WO2015174322A1

WO2015174322A1 - Light-emitting device and display apparatus

Info

Publication number: WO2015174322A1
Application number: PCT/JP2015/063214
Authority: WO
Inventors: 小野崎　学; 憲晃藤井; 裕史北村; 隅谷　憲
Original assignee: シャープ株式会社
Priority date: 2014-05-12
Filing date: 2015-05-07
Publication date: 2015-11-19

Abstract

　The objective of the present invention is to significantly reduce the effects of melatonin suppression. The present invention is provided with an LED chip (14) for emitting light that has a peak light-emitting intensity of 390-420 nm, an LED chip (15) for emitting light that has a peak light-emitting intensity of above 420 nm to 480 nm or less, a fluorescent body cluster (18) for generating fluorescence that has one or more peak light-emitting intensities of 498-830 nm and that is excited by the light that the LED chip (14) generates, and a fluorescent body cluster (19) for generating fluorescence that has one or more peak light-emitting intensities of 498-830 nm and that is excited by the light that the LED chip (15) generates. The LED chip (14) and the LED chip (15) are mutually and independently driven.

Description

Light emitting device and display device

The present invention relates to a light emitting device and a display device that affect biological rhythm.

As a physiological effect of light, many living organisms including humans and other mammals have a circadian rhythm that fluctuates in a cycle of about 24 hours, and the body is stimulated by light stimulation from the outside world including sunlight. Etc. are corrected to an accurate 24-hour diurnal rhythm. It has been clarified that the light stimulus from the outside world is closely related to the melatonin secretion in the organism. FIG. 7 presents a melatonin inhibitory action spectrum. FIG. 7 shows that light in a wide wavelength range having a peak wavelength of about 465 nm suppresses the secretion of melatonin, and elucidates the relationship between the secretion of melatonin and biological rhythms such as sleep-wakefulness and body temperature fluctuations. It is being done.

Also, FIG. 8 shows a known action spectrum of a human retina photoreceptor. In addition to so-called S cones, M cones, L cones, and rods, a photoreceptor called endogenous photosensitive retinal fine (ipRGC) has also been found in the retina, and the photoresponse characteristics shown in FIG. It is shown. Thus, the physiological reaction by light is becoming clear.

The physiological spectrum of light is important for the light spectrum that organisms receive. In the case of the spectrum shown in FIG. 7, artificial light has the same effect as natural light. For this reason, especially when exposed to artificial light including the melatonin inhibitory action spectrum shown in FIG. 7 at night, the organism is disturbed by an accurate 24-hour diurnal rhythm. As a result, adverse effects on various living bodies such as sleep disorders are regarded as problems. For this reason, techniques for solving this problem have been proposed.

In recent years, these studies have progressed, and it has been reported that human circadian rhythm is disturbed even at extremely low illuminance. In particular, in order to correctly maintain a biological rhythm such as nighttime, it is necessary to use artificial light having an emission spectrum that does not include a melatonin inhibitory action spectrum as much as possible, and to simultaneously reduce the amount of radiation.

On the other hand, it is well known that it is important to suppress the secretion of melatonin in the daytime and early morning in order for humans to make an accurate 24-hour diurnal rhythm. For this reason, it is also important to be exposed to artificial light with high illuminance including a large melatonin inhibitory action spectrum in the daytime or early morning.

In view of the above points, various light emitting devices have been proposed in order to adjust the biological rhythm.

In Patent Document 1, a first illuminant having a peak wavelength at 600 nm to 660 nm (red), a second illuminant having a peak wavelength at 530 nm to 570 nm (green), and a peak wavelength at 420 nm to 470 nm are disclosed. Using the third light emitter (blue), the first and second light emitters are provided with a color conversion member and a short wavelength cut filter for reducing the visible light component having a wavelength of 480 nm or less to almost zero, A technique for emitting a visible light component having a wavelength of 480 nm or less from a light emitter is disclosed.

Patent Document 2 discloses a first light emitting unit that emits a daylight color having a high color temperature of 6000 K or more with a light emitting diode chip and a fluorescent material, and a second that emits warm white with a color temperature of 3000 K or less with a light emitting diode chip and a fluorescent material. A technology is disclosed in which the light emitting diode chip emits blue light or UV (Ultra Violet) light.

In Patent Document 3, a first semiconductor light emitting device having a peak wavelength in a wavelength range of 430 nm to 490 nm, a first LED (Light Emitting Diode) that emits white light by a first wavelength conversion member, and 360 nm The second semiconductor light emitting device having a peak wavelength in the wavelength range of ˜420 nm and the second LED that emits white light by the second wavelength conversion member, and matching the color temperature of the white light emitted by each of the first and second LEDs Techniques for making them disclosed are disclosed.

In Patent Document 4, the display unit is divided into a user work area and a non-work area, and in the non-work area, the secretion of melatonin is suppressed by increasing the intensity of blue light in the awakening period, and in the sedation period. Discloses a technique for adjusting the biological clock by increasing the secretion of melatonin by reducing the intensity of blue light.

In Patent Document 5, a first illuminant (blue) having an emission peak wavelength at 445 nm to 480 nm and a second illuminant (blue) having an emission peak wavelength on a shorter wavelength side than the first emitter are selectively used. A technique for lighting is disclosed.

Japanese Patent Publication “Patent No. 538249 Publication (issued on January 8, 2014)” Japanese Patent Gazette "Patent No. 5430394 (issued February 26, 2014)" Japanese Patent Publication “JP 2012-64860 A (published March 29, 2012)” Japanese Patent Gazette "Patent No. 4692528 (issued on June 1, 2011)" Japanese Patent Publication “Japanese Patent Laid-Open No. 2005-63687 (published on March 10, 2005)”

The technique disclosed in Patent Document 1 is mainly intended to maintain color rendering properties, and a blue light component having a peak wavelength in the vicinity of 450 nm to 480 nm remains. Thus, Patent Document 1 does not mention a method for significantly reducing the melatonin suppression effect in the entire light source device. In addition, to maintain human circadian rhythm, a light source device that increases the amount of effective melatonin-suppressed radiation required mainly during early morning or daytime awakenings and a melatonin-suppressed effective radiation that is mainly required during nighttime sleeping. It is important to switch to a light source device whose amount is almost zero. However, Patent Document 1 does not mention a means for realizing this switching.

