JP2011095326A - Illuminating apparatus for microscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an illuminating apparatus for a microscope that has a compact configuration by reducing the entire length of an illuminating system. <P>SOLUTION: The illuminating apparatus for a microscope includes: a light source 1 for emitting illuminating light; an aperture diaphragm for adjusting the luminous flux of the illuminating light; a visual field diaphragm for setting an illuminating area for the illuminating light; and a field lens group disposed so that a front focusing position may coincide with the position of the visual-field diaphragm, and used for causing light passed through the visual field diaphragm to pass through this field lens group, thereby being guided to a specimen. In the illuminating apparatus for the microscope, the light source 1 includes: an LED light source 20 for emitting light; a light guide 22 and scattering sheet 23 for causing light from the LED light source 20 to enter and then propagate and emit in a direction different from the direction of the incidence; and prism sheets 24 and 25 for causing light emitted from the light guide 22 and scattering sheet 23 to enter and then diffuse and emit having a prescribed intensity distribution in the direction of an angle. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an illumination device used in a microscope having an illumination system with a long illumination optical path, and relates to a reflective illumination device that observes an opaque specimen and a transmission illumination device that observes a transparent specimen.

  As a lighting device used for a microscope, there are a reflection lighting device for an opaque sample and a transmission lighting device for a transparent sample. As a reflection illumination device, a device including a light emitting member such as a halogen lamp or an LED and an optical fiber that transmits light of the light emitting member is well known, and light introduced into one end of the optical fiber is emitted from the other end. Some of them are used as secondary light sources. When a halogen lamp or LED is used alone without using an optical fiber, the light emitting part is generally square and has a side of about 1 to 2 mm, and the light distribution angle is about 60 degrees. The projection magnification up to the pupil plane (also referred to as the light source magnification) is about 4 to 7 times, and the Kohler illumination system is assembled with this magnification. On the other hand, when an optical fiber is used, the light emitting portion (end face) has a relatively large diameter of about 3 to 8 mm, but the projection angle is 2 because the light distribution angle is as narrow as about 10 to 20 degrees. Doubled.

  When the projection magnification (light source magnification) described above is increased, the size of the light source image with respect to the effective diameter of the pupil plane of the objective lens (also referred to as a sufficiency rate) increases, and bright Koehler illumination can be realized. However, since the sine of the field angle of the objective lens is a value obtained by multiplying the sine of the light distribution angle of the light source by the reciprocal of the projection magnification, if the projection magnification is too high, the field angle of the objective lens will be reduced and This causes a problem that the area that can be illuminated becomes narrow. Therefore, the projection magnification is determined in a balanced manner by the size of the light source and the light distribution angle.

  The reflective illumination device is provided with a field stop and an aperture stop, and the aperture stop is provided at a position conjugate with the light source. In addition, since the size of the aperture stop (maximum aperture, minimum aperture) is roughly determined by the size of the hardware etc. due to the structure of the apparatus, the magnification from the light source to the aperture stop is determined to be about 2.5 to 3.0 times. . In this way, the magnification is determined from 2.5 to 3.0 times from the light source to the aperture stop, and from 1.3 to 1.5 times from the aperture stop to the pupil of the objective lens, and the projection is performed in two stages. It has become.

  On the other hand, the transmission illumination device uses the same light source as the reflection illumination device, and the light source image is projected onto the pupil of the condenser lens. In a reflective illumination device, an objective lens may serve as both an illumination system and an imaging system, but in a transmissive illumination device, one condenser lens often corresponds to an objective lens of medium to high magnification. For this reason, it is preferable that the condenser lens provides a light beam having the maximum real field of view of the corresponding objective lens and the maximum numerical aperture NA. Therefore, the light source magnification is set to about 3 to 4 times, and more light speed is generated using a diffusion plate or the like. An aperture stop is disposed on the pupil plane of the condenser lens to control the numerical aperture NA. The field stop is arranged at a position that is conjugate with the specimen by the field lens and the condenser lens.

  By the way, in recent years, high-brightness LEDs (Light Emitting Diodes) are used as light sources in various fields, and systems using LEDs as light sources for microscopes have been proposed (for example, see Patent Document 1). reference).

JP 2005-148296 A

  By the way, as described above, a microscope using LEDs as a light source includes a surface light source in which a plurality of LEDs are arranged on a circuit board and collectively illuminated. In this type of microscope, a field stop or an aperture stop cannot be disposed due to structural problems, and there is a problem that flare and ghost cannot be removed. In addition, there is a type of microscope in which a field stop and an aperture stop are arranged to provide an array of Koehler illumination, but this type of microscope has the same lens configuration as a conventional microscope, and the entire illumination device becomes long. there were.

