JP2010025580A - Optical unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical unit capable of preventing the occurrence of aberration in a prism to detect the incident angle of light with high precision and having good ease of operation. <P>SOLUTION: The optical unit for detecting the intensities of reflected light corresponding to respective incident angles totally reflected from a sample arranging part has a light source unit 1 for emitting parallel light, a photodetector row 3 and the prism 2 receiving the incidence of the light from the light source unit to guide the light to the photodetector row. The prism includes a first prism having an incident surface 2a, a second prism having a curved reflecting surface 2b and the sample arranging part 2c, and a third prism having an emitting surface 2d, wherein the first and second prisms are arranged on the side of the same surface as the second prism or arranged at the positions opposed to each other so as to hold the second prism. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical unit used for sample analysis for quantitatively analyzing a sample or a substance in the sample such as a refractive index and an immunoassay.

  Conventionally, as a sample analyzer, light having an incident angle within a predetermined range including an angle of total reflection (hereinafter referred to as predetermined convergent light) is incident on the sample placement unit, and each incident from the sample placement unit. There is a device that detects the intensity of reflected light corresponding to each angle and detects the incident angle when the detected intensity changes abruptly.

  As such a sample analyzer, for example, there is an apparatus for performing analysis using a difference in refractive index between substances. In this sample analyzer, a sample to be inspected is placed in a sample placement portion made of a substance having a known refractive index. Then, predetermined convergent light is made incident on the surface of the sample placement portion. Then, the light incident at an angle smaller than the critical angle is not totally reflected on the surface of the sample placement portion. By detecting the incident angle at this time, the refractive index of the sample to be inspected can be obtained, and the physical properties of the sample to be detected can be analyzed.

  In addition, for example, in a sample analyzer using generation of surface plasmons, a metal film is provided on the surface of the sample placement portion. Then, a sample to be inspected is placed on the metal film of the sample placement portion, and predetermined convergent light is incident on the surface of the metal film. Here, when light having an angle greater than the critical angle is incident, an evanescent wave having an electric field distribution is generated at the interface between the metal film and the sample to be inspected. Then, surface plasmons are excited in the metal film by the evanescent wave. Furthermore, among the light incident at an angle greater than the critical angle, with respect to the light incident at a specific incident angle, the evanescent wave and the surface plasmon are brought into resonance by causing wave number matching. In this resonance state, light energy is transferred to surface plasmons. For this reason, the intensity of the reflected light sharply decreases with light incident at a specific incident angle. Therefore, by detecting the incident angle when the intensity of the reflected light rapidly decreases, the wave number of the surface plasmon can be obtained and the physical properties of the sample to be detected can be analyzed.

  As a sample analyzer (surface plasmon sensor) using generation of surface plasmons, the one described in the following Patent Document 1 is disclosed.

  For example, as shown in FIG. 15, the sample analyzer of Patent Document 1 is arranged so as to face a triangular prism A formed of glass as a dielectric and a lower surface Aa of the prism A with a space therebetween. A metal film C on which the sample B is placed on the surface on the prism A side, a light source that generates one light beam D, the light beam D through the prism A, and the lower surface Aa. The optical system is configured to be incident so that various incident angles including a reflection angle can be obtained, and light detection means E that detects the light amount of the light beam D totally reflected by the lower surface Aa of the prism.

Alternatively, as shown in FIG. 16, the prism is a hemispherical prism F instead of the triangular prism A in FIG. 15, and the prism F is disposed so as to face the lower surface Fa of the prism F with a space therebetween. A metal film C on which the sample B is placed on the surface on the F side, a light source that generates one light beam D, the light beam D through the prism F, and a total reflection angle with respect to the lower surface Fa. The optical system includes an incident optical system so that various incident angles can be obtained, and light detection means E that detects the amount of light beam D totally reflected by the lower surface Fa of the prism.
Japanese Patent No. 3343806

  However, in the sample analyzer described in Patent Document 1, incident light incident on the prism is refracted when incident on the prism, and outgoing light emitted from the prism is also refracted when emitted from the prism. Aberrations occur at points and condensing points.

  For example, in the case of the triangular prism shown in FIG. 15, even if convergent light is incident, if the incident angle is large with respect to the incident surface, aberration occurs and an error occurs in the angular distribution. In the case of the semispherical prism shown in FIG. 16, aberration occurs when a parallel light beam is incident.

  The present invention has been made in view of the above-described conventional problems, and provides an optical unit capable of detecting the incident angle of light with high accuracy while suppressing the occurrence of aberration in the prism while having a simple configuration. The purpose is to do. It is another object of the present invention to provide an optical unit with good operability.

  In order to achieve the above object, an optical unit according to the present invention includes a light source unit that emits parallel light, a light receiving element array, and a reflective optical member disposed in an optical path from the light source unit to the light receiving element array. The reflective optical member includes an incident surface provided at a position where the parallel light is incident, a first curved reflective surface that reflects the parallel light that has passed through the incident surface, and the first curved reflective surface. A plane portion provided at a position facing the plane, a second curve reflection surface provided at a position away from the first curve reflection surface and opposed to the plane portion, and the second curve reflection surface A light emitting surface that emits the light reflected by the light source, including a central ray of the parallel light, and a surface that is orthogonal to the first curved reflective surface, the planar portion, and the second curved reflective surface is a second virtual surface, Including the central ray of parallel light and perpendicular to the entrance surface When the plane parallel to the second imaginary plane is the first imaginary plane, the incident plane and the first curved reflecting plane are arranged such that the first imaginary plane and the second imaginary plane are positioned at a predetermined interval. The planar portion and the second curved reflecting surface are provided.

  In the optical unit of the present invention, when the third virtual surface includes a central ray of the parallel light and is orthogonal to the emission surface and parallel to the second virtual surface, the third virtual surface and It is preferable that the emitting surface is provided so that the second virtual surface is located at a predetermined interval.

  In the optical unit of the present invention, it is preferable that the entrance surface and the exit surface are provided so that the first virtual surface and the third virtual surface overlap.

  In the optical unit according to the aspect of the invention, it is preferable that the incident surface and the emission surface are provided so that the first virtual surface and the third virtual surface are located at a predetermined interval.

