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US 6,476,552 B1Granted
Electroluminescent lamp
AssigneeSeiko Precision Inc.
InventorKoji Yoneda
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AssigneeSeiko Precision Inc.
InventorKoji Yoneda
Estimating the term…
The difference of luminance between a front surface side and a rear surface side as viewed from the front surface side is reduced in a multi-layered EL lamp. An EL lamp includes a first laminate formed by serially laminating a first transparent electrode, a first luminescent layer and a first insulating layer, a second laminate formed by serially laminating a second transparent electrode, a second luminescent layer and a second insulating layer on the first laminate, and a rear electrode formed on the second laminate, wherein a dielectric constant between the first and second transparent electrodes is set to a value smaller than a dielectric constant between the second transparent electrode and the rear electrode. This can be achieved by limiting the amount of a high dielectric material to be mixed in the first insulating layer to not greater than 90% in terms of a weight ratio of a high dielectric material mixed in the second insulating layer, or by increasing the thickness of the first luminescent layer to 130 to 250% of the thickness of the second luminescent layer. After the adjustment is made in this way, the thickness of the first insulating layer may be set to not greater than 90% of the thickness of the second insulating layer or may be omitted.
An EL lamp comprising:
Dependencies are inferred from the claim text.
No related US applications are recorded in the indexed filing history.
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Light sources with substantially two-dimensional [2D] radiating surfaces: characterised by the chemical or physical composition or the arrangement…
Electroluminescent light sources: light sources with substantially two-dimensional [2D] radiating surfaces
Electric heating
Term ended 13 Apr 2020 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
1. Field of the Invention
This invention relates to an electroluminescent lamp (hereinafter referred to as an “EL lamp”).
2. Description of the Related Art
FIG. 1 is a schematic sectional view showing a multi-layered EL lamp in which the amount of a high dielectric material to be mixed in a first insulating layer (on the front surface side) is smaller than in a second insulating layer (on the rear surface side);
FIG. 2 is a schematic sectional view showing a multi-layered EL lamp in which a first luminescent layer (on the front surface side) is formed to a thickness greater than that of a second luminescent layer (on the rear surface side);
FIG. 3 is a schematic sectional view showing a multi-layered EL lamp in which the amount of a high dielectric material to be mixed in a first insulating layer is smaller than in a second insulating layer, and a first luminescent layer is formed to a thickness greater than that of a second luminescent layer;
Hereinafter, EL lamps according to the preferred embodiments of the present invention will be explained with reference to the accompanying drawings in which like reference numerals denotes corresponding elements.
Embodiment 1:
The first embodiment of the invention is based on the concept that the amount of a high dielectric material mixed in a first insulating layer is smaller than the amount in a second insulating layer so that a dielectric constant between a first transparent electrode 1 and a second transparent electrode 4 can be set to a value smaller than the dielectric constant between the second transparent electrode 4 and a rear electrode 7.