HK1160204A - Total internal reflection lens with integrated lamp cover - Google Patents

Description

Total internal reflection lens with integral lamp cover

Cross Reference to Related Applications

The present invention is related to commonly assigned and co-pending U.S. patent application No.12/420,802, filed on 8/4/2009, the entire contents of which are incorporated herein by reference.

Technical Field

The present invention relates generally to lighting devices, and more particularly to a Total Internal Reflection (TIR) lens with an integral lamp cover.

Background

Incandescent bulbs have been in the past for over 100 years. Although it is still widely used, there are many efforts directed to replacing incandescent bulbs with more energy efficient lighting technologies, such as compact fluorescent bulbs or Light Emitting Diode (LED) based lamps.

One challenge faced by these new technologies is in combination with the physical facilities that support the incandescent bulbs. For example, many existing lighting fixtures provide standard threaded sockets into which incandescent light bulbs with standard threaded bases can be inserted, enabling users to easily replace burned out bulbs. Most buildings have permanently installed lighting fixtures such as "drum" shaped luminaires that are installed into the ceiling, "track" luminaires that are capable of arranging individual lighting fixtures along a track, and the like. These fixtures are often designed to accommodate incandescent light bulbs having various standard form factors (form factors).

An example of a standard light bulb form factor is "PAR-38". This art term refers to such bulbs: with a parabolic aluminum reflector, a transparent or translucent front cover to allow light to escape, 38 inches (4.75 inches, or 107.95 millimeters (mm)) in diameter. PAR-38 bulbs are commonly used in applications such as: recessed lighting fixtures, security light fixtures, spotlights, or other applications requiring direct light.

To facilitate the transition from incandescent bulbs to newer technologies, it would be advantageous to manufacture lamps based on LEDs or other more energy efficient technologies with form factors and threaded bases compatible with existing fixtures involved with incandescent bulbs, thereby eliminating the cost and difficulty of replacing existing lighting fixtures to accommodate new types of light fixtures.

To be successful as a replacement for existing light bulbs, LED-based lamps should have a form factor similar to the bulb to be replaced and electrical connections compatible with existing lighting devices. In addition, such lamps should also be durable, provide satisfactory light quality, and have an attractive appearance.

Disclosure of Invention

Embodiments of the present invention provide Total Internal Reflection (TIR) lenses with integral lamp covers that can be used in LED-based lamps. The size and shape of the TIR lens can be adjusted to be optimized for the light output of the lamp, almost without regard to the form factor required for a particular application. The integral lamp cover may extend the front surface of the TIR lens (i.e., the surface where light from the light source exits) outward from the optical axis to better match the form factor of a particular lamp, while providing aesthetic advantages in light quality and a decorative appearance to the installed lamp. In some embodiments, the TIR lens and cover may be adapted for use in a bulb replacement lamp, such a lamp corresponding to a standard form factor (e.g., PAR-38).

According to one embodiment, a lens assembly includes a Total Internal Reflection (TIR) body component and a cover component. The TIR body part is substantially cylindrically symmetric about the optical axis, with an outer surface having a tapered shape along the optical axis such that the TIR body part is wider at one end than at the other end. The tapered shape provides total internal reflection to direct light from a light source location near the narrower end to the wider end. A cover part integral with the TIR body part is arranged at the wider end of the TIR body part. The cover member has a width in a direction perpendicular to the optical axis larger than a widest diameter of the TIR body member and a thickness in a direction along the optical axis smaller than a thickness of the TIR body member.

The lid part may be much thinner than the TIR body part. For example, the thickness of the cover member may be less than about 10% of the total thickness of the lens assembly, and may be at least about 5% of the total thickness.

Similarly, the cover part may be much wider than the wider end of the TIR body part. For example, the widest diameter of the TIR body component may be no greater than about 40% of the width of the lid component, and may be at least about 25% of the width of the lid component.

The following detailed description together with the accompanying drawings may provide a better understanding of the nature and advantages of the present invention.

Drawings

FIG. 1 is a side cross-sectional view of a lens according to an embodiment of the invention.

Fig. 2 is a front view of the lens of fig. 1.

Fig. 3A is a front view of a microlens according to an embodiment of the present invention.

Fig. 3B is a side view of a microlens according to an embodiment of the invention.

Fig. 4 is a side view of the lens of fig. 1.

Fig. 5 is a rear view of the lens of fig. 1.