In the optical unit according to the aspect of the invention, the first planar reflection surface and the second reflection unit may be provided at a position intersecting the first virtual surface and a position intersecting the second virtual surface. A second planar reflecting surface having a third planar reflecting surface provided at a position intersecting with the third virtual surface,
The first planar reflecting surface and the first reflecting portion are arranged to face each other so that normals of the surfaces are orthogonal to each other, and the second planar reflecting surface is the first curved reflecting surface and the second curved surface. It is preferable that the third flat reflecting surface and the second reflecting portion are provided so as to face both of the reflecting surfaces, and are arranged to face each other so that the normals of the surfaces are orthogonal to each other.

  In the optical unit of the present invention, a central ray of the parallel light incident on the incident surface and a central ray of the parallel light emitted from the emission surface are parallel to an imaginary line orthogonal to the plane portion. It is preferable that it is comprised so that it may become.

  In the optical unit of the present invention, a central ray of the parallel light incident on the incident surface and a central ray of the parallel light emitted from the emission surface are orthogonal to a virtual line orthogonal to the plane portion. It is preferable that it is comprised.

  In the optical unit of the present invention, a reflecting surface is provided in the optical path from the incident surface to the first planar reflecting surface and in the optical path from the third planar reflecting surface to the emitting surface. It is preferable.

  In the optical unit according to the aspect of the invention, it is preferable that the reflective optical member is a solid transparent member.

  In the optical unit of the present invention, it is preferable that the reflective optical member is composed of at least two transparent members, and one transparent member is a member including only the flat portion.

  In the optical unit of the present invention, it is preferable that a metal film is deposited on the planar portion.

  According to the present invention, it is possible to obtain an optical unit that can suppress the occurrence of aberration as much as possible while having a simple configuration and can detect the incident angle of a light beam with high accuracy. In addition, since the incident surface for incident light to the prism and the exit surface for outgoing light are on different surfaces from the sample placement unit, the light source unit and the light receiving element array can be placed on a different side from the sample placement unit. Improves the application range.

Prior to the description of the embodiments, the basic configuration and operation of the optical unit will be schematically described.
FIG. 1 is a block diagram conceptually showing the basic structure of the optical unit.
The optical unit has a light source unit 1, a prism 2, and a light receiving element array 3. Note that it is not always necessary to use a prism as long as the individual reflecting surfaces can be arranged independently.
The light source unit 1 is disposed at a position facing the incident surface 2 a of the prism 2. The specific configuration of the prism 2 will be described later. The light source unit 1 is configured to emit parallel light. As long as the configuration can emit parallel light, any configuration such as a configuration in which a collimator lens is combined with a light source, or a configuration in which a fiber is further combined therewith may be used.

  The light receiving element array 3 is disposed at a position facing the emission surface 2 d of the prism 2. Each element of the light receiving element array 3 is arranged along one direction. Here, predetermined convergent light is incident on the sample placement portion (planar portion) 2c. The incident angle of each light beam of the predetermined convergent light gradually changes. Each element of the light receiving element array 3 is arranged in a direction corresponding to the change in the incident angle. The position where the incident light is collected is also the focal position of the curved reflecting surface (first curved reflecting surface and second curved reflecting surface) 2b. The sample placement portion 2 c and the curved reflecting surface 2 b are part of the prism 2. In the optical unit, the incident angle is detected based on the change in the intensity of the received reflected light. The position where the intensity change of the reflected light occurs can be detected from the position of the light receiving element. Therefore, the light source unit 1 and the light receiving element array 3 are adjusted so that such detection can be performed.

The prism 2 is configured to allow parallel light emitted from the light source unit 1 to enter the sample placement portion 2 c and to guide the total reflected light from the sample placement portion 2 c to the light receiving element array 3. Specifically, the prism 2 has an incident surface 2a, a curved reflecting surface 2b, a planar sample placement portion 2c, and an exit surface 2d.
The incident surface 2 a is configured to allow parallel light emitted from the light source unit 1 to enter the prism 2. At this time, it is preferable that the incident surface 2a is a flat surface and parallel light is incident perpendicularly to the incident surface 2a.
The curved reflecting surface 2b is configured to reflect parallel light that has passed through the incident surface 2a and entered the prism 2 toward its focal position (not shown).
The planar sample placement portion 2c is provided at a position facing the curved reflecting surface 2b and including the focal position of the curved reflecting surface 2b.

Then, another curved reflecting surface is provided in the traveling direction of the light totally reflected by the sample placement portion 2c. The another curved reflection surface may be separate from the curved reflection surface 2b, or may be a surface connected to the curved reflection surface 2b (a surface obtained by extending the curved reflection surface 2b). good. When another curved reflecting surface is separate from the curved reflecting surface 2b, the curved reflecting surface 2b becomes the first curved reflecting surface, and the other curved reflecting surface becomes the second curved reflecting surface. become. The light totally reflected by the sample placement portion 2c is reflected by another curved reflecting surface. The light reflected by another curved reflection surface becomes the same parallel light as the incident light.
The emission surface 2d is configured to emit parallel light reflected by another curved reflection surface to the outside of the prism 2. The surface shape of the exit surface 2d is a planar shape in which the normal of the surface is perpendicular to each light ray.
Further, the prism 2 is configured so that the incident surface 2a and the exit surface 2d are located on the opposite side of the sample placement portion 2c, that is, on the same side as the curved reflecting surface 2b (and another curved reflecting surface). . However, a reflection surface may be provided between the entrance surface 2a and the sample placement portion 2c and between the sample placement portion 2c and the exit surface 2d. In this way, the positional relationship between the sample placement portion 2c and the incident surface 2a and the positional relationship between the sample placement portion 2c and the exit surface 2d can be freely set.

  In the optical unit configured as described above, the parallel light emitted from the light source unit 1 enters the incident surface 2 a of the prism 2. The light that has passed through the incident surface 2a and entered the prism 2 is reflected and collected by the curved reflecting surface 2b. Thereby, parallel light turns into predetermined convergent light and enters the focal position of the curved reflecting surface 2b. The sample placement portion 2c is located at the focal position of the curved reflecting surface 2b. Accordingly, the sample is irradiated with predetermined convergent light. Of the predetermined convergent light, a light ray incident at an incident angle greater than the critical angle is totally reflected, reflected by another curved reflecting surface to become parallel light, and is emitted vertically from the emitting surface 2d to the outside of the prism 2. To do. Light emitted from the emission surface 2 d to the outside of the prism 2 is received by each light receiving element of the light receiving element array 3.

