Compact scanning optical system
AssigneeRicoh Company, Ltd.
InventorTomohiro Nakajima
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Abstract
The disclosure of the current invention describes a compact optical system for and method of forming an image on an intermediate image-forming surface such as a photoreceptor drum at a high speed. An image-forming light source such as a laser light source is placed between an image-focusing element such as a focusing mirror and an image-scanning unit such as a polygon mirror. According to one preferred embodiment, the image-forming light source is placed in a scanning area defined by a predetermined scanning angle of the image scanning unit.
Claims15
A method of projecting image-forming light onto a temporary image-forming surface via a rotatable image-reflecting surface and an image-focusing element, comprising the following steps of:
- placing an image-forming light source in an area defined by an extent of the rotatable image-reflecting surface and an image-focusing element;
- placing a flat reflector portion on the image-focusing element;
- projecting the image-forming light towards the flat reflector portion which reflects the image-forming light towards the rotatable image-reflecting surface;
- scanning the image-forming light towards the image-focusing element while rotating the rotatable image-reflecting surface;
- and
- focusing the image-forming light reflected by the rotatable image-reflecting surface onto the temporary image-forming surface.
A compact optical system for projecting image-forming light onto a photoreceptive drum surface, comprising:
- a f.theta. mirror having a curved reflective surface for focusing the image-forming light so as to form an image on the photoreceptive drum surface, the image-focusing element also having an integral flat reflector portion for reflecting the image-forming light;
- a rotatable polygon mirror located near said f.theta. mirror for reflecting the image-forming light towards said f.theta. mirror and for scanning the image-forming light towards said f.theta. mirror while said polygon mirror is being rotated;
- and
- an image-forming light source located in an area defined by an extent of said rotatable polygon mirror and said f.theta. mirror for emitting the image-forming light towards said flat reflector portion which reflects the image-forming light towards said polygon mirror.
Dependencies are inferred from the claim text.