JP2014022223A - Plane light emission device having light-emitting surfaces on both sides, and method for manufacturing light guide plate used in the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plane light emission device having light-emitting surfaces on both sides, which is excellent in a light-emitting effect with an easy structure having a few components.SOLUTION: A place light emission device has light-emitting surfaces on both sides, and irradiates an illuminated picture attached to the surfaces with light. The plane light emission device includes: a base; a light guide plate comprising a transparent plastic whose end part is supported by the base; and a light source part included in the base, opposite to the end surface of the light guide plate, and making light incident toward the inside of the light guide plate from the end surface. On one-side surface of the light guide plate, light reflection printing is performed in a gradation pattern with a white ink by an ink-jet printer.

Description

  The present invention relates to a surface emitting device having light emitting surfaces on both sides and a method for manufacturing a light guide plate used in the device.

2. Description of the Related Art Conventionally, a device that performs light reflection printing as reflection dots on the light irradiation surfaces on both sides of a light-transmitting substrate is known (for example, see Patent Document 1).
In addition, a light guide having a structure in which a reflective film is sandwiched between a pair of light guides and light can be emitted from both the front and back surfaces is known (see, for example, Patent Document 2).
In addition, an indirect illumination device in which an image is printed on a transparent display plate surface with a transparent ink containing light scattering fine particles is conventionally known (see, for example, Patent Document 3).

JP 2011-100701 A JP 2004-94099 A JP 2010-129242 A

The main object of the present invention is to apply a reflection printing by gradation using white ink on one side of a light guide plate so that surface emission can be performed uniformly. It is an object of the present invention to provide a slim double-sided light emitting device that can omit the number of parts by creating a light emitter with a structure that efficiently emits light from both sides without using it.
Another object of the present invention is to prepare a plurality of types of white ink and use the white ink suitable for the light guide plate to be printed, thereby associating the print pattern and the type of the light guide plate with desired light emission characteristics. It is to be able to manufacture a light guide plate having

In order to achieve the above object, the present invention provides a surface emitting device for emitting light to an illuminated image pasted on both surfaces and having a light emitting surface on both surfaces, the base and the base A light guide plate made of transparent plastic with an end supported, and a light source unit that is built in the base and faces the end surface of the light guide plate, and that enters light from the end surface toward the inside of the light guide plate, Light reflection printing is performed on one surface of the light guide plate by an ink jet printer with a gradation pattern using white ink.
In the invention, it is preferable that an end portion of the light guide plate is supported in a state where both surfaces are open to the base.
Further, the present invention is characterized in that a transparent protective plate for protecting the light reflection printing is bonded to one surface of the light guide plate.
The present invention also relates to a method of manufacturing a light guide plate used in a surface emitting device having light emitting surfaces on both sides, and a plurality of types of white ink for determining the color temperature of the light emitting surface of a transparent plastic plate in an inkjet printer. For each type of ink tank, a plurality of recording heads are provided in the ink jet printer, and one of the ink tanks is connected to each recording head. The ink jet printer performs reflective printing with a gradation pattern on one side of the transparent plastic, and a color temperature corresponding to a selected combination of one or more types of white ink. A light guide plate provided with the above is produced.
In the invention, it is preferable that the plurality of types of white ink have different contents of titanium oxide in the respective inks.
Further, the present invention is characterized in that the plurality of types of white ink have different titanium oxide particle size distributions in the respective inks.

  Since the transmitted light can be used by the thin reflection printing by the ink jet, a slim double-sided light emitting device capable of omitting the number of parts can be provided. Moreover, reflection printing suitable for the light guide plate to be used is possible, and a light guide plate having desired light emission characteristics can be manufactured.

It is a whole explanatory drawing of the surface emitting apparatus. It is explanatory drawing of this invention. It is block explanatory drawing of a light-guide plate production apparatus. It is explanatory drawing of this invention. It is explanatory drawing of this invention. It is whole explanatory drawing of a light-guide plate production apparatus. It is explanatory drawing of this invention. It is explanatory drawing of this invention. It is explanatory drawing of this invention. It is explanatory drawing of this invention. It is whole explanatory drawing which shows other embodiment of this invention.

Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 shows an overall side view of a surface emitting device having light emitting surfaces on both sides according to the present invention. The apparatus 2 includes a base 4, a light source unit 6, and a light guide plate 8 erected on the base 4. The light source section 6 includes a storage body 10 having a U-shaped cross-section with a light reflection surface formed inside, and a light-emitting body 12 such as a cold cathode tube or LED (light emitting diode) stored and disposed in the storage body 10.

A lower end surface of the light guide plate 8 is attached to the open portion of the storage body 10. The light emitter 12 in the storage body 10 is disposed to face the lower end surface 8 a of the light guide plate 8. The light emitter 12 is connected to the power supply unit via an electric cord or a power switch. In this embodiment, the light guide plate 8 is configured by a quadrangular hexahedron made of transparent plastic such as an acrylic plate, a urethane plate, or a silicon plate. The light guide plate 8 includes a pair of two parallel surfaces 8b and 8c on the wide side, and four narrow end surfaces 8a, 8d, 8e, and 8f formed at four end portions of the surfaces 8b and 8c. In this embodiment, the light source unit 6 is disposed opposite to one end surface 8a among the four end surfaces. However, the present invention is not particularly limited to the configuration in which the light source unit 6 is provided on one end surface 8a.

A lower end portion of the light guide plate 8 is fitted and disposed in a groove 14 formed in the base 4. One surface 8c of the light guide plate 8 is subjected to reflection printing 16 by gradation drawing using white ink by an ink jet printer. On the upper end face 8f and the left and right end faces 8d and 8e of the light guide plate 8, a strip-like light reflecting member 18 is attached. Here, gradation refers to a print density change pattern formed by the gradation pattern generation mode of the print data creation software. In drawing a gradation pattern, the print density of ink dots can be changed between 0% and 100%.

FIG. 10 is an explanatory diagram of the density of the ink dots 20 in the gradation pattern diagram. In FIG. 10, (A) is 0%, (B) is 25%, (C) is 50%, (D) is 75%, E) shows 100% concentration, respectively. Note that FIG. 10 is merely a simplified description, and in actual printing, printing is performed with a large number of dots, so the location for printing is specified according to the resolution of the printer. Printing in an arbitrary range such as 0 to 100% is possible within the range.

  In the configuration described above, when the light source unit 6 is energized to cause the light emitter 12 to emit light, the light of the light emitter 12 enters from the end face 8 a of the light guide plate 8. The light that has entered the light guide plate 8 is reflected by the reflection printing 16 of the light guide plate 8 and also by the light reflecting member 18. The light that has entered the light guide plate 8 includes light that passes through one surface 8b in the arrow direction A, light that passes through the reflective printing 16 in the arrow direction B, light that reflects off the reflective surface of the reflective member 18, and the like. 8 spreads throughout. Thereby, one surface 8 b of the light guide plate 8 emits light by the light reflected by the reflection printing 16, and one surface 8 c to which the reflection printing 16 is applied emits light by the light transmitted through the reflection printing 16.

If a sheet-like illuminated image (not shown) is attached to the surfaces 8b and 8c of the light guide plate 8, the surface image sheet is irradiated with light emitted from the surface of the light guide plate 8 as a backlight.
In the present embodiment, both sides of the light guide plate 8 are opened and used as the illuminated image pasting surface. However, as shown in FIG. A transparent protective plate 50 for protection may be adhered. In this case, the light source 12 may be provided only on the light guide plate 8 side.

In the above embodiment, the reflection printing 16 is printed by gradation drawing by preparing a plurality of types of white ink in an ink jet printer and using the white ink suitable for the light guide plate 8.
Next, an apparatus that performs reflection printing on the light guide plate 8 to create a light guide plate for double-sided light emission will be described.

3 and 6 are schematic views of a light guide plate printing apparatus including an inkjet printer 22 and a computer 24 such as a personal computer connected to the controller of the printer 22 via an input / output interface. The light guide plate 8 is detachably held on the table 28 of the printing apparatus with one surface 8c facing up.

