Abstract: An apparatus and method for detecting the location of a moving body. The apparatus may include a speaker configured to intermittently generate a pulse signal to a detection space and a microphone array configured to obtain a reflected sound of the pulse signal that is generated in the detection space. The location of a moving body is estimated by extracting a change of a sound field from the reflected sound. The present invention can be applied to an apparatus for detecting a moving body without any side effect because the location of a moving body can be accurately detected up to an angle and distance. Furthermore, the present invention can be applied to various application apparatuses, such as a lighting apparatus, an air conditioning apparatus, a security apparatus, and a parking lot management apparatus because there is no problem in health and there is no side effect in application.

Abstract: An apparatus and method for detecting the location of a moving body. The apparatus may include a speaker configured to intermittently generate a pulse signal to a detection space and a microphone array configured to obtain a reflected sound of the pulse signal that is generated in the detection space. The location of a moving body is estimated by extracting a change of a sound field from the reflected sound. The present invention can be applied to an apparatus for detecting a moving body without any side effect because the location of a moving body can be accurately detected up to an angle and distance. Furthermore, the present invention can be applied to various application apparatuses, such as a lighting apparatus, an air conditioning apparatus, a security apparatus, and a parking lot management apparatus because there is no problem in health and there is no side effect in application.

Abstract: An optical element having an optical multi-layer coating which can function as a phase plate without using quartz crystal or an optical film. The optical multi-layer coating is deposited on a plane which is set up on the optical element by way of a perpendicularly intersecting plane located on perpendicularly intersecting X- and Y-axes in perpendicularly intersecting relation with optical axis of an incident light beam on the optical multi-layer coating, the perpendicularly intersecting plane being inclined through a predetermined angle about the X- and/or Y-axis to establish a phase differential between two linearly polarized components of the incident light beam.

Abstract: A polarizing filter with a gapless polarization separating filter layer formed between a plane of incidence and a plate of transmission of the filter, the polarization separating filter layer being formed by connecting first filter layer sections alternately and crosswise with second inclined filter layer sections in an approximately zigzag shape. The filter is free of the problem of light leakage and can perform the functions of a polarizing filter satisfactorily.

Abstract: A polarizing filter with a gapless polarization separating filter layer formed between a plane of incidence and a plate of transmission of the filter, the polarization separating filter layer being formed by connecting first filter layer sections alternately and crosswise with second inclined filter layer sections in an approximately zigzag shape. The filter is free of the problem of light leakage and can perform the functions of a polarizing filter satisfactorily.

Abstract: An optical element having an optical multi-layer coating which can function as a phase plate without using quartz crystal or an optical film. The optical multi-layer coating is deposited on a plane which is set up on the optical element by way of a perpendicularly intersecting plane located on perpendicularly intersecting X- and Y-axes in perpendicularly intersecting relation with optical axis of an incident light beam on the optical multi-layer coating, the perpendicularly intersecting plane being inclined through a predetermined angle about the X- and/or Y-axis to establish a phase differential between two linearly polarized components of the incident light beam.