METHOD FOR ILLUMINATING AN OBJECT IN A DIGITAL LIGHT MICROSCOPE, DIGITAL LIGHT MICROSCOPE AND BRIGHT FIELD REFLECTED-LIGHT ILLUMINATION DEVICE FOR A DIGITAL LIGHT MICROSCOPE

Abstract

The invention relates to a method for illuminating an object in a digital light microscope, to a digital light microscope, and to a bright field reflected-light illumination device for a digital light microscope. According to the invention, the bright field reflected-light illumination and the dark field reflected-light illumination are configured with light-emitting diodes as light sources and are individually or jointly drivable via a control unit. Both the bright field reflected-light illumination and the dark field reflected-light illumination are configured as “critical” illumination, in which the light source is imaged into the object plane.

Claims

1. A method for illuminating an object in a digital light microscope, wherein a bright field reflected-light illumination is effected by means of an illumination device comprising light-emitting diodes (01) as light sources, wherein a dark field reflected-light illumination is effected by means of a ring illumination device comprising light-emitting diodes (17) as light sources, said ring illumination device being mechanically and electrically coupleable to an objective of the light microscope, wherein the bright field reflected-light illumination and the dark field reflected-light illumination are separately drivable and superimposable and each configured ascritical illumination, in which an image of the light source is projected into an object plane.

2. The method according to claim 1, wherein bright field reflected-light illumination and dark field reflected-light illumination are effected by means of white-light LEDs (01, 17).

3. The method according to claim 1, wherein the ring illumination device is drivable via an electronic interface of the objective, and wherein individual or all light-emitting diodes (01, 17) are driven.

4. A digital light microscope for examining an object, comprising: an objective; a bright field illumination device; a dark field illumination device; and a control unit, wherein the bright field illumination device comprises at least one light-emitting diode (01, 16) as a light source, and the dark field illumination device is embodied as ring illumination comprising at least two light-emitting diodes (17) as light sources and is coupled to the objective via an electronic interface, wherein the bright field illumination device and the dark field illumination device are individually or simultaneously drivable via the control unit and are configured as critical illumination, in which an image of a light source is projected into an object plane (13).

5. A bright field reflected-light illumination device for a digital light microscope comprising: at least one light source embodied as light-emitting diode (01, 16), wherein the at least one light source is configured as critical illumination, in which an image of the light source is projected into an object plane.

6. The bright field reflected-light illumination device according to claim 5, wherein the light source is a semiconductor white-light LED (01) and a homogenizer is arranged in the beam path of the bright field reflected-light illumination device, a field stop (07) having a rectangular cross section being provided at the output of said homogenizer, and wherein the rectangular cross section has the same aspect ratio as an image sensor of the light microscope.

7. The bright field reflected-light illumination device according to claim 6, wherein the homogenizer is a light mixing element.

8. The bright field reflected-light illumination device according to claim 7, wherein the light mixing element realizes a 90° deflection of the light between an entrance opening and an exit opening for the light.

9. The bright field reflected-light illumination device according to claim 6 wherein the homogenizer is a hollow-waveguiding light mixing rod (06, 14) having a rectangular cross section.

10. The brightfield reflected-light illumination device according to claim 6, wherein the size of the field stop (07) is variable.

Description

[0033] In the figures:

[0034] FIG. 1 shows: a first preferred embodiment of a bright field reflected-light illumination device in a basic illustration;

[0035] FIG. 2 shows: a second preferred embodiment of the bright field reflected-light illumination device in a basic illustration;

[0036] FIG. 3 shows: a third preferred embodiment of the bright field reflected-light illumination device in a basic illustration;

[0037] FIG. 4 shows: one preferred embodiment of a dark field illumination device in a perspective basic illustration.

[0038] FIG. 1 shows a first preferred embodiment of a bright field reflected-light illumination device according to the invention in a Nelson configuration or so-called “critical” illumination. The device comprises as light source at least one LED 01, equipped with a corresponding optical assembly as collector 02. The light emitted by the LED 01 passes in an illumination beam path through a plane 03 that is conjugate with respect to an aperture stop 10, via an intermediate optical unit 04 into a homogenizer embodied as a light mixing rod 06. In the conjugate plane 03, in an alternative embodiment, a variable second aperture stop can be used in order to be able to set the illumination and observation apertures independently of one another. Contrast enhancements are thus achieved, in particular.