  Thus, in the optical unit described above, the incident surface 2a of the prism 2 allows the parallel light emitted from the light source unit 1 to enter the prism 2 vertically. Therefore, each light beam constituting the parallel light is kept in a parallel state. Moreover, the reflecting surface 2b is configured in a curved shape. Thereby, all the rays of the parallel light incident on the reflecting surface 2b are reflected toward the focal position. That is, the light incident on the prism 2 is converted into predetermined convergent light and is incident on the focal position of the curved reflecting surface 2b. The light incident on the focal position is totally reflected by the sample placement portion 2c (focal position of the curved reflecting surface 2b) and reflected by another curved reflecting surface to become parallel light. The exit surface 2d emits this parallel light vertically. At this time, each light beam constituting the totally reflected light holds the angle when the light is totally reflected as information on the emission position.

  That is, according to this optical unit, neither incident light to the prism 2 nor outgoing light from the prism 2 is refracted. Moreover, the conversion to the predetermined convergent light is performed on the curved reflecting surface 2b. For this reason, according to this optical unit, the aberration which generate | occur | produces in the prism 2 can be restrained small. In particular, if the curved shape of the reflecting surface 2b is a parabolic shape, no aberration occurs.

  In this way, each light beam constituting the parallel light emitted from the light source unit 1 is converted into a light beam constituting predetermined convergent light. Furthermore, since the aberration is corrected well in the prism 2 (or no aberration), the predetermined convergent light does not cause a positional shift and an angular shift, and the sample placement portion 2c (the focal position of the curved reflecting surface 2b). Incident to Further, the divergent light totally reflected by the sample placement portion 2c (the focal position of the curved reflecting surface 2b) is received by the corresponding light receiving elements in the light receiving element array 3 without causing any positional shift and angular shift.

  Such an optical unit can be used, for example, in a sample analysis apparatus. In the sample analysis apparatus, a sample is placed on the sample placement portion 2c of the optical unit. The focal position of the curved reflecting surface 2 b is irradiated with predetermined convergent light, and the reflected light obtained by total reflection is received by the light receiving element array 3. In the light receiving element row 3, a light intensity distribution is obtained by the light receiving element at a position corresponding to the incident angle. By analyzing the light intensity distribution, it is possible to obtain the incident angle as the critical angle with high accuracy. And various physical properties of the sample can be specified from the incident angle.

  In this optical unit, a metal film is deposited on the sample placement portion 2c, for example, by coating a metal thin film or metal fine particles. In this way, the incident angle when the intensity of the reflected light rapidly changes due to surface plasmon resonance can be obtained with high accuracy. And various physical properties of the sample can be specified from the incident angle.

  As described above, according to the above optical unit, the same point of the object to be inspected can be irradiated with light having an incident angle having a width without causing aberration. For this reason, it is not necessary to use an aberration correction lens or an aspheric lens in order to detect the incident angle of the light beam with high accuracy. Further, the arrangement space can be reduced to reduce the size and further reduce the cost.

First Embodiment FIGS. 2 to 6 are views showing an optical unit according to a first embodiment of the present invention. 2A and 2B are exploded views of the prism used in the optical unit of the present invention. FIG. 2A is a plan view of the second prism portion, and FIG. 2B is a plan view of the incident / exit prism portion. 3 is a perspective view of the prism of FIG. 2, (a) is a perspective view of the second prism portion, (b) is a perspective view of the incident / exit prism portion, (c) is the first virtual surface, and FIG. It is a figure which shows a virtual surface and a 3rd virtual surface. FIG. 4 is a perspective view showing a state where the prism of FIG. 2 is assembled. FIG. 5 is an explanatory diagram showing an optical path of the prism shown in FIG. FIG. 6 is a perspective view showing an example of the optical unit of the present invention using the prism of FIG.

  In the optical unit of the present embodiment, the prism 2 includes an incident / exit prism portion 10 and a second prism portion 20. The incident / exiting prism unit 10 includes a first prism unit 10a and a third prism unit 10b. Each of the first prism portion 10a and the third prism portion 10b has a rectangular plate shape. The second prism portion 20 has a parabolic shape. The incident / exit prism portion 10 is located below the second prism portion 20. Further, the second prism portion 20 has a curved (parabolic) reflecting surface 2b, and the entire second prism portion 20 is formed in a substantially lumpy shape (substantially semi-cylindrical shape). Each of these prism portions is composed of a transparent member of the same medium.

  The first prism portion 10 a has an incident surface 2 a and a first reflecting surface (first flat reflecting surface) 31. The first reflecting surface 31 is disposed to face the incident surface 2a so as to intersect the first virtual surface P1. Specifically, the first reflecting surface 31 is arranged such that the angle formed between the normal line of the surface and the first virtual surface P1 is 45 degrees. Here, as shown in FIG. 3C, the first virtual plane P1 includes a central ray of parallel light, is a plane orthogonal to the incident plane 2a and parallel to the second virtual plane P2. The second virtual surface P2 will be described later.

  The parallel light emitted from the light source unit 1 is incident on the first prism portion 10a via the incident surface 2a. The incident parallel light propagates horizontally in the first prism portion 10 a and enters the first reflecting surface 31. The first reflecting surface 31 is disposed with the reflecting surface facing the second prism portion 20 side. Accordingly, the first reflecting surface 31 reflects this parallel light in the vertical direction toward the second prism portion 20.

The second prism portion 20 includes a curved reflecting surface 2b and a sample placement portion (planar portion) 2c. The curved reflecting surface 2b has a parabolic shape. Therefore, in the following description, the curved reflecting surface 2b is referred to as a curved reflecting surface 2b. The parabolic reflecting surface 2b has a first reflecting region (first curved reflecting surface) 2b ₁ and a second reflecting region (second curved reflecting surface) 2b ₂ . The sample placement portion 2c is provided at the focal position P of the parabolic reflecting surface 2b. And the plane reflective surface (2nd plane reflective surface) is provided in the same side as the sample arrangement | positioning part 2c.

