Outdoor luminaire

Abstract

The invention discloses an outdoor luminaire. The outdoor luminaire comprises a light module comprising at least one LED unit; wherein said light module is configured such that the light emitted by the light module has a first luminous intensity value no less than 10 cd/klm at a first angle (γi), which is a vertical angle of 90 degrees above a direction pointing directly downward from the luminaire. In this way, the luminous intensity of the outdoor luminaire at a vertical angle of 90 degrees is guaranteed to be no less than 10 cd/klm Since the end user sees the light emitted at a vertical angle of 90 degrees no matter how far away he is from the outdoor luminaire, the end user always perceives a certain level of brightness. Such “certain level of brightness” is helpful in increasing the adaptation level of the end user, and can effectively reduce the end user's perception of glare.

Claims

1. An outdoor luminaire comprising: a light module comprising: a housing; a first LED light unit disposed inside the housing; a second LED light unit disposed exterior to the housing; wherein said light module is configured such that the light emitted from the light module has a first luminous intensity value no less than 10 cd/klm at a first angle (γ1), which is a vertical angle of 90 degrees above a direction pointing directly downward from the luminaire; wherein the first LED light unit is configured to emit light in a downward direction and the second LED light unit is configured to emit light in perpendicular direction to the downward direction, to enable the first luminous intensity value and a second luminous intensity at a second angle (γ2); and, wherein the second luminous intensity has a value no less than 40 cd/klm at the second angle (γ2), which is a vertical angle of 80 degrees above the direction pointing directly downward from the luminaire.

2. The outdoor luminaire according to claim 1, wherein the light emitted from the light module has a third luminous intensity value at a third angle (γ3), which is a vertical angle of less than 80 degrees above the direction pointing directly downward from the luminaire; said third luminous intensity value is no less than the second luminous intensity value; said second luminous intensity value is no less than the first luminous intensity value.

3. The outdoor luminaire according to claim 1, wherein each of the first and the second luminous intensity value is no greater than 100 cd/klm.

4. The outdoor luminaire according to claim 1, wherein said light module further comprises a first optical element disposed in front of said first LED light unit; and said first optical element is configured to transform part of the light from said first LED light unit over a first range of angles, which range is from said second angle (γ2) to said first angle (γ1).

5. The outdoor luminaire as claimed in claim 4, wherein said first optical element comprises a curved cover plate, which is made of transparent diffusing material.

6. The outdoor luminaire as claimed in claim 4, wherein said first optical element comprises a curved wire grid, which is made of diffusing material.

7. The outdoor luminaire as claimed in claim 1, wherein said second LED light unit is disposed on a top surface of the housing.

8. The outdoor luminaire as claimed in claim 1, wherein said second light unit comprises at least one of a light array and a light band.

9. The outdoor luminaire as claimed in claim 1, wherein said second LED light unit is disposed on a side surface of the housing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Other features, purposes and advantages of the present invention will become more apparent from the following detailed description of non-limiting exemplary embodiments taken in conjunction with the accompanying drawings.

(2) FIG. 1 illustrates a diagram for a typical outdoor LED luminaire in accordance with the prior art;

(3) FIG. 2 illustrates a diagram for an outdoor LED luminaire according to an embodiment of the present invention;

(4) FIG. 3 illustrates a diagram for an outdoor LED luminaire comprising a curved cover plate according to an embodiment of the present invention;

(5) FIG. 4 illustrates a diagram for an outdoor LED luminaire comprising a curved wired grid according to another embodiment of the present invention;

(6) FIG. 5 illustrates a diagram for an outdoor LED luminaire comprising a light array on the side according to another embodiment of the present invention;

(7) FIG. 6 illustrates a diagram for an outdoor LED luminaire comprising a light panel on the side according to another embodiment of the present invention; and

(8) FIG. 7 illustrates a diagram for an outdoor LED luminaire comprising a light panel at the top according to another embodiment of the present invention.

(9) Identical or similar reference signs indicate identical or similar devices (modules).

DETAILED DESCRIPTION OF EMBODIMENTS

(10) A detailed description of the present invention is given below in connection with the accompanying drawings.

(11) FIG. 2 illustrates a diagram for an outdoor LED luminaire according to an embodiment of the present invention.

(12) As is well-known, the lighting quantities of an outdoor luminaire can be described by means of luminous intensity values at various vertical angles above the direction pointing directly downward from the luminaire. The luminous intensity is normally expressed in candelas per kilolumen (cd/klm) from all light sources in the luminaire. The direction pointing directly downward from the luminaire is also known as the first axis of the luminaire, and the vertical angle above the direction pointing directly downward from the luminaire is also known as vertical photometric angle (of a light path), which is defined as the angle between the light path and the first axis of the luminaire.

(13) Referring to FIG. 2, the direction pointing directly downward from the luminaire 200 is depicted as axis 210, and the vertical angle of the light emitted by the luminaire 200 along light path 220 is depicted as angle y.

(14) According to an embodiment of the present invention, the luminaire 200 comprises a light module comprising at least one LED unit. The light module is configured such that the light emitted from the light module has a first luminous intensity value not less than 10 cd/klm at a first angle γ1, which is a vertical angle of 90 degrees above a direction pointing directly downward from the luminaire. In another embodiment, the first luminous intensity value can be not less than 20 cd/klm.

(15) Additionally, the light emitted from the light module has a second luminous intensity value no less than 40 cd/klm at a second angle γ2, which is a vertical angle of 80 degrees above the direction pointing directly downward from the luminaire.

