Optical multi-beam scanning device and image forming apparatus

Abstract

An optical multi-beam scanning device has a plurality of pre-deflection optical units, an optical path synthesizing member and an excessive light processing member. The excessive light processing member processes excessive light emitted from an excessive light emitting surface with is not an incident surface nor an emitting surface of the optical path synthesizing member. The excessive light processing member has a multi-stage taper constitution with a plurality of taper surfaces having different tilt angles.

1 . An optical multi-beam scanning device, comprising: 
 a plurality of light sources;    pre-deflection optical units for giving a predetermined property to light beams from the light sources, the pre-deflection optical units corresponding to the light sources, respectively;    an optical path synthesizing member for aligning optical paths of the light beams from all or some of the light sources in a horizontal scanning direction after the pre-deflection optical units give the predetermined properties to the light beams or while giving them to the light beams;    an excessive light processing member having an absorbing surface roughly parallel with an excessive light emitting surface for absorbing excessive light emitted from the excessive light emitting surface which is not an incident surface nor an emitting surface of the optical path synthesizing member; and    a light deflecting device for deflecting the light beams from the pre-deflection optical units corresponding to the light sources to the horizontal scanning direction due to reflection from one surface.    
   
   
       2 . The optical multi-beam scanning device according to  claim 1 , wherein the absorbing surface of the excessive light processing member is formed by adhering a light absorbing sheet to the absorbing surface.  
   
   
       3 . The optical multi-beam scanning device according to  claim 1 , wherein the absorbing surface of the excessive light processing member has a repeated convexo-concave pattern for reflecting and absorbing the excessive light.  
   
   
       4 . The optical multi-beam scanning device according to  claim 3 , wherein the convexo-concave pattern has a shape which reflects excessive incident light three times and returns the excessive light to the excessive light emitting surface of the optical path synthesizing member.  
   
   
       5 . The optical multi-beam scanning device according to  claim 3 , wherein 
 the convexo-concave pattern has a shape which reflects excessive incident light so that the excessive incident light recedes more and more from the excessive light emitting surface of the optical path synthesizing member every time of the reflection of the excessive incident light.    
   
   
       6 . The optical multi-beam scanning device according to  claim 1 , wherein a member for regulating the position of the optical path synthesizing member functions also as the excessive light processing member.  
   
   
       7 . An image forming apparatus, comprising: 
 the optical multi-beam scanning device according to  claim 1;  and    photoreceptors having surfaces to be scanned on which latent images are formed based on light beams from the optical multi-beam scanning device.