Luminescent screen for low pressure mercury discharge lamp with specific emission range
AssigneeU.S. Phillips Corporation
InventorDick Van Der Voort
Life of this patent
Estimating the term…
Abstract
Color rendering indices Ra,8 between 80 and 90 and R9 greater than 20, and a color point on or near the Planckian curve, are achieved with a lamp vessel provided with a luminescent screen including a first luminescent substance which emits predominantly between 520 nm and 565 nm, a second luminescent substance which emits predominantly between 590 nm and 630 nm, and a third luminescent substance which emits predominantly in the range between 615 nm and 780 nm.
Claims9
A low-pressure mercury discharge lamp having color rendering indices Ra,8 between 80 and 90 and R9 greater than 20, a color point on or near the Planckian curve and comprising a gastight lamp vessel which allows passage of visible light, contains Hg and one or more inert gases and is provided with a luminescent screen including
- a first luminescent substance which emits predominantly between 520 nm and 565 nm, and
- a second luminescent substance which emits predominantly between 590 nm and 630 nm, and
- a third luminescent substance which emits predominantly between 615 nm and 780 nm.
Dependencies are inferred from the claim text.