JPH02167450A - Hemispherical non-glare lighting apparatus - Google Patents

Abstract

PURPOSE: To reduce the size of a diffuser assembly by positioning a light source for guiding light to the optical medium of a hemispherical translucent diffuser with a recessed surface for preventing any shade of an object from being formed. CONSTITUTION: Light projected on a protruding surface 18 of a translucent and hemispherical diffuser 14 radiates light diffused from a recessed surface 19. Then, the light is transmitted from a lamp 9 of a lamp house 8 that is separated from the diffuser 14 by a fiber optical cable 10. Also, an object 20 to be inspected is located at the side of the recessed surface 19, and light diffused from the diffuser 14 is emitted by all recessed surfaces 19 from every angle, thus achieving light without causing any shading of the surface of the object 20. Then, the uniformity and diffusion of illumination eliminate a bright mirror-surface reflection. Also, by positioning the object 20 away from a diffuser assembly, a lamp 9 with strong light can be used, thus eliminating the need for limiting the shape of the lamp 9.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an illumination device for a visual inspection device. More particularly, it relates to an apparatus and method for hemispherical or shadowless illumination of objects to be visually inspected.

Prior Art and Problems Visual devices and visual testing have faced significant limitations in applications involving viewing highly reflective objects. Examples include items joined by welding, lead wires for electrical components, and metal items with machined or glossy finishes.

Solid-state or tube-type sensors, typically used for imaging in visual devices such as televisions and video cameras, have areas of fairly bright specular reflections or hot spots caused by normal light sources. When looking at things, blurring or cloudiness tends to appear. These blurred hot spots in the image of the object being observed (well, prevent the observation of details in that part of the image, and furthermore obscure nearby areas).

"Specular reflection" is a mirror-like reflection from a highly polished or shiny object that has areas of flat surface. Typically, in visual devices, such violations are likely to occur when metal, shiny materials, or objects with flat areas reflect light from a strong light source.

"Saturation" is seen when the output of a video camera is at its maximum peak-to-peak voltage, and there is no saturation beyond that. When best adjusted in image detail, it is insufficient to accommodate the extreme dynamic range of objects that have bright or highly reflective areas on their surfaces. The blurred parts of an image are under too much stress, so the shape expands and becomes large. This expansion is called "cloudy (Bloomir+g)".The blurred and cloudy parts of the image are important parts of the image. Dynamic range refers to the range of intensity of reflected light in an illuminated object or its visual image, from brightest to darkest.

Similarly, in vision inspection equipment that utilizes a microscope, the image overheating spot creates a problem of human eye fatigue during manual vision inspection. Also, in the case of photographs taken through a microscope, exposure problems arise. That is, because of the limited dynamic range of photographic film and the problems associated with failed film changes, if the exposure time is subtracted for correct exposure of the image in areas that are not hot spots, the visual hot spot Excessive exposure. Additionally, areas that are not hot spots will be underexposed if the exposure time is adjusted to properly expose the hot spot image.

Common light sources for visual inspection equipment include: Incandescent lighting, annular arrays of lamps, LEDs, focused filament projectors, linear or circular fiber objects, and gas or fluorescent lamps of all sizes and shapes. These in-shell light sources create visual hot spots due to the fact that they are all present in objects under illumination or strong light sources. For example, a ring of glass or plastic fibers is often used as a means to conduct light from a remote lamp or other light source. However, such a fiber optic ring? t) provides diffuse illumination only at small fixed angles. And in this way, it still constitutes a strong light source. The fixed angle is measured from the vertex at the position of the object under illumination.

Therefore, what is needed is illumination with an extremely diffuse illumination pattern at a wide fixed angle in order to eliminate or minimize the occurrence of bright reflections or hot spots from objects with highly reflective areas on their surfaces. It was the development of a device. Such a device would produce a reflected light pattern with reduced dynamic range.

