JP2016208136A - Multifunctional image acquisition device and prism therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To equalize optical path lengths of a plurality of emission image lights that are made incident to one imaging apparatus.SOLUTION: An incident image light is split into two light fluxes V1 and V2 by a second prism 10 and made incident vertically from a first face M1 of a first prism 20 in an equilateral triangular prism shape. The first prism 20 includes a splitting plane B1 that passes an intersection α2 of the first face M1 and a third face M3 and is vertical to a second face M2. The first light flux V1 is split into a reflective light V11 and a rectilinear light V12 by the splitting plane B1. The second light flux V2 is split into a reflective light V21 and a rectilinear light V22 by the splitting plane B1. The reflective lights V11 and V21 are fully reflected by the first face M1 without being fully reflected in the first prism 20, and vertically emitted from the second face M2. The rectilinear lights V12 and V22 are fully reflected by the third face M3 without being fully reflected in the first prism 20, and vertically emitted from the second face M2. The emitted image lights are simultaneously imaged by one imaging apparatus 30, and a plurality of images are acquired in a completely synchronized state.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a multifunctional image acquisition apparatus and its rhythm.

  When information is extracted from an image by image processing, a certain function may be given by passing an image through an optical filter, while calculation processing may be performed based on a plurality of images having different specific functions.

  Patent Document 1 (FIG. 2) discloses a regular triangular prism-shaped first prism having a first surface, a second surface, and a third surface, and one incident image light into two light beams parallel to each other. There is disclosed a technique in which four parallel outgoing image lights are obtained using a second prism that performs spectroscopy, and the four outgoing image lights are simultaneously imaged by one imaging device. Specifically, two parallel light beams dispersed by the second prism are vertically incident from the first surface of the first prism, and are emitted from the second surface of the first prism vertically. Four outgoing image lights are obtained. Then, by interposing an appropriate external optical filter corresponding to any outgoing image light between the second surface and the imaging device, a plurality of images having specific functions are synchronized with each other. Can be acquired.

JP2013-238850A

  The one disclosed in Patent Document 1 described above is extremely preferable in that a single imaging apparatus can simultaneously acquire a plurality of images having a specific function. However, among the optical path lengths of the respective outgoing image lights, the optical path lengths of some outgoing image lights are slightly different from the optical path lengths of the other outgoing image lights. That is, in Patent Document 1, the optical path of the output image light W2 is a divided surface set in a region close to the vertex where the second surface and the third surface intersect in the first prism (Patent Document 1). Therefore, it is necessary to set an air gap in the divided surface. However, the formation of the air gap is troublesome in production and is uneasy about the strength, and the handling becomes delicate, for example, the cleaning liquid penetrates into the air gap. In addition, the optical path length corresponding to the air gap is different from the optical path lengths of the other outgoing image lights (W1, W3, W4). In addition, in the divided surface B1 in Patent Document 1, a metal surface is created on a part of the divided surface to completely reflect light. However, it is difficult to deposit the metal surface with high accuracy, and the light is further diffracted at the end of the metal surface, resulting in deterioration of the image quality of the output image.

  The present invention has been made in view of the above circumstances, and a first object thereof is to form a plurality of output image lights parallel to each other from one incident image light without forming a metal film or an air gap. An object of the present invention is to provide a multi-function image acquisition apparatus that can acquire simultaneously.

  A second object of the present invention is to provide a prism suitable for use in the multifunctional image acquisition apparatus.

