Multicolor cholesteric liquid crystal display device and cholesteric liquid crystal display module equipped with a light source

Abstract

A multicolor cholesteric liquid crystal display device and a cholesteric liquid crystal display module with a light source are provided. [Solution] A cholesteric liquid crystal display module (10) equipped with a light source includes a bottom glass (111), a cholesteric liquid crystal unit (13), a top glass (112), multiple light-emitting units (12), and an electrical connection device. Multiple light-emitting units are installed in a storage space (14) on the side of the top glass. Each light-emitting unit includes a flexible circuit board (126), an LED component (129), and a reflector (127). The LED component is electrically connected to the conductive layer and the flexible circuit board, and the electrical connection device electrically connects two adjacent flexible circuit boards. The reflector is installed outside the top glass and spaced apart from the LED component, and is fixed to the top surface of the flexible circuit board or bottom glass at a predetermined inclination angle θr not exceeding 61 degrees. The horizontal projection of the reflector obscures the LED component.

Description

Technical Field

[0001] The present invention relates to liquid crystal display technology, and more particularly to cholesteric liquid crystal display devices and their light source technologies.

Background Art

[0002] Cholesteric liquid crystal is one of the main technologies applied to electronic book displays. Because it has bistable display characteristics, it consumes almost no power when the screen is stationary, so there is an energy-saving effect. At the same time, cholesteric liquid crystal belongs to reflective display technology. When there is external ambient light, it can be clearly seen, while it cannot be seen without external ambient light. To solve this problem, usually, supplementary light by a front light source is adopted, or an illumination is added outside the display surface of the display to directly irradiate the display surface. Or there is a method of arranging a layer of light guide structure to uniformly distribute the light of the external illumination and then irradiate the display surface again. However, in a normal environment, the amount of incident light decreases in the latter case, which affects the reflectivity.

[0003] Regarding the prior art of combining a light source device and a cholesteric liquid crystal display, what is disclosed in Patent Publication No. CN101556410A is a cholesteric liquid crystal display device for autostereoscopic images. It includes a first liquid crystal panel, a second liquid crystal panel installed below the first liquid crystal panel, and a backlight source installed below the second liquid crystal panel and used to emit light. Among them, what is included in the second liquid crystal panel is a cholesteric liquid crystal panel in which a grid region and a slit region are alternately arranged based on the input electric field, a first compensation film installed above the cholesteric liquid crystal panel, and a second compensation film installed below the cholesteric liquid crystal panel. What is included in the backlight source is a reflective sheet for reflecting light. By providing a modularized cholesteric liquid crystal panel and compensation film, it is possible to easily realize the switching between a two-dimensional plane image and a three-dimensional stereoscopic image, simplify the manufacturing process, and reduce the manufacturing cost, which is an autostereoscopic image display device.

[0004] Patent Publication No. CN111308785A discloses a cholesteric liquid crystal display device. It includes: 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 one side of the second substrate away from the blue light backlight source; a light reflection layer located on one side of the blue light backlight source away from the color conversion layer, and the color conversion layer is used to reflect the blue light that could not be completely absorbed, and the light reflection layer includes a cholesteric liquid crystal layer having optical properties; an alignment layer located between the light reflection layer and the first substrate, and aligns the liquid crystal molecules in the cholesteric liquid crystal layer horizontally with respect to the first substrate or the second substrate.

[0005] Patent Publication No. CN114114769A discloses a cholesteric liquid crystal handwriting device. It includes a light source, a first base layer, a second base layer, and a GH-type dyed liquid crystal layer disposed between the first base layer and the second base layer. A first conductive layer is provided on one side of the first base layer close to the second base layer, and a second conductive layer is provided on one side of the second base layer close to the first base layer. The light source is provided on one side of the first base layer away from the second base layer; the GH-type dyed liquid crystal layer includes cholesteric liquid crystal, black dye, and a chiral agent. The cholesteric liquid crystal has a first zero-electric-field stable state, a second zero-electric-field stable state, and an applied-electric-field stable state. When the cholesteric liquid crystal is in the first zero-electric-field stable state and the applied-electric-field stable state, the emitted light rays from the light source are scattered outward. When the cholesteric liquid crystal is in the second zero-electric-field stable state, the emitted light rays from the light source and the ambient light are absorbed by the GH-type dyed liquid crystal layer.

[0006] Patent Publication No. TW202022459A discloses a cholesteric liquid crystal light-emitting device. It includes a light source component, 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, and 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 component and the wavelength conversion layer, and also between the light source component and the second liquid crystal layer.

