Asymmetric linear lens and associated linear lamp

Abstract

The asymmetric linear lens (1) for directing light into a restricted angular space according to the invention comprises a first solid profile section (2) in the form of a right-angled trapezoid and a second solid profile section (3) in the form of a non-right-angled trapezoid, the linear lens being in the form of a one-piece, transparent plastic solid profile, the first solid profile section having one shorter base side and one longer base side (2a, 2b) and having two side edges (2c, 2d), the second solid profile section having one shorter base side and one longer base side (3a, 3b) and having two side edges (3c, 3d), wherein the longer base side (2b) of the first solid profile section (2) and the shorter base side (3a) of the second solid profile section (3) coincide with each other, wherein one of the two side edges (2c) of the first solid profile section (2) and one of the two side edges (3c) of the second solid profile section (3) lie on a straight line, which encloses with the longer base side (3b) of the second solid profile section (2) a first angle (a) in the range between 40° and 50°, and wherein the other side edge (3d) of the second solid profile section (3) is curved outwardly with respect to the other side edge (2d) of the first solid profile section (2) by a second angle (b) in the range between 25° and 35°.

Description

TECHNICAL FIELD

[0001] The invention relates to an asymmetric linear lens for directing light into a limited solid angle and also to a linear lamp having such a linear lens. BACKGROUND

[0002] An asymmetric lens for directing light into a limited solid angle is known from EP 2 421 414 B1, which is in the form of an one-piece, transparent plastic solid profile. The outer side of the solid profile has two profile contours, which each rise from the profile edge towards the profile center, wherein in the profile center one profile contour is set back with respect to the other profile contour. SUMMARY

[0003] In contrast thereto, it is the task of the invention to propose an alternative asymmetric linear lens. In particular, the linear lens should couple out the in-coupled light on one profile side with a side exit angle of not more than about 35° and on the other profile side with a side exit angle of not more than about 80° to 85°.

[0004] According to the invention, this task is solved by an asymmetric linear lens for directing light into a limited solid angle, which is in the form of an one-piece, transparent plastic solid profile, which has a first solid profile section in the form of a right-angled trapezoid and a second solid profile section in the form of a non-right-angled trapezoid, the first solid profile section having one short base side and one longer base side and having two side edges, the second solid profile section having one short base side and one longer base side and having two side edges, wherein the longer base side of the first solid profile section and the shorter base side of the second solid profile section coincide with one another, wherein one of the two side edges of the first solid profile section and one of the two side edges of the second solid profile section lie on a straight line, which encloses with the longer base side of the second solid profile section a first angle in the range between 40° and 50°, and wherein the other side edge of the second solid profile section is curved outwards with respect to the other side edge of the first solid profile section by a second angle in the range between 25° and 35°.

[0005] Preferably, the first angle is in the range between 43° and 47° and in particular 45°. Preferably, the second angle is in the range between 28° and 32° and in particular 30°.

[0006] Each profile latching tab (Profilraststeg) can project from both side edges of the second solid profile section in a direction at right angles to the longer bottom side of the second solid profile section, away from the bottom side.

[0007] The application also relates to a linear lamp having a U-shaped profile, a lamp strip, in particular a LED strip, arranged eccentrically on the inner side of the profile bottom of the U-shaped profile, and an asymmetric linear lens arranged in front of the lamp strip, the linear lens being configured in the manner described above, the linear lens having a coupling-in surface for coupling in light emitted from the lamp strip and a coupling-out surface for coupling out the coupled-in light, wherein the coupling-in surface and the coupling-out surface extend parallel to one another, and the profile width of the linear lens over the coupling-out surface is greater than the profile width over the coupling-in surface.

[0008] Compared to a LED strip without a linear lens arranged in front, the illuminance (in lx) can be significantly increased (by not more than 100%) in the desired functional area and the glare can be significantly reduced (by not more than 85%) in the undesired area in the linear lamp according to the application. The linear lamp according to the application is suitable for use in an under construction (Unterbau) or for flush-mounted embedding and can be used, for example, as work surface lighting in a kitchen or laboratory or as cabinet interior lighting.

[0009] The linear lens preferably encloses the open side of the U-shaped profile and is inserted (einstecken) into the open side and latched.

[0010] In a preferred embodiment of the application, the profile bottom has a bottom groove on the inner side, into which the lamp strip is laid (eingelegt) and fastened. If the bottom groove is wider than the lamp strip used, the groove flanks (Nutflanken) of the bottom groove either constitute a left stop for the laid lamp strip or a right stop for the laid lamp strip.

