WO2006006473A1 - Phosphorescent light bulb - Google Patents

Abstract

A phosphorescent light bulb which is high in parallelism of light beams and light recognizability and higher in luminance, and exhibits a very small decrease in light emission efficiency even under an extended-duration application environment and an excellent persistency, and which is characterized by comprising an LED having a maximum light emission wavelength of up to 360 nm, and a phosphorescent material layer that absorbs and wavelength-converts at least part of light emission from the LED and emits light at a reflection mirror concentrically surrounding the LED. The phosphorescent material is preferably a neutral phosphorescent materialactivated by bivalent eurobium. It is also desirable that the incident angle of a light from the tip end of the LED light emission source to the phosphorescent material layer be up to 45 deg., and the difference in maximum light emission wavelength between the LED and the phosphorescent material layer be at least 100 nm.

Description

 Specification

 Luminous bulb

 Technical field

 TECHNICAL FIELD [0001] The present invention relates to a luminous bulb used for a knock light source, an LED display, an illuminated switch, and various indicators, and in particular, converts at least part of light emitted from an LED as a light emitting element to emit light. The present invention relates to a phosphorescent light bulb having a phosphorescent substance to be used and having high brightness, high efficiency and afterglow regardless of the use environment.

 Background art

 [0002] Today, with the development of portable electronic devices such as transceivers, cameras, pagers, portable radios, video decks and notebook computers, various display devices have been provided to improve visibility.

 One of the displays uses a liquid crystal device, and a backlight is provided so that it can be used even in a dark place.

 Such a backlight, particularly for a portable electronic device, has the advantage that the use time increases as the power consumption is reduced. Therefore, it emits light with particularly low power consumption and high brightness. Is required.

 One such knocklight light source emits light with high brightness by emitting light from an LED in a planar shape.

 LEDs are small, efficient, and emit bright colors. In addition, since it is a semiconductor device, there is no worry of running out of balls. It can be used as a backlight light source that uses the characteristics that it has excellent initial drive characteristics and is strong against vibration and repeated ONZOFF lighting.

[0003] On the other hand, it is obliged to install guide lights in places where many people gather, such as theaters and inns, in accordance with the Ordinance for Enforcement of the Fire Service Act and fire prevention regulations in cities across the country.

 When the regular power supply is cut off due to disasters such as earthquakes and fires, or other sudden accidents, it is automatically switched to the standby power supply and lighting for 20 minutes or more is required.

This kind of guide light can be realized by using an indicator that has the characteristics of LED with high brightness and low power consumption. [0004] However, a backlight or the like formed using an LED is a semiconductor light emitting element, and consumes battery power although it consumes low power. For this reason, when the amount of power stored in the battery power source is small, there is a case where a large load is required to drive the battery for a longer time.

 In addition, if the standby power supply of the display is destroyed in the event of a disaster, or if the feeder circuit is broken, etc., it may turn off.

 Therefore, there is a need for a display device that can display sufficient brightness even when power is low or when a power supply circuit is stopped.

 [0005] As a display device that meets such a demand, a display device having a light emitting diode and a fluorescent material excited by the light emitting diode, a LED chip whose light emitting layer is a gallium nitride compound semiconductor, and light emission from the LED chip. A light-emitting device having a fluorescent material that absorbs and emits light has been proposed.

 [0006] For example, Patent Documents 1 and 2 disclose a technique in which a phosphorescent material is attached to a portion of the lower surface of the lamp umbrella facing the upper surface of the lamp for a rod-shaped or annular lamp (fluorescent lamp tube). It has been done.

 Patent Document 1: Japanese Patent Laid-Open No. 09-265812

 Patent Document 2: Japanese Patent Laid-Open No. 09-223408

[0007] However, some LEDs have various emission wavelengths depending on the composition and structure of the semiconductor, and may emit light in the ultraviolet region. Are prone to deterioration!

 In addition, it is impossible to completely prevent moisture from entering from the outside environment and to completely remove moisture adhering during manufacturing.

 Depending on the fluorescent material, such moisture may accelerate the deterioration of the fluorescent material by the high-energy light or heat of the light emitting device.

