid crystal layer, Scan lines and, A signal line that intersects the aforementioned scan line, A switching element electrically connected to the scan line and the signal line, The switching element and the pixel electrode electrically connected, The scanning line, the signal line, and the organic insulating layer formed in a grid pattern superimposed on the switching element, A transparent electrode covering the aforementioned organic insulating layer, The system comprises an inorganic insulating layer located between the transparent electrode and the pixel electrode. The display device according to claim 1.

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