JPH05323198A - Lighting device - Google Patents

Abstract

PURPOSE:To provide the compact, small-sized lighting device of simple constitution which eliminates a deviation in lighting place from an observation place even if a lighting angle is varied. CONSTITUTION:The lighting device is equipped with an objective 3 which faces an object 1 to be observed, a movable condenser lens 11 which converges the illumination luminous flux from an illumination light source, and a lighting angle varying optical member 7 which converges the illumination luminous flux to irradiate the observation place 1a while varying the irradiation angle of the illumination luminous flux to the object 1 to be observed as the condenser lens 11 moves in a state wherein the distance L from the object 1 to be observed is set constant so as to vary the lighting angle while the lighting place is prevented from deviating from the observation place 1a of the object to be observed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an illuminating device used for a microscope or the like which constitutes a part of an image processing and measuring device.

[0002]

2. Description of the Related Art Conventionally, there is known an illuminating device for illuminating an observation object by guiding the illumination light while converging the illumination light on the observation object in an oblique direction. This conventional illuminating device is provided with an illumination angle changing means for the observation object, in particular, in order to obtain an appropriate illumination state for the observation object, especially for the observation portion having a complicated shape of the observation object.
An annular aspherical mirror is used for the conventional illumination angle changing means, and the illumination angle is changed by moving the aspherical mirror toward and away from the observation object in the vertical direction.

[0003]

However, if the aspherical mirror is simply moved away from the object to be observed in order to change the illumination angle, the illuminated portion is displaced from the observed portion. For this reason, an auxiliary aspherical surface mirror different from this aspherical surface mirror is provided, and the auxiliary aspherical surface mirror is moved up and down in association with the vertical movement of the aspherical surface mirror so that the illumination position does not shift with respect to the observation position. Due to the structure, there is a problem that the structure of the lighting device is complicated.

The present invention has been made in view of the above circumstances, and has a simple structure and is compact and small in size so that the illumination location can be prevented from being displaced with respect to the observation location even if the illumination angle is changed. It is an object of the present invention to provide a lighting device.

[0005]

In order to solve the above-mentioned problems, an illuminating device according to the present invention includes an objective lens which faces an object to be observed, and a movable condenser lens which collects an illumination light beam from an illumination light source. In order to change the illumination angle while preventing the displacement of the illumination point with respect to the observation point of the observation object, the observation is performed with the movement of the condensing lens while the distance from the observation object is set constant. An illumination angle changing optical member for focusing and irradiating the observation light spot with the illumination light flux while changing the irradiation angle of the illumination light flux with respect to the object.

[0006]

According to the illumination device of the present invention, the distance of the illumination angle changing optical member from the observation object is set to be constant.
Then, when the condenser lens is moved, the illumination angle changing optical member converges and irradiates the observation light spot on the observation location while changing the illumination angle with respect to the observation object according to the movement of the illumination lens.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numeral 1 is an object to be observed, which is a precision part made of plastics here. The precision component 1 is mounted on an XY table or a rotary table (not shown). Reference numeral 2 denotes a lens barrel which constitutes a part of the microscope, and the lens barrel 2 has an objective lens 3 and an image pickup tube 4.
And are provided. The objective lens 3 faces the observation object 1 from above, and the image pickup tube 4 is connected to the television monitor 5. Reference numeral O is an optical axis of the objective lens 3. An illumination optical member holding barrel 6 is provided on the outer periphery of the lens barrel 2. The illumination optical member holding barrel 6 is provided with a circular Fresnel lens 7 as an illumination angle changing optical member. A through hole 8 is formed in the center of the Fresnel lens 7. The objective lens 3 faces the observation location 1a of the observation object 1 from above through the through hole 8. The illumination optical member holding barrel 6 has circular condenser lenses 9, 10, 11, 1
2 are provided as shown in FIG. The condenser lenses 9, 10, 11 and 12 have a smaller diameter than the Fresnel lens 7. The condenser lenses 9, 10, 11 and 12 are arranged at intervals of 90 degrees in the circumferential direction of the through hole 8. The condenser lenses 9, 10, 11 and 12 are exposed to the emission end 13 a of the optical fiber 13. The optical fiber 13 is provided for each condenser lens. Each condensing lens and each optical fiber constitute a movable body, and this movable body is driven in the direction described later. Optical fiber 1
Illumination light from an illumination light source (not shown) is incident on an incident end portion (not shown) of 3, and the illumination light is emitted from an emission end 13a of the optical fiber 13. Condensing lenses 9, 10, 1
Reference numerals 1 and 12 are for converging the illumination light emitted from the emission end 13a, converting it into a parallel light flux, and guiding it to the Fresnel lens 7. The Fresnel lens 7 focuses the parallel light flux and guides it to the observation location 1a of the observation object 1. The reflected light flux reflected by the observation object 1 is guided to the image pickup tube 4 via the objective lens 3, the image of the observation spot 1a is formed on the image pickup tube 4, and this image is displayed on the television monitor 5.

