KR102203066B1 - Integrating sphere light source apparatus - Google Patents

Abstract

An embodiment of the present invention discloses an integrating sphere light source. The integrating sphere light source comprises: an integrating sphere including forward hemisphere and backward hemisphere and having a target surface of a predetermined shape in the backward hemisphere; an incident opening formed in the forward hemisphere of the integrating sphere and through which light from the outside is incident; an output opening formed in the forward hemisphere of the integrating sphere and through which light from the inside is emitted; and a reflector disposed on an incident surface on which the light is incident of an inner peripheral surface of the forward hemisphere. Therefore, the spatial luminance uniformity can be improved.

Description

Integrating sphere light source {INTEGRATING SPHERE LIGHT SOURCE APPARATUS}

The embodiment relates to an integrating sphere light source having high spatial luminance uniformity for luminance meter calibration.

In general, since the viewing angle of the reference luminance meter and the viewing angle of the luminance meter to be calibrated are different, the spatial unevenness increases the uncertainty, so the luminance uniformity of the integrating sphere is very important for calibration of the luminance meter.

The integrating sphere is formed in a spherical shape, and the surface of the sphere is painted with high reflectivity paint or is made of PTFE, and has an input opening for light entering and an output opening for exiting. The light incident on the integrating sphere is reflected by multiple diffuse reflections on the sphere surface and then exits through the output opening. In this process, the spatial luminance uniformity increases.

Lamps or lasers are used as incident light sources of the integrating sphere, and their output is limited, so in order to increase S/N, the diameter should be reduced as much as possible and the luminance uniformity should be made high at the same time.

_i)를 적분구에 입사시킨다 해도 적분구의 지름(D)에 따라 출력되는 휘도(L_S)가 달라지는데 적분구의 지름이 입력 개구와 출력 개구의 지름보다 크고 적분구 내부 표면의 반사율이 ρ라고 가정하면 그 관계는 다음의 [수학식1]과 같이 정의된다.Same optical power(

Even if _i ) is incident on the integrating sphere, the output luminance (L _S ) varies according to the diameter (D) of the integrating sphere. Assuming that the diameter of the integrating sphere is larger than the diameters of the input and output openings and the reflectance of the inner surface of the integrating sphere is ρ The relationship is defined as the following [Equation 1].

[Equation 1]

1/D² 로 휘도는 지름의 제곱분의 1로 줄어든다. 그러므로 적분구의 지름이 작을수록 휘도는 높아진다. 그러나 적분구의 지름이 작아지면 적분구의 표면적이 작아지며, 적분구의 표면적이 출력 개구의 면적과 비슷해져 갈수록 휘도 균일도는 점점 더 나빠진다.That is, L _S

With 1/D ² , the luminance is reduced to one square of the diameter. Therefore, the smaller the diameter of the integrating sphere, the higher the luminance. However, as the diameter of the integrating sphere decreases, the surface area of the integrating sphere decreases, and as the surface area of the integrating sphere becomes similar to the area of the output opening, the luminance uniformity becomes worse and worse.

FIG. 1 is a view showing an optical alignment state of a general integrating sphere and a luminance meter, and FIG. 2 is a view illustrating a state of an inside of a front half of the integrating sphere shown in FIG. 1.

Referring to FIG. 1, the integrating sphere has an input opening through which light is incident and an output opening through which light is output, and the luminance meter is aligned with the optical axis at the center of the output opening, and generally incident light is input so that it is perpendicular to the output opening optical axis. Make an opening

Incident light having a diameter of several mm, incident through the input opening in the first half of the integrating sphere, hits a part of the integrating sphere, is diffusely reflected, and spreads over the entire surface of the integrating sphere. These lights are again reflected countless times over the entire inner surface of the integrating sphere, so that the integrating sphere operates like countless number of identical light sources, thereby increasing the luminance uniformity at the output opening.

Referring to FIG. 2, the presence of the integrating sphere output opening means that there is no light source as much as the output opening area, and in principle, the luminance is low at the center of the target surface, and the luminance increases as the distance from the center is increased.

Registered Patent Publication No. 10-2015203 Registered Patent Publication No. 10-0996881

The embodiment may provide an integrating sphere light source having high spatial luminance uniformity for luminance meter calibration.

