Optical scanning apparatus and devices including an optical scanning apparatus

An optical apparatus comprising:

• scanning means for scanning light irradiated from a light source to an object to be scanned at predetermined scanning periods in a constant direction;
• reference timing signal generating means for generating a reference timing signal upon receipt of the light scanned by the scanning means;
• and
• control means for measuring a period of the reference timing signal generated by the reference timing signal generating means and setting a driving timing for the light source by calculation on the basis of a predetermined relationship between the period of the reference timing signal and the driving timing for the light source as well as of the measured period of the reference timing signal.

An electrophotographic type printer comprising a photosensitive body and optical means for irradiating a surface of the photosensitive body with a laser beam modulated based on a signal showing an image to be printed, wherein the optical means includes:

• a light source for outputting the laser beam;
• scanning means for scanning the laser beam toward the surface of the photosensitive body at predetermined scanning periods in a constant direction;
• reference timing signal generating means for generating a reference timing signal upon receiving the light beam scanned by the scanning means;
• memory means for storing a table comprising driving timing data for each of a plurality of corresponding periods of the reference timing signal;
• and
• control means for measuring the period of the reference timing signal generated by the reference timing signal generating means, for reading out from the table stored in said memory means the driving timing data corresponding to the measured period of the reference timing signal, for setting the driving timing in accordance with the read-out driving timing data, and for controlling output and stoppage of the laser beam from the light source based on the set driving timing.

An image irradiating apparatus comprising a screen which is irradiated with a laser beam to display an image and optical means for irradiating a surface of the screen with the laser beam modulated based on a signal showing the image to be displayed, wherein the optical means includes:

• a light source for outputting the laser beam;
• scanning means for scanning the laser beam toward the screen in a specified direction at predetermined scanning periods in a constant direction;
• reference timing signal generating means for generating a reference timing signal upon receipt of the laser beam scanned by the scanning means;
• memory means for storing a table comprising driving timing data for each of a plurality of corresponding periods of the reference timing signal;
• and
• control means for measuring the period of the reference timing signal generated by the reference timing signal generating means, reading out from the table stored in said memory means the driving timing data corresponding to the measured period of the reference timing signal, setting the driving timing in accordance with the read-out driving timing data, and controlling output and stoppage of the laser beam from the light source based on the set driving timing.

An optical scanning apparatus comprising:

• a light source;
• scanning circuitry for scanning light from said light source across a scanned object during a scan period;
• a control circuit configured to set a timing for driving said light source, said control circuit being further configured to measure the scan period and to automatically set the timing for driving said light source in accordance with the measured scan period;
• and
• a memory for storing a plurality of different scan periods each associated with a respective corresponding timing for driving said light source,
• wherein said control circuit is further configured to read out one of the timings from said memory based on the measured scan period and to set the timing for driving said light source using the read out timing.

An optical scanning apparatus comprising:

• a light source;
• scanning circuitry for scanning light from said light source across a scanned object during a scan period;
• and
• a control circuit configured to set a timing for driving said light source, said control circuit being further configured to measure the scan period and to automatically set the timing for driving said light source in accordance with the measured scan period,
• wherein said control circuit is further configured to calculate a timing for driving said light source based on the measured scan period and to set the timing for driving said light source to the calculated timing.