Microform reader

In a microform reading apparatus of the type which projects a magnified image of a film frame onto a viewing screen and which includes a light source, a condensing lens, a film holder, and a projection assembly including a projecting lens and a plurality of mirrors for projecting the magnified image onto the back side of a viewing screen to provide front viewing of the displayed image, the improvement of an adjustable mirror assembly for maximizing the light delivered to the projection lens to optimize the brightness of the displayed image comprising:

• a mirror positioned in between the light source and the condensing lens and having a major reflecting surface for reflecting the light provided by the light source to the condensing lens;
• a universal mount comprising first and second members, said second member having a mirror holder at one end for holding said mirror, said first member being pivotable about a first axis, said second member being pivotably mounted to said first member to thereby pivot about a second axis which is perpendicular to said first axis whereby said mirror has freedom of arcuate movement about said first and second perpendicular axes;
• a first eccentric cam having a cam surface abutting said first member and being rotatable to thereby cause said mirror to move about said first axis as said first cam rotates;
• a second eccentric cam having a cam surface abutting said mirror of said second member and being rotatable to thereby cause said mirror to move about said second axis as said second cam rotates;
• and
• means for holding said first and second surfaces in constant abutmemt relation to said first member and said mirror holder respectively to thereby hold said mirror in a fixed position about said first and second axes.

In a microform reader apparatus of the type which projects a magnified image of a film frame image onto a viewing screen and which includes a light source, a condensing lens, a film holder and a projection system including a plurality of mirrors for projecting the magnified image onto the viewing screen, the improvement of an adjustable lens assembly which allows the optical axis of the lens assembly to be adjusted for perpendicularly to the image frame surface comprising:

• a generally cylindrical lens holder assembly having a major center axis for holding at least one projection lens having a center optical axis in a predisposed relation such that said major axis and said optical axis substantially coincide, said lens holder assembly comprising a lens holder cylinder for holding said lens, an outer lens cylinder dimensioned for receiving and holding said lens holder cylinder, and a cylindrical sleeve dimensioned for receiving said outer lens cylinder in radially spaced relation for allowing focusing movement of said outer lens cylinder;
• a generally cylindrical first adjustment ring dimensioned for receiving said lens holder assembly and having a continuous circumferential flange having an upper surface and a ramped under surface;
• said cylindrical sleeve comprising a circumferential flange communicating with said upper surface of said first ring flange for holding said lens holder assembly in fixed relation to said first ring;
• and
• a second adjustment ring dimensioned for receiving said first adjustment ring and having an inner circumferential ramped surface portion communicating with said ramped under surface.