JP2021173822A - Incoherent digital hologram imaging device and imaging method thereof - Google Patents

Abstract

To provide an incoherent digital hologram imaging device capable of improving SNR of a reconfigured image, and an imaging method thereof.SOLUTION: An incoherent digital hologram imaging device comprises: a beam splitter 2 which splits an incoherent light wave from an object 1 and performs recomposition; two mirrors 3a, 3b which modulate a radius of curvature of a wavefront of one of a first split light wave and a second split light wave obtained by the splitting, and relatively impart a distribution of spherical phases to the wavefronts of those light waves; an image sensor 5 which captures interference fringes formed by interference between two split light waves emitted from those two mirrors 3a, 3b and multiplexed by the beam splitter 2; opening means 6 which guides a light of a part of the object 1 toward the beam splitter 2; opening position moving means 10 which moves an opening part 6a of the opening means 6; and arithmetic means 9 which obtains a reconstituted image of the whole object based upon a plurality of holograms by the interference fringes obtained by the image sensor 5 each time the opening part is moved.SELECTED DRAWING: Figure 1

Description

The present invention relates to an incoherent digital hologram imaging device and an imaging method thereof, and more particularly to an incoherent digital hologram imaging device used in a three-dimensional television system or the like.

Incoherent holography technology does not require a light source with high coherence such as a laser, and can record a hologram of an object using a light source with low coherence such as sunlight or fluorescence. As described above, incoherent holography can alleviate the coherence condition of the light source required in the conventional holography, so that the range of application of holography can be expanded.

FIG. 10 shows an example of a conventionally known optical system for incoherent holography.
In the incoherent holography using the Michelson interferometer, which is a representative of the non-common path interferometer shown in FIG. 10, the spatially incoherent light wave propagated from the object 701 is split by the beam splitter 702. Split into two light waves. One of these two divided light waves is referred to as a first divided light, and the other is referred to as a second divided light. Of these two divided lights, the first divided light is reflected by the flat mirror 703a, and the second divided light is reflected by the concave mirror 703b having a radius of curvature different from that of the mirror 703a so as to be slightly focused. Modulate the relative phase distribution.

The two light waves reflected by the mirror 703a and the concave mirror 703b are incident on the beam splitter 702 again and superposed. When the optical path length difference between the two light waves is shorter than the coherence length of the light source, the first division light and the second division light interfere with each other, so that the image sensor 705 can image the interference fringes of self-interference. When the coherence length of the light source is short and interference fringes are not formed, a bandpass filter or the like is inserted into the optical path in order to narrow the wavelength range of the light wave from the light source.

In this state, the positions of the flat mirror 703a or the concave mirror 703b are set by a distance of 1/8 of the wavelength of light in the optical axis direction (optical path length difference of 1/4 wavelength in a round trip) using a piezo element or the like. By moving, the interference fringes of four different phase patterns are acquired by the image sensor 705. From these interference fringes, a predetermined calculation is performed by the arithmetic unit 709 to calculate the hologram of the object 701.
Further, the arithmetic unit 709 can perform back propagation calculation from this hologram and acquire a reconstructed image of the object 701 at an arbitrary position (see Patent Document 1 below).

Japanese Patent Application Laid-Open No. 2016-533542

By the way, when the object 701 is considered as a set of points, the interference fringes of light from each point of the object 701 form a Fresnel zone plate (FZP). Therefore, the interference fringes of the object 701 acquired by the image sensor 705 are a combination of a large number of FZPs.

As the size of the object 701 increases, that is, as the number of points constituting the object 701 increases, a large number of FZPs overlap each other, so that the amplitude (contrast) of the interference fringes decreases and the object becomes more susceptible to noise. Further, when the number of gradations of the image sensor 705 is small, the interference fringes cannot be accurately acquired.

