Patent Publication Number: US-8985793-B2

Title: Illumination device

Description:
This application is a National phase filing under 35 U.S.C. §371 of International Application No. PCT/JP2011/064638 filed on 27 Jun. 2011, and which claims priority to Japanese Application No. 2010-173399 filed on Aug. 2, 2010, the entire contents of each of which are hereby incorporated by reference. 
     TECHNICAL FIELD 
     The present invention relates to an illumination device that use a semiconductor light emitting element such as a light emitting diode (hereinafter appropriately abbreviated as “LED”) as a light source, and in particular, to an illumination device having a dimming function. 
     BACKGROUND ART 
     In recent years, the LED is frequently used for the light source of the illumination device. In the illumination device using the LED, one of the methods of obtaining white light is a method that uses three types of LEDs, a red LED, a blue LED, and a green LED. 
     However, the manufacturing cost increases with such a method since three types of LED element are required. Thus, an illumination device capable of irradiating white light with one type of LED element has been developed. 
       FIGS. 8A and 8B  are schematic views showing one example of an LED illumination device disclosed in Patent Document 1 listed below, where  FIG. 8A  shows a front view and  FIG. 8B  shows a partially cutout plan view. 
     A conventional illumination device  101  shown in  FIGS. 8A and 8B  has a rotation plate  102  arranged above an LED element (light emitting element)  105 . The rotation plate  102  has a plurality of circular through-holes radially arranged at equal intervals, and fluorescent-substance sheets  103  having different colors are each fitted into the through-holes. In the example of Patent Document 1, blue, green, yellow, orange, and red fluorescent-substance sheets are provided. 
     The rotation plate  102  has one portion projecting out to an outer side of a case  106  so as to be manually rotated by a user. The rotation plate  102  is configured to be rotatable by 360° in both clockwise and counterclockwise directions with a shaft  104  as a center. 
     When the rotation plate  102  is rotated, a relative positional relationship between the LED element  105  and each fluorescent-substance sheet  103  changes, so that the color temperature of the light irradiated from the illumination device can be changed in a stepless manner in the order of “daylight color”→“neutral white color”→“incandescent lamp color” or in the reverse order. 
     PRIOR ART DOCUMENT 
     Patent Document 
     Patent Document 1: Japanese Patent Application Laid-Open Publication No. 2007-059260 
     SUMMARY OF THE INVENTION 
     Problems to be Solved by the Invention 
     In the technique of Patent Document 1, a configuration in which the rotation plate  102  and the fluorescent-substance sheet of each color integrally rotate is adopted. Since the rotation plate  102  projects to the outer side of the case  106 , moisture and dust are assumed to be attached to the rotation plate  102 . The projecting portion moves inside the case  106  when the rotation plate  102  is rotated, and hence the moisture and dust eventually intrudes into the case  106  and may lower the brightness and degrade the toning function. In order to prevent this, a complex sealing mechanism is to be provided so that moisture and dust do not intrude into the case  106 , but this complicates the manufacturing process and increases the manufacturing cost. 
     In view of the above problems, it is an object of the present invention to realize an illumination device with a toning function in which possibility of moisture and dust intruding into the case is reduced with a simple mechanism. 
     Means for Solving the Problem 
     In order to achieve the above object, the present invention provides an illumination device in which a main body is covered with a case unit, the illumination device being characterized by comprising: 
     a light emitting element light source mounted on a substrate on an inner side of the case unit; 
     a variable color fluorescent-substance unit having a configuration in which a light emitting color of an applied fluorescent substance differs according to position and being arranged above the light emitting element light source on the inner side of the case unit; and 
     a toning adjusting unit mechanically coupled with the variable color fluorescent-substance unit, wherein 
     the toning adjusting unit is formed such that an end positioned on a side opposite to the variable color fluorescent-substance unit projects to an outer side of the case unit, and is configured such that a relative positional relationship between a color distribution of the fluorescent substance applied on the variable color fluorescent-substance unit and the light emitting element light source is changed when the end is operated. 