 Disclosure of the invention

 Problems to be solved by the invention

[0008] Therefore, the present invention solves the above-mentioned problems, and the parallelism of light flux and the recognition of light are higher. The brightness is higher, and the longevity is extremely low in the light emission efficiency even under a long-term use environment. An object of the present invention is to provide a phosphorescent light bulb having an afterglow. Means for solving the problem

 [0009] A phosphorescent bulb according to claim 1 of the present invention includes a high-intensity LED having a maximum emission wavelength of 360 nm or less, a frustoconical reflector that concentrically surrounds the LED, and the LED force in the reflector. It has a phosphorescent material layer that absorbs at least part of the emitted light and converts the wavelength to emit light.

 [0010] Here, the phosphorescent material is preferably a neutral phosphorescent material activated with divalent europium (Eu).

 [0011] Further, the phosphorescent light bulb according to claim 2 of the present invention is characterized in that an incident angle of light from the light emitting source tip of the LED to the phosphorescent material layer is 45 degrees or less.

In this way, it is possible to prevent deterioration of the phosphorescent material layer as the light emitting layer while ensuring the parallelism of the irradiation light.

[0013] Further, the phosphorescent light bulb according to claim 3 of the present invention is characterized in that the maximum emission wavelengths of the LED and the phosphorescent material layer are different by lOOnm or more.

[0014] In this way, a further light emitting effect can be provided.

 The invention's effect

 [0015] According to the present invention, it is possible to provide a luminous bulb that has high luminous efficiency even when used for a long time with high luminance, and has a very low decrease in luminous efficiency and afterglow even when used for a long time. be able to.

 In addition, it can be used as a low-power phosphorescent light bulb that can arbitrarily change the emission color when it is turned on and off.

[0016] In addition, by adopting the configuration of claim 2 of the present invention, it is possible to extremely reduce the light emission efficiency and the afterglow even when used for a long time with high brightness. Since unevenness can be dispersed and differentiated by a phosphorescent substance, it is possible to provide a luminous bulb having light emission with higher visual sensitivity.

 Brief Description of Drawings

FIG. 1 is a diagram showing an embodiment of a phosphorescent bulb according to the present invention.

FIG. 2 is a diagram showing the shapes of incident and reflected light beams in FIG. Explanation of symbols

[0018] 1 LED (Light Emitting Diode)

 2 Holding member

 3 Reflector

 4 Phosphor layer

 BEST MODE FOR CARRYING OUT THE INVENTION

[0019] As a result of various experiments, the inventor of the present application selects a specific semiconductor and a phosphorescent substance in a phosphorescent bulb in which light energy is relatively high and at least a part of light emitted from the LED is wavelength-converted by the phosphorescent substance. As a result, the present inventors have found that it is possible to prevent a reduction in light efficiency and afterglow in high luminance and long-time use.

That is, the phosphorescent material must have characteristics such as excellent light resistance, good temperature characteristics, and no deterioration in afterglow.

[0021] As satisfying these conditions, the present invention provides a high-intensity LED having a maximum emission wavelength of 360 nm or less and a reflection mirror concentrically surrounded by a light incident angle of 45 degrees or less.

The present inventors have found a phosphorescent bulb having a phosphorescent material that emits light having a maximum emission wavelength different from that of the LED by more than lOOnm.

 As a result, even when high-energy light in the visible light castle emitted by the light-emitting element is irradiated with high brightness near a long time, it is possible to obtain a luminous bulb with extremely little reduction in light emission luminance and afterglow. Is.

[0022] The phosphorescent substance used in the present invention has sufficient light resistance even when placed in contact with or in close proximity to the LED.

 The phosphorescent material used in the present invention is, for example, SrO, MgO, Al 0, Eu 0 as a raw material.

 By firing at a high temperature such as 2 3 2 3 metal oxides or CaCO, SrCO, BaCO

 3 3 3

 It is preferable to select compounds that easily become acidic.

 Such compounds include nitrates, oxalates, hydroxides and the like in addition to carbonates. As the boron compound, boric acid or an alkaline earth borate can be used, and boric acid is particularly preferable.

[0023] The purity of the raw material greatly affects the afterglow luminance, and it is preferable that the purity is 99.9% or more. More preferably, it is 9% or more.

