WO2004001705A1

WO2004001705A1 - Flat plate light guide display and manufacturing method for the same

Info

Publication number: WO2004001705A1
Application number: PCT/CN2003/000464
Authority: WO
Inventors: Jinggui Lu; Jian Lu; Qiang Wu; Xuemei Lu
Original assignee: Jinggui Lu; Jian Lu; Qiang Wu; Xuemei Lu
Priority date: 2002-06-24
Filing date: 2003-06-16
Publication date: 2003-12-31
Also published as: AU2003242217A1

Abstract

The present invention relates to a flat plate display and a manufacturing method for the same. Said flat plate display includes: a light guide sheet; a group of cavities around the light guide sheet, inside which LEDs are disposed; LEDs; a astigmatism surface layer, which is on the surface of the light guide sheet, and the astigmatism surface layer is coated with luminescent paint. The present invention can be applied to make monocolor light guide display, multicolor light guide display or LED light guide display.

Description

TECHNICAL FIELD The present invention relates to a flat panel display device using a light emitting diode as a light source and a manufacturing method thereof. BACKGROUND In recent years, LED materials such as ultra-high-brightness green, blue, and red light have made major breakthroughs and rapid development at home and abroad, and have been called new photoelectron light sources by domestic and foreign experts. Single crystal LED light-emitting chips are usually 0.2 X 0.2-0.3 X 0.3 mm ² , which are very small point light sources. In order to give full play to the performance characteristics of LEDs, it is common to use external packaging to change the light intensity distribution, such as lens packaging and matrix injection molding modules made of plastic injection molded frames. The display icon of the above display module and the operating point of the LED chip basically correspond to each other. It is difficult to change from a point light source to a surface light source, which affects the development of the LED to a flat and thin shape. Another type of flat panel display product uses a fluorescent lamp display board. The icon groove processed by the display board makes the illumination light source reflect an indistinct contrast display, or the text is pasted into a non-luminous color film and the contour is carved The rough lines appear on the rough surface to show the scattered light outline of the light source. The above flat panel display products all have the disadvantages of high power consumption of fluorescent lamps, low lifespan, and low light output efficiency for displaying icons. SUMMARY OF THE INVENTION The present invention is an organic combination of geometrical optics principles of optical materials and semiconductor light-emitting devices, which enables high-performance LEDs to be successfully converted from point light sources to high-efficiency thin surface light source displays.

The flat panel light guide display of the present invention utilizes the principle that light is transmitted from one medium to another. At the interface, the principle of refraction or reflection will occur due to different angles of incidence. Around the light guide plate composed of a single optical material or a composite optical material, A group of cylindrical lens top cavities are made on one or more sides, and the LED light emitting tubes that are oriented in parallel with the two sides of the light guide plate are packaged in the cavity. The LED light emitting tube is not provided around the light guide plate, and a metal reflective film is provided. ; Forming a rough astigmatism surface layer for displaying symbols on the surface of the light guide plate through a film molding process, and on top of this, a luminescent coating layer is coated; the transmission wavelength of the transparent pigment of the luminescent coating matches that of the LED. As described above, a flat light guide display, the light guide plate may be a single material layer of organic polymethyl methacrylate (PmmA), polycarbonate (PC), or the substrate may be polymethyl methacrylate (PmmA) The surface is made of polycarbonate (PC) or coated with a silicone abrasion-resistant thin layer, and the inorganic optical sheet glass and the organic substrate can also be compounded on the surface.

As described above, in a flat light guide display, an epoxy-type optical resin glue is injected between a light guide substrate and a prefabricated cylindrical cavity of a lens and an LED.

As described above, a flat light guide display, wherein the light guide plate corresponds to different LED edge light sources and has different matching thicknesses. When the LED component light sources are Φ 2, Φ 3, and Φ 5, respectively, 3mm, 5mm, and 6-8mm are selected. Or light guide plate with a thickness of 8mm or more.

As described above, a flat light guide display, the device is composed of a light guide plate and a double-sided metal encapsulation shell. The two sides of the light guide plate are rough astigmatism layer or rough astigmatism icon. The light guide plate is packaged on the front and back sides. In the side metal encapsulation shell, an icon window is embossed on the front cover and the back cover of the double-sided metal encapsulation shell, and the icon-shaped window and the rough scattered light emitting layer on the light guide plate may be single-sided or double-sided. The windows of the front and rear panels are filled with a sealing layer of an optical resin material by hot extrusion or filled with a transparent protective film on the surface of the front cover and the back cover of the double-sided metal encapsulation shell.

