Multifaceted mirror and assembly fixture and method of making such mirror

A method of making a multifaceted scanning mirror rotatable on an axis to direct light along a scanning path, said mirror being formed of a plurality of individual mirrors secured to a single piece support element to form a plurality of faces, and said method comprising:

• a. making said plurality of individual mirrors the same size and mass with plane outer surfaces to form said mirror faces;
• b. coating said outer faces of said individual mirrors uniformly and simultaneously with an optical coating;
• c. by using an assembly fixture with surfaces that establish positions for said outer faces of said individual mirrors and by placing said individual mirrors against said fixture surfaces, positioning each outer face of each of said individual mirrors accurately at predetermined angles to each other, at the same predetermined angle to said mirror axis, and at equal radii from said axis;
• d. using vacuum to hold said individual mirrors against said fixture surfaces in said accurate positions;
• e. fitting an axial hole on a centering pin of said fixture to locate a support element within said positioned individual mirrors so that faces of said support element are spaced uniformly from inner faces of said individual mirrors, and said support element is symmetrical and balanced for high speed rotation on said mirror axis;
• and
• f. filling gaps between said support element faces and said inner faces of said individual mirrors with a cement that bonds said individual mirrors securely to said support element faces while said individual mirrors are held accurately in said positions, said cement being uniformly distributed and balanced for high speed rotation on said mirror axis.

A fixture for assembling multifaceted mirrors having a plurality of faces disposed in respective planes that are angled relative to each other, said fixture comprising:

• a. a base having a plurality of faces corresponding with the faces of said multifaceted mirror, each face of said base being accurately in the plane of a respective face of said multifaceted mirror;
• b. a plurality of locator blocks corresponding to said faces of said base and said multifaceted mirror, each of said locator blocks having a mounting surface for removably engaging one of said faces of said base and a mirror support surface in the plane of said mounting surface and extending beyond said base;
• c. means for removably securing said locator blocks to respective faces of said base;
• d. means for removably securing a plurality of individual mirrors respectively to said support surfaces of said locator blocks to position said individual mirrors at the faces of said multifaceted mirror;
• and
• e. means on said base for receiving and holding a support element positioned adjacent said individual mirrors so said individual mirrors can be cemented to said support element while secured to said locator blocks to form said multifaceted mirror.

A multifaceted mirror having a plurality of faces disposed in respective planes that are angled relative to each other, said mirror comprising:

• a. a single-piece support element having faces corresponding to the faces of said multifaceted mirror;
• b. a plurality of individual mirrors, each individual mirror being spaced from a respective face of said support element;
• c. cement securing each of said individual mirrors to said respective face of said support element in an accurate position that is independent of said face of said support element;
• d. said individual mirrors being arranged with clearance space between each of said individual mirrors;
• e. said support element having retainer slots between each face of said support element;
• and
• f. trim strips secured in each of said retainer slots to extend between each of said individual mirrors.

A multifaceted scanning mirror rotatable on an axis to direct light along a scanning path, said mirror being formed of a plurality of individual mirrors secured to a single piece support element to form a plurality of faces, and said mirror comprising:

• a. said support element having a shaft-receiving central opening accurately concentric with and aligned with said axis;
• b. said support element being generally symmetrical and balanced for high speed rotation on said axis;
• c. said support element having faces corresponding to and generally parallel with said mirror faces and disposed radially toward said axis from said mirror faces;
• d. said individual mirrors having uniform optical coatings and having the same size and mass;
• e. each of said individual mirrors having plane inner surfaces equally spaced from and generally parallel with a respective face of said support element;
• f. each of said individual mirrors having plane outer surfaces forming said mirror faces and accurately disposed at predetermined angles to each other, at the same predetermined angle to said axis, and at equal radii from said axis in positions that are independent of said faces of said support element;
• g. cement securing said inner faces of said individual mirrors to respective faces of said support element;
• and
• h. said cement uniformly filling the spaces between said inner faces of said individual mirrors and said faces of said support element and being balanced for said high speed rotation on said axis.