1. Technical Field
The present invention relates to lamps, and particularly to an indoor lamp with anti-glare function.
2. Description of Related Art
Lamps have numerous applications. Indoor lamps are used for a variety of purposes, such as illuminating a book that one wants to read.
Generally, visible light emitted from a lamp falls within a particular luminance range. When the luminance of the light is too low, visibility is impaired. On the other hand, when the luminance is too high, glare also limits visibility. In the latter case, the light may also cause discomfort or pain. Glare can also occur when light reflects from a target object to a person. In this situation, the occurrence of glare varies according to both the amount of luminance and the relative positions of the light source, the target object and the person. Considerable research has been carried out regarding elimination of glare.
An indoor lamp which provides good luminance without glare is desired.
Many aspects of the present embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present embodiments. Moreover, in the drawings, all the views are schematic, and like reference numerals designate corresponding parts throughout the several views.
Referring to
The light source 12 can be a single light emitting diode (LED), an LED array, a fluorescent lamp, an incandescent lamp, a gas discharge lamp, or a halogen lamp. In other embodiments, there can be a plurality of light sources 12.
The shade 14 is generally dome-like or cup-like in shape, and tapers in profile from bottom to top. The shade 14 defines a receiving cavity 140 therein. The light source 12 is installed in the receiving cavity 140. The shade 14 has a round opening 142 at the bottom of the receiving cavity 140. A flange portion 14A is formed on an outer surface of a bottom end of the shade 14. The flange portion 14A is annular, and surrounds the round opening 142.
Referring also to
The U-shaped portion 1622 extends from an outer side of the connection portion 1624. Preferably, the connection portion 1624 is integrally formed with the U-shaped portion 1622, with the U-shaped portion 1622 and the connection portion 1624 being parts of a single continuous body of material. The connection portion 1624 is parallel to and faces the round opening 142. An inner side of the connection portion 1624 is connected with the optical sheet 164. The position of the optical sheet 164 in the round opening 142 can be changed by sliding the U-shaped portion 1622 along the flange portion 14A.
The optical sheet 164 has an area less than that of the round opening 142. In the illustrated embodiment, a diameter of the optical sheet 164 is less than half a diameter of the round opening 142. The optical sheet 164 is parallel to and faces the round opening 142 and covers a region M thereof. The region of the round opening 142 not covered by the optical sheet 164 is defined as a region N. In this embodiment, the optical sheet 164 is a diffuser.
The indoor lamp 10 is used, for example, with a desktop 200. The indoor lamp 10 is positioned over the desktop 200, and the optical sheet 164 faces the desktop 200. Light emitted from the light source 12 does not directly reach the eyes of a user 202 due to the shade 14. The light emitted from the light source 12 passes through the regions M and N and is then reflected by the desktop 200. In this embodiment, the optical sheet 164 is positioned at a side of the shade 14 adjacent to the user 202.
As shown by the dashed portion of the line I in
Additionally, when the position of the user 202 changes relative to the indoor lamp 10, the position of the optical sheet 164 can be changed accordingly by sliding the U-shaped portion 1622 along the flange portion 14A. For improved anti-glare function, a transmission rate of the optical sheet 164 may be less than 80%, and even less than 60%. An annular end face 144 of the shade 14 at the flange portion 14A defines a reference plane 146. In the illustrated embodiment, the light source 12 is installed in the receiving cavity 140 such that a center axis of the light source 12 is coaxial with a center axis III of the shade 14. The center axis III is perpendicular to the reference plane 146. An angle θ is defined between the center axis III and the continuous portion of the line I. The optical sheet 164 provides effective anti-glare function when the angle θ is in the range from 30° to 75°.
It is to be understood that in alternative embodiments, the optical sheet 164 can be a reflector or a light filter. The light filter can be a neutral density filter or a bandpass filter. The bandpass filter can filter out light with a wavelength in the range from 410 nanometers (nm) to 780 nm. In other alternative embodiments, the optical sheet 164 can be a sheet with an anti-dazzling function.
Referring to
Referring to
A shade 54 and a light source 52 of the indoor lamp 50 have elongated structures. The shade 54 has a generally U-shaped cross section, with two elongated free ends 544. In the illustrated embodiment, the shade 54 has a generally semi-elliptical cross section. An elongated rectangular opening 542 is defined between the two free ends 544. Two straight flange portions 54A are formed on an outer wall of the shade 54 at the two free ends 544, respectively. The flange portions 54A are parallel with each other, and extend from the two free ends 544 in opposite directions away from each other. Two hooked members 58 are connected with two opposite ends of a flat optical sheet 56, respectively. The hooked members 58 are slidably connected with the two flange portions 54A, respectively, in a manner similar to that of the hooked member 162 slidably connecting with the flange portion 14A. However, the hooked members 58 are straight along lengths thereof that are parallel to the flange portions 54A. With this arrangement, the optical sheet 56 is parallel to and faces the opening 542. A transverse width of the optical sheet 56 measured parallel to a longitudinal axis of the opening 542 is less than a corresponding length of the opening 542.
Referring to
Referring to
It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the disclosure or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the disclosure.
Number | Date | Country | Kind |
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2008 1 0305861 | Nov 2008 | CN | national |
Number | Name | Date | Kind |
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1471395 | Garwood | Oct 1923 | A |
2063504 | Horwitt et al. | Dec 1936 | A |
2834875 | Grohskopf | May 1958 | A |
5662403 | Akashi et al. | Sep 1997 | A |
20050036322 | Veffer | Feb 2005 | A1 |
Number | Date | Country |
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581849 | Apr 2004 | TW |
M343107 | Oct 2008 | TW |
2008050444 | May 2008 | WO |
Number | Date | Country | |
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20100135027 A1 | Jun 2010 | US |