Therefore, the larger the object 701, the lower the signal-to-noise ratio (SNR) of the interference fringes, and the lower the SNR of the hologram calculated from the interference fringes, and thus the reconstructed image.
The present invention has been made in view of such circumstances, and is an incoherent digital hologram imaging device and an imaging method thereof, which can improve the SNR of the reconstructed image and realize a reconstructed image having a higher image quality than the conventional one. The purpose is to provide.

The incoherent digital hologram imaging device of the present invention
An optical dividing means for dividing an incoherent light wave from an object into two light waves consisting of a first divided light and a second divided light.
A phase distribution variable means for modulating the radius of curvature of at least one wavefront of the first divided light and the second divided light to impart a relative spherical phase distribution to the wavefronts of the two divided light waves.
A photosynthetic means for synthesizing two light waves composed of the first divided light and the second divided light that have passed through the phase distribution variable means.
An interference fringe imaging means for imaging interference fringes formed by the first division light and the second division light synthesized by the photosynthesis means interfering with each other.
An opening means that guides the light of only a part of an object in the direction of the light dividing means,
An opening position movement setting means for moving and setting the opening position of the opening means,
The position of the opening of the opening means is moved by the opening position movement setting means, a hologram of the object is obtained based on the interference fringes imaged by the interference fringe imaging means at each moved position, and the position of the opening is obtained. A reconstructed image calculation means for obtaining a reconstructed image of the entire object based on the hologram obtained for each, and
It is characterized by having.
Here, the above-mentioned "each moved position" can include the first opening position before moving.

Further, the opening means can be arranged at a position between the object and the illumination, or a position between the object and the light dividing means.
Further, it is preferable to provide a lens for forming an image of the object at the position of the opening of the opening means arranged between the object and the light dividing means.

In addition, it is possible to combine the obtained plurality of the holograms with each other to obtain a composite hologram, and to obtain a reconstructed image of the entire object based on the composite hologram.
In addition, a reconstructed image of each part of the object can be obtained from each of the obtained plurality of holograms, and a reconstructed image of the entire object can be obtained based on the obtained reconstructed image of each part of the object. It is possible.

Further, the incoherent digital hologram imaging method of the present invention can be used.
Only a part of the incoherent light wave from the object is guided in the direction of the light dividing means through the opening, and the incoherent light wave from the object is converted into two light waves consisting of the first divided light and the second divided light by the light dividing means. It is divided and the radius of curvature of at least one wave surface of the first divided light and the second divided light is modulated to give a relative spherical phase distribution to the wave surfaces of the two divided light waves, and relative to each other. The interference fringe acquisition step of combining the first divided light and the second divided light to which the distribution of the spherical phase is given to the light and imaging the interference fringes obtained by the combined waves.
The step of obtaining a hologram relating to a part of the object based on the imaged interference fringes.
Each time the opening is moved and set, the process is repeated to obtain a reconstructed image of the entire object based on the hologram relating to a part of the object obtained each time.
It is characterized by that.
Here, the above-mentioned "every time the movement is set" can include the case where the first opening position before the movement is set.

In the incoherent digital hologram imaging apparatus and imaging method of the present invention, the position of an opening through which a part of the light from an object passes is set, and then the opening position is set to be sequentially shifted, and each time the setting is made. The interference fringes are imaged, holograms of each part of the object are obtained based on the obtained interference fringes, and a reconstructed image of the entire object is obtained from the obtained holograms of each part of the object.
As a result, the number of points constituting the object passing through the position of the aperture at the time of one imaging can be reduced, and the number of overlapping FZPs corresponding to each of these points can be reduced.

Therefore, it is possible to suppress the amplitude (contrast) of the interference fringes from becoming small, make it less susceptible to noise, and suppress the decrease in the SNR value.
Further, even when the number of gradations of the image obtained by the image pickup apparatus is small, it is possible to accurately acquire the interference fringes.

