Multicolor cholesterol liquid crystal display device with light source and cholesterol liquid crystal display module

Abstract

The utility model provides a cholesterol liquid crystal display module with a light source. The cholesterol liquid crystal display module comprises lower glass, a cholesterol liquid crystal unit, upper glass, a plurality of light-emitting units and an electric connecting device. A containing space is formed in the side of the upper glass and used for containing a plurality of light-emitting units. Each light-emitting unit comprises a flexible circuit board, an LED assembly and a reflector, the LED assembly is electrically connected to the conductive layer and the flexible circuit board, and the electric connection device is electrically connected with two adjacent flexible circuit boards. The reflector is arranged on the outer side, away from the upper glass, of the LED assembly and fixed to the flexible circuit board or the upper surface of the lower glass at a preset inclination angle theta r, the inclination angle theta r is not larger than 61 degrees, and the horizontal projection of the reflector covers the LED assembly. The utility model further provides a multi-color cholesterol liquid crystal display device which is formed by the three-layer cholesterol liquid crystal display module and provided with the light source.

Description

Technical Field

[0001] The present application relates to the technical field of liquid crystal displays, and particularly to a cholesteric liquid crystal display device and its light source technology. Background Art

[0002] Cholesteric liquid crystal is one of the main technologies applied to e-book displays. Due to its bistable display characteristics, that is, when the screen is static, almost no electricity is required, so it has the effect of power saving. At the same time, cholesteric liquid crystal belongs to reflective display technology and can be clearly viewed in the presence of external ambient light, but it cannot be viewed in the absence of external ambient light. To solve this problem, generally, a front light source is used for supplementary lighting. Some externally add a lamp outside the viewing surface of the display and directly irradiate the viewing surface of the display, and some will further configure a light guide plate to evenly guide the light of the external lamp and then irradiate the viewing surface of the display. However, the latter will reduce the light input amount in a normal environment and affect the reflectivity.

[0003] Regarding the prior art of combining a light source device and a cholesteric liquid crystal display, Patent No. CN101556410A discloses a cholesteric liquid crystal display device related to autostereoscopic imaging, including: a first liquid crystal panel, a second liquid crystal panel disposed below the first liquid crystal panel, and a backlight source disposed below the second liquid crystal panel and used for emitting light. Among them, the second liquid crystal panel includes a cholesteric liquid crystal panel in which a grid area and a slit area are alternately arranged according to the input electric field, a first compensation film disposed above the cholesteric liquid crystal panel, and a second compensation film portion disposed below the cholesteric liquid crystal panel; the backlight source includes a reflector for reflecting light. Thereby, an autostereoscopic imaging display device is provided that can easily switch between two-dimensional planar images and three-dimensional stereoscopic images through a modular cholesteric liquid crystal panel and a compensation film, simplifies the manufacturing process, and reduces the manufacturing cost.

[0004] In the prior art, Patent No. CN111308785A discloses a cholesteric liquid crystal display device, including: a first substrate and a second substrate disposed opposite to each other; a blue light backlight source located between the first substrate and the second substrate; a color conversion layer located on the side of the blue light backlight source away from the second substrate; a light reflection layer located on the side of the color conversion layer away from the blue light backlight source and used for reflecting the blue light that is not completely absorbed by the color conversion layer. The light reflection layer includes a cholesteric liquid crystal layer having optical rotation; an alignment layer located between the light reflection layer and the first substrate, and horizontally aligns the liquid crystal molecules in the cholesteric liquid crystal layer with respect to the first substrate or the second substrate.

[0005] In the prior art, patent number CN114114769A discloses a cholesteric liquid crystal handwriting device, which includes a light source, a first substrate, a second substrate, and a guest-host type dyeing liquid crystal layer disposed between the first substrate and the second substrate. A first conductive layer is provided on one side of the first substrate close to the second substrate, and a second conductive layer is provided on one side of the second substrate close to the first substrate. The light source is disposed on the side of the second substrate away from the first substrate. The guest-host type dyeing liquid crystal layer includes cholesteric liquid crystal, black dye, and chiral agent. The cholesteric liquid crystal has a first zero-field steady state, a second zero-field steady state, and an applied electric field steady state. When the cholesteric liquid crystal is in the first zero-field steady state and the applied electric field steady state, the emitted light of the light source diverges outward. When the cholesteric liquid crystal is in the second zero-field steady state, the emitted light of the light source and the ambient light are absorbed by the guest-host type dyeing liquid crystal layer.

[0006] In the prior art, patent number TW202022459A discloses a cholesteric liquid crystal light-emitting device, which includes: a light source element, a wavelength conversion layer, a first liquid crystal layer, and a second liquid crystal layer. The first liquid crystal layer includes cholesteric liquid crystal in a planar state. The second liquid crystal layer includes cholesteric liquid crystal in a focal-conic state. The first liquid crystal layer is located between the light source element and the wavelength conversion layer, and is also located between the light source element and the second liquid crystal layer.

[0007] The above prior art still has deficiencies in industrial implementation and needs to be optimized and improved. Summary of the Utility Model

[0008] The purpose of this application is to solve the deficiencies of the prior art, integrate the LED light source and the reflective technology into the cholesteric liquid crystal display, and complete a self-luminous cholesteric liquid crystal display module and a multicolor cholesteric liquid crystal display device that can be operated without external light source illumination.