[0011] Further advantages of the application result from the description, the claims and the drawings. Likewise, the features mentioned above and further features listed can be used individually or in any combination in multiple forms. The embodiments shown and described are not to be understood as an exhaustive enumeration, but rather have exemplary features for the recitation of the application. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 A profile cross-sectional view of a linear lens according to the application is shown;

[0013] Figure 2 A linear lamp having a linear lens according to the application is shown and the relevant beam path through the linear lens is shown schematically.

[0014] Figure 3 A cabinet is shown with two linear lamps for interior lighting and a kitchen top cabinet with a linear lamp for work surface lighting. DETAILED DESCRIPTION

[0015] The asymmetric linear lens 1 shown in Figure 1 is used to direct light into a limited angular space and is configured as a one-piece, solid plastic profile which is transparent to visible light.

[0016] The linear lens 1 comprises a first solid profile section 2 in the form of a right-angled trapezium having one short and (imaginary) longer base side 2a, 2b and two side edges 2c, 2d and a second solid profile section 3 in the form of a non-right-angled trapezium having (imaginary) short and longer base sides 3a, 3b and two side edges 3c, 3d. The longer base side 2b of the first solid profile section 2 and the shorter base side 3a of the second solid profile section 3 coincide with each other, i.e. the longer base side 2b of the first solid profile section 2 and the shorter base side 3a of the second solid profile section 3 are formed by the same imaginary line. The shorter base side 2a of the first solid profile section 2 and the longer base side 3b of the second solid profile section 3 are parallel to each other. The thickness dl of the first solid profile section 2 is preferably about 1.25 times the thickness d2 of the first solid profile section 3. In a preferred embodiment, dl is 4.4 mm and d2 is 5.6 mm, i.e. the total thickness D is 10 mm and the width of the shorter base side 2a is 19 mm.

[0017] The side edge 2c of the first solid profile section 2 and the side edge 3c of the second solid profile section 3 lie on a straight line which encloses a first angle a of preferably about 45° with the longer base side 3b of the second solid profile section 2. The other side edge 3d of the second solid profile section 3 is curved outwards with respect to the other side edge 2d of the first solid profile section 2 at a second angle β of about 30°. The second solid profile section 3 is provided with a panel-shaped extension 4 of the side surface in the two corner regions formed by the longer base side 3b and the respective side edges 3c, 3d.

[0018] In a preferred embodiment, the linear lens 1 is used as a light guide for a linear light source 6, which is arranged in the interior of the first solid profile section 2 and which is directed through the linear lens 1 in the direction of the longer base side 3b of the second solid profile section 3. Figure 2 ​The linear light 10 shown in Fig. 1 comprises a U-profile 11, e.g. of metal, preferably of aluminum, a strip of LEDs 12 arranged eccentrically on the inner side of the profile base 11a of the U-profile 11, and a linear lens 1, the strip of LEDs 12 being in the form of an LED strip 12, e.g. 5 mm or 8 mm wide, having a plurality of LEDs 13 spaced apart in the strip longitudinal direction, the linear light further comprising a linear lens arranged in front of the strip of LEDs 12. The profile base 11a has a base groove 14 on the inner side into which the LED strip 12 is placed and glued. As shown, when the base groove 14 is wider than the LED strip 12, the two groove side walls of the base groove 14 serve as left and right stops for the LED strip 12 placed therein.

[0019] The linear lens 1 is inserted into the open side of the U-profile 11 by means of the profile snap-in tabs 5 on both sides thereof and is snapped with the two profile edges 11b of the U-profile 11, thereby closing the open side of the U-profile 11.

[0020] The shorter bottom side 2a of the first solid profile section 2 forms a coupling-in face for coupling in the light 15 emitted from the LED strip 12, and the longer bottom side 3b of the second solid profile section 3 forms a coupling-out face for coupling out the coupled-in light 15, wherein the coupling-in and coupling-out faces 2a, 3b extend parallel to each other. The coupled-in light 15 either exits from the coupling-out face 3b without being reflected on the side edges 2, 2d, 3c, 3d of the two solid profile sections 2, 3 or exits after total reflection on the side edges 2, 2d, 3c, 3d. The light 15 exits on the left profile side in Fig. 1 with a side exit angle of not more than about 35°, and on the right profile side in Fig. 1 with a side exit angle of not more than about 80° to 85°, so that overall a total exit angle of 115° to 120° is achieved. Ideally, the degree of transmission of the linear lens 1 for the emitted visible light is at least about 90%. Figure 2 Figure 2