As described above, a flat light guide display, the light guide plate is formed by a plurality of shapes corresponding to the fixing grooves of the fixing frame, and is respectively fixed in the fixing grooves of the fixing frame, arranged in an arrangement; the periphery of each light guide plate A plurality of cylindrical lens top concave holes are prefabricated on the upper and lower sides or on one side, and an LED light-emitting tube is built in. The front surface of the light guide plate is a rough astigmatism layer, and the astigmatism layer is covered with a metal sheet window cover or reflective light for displaying icons Window film, the window cover or window film is also placed in the fixing groove of the fixing frame, and its surface is flush with the slot of the fixing frame; the window cover or window film is provided with an icon-shaped window, The window part is sealed by thermal extrusion or transparent film of the optical resin material; the surface of the window cover or reflective window film and the fixing frame is covered with a light-transmitting protective film, and the back of the fixing frame is inserted into the Attach a rear cover.

A method for preparing a flat-panel display; a light guide plate composed of a single organic material polymethylmethacrylate PmmA or polycarbonate PC, or a composite layer structure of the two materials; the light guide plate meets the requirements of optical mirror surface It is made in a mold; the icon-shaped dotted line interlaced rough astigmatism surface is made on the surface layer of the light guide plate; the icon-shaped rough astigmatism surface is coated with the luminous paint prepared according to the following method; the preparation of the luminous paint Step: Mix the medium temperature curing agent and the low molecular weight optical epoxy resin which is liquid at room temperature according to the equivalent value of epoxy value and amine value. When the resin is heated to 60 ° C-80 ° C before batching, in 5-6 minutes The temperature is reduced to 18O-2rC, and the above amount of curing is added. Agent and appropriate amount of visible light at 400nm-750nm full-color wavelength and colorless optical glass particles or pure quartz powder particles with good light transmittance, stirred and hooked, after removing the air bubbles by vacuum, apply on the surface of the light guide plate The rough astigmatism surface forms a display layer of luminous paint; the light guide plate coated with luminous paint is pre-baked for 2 hours at 40 ° C-50 ° C, and then baked in the oven at 60 ° C-80 ° C for 3 hours. Hours to complete curing; colorless optical glass particles or pure quartz particles in the luminescent coating account for 30% -70% of the weight of the mixture, and the balance is a low molecular weight optical epoxy resin with a medium temperature curing agent; An epoxy-type optical resin glue is injected into the preformed cylindrical cavity of the lens, and the LED chip and the current limiting resistor are assembled therein, ensuring that the LED chip is directed parallel to both sides of the light guide plate, and the temperature is 50 ° C-70 ° C. 3 hours curing; Soldering to connect the above LED components; Bare component connection wires are coated with insulation cold-dry paint; the LED components are aged for 8 hours at the specified current, and the preparation is completed.

A method for preparing a flat-panel light guide display as described above, wherein the optical glass particles are preferably as follows: heavy crown glass ZK501, ZK506, ZK509 in crown glass; F503, F504, F506c selected from fire glass

A method for manufacturing a flat panel light guide display as described above, wherein the optical glass particles or pure quartz particles should be in a range of 20 μm to 100 μm.

The method for manufacturing a flat panel light guide display as described above has a low molecular weight epoxy resin molecular weight range: 300-400, and an epoxy value range: E0.38-E0.54.