     Moreover, in addition to the above characteristic, the illumination device according to the present invention has another characteristic that the device comprises 
     a dimming unit for adjusting an amount of light actually radiated outside the illumination device with respect to an amount of light radiated from the light emitting element light source; and 
     a dimming adjusting unit mechanically coupled to the dimming unit, wherein 
     the dimming adjusting unit is formed such that an end positioned on a side opposite to the variable color fluorescent-substance unit projects to an outer side of the case unit, and is configured such that a relative positional relationship between the dimming unit and the light emitting element light source is changed when the end is operated. 
     Moreover, in addition to the above characteristics, the illumination device according to the present invention has another characteristic that the device comprises a plurality of variable color fluorescent-substance units, each corresponding to the variable color fluorescent-substance unit, in which the color distribution of the applied fluorescent substance differs from each other, wherein 
     the variable color fluorescent-substance units are mechanically coupled to different toning adjusting units, respectively, the different toning adjusting units each corresponding to the toning adjusting unit. 
     More specifically, the illumination device according to the present invention is characterized by including the following configuration. That is, 
     the variable color fluorescent-substance unit includes a fluorescent-substance plate applied with fluorescent substance, and a first gear physically fixed to the fluorescent-substance plate, the first gear being rotatable in a clockwise direction or a counterclockwise direction, and 
     the toning adjusting unit is configured by a second gear which is rotatable in a clockwise direction or a counterclockwise direction, the second gear meshing with the first gear. 
     Moreover, the illumination device according to the present invention is characterized by including the following another configuration. That is, 
     the variable color fluorescent-substance unit is configured by a plurality of small regions capable of being folded like a folding fan, and 
     the toning adjusting unit has a movable lever-shaped structure, and the folded small regions of the variable fluorescent-substance unit are opened or the opened small regions of the variable fluorescent-substance unit are folded when the toning adjusting unit is moved. 
     Moreover, the illumination device according to the present invention is characterized by including the following another configuration. That is, 
     the variable color fluorescent-substance unit is a circular plate shaped gear with external teeth, and is configured to rotate on a fixing shaft provided at a center portion in a clockwise direction or a counterclockwise direction, 
     the toning adjusting unit is a circular ring-shaped gear with internal teeth which couples to an outer periphery of the case unit and is rotatable in the clockwise direction or the counterclockwise direction, 
     the variable color fluorescent-substance unit is arranged such that the external teeth mesh with the internal teeth of the toning adjusting unit, and 
     the variable color fluorescent-substance unit rotates when the toning adjusting unit is rotated. 
     Moreover, the illumination device according to the present invention is characterized by including the following another configuration. That is, 
     the variable color fluorescent-substance unit is configured to have a roll screen shape capable of being wound in both forward and reverse directions on a predetermined surface, and 
     the toning adjusting unit includes a screw which is rotatable in a clockwise direction or a counterclockwise direction, and a winding unit which is arranged on the inner side of the case unit and couples the screw with the variable color fluorescent-substance unit, and the winding unit rotates to perform a winding operation of the variable color fluorescent-substance unit when the screw is rotated. 
     Effects Of The Invention 
     According to the configuration of the present invention, the portion applied with the fluorescent substance for realizing the dimming function can be completely accommodated on the inner side of the case unit. Therefore, moisture and dust will not intrude into the fluorescent substance even if a dedicated intrusion preventing member such as the sealing mechanism or the like is not separately arranged. Thus, a situation in which the toning function degrades with the intruding in of the moisture and dust can be avoided while suppressing the manufacturing cost. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1A and 1B  show an LED illumination device according to a first embodiment of the present invention. 
         FIGS. 2A and 2B  show another configuration example of an LED illumination device according to the first embodiment of the present invention. 
         FIGS. 3A and 3B  show an LED illumination device according to a second embodiment of the present invention. 
         FIGS. 4A and 4B  show an LED illumination device according to a third embodiment of the present invention. 
         FIGS. 5A and 5B  show another configuration example of an LED illumination device according to the third embodiment of the present invention. 
         FIGS. 6A and 6B  show an LED illumination device according to a fourth embodiment of the present invention. 
         FIG. 7  shows another configuration example of an LED illumination device according to the fourth embodiment of the present invention. 
         FIGS. 8A and 8B  show a conventional LED illumination device. 
         FIGS. 9A and 9B  show an LED illumination device according to a fifth embodiment of the present invention. 