Patent Documents

2 and 3 disclose a technique for switching between two types of light emitting units in accordance with a human circadian rhythm (according to awakening in the daytime or sleeping at night). It is desirable that the effective radiation dose for suppressing melatonin is as small as possible at bedtime at night, but the blue light component having a peak wavelength in the vicinity of 450 nm to 480 nm remains. It is difficult to reduce significantly.

Patent Document 4 discloses an example of use in an image display device, but since the blue light component remains even in the sedation period, it is difficult to significantly reduce the melatonin suppression effect.

Regarding Patent Document 5, while focusing on making the light from the first illuminant have a melatonin suppressing effect, the light from the second illuminant has almost no melatonin suppressing effect. Is not focused. Therefore, the light from the second light emitter still has a somewhat large melatonin suppression effect, and it is difficult to significantly reduce the melatonin suppression effect in the entire light source device.

The present invention has been made in view of the above-described problems, and an object thereof is to provide a light-emitting device and a display device that can greatly reduce the melatonin suppressing effect.

In order to solve the above-described problem, a light-emitting device according to one embodiment of the present invention includes at least one first semiconductor light-emitting element that emits light having a light emission intensity peak in a first wavelength range of 390 nm to 420 nm, Excited by light emitted from the first semiconductor light emitting element and at least one second semiconductor light emitting element that emits light having an emission intensity peak in a second wavelength region that is greater than 420 nm and less than or equal to 480 nm, and is 498 nm or more and 830 nm or less. Excited by the light emitted from the first light conversion member that generates fluorescence having one or more emission intensity peaks in a certain third wavelength region, and the second semiconductor light emitting element, the emission intensity peaks in the third wavelength region. Drive for independently driving the second light conversion member that generates one or more fluorescent light, the first semiconductor light emitting element, and the second semiconductor light emitting element. It is characterized in that it comprises a part.

According to one aspect of the present invention, the melatonin suppressing effect can be greatly reduced.

It is sectional drawing which shows the structure of Embodiment 1 of the LED package which concerns on this invention. It is sectional drawing which shows the structure of Embodiment 2 of the LED package which concerns on this invention. It is a circuit block diagram which shows schematic structure of the light-emitting device which concerns on Embodiment 3 of this invention. It is the graph which contrasted the melatonin inhibitory action spectrum and the emission spectrum of the light obtained from the 1st semiconductor light-emitting device and the 1st light conversion member. It is a graph of Smith and Pokony's cone sensitivity function. It is the graph which showed the degree (specific visibility) which feels brightness to the wavelength of visible light. It is a graph which shows the melatonin inhibitory action spectrum known well conventionally. It is a graph which shows the action spectrum of the photoreceptor of a human retina known well conventionally. It is a graph which shows the optical response characteristic of an intrinsic light sensitive retinal cell. It is a circuit block diagram which shows schematic structure of the light-emitting device which concerns on Embodiment 4 of this invention. It is a circuit block diagram which shows schematic structure of the light-emitting device which concerns on Embodiment 5 of this invention. It is a circuit block diagram which shows schematic structure of the light-emitting device which concerns on Embodiment 6 of this invention. It is a circuit block diagram which shows schematic structure of the sensor part of the light-emitting device shown in FIG.

[Summary of the Invention]
White using a purple LED (first semiconductor light emitting element) emitting purple light having almost no melatonin suppression action and a phosphor group (first light conversion member) excited by the purple light emitted from this purple LED It is a light emitting device that realizes light and obtains illumination light.

By using together a blue LED (second semiconductor light-emitting element) that emits blue light with a large melatonin-inhibiting action and a phosphor group (second light conversion member) that is excited by the blue light emitted by this blue LED. It is possible to realize a light emitting device more suitable for biological rhythm. Note that the phosphor group excited by the blue light is not an essential component and can be omitted as appropriate.

Note that the purple LED emits light having a peak of emission intensity in the range of 390 nm to 420 nm (first wavelength region). In addition, the blue LED emits light having a peak of emission intensity in the range from 420 nm to 480 nm or less (second wavelength range). Further, each excited phosphor group generates fluorescence having one or more emission intensity peaks in the range of 498 nm to 830 nm (third wavelength region).

Further, the purple LED and the blue LED are driven independently from each other (that is, provided with a drive unit).

[Embodiment 1]
FIG. 1 is a cross-sectional view showing the configuration of the first embodiment of the LED package.

1 includes LED chips 14 and 15, resins 16 and 17, phosphor groups 18 and 19, and cavities 20 and 21. The LED package 13 shown in FIG.

The LED chip (first semiconductor light emitting element) 14 emits purple light having a peak of emission intensity in a range of 390 nm to 420 nm (first wavelength region). The purple light has almost no melatonin inhibitory action. The LED chip 14 is stored in the cavity 20 and is sealed with a resin 16 including a phosphor group 18.

The LED chip (second semiconductor light emitting element) 15 emits blue light having a peak of light emission intensity in the range of 420 nm to 480 nm (second wavelength region). The blue light has a large melatonin suppressing effect. The LED chip 15 is stored in the cavity 21 and is sealed with a resin 17 including a phosphor group 19.

Resin (sealing member) 16 includes a phosphor group 18 and seals the LED chip 14 stored in the cavity 20.

Resin (sealing member) 17 includes the phosphor group 19 and seals the LED chip 15 stored in the cavity 21.

The phosphor group (first light conversion member) 18 is excited by purple light emitted from the LED chip 14 and generates fluorescence having one or more emission intensity peaks at 498 nm or more and 830 nm or less (third wavelength region). And consists of a plurality of phosphors 18s. Although illustration of the phosphor group 18 in FIG. 1 is omitted for the sake of brevity, a group composed of a plurality of phosphors 18 s contained in the resin 16 is referred to as a phosphor group 18.