[0009] The first preferred embodiment proposed by this application is a self-luminous cholesteric liquid crystal display module for monochromatic display, which includes a lower glass, a flexible circuit board, a cholesteric liquid crystal unit, an upper glass, a transparent optical adhesive, and a plurality of light-emitting units. The horizontal projection of the lower glass is larger than and covers the horizontal projection of the upper glass, and a receiving space is formed in the intersection area above the lower glass and on one side of the upper glass.

[0010] A plurality of light-emitting units are disposed in the receiving space, and each light-emitting unit includes an LED component and a reflective sheet. The flexible circuit board is disposed on the upper surface of the lower glass, and a conductive layer is further formed above the flexible circuit board. The LED component is electrically connected to the conductive layer.

[0011] The cholesterol liquid crystal display module with a built-in light source further includes at least one electrical connection device disposed between the flexible circuit boards of two adjacent light-emitting units, and the electrical connection device electrically connects the two adjacent flexible circuit boards.

[0012] The reflective sheet is disposed on the outer side of the LED component away from the upper glass and is fixed to one of the flexible circuit board and the upper surface of the lower glass at a preset inclination angle θr, and the inclination angle θr is not greater than 61 degrees, and the horizontal projection of the reflective sheet covers the LED component.

[0013] By means of the light reflection function of the reflective sheet with a special angle setting in the light-emitting unit, the light emitted by the LED component can be effectively reflected into the upper glass, and total reflection is formed on the upper surface of the upper glass, and then penetrates downward through the lower surface of the upper glass and the ITO and then enters the cholesterol liquid crystal unit, serving as the light required for the reflective cholesterol liquid crystal to display colors and images, so that the cholesterol liquid crystal unit generates the function of image display. Thereby, the cholesterol liquid crystal display module with a built-in light source can provide monochromatic display without an external light source.

[0014] Preferably, a plurality of light-emitting units are disposed in the accommodation space outside the periphery of the upper glass. By electrically connecting the flexible circuit boards of two adjacent light-emitting units through the electrical connection device, a plurality of light-emitting units outside the periphery of the upper glass can be synchronously driven to provide a brighter and more uniform light source for the cholesterol liquid crystal unit.

[0015] Based on the same technical concept, the present application further provides a second preferred embodiment, which is a multicolor cholesterol liquid crystal display device with a built-in light source capable of full-color display, including three cholesterol liquid crystal display modules with built-in light sources connected in sequence from bottom to top, and a transparent optical adhesive is disposed between the cholesterol liquid crystal display modules with built-in light sources. The features of each cholesterol liquid crystal display module are as described in the foregoing first preferred embodiment.

[0016] Through the overall action of three cholesterol liquid crystal display modules with built-in light sources of different colors, the multicolor cholesterol liquid crystal display device with a built-in light source can provide full-color display without an external light source.

[0017] The advantages and spirit of the present application can be further understood through the following detailed description and the accompanying drawings. Brief Description of the Drawings

[0018] The provided diagrams are used to provide a further understanding of the embodiments of the present application, which form a part of the specification, illustrate the implementation manners of the present application, and explain the principles of the present application together with the written description. Obviously, the diagrams in the following description are only some embodiments of the present application and are not used to limit the implementation manners of the present application. For those of ordinary skill in the art, without creative efforts, other diagrams can be derived based on these diagrams. The provided diagrams include:

[0019] Figure 1 is the first preferred embodiment proposed by the present application, a schematic cross-sectional view of a cholesterol liquid crystal display module with a built-in light source;

[0020] Figure 2 is the first preferred embodiment proposed by the present application, a schematic cross-sectional view of a light transmission medium which is a light guiding structure;

[0021] Figure 3 is a perspective view of an embodiment of a cholesterol liquid crystal display module with a built-in light source, having two light emitting units proposed by the present application;

[0022] Figure 4 is a perspective view of an embodiment of a cholesterol liquid crystal display module with a built-in light source, having four light emitting units proposed by the present application;

[0023] Figure 5 is a combined schematic view of an LED component and a flexible circuit board of a cholesterol liquid crystal display module with a built-in light source proposed by the present application;

[0024] Figure 6 is a perspective view of an embodiment of a reflective sheet of a cholesterol liquid crystal display module with a built-in light source proposed by the present application;

[0025] Figure 7 is the second preferred embodiment proposed by the present application, an exploded view of a multi-color cholesterol liquid crystal display device with a built-in light source.

[0026] Reference numerals:

[0027] 3: Multi-color cholesterol liquid crystal display device with a built-in light source

[0028] 10: Cholesterol liquid crystal display module with a built-in light source

[0029] 111: Lower glass

[0030] 112: Upper glass

[0031] 12: Light emitting unit

[0032] 125: Light guiding structure

[0033] 126: Flexible circuit board

[0034] 127: Reflective sheet

[0035] 1271: Horizontally extending portion

[0036] 128: Conductive layer

[0037] 129: LED component

[0038] 13: Cholesteric liquid crystal cell

[0039] 14: Accommodating space

[0040] 15: Electrical connection device

[0041] 17: Transparent optical adhesive

[0042] θr: Tilt angle

[0043] W_led: Width of the LED component

[0044] L: Hypotenuse length of the reflective sheet along θr

[0045] θ_int: Incident angle of light entering from the side of the upper glass 112

[0046] θ_gls: Incident angle of light entering the transparent optical adhesive from the upper surface of the upper glass 112 Detailed implementation manners

[0047] The specific structures and functional details disclosed in the description of the present application are only representative and are for the purpose of describing the exemplary embodiments of the present application. The present application can be specifically implemented in many alternative forms and should not be construed as being limited only to the embodiments disclosed herein.