[0021] Figure 3 ​​A cabinet 30 is shown with two linear lamps 10 fastened on the underside of the upper or middle bottom 31, respectively, for interior lighting of the cabinet, and an overhead cabinet 32 with a linear lamp 10 fastened on the underside for lighting a work surface 33 arranged below the overhead cabinet 32. The linear lamps 10 are arranged on the front side of the upper or middle bottom 31, respectively, or of the overhead cabinet 32, preferably mounted on the underside of the upper or middle bottom or of the overhead cabinet or flush embedded into the upper or middle bottom or into the overhead cabinet, and radiate forward with an exit angle of not more than about 35° and backward with an exit angle of not more than about 80° to 85°. Compared to an LED strip 12 without a linear lens arranged in front, the illuminance (in lx) is increased by 100% in the desired functional area and the glare is reduced by 85% in the undesired area.

Claims

1. An asymmetric linear lens (1) for directing light into a restricted angular space, the linear lens being in the form of a one-piece, transparent, plastic solid profile, the linear lens having a first solid profile section (2) in the form of a right-angled trapezium with one shorter base side and one longer base side (2a, 2b) and with two side edges (2c, 2d) and a second solid profile section (3) in the form of a non-right-angled trapezium with one shorter base side and one longer base side (3a, 3b) and with two side edges (3c, 3d), wherein The longer bottom side (2b) of the first solid profile section (2) and the shorter bottom side (3a) of the second solid profile section (3) coincide with one another, wherein one of the two side edges (2c) of the first solid profile section (2) and one of the two side edges (3c) of the second solid profile section (3) lie on a straight line which encloses a first angle (a) in the range between 40° and 50° with the longer bottom side (3b) of the second solid profile section (2), wherein the other side edge (3d) of the second solid profile section (3) is curved outwards with respect to the other side edge (2d) of the first solid profile section (2) by a second angle (β) in the range between 25° and 35°.

2. The linear lens of claim 1, wherein, The first angle (a) is in the range between 43° and 47°.

3. The linear lens of claim 2, wherein, The first angle (a) is 45°.

4. The linear lens according to claim 1 or 2, characterized in that, The second angle (β) is in the range between 28° and 32°.

5. The linear lens of claim 4, wherein, The second angle (β) is 30°.

6. The linear lens of claim 1 or 2, wherein, One profile latching tab (5) of the integral, transparent plastic solid profile protrudes from each of the two side edges (3c, 3d) of the second solid profile section (3) in a direction at right angles to the longer bottom side (3b) of the second solid profile section (3) in such a way as to be remote from the bottom side (3b).

7. The linear lens of claim 1 or 2, wherein The second solid profile section (3) has a lateral extension (4) of the side in the two corner regions of the longer bottom side (3b) and the two side edges (3c, 3d).

8. A linear lamp (10) having a U-shaped profile (11), a lamp strip (12) arranged eccentrically on the inner side of the profile base (11a) of the U-shaped profile (11), and an asymmetric linear lens (1) according to claim 1 or 2 arranged in front of the lamp strip (12), the linear lens having a coupling-in face (2a) for coupling in light (15) emitted from the lamp strip (12) and a coupling-out face (3b) for coupling out the coupled-in light (15), wherein The incoupling and outcoupling faces (2a, 3b) extend parallel to one another, the profile width of the linear lens (1) on the outcoupling face (3b) being greater than the profile width on the incoupling face (2a).

9. The linear lamp according to claim 8, characterized in that, The linear lens (1) closes the open side of the U-shaped profile (11).

10. The linear lamp according to claim 8 or 9, characterized in that The linear lens (1) is inserted into the open side of the U-shaped profile (11) and latches with the U-shaped profile (11).

11. The linear lamp according to claim 8 or 9, characterized in that The profile base (11a) has a base groove (14) on the inner side into which the light strip (12) is placed and fastened.

12. The linear lamp of claim 11, wherein, The base groove (14) is wider than the light strip (12), the groove side walls of the base groove (14) either constituting a left stop for the light strip (12) placed therein or a right stop for the light strip (12) placed therein.

13. The linear lamp according to claim 8 or 9, characterized in that, Light (15) exits the outcoupling face (3b) on one profile side with a lateral exit angle of not more than 35° and on the other profile side with a lateral exit angle of not more than 85°.

14. The linear lamp according to claim 13, characterized in that, Light (15) exits the outcoupling face (3b) on one profile side with a lateral exit angle of not more than 35° and on the other profile side with a lateral exit angle of not more than 80°.

15. The linear lamp of claim 8, wherein, The light strip (12) is an LED strip.

Images