JP2012256535A - Illumination system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an illumination system that can easily control illumination light and that has high safety and reliability.SOLUTION: An illumination system has a first light-emitting element, a second light-emitting element, a wavelength conversion body, a first light guide body, a second light guide body, and a driving circuit. The first light-emitting element can emit first light in a wavelength range from ultraviolet light to visible light. The second light-emitting element can emit infrared light. The wavelength conversion body can absorb the first light, and emit conversion light with a wavelength longer than that of the first light. The first light guide body can transmit the first light toward the wavelength conversion body. The second light guide body can transmit the infrared light toward the wavelength conversion body. The driving circuit can control an output of the first light, and drive the second light-emitting element. The first light is mixed with the conversion light, and the illumination light is emitted. Also, the infrared light is emitted as a control light signal.

Description

  Embodiments described herein relate generally to a lighting system.

  When a light emitting element (LD) is used for the lighting device, the configuration of the lighting system having a communication function becomes easy.

  Illumination systems include a visible light communication method in which a signal is superimposed on illumination light, a light control method using a remote controller, and an illumination monitoring control method having a wireless function.

  When visible light or radio waves are propagated in the air and the lighting device is controlled by remote control, it is difficult to maintain high communication quality due to signal intensity limitations due to noise and EMI (Electromagnetic interference). For this reason, there is a problem in using it for lighting systems such as airports and roads that require high safety.

JP 2003-318836 A

  The problem to be solved by the present invention is to provide an illumination system that is easy to control illumination light and has high safety and reliability.

  An illumination system according to an embodiment of the present invention includes a first light emitting element, a second light emitting element, a wavelength converter, a first light guide, a second light guide, a drive circuit, Have The first light emitting element can emit first light in a wavelength range from ultraviolet to visible light. The second light emitting element can emit infrared light. The wavelength converter can absorb the first light and emit converted light having a wavelength longer than the wavelength of the first light. The first light guide can transmit the first light toward the wavelength converter. The second light guide can transmit the infrared light toward the wavelength converter. The drive circuit can control the output of the first light and can drive the second light emitting element. The first light and the converted light are mixed to emit illumination light. The infrared light is emitted as a control light signal.

  An illumination system according to another embodiment of the present invention includes a light emitting element, a light guide, a wavelength converter, a light receiving element, and a drive circuit. The light emitting element can emit light in a wavelength range from ultraviolet to visible light. The light guide has a first end and a second end provided on the opposite side of the first end. The light guide can propagate toward the second end after the light emitted from the light emitting element is incident on the first end. The wavelength converter can absorb the light emitted from the second end and emit converted light having a wavelength longer than the wavelength of the light. The light receiving element is a light receiving element capable of detecting the converted light, and detects the converted light emitted from the first end after being incident and propagated to the second end. The drive circuit detects that the light receiving element has detected that the converted light has fallen below a predetermined value, or when the light receiving element of the drive circuit has not detected the converted light for a preset time. When the result is generated, the driving of the light emitting element can be stopped. The light emitted from the light emitting element and the converted light are mixed and emitted as illumination light.

  An illumination system that can easily control the illumination light and has high safety and reliability is provided.

It is a block diagram of the illumination system concerning 1st Embodiment. It is a block diagram of the illuminating device concerning 1st Embodiment. It is a graph which shows the transmission loss of the optical fiber with respect to incident light wavelength. It is a block diagram of the illumination system concerning 2nd Embodiment. It is a block diagram of 2nd Embodiment. FIG. 6A is a configuration diagram of a first modification of the second embodiment, and FIG. 6B is a configuration diagram of a second modification of the second embodiment. FIG. 7A is a configuration diagram of the illumination system according to the third embodiment, FIG. 7B is a configuration diagram of the first modification, and FIG. 7C is a configuration diagram of the second modification.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram of a lighting system according to the first embodiment.
In the first embodiment, light in a wavelength range from ultraviolet to visible light is transmitted using a light guide such as an optical fiber to illuminate a space away from the light source, and illuminate light having a wavelength that does not contribute to illumination. It is an illumination system that transmits near the space. That is, the first embodiment can be said to be an illumination system having a communication function.

