Backlight Unit Integrally Formed with Conductive, Chemically Toughened Glass and Method for Fabricating the same

• US 20130170246A1
• Filed: 12/05/2012
• Published: 07/04/2013
• Est. Priority Date: 12/06/2011
• Status: Active Grant

• Current Assignee: Shui-Lung Chen
• Original Assignee: Shui-Lung Chen
• Inventors: Chen, Shui-Lung
• Granted Patent: US 9,217,819 B2
• Time in Patent Office: Days
• US Class Current: 362/607
• CPC Class Codes: G02B 6/0011 the light guides being planar or of plate-like form
• CPC Class Codes: G02B 6/0043 provided on the surface of the light guide
• CPC Class Codes: G02B 6/0051 Diffusing sheet or layer
• CPC Class Codes: G02B 6/0055 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0083 Details of electrical connections of light sources to drivers, circuit boards, or the like

Abstract

A backlight unit integrally formed with conductive, chemically toughened glass and method for fabricating the same is disclosed. The integrally formed backlight unit uses conductive, chemically toughened glass as substrate and comprises a diffusion layer, a light guide layer, an optical microstructure layer, a transparent layer, a reflective layer and a light source module. The integrally formed backlight unit is fabricated using photochemical lithography, printing-coating, and ultrasonic hot melt adhesion processes, and offers the advantages of high luminance, ultra thinness and high efficiency in fabrication. The backlight unit product can be designed as bottom lit or edge lit and used mainly for the illumination of keyboards or non-self-luminous display devices.

Claims

1. A backlight unit integrally formed with conductive, chemically toughened glass, comprising:

a light guide layer in the form of a transparent substrate having the shape of a thin plate and made of chemically toughened glass with a thickness ranging from 0.1 mm to 5 mm;

a conductive film being transparent and made of conductive material forming a predetermined circuit pattern on the transparent substrate of the light guide layer using photochemical lithography or laser beam, and having a surface resistance in the range of 4.5Ω

/□

to 650Ω

/□

;

a diffusion layer for scattering light from emitting surface uniformly into a planar light source and adjusting the color temperature of the planar light source, the diffusion layer being made of transparent resin, diffusing particles and dye in different proportions, and having a light transmittance in the range of 30% to 98%;

an optical microstructure layer made of high refractive index material and forming a predetermined optical microstructure pattern on the transparent substrate of the light guide layer using photochemical lithography or coating-printing process, the optical microstructure layer being used for refracting incident light with its predetermined optical microstructure pattern;

the predetermined optical microstructure pattern being adjustable to adjust the distribution of incident light from a planar light source module;

a transparent layer made of transparent resin coated on the reflective surface of transparent substrate of light guide layer and optical microstructure layer using coating-printing process to allow the passage of light ray not refracted by the optical microstructure layer to a reflective layer;

a reflective layer mainly for reflecting the light ray having passed through the transparent layer to the light guide layer, which is then refracted by the optical microstructure layer to the diffusion layer; and

a light source module consisting of conductive material, a plurality of light emitting diodes and flexible circuit boards and being adhered and connected to the electrode circuit with a predetermined pattern on the conductive film using ultrasonic hot melt adhesive process, the light source module being used mainly for providing an incident light source in the integrally formed backlight unit to illuminate the connected keyboard or non-self-luminous display panel.

2. The backlight unit integrally formed with conductive, chemically toughened glass according to claim 1, wherein each microstructure in the optical microstructure layer ranges from 0.028 micron to 200 micron if the layer is fabricated using photochemical lithography and ranges from 10 micron to 200 micron if the layer is fabricated using coating-printing process.

3. The backlight unit integrally formed with conductive, chemically toughened glass according to claim 2, wherein the material used in photochemical lithography is photoresist added with titanium dioxide (TiO₂), which is etched by photochemical lithography into the optical microstructure layer, or a layer of silver or aluminum is coated in the optically active region on the reflective surface of the light guide layer and then photoresist is coated thereon, which is then etched into the optical microstructure layer using photochemical lithography.

4. The backlight unit integrally formed with conductive, chemically toughened glass according to claim 2, wherein the material used in the coating-printing process consists of TiO₂ or silver or aluminum micro- and nanoparticles and acrylic resin or epoxy resin or mixture thereof.

5. The backlight unit integrally formed with conductive, chemically toughened glass according to claim 1, wherein the conductive film is selected from a group consisting of indium tin oxide (ITO), zinc oxide (ZnO), Ga-doped ZnO, and conductive polymer.

6. The backlight unit integrally formed with conductive, chemically toughened glass according to claim 1, wherein the conductive material used in the light source module is selected from a group consisting of gold, silver, copper, titanium, tin, cobalt, nickel and mixtures thereof.

7. The backlight unit integrally formed with conductive, chemically toughened glass according to claim 1, wherein the transparent resin in the diffusion layer consists of acrylic resin or epoxy resin or mixture thereof, the diffusing particle is TiO₂, acrylic resin or SiO₂ micro- and nanoparticles or mixture thereof, the dye is mainly for adjusting the color temperature of the planar light source when there is a need for color temperature compensation.

8. The backlight unit integrally formed with conductive, chemically toughened glass according to claim 1, wherein the material of the transparent layer is acrylic resin or epoxy resin or mixture thereof.

9. A method for fabricating backlight unit integrally formed with conductive, chemically toughened glass, comprising the steps of:

preparing a conductive, chemically toughened glass substrate;

forming a conductive film and fabricating an electrode circuit in the optically inactive region of the conductive film;

fabricating an optical microstructure layer in the optically active region on the reflective surface of the conductive layer;

fabricating a transparent layer on the electrode circuit in a region other than that for accommodating a light source module connected using hot melt adhesive process and on the surface of the optical microstructure layer;

fabricating a reflective layer on the surface of the transparent layer and on the three non-incident side surfaces of the light guide layer and transparent layer;

fabricating a diffusion layer on the light emitting surface of the light guide layer;

adhering a light source module to the electrode circuit on the conductive, chemically toughened glass substrate using ultrasonic hot melt adhesive process; and

forming a backlight module integrally formed with conductive, chemically toughened glass.