In the LED package 13, the phosphor group 18 is included in the resin 16. Each of the phosphors 18s constituting the phosphor group 18 may generate the same color fluorescence, or at least one of the phosphors 18s may generate fluorescence of a color different from that of the other phosphors 18s. There may be. As a specific example, all of the phosphors 18s constituting the phosphor group 18 may be phosphors 18s that produce yellow fluorescence, or the phosphor group 18 and the phosphors 18s that produce red fluorescence may be green. You may consist of the combination with fluorescent substance 18s which produces | generates fluorescence.

The phosphor group (second light conversion member) 19 is excited by blue light emitted from the LED chip 15 and generates fluorescence having one or more emission intensity peaks at 498 nm or more and 830 nm or less. It consists of a body 19s. Although the illustration of the phosphor group 19 in FIG. 1 is omitted for the sake of brevity, a group composed of a plurality of phosphors 19 s contained in the resin 17 is referred to as a phosphor group 19.

In the LED package 13, the phosphor group 19 is included in the resin 17. Each of the phosphors 19s constituting the phosphor group 19 may generate the same color of fluorescence, or at least one of the phosphors 19s may generate a fluorescence of a color different from that of the other phosphors 19s. There may be. As a specific example, all of the phosphors 19s constituting the phosphor group 19 may be phosphors 19s that generate yellow fluorescence, or the phosphor group 19 and the phosphors 19s that generate red fluorescence may be green. It may consist of a combination with a phosphor 19s that generates fluorescence.

Further, the phosphor group 18 and the phosphor group 19 may include the same type of phosphor, or may be composed of different materials (for example, each phosphor) or a blending ratio of the materials.

The cavity (first cavity) 20 is a recess (such as a container) that stores the LED chip 14. The cavity 20 is filled with the resin 16 including the phosphor group 18.

The cavity (second cavity) 21 is a recess (such as a container) that stores the LED chip 15. The cavity 21 is filled with the resin 17 including the phosphor group 19.

In the LED package 13, white light is realized by a combination of the LED chip 14 and the phosphor group 18. Independent of driving the LED chip 14, the LED package 13 includes an LED chip 15. About the fluorescent substance group 19, it is omissible suitably as needed.

In the LED package 13, one LED chip 14 is mounted in the cavity 20, but a plurality of LED chips 14 may be mounted in the cavity 20. Similarly, in the LED package 13, one LED chip 15 is mounted in the cavity 21, but a plurality of LED chips 15 may be mounted in the cavity 21.

Furthermore, the number of the LED chips 14 mounted in the cavity 20 and the number of the LED chips 15 mounted in the cavity 21 may be different from each other. Thereby, according to desired brightness, the brightness of light obtained from the purple light emitted from each LED chip 14 and the brightness of light obtained from the blue light emitted from each LED chip 15 can be arbitrarily set. Can be set to

Further, a light diffusion member (not shown) for diffusing light may be provided in the path of light emitted from the cavity 20 and / or the path of light emitted from the cavity 21. Examples of the light diffusing member include a lens mounted in the opening of the cavity 20 and / or the opening of the cavity 21, and a diffusing agent contained in the resin 16 and / or the resin 17. This facilitates color mixing between the light emitted from the cavity 20 and the light emitted from the cavity 21.

Note that the cavity 20 and the cavity 21 may be separated as separate packages and configured as two packages.

Although the case where the depression is used for storing the LED chip has been described above, it is not necessarily limited to such a form. For example, a form in which an LED chip is mounted on a substrate having a lead frame and potted with a sealing resin is possible.

[Embodiment 2]
FIG. 2 is a cross-sectional view showing the configuration of the LED package according to the second embodiment.

The LED package 23 shown in FIG. 2 includes LED chips 14 and 15, a resin 26, a phosphor group 28, and a cavity 30.

The LED chips 14 and 15 are housed in the cavity 30 and sealed with a resin 26 including a phosphor group 28.

Resin (sealing member) 26 includes phosphor group 28 and seals LED chips 14 and 15 stored in cavity 30.

The phosphor group (light converting member) 28 is excited by the purple light emitted from the LED chip 14 and generates fluorescence having one or more emission intensity peaks at 498 nm or more and 830 nm or less. Consists of. Further, the phosphor group 28 may be excited by blue light emitted from the LED chip 15 to generate fluorescence having one or more emission intensity peaks in the range from 498 nm to 830 nm. Although illustration of the phosphor group 28 in FIG. 2 is omitted for the sake of brevity, a group composed of a plurality of phosphors 28 s contained in the resin 26 is referred to as a phosphor group 28.

In the LED package 23, the phosphor group 28 is included in the resin 26. Each of the phosphors 28s constituting the phosphor group 28 may generate the same color of fluorescence, or at least one of the phosphors 28s may generate fluorescence of a color different from that of the other phosphors 28s. There may be. As a specific example, all of the phosphors 28s constituting the phosphor group 28 may be phosphors 28s that produce yellow fluorescence, or the phosphor group 28 and the phosphors 28s that produce red fluorescence may be green. You may consist of the combination with the fluorescent substance 28s which produces fluorescence.

The cavity 30 is a recess (such as a container) that stores the LED chips 14 and 15. The cavity 30 is filled with a resin 26 including a phosphor group 28.

[Embodiment 3]
FIG. 3 is a circuit block diagram showing a schematic configuration of the light emitting device according to the present embodiment.

The light emitting device 1 shown in FIG. 3 includes a dimming control unit 2, constant

current circuits

3 and 4, and

LED circuits

5 and 6.

The dimming control unit 2 is connected to the constant

current circuits

3 and 4. The constant current circuit 3 is connected to the LED circuit 5. The constant current circuit 4 is connected to the LED circuit 6.

LED circuits

5 and 6 are a series circuit of a plurality of LED packages 13 mounted on a substrate. The LED circuit 5 has a plurality of LED chips 14 connected in series, and the LED circuit 6 has a plurality of LED chips 15 connected in series.

