JPS63269875A - Spectral image pickup device - Google Patents

Abstract

PURPOSE:To obtain the spectral picture of various types of wavelength by one camera by forming spectral sample image corresponding to a wavelength selection signal on the output surface of a photoelectric conversion device by a reflection type objective lens and picking up the image and monitoring it. CONSTITUTION:A selected wavelength light is made incident on the sample 4 from a light source 1 and the light image as formed on the photoelectric surface of an image converter tube 6 through the reflection type objective lens 5. Since this formed image is converted to a visible light image, it is picked up by a TV camera 10 through a relay lens 9. Thereby, the image of the various types of wavelength is obtained in a TV monitor 11. A video signal processing circuit 12 matches the video signal of the camera 10 based on the wavelength selection signal outputted from a wavelength designating signal generator 8, for instance, an ultraviolet ray image to a blue color image, a visible image to a green color image and an infrared ray image to a red color image to synthesize a pseudo color video signal and displays on a TV monitor 13 as a color image and obtains useful data more conveniently.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a spectral imaging system 1affi capable of capturing an optical image of an object image in a very wide wavelength band at various wavelengths almost in real time.

[Conventional technology]

When capturing temporal changes in the optical image of an object, it is possible to obtain more information by simultaneously observing images of ultraviolet light, visible light, infrared light, etc., rather than just observing the light image of one wavelength. Become. Therefore, conventionally, for example, an ultraviolet imaging device, a visible imaging device, an infrared imaging device, and independent cameras have been used to capture temporal changes in the optical image of an object.

[Problems to be solved by the invention]

However, when observed using independent cameras,
Since the viewing angle of each camera is different, it cannot be said that they are spectral images of the same light image, and since separate cameras are used, they are expensive. Particularly when observing microorganisms using a microscope, it is difficult to install multiple cameras due to space considerations.

The present invention is intended to solve the above problems, and aims to provide an inexpensive spectroscopic imaging device that can capture images of objects in different wavelength bands in real time using the same camera.

[Means for solving problems]

To this end, the spectral imaging device of the present invention includes a wavelength specifying signal generator, a spectral sample image forming means to which a wavelength selection signal from the wavelength specifying signal generator is applied, and a reflective objective lens into which the spectral sample image is incident. A photoelectric conversion image device in which a spectral sample image is formed on a photoelectric conversion surface by a reflective objective lens, an imaging means for capturing an output image obtained on the output surface of the photoelectric conversion image device, and a monitor means, It is characterized by obtaining a spectral image of a wavelength designated by a wavelength designation signal generator.

[Effect]

The spectral imaging device of the present invention focuses a spectral sample image according to a wavelength selection signal from a wavelength specification signal generator on a photoelectric conversion surface of a photoelectric conversion image device using a reflective objective lens,
Capture the output image obtained on the output surface of the photoelectric conversion image device to obtain a spectral image of the wavelength specified by the wavelength specification signal generator, and display it on a monitor to capture images of different wavelength bands in real time. becomes possible.

〔Example〕

Examples will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the overall configuration of a spectroscopic imaging device according to the present invention, in which 1 is a light source, 2 is a sample support stage, 3 is a substrate, and 4
is a sample, 5 is a reflective objective lens, 5a is a convex mirror, 5b is a concave mirror, 6 is an image converter tube, 7 is a driving power source,
8 is a wavelength specification signal generator, 9 is a relay lens, 10 is T
11 is a TV monitor, 12 is a video signal processing circuit, and 13 is a TV monitor.

In the figure, a light source 1 is configured to sequentially and repeatedly generate rays of different wavelengths such as ultraviolet, visible, and infrared.

An embodiment of such a light source 1 will be explained with reference to FIGS. 2 to 4.

FIG. 2 is a diagram showing an example of a light source, in which 21 is a visible laser, 22 is an infrared laser, 23 is an ultraviolet laser,
24 is a half mirror.

In this embodiment, by inputting a wavelength selection signal from the wavelength designation signal generator 8 to each laser driving section, each laser is sequentially switched and driven in real time.