  The lighting system 5 includes a lighting device 10. The lighting device 10 includes a first light emitting element 20 (20a, 20b), a first light guide 40 (40a, 40b), a wavelength converter 60, and a drive circuit 70 capable of driving the first light emitting element 20. have. In the drawing, the first light emitting element 20 includes a light emitting element 20a driven by a drive signal S1a from the drive circuit 70 and a light emitting element 20b driven by a drive signal S1b.

  The emitted light from the light emitting element 20a propagates in the light guide 40a and irradiates the wavelength converter 60. The emitted light from the light emitting element 20a propagates in the light guide 40b and irradiates the wavelength converter 60. A part of each of the propagation lights LBa and LBb irradiated with the wavelength converter 60 is absorbed by the wavelength converter 60 and emits converted light LY having a wavelength longer than the wavelength of the emitted light.

  If the number of the first light emitting elements 20 connected in parallel is increased, both the converted light LY and the propagated lights LBa and LBb emitted without wavelength conversion increase, and a high light output can be obtained. . The propagation light LB (LBa, LBb) and the converted light LY are mixed to become the illumination light LW. When a plurality of light emitting elements 20 are provided, for example, a high luminous flux of 10,000 lumens (lm) can be obtained.

  The light guide 40 is made of an optical fiber, a transparent resin, glass, or the like, and has a cross section such as a circle or a rectangle. The light is propagated in the direction in which the light guide 40 extends.

  On the other hand, the illumination system 5 includes a second light emitting element 30 and a second light guide 50 in addition to the illumination device 10. The second light emitting element 30 is driven by the drive signal S2 from the drive circuit 70. The emitted light from the second light emitting element 30 is a control light signal that does not contribute to the illumination light, and is propagated through the second light guide 50 and then emitted into the irradiation space of the illumination light LW. The emitted light irradiates the wavelength converter 60 and is transmitted or scattered.

  In addition, the light emission part containing the 1st light guide 20, the 2nd light guide 50, the wavelength converter 60, etc. is comprised with an optical component. That is, since it does not include electrical components such as a light emitting element and its driving circuit, it is not necessary to supply power to the light emitting unit. For this reason, maintenance is easy and remote control is easy.

FIG. 2 is a configuration diagram of the illumination system according to the first embodiment.
The first light emitting element 20 and the second light emitting element 30 can be LD (Laser Diode). In FIG. 2, it is assumed that the first light emitting elements 20a and 20b are blue LDs made of an InGaN-based material or the like, and the emission wavelength is around 450 nm. In the case of LD, the full width at half maximum can be narrowed to about 30 degrees in the vertical direction and about 15 degrees in the horizontal direction, and the light emitting point can also be reduced to about 10 μm or less. For this reason, since emitted light can be efficiently introduced into an optical fiber or the like, it is preferable. The emitted light from the second light emitting element 30 is in the infrared wavelength range (for example, 780 nm or more).

  Moreover, the light guide 40 shall consist of optical fibers. The emitted light from the first light emitting element 20 a is incident on one end of the first optical fiber 40 via the optical connector 80. The emitted light from the first light emitting element 20 b is incident on one end of the first optical fiber 40 via the optical connector 80. The emitted light from the second light emitting element 30 enters one end of the optical fiber 40 via the optical connector 80. The length D of the optical fiber 40 can be set to 20 to 30 m, for example.

  The light incident on the optical fiber 40 is guided to the light guide transparent member 84 through the optical connector 82 provided at the other end of the optical fiber 40. A wavelength converter 60 made of a phosphor or the like is provided inside or on the outer periphery of the light guide transparent member 84.

  The optical fiber 40 may be composed of independent optical fibers 40a, 40b, and 50 as shown in FIG. Alternatively, a common optical fiber may be used as shown in FIG. Further, for example, a combiner structure in which the core portion divided on the input side is bundled by fusion or the like to form one core portion may be used.