  Further, the conventional reflection illumination apparatus has a problem that the entire length of the illumination system is increased because the light source image is relayed twice and guided to the pupil of the objective lens. Further, even in the conventional transmission illumination device, there is a problem that the total length becomes long if a configuration in which the relay lens and the diffusion plate are arranged is adopted.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a microscope illumination apparatus that can be configured compactly by shortening the overall length of the illumination system.

  In order to achieve such an object, a microscope illumination device (reflection illumination device) according to a first invention is provided near a light source that emits illumination light and an exit surface of the light source, and adjusts the luminous flux of the illumination light. An aperture stop having an aperture that allows illumination light to pass through, a field stop that is provided in the optical path of the light that has passed through the aperture stop, sets the illumination area of the illumination light, and passes the light that has passed through the aperture stop, and the front side A field lens group that is provided so that the focal position overlaps the position of the field stop, and a field lens group that passes light that has passed through the field stop, and an object that irradiates the sample with light that has passed through the field lens group and receives reflected light from the sample A light-emitting member that emits light; a light-propagating member that emits light emitted from the light-emitting member in a direction different from an incident direction; and light emitted from the light-propagating member in an angular direction. Strength of Characterized in that it is constituted by a light diffusing member which diffuses and emitted to have a cloth.

の条件を満足することが好ましい。 In the illumination device for a microscope according to the first invention, the imaging magnification of the pupil plane of the objective lens with respect to the light source is β, the maximum value obtained by dividing the numerical aperture of the objective lens by the magnification of the objective lens is NA ′, the focal length of the imaging lens is f _t, the diameter of the exit surface of the light source and d, the angle formed by the optical path having a 80% of the intensity of the light path and the highest intensity with the highest intensity among the light emitted from the light source When α and the number of field of view of the microscope are FOV,

It is preferable to satisfy the following conditions.

  The microscope illumination device (transmission illumination device) according to the second invention is provided near a light source that emits illumination light and an exit surface of the light source, and sets an illumination area of the illumination light to allow the illumination light to pass therethrough. A field stop, a field lens group that collects light that has passed through the field stop, and an aperture that is provided in the optical path of the light collected by the field lens group and that passes the collected light by adjusting the light flux And a condenser lens that is provided so that the front focal position overlaps the position of the aperture stop, passes the light that has passed through the aperture stop, and guides it to the sample. The field stop is conjugate with the sample with respect to the field lens group. The light source includes a light emitting member that emits light, a light propagation member that causes light from the light emitting member to enter and propagate in a direction different from the incident direction, and light emitted from the light propagation member. The Characterized in that it is constituted by a light diffusing member which diffuses and emitted to have a predetermined intensity distribution in the angular direction Te.

の条件を満足することが好ましく、更に、光源が、視野絞りから１５ｍｍより長い距離だけ離れた位置に配置されることが好適である。 In the microscope illumination apparatus according to the second aspect of the present invention, the microscope is provided with an objective lens for condensing the light transmitted through the specimen, provided with an exit surface for emitting the illumination light to the light source, and the imaging magnification of the specimen with respect to the field stop is β , NA _max is the maximum numerical aperture of the objective lens corresponding to the condenser lens, Φ _max is the maximum real field of the objective lens corresponding to the condenser lens, d is the diameter of the exit surface of the light source, and When the angle formed by the optical path having the highest intensity and the optical path having 80% of the maximum intensity is α,

It is preferable that the above condition is satisfied, and it is preferable that the light source is disposed at a position separated from the field stop by a distance longer than 15 mm.

  According to the microscope illumination apparatus of the first invention, by arranging the light source at a position near the aperture stop, the optical system on the light source side can be omitted from the conventional aperture stop, and the illumination system is compact. Can be configured.

  Further, according to the illumination device for a microscope according to the second invention, by arranging the light source at a position near the field stop, the optical system on the light source side can be omitted from the conventional field stop. Can be configured compactly.