     
    
    
     MODE FOR CARRYING OUT THE INVENTION 
     Embodiments of an illumination device of the present invention will be described with reference to the drawings. Each of the embodiments is described with a light source as an LED element, but the light source is not limited to the LED element and other semiconductor light emitting elements may be used. The structure shown in each figure below is merely an example, and various design changes can be made within a scope having similar functions. 
     [First Embodiment] 
       FIGS. 1A and 1B  show a schematic structure of an illumination device of a first embodiment.  FIG. 1A  is a front view and  FIG. 1B  is a top view of a light source portion. 
     The illumination device  1  includes a lens dome  11  with a scattering material, a light reflection cover  13 , a fluorescent-substance plate  15 , a fluorescent-substance plate moving gear  16 , an LED light source  17 , an adjustment gear  19 , a case unit  21 , a resin plate  23 , and a cap  28 . The case unit  21  has a configuration of covering a main body unit, and also serves as a heat dissipating unit in the present embodiment. In both of  FIGS. 1A and 1B , all members are not illustrated for the convenience of illustration. The fluorescent-substance plate moving gear  16  corresponds to a “first gear” and the adjustment gear  19  corresponds to a “second gear”. 
     The LED light source  17  (corresponding to “light emitting element light source”) is mounted on a ceramic substrate substantially at a central part of the resin plate  23 . By way of example, the LED light source  17  is realized by arranging, in parallel, three rows of series circuits, each having twenty blue LED elements connected in series, which size is 15 mm×12 mm. The periphery of the circuit is surrounded with a resin dam, and a translucent resin is filled into the resin dam so as to cover the blue LED elements. 
     The light reflection cover  13  has a function of preventing attenuation of light in the lens dome  11  and adjusting the light emitting color. 
     The fluorescent-substance plate moving gear  16  is rotatably movable in a clockwise direction or a counterclockwise direction with a fixing shaft  18  as a center. The gear  16  is physically integrated with the fluorescent-substance plate  15  by the fixing shaft  18 . That is, when the gear  16  rotates in the clockwise direction, the fluorescent-substance plate  15  also rotates therewith in the clockwise direction with the fixing shaft  18  as the center, whereas when the gear  16  rotates in the counterclockwise direction, the fluorescent-substance plate  15  also rotates therewith in the counterclockwise direction with the fixing shaft  18  as the center. In the present embodiment, the fluorescent-substance plate  15  and the fluorescent-substance plate moving gear  16  serve as a “variable color fluorescent-substance unit”. 
     The fixing shaft  18  is positioned not at the center position but slightly near the end on the fluorescent-substance plate  15 . 
     The fluorescent-substance plate  15  has a configuration in which the color of the applied fluorescent substance differs according to the position, and the color of the light radiated from the illumination device  1  to the outside changes when the relative positional relationship between the color distribution and the LED light source  17  changes. The fluorescent-substance plate  15  is accommodated on the inner side of the case unit  21 , and does not project to the outer side of the case unit  21 . In the figure, the fluorescent-substance plate  15  has an oval shape, but the fluorescent-substance plate  15  may have any shape. 
     The adjustment gear  19  partially projects to the outer side of the case unit  21  so as to be manually operable from the outside. The adjustment gear  19  is arranged such that part of the irregularities thereof meshes with (gears with) part of the irregularities of the fluorescent-substance plate moving gear  16 . When the adjustment gear  19  rotates in the clockwise direction or the counterclockwise direction, the meshing position of the both gears shifts and the fluorescent-substance plate moving gear  16  rotates in the direction opposite to the adjustment gear  19 . Then, the fluorescent-substance plate  15  also rotates and moves therewith (in direction of arrow D 1 ). The relative positional relationship between the LED light source  17  and the color distribution on the fluorescent-substance plate  15  thus can be changed. In the present embodiment, the adjustment gear  19  serves as a “toning adjusting unit”. 
     The fluorescent-substance plate  15  realizes the change in color distribution according to the position by changing the mixing ratio of the fluorescent substance according to the area. For example, two types of fluorescent substances, Ca 3 (Sr,Mg)2Si 3 O 12 :Ce (cerium added fluorescent substance) and fluorescent substance (Sr,Ca)AlSiN 3 :Eu (europium added fluorescent substance) are used, and the mixing ratio thereof is changed to change the light emitting color. 