The prior art attempts to provide light sources that spread light over a large fixed angle. And that is the British IFS
It is described on page 105 of ``Automatic Visual Inspection'' published by Co., Ltd. and illustrated in FIG. In FIG. 1, a hemispherical reflector 1 covers an object 2 under inspection. The light source is an annular lamp 3, which is located on the inner surface 4 of a hemispherical reflector 1.
Guide light against. The light from the annular lamp 3 is scattered like light 5 scattered by the inner surface 4. Perhaps some of the scattered light 5 reaches the object 2 under examination.

The inner surface 4 is painted matt white or stippled in order to achieve a scattering of light. lamp reflector 6
is located between the object under inspection 2 and the annular lamp 3. A camera opening 7 at the top of the hemispherical reflector 1 allows the camera to observe and form an image of the object 2 under inspection.

One disadvantage of prior art hemispherical reflectors is that only one diffusing element, hemispherical reflector 1, works by reflection. Thus, inside the hemispherical reflector 1, all light sources must be located and all diffusion must occur. In particular, as a result,
Lighting increases the size of equipment that is required to fit into a small space, such as a microscope or optical inspection equipment on a production line. Also, although the light source in the hemispherical reflector 1 required electrical wires to be connected to the reflector, in some situations where the presence of electrical power is undesirable, this is undesirable. If the problem is exacerbated in the annular lamp 3, there is a need for maintenance to be done on the hemispherical reflector. Presumably, the removal of the glue frefter from the optical device of which it is a part is desired. The position of the annular lamp 3 limits the selection of possible lamp types. For example, size constraints preclude the use of lamps that emit incandescent light at high intensities.

Another disadvantage is that hemispherical reflectors are simply diffusing elements.

A further disadvantage is that the lamp reflector 6 reduces the size of the fixed angle for the area from which the diffused light emanates.

SUMMARY OF THE INVENTION Embodiments of the present invention provide a translucent hemispherical diffuser with a convex surface and a concave surface that absorbs light projected onto the convex surface and emits diffused light from the concave surface.

Since the object to be inspected or tested is located on the concave side of the diffuser, the diffused light emitted by the diffuser illuminates the side of the object facing the diffuser from all angles. The light is directed to be projected onto virtually all of the concave surfaces of the diffuser. In this way, the diffused light is "emitted" by virtually all of the concave surfaces. Therefore, the diffused radiation illuminates the object at a fixed angle of substantially 2π steradians (i.e., a fixed angle of 180 degrees). The viewing boat may be located on-axis at the center of the hemispherical diffuser or off-axis for viewing the illuminated object from an oblique angle.

Some embodiments of hemispherical diffusers include a lamp spaced from the hemispherical diffuser. In these embodiments, light is conducted from the lamp by a fiber optic cable for emission onto the convex surface of the diffuser.

One of these embodiments includes a negative diverging lens and a conical reflector to diffuse the light emitted by the fiber optic cable before being projected onto the convex surface of the diffuser.

In this embodiment, an off-axis observation boat is provided to one side of the negative diverging lens.

In another of these embodiments, two conical reflectors are used to diffuse the light emitted by the fiber optical cable. A negative diverging lens is not used in this embodiment to allow on-axis viewing of the illuminated object.

Yet another embodiment of the invention includes a separate lamp and fiber optic cable for conducting light from the lamp to a hemispherical diffuser. The hemispherical diffuser is translucent and has four sides and opposing flat surfaces. The fiber optic cable terminates in a fiber optic ring attached to the plane of the diffuser. The light emitted by the fiber optics ring enters the plane of the diffuser and is reflected and re-reflected within the optical medium of the diffuser;
It is then radiated from the concave surface and directed generally towards the object to be illuminated. A stage of light diffusion occurs when light is reflected and re-reflected within the optical medium of the diffuser. The next stage of diffusion occurs when light is emitted from the concave surface of the diffuser.