The second planar reflecting surface is provided at a position intersecting with the second virtual surface P2, and has a twenty-first reflecting surface (first reflecting portion) 32 and a twenty-second reflecting surface (second reflecting portion) 33. The 21st reflecting surface 32 and the 22nd reflecting surface 33 are disposed at symmetrical positions with the sample placement portion 2c interposed therebetween. As shown in FIG. 3C, the second virtual plane P2 includes a central ray of parallel light and is orthogonal to the first reflection region 2b ₁ , the sample placement portion 2c, and the second reflection region 2b ₂ . Surface.

  The 21st reflective surface 32 and the 1st reflective surface 31 are arrange | positioned facing each other so that a normal line may mutually orthogonally cross. The twenty-first reflecting surface 32 reflects the parallel light from the first reflecting surface 31 in the horizontal direction (in the second virtual plane). Thereby, the parallel light propagates into the second prism portion 20. Moreover, the 22nd reflective surface 33 and the 3rd reflective surface 34 (3rd plane reflective surface) are opposingly arrange | positioned so that a normal line may mutually orthogonally cross. Accordingly, the twenty-second reflecting surface 33 reflects the light beam from the parabolic reflecting surface 2b toward the third reflecting surface 34 in the vertical direction. In the present embodiment, the twenty-first reflecting surface 32 and the twenty-second reflecting surface 33 are arranged so that the reflecting surfaces are parallel. Therefore, the direction in which the parallel light travels is opposite between the direction from the first reflecting surface 31 to the twenty-first reflecting surface 32 and the direction from the twenty-second reflecting surface 33 to the third reflecting surface 34.

  The third prism portion 10b has an exit surface 2d and a third reflecting surface 34 (third flat reflecting surface). The third reflecting surface 34 is disposed to face the emission surface 2d so as to intersect with the third virtual surface P3. Specifically, the third reflecting surface 34 is arranged such that the angle formed between the normal line of the surface and the third virtual surface P3 is 45 degrees. Here, as shown in FIG. 3C, the third virtual surface P3 is a surface that includes the central ray of parallel light, is orthogonal to the exit surface 2d, and is parallel to the second virtual surface P2.

  The third reflecting surface 34 reflects the parallel light from the twenty-second reflecting surface 33 in the horizontal direction (within the third virtual surface). Thereby, parallel light propagates in the third prism portion 10b. The parallel light propagating through the third prism portion 10b is emitted to the outside through the emission surface 2d.

As described above, in the optical unit of the present embodiment, the incident surface 2a, the first reflection region 2b ₁ , the sample placement unit 2c, and the first virtual surface P1 and the second virtual surface P2 are positioned at a predetermined interval. A second reflection region 2b ₂ is provided. In addition, the emission surface 2d is provided so that the third virtual surface P3 and the second virtual surface P2 are located at a predetermined interval. The incident surface 2a and the exit surface 2d are provided so that the first virtual surface P1 and the third virtual surface P3 overlap.

As described above, the reflecting surface 2b of the parabolic shape of the second prism portions 20 includes a first reflective region 2b _1, the second reflective region 2b _2.
The first reflective region 2b ₁ further reflects the parallel light reflected by the second 21 reflective surface 32. The parallel light is converted into predetermined convergent light by this reflection, and is incident on the focal position P of the parabolic reflecting surface 2b. A sample placement portion 2c is provided at the focal position P.
The second reflection region 2b ₂ further reflects the predetermined divergent light totally reflected by the sample placement unit 2c. By this reflection, divergent light is converted into parallel light, and the parallel light is incident on the twenty-second reflecting surface 33.

That is, the parallel light is incident on the inside of the first prism unit 10a via the incident surface 2a of the first prism unit 10a. The parallel light is reflected by the first reflecting surface 31 and the twenty-first reflecting surface 32 and enters the second prism unit 20. The reflecting surface 2b of the parabolic shape of the second prism portions 20, more specifically, the first reflective region 2b ₁ reflects the incident parallel light. By this reflection, the parallel light is converted into incident light having a predetermined range of continuous incident angles. Note that the predetermined range includes the angle of total reflection. The light thus converted enters the focal position P of the parabolic reflecting surface 2b. At this focal position P, a sample placement portion 2c is provided. The light totally reflected by the sample placement portion 2c (focal position P of the parabolic reflecting surface 2b) becomes divergent light and enters the _second reflecting region 2b2. The second reflection region 2b ₂ reflects divergent light and converts it into parallel light. The parallel light is reflected by the twenty-second reflecting surface 33 and the third reflecting surface 34 and is emitted to the outside from the emitting surface 2d of the third prism portion 10b.

  In the first prism portion 10a and the second prism portion 20, the first reflecting surface 31 and the twenty-first reflecting surface 32 are joined so as to face each other. In the third prism portion 10b and the second parabolic prism portion 20, the third reflecting surface 34 and the twenty-second reflecting surface 33 are joined so as to face each other. The first prism portion 10 a and the second prism portion 10 b are disposed on the same side of the second prism portion 20.

The light source unit 1 is disposed so that the emitted parallel light enters the incident surface 2a of the first prism portion 10a perpendicularly.
Each of the light receiving elements 3 ₁ , 3 ₂ ,..., 3 _n of the light receiving element array 3 receives light (each light beam constituting parallel light) vertically emitted from the emission surface 2 d of the third prism portion 10 b. It is arranged in a one-dimensional direction so as to receive light vertically.

In the optical unit of the first embodiment configured as described above, the parallel light emitted from the light source unit 1 is incident on the incident surface 2a of the first prism portion 10a perpendicularly. The parallel light that has passed through the incident surface 2a and entered the first prism portion 10a is reflected by the first reflecting surface 31 in the vertical direction as parallel light. The parallel light is further reflected in the horizontal direction by the twenty-first reflecting surface 32 of the second prism unit 20. Thereby, the parallel light propagates into the second prism unit 20. Then, the parallel light which has entered the second prism portions 20 is reflected by the first reflecting region 2b _1. Thereby, parallel light is converted into predetermined convergent light, and is incident on the sample placement portion 2c, more specifically, on the focal position P of the parabolic reflecting surface 2b.