In order to achieve the first object, the following first solution is adopted in the multi-function image acquisition apparatus according to the present invention. That is, as described in claim 1,
A first surface, a second surface continuous to form an apex angle of 60 degrees at one end of the first surface, and an apex angle of 60 degrees at the other end of the first surface A first prism having a third surface that is continuous and forms an angle of 60 degrees with respect to the second surface;
A second prism that splits the incident image light into a first light beam and a second light beam that are parallel to each other, and causes the two light beams to enter the first surface perpendicularly;
One imaging device disposed facing the second surface;
With
The first prism has a split surface that is orthogonal to the second surface through an intersection of the first surface and the third surface;
A first internal optical filter that splits the first light beam into first straight light and first reflected light on the splitting surface, and a second light that splits the second light beam into second straight light and second reflected light. With an internal optical filter,
The first rectilinear light and the second rectilinear light are not totally reflected within the first prism, but are totally reflected only by the third surface, and then emitted vertically from the second surface. Two outgoing image lights,
The first reflected light and the second reflected light are totally reflected only on the first surface without being totally reflected in the first prism, and then emitted perpendicularly from the second surface. Two outgoing image lights,
The imaging device captures each of the emitted image light at the same time to obtain a plurality of images at the same time.
It is like that. According to the above solution, since it is not necessary to form an air gap, the optical path length of each outgoing image light without causing problems of manufacturing, strength instability, and delicate handling due to the formation of the air gap. Can be set to be completely equal, and a plurality of images simultaneously acquired by the imaging apparatus can be completely synchronized. Furthermore, since it is not necessary to provide a metal film on a part of the dividing surface, film formation on the dividing surface is facilitated. As a result, the number of constituent optical elements can be reduced, and the shape becomes simple.

A preferred mode based on the first solution is as set forth in claims 2 to 4 in the claims. That is,
An external filter is disposed between the second surface and the imaging device so as to correspond to any one or more of the emitted image light (corresponding to claim 2). In this case, an external optical filter can be used to simultaneously acquire images having different functions in a completely synchronized state.

The first light beam and the second light beam separated by the second prism are color-separated into yellow light and blue light,
The yellow light is color-separated into red light and green light by the dividing plane,
The plurality of outgoing image lights are red light, blue light and green light,
(Corresponding to claim 3). In this case, the emitted image light separated into the three primary colors of blue light, red light and green light can be simultaneously acquired in a completely synchronized state. It is particularly suitable for high-speed multicolor cameras.

  The first prism has a regular triangular prism shape (corresponding to claim 4). In this case, the first prism can be configured by using two prisms of a general right triangular prism.

In order to achieve the first object, the following second solution is adopted in the present invention. That is, as described in claim 5,
A first surface, a second surface continuous to form an apex angle of 60 degrees at one end of the first surface, and an apex angle of 60 degrees at the other end of the first surface A first prism having a third surface that is continuous and forms an angle of 60 degrees with respect to the second surface;
A second prism that splits incident image light into blue light and yellow light that are parallel to each other, and makes the two light beams vertically incident on the first surface;
One imaging device disposed facing the second surface;
With
The first prism has a split surface that is orthogonal to the second surface through an intersection of the first surface and the third surface;
On the dividing surface, a reflective film that reflects the blue light, and an internal optical filter that separates the yellow light into straight light and reflected light and color-separates into red light and green light, are set.
The blue light incident on the first surface is reflected by the reflective film, then totally reflected by the first surface, and is emitted image light emitted perpendicularly from the second surface,
The straightly traveling light is totally reflected by the third surface, and then is emitted image light emitted vertically from the second surface;
After the reflected light is totally reflected by the first surface, the reflected light is emitted image light emitted vertically from the second surface,
The imaging device simultaneously captures emitted image light of blue light, red light, and green light.
(Corresponding to claim 5). In this case, the emitted image light separated into the three primary colors of blue light, red light, and green light can be simultaneously acquired with completely equal optical path lengths and in a completely synchronized state. It is particularly suitable for high-speed multicolor cameras.

Based on the above second solution method, the following solution method can be adopted. That is,
The first prism has a fourth surface which is formed in a shape in which a vertex portion far from the first surface is cut out of a regular triangular prism, and extends substantially parallel to the division surface. (Corresponding to claim 6). In this case, the first prism is preferable in terms of size reduction, weight reduction, reduction in the amount of prism material used, and the like.

In order to achieve the second object, the following third solution is adopted in the present invention. That is, as described in claim 7,
A first surface, a second surface continuous to form an apex angle of 60 degrees at one end of the first surface, and an apex angle of 60 degrees at the other end of the first surface A third surface that is continuous and forms an angle of 60 degrees with respect to the second surface,
Having a split surface orthogonal to the second surface through the intersection of the first surface and the third surface;
A first internal optical filter that splits the first light beam incident perpendicularly to the first surface into first straight light and first reflected light on the split surface, and the first parallel to the first light beam. A second internal optical filter that splits the second light flux incident on the surface into second straight light and second reflected light is set,
The first rectilinear light and the second rectilinear light are totally reflected only on the third surface without being totally reflected in the first prism, and then emitted perpendicularly from the second surface. Two outgoing image lights parallel to each other,
The first reflected light and the second reflected light are totally reflected only on the first surface without being totally reflected internally, and then are parallel to each other and are emitted perpendicularly from the second surface. With two outgoing image lights,
It is like that. According to the said solution technique, the prism used as a 1st prism in the multifunctional image acquisition apparatus of Claims 1-4 can be provided.