It is the schematic which shows the illuminating device for microscopes (reflective illuminating device) which concerns on 1st invention. It is a figure which shows the light-guide plate (surface light source) in the illuminating device for microscopes concerning 1st invention, (a) is the schematic seen from the direction where light is irradiated, (b) is the direction where light is irradiated. The figure which shows the layer structure seen from the perpendicular | vertical direction, (c) is the schematic seen from this perpendicular | vertical direction. It is the schematic which shows the illuminating device for microscopes (transmission illumination device) concerning 2nd invention, (a) is the example (1st Example) which reflects the light inject | emitted from the light source with a mirror, (b) is a light source. It is a figure which shows the example (2nd Example) which does not reflect the light inject | emitted from the mirror. It is a figure which shows the light-guide plate (surface light source) in the illuminating device for microscopes concerning 2nd invention, (a) is the schematic seen from the direction where light is irradiated, (b) is the direction where light is irradiated. The figure which shows the layer structure seen from the perpendicular | vertical direction, (c) is the schematic seen from this perpendicular | vertical direction. It is the schematic which shows the conventional reflective illuminating device. It is the schematic which shows the conventional transmission illuminating device.

  Hereinafter, the reflective illumination device of the first embodiment according to the first invention and the transmission illumination device of the second embodiment according to the second invention will be described with reference to the drawings. These embodiments do not limit the invention according to the claims. Moreover, not all the combinations of configurations and features described in the embodiments are necessarily essential to the solution means of the invention. The reflective illumination device in the first embodiment is a microscope device capable of observing a specimen such as an opaque cell by reflecting light, and the transmission illumination device in the second embodiment is a sample of a transparent cell or the like. Is a microscope apparatus that can be observed by transmitting the light.

  First, before describing the reflective illumination device of the first embodiment, a conventional reflective illumination device will be described with reference to FIG. A conventional reflective illumination device includes a light source 101, a collector lens 102, a filter group 103, a relay optical system 104, an aperture stop 105, a field stop 106, a field lens group 107, a half mirror 108, An objective lens 109 and a second objective lens 111 are provided. A halogen lamp or the like is used as the light source 101, and light emitted from the light source 101 is converted into parallel light by the collector lens 102, and the converted parallel light passes through the filter group 103, and brightness or The color temperature is adjusted. The light thus adjusted passes through the relay optical system 104, and a light source image 101 ′ is formed by the relay optical system 104. An aperture stop 105 is disposed in the vicinity of the position where the light source image 101 ′ is formed, and a field stop 106 is disposed in the vicinity of the image F 2 ′ by the relay optical system 104 of the rear focal point F 2 of the collector lens 102. A field lens group 107 is disposed after the field stop 106 so that the front focal position of the field lens group 107 overlaps the position of the field stop 106.

  The light that has passed through the relay optical system 104 passes through the aperture stop 105, the field stop 106, and the field lens group 107, is deflected in the direction of the first objective lens 109 by the half mirror 108, and passes through the first objective lens 109. Light is irradiated to the specimen 110 which is an opaque cell or the like. Then, the reflected light reflected from the specimen 110 by the light irradiation to the specimen 110 is collected by the first objective lens 109, passes through the half mirror 108 and the second objective lens 111, and exits from the second objective lens 111. The specimen image 112 is formed by the light that is emitted. The sample image 112 is imaged by an imaging optical system (not shown) or relayed by another relay optical system (not shown) to form a second sample image (not shown) to form an observation optical system (not shown). And an imaging optical system (not shown).

  As described above, in the conventional reflective illumination apparatus, the specimen 110 can be observed and imaged. However, since the filter group 103, the relay optical system 104, and the like are provided and a large number of parts are required, the overall length of the illumination system is long. There was a problem of becoming. Therefore, the reflective illumination device of the first embodiment uses an LED as a light source. Since the color temperature of the LED does not change even when the voltage is changed, the brightness can be changed by changing the voltage without using filters as in the case of the conventional reflective illumination device. In addition, as described later, the light guide is used to convert the light from the LED light source into a light emitter of an appropriate area, and the light distribution angle is controlled by a prism sheet, so that it is optimal without using a collector lens or a relay optical system. Light source size can be achieved. Therefore, the collector lens, the filter group, and the relay optical system can be omitted (detailed later), and the above-described problems can be solved.

  The reflective illumination device of the first embodiment will be described with reference to FIG. The reflective illumination device includes a light source 1, an aperture stop 5, a field stop 6, a field lens group 7, a half mirror 8, a first objective lens 9, and a second objective lens 11. . The light source 1 is a square plate-like surface light source having a square light emission surface. A plurality of LED light sources 20 (detailed later) are arranged on the light emission surface of the light source 1, and light is emitted from the individual LED light sources 20. In the reflective illumination device of the first embodiment, α is an angle formed by an optical path with the highest intensity of light emitted from the light source 1 and an optical path with 80% of the highest intensity (hereinafter referred to as a light distribution angle). The diameter of the circle inscribed in the light source 1 is d (mm). The configuration of the light source 1 will be described in detail later.