[0007] Since the prior art still has insufficient parts in industrial implementation, further improvement was needed.

Summary of the Invention

Problems to be Solved by the Invention

[0008] In order to solve the deficiencies of the prior art, the present invention mainly aims to introduce and integrate LED light sources and reflection technologies into cholesteric liquid crystal displays, and provide a cholesteric liquid crystal display module with a light source and a multicolor cholesteric liquid crystal display device that can be operated and used without external light source irradiation.

Means for Solving the Problems

[0009] The first preferred embodiment of the present invention is a cholesteric liquid crystal display module with a monochromatic display light source. It includes one lower glass, one flexible circuit board, one cholesteric liquid crystal unit, one upper glass, one optically transparent adhesive, and a plurality of light-emitting units. The horizontal projection of the lower glass is larger than that of the upper glass and covers it, and a storage space is formed in the region where the upper part of the lower glass and one side surface of the upper glass intersect.

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

[0011] The cholesteric liquid crystal display module with a light source further includes at least one electrical connection device, which is installed between the flexible circuit boards of two adjacent light-emitting units, and through the electrical connection device, the two adjacent flexible circuit boards are electrically connected.

[0012] The reflective sheet is installed outside the upper glass of the LED component and fixed to one of the upper surfaces of the flexible circuit board and the lower glass at a predetermined inclination angle θr, where the inclination angle θr does not exceed 61 degrees, and the horizontal projection of the reflective sheet covers the LED component.

[0013] Through the light reflection effect of the reflective sheet with a special angle setting in the light-emitting unit, the light emitted from the LED component is effectively reflected into the upper glass, and after forming total reflection on the upper surface of the upper glass, it penetrates downward through the lower surface of the upper glass and the ITO, and then enters the cholesteric liquid crystal unit again, becoming the light necessary for the reflective cholesteric liquid crystal to display color and the screen, so that the cholesteric liquid crystal unit plays a role in generating a screen display. Thereby, the cholesteric liquid crystal display module equipped with a light source can provide monochromatic display without the need for external light source irradiation.

[0014] More preferably, a plurality of light-emitting units are installed in the storage space on the outer periphery of the upper glass. When the flexible circuit boards of two adjacent light-emitting units are electrically connected through an electrical connection device, a plurality of light-emitting units on the outer periphery of the upper glass can be synchronously driven, the brightness of the cholesteric liquid crystal unit is higher, and a more uniform light source can be provided.

[0015] Based on the same technical idea, the second preferred embodiment further provided by the present invention is a multicolor cholesteric liquid crystal display device equipped with a light source capable of full-color display. It includes a cholesteric liquid crystal display module equipped with three light sources connected in sequence from bottom to top, and an optically transparent adhesive is installed between the cholesteric liquid crystal display modules equipped with light sources respectively. The characteristics of each cholesteric liquid crystal display module are as described in the first preferred embodiment.

[0016] Through the overall role of the cholesteric liquid crystal display module equipped with three light sources of different colors, the multicolor cholesteric liquid crystal display device equipped with a light source can provide full-color display without the need for external light source irradiation.

Advantages of the Invention

[0017] The cholesteric liquid crystal display module and the multicolor cholesteric liquid crystal display device equipped with the light source provided by the present invention use a built-in LED component, an electrical connection device, and a reflective sheet with a special angle setting, and can provide a monochromatic or full-color display effect without the need for external light source irradiation.

Brief Description of the Drawings

[0018] The drawings provided are for further understanding of the embodiments of the present invention, show the embodiments of the present invention, and explain the principle of the present invention together with the text. The following drawings do not limit the implementation method of the present invention, and those with ordinary knowledge in the art can derive other drawings based on these drawings without creative effort.

Figure 1

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Best Mode for Carrying Out the Invention

[0019] Hereinafter, the structure, features, and effects of the present invention will be described in detail with reference to the best embodiment and the drawings.

[0020] The details of the specific structure and functions disclosed in the present invention are merely representative and are used to explain the embodiments of the present invention. The present invention can be embodied in various modified forms and is not limited only to the embodiments disclosed herein.

[0021] The directions or positional relationships indicated by terms such as "center", "lateral direction", "upper", "lower", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. used in the present invention are based on the directions or positional relationships shown in the drawings. Unless the applicant particularly emphasizes or limits the function of the role, it is only for conveniently explaining the present invention and does not indicate or imply a specific orientation or a specific orientation structure and operation for a specified device or component. Furthermore, "first" and "second" are used only for the purpose of explanation and do not indicate relative importance. Unless otherwise clearly described in the context, the terms "one" and "one item" of the present invention shall also include a plurality.

