Method of manufacturing reflective mirror, illumination device, and projector

Abstract

A reflective mirror manufacturing method for manufacturing a reflective mirror used in an illumination device including an arc tube including a light-emitting portion and a reflective mirror including a reflective surface that reflects light from the light-emitting portion in a predetermined direction, includes: a first step of forming a tube by heating a tube including a material of the reflective mirror, thereafter putting the tube in a form block, applying internal pressure with an inert gas to cause a center portion of the tube to expand, so that part of an inner surface of the expanded center portion includes a shape corresponding to the reflective surface of the reflective mirror; a second step of cutting the tube at the center portion to form a reflective mirror member; and a third step of forming a reflective layer on an inner surface of the reflective mirror member.

1. A method for manufacturing a reflective mirror manufacturing method for manufacturing a reflective mirror  used in an illumination device including an arc tube including  having a light-emitting portion and a reflective mirror including  having a reflective surface that reflects light from the light-emitting portion in a predetermined direction, the method comprising:
 a first step of formingheating a tube by heating a tube includingcomprising a material of the reflective mirror, thereafter putting the tube in a form block,  
 applying internal pressure with an inert gas to cause a center portion of the tube to expand, so that part of an inner surface of the expanded center portion includes a shape corresponding to the reflective surface of the reflective mirror; the expanded center portion being continuous with a part of a tube portion that includes a shape corresponding to a fixing portion where the arc tube is fixed to the reflective mirror;  
 a second step of  cutting the tube at the expanded center portion to form a reflective mirror member; and  
 a third step of  forming a reflective layer on an inner surfacethe reflective surface of the reflective mirror member.  
 
     
     
       2. The reflective mirror manufacturing method of  method according to  claim 1 , further including  comprising:
 in the first step,  forming the tube so that it has a shape where two reflective mirror members mutually face each other, when the center portion of the tube expands by applying internal pressure with an inert gas, and  
 in the second step,  forming the two reflective mirror members, when the tube cutting at the expanded center portion.  
 
     
     
       3. The reflective mirror manufacturing method of  method according to  claim 1 , the reflective mirror being a reflective mirror disposed with an effective reflective surface in a range from a portion of at least 40° with respect to an optical axis of the reflective mirror, using a light emission center of the light-emitting portion as a reference, to an open end portion of the reflective mirror. 
     
     
       4. An illumination device, comprising:
 an arc tube including a light-emitting portion; and  
 a reflector including a reflective surface without mold marks that reflects light from the light-emitting portion in a predetermined direction, the reflector being a reflector manufactured by a reflector manufacturing method comprising:  
 a first step of formingheating a tube by heating a tube includingcomprising a material of the reflector, thereafter putting the tube in a form block,  
 applying internal pressure with an inert gas to cause a center portion of the tube to expand, so that part of an inner surface of the expanded center portion includes a shape corresponding to the reflective surface of the reflector; the expanded center portion being continuous with a part of a tube portion that includes a shape corresponding to a fixing portion where the arc tube is fixed to the reflector;  
 a second step of  cutting the tube at the expanded center portion to form a reflector member; and  
 a third step of  forming a reflective layer on an inner surfacethe reflective surface of the reflector member.  
 
     
     
       5. A projector, comprising:
 thean illumination optical system including the illumination device of  claim 4 ;  
 an electro-optical modulation device that modulates light from the illumination optical system in accordance with image information; and  
 a projection optical system that projects the light modulated by the electro-optical modulation device.  
 
     
     
       6. The illumination device of  according to  claim 4 , the reflector being a reflector manufactured by the reflector manufacturing method where
 in the first step,  forming the tube so that it has a shape where two reflector members mutually face each other, when the center portion of the tube expands by applying internal pressure with an inert gas, and  
 in the second step,  forming the two reflector members, when the tube cutting at the expanded center portion.  
 
     
     
       7. A projector, comprising:
 an illumination optical system including the illumination device of  claim 6 ;  
 an electro-optical modulation device that modulates light from the illumination optical system in accordance with image information; and  
 a projection optical system that projects the light modulated by the electro-optical modulation device.  
 
     
     
       8. The illumination device of  according to  claim 4 , the reflector being a reflector disposed with an effective reflective surface in a range from a portion of at least 40° with respect to an optical axis of the reflector, using a light emission center of the light-emitting portion as a reference, to an open end portion of the reflector. 
     