A conceptual diagram for explaining the principle of the incoherent digital hologram imaging device according to the present embodiment ((a) is an optical system for imaging the left half of an object, and (b) is an optical system for imaging the right half of an object). be. A reconstructed image obtained by using the incoherent digital hologram imaging device (embodiment) according to FIG. 1 ((a) is a reconstructed image relating to the left half of an object, and (b) is a reconstructed image relating to the right half of the object. The image (c) shows an enlarged image of the lower right portion of FIG. 2 (b). A reconstructed image obtained by using an incoherent digital hologram imaging device according to a prior art ((a) is a reconstructed image of the entire object, (b) is an enlarged image of the lower right region of FIG. 3 (a)). Is shown. It shows a reconstructed image of the whole object obtained by synthesizing a partial image by using the incoherent digital hologram imaging apparatus (embodiment) shown in FIG. The optical system of the incoherent digital hologram imaging apparatus according to the first embodiment is shown ((a) is a case where an opening is provided in front of an object, and (b) is a case where an opening is provided in the rear of an object. If). The optical system of the incoherent digital hologram image pickup apparatus which concerns on Example 2 is shown. It is a figure which shows the example (the example of 4 patterns of (a)-(d)) of the moving state of the opening by the spatial light modulator which concerns on Example 2. FIG. The optical system of the incoherent digital hologram image pickup apparatus which concerns on the modification of Example 2 is shown. The optical system of the incoherent digital hologram imaging apparatus according to the third embodiment is shown ((a) is an optical system for acquiring the brightness distribution of an object, (b) is an optical system for acquiring interference fringes, and (c) is an optical system for acquiring interference fringes. (Example) of the moving state of the aperture by the spatial light modulator according to the third embodiment). It shows the optical system of the incoherent digital hologram image pickup apparatus which concerns on the prior art.

Hereinafter, the incoherent digital hologram imaging device and the imaging method according to the embodiment of the present invention will be described with reference to the drawings.

<Embodiment>
FIG. 1 mainly shows the optical system of the incoherent digital hologram imaging device according to the embodiment of the present invention, and the principle of the incoherent digital hologram imaging device of the present invention will be described with reference to FIG.

That is, the incoherent digital hologram imaging device shown in FIG. 1 allows the spatially incoherent light wave propagating from the object 1 to pass through the lens 4 and is parallel light (relative to the light from the focal position of the lens 4). Then, it is divided by the beam splitter 2 to obtain the first divided light and the second divided light. The first split light is positively reflected by the planar mirror 3a and the plane wave returns to the beam splitter 2, while the second split light is made into a spherical wave by the concave mirror 3b and is reflected so as to be slightly converged to the beam splitter. Return to 2.

The first split light returned to the beam splitter 2 is reflected in the image sensor 5 direction, while the second split light returned to the beam splitter 2 is transmitted in the image sensor 5 direction, so that these two split lights are superimposed. The interference fringes are formed on the imaging surface of the image sensor 5.
Here, the opening means 6 is arranged between the object 1 and the beam splitter 2, and one interference fringe is formed only by the light wave from a part of the object that has passed through the opening 6a of the opening means 6. NS.

The opening means 6 may have an opening 6a that allows a part of the light wave from the object 1 to pass through, and the position of the opening 6a may be movable, and the light wave from the object 1 is physically formed. It may have a shutter that blocks a part of the light wave, or it may be an optical space modulation element that transmits or reflects a part of the light wave.

For example, as shown in FIG. 1A, the light wave from the right half of the object 1 (upper half of the opening means 6 in the figure) is blocked, and the left half of the object 1 (below the opening means 6 in the figure) is blocked. By transmitting only the light wave from (half), an interference fringe corresponding to the left half of the object 1 with the constituent points of the object 1 being substantially half is formed.
An image obtained by reconstructing a hologram (hereinafter referred to as hologram A) obtained from the interference fringes is shown in FIG. 2A (reconstructed image of the left half of the object 1).