The previously described embodiments of the present invention solve some of the previously mentioned problems of prior art hemispherical glue deflectors by locating the lamps at a distance from daylight 1f. In this way it was possible to reduce the physical size of the diffuser assembly. This makes it easier to use the diffuser assembly in relatively small optical devices such as microscopes and relatively small video cameras such as COD cameras. There is no need to run wires to the diffuser assembly. And if it cannot be located far from the diffuser assembly, a high-light lamp that is too large or bulky may be used. Furthermore, there are no restrictions on the shape of the lamp.

As shown in FIG. 1, the shape of the prior art lamp was annular. The spaced apart lamps of the present invention permit changes in lamp shape and maintenance to be performed on the lamp assembly without disturbing or removing the diffuser assembly. In addition, a translucent diffuser allows the lamp to be spaced apart by having the light source come from the convex side of the diffuser, the side of the diffuser opposite the object being illuminated. .

Another embodiment of the invention includes a gas discharge light source, which is generally helically wound in a hemispherical shape, so that a translucent helical diffuser is defined by the concave surface of the hemispherical light source. can be located within space. That is,
A helical light source is disposed on the convex surface of the diffuser to provide a uniform light source over substantially the entire convex surface of the diffuser.

The diffuser further diffuses the light and emits the diffused light from the concave surface of the diffuser. The object to be illuminated is usually
It is located at the center of curvature of the concave surface of the diffuser. This embodiment includes a viewing port centered on the on-axis area of the diffuser.

Spiral light source and day 7'' - The is usually hemispherical or
The axial central portions of the light source and diffuser have a flattened hemispherical shape. Embodiments of the present invention include a hemispherical reflector over a helical light source to help reflect and diffuse light bounce back to the light source and thus to the diffuser. Alternatively, the reflector may be omitted.

A translucent diffuser allows the light source to be positioned on the convex side of the diffuser, which is the side of the diffuser opposite to the side facing the object being illuminated.

This allows for more freedom in positioning the light source as there is no interference or interference between the diffuser and the object being illuminated by what happens on the convex surface of the diffuser.

The translucent diffuser allows several stages of diffusion to occur before the light reaches the concave surface of Day-1f.

For example, various glue flaps or spiral lamps can be used to provide a light source to an already diffused diffuser.

Figure 2A of the X-card shows a standard 150 watt glue deflector for focusing the light beam onto the fiber optic cable 10.
1 illustrates an embodiment of the invention having a separate lamphouse 8 containing a projection lamp 9. FIG. The light intensity of the lamp 9 can be controlled by a rheostat. Lamphouse 8 is a type of commercially useful light source commonly used for fiber optic lighting. Fiber optical cable is a commercially useful flexible fiber bundle that is a bundle of glass fibers arranged into a 1/4 inch to 1/2 inch diameter optical conduit.
It is an optics light guide. A typical length of cable 10 is 1-2 m.

The emission emitted by lamp 9 is not limited to the visible spectrum. Through the use of suitable filters or lamps 9, ultraviolet and infrared light can be transmitted through fiber optics.
Couple 108I.

The fiber optic cable 10 has a removable flapper made of machined aluminum.
It is connected to housing top 11. Reflector housing 1 heb 11 provides a container for terminating fiber optical cable 10.

As seen in Figure 2A, the fiber optic
The light beam 12 emitted from the cable 10 is split by several cut features in the fiber optic cable 10. The light beam 12 is provided with a negative beam that splits the light beam as a prelude to illuminating the hemispherical diffuser 14.
The beam is projected onto a diverging lens 13. Lens 13 is a colorless negative lens with an effective focal length of -441.
It's a lens. The diverging lens 13 is a hemispherical diffuser 1
4 and the conical reflector 17 &! ! It is used to shape and direct the projected light ray 12 to produce an output ray 15 which is projected onto 16. A diverging lens is required to provide a correctly angled light beam 15 for the -like distribution of light across the convex surface 18 of the hemispherical diffuser 14. The elements, size and focal length of the diverging lens 13 may be varied to suit the application.

