The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 29, 2015
Filed:
Jul. 02, 2014
Semiconductor Energy Laboratory Co., Ltd., Atsugi-shi, Kanagawa-ken, JP;
Keisuke Miyagawa, Kanagawa, JP;
Jun Koyama, Kanagawa, JP;
Semiconductor Energy Laboratory Co., Ltd., Kanagawa-ken, JP;
Abstract
A conventional setting voltage was a value with an estimated margin of a characteristic change of a light emitting element. Therefore, a voltage between the source and drain of a driver transistor Vhad to be set high (V≧V−V+a). This caused high heat generation and power consumption because a voltage applied to the light emitting element. The invention is characterized by feedbacking a change in a current value in accordance with the deterioration of a light emitting element and a power source voltage controller which modifies a setting voltage. Namely, according to the invention, the setting voltage is to be set in the vicinity of the boundary (critical part) between a saturation region and a linear region, and a voltage margin for the deterioration is not required particularly for an initial setting voltage.