[0048] It should be understood that the orientation or positional relationships indicated by the terms "center", "lateral", "upper", "lower", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. in the description of the present application are based on the orientation or positional relationships shown in the drawings. Except where the applicant specifically emphasizes and defines their functional roles, they are only for the convenience of describing the present application and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present application. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating relative importance or implying the number of technical features. In the description of the present application, unless otherwise stated, "a plurality of" means two or more. Additionally, the term "comprising" and any variations thereof mean "including at least".

[0049] It should also be understood that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "linked" in the description of this application should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrally formed connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in this application according to specific circumstances.

[0050] Unless the context clearly indicates otherwise, the terms "a" and "an" in the description of this application also intend to include the plural. It should also be understood that the terms "include" and / or "comprise" specify the existence of the stated features, steps, operations, units, and / or components, without excluding the existence or addition of one or more other features, steps, operations, units, components, and / or their combinations.

[0051] The objective of this application is to provide a cholesterol liquid crystal display module with a built-in light source and a multicolor cholesterol liquid crystal display device. By using the embedded LED components, electrical connection devices, and reflectors with special angle settings, a monochromatic or full-color display effect can be provided without an external light source.

[0052] The first preferred embodiment

[0053] The first preferred embodiment proposed in this application is a cholesterol liquid crystal display module 10 with a built-in light source. Please refer to Figures 1 to 6 .

[0054] Please see Figure 1 , the cholesterol liquid crystal display module 10 with a built-in light source includes a lower glass 111, a flexible circuit board 126, a conductive layer 128, a cholesterol liquid crystal cell 13, an upper glass 112, a transparent optical adhesive 17, a plurality of light-emitting units 12, and at least one electrical connection device 15.

[0055] As Figure 1 shown in Figure 2 , the horizontal projection of the upper glass 112 is larger than and covers the horizontal projection of the cholesterol liquid crystal cell 13, and the horizontal projection of the lower glass 111 is larger than and covers the horizontal projection of the upper glass 112. Therefore, a receiving space 14 is formed in the intersection area on the side of the upper glass 112 and above the lower glass 111. The receiving space 14 can be on two adjacent sides of the upper glass 112 or on all four sides of the upper glass 112.

[0056] A plurality of light-emitting units 12 are arranged in the receiving space 14. Please see Figure 5 shown in Figure 6, each light-emitting unit 12 includes a flexible circuit board 126, an LED component 129, and a reflective sheet 127. The flexible circuit board 126 is disposed on the upper surface of the lower glass 111, and a conductive layer 128 is further formed above the flexible circuit board 126. The LED component 129 is electrically connected to the conductive layer 128. In order to improve the display brightness or uniformity of the self-luminous cholesteric liquid crystal display module 10, or the areas of the cholesteric liquid crystal cells 13 and the upper glass 112 are relatively large, light-emitting units 12 can be respectively disposed in two adjacent accommodating spaces 14 of the upper glass 112, as shown in Figure 3 ; more preferably, light-emitting units 12 can be respectively disposed in the accommodating spaces 14 on four sides, as shown in Figure 4 .

[0057] The electrical connection device 15 is one of the focuses of the present application. Since there are multiple light-emitting units 12, considering synchronous light emission and control, the electrical connection device 15 proposed in the present application has a conductive structure inside, and it plays its role. The electrical connection device 15 is disposed between the flexible circuit boards 126 of two adjacent light-emitting units 12, as shown in Figure 4 , and electrically connects the two adjacent flexible circuit boards 126. Therefore, as long as one flexible circuit board 126 is electrically conductive, all the flexible circuit boards 126 of the light-emitting units 12 can be made electrically conductive through the electrical connection device 15. When the number of light-emitting units 12 is two, only one or less electrical connection devices 15 are required; when the number of light-emitting units 12 is four and they are arranged around the outer periphery of the upper glass 112, more than three electrical connection devices 15 are required.

[0058] Please refer to Figure 1 and Figure 2 . In terms of a cross-sectional view, the light emitted by the LED component 129 is not in a single direction in principle, but in a fan shape. However, the main direction is upward because the top surface of the LED chip in the LED component 129 is upward. Since the light-emitting direction of the LED component 129 does not directly enter the upper glass 112, a reflective sheet 127 is required to guide the light emitted by the LED component 129 into the upper glass 112.