[0022] Unless otherwise clearly defined or limited, the terms "attach", "adjacent to", and "connect" of the present invention shall be interpreted broadly. For example, a fixed connection can also be a detachable connection or a connection by integral molding, and can be interpreted broadly as a mechanical connection, an electrical connection, a direct connection, an indirect connection through an intermediate medium, or the interiors of two components communicating with each other. Those of ordinary skill in the art can understand the specific meaning of the above terms in the present invention based on the specific situation.

[0023] The object of the present invention is to provide a cholesteric liquid crystal display module equipped with a light source and a multicolor cholesteric liquid crystal display device. By using a built-in LED component, an electrical connection device, and a reflective sheet with a special angle setting, a monochromatic or full-color display effect can be provided without the need for external light source irradiation.

Embodiment

[0024] The first preferred embodiment of the present invention is a cholesteric liquid crystal display module 10 equipped with a light source, as shown in FIGS. 1 to 6.

[0025] As shown in FIGS. 1, 4, and 5, the cholesteric liquid crystal display module 10 equipped with a light source includes a lower glass 111, a flexible circuit board 126, a cholesteric liquid crystal unit 13, an upper glass 112, an optically transparent adhesive 17, a plurality of light-emitting units 12, and at least one electrical connection device 15.

[0026] As shown in FIGS. 1 and 2, the horizontal projection of the upper glass 112 is larger than the horizontal projection of the cholesteric liquid crystal unit 13 and covers it, and the horizontal projection of the lower glass 111 is larger than the horizontal projection of the upper glass 112 and covers it. Therefore, a storage space 14 is formed in the side surface of the upper glass 112 and the intersecting area above the lower glass 111. The storage space 14 may be either two adjacent side surfaces of the upper glass 112 or four side surfaces of the upper glass 112.

[0027] As shown in FIGS. 5 and 6, a plurality of light emitting units 12 are installed in the accommodation space 14, and each light emitting unit 12 includes one LED component 129 and one reflective sheet 127. A flexible circuit board 126 is installed on the upper surface of the lower glass 111, and a conductive layer 128 is further formed above the flexible circuit board 126, and the LED component 129 is electrically connected to the conductive layer 128. In order to improve the display brightness or uniformity of the cholesteric liquid crystal display module 10 provided with a light source, or because the areas of the cholesteric liquid crystal unit 13 and the upper glass 112 are larger, as shown in FIG. 3, light emitting units 12 can be installed in two adjacent accommodation spaces 14 of the upper glass 112 respectively. Further, as shown in FIG. 4, light emitting units 12 can be installed in the accommodation spaces 14 on the four side surfaces respectively.

[0028] The electrical connection device 15 is one of the important points of the present invention. There are a plurality of light emitting units 12. Considering simultaneous light emission and control, inside the electrical connection device 15 provided by the present invention, there is a conductive structure that plays its role. As shown in FIG. 4, the electrical connection device 15 is installed between the flexible circuit boards 126 of two adjacent light emitting units 12 to electrically connect the two adjacent flexible circuit boards 126. Thereby, if an electrical connection is formed on one flexible circuit board 126, an electrical connection is formed on the flexible circuit boards 126 of all the light emitting units 12 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 there are four light emitting units 12 and the outer periphery of the upper glass 112 is surrounded, three or more electrical connection devices 15 are required.

[0029] As shown in FIGS. 1 and 2, when seen in a cross-sectional view, the light emitted from the LED component 129 forms a fan shape in principle rather than a single direction. The main reason for emitting upward is that the upper surface of the LED chip of the LED component 129 faces upward. Since the light emitting direction of the LED component 129 is not directly emitted to the upper glass 112, a reflective sheet 127 is required to introduce the light emitted by the LED component 129 into the upper glass 112.

[0030] The reflective sheet 127 is installed outside and away from the upper glass 112 of the LED component 129 and is fixed at a predetermined inclination angle θr, and the inclination angle θr does not exceed 61 degrees. As shown in FIG. 6, since the reflective sheet 127 does not require conductivity, it can be fixed to the flexible circuit board 126, or as shown in FIGS. 1 and 2, it can also be fixed to the upper surface of the lower glass 111. When the reflective sheet 127 is fixed to the flexible circuit board 126, it can be connected and fixed by methods 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 adhesion method is more preferable. The above is the best embodiment, and the present invention is not limited thereto.

