BigPatents India

A lighting device for installation in a substantially plane surface (101), comprising at least one lamp device (8) that emits light HVVHQWLDOO\LQDOLJKWGLUHFWLRQZKLFKIRUPVDQDQJOHZLWKDH[LWface (121) of a light refracting means (1) in the lamp device (8). The lamp device comprises a light source (107) that emits light towards an incident face (114) of the light refracting means (1), where the light refracting means (1) has a longitudinal direction coincident with the said light direction, and where the exit face (121) is approximately parallel to the substantially plane surface (101). The exit face (121) is VHWDVOLJKWDQJOHRILQFOLQDWLRQUHODWLYHWRWKHVXEVWDQWLDOO\SODQHVXUIDFHWKHDQJOHDQGWKHDQJOHRILQFOLQDWLRQLQcombination causing light from the light source (107) to be brought to an emergent angle above the face (101) that satisfies pre-set requirements for light intensity close to the surface (101). A prism is also described wherein at least the edge formed between the exit face (121) of the prism and a side face (110) which forms an acute angle with the exit face (121) is rounded. (FIG. 1)