Optical deflector and optical scanner having the optical deflector

Abstract

The present invention provides an optical deflector capable of reducing a rise in heat of integrated circuits and a housing without increasing noises caused by a wind sound of a rotative polygon mirror, and an optical scanner having the optical deflector. Heat in a lover face of an integrated circuit of a printed board can be allowed to escape by providing a through hole in a lower position of the integrated circuit. By bringing a radiating member into direct contact with the integrated circuit through the through hole, heat of the integrated circuit can be conducted to the radiating member and radiated. Therefore, a rise in a temperature of the housing can be reduced. As a result, life of a bearing can be prolonged and reliability of the integrated circuit can be increased.

1 - 2 . (canceled)  
   
   
       3 . An optical deflector comprising: 
 a motor that drives a rotative polygon mirror deflecting and scanning rays emitted from a light source; and    a drive circuit board, mounted in a housing, on which an electronic part such as an integrated circuit controlling the motor is mounted,    wherein the drive circuit board is constructed from a metal, the rotative polygon mirror is on an upper face of the drive circuit board, and the electronic part is mounted on a lower face of the drive circuit board.    
   
   
       4 . The optical deflector according to  claim 3 , wherein the lower face of the drive circuit board is a wiring pattern face, a connection hole is formed on the drive circuit board, and drive coils constituting the motor and a wiring pattern are electrically connected through the connection hole.  
   
   
       5 . The optical deflector according to  claim 4 , wherein a hole is formed in the drive circuit board in opposed relation to drive magnets disposed to face the drive coils and a position detector for detecting the position of the drive magnets is disposed within the hole.  
   
   
       6 . An optical deflector comprising: 
 a motor that drives a rotative polygon mirror deflecting and scanning rays emitted from a light source;    a drive circuit board, mounted in a housing, on which an electronic part such as an integrated circuit controlling the motor is mounted; 
 wherein:  
 the rotative polygon mirror is on an upper face of the drive circuit board, and on a lower face of the drive circuit board, a first wiring pattern is formed and the electronic part is mounted;  
 on the upper face of the drive circuit board, a second wiring pattern electrically connected with drive coils constituting the motor is formed and a position detector for detecting positions of drive magnets disposed to face the drive coils is disposed; and  
 the first wiring pattern and the second wiring pattern are electrically connected by a connection hole formed on the drive circuit board.  
   
   
   
       7 . An optical deflector comprising: 
 a motor that drives a rotative polygon mirror deflecting and scanning rays emitted from a light source;    a drive circuit board on which an electronic part such as an integrated circuit controlling the motor is mounted; 
 wherein:  
 the rotative polygon mirror is on an upper face of the drive circuit board, and on a lower face of the drive circuit board, a first wiring pattern is formed and the electronic part is mounted;  
 on the upper face of the drive circuit board, a second wiring pattern electrically connected with drive coils constituting the motor is formed and a subboard on which a position detector for detecting positions of drive magnets disposed to face the drive coils is disposed is secured; and  
 the first wiring pattern and the second wiring pattern are electrically connected by a connection hole formed on the drive circuit board.  
   
   
   
       8 . The optical deflector according to  claim 7 , wherein a hole is formed on the drive circuit board, the subboard bridges the hole, and the position detector is disposed on an upper face of the subboard within the hole.  
   
   
       9 - 11 . (canceled)  
   
   
       12 . An optical scanner comprising: 
 an optical deflector comprising:    a motor that drives a rotative polygon mirror deflecting and scanning rays emitted from a light source; and    a drive circuit board, mounted in a housing, on which an electronic part such as an integrated circuit controlling the motor is mounted;    wherein a bottom wall of the housing is constructed from the drive circuit board, the electronic part is mounted outside the housing.