JP3132354U - Color confocal microscope - Google Patents

Abstract

A color confocal microscope that is small and inexpensive to manufacture is realized.
A color confocal microscope according to the present invention includes a light source device that generates a linear illumination beam extending in a first direction, and a linear illumination beam emitted from the light source device orthogonal to the first direction. A beam deflecting device that deflects in a second direction, a slit disposed in an optical path between the light source device and the beam deflecting device and having an opening extending in the first direction, and the beam deflecting device An objective lens for focusing the line-shaped illumination beam and projecting it toward the sample to be observed; a color separation optical system for separating the line-shaped reflected beam emitted from the sample into three color lights of RGB;
A line sensor having a plurality of light receiving elements arranged in a direction corresponding to the first direction and receiving each color light of RGB color-separated, and color based on an output signal from the RGB line sensor And a signal processing circuit for outputting a video signal.
[Selection] Figure 1

Description

  The present invention relates to a color confocal microscope.

  A color confocal microscope that uses three RGB light sources, scans the surface of the sample with RGB scanning beams, receives reflected light from the sample with a photodetector, and displays a color image is known (for example, a patent) Reference 1). In this known color confocal microscope, laser beams emitted from three RGB lasers are periodically deflected in the main scanning direction by acousto-optic elements (AO elements), and the three deflected laser beams are combined. It is combined into one light beam by the optical system. Then, the combined beam is incident on the vibrating mirror, periodically deflected in the sub-scanning direction, and incident on the sample surface via the objective lens, and the sample surface is two-dimensionally scanned.

The reflected beam from the sample surface is again collected by the objective lens, enters the dichroic mirror via the vibrating mirror, and RGB reflected light is generated through the two dichroic mirrors. Each RGB reflected light is incident on the linear image sensor, RGB image signals are output from the linear image sensor, and color video signals are output from the signal processing circuit.
Japanese Patent Laid-Open No. 62-18179

The above-described color confocal microscope is formed by synthesizing three colors of RGB confocal images, and thus has an advantage of obtaining a high-resolution color image.
However, since main scanning is performed using AO elements individually for each of the RGB laser beams, three acousto-optic elements are required, which has the disadvantage that the structure of the optical system is complicated and the size is increased. It was. Further, since the acousto-optic element is expensive, there is a drawback that the manufacturing cost is high. Further, since a color image is formed by scanning the sample surface with a laser beam emitted from an RGB laser, it has been pointed out that a color image slightly shifted from a natural color is output.

An object of the present invention is to realize a color confocal microscope that eliminates the above-described drawbacks and is small in size and low in manufacturing cost.
Furthermore, an object of the present invention is to realize a color confocal microscope that can display a color confocal image having a natural hue on the surface of a sample to be observed.

A color confocal microscope according to the present invention includes a light source device that generates an illumination beam,
A beam shaping optical system for converting the illumination beam into a linear illumination beam extending in a first direction;
A beam deflecting device for deflecting the linear illumination beam in a second direction orthogonal to the first direction;
An objective lens that focuses the line-shaped illumination beam emitted from the beam deflecting device and projects it toward the sample to be observed;
A color separation optical system that separates the line-shaped reflected beam emitted from the sample into three color lights of RGB;
A line sensor having a plurality of light receiving elements arranged in a direction corresponding to the first direction, and receiving each color light of RGB that has undergone color separation;
A signal processing circuit for outputting a color video signal based on an output signal from an RGB line sensor,
The reflected beam from the sample is incident on the color separation optical system via the objective lens and the beam deflecting device.

  In the present invention, the sample surface is scanned with a line-shaped white beam, the reflected beam from the sample is color-separated into an RGB image by a color separation optical system, and the RGB reflected beam is received by a line sensor to output an image signal. To do. As a result, the configuration of the optical system is greatly simplified and the size can be reduced. In addition, since no acousto-optic element is used, the manufacturing cost is significantly reduced.

  A color confocal microscope according to the present invention includes a beam splitter that separates an illumination beam from a light source device toward a sample and a reflected beam from the sample toward a color separation optical system in an optical path between the beam deflecting device and the color separation optical system. The lens system is disposed in a common optical path between the beam splitter and the beam deflecting device, and the lens system acts as a relay lens for light traveling from the light source device to the sample, and from the sample. It acts as an imaging lens for the light traveling toward the line sensor. As described above, the optical path of the illumination optical system and the optical path of the imaging optical system are shared, and the lens system is arranged in the common optical path, and the lens system is shared by the illumination optical system and the imaging optical system, thereby Can be further reduced in size.

