JP2003156688A - Uniformly distributed illuminator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a uniformly distributed illuminator in which the light intensity distribution of a light source is quite easily uniformized with a simple structure. SOLUTION: In the illuminator in which spherical lenses are arranged two- dimensionally, a second spherical lens array 12 is laminated in a way that spherical lenses 25 having the same structure and dimension are so arranged that the spherical lenses are superposed in gaps 31 between spherical lenses 21 in a spherical lens array 11 and a light flux which passes through the gaps 31, which is not shown in attached figure, among spherical lenses 21 in the first spherical lens array 11 passes through the spherical lenses 25 in the second spherical lens array 12. Thus, the illuminator which has a uniform distribution is composed because a light beam which passes through the gaps 31 among spherical lenses is given a convergent and divergent effect by the spherical lenses 25 in the second spherical lens array 12.

Description

Detailed Description of the Invention

[0001]

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an illuminating device for exposing or illuminating a light source for uniformizing the light intensity distribution of the light source.

[0003]

2. Description of the Related Art In an exposure light source device or an illuminating device, when the light intensity of a light source is not uniform, it is required to make the light intensity distribution uniform and illuminate a surface to be illuminated uniformly. Lighting devices have been proposed. Conventionally, as a method for uniformly illuminating a flat surface, there is an illuminating device in which a lens array in which minute lenses are formed into a two-dimensional array is arranged between a light source light emitting portion and an illuminated surface. Further, two two-dimensional array lenses are provided in order from the light emitting unit side as a first lens array and a second lens array, and the light emitting unit and the second lens array are optically conjugated with the first lens array and the illuminated surface, respectively. There is an illuminating device using an optical integrator arranged so as to have a relationship with each other, for example, Japanese Patent Laid-Open No. 21785/1993.
No. 5 and Japanese Patent Application Laid-Open No. 6-13289.

In the optical integrator, the light flux emitted from the light emitting portion is divided into a plurality of light fluxes by the first lens array, and an image is formed in the vicinity of the second lens array. Therefore, as a plurality of secondary light sources for the second lens array. Function. That is, the light fluxes passing through the first lens array and the second lens array are superimposed on the illuminated surface, and the illuminated surface can be illuminated uniformly.

A method of fixing a lens array in which minute lens spheres are arranged in order to form a lens array is disclosed in JP-A-7-104105 and JP-A-7-1342.
No. 02 publication.

[0006]

However, the above-mentioned conventional method has a problem that it is difficult to improve the manufacturing yield and reduce the manufacturing cost because high accuracy is required in the processing of parts.

Further, it is difficult for the method disclosed in Japanese Patent Laid-Open No. 7-104105 to prevent the loss of the amount of light in the lens gap. In addition, JP-A-7-134202
The method disclosed in the publication has a problem that it is difficult to simplify the process and prevent the loss of the light amount in the lens gap.

The object of the present invention is to solve the above problems,
An object of the present invention is to provide a uniform lighting device with a simple structure and very easily.

[0009]

In order to solve the above problems, in a lighting device in which spherical lenses are arranged in a two-dimensional array, a light beam passing through a gap between the spherical lenses in the first spherical lens array is The second spherical lens array is laminated so as to pass through the spherical lenses of the second spherical lens array, and the paraxial focal position of the spherical lenses in the second spherical lens array is It is characterized in that they are laminated so as to be substantially equal to the paraxial focal position of the spherical lenses in the first spherical lens array. The first spherical lens array and the second spherical lens array are arranged so that the paraxial focal position of the spherical lens in the second spherical lens array is substantially equal to the focal position of the spherical lens in the first spherical lens array. Is characterized in that the refractive index of the spherical lenses constituting the spherical lens array is set, and the space between the spherical lenses in the uniform distribution illumination device using the spherical lens array is molded with a transparent resin. It is a uniform distribution illuminating device characterized in that

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 5 schematically shows an illumination device in which spherical lenses are arranged in a two-dimensional array. Reference numeral 10 is a spherical lens array in which spherical lenses 20 are two-dimensionally arranged. Reference numeral 30 denotes a gap between the spherical lenses in the spherical lens array. When light rays are incident on the two-dimensional array from the light source, the spherical lens array 1
The light rays incident on 0 are subjected to a converging effect by the spherical lens 20, and have an effect of forming a uniform distribution as a set of divergent light by a large number of spherical lenses at a distance from the focal position. Since the light flux passing through 30 does not undergo the scattering effect and passes therethrough, there are places where the light intensity is strong corresponding to the respective gaps, so that it is not possible to construct an illumination device having a uniform distribution as a whole. [First Embodiment] An embodiment of the present invention will be described below. A partial plan view of the first embodiment is shown in FIG. 1, and a partial side view thereof is shown in FIG. The spherical lens array so that the light flux passing through the gap 31 not shown in FIG. 1 between the spherical lenses 21 in the first spherical lens array 11 passes through the spherical lenses 25 of the second spherical lens array 12. By stacking the second spherical lens array 12 in which the spherical lenses 25 having the same structural dimensions are arranged so as to overlap the gap 31 not shown in FIG. 1 between the spherical lenses 21 in FIG. Since the spherical lens 25 in the second spherical lens array 12 can also exert a converging / diverging effect on a light beam passing through the gap 31 between the circular lenses, an illumination device having a uniform distribution can be configured. it can.

