JPH08285688A - Spectrum image analyzing device - Google Patents

Abstract

PURPOSE: To facilitate the spectrum image analysis of an object by detachably fitting an attachment means in which a band transmitting interference filter and a convex lens have been combined, and by providing with a subtraction means or the like for obtaining the output difference of a plurality of light- receiving cells that have been set in a transmitting band region. CONSTITUTION: An image pickup means 21 arranged inside a casing 20 and a convex lens 22 for forming the image on a band transmitting interference filter 9 onto the means 21 are fitted to an image pickup device body 2. The rear part 5 of an attachment means 3 is detachably fitted to the front part 4 of the body 2, and a convex lens 7 and a filter 9 having its optical axis on the optical axis 8 thereof are fitted to the supporting tube 6 of the means 3. The electric signals from the respective light-receiving cells in the means 21 are successively given by a processing circuit. Different voltages are applied to a piezoelectric element, and the digital signals representing the level of the electric signal are stored in a memory for each color of the light-receiving cell, and the output of each memory is read out, and the spectrum differential action is carried out by a subtraction circuit for each color.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spectral image analysis device that can be used to enable accurate color discrimination.

[0002]

BACKGROUND OF THE INVENTION Accurate color identification and spectral image analysis is required in many technical fields. For example, even for a tree that looks the same in human vision, for example, a yellow-green color, by accurately performing its spectral image analysis, it is possible to accurately grasp the growth status of that tree and create an environment suitable for that tree. It can be devised so that it can be provided.

Conventionally, no apparatus has been realized for simply performing a spectral image analysis for accurately identifying the color of an object.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a spectral image analysis device capable of easily performing spectral image analysis of an object with a simple structure.

[0005]

According to the present invention, there is provided a band-pass interference filter capable of changing a light transmission band, an image pickup means having a plurality of light-receiving cells, and a first object for forming an image on the interference filter. Optical means and the image on the interference filter,
Second optical means for forming an image on each light receiving cell of the image pickup means, first output of each light receiving cell when the interference filter is set to the first transmission band, and second transmission band different from the first transmission band A spectrum including: a subtracting unit that calculates a difference between the second output of each light receiving cell when set to 1 and a corresponding light receiving cell, and a display unit that visually displays the output of the subtracting unit. It is an image analysis device. Further, the present invention has a band-pass interference filter capable of changing the transmission band of light, a plurality of pixels, each pixel by a blue, green and red color filter, and a light-receiving cell for each color filter. The configured image pickup means, the first optical means for forming an image of an object on the interference filter, the second optical means for forming an image on the interference filter on each pixel of the image pickup means, and the interference filter for the first. The difference between the first output of each light receiving cell when set to the transmission band and the second output of each light receiving cell when set to the second transmission band different from the first transmission band is set for each corresponding light receiving cell. Subtraction means for calculating and
And a display unit for displaying the output of the subtraction unit in color. According to the present invention, in an interference filter, a pair of substrates are arranged so as to face each other, and a gap between these substrates can be changed by a piezoelectric element. Each substrate is a plate-shaped body made of a translucent material and its plate. It is characterized in that it is composed of a thin film having a light-transmitting property for interference of light formed on the strip, and is applied by applying a voltage from a DC power source to the piezoelectric element. The present invention also provides an interference filter,
It includes a plate-like body that is translucent and whose thickness can be changed by an applied voltage, and a thin transparent film that is formed on both surfaces of the plate-like body and that interferes with light. It is characterized in that a voltage is applied to the plate-like body from a DC power source to give it. Further, according to the present invention, the interference filter and the first optical means are fixed to constitute an attachment means, the image pickup means and the second optical means are fixed to constitute an image pickup apparatus main body, and the second optical means of the image pickup apparatus main body is fixed. It is characterized in that the attachment means can be attached to and detached from the front side. Further, the present invention relates to a band-pass interference filter capable of changing the transmission band of light, a light receiving means for receiving the transmission spectrum light from the interference filter, and a light receiving means when the transmission band of the interference filter is different. And a subtraction unit that calculates a difference between outputs. Further, according to the present invention, a pair of substrates are arranged so as to face each other, and an interval between these substrates can be changed by a piezoelectric element, and each substrate is formed of a plate-shaped body made of a translucent material and the plate-shaped body A band-pass interference filter capable of changing the transmission band of light, which is characterized by comprising a thin film having a light-transmitting property for causing light to interfere, and applying a voltage from a DC power source to the piezoelectric element. is there. Further, the present invention is a translucent plate-like body whose thickness can be changed by an applied voltage,
A band-pass interference filter capable of changing a light transmission band, which is formed on both surfaces of the plate-like body and includes a light-transmissive thin film for light interference.