Next, as shown in FIG. 1B, the opening 6a of the opening means 6 is moved to the upper half position in the drawing of the opening means 6. As a result, the light wave from the left half of the object 1 (lower half of the opening means 6 in the figure) is shielded, and only the light wave from the right half of the object 1 (upper half of the opening means 6 in the figure) is transmitted. As a result, interference fringes corresponding to the right half of the object 1 with the constituent points of the object 1 being substantially half are formed.
An image obtained by reconstructing a hologram (hereinafter referred to as hologram B) obtained from the interference fringes is shown in FIG. 2 (b) (reconstructed image of the right half of the object 1).

The opening 6a of the opening means 6 is moved by the opening position moving means 10 performing a moving operation on the opening means 6 in response to an instruction from the arithmetic unit 9.
If the opening means 6 is a physical opening position switching means, the opening position moving means 10 is an XY 2-axis moving stage for moving the opening 6a, and if the opening means 6 is a spatial light modulator, the opening is opened. It is a pattern display driver, driver drive program, etc.

After that, the image in which the hologram A is reconstructed shown in FIG. 2A and the image in which the hologram B is reconstructed shown in FIG. 2B are combined to form the entire object 1 as shown in FIG. Obtain a reconstructed image.
When a reconstructed image is obtained from the above-mentioned hologram A or hologram B, a conventionally known back-propagation method or the like is used.

Further, the method of obtaining the hologram A or the hologram B from the interference fringes is performed by using a conventionally known phase shift method or Fourier transform method.
For example, in the 4-step phase shift method, the position of the planar mirror 3a (which may be a concave mirror 3b) is set to 1/8 (reciprocating) of the wavelength of light in the optical axis direction by using a piezo element or the like. While the position of the opening 6a in the opening means 6 is fixed by moving the optical path length by 1/4 wavelength in the path, interference fringes of four different phase patterns are acquired by the image sensor 5, and these From the interference fringes, the hologram is calculated by the arithmetic unit 9 by a well-known calculation method.

As described above, according to the incoherent digital hologram imaging device according to the present embodiment, the range of the object 1 to be imaged (the number of points constituting the object 1) is halved for each hologram to be imaged (image sensor). Since the imaging region of 5 is left as it is), the number of overlapping FZPs (Frenel zone plates) can be halved.
As a result, it is possible to suppress the amplitude (contrast) of the interference fringes from becoming small, make it less susceptible to noise, and suppress a decrease in the SNR value.

Note that FIG. 2 (c) shows the lower right corner portion (see the black triangle marker) of the above-mentioned reconstructed image (FIG. 2 (b)) obtained by using the incoherent digital hologram imaging apparatus according to the present embodiment. The lower right corner (see the black triangle marker) of the reconstructed image (FIG. 3 (a)) obtained by using the image pickup device (see FIG. 10) according to the prior art is enlarged. It is clear that the image noise is clearly reduced and the SNR is improved when compared with the one (see FIG. 3B).

Hereinafter, specific examples of the present invention will be described.
<Example 1>
In this embodiment, a basic incoherent digital hologram imaging method will be described with reference to FIGS. 5 (a) and 5 (b). Although the configuration is substantially the same as that of the imaging device according to the embodiment shown in b), the arrangement position of the opening means 6 may be any of the positions shown in FIGS. 5 (a) and 5 (b). The members corresponding to the members shown in FIGS. 1 (a) and 1 (b) shall be designated by adding 100 to the reference numerals given to the members shown in FIGS. Detailed explanation will be omitted.

That is, as shown in FIG. 5 (a), the opening means 106 may be provided in front of the object 101 (interferometer side), or as shown in FIG. 5 (b), behind the object 101 (interference). The opening means 106 may be provided on the side opposite to the meter side).