A conical reflector 17 mounted on the reflector housing top 11 is constructed of machined aluminum and reflects the outgoing light 1i 115 for illumination of the lower part of the convex surface 18 of the diffuser 14. It is used for twisting. The inner wall 16 of the conical reflector 17 is polished at a critical angle for reflecting the outgoing light ray 15 into the correct area of the convex surface 18 of the diffuser. wall 16 minutes 1114
It is also critical for correct reflection of light.

The hemispherical diffuser 14 is a hollow hemisphere made of thin-walled plastic or other translucent material with optical opalescent glass having light-diffusing features. Examples include Lef 1 non, 20 to 30 mils thick;
Polypropylene or molded glass. Diffusing characteristics are inherent in the optical medium of opalescent glass or translucent materials of the diffuser, which have a cloudy appearance. And/or the diffusing feature may be provided by making the convex surface 18 and/or the concave surface 19 of the hemispherical diffuser 14 like a woven fabric. The woven fabric is formed by sandblasting or etching the convex and/or concave surfaces.

The object 20 under illumination is located approximately at the center of curvature of the concave surface 19. Typically, the working distance from the object 20 to the bottom edge of the hemispherical diffuser 14 is
istance) from 0.0625 inches for smaller diffusers used for purposes such as weld joint inspection with a diameter of approximately 1.5 inches, and 1.
Ranges up to several inches, with larger diffusers having diameters of two inches or more.

A fixed angle r of approximately 2π steradians, measured at the top surface of the object 20 being illuminated! 1 (fixed angle of 11,180 degrees), the diffuser emits light from the concave surface 19 in a negative manner.In this way, the surface of the object 20 is the concave surface 19.
The light coming from the whole is distributed in a similar way. Things like this□2
Shadowless illumination of the 0 surface is achieved. This feature eliminates bright specular reflections so that the uniformity and diffusion of illumination is increased more than in conventional lighting systems. The video camera can be safely used without the risk of fogging, smearing or overloading the video. Therefore, video cameras can now be used for applications that were not possible before. Objects with high reflectivity
With the use of a video camera or regular photography, it can be seen exactly as it is.

The object 20 under illumination can be virtually any type or shape of object that can typically be observed at visible, U2, or IR emission wavelengths. Welded joints can be inspected in an electric field.

2Δ and 2B show the video camera 21 observing the object 20 through the off-axis observation boats 1-22 of the diffuser 14 and the off-axis observation boat 23 of the conical reflector 17. .

The video camera 21 is a tube type or C
It is from an OD device. Instead of a video camera, the viewing device may be a still or video camera, a microscob or other optical magnifier with the same improvements in image quality.

Figures 3A and 3B illustrate an on-axis observation boat according to an embodiment of the invention. In this embodiment, the configuration is the second
This is similar to the off-axis observation boat embodiment illustrated in Figures A and 2B. In this example, the observation of object 20 is
Instead of having an angle carved into the object 20 being observed, from the perpendicular,
This is achieved through the center of the luminaire 24. Observations are made through observation boats 1-26 of the diffuser 14 and through observation boats 27 of the fiber optic ring.

This practical example is useful for use as illumination for human viewing microscopes, as well as television and video monitors.

Remote lamp house 8 and fiber optical couple 10 are shown in Figure 2A. Fiber optical cable 10 terminates in a commercially available fiber optic ring 25. The fiber optic cable 10 used in the on-axis embodiment terminates in a fiber optics ring 25, which is a ring of fibers that radiates light.

Typical sizes are 2 inches to 4 inches in diameter and annulus widths of 0.20 to 0.50 inches.

The fibers are arranged to collect light from the annulus to produce a smooth, even distribution of light at a predetermined working distance. The typical working distance of commercially useful fiber optics rings is 1.5 inches, providing spora l-like illumination of 1 inch or more in diameter.

Fiber optical ring 25 directs a beam of light 29 that is projected onto convex surface 18 of diffuser 14 .

and for conical reflectors 28 and 30. It then directs the reflected light beam to illuminate the lower area of the convex surface 18.

The diffuser 14 has a second diffuser 14 excluding the observation port position.
This is as stated in relation to Figure A.