[0006]

According to the present invention, the first optical means, for example, the convex lens, forms an image of an object, for example, the above-mentioned tree,
An image is formed on the band-pass interference filter, and this interference filter
The interference filter has a configuration capable of changing the transmission band, and each position in the direction perpendicular to the optical axis of the interference filter is provided by the second optical means, for example, a convex lens, for blue B, green G and red R in the image pickup means. An image is individually formed corresponding to each of a plurality of pixels realized by a combination of a color filter and a light receiving cell for each color filter, and the subtraction means sets the first image of each cell when the first transmission band is set. 1 output,
The difference with the second output of each cell when set in the second transmission band is obtained, so to speak, spectral differentiation is performed, and the image of the spectral differentiation thus obtained is displayed in color. This performs a spectral image analysis of the color of the object, and by looking at the result of the analysis, for example, even if the human eyes see the same color, the exact color difference, that is, the spectral It is possible to easily detect the difference.

The image pickup means may have a structure in which each pixel is realized by a light receiving cell which is not provided with a color filter. At this time, the display means has a function of displaying a gray scale of a single color, for example, black and white. May be.

The interference filter has a structure in which the distance between a pair of substrates can be changed by a piezoelectric element, and is a transparent member for causing light interference on the surface of a plate made of a transparent material such as glass. Light thin film, for example 200-
Each substrate is formed by forming a 300 Å thin Au layer, and the visible light transmission band corresponding to the distance is changed by changing the DC voltage applied to the piezoelectric element.

The plate-shaped body of the substrate is, for example, a glass plate as described above, and the surface thereof has fine irregularities that change in a minute manner, for example, of the order of microns, but there is no problem in spectral image analysis. By forming an image on the interference filter on each pixel of the image pickup means or on the light receiving cell, each position in the direction perpendicular to the optical axis of the interference filter, that is, each position on the surface of the plate-shaped body of the substrate,
A configuration in which an image is formed by the second optical means individually corresponding to each pixel including a total of three color filters of B, G, and R in the image pickup means or each light receiving cell not provided with the color filter. Therefore, the spectral intensity for each of the two different transmission bands due to the interference filter is
Each light-receiving cell can be converted into an electrical signal with a level corresponding to its spectral intensity, which allows an accurate spectral image analysis of the color of the object.

The visual display means may be configured to display an image, but may be a bar graph of one horizontal scanning line or the like, or a sound or the like.

[0011]

1 is a sectional view showing a simplified overall structure of a spectral image analyzer 1 according to an embodiment of the present invention. This spectral image analysis device 1 basically comprises an image pickup device main body 2 realized by an existing color television camera and the like, and an attachment means 3, and a front portion 4 of the image pickup device main body 2 is provided with an attachment means 3. The rear part 5 is detachably attached.

A convex lens 7 as a first optical means and a band-pass interference filter 9 having an optical axis on its optical axis 8 are attached to the support cylinder 6 of the attachment means 3.

FIG. 2 is an enlarged sectional view showing a specific structure of the interference filter 9. In this interference filter 9, a pair of substrates 10 and 11 are arranged so as to face each other, and a piezoelectric element 12 is provided in the peripheral portion of the substrates 10 and 11 in order to change an air gap d1 between the substrates 10 and 11. To be done. The substrate 10 is a plate-shaped body 1 made of a translucent material such as glass.
3 and a light-transmissive thin metal film 14 formed on the surface of the plate-shaped body 13 on the side of the other plate-shaped body 11. Similarly, the other substrate 11 is also composed of a plate-shaped body 15 and a thin metal film 16 formed on the surface of one substrate 10 side.

The metal films 14 and 16 are, for example, 200 to 3
It has a structure in which Au having a thickness of about 00Å is formed by vapor deposition. The substrates 10 and 11 have the same structure,
The thickness of the plate-like bodies 13 and 15 is uniform over the entire surface,
For example, it is transparent, or so-called translucent, which is partially transparent. The piezoelectric element 12 has a DC power supply 17
, The power is supplied by changing the voltage. Board 1
The interval d1 between 0 and 11 is, for example, 50 μm when no voltage is applied to the piezoelectric element 12, and is, for example, 5 μm.
By applying 0V voltage, 50.05μm
Can change up to.