These

LED circuits

5 and 6 have different emission spectra. That is, the emission spectrum of each LED chip 14 of the LED circuit 5 has a peak of emission intensity in the first wavelength range of 390 nm to 420 nm. The light emission spectrum of each LED chip 15 of the LED circuit 6 has a peak of light emission intensity in the second wavelength region that exceeds 420 nm and is 480 nm or less. Accordingly, the violet light emitted from each LED chip 14 and the blue light emitted from each LED chip 15 have different amounts of action on the intrinsic light-sensitive retinal fine. For this reason, the purple light and the blue light have different effects on the biological rhythm. The amount of action is the amount of reaction that reacts when the photoreceptor receives light. It is obtained by integrating the action spectrum with the spectrum of the irradiation light and integrating it with the wavelength.

The dimming control unit (drive unit) 2 controls the lighting time of the LED chip 14 of the LED circuit 5 and the LED chip 15 of the LED circuit 6 by PWM (Pulse Width Modulation: pulse width modulation). The dimming control unit 2 individually controls the LED circuit 5 (LED chip 14) and the LED circuit 6 (LED chip 15). For the control by the PWM, the dimming controller 2 has a PWM circuit (not shown) that individually generates a PWM signal to be supplied to each of the

LED circuits

5 and 6. This PWM circuit changes the duty ratio of each PWM signal in accordance with, for example, an instruction from the outside of the illumination control unit 7 or the light emitting device 1.

The constant current circuit (drive unit) 3 generates a constant current based on the PWM signal supplied from the dimming control unit 2 and supplies the constant current to the LED circuit 5. The constant current circuit 3 supplies the constant current to the LED circuit 5 by being turned on during the high level period of the PWM signal, while the constant current circuit 3 is turned off during the low level period of the PWM signal. No current is supplied to the LED circuit 5.

The constant current circuit (drive unit) 4 generates a constant current based on the PWM signal supplied from the dimming control unit 2 and supplies the constant current to the LED circuit 6. The constant current circuit 4 supplies the constant current to the LED circuit 6 by being turned on during the high level period of the PWM signal, while being turned off during the low level period of the PWM signal. No current is supplied to the LED circuit 6.

In the light emitting device 1, the constant current circuit 3 controls the constant current supplied to the LED circuit 5 by the PWM signal generated individually by the dimming control unit 2 for each of the

LED circuits

5 and 6, and the constant current circuit 4 The constant current supplied to the LED circuit 6 is controlled. As a result, the LED chip 14 and the LED chip 15 are individually controlled. Therefore, the light emitting device 1 emits light of mixed colors having different colors according to the light intensity of the LED chip 14 and the LED chip 15 by adjusting the constant current supplied to the

LED circuits

5 and 6. Can do.

Note that the control of the

LED circuits

5 and 6 by the dimming control unit 2 includes changing the light emission luminance, turning on and off, and blinking of the LED chips 14 and 15.

Of course, in the light emitting device 1, the LED package 23 may be used instead of the LED package 13.

The illumination control unit 7 includes necessary components according to the use conditions of the light emitting device 1 and controls the

LED circuits

5 and 6 by sending instructions to the dimming control unit 2. Purple light having a peak of emission intensity in the wavelength range of 390 nm or more and 420 nm or less has a smaller amount of visual effect than blue light having a peak of emission intensity in the wavelength range of more than 420 nm and less than or equal to 480 nm. . That is, when these lights are emitted with the same intensity, the purple light appears darker than the blue light. These lights look different from each other in the brightness of the blue, so the colors are different from each other, but because human vision has a function of chromatic adaptation, eventually they become used to the difference in the colors and both of these lights are natural. Become visible.

Since the screens of portable devices and television receivers are watched during use, the light emitting device 1 is suitable as a light source for display devices such as portable devices and television receivers. Currently, a liquid crystal display is mainly used as the display device. Most liquid crystal displays realize multi-coloring by combining color filters and liquid crystals. In general, the liquid crystal has a low transmittance for a component on the short wavelength side of visible light. Of the color filters, blue ones are usually selected that are optimal for blue wavelengths having a peak in the vicinity of 450 to 460 nm, and many have low transmittance at 420 nm. Therefore, when the light emitting device 1 is applied to a liquid crystal display, it is necessary to make adjustments so that the light emission intensity of light having many components on the short wavelength side is increased. On the other hand, a digital micromirror device that uses reflection instead of transmission does not require a color filter or liquid crystal, so that the attenuation of the short wavelength component is small. Therefore, it can be said that it is more suitable for application of the light emitting device 1.

[Embodiment 4]
FIG. 10 is a circuit block diagram showing a schematic configuration of the light emitting device according to the present embodiment. Those not specifically described have the same functions as those shown in FIG.

The light emitting device 101 shown in FIG. 10 is included in the concept of the light emitting device 1 shown in FIG. However, in order to clearly indicate that the light emitting device 101 includes the timer unit 105, in FIG. 10, the light source control unit (control unit) 104 and the timer unit 105 are clearly shown in the block of the illumination control unit 7. Yes.

The timer unit 105 is a functional block that detects at least one of time and lapse of time by some configuration. For example, the timer unit 105 can be realized by the configurations exemplified in the following (A) to (C).

(A) A configuration that directly obtains time and / or time passage, such as a real-time clock (RTC) device, a radio clock receiver module, or a GPS (Global Positioning System) receiver module.

(B) A configuration (function unit) that connects to a network or the like and obtains time from other connection nodes.

(C) A configuration (method) for obtaining the time and / or the passage of time by counting the passage of time with a CPU (Central Processing Unit).

The light source control unit 104 receives information indicating at least one of the time and the passage of time from the timer unit 105, and appropriately controls the constant

current circuits

3 and 4 by the dimming control unit 2 in accordance with this information, and the LED circuit 5 The lighting time of each LED chip 14 and each LED chip 15 of the LED circuit 6 is controlled. For example, the lighting time is controlled so that the light emission intensity by each LED chip 15 mainly increases during the day, and the light emission intensity by each LED chip 15 gradually decreases and the light emission intensity by each LED chip 14 increases by night. It is possible to control the lighting time so that

When the light emitting device 101 is used as a light source of a display device such as a liquid crystal display, the display color changes depending on the lighting time of each LED chip 14 and each LED chip 15. However, human vision has a function of chromatic adaptation, and even if the displayed hue is different from the original hue, the chromatic adaptation function can identify colors without feeling unnatural. is there. Therefore, there is no problem in using the light emitting device 101 as the light source of the display device.