  As described above, the parabolic reflecting surface 2b is a part of the parabolic surface. However, only the longitudinal direction has a parabolic shape. This longitudinal direction is a direction in which the twenty-first reflecting surface 32, the sample placement portion 2c, and the twenty-second reflecting surface 33 of the second prism portion 20 are arranged. In the case of substantially rectangular parallel light, the longitudinal direction is also the long axis direction of the rectangle. On the other hand, the parabolic reflecting surface 2b does not have optical power in the lateral direction (direction orthogonal to the longitudinal direction). Therefore, the parallel light reflected by the parabolic reflecting surface 2b becomes convergent light whose width is kept constant in the short direction. Therefore, strictly speaking, the light collected on the sample placement portion 2c is collected on a line including the focal point P.

Of light incident on the sample placement portion 2c (focal position P of the parabolic reflecting surface 2b), light incident at an incident angle greater than the critical angle is totally reflected. The reflected light totally reflected toward the second reflecting region 2b _2. This reflected light is reflected by the second reflection region 2b ₂ and converted into parallel light. The reflected light converted into parallel light is reflected in the vertical direction by the 22nd reflecting surface 33 and reflected in the horizontal direction by the third reflecting surface 34 of the third prism portion 10b. Thereby, parallel light propagates toward the inside of the third prism portion 10b. Then, the parallel light is emitted vertically from the emission surface 2d of the third prism portion 10b to the outside. Light emitted from the emission surface 2 d to the outside of the prism 2 is received by each light receiving element of the light receiving element array 3.

Thus, in the optical unit of the first embodiment, the light source unit 1 and the prism 2 are configured so that the parallel light emitted from the light source unit 1 is perpendicularly incident on the incident surface 2a of the first prism portion 10a. ing. Then, on the first reflecting surface 31 of the first prism portion 10a and the twenty-first reflecting surface 32 of the second prism portion 20, light rays (each light ray of the incident parallel light) are deflected as parallel light. Therefore, each light beam constituting the parallel light is guided into the second prism portion 20 in a state in which all the light beams remain in a parallel state. Further, the first reflection region 2b ₁ in the second prism unit 20 reflects all incident light rays (each incident parallel light ray) toward the focal position P of the parabolic reflection surface 2b. Have For this reason, the parallel light incident on the inside of the second prism unit 20 is converted into predetermined convergent light and enters the focal position P. At this time, the parallel light incident on the inside of the prism 2 does not pass through a medium other than the prism 2.

Further, the second reflection region 2b ₂ in the second prism portion 20 has an action of reflecting all the light rays totally reflected at the focal position P and converting them into parallel light. For this reason, the light totally reflected at the focal position P is converted into parallel light. The converted light is deflected as parallel light at the 22nd reflecting surface 33 of the second prism portion 20 and the third reflecting surface 34 of the third prism portion 10b. Therefore, each light beam constituting the parallel light is perpendicularly incident on the emission surface 2d of the third prism portion 10b in a state where the parallel state is maintained. The totally reflected light does not pass through a medium other than the prism 2. Then, the emission surface 2d of the third prism portion 10b emits the incident parallel light perpendicularly to the outside. Therefore, each light beam constituting the parallel light is kept in a parallel state. At this time, each of the parallel light beams emitted from the emission surface 2d retains the angle at the time of total reflection as the emission position information.

  That is, according to the optical unit of the first embodiment, neither the incident light to the prism 2 nor the emitted light from the prism 2 is refracted. In addition, conversion into predetermined convergent light and conversion of light totally reflected at the focal position P into parallel light are performed on the parabolic reflecting surface 2b inside the prism 2 which is the same medium. For this reason, according to the optical unit of the present embodiment, no aberration occurs in the prism 2.

  As described above, each light beam constituting the parallel light emitted from the light source unit 1 is converted into a light beam constituting a predetermined convergence. Further, since no aberration occurs in the prism 2, the predetermined convergent light is incident on the sample placement portion 2c (the focal position P of the parabolic reflecting surface 2b) without causing a positional shift and an angular shift. Further, the divergent light totally reflected at the focal position P of the parabolic reflecting surface 2b is converted into parallel light without causing positional deviation and angular deviation. The parallel light is received by the corresponding light receiving elements in the light receiving element array 3.

Such an optical unit of the present embodiment can be used for, for example, a sample analysis apparatus. In the sample analysis apparatus, a sample is placed on the sample placement portion 2c of the optical unit of the first embodiment. The focal position P of the parabolic reflecting surface 2 b is irradiated with predetermined convergent light, and the reflected light obtained by total reflection is received by the light receiving element array 3. In the light receiving element row 3, a light intensity distribution is obtained by the light receiving element at a position corresponding to the incident angle. By analyzing the light intensity distribution, it is possible to obtain the incident angle as the critical angle with high accuracy. And various physical properties of the sample can be specified from the incident angle.
In the optical unit of the first embodiment, a metal film is deposited on the sample placement portion 2c, for example, by coating a metal thin film or metal fine particles. In this way, the incident angle when the intensity of the reflected light rapidly changes due to surface plasmon resonance can be obtained with high accuracy. And various physical properties of the sample can be specified from the incident angle.

  Thus, according to the optical unit of the first embodiment, it is possible to irradiate the same point of the object to be inspected with light having an incident angle having a width without causing aberration. For this reason, it is not necessary to use an aberration correction lens or an aspheric lens in order to detect the incident angle of the light beam with high accuracy. Further, the arrangement space can be reduced to reduce the size and further reduce the cost.

  Further, both the incident light incident on the incident surface 2a of the first prism portion 10a and the emitted light emitted from the exit surface 2d of the third prism portion 10b pass on the extended surface of the plane including the sample placement portion 2c. There is no. That is, the entrance surface 2a and the exit surface 2d are opposite to the sample placement portion 2c, and are located on the same side as the curved reflecting surface 2b. Moreover, the incident light incident on the incident surface 2a is parallel to the outgoing light exiting from the exit surface 2d. Therefore, the freedom degree of the installation method of the sample arrangement | positioning part 2c increases, and it can be set as the optical unit which improved operativity.

  In the illustrated example, the first prism portion 10a and the third prism portion 10b are configured by a single rectangular plate-shaped entrance / exit prism portion 10, but the first prism portion 10a and The third prism portion 10b may be configured as a completely separate body. In addition, for convenience of explanation, the prism 2 is divided into each prism part and assembled, but these prism parts may be integrally formed from the beginning.

