Optical scanning apparatus and image forming apparatus having defective light source detection

An optical scanning apparatus comprising:

• a light source unit including a plurality of light source elements generating a plurality of light beams;
• a light aperture unit receiving said plurality of light beams and regulating the light flux of the plurality of light beams;
• a line image forming optical system for forming a line image from the plurality of light beams transmitted through the aperture unit;
• a deflector arranged to deflect the line image generated by the line image forming optical system and to transmit the deflected line image to a surface to be scanned;
• a sensor arranged to sense a defective operation of at least one of the light source elements;
• a correcting unit connected to the sensor and arranged to receive an indication from the sensor of a defective condition of said at least one of the plurality of light source elements, the correcting unit arranged to correct the defective condition of said at least one of the plurality of light source elements without changing an image formation speed of the apparatus.

An image forming apparatus comprising:

• a light source unit including a plurality of light source elements generating a plurality of light beams;
• a light aperture unit receiving said plurality of light beams and regulating the light flux of the plurality of light beams;
• a line image forming optical system for forming a line image from the plurality of light beams transmitted through the aperture unit;
• a deflector arranged to deflect the line image generated by the line image forming optical system and to transmit the deflected line image to a surface to be scanned;
• a sensor for sensing a defective operation of at least one of the light source elements;
• and
• a correcting unit connected to the sensor and receiving an indication from the sensor of a defective condition of said at least one of the light source elements, the correcting unit arranged to correct the defective condition of said at least one of the light source elements without changing an image formation speed of the apparatus.

A method of optical scanning comprising the steps of:

• modulating a plurality of light source elements to produce a plurality of light beams;
• passing the plurality of light beams through a light receiving element;
• detecting at least one of a light intensity and a light volume of the plurality of light beams passed through the light receiving element;
• and
• comparing the detected light intensity or the detected light volume to a reference light intensity or reference light volume, respectively, to determine whether one or more of the light source elements is defective.

An optical scanning apparatus comprising:

• a light source unit including a plurality of light source elements generating a plurality of light beams;
• a light aperture unit receiving said plurality of light beams and regulating the light flux of the plurality of light beams;
• a line image forming optical system for forming a line image from the plurality of light beams transmitted through the aperture unit;
• a deflector arranged to deflect the line image generated by the line image forming optical system and to transmit the deflected line image to a surface to be scanned;
• a sensor unit including a light receiving element arranged to receive the deflected line image to detect at least one of a light intensity and a light volume of the deflected line image;
• and
• a calculating unit arranged to receive from the sensor unit data representative of the detected light intensity or the detected light volume and to compare the detected light intensity or the detected light volume to a reference light intensity or reference light volume, respectively, to determine whether one or more of the light source elements is defective.

An image forming apparatus comprising:

• a light source unit including a plurality of light source elements generating a plurality of light beams;
• a light aperture unit receiving said plurality of light beams and regulating the light flux of the plurality of light beams;
• a line image forming optical system for forming a line image from the plurality of light beams transmitted through the aperture unit;
• a deflector arranged to deflect the line image generated by the line image forming optical system and to transmit the deflected line image to a surface to be scanned;
• a sensor unit including a light receiving element arranged to receive the deflected line image to detect at least one of a light intensity and a light volume of the deflected line image;
• and
• a calculating unit arranged to receive from the sensor unit data representative of the detected light intensity or the detected light volume and to compare the detected light intensity or the detected light volume to a reference light intensity or reference light volume, respectively, to determine whether one or more of the light source elements is defective.