[0031] Furthermore, the inclination angle θr first satisfies the following conditions: θr ≧ Cos -1 (W_led / L) (1) Where W_led represents the width of the LED component 129, and L represents the length of the hypotenuse of the reflective sheet 127 along θr. The meaning of formula (1) is that only when the horizontal projection of the reflective sheet 127 covers the LED component 129 can the light emitted by the LED component 129 be reflected to the maximum extent.

[0032] As shown in FIG. 6, when the reflective sheet 127 further includes a horizontal extension portion 1271 facing the upper glass 112, the reflection effect is better.

[0033] To reduce the overall thickness of the cholesteric liquid crystal display module 10 equipped with a light source, it is desirable that the lower glass 111 and the upper glass 112 be 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 further includes a plurality of LED parts. The LED parts can adopt packaged LEDs, and can also use unpackaged micro-LEDs or mini-LEDs with a base added. Since the sizes of micro-LEDs and mini-LEDs are small, after forming an LED array, they can be arranged more densely. When used as a light source, the difference between light and dark is reduced, and the overall light uniformity is further improved.

[0034] Basically, an LED is a point light source, and its light uniformity is relatively poor. To achieve a more preferable light guiding and uniform light effect, as shown in FIGS. 2 and 6, the cholesteric liquid crystal display module 10 equipped with a light source further has a light guiding structure 125, which can be installed between the reflective sheet 127 and the upper glass 112. A plurality of light-transmissive scattering fine particles are mixed in the light guiding structure 125 (not shown in the figure). Its refractive index is different from that of the light guiding structure 125 itself, and its shape can be a sphere, a pyramid or an irregular body. When a light ray contacts the light-transmissive scattering fine particles, at the interface between the light guiding structure 125 and the scattering fine particles, interface refraction and interface reflection occur, and the directions of the refracted light and the reflected light are both different from the direction of the incident light. Therefore, when the size of the scattering fine particles is smaller and the number reaches a certain amount, the effect of uniformizing the light rays through scattering is achieved.

[0035] In one embodiment, to obtain a better light ray uniformizing effect, the light guiding structure 125 is further extended to cover the LED component 129, so that the light emitted upward by the LED component 129 is directly guided and scattered, and the light ray uniformizing effect is achieved.

[0036] The tilt angle θr of the reflective sheet 127 is one of the important points of the present invention. In general common sense, if the reflective sheet 127 is tilted, it is considered that reflected light is formed and incident on the upper glass 112. However, in the present invention, in order for the light ray to reach a more preferable traveling distance in the upper glass 112 and to improve the irradiation effect of the cholesteric liquid crystal unit 13, the light ray must necessarily form total reflection on the upper surface of the upper glass 112, and after reflection, it travels downward, passes through the lower surface of the upper glass 112 and ITO (not shown in the figure), and is incident on the cholesteric liquid crystal unit 13 again. In order to obtain such a more preferable effect, the tilt angle θr needs to be greater than 45 degrees and not exceed 61 degrees.

[0037] If the tilt angle θr is less than 45 degrees, the light reflected from the reflective sheet 127 is directly incident on the lower surface of the upper glass 112. Therefore, the transmission distance of such a light ray is shorter and it cannot be transmitted to the end of the upper glass 112. If the tilt angle θr is 45 degrees, the light reflected from the reflective sheet 127 becomes parallel to the lower surface of the upper glass 112 and does not pass through the lower surface and enter the cholesteric liquid crystal unit 13. Therefore, the tilt angle must necessarily be greater than 45 degrees.

[0038] Subsequently, a further explanation will be given regarding the setting of the tilt angle θr.

[0039] Based on the law of refraction, when a light ray is incident from a propagation medium 1 to a propagation medium 2, refraction occurs. n1 * Sin(θ1) = n2 * Sin(θ2) (2) Among them, n1 is the refractive index of the propagation medium 1, and n2 is the refractive index of the propagation medium 2. θ1 is the angle (incident angle) of the light ray with respect to the normal of the interface of the propagation medium in the propagation medium 1, and θ2 is the angle (refraction angle) of the light ray with respect to the normal of the interface of the propagation medium after the light ray is incident from the propagation medium 1 to the propagation medium 2.

[0040] As shown in the embodiments of FIGS. 1 and 2, regarding the cholesteric liquid crystal display module 10 equipped with a single-color light source, there is one propagation medium between the reflective sheet 127 and the upper glass 112, and this propagation medium can be the air shown in FIG. 1, or can also be the light guide structure 125 shown in FIG. 2. An optically transparent adhesive 17 is further bonded above the upper glass 112.