The LED light output of the flat panel light guide display of the present invention has high directivity, so that most of its light emission meets the surface of the light guide plate, so that the incident surface is larger than the critical angle of total reflection, thereby generating air specular reflection and improving light guide efficiency; The luminous paint is combined with the light guide plate through resin to produce a highly efficient scattered light luminous paint, with high luminous output efficiency, high luminous brightness, and clear and clear display performance; the display icon of the present invention can uniformly and brightly emit light over a large area; the present invention can be appropriately selected Formulated into monochrome, multi-color and LED light guide displays. The device uses hot extrusion to seal optical resins such as polymethyl methacrylate at the windows on both sides of the metal envelope, and combines the metal envelope with a plug-in form and fills it with sealant. Safe use in harsh environments such as acid, alkali, flammable and explosive. When the device is used for a motor vehicle number plate, it has excellent photoelectric performance, high luminous brightness, uniformity, and convenient process assembly. Suitable for large-scale batch production and personalized assembly. This device can display a variety of colors. Under the vehicle power supply DC 12V, according to the GA36-92 standard seven-character digital number plate, the power consumption is 1.68-3.36W, and the average light emission Lvtyp 50Cd / m ² to 150Cd / m ² . BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a flat panel light guide display according to the present invention;

FIG. 2 is a schematic diagram of a front structure of a flat panel light guide display according to the present invention; FIG.

3 is a light transmission distribution diagram of the LED chip of the flat panel light guide display in the light guide plate after passing through the lens;

4 is a sectional plan view of a plan view of a second embodiment of a flat panel light guide display according to the present invention; and FIGS. 5 and 6 are front and side sectional views of FIG. 4;

7 is a front view of a third embodiment of the flat panel light guide display according to the present invention; FIGS. 8 and 9 are a side sectional view and a bottom sectional view of FIG. 7;

10 is a front view of the back cover structure of FIG. 7;

FIG. 11 is a front view of the structure of the sheet metal window cover or reflective window film of FIG. 7.

Drawing number

1. LED edge light source cylindrical lens top package cavity

2. Luminous display astigmatism and luminous coating 3. Transparent light guide substrate 4. Air mirror surface

5. Metal reflective film 6 丄 ED chip 7. Fixed frame

8. LED IQ distribution in light guide plate 9. Front cover 10. Back cover

11. Transparent protective film on the back cover 12. Rough light-diffusing layer on the rear side of the light guide plate

13. Back cover window and packaging material 14. Front cover transparent protective layer

15. Front cover window and packaging material 16. Rough light diffusion layer on the front side of the light guide plate

17. Transparent protective film made of nylon material 18. Metal sheet window cover or reflective window film

19.Metal sheet window plate or reflective window film icon light transmission window

20. Rough light-diffusing layer on the surface of the light guide plate 21. Rear cover 22. Fixing frame The embodiment of the present invention has the description of the present embodiment and process method:

(I) Process requirements and manufacturing methods of light guide plate specification parts:

1. The surface of the substrate mold requires an optical mirror surface;

2. The astigmatism part of the icon is the point and line staggered astigmatism surface produced by the surface layer of the light guide plate through a molding process; 3. Abrasion-resistant coating can be prepared on the surface of the light guide plate such as PmmA material, that is, sprayed silicone resin. The light guide plate can also be made of PmmA substrate and PC material on the surface.

(2) Optional paint for light guide plate

Use colorless transparent optical glass particles or pure quartz particles with a full-color wavelength of 400nm-700nm for visible light and good light transmittance to prepare light-emitting coatings. The two kinds of particles should be between 20 μm and 100 μm, and the pure quartz (Si0 ₂ ) particles should be above the spectrally pure level. If a single-color light-emitting coating is prepared, a transparent single-color light-emitting pigment can be incorporated into the above-mentioned fine particles.

(Three) full color LED light guide display

The LED is composed of three primary colors of red, blue and green mixed on a light guide plate. The light guide plate light-emitting coating can be selected without pigment. The control of various light-emitting colors of the light-emitting display is completed by the driving circuit through the gating combination of the LEDs of each color.

(IV) Operation process of light guide display board:

1. Preparation for cleaning the light guide plate;

2. Liquid low-molecular-weight optical epoxy resin at room temperature, such as: 634 # (international brand EPon834), E42 model with epoxy value 0.38-0.45; domestic 6101 # (international brand Εοιι839), epoxy value 0.41-0.47 E44 model; domestic brand 618 # (international brand Epon828) E51 model with epoxy value of 0.48-0.54, and medium temperature curing agent (such as: 593 #, xylylenediamine produced by Shanghai Resin Factory), press the ring The oxygen value and the amine value are mixed in an equivalent ratio. After the above resin is heated to 80 ° C, it is quickly cooled to the standard room temperature (18 ° C-2rC) within 6 minutes, adding an appropriate amount of curing agent and visible light at 400nm-700nm full color wavelength. Colored optical glass particles or pure quartz powder particles, and stir well.

