Light source apparatus equipped with a GaN type semiconductor laser, a method of eliminating stray light, and an image forming apparatus

A method of eliminating stray light comprising the step of

• emitting light from a GaN type semiconductor light emitting element;
• eliminating, by use of a spatial filter, stray light from the light emitted from the light source apparatus equipped with the GaN type semiconductor light emitting element;
• wherein
• said stray light amounts to 20% or lees of the total output of the light emitted from said GaN type semiconductor light emitting element when said GaN type semiconductor light emitting element is driven at the maximum output thereof,
• the GaN type semiconductor light emitting element has an active layer having stripe portions,
• the stray light is randomly polarized light emitted from portions of the semiconductor light emitting element other than the stripe portions of the active layer, and
• the stray light is cutoff by one of a slit panel and a pinhole panel.

A method of eliminating stray light comprising the step of

• emitting light from a GaN type semiconductor light emitting element;
• eliminating, by use of a spatial filter, stray light from the light emitted from the light source apparatus equipped with the GaN type semiconductor light emitting element;
• wherein
• said stray light amounts to 20% or less of the total output of the light emitted from said GaN type semiconductor light emitting element when said GaN type semiconductor light emitting element is driven at the maximum output thereof, and
• the stray light is stray light that is generated when the drive current of the GaN type semiconductor light emitting element is less than the laser oscillation threshold value.

A light source apparatus equipped with a GaN type semiconductor light emitting element, comprising

• a GaN type semiconductor light emitting element;
• a spatial filter for eliminating stray light from the light emitted from the GaN type semiconductor light emitting element, wherein
• said stray light amounts to 20% or less of the total output of the light emitted from said GaN type semiconductor light emitting when said GaN type semiconductor light emitting element is driven at the maximum output thereof, further comprising
• a focusing optical system for focusing the light emitted from the GaN type semiconductor light emitting element, wherein
• the spatial filter is formed of a slit panel or a pinhole panel disposed adjacent to the convergence position of the light focused by the focusing optical system, and
• the stray light is stray light that is generated when the drive current of the GaN type semiconductor light emitting element is less than the laser oscillation threshold value.

A light source apparatus equipped with a GaN type semiconductor light emitting element, comprising

• a GaN type semiconductor light emitting element;
• a spatial filter for eliminating stray light from the light emitted from the GaN type semiconductor light emitting element, wherein
• said stray light amounts to 20% or less of the total output of the light emitted from said GaN type semiconductor light emitting element when said GaN type semiconductor light emitting element is driven at the maximum output thereof, further comprising
• a focusing optical system for focusing the light emitted from the GaN type semiconductor light emitting element, wherein
• the spatial filter is formed of a partially reflective mirror that partially reflects the light near the convergence position of the light focused by the focusing optical system, and
• the stray light is stray light that is generated when the drive current of the GaN type semiconductor light emitting element is less than the laser oscillation threshold value.

A light source apparatus equipped with a GaN type semiconductor light emitting element, comprising

• a GaN type semiconductor light emitting element;
• a spatial filter for eliminating stray light from the light emitted from the GaN type semiconductor light emitting element, wherein
• said stray light amounts to 20% or less of the total output of the light emitted from said GaN type semiconductor light emitting element when said GaN type semiconductor light emitting element is driven at the maximum output thereof,
• the spatial filter is a polarization element that eliminates the light components other than the TE mode components of the light emitted from the GaN type semiconductor light emitting element, and
• the stray light is stray light that is generated when the drive current of the GaN type semiconductor light emitting element is less than the laser oscillation threshold value.

A method of eliminating stray light comprising the steps of

• equipping a light source apparatus with a GaN type semiconductor light emitting element;
• providing the light source with a spatial filter;
• and
• eliminating, by the use of the stray filter, stray light from the emitted light, wherein
• the stray light amounts to 20% or less of the total output of the light emitted from the GaN type semiconductor light emitting element when the GaN type semiconductor light emitting element is driven at the maximum output thereof,
• the GaN type semiconductor light emitting element has an active layer having stripe portions,
• the stray light is randomly polarized light emitted from portions of the semiconductor light emitting element other than the stripe portions of the active layer, and
• the stray light is cutoff by one of a slit panel and a pinhole panel.

A method of eliminating stray light comprising the steps of

• equipping a light source apparatus with a GaN type semiconductor light emitting element;
• providing the light source with a spatial filter;
• and
• eliminating, by use of the stray filter, stray light from the emitted light, wherein
• the stray light amounts to 20% or less of the total output of the light emitted from the GaN type semiconductor light emitting element when the GaN type semiconductor light emitting element is driven at the maximum output thereof, and
• the stray light is stray light that is generated when the drive current of the GaN type semiconductor light emitting element is less than the laser oscillation threshold value.

A light source apparatus equipped with a GaN type semiconductor light emitting element, comprising

• a GaN type semiconductor light emitting element;
• a spatial filter for eliminating stray light from the light emitted from the GaN type semiconductor light emitting element, wherein
• said stray light amounts 20% or less of the total output of the light emitted from said GaN type semiconductor light emitting element when said GaN type semiconductor light emitting element is driven at the maximum output thereof, further comprising
• a focusing optical system for focusing the light emitted from the GaN type semiconductor light emitting element, wherein
• the spatial filter is formed of a slit panel or a pinhole panel disposed adjacent to the convergence position of the light focused by the focusing optical system,
• the GaN type semiconductor light emitting element has an active layer having stripe portions,
• the stray light is randomly polarized light emitted from portions of the semiconductor light emitting element other than the stripe portions of the active layer, and
• the stray light is cutoff by the slit panel.