  The blue propagation lights LBa and LBb travel outside the light guide transparent member 84 and are also emitted outward. In this case, when a yellow phosphor using, for example, a silicate material or a YAG (Yttrium-Aluminum-Garnet) material is used as the wavelength converter 60, yellow light LY having a peak of emission intensity of about 560 nm is obtained. Can do. As a result, (pseudo) white light LW in which the blue propagation light LB and the yellow light LY are mixed can be obtained. When the wavelengths of the propagating lights LBa and LBb are close to the wavelength where the excitation spectrum intensity of the wavelength converter 60 is maximized, the emission spectrum intensity can be easily increased.

  When the second light emitting element 30 is made of, for example, an AlGaAs / GaAs material, infrared light having a wavelength near 860 nm can be obtained. When an InGaAsP / InP material is used, infrared light in the vicinity of 980 nm, 1300 nm, and 1550 nm can be obtained. Since a wavelength converter such as a phosphor is transparent to infrared light, the infrared light LI passes through or is scattered by the wavelength converter 60 and is emitted to the outside without impairing the illumination effect.

  When the modulation signal is superimposed on the current that drives the infrared light, the infrared light detector 89 provided in the space irradiated with the illumination light performs optical / electrical conversion and transmission of the modulated infrared light LI. Can be demodulated. That is, an illuminated body such as a person or a vehicle can receive useful information from the infrared light LI emitted together with the illumination light LW.

  Further, in the lighting device, in order to control the lighting system from a distance of 30 m or more, it is preferable to use infrared light transmitted through the optical fiber. The wavelength range of infrared light propagates in the air farther than visible light even in bad weather such as fog. For this reason, by using the infrared light detector 89, it is easy for a vehicle operator to check an obstacle, a person, a lighting position, etc. in an airport or a road, and safety is improved.

FIG. 3 is a graph showing transmission loss of an optical fiber with respect to the wavelength of incident light.
Examples of the optical fiber include a quartz optical fiber, a PCF (plastic clad optical fiber), and a POF (plastic optical fiber). The transmission loss of a quartz optical fiber whose core and cladding are made of quartz is smaller than that of PCF or POF. However, blue light is highly scattered in the optical fiber and has a large transmission loss. For this reason, the transmission distance as illumination light is practically about 30 m even if a quartz optical fiber is used.

  On the other hand, infrared light having a wavelength of 780 nm or more has a small transmission loss of about 3.5 dB / km or less in the quartz optical fiber. For this reason, signal transmission up to 10 km is easy. Further, since the PCF has a transmission loss of 6 dB / km, signal transmission of 1 to 5 km is possible. Further, the control light signal may have a low intensity as long as the sensitivity of the detector is exceeded. For this reason, the tolerance for transmission loss is wide.

FIG. 4 is a block diagram of a lighting system according to the second embodiment.
The second embodiment further includes a third light guide 52 and an optical / electrical converter 72. The 3rd light guide 52 is longer than the 1st light guide 40 which transmits the emitted light from the 1st light emitting element 20 for producing | generating illumination light.

  Infrared return light LIR scattered by the wavelength converter 60 is incident on the third light guide 52, and the emitted light is converted into a drive control signal SC by the optical / electrical converter 72. For example, when the intensity of the infrared return light LIR changes due to deterioration of the wavelength converter 60 or damage of the light guide 40, the first light emitting element 20 is changed according to the drive control signal SC. Shut down. If it does in this way, it can control that blue light LB which has high energy irradiates a human eye etc. directly.

FIG. 5 is a configuration diagram of an illumination system according to the second embodiment.
The length DR of the second light guide (optical fiber) 30 is longer than the length D of the first light guide (optical fiber) 20, for example, 30 m or more and 10 km or less. The infrared return light LIR (control light signal) transmitted through the length DR and attenuated by the light / electricity conversion unit 72 provided in the second optical fiber 52 is converted into an electrical signal by the infrared light receiving element 72a. Amplified by the amplification control circuit 72b. The drive circuit 70 is driven using the drive control signal SC generated in this way. It is easy to transmit the drive control signal SC to the drive circuit 70 by making the length DR of the third optical fiber 52 larger than the length D of the first optical fiber 40. That is, it is possible to monitor and control a large number of distributed illumination devices at a long distance.