At this time, the output of these lasers can be applied to the sample 3 through the half mirror 24.

FIG. 3 is a diagram showing another embodiment of the light source, and the same numbers as in FIG. 2 indicate the same contents. In addition, in the figure, 31 is a rotating mirror, and 32 is a rotating shaft.

In this embodiment, the rotating mirror 31 is rotated to sequentially irradiate the sample with each laser. The wavelength is switched by controlling the rotation angle with a wavelength selection signal from a wavelength designation signal generator.

FIG. 4 is a diagram showing another embodiment of the light source, in which 41 is a white light source, 42 is a rotating disk, 43 is a disk drive motor power source, 44 is a visible light transmission filter, 45 is an infrared light transmission filter, 46 is an ultraviolet light transmission filter, and 47 is a drive motor.

In this example, between white light [41 and sample 4,
For example, a filter 43 that transmits only visible light, a filter 45 that transmits only infrared light, and a filter 46 that transmits only ultraviolet light are arranged around the rotating disk 42,
By rotating this, the wavelength with which the sample is irradiated is selected. In this case, the wavelength can be switched by controlling the rotation angle with a wavelength selection signal from the wavelength designation signal generator 8.

In this way, light from the light source 1 is made incident on the sample 4 fixed to the sample support stand 2. In this case, as shown in Figure 1, attach the substrate 3 to the sample support stand 2 and place the sample on it! ! Place,
When the light from the light 'llAl is incident on the sample 4 through the substrate 3, the substrate needs to be transparent to a wide wavelength range. In this case, M g F! exhibits good transmission characteristics across the ultraviolet, visible, and infrared wavelengths. A substrate made of a material such as UV glass or the like may be used.

Next, an optical image of the sample 4 is formed through a reflective objective lens 5 on a photocathode of an image converter tube 6, which is a photoelectric conversion imaging device. In this case, as the objective lens, a reflective lens 5 is used as shown in the figure, instead of the conventionally widely used transmissive refractive lens. This is to take advantage of two important characteristics unique to reflective lenses.

In other words, in a transmissive refractive lens, the light is absorbed by the lens material, so it is not possible to efficiently transmit all of the ultraviolet, visible, and infrared light. It is possible, but using a single material will cause chromatic aberration and it will not be possible to maintain good resolution for light of various wavelengths, so it will be necessary to correct chromatic aberration using multiple materials, and if that happens, No combination of materials has been found that provides good transmission characteristics over a wide infrared wavelength range. Further, even if chromatic aberration is corrected, it cannot be completely corrected over a wide range from ultraviolet to infrared, and at most only a narrow range within visible light can be corrected.

In addition, in a wide wavelength range from ultraviolet to infrared, changing the wavelength will cause the position of the image formation plane of the output image of the optical system to change on the optical axis, so the position of the optical lens must be adjusted to obtain the best resolution on the photoelectric conversion surface. It is necessary to move and adjust it on the optical axis. This adjustment takes too much time and is inappropriate for obtaining images of various wavelengths in real time. On the other hand, reflective lens systems are known to have almost no difference in light transmission efficiency depending on wavelength from ultraviolet to infrared, and to have no chromatic aberration or movement of the imaging plane depending on wavelength, making them ideal as the objective lens of the present invention. . The reflective objective lens 5 shown in FIG. 1 consists of a convex mirror 5a and a concave mirror 5b.

Note that, as shown in FIG. 5, an oblique incidence reflective objective lens consisting of a hyperboloid of revolution 51 and an ellipsoid of revolution 52 may be used to form an image on the photocathode surface.

In this way, light images obtained when the sample is irradiated with various wavelengths are formed by the reflective objective lens 5 on the photoelectric conversion surface of the photoelectric conversion imaging device. The photoelectric conversion device consists of an electron tube 6 called an image converter tube or image tube.

Figure 6 is a diagram showing the image converter tube.
1 is MgF, window, 62 is a multi-alternative photocathode, 63 is an incident light image, 64 is a photoelectron, 65 is a focusing electrode, 66 is an anode,
67 is a fluorescent surface, 68 is an output light image, and 69 is a driving power source.