FIG. 3 is a graph showing the band transmission characteristic of the interference filter 9. When visible light having a uniform intensity is made to enter from one side (the right side in FIG. 2) of the interference filter 9, the piezoelectric element 12
In addition, the spectral intensity of the light transmitted to the downstream side (left side in FIG. 2) of the interference filter 9 when the first voltage, which may be zero, is applied is shown by the solid line in FIG. The first transmission band indicated by such a solid line is the substrate 10, 11,
Therefore, light having a plurality of types of spectra is selectively transmitted corresponding to the interval d1 due to multiple interference caused by the light transmitting through the metal films 14 and 16.

When the aforementioned second voltage of, for example, 50 V is applied to the piezoelectric element 12, d1 between the substrates 10 and 11 changes, whereby the spectral intensity of the light transmitted through the interference filter 9 is shown by the broken line in FIG. It changes as shown.

The image of the object 19 is formed by the convex lens 7 at the center of the interference filter 9 in the optical axis direction. Object 19
Is present at a distance far enough from the focal length of the convex lens 7, the distance between the convex lens 7 and the interference filter 9 is set equal to the focal length.

Referring again to FIG. 1, the image pickup device main body 2 has an image pickup means 21 arranged inside a casing 20.
And a convex lens 22 as a second optical means for forming an image on the interference filter 9 on the imaging means 21. The image pickup means 21 and the convex lens 22 have an optical axis common to the optical axis 8. The convex lenses 7, 22 may be adjustable in displacement along their optical axis 8 for imaging.

FIG. 4 is a simplified front view of an example showing a part of the image pickup means 21 in an enlarged manner. The imaging unit 21 is configured by arranging a plurality of pixels 23 adjacent to each other. Each pixel 23 is composed of a total of three color filters of blue B, green G and red R, and a light receiving cell formed of a CCD (charge coupled device) for each color filter. The light receiving cell receives the light from the color filter and derives an electric signal having a level corresponding to the intensity of the light of the received color.

Referring again to FIG. 3, this FIG.
The characteristics of the color filter included in each pixel 23 are shown. Reference numeral 24 indicates the characteristic of the blue B color filter, and reference numeral 2
5 indicates the characteristics of the green G color filter, and reference numeral 26 indicates
The characteristic of the red R color filter is shown. Image pickup apparatus main body 2 including the image pickup means 21 and the convex lens 22 for forming an image
The configuration of is similar to that of a conventionally known television camera, and the output of each light receiving cell is scanned and read along the horizontal scanning line for each field. In practice, in order to form an image on the image pickup means 21 on the interference filter 9 while the attachment means 3 is attached to the image pickup apparatus main body 2,
It is preferable that the convex lens 22 has a very short focal length capable of so-called close-up photography, for example, a focal length of a value close to zero to about 3 cm from the viewpoint of miniaturization of the configuration.

Due to the function of the convex lens 22, it is possible to form an image on each pixel 23 corresponding to each position in the direction perpendicular to the optical axis 8 of the interference filter 9 individually. Therefore, the plate-like bodies 13, 15 of the substrates 10, 11 of the interference filter 9 are
Even if there are fine, for example, micron-order gently changing irregularities on the surface of the, the spectrum differentiating operation can be performed without adversely affecting the spectrum image analysis.

FIG. 5 is a block diagram showing the electrical construction of the embodiment shown in FIGS. The electric signal from each light receiving cell in the image pickup means 21 is sequentially given to the processing circuit 28 realized by a microcomputer or the like by scanning. The piezoelectric element 12 is controlled by the DC power supply 17.
Is applied with a first voltage, which causes the interference filter 9
3 has a first band transmission characteristic of light indicated by the solid line in FIG. 3, signals from the respective light receiving elements of the image pickup means 21 are color filters for each of blue B, green G and red R of each pixel 23. Are stored in the memories 29, 30, 31 respectively corresponding to. For the intensity of each light receiving cell, refer to the reference symbol B as a whole.
1, G1 and R1 respectively.

