Optical tomographic image obtaining apparatus
First Claim
1. An optical tomographic image obtaining apparatus that divides a low coherent light beam, having a coherence length of 20 μ
- m or less, into a measuring light beam and a reference light beam;
changes the optical path length of at least one of the reference light beam and the measuring light beam;
irradiates the measuring light beam onto a target of measurement;
receives the measuring light beam, which is reflected from the target of measurement;
causes the reflected measuring light beam and the reference light beam to interfere; and
measures the light intensity of the coherent light after the interference, to obtain optical tomographic images of the target of measurement, comprising;
irradiation direction rotating means, for causing the irradiation direction of the measuring light beam to rotate about a single point;
optical path length changing means, for changing the optical path length of at least one of the reference light beam and the measuring light beam, synchronous with the rotation of the irradiation direction of the measuring light beam;
an objective lens system, for focusing the measuring light beam; and
focusing position moving means, for moving the focusing position in the direction of the optical axis of the measuring light beam, by moving the focal point of the objective lens system, synchronous with the rotation of the irradiation direction of the measuring light beam.
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Accused Products
Abstract
An optical tomographic image obtaining apparatus, capable of obtaining optical tomographic images at high resolution, is miniaturized. During obtainment of an optical tomographic image, a mirror rotating section rotates a mirror, to rotate the irradiation direction of a measuring light beam. Operations of an optical path length changing section are controlled such that a measurement point along the optical path direction is moved for every rotation of the irradiation direction. A sheath rotating section rotates a sheath to move the position of a lens fixed within a lens holder by a threaded mechanism, to move the focusing position of the measuring light beam in the optical path direction, to match the position of the measurement point. Therefore, the movement speed of the focusing position can be reduced compared to conventional apparatuses. Accordingly, the necessity of a large focusing position moving means, which is capable of high speed movement, is obviated.
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Citations
15 Claims
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1. An optical tomographic image obtaining apparatus that divides a low coherent light beam, having a coherence length of 20 μ
- m or less, into a measuring light beam and a reference light beam;
changes the optical path length of at least one of the reference light beam and the measuring light beam;
irradiates the measuring light beam onto a target of measurement;
receives the measuring light beam, which is reflected from the target of measurement;
causes the reflected measuring light beam and the reference light beam to interfere; and
measures the light intensity of the coherent light after the interference, to obtain optical tomographic images of the target of measurement, comprising;irradiation direction rotating means, for causing the irradiation direction of the measuring light beam to rotate about a single point; optical path length changing means, for changing the optical path length of at least one of the reference light beam and the measuring light beam, synchronous with the rotation of the irradiation direction of the measuring light beam; an objective lens system, for focusing the measuring light beam; and focusing position moving means, for moving the focusing position in the direction of the optical axis of the measuring light beam, by moving the focal point of the objective lens system, synchronous with the rotation of the irradiation direction of the measuring light beam. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
- m or less, into a measuring light beam and a reference light beam;
Specification