The integrating sphere light source according to the embodiment includes an integrating sphere including a first half sphere and a second half sphere, and having a target surface of a predetermined shape on the second half sphere; An incidence opening formed in the front half of the integrating sphere and into which light from outside is incident; An output opening formed in the first half sphere of the integrating sphere and through which light is emitted from the inside; And a reflector disposed on an incidence surface on which the light is incident among the inner circumferential surfaces of the integrating sphere.

The target surface may be any one of a concave shape, a planar shape, and a convex shape based on the outer circumferential surface of the integrating sphere.

The target surface may be defined by a wide angle of a luminance meter, a diameter of the integrating sphere, and a diameter of the output opening.

The reflector may reflect the incident light to form light in a ring pattern on the inner peripheral surface of the front half sphere.

The reflector may have a polygonal cross section or a circular shape.

The reflector may be coated with a metal material having a predetermined reflectivity on the surface.

The integrating sphere light source according to the embodiment includes an integrating sphere including a first half sphere and a second half sphere, and in which a target region having a predetermined shape is formed in the second half sphere; A target unit coupled to the target region of the integrating sphere and having a target surface formed on one side thereof; An incidence opening formed in the front half of the integrating sphere and into which light from outside is incident; An output opening formed in the first half sphere of the integrating sphere and through which light is emitted from the inside; And a reflector disposed on an incidence surface on which the light is incident among the inner circumferential surfaces of the integrating sphere.

The target surface may be any one of a concave shape, a planar shape, and a convex shape based on the outer circumferential surface of the integrating sphere.

The target surface may be defined by a wide angle of a luminance meter, a diameter of the integrating sphere, and a diameter of the output opening.

The reflector may reflect the incident light to form light in a ring pattern on the inner peripheral surface of the front half sphere.

The reflector may have a polygonal cross section or a circular shape.

The reflector may be coated with a metal material having a predetermined reflectivity on the surface.

According to an embodiment, by disposing a reflector having a predetermined shape on an incidence plane on which incident light is incident, light incident therein may be spatially and uniformly reflected.

According to the embodiment, by forming the target surface with a curvature different from that of the integrating sphere, the luminance uniformity of the luminance meter target surface can be increased.

According to the embodiment, the diameter of the integrating sphere may be small and the uniformity of spatial luminance may be improved.

1 is a diagram illustrating a general integrating sphere and a luminance meter in a light alignment state.
FIG. 2 is a diagram illustrating a state of an inside of the first half of the integrating sphere shown in FIG. 1.
3 is a diagram illustrating an integrating sphere light source according to an embodiment of the present invention.
FIG. 4 is a view showing the inside of the front half of the integrating sphere light source shown in FIG. 3.
5 is a view showing a cross-sectional shape of a reflector according to an embodiment of the present invention.
6A to 6C are views showing a first shape of the integrating sphere target surface shown in FIG. 3.
7A to 7C are views showing a second shape of the integrating sphere target surface shown in FIG. 3.
8 is a graph showing spatial luminance uniformity measured by a general integrating sphere.
9 is a graph showing spatial luminance uniformity measured by an integrating sphere according to an embodiment.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

However, the technical idea of the present invention is not limited to some embodiments to be described, but may be implemented in various different forms, and within the scope of the technical idea of the present invention, one or more of the constituent elements may be selectively selected between the embodiments. It can be combined with and substituted for use.

In addition, terms (including technical and scientific terms) used in the embodiments of the present invention are generally understood by those of ordinary skill in the art, unless explicitly defined and described. It can be interpreted as a meaning, and terms generally used, such as terms defined in a dictionary, may be interpreted in consideration of the meaning in the context of the related technology.

In addition, terms used in the embodiments of the present invention are for describing the embodiments and are not intended to limit the present invention.

In the present specification, the singular form may include the plural form unless specifically stated in the phrase, and when described as “at least one (or more than one) of A and (and) B and C”, it is combined with A, B, and C. It may contain one or more of all possible combinations.

In addition, in describing the constituent elements of the embodiments of the present invention, terms such as first, second, A, B, (a), and (b) may be used.

These terms are only for distinguishing the component from other components, and are not limited to the nature, order, or order of the component by the term.

And, when a component is described as being'connected','coupled' or'connected' to another component, the component is not only directly connected, coupled or connected to the other component, but also the component and It may also include the case of being'connected','coupled' or'connected' due to another component between the other components.

In addition, when it is described as being formed or disposed on the “top (top) or bottom (bottom)” of each component, the top (top) or bottom (bottom) is one as well as when the two components are in direct contact with each other. It also includes a case in which the above other component is formed or disposed between the two components. In addition, when expressed as "upper (upper) or lower (lower)", the meaning of not only an upward direction but also a downward direction based on one component may be included.