[0041] Since the tilt angle of the reflective sheet 127 is θr, when the light emitted from the LED component 129 hits the reflective sheet 127, it is reflected. The incident angle and the reflection angle with respect to the normal line of the reflective sheet 127 are both θr. The reflected light enters the upper glass 112 through the propagation medium. For this, the incident angle with respect to the normal line of the side surface of the upper glass 112 is θ_int, and the refraction angle in the upper glass 112 is 90 - θ_gls.

[0042] Based on the trigonometric relationship, θ_int + 90 = 2 * θr, so, θr = 45 + 0.5 * θ_int. (3)

[0043] When θ_int increases, θr also increases; when θ_int decreases, θr also decreases. When θ_int = 0 and θr = 45, θr is 45 degrees, which is the minimum value. However, when θr is 45 degrees, the reflected light cannot reach the upper surface of the upper glass. When θ_int = 90 and θr = 90, θr is 90 degrees, which is the maximum value. However, when θr is 90 degrees, the reflective sheet 127 actually cannot exert a reflection effect either, and most of the light emitted by the LED component 129 cannot reach the upper glass 112.

[0044] Regarding the side surface of the upper glass 112, when light rays enter the upper glass 112 from the propagation medium, refraction occurs. n_int * Sin(θ_int) = n_gls * Sin(90 - θ_gls) Sin(θ_int) = Sin(90 - θ_gls) * n_gls / n_int θ_int = Sin -1(Sin(90 - θ_gls) * n_gls / n_int) (4) Among them, n_int is the refractive index of the propagation medium, n_gls is the refractive index of the upper glass 112, and θ_gls is the incident angle at which the light ray enters the optical transparent adhesive 17 from the upper surface of the upper glass 112.

[0045] When θ_int increases, 90 - θ_gls also increases, and θ_gls decreases.

[0046] The refractive index n_gls of the upper glass 112 is usually 1.5. If the propagation medium is air, since the refractive index of air is n_int = 1.0, the formula (4) is as follows. θ_int = Sin -1 (Sin(90 - θ_gls) * 1.5) (5)

[0047] When the minimum value of θ_int is 0 degrees, 90 - θ_gls = 0, θ_gls = 90, which is the maximum value of θ_gls.

[0048] When the maximum value of θ_int is 90 degrees, 1 = 1.5 * Sin(90 - θ_gls), 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) Only when θ_gls is 48.2 degrees or more can the reflected light of the reflection sheet 127 enter the side surface of the upper glass 112.

[0049] If the propagation medium is the light guide structure 125 and the material of the light guide structure 125 mainly uses an optical transparent adhesive, the refractive index) n_int varies depending on the material and is in the range of 1.4 to 1.45. When n_int = 1.4, the formula (4) is as follows. θ_int = Sin -1 (Sin(90 - θ_gls) * 1.5 / 1.4) (7)

[0050] When the minimum value of θ_int is 0 degrees, 90 - θ_gls = 0 and θ_gls = 90, which is the maximum value of θ_gls. When the maximum value of θ_int is 90 degrees, 1 = Sin(90 - θ_gls) * 1.5 / 1.4, 90 - θ_gls = Sin -1 (1.4 / 1.5) = 69.0, θ_gls = 21.0, which is the minimum value of θ_gls, that is θ_gls ≧ 21.0 (8) When the refractive index of the light guide structure 125 is n_int = 1.4, θ_gls must be 21.0 degrees or more for the reflected light of the reflection sheet 127 to enter the upper glass 112 from above the end of the upper glass 112.

[0051] When n_int = 1.45 1 = Sin(90 - θ_gls) * 1.5 / 1.45, 90 - θ_gls = Sin -1 (1.45 / 1.5) = 75.2, θ_gls = 14.8, which is the minimum value of θ_gls, that is θ_gls ≧ 14.8 (9) When the refractive index of the light guide structure 125 is n_int = 1.45, θ_gls must be 14.8 degrees or more for the reflected light of the reflection sheet 127 to enter the upper glass 112 from above the end of the upper glass 112.

[0052] As shown in FIGS. 1 and 2, with respect to the interface between the upper glass 112 and the optical transparent adhesive 17 above it, when light rays are incident from the upper glass into the optical transparent adhesive 17, refraction occurs. n_gls * Sin(θ_gls) = n_oca * Sin(θ_oca) (10) Among them, θ_gls is the incident angle of the light ray in the upper glass 112, n_oca is the refractive index of the optical transparent adhesive 17, and θ_oca is the refraction angle of the light ray in the optical transparent adhesive 17 (not shown in the figure).

