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Patent Searching and Data


Title:
LIGHT EMITTING ELEMENT DRIVING CIRCUIT
Document Type and Number:
Japanese Patent JPS6333920
Kind Code:
A
Abstract:

PURPOSE: To make the change in a current at cut-off steep without lowering the lighting efficiency by providing an anri-parallel diode giving 1 current in opposite direction to a light emitting element so as to make the change in the cut-off current of the element steep to the light emitting element connected between collectors of differential transistor (TR).

CONSTITUTION: When the phase of a control signal IB1 is inverted and a TR 2 is turned off, the electric charge in the inter-electrode capacitor Cs of the light emitting element 1 is apt to be discharged through electrodes A, K of the element 1, but since a TR 2' is turned on as soon as the TR 2 is turned off, a current in an opposite direction before through a resistor 7 and the TR 2', flows to the diode 6. In this case, a current whose polarity is positive at the anode A and negative at the cathode K flows through the capacitor Cs in opposite direction to the preceding current. thus, the waveform of the current I1 at the element 1 is shown in figure as (a)→(b) →(d) from a time t1 and steep cut-off is applied.


Inventors:
KOBAYASHI MASAHIKO
NAITO SEIGO
Application Number:
JP17732086A
Publication Date:
February 13, 1988
Filing Date:
July 28, 1986
Export Citation:
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Assignee:
HITACHI CABLE
International Classes:
H03K17/78; (IPC1-7): H03K17/78