JPH09179512A - Surface light emission display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to perform high quality multi-color display and white light display with a display device using an LED as a light source. SOLUTION: This device is formed in combination of the light source 41 arranged with plural LEDs 40 emitting blue color light, a light transmission plate 42 to perform surface light emitting of the light of the light source 41 received from one side surface 42a, a color conversion member 4 converting the light emission color of the light source 41 to another color and a display panel 46 formed with a display pattern such as figure pattern and a character displayed by lighting from a rear. Then, by converting the blue color light to the white light or the light having the other light spectrum components such as green, yellow, red by the color conversion member 44, the blue color light is converted to the white light or the other different colors required for a display of a display panel 46, and a display pattern is displayed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an edge-light type surface-emitting display device, including an emergency light, a guide light, a road sign,
It is used as a backlight of a display device such as an advertising light, a display label for a room, and a nameplate, and the surface light is emitted by itself to allow a user to recognize characters, patterns, and the like.

[0002]

2. Description of the Related Art In a conventional display device for an emergency exit light, for example, as shown in FIGS. 13 and 14, a display panel 1 displaying a display pattern such as characters and patterns is mounted on a frame 2 suspended from a ceiling. Then, a fluorescent lamp 4 as a light source is arranged on the back surface of the display panel 1 through the diffusion plate 3, and the display panel 1 is illuminated directly from the back surface so that the displayed contents are recognized.

A block diagram of an electric circuit of the display device is shown in FIG. Here, since the power supply circuit 5 converts the power supply of AC100V into the power supply of DC5V, the DC power supply is normally converted into the AC high voltage by the inverter 6 to turn on the fluorescent lamp 4. Further, the storage battery 8 is usually charged through the charging circuit 7.

When a power failure occurs, the power failure detection circuit 9 detects the power failure, the switches 10 and 11 such as transistors and relays operate, the storage battery 8 becomes a DC power source, and the inverter 6 causes a high AC voltage. The fluorescent lamp 4 is turned on.

However, since the conventional display device uses a fluorescent lamp as a light source, it has the following problems.

Since it is necessary to arrange a fluorescent lamp on the back surface of the display panel to take a space, it is difficult to manufacture a thin display device.

The life of the fluorescent lamp is short, and it is necessary to replace the fluorescent lamp on a regular basis in about 0.5 to 1 year, which requires time and labor for maintenance.

Fluorescent lamps are not suitable for blinking light emission operation, and it has been difficult to add a function of raising the degree of recognition of the display device by causing the blinking light emission operation in an emergency such as a power failure.

In order to turn on the fluorescent lamp at the time of power failure,
An inverter for converting the DC power supply into the AC power supply is required, which has been a factor of cost increase.

Therefore, in order to solve the problem in the direct light type display device using a fluorescent lamp as a light source, an edge light type surface emitting display device has been proposed. In the edge-light type display device, in order to enable nighttime recognition or to improve visibility of display contents such as characters and figures, the display panel on which the display contents are written is translucent or semi-translucent. , Illuminate this display panel from the back to visually display the information.

FIG. 16 shows a conventional example of an edge light type display device. The light guide plate 15 is made of a translucent material such as acrylic resin, and the light of the light source 16 that is incident on one side of the light guide plate 15 is provided on the surface of the light guide plate 15 by printing or grooving. Has a function of scattering light by a pattern for diffusing light and making the entire surface of the light guide plate 15 emit light, and in recent years, it has been used as a backlight of a liquid crystal display panel or the like. As the light source 16, a plurality of LEDs 18 mounted on a printed circuit board 17 are arranged opposite to each other on one side surface of the light guide plate 16. The surface light source having such a structure is arranged on the back surface of the display panel 19 via the diffusion sheet 20 to form a display device. In the figure, 21 is a reflection sheet.