Hereinafter, this embodiment will be described with reference to the configuration shown in FIG. 5 (a).
First, the opening means 106 mounted on the opening position moving means (XZ 2-axis stage (stage that can move in the biaxial direction orthogonal to the optical axis) 110) is arranged between the object 101 and the lens 104. The light wave from the object 101 that has passed through the opening 106a provided so as to open a part of the opening means 106 is divided into two paths by the beam splitter 102, and as described in the embodiment shown in FIG. 1, the image sensor 105 In, the interference fringes of the object 101 are obtained.

Similar to the conventional technique, the position of the flat mirror 103a (concave mirror 103b is also possible) is moved in the optical axis direction by a distance of 1/8 of the wavelength of light (a distance at which the round-trip optical path length becomes 1/4 wavelength). To acquire the interference fringes of four different phase patterns. A hologram is calculated from the acquired interference fringes of the four phase patterns, and a partial image corresponding to the opening ratio of the opening 106a of the object 101 at an arbitrary depth direction position is reconstructed by back propagation calculation.

Next, the position of the opening 106a of the opening means 106 is moved in the vertical direction and the horizontal direction by using the opening position moving means (XZ 2-axis stage) 110 to acquire interference fringes of various parts of the object 101. Then, each time the position of the opening 106a is moved, the interference fringes of the four-phase pattern are acquired and the hologram is calculated to reconstruct the partial image, as in the case described above.

Finally, the image of the object 101 having a high SNR can be reconstructed by synthesizing each of the reconstructed partial images according to the position of the opening.
In the above, the opening moving means 110 automatically shifts the position of the opening 106a of the opening means 106 by a predetermined amount of the XZ 2-axis stage equipped with the opening means 106 in response to an instruction signal from the arithmetic unit 109. Although the case of moving only the XZ 2-axis stage is described, the operator may manually operate the XZ 2-axis stage to move the opening 106a in the vertical direction and the horizontal direction by a predetermined amount at a predetermined timing.

<Example 2>
As shown in FIG. 6, this embodiment basically has the same steps as the incoherent digital hologram imaging method of the first embodiment, but uses a spatial light modulator as the aperture means 206. It has characteristics. In addition, about the member corresponding to the member of FIGS. 5 (a) and 5 (b), the code attached to each member of FIGS. Detailed explanation will be omitted.

That is, as shown in FIG. 6, an opening means 206 (hereinafter, also referred to as a spatial light modulator 206) composed of a spatial light modulator is provided between the object 201 and the lens 204, and the spatial light modulator 206 is shown in FIG. Each pattern ((a) to (d)) as shown is displayed to acquire interference fringes from a part of the object 201. As the spatial light modulator 206, a liquid crystal display element (transmissive type or reflective type) or a DMD (digital micromirror device) can be used.
In FIG. 7, the opening means (spatial light modulator) is represented by 306, and the openings are represented by 306a to 306a to c.

The pattern (a) displayed on the spatial light modulator 306 sequentially scans the opening 306a corresponding to one pixel from the upper left pixel to the lower right pixel of the spatial light modulator 306.
Further, in the pattern (b) displayed on the spatial light modulator 306, the opening 306a in a square region composed of a plurality of pixels (here, 4 pixels) is extended from the upper left region to the lower right region of the spatial light modulator 306. It scans sequentially.

Further, as a pattern to be displayed on the spatial light modulator 306, a pattern (c) or (d) in which a plurality of pixels separated from each other represented by 1 in a sparse matrix of 1 and 0 are used as openings 306a to 306a to c. ) May be. In this case, it is particularly preferable to set the average value of the distances between the distant openings 306a to 306 to be large. As a result, the ratio of the interference fringes generated by the light waves passing through the openings 306a to 306c of each other on the imaging surface of the image sensor 205 can be reduced, so that a decrease in SNR can be prevented.

FIG. 8 shows a modified example of the second embodiment. In addition, about the member corresponding to the member of FIGS. 6 (a) and 6 (b), the code attached to each member of FIGS. Detailed explanation will be omitted.

