JPH11162660A - LED light source - Google Patents

Abstract

(57) [Abstract] [Problem] A plurality of LEDs that can easily control light distribution and light color
The light source 2 is constituted by arranging a plurality of LEDs 1 vertically and horizontally on a base 2a.
1 ... LED1 at the center of the surface ... LED1 at the periphery of LED1 ...
Are provided with a power control unit 3 which can send more power to the power control unit. The power control unit 3 gives a larger amount of power to the peripheral LEDs 1 than the central LEDs 1 forming the light emitting body 2 so as to reduce the amount of light emitted from the peripheral LEDs 1. The power control is performed so that the light distribution to the front of the light emitting surface is made substantially uniform by increasing the amount of light to be emitted more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light source using an LED.

[0002]

2. Description of the Related Art When centralized light sources such as incandescent lamps and discharge lamps are used as illumination and display light sources, the size of the light source is not negligible with respect to the distance to the surface to be irradiated. In order to obtain a desired light distribution and light color over a wide range of the surface to be illuminated, a large optical system is provided, or an instrument design that considerably sacrifices the instrument efficiency is performed. Further, the control for making the light distribution and light color pattern variable involves considerable additional devices.

[0003]

Even when an LED is used, the same problem as when the above-mentioned centralized light source is used occurs when used alone. Also, when a plurality of LEDs are used, simply arranging them produces the same result as when using the above-mentioned concentrated light source.

[0004] The present invention has been made in view of the above problems, and an object of the present invention is to provide an LED light source including a plurality of LEDs that can easily control light distribution and light color.

[0005]

According to a first aspect of the present invention, there is provided a light emitting device comprising a plurality of LEDs, and control means for controlling the light output of the LEDs. Features. According to a second aspect of the present invention, in the first aspect of the present invention, the control means performs power control on the plurality of LEDs at once.

A third aspect of the present invention is characterized in that, in the first aspect of the present invention, a plurality of LEDs are connected in series. According to a fourth aspect of the present invention, in the first aspect, a plurality of LEDs are connected in parallel. In the invention of claim 5, in the invention of claim 1,
It is characterized in that a plurality of LEDs are connected in series and parallel.

According to a sixth aspect of the present invention, in the first aspect, the control means performs power control so that the temperature of the LED is constant. According to a seventh aspect of the present invention, in the first aspect of the present invention, the control means performs power control so that the light output from the light emitter has a wide-angle light distribution. In the invention of claim 8, in the invention of claim 1,
The control means controls the power so that the light output from the light emitter has a narrow angle light distribution.

According to a ninth aspect of the present invention, in the first aspect of the present invention, the control means controls the power so that the light output from the illuminant has a substantially uniform light distribution on the irradiated surface. . According to a tenth aspect of the present invention, in the first aspect of the present invention, a plurality of LEDs having different emission colors are combined to constitute a light emitting body, and the control means performs power control so as to obtain an arbitrary color.

According to an eleventh aspect of the present invention, in the first aspect of the present invention, a plurality of LEDs having different emission colors are combined to form a luminous body, and the control means performs power control so as to attain an arbitrary color temperature. Features. According to a twelfth aspect of the present invention, in the tenth or eleventh aspect, the control means performs power control on the light output from the illuminant so as to reduce color unevenness on the surface to be irradiated.

According to a thirteenth aspect of the present invention, in the first aspect of the present invention, the control means supplies the electric power divided into narrow pulse widths. According to a fourteenth aspect of the present invention, in the first aspect of the invention, the control means includes a heat radiating means using a Peltier element. According to a fifteenth aspect of the present invention, there is provided the LED light source according to the first aspect, wherein the control means includes a heat radiating means using fins.

According to a sixteenth aspect of the present invention, in the first or sixth aspect, the control means comprises: a series circuit in which a plurality of LEDs are connected in series; a current control element connected in series;
Means for detecting the temperature in the vicinity of D or the LED, and controlling the current control element so that the detected temperature becomes substantially constant to control the current flowing through the DC circuit.

According to a seventeenth aspect of the present invention, in the first or sixth aspect, the control means comprises: a parallel circuit in which a plurality of LEDs are connected in parallel; a voltage control element connected in parallel to the parallel circuit; Alternatively, a means for detecting a temperature near the LED and controlling a voltage control element so that the detected temperature becomes substantially constant to control a voltage applied to the parallel circuit is provided.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to embodiments. (Embodiment 1) In this embodiment, as shown in FIG. 1, a plurality of LEDs (or LED chips) 1.
a to form a luminous body 2, and at the periphery of the LEDs 1, constituting the luminous body 2, to transmit more power to the peripheral LEDs 1 than the central LED 1. .. And a central LED 1... Group, and a power control unit 3 capable of controlling power supply to each of the groups.