Another conventional display device is disclosed in Japanese Patent Laid-Open No. 4-85.
It is also described in Japanese Patent No. 588. In this display device,
As shown in FIG. 17, LEDs 23 arranged in series as light sources are arranged on the side surface 22 a of the light guide plate 22, a reflection plate 24 is arranged on the back surface of the light guide plate 22, and a diffusion sheet 25 is arranged on the front surface of the light guide plate 22. Are superposed on each other, and a display panel 26 is arranged on the front surface thereof. This display panel 26 is L
It has a structure in which a light shielding plate 29 having a display pattern 28 formed thereon is stacked on a color filter 27 that transmits the same color as the emission color of the ED 23. On the display panel 26, in many cases, a character portion is formed by a method such as screen printing, pattern attachment by etching, and spray painting by masking.

In this structure, the light emitted from the LED 23 is extracted to the front of the light guide plate 22 through the inside of the light guide plate 22. The light emitted to the front of the light guide plate 22 illuminates the display panel 26 installed in front of the light guide plate 22 from the back side through the scattering sheet 25 on the front surface of the light guide plate 22, and the color filter 27.
Then, the light passes through the display pattern 28 of the light shielding plate 29 and is emitted to the front of the display device. In this display device, the display panel 2
The display color of 6 is the same as the emission color of the LED 23 of the light source.

In the case where two or more display colors or white light display colors are required, Japanese Patent Application No. 7-123 filed by the present applicant.
No. 878 is proposed. In this display device, when the LEDs of the light source 16 in the display device of the conventional example shown in FIG. 16 are required to have two display colors, for example, red and green, two types of red LED 30a and green LED 30b are shown in FIG. 18 (a). As shown in FIG. 5, they are alternately arranged on the printed circuit board 31. Also, when the display color of the display panel is color display or white light, red, green, and blue LEDs are used.
32a, 32b and 32c are arranged side by side as shown in FIG.

Further, as a light source for a direct-light type display device, there is a light emitting device using a white light emitting EL (electroluminescence) panel for thinning, which emits light by applying an AC voltage.

[0016]

However, the conventional surface-emitting type display device using the LED as the light source is suitable for a single color display because the emission color of the LED becomes the display color of the display panel. When two or more display colors are required or the display color is white light, it is necessary to alternately arrange LEDs of different emission colors to form a light source, and the following problems occur.

Since the LEDs of different emission colors are arranged alternately, the emission colors are not mixed in the vicinity of the LEDs, and color unevenness occurs in the light source.

For white light, red, green, and blue L
There is a case where the light amount deviates from white due to variations in the light amount of the ED, and it is necessary to adjust the light amount by adjusting the power source of the LEDs of each color.

When displaying two or more colors, the color of the display pattern of the display panel cuts off light other than the display color to display the required display color, so that the brightness of the display surface becomes low.

Further, a display device using an EL panel as a light source has the same problem as above when two or more display colors are required. Furthermore, in order to emit light and display when a power failure occurs, an inverter for converting the power source of the storage battery, which is a backup power source, into an alternating current is required, which causes a cost increase as in the case of the fluorescent lamp.

In view of the above, it is an object of the present invention to provide a thin and long-life surface-emitting display device that uses LEDs as a light source and can display multicolor or white.

[0022]

According to the present invention, there is provided a light source in which a plurality of LEDs are arranged, a light guide plate for making the light of the light source incident from a side surface emit light, and a light emission color of the light source is converted into a different color. And a display panel on which a display pattern such as a design or a character displayed by illumination from the back is formed. Then, the light source is an LED of a single emission color and emits blue light. Further, the color conversion member converts blue light into white light or light having other light spectrum components such as green, yellow and red.

Therefore, the blue light emitted from the LED is uniformly surface-emitted by the light guide plate, and is converted into white light or another different color required for display on the display panel by the color conversion member, so that the display panel is viewed from the rear side. Illuminate and display the display pattern.

