1. Field of the Invention
This invention relates to a medical lighting apparatus for illuminating an area such as an operative area of a patient in the medical field.
2. Related Art
This kind of conventional medical lighting apparatus employs incandescent bulbs such as halogen lamps as the light sources (see, for example, Japanese Laid-Open Patent Publication No. 4-312457).
The conventional medical lighting apparatus using incandescent bulbs presents the following problems, since the light sources generate a significant amount of heat. There is danger of the heat drying out an affected area of a patient or causing a low-temperature burn. The heat also causes discomfort to an operator with being radiated to his or her head, neck or shoulder.
On the other hand, recently high-intensity LEDs (Light Emitting Diodes) have been developed and they generate much less heat than incandescent bulbs. Therefore, it can be expected that the prior art problems will be overcome by use of high-intensity LEDs instead of incandescent bulbs.
However, LEDs now available present a problem that their color rendering properties are unsatisfactory for use in medical lighting apparatus.
Also, there are problems that, if lights from LEDs are condensed with lenses, it is prone to produce a nonuniform light distribution, resulting in shadows on the area to be illuminated, and of the lights emitted from light emitting parts of LEDs, those go toward the periphery far from the axis of the LEDs cannot be put to effective use, resulting in low light efficiency.
Furthermore, though LEDs produce much less heat than incandescent lamps and their heat generation does not cause harmful effects to the patient or the operator, still there is a problem that, unless adequate heat dissipation is provided, the LED itself's life is shortened considerably.
It is accordingly an object of the present invention to provide a medical lighting apparatus that uses LEDs as the light sources, and still has good color rendering properties.
It is another object of the present invention to provide a medical lighting apparatus that uses LEDs as the light source, and still can minimize the formation of shadows.
It is still another object of the present invention to provide a medical lighting apparatus that can make highly effective use of LEDs' light output.
It is a further object of the present invention to provide a medical lighting apparatus that can provide good heat dissipation from LEDs to extend the LEDs' life.
The other objects of the present invention will become apparent from the following detailed description.
A medical lighting apparatus in accordance with the present invention includes single or plural LED units. Each of the LED units comprises a plurality of concave reflecting surfaces and an LED element disposed in front of each of the reflecting surfaces so as to radiate light toward each of the reflecting surfaces. Each of the LED units is arranged so that the lights radiated from its LED elements are reflected by the reflecting surfaces, emerge outside and are superimposed on each other on an area to be illuminated, respectively, while illuminating the area. The LED elements of each of the LED units comprise a combination of different emitting colors so as to enhance the color rendering properties.
The medical lighting apparatus of the present invention uses a combination of LED elements of different emitting colors in every LED unit instead of using LED elements of the same single emitting color. Therefore, the color rendering properties can be improved as a whole.
In the medical lighting apparatus of the present invention, since the lights radiated from the LED elements are converged by the concave reflecting surfaces, uniform light distribution can be achieved, minimizing the formation of shadows, and even the lights from the light emitting parts of the LED elements which go toward the periphery far from the axis of the LED elements can be put to effective use, achieving highly effective use of LED elements' light output.
In a particular aspect of the medical lighting apparatus of the present invention, there are provided an LED supporting member supporting the LED element and heatsink plates extending radially from the LED supporting member. The heatsink plates are arranged to extend widthwise in the plane substantially parallel to the optical axis of the concave reflecting surface. Accordingly, when viewed in parallel to the optical axis of the reflecting surface, the plate thickness of the heatsink plates can be seen. Such construction enables adequate heat dissipation from LEDs to extend the LEDs' life, and still substantially prevents the presence of the heatsink plates from obstructing the light illumination.
The foregoing and the other objects, features and advantages of the present invention will become apparent from the following detailed description when taken in connection with the accompanying drawings. It is to be understood that the drawings are designated for the purpose of illustration only and are not intended as defining the limits of the invention.
The present invention will hereunder be described in conjunction with a preferred embodiment of the invention which is shown in the drawings. In the drawings like reference numerals are used throughout the various views to designate like parts.