  As shown in FIG. 1, the light emitted from the light source 1 passes through the aperture stop 5 and the field stop 6, is deflected in the direction of the first objective lens 9 by the half mirror 8, and passes through the first objective lens 9. Light is irradiated to the specimen 10 which is an opaque cell or the like. The aperture stop 5 is disposed in the vicinity of the light source 1. Then, similarly to the conventional reflective illumination device, the reflected light reflected from the specimen 10 is collected by the first objective lens 9 and passes through the half mirror 8 and the second objective lens 11 (imaging lens), Thereby, the sample image 12 is formed. The sample image 12 is guided to an observation optical system (not shown) and an imaging optical system (not shown).

Here, if the projection magnification from the light source 1 to the pupil P of the first objective lens 9 by the field lens group 7 is β, the size of the light source image formed on the pupil P is d × β. On the other hand, the numerical aperture of the first objective lens 9 is NA, and the value obtained by dividing the NA by the magnification of the first objective lens 9 is NA ′. Further, the focal length of the microscope imaging lens 11 when the f _t, the diameter of the pupil P of the first objective lens 9 can be expressed as NA '× f _t × 2. When the size of the light source image is smaller than the size of the pupil P of the first objective lens 9, the numerical aperture NA becomes insufficient when observing a sample with little scattering of the reflected light, and the exit pupil diameter becomes small, resulting in the observation. The flickering becomes noticeable. Therefore, it is necessary to make the size of the light source image larger than the size of the pupil P, that is, to satisfy the following formula (1). Note that NA ′ in the equation (1) is the maximum NA ′ value among the assumed objective lenses.

Further, if the focal length of the first objective lens 9 is f _obj , and the light distribution angle of the light source 1 is α and the projection magnification is β as described above, the illumination area by the light source 1 is 2 × f _obj × tan (α / Β) (see FIG. 1). On the other hand, if the number of fields of the microscope is FOV, the actual field on the sample surface of the microscope is FOV using this FOV, the focal length f _obj of the first objective lens 9 and the focal length f _t of the imaging lens of the microscope. / ( _Ft / f _obj ). By the way, if the illumination area described above is smaller than the actual visual field, the visual field unevenness that darkens the periphery of the visual field occurs or the visual field lacks. Therefore, it is necessary to make the illumination area larger than the actual field of view, that is, satisfy the following formula (2).

  As described above, when the projection magnification β from the light source 1 to the pupil P of the first objective lens 9 satisfies the above-described expressions (1) and (2), the collector lens 102, the filter group 103, and the relay in the conventional reflective illumination device. While omitting the lens group 104 and making the illumination system compact, it is possible to suppress flicker during observation, to prevent occurrence of unevenness of field of view and lack of field of view, and to obtain a good sample image 12. Below, the structure of the light source 1 which is a surface light source in the reflective illumination apparatus of 1st Embodiment is demonstrated, referring FIG. FIG. 2 is a diagram showing a light emission mechanism of the light source 1.

  As shown in FIG. 2A, the light source 1 is a so-called light guide plate that emits light on the same principle as the backlight of a liquid crystal display device. In the light guide plate, a plurality of light sources such as LEDs are arranged and arranged on a circuit board and sealed by upper and lower frames or the like. Light emitted from a light source such as an LED propagates while repeating total reflection in a light guide, which will be described later, and is emitted out of the substrate when the light enters the light guide at a predetermined incident angle. Yes. The light emitted to the outside of the substrate passes through one or more sheet-like members capable of controlling the light flux, and is emitted with a predetermined light distribution angle as a whole.

  As shown in FIG. 2A, the light source 1 includes an LED light source 20, an LED module 21, a light guide 22, a scattering sheet 23, prism sheets 24 and 25, a protective glass 26, and a square substrate 30. And is configured. The LED light source 20 is disposed on the upper surface of the substrate 30. The LED module 21 is an electric circuit, and supplies power to the LED light source 20 disposed on the substrate 30 via the substrate 30, whereby the LED light source 20 emits light.