     According to another example, the fluorescent-substance plate  15  can be realized by simply increasing/decreasing the content of fluorescent substance in one direction to give gradation. The light emitting efficiency and the brightness of the present illumination device  1  can be adjusted by changing the content of yellow fluorescent substance and changing the fluorescent-substance amount of the fluorescent-substance plate  15  through which the radiated light from the LED light source  17  passes. Similar adjustment may be made by changing the content of the red fluorescent substance and the green fluorescent substance. In this case, adjustment that places a great significance on the color rendering properties may be carried out. 
     When the adjustment gear  19  is rotated in the clockwise direction in such a state, the relative positional relationship between the LED light source  17  and the color distribution on the fluorescent-substance plate  15  changes, and as a result, the color of light radiated from the illumination device  1  can be changed in the order of “daylight color”→“neutral white color”→“white color”→“incandescent lamp color”. Furthermore, when the adjustment gear  19  is rotated in the counterclockwise direction, the color of the radiated light from the illumination device  1  can be changed in the reverse order. 
     According to the configuration of the present embodiment, since only one portion of the adjustment gear  19  projects to the outside of the case unit  21 , moisture and dust are not attached to the surface of the fluorescent-substance plate  15  that realizes the toning function. 
     Furthermore, only the blue LED element needs to be mounted as the constituent light emitting element of the present embodiment, and the toning function can be realized by manually rotating the adjustment gear  19 . Thus, the manufacturing cost is greatly reduced compared to the LED illumination device in which a plurality of LED elements having different light emitting colors are mounted and each LED element electrically adjusts the luminance of the arrangement to realize the dimming and toning function. 
     When the LED light source is manufactured, the LED element is generally covered with translucent resin containing fluorescent substance, but chromaticity may shift or vary at this time. Even if the chromaticity shifts or varies, the translucent resin cannot be removed to reuse the LED element, and hence a relatively expensive LED element becomes a waste. 
     As described above, in the case of the illumination device in which a plurality of LED elements having different light emitting colors are mounted and luminance of each LED element is made different to carry out toning, when the chromaticity of each LED element shifts or varies, this directly influences the radiated light from the illumination device. As a result, the device is considered to be defective. On the other hand, in the case of the configuration of the present embodiment, since only the blue LED element is mounted as the light emitting element and the toning function is realized by the fluorescent-substance plate  15 , the illumination device that correctly exhibits the toning function can be realized by managing the fluorescent-substance plate  15 , and the defective rate of the device can be lowered. 
     According to a modification of the present embodiment, an illumination device having a dimming function in addition to the toning function is realized by including a light reducing plate  22 , a light reducing plate moving gear  24 , and an adjustment gear  20 , in addition to the fluorescent-substance plate  15  (see  FIG. 2 ). The light reducing plate  22  and the light reducing plate moving gear  24  correspond to a “dimming unit”, and the adjustment gear  20  corresponds to a “dimming adjusting unit”. 
     Similarly to the case of the fluorescent-substance plate  15 , the light reducing plate  22  is integrated with the light reducing plate moving gear  24  with a fixing shaft  26 , so that when the adjustment gear  20  is rotated, the light reducing plate moving gear  24  rotates therewith in the opposite direction with the fixing shaft  26  as the center. The light reducing plate  22  also rotates with the rotation of the light reducing plate moving gear  24 . The light reducing plate  22  and the light reducing plate moving gear  24  are completely positioned on the inner side of the case unit  21 , and the adjustment gear  20  is partially projected to the outer side of the case unit  21 . 
     When the relative positional relationship between the light reducing plate  22  and the LED light source  17  changes, the region in which the light is blocked by the light reducing plate  22  increases, and as a result, the amount of light radiated from the illumination device  1  to the outside is reduced. Therefore, by touching the portion of the adjustment gear  20  projected to the outer side and rotating the adjustment gear  20 , the amount of light radiated from the illumination device  1  is adjusted and the dimming function is realized. The light reducing plate  22  may have a configuration provided with gradation such that the transmissivity changes according to the area on the plate, whereby the dimming function is realized. 
     In  FIG. 2 , the adjustment gear  20  is provided on the side opposite to the adjustment gear  19 , but the adjustment gear  20  may be shifted in the vertical direction on the same side as the adjustment gear  19 . 