FIG. 6 is a flow chart for explaining the operation of the processing circuit 28. When performing the spectral image analysis in step a1, the first voltage is applied to the piezoelectric element 12 in step a2 as described above with the switch 44 turned off. The processing circuit 28 sets the output voltage of the DC power supply 17 to a predetermined first voltage by the drive circuit 43, and the first voltage is applied to the piezoelectric element 12 by this. In step a3, the object surface is imaged as described above, and a digital signal representing the level of the electric signal for each color of the light receiving cell is stored in the memories 29, 30, 31.

In the next step a4, the above-mentioned step a
With respect to the same object 19 as in operation at 2, a3, a second voltage different from the first voltage is applied to the piezoelectric element 12 of the interference filter 9, whereby the interference filter 9
Has the second band transmission characteristic indicated by the broken line in FIG. 3, and in step a5, the electric signals having the levels corresponding to the light receiving intensities of the light receiving cells of the image pickup means 21 are blue B and green. Memory 32, 33, 3 for each G and red R
Stored in 4 respectively. This memory 32, 33, 3
The digitized signals of the respective light receiving cells stored in 4 are generally designated by B2, G2 and R2, respectively.

At step a6, the memories 29, 30, 3
The outputs of 1; 32, 33, and 34 are read out, and the spectrum differentiating operation is performed. This spectrum differentiation operation is performed for each color B,
The differences ΔB, ΔG, and ΔR, which are achieved by the subtraction circuits 35, 36, and 37 for each G and R and are obtained by the subtraction, are stored in the memories 38, 39, and 40 for each light receiving cell.

ΔB = B1-B2 (1) ΔG = G1-G2 (2) ΔR = R1-R2 (3) At step a7, the drive circuit 41 causes the memory 38, 3 to be stored.
An electric signal representing the level of each pixel difference ΔB, ΔG, and ΔR of the image pickup means 21 stored in the image pickup means 9 and 40 is read out, and a spectral differential image is displayed on a color display means 42 such as a color cathode ray tube with a blue B , Green G and red R are used as color signals for visual display. At step a8, such a series of operations is completed.

The processing circuit 28 sets the output voltage of the DC power supply 17 to a predetermined first voltage by the drive circuit 43, and the first voltage is applied to the piezoelectric element 12 by this.

By visually observing the spectrum-differentiated image displayed by the display means 42, the color of the object 1 can be accurately identified and the spectral image analysis can be performed.

As another embodiment of the present invention, the interference filter 9 may have another structure, and instead of the piezoelectric element 12, a displacement drive element having another structure may be used. As the metal films 14 and 16, other metals may be used instead of Au described above. Alternatively, another conductive ceramic or the like may be used as the thin film, and another material may be used. Instead of the metal films 14 and 16,
Other translucent films that interfere with light may be used. Further, the metal films 14 and 16 may be formed as described above over the entire surfaces of the plate-like bodies 13 and 15, but as another embodiment, for example, in the form of a strip grid or in other shapes. It may be partially formed.

In the embodiment described above, the image pickup means 2 is activated by turning on the switch 44 and deactivating the processing circuit 28.
1 enables color imaging. Further, although the display means 42 has a structure capable of color display, as another embodiment of the present invention, the image pickup means 21 is not provided with a color filter, and the display means 42 is a so-called black and white shade. The configuration may be such that only display is performed, and at this time, the memory 2
There is only one 9, 30, 31 and the memories 32, 33, 3
4 is provided only one, and further, only one memory 38, 39, 40 is provided, and only one subtracting means 35, 36, 37 is provided. Other configurations are the same as those in the above-mentioned embodiment.

As another embodiment of the present invention, the metal film 14,
Instead of 16, a superconductor film may be used. As still another embodiment, the band-pass interference filter uses a piezoelectric element whose light-transmitting thickness changes according to an electric signal such as a voltage, and transmits light to both surfaces of the plate-shaped piezoelectric element. It may have a structure in which a film such as a thin metal film for interfering with is formed by vapor deposition or the like.

A plurality of interference filters 9 having different light transmission bands may be arranged in series along the optical axis 8.

[0033]

According to the present invention, with a simple structure,
For the first time, spectral image analysis can be performed using a bandpass interference filter to accurately identify the color of an object.

In this interference filter, the voltage from the DC power source is changed and applied to the piezoelectric element to change the distance between the pair of substrates to cause multiple interference of light, thereby simplifying the transmission band of light. It can be easily changed with various configurations.