Figures 4A and 4B illustrate an embodiment of the invention having a one-piece diffuser assembly 31 machined from a solid piece of acrylic plastic. In other words, instead of being machined, the diffuser assembly may be molded into the final shape. Also, instead of being one single unit, it may be made or separated in several configurations. This embodiment of the invention is an on-axis design with an on-axis viewing port 27 in the fiber optics ring 25 and an on-axis viewing port 26 in the diffuser assembly 31. The hemispherical concave surface 19 is sandblasted, etched, molded, or otherwise treated to form a woven fabric for diffusion. In other words, or in addition, a thin opalescent glass-plastic insert can be used with the fiber optics ring 25 and diffuser assembly 3 to achieve the desired diffusion properties.
1. Reflective surface 32 is at a critical angle for obtaining internal reflection of light projecting from fiber optics ring 25. This is a critical angle for directing the elongated light toward the lower region of the hemispherical four faces 19 in order to achieve the -like illumination of the concave surface 19. The anti-peeling surface 32 is made of silver to increase the intensity of reflected light.

This embodiment can be mounted directly onto a conventional microscope in much the same way as commercially useful fiber optic ring illumination. The objective lens 33 of such a microscope is It is shown placed directly over the optics ring 25. This embodiment can be molded from a plastic compound as a low cost lighting accessory for a wide range of microscopic applications.

5A, 5B, 6A and 6B are illustrations of two similar embodiments of the invention having an on-axis viewing port 1-. Each of this example has a hemispherical date
A locally placed spirally wound lamp 34 is included to provide a light source with a highly variable distribution of light to f14.

The locally located spirally wound lamp 34 is similar to the remotely located lamp, fiber optic cable 10. of the previously described embodiments. It replaces the fiber optics ring 25, the diverging lens 13, and the various glue deflectors. The spiral-wound lamp consists of a neon-filled Pyrex glass tube with a diameter of 9111III. The glass tube can be wrapped into one complete tube or can be constructed into separate sections. Typically, this lamp is energized at 94:45 mA. Synthetic luminescence is classified as a bright color depending on the color temperature and is considerably brighter than a standard fluorescent lamp. Can be manufactured to any size.

An on-axis viewing boat 26 is provided in the diffuser 14 . And a corresponding on-axis viewing port 35 is provided at the center of the spirally wound lamp. Figures 5A and 5
The embodiment of FIG. 6A and FIG. 6B differs from the embodiment of FIGS.
6A and 6B differ in that they are somewhat flat in the embodiments of FIGS. and 5B, while FIGS. 6A and 6B have a true hemispherical shape. The flat shape is a low profile lighting fixture 3
6, allowing it to be used in narrower situations.

7A and 7B are embodiments in which a hemispherical reflector 37 having an axial observation port 38 at the center of the reflector 37 is added to FIGS. 6A and 6B.

The various illustrated embodiments of the invention include a viewing port in the diffuser 14 or diffuser assembly 31. For some applications involving extremely specular reflective surfaces, a relatively approximate area of the diffuser 14 associated with the observation boat 26 will be deflected from the object 2o, resulting in a dark area image picked up by the video camera 21. Images in dark areas are
In some cases, debris obscures small features and details on the surface of the object 20. In FIG. 8, beam splitter 40. In other words, half Silva Mira is observation po 1-2
6 at a 45 degree angle.

Light beam 41 from fiber optics ring 25
is reflected from the counterface 39 and the reflected light [1142 is directed to be projected onto the surface 45 of the beam splitter 4o. Light ray 42 is reflected from surface 45 and reflected light 143 is directed axially onto object 20 to be illuminated. Most of the rays reflected by the object 2o and projected onto the beam splitter 4o pass through the beam splitter as the light JI 44 and are sent to the video camera 21.
Detected by. In this way, the object 2o is surrounded by a -like distribution of light originating from all angles to it by the diffuser 14. The observation boat 26 then becomes invisible to the camera. For this embodiment to work most effectively, the light from the fiber optics ring should be intense. A beam splitter, for example,
Although not normally necessary for most inspection and observation applications, it may be used in various other embodiments of the invention.