3. Vacuum the finished luminous paint to remove air bubbles;

4. Apply the prepared luminous paint according to the light guide plate astigmatism surface to form a luminous layer;

5. Pre-bake at 40 ° C- 50 ° C for 2 hours;

6. Bake in oven 60 ° C-70 ° C for 3 hours to complete curing;

7. Eliminate unqualified products by visual inspection;

8. Include qualified products for storage;

(5) Light guide display panel LED assembly assembly process:

1. According to the design, the LED devices and current-limiting resistors are tested in advance to meet the specifications;

2. Cut the lead wires of the above components to appropriate lengths and dip them in tin;

3. The light guide substrate is prefabricated with a cylindrical cavity on the top of the lens and injected with epoxy-type optical resin glue to ensure the optical coupling and matching between the LED chip and the light guide plate and the high efficiency transmission effect of the light guide plate; 4. Assemble LED and current limiting resistor;

5. LED cavity resin diameter 50 ° C-70 ° C for 3 hours curing;

6. Solder the above components;

7. The surface of the bare component connection line is coated with insulation cold-dry paint;

8. Detected in storage after aging for 8 hours at the specified current.

(6) General assembly process of LED light guide display:

1. Prepare the frame and accessories; it can be extruded from aluminum profiles and molds, and the surface requires good decorative effects.

2. Docking the prefabricated light guide plate with the frame;

3. Pull out the lead of the light guide plate through the frame lead-out hole and seal it;

4. LED light guide display for electrical and optical performance testing;

5. The above-mentioned technical products that pass the test are riveted and fixed with aluminum rivets at the frame position, and the two ends are sealed and sealed (the prefabricated plugs are glued firmly);

6. The finished product is qualified and put into storage.

Example 1 of preparing a luminescent coating:

The colorless optical glass particles (50 μηι) are mixed with a low molecular weight optical epoxy resin (E44) with a medium temperature curing agent. The colorless optical glass particles account for 30% of the weight of the composition, and the balance is the medium temperature. Curing agent of low molecular weight optical epoxy resin.

Preparation of luminescent paint

The colorless optical glass particles (20 μm) are mixed with a low molecular weight optical epoxy resin (E42) with a medium temperature curing agent. The colorless optical glass particles make up 50% of the weight of the composition, and the balance is medium temperature. Curing agent of low molecular weight optical epoxy resin.

Example 3 of preparing a luminescent coating:

The colorless optical glass particles (100 μηι) are mixed with a low-molecular-weight optical epoxy resin (E51) added with a medium-temperature curing agent. The colorless optical glass particles account for 70% of the weight of the composition, and the balance is added with intermediate temperature. Curing agent of low molecular weight optical epoxy resin.

(VII) For an embodiment of the metal-encapsulated combined flat-panel light guide display of the present invention, refer to FIGS. 4, 5 and 6. The specific manufacturing steps are as follows: First, prefabricated light guide plate: The thickness of the light guide plate matches the size of the LED: Φ 3 LED with 5mm thickness light guide plate, Φ 5 LED with 6-8mm thick light guide plate, Φ 2 LED with 3mm Thick light guide. The light guide plate can be a single material layer of organic material polymethyl methacrylate (PmmA) or polycarbonate (PC), or the substrate can be

(PmmA), the surface is PC or coated with silicone wear-resistant thin layer, and inorganic optical sheet glass can also be coated Glass and organic substrate are compounded on the surface. The top concave holes of the cylindrical lens are prefabricated on both sides, and the light-emitting diode is embedded therein, and an epoxy-type optical resin glue is injected to ensure the optical coupling between the LED chip and the light guide plate and the efficient transmission of the optical plate. A light-emitting tube can be coated with a reflective film on the opposite side. On one or both sides of the light guide plate, rough diffusing layers 12, 16 are injected through a mold.

Secondly, a metal envelope is made according to the size of the light guide plate. The metal envelope is composed of a front cover and a back cover, and they are tightly fitted in a plug-in form to play a role of packaging the light guide plate. Icon-shaped windows are cut on the front cover and back cover by die stamping or plasma numerical control, and the windows can be sealed by hot extrusion or filling with high tenacity white or color film nylon or high density polyvinyl chloride. The metal envelope can be made of thin metal plates such as aluminum, iron, and steel. The rear cover can be 0.4-0.6 mm smaller than the front cover, which is convenient for matching and assembly. The outer surface of the metal envelope can be sprayed with a layer of paint.