Another means for solving the problems comprises a light source in which a plurality of LEDs are arranged, a light guide plate for making the light of the light source incident from the side surface emit light, and a color conversion member for converting the emission color of the light source into a different color. A plurality of color conversion members are combined to form a display pattern such as a design or a character. Then, an LED that emits blue light is used as a light source, and the color conversion member converts the blue light into other light according to the color of the display pattern.

Therefore, the light emitted from the LED is converted into a desired color by the color conversion member in accordance with the color of the display pattern, and it is possible to easily display two or more colors. Moreover, since the light component that has been cut off in the display panel is eliminated, a brighter display surface brightness can be obtained.

Here, the display panel on which the display pattern is formed is arranged on the front surface of the color conversion member, and two or more kinds of colors are used so as to convert the emission color of the light source into different colors according to the display pattern of the display panel. A combination of conversion members. Then, the color conversion member converts the light emission color of the LED into a color according to the display pattern, and further, there is no light to be cut off in the display panel and the light passes through as it is, so that the brightness on the display surface increases and the brightness increases.

Further, if a control means for arbitrarily changing the visibility of the LED is provided, the LED can be turned off or turned on in accordance with the situation of day or night, or the LED can be used in an emergency such as an earthquake or a fire.
By blinking, the visibility can be changed, and the display according to the situation can be functionally performed.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION As shown in FIG. 1, an embodiment of a surface-emitting type display device of the present invention is a light source 41 in which a plurality of LEDs 40 of a single emission color are arranged, and a light source 41 incident from one side surface 42a. The light guide plate 42 that scatters the light inside to emit light from the front surface, the reflection plate 43 that reflects the light emitted from the light guide plate 42 to the outside, and the light emission color of the light source 41 is converted into different colors. The color conversion member 44, a diffusion plate 45 that scatters light to make the directivity of the intensity of the light uniform, and a display panel 46 on which a display pattern such as a pattern or characters displayed by illumination from the back surface is formed. I have it.

Then, as shown in FIG. 2, the display panel 46, the diffusion plate 45, the color conversion member 44, the light guide plate 42, and the like in this order from the front side.
The reflector 43 is overlaid and inserted into the holder 47,
The bolts are passed through the four corners of the respective members and through holes formed in the holder 47 and fixed by the nuts, whereby the respective members are easily positioned and held. The holder 47 is attached to a ceiling, a wall, a pillar, etc. indoors or outdoors,
The display device is installed by connecting an electric circuit for driving the LED 40 of the light source 41 installed in the holder 47 to an AC power supply.

As the light source 41, an LED 40 that emits blue light is used, and the plurality of LEDs 40 are the glass epoxy substrate 4
8 is mounted on the surface of the substrate 48 at a constant pitch, and white paint is printed on the surface of the substrate 48 so as to reflect light in the visible range. The substrate 48 is detachably attached to the holder 47 so as to be close to the one side surface 42 a of the light guide plate 42, and the light emitted to the side of the LED 40 is guided by the light guide plate 42.
Reflecting plates 49 for reflecting the light are provided on both sides of the substrate 48.

The light guide plate 42 is made of a colorless and transparent acrylic plate having a thickness equal to or slightly larger than the width of the LED 40, and the light which has propagated through the inside of the light guide plate 42 by repeating the total reflection is extracted from the front surface. A light extraction body 50 is provided. The light extraction body 50 is formed by arranging V-shaped grooves in a straight line in a direction parallel to the side surface on which light is incident, and is arranged so as to become denser as the distance from the light source increases. The individual grooves are formed directly on the back surface of the light guide plate 42 by a transparent resin such as acrylic or epoxy resin in a convex shape by a printing method, or by a thermal transfer processing method, a laser processing method, an etching, a cutting and polishing processing method, or the like. , Its surface is a rough surface that causes light scattering, is colorless and transparent and does not absorb light. Further, the back surface and the front surface of the light guide plate 42 other than the portion where the light extraction body 50 is provided are very smooth surfaces, and a light image can be transmitted clearly in the thickness direction. Further, the one side surface 42a opposite to the light source 41 is also polished to a very smooth surface so that an optical image can be clearly transmitted.