In connection with the above description, the following sections are further disclosed.

(1) A diffuser assembly for shadowless illumination, comprising a translucent diffuser having a substantially hemispherical concave surface and a position for directing light to an optical medium of the diffuser. a diffuser assembly including a light source;

(2) A diffuser assembly according to paragraph (1), wherein the light source includes a lamp spaced from the diffuser and transmitting light from the lamp to the location for directing the light to an optical medium of the diffuser. Includes fiber optic cables for

(3) The diffuser assembly described in item (1) further includes a diverging lens positioned to distribute light from the light source to the diffuser.

(4) The diffuser assembly according to paragraph (1), further including at least one deflector for reflecting light to an optical medium of the diffuser.

(5) In the diffuser assembly described in paragraph (1), the optical medium of the diffuser has an opalescent glass optical density for diffusing light.

(6) In the diffuser assembly described in item (1), the concave surface is shaped like folded fabric to diffuse light.

(7) (In the diffuser assembly described in item 61, the concave surface is a sandblasted surface.

(8) In the diffuser assembly described in item (6), the concave surface is an etched surface.

(9) In the diffuser assembly described in item (1), the diffuser is made of plastic.

(10) In the diffuser assembly described in item (1), the diffuser is made of glass.

(11) The diffuser assembly according to item (1), wherein the diffuser further includes a concave surface positioned to receive the guided light from the light source.

(12) In the diffuser assembly described in paragraph (11), the concave surface is woven to scatter the directed light into the optical medium of the diffuser.

(13) The diffuser assembly described in item (1) further includes an observation boat positioned on the axis of the diffuser.

(14) The diffuser assembly described in item (1) further includes an observation boat located off-axis of the diffuser.

(15) A lighting method that does not create shadows of objects, (2)
defining a substantially hemispherical, translucent diffuser having a concave surface; 0 positioning the object to be illuminated near the center of curvature of said concave surface; 0 directing light towards an optical medium of said diffuser; the steps include uniformly emitting light from the concave surface toward the object to illuminate the object.

(16) In the method described in paragraph (15), step 0 includes positioning the object under the bottom edge of the 1tJ concave surface for illumination.

(17) In the method described in paragraph (15), step O includes defining a flefter positioned to reflect light toward an optical medium of the diffuser.

(18) In the method described in item (15), step (2) includes defining an observation boat in the translucent diffuser.

(19) The method described in item (18) further includes the following steps. 0 Observe the illuminated objects through the observation boat.

(20) In the method described in item (19), step O includes observing the object through the observation boat with a video camera.

(21) In the method described in item (19), step 0 includes observing the object through the observation boat with a microscope.

(22) The method described in item (18) further includes the following steps. @Providing means for directing light through the observation boat to the object to intercept images of the observation boat reflecting from the object.

(23) In the method described in item (22), the guiding means includes means for transmitting the elongated light from the object.

(24) A diffuser assembly for shadowless illumination of objects, comprising: a substantially hemispherical, concave, translucent diffuser; a light source for directing light to an optical medium of the diffuser; a diffuser for observing an object M1t' located near the center of curvature of the concave surface;
and means for transmitting light reflected from said object.

(25) In the diffuser assembly described in item (24), the means is a beam splitter.

(26) In the diffuser assembly described in item (24), the means is a half silver mirror.

(27) In the diffuser assembly of paragraph (24), the means includes a long sword surface positioned to reflect light to the object through the WA sensing port.

(28) A diffuser assembly for uniform illumination of at least one object, which is substantially hemispherical and has a concave surface on one side, and is substantially hemispherical and has a convex surface in the long direction of the diffuser. and a viewing boat in the diffuser for viewing objects located approximately at the center of curvature of the concave surface.

(29) In the diffuser assembly described in item (28), the optical medium of the diffuser is
It has the optical characteristics of opalescent glass to diffuse light.