In printing (printing) on the light guide plate 8, the horizontal rail 26 is sent in a printing unit set in one direction (sub-scanning direction) under the control of the printing apparatus main body drive unit. The head carriage 38 including the ink jet recording heads 30, 32, 34, 36 is moved in the main scanning direction perpendicular to the conveying direction of the horizontal rail 26 under the control of the carriage driving unit. When the head carriage 38 moves in the main scanning direction, ink is ejected from the nozzles of the recording heads 28 to 34, and print data transferred from the computer 24 to the controller of the ink jet printer 22 is transferred to the software stored in the controller. Printing is performed on the printing surface of the light guide plate 8 by the control. Note that printing in the sentence is synonymous with printing.

The storage device of the computer 24 stores a printing program for controlling the controller of the inkjet printer 22 and performing printing. A horizontal rail 26 is arranged on the table 28 so as to be movable in parallel in the sub-scanning direction, and a head carriage 38 is connected to the horizontal rail 26 so as to be movable in the main scanning direction. The head carriage 38 holds a plurality of ink jet recording heads 30, 32, 34, and 36 as shown in FIG.

Each of the recording heads 30, 32, 34, and 36 includes a number of nozzles that eject ink. As shown in FIG. 5, each of the heads 30, 32, 34, and 36 has an ink tank 40 corresponding to each of the white ink supply units A, B, C, and D provided with an ink tank disposed in the body of the printer 22. , 42, 44, 46 communicate with each other via an ink supply means such as a tube. The plurality of recording heads 30, 32, 34, 36 are arranged in parallel so that their print areas overlap in the main scanning direction along the horizontal rail 26.

The storage device of the computer 24 stores software (print program) for creating print data of the light reflection pattern, and an ink data table 48 is provided. This data table 48 changes the concentrations of light guide plates and titanium oxides of various color temperatures by printing a plurality of types of white inks A, B, C, and D individually or in combination on the light guide plate 8. In order to make it possible to create a light guide plate in which the thickness of the ink after printing is very thin, a combination of inks A, B, C, and D in which the color temperature and the titanium oxide concentration are changed is previously set. By using this data table 48, it is possible to easily change the color temperature and the concentration of titanium oxide and create a light guide plate that makes the ink thickness very thin after printing. It is something that can be done.

In FIG. 4, white inks A and B indicate two types of inks having different color temperatures with respect to the particle diameter of titanium oxide, and white ink C has a content of titanium oxide in white ink A. A different white ink is shown, and a white ink D is a white ink having a titanium oxide content different from that of the white ink B. In this embodiment, by preparing a plurality of types of white ink with respect to the particle size and content of titanium oxide, printing at a plurality of color temperatures or a combination of these can be easily performed. The content of titanium oxide in the white ink is preferably 10% or less and may be 1% or less. By reducing the content of titanium oxide, it becomes easy to change the brightness of the fine gradation on the light emitting surface of the light guide plate and to control the transmitted light.

In FIG. 4, the light guide type indicates the type of light guide plate to be printed, for example, the type of light guide such as an acrylic plate, a urethane plate, or a silicon plate, and the print pattern has a required luminance. A gradation drawing printing pattern in which a plurality of distributions and light distributions are prepared is shown. In creating the light guide plate, the manufacturer can select a desired one from a plurality of light guide printed patterns for the light guide plate.
When using ink with titanium oxide in the light guide plate printing, prepare white ink with different color temperature depending on the particle size distribution of titanium oxide in the ink, and change the dispersion of the particle size distribution. Difference in reflected light and color temperature. This is because the particle diameter of titanium oxide in the ink is different, so that the intensity of light scattered after printing differs depending on the wavelength of light, and as a result, the color temperature of the scattered light of the printed light guide plate is different.

[About white ink and color temperature]
White ink uses titanium oxide as an ink pigment. Titanium oxide particles have the property of reflecting light with a wavelength twice as large as the particle diameter. The ideal white ink has a uniform titanium oxide particle size distribution of 200 nm to 400 nm as shown in FIG. Is to exist. In that case, it becomes white which uniformly reflects light 400 nm-800 nm (visible light) having a wavelength twice as large as the particle diameter 200 nm-400 nm.