In the figure, the photoelectric conversion surface is made of a multi-alkali photocathode 62 deposited on the inside of a window 61 made of MgF, for example, in order to have sensitivity in a wide wavelength band from ultraviolet to visible. When a wavelength light image 63 is formed on the photocathode, photoelectrons 64 are emitted from the photocathode in accordance with the spatial distribution of the light intensity. Since these photoelectrons are emitted from each point on the photocathode in various directions at various speeds, they become blurry if left as they are, but a so-called electron lens formed by a focusing electrode 65 and an anode 66 redirects them to the fluorescent surface 67. The output light image 68 is formed on the phosphor surface and hits the phosphor surface 1i to obtain a luminescent image on the phosphor surface. In this way, an invisible ultraviolet or infrared image can be converted into a visible light image on the fluorescent surface, which is the output surface of the image converter.

The image forming state of the electron optical system can be optimized by supplying, for example, a voltage as shown in the figure from the drive type a69 of this image converter tube and adjusting the voltage applied to the focusing electrode. Although it is not necessary, it is possible to change the voltage of the focusing electrode for each wavelength of light incident on the photocathode.
Better resolution can be obtained. This is because the energy of photoelectrons emitted from the photocathode differs depending on the wavelength of light incident on the photocathode, so the optimum voltage of the focusing electrode differs somewhat. In this case, if the voltage value for each wavelength is determined in advance, the wavelength selection signal from the wavelength designation signal generator 238 can be used to control the drive power supply 69 of the image converter tube.
The focusing electrode voltage can be controlled and the optimal voltage can be applied in real time.

FIG. 7 is a diagram showing a magnifying tube as another embodiment of the photoelectric conversion device, and the same reference numerals as in FIG. 6 indicate the same contents.

In addition, in the figure, 71 is a mesh accelerating electrode, 72 is a first focusing coil, 73 is a second focusing coil, 74 is a deflection coil, 7
5 is a drive power source, and 76 is a coil drive power source.

The magnifying tube in this embodiment can be said to be a variant of an image converter tube, and can magnify the structure obtained on the output fluorescent surface several times to several hundred times with respect to the optical image formed on the photocathode. A first converging coil 72 that enlarges the optical image and also forms a photoelectron image;
This is done by adjusting the current of the second converging coil 73.

Furthermore, by adjusting the current of the deflection coil 74, a desired location of the optical image on the photocathode can be obtained as an enlarged optical image on the fluorescent surface. This function is extremely useful when the sample is minute, such as biological cells. Further, the adjustment of the focusing conditions is performed by the coil drive power source 76 that controls the first and second focusing coils 7.
2. Finely adjust the current to 73.

The light image thus obtained on the fluorescent surface is captured by the TV left camera 0 via the relay lens 9, and images of various wavelengths are displayed on the TV.
Obtained on monitor 11. In order to obtain more convenient and useful data, the video signal is passed through the video signal processing circuit 12 and then the image is displayed on the TV monitor 13. In this case, for example, each of the ultraviolet, visible, and infrared video signals obtained by sequentially switching the wavelength specifying signal generator 8 is applied with a wavelength selection signal to the video signal processing circuit 12, so that the ultraviolet image is changed to blue, for example, or The visible image corresponds to green and the infrared image corresponds to red,
It is also possible to synthesize pseudo-color video signals and display them as a color image on the TV monitor 13. Also, TV
Three monitors may be provided to display ultraviolet, visible, and infrared images separately.

In addition, the reflective objective lens can also form an X-ray image, so the light source is an X-ray tube, and the image converter tube is a thin window made of an organic material sensitive to X-rays and ultraviolet rays.
Using a photocathode, it is also possible to observe X-ray images and ultraviolet images almost in real time.

Furthermore, as another modification, the sample itself may emit light. In this case, the light tA1 shown in FIG. Wavelength selection can be performed by inserting a rotary plate surrounded by many spectral filters as shown in Figure 4. However, in this case, since it is a transmission filter, the imaging plane of the optical system is slightly different. However, this can be corrected by adjusting the thickness of the filter.