In order to achieve the second object, the following fourth solution is adopted in the present invention. That is, as described in claim 8,
A first surface, a second surface continuous to form an apex angle of 60 degrees at one end of the first surface, and an apex angle of 60 degrees at the other end of the first surface A third surface that is continuous and forms an angle of 60 degrees with respect to the second surface,
Having a split surface orthogonal to the second surface through the intersection of the first surface and the third surface;
An internal optical filter that splits yellow light incident perpendicularly to the first surface into straight light and reflected light and color-separates it into red light and green light, and parallel to the first light flux. And a reflective film that reflects the second light beam that is blue light incident on the first surface is set,
The straightly traveling light is totally reflected only on the third surface without being totally reflected inside, and then emitted vertically from the second surface,
The reflected light and the second light flux reflected by the reflective film are totally reflected on the first surface without being totally reflected internally, and then emitted vertically from the second surface.
It is like that. According to the above solution, it is possible to provide a prism used as the first prism in the multi-function image acquisition device according to claim 5 or 6.

On the premise of the fourth solution method, the following solution method can be adopted. That is,
Of the regular triangular prisms, the vertex portion far from the first surface is cut and has a fourth surface extending substantially parallel to the divided surface. (Corresponding to claim 9). In this case, it is preferable in terms of size reduction, weight reduction, reduction in the amount of prism material used, and the like.

On the premise of the first solution technique, the following solution technique can be adopted. That is,
The external filter is for delay (corresponding to claim 10). In this case, it is possible to simultaneously acquire a plurality of outgoing image lights whose time is slightly shifted from each other, using incident image light as a pulse beam, for example.

On the premise of the first solution technique, the following solution technique can be adopted. That is,
The first prism acts on the two light fluxes from the second prism on the splitting surface of the first prism, and passes only the intermediate wavelength between the first wavelength and the second wavelength larger than the first wavelength. 1 filter is provided,
The second prism is provided with a second filter that allows incident image light to pass only a longer wavelength that is not less than a third wavelength that is a wavelength between the first wavelength and the second wavelength,
The emitted image light emitted from the second surface is four emitted image lights having different wavelength ranges,
(Corresponding to claim 11). In this case, four outgoing image lights having different wavelength ranges can be simultaneously acquired. For example, it is possible to obtain four outgoing image lights of blue light, green light, red light, and near infrared light, which is preferable in simultaneously obtaining a color image and a thermal image.

The first prism is arranged in two or more stages between the second prism and the imaging device, and the total number of the second prism and the plurality of first prisms is n. (N ≧ 3), the number of parallel output image lights emitted from the first prism in the final stage located immediately before the imaging device is set to 2 ⁿ (claim 12). Correspondence). In this case, the number of output image lights synchronized with each other in parallel can be dramatically increased.

  According to the multifunctional image acquisition device of the present invention, the optical path lengths of the plurality of outgoing image light beams emitted vertically from the second surface can be made equal to each other, whereby a plurality of images acquired by one imaging device can be obtained. Can be completely synchronized. In addition, according to the prism of the present invention, it is possible to provide a suitable first prism in the multifunctional image acquisition apparatus.

BRIEF DESCRIPTION OF THE DRAWINGS Whole explanatory drawing which shows one Embodiment of this invention. The detail of the part enclosed by D of FIG. 1, which shows the detail of the prism part of this invention. The 2nd Embodiment of this invention is shown, and the figure corresponding to FIG. The figure which shows the 3rd Embodiment of this invention. The figure which shows the 4th Embodiment of this invention, and is a figure corresponding to FIG. The figure which shows the characteristic of the filter in embodiment of FIG.

