Optical imaging device

An optical imaging device for irradiating a subject with low coherence light, to produce a tomogram of the subject from data on light scattered by the subject, said optical imaging device comprising:

• light irradiation and reception means for irradiating the subject with low coherence light and for receiving reflection from the subject;
• propagation delay time-varying means connected to said light irradiation and reception means for causing low coherence light returning from the subject to interfere with a reference beam, and for varying the propagation delay time of the reference beam, depending on a scanning range, in order to scan the interference location axially along the optical axis, wherein said propagation delay time-varying means varies the interference location, depending on an axial scan of an optical element, and wherein the repetitive axial scan of said optical element continuously varies the interference location;
• a light detector for detecting interference light intensity in the form of an interference signal;
• reference position detection means for said optical element;
• first memory means for preserving an interference contrast signal that corresponds to a particular one-way axial scan based on the detection by said reference position detection means;
• and
• a second memory means for preserving an interference signal that corresponds to an axial scan in the opposite direction to said particular one-way axial scan;
• wherein backward reading of data stored in said first memory means and said second memory means produces interference signals that indicate scanning in the same direction.

An optical imaging device for irradiating a subject with low coherence light, to produce a tomogram of the subject from data on light scattered by the subject, said optical imaging device comprising:

• light irradiation and reception means for irradiating the subject with low coherence light and for receiving reflection from the subject;
• propagation delay time-varying means connected to said light irradiation reception means for causing low coherence light returning from the subject to interfere with a reference beam, and for varying the reference beam propagation delay time, depending on the scanning range, in order to scan the interference location axially along the optical axis, wherein said propagation delay time-varying means varies the interference location, depending on the movement of an optical element, and wherein the continuous movement of said optical element continuously varies the interference location;
• a light detector for detecting interference light intensity in the form of an interference signal;
• position detection means for the interference location;
• memory means for preserving interference intensity signals in time series;
• and
• calculation means for calculating an address in said memory means, said address corresponding to the interference location;
• wherein said calculation means reads data stored in said address and produces an interference signal that corresponds to the interference location.

An optical imaging device for irradiating a subject with low coherence light, to produce a tomogram of the subject, from data on light scattered by the subject, said optical imaging device comprising:

• light irradiation and reception means for irradiating the subject with low coherence light and for receiving reflection from the subject;
• propagation delay time-varying means connected to said light irradiation and reception means for causing low coherence light returning from the subject to interfere with a reference beam, and for varying the reference beam propagation delay time, depending on the scanning range, in order to scan the interference location axially along the optical axis;
• a light detector for detecting interference light intensity in the form of an interference signal;
• calculation means for calculating a Doppler frequency of an interference signal produced by scanning the reference beam propagation delay time;
• a demodulator for demodulating the signal from said light detector, and
• a frequency characteristics setting means for varying frequency characteristics of said demodulator depending on the calculated Doppler frequency.

An optical imaging device for irradiating a subject with low coherence light to produce a tomogram of the subject from data on light scattered by the subject, said optical imaging device comprising:

• an optical probe having an elongated flexible insertion unit capable of being introduced into the subject, said optical probe having a light guide including a single mode fiber for emitting low coherence light from an end surface on a distal end of said insertion unit to said subject, and for detecting reflection from said subject;
• interference means for causing low coherence light returning from the subject to interfere with a reference beam;
• optical probe attachment means provided on an optical path between said optical probe and said interference means;
• propagation delay time-varying means connected to said interference means for varying the propagation delay time of the reference beam, depending on the scanning range, in order to scan the interference location axially along the optical axis;
• polarization adjustment means provided in at least one place on optical paths including a path from said interference means to said optical probe, and a path from said interference means to said propagation delay time-varying means;
• reference reflection means provided close to a distal end of said optical probe insertion unit;
• and
• polarization optimization means for obtaining reflection data from said reference reflection means in the form of an interference intensity signal produced from said interference means, and for setting said polarization adjustment means so that the interference intensity signal may be maximized.

An optical imaging device for irradiating a subject with low coherence light to produce a tomogram of the subject from data on light scattered by the subject, said optical imaging device comprising:

• light irradiation and reception means for irradiating the subject with low coherence light and for receiving reflections from the subject;
• propagation delay time-varying means connected to said light irradiation and reception means for causing the low coherence light returning from the subject to interfere with a reference beam, and for varying the propagation delay time, depending on the scanning range, in order to scan the interference location axially along the optical axis;
• said propagation delay time-varying means having a dispersive means, imagine means, and reflection mirror;
• and
• said reflection mirror including a polygonal mirror, wherein the rotation of said polygonal mirror enables scanning the interference location.