(16) Further referring to FIG. 2, the light emitted from the luminaire 200 along the light path 220 illuminates the space extending over a distance d from the luminaire at a given height h, and the smaller the vertical angle γ, the smaller the distance d is.

(17) According to an embodiment of the present invention, the luminous intensity values at smaller vertical angles are set to be relatively large so as to sufficiently illuminate the space around the outdoor luminaire, and the luminous intensity values at larger vertical angles are set to be relatively small so as to avoid causing glare.

(18) In an example, the light module of the outdoor luminaire 200 has a third luminous intensity value at a third angle γ3, which is a vertical angle of less than 80 degrees above the direction pointing directly downward from the luminaire. The third luminous intensity value is no less than the second luminous intensity value, and the second luminous intensity value is no less than the first luminous intensity value. For example, the luminous intensity values at various vertical angles can increase with the decrease of the vertical angles.

(19) In another example, each of the first and the second luminous intensity value is not greater than 100 cd/klm.

(20) FIG. 3 illustrates a diagram for an outdoor LED luminaire comprising a curved cover plate according to an embodiment of the present invention.

(21) Referring to FIG. 3, the outdoor luminaire 300 comprises a housing 310, and a first LED light unit disposed inside the housing 310. The outdoor luminaire 300 further comprises a curved cover plate 320, which is made of transparent material. The curved cover plate 320 is disposed in front of the first LED light unit.

(22) The first LED light unit is configured to emit no light or insufficient light over a first range of vertical angles from 80 degrees to 90 degrees, e.g. with an intensity value less than the first luminous intensity value at a vertical angle of 90 degrees and/or with an intensity less than the second luminous intensity value at a vertical angle of 80 degrees.

(23) The curvature of the plate transforms part of the light emitted at small vertical angels (i.e. vertical angles less than 80 degrees) over the first range of vertical angles such that the light emitted from the outdoor luminaire 200 has desired luminous intensity values over the first range of vertical angles. For example, the desired luminous intensity values include the first luminous intensity value at the vertical angle of 90 degrees and the second luminous intensity value at the vertical angle of 80 degrees.

(24) Different transparent material diffuses a different amount of light. Thus, by choosing proper transparent material, a desired amount of light can be transformed.

(25) FIG. 4 illustrates a diagram for an outdoor LED luminaire comprising a curved wire grid according to another embodiment of the present invention.

(26) Referring to FIG. 4, the outdoor luminaire 400 is similar to the outdoor luminaire 300 of FIG. 3, and the difference resides in that the curved cover plate 320 is replaced by a curved wire grid 420. The curved wire grid 420 is made of diffusing material and can at least diffuse most of the incident light. Thus, similar to the curved cover plate 320, the curved wire grid 420 can transform part of the light emitted by the first LED unit over the first range of vertical angles, which is from 80 degrees to 90 degrees.

(27) FIG. 5 illustrates a diagram for an outdoor LED luminaire comprising a light array on the side according to another embodiment of the present invention.

(28) Referring to FIG. 5, the outdoor luminaire 500 comprises a light module and a pole 540 on which the light module is installed. The light module of the outdoor luminaire 500 comprises a housing 510 and a first LED light unit disposed inside the housing 510. The light module further comprises a second light unit 530 disposed on the side of housing 410. Preferably, the second light unit 530 is also a LED light unit.

(29) In order to achieve that the light emitted from the light module has a first luminous intensity value at a first angle γ1, i.e. a vertical angle of 90 degrees, and a second luminous intensity value at a second angle γ2, i.e. a vertical angle of 80 degrees, the first LED light unit and the second light unit can be configured as follows: the first LED light unit is configured such that the light emitted from said first LED light unit has a luminous intensity value less than the first luminous intensity value at said first angle γ1, and has a luminous intensity value less than the second luminous intensity value at said second angle γ2. Moreover, the second light unit is configured to emit light at least over a second range of angles from said first angle γ2 to first angle γ1.

(30) As shown in FIG. 5, the second light unit 530 can be a light array. Alternatively, the second light unit 530 can be a light panel 630, as shown in FIG. 6.

(31) FIG. 7 illustrates a diagram for an outdoor LED luminaire comprising a light panel at the top according to another embodiment of the present invention.

(32) Similar to the outdoor luminaire 500 of FIG. 5, the outdoor luminaire 700 comprises a light module and a pole 740 on which the light module is installed; the light module of the outdoor luminaire 700 comprises a housing 710 and a first LED light unit disposed inside the housing 710; the light module further comprises a second light unit 730.

(33) Unlike the outdoor luminaire 500 of FIG. 5, the second light unit 730 is disposed at the top of housing 710.

(34) Similarly to the second light unit 530 of the outdoor luminaire 500, the second light unit 730 of the outdoor luminaire 700 can emit light at least over a second range of angles, which is from said second angle γ2 to first angle γ1.

(35) As shown in FIG. 7, the second light unit 730 can be a light panel. Alternatively, the second light unit 730 can be a light array or the like.

(36) A person skilled in the art realizes that the present invention by no means is limited to the preferred embodiments described above. On the contrary, many modifications and variations are possible within the scope of the appended claims. It should be noted that the above-mentioned embodiments illustrate rather than limit the invention and that those skilled in the art will be able to design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be constructed as limiting the claim. The word “comprising” does not exclude the presence of elements or steps not listed in a claim. The word “a” or “an” preceding an element does not exclude the presence of a plurality of such elements. The usage of the words first, second and third, etc., does not indicate any ordering. These words are to be interpreted as names. No specific sequence of acts is intended to be required unless specifically indicated.