LIGHT-EMITTING DISPLAY SYSTEM AND HEAD-UP DISPLAY

Abstract

The present invention aims to provide a luminescent display system capable of safely and easily displaying information at a predetermined luminance over a wide area, and a head-up display including the luminescent display system. Provided is a luminescent display system including: a luminescent resin film containing a thermoplastic resin and a luminescent material; and two or more light sources each configured to emit a light beam of excitation wavelength for the luminescent material, the luminescent resin film and two or more light sources being placed such that the light beams emitted from the light sources at least partly overlap on the luminescent resin film.

Claims

1. A luminescent display system comprising: a luminescent resin film containing a thermoplastic resin and a luminescent material; and two or more light sources each configured to emit a light beam of excitation wavelength for the luminescent material, the luminescent resin film and two or more light sources being placed such that the light beams emitted from the light sources at least partly overlap on the luminescent resin film.

2. The luminescent display system according to claim 1, wherein the luminescent resin film is provided in the form of a multilayer resin film in which the luminescent resin film and a different resin film are stacked.

3. The luminescent display system according to claim 1, wherein the luminescent resin film is reinforced with at least one glass plate.

4. The luminescent display system according to claim 1, wherein the luminescent resin film is provided in the form of a laminated glass in which the luminescent resin film is interposed between a pair of glass plates.

5. The luminescent display system according to claim 1, wherein the light beam of excitation wavelength emitted from each light source has an irradiation intensity of 200 mW/cm.sup.2 or lower.

6. A head-up display comprising the luminescent display system according to claim 1.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0139] FIG. 1 is a schematic view illustrating a method of displaying information by the luminescent display system of the present invention.

[0140] FIG. 2 is a schematic view illustrating a method of displaying information by a luminescent display system including only one light source.

DESCRIPTION OF EMBODIMENTS

[0141] The present invention is more specifically described in the following with reference to, but not limited to, examples.

Example 1

(1) Preparation of Polyvinyl Butyral

[0142] To a 2 m.sup.3 reactor equipped with a stirrer were charged 1,700 kg of a 7.5% by mass aqueous solution of PVA (degree of polymerization: 1,700, degree of saponification: 99 mol %), 74.6 kg of n-butyraldehyde, and 0.13 kg of 2,6-di-t-butyl-4-methyl phenol, and the entire mixture was cooled to 14 C. Subsequently, 99.44 L of 30% by mass nitric acid was added to the mixture to initiate the butyralization of PVA. Ten minutes after the end of the addition, the temperature was raised to 65 C. over 90 minutes, followed by further reaction for 120 minutes. Thereafter, the temperature was lowered to room temperature, and the precipitated solid was obtained by filtration. The solid was washed ten times with a 10-fold amount (by mass) of ion exchange water. The washed solid was sufficiently neutralized using a 0.3% by mass sodium hydrogen carbonate aqueous solution and was then washed ten times with a 10-fold amount (by mass) of ion exchange water. The resulting solid was dehydrated and dried, thereby obtaining polyvinyl butyral resin (PVB).

(2) Production of Luminescent Resin Film and Laminated Glass

[0143] A luminescent plasticizer solution was prepared by adding 0.54 parts by weight of diethyl-2,5-dihydroxyterephthalate (available from Sigma-Aldrich, diethyl 2,5-dihydroxyterephthalate) to 40 parts by weight of triethylene glycol di-2-ethylhexanoate (3GO). The entire amount of the obtained plasticizer solution was mixed and sufficiently kneaded with 100 parts by weight of the obtained polyvinyl butyral using a mixing roll to prepare a resin composition.

[0144] The obtained resin composition was extruded using an extruder to provide a luminescent resin film having a thickness of 760 m.

[0145] The obtained luminescent resin film as an interlayer film for a laminated glass was interposed between a pair of clear glass plates (thickness: 2.5 mm, 5 cm in length5 cm in width) to prepare a laminate. The laminate was pressed under vacuum at 90 C. for 30 minutes to be press-bonded using a vacuum laminator. The press-bonded laminate was subjected to further 20-minute press-bonding under 14 MPa at 140 C. using an autoclave, thereby obtaining a laminated glass.

(3) Construction of Luminescent Display System

[0146] Two or three pico projectors (available from Sony Corporation) were provided as light sources. Each light source was set such that its light beam of a wavelength 405 nm had an irradiation intensity of 200 mW/cm.sup.2.

[0147] The light sources were placed such that light beams emitted therefrom would overlap on the obtained laminated glass.

Example 2

[0148] Europium acetate (Eu(CH.sub.3COO).sub.3) in an amount of 12.5 mmol was dissolved in 50 mL of distilled water. To the solution was added 33.6 mmol of trifluoroacetylacetone (TFA, CH.sub.3COCH.sub.2COCF.sub.3), and the mixture was stirred at room temperature for 3 hours. The mixture was filtered to obtain precipitated solid. The precipitated solid was washed with water, and recrystallized using methanol and distilled water to give Eu(TFA).sub.3(H.sub.2O).sub.2. Then, 5.77 g of the resulting complex (Eu(TFA).sub.3(H.sub.2O).sub.2) and 2.5 g of 1,10-phenanthroline(phen) were dissolved in 100 mL of methanol, followed by heating under reflux for 12 hours. After 12 hours, methanol was distilled off under reduced pressure, thereby obtaining a white product. The white product powder was washed with toluene so that unreacted materials were removed by suction filtration. Subsequently, toluene was distilled off under reduced pressure, thereby preparing a powder. Through recrystallization using a solvent mixture of toluene and hexane, Eu(TFA).sub.3phen was obtained.