The light extraction body 50 has a cross-sectional shape of V
Instead of the rectangular groove, another shape such as a U-shaped groove or a sawtooth groove may be used. Further, instead of these structures, a structure in which the surface of the light guide plate 42 is partially roughened by a method such as a thermal transfer processing method, a chemical etching method, or a blast to form a scattering surface,
A structure in which a scattering material such as micro glass beads is coated on the surface of the light guide plate 42 with a transparent resin or the like may be used. Further, in order to make the brightness on the light guide plate 42 uniform when the light source is turned on, it is sufficient if the probability that the light propagating inside the light guide plate 42 is scattered increases as the distance from the light source 41 increases. The grooves or the scattering regions are formed on the surface of the light guide plate 42 discretely in various shapes such as circles, rectangles, and straight lines as grooves or surface scattering regions with a constant pitch, and the size of the grooves or the scattering regions is increased as the distance from the light source 41 increases. It is also possible to adopt a structure such as going on.

On the other hand, the side surface 42 of the light guide plate 42 on which the light is incident
Except for a, the three side surfaces are roughly polished on a smooth surface and have high reflectance (about 80% or more for visible light).
l A reflective tape having a reflective film deposited on the surface is attached. Further, a reflecting plate 43 made of a material such as Al or white ink is arranged so as to face the back surface of the light guide plate 42.

The color conversion member 44 is a sheet-shaped member containing an organic phosphor such as an organic fluorescent pigment, and contains a green conversion phosphor and a red conversion phosphor. The organic fluorescent pigment can be generally produced by dissolving a fluorescent aromatic hydrocarbon dye in a transparent solid carrier resin, and processing this carrier resin as it is on a sheet or Examples include a method in which the resin is once pulverized, and then granulated, and then contained in the resin and processed into a sheet shape.

The color conversion member 44 has a function of color-converting short-wavelength light into long-wavelength light.
When the blue light emitted from the color conversion member 44 passes through the color conversion member 44, it is converted into green and red light by the green conversion phosphor and the red conversion phosphor in the color conversion member 44.
Part of the blue light that has passed through is combined into white light.
FIG. 3 shows optical spectra of incident light (broken line) and transmitted light (solid line) at this time.

As the color conversion member 44 for converting to white light, as shown in FIG. 4, a yellow conversion phosphor is included to convert it into yellow light, and a part of the blue light transmitted through the color conversion member 44 is transmitted. It is also possible to make white light together with the light.

In the display panel 46, a color filter 52 containing a dye such as a pigment that absorbs an arbitrary color is printed in a predetermined shape on the surface of a transparent flat plate 51 such as an acrylic resin.
Alternatively, it is formed into a sheet and pasted. As a result, the base region 53 where the incident light is transmitted as it is and the conversion region 54 where the specific color is transmitted by the color filter 52.
And are formed, and a display pattern is configured by combining these. For example, when the display device is used for an emergency exit light, a display pattern is formed by printing and pasting a green transparent color filter 52 on a white transparent flat plate 51 as shown in FIG. This conversion area 54 is shown in FIG.
The filter characteristics (broken line) of the display panel 46 and the optical spectrum of the transmitted light (solid line) in FIG.

A block diagram of the electric circuit of the display device is shown in FIG. Here, the power supply circuit 60 converts a power supply of AC100V into a power supply of DC5V, and turns off the light.
A control circuit 61 including a logic circuit for controlling blinking is provided, a first switch 62 such as a transistor and a relay is turned on, and the DC power source drives the LED 40 to constantly emit light.

Further, the control circuit 61 controls the LE depending on the situation.
It has a function of drivingly controlling the D40 to arbitrarily change the visibility. Normally, the storage battery 64 is charged through the charging circuit 63, and when a power failure occurs, the power failure detection circuit 65 detects the power failure, and the first, second
The switches 62 and 66 are turned on, the storage battery 64 becomes a battery, and the LED 40 blinks or constantly emits light. If the control circuit 61 variably controls the drive current value of the LED 40, the brightness can be easily adjusted.