Fig. 6 is a rear perspective view of the lens of fig. 1.

FIG. 7A is a simplified cross-sectional side view of a lamp including a lens according to an embodiment of the present invention.

Fig. 7B is a front perspective view of a lamp incorporating a lens according to an embodiment of the invention.

FIG. 8A is a top view of an LED-based light source suitable for use with a lens according to an embodiment of the present invention.

FIG. 8B is a side cross-sectional view of an LED-based light source suitable for use with a lens according to an embodiment of the present invention.

Detailed Description

Certain embodiments of the present invention relate to auxiliary lenses for LED-based lamps, and more particularly to auxiliary lenses having integral lamp covers. The light cover may be formed as an outward radial extension of the front surface of a Total Internal Reflection (TIR) lens, and the front surface of the cover may be provided with a microlens pattern to distribute the light with an aesthetically pleasing effect.

FIG. 1 is a side cross-sectional view of a lens 100 according to an embodiment of the invention. Lens 100 has a TIR body portion 102 with a generally cylindrical open channel 104 extending through the portion from a front surface 106 to a rear surface 108. A light source (not specifically shown) may be disposed at the light source location 110, the light source location 110 being proximate to the opening 104 at the rear end (defined by the rear surface 108). Specific examples of LED-based light sources suitable for use as a light source with the lens 100 will be described below.

The TIR body portion 102 is preferably shaped to direct light from a light source at location 110 outwardly through the front surface 106 to provide illumination. In particular, the outer side surface 112 of the TIR body portion 102 is generally (i.e., within manufacturing tolerances) symmetric about the optical axis 101 and is preferably curved to provide total internal reflection of light from the light source at location 110 to the front surface 106. For example, in some embodiments, the shape of the side surface 112 may be described by the following equation in cylindrical coordinates (r, z), where z is an ordinate along the optical axis 101 and r is a radial coordinate representing the distance from the optical axis 101:

in equation (1), c (curvature) and k (conic constant) are constants that can be adjusted to optimize total internal reflection and/or light output for a particular light source. In one embodiment optimized for a PAR-38 lamp for a light source having 12-LEDs (described below), c-0.181 and k-1.1192. For other applications, these values may vary. In some embodiments, the plane of z ═ 0 (the apex of the cone described by equation (1)) does not exactly coincide with the back surface 108 of the lens 100. For example, in one embodiment suitable for use in a PAR-38 lamp, the plane with z-0 is about 2.2mm behind the back surface 108, corresponding to the light source position 110. More examples of shaping the surface 112 for a particular LED light source can be found in the above-referenced U.S. patent application No.12/420,802.

The thickness (in the z-direction) of the lens 100 may be selected to optimize the light output, which is constrained by the overall shape factor associated with the lamp in which the lens 100 is to be used. In one embodiment suitable for use in a PAR-38 lamp, the lens 100 is about 25mm thick.

The inner side wall 103 is also generally symmetrical about the optical axis 101 and defines an open channel 104 through the middle of the lens. The inner sidewall 103 may have a slight taper (taper, e.g., an inward angle of about 1 °, 2.5 °, 5 °, etc.) to facilitate manufacturing; thus, for example, the open channel 104 may be slightly wider at the front surface 106 than at the rear surface 108. In some embodiments, the presence of open channels 104 provides for impingement of light in the central region and greater light reflection, and also mixes light from multiple LEDs within one light source to improve uniformity of light output.

The radius of the open channel 104 may be selected to optimize light output subject to the following constraints: for any particular value of z within the lens 100, the radius of the open channel 104 must be less than the radius r that satisfies equation (1). In one embodiment suitable for use in a PAR-38 lamp, the open channel 104 has a radius of about 4.3mm at the rear surface 108 and a radius of about 4.8mm at the front surface 106.

In operation, light from a light source generally at 110 enters the lens 100 from the rear. Some of the light strikes surface 112 from the inside and is internally reflected toward front surface 106, thereby reducing light loss through the sides of lens 100 and increasing light output through front surface 106. Note that total internal reflection need not be 100% efficient, and some optical loss can occur. For example, the efficiency of the lens 100 may be 70% or higher; in some embodiments, the efficiency is about 80% -85%.