When a GPS receiving module is used for the timer unit 105, not only time information but also date and latitude / longitude position information can be obtained. By using these pieces of information as necessary, the light emitting device 101 can adjust the above time profile to sunlight according to the time and place. That is, it is possible to change the color and intensity of light emission in accordance with the actual sunshine duration.

[Embodiment 5]
FIG. 11 is a circuit block diagram showing a schematic configuration of the light emitting device according to the present embodiment. Those not specifically described have the same functions as those shown in FIG.

The light emitting device 102 shown in FIG. 11 is included in the concept of the light emitting device 1 shown in FIG. However, in order to clearly indicate that the light emitting device 102 includes the timer unit 105 and the communication unit 106, in FIG. 11, the light source control unit 104, the timer unit 105, and the communication unit 106 are included in the block of the illumination control unit 7. Each is clearly indicated. A difference between the light emitting device 102 illustrated in FIG. 11 and the light emitting device 101 illustrated in FIG. 10 is the presence or absence of the communication unit 106.

In the fourth embodiment, the application example in which the color of the display on the display device is different from the original one using the human visual color adaptation function has been described. At this time, even if the color of the display by the display device is changed, if the color of the ambient light of the display device does not change accordingly, the chromatic adaptation is also affected by the ambient light of the display device. It becomes. By controlling the light around the display device according to the configuration of the light emitting device 102, it is possible to further promote chromatic adaptation to lubrication.

The communication unit 106 is a communication function block for controlling ambient light around a display device outside the light emitting device 102. Communication means include wireless communication such as infrared remote control and Bluetooth (registered trademark), lighting control interface such as Dali (Digital Addressable Lighting Interface) and DMX512 signal interface, and other general purpose or dedicated connections Means can be used. And the communication part 106 according to the selected said connection means is prepared. The communication unit 106 outputs a signal for controlling the ambient light to the outside using this connection means, and this signal makes the hue of the ambient light close to the hue of the light emitted from the light emitting device 102. Trigger.

When the light emitting device 102 is used as the light source of the display device, the ambient light irradiated from the lighting device or the like using the communication unit 106 is also changed in accordance with the change in the emission spectrum of the light emitted from the LED chips 14 and 15. Can be made. The image of the display device and the ambient light are incident on the user's eyes. By making these colors similar, adaptation to the color of the image of the display device is facilitated.

In the light emitting device 102, the timer unit 105 may be omitted.

[Embodiment 6]
FIG. 12 is a circuit block diagram showing a schematic configuration of the light emitting device according to the present embodiment. Those not specifically described have the same functions as those shown in FIG.

The light emitting device 103 shown in FIG. 12 is included in the concept of the light emitting device 1 shown in FIG. However, in order to clearly indicate that the light emitting device 103 includes the sensor unit 107, in FIG. 12, the light source control unit 104 and the sensor unit 107 are clearly shown in the block of the illumination control unit 7.

The sensor unit 107 is a functional block that detects how much blue component the ambient light irradiated to the surroundings contains. An example of the configuration of the sensor unit 107 will be described with reference to FIG.

The sensor unit 107 includes a sensor control unit 108,

illuminance sensors

109a and 109b, and

color filters

110a and 110b. The

color filters

110a and 110b have different transmission spectra. The light transmitted through the

color filters

110a and 110b is incident on the

illuminance sensors

109a and 109b, respectively. With this configuration, the reaction between the illuminance sensor 109a and the illuminance sensor 109b (for example, as an index indicating the intensity of the blue component) according to the intensity of the blue component (short wavelength component of visible light) included in the light such as ambient light. The balance of the output value is adjusted. In other words, the illuminance sensor 109a and the illuminance sensor 109b have different frequencies of light to be detected.

For example, the color filter 110a transmits a long wavelength component (green or red) of visible light relatively well, and the color filter 110b transmits a short wavelength component (blue) of visible light relatively well. . When the intensity of the blue component of the ambient light is large, the light transmitted through the color filter 110a is small and the light transmitted through the color filter 110b is large. Accordingly, the response of the illuminance sensor 109b is greater than the response of the illuminance sensor 109a. Conversely, when the intensity of the blue component of the ambient light is small, much light is transmitted through the color filter 110a and little light is transmitted through the color filter 110b. Accordingly, the response of the illuminance sensor 109a is greater than the response of the illuminance sensor 109b. The sensor control unit 108 can read the magnitude of the response of the

illuminance sensors

109a and 109b and detect the hue of the ambient light (blue component intensity) from the balance.

The light source control unit 104 adjusts the light emission of the light emitting device 103 according to the result (detection result of the sensor control unit) detected by the sensor control unit 108. For example, when the intensity of the blue component of the ambient light is large, the light emission of each LED chip 15 with high blue visibility is controlled to be more dominant than the light emission of each LED chip 14 with low blue visibility. It is assumed that the light emission has a high intensity of the component. Conversely, when the intensity of the blue component of the ambient light is small, the light emission intensity of each LED chip 15 is reduced and the light emission intensity of each LED chip 14 is increased. In this way, the light emitting device 103 can change the color of light emission in accordance with the color of ambient light. When the light emitting device 103 is used as a light source of a display device, since the light emitting color of the light emitting device 103 and the color of the ambient light are close to each other, the chromatic adaptation proceeds to lubrication and it is difficult to feel unnaturalness in the color of the display.

As a configuration example of the sensor unit 107 other than the above, for example, a configuration in which no color filter is used can be obtained by using a plurality of illuminance sensors having different reacting spectra. Further, instead of using two types of color filters, a structure in which a color filter is used only for one illuminance sensor and a color filter is not used for the other illuminance sensor is possible. In addition to using an illuminance sensor such as a photodiode, it is possible to detect the hue of ambient light by using a camera module.

[Operation effect 1]
FIG. 4 is a graph comparing the melatonin inhibitory action spectrum (see FIG. 7) with the emission spectrum of light obtained from the LED chip 14 and the phosphor group 18 or 28.