However, in the actual white ink, the particle size distribution rarely exists uniformly at 200 nm-400 nm,
(1) When there are many particles having a particle diameter of 200 nm (see FIG. 8), white ink that strongly reflects 400 nm light (short wavelength), and white ink that has a high color temperature and is bluish.
(2) When there are many particles having a particle diameter of 400 nm (see FIG. 9), white ink that strongly reflects light (long wavelength) at 800 nm, white ink with a low color temperature, red, yellow, or green is obtained.

In adjusting the color temperature, a light guide plate having a desired color temperature = desired titanium oxide distribution = desired wavelength range of light is created by combining the white inks having different color temperatures (different titanium oxide distributions). To do. However, when it is difficult to adjust the color temperature only with the particle diameter of titanium oxide, a desired light wavelength region may be obtained by adding other particles, copper phthalocyanine, or the like.

7 to 9 are distribution image diagrams of the particle diameter of titanium oxide in the ink. The horizontal axis indicates the particle diameter, and the vertical axis indicates the degree of distribution. FIG. 7 shows the distribution of titanium oxide particles in an ideal white ink, and FIGS. 8 to 9 show the distribution of titanium oxide particles in an actual white ink.

A small amount of copper phthalocyanine is added to the ink used in this embodiment. The amount of this addition has been experimentally selected so that the color temperature of the ink can be easily controlled by selecting an appropriate amount experimentally. When printing on the light guide plate 6, the operator can select the white inks A, B, C, and D by hitting an ink selection button displayed on the display of the computer 24 with a mouse or the like. It is also possible to specify a plurality of inks such as A and B, A and C, and to specify what ink is to be used in which print portion in correspondence with the created print data. .

2 Surface light emitting device 4 Base 6 Light source unit 8 Light guide plate 8a Lower end surface 8b Surface 8c Surface 10 Storage body 12 Light emitter 14 Groove 16 Reflective printing 18 Reflective member 20 Ink dot 22 Inkjet printer 24 Computer 26 Horizontal rail 28 Table 30 Recording Head 32 Recording head 34 Recording head 36 Recording head 38 Carriage 40 Ink tank 42 Ink tank 44 Ink tank 46 Ink tank 48 Data table

Claims (6)

A surface emitting device having a light emitting surface on both surfaces and irradiating light to an illuminated image pasted on both surfaces, comprising a base and a transparent plastic having an end supported by the base A light guide plate; and a light source unit that is built in the base and faces an end surface of the light guide plate and that enters light from the end surface toward the inside of the light guide plate. A surface emitting device having light emitting surfaces on both sides, wherein light reflection printing is performed with a gradation pattern using white ink. The light guide plate has a light emitting surface on both sides, wherein the light guide plate has ends supported on both sides of the light guide plate. 2. The surface emitting device according to claim 1, wherein a transparent protective plate for protecting the light reflection printing is adhered to one surface of the light guide plate. A method of manufacturing a light guide plate used in a surface emitting device having a light emitting surface on both sides, wherein a plurality of types of white ink for determining a color temperature of a light emitting surface of a transparent plastic plate are used for an ink jet printer. A white ink supply unit housed in a tank is provided, a plurality of recording heads are provided in the ink jet printer, and one of the ink tanks is connected to each of the recording heads. A light guide plate configured to eject white ink, wherein the ink jet printer performs reflection printing on one side of the transparent plastic with a gradation pattern, and has a color temperature corresponding to a selected combination of one or more types of white ink Manufactures light guide plates used in surface light-emitting devices with light-emitting surfaces on both sides How. The light guide plate used in a surface light emitting device having light emitting surfaces on both sides according to claim 3, wherein the plurality of types of white ink have different titanium oxide contents in each ink. Method. The method for producing a light guide plate used in a surface light emitting device having light emitting surfaces on both sides, wherein the plurality of types of white inks have different particle size distributions of titanium oxide in each ink.

Images