The power control unit 3 supplies more power to the peripheral LEDs 1 than to the central LEDs 1 constituting the luminous body 2 so that the peripheral LEDs 1.
Since the amount of light emitted from the LED 1 increases in comparison with the amount of light emitted from the LEDs 1 at the center, the light distribution from the light emitting surface of the light emitting body 2 has a light emission as shown by a light distribution curve I in FIG. Light distribution to the front of the surface can be made substantially uniform distribution. When the same power is supplied to all the LEDs 1, the light distribution is as shown by the light distribution curve II, and the light distribution is not uniform.

(Embodiment 2) As shown in FIG. 3, the luminous body 2 may be constituted by combining a plurality of LEDs 1 having different luminescent colors (red (R), green (G), blue (B), etc.). ,
In the present embodiment, the power transmitted to the LEDs 1 of each color is controlled by the power control unit 3 to control the light color to be output.

In this embodiment, the light output from the light source can be of any color. LED1
Is not only easy to control, but also the luminous body 2 can be manufactured in a small size, so that it is possible to design a lighting fixture with less color unevenness on the luminous surface. (Embodiment 3) In this embodiment, as shown in FIG. 4, LEDs 1... With the central axis of the light output being vertical and LEDs 1 ′... LE
The power supply to D1..., 1 ′.

Thus, in this embodiment, when power is supplied only to the LEDs 1 having a central axis of light output in the vertical direction, a luminaire having a narrow angle light distribution can be constructed.
In the case where power is also supplied to the LEDs 1 ′... In which the central axis of the light output is shifted circumferentially, a wide-angle light distribution lighting device can be configured. (Embodiment 4) In this embodiment, the LED 1 (or LED 1) to which the same power is collectively supplied in each of the above-described embodiments.
1 ′ are connected in parallel as shown in FIG. 5, and a transistor Q _{0 as} a voltage control element of the power control unit 3 is connected to this parallel circuit.
And a resistor R connected in parallel via a current limiting resistor _R0 . Then, the control circuit 3a of the control unit 3
Are controlled by the transistor Q so that the temperature detected by the temperature detecting element 4 such as a thermistor for detecting the temperature of the LEDs 1...

(Embodiment 5) In Embodiment 4, LEDs 1 ...
Are connected in parallel with each other to supply power. In the present embodiment, as shown in FIG.
D1... Are connected in series, and this series circuit is connected to a power supply + V via a series circuit of a transistor Q of the power control unit 3 and a current control circuit element 5 such as a resistor.
Are controlled by the control signal of the control circuit 3a to control the current flowing in the series circuit of the LEDs 1. Then, the control circuit 3a detects the temperature of the LED 1 or a nearby temperature by a change in the forward voltage of any one of the LEDs 1, and performs the above-described current control by the transistor Q so that the temperature becomes constant. .

By using the circuit shown in FIG. 6 as one unit and having a plurality of units A ₁ ... As shown in FIG. 7, a light emitting body 2 of one module is formed. can do. As shown in FIG.
Central portion in the light emitting element 2 of the module, for example, FIGS. 7 (a) In the circuit units A ₅ is less emission amount for the emission current is limited by a high temperature, the circuit unit of a relatively low temperature periphery _{a 1 ~A 4, a 6 ~A} 9 emission amount in (circuit unit shown by oblique lines in FIG. 7 (b)) becomes greater than the circuit unit a ₅ in the center. This is combined with the characteristic that a general LED has a better luminous efficiency at a low temperature, and can be used for a lighting fixture to increase the fixture efficiency. Further, similarly to the case of the first embodiment, the light distribution in the front direction of the light emitting surface (front of the device) can be made uniform distribution.

Further, as shown in FIG. 8, when a plurality of light emitters 2 (modules) are combined, the temperature at which the light emitters 2 come into contact with each other becomes high temperature, and each of the circuit units A ₁ .
, The light output of the circuit unit (white circuit unit in the figure) of that portion is reduced. As a result, the light emission amount of the peripheral portion (the circuit unit indicated by oblique lines) in the combined whole increases, and the light emission amount of the central portion decreases. In this manner, even when the number of the luminous bodies 2 is one, or in any combination, the light distribution in the front direction of the luminous surface (front of the appliance) can be made uniform distribution similarly to the first embodiment. it can.

(Embodiment 6) By the way, when power is supplied to the LEDs 1, it is usual to connect a current limiting resistor in series, but in this embodiment, as shown in FIG. A voltage application unit 3b that connects the LEDs 1 to be supplied in parallel and applies a pulsed voltage to the parallel circuit.
Are provided in the power control unit 3, and a pulsed voltage is applied to the LEDs 1 for a shorter time than in the normal operation,
Are operated to perform power control.

