Optical module
An optical module is formed of a first optical block and a second optical block each equipped with a lens the optical axis of which needs to be aligned, the blocks being positioned and secured to each other, and has stepwise positioning means. A positioning means includes spring pieces each having an abutting slope, and edges. Four spring pieces are formed in the second optical block such that their abutting slopes are disposed at four corners of the second optical block. Positioning is implemented when the abutting slopes meet the edges of the first optical block. Another positioning means includes a depressed part and a guide slope formed in one of the two optical blocks and a raised part formed in the other optical block. The raised part is fitted into the depressed part.
1. An optical module comprising a first optical block having a first lens and a second optical block having a second lens, wherein
the first optical block is combined with the second optical block;
the first optical block includes four ridge-like portions;
the second optical block includes four rod-like spring portions disposed in a same extension direction, four protrusions peaking toward the first optical block, and four slopes disposed on a same plane and parallel to the extension direction;
each of the four rod-like spring portions has, at a distal end portion thereof, a corresponding one of the four protrusions and a corresponding one of the four slopes which is formed on the corresponding one of the four protrusions;
the four rod-like spring portions are positioned such that the four slopes are positioned in a vicinity of four corners of the second optical block;
one of the four slopes and another of the four slopes, which constitute a first pair, are situated in a mirror-image symmetry;
one of remaining two slopes and another of the remaining two slopes, which constitute a second pair, are situated in a mirror-image symmetry;
one of the first optical block and the second optical block has a raised part, and another of the first optical block and the second optical block has a depressed part into which the raised part is fitted, and a guide slope which guides the raised part into the depressed part;
the guide slope is parallel to a direction that is orthogonal to the extension direction and is orthogonal to a facing direction in which the first optical block and the second optical block face to each other;
the first optical block and the second optical block are configured respectively such that a), in a course of combining the first optical block and the second optical block, the four ridge-like portions make contact with the four slopes before the raised part makes contact with the guide slope, and b), subsequent to contact of the four ridge-like portions with the four slopes, the raised part makes contact with the guide slope after curving first two of the four rod-like spring portions and curving second two of the four rod-like spring portions by pressing one of the first optical block and the second optical block to another of the first optical block and the second optical block, the first two of the four rod-like spring portions including said first pair and the second two of the four rod-like spring portions including said second pair; and
the first lens is aligned optically with the second lens at least by going through the contact of the four ridge-like portions with the four slopes and contact of the raised part with the guide slope.
2. The optical module according to claim 1 , wherein,
the first optical block and the second optical block are configured respectively such that c), when the second optical block is parallel placed over the first optical block in the course of combining the first optical block and the second optical block, a distance in the facing direction between a top face of the raised part and a plane including an opening of the depressed part is larger than a distance in the facing direction between the four ridge-like portions and portions of the four slopes directly above the four ridge-like portions.
3. The optical module according to claim 2 , wherein
one of the first optical block and the second optical block has a guide pin, and another of the first optical block and the second optical block has a notch into which the guide pin is inserted; and
the first optical block and the second optical block are configured respectively such that d), in the course of combining the first optical block and the second optical block, the guide pin is inserted into the notch before the contact of the four ridge-like portions with the four slopes.
4. The optical module according to claim 2 , wherein
one of the first optical block and the second optical block has a long cut, and another of the first optical block and the second optical block has a long protruding part which is inserted into the long cut; and
the first optical block and the second optical block are configured respectively such that e), in the course of combining the first optical block and the second optical block, the long protruding part is inserted into the long cut before the contact of the four ridge-like portions with the four slopes.
5. The optical module according to claim 1 , wherein
one of the first optical block and the second optical block has a guide pin, and another of the first optical block and the second optical block has a notch into which the guide pin is inserted; and
the first optical block and the second optical block are configured respectively such that d), in the course of combining the first optical block and the second optical block, the guide pin is inserted into the notch before the contact of the four ridge-like portions with the four slopes.
6. The optical module according to claim 1 , wherein
one of the first optical block and the second optical block has a long cut, and another of the first optical block and the second optical block has a long protruding part which is inserted into the long cut; and
the first optical block and the second optical block are configured respectively such that e), in the course of combining the first optical block and the second optical block, the long protruding part is inserted into the long cut before the contact of the four ridge-like portions with the four slopes.
7. The optical module according to claim 1 , wherein
the four protrusions have lug portions; and
the lug portions each getting caught on a step part which the first optical block includes secure the first optical block to the second optical block.
8. The optical module according to claim 1 , wherein
the first lens is positioned at a top face of the raised part; and
the second lens is positioned at a bottom face of the depressed part.
9. The optical module according to claim 1 , wherein
the first optical block is mounted on a board equipped with an optical device; and
the second optical block has a structure for positioning and holding an optical fiber.