That is, as shown in FIG. 8, the aperture means 406 composed of the spatial light modulator can be provided at the position of the image plane when the object 401 is imaged by the lens 404b. Thereby, the SNR at the opening of the opening means 406 can be made particularly high.
The luminous flux diverging from this opening is made into a parallel luminous flux by the lens 404c and is incident on the beam splitter 402.

<Example 3>
This embodiment basically has the same steps as the incoherent digital hologram imaging method of the second embodiment, but when there is a bias in the brightness of the object 501, the opening means according to this bias. The size of the opening 506a of the (spatial light modulator) 506 (hereinafter, also referred to as the spatial light modulator 506) is weighted (the opening 506a is inversely proportional to the brightness of each part of the object 501). (By averaging the amount of light passing through this opening 506a), it is characterized by improving the SNR. In addition, about the member corresponding to the member of FIGS. 6 (a) and 6 (b), the code attached to each member of FIGS. Detailed explanation will be omitted.

That is, first, as shown in FIG. 9A, a mask 508 is provided between the concave mirror 503b of the interferometer and the beam splitter 502 to prevent the concave mirror 503b from being irradiated with light, and is reflected from the flat mirror 503a. Only the object light to be split is acquired by the image sensor 505. As a result, the brightness distribution of the object is acquired. Based on this acquired image, as shown in FIG. 9A, for example, it is discriminated into three regions of a bright (B) region, an intermediate (G) region, and a dark (D) region, and the result is determined by the arithmetic unit 509. It is stored in a memory or the like provided inside.

Next, as shown in FIG. 9B, the mask 508 is removed, and the interference fringes generated by the interference between the reflected light from the concave mirror 503b and the reflected light from the planar mirror 503a are acquired by the image sensor 505.

FIG. 9C shows the opening 506a displayed on the spatial light modulator 506. Based on the brightness distribution of the object 501 acquired by the image sensor 505 and stored in the memory or the like, the opening 506a of the region corresponding to the bright place of the object 501 is small, and the opening of the region corresponding to the dark place of the object 501 506a is set large. This makes it possible to reconstruct an image with a higher SNR without significantly increasing the number of patterns.

The incoherent digital hologram imaging apparatus and manufacturing method of the present invention are not limited to those of the above-described embodiment, and can be changed to various other aspects. For example, the configuration of the optical system of the device is not limited to that of the above embodiment.
Further, in the first embodiment, a reconstructed image of each part of the object is obtained from each of the obtained plurality of holograms, and a reconstructed image of the entire object is acquired based on the reconstructed image of each part of the obtained object. However, as the incoherent digital hologram imaging apparatus and manufacturing method of the present invention, a plurality of obtained holograms are combined with each other to obtain a composite hologram, and then the entire object is obtained based on the composite hologram. It may be configured to acquire the reconstructed image of.

This aspect will be briefly described with reference to FIG. That is, as in the first embodiment, the position of the flat mirror 103a (concave mirror 103b is also possible) is a distance of 1/8 of the wavelength of light in the optical axis direction (a distance at which the round-trip optical path length is 1/4 wavelength). ) Is moved to obtain interference fringes of four different phase patterns. The hologram is calculated from the interference fringes of the four acquired phase patterns.
Next, the position of the opening 106a of the opening means 106 is moved in the vertical direction and the horizontal direction by using the opening position moving means (XZ 2-axis stage) 110 to acquire interference fringes of various parts of the object 101. Then, each time the position of the opening 106a is moved, interference fringes of four phase patterns are acquired and a hologram (partial hologram) is calculated for each, as in the case described above.

After that, the obtained partial holograms for each part of the object are joined to create an entire hologram for the entire object.
By performing back propagation calculation on the entire hologram created in this way, the entire image of the object 101 at an arbitrary depth direction position can be reconstructed.
Further, in the above embodiment, the concave mirror that applies the spherical wave is arranged in one of the optical paths of the two divided lights, but the spherical wave is applied to both the optical paths of the two divided lights. A spherical mirror to be applied may be arranged to apply spherical waves having different radius of curvature to each of the passing divided lights.