The ambient light is detected by the optical sensor 67 even when there is no power failure, and when it is bright, the first switch 6
2 has a function of turning off the LED 40 and turning off the LED 40, and when it is dark, turning on the first switch 62 to cause the LED 40 to emit light or turning on and off the first switch 62 to cause blinking light emission. Furthermore, it is also possible to add a function of receiving an external signal from the outside in an emergency and causing the light to blink.

As described above, the light source 41 is capable of blinking and emitting L light.
By using the ED40, the surrounding brightness and earthquakes,
Since the blinking operation of the display device can be easily performed when an emergency such as a fire occurs, the visibility of the LED 40 changes depending on the situation, and the display can be changed to obtain an excellent recognition effect. The utility value increases as a display device. Furthermore, since the display can be sufficiently recognized when it is bright in the daytime, the power consumption can be reduced by turning off the LED 40. On the contrary, by making the display pattern unrecognizable when the light is off and turning on the light only when necessary at night or in an emergency, the use of this display device can be expanded.

Here, when the LED 40 is driven and turned on, blue light is emitted. Most of the light emitted from the LED 40 to the front is incident on the inside of the light guide plate 42 from one side surface 42a of the light guide plate 42 arranged in front of the LED 40.
Most of the light emitted laterally from D40 is reflected toward the front light guide plate 42 by the reflection plate 49 arranged laterally, and enters the inside of the light guide plate 42. Since the light guide plate 42 is thin, most of the light incident on the light guide plate 42 strikes the front surface or the back surface. At this time, one side surface 42a of the light guide plate 42
The incident angle θ ₂ of light entering the light guide plate 42 from the outside at an incident angle θ ₁ is θ ₂ = sin according to Snell's law.
^-1 (sin θ ₁ / n), (n: refractive index of light guide plate). Further, the light incident on the inside of the light guide plate 42 at the angle θ ₂ is incident on the front surface or the rear surface perpendicular to the one side surface 42a at the incident angle θ ₃ =
It is incident at 90-θ ₂ . From this relationship, as the incident angle θ _{1 of the} light entering the light guide plate 42 increases, the incident angle θ ₃ on the front surface or the back surface decreases, but the refractive index of the light guide plate 42 is n = 1.5. , Even if the incident angle on the one side surface 42a is maximum (that is, θ ₁ = 90 °), θ ₂
= 41.81 ° and θ ₃ = 48.19 °, the incident angle θ ₃ on the front surface or the back surface is never smaller than this value (48.19 °). On the other hand, since the critical angle for causing total reflection on the front surface or the back surface is θr = 41.81 °, all the light that hits the front surface or the back surface from the inside is totally reflected. In this way, most of the light totally reflected at the angle θ ₃ on the front surface or the back surface is the light guide plate 4.
The light is incident on both surfaces, which are parallel surfaces separated by a thickness of 2, at the same angle θ ₃ and is totally reflected again. In this way, the light guide plate 4
The light incident on the front surface 2 and incident on the front surface or the back surface from the inside is confined inside the light guide plate 42 by repeating total reflection, and propagates inside the light guide plate 42 with high efficiency without reflection loss.

Of the light propagating inside the light guide plate 42, the light that hits the light extraction body 50 is scattered and diffusely reflected without being absorbed by the roughened surface. Most of the light diffusely reflected on the back reaches the front,
Light of which the incident angle θ ₄ on the front surface is equal to or less than the critical angle θr is emitted from the light guide plate 42 to the outside. On the other hand, the light extraction body 50
The light that is scattered and transmitted through and is emitted to the back side of the light guide plate 42 is
Hit the reflector 43 that is installed closely on the back,
It is diffusely reflected with a high reflectance of about 0% and again enters the light guide plate 42 through its back surface. Most of the re-incident light reaches the front surface, of which light with an incident angle equal to or greater than the critical angle θr repeats the above-described behavior of total reflection, and light with an incident angle equal to or less than the critical angle θr goes out from the front surface of the light guide plate 42. To eject.