That is, in the present embodiment, the overcurrent can be suppressed without connecting a current limiting element such as a current limiting resistor to the LEDs 1..., And the power consumed by the current limiting element can be eliminated. As a result, the luminous efficiency is improved. (Embodiment 7) As described above, the LED has the characteristic that the luminous efficiency is better at low temperatures. Therefore, in the present embodiment,
The heat radiation fins 6 for promoting more heat radiation are attached to the portions of the LEDs 1 to be strongly illuminated as shown in FIG.

As a result, in this embodiment, any light distribution and light color can be obtained without complicating the power control for the LEDs 1. (Eighth Embodiment) In the seventh embodiment, the radiating fins 6 are attached to the LEDs 1 in order to promote heat radiation. In the present embodiment, as shown in FIG. The luminous body 2 is cooled by cooling
The overall temperature is lowered, the luminous efficiency of each LED 1 is increased, and more light output of the entire light emitting body 2 is taken out.

In this embodiment, the temperature of the LEDs 1 is controlled by controlling the operation of each Peltier element 7,
The light emission of each LED 1 can also be controlled. In the case of the present embodiment, the Peltier element 7 and the LED chip may be integrated. As shown in FIGS. 12 (a) and 12 (b), LEDs 1 are arranged on a fan 8 rotated by a motor, and by rotating the fan 8, the light-emitting body 2 serving as a circular light source can be realized. In this case, the rotation of the fan 8 can cool the LEDs 1... As a whole, thereby improving the luminous efficiency and increasing the light output.

Further, as shown in FIGS. 13 (a) and 13 (b), the fixed luminous body 2 is arranged in a vortex air flow formed by the rotation of the vortex fan 9 and The LEDs 1 may be cooled similarly. Needless to say, even in the embodiment in which the power supply of the LEDs 1... Is not described, the power control unit 3 for supplying power to the LEDs 1 is provided.

[0026]

According to the first aspect of the present invention, since there are provided a luminous body composed of a plurality of LEDs and a control means for controlling the light output of these LEDs, light distribution and light color can be easily controlled. An LED light source can be realized. According to a second aspect of the present invention, in the first aspect of the present invention, since the control means performs power control on a plurality of LEDs at once, power control can be performed on a plurality of LEDs.

According to a sixth aspect of the present invention, in the first aspect of the invention, power control is performed so that the temperature of the LED is constant, so that a difference in light output due to uneven temperature can be eliminated. According to a seventh aspect of the present invention, in the first aspect of the present invention, the control means performs the power control so that the light output from the light emitter becomes a wide-angle light distribution. It can be realized by doing.

According to an eighth aspect of the present invention, in the first aspect of the invention, the control means controls the power so that the light output from the light emitter has a narrow-angle light distribution. It can be realized by controlling the power of the device. According to a ninth aspect of the present invention, in the first aspect of the present invention, the control means controls the power so that the light output from the illuminant has a substantially uniform light distribution on the surface to be illuminated. Can be easily realized.

According to a tenth aspect of the present invention, in the first aspect of the present invention, a plurality of LEDs having different luminescent colors are combined to form a luminous body, and the control means performs power control so as to have an arbitrary color. Illumination of any light color can be performed simply by performing control. According to an eleventh aspect of the present invention, in the first aspect of the present invention, a plurality of LEDs having different emission colors are combined to form a luminous body, and the control unit performs power control so as to have an arbitrary color temperature. By simply performing this, illumination with an arbitrary color temperature can be performed.

[0030] The invention of claim 12 is the invention of claim 10 or 11.
In the present invention, the control means controls the power so that the light output from the light emitter reduces the color unevenness on the surface to be illuminated, so that illumination having a light color without color unevenness can be easily performed.
According to a thirteenth aspect of the present invention, in the first aspect of the present invention, since the control means supplies the electric power in a narrow pulse width, there is no need to use a current control element.

According to a fourteenth aspect of the present invention, in the first aspect of the present invention, since the control means is provided with a heat radiating means using a Peltier element, it is possible to enhance the luminous efficiency and realize a light source having a large light output, and to control the temperature by controlling the temperature. Light distribution and light color can be set. According to a fifteenth aspect of the present invention, in the first aspect of the present invention, since the control means includes a radiating means using fins, the luminous efficiency can be increased, a light source having a large light output can be realized, and complicated power control is not performed. Arbitrary light distribution and light color can be set.