  In FIG. 1, 1 is a laser transmitter (for example, He-Ne system). The laser transmitted from the laser transmitter 1 passes through the spatial filter 2, the lens 3, and the reflection mirror 4, enters the beam splitter 5 as parallel light, and is split into two light beams by the beam splitter 5.

  One light beam from the beam splitter 5 is converted to a P wave, which is incident on the beam splitter 7 via the reflection mirror 6. Further, the other light beam passing through the beam splitter 5 is converted into an S wave, which is incident on the beam splitter 7 via the reflection mirror 8. These light beams serve as incident image light for a first prism, which will be described later.

  One light beam that has passed through the beam splitter 5 is, for example, reference light, and the other light beam is detection light that passes through the test target substance. That is, for example, when measuring the turbulent state of air by an object, the optical path is set so that the detection light passes behind the object installed in a wind tunnel through which laminar air flows. Further, the inside of the wind tunnel is heated to form a temperature distribution state having a temperature difference in the vertical direction, for example. When laminar air flows through a certain object in the wind tunnel, the air is disturbed by the certain object, so that the temperature distribution state behind the certain object changes. When there is a temperature change, the refractive index of air changes and the phase of the detection light changes. Then, interference occurs between the reference light and the detection light whose phase has been changed, and interference fringes can be formed. However, since the reference light is an S wave and the detection light is a P wave, If both lights are simply condensed, it is difficult to confirm the interference fringes in the image, and an interference fringe image having a high contrast is acquired by forming an optical path to be described later. The P wave can be used as reference light, and the S wave can be used as detection light.

  As will be described later, the incident image light that has passed through the beam splitter 7 passes through the second prism 10 and the first prism 20 as a spectral prism and enters a CCD camera 30 as an imaging unit.

  FIG. 2 is an enlarged view of a portion after passing through the beam splitter 7 in FIG. 1 (D portion in FIG. 1). The second prism 10 branches the incident image light from the beam splitter 7 into two light beams V1 and V2 that are parallel to each other in the emission state, and each of the light beams V1 and V2 is a first prism. 20 is incident. The intensity (brightness) of the light beams V1 and V2 is set to be substantially equal to each other, and the second prism 10 includes a non-polarizing beam splitter film that bisects the incident light while maintaining the polarization state. doing. Since the second prism 10 itself as such a spectroscopic prism is well known, detailed description thereof is omitted.

  As will be described later, the first prism 20 splits the first light beam V1 into two light beams, and the two light beams are parallel to each other and are directed to the same direction in the first and second outgoing image light W1, It has the function of emitting as W2. The first prism 20 splits the second light flux V2 into two, and the third and fourth two parallel to the first and second emission image lights W1 and W2 and directed in the same direction. It has a function of emitting the emitted image lights W3 and W4.

  Details of the first prism 20 will be described. First, the first prism 20 is generally formed into a regular triangular prism shape having a regular triangular cross section, and has a first surface M1, a second surface M2, and a third surface M3. Three vertices (intersections between the surfaces M1 to M3) of the first prism 20 are indicated as α1, α2, and α3. The angle formed by each vertex is 60 degrees.

  The first prism 20 is configured by joining two prisms P1 and P2 each having a right triangular prism shape, and a joint surface thereof is a split surface B1. That is, the dividing plane B1 is set to be orthogonal to the second plane M2 through the vertex α2 that is the intersection of the first plane M1 and the third plane M3. On the splitting surface B1, first and second internal optical filters for splitting the two light beams from the second prism 10 into two are set (consisting of a non-polarizing beam splitter film). .

  On the total reflection surfaces of the first surface M1 and the third surface M3, a phase control film for reducing a phase change caused by total reflection is applied. This phase control film has an antireflection function at normal incidence and also has an effect of reducing stray light.

  The first light beam V1 incident perpendicularly to the first surface M1 of the first prism 20 is split into reflected light V11 and straight light V12 by the splitting surface B1 (first internal optical filter). The reflected light V11 is totally reflected only on the first surface M1, and is used as the first emission image light W1 emitted perpendicularly from the second surface M2. Further, the straight traveling light V12 is totally reflected only on the third surface M3, and becomes the second emission image light W2 emitted perpendicularly from the second surface M2.