  The light guide 22 is provided above the LED light source 20 disposed on the substrate 30 so as to face the LED light source 20. The light emitted from the LED light source 20 is taken into the light guide 22 and repeatedly reflected inside and transmitted to the scattering sheet 23. The light is repeatedly reflected in the light guide 22, but the light is transmitted to the scattering sheet 23 only when the angle formed by the traveling direction of the light and the reflection surface of the light guide 22 is a predetermined angle. When it is not an angle, it is totally reflected. The light emitted from the light guide 22 is appropriately diffused by the scattering sheet 23 and transmitted to the prism sheets 24 and 25. The prism sheets 24 and 25 transmit light and emit with a predetermined light distribution angle. The prism sheets 24 and 25 have a large number of concavo-convex parts formed in a line shape in the direction of the side of the substrate 30 on the transmission surface that transmits the light, and are arranged so that the lines of the concavo-convex parts are orthogonal to each other. Has been. 2B and 2C show an example in which the prism sheet 24 is arranged in the depth direction of the paper surface and the prism sheet 25 is arranged in the left-right direction of the paper surface so that the lines of the concavo-convex portions extend. Yes.

  The light guide 22, the scattering sheet 23, and the prism sheets 24 and 25 are arranged above the LED light source 20 in that order, and the upper surface of the prism sheet 25 is covered and protected by a protective glass 26. The light guide 22, the scattering sheet 23, the prism sheets 24 and 25, and the protective glass 26 are integrated and configured so as to be sandwiched between upper and lower frames (see FIG. 2C).

In the light source 1 configured as described above, the luminance of light emitted from the light source 1 can be improved by increasing the number of LED light sources 20 on the substrate 30. Therefore, for example, if the length of one side of the substrate 30 is 8 (mm), the value of d described above is also 8 (mm), and as shown in FIG. When four are provided on the side facing the side, a luminance of 30,000 candela / cm ² can be realized.

一方、光源１の配光角αを７．５°とすると、式（２）からβの値の範囲が以下のように導かれる。

In the reflective illumination device of the first embodiment, when the magnification of the first objective lens 9 is 10 times and the numerical aperture NA is 0.3, the above-mentioned NA ′ (value obtained by dividing the numerical aperture NA by the magnification) is (0.3 / 10) = 0.03. When the focal length f _{t of the} imaging lens is 200 (mm) and the field number FOV of the microscope is 22, the projection magnification β up to the pupil of the first objective lens 9 with respect to the light source 1 in the first embodiment is ) Can be derived as follows by substituting the above values into

On the other hand, when the light distribution angle α of the light source 1 is 7.5 °, the range of the value of β is derived from the equation (2) as follows.

  From the above, it is preferable that the projection magnification β is between 1.5 and 2.3 times, but it is preferable that the projection magnification β is low in consideration of the uniformity of illumination. Therefore, the optimum value of β is 1.5 times.

  As described above, in the reflective illumination device according to the first embodiment, by using an LED as a light source, the brightness can be increased by changing the voltage without using filters such as a neutral neutral density filter as in the conventional reflective illumination device. Can be changed. In addition, as described later, light from an LED light source is converted into a light emitter of an appropriate area using a light guide, and the light distribution angle is controlled by a prism sheet, so that it is optimal without using a collector lens or a relay optical system. Therefore, the optical system can be made simple and compact. The LED used as the light source is a type that emits white light by combining a blue light emitting LED and a phosphor, or a type that emits white light by integrating LED chips of three colors RGB. Is possible. Of these two types, the latter type tends to have lower emission luminance than the power used. However, since it is possible to independently control the amount of light for each of R, G, and B, the color temperature can be easily adjusted. There is an advantage that it can be controlled.

  Next, the transmission illumination device will be described. First, before describing the transmission illumination device of the second embodiment, a conventional transmission illumination device will be described with reference to FIG. A conventional transmission illumination device includes a light source 131, a collector lens 132, a filter group 133, a relay optical system 134, a diffusion plate D, a field stop 136, a mirror 138, a field lens group 137, and an aperture stop 135. And a condenser lens 139 and an objective lens 141. A halogen lamp or the like is used as the light source 131, and the light emitted from the light source 131 is converted into parallel light by the collector lens 132, and the converted parallel light passes through the filter group 133, and the brightness and color temperature are converted by the filter group 133. Is adjusted. The field stop 136 is disposed at the conjugate position C of the rear focal point of the collector lens 132 by the relay optical system 134. In addition, a diffusing plate D is disposed downstream of the relay optical system 134 so that light that has passed through the relay optical system 134 is diffused by the diffusing plate D. The mirror 138 is disposed downstream of the field stop 136, and the field lens group 137 is disposed downstream of the mirror 138. The light passing through the field stop 136 is reflected by the mirror 138 and guided to the field lens group 137.