The light emission spectrum distribution graph of FIG. 4 uses a chip that emits purple light with a peak of 405 nm as the LED chip 104, and the phosphor group 18 or 28 includes β-sialon of a green phosphor and CASN of a red phosphor. The example when combining is shown.

As shown in the melatonin inhibitory action spectrum, light having a wavelength of 430 nm to 500 nm has a melatonin inhibitory effect of 60% or more with respect to the peak value. Since the light obtained from the LED chip 14 and the phosphor group 18 or 28 has an emission spectrum that hardly includes a wavelength of 430 nm to 500 nm, the melatonin suppressing effect is very small.

Therefore, it is effective to use the light obtained from the LED chip 14 and the phosphor group 18 or 28 as the illumination before going to bed according to the biological rhythm. That is, by using light derived from blue light emitted from the LED chip 15 in the morning and using light derived from purple light emitted from the LED chip 14 at night, the light source is switched in accordance with the biological rhythm. Is possible.

[Operation effect 2]
The light emitting device 1 does not cut all light having a wavelength shorter than about 500 nm, but emits light having a light emission intensity peak at a wavelength of 390 nm to 420 nm by the LED chip 14.

Thereby, as a first advantage, it becomes possible to apply the light emitting device 1 to a display device that performs display by combining colors in three primary colors, such as a backlight of a liquid crystal display device. As a second advantage, when applied to a lighting device that illuminates a room or the like, it becomes possible to obtain whited light.

[Explanation of the first advantage]
Generally, in a television receiver and a display device, various colors are displayed by adjusting these ratios using three primary colors of red, green, and blue. As a human color vision mechanism, humans distinguish colors by the difference (ratio) in the amount of stimulation of L cone, M cone, and S cone that are on the retina of the eye and have different spectral characteristics. The theory is influential.

Note that it is not essential to select three primary colors of red, green, and blue in order to change the amount of stimulation to the L cone, M cone, and S cone.

(Explanation that choosing the three primary colors red, green and blue is not essential)
FIG. 5 is a graph of Smith, Pokony's cone sensitivity function, well known among color engineering researchers as the spectral sensitivity of the L, M, and S cones. This is a spectral characteristic including the optical system of the eyeball, and it is convenient to discuss the relationship between the mechanism that feels light and color when light enters the eye.

The light obtained from the LED chip 14 and the phosphor group 18 or 28 contains almost no light having a wavelength of 450 nm to 495 nm classified as blue light, while the violet light near the wavelength of 405 nm is dominant. According to the graph shown in FIG. 5, the purple light hardly stimulates the L cone and the M cone, and substantially stimulates the S cone. For this reason, this purple light has various colors on the human eye by changing the amount of stimulation of the L cone, M cone, and S cone, despite having almost no melatonin suppression effect. Can be used as a light source.

Strictly speaking, when projecting an image that assumes three primary colors, such as a television broadcast image, the combination of red, green, and blue light intensity is changed to a combination of red, green, and purple light intensity. It is preferable to add a process for converting the video signal. However, even if this processing is not added, it is possible for humans to view color images without extremely unnatural feeling due to their ability to adapt to color. Further, depending on the application to be used, there is a case where the color balance does not have to be more than necessary, and in this case, this processing need not be added. For example, this is the case when text, monochrome drawings, and the like are viewed on a display device.

(Explanation when using a light emitting device in an environment where chromatic adaptation works)
The degree to which human eyes perceive brightness varies depending on the wavelength of light. FIG. 6 is a graph showing the degree of feeling brightness (specific luminous sensitivity) with respect to the wavelength of visible light. In FIG. 6, the degree of feeling the brightness of light of other wavelengths, where the degree of feeling the brightness of light with a wavelength of 555 nm that humans feel the brightest in an environment of brightness that can feel color is defined as 1. The ratio is shown. FIG. 6 is a graph of photopic standard relative luminous sensitivity characteristics.

The relative visibility of violet light near 405 nm is lower than that of blue light near 450 nm. In general, the specific visibility curve is said to be a curve close to the spectral sensitivity of the L cone and the M cone due to the density of cone cells on the retina. In order to describe the difference between the sensitivity to blue light and the sensitivity to purple light, it is considered appropriate to compare the spectral sensitivity characteristics of the S cone shown in FIG. The sensitivity of purple light is low.

Assuming that the light emitting device is used in an environment exposed to various external light, it is necessary to increase the amount of purple light according to the relative luminous sensitivity between blue light and purple light.

On the other hand, depending on the conditions of the room where the display device is viewed, it may not be necessary to increase the amount of purple light. As a specific example, when the room illumination is dark, when the emission spectrum of the illumination light illuminating the room is close to the emission spectrum of the purple light emitted from the LED chip 14, the chromatic adaptation effect of the human eye Even without increasing the amount of purple light, it is possible to view images with a color balance that makes humans feel extremely unnatural. It is not difficult to realize a room that satisfies these conditions at night or before going to bed, where it is desirable to avoid exposure to light with a melatonin inhibitory effect.

(About color adaptation)
Humans have the ability of chromatic adaptation to be able to see things in natural colors even in environments with different spectral distributions of light that illuminates them. As an example of chromatic adaptation, an object appears reddish or yellowish as a whole immediately after entering a room illuminated with incandescent bulbs from sunlight, but gradually becomes a natural color. Is mentioned.

The Von Kries model is well known to explain the mechanism of this chromatic adaptation. The Von Kries model will be briefly described. The balance of the L, M, and S cones makes the white appearance constant even when objects are placed in an illumination environment with different spectral distributions. It is a theory that changed and things looked closer to natural colors. The light emitted by the incandescent bulb has a spectrum that has a smaller intensity on the short wavelength side (purple and blue) and a higher intensity on the long wavelength side (red) than sunlight. In an environment illuminated by this incandescent light bulb, it is explained that the sensitivity of the S cone increases and the sensitivity of the L cone decreases, thereby approaching the color balance seen under sunlight.

Using Von Kries's model, the operation when the light obtained from the LED chip 14 and the phosphor group 18 or 28 is applied to a backlight of a liquid crystal display device or the like will be described.