According to a sixteenth aspect of the present invention, in the first or sixth aspect, the control means includes a series circuit in which a plurality of LEDs are connected in series, a current control element connected in series, and an LED or a temperature near the LED. Means for controlling the current flowing through the DC circuit by controlling the current control element so that the detected temperature becomes substantially constant.
According to a seventh aspect of the present invention, in the first or sixth aspect, the control means comprises: a parallel circuit in which a plurality of LEDs are connected in parallel; a voltage control element connected in parallel to the parallel circuit; And means for controlling the voltage control element so that the detected temperature is substantially constant to control the voltage applied to the parallel circuit, so that the luminous efficiency is increased,
A light source with a large light output can be realized, and arbitrary light distribution and light color can be set without performing complicated power control.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of Embodiment 1 of the present invention.

FIG. 2 is an explanatory diagram of a light distribution according to the first embodiment.

FIG. 3 is a schematic configuration diagram of Embodiment 2 of the present invention.

FIG. 4 is a schematic configuration diagram of Embodiment 3 of the present invention.

FIG. 5 is a circuit configuration diagram according to a fourth embodiment of the present invention.

FIG. 6 is a circuit configuration diagram according to a fifth embodiment of the present invention.

FIG. 7 is an explanatory view of use of the above.

FIG. 8 is another use explanatory view of the above embodiment.

FIG. 9 is a circuit configuration diagram according to a sixth embodiment of the present invention.

FIG. 10 is a schematic configuration diagram of a main part according to a seventh embodiment of the present invention.

FIG. 11 is a schematic configuration diagram of a main part according to an eighth embodiment of the present invention.

FIG. 12 (a) is a schematic side view of another embodiment of the present invention. (B) is a schematic front view of the same.

FIG. 13 (a) is a schematic side view of another embodiment of the present invention. (B) is a schematic front view of the same.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 LED 2a base 2 light-emitting body 3 power control part

Continued on the front page (72) Inventor Sakuo Kamada 1048 Odakadoma, Kadoma, Osaka Prefecture Inside Matsushita Electric Works Co., Ltd. Person Nobuyuki Asahi 1048 Kadoma Kadoma, Kadoma City, Osaka Pref. (72) Inventor Toshiyuki Suzuki 1048 Kadoma Kadoma, Kadoma, Osaka Pref. 1048 Kadoma Matsushita Electric Works Co., Ltd. (72) Inventor Koji Tanaka 1048 Kadoma, Kadoma City, Osaka Pref. Inside

Claims (17)

[Claims] 1. An LED light source comprising: a luminous body comprising a plurality of LEDs; and control means for controlling the light output of these LEDs. 2. The LED light source according to claim 1, wherein the control means performs power control on the plurality of LEDs at once. 3. The LED light source according to claim 1, wherein a plurality of LEDs are connected in series. 4. The LED light source according to claim 1, wherein a plurality of LEDs are connected in parallel. 5. The LED light source according to claim 1, wherein a plurality of LEDs are connected in series and parallel. 6. The LE according to claim 1, wherein the control means controls the power so that the temperature of the LED is constant.
D light source. 7. The LED light source according to claim 1, wherein the control means controls the power so that the light output from the light emitter has a wide-angle light distribution. 8. The LED light source according to claim 1, wherein the control means controls the power so that the light output from the light emitter has a narrow angle light distribution. 9. The LED light source according to claim 1, wherein the control means controls the power so that the light output from the illuminant has a substantially uniform light distribution on the surface to be illuminated. 10. The LE according to claim 1, wherein a luminous body is formed by combining a plurality of LEDs having different luminescent colors, and the control means performs power control so as to obtain an arbitrary color.
D light source. 11. An LED light source according to claim 1, wherein a plurality of LEDs having different emission colors are combined to form a light emitting body, and said control means controls power so as to attain an arbitrary color temperature. 12. The LED light source according to claim 10, wherein the control means controls the power so that the light output from the light emitting body has less color unevenness on the surface to be illuminated. 13. The LED light source according to claim 1, wherein the control means supplies the electric power by dividing the electric power into narrow pulse widths. 14. The LED light source according to claim 1, wherein said control means comprises heat radiation means using a Peltier element. 15. The LED light source according to claim 1, wherein the control means includes a radiating means using fins. 16. A control circuit comprising: a series circuit in which a plurality of LEDs are connected in series; a current control element connected in series;
And means for controlling a current flowing through the DC circuit by detecting a temperature in the vicinity of D or the LED and controlling a current control element so that the detected temperature becomes substantially constant. Or the LED light source according to 6. 17. The control means detects a parallel circuit in which a plurality of LEDs are connected in parallel, a voltage control element connected in parallel to the parallel circuit, and an LED or a temperature in the vicinity of the LED. 7. The LED light source according to claim 1, further comprising: means for controlling a voltage control element so as to be constant to control a voltage applied to the parallel circuit.