     
       9. A projector, comprising:
 an illumination optical system including the illumination device of  claim 8 ;  
 an electro-optical modulation device that modulates light from the illumination optical system in accordance with image information; and  
 a projection optical system that projects the light modulated by the electro-optical modulation device.  
 
     
     
       10. An illumination device, comprising:
 an arc tube including a light-emitting portion;  
 a reflector including a reflective surface without mold marks that reflects light from the light-emitting portion to an illuminated region; and  
 an auxiliary mirror that is disposed facing the reflector with the light-emitting portion sandwiched therebetween, the auxiliary mirror including a reflective surface without mold marks and which reflects part of the light emitted from the light-emitting portion towards the light-emitting portion, the auxiliary mirror being an auxiliary mirror manufactured by an auxiliary mirror manufacturing method including  comprising:  
 a first step of formingheating a tube by heating a tube includingcomprising a material of the auxiliary mirror, thereafter putting the tube in a form block,  
 applying internal pressure with an inert gas to cause a center portion of the tube to expand, so that part of an inner surface of the expanded center portion includes a shape corresponding to the reflective surface of the auxiliary mirror, the expanded center portion being continuous with a part of a tube portion that includes a shape corresponding to a fixing portion where the arc tube is fixed to the auxiliary mirror;  
 a second step of  cutting the tube at the expanded center portion to form an auxiliary mirror member; and  
 a third step of  forming a reflective layer on an inner surfacethe reflective surface of the auxiliary mirror member.  
 
     
     
       11. A projector, comprising:
 an illumination optical system including the illumination device of  claim 10 ;  
 an electro-optical modulation device that modulates light from the illumination optical system in accordance with image information; and  
 a projection optical system that projects the light modulated by the electro-optical modulation device.  
 
     
     
       12. The illumination device of  according to  claim 10 , the auxiliary mirror being an auxiliary mirror manufactured by the auxiliary mirror manufacturing method where
 in the first step,forming the tube is formed  so that it has a shape where two auxiliary mirror members mutually face each other, when the center portion of the tube expands by applying internal pressure with an inert gas, and  
 in the second step,forming the two auxiliary mirror members are formed, when the tube cutting at the expanded center portion.  
 
     
     
       13. A projector, comprising:
 an illumination optical system including the illumination device of  claim 12 ;  
 an electro-optical modulation device that modulates light from the illumination optical system in accordance with image information; and  
 a projection optical system that projects the light modulated by the electro-optical modulation device.  
 
     
     
       14. The illumination device of  according to  claim 10 , the auxiliary mirror being an auxiliary mirror disposed with an effective reflective surface in a range from a portion of at least 40° with respect to an optical axis of the auxiliary mirror, using a light emission center of the light-emitting portion as a reference, to an open end portion of the auxiliary mirror. 
     
     
       15. A projector, including  comprising:
 an illumination optical system including the illumination device of  claim 14 ;  
 an electro-optical modulation device that modulates light from the illumination optical system in accordance with image information; and  
 a projection optical system that projects the light modulated by the electro-optical modulation device.  
 
     
     
       16. The illumination device of  according to  claim 10 , the reflector being a reflector manufactured by a reflector manufacturing method including  comprising:
 a first step of forming aheating a tube by heating a tube includingcomprising a material of the reflector, thereafter putting the tube in a form block,  
 applying internal pressure with an inert gas to cause a center portion of the tube to expand, so that part of an inner surface of the expanded center portion includes a shape corresponding to the reflective surface of the reflector, the expanded center portion being continuous with a part of a tube portion that includes a shape corresponding to a fixing portion where the arc tube is fixed to the reflector;  
 a second step of  cutting the tube at the expanded center portion being continuous with a part of a tube portion that includes a shape corresponding to a fixing portion where the arc tube is fixed to the reflector;  
   cutting the tube at the expanded center portion  to form a reflector member; and  
 a third step of  forming a reflective layer on an inner surfacethe reflective surface of the reflector member.  
 
     
     
       17. A projector, comprising:
 an illumination optical system including the illumination device of  claim 16 ;  
 an electro-optical modulation device that modulates light from the illumination optical system in accordance with image information; and  
 a projection optical system that projects the light modulated by the electro-optical modulation device.