The light propagating in the light guide plate 42 while repeating the total reflection strikes the light extraction body 50 and emits a certain proportion of the light to the outside. Therefore, the light guide plate 42
Light propagating inside has the same probability regardless of the location.
When it hits 0, the light-extracting body 50 becomes denser as it goes away from the light source 41.
The further the distance from 1, the larger the brightness becomes, and the brightness of the surface-emitted light from the light guide plate 42 becomes uniform.

The blue light uniformly emitted to the front surface of the light guide plate 42 is converted into green and red light by passing through the color conversion member 44, and is mixed with the blue light transmitted through the color conversion member 44 to be white. Become light. This white light passes through the diffuser plate 45 and reaches the display panel 46. The light incident on the base region 53 is transmitted as it is, and white light is emitted. The color filter 52 removes components other than the green light spectrum from the light that has entered the conversion region 54, and emits green light. In this way, two-color display of white and green according to the display pattern is performed.

Also, here, the case of displaying white and green is shown, but when displaying two or more colors of other colors, the type of color conversion phosphor in the color conversion member 44 or the display panel. This can be achieved by changing the characteristics of the color filter 52 forming the 46 display patterns. For example, when the display device is used for a fire extinguisher indicator light, a display pattern is formed by printing and pasting a color filter 52 composed of white opaque characters on a flat plate 51 having a characteristic of transmitting red as shown in FIG. do it.

As described above, the side edge type surface-emitting display device using the LED 40 as the light source 41 can be made thinner and have a longer life than the direct-light type display device using the fluorescent lamp as the light source. it can. That is, the thickness of the direct light type display device is 150 to 200 mm, while the display panel 46 is 1 mm and the diffusion plate 45 is 0.
3 mm, color conversion member 44 0.3 mm, light guide plate 42 5
-10 mm, the reflection plate 43 is 0.5 mm, and the total thickness is about 20 mm. Therefore, restrictions on the installation place are reduced, and the range of application can be expanded. Further, the life of the fluorescent lamp is about 6000 hours, while that of the LED 40 is about 50,000 hours. As a result, the frequency of light source replacement is reduced, the maintenance work can be saved, and the cost can be saved. Furthermore, since it can be driven by a DC power source, an inverter for converting from a DC power source to an AC power source, such as a fluorescent lamp, becomes unnecessary, and the cost can be reduced.

By converting the emission color of the LED 40 into a different color by the color conversion member 44, it is possible to generate uniform white light within the plane, and it is possible to perform a clear display without color unevenness. As the visibility is improved, the control for adjusting the current value of each of the red, green, and blue LEDs to obtain white light in the related art is unnecessary, the electric circuit is simplified, and the cost can be further reduced.
In this way, since white display and color display can be easily performed, it becomes possible to replace a display device using a conventional fluorescent lamp as a light source, and thin, inexpensive, long life,
A display device with an excellent recognition effect can be provided.

Next, another embodiment of the display device will be described with reference to FIGS.
0 is shown. Here, the display panel is abolished and replaced by 2
The color conversion members 44a and 44b of different types are combined to form a display pattern such as a design or a character. That is, FIG.
In the display panel 46, a white color conversion member 44a that converts blue light into white light is provided in a portion corresponding to the base region 53.
The color conversion member 44b for green containing only the green conversion phosphor is used in the portion corresponding to the conversion region 54 in order to convert it into green light. Each color conversion member 44a, 4
4b is formed into a sheet shape and punched into a predetermined shape to be bonded to the translucent resin base material 70, or a paint-like phosphor is directly drawn to the translucent resin base material 70 in a predetermined shape. It is configured by being printed or applied. In this way, the display pattern is formed by the combination of the two types of color conversion members 44a and 44b. The color conversion members 44a and 44b may be directly provided on the front surface of the light guide plate 42. Further, other configurations are the same as those in the above-described embodiment.