If the intensity of light entering the retina from outside the display device, such as room illumination or extraneous light, is small, each of the L cone, M cone, and S cone according to the spectral distribution of the light output from the display device The chromatic adaptation that determines the sensitivity works.

Since purple light has a low specific sensitivity, if a large amount of blue light that causes the S cone to react strongly with the illumination light in the room is included, the light from the display device is reflected as light that affects the sensitivity of the S cone. The illumination of the room becomes more dominant than that, and chromatic adaptation in accordance with the light emitted from the display device hardly occurs. Therefore, when the light obtained from the LED chip 14 and the phosphor group 18 or 28 is used for a display device, it is preferable to combine it with room lighting that does not include the spectrum of blue light.

[Explanation of second advantage]
When all light having a wavelength shorter than about 500 nm is cut, it becomes yellowish to reddish light. However, the light obtained from the LED chip 14 and the phosphor group 18 or 28 may be whited light. it can.

This is the effect of the light from the LED chip 14 stimulating the S cone.

If all light with a wavelength shorter than 500 nm is cut in order to reduce the melatonin inhibitory action spectrum, it becomes a light bulb color with a low color temperature. The reddish light bulb color is a light that feels warm, but in some seasons it can make you feel hot. If light having a wavelength of about 405 nm, which has a small melatonin-inhibiting effect, is added here, the S cone is also stimulated and approaches white, so that it is difficult to feel the heat even in summer.

As a result, it is possible to realize white light while avoiding the melatonin inhibitory action spectrum. Regardless of the color temperature, it can be suitably used for a night-light from white adjusted with an apparent hue.

[Summary]
A light-emitting device according to one embodiment of the present invention includes at least one first semiconductor light-emitting element (LED chip 14) that emits light having a peak of light emission intensity in a first wavelength range of 390 nm to 420 nm, and more than 420 nm to 480 nm. Excited by light emitted from at least one second semiconductor light emitting element (LED chip 15) that emits light having a peak of emission intensity in the second wavelength range, and from 498 nm to 830 nm. The third wavelength is excited by light emitted from the first light conversion member (phosphor group 18) that generates fluorescence having one or more emission intensity peaks in the third wavelength region and the second semiconductor light emitting element, and the third wavelength. A second light conversion member (phosphor group 19) that generates fluorescence having one or more peaks of emission intensity in the region, the first semiconductor light emitting element, and the second And it includes driving unit for driving independently of each other and the conductor light emitting element and (dimming controller 2).

According to the above configuration, the light obtained from the first semiconductor light emitting element and the first light conversion member has an emission spectrum that hardly includes a wavelength of 430 nm to 500 nm, and therefore has little melatonin suppression effect. On the other hand, the light obtained from the second semiconductor light emitting element and the second light conversion member has a large melatonin suppressing effect. Then, by driving the first semiconductor light emitting element and the second semiconductor light emitting element independently of each other by the driving unit, it is possible to switch between light having almost no melatonin suppressing effect and light having a large melatonin suppressing effect.

Therefore, the light source derived from the light emitted from the second semiconductor light emitting element is used in the morning and the light derived from the light emitted from the first semiconductor light emitting element is used at night to switch the light source according to the biological rhythm. Is possible. As a result, the melatonin suppressing effect can be greatly reduced.

In the light-emitting device according to another aspect of the present invention, the first light conversion member and the second light conversion member further include the same type of phosphor.

In the light emitting device according to another aspect of the present invention, the number of the first semiconductor light emitting elements mounted is different from the number of the second semiconductor light emitting elements mounted.

According to said structure, according to desired brightness, the brightness of the light obtained from the light which each 1st semiconductor light-emitting device emitted, and the brightness of the light obtained from the light which each 2nd semiconductor light-emitting device emitted Can be arbitrarily set.

The light emitting device according to another aspect of the present invention further includes a first cavity (cavity 20) and a second cavity (cavity 21), and the first semiconductor light emitting element is stored in the first cavity. In addition, the second light-emitting element is sealed in the second cavity, and is sealed with a sealing member (resin 16) including the first light conversion member.

In the light emitting device according to another aspect of the present invention, the second cavity is further filled with a sealing member (resin 17) including the second light conversion member, and the first light conversion member and the second light emitting device are filled. A light conversion member consists of a mutually different raw material or the compounding ratio of a raw material.

The light-emitting device according to another aspect of the present invention further includes a light diffusion member that diffuses light in at least one of a path of light emitted from the first cavity and a path of light emitted from the second cavity. It has been.

According to the above configuration, color mixing between the light emitted from the first cavity and the light emitted from the second cavity becomes easy.

A light-emitting device according to a different aspect of the present invention includes at least one first semiconductor light-emitting element that emits light having an emission intensity peak in a first wavelength range of 390 nm or more and 420 nm or less, and a second that is greater than 420 nm and 480 nm or less. At least one second semiconductor light emitting element that emits light having a peak of light emission intensity in the wavelength region, and the light emission intensity in the third wavelength region that is excited by light emitted from the first semiconductor light emitting element and is not less than 498 nm and not more than 830 nm. A light conversion member (phosphor group 28) that generates fluorescence having one or more peaks, a driving unit that drives the first semiconductor light emitting element and the second semiconductor light emitting element independently of each other are provided.

According to the above configuration, even if the first light conversion member and the second light conversion member are not provided, the same effect as that of the light emitting device according to the above aspect can be obtained.

In the light emitting device according to another aspect of the present invention, the light conversion member is further excited by light emitted from the second semiconductor light emitting element, and has a fluorescence having one or more emission intensity peaks in the third wavelength region. Produce.

In the light emitting device according to another aspect of the present invention, the first semiconductor light emitting element and the second semiconductor light emitting element are housed in the same cavity (cavity 30) and include the light conversion member. It is sealed with a stop member (resin 26).

A light-emitting device according to still another aspect of the present invention includes a control unit (light source control unit 104) that controls a lighting time of the first semiconductor light-emitting element and the second semiconductor light-emitting element, and the first semiconductor light-emitting element The light emitted from the second semiconductor light-emitting element and the light emitted from the second semiconductor light emitting element are characterized in that the amount of action on the intrinsic light-sensitive retinal fine particles is different from each other.