[0053] When the light forms total internal reflection on the upper surface of the upper glass 112, θ_oca = 90 and Sin(θ_oca) = 1, so Sin(θ_gls) = n_oca / n_gls. θ_gls = Sin -1 (n_oca / n_gls) (11) This is the minimum value of θ_gls when total internal reflection is formed, that is, total internal reflection is formed under the following conditions: θ_gls ≧ Sin -1 (n_oca / n_gls) (12)

[0054] The refractive index n_oca of the optically transparent adhesive 17 varies depending on the material and is in the range of 1.4 to 1.45. 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) When the refractive index n_oca of the optically transparent adhesive 17 is 1.4, the light can form total internal reflection on the upper surface of the upper glass 112 only when θ_gls is 69.0 degrees or more.

[0055] 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) When the refractive index of the optically transparent adhesive 17 is n_oca = 1.45, the light can form total internal reflection on the upper surface of the upper glass 112 only when θ_gls is 75.2 degrees or more.

[0056] Summarizing the above, the conditions for satisfying θr are equations (12), (4), (3) and (1): θ_gls ≧ Sin -1 (n_oca / n_gls) θ_int = Sin -1 (Sin(90 - θ_gls) * n_gls / n_int) θr = 45 + 0.5 * θ_int θr ≧ Cos -1 (W_led / L)

[0057] The present invention can be further summarized into two implementation situations: (1) The propagation medium between the reflective sheet 127 and the end of the upper glass 112 is air, and (2) The propagation medium between the reflective sheet 127 and the end of the upper glass 112 is the light guide structure 125.

[0058] When the propagation medium between the reflective sheet 127 and the end of the upper glass 112 in the implementation situation (1) is air, n_int = 1.0. At this time, two situations can be considered: (1.1) n_int = 1.0, n_oca = 1.4; (1.2) n_int = 1.0, n_oca = 1.45. The following is an explanation for each of them.

[0059] (1.1) n_int = 1.0, n_oca = 1.4. Based on Equation (12) θ_gls ≧ Sin -1 (n_oca / n_gls).

[0060] Since n_gls = 1.5, θ_gls ≧ 69.0.

[0061] Based on Equation (4), θ_int = Sin -1 ( Sin(90 - θ_gls) * n_gls / n_int) θ_int = Sin -1 ( Sin(90 - 69.0) * 1.5) = 32.6, which is the maximum value of θ_int.

[0062] Based on Equation (3), θr = 45 + 0.5 * θ_int = 45 + 16.3 = 61.3, which is the maximum value of θ_int, that is, θr ≤ 61.3 (15) Only when the inclination angle θr of the reflection sheet 127 does not exceed 61.3 degrees can the light ray form total reflection on the upper surface of the upper glass 112.

[0063] (1.2) n_int = 1.0, n_oca = 1.45. Based on Equation (12), θ_gls ≥ Sin -1 (n_oca / n_gls).

[0064] Since n_gls = 1.5, θ_gls ≥ 75.2.

[0065] Based on Equation (4), θ_int = Sin -1 (Sin(90 - θ_gls) * n_gls / n_int) θ_int = Sin -1 (Sin(90 - 75.2) * 1.5) = 22.6, which is the maximum value of θ_int.

[0066] Based on Equation (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) Only when the inclination angle θr of the reflection sheet 127 does not exceed 56.3 degrees can the light ray form total reflection on the upper surface of the upper glass 112.

[0067] The following table summarizes the inclination angle θr of the implementation situation (1).

Table 1

[0068] When the propagation medium between the reflective sheet 127 and the end of the upper glass 112 in the implementation situation (2) is the light guide structure 125, n_int = 1.4 - 1.5. At this time, four situations can be considered: (2.1) n_int = 1.4, n_oca = 1.4; (2.2) n_int = 1.4, n_oca = 1.45; (2.3) n_int = 1.45, n_oca = 1.4; (2.4) n_int = 1.45, n_oca = 1.45. The following is an explanation of each one.

[0069] (2.1) n_int = 1.4, n_oca = 1.4. Based on Equation (12), θ_gls ≧ Sin -1 (n_oca / n_gls).

[0070] Since n_gls = 1.5, θ_gls ≧ 69.0.

[0071] Based on Equation (4), θ_int = Sin -1 (Sin(90 - θ_gls) * n_gls / n_int) θ_int = Sin -1 (Sin(90 - 69.0) * 1.5 / 1.4) = 22.6, which is the maximum value of θ_int.