The blue light surface-emitted from the light guide plate 42 is converted into white light when passing through the white color converting member 44a, and is converted into white light when passing through the green color converting member 44b. Converted to green light. Therefore, two-color display of white and green according to the display pattern is performed. Moreover, in this case, since the number of members through which light passes is reduced, attenuation of light is reduced, high brightness can be obtained, and further reduction in thickness can be achieved.

Further, as shown in FIG. 12, the color conversion member 44
A display panel 46 having the same display pattern as the display patterns formed by a and 44b may be arranged on the front surface of the diffusion plate 45. As a result, all the blue incident light is converted into green light, and further, there is no light component cut in the display panel 46, so that green light of higher intensity is obtained as compared with the cases of the above two embodiments, The brightness of the green conversion region 54 of the display panel 46 is increased, the display becomes clear, and it is possible to appeal to human vision from a distance.

The present invention is not limited to the above embodiment, and it goes without saying that many modifications and changes can be made to the above embodiment within the scope of the present invention. Blue LED is used as a light source, but L that emits violet and ultraviolet light
ED may be used. Further, as the color conversion member, one that converts long-wavelength light into short-wavelength light may be used, and in this case, an LED that emits red or other long-wavelength light is used.

By disposing the light source so as to face a plurality of side surfaces of the light guide plate, more light is incident on the light guide plate, the amount of light emission is increased, and the brightness as a surface light emitting source can be increased. Become. In addition, a plurality of L emitting light of different colors to the light source
By using the ED and switching the driving of each LED to emit light, multicolor display is possible. Furthermore, by combining color conversion members according to the emission color of the LEDs,
A plurality of different displays can be displayed on one display device by switching the driving of.

The color conversion member may be arranged between the light source and the light guide plate, and the light whose color has already been converted will enter the light guide plate. By doing so, it is possible to reduce the thickness of the color conversion member and further reduce the installation area of the color conversion member, thus contributing to cost reduction.

[0055]

As is apparent from the above description, according to the present invention, the light source in which a plurality of LEDs are arranged, the light guide plate for emitting the light of the light source incident from the side surface, and the light emission color of the light source are set to different colors. By providing a color conversion member for conversion and a display panel on which a display pattern such as a pattern or characters displayed by illumination from the back is formed, white display and color display can be easily performed, and in-plane display is possible. It becomes a side-edge type surface-emitting display device capable of uniform light emission without color unevenness, which makes it possible to replace a conventional display device using a fluorescent lamp as a light source, and achieve a reduction in thickness and a longer life. Also, L
By using the ED, it can be driven by a DC power source, the circuit configuration of the backup power source for power failure can be simplified, and the cost can be reduced. Moreover, the brightness can be easily adjusted and the blinking operation can be easily performed, and various displays can be performed.

The light source may be an LED of a single emission color due to a color conversion member capable of converting an arbitrary color, and LEs of different emission colors may be used.
It is possible to obtain the luminescent color required for display without arranging D alternately.
Color unevenness in the vicinity of the LED is eliminated, uniform surface emission can be performed, and high quality display can be obtained.

Since an LED emitting blue light is used as a light source and the color conversion member collectively converts the blue light into white light,
White light can be obtained with only one type of LED, and it is not necessary to adjust the light amounts of the red, green, and blue LEDs to obtain white light, and the control is simple. Further, when the blue light is converted into the light having other light spectrum components according to the display pattern by the color conversion member, the light other than the display color is not cut by the color filter for forming the display pattern of the display panel. All display colors are possible, and a clear display can be obtained without lowering the brightness of the display surface.