 A raw material in which these materials are mixed is fired in a reducing atmosphere at a temperature range of 1200 ° C to 1600 ° C, and the fired product is pulverized and sieved to obtain a fluorescent material. The mixing ratio of the raw materials can be determined by mixing theoretical amounts for obtaining the target composition.

For example, when the power consumption of the LED is 1 W or more, it is possible to continuously emit light with a luminance of 0.2 cdZm ² or more for 2 hours or more after the LED is turned off.

[0024] The phosphorescent substance used in the present invention is basically strong and luminescent due to the divalent Eu of the activator, but the divalent Eu absorbs visible light power over a wide range in the ultraviolet region. Accordingly, sufficiently high-efficiency light emission is possible even when a gallium nitride compound semiconductor is used.

 Further, as a co-activator, at least one selected from the group consisting of Mn, Zr, Nb, Pr, Nd, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu is doped into the matrix of the phosphorescent material. By doing so, an afterglow phenomenon appears.

 [0025] When boron is contained in the phosphorescent substance, the crystallinity of the aluminate is improved, and the afterglow time and afterglow luminance can be further improved by stabilizing the light emission center and the capture center. Boron also acts as a flux and has the effect of promoting crystal growth of the phosphorescent material.

 [0026] When the luminous bulb of the present invention efficiently emits light and afterglow, the maximum emission wavelength of the light emitting element is preferably 360 nm or less in consideration of the excitation wavelength with the phosphorescent material. Considering the improvement in luminous efficiency due to the color difference with the phosphorescent material layer, it is preferable that the maximum emission wavelength of the phosphorescent material and the LED has a difference of lOOnm or more.

 [0027] By making the reflection angle of the LED light emission at the phosphorescent material layer 45 degrees or less, the parallelism of the luminous flux is maintained, which is more efficient. The phosphorescent bulb thus formed can be used as a planar light source capable of obtaining sufficient brightness.

 Example 1

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing one embodiment of the present invention. In FIG. 1, 1 is an LED (light emitting diode), 2 is a holding member that holds the light emitting diode, 3 is a reflecting mirror that reflects light emitted from the light emitting diode, 4 is a light emitting diode that emits light Stores light and emits light by itself It is a phosphorescent material layer coated with a phosphorescent material having a function.

 The light emitting diode 1 is held and fixed to the holding member 2.

 [0031] The reflecting mirror 3 is coupled to the holding member 2, and as shown in FIG. 2, the light emitting diode 1 reflects light emitted in a certain angular range and sends the light forward. Its function and shape are the same as those used in commercial flashlights.

The phosphorescent material layer 4 is coated with a phosphorescent pigment, is mounted along the shape of the reflecting mirror 3, and is disposed so as to cover a part of the reflecting mirror 3.

 At this time, the incident angle of light incident on the phosphorescent material layer 4 out of the light emitted from the light emitting diode 1 is set to be 45 degrees or less, so that the phosphorescent material layer as the light emitting layer is deteriorated. Is minimized.

[0033] In order to cover the extent of the area of the reflecting mirror 3, the illuminance obtained when the light emitting diode emits light when energized and the illuminance obtained when the phosphorescent material emits light when not energized are set to be different. It is decided by what.

 Industrial applicability

[0034] According to the present invention, the parallelism of light flux and the recognition of light are higher than that of the LED, which is a light-emitting element, in particular, since it has a higher luminance and has a very low decrease in light emission efficiency even under long-term use environments. Since it is possible to provide a phosphorescent light bulb that has a phosphorescent substance that converts at least part of the emitted light to emit light and has a high brightness, high efficiency, and long-lasting afterglow regardless of the usage environment, a backlight light source, It is suitable as a luminous bulb used in LED displays, illuminated switches and various indicators.

Claims

The scope of the claims  [1] A high-intensity LED having a maximum emission wavelength of 360 nm or less, a frustum-shaped reflecting mirror that concentrically surrounds the LED, and at least a part of the light emission of the LED power A phosphorescent light bulb having a livestock material layer that absorbs light and converts the wavelength to emit light.  [2] The luminous bulb according to claim 1, wherein an incident angle of light from the tip of the light emitting source of the LED to the luminous material layer is 45 degrees or less.  [3] The luminous bulb according to claim 1 or 2, wherein a maximum emission wavelength of each of the LED and the phosphorescent material layer differs by lOOnm or more.