The front surface 106 may also be generally symmetrical about the optical axis 101, extending in a general radial direction of the TIR body part 102 and outwardly from the TIR body part 102, thereby providing a cover part 114. The cover portion 114 is preferably integral with the TIR body portion 102 (i.e., is a continuous piece of material) such that there is no material boundary between the two portions.

The cover portion 114 may be circular (e.g., disk-shaped) and as thin as possible. In general, the cover portion 114 may be thick enough to provide rigidity and strength, and thin enough so that total internal reflection provided by the side surfaces 112 of the body portion 108 is not adversely affected. For example, the cover portion 114 may be 1.5 millimeters thick. In this embodiment, the front surface 106 is provided with a microlens pattern, as described below.

The radius of the cover portion 114 may be selected as desired. In some embodiments, the cover portion 114 may provide further beam shaping by a microlens as described below. The cover portion 114 may also provide aesthetic and/or protective advantages. For example, as described below, the cover portion 114 may help to shield the LED-based light source from view by a user and/or to block foreign objects that may cause damage from outside the area of the LED-based light source.

In the embodiment of fig. 1, a flange 116 extends rearwardly from the peripheral edge of the cover portion 114. The size and shape of the flange 116 may be adjusted to provide support and alignment for mounting the lens 100 in a lamp, such as the lamp described below. In the example shown, the flange 116 has a tapered outer surface 118. The thickness and shape of the flange 116 may be varied as desired and may preferably be modified to facilitate mounting of the lens 100 in a particular lamp. In one embodiment suitable for a PAR-38 lamp, the flange 116 has a thickness (in the z-direction) of about 11 mm.

A plurality of mounting posts 120 may also be provided at the outer peripheral edge of the cover portion 114; in some embodiments, the mounting posts 120 are integral with the flange 116 and may locally protrude from the material of the flange 116. Any number of mounting posts 120 may be provided. For example, one or two mounting posts 120 may be sufficient to secure the lens 100 in the lamp; three mounting posts 120 may define a planar orientation for front surface 106; more struts 120 may be provided as needed to enhance stability and/or safety of the installation; thus, various embodiments may have a different number of mounting posts.

Fig. 2 is a front view of the lens 100 showing the front surface 106 with a pattern of microlenses 200. In this embodiment, the microlenses 200 are hexagonally closely packed, filling the front surface 106 in a honeycomb pattern. Other patterns may be substituted.

Fig. 3A and 3B are a front view and a side view, respectively, of one microlens 200. As shown in fig. 3A, the microlenses 200 can be regular hexagons having a lateral dimension L. As shown in fig. 3B, the microlens 200 may have a radius of curvature R and a height H. Parameters L, R and H can be varied to produce beams having different beam spread characteristics. In one embodiment suitable for a PAR-38 lamp, L-1.51 mm, R-2.00 mm, and H-0.20 mm. This provides a "medium" beam spread of about 20-24 ° (full width at half maximum, or FWHM). Other choices of parameters will result in different beam spreads. For example, L-1.33 mm, R-3.0 mm, and H-0.1 mm provide a "narrow" beam spread of about 12-15 ° FWHM; l3.0 mm, R3.00 mm and H0.55 mm provide a "wide" beam spread of about 32-36 ° FWHM. It should be noted that the choice of the value of (R, H, L) that determines the beam shape may be largely independent of the choice of the curvature parameters k and c of equation (1). Further examples of microlenses are described in the above-mentioned U.S. patent application No.12/420,802.

Fig. 4-6 are side, rear, and rear perspective views, respectively, of the lens 100, further illustrating the layout of the parts. As shown, the flange 116 may extend rearwardly from the entire perimeter of the cover portion 114. The flange 116 may have a tapered outer surface 118 from which mounting posts 120 may protrude. As best seen in fig. 4, the rear surface of the mounting post 120 may extend slightly beyond the rear end of the flange 116. (e.g., the mounting posts 120 may be about 1.5mm longer than the anteroposterior thickness of the flange 116.) as best seen in FIGS. 5 and 6, in one embodiment, five mounting posts 120 are equally spaced around the perimeter of the flange 116; other embodiments may include other numbers and/or arrangements of mounting posts. As best seen in fig. 5, the mounting post 120 may be generally cylindrical with a central bore 502 extending forwardly from the rear surface. The holes 502 may receive pins, posts, screws, etc. to align and/or clamp the lens 100 in the lamp.

Additionally, as can be seen in fig. 5 and 6, the back surface 504 of the cover portion 114 of the lens 100 may include a flat surface area extending from the TIR body portion 102 to the flange 116.