[0039] Ideally, an image of the light source, of the emitting LED chip in the embodiment illustrated, arises at the entrance of the homogenizer. However, it can he advantageous to slightly defocus said image in order already to achieve a first blurring of the bonding wires of the light source. In this embodiment, the light mixing rod 06 is a straight hollow-waveguiding rod having a rectangular cross section.

[0040] A preferably variable field stop 07 having a rectangular cross section in the format or aspect ratio of the image detection sensor (not illustrated) of the microscope is arranged at the output of the homogenizer 06. By varying the cross section, it is possible for the illumination device to be configured advantageously for different zoom settings of the objective, in order that the size of the object illumination corresponds as far as possible to the size of the image sensor. Even in the event of a change of objective, it is possible to adapt the size of the object illumination with said stop. For the efficiency of the illumination it has proved to be particularly advantageous if the cross section of the light mixing rod 06 and the LED chip also have the format or the aspect ratio of the image detection sensor.

[0041] Via a deflection mirror 08, the illumination light is collimated via a further intermediate optical unit 09 and is incident in an objective 12 through the aperture stop 10. The objective 12 generates the image of the variable field stop 07 in the object plane 13.

[0042] A plane glass 11 is arranged in the beam path in a known manner in order to feed the detected image to the image detection sensor (not illustrated).

[0043] The advantages of this embodiment can he seen, in particular, in the fact that the assembly from the light source as far as the deflection mirror can be embodied in a very compact fashion.

[0044] A second preferred embodiment of the bright field reflected-light illumination device is illustrated in FIG. 2. In this case, identical reference numerals denote identical component parts. The embodiment illustrated differs from the embodiment described above in that the homogenizer is fashioned as an angular light mixing element 14. The deflection mirror can advantageously be omitted as a result. This embodiment is even more compact in its design.

[0045] In the case of the embodiment illustrated in FIG. 3, instead of a semiconductor LED an OLED 16 (organic light-emitting diode) is used, which has the same format as the image detection sensor. This embodiment is particularly space-saving and efficient since further optical assemblies, such as are otherwise required for bright field illumination, are not necessary. Moreover, OLEDs are inexpensive to produce because they are producible using printing technology, for example. A white-light OLED is preferably used. Alternatively, by means of dichroic splitters, an RGB illumination can be dimensioned or a fluorescence excitation can even be effected by means of monochromatic OLEDs.

[0046] FIG. 4 illustrates a basic schematic diagram of an arrangement of LEDs 17 in an illumination ring. The LEDs are inclined at an angle a with respect to an optical axis 19 of the objective (not illustrated), such that the light is mixed, homogenized and focused on the object plane 13 in accordance with the requirements by means of an optical assembly 19.

[0047] Here as well, an efficient and space-saving arrangement is achieved by means of a critical illumination, i.e. the light source or light-emitting diode is imaged into the object plane.

[0048] For an even better efficiency, it is advantageous to align rectangular LED chips, depending on their position in the illumination ring, in accordance with the rectangular object field form. An even better efficiency is achieved as a result, because only the region actually detected by the image sensor is illuminated.

[0049] For a simplified mounting it may be advantageous for the LED chips always to be aligned identically with respect to the concentric ring. As a result, component parts can be embodied identically and the alignment of individual groups is identical. However, that leads to a slight loss of efficiency.

LIST OF REFERENCE SIGNS

[0050] 01 LED

[0051] 02 emission optical unit

[0052] 03 plane that is conjugate with the aperture stop

[0053] 04 intermediate optical unit

[0054] 05 —

[0055] 06 light mixing rod

[0056] 07 field stop

[0057] 08 deflection mirror

[0058] 09 intermediate optical unit

[0059] 10 aperture stop

[0060] 11 plane glass

[0061] 12 objective

[0062] 13 object plane

[0063] 14 light mixing rod, angular

[0064] 15 —

[0065] 16 OLED

[0066] 17 LED

[0067] 18 optical axis of the objective

[0068] optical assembly