[0072] Based on Equation (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) Only when the inclination angle θr of the reflective sheet 127 does not exceed 56.15 degrees can the light ray form total reflection on the upper surface of the upper glass 112.

[0073] (2.2) n_int = 1.4, n_oca = 1.45. Based on Equation (12), θ_gls ≧ Sin -1 (n_oca / n_gls).

[0074] Since n_gls = 1.5, θ_gls ≧ 75.2.

[0075] Based on Equation (4), θ_int = Sin -1 (Sin(90 - θ_gls) * n_gls / n_int) θ_int = Sin -1 (Sin(90 - 75.2) * 1.5 / 1.4) = 15.9, which is the maximum value of θ_int.

[0076] Based on Equation (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) Only when the tilt angle θr of the reflection sheet 127 does not exceed 53.0 degrees can the light form total reflection on the upper surface of the upper glass 112.

[0077] (2.3)n_int = 1.45, n_oca = 1.4, based on Equation (12), θ_gls ≧ Sin -1 (n_oca / n_gls)

[0078] Since n_gls = 1.5, θ_gls ≧ 69.0.

[0079] Based on Equation (4), θ_int = Sin -1 (Sin(90 - θ_gls) * n_gls / n_int) θ_int = Sin -1 (Sin(90 - 69.0) * 1.5 / 1.45) = 21.8, which is the maximum value of θ_int.

[0080] Based on Equation (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) Only when the tilt angle θr of the reflection sheet 127 does not exceed 55.9 degrees can the light ray form total reflection on the upper surface of the upper glass 112.

[0081] (2.4) n_int = 1.45, n_oca = 1.45. Based on Equation (12), θ_gls ≧ Sin -1 (n_oca / n_gls).

[0082] Since n_gls = 1.5, θ_gls ≧ 75.2.

[0083] When n_oca = 1.45, θ_gls ≧ 75.2.

[0084] Based on Equation (4), θ_int = Sin -1 (Sin(90 - θ_gls) * n_gls / n_int) θ_int = Sin -1 (Sin(90 - 75.2) * 1.5 / 1.45) = 15.4, which is the maximum value of θ_int.

[0085] Based on Equation (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) Only when the tilt angle θr of the reflection sheet 127 does not exceed 52.7 degrees can the light ray form total reflection on the upper surface of the upper glass 112.

[0086] The following table summarizes the tilt angle θr of the implementation status (2).

Table 2

[0087] Summarizing the two situations of the implementation status (1), the tilt angle θr of the reflection sheet 127 should not exceed 61 degrees, and more preferably, it should not exceed 56 degrees. Summarizing the four situations of the implementation status (2), the tilt angle θr of the reflective sheet 127 should not exceed 56 degrees, and more preferably, it should not exceed 52 degrees. By doing so, after the reflected light of the reflective sheet 127 is incident on the upper glass 112, total reflection is formed on the upper surface of the upper glass 112, then it penetrates downward through the lower surface of the upper glass 112 and the ITO, and is incident again into the cholesteric liquid crystal unit 13, becoming the light necessary for the reflective cholesteric liquid crystal to display colors and images.

Embodiment

[0088] Based on the same technical concept, the second preferred embodiment further provided by the present invention is a multicolor cholesteric liquid crystal display device 3 equipped with a light source, as shown in FIG. 7.

[0089] The multicolor cholesteric liquid crystal display device 3 equipped with a light source includes a cholesteric liquid crystal display module 10 equipped with three light sources connected in sequence from bottom to top, and an optically transparent adhesive 17 is installed between the cholesteric liquid crystal display modules 10 each equipped with a light source to adhere to each other. The structural features of the cholesteric liquid crystal display module 10 equipped with each light source are as described in the above first preferred embodiment, and will not be repeatedly described here. The main difference of the cholesteric liquid crystal display module 10 equipped with three light sources is the color display. The cholesteric liquid crystal display module 10 equipped with the lowermost light source displays a red light screen, and the LED component 129 therein uses a red LED. The cholesteric liquid crystal display module 10 equipped with the middle light source displays a green light screen, and the LED component 129 therein uses a green LED. The cholesteric liquid crystal display module 10 equipped with the uppermost light source displays a blue light screen, and the LED component 129 therein uses a blue LED. When the three-color screens displayed by the cholesteric liquid crystal display module 10 equipped with three light sources are combined, a full-color screen will be presented to the user's eyes.

[0090] Summarizing the above, the features of the present invention are as follows.

