Optical encoder and optical lens module

Abstract

A reflective type optical encoder has a light source, a scale which moves relatively with respect to the light source and which has a periodic optical pattern, and a photodetector which can detect a change in an intensity pattern of a light beam that is emitted from the light source and is reflected and modulated by the scale. The photodetector and a concave portion are formed on a semiconductor substrate, the light source is disposed at the concave portion on the semiconductor substrate, a slit is also disposed on the concave portion, and the light beam emitted from the light source irradiates the scale after passing through the slit.

1 - 3 . (canceled) 
   
   
       4 . A reflective type optical encoder comprising:
 a light source;   a scale which moves relatively with respect to the light source and which has a periodic optical pattern; and   a photodetector which can detect a change in an intensity pattern of a light beam that is emitted from the light source and is reflected and modulated by the scale,   wherein a through hole extending between a surface of a semiconductor substrate where the photodetector is formed and an opposing surface thereof, is provided on the semiconductor substrate, a slit is disposed on an opening of the through hole on a side where the photodetector is formed, the slit is a transmission-type slit having penetrated opening portions and light-shielding portions arranged alternately, the light-shielding portions of the slit function as a light shielding member to shield a circumferential portion of the photodetector, and the light source is disposed in the through hole in a position where light emitted from the light source passes through the slit and irradiates the scale.   
   
   
       5 - 7 . (canceled) 
   
   
       8 . An optical encoder according to  claim 4 , wherein the light shielding member is a metal film formed on the semiconductor substrate. 
   
   
       9 . (canceled) 
   
   
       10 . An optical encoder according to  claim 8 , wherein a reinforcing member is provided at the scale side and/or the light source side of the metallic film, the reinforcing member is a member having a translucency with respect to light emitted from the light source, and a film thickness which reduces a reflection factor of the light beam emitted from the light source. 
   
   
       11 . (canceled) 
   
   
       12 . An optical encoder according to  claim 10 , wherein given that a wavelength of the light beam emitted from the light source is α, a refraction factor of the member having a translucency is n, and k is an integer, the film thickness of the reinforcing member is ((¼+k/2)λ)/n. 
   
   
       13 . An optical encoder according to  claim 10 , wherein the reinforcing member is a polyimide film or a silicon oxide film or a silicon nitride film. 
   
   
       14 - 17 . (canceled) 
   
   
       18 . A reflective type optical encoder comprising:
 a light source;   a scale which moves relatively with respect to the light source and which has a periodic optical pattern; and   a photodetector which can detect a change in an intensity pattern of a light beam that is emitted from the light source and is reflected and modulated by the scale,   the reflective type optical encoder having at least two semiconductor substrates, each having at least one photodetector, the semiconductor substrates having substantially the same thickness, wherein said at least two semiconductor substrates are disposed on a common substrate such that respective light receiving surfaces thereof are made to face a surface of the scale, and the light source is fixed on the common substrate between said at least two semiconductor substrates, a slit which is independent of the semiconductor substrates is disposed in a light path where light emitted from the light source passes through the slit and irradiates the scale and the slit is fixed so as to bridge surfaces on which the photodetectors of the at least two semiconductor substrates are formed.   
   
   
       19 - 21 . (canceled) 
   
   
       22 . An optical encoder according to any one of  claims 4  and  18 , wherein the slit has an optical pattern formed from a shielding member having a shielding effect for a wavelength of the light beam emitted from the light source, on a transparent member having a translucency for a wavelength of the light beam emitted from the light source, and the slit has a light shielding region including a light receiving portion of the photodetector as an opening portion, and a light shielding portion surrounding the light receiving portion. 
   
   
       23 . An optical encoder according to  claim 22 , wherein the transparent member is a glass member. 
   
   
       24 . An optical encoder according to  claim 22 , wherein the transparent member is polyethlene terephthalate or a resin material having a light permeability. 
   
   
       25 . An optical encoder according to  claim 22 , wherein the surface of the optical pattern formed on the slit faces the light source. 
   
   
       26 . An optical encoder according to  claim 22 , wherein the slit is attached such that the surface of the slit on which the optical pattern is formed is made to contact the surface of the semiconductor substrate on which the photodetectors are formed. 
   
   
       27 . An optical encoder according to any one of  claims 4  and  18 , wherein the slit is formed by molding a shielding member having a shielding effect for a wavelength of the light beam emitted from the light source in a slit form. 
   
   
       28 . An optical encoder according to  claim 27 , wherein the shielding member is a metallic material. 
   
   
       29 . An optical encoder according to  claim 27 , wherein the shielding member is a resin material. 
   
   
       30 - 31 . (canceled) 
   
   
       32 . An optical encoder according to any one of  claims 4  and  18 , wherein a shielding member is formed on at least a part of a region, onto which the light beam emitted from the light source is directly irradiated, of the semiconductor substrate on which the photodetector is formed. 
   
   
       33 . An optical encoder according to  claim 4 , wherein a shielding member is formed on at least a part of a wall surface of the concave portion or the through hole formed on the semiconductor substrate. 
   
   
       34 . An optical encoder according to  claim 18 , wherein a shielding member is formed on at least a part of a region, onto which the light beam emitted from the light source is directly irradiated, of said plurality of semiconductor substrates. 
   
   
       35 . An optical encoder according to any one of  claims 4  and  18 , wherein given that a distance from the slit to the scale is z 1 , a distance from the scale to the light receiving surface of the photodetector is z 2 , a period of the optical pattern formed on the scale is p 1 , a wavelength of the light beam emitted from the light source is λ, and n is a natural number, the slit, the scale, and the photodetector are disposed so as to substantially satisfy a relationship of 1/z 1 +1/z 2 =λ/(n×(p 1 ) 2 ). 
   
   
       36 - 38 . (canceled) 
   
   
       39 . An optical encoder according to any one of  claims 4  and  18 , wherein an electric circuit is integrated on the semiconductor substrate. 
   
   
       40 . An optical encoder according to  claim 39 , wherein the electric circuit is a signal processing circuit and/or a light source driving circuit. 
   
   
       41 . An optical encoder according to any one of  claims 4  and  18 , wherein the light source and the semiconductor substrate are fixed on a common substrate, and a portion of the common substrate on which the light source is disposed has a height different from that of a portion on which the semiconductor substrate is fixed. 
   
   
       42 . An optical encoder according to  claim 41 , wherein the portion of the common substrate on which the light source is disposed is a concave portion with respect to the portion on which the semiconductor substrate is fixed. 
   
   
       43 . An optical encoder according to any one of  claims 4  and  18 , wherein given that a distance from the slit to the scale is z 1 , and a distance from the scale to the light receiving surface of the photodetector is z 2 , z 1  and z 2  are configured to be substantially equal to one another. 
   
   
       44 - 47 . (canceled) 
   
   
       48 . A method for producing an optical encoder according to  claim 18 , comprising:
 disposing a light source on a substrate;   arranging at least two semiconductor substrates, each having a photodetector, with the light source interposed therebetween; and   attaching slits on surfaces of the semiconductor substrates on which the photodetectors are formed.