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Each LED unit 10 has a flat-shaped unit board 11 formed of a punched metal plate with a number of small holes (not shown). Each unit board 11 is rotatably mounted to the main body 4, through a unit supporting member 12 (see
Three reflecting members 15 are supported by each of the unit boards 11. Each reflecting member 15 has a concave reflecting surface 16 having a paraboloidal surface or similar shaped surface, and is loosely mounted to the unit board 11 with a screw 17 and a nut 18 at the center of the concave reflecting surface 16. With this arrangement, each of the reflecting members 15 is tiltable to some extent in every direction relative to the unit boards 11. A foamed material member 19 having rubber elasticity such as urethane foam is interposed between the back of the center portion of the concave reflecting surface 16 of each reflecting member 15 and the unit board 11. As shown in
Each of the reflecting members 15 is accommodated inside a reflecting member case 21 formed of metal having a generally short cylindrical-shape. Each of the reflecting member cases 21 is adapted to be movable relative to the unit board 11 and reflecting member 15 in a direction normal to the unit board 11 (generally the direction parallel to the optical axis of the reflecting member 15). As shown in
An LED supporting member 25 formed of metal such as cupper alloy or aluminum alloy is mounted on each of the reflecting member cases 21 through three strip-shaped heatsink plates 24 formed of metal such as cupper alloy or aluminum alloy. Each of the LED supporting members 25 is disposed in front of the concave reflecting surface 16 and on the optical axis of the concave reflecting surface 16. As shown in
The total of three LED elements 26 provided on each of the LED units 10 are not of the same emitting color or emission spectrum, but comprise a combination of different emitting colors, white, blue and red so as to enhance the color rendering properties as a whole.
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Now, the operation of this embodiment will be described. The lights radiated from the LED elements 26 are reflected by the reflecting surfaces 16, converted to generally parallel rays of lights and emerge outside through the openings 29 and the lamp covers 30 (see
The angle adjustments of the concave reflecting surfaces 16 in each of the LED unit 10 are achieved by turning the reflection angle adjusting screws 20 to change the distances the screws 20 travel pushing the backs of the reflecting members 15, respectively. By these angle adjustments, the light spots from three reflecting surfaces 16 in each of the LED units 10 are supposed to be superimposed at one point on the area to be illuminated which is supposed to be, for example, about one meter apart from the medical lighting apparatus 1.
In this embodiment, since a plurality of concave reflecting surfaces 16 in each of the LED units 10 are formed of separate members and thereby it is hard to accurately set the angle of each of the concave reflecting surfaces 16 from the beginning due to the manufacturing process, the concave reflecting surfaces 16 are constructed so that the inclination angles thereof can be adjusted, respectively, as stated above. However, for example, if a plurality of concave reflecting surfaces 16 in each LED unit 16 are integrally formed together, mechanisms for adjusting the angle inclination of reflecting surfaces 16 are not necessary.
Next, the adjustment of the light rays focus of the medical lighting apparatus 1 as a whole is achieved as follows. By rotating the center focus handle 6 or the focus control knob 7 to rotate the rotating member 8 through the power transmission mechanism 9 and thereby to pull or push the focus connecting rods 27, the LED units 10 are rotated simultaneously about the rotational axes 14 as shown by the arrow A in
When thus adjusted, the lights radiated from LED elements 26 are reflected by the reflecting surfaces 16, emerge outside, respectively, and are superimposed on one another on an area to be illuminated, while at the same time illuminating the area. Since this medical lighting apparatus 1 uses a combination of LED elements of different colors in every LED unit 10 instead of using LED elements of the same single color, the color rendering properties as a whole can be highly enhanced.
Also, since the lights radiated from the LED elements 26 are converged by the concave reflecting surfaces 16, uniform light distribution can be achieved, minimizing the formation of shadows, and even the lights emerged from light emitting parts of LED elements 26 toward the periphery far from the axis of the LED elements 26 can be put to effective use, achieving highly effective use of LED elements' light output.
Further, in this embodiment, since there are provided the LED supporting members 25 supporting the LED elements 26 and heatsink plates 24 extending radially from the LED supporting members 25, and the heatsink plates 24 are arranged to extend widthwise in the plane substantially parallel to the optical axis of the concave reflecting surfaces 16, adequate heat dissipation from LED elements 26 can be realized to extend the LED elements' life, and still the presence of the heatsink plates 24 is substantially prevents from obstructing the light illumination.
Though in the aforementioned embodiment, the combination of the emitting colors of the LED elements 26 in each LED unit 10 is white, blue and red, other color combinations may be used.
Though in the aforementioned embodiments, the number of the LED units 10 is five, it may be any number.
Though in the aforementioned embodiments, the number of LED elements 26 of each LED unit 10 is three, it may be any number equal to or greater than two.
Although a preferred embodiment of the present invention has been shown and described herein, it should be apparent that the present disclosure is made by way of example only and that variations thereto are possible within the scope of the disclosure without departing from the subject matter coming within the scope of the following claims and a reasonable equivalency thereof.
Number | Date | Country | Kind |
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2005-239172 | Aug 2005 | JP | national |