     According to another modification, a plurality of fluorescent-substance plates  15  having different color modes may be arranged. This enables fine toning. In this case, in order to rotate the respective fluorescent-substance plates  15 , the adjustment gear is required for each fluorescent-substance plate  15 . 
     [Second Embodiment] 
     In the present embodiment and the embodiments described below, only the aspect different from the first embodiment will be described, and the description on the common aspect will be omitted. 
     The present embodiment and the embodiments described below differ from the first embodiment in terms of the specific structure of the variable color fluorescent-substance unit and the toning adjusting unit. 
     In comparison with the illumination device  1  of the first embodiment, an illumination device la of the present embodiment has a configuration including a fluorescent-substance accordion  31  in place of the fluorescent-substance plate  15 , and an adjustment lever  29  in place of the adjustment gear  19 . In the present embodiment, the fluorescent-substance accordion  31  serves as the “variable color fluorescent-substance unit”, and the adjustment lever  29  serves as the “toning adjusting unit”. 
     The fluorescent-substance accordion  31  is configured by a plurality of small regions that can be folded into a fan-shape, and the small regions of the fluorescent-substance accordion  31  can be folded or the folded small regions can be opened by moving the adjustment lever  29  in the horizontal direction. Also in the present embodiment, the different color distributions corresponding to the area are realized by making the mixing ratios of the fluorescent substances differ according to each area in a state where the fluorescent-substance accordion  31  is opened. 
     In other words, when the toning is performed, the adjustment lever  29  is moved to open the fluorescent-substance accordion  31 , and the relative positional relationship between the LED light source  17  and the color distribution on the fluorescent-substance accordion  31  is changed. When the toning is not performed, the adjustment lever  29  is moved to completely close the fluorescent-substance accordion  31 . Accordingly, a fluorescent-substance accommodating region at the time of not performing toning thus can be reduced as compared to the case of the first embodiment, and the illumination device la can be reduced in size. 
     Also in the present embodiment, a configuration may be adopted in which a light reducing accordion (corresponding to “dimming unit”) for dimming and an adjustment lever (corresponding to “dimming adjusting unit”) for folding and opening the light reducing accordion are separately and additionally arranged. A plurality of fluorescent-substance accordions having different color distributions may be arranged. In such a case, the adjustment lever for operating the accordion may be provided as many as the number of accordions. 
     In the present embodiment, the adjustment lever  29  is moved in the horizontal direction, but the moving direction of the adjustment lever  29  is not limited to the horizontal direction as long as the accordion can be opened and folded by the movement of the adjustment lever  29 . 
     [Third Embodiment] 
       FIGS. 4A and 4B  show a schematic structure of an illumination device of a third embodiment.  FIG. 4A  is a front view and  FIG. 4B  is a top view of a light source portion. 
     In comparison with the first embodiment, an illumination device lb of the present embodiment includes, in place of the fluorescent-substance plate  15 , a (external gear-shaped) fluorescent-substance plate  41  having a substantially circular plate shape and having gear-shaped irregularities on the outer peripheral portion. Moreover, an adjustment ring  43  that can be rotated in the clockwise direction or the counterclockwise direction is arranged in place of the adjustment gear  19 . The adjustment ring  43  is arranged to be positioned on the outer periphery of the main body at a lower side position of the lens dome  11 . In the present embodiment, the fluorescent-substance plate  41  serves as the “variable color fluorescent-substance unit”, and the adjustment ring  43  serves as the “toning adjusting unit”. 
     The adjustment ring  43  has a (internal gear-shaped) circular ring-shaped structure with gear-shaped irregularities on the inner peripheral portion, and is arranged such that the irregularities mesh with the irregularities of the fluorescent-substance plate  41 , that is, the internal teeth of the adjustment ring  43  mesh with the external teeth of the fluorescent-substance plate  41 . That is, when the adjustment ring  43  is rotated in the D 3  direction, the fluorescent-substance plate  41  also rotates therewith. Similarly to the fluorescent-substance plate  15  of the first embodiment, the fluorescent-substance plate  41  may also realize different color distributions according to the area by making the mixing ratio of the fluorescent substances differ according to each area. 