  In the color confocal microscope according to the present invention, the beam shaping optical system includes a converging lens system, and a slit having an opening portion disposed in a pupil position of the converging lens system and extending in a first direction, An optical path bypassing optical system for removing the slit from the optical path is detachably disposed in the optical path in which the slit is disposed, and a confocal color image and a non-confocal color image are selectively displayed. . The confocal optical system captures a high-resolution image, but has a relatively shallow depth of focus. On the other hand, the non-confocal optical system has a characteristic that the resolution is lower but the depth of focus is deeper than that of the confocal optical system. Therefore, if a confocal image or a non-confocal image can be selectively picked up according to characteristics such as unevenness on the surface of the sample, better sample observation can be performed. Therefore, in the present invention, an optical path bypassing optical system is detachably disposed in the optical path in which the slit is disposed so that a confocal image and a non-confocal image can be selectively captured according to a user's request. Constitute. The optical path detouring optical system can be composed of two rhombus prisms arranged to face each other with a slit interposed therebetween.

  In the color confocal microscope according to the present invention, a positioner that displaces the optical path of the reflected beam in a direction orthogonal to the optical axis is disposed in the optical path between the beam splitter and the color separation optical system, and the positioner is adjusted. The incident position with respect to the line sensor of the RGB color light color-separated by the above can be adjusted.

  The color confocal microscope according to the present invention is characterized in that the light source device has a light source that emits white light and a bundle of a plurality of optical fibers, and emits a linear illumination beam from an emission end of the optical fiber bundle. To do.

  In the present invention, the surface of the sample is scanned two-dimensionally with a line-shaped white beam, and the reflected beam from the sample is decomposed into RGB images by the color separation optical system, and each is received by the line sensor. Is simplified and downsizing is achieved. In addition, the lens system is arranged in a common optical path of the illumination beam from the light source to the sample and the reflected beam from the sample to the line sensor, and the lens system is shared by the illumination system and the imaging system. Can be reduced in size.

  FIG. 1 is a diagram showing the configuration of an example of a color confocal microscope according to the present invention. As the light source 1, a white light source that emits white light, such as a mercury lamp or a xenon lamp, is used. White light emitted from the light source 1 enters an optical fiber bundle 2 in which a plurality of optical fibers are stacked in a circle, propagates through the optical fiber, and is emitted as a divergent beam having a substantially circular cross section. The illumination beam constitutes a beam shaping optical system that converts the illumination beam emitted from the light source into a linear illumination beam. The beam shaping optical system includes a converging lens 3 and a slit 4. The illumination beam emitted from the optical fiber bundle 2 is converted into a parallel illumination beam by the converging lens 3 and enters the slit 4. The slit 4 is disposed at the pupil position of the converging lens 3 and passes through an opening extending in a first direction (a direction orthogonal to the paper surface). The width of the opening of the slit is set to 10 to 20 μm, for example. Therefore, a linear illumination beam extending in the first direction is emitted from the slit 4. The line-shaped illumination beam emitted from the slit 4 is reflected by the half mirror 5 functioning as a beam splitter, and enters the vibrating mirror 7 through the relay lens 6.

  The oscillating mirror 7 periodically deflects the incident line-shaped illumination beam in a second direction orthogonal to the first direction based on a drive signal supplied from signal processing described later. The beam emitted from the vibrating mirror enters the objective lens 10 through the relay lenses 8 and 9. The objective lens 10 focuses the incident linear illumination beam and projects it onto the sample 11 to be observed. Therefore, the sample 11 is scanned two-dimensionally by the focused line-shaped illumination beam. The objective lens 10 can be observed using an objective lens having a desired magnification by mounting a plurality of objective lenses having different magnifications on the revolver and rotating the revolver. The revolver is mounted so as to be movable in the optical axis direction, and can be moved in the optical axis direction by an actuator (not shown).

  The sample 11 is placed on the XY stage 12, and an image of a desired part can be displayed by driving the stage in the XY direction.