The device can be made into a thickness of 0.6-1.0 cm, which can be directly mounted on the wall without destroying the building structure. It can display illuminated display cards on one or both sides, and is especially suitable for hanging in the air.

(Eight) For an embodiment of the component combination integrated flat light guide display of the present invention, refer to FIGS. 7, 8, 9, and 10. The specific manufacturing steps are as follows: First, prefabricated light guide plate: the light guide plate can be a single organic PmmA or PC material, or the substrate is PmmA, the surface is PC or coated with a silicone wear-resistant thin layer, and the inorganic optical sheet glass and The organic substrate is compounded on the surface. The top concave holes of the cylindrical lens are prefabricated on both sides, and the light-emitting diodes are embedded therein, and epoxy-type optical resin glue is injected. If the LED light emitting tube is provided on one side, a reflective film can be applied on the opposite side. On the front surface of the light guide plate, a rough light diffusion layer 20 is injected through a film, and the rough light diffusion layer 20 can be formed into a prism-shaped unevenness by staggered lines.

Secondly, the fixed frame is made into a set of grooves corresponding to the shape of the light guide plate, and the prefabricated light guide plate unit parts are placed in the corresponding grooves respectively, and the LED component leads are connected and led out of the frame. A rear cover is placed in the fixing frame clamping slot on the rear side of the light guide plate, and its connection surface is sealed with glue.

The above-mentioned frame 22 and the light guide plate combined product are combined with a 0.5-1.0 mm thick metal sheet cover or reflective film 18 with an icon window to form a required vehicle number plate or other display plate. The light guide plate is placed in the groove of the fixed frame, and its rough astigmatism surface 20 is slightly at the mouth of the groove. After the metal sheet or the reflective film 18 is pasted, the light guide plate is flush with the mouth of the groove. Paste metal sheets or reflective films 18 that represent different icons to assemble different number plates. After the above process is completed, a light-transmitting protective layer can be adhered to the outermost layer.

The fixing frame 22 may be made of ABS plastic through injection molding, or may be made of a metal material. The rear cover 21 may be injection-molded from ABS plastic, or may be punched from a 1.0-1.2mm aluminum plate. A stiffener structure may be provided on the rear cover, as shown in FIG. 10. The metal sheet window plate can be used without Rust steel is 0.5mm thick or aluminum is 1.0mm thick, made by die stamping. The protective light-transmitting layer 17 may be a nylon film or a high-density polyvinyl chloride film.

The LED component light source matches the light guide substrate: Φ 3 LED with 5mm thickness light guide plate, Φ 5 LED with 6-8mm thickness light guide plate, Φ 2 LED with 3mm thickness light guide plate, LED large size 12〃, in the chip Lead ball welding.

Claims

Claim

1. A flat panel light guide display, characterized in that: a set of cylindrical lens head cavities are formed on one or more sides of a light guide plate composed of a single optical material or a composite optical material layer, and are aligned in parallel with both sides of the light guide plate The LED light-emitting tube is enclosed in the cavity, and a metal reflective film is provided on the surface of the LED light-emitting tube around the light guide plate; a rough astigmatism surface layer for displaying icons is formed on the surface of the light guide plate through a film molding process, and above this And coated with a luminescent paint; the transparent pigment transmission wavelength of the luminescent paint matches the light emitting wavelength of the LED.

2. The flat light guide display according to claim 1, wherein: the light guide plate is a single layer of organic polymethyl methacrylate (PmmA) or polycarbonate (PC); or the substrate is polymethacrylic acid Methyl grease (PmmA), whose surface is made of polycarbonate (PC) or coated with an abrasion-resistant thin layer of silicone; or an inorganic optical sheet glass and an organic substrate are compounded on the surface.

3. The flat-panel light guide display according to claim 1, wherein: an epoxy-type optical resin glue is injected between the light guide substrate and the preformed cylindrical cavity of the lens and the LED.