  The second light beam V2 incident perpendicularly to the first surface M1 of the first prism 20 is split into the reflected light V21 and the straight light V22 by the split surface B1 (second internal optical filter). The reflected light V21 is totally reflected only on the first surface M1, and becomes the third emission image light W3 emitted perpendicularly from the second surface M2. Further, the straight traveling light V12 is totally reflected only on the third surface M3, and becomes the second emission image light W2 emitted perpendicularly from the second surface M2.

  The outgoing image lights W1 to W4 emitted perpendicularly from the second surface M2 are incident on the CCD camera 30 from positions parallel to each other and shifted from each other along the second surface M2. That is, the CCD of the CCD camera 30 is indicated by reference numeral 31, and this CCD 31 extends elongated along the second surface M2. Images corresponding to the respective outgoing image lights W1 to W4 are obtained as four images arranged in a single plane in the CCD 31. For this reason, the four images displayed on one CCD 31 can perform calculations between pixels in the same CCD 31. Images corresponding to the respective outgoing lights W1 to W4 can be clearly distinguished by the pixel position of the CCD 31. Image separation positions corresponding to the emitted lights W1 to W4 are indicated by reference numerals 31a to 31c.

  Between the first prism 20 and the CCD camera 30, optical filters 41 to 43 serving as a plurality of external optical filters are disposed. The optical filter 41 is disposed corresponding to the outgoing light W1, and only the outgoing light W1 passes through it. The optical filter 42 is disposed corresponding to the outgoing light W2, and only the outgoing light W2 passes through it. The optical filter 43 is disposed corresponding to the outgoing light W3, and only the outgoing light W3 passes therethrough. An optical filter is not provided for the outgoing light W4.

  The optical filters 41 to 43 are polarizing plates in one embodiment, and their polarization angles (polarization directions) are shifted from each other by 120 degrees. As a result, the CCD camera 30 obtains an image of interference fringes whose phases are shifted by 120 degrees. Further, the fourth outgoing image light W4 is not provided with an optical filter, and the intensity (brightness) of the outgoing light is acquired. As an external optical filter, a color filter, a band pass filter, a phase plate, an RGB filter, a UV / IR cut filter, a dichroic filter, an ND filter, an antireflection film, a half mirror, or a combination thereof, as well as a polarizing plate, or a combination thereof Can be used. The external optical filters 41 to 43 can be provided for any one or two or more outgoing image lights.

  Here, the optical path lengths from the incidence to the emission in the first prism 20 are equal to each other between the emission image lights W1 to W4. In particular, since an air gap for total reflection is not set in the optical path in the first prism 20 corresponding to each of the outgoing image lights W1 to W4, the optical path length of each of the outgoing image lights W1 to W4 is set. It can be set to be completely equal (ensuring perfect synchronization of the four images acquired by the CCD camera 30).

  By using a high-speed CCD camera 30 (for example, a camera having several tens of frames per second or several hundred to several thousand frames can be used), a phenomenon that changes within a very short time has a function. A plurality of images can be acquired simultaneously. There is no limit on the frame rate. Therefore, in the method of the present invention, the upper limit for high-speed shooting is attributed to the performance of the CCD camera and not to the system of the present invention. Of course, as the image pickup means, a camera other than the CCD camera 30, for example, a camera using a CMOS image sensor used for a high-speed camera, a film camera, or the like can be used as appropriate.

  Next, an example suitable for application to a high-speed multi-color camera that captures images in a state where a plurality of outgoing image lights are separated into blue, red, and green will be described. First, the spectrum of the second prism 10 is separated into blue light and yellow light and separated (use of a color separation film). For example, the first light beam V1 is yellow light, and the second high-speed V2 is blue light. In addition, when the light is split on the dividing surface B1, the first light beam V1 of yellow light is split using the color separation film in a state of being color-separated into straight light of green light and reflected light of red light. Thereby, the outgoing image light W1 is red light, and the outgoing image light W2 is green light. Further, the third and fourth emission image lights W3 and W4 that are blue light are each blue light. The external optical filters 41 to 43 are abolished. In this way, the CCD camera 30 can capture the incident image light in a state of being separated into the blue light, the red light, and the green light that are synchronized with each other (R (red), G (green), B). (Blue) is decomposed and picked up for each wavelength of the three colors). The first light beam V1 can be blue light, and the second light beam V2 can be yellow light.