     According to the present embodiment, the fluorescent-substance plate  41  rotates by rotating the adjustment ring  43 , so that the relative positional relationship between the LED light source  17  and the color distribution on the fluorescent-substance plate  41  changes, whereby the toning function can be exhibited. Since the fluorescent-substance plate  41  is completely accommodated in the case unit  21 , moisture and dust are not attached to the surface. 
     Also in the present embodiment, a plate (light reducing plate)  42  for realizing the dimming function may be arranged (see  FIG. 5 ). In this case, an adjustment ring  44  for rotating the light reducing plate  42  is arranged separately from the adjustment ring  43 . In this case, the light reducing plate  42  corresponds to the “dimming unit” and the adjustment ring  44  corresponds to the “dimming adjusting unit”. 
     Alternatively, a plurality of fluorescent-substance plates  41  having different color distributions may be arranged. In this case as well, the adjustment ring  43  may be arranged according to the number of fluorescent-substance plates  41 . 
     [Fourth Embodiment] 
       FIGS. 6A and 6B  show a schematic structure of an illumination device of a fourth embodiment.  FIG. 6A  is a front view and  FIG. 6B  is a top view of a light source portion. 
     In comparison with the first embodiment, an illumination device  1   c  of the present embodiment includes a fluorescent-substance roll  51  in place of the fluorescent-substance plate  15 . Furthermore, an adjustment screw  53  is arranged in place of the adjustment gear  19 . A winding unit  54  for coupling the adjustment screw  53  and the fluorescent-substance roll  51  is also arranged. In the present embodiment, the fluorescent-substance roll  51  serves as the “variable color fluorescent-substance unit”, and the adjustment screw  53  and the winding unit  54  serve as the “toning adjusting unit”. 
     The fluorescent-substance roll  51  and the winding unit  54  are arranged on the inner side of the case unit  21 . The adjustment screw  53  is partially projected to the outer side of the case unit  21  so as to be manually operable. 
     When the adjustment screw  53  is rotated, the winding unit  54  also rotates with such rotation, and the fluorescent-substance roll  51  is moved therewith in the D 4  direction to be wound like a roll screen. As a result, the relative positional relationship between the LED light source  17  and the color distribution on the fluorescent-substance roll  51  changes. The fluorescent-substance roll  51  is similar to the above embodiments in terms of the manner of changing of the color distribution except that the changing direction thereof is in the D 4  direction. 
     By way of example, the mixing ratio of the cerium added fluorescent substance and the europium added fluorescent substance is &lt;&lt;1.1:1&gt;&gt; in the “daylight color” region, &lt;&lt;2:1&gt;&gt; in the “neutral white color” region, &lt;&lt;4:1&gt;&gt; in the “white color” region, and &lt;&lt;5:1&gt;&gt; in the “incandescent lamp color” region, and the mixtures of fluorescent substances in which the mixing ratio is changed in such a manner are successively mixed to silicon resin in this order. Thus, when the adjustment screw  53  is rotated, change can be made in the order of (or in the reverse order of) “daylight color”→“neutral white color”→“white color”→“incandescent lamp color”. An Ra value (average color rendering index) in such a configuration is about  90 . 
     According to the present embodiment, the fluorescent-substance roll  51  moves in the D 4  direction by rotating the adjustment screw  53 , so that the relative positional relationship between the LED light source  17  and the color distribution on the fluorescent-substance roll  51  changes, whereby the toning function can be exhibited. Since the fluorescent-substance roll  51  is completely accommodated in the case unit  21 , moisture and dust are not attached to the surface. 
     In the present embodiment, a configuration which further includes a light reducing roll  57  for dimming may be adopted as a configuration capable of realizing the toning and dimming function (see  FIG. 7 ). The configuration shown in  FIG. 7  includes a light reducing roll  57  that moves in a D 5  direction in addition to the fluorescent-substance roll  51  that moves in the D 4  direction. A winding unit  56  for winding the light reducing roll  57  and an adjustment screw  55  are also arranged. The light reducing roll  57  corresponds to the “dimming unit” and the adjustment screw  55  and the winding unit  56  correspond to the “dimming adjusting unit”. When the adjustment screw  55  is rotated to change the relative positional relationship between the light reducing functioning portion of the light reducing roll  57  and the LED light source  17 , the dimming function is realized. The toning and dimming function can be realized by rotating both of the adjustment screws  53  and  55 . In  FIG. 7 , only the top view of the light source portion is shown for the sake of convenience of illustration. 