[0091] 1. The present invention relates to a cholesteric liquid crystal display module equipped with a light source and a multicolor cholesteric liquid crystal display device equipped with a light source. In the cholesteric liquid crystal display module, a plurality of light source modules are installed in the storage space on the side surface of the upper glass, and electrical connections are formed between the respective light source modules via an electrical connection device, which is advantageous for synchronous driving and control.

[0092] 2. A reflective sheet and an LED component are installed in the light source module. The reflective sheet is installed at a predetermined inclination angle, reflects the light emitted from the LED component and enters it into the upper glass, and after forming total reflection on the upper surface of the upper glass, it transmits downward through the lower surface of the upper glass and the ITO, and then enters the cholesteric liquid crystal unit again, becoming the light necessary for the reflective cholesteric liquid crystal to display colors and images.

[0093] 3. To achieve a more preferable display effect, the inclination angle θr of the reflective sheet must be greater than 45 degrees and not exceed 61 degrees.

[0094] Through this, the cholesteric liquid crystal display module equipped with the light source of the present invention and the multicolor cholesteric liquid crystal display device equipped with the light source can provide a single-color or full-color display effect without the need for external light source irradiation.

[0095] The detailed description of the above best embodiment is intended to more clearly explain the features and spirit of the present invention and does not limit the scope of the present invention. Even if those skilled in the art make changes or adjustments within the scope of the present invention, the important significance of the present invention will not be lost and it will be included in the scope of the present invention.

Description of Reference Numerals

[0096] 3 Multicolor cholesteric liquid crystal display device equipped with a light source 10 Cholesteric liquid crystal display module equipped with a light source 111 Lower glass 112 Upper glass 12 Light-emitting unit 125 Light guide structure 126 Flexible circuit board 127 Reflective sheet 1271 Horizontally extending portion 128 Conductive layer 129 LED component 13 Cholesteric liquid crystal unit 14 Storage space 15 Electrical connection device 17 Optically transparent adhesive θr Tilt angle W_led: Width of the LED component L: Length of the hypotenuse of the reflective sheet along θr θ_int: Incident angle at which the light ray enters from the side surface of the upper glass 112 θ_gls: Incident angle at which the light ray enters the optically transparent adhesive from the upper surface of the upper glass 112

Claims

1. It includes one lower glass 111, one flexible circuit board 126, one cholesteric liquid crystal unit 13, one upper glass 112, one optically transparent adhesive 17 and a plurality of light-emitting units 12. The horizontal projection of the lower glass 111 is larger than and covers the horizontal projection of the upper glass 112. In the region where the upper part of the lower glass 111 intersects with one side surface of the upper glass 112, one storage space 14 is formed. The plurality of light-emitting units 12 are installed in the storage space 14. Each light-emitting unit 12 includes one LED component 129 and one reflective sheet 127. The flexible circuit board 126 is installed on the upper surface of the lower glass 111. One conductive layer 128 is further formed above the flexible circuit board 126. The LED component 129 is electrically connected to the conductive layer 128. The cholesteric liquid crystal display module with the light source further includes at least one electrical connection device 15, which is installed between the flexible circuit boards 126 of two adjacent light-emitting units 12. The electrical connection device 15 electrically connects two adjacent flexible circuit boards 126. The reflective sheet 127 is installed on the outer side away from the upper glass 112 of the LED component 129 and fixed to one of the upper surfaces of the flexible circuit board 126 and the lower glass 111 at a predetermined inclination angle θr. The inclination angle θr is greater than 45 degrees but does not exceed 61 degrees, and the horizontal projection of the reflective sheet 127 covers the LED component 129. A cholesteric liquid crystal display module with a light source is characterized by this.

2. Each of the light-emitting units 12 further includes one light guide structure 125, which is installed between the reflective sheet 127 and the upper glass 112 and covers the LED component 129. A plurality of light-transmissive scattering fine particles are mixed in the light guide structure 125. The refractive index of the scattering fine particles is different from that of the light guide structure 125. The shape of the scattering fine particles is a sphere, a pyramid or an irregular body. The inclination angle θr does not exceed 56 degrees. A cholesteric liquid crystal display module with a light source according to Claim 1 is characterized by this.

3. A cholesteric liquid crystal display device with a light source, comprising a cholesteric liquid crystal display module 10 having three light sources connected in sequence from bottom to top, and an optically transparent adhesive 17 is installed between the cholesteric liquid crystal display modules 10 each having the light source, and the cholesteric liquid crystal display module 10 having the light source is a cholesteric liquid crystal display module having the light source described in claim 1 or claim 2.

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