Further, according to the present invention, the interference filter and the first optical means are fixed, and the attachment means can be attached to and detached from the image pickup apparatus main body including the image pickup means and the second optical means such as an existing television camera. By attaching to
It is possible to perform imaging similar to human vision using an existing imaging device that is a television camera, and when performing spectrum image analysis, the attachment means may be attached, improving usability and existing. Since the TV camera can be used as it is, there is an effect that operability is improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing an overall configuration of a spectrum analyzer according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of an interference filter 9.

FIG. 3 is a diagram showing characteristics of an interference filter 9.

FIG. 4 is a simplified front view of the imaging means 21.

5 is a block diagram showing the electrical configuration shown in FIGS. 1 to 4. FIG.

6 is a flowchart for explaining the operation of the processing circuit 28 shown in FIG.

[Explanation of reference numerals] 1 spectrum image analyzer 2 image pickup device main body 3 attachment means 7, 22 convex lens 8 optical axis 9 band pass interference filter 10, 11 substrate 12 piezoelectric element 13, 15 plate-like body 14, 16 metal film 17 DC power supply 19 object 20 casing 21 imaging means 28 processing circuit 29, 30, 31; 32, 33, 34; 38, 39, 4
0 memory 35, 36, 37 subtraction means

Claims (8)

[Claims] 1. A band-pass interference filter capable of changing a transmission band of light, an imaging means having a plurality of light-receiving cells, a first optical means for forming an image of an object on the interference filter, and an on-interference filter. The second optical means for forming an image on each light receiving cell of the image pickup means, the first output of each light receiving cell when the interference filter is set to the first transmission band, and the first output different from the first transmission band It is characterized by including subtraction means for calculating a difference from the second output of each light receiving cell when set to two transmission bands for each corresponding light receiving cell, and display means for visually displaying the output of the subtracting means. Spectral image analyzer. 2. A band-pass interference filter capable of changing the transmission band of light, a plurality of pixels, each pixel comprising a blue, green and red color filter and a light-receiving cell for each color filter. A first optical unit configured to form an image of an object on an interference filter; a second optical unit configured to form an image on the interference filter on each pixel of the image pickup unit; The first output of each light receiving cell when set to the transmission band and the second output different from the first transmission band
It is characterized by including subtraction means for calculating a difference from the second output of each light receiving cell when set in the transmission band for each corresponding light receiving cell, and display means for displaying the output of the subtracting means in color. Spectral image analyzer. 3. The interference filter has a pair of substrates arranged to face each other, and a gap between the substrates can be changed by a piezoelectric element. Each substrate is a plate-shaped body made of a light-transmissive material, and the plate. 3. A spectrum image analyzer according to claim 1, wherein the piezoelectric element is provided with a light-transmitting thin film for interference of light formed on the sheet, and the voltage is applied to the piezoelectric element from a DC power source. . 4. The interference filter is a translucent plate-shaped member whose thickness can be changed by an applied voltage, and is formed on both surfaces of the plate-shaped member to prevent light from interfering with each other. 3. A spectral image analysis device according to claim 1, further comprising: a thin film having a light-transmitting property, which is applied to the plate-shaped body by applying a voltage from a DC power source. 5. An interference filter and a first optical means are fixed to constitute an attachment means, an image pickup means and a second optical means are fixed to constitute an image pickup apparatus main body, and a second optical means of the image pickup apparatus main body. The attachment means is attachable to and detachable from the front side.
Spectral image analyzer of one of three. 6. A band-pass interference filter capable of changing a transmission band of light, a light receiving means for receiving transmission spectrum light from the interference filter, and a light receiving means when the transmission band of the interference filter is different. A spectral image analysis device comprising: a subtraction unit that calculates an output difference. 7. A pair of substrates are arranged so as to face each other, and an interval between the substrates can be changed by a piezoelectric element, each substrate being a plate-shaped body made of a translucent material and formed on the plate-shaped body. A band-pass interference filter capable of changing the transmission band of light, which is characterized by comprising a thin film having a light-transmitting property for allowing the light to interfere, and applying a voltage from a DC power supply to the piezoelectric element. 8. A translucent plate-like member whose thickness can be changed by an applied voltage, and a translucent plate formed on both surfaces of the plate-shaped member for allowing light to interfere with each other. A band-pass interference filter capable of changing a light transmission band, comprising a thin film.