In the embodiment, a reflector of a predetermined shape is disposed on an incidence plane on which the incident light is incident, and the incident light is not directly reflected to the target surface by the reflector, but is reflected on the inner surface of the integrating sphere to form a reflected light ring pattern. Suggest.

In the embodiment, a new structure is proposed in which the target surface is formed to have a curvature different from that of the integrating sphere, and the target surface is formed in a concave shape, a planar shape, and a convex shape.

FIG. 3 is a diagram illustrating an integrating sphere light source according to an exemplary embodiment of the present invention, and FIG. 4 is a diagram illustrating a state of the integrating sphere light source shown in FIG.

Referring to FIG. 3, an integrating sphere light source according to an embodiment of the present invention may include an integrating sphere 100, an input opening 200, an output opening 300, and a reflector 400.

The integrating sphere 100 may have a spherical shape, and its inner circumferential surface may also be a spherical surface. A coating layer for reflecting incident light may be formed on the inner peripheral surface of the integrating sphere 100.

The integrating sphere 100 may not have a complete spherical shape, because the target surface 130 positioned opposite to the output opening may be formed to have a curvature different from that of the integrating sphere 100. The target surface may be defined by the wide angle of the luminance meter, the diameter of the integrating sphere, and the diameter of the output opening.

The target surface 130 may be formed in, for example, a concave shape, a planar shape, a convex shape based on the outer circumferential surface of the integrating sphere 100, but is not limited thereto and may be variously modified.

For example, the integrating sphere 100 may include a first half sphere 110 and a second half sphere 120, and a target surface 130 may be formed on the second half sphere 120.

As another example, in the integrating sphere 100, a target area may be formed in the second half sphere 120, and a target unit 130 ′ may be coupled to the target area. A target surface may be formed on one side of the target unit 130 ′.

The input opening 200 is formed in the front half sphere 110 of the integrating sphere 100 and may be an opening through which light from outside is incident.

The output opening 300 is formed in the first half sphere 110 of the integrating sphere 100 and may be an opening through which light is emitted from the inside.

The reflector 400 may be positioned on an incidence surface on which incident light is incident among the inner circumferential surfaces of the integrating sphere 100 and may play a role of preventing the incident light from being directly reflected to the target surface.

The reflector 400 may be coated with a metal material having a predetermined reflectivity on its surface. Here, the metal material having a predetermined reflectivity may be, for example, gold or silver. By plating the metal reflector 400 with a material such as gold, the diffuse reflectance may be minimized.

4, incident light of several mm diameter incident through the input opening in the half sphere 110 of the integrating sphere 100 hits the inner circumferential surface of the half sphere 110 before hitting the reflector 400 of several mm diameter. It hits first, and can be uniformly reflected on the plane of incidence of light perpendicular to the optical axis of the output opening.

The light hitting the reflector 400 may be regularly reflected in all directions to form a ring pattern on the inner circumferential surface of the front bulb 110. The light hitting the reflector 400 may be generated on the inner circumferential surface of the front bulb 110 as light having a ring pattern having a distance between the center of the output opening and the center of the reflector as a radius.

The light of the ring pattern thus generated can be diffusely reflected and spread evenly over the entire inner peripheral surface of the integrating sphere. Unlike the point light source of FIG. 2 described above, in the embodiment, it may be treated as a light source of a ring pattern symmetrical with respect to the center of the output opening.

At this time, if the reflector is disposed away from the center of the integrating sphere, there is no light going directly to the target surface. Thus, the input opening and the reflector can be disposed at a position close to the output opening.

5 is a view showing a cross-sectional shape of a reflector according to an embodiment of the present invention.

Referring to FIG. 5, the reflector 400 according to the embodiment may have various shapes according to the light distribution of incident light. The reflector 400 may have a polygonal or circular cross section, and may include, for example, a circular pillar, a triangular pillar, and a square pillar.

The light incident on the integrating sphere and reflected from the reflector is repeatedly reflected countless times over the entire inner circumferential surface of the integrating sphere, so that the inner circumferential surface of the integrating sphere operates like countless number of identical light sources, thereby increasing luminance uniformity at the output aperture. However, since the output opening must exist, there is no light source as much as the area of the output opening, and in principle, the central portion of the target surface has a low luminance, and the luminance increases as the distance from the center portion increases. This luminance pattern can be corrected by changing the surface shape of the target surface.