  In addition, it is preferable to provide a slit (light shielding member) on the joint surface between the incident / exit prism portion 10 and the second prism portion 20. As the portion where the slit is disposed, for example, the light path portion where the light deflected by the first reflecting surface 31 is directed to the twenty-first reflecting surface 32 or the light deflected by the twenty-second reflecting surface 33 is the third reflecting surface 34. There is an optical path part to

Second Embodiment FIGS. 7 and 8 show a modification of the first embodiment. Here, the second prism portion 20 of the first embodiment is constituted by a 21st prism portion 21 and a 22nd prism portion 22. The twenty-first prism portion 21 has a semi-doughnut-shaped parabolic plate shape. The twenty-second prism portion 22 is semicircular. The 22nd prism part 22 has only the sample arrangement | positioning part 2c. The twenty-second prism portion 22 is configured to be removable from the twenty-first prism portion 21. With this configuration, it is possible to easily replace only the sample without moving the entire optical unit. Therefore, it is not necessary to readjust the optical unit every time the sample is replaced, and the measurement can be performed efficiently.

Third Embodiment FIGS. 9 to 14 are views showing an optical unit according to a third embodiment of the present invention. FIG. 9 is an exploded view of the prism used in the optical unit of the present invention, where (a) is a plan view of the first prism portion, (b) is a plan view of the second prism portion, and (c) is a view of the third prism portion. It is a top view. FIG. 10 is a plan view of the prism of FIG. FIG. 11 is a front view of the prism of FIG. 12 is a perspective view of the appearance of the prism of FIG. FIG. 13 is a perspective view showing an optical path in a state where the prism of FIG. 9 is assembled. FIG. 14 is an explanatory diagram showing an optical path of the prism shown in FIG. In the present embodiment, description of the same components as those in the first embodiment will be omitted as appropriate, and different points will be described.

  In the optical unit of the present embodiment, the prism 2 includes a first prism unit 40a, a third prism unit 40b, and a second prism unit 20. The first prism part 40a and the third prism part 40b have a triangular plate shape. The second prism portion 20 has a parabolic shape. The first prism part 40 a is located below the second prism part 20, and the third prism part 40 b is located above the second prism part 20. Further, the second prism portion 20 has a curved (parabolic) reflecting surface 2b, and the entire second prism portion 20 is formed in a substantially lumpy shape (substantially semi-cylindrical shape). Each of these prism portions is composed of a transparent member of the same medium.

  The first prism portion 40 a has an incident surface 2 a, a reflective surface 41, and a first reflective surface (first flat reflective surface) 31. The reflecting surface 41 is disposed at a position facing the incident surface 2 a and the first reflecting surface 31. Here, the 1st reflective surface 31 is arrange | positioned so that the 1st virtual surface P1 may be crossed. Specifically, the first reflecting surface 31 is arranged such that the angle formed between the normal line of the surface and the first virtual surface P1 is 45 degrees.

  The parallel light emitted from the light source unit 1 enters the first prism portion 40a via the incident surface 2a. The incident parallel light propagates horizontally inside the first prism portion 40 a and enters the reflecting surface 41. The reflection surface 41 is disposed so as to deflect parallel light horizontally by 90 degrees. The parallel light deflected by the reflecting surface 41 enters the first reflecting surface 31. The first reflecting surface 31 is disposed with the reflecting surface facing the second prism portion 20 side. Accordingly, the first reflecting surface 31 reflects this parallel light in the vertical direction toward the second prism portion 20.

As in the first embodiment, the second prism unit 20 includes a curved reflecting surface 2b (first reflecting region 2b ₁ and second reflecting region 2b ₂ ), a sample placement unit (planar unit) 2c, and a plane. It has a reflective surface (the 21st reflective surface 32 and the 22nd reflective surface 33).

  In this embodiment, the 21st reflective surface 32 and the 22nd reflective surface 33 are arrange | positioned so that a reflective surface may orthogonally cross. Therefore, the direction in which the parallel light travels is the same between the direction from the first reflecting surface 31 to the twenty-first reflecting surface 32 and the direction from the twenty-second reflecting surface 33 to the third reflecting surface 34.

  The third prism portion 40 b has an emission surface 2 d, a reflection surface 42, and a third reflection surface (third plane reflection surface) 34. The reflection surface 42 is disposed at a position facing the third reflection surface 34 and the emission surface 2d. The third reflecting surface 34 is disposed so as to intersect with the third virtual surface P3. Specifically, the third reflecting surface 34 is arranged such that the angle formed between the normal line of the surface and the third virtual surface P3 is 45 degrees.

  The third reflecting surface 34 reflects the parallel light from the twenty-second reflecting surface 33 in the horizontal direction (within the third virtual surface). Thereby, parallel light propagates in the third prism portion 40b. The light propagating through the third prism portion 40b enters the reflecting surface 42. The reflecting surface 42 is disposed so as to deflect parallel light horizontally by 90 degrees. The parallel light deflected by the reflection surface 42 is emitted to the outside through the emission surface 2d.

As described above, in the optical unit of the present embodiment, the incident surface 2a, the first reflection region 2b ₁ , the sample placement unit 2c, and the second so that the first virtual surface and the second virtual surface are positioned at a predetermined interval. The reflection region 2b ₂ is provided. In addition, the exit surface 2d is provided so that the third virtual surface and the second virtual surface are located at a predetermined interval. The entrance surface 2a and the exit surface 2d are provided so that the first virtual surface and the third virtual surface are located at a predetermined interval.

  In the first prism portion 40a and the second prism portion 20, the first reflecting surface 31 and the twenty-first reflecting surface 32 are joined so as to face each other. In the third prism portion 40b and the second prism portion 20, the third reflecting surface 34 and the twenty-second reflecting surface 33 are joined so as to face each other. The first prism portion 40a and the second prism portion 40b are arranged at upper and lower positions with the second prism portion 20 interposed therebetween.