[0059] The reflective sheet 127 is disposed on the outer side of the LED component 129 away from the upper glass 112 and fixed at a preset inclination angle θr, and the inclination angle θr is not greater than 61 degrees. Since the reflective sheet 127 does not need to be conductive, it can be fixed on the flexible circuit board 126 (such as Figure 6 ), or fixed on the upper surface of the lower glass 111 (such as Figure 1 and Figure 2) It is also acceptable. When the reflective sheet 127 is fixed to the flexible circuit board 126, it can be connected and fixed by means such as double-sided tape, anisotropic conductive adhesive, lead-free solder, or other metal welding. When the reflective sheet 127 is fixed to the upper surface of the lower glass 111, the bonding method is preferred. Of course, these are only preferred embodiments, and the present application is not limited thereto.

[0060] Furthermore, the tilt angle θr must first satisfy the following condition:

[0061] θr≥Cos -1 (W_led / L) (1)

[0062] Wherein, W_led is the width of the LED component 129, and L is the hypotenuse length of the reflective sheet 127 along θr. The meaning of formula (1) is that the horizontal projection of the reflective sheet 127 must cover the LED component to reflect the light emitted by the LED component 129 to the greatest extent.

[0063] Furthermore, the horizontal projection of the reflective sheet 127 must cover the LED component to reflect the light emitted by the LED component 129 to the greatest extent.

[0064] Furthermore, the reflective sheet 127 may further include a horizontal extension portion 1271 facing the upper glass 112, such as Figure 6 , and the reflection effect is better.

[0065] In order to reduce the overall thickness of the self-luminous cholesteric liquid crystal display module 10, the lower glass 111 and the upper glass 112 are preferably thin glass sheets with a thickness of 0.1 - 0.7 mm. The LED component 129 is electrically connected to the conductive layer 128 by means such as anisotropic conductive adhesive, lead-free solder, or other metal welding. The LED component 129 includes a plurality of LED elements. The LED elements can be packaged LEDs, or unpackaged micro-LEDs or mini-LEDs with a base. Since the sizes of micro-LEDs and mini-LEDs are small, after forming an LED array, they can be arranged more densely. As a light source, the difference between light and dark can be reduced, and the overall light uniformity is better.

[0066] Basically, an LED is a point light source, and the light uniformity effect is poor. In order to achieve a better light guiding and light homogenizing effect, the self-luminous cholesteric liquid crystal display module 10 may further include a light guiding structure 125 disposed between the reflective sheet 127 and the upper glass 112. Please refer to Figure 2 and Figure 6。The light guide structure 125 is internally mixed with a plurality of light-transmitting light-scattering particles (not shown), whose refractive index is different from that of the light guide structure 125 itself, and whose shape can be spherical, pyramidal or irregular. When light encounters the light-transmitting light-scattering particles, at the interface between the light guide structure 125 and the light-scattering particles, interface refraction and interface reflection will occur, and the directions of the refracted light and the reflected light are different from the direction of the incident light. Therefore, when the size of the light-scattering particles is small and the number reaches a certain level, the light can be homogenized through light scattering.

[0067] In one embodiment, in order to achieve a better light homogenization effect, the light guide structure 125 can extend to cover the LED assembly 129, so that the light emitted upward by the LED assembly 129 can be directly guided and scattered, achieving the effect of light homogenization.

[0068] The tilt angle θr of the reflective sheet 127 is one of the key points of this application. In common sense, it may be thought that as long as the reflective sheet 127 is tilted and can form reflected light into the upper glass 112. However, this application proposes that to achieve a better traveling distance of light in the upper glass 112 and the irradiation effect on the cholesterol liquid crystal cell 13, total internal reflection must be formed on the upper surface of the upper glass 112, and after reflection, it travels downward, then penetrates the lower surface of the upper glass 112 and the ITO (not shown), and then enters the cholesterol liquid crystal cell 13. To achieve this better effect, the tilt angle θr must be greater than 45 degrees and not greater than 61 degrees.

[0069] Because, if the tilt angle θr is less than 45 degrees, the light reflected by the reflective sheet 127 directly enters the lower surface of the upper glass 112, so the distance of light transmission is short and it cannot reach the far end of the upper glass 112. If the tilt angle θr is equal to 45 degrees, the light reflected by the reflective sheet 127 will be parallel to the lower surface of the upper glass 112 and will not penetrate the lower surface and enter the cholesterol liquid crystal cell 13. Therefore, the tilt angle θr must be greater than 45 degrees.

[0070] Next, a further explanation of the setting of the tilt angle θr is made.

[0071] According to the law of refraction, when light travels from transmission medium 1 to transmission medium 2, refraction will occur.

[0072] n1 * Sin(θ1) = n2 * Sin(θ2) (2)

[0073] Where n1 is the refractive index of transmission medium 1, n2 is the refractive index of transmission medium 2, θ1 is the angle of the light in transmission medium 1 relative to the normal of the transmission medium interface (angle of incidence), and θ2 is the angle of the light relative to the normal of the transmission medium interface after entering transmission medium 2 from transmission medium 1 (angle of refraction).

[0074] For the monochromatic self-luminous cholesteric liquid crystal display module 10, see Figure 1 and Figure 2 In the embodiment of, there is a transmission medium between the reflective sheet 127 and the upper glass 112, and this transmission medium can be Figure 1 the air shown in Figure 2 or the light guide structure 125 shown in

[0075] Because the tilt angle of the reflective sheet 127 is θr, the light emitted by the LED component 129 hits the reflective sheet 127 and is reflected, and the incident angle and the reflection angle with respect to the normal of the reflective sheet 127 are both θr. The reflected light enters the upper glass 112 through the transmission medium, and the incident angle with respect to the normal of the side of the upper glass 112 is θ_int, and the refraction angle in the upper glass 112 is 90 - θ_gls.

