Optical encoder and optical lens module

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.

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.