FIG. 6A is a configuration diagram of a first modification of the second embodiment, and FIG. 6B is a configuration diagram of a second modification of the second embodiment.
6A, between the light receiving side of the second optical fiber 52 and the drive circuit 70, an infrared light receiving element 72a, an amplification control circuit 74, a third light emitting element 75, An optical fiber 76 and an optical / electrical converter 73 are provided. The second light emitting element 30 is an LD made of InGaAsP / InP and having a wavelength range of 1300 nm to 1550 nm. In this way, even if the length DR of the third optical fiber 52 is increased to, for example, 10 km, the lighting system can be easily monitored and controlled.

  For this reason, monitoring and communication can be concentrated in the control center and provided at a distance farther than the white light emitting unit 87 that is an illumination space. That is, failures in the white light emitting unit 87, the first light emitting element 20, the first optical fiber 40, and the like can be monitored at a long distance.

  A reception signal from the infrared light receiving element 72 a is determined by the amplification control circuit 74, and a shutdown signal or the like can be transmitted from the third light emitting element 75 to the drive circuit 70 via the optical fiber 76. Instead of using the optical fiber 76, the optical fiber 52 may be used. In this case, a branching section to the drive circuit 70, an optical switch, or the like may be provided in the middle of the optical fiber 52.

  Optical fiber communication is less susceptible to electromagnetic noise. For this reason, the illumination system remote monitoring and control system using the optical fiber can be collectively monitored and controlled while maintaining safety and reliability over a wide area. Optical fibers can be used for monitoring and control of lighting systems as they are because they are already buried in highways and airports.

  In the second modification of FIG. 6B, a light emitting / receiving element is also provided on the illumination space side. An optical signal from the object to be illuminated 98 is detected by an infrared light receiving element 90 as an external detector, and drives a fourth light emitting element 94 via an amplification control circuit 92. The infrared light return light LIR from the fourth light emitting element 94 is incident on the third optical fiber 52 through the optical fiber 53.

  Examples of the optical signal from the object to be illuminated 98 include light emission of a headlamp and a rear lamp of an automobile and a video signal from an infrared / visible light monitor camera. Thus, external signals other than the failure signal inside the lighting device can also be transmitted to the control center that monitors and controls the lighting system via the third optical fiber 52 that is a long distance.

FIG. 7A is a configuration diagram of the illumination system according to the third embodiment, FIG. 7B is a configuration diagram of the first modification, and FIG. 7C is a configuration diagram of the second modification.
The illumination system of FIG. 7A includes a first light emitting element 20, a first end and a second end serving as a first light guide (optical fiber) 40, a wavelength converter 60, and a light receiving element. 71 and a drive circuit 70. The first light emitting element 20 is a blue LD, and the first optical fiber 40 is a quartz fiber. However, the present invention is not limited to this.

  The wavelength converter 60 is made of a yellow phosphor made of, for example, a silicate material or a YAG material. The blue light enters the first end and propagates through the optical fiber 40. Thereafter, the blue light exits from the second end opposite to the first end and enters the light guide transparent member 84. The yellow phosphor 60 provided on the outer edge of the light guide transparent member 84 absorbs part of the blue light LB and emits yellow light.

  The blue light LB released to the outside of the light guide transparent member 84 without being absorbed by the yellow phosphor 60 and the yellow light are mixed to generate a (pseudo) white light LW, which can be used as illumination light. . In the figure, the first light emitting element 20 includes two (20a, 20b), but may be one. Increasing the number of light emitting elements can increase the output.

  Part of the blue light LB is scattered and spread by the yellow phosphor 60, enters the second end of the optical fiber 40, becomes blue return light LBR, and exits from the first end. Further, a part of yellow light having a wide radiation angle enters the second end, propagates as yellow return light LYR, and exits from the first end. That is, the white return light propagates from the second end toward the first end.