At the time of observation, the lens barrel 2 is moved up and down to fix the position of the objective lens 3 in the optical axis direction so that the image of the observation portion 1a becomes clear. Next, the illumination optical member holding barrel 6 is moved up and down, and the distance L from the observation object 1 to the Fresnel lens 7 is set so that the focal plane of the Fresnel lens 7 coincides with the observation location 1a. In this way, with the distance L in the optical axis direction from the Fresnel lens 7 to the observation point 1a being maintained, the movable body approaches the through hole 8 or the through hole 8 in a plane orthogonal to the optical axis O of the objective lens 3. It is moved in the direction away from (the radial direction Z of the Fresnel lens 7).

When the movable body is moved from the position shown by the solid line in FIG. 1 to the position shown by the chain double-dashed line, the illumination angle K of the illumination light flux P emitted from the Fresnel lens 7 changes, whereby the observation target location. It is possible to change the illumination state while matching the illumination location with 1a. Here, when the respective condenser lenses 9, 10, 11, 12 are moved in the direction away from the through hole 8, the illumination state at the observation location 1a becomes dark.

Although the embodiment has been described above, the present invention is not limited to this, and includes the following.

(1) Instead of the Fresnel lens 7 as the focusing state changing optical member, a circular prism having a triangular cross section or a circular convex lens may be used.

(2) Circumferential direction of the through hole 8 (θ shown in the figure)
The movable body may be rotated in the (direction).
The rotation of the movable body rotates the movable body separately,
Any of the configurations in which the movable body is simultaneously rotated by the same angle can be adopted.

[0013]

EFFECTS OF THE INVENTION Since the present invention is constructed as described above, even if the illumination angle is changed, it is possible to prevent the illumination portion from being displaced with respect to the observation portion, and it is compact and compact in size. A lighting device can be provided.

[Brief description of drawings]

FIG. 1 is a side view showing an optical system of an illumination device according to the present invention.

FIG. 2 is a plan view showing an arrangement state of movable lenses with respect to a Fresnel lens of an optical system of an illumination device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Observation object 1a Observation location 3 Objective lens 7 Fresnel lens (illumination angle changing optical member) 9-12 Condensing lens L Distance

Claims (2)

[Claims] 1. An objective lens that faces an object to be observed, a movable condenser lens that collects an illumination light flux from an illumination light source,
The object to be observed along with the movement of the condenser lens in a state in which the distance from the object to be observed is set to be constant in order to change the illumination angle while preventing the displacement of the illuminated part from the position to be observed on the object to be observed. And an illumination angle changing optical member for converging and irradiating the observation light spot with the illumination light flux while changing the irradiation angle of the illumination light flux. 2. The illumination angle changing optical member comprises a Fresnel lens or a convex lens having a diameter larger than that of the illumination lens, and the illumination lens is movable in the radial direction of the Fresnel lens or the convex lens. The lighting device according to.