Patent application number | Description | Published |
20090252504 | Optical Receiver - Provided is an optical receiver which has a wide dynamic range characteristic for stably reproducing packets having different light receiving levels, and which is superior in high-speed responsiveness and consecutive same binary symbols tolerance. | 10-08-2009 |
20100067924 | OPTICAL RECEIVER - An optical receiver of wide-dynamic range characteristic that stably reproduces a burst signal having different light receiving levels. A preamplifier converts an output from a light receiving element into a voltage signal. A level detecting circuit includes: a first level detecting unit having a shorter time constant; and a second level detecting unit having a longer time constant and switching over to any of the level detecting units in response to a time constant switching signal to detect a voltage level of an output voltage signal output from the preamplifier. An amplifier variably controls conversion gain of the preamplifier based on the detecting result. A time constant switching control outputs the time constant switching signal to the level detecting unit based on the output voltage signal from the preamplifier, to select the first level detecting unit or the second detecting unit based on a number of consecutive identical digits being equal to, smaller, or larger than the predetermined number. | 03-18-2010 |
20100181937 | OPTICAL TRANSMITTER - An optical transmitter that can perform high-speed ON/OFF control of bias light that is input to an optical modulator. A high-speed current switching circuit performs a high-speed ON/OFF control of a drive current of an LD according to an LD ON/OFF signal. Thus, high-speed ON/OFF control of an optical output from the LD can be performed. A temperature detecting current generation circuit detects the ambient temperature, and generates the drive current adjusted according to the ambient temperature detected thereby so that the optical output from the LD is not affected by the ambient temperature. | 07-22-2010 |
20100221345 | OSTEOGENIC BIOMATERIAL CONTAINING OSTEOGENESIS PROMOTING SUBSTANCE AND NANOGEL - An object of the present invention is to provide an osteogenic biomaterial which achieves long-term sustained release and localized functional expression of a substance which promotes the formation of bone tissue. The present inventors have found out that a nanogel efficiently encloses an osteogenesis promoting substance to suppress the substance from diffusion into blood, and that the nanogel functions as a carrier for local administration of the osteogenesis promoting substance. Furthermore, they have found out that the osteogenesis promoting substance-containing nanogel can be cross-linked with a water-soluble polymer to allow sustained release of the osteogenesis promoting substance at a local area over a long period of time. Based on these findings, the present invention was completed. The osteogenic biomaterial of the present invention which contains the osteogenesis promoting substance and the nanogel shows osteogenesis promoting activity over a long period of time, and can be used as a preventive and therapeutic agent against bone diseases. | 09-02-2010 |
20120128348 | LIGHT-EMISSION ERROR PREVENTING CIRCUIT FOR OPTICAL TRANSMITTER - A subscriber-side optical network unit (ONU) includes a control LSI for outputting a data signal and a pre-bias signal at fixed intervals, an optical transmitter-receiver for producing optical output in response to these signals, and a light-emission error preventing circuit for preventing light-emission error. First and second light-emission error detecting circuits output an abnormality detection alarm signal when no rising edge occurs in the data signal and pre-bias signal for a prescribed period of time. An OR element, when receiving the abnormality detection alarm signal from at least one of the first and second light-emission error detecting circuits, supplies the optical transmitter-receiver with a shutdown signal and halts the optical output. | 05-24-2012 |
20130343769 | OPTICAL RECEIVER - An optical receiver including: a preamplifier capable of changing a conversion gain in accordance with a reception level of a received burst signal; a gain control circuit capable of switching between a fast time constant and a slow time constant; and a convergence determination circuit for outputting a time constant switching signal in accordance with a state of the gain control circuit (transient state or steady state) and a reset signal between the burst signals. This configuration can switch the time constant of the gain control circuit at an appropriate timing. | 12-26-2013 |
20140341571 | OPTICAL TRANSMITTER - A photodiode converts an optical signal output from a laser diode to a current signal, and a current-to-voltage conversion circuit converts the current signal to a voltage signal. A comparison amplifier compares the voltage signal with a reference voltage to control the current flowing from a variable current source and increases or decreases a bias current for driving the laser diode. The current-to-voltage conversion circuit comprises a resistor and a variable current source that are connected in parallel. Therefore, it is possible to change the bias current without changing the resistance value of the resistor and to avoid limiting the dynamic range of the optical signal that is output. In addition, since the resistance value of the resistor does not change, the loop gain does not change, thereby stabilizing the control operation. | 11-20-2014 |
20150295659 | OPTICAL RECEIVER, STATION-SIDE OPTICAL NETWORK UNIT, AND LIGHT RECEPTION LEVEL MONITORING METHOD - An optical receiver includes a light receiving element configured to convert an input light signal into an electric current, a current mirror circuit including a reference current side transistor and a mirror current side transistor, the transistor being connected to the light receiving element, a current-voltage conversion circuit configured to convert an output current from the transistor into a voltage and output the voltage as a light reception level monitor voltage of the light receiving element, and a current sink circuit connected to the transistor and configured to feed an electric current to the transistor. | 10-15-2015 |