4. The flat light guide display according to claim 1, wherein: the light guide plate corresponds to different LED edge light sources and has different matching thicknesses, and when the LED component light sources are 02mm, Φ3ιηη, and Φ5πηη, respectively, Use 3mm, 5mm, 6-8mm or 8mm thick light guide plate.

5. A flat light guide display according to claim 1, characterized in that: the device is composed of a light guide plate and a double-sided metal encapsulation shell, and both sides of the light guide plate are a rough astigmatism layer or a rough astigmatism icon, The light guide plate is encapsulated in a front and back metal-encapsulated shell. The front and rear covers of the metal-enclosed shell are provided with icon windows. The windows of the front and rear panels are filled with hot extrusion or filled with An optical resin material sealing layer; a transparent protective film is pasted on the front and back covers of the double-sided metal-encapsulated shell; the rough diffuser layer on the icon-shaped window and the light guide plate can also be provided on one side.

6. The flat light guide display according to claim 1, characterized in that: the light guide plate is formed by a plurality of shapes corresponding to the fixing grooves of the fixing frame, and arranged in a plurality of fixing grooves of the fixing frame, respectively. The top and bottom sides of each light guide plate, or one side, are prefabricated with several cylindrical lens top concave holes, and the LED light-emitting tube is built in. The front side of the light guide plate is a rough light diffusion layer, and the display is covered on the light diffusion layer. A metal sheet window cover or reflective window film, said window cover or window film is also placed in the fixing groove of the fixing frame, and its surface is flush with the notch portion of the fixing frame; An icon-shaped window is opened, and the window part is covered with optical resin The material is sealed by heat extrusion or transparent film; the surface of the window cover or reflective window film and the surface of the fixing frame are covered with a light-transmitting protective film, a card slot is arranged on the back of the fixing frame, Attach a rear cover.

7. A method for preparing a flat panel light guide display, comprising: a light guide plate composed of a single organic material, polymethyl methacrylate PmmA or polycarbonate PC, or a composite layer structure composed of the two materials; It is made in a mold that meets the requirements of optical mirrors; the icon-shaped dotted-line staggered rough astigmatism surface is made on the surface of the light guide plate; the icon-shaped rough astigmatism surface is coated with the following method Luminous paint; Luminous paint preparation steps: Mix the medium temperature curing agent and the low molecular weight optical epoxy resin which is liquid at room temperature according to the equivalent ratio of epoxy value and amine value, and heat the resin to 60 ° C -80 ° C before compounding. In 5-6 minutes, reduce the temperature to 18 ° C-21 ° C, add the above amount of curing agent and appropriate amount of visible light at 400nm-750nm full color wavelength and colorless optical glass particles with good light transmittance or Pure quartz powder particles and stir well. After removing the air bubbles by vacuuming, apply the coating on the surface of the light guide plate to the rough rough light scattering surface to form a light-emitting paint display layer. The light-guide plate coated with the light-emitting paint is first subjected to 40 ° C- 5 (T Pre-bake for 2 hours, then dry in the oven at 60 ° C-80 ° 0 for 3 hours, until it is completely cured; colorless optical glass particles or pure quartz particles in the luminescent coating account for 30% -70 of the weight of the mixture %, The balance is low-molecular-weight optical epoxy resin with a medium-temperature curing agent; epoxy-type optical resin glue is injected into the cylindrical cavity on the top of the lens prefabricated around the light guide plate, and the LED chip and the current-limiting resistor are assembled to ensure that The LED chip points parallel to the two sides of the light guide plate and is cured at 50 C -70 ° C for 3 hours; soldered to the above-mentioned LED components; the surface of the bare component connection lines is coated with insulating cold-dry paint; aged under the specified current After 8 hours, the LED assembly was prepared.

The method for preparing a flat-panel light-guide display according to claim 7, characterized in that: the optical glass particles are preferably as follows: heavy crown glass ZK501, KK 506, KK 509 in crown glass; F503, F504, F506.

The method for preparing a flat panel light guide display according to claim 7, characterized in that: the optical glass particles or pure quartz particles should be between 20 U m and 100 μm.

10. The method for preparing a flat panel light guide display according to claim 1, wherein the low molecular weight epoxy resin has a molecular weight range of 300-400 and an epoxy value range of E0.38-E0.54.