  The field lens group 137 is disposed at a position where its front focal plane overlaps the field stop 136, and the aperture stop 135 is an image of the light source 131 formed by the collector lens 132, the relay optical system 134, and the field lens group 137. It is arranged in the vicinity of 131 '. The condenser lens 139 is disposed at a position where its front focal plane overlaps the aperture stop 135, and the transparent specimen 140 is transmitted and illuminated with Koehler illumination by the light passing through the condenser lens 139. The objective lens 141 is provided on the opposite side of the condenser lens 139 with respect to the specimen 140, and light transmitted through the specimen 140 by the Koehler illumination passes through the objective lens 141. As described above, the specimen image of the specimen 140 transmitted and illuminated by the conventional transmission illumination apparatus shown in FIG. 6 is formed at a predetermined position by the objective lens 141 and the second objective lens (not shown). For example, the specimen image of the specimen 140 is observed and imaged by an observation optical system (not shown) and an imaging optical system (not shown) provided at the subsequent stage of the position.

  As described above, in the conventional transmission illumination device, the specimen 140 can be observed and imaged, but for the same reason as the conventional reflection illumination device, there is a problem that the entire length of the illumination system becomes long. Therefore, the transmission illumination device of the second embodiment can omit the collector lens, the filter group, and the relay optical system by using an LED as a light source, as in the case of the reflection illumination device of the first embodiment (later Detailed description), the above-mentioned problems can be solved.

  A transmission illumination device according to a second embodiment will be described with reference to FIG. Note that there are two types of examples of the transmission illumination device of the second embodiment, which will be described below as the first example and the second example.

  First, as shown in FIG. 3A, the transmission illumination device of the first embodiment includes a light source 31, a field stop 36, a mirror 38, a field lens group 37, an aperture stop 35, a condenser lens 39, and the like. And an objective lens 41. The field stop 36 is disposed in the vicinity of the light source 31. The light source 31 is a surface light source having a light emission surface as in the first embodiment, and a plurality of LED light sources 70 are arranged on the emission surface. As in the first embodiment, the light distribution angle, which is the angle formed by the light path from which the intensity of the light emitted from the light source 31 is the highest and 80% of the light path, is α, and a circle inscribed in the light source 31 Is the diameter d (mm). The configuration of the light source 31 will be described in detail later.

  The light emitted from the light source 31 passes through the field stop 36, is deflected in the direction of the field lens group 37 by the mirror 38, and proceeds in the order of the field lens group 37, the aperture stop 35, and the condenser lens 39. Then, the light transmitted through the condenser lens 39 is irradiated to the specimen 40 which is a transparent cell or the like. Similarly to the conventional transmission illumination apparatus, the objective lens 41 is provided on the opposite side of the condenser lens 39 with respect to the specimen 40, and light transmitted through the specimen 40 passes through the objective lens 41. A specimen image of the specimen 40 is formed at a predetermined position by an objective lens 41 and a second objective lens (not shown), and is observed and imaged by an observation optical system (not shown) and an imaging optical system (not shown). It has become so.

Below, the structure of the light source 31 is demonstrated easily, referring FIG. Similar to the light source 1 of the first embodiment, the light source 31 includes an LED light source 70, an LED module 71, a light guide 72, a scattering sheet 73, prism sheets 74 and 75, a protective glass 76, and a substrate 80. It is configured with. These members are the same members as the LED light source 20, the LED module 21, the light guide 22, the scattering sheet 23, the prism sheets 24 and 25, the protective glass 26, and the substrate 30 of the first embodiment. It is the same composition. The difference from the first embodiment is the size of the substrate 80 and the number of LED light sources 70 arranged on the substrate 80. In the substrate 80 of the second embodiment, one side has a length of 35 (mm), and as shown in FIG. 4A, seven LED light sources 70 are provided along the end side. Yes. In this case, the luminance is 20000 candela / cm ² .

Further, in the transmission illumination device of the second embodiment, it is assumed that the light distribution angle α of the light source 31 is 10 °, and the condenser lens 39 corresponds to the objective lens 4 to 100 times, and the maximum numerical aperture NA _max is It is assumed that 0.88 and the maximum visual field Φ _max is 5.5 (mm). When the focal length of the field lens group 37 is f _f (mm), the focal length of the condenser lens 39 is f _c (mm), and the imaging magnification from the field stop 36 to the specimen 40 is β ₂ , β ₂ = It can be expressed as f _c / f _f . Further, NA _max and Φ _max preferably satisfy the following formulas (3) and (4).

Furthermore, since it is preferable to limit the size of the aperture stop 35 disposed on the focal plane of the condenser lens 39 to some extent, it is convenient to satisfy the following expression (5).