In the lens 100, the outer surface 112 of the TIR body part 102 is shaped to provide total internal reflection, preventing light loss. The inner open channel 104 readily collimates the light in the central region. The micro-lenses 200 on the front surface 106 enable the light to be uniformly distributed and shape the beam to provide the desired illumination area. The dimensions and shape of the lens 100 may be selected as desired based on considerations such as: a light source, a desired degree of beam collimation, an overall form factor of a lamp in which lens 100 is to be used, etc.

The cover portion 114, which is preferably integral with the TIR body portion 102, provides further light distribution (through the microlenses 200) and aesthetic and/or protective benefits. Thus, in some embodiments, it is desirable that the cover portion 114 extend almost to the outer diameter of the lamp in which the lens 100 is to be used. For example, in one embodiment for a PAR-38 lamp, the cover portion 114 has a diameter of about 102.6 mm. This is slightly less than the 107.95mm diameter of a standard PAR-38 bulb. This design choice leaves room for other peripheral lens holding and support structures, examples of which will be described below. Different diameters may also be selected depending on the form factor and overall design of the particular lamp.

It is to be understood that lens 100 as described herein is exemplary and that various alterations and modifications are possible. The size, shape and curvature of the TIR body portion and/or cover portion may be varied. Other microlens patterns may be used. As noted above, the size and shape of the TIR body portion 102 and the microlens 200 may preferably be optimized for a particular light source and lamp form factor. Furthermore, while the open channel 104 can provide improved lens performance for some light source configurations, the presence of the open channel 104 is optional and some embodiments may provide a solid TIR lens body without any through holes.

Preferably, the size and shape of the cover portion 114 can be optimized for the lamp form factor without adversely affecting the optical characteristics of the lens 100. Providing the cover portion 104 as an integral part of the lens 100 rather than adding a separate cover can reduce optical losses by reducing the number of refractive surface boundaries in the optical path.

The relative thicknesses (along the optical axis) of the TIR body portion 102 and the cover portion 114 may also be varied as desired. It should be noted that the cover portion 114 does not provide significant total internal reflection in the opposite direction to the optical axis, so a thicker cover portion may cause wider light scattering and a weaker center beam. (in some applications this effect may be advantageous.) thus, the tapered outer surface 112 of the TIR body portion 102 preferably extends far enough along the optical axis to provide the desired degree of collimation and light output; the cover portion 114 can be kept thin. For example, in one of the above-described embodiments, the flat portion of the cover portion 114 has a thickness of about 1.5mm, while the lens 100 has a thickness of about 25 mm; in this case, the thickness of the cover portion 114 is about 6% of the total thickness of the lens 100. In other embodiments, the cover portion 114 may be relatively thicker (e.g., 10% of the total thickness) or relatively thinner (e.g., 5% of the total thickness or less).

The width of the TIR body portion 102 (perpendicular to the optical axis) is preferably determined by the need for optimization of the output light. The cover portion 114 has little optical effect and therefore its dimensions can be selected based on aesthetic and manufacturing considerations. For example, the width of the cover portion 114 is preferably determined based on the desired aesthetic appearance and form factor of the lamp in which the lens 100 is to be used. Thus, where the cover portion 114 intersects the TIR body portion 102, the cover portion may be much wider than the width of the TIR body portion. For example, in one embodiment, the maximum width of the TIR body portion 102 is between 25% and 40% of the width of the cover portion 114. In other embodiments, the maximum width of the TIR body portion may be, for example, less than half the width of the cover portion 114, or less than 75% of its width.

The thickness of the cover portion 114 may be determined according to the manufacturing process and the required durability. For example, a thicker cover portion 114 may be more susceptible to flatness distortion during the molding process, while a thinner cover portion may be more susceptible to breakage.

The flange 116 has a negligible effect on the optical properties of the lens 100 and may be omitted or replaced by other stiffening and/or alignment features. For example, alignment tabs (tabs), notches, etc. may be used. Additionally, although the flange 116 is shown as being integral with other portions of the lens 100, in some embodiments, the flange or other stiffening and/or alignment structure may be formed separately and attached to the back or peripheral edge of the integral lens cover.