〔Effect of the invention〕

As described above, according to the present invention, a spectral sample image corresponding to a wavelength selection signal from a wavelength specification signal generator is focused on a photoelectric conversion surface of a photoelectric conversion image device having a wide spectral sensitivity range using a reflective objective lens. , the output image obtained on the output surface of the photoelectric conversion image device is imaged to obtain a spectral image of the wavelength specified by the wavelength specification signal generator, and each device is controlled synchronously by the wavelength specification signal generator. This makes it possible to capture spectral images of various wavelengths at the same viewing angle and field of view with high accuracy in almost real time with a single camera, and also to reduce costs.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the overall configuration of a spectroscopic imaging device according to the present invention, FIGS. 2, 3, and 4 are diagrams showing embodiments of a light source, and FIG. 5 is a diagram showing an oblique incidence reflective objective lens. Figure, 6th
The figure shows an image converter tube, and FIG. 7 shows a magnifying tube. ■...Light source, 2...Sample support stand, 3...Substrate, 4
... Sample, 5... Reflection type objective lens, 5a... Convex mirror, 5b... Concave mirror, 6... Image converter tube, 7... Drive power supply, 8... Wavelength specification signal generator , 9...Relay lens, IO...TV camera, 11
...TV monitor, 12...Video signal processing circuit, 1
3...TV monitor, 21...Visible laser, 22
...Infrared laser, 23...Ultraviolet laser, 24.
...Half mirror 131...Rotating mirror, 32...
Rotating shaft, 41... White light source, 42... Rotating disk, 4
3... Disc drive motor power supply, 44... Visible light transmission filter, 45... Infrared light transmission filter, 46.
...Ultraviolet light transmission filter, 47...Drive motor,
51... Hyperboloid of revolution, 52... Ellipsoid of revolution. Applicant Hamamatsu Photonics Co., Ltd. Representative
Person Patent Attorney Masaru Hirukawa Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (10)

[Claims] (1) A wavelength specifying signal generator, a spectroscopic sample image forming means to which a wavelength selection signal from the wavelength specifying signal generator is applied, a reflective objective lens into which the spectroscopic sample image is incident, and a spectroscopic sample using the reflective objective lens. A photoelectric conversion imaging device in which an image is formed on a photoelectric conversion surface, an imaging means for capturing an output image obtained on an output surface of the photoelectric conversion imaging device, and a monitoring means, and the wavelength is designated by a wavelength designation signal generator. A spectral imaging device characterized by obtaining a wavelength spectral image. (2) The spectroscopic imaging device according to claim 1, wherein the spectroscopic sample image forming means comprises a light source that irradiates the sample with different wavelengths according to a wavelength selection signal. (3) The spectroscopic imaging device according to claim 2, wherein the light source includes a visible laser, an infrared laser, and an ultraviolet laser. (4) The spectroscopic imaging device according to claim 1, wherein the spectroscopic sample image forming means comprises a white light source and a filter that selects light from the white light source according to a wavelength selection signal and irradiates the sample. (5) The spectroscopic imaging device according to claim 1, wherein the spectroscopic sample image forming means comprises a filter that selects light from the self-luminous sample according to a wavelength selection signal. (6) The spectroscopic imaging apparatus according to claim 1, wherein the focusing electrode voltage applied to the photoelectric conversion imaging device is controlled by a wavelength designation signal from a wavelength designation signal generator. (7) The spectroscopic imaging device according to claim 1, wherein the video signal from the imaging means is processed by a video signal processing circuit controlled by a wavelength selection signal from a wavelength designation signal generator. (8) The spectroscopic imaging device according to claim 1, wherein the reflective objective lens includes a concave mirror and a convex mirror. (9) The spectroscopic imaging device according to claim 1, wherein the reflective objective lens is an oblique incidence reflective objective lens. (10) The spectroscopic imaging apparatus according to claim 1, wherein the photoelectric conversion imaging device has an Au photocathode provided on a thin window made of an organic material.