Hereinafter, a range of values of the focal length f _f of the field lens group 37 and the focal length f _c of the condenser lens 39 that satisfies the above expressions (3), (4), and (5) will be considered. First, since NA _max = 0.88 as described above, 15 / NA _max ≈17.045, and f _c <17.04 is obtained from the equation (5). Therefore, as _{f c = 17, f c =} 17, NA max = 0.88 in equation (4), and substituting [Phi _max = 5.5, the _{f f <35 × 17 / 5.5} = 108. Therefore, as _f f = 100, and substituting the values and f _c = 17 in this f _f in equation (3), the left-hand side of equation (3) becomes sin10 ° × 100/17 = 1.02 . Since this value is larger than NA _max = 0.88, Expression (3) is satisfied.

  The transmitted illumination device of the second embodiment will be described below. As shown in FIG. 3B, the transmission illumination device of the second embodiment includes a light source 51, a field stop 56, a field lens group 57, an aperture stop 55, a condenser lens 59, and an objective lens 61. Since these members have the same configuration and function as the light source 31, the field stop 36, the field lens group 37, the aperture stop 35, and the condenser lens 39 of the first embodiment, the overlapping description is omitted. In the transmission illumination device of the second example, the field lens group 57 and the condenser lens 59 have a finite system configuration. Therefore, the focal length of the field lens group 57 is smaller than that of the first example. It becomes possible to shorten, and the length of the whole illumination system can be further shortened. Further, the transmission illumination device of the second embodiment can increase the object distance (distance from the surface facing the sample of the condenser lens to the sample) when the focal length of the condenser lens is constant. Suitable for observing large specimens.

The transmission illumination devices of the first and second examples have been described above. The light source 31 and 51 of the transmission illumination device of the second embodiment includes prism sheets 24 and 25 of the reflection illumination device of the first embodiment. The prism sheets 74 and 75 having the same structure are used. For this reason, there is a possibility that the structure of the concave and convex portions of the prism sheets 74 and 75 may be seen overlapping with the specimen image. However, if the eyepiece (not shown) has a diopter of less than 10 diopters, the prism sheets 74 and 75 are visible. It is said that such a structure is not visible. This condition is that in the transmission illumination device of the second embodiment, f _b is the focal length (mm) of the eyepiece, β ₂ is the magnification from the field stop 36, 56 to the specimen 40, 60, and M is the specimen 40, 60. When the enlargement ratio from L to the eyepiece observation image and L is the distance from the light sources 31 and 51 to the field stops 36 and 56, the following expression (6) is obtained.

The value of the distance L from the light sources 31 and 51 to the field stops 36 and 56 will be examined using the above-described equation (6). Here, the focal length f _b of the eyepiece on the assumption that the standard 10-fold and 25 (mm). Since β ₂ can be expressed as β ₂ = f _c / f _f as described above, β ₂ = 17/100 = 0.17. The magnification M from the specimens 40 and 60 to the eyepiece observation image is a value between 4 and 100, but M is 4 when L is the largest. Therefore, when f _b = 25 (mm), β ₂ = 0.17, and M = 4, L> 13.5 is obtained from the equation (6). However, in consideration of a case where the eyepiece is other than the standard (when an eyepiece having f _b larger than 25 mm is used), it is preferable that L> 15. Therefore, in the transmission illumination device of the second embodiment, the light sources 31 and 51 are arranged at positions separated by about 15 mm from the positions of the field stops 36 and 56.

  As described above, instead of disposing the light sources 31 and 51 by a predetermined distance from the positions of the field stops 36 and 56, a member having a complete diffusion surface such as opal glass can be disposed. When such a member is arranged, the illuminance becomes dark because the light flux is diffused. However, if there is a margin in the amount of light, even if it overlaps with the images of the specimens 40 and 60, it looks practically uniform. Can solve the problem.

  In the reflective illumination device of the first embodiment, since the light source 1 is arranged in the vicinity of the aperture stop 5 and not in the vicinity of the field stop 6, like the transmission illumination device of the second embodiment. The structures of the prism sheets 24 and 25 are not visually recognized on the specimen image. Therefore, the light source 1 and the field stop 6 may be arranged apart from each other by a structurally necessary distance.

  As described above, in the reflective illumination device of the first embodiment described above, an optical system in front of the aperture stop is configured by using the surface light source on which the LED is mounted and arranging the surface light source in the vicinity of the aperture stop. (Collector lens, filter group, relay optical system) can be omitted, and the entire apparatus can be made compact.