According to the above configuration, the light obtained from the first semiconductor light emitting element has an emission spectrum that hardly includes a wavelength of 430 nm to 500 nm, and therefore has little melatonin suppressing effect. On the other hand, the light obtained from the second semiconductor light emitting device has a great melatonin suppression effect. And by controlling light emission by the first semiconductor light emitting element and light emission by the second semiconductor light emitting element by the control unit, it is possible to switch between light having almost no melatonin suppressing effect and light having a large melatonin suppressing effect.

Therefore, it is possible to switch the light source according to the biological rhythm by using the light emitted from the second semiconductor light emitting element in the morning and using the light emitted from the first semiconductor light emitting element at night. As a result, the melatonin suppressing effect can be greatly reduced.

The light emitting device according to still another aspect of the present invention further includes a timer unit that detects at least one of time and time, and the control unit receives the time and time from the timer unit. The lighting time is controlled according to information indicating at least one of the above.

According to the above configuration, the lighting time of the first semiconductor light emitting element and the second semiconductor light emitting element can be controlled according to the time and the passage of time. For example, the lighting time is controlled mainly during the day so that the light emission intensity of the second semiconductor light-emitting element increases, and the light emission intensity of the second semiconductor light-emitting element gradually decreases as the night goes on. The lighting time can be controlled to increase the intensity.

The light-emitting device according to yet another aspect of the present invention further includes a plurality of illuminance sensors that detect the intensity of light around the display device on which the light-emitting device is mounted and have different frequencies to be detected, and the plurality of illuminances. A sensor control unit that detects the intensity of the blue component contained in the ambient light of the display device from the detection result of the sensor, and the control unit turns on the light according to the detection result of the sensor control unit. Control the time.

According to the above configuration, the lighting time of the first semiconductor light emitting element and the second semiconductor light emitting element can be controlled in accordance with the result of detecting the intensity of the blue component contained in the ambient light of the display device. For example, when the intensity of the blue component of the light is large, the light emission of the second semiconductor light emitting element is controlled to be dominant over the light emission of the first semiconductor light emitting element, so that the light emission of a hue with a large blue component intensity is obtained. Is possible. On the other hand, when the intensity of the blue component of light is small, it is possible to control to reduce the emission intensity of the second semiconductor light emitting element and increase the emission intensity of the first semiconductor light emitting element.

The light emitting device according to still another aspect of the present invention further includes a communication unit that outputs a signal for controlling light around the display device outside the light emitting device in accordance with the control of the lighting time by the control unit. Yes.

According to the above configuration, the ambient light of the display device can be controlled in accordance with information from the communication unit.

A display device according to one embodiment of the present invention includes a light-emitting device according to still another embodiment of the present invention as a light source.

According to the above configuration, the display device has the same effect as the light emitting device according to still another aspect of the present invention.

The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention. Furthermore, a new technical feature can be formed by combining the technical means disclosed in each embodiment.

The present invention can be used for light-emitting devices and display devices that affect biological rhythms.

1, 101, 102, and 103 Light-emitting device 2 Dimming control unit (drive unit)
14 LED chip (first semiconductor light emitting device)
15 LED chip (second semiconductor light emitting device)
16 Resin (sealing member)
17 Resin (sealing member)
18 Phosphor group (first light conversion member)
18s phosphor 19 phosphor group (second light conversion member)
19s phosphor 20 cavity (first cavity)
21 cavity (second cavity)
26 Resin (sealing member)
28 Phosphors (light conversion member)
28s phosphor 30 cavity 104 light source control unit (control unit)
105 Timer unit 106 Communication unit 108

Sensor control units

109a and 109b Illuminance sensor

Claims

At least one first semiconductor light emitting element that emits light having a peak of emission intensity in a first wavelength range of 390 nm or more and 420 nm or less;
At least one second semiconductor light emitting element that emits light having a peak of emission intensity in a second wavelength region that is greater than 420 nm and less than or equal to 480 nm;
A first light conversion member that is excited by light emitted from the first semiconductor light emitting element and generates fluorescence having one or more peaks of emission intensity in a third wavelength range of 498 nm or more and 830 nm or less;
A second light conversion member that is excited by light emitted by the second semiconductor light emitting element and generates fluorescence having one or more peaks of emission intensity in the third wavelength region;
A light emitting device, comprising: a drive unit that drives the first semiconductor light emitting element and the second semiconductor light emitting element independently of each other.
The light-emitting device according to claim 1, wherein the first light conversion member and the second light conversion member contain the same type of phosphor.
A first cavity and a second cavity;
The first semiconductor light emitting element is housed in the first cavity and sealed by a sealing member including the first light conversion member,
The light emitting device according to claim 1, wherein the second semiconductor light emitting element is stored in the second cavity.
The second cavity is filled with a sealing member including the second light conversion member,
The light emitting device according to claim 3, wherein the first light conversion member and the second light conversion member are made of different materials or mixing ratios of the materials.
4. The light diffusing member for diffusing light is provided in at least one of a path of light emitted from the first cavity and a path of light emitted from the second cavity. Light emitting device.
A control unit for controlling lighting times of the first semiconductor light emitting element and the second semiconductor light emitting element;
6. The light emitted from the first semiconductor light emitting element and the light emitted from the second semiconductor light emitting element are different from each other in the amount of action on the intrinsic light-sensitive retina. The light emitting device according to any one of the above.
It has a timer part that detects at least one of time and the passage of time,
The light emitting device according to claim 6, wherein the control unit controls the lighting time according to information received from the timer unit and indicating at least one of the time and the passage of time.
A plurality of illuminance sensors that detect the intensity of light around the display device on which the light emitting device is mounted and that have different frequencies to be detected;
From the detection results of the plurality of illuminance sensors, a sensor control unit that detects the intensity of the blue component contained in the ambient light of the display device,
The light-emitting device according to claim 6, wherein the control unit controls the lighting time according to a detection result of the sensor control unit.
The light emitting device according to claim 6, further comprising: a communication unit that outputs a signal for controlling light around the display device outside the light emitting device in accordance with control of a lighting time by the control unit. .
A display device comprising the light-emitting device according to claim 6 as a light source.