Abstract: A linear scale that is used for displacement measurement is provided. The linear scale includes a scale board, a graduation unit, and an attachment unit. The scale board is made of low expansion ceramics. The graduation unit is fixed to an upper surface of the scale board. The graduation unit is read at the time of measurement. The attachment unit is a unit for attaching the scale board to a base member.

Abstract: A linear scale that is used for displacement measurement is provided. The linear scale includes a scale board, a graduation unit, and an attachment unit. The scale board is made of low expansion ceramics. The graduation unit is fixed to an upper surface of the scale board. The graduation unit is read at the time of measurement. The attachment unit is a unit for attaching the scale board to a base member.

Abstract: A displacement measuring device allows a plurality of light beams to be incident at positions on a scale or diffracted at points on a scale grating, which are farther spaced away from each other than the diameter of the light beams on the scale grating, and makes an angle of incidence of each light beam on the scale equal generally to an angle of transmission of the diffracted light beam of each light beam. This makes the strength of a detection signal impervious to variations in pitch angle and allows for providing good signals. Accordingly, it is possible to attach the device easily to an apparatus and provide improved ease of use for the device.

Abstract: A displacement measuring device allows a plurality of light beams to be incident at positions on a scale or diffracted at points on a scale grating, which are farther spaced away from each other than the diameter of the light beams on the scale grating, and makes an angle of incidence of each light beam on the scale equal generally to an angle of transmission of the diffracted light beam of each light beam. This makes the strength of a detection signal impervious to variations in pitch angle and allows for providing good signals. Accordingly, it is possible to attach the device easily to an apparatus and provide improved ease of use for the device.

Abstract: A lattice interference-type displacement detection device including a scale having a penetration-type diffraction lattice formed on one side thereof, and an optical system positioned adjacent to the diffraction lattice and remote from the scale. The optical system includes a light source which emits a light beam along a light source optical path, a light beam divergence arrangement for branching the light beam into first and second divergence beams along first and second optical paths, respectively, and for causing the first and second divergence beams to be incident at a diffraction point on the diffraction lattice, a light beam mixing arrangement for generating first and second mixing light beams from a first group of diffraction light beams generated at the diffraction point, and an arrangement for converting the first and second mixing light beams into respective electrical signals. The scale also includes a light reflection surface remote from the optical system with respect to the diffraction lattice.

Abstract: A displacement sensor is disclosed, which permits a semiconductor laser to be used as a light source with less thermal effects thereof. A spindle 18 with a scale 32 mounted thereon is disposed in a housing 11 or displacement. In the housing are also provided a semiconductor laser 35 for projecting a laser beam onto the scale and a transducer 36 for converting light form the scale into an electric signal. A heat insulation arrangement 41 is provided between the semiconductor laser 35 and the scale 32 to prevent transmission of heat from the semiconductor laser 35 to the scale 32. A heat radiation arrangement for radiating heat from the semiconductor laser 35 to the outside of the housing 11 is mounted in the housing 11. Thus, thermal effects of the semiconductor laser 35 on the scale 32 are reduced, and thus the accuracy of measurement is improved.

Abstract: A laser measuring apparatus is provided with an air stirring means for making the temperature of the air in the casing uniform at every portion. The linearity of laser light in the casing is maintained regardless of generation of heat or cold transmitted to the casing, and the optical path is maintained as predetermined, thereby producing a measuring result including no error caused by the influence of heat.