[0076] According to the trigonometric relationship, θ_int + 90 = 2 * θr, so

[0077] θr = 45 + 0.5 * θ_int (3)

[0078] As θ_int increases, θr increases accordingly; as θ_int decreases, θr decreases accordingly. When θ_int = 0, θr = 45, and at this time θr is 45 degrees, which is the minimum value. However, if θr is equal to 45 degrees, the reflected light cannot hit the upper surface of the upper glass. When θ_int = 90, θr = 90, and at this time θr is 90 degrees, which is the maximum value. However, if θr is equal to 90 degrees, the reflective sheet 127 actually cannot play a reflective role either, and most of the light emitted by the LED component 129 cannot enter the upper glass 112.

[0079] For the side of the upper glass 112, when light enters the upper glass 112 from the transmission medium, refraction will occur, n_int * Sin(θ_int) = n_gls * Sin(90 - θ_gls)

[0080] Sin(θ_int) = Sin(90 - θ_gls) * n_gls / n_int

[0081] θ_int = Sin -1 (Sin(90 - θ_gls) * n_gls / n_int) (4)

[0082] Among them, n_int is the refractive index of the transmission medium, n_gls is the refractive index of the upper glass 112, and θ_gls is the incident angle of the light when it enters the transparent optical adhesive 17 from the upper surface of the upper glass 112.

[0083] When θ_int increases, 90 - θ_gls increases accordingly, and θ_gls decreases accordingly.

[0084] The refractive index n_gls of the upper glass 112 is generally 1.5; if the transmission medium is air, the refractive index of air n_int = 1.0, so formula (4) thus becomes

[0085] θ_int = Sin -1 (Sin(90 - θ_gls) * 1.5) (5)

[0086] The minimum value of θ_int is 0 degrees. At this time, 90 - θ_gls = 0, and θ_gls = 90, which is the maximum value of θ_gls.

[0087] The maximum value of θ_int is 90 degrees. At this time, 1 = 1.5 * Sin(90 - θ_gls),

[0088] 90 - θ_gls = Sin -1 (1 / 1.5) = 41.8, θ_gls = 48.2, which is the minimum value of θ_gls, that is, θ_gls ≥ 48.2 (6)

[0089] θ_gls must be not less than 48.2 degrees to allow the reflected light of the reflector 127 to enter the side of the upper glass 112.

[0090] If the transmission medium is the light guide structure 125, the material of the light guide structure 125 mainly uses transparent optical glue, and the refractive index n_int ranges from 1.4 to 1.45 depending on the material. When n_int = 1.4, formula (4) thus becomes

[0091] θ_int = Sin -1 (Sin(90 - θ_gls) * 1.5 / 1.4) (7)

[0092] The minimum value of θ_int is 0 degrees. At this time, 90 - θ_gls = 0, and θ_gls = 90, which is the maximum value of θ_gls. The maximum value of θ_int is 90 degrees. At this time,

[0093] 1 = Sin(90 - θ_gls) * 1.5 / 1.4,

[0094] 90 - θ_gls = Sin -1 (1.4 / 1.5) = 69.0,

[0095] θ_gls = 21.0, which is the minimum value of θ_gls, that is,

[0096] θ_gls ≥ 21.0 (8)

[0097] When the refractive index n_int of the light guide structure 125 is 1.4, θ_gls must be not less than 21.0 degrees so that the reflected light of the reflector 127 can pass through the side edge of the upper glass 112 and enter the upper glass 112.

[0098] When n_int = 1.45, at this time,

[0099] 1 = Sin(90 - θ_gls) * 1.5 / 1.45,

[0100] 90 - θ_gls = Sin -1 (1.45 / 1.5) = 75.2,

[0101] θ_gls = 14.8, this is the minimum value of θ_gls, that is,

[0102] θ_gls ≥ 14.8 (9)

[0103] When the refractive index n_int of the light guide structure 125 is 1.45, θ_gls must be not less than 14.8 degrees so that the reflected light of the reflector 127 can pass through the side edge of the upper glass 112 and enter the upper glass 112.

[0104] Please continue to see Figure 1 And Figure 2 , for the interface between the upper part of the upper glass 112 and the transparent optical adhesive 17, when light enters the transparent optical adhesive 17 from the upper glass, refraction will occur.

[0105] n_gls * Sin(θ_gls) = n_oca * Sin(θ_oca) (10)

[0106] Among them, θ_gls is the incident angle of the light in the upper glass 112, n_oca is the refractive index of the transparent optical adhesive 17, and θ_oca is the refraction angle of the light in the transparent optical adhesive 17 (not shown).