  The yellow return light LYR is detected using a light receiving element 71 having light receiving sensitivity in the yellow light wavelength range. For example, a filter that blocks blue light is provided on the light receiving surface of the Si photodiode. In this way, it is possible to instantly detect a failure mode in which white light cannot be emitted or output is reduced due to damage to the optical fiber 40 or damage to the yellow phosphor 60, and the lighting device can be shut down quickly. In this case, since the failure can be detected on the output side away from the damaged portion, the detection and the control portion can be prevented from being damaged. For this reason, it can suppress that a high output blue laser beam damages a human eye etc., and it can be set as the illumination system which can monitor an illuminating device with high reliability.

  In the first modification of FIG. 7B, the white return light LWR travels in the second optical fiber 51 toward the light emitting element and enters the light receiving element 71. In the second modification of FIG. 7C, the length DR of the third optical fiber 52 can be longer than the length D of the first optical fiber 40. As shown in FIG. 3, for example, blue light (for example, wavelength 450 nm) and yellow light (for example, wavelength 560 nm) have a larger transmission loss than infrared light. However, the white return light LWR is not used as illumination light, but is used for controlling the illumination system. Any signal that can control the drive circuit 70 may be at a low level. That is, a signal can be transmitted to a control center located farther than the transmission distance of illumination light.

  The embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to these embodiments. Even if those skilled in the art have made various design changes regarding the material, shape, size, arrangement, etc. of the light guide, optical fiber, light emitting element, light receiving element, wavelength converter, drive circuit, etc. constituting the present invention. Unless it deviates from the main point of this invention, it is included in the scope of the present invention.

  DESCRIPTION OF SYMBOLS 5 Illumination system, 20 1st light emitting element, 30 2nd light emitting element, 40 1st light guide (optical fiber), 50 2nd light guide (optical fiber), 52 3rd light guide (optical fiber) 60 wavelength converter, 70 drive circuit, 72 photoelectric conversion unit, 72a infrared light receiving element, SC drive control signal, LW illumination light, LI (infrared) control light signal, LIR (infrared) control light signal, LB propagating light, LY converted light

Claims (8)

A first light emitting element capable of emitting first light in a wavelength range from ultraviolet to visible light;
A second light emitting element capable of emitting infrared light;
A wavelength converter capable of absorbing the first light and emitting converted light having a wavelength longer than the wavelength of the first light;
A first light guide capable of transmitting the first light toward the wavelength converter;
A second light guide capable of transmitting the infrared light toward the wavelength converter;
A drive circuit capable of controlling the output of the first light and driving the second light emitting element;
With
Mixing the first light and the converted light to emit illumination light;
An illumination system that emits the infrared light as a control light signal. A third light guide capable of transmitting the control light signal scattered by the wavelength converter;
A photoelectric conversion unit capable of converting the control light signal emitted from the third light guide into an output electric signal;
With
The illumination system according to claim 1, wherein the drive circuit controls the output of the first light in accordance with the output electric signal.   The illumination system according to claim 2, wherein the infrared light incident on the third light guide includes infrared light other than the infrared light from the second light emitting element. The length of the third light guide is greater than the length of each of the first and second light guides,
4. The illumination system according to claim 2, wherein a signal corresponding to light emitted from the third light guide is amplified and then input to the drive circuit. 5.   The illumination system according to claim 2, wherein each of the first, second, and third light guides includes an optical fiber.   The illumination system according to claim 1, wherein the first light guide and the second light guide are common. A light emitting device capable of emitting light in a wavelength range from ultraviolet to visible light;
A light guide having a first end and a second end provided on the opposite side of the first end, wherein the light emitted from the light emitting element is the first end A light guide capable of propagating toward the second end after being incident on the portion;
A wavelength converter capable of absorbing the light emitted from the second end and emitting converted light having a wavelength longer than the wavelength of the light;
A light receiving element capable of detecting the converted light, wherein the light receiving element detects the converted light emitted from the first end after being incident and propagated to the second end;
A drive circuit capable of stopping driving of the light emitting element when the light receiving element detects that the converted light has decreased below a predetermined value;
With
An illumination system, wherein the light emitted from the light emitting element and the converted light are mixed and emitted as illumination light.   The illumination system according to claim 7, wherein the light guide is an optical fiber.

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