  Also, in the transmission illumination device of the second embodiment, because the surface light source is mounted in the vicinity of the field stop using a surface light source on which LEDs are mounted in the same manner as the reflection illumination device of the first embodiment, The optical system in front of the field stop can be omitted, and the entire apparatus can be made compact.

  In each of the above-described embodiments, an example in which a square plate-like surface light source is used as the light source has been described. However, the shape and structure of the light source are not limited to those of the above-described embodiments. For example, the shape may be other than a square, or the number and position of LED light sources arranged on the substrate may be changed. Further, the positions of the light guide, the scattering sheet, the prism sheet, and the like, which are members constituting the light source, may be changed, or different types may be used.

1 Light source (first embodiment)
5 Aperture stop (first embodiment)
6 Field stop (first embodiment)
7 field lens group (first embodiment)
9 First objective lens (first embodiment)
10 specimens (first embodiment)
11 Second objective lens (first embodiment, imaging lens)
20 LED light source (first embodiment, light emitting member)
22 Light guide (first embodiment, light propagation member)
23 Scattering sheet (first embodiment, light propagation member)
24, 25 Prism sheet (first embodiment, light diffusion member)
31, 51 Light source (second embodiment)
35, 55 Aperture stop (second embodiment)
36, 56 Field stop (second embodiment)
37, 57 field lens group (second embodiment)
39, 59 condenser lens (second embodiment)
40,60 specimens (second embodiment)
41, 61 Objective lens (second embodiment)
70 LED light source (second embodiment, light emitting member)
72 Light guide (second embodiment, light propagation member)
73 Scattering sheet (second embodiment, light propagation member)
74, 75 Prism sheet (second embodiment, light diffusion member)

Claims (5)

A light source that emits illumination light;
An aperture stop provided in the vicinity of an emission surface of the light source, and having an aperture through which the illumination light passes by adjusting a light flux of the illumination light;
A field stop that is provided in an optical path of light that has passed through the aperture stop, sets an illumination area of the illumination light, and passes light that has passed through the aperture stop; and
A front lens position is provided so as to overlap the position of the field stop, and a field lens group that allows light that has passed through the field stop to pass therethrough, and light that has passed through the field lens group is applied to the specimen and reflected light from the specimen In an illumination device for a microscope provided with an objective lens for receiving light,
The light source includes: a light emitting member that emits light; a light propagation member that emits light emitted from the light emitting member in a direction different from the direction of incidence; and light emitted from the light propagation member with a predetermined intensity in an angular direction. An illumination device for a microscope, comprising: a light diffusing member that diffuses and emits light with a distribution. The imaging magnification of the pupil plane of the objective lens relative to the light source is β, the maximum value obtained by dividing the numerical aperture of the objective lens by the magnification of the objective lens is NA ′, and the focal length of the imaging lens is f. _t is the diameter of the exit surface of the light source, d is the angle formed by the optical path having the highest intensity of the light emitted from the light source and the optical path having 80% of the highest intensity, and α When the number of fields of view is FOV,

The microscope illumination device according to claim 1, wherein the following condition is satisfied. A light source that emits illumination light;
A field stop that is provided in the vicinity of an emission surface of the light source, sets an illumination area of the illumination light, and passes the illumination light;
A field lens group for condensing light that has passed through the field stop;
An aperture stop provided in the optical path of the light collected by the field lens group, and having an aperture for adjusting the luminous flux to pass the collected light;
In a microscope illumination device provided with a condenser lens that is provided so that a front focal position overlaps with the position of the aperture stop, and that passes through the aperture stop and guides the light to a sample,
The field stop is provided at a position conjugate with the sample with respect to the field lens group,
The light source includes a light emitting member that emits light, a light propagation member that causes the light from the light emitting member to enter and propagate in a direction different from the incident direction, and the light emitted from the light propagation member to enter. An illumination device for a microscope comprising: a light diffusing member that diffuses and emits light with a predetermined intensity distribution in an angular direction. An objective lens for condensing the light transmitted through the specimen;
An emission surface for emitting illumination light to the light source is provided,
The imaging magnification of the sample with respect to the field stop is β, the maximum numerical aperture of the objective lens corresponding to the condenser lens is NA _max, and the maximum value of the real field of the objective lens corresponding to the condenser lens is Φ _max , the diameter of the exit surface of the light source is d, and the angle formed by the optical path having the highest intensity and the optical path having 80% of the highest intensity among the light emitted from the light source is α. When

The microscope illumination device according to claim 3, wherein the following condition is satisfied.   5. The microscope illumination device according to claim 3, wherein the light source is disposed at a position separated from the field stop by a distance longer than 15 mm.

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