     A plurality of fluorescent-substance rolls  51  having different color distributions may be adopted. 
     [Fifth Embodiment] 
       FIGS. 9A and 9B  show a schematic structure of an illumination device of a fifth embodiment.  FIG. 9A  is a front view and  FIG. 9B  is a top view of a light source portion. 
     In comparison with the first embodiment, an illumination device ld of the present embodiment is a spotlight type device and includes a flat-shaped lens  11   a  in place of the lens dome  11 . Similarly to the third embodiment, the illumination device ld of the present embodiment includes, in place of the fluorescent-substance plate  15 , a (external gear-shaped) fluorescent-substance plate  41  having a substantially circular plate shape and having gear-shaped irregularities on the outer peripheral portion. An adjustment ring  43  that can be rotated in the clockwise direction or the counterclockwise direction is arranged in place of the adjustment gear  19 . The configuration of the adjustment ring  43  and the fluorescent-substance plate  41  is the same as the third embodiment. 
     According to the present embodiment, the fluorescent-substance plate  41  rotates by rotating the adjustment ring  43 , so that the relative positional relationship between the LED light source  17  and the color distribution on the fluorescent-substance plate  41  changes, whereby the toning function can be exhibited. Since the fluorescent-substance plate  41  is completely accommodated in the case unit  21   a , moisture and dust are not attached to the surface. 
     Also in the present embodiment, a plate (light reducing plate  42 ) for realizing the dimming function may be arranged (not shown). A plurality of fluorescent-substance plates  41  having different color distributions may also be arranged. In this case as well, the adjustment ring  43  may be arranged according to the number of fluorescent-substance plates  41 . 
     According to each of the configurations of the embodiments described above, the fluorescent substance for realizing the dimming function can be completely accommodated on the inner side of the case unit  21 . Thus, even if a sealing mechanism or the like is not separately arranged, moisture and dust do not intrude into the fluorescent substance to degrade the toning function. 
     In all of the embodiments described above, a general light bulb type structure has been illustratively described, but it can be similarly realized with structures of other shapes such as ball type, spotlight type, midget reflector type, chandelier type, and the like. In any of the structures, as long as the variable color fluorescent-substance unit (fluorescent-substance plate  15 , fluorescent-substance accordion  31 , fluorescent-substance plate  41 , fluorescent-substance roll  51 ) is formed so as not to project to the outer side of the case unit  21 , and the adjustment unit (adjustment gear  19 , adjustment lever  29 , adjustment ring  43 , adjustment screw  53 ) for changing the relative positional relationship between the color distribution of the fluorescent substance applied on the variable color fluorescent-substance unit and the light source is arranged, and an end of the adjustment unit positioned on the side opposite to the variable color fluorescent-substance unit is projected to the outer side of the case unit  21  so as to be easily operable, the structures are all within the assumed scope of the present invention. 
     EXPLANATION OF REFERENCES 
     
         
           1 ,  1 a,  1   b ,  1   c:  Illumination Device of the present invention 
           11 : Lens Dome 
           11   a:  Lens 
           13 : Light Reflection Cover 
           15 : Fluorescent-substance Plate 
           16 : Fluorescent-substance Plate Moving Gear 
           17 : LED Light Source 
           18 : Fixing Shaft 
           19 : Adjustment Gear 
           20 : Adjustment Gear 
           21 : Case Unit 
           21   a:  Case Unit 
           22 : Light Reducing Plate 
           23 : Resin Plate 
           24 : Light Reducing Plate Moving Gear 
           26 : Fixing Shaft 
           28 : Cap 
           29 : Adjustment Lever 
           31 : Fluorescent-substance Accordion 
           41 : Fluorescent-substance Plate 
           42 : Light Reducing Plate 
           43 : Adjustment Ring 
           44 : Adjustment Ring 
           51 : Fluorescent-substance Roll 
           53 : Adjustment Screw 
           54 : Winding Unit 
           55 : Adjustment Screw 
           56 : Winding Unit 
           57 : Light Reducing Roll 
           101 : Conventional Illumination Device 
           102 : Rotation Plate 
           103 : Fluorescent-substance Sheet 
           104 : Shaft 
           105 : LED Element 
           106 : Case