Light emitting device with phosphors
AssigneesCitizen Electronics Co., Ltd., Citizen Watch Co., Ltd.
InventorsYuki Suto, Jo Kinosita
Life of this patent
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Abstract
A light emitting device includes a first light emitting element, a second light emitting element, a first phosphor sheet containing a first phosphor and a third phosphor, and covering a top face of the first light emitting element, and a second phosphor sheet containing a second phosphor and a fourth phosphor, and covering a top face of the second light emitting element, wherein a peak wavelength of light which is wavelength-converted by the first phosphor or the third phosphor is equal to or less than a peak wavelength of light which is wavelength-converted by the second phosphor or the fourth phosphor.
Claims6
A light emitting device comprising:
- a first blue light emitting element;
- a second blue light emitting element;
- a first phosphor mixture containing a first phosphor and a third phosphor different from the first phosphor, and covering the first blue light emitting element;
- and
- a second phosphor mixture containing a second phosphor different from the first phosphor and a fourth phosphor different from the second phosphor, and covering the second blue light emitting element,
- wherein a peak wavelength of light which is wavelength-converted by the first phosphor is less than a peak wavelength of light which is wavelength-converted by the third phosphor, the peak wavelength of light which is wavelength-converted by the third phosphor is equal to or less than a peak wavelength of light which is wavelength-converted by the second phosphor, and the peak wavelength of light which is wavelength-converted by the second phosphor is less than a peak wavelength of light which is wavelength-converted by the fourth phosphor, and
- the first phosphor mixture does not contain a phosphor wavelength-converting to lights having peak wavelength more than the peak wavelength of light which is wavelength-converted by the second phosphor, and the second phosphor mixture does not contain a phosphor wavelength-converting to lights having peak wavelength less than the peak wavelength of light which is wavelength-converted by the third phosphor.
A light emitting device comprising:
- a first light emitting element;
- a second light emitting element;
- a third light emitting element;
- a first phosphor mixture containing a first phosphor and covering the first light emitting element;
- a second phosphor mixture containing a second phosphor different from the first phosphor and covering the second light emitting element;
- and
- a third phosphor mixture containing a third phosphor and a fourth phosphor different from the third phosphor and covering the third light emitting element;
- and
- a second reflection element provided between the second phosphor mixture and third phosphor mixture,
- wherein a peak wavelength of light which is wavelength-converted by the first phosphor is equal to or less than a peak wavelength of light which is wavelength-converted by the second phosphor, and a peak wavelength of light which is wavelength-converted by the second phosphor is equal to or less than the peak wavelength of light which is wavelength-converted by the third phosphor and is equal to or less than a peak wavelength of light which is wavelength-converted by the fourth phosphor.
Dependencies are inferred from the claim text.