In the above embodiment, the optical dividing means also serves as a photosynthetic means, but both means may be configured as separate members, such as a detour type Fizeau interferometer.
Further, although the Michelson interferometer is used in the above embodiment, it is also possible to use another iso-optical path length type interferometer such as a Mach-Zehnder interferometer or a Fizeau interferometer with a detour.
Further, in the above embodiment, in order to add a relative spherical wave between the two divided light waves, two mirrors having different curvatures are used. As such a spherical wave imparting means, A transmission type spherical wave imparting member may be used.

1, 101, 201, 401, 501, 701 Object 2, 102, 202, 402, 502, 702 Beam splitter 3a, 103a, 203a, 403a, 503a, 703a Mirror 3b, 103b, 203b, 403b, 503b, 703b Concave mirror 4, 104, 204, 404b, 404c, 504, 704 Lens 5, 105, 205, 405, 505, 705 Image sensor 6, 106, 206, 306, 406, 506 Aperture means (spatial light modulator)
6a, 106a, 306a to c, 506a Openings 9, 109, 209, 409, 509, 709 Arithmetic logic units 10, 110, 210, 410, 510 Opening position moving means 508 Mask

Claims (6)

An optical dividing means for dividing an incoherent light wave from an object into two light waves consisting of a first divided light and a second divided light.
A phase distribution variable means for modulating the radius of curvature of at least one wavefront of the first divided light and the second divided light to impart a relative spherical phase distribution to the wavefronts of the two divided light waves.
A photosynthetic means for synthesizing two light waves composed of the first divided light and the second divided light that have passed through the phase distribution variable means.
An interference fringe imaging means for imaging interference fringes formed by the first division light and the second division light synthesized by the photosynthesis means interfering with each other.
An opening means that guides the light of only a part of an object in the direction of the light dividing means,
An opening position movement setting means for moving and setting the opening position of the opening means,
The position of the opening of the opening means is moved by the opening position movement setting means, a hologram of the object is obtained based on the interference fringes imaged by the interference fringe imaging means at each moved position, and the position of the opening is obtained. A reconstructed image calculation means for obtaining a reconstructed image of the entire object based on the hologram obtained for each, and
An incoherent digital hologram imaging device characterized by being equipped with. The incoherent digital hologram imaging device according to claim 1, wherein the opening means is arranged at a position between the object and the illumination, or a position between the object and the light dividing means. The incoherent digital hologram imaging according to claim 1 or 2, wherein a lens for forming an image of an object is provided at a position of an opening of the opening means arranged between the object and the light dividing means. Device. The invention according to any one of claims 1 to 3, wherein the obtained plurality of the holograms are combined with each other to obtain a composite hologram, and a reconstructed image of the entire object is obtained based on the composite hologram. Incoherent digital hologram imaging device. A feature is that a reconstructed image of each part of the object is obtained from each of the obtained plurality of holograms, and a reconstructed image of the entire object is obtained based on the obtained reconstructed image of each part of the object. The incoherent digital hologram imaging apparatus according to any one of claims 1 to 3. Only a part of the incoherent light wave from the object is guided in the direction of the light dividing means through the opening, and the incoherent light wave from the object is converted into two light waves consisting of the first divided light and the second divided light by the light dividing means. It is divided and the radius of curvature of at least one wave surface of the first divided light and the second divided light is modulated to give a relative spherical phase distribution to the wave surfaces of the two divided light waves, and relative to each other. The interference fringe acquisition step of combining the first divided light and the second divided light to which the distribution of the spherical phase is given to the light and imaging the interference fringes obtained by the combined waves.
The step of obtaining a hologram relating to a part of the object based on the imaged interference fringes.
Each time the opening is moved and set, the process is repeated to obtain a reconstructed image of the entire object based on the hologram relating to a part of the object obtained each time.
An incoherent digital hologram imaging method characterized by this.

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