In the optical unit of the third embodiment configured as described above, the parallel light emitted from the light source unit 1 is incident on the incident surface 2a of the first prism portion 40a perpendicularly. The parallel light that has passed through the incident surface 2a and entered the first prism portion 40a is changed in direction by the reflection surface 41 as parallel light, and is reflected by the first reflection surface 31 in the vertical direction. The parallel light is further reflected in the horizontal direction by the twenty-first reflecting surface 32 of the second prism unit 20. Thereby, the parallel light propagates into the second prism unit 20. Then, the parallel light which has entered the second prism portions 20 is reflected by the first reflecting region 2b _1. Thereby, parallel light is converted into predetermined convergent light, and is incident on the sample placement portion 2c, more specifically, on the focal position P of the parabolic reflecting surface 2b.

  As described above, the parabolic reflecting surface 2b is a part of the parabolic surface. However, only the longitudinal direction has a parabolic shape. This longitudinal direction is a direction in which the twenty-first reflecting surface 32, the sample placement portion 2c, and the twenty-second reflecting surface 33 of the second prism portion 20 are arranged. In the case of substantially rectangular parallel light, the longitudinal direction is also the long axis direction of the rectangle. On the other hand, the parabolic reflecting surface 2b does not have optical power in the lateral direction (direction orthogonal to the longitudinal direction). Therefore, the parallel light reflected by the parabolic reflecting surface 2b becomes convergent light whose width is kept constant in the short direction. Therefore, strictly speaking, the light collected on the sample placement portion 2c is collected on a line including the focal point P.

Of light incident on the sample placement portion 2c (focal position P of the parabolic reflecting surface 2b), light incident at an incident angle greater than the critical angle is totally reflected. The reflected light totally reflected toward the second reflecting region 2b _2. This reflected light is reflected by the second reflection region 2b ₂ and converted into parallel light. The reflected light converted into parallel light is reflected in the vertical direction by the 22nd reflecting surface 33 and reflected in the horizontal direction by the third reflecting surface 34 of the third prism portion 40b. Thereby, the parallel light propagates inside the third prism portion 40b. Then, the parallel light changes its direction at the reflecting surface 42 and is emitted vertically from the emitting surface 2d to the outside. Light emitted from the emission surface 2 d to the outside of the prism 2 is received by each light receiving element of the light receiving element array 3.

Thus, in the optical unit of the third embodiment, the light source unit 1 and the prism 2 are configured so that the parallel light emitted from the light source unit 1 is perpendicularly incident on the incident surface 2a of the first prism portion 40a. ing. Then, on the reflecting surface 41 and the first reflecting surface 31 of the first prism portion 40a and the twenty-first reflecting surface 32 of the second prism portion 20, light rays (each ray of incident parallel light) are deflected as parallel light. . Therefore, each light beam constituting the parallel light is guided into the second prism portion 20 in a state in which all the light beams remain in a parallel state. Further, the first reflection region 2b ₁ in the second prism unit 20 reflects all incident light rays (each incident parallel light ray) toward the focal position P of the parabolic reflection surface 2b. Have For this reason, the parallel light incident on the inside of the second prism unit 20 is converted into predetermined convergent light and enters the focal position P. At this time, the parallel light incident on the inside of the prism 2 does not pass through a medium other than the prism 2.

Further, the second reflection region 2b ₂ in the second prism portion 20 has an action of reflecting all the light rays totally reflected at the focal position P and converting them into parallel light. For this reason, the light totally reflected at the focal position P is converted into parallel light. Then, the converted light is deflected as parallel light at the 22nd reflecting surface 33 of the second prism portion 20 and the reflecting surface 42 and the third reflecting surface 34 of the third prism portion 40b. Therefore, each light beam constituting the parallel light is perpendicularly incident on the exit surface 2d of the third prism portion 40b in a state where the parallel state is maintained. The totally reflected light does not pass through a medium other than the prism 2. Then, the exit surface 2d of the third prism portion 40b emits the incident parallel light to the outside vertically. Therefore, each light beam constituting the parallel light is kept in a parallel state. At this time, each of the parallel light beams emitted from the emission surface 2d retains the angle at the time of total reflection as the emission position information.

  That is, according to the optical unit of the third embodiment, neither the incident light on the prism 2 nor the emitted light from the prism 2 is refracted. In addition, conversion into predetermined convergent light and conversion of light totally reflected at the focal position P into parallel light are performed on the parabolic reflecting surface 2b inside the prism 2 which is the same medium. For this reason, according to the optical unit of the present embodiment, no aberration occurs in the prism 2.

  As described above, each light beam constituting the parallel light emitted from the light source unit 1 is converted into a light beam constituting a predetermined convergence. Further, since no aberration occurs in the prism 2, the predetermined convergent light is incident on the sample placement portion 2c (the focal position P of the parabolic reflecting surface 2b) without causing a positional shift and an angular shift. Further, the divergent light totally reflected at the focal position P of the parabolic reflecting surface 2b is converted into parallel light without causing positional deviation and angular deviation. The parallel light is received by the corresponding light receiving elements in the light receiving element array 3.

Such an optical unit of the present embodiment can be used for, for example, a sample analysis apparatus. In the sample analysis apparatus, a sample is placed on the sample placement portion 2c of the optical unit of the third embodiment. The focal position P of the parabolic reflecting surface 2 b is irradiated with predetermined convergent light, and the reflected light obtained by total reflection is received by the light receiving element array 3. In the light receiving element row 3, a light intensity distribution is obtained by the light receiving element at a position corresponding to the incident angle. By analyzing the light intensity distribution, it is possible to obtain the incident angle as the critical angle with high accuracy. And various physical properties of the sample can be specified from the incident angle.
Further, in the optical unit of the third embodiment, a metal film is deposited on the sample placement portion 2c, for example, by coating a metal thin film or metal fine particles. In this way, the incident angle when the intensity of the reflected light rapidly changes due to surface plasmon resonance can be obtained with high accuracy. And various physical properties of the sample can be specified from the incident angle.

  Thus, according to the optical unit of the third embodiment, the same point of the object to be inspected can be irradiated with light having an incident angle having a width without causing aberration. For this reason, it is not necessary to use an aberration correction lens or an aspheric lens in order to detect the incident angle of the light beam with high accuracy. Further, the arrangement space can be reduced to reduce the size and further reduce the cost.

  In the present embodiment, the incident surface 2a of the first prism portion 40a and the exit surface 2d of the third prism portion 40b are both perpendicular to the extended surface of the plane including the sample placement portion 2c, and Since the first prism portion 40a and the third prism portion 40b are arranged above and below the second prism portion 20, the entire optical unit can be reduced in size.

