Shape measuring method and apparatus using interferometer

A shape measuring apparatus using an interferometer, comprising:

• a light source;
• a condensing lens for condensing temporarily light waves from the light source;
• a light wave shaping plate in which a pinhole adapted to convert the condensed light waves into an ideal spherical wave and a window provided in the vicinity of the pinhole and adapted to pass therethrough the light wave surface information are formed;
• a mirror member having an optical surface becoming a reference surface for reflecting the light waves passed through the pinhole, and arranged in a position where the light waves reflected by the reference surface pass through the pinhole again;
• at least one lens having an optical surface becoming a surface to be measured, and arranged between the pinhole and the mirror member, adjusted in the position where the light waves reflected by the measurement surface pass through the window;
• and
• image pickup means for making the reflected light reflected by the reference surface to pass through the pinhole again and the reflected light reflected by the surface to be measured to pass through the window interfere with each other to measure a shape of the surface to be measured.

A shape measuring method using an interferometer for measuring a shape of a surface to be measured, the method comprising:

• preparing a light source, a condensing lens for condensing temporarily light waves from the light source, and a light wave shaping plate in which a pinhole adapted to convert the condensed light waves into an ideal spherical wave and a window provided in the vicinity of the pinhole and adapted to pass therethrough the light wave surface information are formed;
• arranging at least one lens having a reference surface and a surface to be measured the optical axes of which are decentered from each other in an optical path of the light waves passed through the pinhole;
• adjusting the lens in a position where the light waves reflected by the reference surface pass through the pinhole again, and the light waves reflected by the measurement surface pass through the window;
• and
• capturing the light waves obtained by making the reflected light reflected by the reference surface to pass through the pinhole again, and the reflected light reflected by the surface to be measured to pass through the window interfere with each other with image pickup means.

A shape measuring method using an interferometer for measuring a shape of a surface to be measured, the method comprising:

• preparing a light source, a condensing lens for condensing temporarily light waves from the light source, and a light wave shaping plate in which a pinhole adapted to convert the condensed light waves into an ideal spherical wave and a window provided in the vicinity of the pinhole and adapted to pass therethrough the light wave surface information are formed;
• arranging a mirror member having an optical reflecting surface for reflecting the light waves passed through the pinhole;
• arranging at least one lens having a surface to be measured the optical axis of which is decentered from the optical axis of other optical surface between the pinhole and the mirror member;
• adjusting the mirror member in a position where light is made incident perpendicularly to the optical reflecting surface and the reflected light waves pass through the pinhole again;
• and
• capturing the light waves obtained by making the reflected light reflected by the optical reflecting surface to pass through the pinhole again and the reflected light reflected by the surface to be measured to pass through the window interfere with each other with image pickup means.

A shape measuring apparatus using an interferometer for measuring a shape of a surface to be measured of a lens having an optical surface becoming a reference surface and an optical surface becoming the surface to be measured, the apparatus comprising:

• reversal means for reversing the lens;
• first measurement means for making light waves incident to the surface to be measured to make the reflected light from the reference surface and the reflected light from the surface to be measured interfere with each other to measure a shape of the surface to be measured,
• the first measurement means being adapted to measure, after reversing the lens, the surface to be measured from the opposite two directions;
• and
• arithmetic operation means for arithmetically operating a shape of the surface to be measured from the two measurement results provided by the first measurement means.

A shape measuring apparatus using an interferometer for measuring a shape of a surface to be measured of a lens having an optical surface becoming a reference surface and an optical surface becoming the surface to be measured, the apparatus comprising:

• second measurement means for making light waves incident from one direction of an optical axis of the surface to be measured to make the reflected light from the reference surface and the reflected light from the surface to be measured interfere with each other to measure a shape of the surface to be measured;
• third measurement means arranged opposite to the second measurement means for making light incident from an opposite direction of an optical axis of the surface to be measured to make the reflected light from the reference surface and the reflected light from the surface to be measured interfere with each other to measure a shape of the surface to be measured, the lens being arranged between the first measurement means and second measurement means;
• and
• arithmetic operation means for arithmetically operating the shape of the surface to be measured on the basis of the two measurement results provided by the second measurement means and third measurement means.

A shape measuring method using an interferometer for measuring a shape of a surface to be measured of a lens having an optical surface becoming a reference surface and an optical surface becoming the surface to be measured, the method comprising:

• carrying out first measurement of making light incident from one direction of an optical axis of the surface to be measured to make the reflected light from the reference surface and the reflected light from the surface to be measured interfere with each other to measure the shape of the surface to be measured with first measurement means having a light source, a condensing lens for condensing temporarily the light waves from the light source, and image pickup means for capturing the light waves obtained by making the reflected light reflected by the reference surface and the reflected light reflected by the surface to be measured interfere with each other;
• reversing the lens;
• carrying out second measurement of making light incident from the opposite direction of the optical axis of the surface to be measured to make the reflected light reflected by the reference surface and the reflected light reflected by the surface to be measured interfere with each other with the first measurement means;
• and
• arithmetically operating the shape of the surface to be measured on the basis of the two measurement results provided through the first measurement and second measurement.

A shape measuring method using an interferometer for measuring a shape of a surface to be measured of a lens having an optical surface becoming a reference surface and an optical surface becoming the surface to be measured, the method comprising:

• preparing second and third measurement means having a light source, a condensing lens for condensing temporarily light waves from the light source, and image pickup means for capturing the light waves obtained by making a reflected light reflected by the reference surface and a reflected light reflected by the surface to be measured interfere with each other;
• carrying out third measurement of making light incident from one direction of an optical axis of the surface to be measured to make the reflected light from the reference surface and the reflected light from the surface to be measured interfere with each other to measure the shape of the surface to be measured with the second measurement means;
• carrying out fourth measurement of making light incident from the opposite direction of the optical axis of the surface to be measured to make the reflected light from the reference surface and the reflected light from the surface to be measured interfere with each other to measure the shape of the surface to be measured with the third measurement means arranged across the lens from the second measurement means;
• and
• arithmetically operating the shape of the surface to be measured on the basis of two measurement results obtained from the third and fourth measurements.