[0107] When total internal reflection occurs on the upper surface of the upper glass 112, θ_oca = 90, Sin(θ_oca) = 1, so Sin(θ_gls) = n_oca / n_gls

[0108] θ_gls = Sin -1 (n_oca / n_gls) (11)

[0109] This is the minimum value of θ_gls when total internal reflection occurs, that is to say, total internal reflection will occur in the following situation:

[0110] θ_gls ≥ Sin -1(n_oca / n_gls) (12)

[0111] The refractive index n_oca of the transparent optical adhesive 17 is between 1.4 and 1.45 depending on the material. When n_oca = 1.4, θ_gls = Sin -1 (n_oca / n_gls) = Sin -1 (1.4 / 1.5) = 69.0, which is the minimum value of θ_gls, that is, θ_gls ≥ 69.0 (13)

[0112] That is to say, when the refractive index n_oca of the transparent optical adhesive 17 is 1.4, θ_gls must be not less than 69.0 degrees so that total internal reflection can be formed on the upper surface of the upper glass 112.

[0113] When n_oca = 1.45, θ_gls = Sin -1 (n_oca / n_gls) = Sin -1 (1.45 / 1.5) = 75.2, which is the minimum value of θ_gls, that is, θ_gls ≥ 75.2 (14)

[0114] That is to say, when the refractive index n_oca of the transparent optical adhesive 17 is 1.45, θ_gls must be not less than 75.2 degrees so that total internal reflection can be formed on the upper surface of the upper glass 112.

[0115] Based on the above, we can summarize the satisfaction conditions of θr, that is, Formula (12), Formula (4), Formula (3) and Formula (1):

[0116] θ_gls ≥ Sin -1 (n_oca / n_gls)

[0117] θ_int = Sin -1 (Sin(90 - θ_gls) * n_gls / n_int)

[0118] θr = 45 + 0.5 * θ_int

[0119] θr ≥ Cos -1 (W_led / L)

[0120] This application further summarizes two implementation cases: (1) The transmission medium between the reflective sheet 127 and the side edge of the upper glass 112 is air, and (2) The transmission medium between the reflective sheet 127 and the side edge of the upper glass 112 is the light guide structure 125.

[0121] In implementation case (1), when the transmission medium between the reflective sheet 127 and the side edge of the upper glass 112 is air, n_int = 1.0, and there are two situations at this time:

[0122] (1.1) n_int = 1.0, n_oca = 1.4;

[0123] (1.2) n_int = 1.0, n_oca = 1.45.

[0124] The following will be described separately.

[0125] (1.1) n_int = 1.0, n_oca = 1.4. According to formula (12),

[0126] θ_gls ≥ Sin -1 (n_oca / n_gls)

[0127] Since n_gls = 1.5, so θ_gls ≥ 69.0

[0128] According to formula (4), θ_int = Sin -1 (Sin(90 - θ_gls) * n_gls / n_int)

[0129] θ_int = Sin -1 (Sin(90 - 69.0) * 1.5) = 32.6, this is the maximum value of θ_int.

[0130] According to formula (3), θr = 45 + 0.5 * θ_int = 45 + 16.3 = 61.3, this is the maximum value of θr, that is, θr ≤ 61.3 (15)

[0131] The tilt angle θr of the reflector 127 must not be greater than 61.3 degrees so that total reflection can be formed on the upper surface of the upper glass 112.

[0132] (1.2) n_int = 1.0, n_oca = 1.45. According to formula (12),

[0133] θ_gls ≥ Sin -1 (n_oca / n_gls)

[0134] Since n_gls = 1.5, θ_gls ≥ 75.2

[0135] According to formula (4), θ_int = Sin -1 (Sin(90 - θ_gls) * n_gls / n_int)

[0136] θ_int = Sin -1 (Sin(90 - 75.2) * 1.5) = 22.6, this is the maximum value of θ_int.

[0137] According to formula (3), θr = 45 + 0.5 * θ_int = 45 + 11.3 = 56.3, which is the maximum value of θr, that is, θr ≤ 56.3 (16)

[0138] The tilt angle θr of the reflector 127 must not be greater than 56.3 degrees so that total internal reflection can occur on the upper surface of the upper glass 112.

[0139] The tilt angles θr in implementation case (1) are summarized in the following table

[0140]

[0141] In implementation case (2), when the transmission medium between the reflector 127 and the side edge of the upper glass 112 is the light guide structure 125, n_int = 1.4 - 1.5, and there are four situations at this time:

[0142] (2.1) n_int = 1.4, n_oca = 1.4;

[0143] (2.2) n_int = 1.4, n_oca = 1.45;

[0144] (2.3) n_int = 1.45, n_oca = 1.4;

[0145] (2.4) n_int = 1.45, n_oca = 1.45.

[0146] They are described separately below.

[0147] (2.1) n_int = 1.4, n_oca = 1.4. According to formula (12),

[0148] θ_gls ≥ Sin -1 (n_oca / n_gls)

[0149] Since n_gls = 1.5, so θ_gls ≥ 69.0

[0150] According to formula (4), θ_int = Sin -1 (Sin(90 - θ_gls) * n_gls / n_int)

[0151] θ_int = Sin -1 (Sin(90 - 69.0) * 1.5 / 1.4) = 22.6, which is the maximum value of θ_int.