  FIG. 3 shows a second embodiment of the present invention, and shows a suitable example as a high-speed multi-color camera by obtaining three light beams of blue light, red light and green light as emitted image light. In addition, the same code | symbol is attached | subjected to the same component as the said embodiment, and the duplicate description is abbreviate | omitted.

  In the present embodiment, the color separation in the second prism 10 is such that the first light beam V1 is blue light and the second light beam V2 is yellow light. A reflective film H that reflects blue light is set on the dividing surface M1 of the first prism 20. The first light beam V1 converted to blue light is reflected by the reflective film H, then totally reflected by the first surface M1, and emitted as blue light vertically from the second surface M2.

The second light beam V2 that has been converted into yellow light is split into reflected light V21 that has been converted into green light and straight light V22 that has been converted into red light by the color separation film set on the dividing surface B1. The reflected light V21 is totally reflected by the first surface M1 and emitted as green light vertically from the second surface M2. Further, the straight light V22 is totally reflected by the third surface M3, and is emitted as red light vertically from the second surface M2. As a result, the CCD camera 30 separates and captures images for each of the three wavelengths of R (red), G (green), and B (blue). In the embodiment of FIG. Therefore, the shape of the second prism 20 is slightly changed from the case of FIG. That is, in the embodiment of FIG. 3, a part of the corner area in the regular triangular prism shown in FIG. 2 is cut (the cut area C is surrounded by a one-dot chain line). That is, a region near the intersection extending from the second surface M2 and the third surface M3 is cut from the regular triangular prism to have the fourth surface M4. The fourth surface M4 is substantially parallel to the dividing surface B1 (completely parallel in the embodiment). The cut area C is reduced in size and weight, and the prism material used is also saved.

  Here, in the embodiment of FIG. 2, the effective diameter of each of the emitted image lights W1 to W4 is increased, and the interval between the emitted image lights W1 to W4 (the boundary where no image exists on the imaging surface of the imaging device 30). It is desired to make the area as small as possible. For example, when the effective diameter of each of the output image lights W1 to W4 is, for example, 3.5 mm, and the interval is, for example, 0.4 to 0.55 mm, the lengths of the three surfaces M1, M2, and M3 in the first prism 20 For example, the length of one side between the vertices α1 and α2 can be made extremely small, for example, about 16 mm (the length of one side of the second prism 10 is about 8 mm).

  FIG. 4 shows a third embodiment of the present invention. In the present embodiment, a plurality of images (four in the embodiment) having slightly different times are acquired using the prisms 10 and 20 shown in FIG. That is, the pulse beam from the pulsed laser 50 is incident on the prism 10 after passing through the subject, and four pulsed emitted lights are emitted from the prism 20.

  On the second surface (outgoing surface) M2 of the prism 20, delay glasses 51 to 53 having different thicknesses are arranged as delay filters at positions where the three outgoing lights W1 to W3 pass. Yes. As a result, four images with different times are taken by the CCD camera 30. When the retardation glass has a refractive index of 1.5 and a thickness of 3 mm, the retardation glass is delayed by 3.3 ps as compared to the case without the retardation glass. By the way, when the thickness of the delay glass 51 to 53 is set to 3 mm, 2 mm, and 1 mm, they are delayed by 3.3 ps, 2.2 ps, and 1.2 ps, respectively, as compared to the case without the delay glass. Will be.

  5 and 6 show a fourth embodiment of the present invention. In this embodiment, four outgoing image lights having different wavelength ranges are obtained using the prisms 10 and 20 shown in FIG. That is, as shown in FIG. 5, the first filter H <b> 1 that allows only the wavelength in the intermediate region to pass is provided on the dividing plane B <b> 1 of the first prism 20. Specifically, as shown by the broken line in FIG. 6, the first filter H1 is set to pass only the intermediate position wavelength between the first wavelength λ1 and the second wavelength λ2 larger than λ1. (Reflects light other than the mid-range wavelength).

  On the other hand, the second prism 10 is provided with a second filter H2. As shown by the solid line in FIG. 6, the second filter H2 is set so as to pass only the wavelength of the third wavelength λ3 or more (light having a wavelength less than the third wavelength is reflected). The third wavelength λ3 is an intermediate wavelength between the first wavelengths λ1 and λ2.