In the illustrated example, the example in which the prism 2 is configured by the three prism portions of the first prism portion 40a, the third prism portion 40b, and the second prism portion 20 is shown. For this reason, it is divided into three parts, and these may be integrated from the beginning.
In addition, it is preferable to provide a slit (light-shielding member) on the joint surface between the first prism portion 40 a and the second prism portion 20. As the portion where the slit is disposed, for example, the light path portion where the light deflected by the first reflecting surface 31 is directed to the twenty-first reflecting surface 32 or the light deflected by the twenty-second reflecting surface 33 is the third reflecting surface 34. There is an optical path part to

  The optical unit of the present invention is useful in the medical, medical, and biological fields in which the physical properties of a sample are analyzed using total reflection.

It is a block diagram which shows notionally the basic composition of the optical unit of this invention. It is an exploded view of the prism used for the optical unit concerning a 1st embodiment of the present invention, (a) is a top view of the 2nd prism part, and (b) is a top view of the prism part for entrance and exit. FIG. 3 is a perspective view of the prism of FIG. 2, where (a) is a second prism portion, (b) is an incident / exit prism portion, and (c) is a first virtual surface, a second virtual surface, and a third virtual portion. It is a figure which shows a surface. It is a perspective view which shows the state which assembled the prism of FIG. It is explanatory drawing which shows the optical path of the prism of FIG. It is a perspective view which shows an example of the optical unit of this invention using the prism of FIG. It is a perspective view of the prism used for the optical unit concerning 2nd Embodiment of this invention. It is a top view of the prism of FIG. It is an exploded view of the prism used for the optical unit concerning 3rd Embodiment of this invention, (a) is a top view of a 1st prism part, (b) is a top view of a 2nd prism part, (c) is 3rd. It is a top view of a prism part. FIG. 10 is a plan view of the prism of FIG. 9. FIG. 10 is a front view of the prism of FIG. 9. FIG. 10 is a perspective view of the appearance of the prism of FIG. 9. It is a perspective view which shows the optical path in the state which assembled the prism of FIG. It is explanatory drawing which shows the optical path of the prism of FIG. It is a schematic block diagram which shows an example of the conventional sample analyzer. It is a schematic block diagram which shows the other example of the conventional sample analyzer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light source unit 2 Prism 2a Incident surface 2b Curved reflection surface (parabolic reflection surface)
2b ₁ 1st reflection area 2b ₂ 2nd reflection area 2c Sample arrangement part 2d Outgoing surface 3 Light receiving element row 3 ₁ , 3 ₂ ,..., 3 _n Each light receiving element row 10 Incoming / outgoing prism Part 10a First prism part 10b Third prism part 20 Second prism part 21 21st prism part 22 22nd prism part 31 First reflecting surface (first flat reflecting surface)
32 21st reflective surface 33 22nd reflective surface 34 3rd reflective surface (3rd plane reflective surface)
40a First prism portion 40b Third prism portion 41 Reflecting surface 42 Reflecting surface P1 First virtual surface P2 Second virtual surface P3 Third virtual surface P Focus position

Claims (11)

A light source unit that emits parallel light;
A light receiving element array;
A reflective optical member disposed in an optical path from the light source unit to the light receiving element array;
The reflective optical member includes an incident surface provided at a position where the parallel light is incident, a first curved reflective surface that reflects the parallel light that has passed through the incident surface, and a position that faces the first curved reflective surface. And a light reflected by the second curved reflecting surface and a second curved reflecting surface provided at a position away from the first curved reflecting surface and at a position facing the flat portion. Has an exit surface for emitting
A plane including the central ray of the parallel light, a plane orthogonal to the first curved reflection surface, the plane portion, and the second curved reflection surface is a second virtual plane, and includes a central ray of the parallel light and orthogonal to the incident plane. In addition, when the plane parallel to the second imaginary plane is defined as the first imaginary plane, the incident plane and the first curved reflection so that the first imaginary plane and the second imaginary plane are positioned at a predetermined interval. An optical unit comprising a surface, the flat portion, and the second curved reflecting surface.   The third virtual surface and the second virtual surface are spaced at a predetermined interval when a surface including the central ray of the parallel light and orthogonal to the emission surface and parallel to the second virtual surface is a third virtual surface. The optical unit according to claim 1, wherein the emission surface is provided so as to be positioned apart from each other.   The optical unit according to claim 2, wherein the entrance surface and the exit surface are provided so that the first virtual surface and the third virtual surface overlap each other.   3. The optical unit according to claim 2, wherein the entrance surface and the exit surface are provided such that the first virtual surface and the third virtual surface are located at a predetermined interval. A first planar reflecting surface provided at a position intersecting with the first virtual surface;
A second planar reflecting surface provided at a position intersecting with the second imaginary surface and having a first reflecting portion and a second reflecting portion;
A third planar reflecting surface provided at a position intersecting with the third virtual surface;
The first flat reflecting surface and the first reflecting portion are arranged to face each other so that normals of the surfaces are orthogonal to each other,
The second flat reflective surface is provided to face both the first curved reflective surface and the second curved reflective surface,
5. The optical unit according to claim 2, wherein the third planar reflecting surface and the second reflecting portion are arranged to face each other so that normals of the surfaces are orthogonal to each other. .   A central ray of the parallel light incident on the incident surface and a central ray of the parallel light emitted from the emission surface are configured to be parallel to a virtual line orthogonal to the plane portion. The optical unit according to claim 1.   The center ray of the parallel light incident on the incident surface and the center ray of the parallel light emitted from the emission surface are configured to be orthogonal to a virtual line orthogonal to the plane portion. The optical unit according to claim 1.   8. The reflecting surface is provided in an optical path from the incident surface to the first planar reflecting surface and in an optical path from the third planar reflecting surface to the exit surface, respectively. The optical unit described in 1.   The optical unit according to claim 1, wherein the reflective optical member is formed of a solid transparent member.   The optical unit according to claim 9, wherein the reflective optical member includes at least two transparent members, and one transparent member includes only the flat portion.   The optical unit according to claim 1, wherein a metal film is deposited on the flat portion.

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