[0152] According to formula (3), θr = 45 + 0.5 * θ_int = 45 + 11.3 = 56.3, which is the maximum value of θr, that is, θr ≤ 56.3 (17)

[0153] The tilt angle θr of the reflector 127 must not be greater than 56.15 degrees so that total internal reflection can occur on the upper surface of the upper glass 112.

[0154] (2.2) n_int = 1.4, n_oca = 1.45. According to formula (12),

[0155] θ_gls ≥ Sin -1 (n_oca / n_gls)

[0156] Since n_gls = 1.5, then θ_gls ≥ 75.2

[0157] According to formula (4), θ_int = Sin -1 (Sin(90 - θ_gls) * n_gls / n_int)

[0158] θ_int = Sin -1 (Sin(90 - 75.2) * 1.5 / 1.4) = 15.9, which is the maximum value of θ_int.

[0159] According to formula (3), θr = 45 + 0.5 * θ_int = 45 + 8.0 = 53.0, which is the maximum value of θr. That is, θr ≤ 53.0 (18)

[0160] The tilt angle θr of the reflector 127 must not be greater than 53.0 degrees so that total internal reflection can occur on the upper surface of the upper glass 112.

[0161] (2.3) When n_int = 1.45, n_oca = 1.4. According to formula (12),

[0162] θ_gls ≥ Sin -1 (n_oca / n_gls)

[0163] Since n_gls = 1.5, then θ_gls ≥ 69.0

[0164] According to formula (4), θ_int = Sin -1 (Sin(90 - θ_gls) * n_gls / n_int)

[0165] θ_int = Sin -1 (Sin(90 - 69.0) * 1.5 / 1.45) = 21.8, which is the maximum value of θ_int.

[0166] According to formula (3), θr = 45 + 0.5 * θ_int = 45 + 10.9 = 55.9, which is the maximum value of θr. That is, θr ≤ 55.9 (19)

[0167] The tilt angle θr of the reflective sheet 127 must not be greater than 55.9 degrees so that total internal reflection can occur on the upper surface of the upper glass 112.

[0168] (2.4) n_int = 1.45, n_oca = 1.45. According to formula (12),

[0169] θ_gls ≥ Sin -1 (n_oca / n_gls)

[0170] Since n_gls = 1.5, then θ_gls ≥ 75.2

[0171] When n_oca = 1.45, θ_gls ≥ 75.2

[0172] According to formula (4), θ_int = Sin -1 (Sin(90 - θ_gls) * n_gls / n_int)

[0173] θ_int = Sin -1 (Sin(90 - 75.2) * 1.5 / 1.45) = 15.4, which is the maximum value of θ_int.

[0174] According to formula (3), θr = 45 + 0.5 * θ_int = 45 + 7.7 = 52.7, which is the maximum value of θr. That is, θr ≤ 52.7(20)

[0175] The tilt angle θr of the reflective sheet 127 must not be greater than 52.7 degrees so that total internal reflection can occur on the upper surface of the upper glass 112.

[0176] The tilt angle θr of the implementation case (2) is summarized in the following table

[0177]

[0178] Combining the two situations of the implementation case (1), the tilt angle θr of the reflective sheet 127 should not be greater than 61 degrees, preferably not greater than 56 degrees. Combining the four situations of the implementation case (2), the tilt angle θr of the reflective sheet 127 should not be greater than 56 degrees, preferably not greater than 52 degrees. Thus, after the reflected light of the reflective sheet 127 enters the upper glass 112, total internal reflection can occur on the upper surface of the upper glass 112, and then it penetrates downward through the lower surface of the upper glass 112 and the ITO, and then enters the cholesterol liquid crystal cell 13, serving as the light required for the reflective cholesterol liquid crystal to display colors and images.

[0179] Second preferred embodiment

[0180] Based on the same technical concept, the present application further proposes a second preferred embodiment, which is a multi-color cholesteric liquid crystal display device 3 with a built-in light source. Please refer to Figure 7 .

[0181] The multi-color cholesteric liquid crystal display device 3 with a built-in light source includes three cholesteric liquid crystal display modules 10 with built-in light sources that are sequentially connected in series from bottom to top. A transparent optical adhesive 17 is provided between each of the cholesteric liquid crystal display modules 10 with built-in light sources to bond them to each other. The structural features of each of the cholesteric liquid crystal display modules 10 with built-in light sources are as described in the aforementioned first preferred embodiment, and will not be elaborated here. The main difference among the three cholesteric liquid crystal display modules 10 with built-in light sources lies in the display color. The bottom cholesteric liquid crystal display module 10 with a built-in light source displays a red picture, and the LED component 129 therein uses a red LED; the middle cholesteric liquid crystal display module 10 with a built-in light source displays a green picture, and the LED component 129 therein uses a green LED; the top cholesteric liquid crystal display module 10 with a built-in light source displays a blue picture, and the LED component 129 therein uses a blue LED. Through the combination of the three color pictures displayed by the three cholesteric liquid crystal display modules 10 with built-in light sources, a full-color picture can be seen by the user.