6A to 6C are views showing a first shape of the integrating sphere target surface shown in FIG. 3, and FIGS. 7A to 7C are views showing a second shape of the integrating sphere target surface shown in FIG. 3.

6A to 6C, the surface shape of the target surface is changed, and thus it may be formed integrally with the integrating sphere. The target surface 130 may be formed in a concave shape 130a as shown in FIG. 6A, a planar shape 130b as shown in FIG. 6B, and a convex shape 130c as shown in FIG. 6C based on the outer peripheral surface of the integrating sphere.

7A to 7C, the target unit can be detachably coupled to the integrating sphere by changing the surface shape of the target surface formed on the target unit. The target surface of the target unit 130' is formed in a concave shape 130a' as shown in Fig. 7A, a planar shape 130b' as in Fig. 7B, and a convex shape 130c' as in Fig. 7C based on the outer circumferential surface of the integrating sphere. Can be.

8 is a graph showing spatial luminance uniformity measured by a general integrating sphere, and FIG. 9 is a graph showing spatial luminance uniformity measured by an integrating sphere according to an embodiment.

Referring to FIG. 8, it can be seen that a general integrating sphere having a diameter of 50 mm is biased to one side as a result of the spatial luminance uniformity measured with a luminance meter, and the relative standard uncertainty is about 0.06%.

Referring to FIG. 9, it can be seen that the integrating sphere according to the embodiment had the same diameter as the general integrating sphere, but was not biased to one side, and the relative standard uncertainty was reduced by about 4 times to 0.015%.

As described above, in the embodiment, it can be seen that spatial luminance uniformity is greatly improved.

Although the above has been described with reference to preferred embodiments of the present invention, those skilled in the art will variously modify and change the present invention within the scope not departing from the spirit and scope of the present invention described in the following claims. You will understand that you can do it.

100: integrating sphere
200: input opening
300: output opening
400: reflector

Claims (12)

An integrating sphere including a first half sphere and a second half sphere, and having a target surface deformed into a predetermined surface shape based on an outer circumferential surface on the second half sphere;
An incidence opening formed in the front half of the integrating sphere and into which light from outside is incident;
An output opening formed in the first half sphere of the integrating sphere and through which light is emitted from the inside; And
Includes a reflector disposed on an incidence surface of the inner circumferential surface of the integrating sphere on which light incident through the incidence opening collides,
The reflector is formed in a polygonal or circular shape in cross section,
The light hitting the reflector has a distance between the center of the output opening and the center of the reflector as a radius, and is formed on the inner circumferential surface of the front sphere in a ring pattern symmetrical with respect to the center of the output opening to operate as a light source of the ring pattern. , The integrating sphere light source. The method of claim 1,
The target surface,
An integrating sphere light source having any one of a concave shape, a planar shape, and a convex shape based on the outer peripheral surface of the integrating sphere. The method of claim 1,
The target surface,
An integrating sphere light source defined by a wide angle of a luminance meter, a diameter of the integrating sphere, and a diameter of the output opening. delete delete The method of claim 1,
The reflector is an integrating sphere light source coated with a metal material having a predetermined reflectivity on a surface. An integrating sphere including a first half sphere and a second half sphere, in which a target region deformed in a predetermined surface shape based on an outer circumferential surface is formed on the second half sphere;
A target unit coupled to the target region of the integrating sphere and having a target surface formed on one side thereof;
An incidence opening formed in the front half of the integrating sphere and into which light from outside is incident;
An output opening formed in the first half sphere of the integrating sphere and through which light is emitted from the inside; And
Includes a reflector disposed on an incidence surface of the inner circumferential surface of the integrating sphere on which light incident through the incidence opening collides,
The reflector is formed in a polygonal or circular shape in cross section,
The light hitting the reflector has a distance between the center of the output opening and the center of the reflector as a radius, and is formed on the inner circumferential surface of the front sphere in a ring pattern symmetrical with respect to the center of the output opening to operate as a light source of the ring pattern. , The integrating sphere light source. The method of claim 7,
The target surface,
An integrating sphere light source having any one of a concave shape, a planar shape, and a convex shape based on the outer peripheral surface of the integrating sphere. The method of claim 7,
The target surface,
An integrating sphere light source defined by a wide angle of a luminance meter, a diameter of the integrating sphere, and a diameter of the output opening. delete delete The method of claim 7,
The reflector is an integrating sphere light source coated with a metal material having a predetermined reflectivity on a surface.

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