An optical imaging device for irradiating a subject with low coherence light to produce a tomogram of the subject from data on light scattered by the subject, said optical imaging device comprising:

• light irradiation and reception means for irradiating the subject with low coherence light and for receiving reflections from the subject;
• propagation delay time-varying means connected to said light irradiation and reception means for causing the low coherence light returning from the subject to interfere with a reference beam, and for varying the propagation delay time, depending on a scanning range, in order to scan the interference location axially along the optical axis;
• said propagation delay time-varying means having a dispersive means, imaging means, and reflection mirror;
• a resonant scanner including said reflection mirror;
• and
• a scanner driver which generates a drive signal for a resonant scanner containing additional one or higher frequency harmonic components.

An optical scanning probe unit for optical imaging instruments, which forms tomographic images of an object by irradiating low-coherent light on the object and collecting data of light scattered from the object comprising:

• a sheath comprising a resin tube having flexibility throughout most of its length and having a tip end formed of material with high light permeability;
• and
• an optical emitter and receiver provided inside said tip end formed of material with high light permeability for emitting the light toward the sheath inside, irradiating the permeated light on the object located outside the sheath, and receiving the light which is at least one of reflected, scattered and excited from the object via the sheath;
• wherein at least the part provided with said optical emitter and receiver on the sheath has a reflection reduction coating.

An optical scanning probe unit for optical imaging instruments, which forms tomographic images of an object by irradiating low-coherent light on the object and collecting data of light scattered from the object comprising:

• a sheath comprising a resin tube having flexibility throughout most of the length;
• an optical window at the tip of the said sheath and formed of material with high light permeability;
• and
• an optical emitter and receiver provided inside said optical window for emitting light toward the optical window inside, irradiating the permeated light on the object located outside the optical window, and receiving the light which is one of reflected, scattered, or excited from the object via the optical window;
• wherein at least a part provided with said optical emitter and receiver inside the optical window has anti-wearable coating.

An optical diagnosis device for observing a tomography structure by changing the length of an optical path on the side of a reference light when getting an interference signal by composing the signal light and the reference light again after dividing low coherence light radiated from a light source with short coherence length into a signal light side and a reference light side and irradiating signal light to an observed object, comprising:

• an end optical system on the side of the signal light of the optical tomography diagnosis device said end optical system including a plurality of optical elements having end surfaces, wherein:
• said side of the signal light includes single mode fiber and the end optical system on the side of the signal light;
• and
• when the number of times of light reflection between said end surfaces of each optical element is less than three times, said reflection light does not return to said single mode fiber.

An optical scanning probe device for an optical imaging devise for irradiating low interference light to a subject and constructing a tomographic image of a subject from information of light scattered in the subject, the optical scanning probe devise comprising:

• a single mode fiber;
• a hollow fiber end matter for inserting and fixing said single mode fiber, the fiber end matter being slantly polished so that an end surface of said single mode fiber and the end surface of the fiber end matter are the same surface;
• a GRIN lens contacted with an optical axis agreed with said fiber end matter and slantly polished on the contact surface at least on the side of the fiber end;
• an optical system including at least an optical element disposed on the side of another end surface of said GRIN lens, the end optical system, wherein the perpendicular of an outgoing or an incident surface of at least a ray of the optical element in said optical system has the specific angle to an optical flux of signal light;
• and
• means for agreeing with an optical center axis for agreeing and contacting said fiber end matter with the optical center axis of said GRIN lens.

An optical scanning probe device for an optical imaging devise for irradiating low interference light to a subject and constructing a tomographic image of a subject from information of light scattered in the subject, the optical scanning probe device comprising:

• an elongated and flexible cylindrical sheath having an end which is not open, said sheath having at least a side surface on a side of the end that is formed of a material with good light transmission;
• a single mode fiber provided in an inner cavity of said sheath and from which low interference light outgoes;
• a lens for collecting the light outgoing from said single mode fiber;
• means fixed on said lens for changing the light path of outgoing light in an almost perpendicular direction to the cylindrical surface of the sheath;
• and
• a correcting optical system having positive and negative refractive force in the direction of the specific axis on the cross section of the beam of said outgoing light.