Next, a specific example of the first embodiment will be shown. P-
The first spherical lens array in which spherical lenses having a diameter of 2 mm made of SK100 glass are arranged in a lattice shape as shown in FIGS. 1 and 2 is formed, and the same P-SK100 glass is used in the gap between the spherical lenses. A spherical lens array in which a second spherical lens having a diameter of 2 mm is arranged is laminated 2
A dimensional array was constructed. Here, the refractive index (nd) of P-SK100 glass is 1.5917, and the diameter is 2 m.
The focal length (fd) of the spherical lens of m is 1.345 mm
Met. When the distribution of the emitted light when a light ray is incident on the spherical lens array having the two-layer structure is obtained,
Light rays that directly pass through the gaps between the spherical lenses of the layer are subjected to the converging effect by the second spherical lens, so that in the case of only the first spherical lens array shown in FIG. The standard deviation of the light intensity distribution at a distance was 16.3, and the standard deviation at a distance of 10 mm was 18.5, which was significantly improved to 5.97 and 3.51, respectively.

As described above, by stacking the second spherical lens array so as to overlap the gap between the spherical lenses in the first spherical lens array, an illumination device having a uniform distribution can be constructed. It will be possible. [Second Embodiment] An illumination device according to a second embodiment of the present invention will be described below. The second embodiment is the first
The third embodiment is different from the first embodiment in that the paraxial focal position of the spherical lenses in the second spherical lens array is different from the paraxial focal position of the first spherical lens array.

The spherical lens 27 such that the paraxial focal position of the spherical lens 27 in the second spherical lens array 14 is approximately equal to the paraxial focal position of the spherical lens 22 in the first spherical lens array 13. FIG. 3 is a plan view of a structure in which the first and second are stacked so as to overlap the positions of the gaps 32 between the spherical lenses in the spherical lens array 13 which are not shown in FIG. Show. By making the paraxial focal positions substantially equal in this way, it is possible to further improve the characteristics.

Next, a specific example of the second embodiment will be shown. P-
A spherical lens having a diameter of 2 mm and made of SK100 glass is arranged in a two-dimensional array as shown in FIGS. 3 and 4 to form a first spherical lens array. -SK100 glass has a diameter of 0.
A spherical lens array in which a 74 mm second spherical lens was arranged was laminated. Here, the focal length (fd) of the second spherical lens was 0.498 mm. In this case, it was possible to obtain a uniform distribution characteristic with a standard deviation of 3 or less, which is better than that in the first embodiment. Also, by using the optimum material with the fine adjustment of the refractive index of the spherical lens, it is possible to make the paraxial focal points of both lens arrays almost equal, so that a more uniform and uniform light intensity distribution characteristic can be obtained. Obtainable.

[0015]

As described above, according to the present invention,
It is possible to provide a uniform lighting device with a simple structure very easily.

[Brief description of drawings]

FIG. 1 is a partial plan view showing a first embodiment of the present invention.

FIG. 2 is a partial side view showing the first embodiment of the present invention.

FIG. 3 is a plan view showing a second embodiment of the present invention.

FIG. 4 is a partial side view showing a second embodiment of the present invention.

FIG. 5 is a partial plan view of a distributed lighting device in which spherical lenses are arranged two-dimensionally or more.

[Explanation of symbols]

10, 11, 12, 13, 14 Spherical lens array 20, 21, 22, 25, 27 Spherical lens 30, 31, 32 Gap between spherical lenses

Claims (4)

[Claims] 1. In an illuminating device in which spherical lenses are arranged in a two-dimensional array, a light beam passing through a gap between spherical lenses in a first spherical lens array causes spherical lenses of a second spherical lens array to pass through the spherical lenses. A uniform distribution illumination device, wherein a second spherical lens array is laminated so as to pass therethrough. 2. Laminated so that the paraxial focal position of the spherical lenses in the second spherical lens array is approximately equal to the paraxial focal position of the spherical lenses in the first spherical lens array. The uniformly distributed lighting device according to claim 1, which is characterized in that: 3. The first spherical lens array so that the paraxial focal position of the spherical lens in the second spherical lens array is approximately equal to the focal position of the spherical lens in the first spherical lens array. The uniform distribution illuminating device according to claim 2, wherein the refractive index of the spherical lens forming the second spherical lens array is set. 4. The uniform distribution lighting device according to claim 1, wherein a space between the spherical lenses in the uniform distribution lighting device using the spherical lens array is molded with a transparent resin.