A plurality of color conversion members are provided, which are provided with a light source in which a plurality of LEDs are arranged, a light guide plate for making the light of the light source incident from the side surface emit light, and a color conversion member for converting the emission color of the light source into a different color. Since display patterns such as designs and characters are formed in combination, an arbitrary display pattern can be drawn without using the display panel, and further reduction in thickness can be achieved by eliminating the display panel. Also, the number of members through which light passes is reduced, and the attenuation of light is reduced, resulting in high brightness,
The display can be clear.

The display panel on which the display pattern is formed is arranged in front of the color conversion member, and two or more kinds of color conversion members are provided so as to convert the light emission color of the light source into different colors according to the display pattern of the display panel. By being combined,
The light component cut off by the display panel is eliminated, high brightness is obtained, the display surface is brightened, and the visibility is improved.

By arbitrarily changing the visibility of the LED, the display can be changed and the human attention can be drawn. Therefore, the function as a display device can be enhanced. When the display is not needed, the power consumption can be reduced by turning off the light or dimming it.
The life of can be extended.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a surface emitting display device according to an embodiment of the present invention.

FIG. 2 is a sectional view of the same display device.

FIG. 3 is a wavelength distribution chart of incident light and transmitted light of a color conversion member.

FIG. 4 is a wavelength distribution chart of incident light and transmitted light of another color conversion member.

FIG. 5 is a front view of a display panel of an emergency exit light.

FIG. 6 is a diagram showing a filter characteristic of a display panel and a wavelength distribution of transmitted light.

FIG. 7 is a block diagram of an electric circuit of a display device.

FIG. 8 is a front view of the display panel of the fire extinguisher indicator light.

FIG. 9 is an exploded perspective view of a display device according to another embodiment.

FIG. 10 is a sectional view of the same display device.

FIG. 11 is a wavelength distribution diagram of incident light and transmitted light of the color conversion member.

FIG. 12 is an exploded perspective view of a display device according to another embodiment.

FIG. 13 is an exploded perspective view of a display device using a conventional fluorescent lamp as a light source.

FIG. 14 is a sectional view of the same display device.

FIG. 15 is a block diagram of an electric circuit of the display device.

FIG. 16 is an exploded perspective view of a conventional surface emitting display device.

FIG. 17 is an exploded perspective view of another conventional display device.

18A is a diagram showing a conventional light source for performing two-color display, and FIG. 18B is a diagram showing a conventional light source for emitting white light.

[Explanation of symbols]

 40 LED 41 Light source 42 Light guide plate 43 Reflector plate 44 Color conversion member 45 Diffusion plate 46 Display panel 53 Base area 54 Conversion area

Claims (7)

[Claims] 1. A light source in which a plurality of LEDs are arranged, a light guide plate for surface-emitting the light of the light source incident from a side surface, a color conversion member for converting the emission color of the light source into a different color, and illumination from the back surface. And a display panel on which a display pattern such as a pattern or characters displayed by the display panel is formed. 2. The surface-emitting display device according to claim 1, wherein the light source is an LED of a single emission color. 3. The surface emitting display device according to claim 2, wherein an LED emitting blue light is used as a light source, and the color conversion member converts blue light into white light. 4. A light source in which a plurality of LEDs are arranged, a light guide plate for surface-emitting the light of the light source incident from a side surface, and a color conversion member for converting the emission color of the light source into a different color,
A surface-emitting type display device characterized in that a display pattern such as a design or a character is formed by combining a plurality of color conversion members. 5. A display panel on which a display pattern such as a pattern or characters displayed by illumination from the back is formed is arranged on the front surface of the color conversion member, and the emission color of the light source is changed according to the display pattern of the display panel. 5. The surface emitting display device according to claim 4, wherein two or more kinds of color conversion members are combined so as to convert into different colors. 6. The surface emitting device according to claim 1, wherein an LED emitting blue light is used as a light source, and the color conversion member converts the blue light into another light according to the color of the display pattern. Type display device. 7. The surface emitting display device according to claim 1, further comprising a control means for arbitrarily changing the visibility of the LED.