  The line-like reflected beam emitted from the sample surface is condensed by the objective lens and propagates in the opposite direction along the original optical path. Then, the light enters the vibrating mirror 7 through the relay lenses 9 and 8 and is descanned by the vibrating mirror. The reflected beam emitted from the vibration mirror 7 passes through the lens 6 and is separated from the illumination beam by the half mirror 5. The lens 6 acts as a relay lens for the illumination beam from the light source toward the sample, and acts as an imaging lens for the reflected beam from the sample toward the photodetector.

  The reflected beam that has passed through the half mirror 5 enters the positioner 13. The positioner 13 is composed of a plane parallel plate, and by adjusting the angle with respect to the optical axis, the amount of displacement of the reflected beam from the optical axis can be adjusted, and the position incident on the line sensor described later can be adjusted. The line-shaped reflected beam emitted from the positioner enters the spectral prism 14 that functions as a color separation optical system, and is color-separated into three color lights of RGB. The spectral prism 14 is shown as a box diagrammatically, but its detailed configuration will be described later.

  The color-separated RGB color lights are respectively incident on the line sensors 15 to 17. Each line sensor 15-17 has a some light receiving element, and these light receiving elements are arranged in the direction corresponding to the 1st direction which is the extension direction of a linear illumination beam. Therefore, the extending direction of the incident line-shaped reflected beam coincides with the arrangement direction of the light receiving elements of each line sensor, and the reflected beam from the sample is incident on each line sensor in a stationary state.

  The charges accumulated in the line sensors 15 to 17 are sequentially read by the read drive signal supplied from the signal processing circuit 18, amplified by the amplifiers 19 to 21, and output to the signal processing circuit 18. The signal processing circuit 18 performs signal processing on the input RGB video input, synthesizes the RGB video signals, and outputs a color video signal.

  A focus error signal can be formed by disposing a half mirror in the optical path between the relay lenses 8 and 9 and causing a part of the reflected light to enter the focus error signal generator. By supplying this focus error signal to an actuator that drives the objective lens 10, a focused confocal image can be taken. As the focus error signal generator, various focus error signal generators such as the Focalt method and the knife edge method can be used.

  FIG. 2 is a diagram showing a detailed arrangement of the color separation optical system and the line sensor. In this example, a spectral prism in which three prisms and a dichroic film are combined is used as the color separation optical system. The spectroscopic prism has first to third three prisms 14a to 14c. These three prisms are prisms having a prismatic shape extending in a direction orthogonal to the paper surface, and FIG. 2 shows the prism as a cross section. A first dichroic film 14d that reflects only green light is formed between the first prism 14a and the second prism 14b, and blue light is formed between the second prism 14b and the third prism 14c. A second dichroic film 14e that reflects only the light is formed.

  Of the reflected beam from the sample incident on the light incident surface 14f of the spectral prism, only the red light is reflected by the first dichroic film 14d and the remaining light is transmitted. The reflected red light is reflected by the light incident surface 14 f, emitted from the first light emitting surface 14 g, and enters the line sensor 16. The light transmitted through the first dichroic film is incident on the second dichroic film 14e, only the blue light is reflected, and the blue light is emitted from the second light emitting surface 14h and is incident on the line sensor 17. . The red light that has passed through the second dichroic film 14 e exits from the third light exit surface 14 i and enters the line sensor 15. RGB video signals are output from the line sensors 15 to 17.

  Next, the imaging mode switching function between the confocal image capturing mode and the non-confocal image capturing mode will be described. The confocal optical system captures a high-resolution image, but has a relatively shallow depth of focus. On the other hand, the non-confocal optical system has a characteristic that the resolution is lower but the depth of focus is deeper than that of the confocal optical system. Therefore, there are cases where it is desired to observe the sample surface as a confocal image or a non-confocal image depending on the unevenness characteristics of the sample surface. Therefore, the present invention has an imaging mode switching function that can selectively capture a confocal image and a non-confocal image. FIG. 1 shows an optical system in a confocal image capturing mode. The illumination beam emitted from the optical fiber bundle 2 is converged by the converging lens 3 and converted into a linear illumination beam shaped by passing through the opening of the slit 4. The illumination beam is focused by the objective lens 10 and is incident on the sample surface as a focused line beam. In addition, since the line sensor is equivalent to one in which a slit is disposed on the light incident surface, a confocal image signal is output from each line sensor.