  In the configuration as described above, the first light beam V1 passing through the second filter H2 becomes light having a long wavelength equal to or longer than the third wavelength λ3. The first light beam V1 is split into reflected light and passing light by the first filter H1, and becomes output image light W1 and W2. The outgoing image light W1 that is reflected light is red light, and the outgoing image light W2 that is passing light is near infrared light.

  The second light beam V2 reflected by the second filter H2 has a short wavelength less than the third wavelength λ3. The second light beam V2 is split into reflected light and passing light by the first filter H1, and then emitted. The image lights W3 and W4 are obtained. The outgoing image light W3 that is reflected light is blue light, and the outgoing image light W4 that is passing light is green light.

  Thus, in the present embodiment, blue light, green light, red light, and near-infrared light can be simultaneously acquired, and a color image and a thermal image can be simultaneously acquired. Of course, by changing the settings of the wavelengths λ1, λ2, and λ3 shown in FIG. 6, it is possible to simultaneously acquire four outgoing image lights that are decomposed into arbitrary four different wavelength ranges.

  As an application example of the present invention, two or more first prisms 20 are provided, and image light emitted from the second surface M2 of a certain first prism 20 is perpendicular to the first surface M1 of the next first prism 20. The number of outgoing image lights can be increased. That is, when the number of the first prisms 20 is 1, the spectral number is 4 (corresponding to the embodiment of FIG. 2), but when two first prisms 20 are provided, the final number of the spectrals is When the number of the first prisms 20 is three, the final number of the spectra is 16. That is, if the sum of the number of the second prisms 10 and the number of the first prisms 20 is n, the finally obtained spectral number is “2 to the power of n”.

  Although the embodiments have been described above, the present invention is not limited to this, and appropriate modifications can be made. In particular, the contents disclosed in Patent Document 1 can be applied (utilized) as they are. Of course, the object of the present invention is not limited to what is explicitly stated, but also implicitly includes providing what is substantially preferred or expressed as an advantage.

  The present invention is suitable, for example, as an image acquisition device used for analyzing fluid flow or as a small color image acquisition device.

10: 2nd prism 20: 1st prism 30: CCD camera (imaging means)
31: CCD
41 to 43: external optical filter S wave: detection light P wave: reference light H: reflection film M1: first surface M2: inner surface M3: third surface B1: divided surface W1: first outgoing image light W2: Second outgoing image light W3: Third outgoing image light W4: Fourth outgoing image light

Claims (12)