Lens 100 may be fabricated from any suitable optically transparent material. In some embodiments, conventional optical plastics are used, such as poly (methyl methacrylate) (PMMA); other optically clear plastics or glass may also be used. The lens 100 may be manufactured, for example, by conventional techniques for manufacturing plastic articles (e.g., molding). The cover portion 114 and the TIR body portion 102 are preferably formed as one integral object from the same material, thereby reducing the number of material interfaces that may cause optical loss. Thus, for example, lens 100 may be formed in one molding process.

The lens 100 may be integrated into an LED-based lamp having a desired form factor. An example is shown in fig. 7A and 7B, and fig. 7A and 7B are simplified cross-sectional side and front perspective views, respectively, of a lamp 700 incorporating a lens 100 according to an embodiment of the present invention. In this example, the lamp 700 is an LED-based replacement for a standard PAR-38 lamp and has substantially the same size and overall shape as a conventional incandescent PAR-38 bulb.

The lamp 700 includes a threaded base 702 and a frame 704. The threaded base 702 may be electrically and mechanically compatible with a standard incandescent light bulb socket. The frame 704 may be made of aluminum or other metal or other material and has an outer surface 705 that is substantially similar in shape to a conventional PAR-38 bulb. In some embodiments, the frame 704 may be designed to facilitate heat dissipation and may include various openings, fins, etc., to enable ventilation and/or weight reduction.

As best seen in fig. 7A, the frame 704 defines a platform 706. The platform 706 holds a light source 707, which may be an LED-based light source (an example of which is described below). The frame 704 and the platform surface 706 may contain electrical connections (not shown) to provide electrical power from the threaded base 702 to the light source 707. In some embodiments, these connections may include exposed wires and/or elements disposed on the surface of the platform 706.

The frame 704 also includes an arm 708 that extends toward the front of the light 700. The arm 708 may be shaped to receive the lens 100, and a portion or all of the arm 708 may include a mounting structure 710 that receives and connects with the mounting post 120 of the lens 100 to hold the lens 100 in place relative to the light source 707 and the frame 704. In some embodiments, the arm 708 may extend forward slightly beyond the front surface 106 of the lens 100. The arms 708 may be connected to each other by a peripheral metal rib 711, which protects the lens 100 and provides the following surfaces: a user may grip the surface to facilitate installation of the lamp 700 in a lighting fixture and/or removal of the lamp 700 from the lighting fixture.

In this embodiment, cover part 114 of lens 100 extends to the inner edge of metal rib 711. This configuration protects the edges of cover member 114 while providing the aesthetic advantage of the front face of lamp 700 being covered by cover member 114. The micro-lenses 200 on the front surface 106 of the lens 100 spread the light so that a person viewing the light 700 from the front will not clearly see the platform surface 706 or any wires or other functional elements that may be disposed thereon, whether or not the light 700 is emitting light. In this way, cover member 114 may provide the following aesthetic advantages when viewing lamp 700 from the front, as is typically installed in recessed or barrel lighting fixtures: the working structures within the fixture 700 are hidden from the user. Cover member 114 also limits access to the interior area of lamp 700 when lamp 100 is installed in a recessed lighting fixture, which may help protect light source 708 and/or associated wires or other components from damage.

Fig. 8A and 8B are top and side cross-sectional views, respectively, of an LED-based light source 800 suitable for use with a lens 100 according to embodiments of the present invention (e.g., in the lamp 700 of fig. 7). Light source 800 may be built up on substrate 802, for example in a recess 804 defined by sidewalls 805. A plurality (e.g., 12) of LEDs 806 are disposed within the recess 804. The LEDs 806 may be, for example, white LEDs having similar or different color temperatures. In some embodiments, the LEDs 806 are blue LED dies, each die having a top surface coated with a yellow phosphor coating; other types of LEDs may also be used.

The recess 804 is at least partially filled with an optically transparent material (e.g., silicone gel) to protect the LEDs 806. The primary lens 808 is disposed above the recess 804 and may extend into the recess 804, such as shown in fig. 8B.

In some embodiments, light source 800 may be constructed similar to the light sources described in U.S. patent application No.12/420,800 filed on 8/4/2009, commonly assigned and co-pending, and U.S. provisional patent application No.61/167,761 filed on 8/4/2009, commonly assigned and co-pending. For example, the LEDs 806 may include LEDs having different color temperatures; electrical connections may be provided in a manner that allows individual LEDs 806 and/or groups of LEDs 806 to be independently current controlled, allowing the color temperature of the light produced by light source 800 to be adjusted by adjusting the relative amounts of current sent to the different LEDs 806. In other embodiments, other types and configurations of LEDs may be used.