  FIG. 3 shows a configuration in which the optical path detouring optical system 30 is inserted and disposed in the optical path where the slit 4 is disposed. The optical path detouring optical system 30 includes first and second rhomboid prisms 31 and 32 having a rhombus cross section, and these rhombus prisms are arranged to face each other with the slit 4 interposed therebetween. The illumination beam incident on the first rhomboid prism 31 disposed on the side close to the light source is reflected by the two oblique sides 31a and 31b and is emitted as an illumination beam displaced from the optical axis. The illumination beam displaced from the optical path enters the second rhombus prism 32, is similarly reflected by the two oblique sides 32a and 32b, and is emitted as a beam propagating on the optical axis. As a result, an optical path that bypasses the slit 4 is formed, and the illumination beam propagating on the bypass optical path is a light beam having a certain extent with a circular cross section. Therefore, since the sample surface is scanned by a circular illumination beam having a spread, a non-confocal image is captured. In this way, by arranging the optical path detour optical system composed of two rhombus prisms so as to be detachable so as to sandwich the slit, confocal images and non-confocal images can be selected according to the characteristics of the sample to be observed. Can be selectively imaged.

The present invention is not limited to the above-described embodiments, and various modifications and changes can be made. For example, in the above-described embodiments, the beam shaping optical system is composed of a converging lens and a slit having a strip-shaped opening, but a cylindrical lens is arranged instead of the slit to generate a linear illumination beam. It is also possible to make it.
Although the spectral prism is used as the color separation optical system, the color separation optical system can also be configured using a dichroic mirror.

It is a diagram which shows an example of the color confocal microscope by this invention. It is a diagram which shows the structure of a spectroscopic prism. It is a diagram explaining the mode switching function between the confocal image capturing mode and the non-confocal image capturing mode.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light source 2 Optical fiber bundle 3 Focusing lens 4 Slit 5 Half mirror 6 Relay lens (imaging lens)
7 Vibrating mirror 8, 9 Relay lens 10 Objective lens 11 Sample 12 Stage 13 Positioner 14 Spectral prism 15, 16, 17 Line sensor 18 Signal processing circuit 19, 20, 21 Amplifier
30 Optical path detour optical system 31, 32 Rhombus prism

Claims (5)

A light source device for generating an illumination beam;
A beam shaping optical system for converting the illumination beam into a linear illumination beam extending in a first direction;
A beam deflecting device for deflecting the linear illumination beam in a second direction orthogonal to the first direction;
An objective lens that focuses the line-shaped illumination beam emitted from the beam deflecting device and projects it toward the sample to be observed;
A color separation optical system that separates the line-shaped reflected beam emitted from the sample into three color lights of RGB;
A line sensor having a plurality of light receiving elements arranged in a direction corresponding to the first direction, and receiving each color light of RGB that has undergone color separation;
A signal processing circuit for outputting a color video signal based on an output signal from an RGB line sensor,
A color confocal microscope characterized in that a reflected beam from a sample enters a color separation optical system via the objective lens and a beam deflecting device.   The color confocal microscope according to claim 1, wherein an illumination beam from the light source device to the sample and a reflected beam from the sample to the color separation optical system are provided in an optical path between the beam deflecting device and the color separation optical system. A beam splitter to be separated is disposed, and a lens system is disposed in a common optical path between the beam splitter and the beam deflecting device, and the lens system acts as a relay lens for light traveling from the light source device to the sample. And a color confocal microscope characterized by acting as an imaging lens for light traveling from the sample toward the line sensor.   3. The color confocal microscope according to claim 1, wherein the beam shaping optical system includes a converging lens system and an opening that is disposed at a pupil position of the converging lens system and extends in a first direction. The optical path detouring optical system that removes the slit from the optical path is detachably disposed in the optical path in which the slit is disposed, and a confocal color image and a non-confocal color image are selectively displayed. A color confocal microscope.   4. The color confocal microscope according to claim 1, wherein an optical path of the reflected beam is displaced in a direction orthogonal to an optical axis in an optical path between the beam splitter and a color separation optical system. 5. A color confocal microscope characterized in that an incident position on a line sensor of RGB color light subjected to color separation can be adjusted by arranging a positioner to be adjusted and adjusting the positioner.   5. The color confocal microscope according to claim 1, wherein the light source device includes a light source that emits white light and a bundle of a plurality of optical fibers, and an emission end of the optical fiber bundle. A color confocal microscope characterized by emitting an illumination beam from a light source.

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