Mitsumi Electric Company Ltd.

Riichiro Hibiya

Yuji Kimura

Hisamichi Sekine

Kensuke Yamada

Toyoki Tanaka

Kenichi Hori

Hisanori Aga

Motoi Komatsu

Tanemichi Fukui

Somei Takahashi

An optical scanning apparatus that oscillates a mirror in at least one direction, includes a mirror driving circuit including a digital-to-analog converter and an amplifier and generating a pair of driving signals for driving the mirror based on digital driving waveform data, a reference waveform data generator generating a reference waveform data, and an offset setting circuit setting an offset value of the reference waveform data, based on a dead band of the amplifier and a periodic integral non-linearity error of the digital-to-analog converter, to generate the driving waveform data.

Optical scanning apparatus and method of controlling optical scanning apparatus

It is an object of the present invention to provide an optical scanning apparatus and a retinal scanning head-mounted display that prevent an overcurrent from being supplied to a light source. An optical scanning apparatus of the present invention includes a light source () configured to emit light; a light source driving unit () configured to supply a driving current to the light source; an optical scanning unit () configured to scan the light emitted from the light source in accordance with an image signal such that the light is projected onto a projection surface; a light amount sensor configured to detect an amount of the light; a current sensor () configured to detect the driving current; a primary stop control unit () configured to stop an operation of the light source driving unit when the amount of the light is equal to or exceeds a predetermined amount of light; and a secondary stop control unit () configured to stop supply of the driving current to the light source when a value of the driving current is equal to or exceeds a predetermined threshold.

Optical scanning apparatus and retinal scanning head-mounted display

A display device that includes an attachment part mountable on a head of a user, a control device to control the attachment part, and a transmission cable to connect the attachment part with the control device, further includes an imager; a first converter configured to convert a digital signal from the imager into an analog signal; a second converter configured to convert the analog signal into a video signal; a laser light generator configured to generate a laser light modulated depending on the video signal; an optical scanner configured to scan the laser light; and an optical projection system configured to project the scanned laser light to form an image. The imager, the first converter, the optical scanner, and the optical projection system are placed in the attachment part. The second converter and the laser light generator are placed in the control device. The analog signal and the laser light are transmitted via the transmission cable.

Display device

An optical scanning control device includes a scanner that scans light emitted from a laser in accordance with an image signal to form an image on a screen; a first optical detector that detects light scanned by the scanner; a second optical detector that detects light scanned by the scanner; and a controller that controls a deflection angle of the scanner based on a time difference between an output of the first optical detector and an output of the second optical detector.

Optical scanning control device

A light scanning apparatus includes torsion beams supporting a mirror supporting portion on opposite sides of the mirror supporting portion along an axis direction, the mirror supporting portion being swung around the axis direction by the torsion beams; a pair of drive beams sandwiching the mirror and the mirror supporting portion in a direction orthogonal to the axis direction; connection beams that connect mutually facing sides of each drive beam with the torsion beams; and a piezoelectric sensor formed on the connection beams and detecting displacement of the connection beams caused by a swing of the torsion beams around the axis when the mirror swings by a drive voltage, wherein a first bias voltage having a positive or negative polarity is applied to an upper electrode of the piezoelectric sensor, and a second bias voltage having an opposite polarity is applied to a lower electrode.

Light scanning apparatus, light scanning control apparatus, and light scanning unit

An optical scanner apparatus includes first and second torsion beams which support a mirror support portion supporting a mirror from both sides in an axial direction; first and second horizontal driving beams configured to include first and second horizontal driving sources, respectively, a connecting beam; a first piezo-electric sensor; first and second sensor interconnects connected to one of and the other of an upper electrode and a lower electrode of the first piezo-electric sensor, respectively, the first sensor interconnect and the second sensor interconnect being formed to extend toward the first horizontal driving beam and the second horizontal driving beam, respectively.

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Tokyo, Japan

Riichiro Hibiya