It will be appreciated that the lamps and LED-based light sources described herein are exemplary and that various alterations and modifications are possible. LED-based lamps can be constructed in a variety of form factors, including form factors compatible with a variety of existing bulb models; the electrical connections and light output may be varied. The light sources in a particular lamp may also be varied and may include any number and arrangement of LEDs. In some examples, light from different color LEDs may be mixed by a TIR lens to produce white light or other desired lighting effects.

While the invention has been described in conjunction with specific embodiments, it will be appreciated by those skilled in the art that many modifications are possible. For example, certain embodiments described herein are suitable for use in PAR-38 lamps and have dimensions that conform to a standard PAR-38 form factor. The invention is not limited to PAR-38 lamps or any particular form factor. Indeed, as noted above, the TIR lens may be optimized for different LED light source configurations suitable for use in a variety of different lamps. An integral cover (such as described in this application) may be added to any TIR lens, and the dimensions of the lens and cover may also be optimized for compatibility with the form factor of a particular lamp. Accordingly, all examples set forth in this application should be considered in all respects as illustrative and not restrictive.

As mentioned above, the shape of the cover and the cover portion of the integral lens may be selected according to aesthetic considerations. For example, while a circular cover has been described that is compatible with the form factor of some conventional lamps, the cover portion may be non-circular (e.g., oval or rectangular). Similarly, although the cover portion is shown in some embodiments as being flat, the surface of the cover portion may also be curved.

Therefore, while the invention has been described in connection with specific embodiments thereof, it should be understood that the invention is intended to cover all modifications and equivalents within the scope of the appended claims.

Claims (16)

1. A lens assembly, comprising:

a Total Internal Reflection (TIR) body component having a first end, a second end opposite the first end, and an outer surface, the TIR body component being generally cylindrically symmetric about an optical axis, the outer surface having a tapered shape such that the TIR body component is wider at the second end than at the first end, the tapered shape providing total internal reflection to direct light from a light source location near the first end toward the second end; and

a lid member disposed at the second end of the TIR body member and integral with the TIR body member, the lid member having a width in a direction perpendicular to the optical axis that is greater than a widest diameter of the TIR body member and a thickness in a direction along the optical axis that is less than a thickness of the TIR body member.

2. The lens assembly of claim 1, wherein the cover member has a thickness that is no greater than about 10% of an overall thickness of the lens assembly.

3. The lens assembly of claim 2, wherein the thickness of the cover member is between about 5% and about 10% of the total thickness of the lens assembly.

4. The lens assembly of claim 1, wherein the widest diameter of the TIR body component is no greater than about 40% of the width of the cover component.

5. The lens assembly of claim 4, wherein the widest diameter of the TIR body component is between about 25% and about 40% of the width of the cover component.

6. The lens assembly of claim 1, wherein the TIR body component further comprises interior sidewalls defining a central open channel extending longitudinally from the first end to the second end, the central open channel centered about and generally symmetrical about the optical axis.

7. The lens assembly of claim 6, wherein the central open channel extends through the cover member.

8. The lens assembly of claim 7, wherein the inner sidewalls and outer surfaces of the TIR body component are shaped to provide mixing of light from a plurality of light emitting diodes within a light source.

9. The lens assembly of claim 7, wherein the inner side wall tapers at an angle of between about 1 ° to about 5 ° relative to the optical axis such that the open channel is wider at the second end than at the first end.

10. The lens assembly of claim 1, wherein the TIR body component and the cover component are fabricated from polymethyl methacrylate.

11. The lens assembly of claim 1, further comprising a flange disposed adjacent to and extending rearwardly from a peripheral edge of the cover member.

12. The lens assembly of claim 11, further comprising a plurality of mounting posts extending rearwardly from the flange.

13. The lens assembly of claim 12, wherein the flange and the mounting post are integrally formed with the cover member and the TIR body member.

14. The lens assembly of claim 1, wherein the cover member has a plurality of microlenses disposed to a front surface thereof.

15. The lens assembly of claim 1, wherein the front surface of the cover member is circular.

16. The lens assembly of claim 15, further comprising a plurality of mounting posts extending rearwardly from an area proximate a peripheral edge of the cover member.