[0182] In summary, the features of the present application are as follows:

[0183] 1. For the cholesteric liquid crystal display module with a built-in light source and the multi-color cholesteric liquid crystal display device with a built-in light source proposed by the present application, a plurality of light source modules are provided in the accommodation space on the side of the upper glass of the cholesteric liquid crystal display module, and the light source modules are electrically connected through an electrical connection device, which is conducive to synchronous driving and control;

[0184] 2. A reflective sheet and an LED component are provided in the light source module. The reflective sheet is arranged at a preset inclination angle to reflect the light emitted by the LED component into the upper glass, and total reflection is formed on the upper surface of the upper glass, and then penetrates downward through the lower surface of the upper glass and the ITO, and then enters the cholesteric liquid crystal cell, serving as the light required for the reflective cholesteric liquid crystal to display colors and pictures.

[0185] 3. To achieve a better display effect, the inclination angle θr of the reflective sheet must be greater than 45 degrees and not greater than 61 degrees.

[0186] Therefore, the cholesteric liquid crystal display module with a built-in light source and the multi-color cholesteric liquid crystal display device with a built-in light source proposed by the present application can provide a single-color or full-color display effect without external light source illumination.

[0187] The detailed description of the above preferred specific embodiments is intended to more clearly describe the features and spirit of the present application, rather than limiting the scope of the present application by the above-disclosed preferred specific embodiments. On the contrary, the purpose is to cover various equivalent changes within the scope of the claims that the present application intends to claim.

Claims

1. A cholesteric liquid crystal display module with its own light source, comprising a lower glass (111), a flexible circuit board (126), a cholesteric liquid crystal unit (13), an upper glass (112), a transparent optical adhesive (17), and a plurality of light-emitting units (12), wherein the horizontal projection of the lower glass (111) is larger than and covers the horizontal projection of the upper glass (112), and an accommodating space (14) is formed above the lower glass (111) and at an intersection area on a side of the upper glass (112); characterized in that: The plurality of light-emitting units (12) are arranged in the accommodating space (14), and each of the light-emitting units (12) comprises an LED component (129) and a reflective sheet (127); the flexible circuit board (126) is arranged on the upper surface of the lower glass (111), and a conductive layer (128) is formed above the flexible circuit board (126), and the LED component (129) is electrically connected to the conductive layer (128); The cholesteric liquid crystal display module with its own light source further comprises at least one electrical connection device (15), which is arranged between the flexible circuit boards (126) of two adjacent light-emitting units (12), and the electrical connection device (15) electrically connects the two adjacent flexible circuit boards (126); The reflective sheet (127) is arranged on the outer side of the LED component (129) away from the upper glass (112), and is fixed to one of the upper surfaces of the flexible circuit board (126) and the lower glass (111) at a preset tilt angle θr, wherein the tilt angle θr is greater than 45 degrees but not greater than 61 degrees, and the horizontal projection of the reflective sheet (127) covers the LED component (129).

2. The cholesteric liquid crystal display module with its own light source according to claim 1, characterized in that: The inclination angle θr is not greater than 56 degrees.

3. The cholesteric liquid crystal display module with its own light source according to claim 1, characterized in that: The reflective sheet (127) is connected and fixed to the flexible circuit board (126) by double-sided adhesive, anisotropic conductive adhesive, lead-free solder or other metal welding methods.

4. The cholesteric liquid crystal display module with its own light source according to claim 1, characterized in that: The reflective sheet (127) is fixed to the upper surface of the lower glass (111) by bonding.

5. The cholesteric liquid crystal display module with its own light source according to claim 1, characterized in that: The reflective sheet (127) further comprises a horizontally extending portion (1271) facing the upper glass (112).

6. The cholesteric liquid crystal display module with its own light source according to claim 1, characterized in that: Each of the light-emitting units (12) further comprises a light-guiding structure (125), which is arranged between the reflective sheet (127) and the upper glass (112) and covers the LED assembly (129); a plurality of light-transmitting scattered light particles are mixed in the light-guiding structure (125); the refractive index of the scattered light particles is different from that of the light-guiding structure (125); the shape of the scattered light particles is a sphere, a pyramid or an irregular body; and the inclination angle θr is not greater than 56 degrees.

7. The cholesteric liquid crystal display module with its own light source according to claim 6, characterized in that: The inclination angle θr is not greater than 52 degrees.

8. The cholesteric liquid crystal display module with its own light source according to claim 1, characterized in that: The lower glass (111) and the upper glass (112) are thin glass sheets with a thickness of 0.1 to 0.7 mm; the LED component (129) comprises a plurality of LED elements, and the LED elements are generally packaged LEDs, unpackaged micro-LEDs, or mini-LEDs with bases; the LED component (129) is electrically connected to the conductive layer (128) by anisotropic conductive adhesive, lead-free solder or other metal welding methods.

9. A multi-color cholesteric liquid crystal display device with its own light source, comprising three cholesteric liquid crystal display modules (10) with their own light sources connected in sequence from bottom to top, characterized in that: A transparent optical glue (17) is arranged between each of the cholesteric liquid crystal display modules (10) with its own light source, and the cholesteric liquid crystal display module (10) with its own light source is the cholesteric liquid crystal display module with its own light source as claimed in any one of claims 1 to 8.

10. The multi-color cholesteric liquid crystal display device with its own light source according to claim 9, characterized in that: The LED components (129) contained in the three cholesterol liquid crystal display modules (10) with their own light sources emit lights of different colors, namely red light, green light and blue light from bottom to top.

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