A first surface, a second surface continuous to form an apex angle of 60 degrees at one end of the first surface, and an apex angle of 60 degrees at the other end of the first surface A first prism having a third surface that is continuous and forms an angle of 60 degrees with respect to the second surface;
A second prism that splits the incident image light into a first light beam and a second light beam that are parallel to each other, and causes the two light beams to enter the first surface perpendicularly;
One imaging device disposed facing the second surface;
With
The first prism has a split surface that is orthogonal to the second surface through an intersection of the first surface and the third surface;
A first internal optical filter that splits the first light beam into first straight light and first reflected light on the splitting surface, and a second light that splits the second light beam into second straight light and second reflected light. With an internal optical filter,
The first rectilinear light and the second rectilinear light are not totally reflected within the first prism, but are totally reflected only by the third surface, and then emitted vertically from the second surface. Two outgoing image lights,
The first reflected light and the second reflected light are totally reflected only on the first surface without being totally reflected in the first prism, and then emitted perpendicularly from the second surface. Two outgoing image lights,
The imaging device captures each of the emitted image light at the same time to obtain a plurality of images at the same time.
A multi-function image acquisition apparatus characterized by that. In claim 1,
A multi-function image acquisition device, wherein an external filter is disposed between the second surface and the imaging device so as to correspond to any one or more of the emitted image light. In claim 1,
The first light beam and the second light beam separated by the second prism are color-separated into yellow light and blue light,
The yellow light is color-separated into red light and green light by the dividing plane,
The plurality of outgoing image lights are red light, blue light and green light,
A multi-function image acquisition apparatus characterized by that. In any one of Claims 1 thru | or 3,
The multifunction image acquisition apparatus according to claim 1, wherein the first prism has a regular triangular prism shape. A first surface, a second surface continuous to form an apex angle of 60 degrees at one end of the first surface, and an apex angle of 60 degrees at the other end of the first surface A first prism having a third surface that is continuous and forms an angle of 60 degrees with respect to the second surface;
A second prism that splits incident image light into blue light and yellow light that are parallel to each other, and makes the two light beams vertically incident on the first surface;
One imaging device disposed facing the second surface;
With
The first prism has a split surface that is orthogonal to the second surface through an intersection of the first surface and the third surface;
On the dividing surface, a reflective film that reflects the blue light, and an internal optical filter that separates the yellow light into straight light and reflected light and color-separates into red light and green light, are set.
The blue light incident on the first surface is reflected by the reflective film, then totally reflected by the first surface, and is emitted image light emitted perpendicularly from the second surface,
The straightly traveling light is totally reflected by the third surface, and then is emitted image light emitted vertically from the second surface;
After the reflected light is totally reflected by the first surface, the reflected light is emitted image light emitted vertically from the second surface,
The imaging device simultaneously captures emitted image light of blue light, red light, and green light.
A multi-function image acquisition apparatus characterized by that. In claim 5,
The first prism has a fourth surface which is formed in a shape in which a vertex portion far from the first surface is cut out of a regular triangular prism, and extends substantially parallel to the division surface. A multi-function image acquisition apparatus. A first surface, a second surface continuous to form an apex angle of 60 degrees at one end of the first surface, and an apex angle of 60 degrees at the other end of the first surface A third surface that is continuous and forms an angle of 60 degrees with respect to the second surface,
Having a split surface orthogonal to the second surface through the intersection of the first surface and the third surface;
A first internal optical filter that splits the first light beam incident perpendicularly to the first surface into first straight light and first reflected light on the split surface, and the first parallel to the first light beam. A second internal optical filter that splits the second light flux incident on the surface into second straight light and second reflected light is set,
The first rectilinear light and the second rectilinear light are totally reflected only on the third surface without being totally reflected in the first prism, and then emitted perpendicularly from the second surface. Two outgoing image lights parallel to each other,
The first reflected light and the second reflected light are totally reflected only on the first surface without being totally reflected internally, and then are parallel to each other and are emitted perpendicularly from the second surface. With two outgoing image lights,
Prism characterized by that. A first surface, a second surface continuous to form an apex angle of 60 degrees at one end of the first surface, and an apex angle of 60 degrees at the other end of the first surface A third surface that is continuous and forms an angle of 60 degrees with respect to the second surface,
Having a split surface orthogonal to the second surface through the intersection of the first surface and the third surface;
An internal optical filter that splits yellow light incident perpendicularly to the first surface into straight light and reflected light and color-separates it into red light and green light, and parallel to the first light flux. And a reflective film that reflects the second light beam that is blue light incident on the first surface is set,
The straightly traveling light is totally reflected only on the third surface without being totally reflected inside, and then emitted vertically from the second surface,
The reflected light and the second light flux reflected by the reflective film are totally reflected on the first surface without being totally reflected internally, and then emitted vertically from the second surface.
Prism characterized by that. In claim 8.
Of the equilateral triangular prisms, the apex portion on the side far from the first surface is cut and has a fourth surface extending substantially parallel to the divided surface. Prism to do. In claim 2,
The multi-function image acquisition apparatus according to claim 1, wherein the external filter is for delay. In claim 1 or claim 2,
The first prism acts on the two light fluxes from the second prism on the splitting surface of the first prism, and passes only the intermediate wavelength between the first wavelength and the second wavelength larger than the first wavelength. 1 filter is provided,
The second prism is provided with a second filter that allows incident image light to pass only a longer wavelength that is not less than a third wavelength that is a wavelength between the first wavelength and the second wavelength,
The emitted image light emitted from the second surface is four emitted image lights having different wavelength ranges,
A multi-function image acquisition apparatus characterized by that. In claim 1,
The first prism is arranged in two or more stages between the second prism and the imaging device, and the total number of the second prism and the plurality of first prisms is n. A multi-function image characterized in that the number of parallel output image lights emitted from the first prism in the final stage located immediately before the imaging device is 2 ^n. Acquisition device.

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