| 摘要 |
<P>PROBLEM TO BE SOLVED: To prevent outgassing generated from an adhesive from adhering to a lens. <P>SOLUTION: A lens barrel 25 is equipped with: first to third lenses 11-13; and a barrel body 41 housing each lens 11-13. The second lens 12 and the third lens 13 are bonded by the adhesive 43 using as bonding surfaces the convex surface 12a of the second lens 12 and the concave surface 13a of the third lens 13. Gaps are formed between the outer circumferential surface of each lens 12, 13 and the inner circumferential surface of the barrel body 41. An upper vent hole 41e and a lower vent hole 41f are formed approximately directly above and below the connection parts of the second and third lenses 12, 13 on the outer circumferential surface of a second diameter part 41b of the barrel body 41. The outgassing generated due to high temperatures of the adhesive 43 accompanying temperature increase of the second and third lenses 12, 13 through which image light passes is discharged outside of the lens barrel 25 through the gaps between the outer circumferential surface of each lens 12, 13 and the inner circumferential surface of the barrel body 41, and through each vent hole 41e, 41f. <P>COPYRIGHT: (C)2011,JPO&INPIT |