[0149] A luminescent resin film and a laminated glass were produced as in Example 1 except that instead of 0.54 parts by weight of diethyl-2,5-dihydroxyterephthalate (available from Sigma-Aldrich, diethyl 2,5-dihydroxyterephthalate), 0.4 parts by weight of the obtained Eu(TFA).sub.3phen was added to 40 parts by weight of 3GO. A luminescent display system was constructed by placing two or three light sources.

Example 3

[0150] Terbium acetate (Tb(CH.sub.3COO).sub.3) in an amount of 12.5 mmol was dissolved in 50 mL of distilled water. To the solution was added 33.6 mmol of trifluoroacetylacetone (TFA, CH.sub.3COCH.sub.2COCF.sub.3), and the mixture was stirred at room temperature for 3 hours. The mixture was filtered to obtain precipitated solid. The precipitated solid was washed with water, and recrystallized using methanol and distilled water to give Tb(TFA).sub.3(H.sub.2O).sub.2. Then, 5.77 g of the obtained complex (Tb(TFA).sub.3(H.sub.2O).sub.2) and 2.5 g of 1,10-phenanthroline(phen) were dissolved in 100 mL of methanol, followed by heating under reflux for 12 hours. After 12 hours, methanol was distilled off under reduced pressure, thereby obtaining a white product. The white product powder was washed with toluene so that unreacted materials were removed by suction filtration. Subsequently, toluene was distilled off under reduced pressure, thereby preparing a powder. Through recrystallization using a solvent mixture of toluene and hexane, Tb(TFA).sub.3phen was obtained.

[0151] A luminescent resin film and a laminated glass were produced as in Example 1 except that instead of 0.54 parts by weight of diethyl-2,5-dihydroxyterephthalate (available from Sigma-Aldrich, diethyl 2,5-dihydroxyterephthalate), 0.4 parts by weight of the obtained Tb(TFA).sub.3phen was added to 40 parts by weight of 3GO. A luminescent display system was constructed by placing two or three light sources.

Comparative Examples 1 to 3

[0152] Luminescent resin films and laminated glasses were produced as in Examples 1 to 3 except that the number of light sources and the irradiation intensity were as shown in Table 2. Luminescent display systems were constructed by placing two or three light sources.

(Evaluation)

[0153] The luminescent display systems obtained in the examples and comparative examples were evaluated by the following methods.

[0154] Tables 1 and 2 show the results.

(1) Safety Evaluation

[0155] The safety of the luminescent display system was evaluated as follows.

(Good): Each light source had an irradiation intensity of 200 mW/cm.sup.2 or lower.
x (Poor): Each light source had an irradiation intensity of higher than 200 mW/cm.sup.2.

(2) Display Luminance Evaluation

[0156] A luminance meter (SR-3AR, available from Topcon Technohouse Corporation) was placed on the side to be irradiated with light, at an angle of 45 degrees relative to the surface of the laminated glass to be irradiated with light and at a shortest distance of 35 cm from the surface of the laminated glass. The laminated glass was then irradiated with light from the light source(s), and the luminance of information displayed on the laminated glass was measured.

[0157] In the case where multiple light sources were used, the luminance was measured at an overlapping portion of the light beams from all the light sources.

TABLE-US-00001 TABLE 1 Example 1 Example 2 Example 3 Interlayer Thermoplastic resin 100 100 100 film formulation Plasticizer 40 40 40 (parts by weight) Luminescent Diethyl 2,5- 0.54 material dihydroxyterephthalate Eu(TFA).sub.3phen 0.4 Tb(TFA).sub.3phen 0.4 Light source The number of light sources 3 2 2 3 2 2 3 2 2 Overlapping ratio (%) 100 100 100 100 100 100 100 100 100 Irradiation intensity of each 200 200 100 200 200 100 200 200 100 light source (mW/cm.sup.2) Evaluation Safety Luminance (cd/m.sup.2) 20000 13000 6700 50800 34000 17000 15000 10000 5000

TABLE-US-00002 TABLE 2 Comparative Comparative Comparative Example 1 Example 2 Example 3 Interlayer Thermoplastic resin 100 100 100 film formulation Plasticizer 40 40 40 (parts by weight) Luminescent Diethyl 2,5- 0.54 material dihydroxyterephthalate Eu(TFA).sub.3phen 0.4 Tb(TFA).sub.3phen 0.4 Light source The number of light sources 1 1 1 1 1 1 1 1 1 Irradiation intensity of each 600 400 100 600 400 100 600 400 100 light source (mW/cm.sup.2) Evaluation Safety x x x x x x Luminance (cd/m.sup.2) 20000 13000 3300 50800 34000 8500 15000 10000 2500

INDUSTRIAL APPLICABILITY

[0158] The present invention can provide a luminescent display system capable of safely and easily displaying information at a predetermined luminance over a wide area, and a head-up display including the luminescent display system.

REFERENCE SIGNS LIST

[0159] 1 luminescent resin film [0160] 2 light source [0161] 3 light source [0162] 4 light source