(30) In the diffuser assembly described in paragraph (29), the concave surface is shaped like a woven fabric to scatter the light emitted by the concave surface.

(31) (In the diffuser assembly described in paragraph 291, the convex surface is shaped like a woven fabric to scatter the light emitted by the concave surface.

(32) A translucent flat spherical diffuser provides uniform, shadow-free illumination for inspecting and observing objects. The translucent diffuser optical medium has an opalescent glass optical density to homogenize the light, and/or one or more surfaces of the diffuser are transparent to the diffuser optical medium. It looks like woven fabric to diffuse the light that comes out. A translucent diffuser is located between the light source and the object being observed. Light entering the optical medium of the diffuser from the light source is uniformly re-radiated from the concave surface of the diffuser. The observed object is located approximately at the center of curvature of the translucent diffuser. Thus, the radiating concave surface of the diffuser is carved at a fixed angle of approximately 2π steradians. Light is diffused by any reflective surfaces external to the diffuser before entering the optical medium of the daylight source. One diffuser embodiment includes a reflective surface as an integral part of the diffuser.

The light source is a locally spirally wound neon tube over a remote lamp and fiber optic system or diffuser.

Each diffuser includes a viewing boat for viewing the illuminated object. The observation boat has an associated beam
A splitter or half-silvered mirror assembly that directs light toward the object to prevent the boat's image from being reflected by the object and directs the light toward the object to prevent it from being reflected by the object. Through the light reflected by.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of a prior art illumination device with a hemispherical reflector. FIG. 2A is a side cross-sectional view of an embodiment of the invention with spaced lamps and off-axis viewing ports 1-. FIG. 2B is a perspective view of the embodiment of the invention shown in FIG. 2A. FIG. 3A is a side cross-sectional view of an embodiment of the invention with spaced lamps and an on-axis viewing boat. FIG. 3B is a perspective view of the embodiment of the invention shown in FIG. 3A. FIG. 4A is a side cross-sectional view of an embodiment of the invention with spaced lamps and a flat diffuser surface versus a convex surface. FIG. 4B is a perspective view of the embodiment of the invention shown in FIG. 4A. Figure 5A shows the flattened hemispherical lattice covering the diffuser /υ
1 is a side sectional view of an embodiment of the invention with a lamp; FIG. FIG. 5B is a perspective view of the embodiment of the invention shown in FIG. 5A. FIG. 6A is a side cross-sectional view of an embodiment of the invention with a hemispherical spiral lamp covering a diffuser. FIG. 6B is a perspective view of the embodiment of the invention shown in FIG. 6A. FIG. 7A is a side cross-sectional view of an embodiment of the invention with a hemispherical reflector that then covers a hemispherical helical lamp that covers the eye user. FIG. 7B is a perspective view of the embodiment of the invention shown in FIG. 7A. FIG. 8 is a side cross-sectional view of an embodiment of the invention with a beam splitter or half silvered mirror. Explanation of main symbols 9: Lamp 10: Fiber optical cable 14: Translucent diffuser 18: Convex: Concave Engraving of drawing (no change in content) h'g, / Ft'g, 6 汐Ft'q, 7a Ft, 7b Procedural amendment (method) Name of the invention Hemispherical non-glare lighting device and lighting method Name (name) Texas Instruments Incorporated Agent Neho Masako to Shiso Karo's number of amendments The contents of the target drawing Ida Tadashi are as shown in the attached sheet.

Claims (2)

[Claims] (1) Diffuser for lighting that does not create shadows
A diffuser assembly comprising: a translucent diffuser having a substantially hemispherical concave surface; and a light source positioned to direct light to an optical medium of the diffuser. (2) A method of illumination that does not cast shadows of objects, the method comprising: (a) defining a substantially hemispherical, semi-transparent diffuser having a concave surface; (b) such that a portion near the center of the curvature of the concave surface is illuminated; (c) directing light toward an optical medium of the diffuser;
In order to illuminate the object in that direction, light is emitted uniformly from the concave surface toward the object.