A water purifier or other liquid dispenser may sense a height of the inlet of a container accurately through an infrared transmitter and an infrared receiver that are disposed at different positions of a water discharge module moving vertically. Additionally, in the water purifier, the water discharge module may discharge purified water at a point spaced a certain distance apart from the inlet of the container, based on infrared sensing, thereby preventing the inlet of the container from contacting the lower surface of the water discharge module.

A water purifier or other liquid dispenser may sense a height of the inlet of a container accurately through an infrared transmitter and an infrared receiver that are disposed at different positions of a water discharge module moving vertically. Additionally, in the water purifier, the water discharge module may discharge purified water at a point spaced a certain distance apart from the inlet of the container, based on infrared sensing, thereby preventing the inlet of the container from contacting the lower surface of the water discharge module.

An electromagnetic wave detection apparatus 10 includes a first image forming unit 15, a prism 17 having a fourth surface s3 for emitting electromagnetic waves incident from the first image forming unit 15, a progression unit 16 that includes a plurality of pixels arranged along a reference surface and is configured to cause electromagnetic waves incident on the reference surface from a fourth surface s4 to progress in a particular direction using each of the pixels, and a first detector 19 configured to detect electromagnetic waves progressing in the particular direction. The prism 17 includes a reflection suppressor 90 that is provided at a position out of a progression path of electromagnetic waves incident from the first image forming unit 15 to be detected by the first detector 19.

An object detector including a light-emitting system to emit light to an object, a light detector, a signal detector, and a threshold adjuster. The light detector receives the light emitted from the light-emitting system and reflected by the object, and output a signal. The signal detector detects the signal output from the light detector based on a threshold value of voltage. The threshold adjuster changes the threshold value between when the light-emitting system emits light to a part of a light-emission range of the light-emitting system and when the light-emitting system emits light to other part of the light-emission range other than the part of the light-emission range.

An object detector including a light-emitting system to emit light to an object, a light detector, a signal detector, and a threshold adjuster. The light detector receives the light emitted from the light-emitting system and reflected by the object, and output a signal. The signal detector detects the signal output from the light detector based on a threshold value of voltage. The threshold adjuster changes the threshold value between when the light-emitting system emits light to a part of a light-emission range of the light-emitting system and when the light-emitting system emits light to other part of the light-emission range other than the part of the light-emission range.

An electromagnetic wave detection apparatus 100 includes a wavelength separator 123 having a transmittance of electromagnetic waves in a first wavelength band larger than a transmittance of electromagnetic waves in a wavelength band other than the first wavelength band, a wavelength selector 124 having a transmittance of electromagnetic waves in a second wavelength band larger than a transmittance of electromagnetic waves in a wavelength band other than the second wavelength band, and a first detector 130 configured to detect electromagnetic waves progressing via the wavelength separator 123 and the wavelength selector 124. The first wavelength band and the second wavelength band partially overlap with each other.

An electromagnetic wave detection apparatus 10 includes a first image forming unit 15, a prism 17 having a fourth surface s3 for emitting electromagnetic waves incident from the first image forming unit 15, a progression unit 16 that includes a plurality of pixels arranged along a reference surface and is configured to cause electromagnetic waves incident on the reference surface from a fourth surface s4 to progress in a particular direction using each of the pixels, and a first detector 19 configured to detect electromagnetic waves progressing in the particular direction. The prism 17 includes a reflection suppressor 90 that is provided at a position out of a progression path of electromagnetic waves incident from the first image forming unit 15 to be detected by the first detector 19.

A detecting system for protection of equipment is provided. The equipment is disposed on a working surface, which is defined with a working space. The detecting system comprises a first diverting element, a detecting apparatus, and a three-dimensional first safety wave curtain. The diverting element approximately surrounds the equipment and is disposed away from the working surface with respect to the equipment. The detecting apparatus includes an electronic control device and a first detector, and the first detector has a transmitter, a receiver, and a controller. The controller controls the transmitter and the receiver to synchronously rotate about an axis, N detection waves are sequentially transmitted with N times of time detections correspondingly during every rotation. The detection waves cooperate with the diverting surface of the first diverting element and the working surface to form the first safety wave curtain.

A high resolution inspection apparatus using a terahertz Bessel beam. The high resolution inspection apparatus comprises a terahertz wave generating unit for generating a terahertz wave; a Bessel beam forming unit for generating a terahertz Bessel beam using the terahertz wave incident from the terahertz wave generating unit; a ring beam forming unit for forming a ring beam using the terahertz Bessel beam and concentrating the formed ring beam to an inspection target object; a scattered light detecting unit for detecting scattered light generated from the inspection target object; and a ring beam detecting unit for detecting a ring beam transmitted through the inspection target object.

A high resolution inspection apparatus using a terahertz Bessel beam. The high resolution inspection apparatus comprises a terahertz wave generating unit for generating a terahertz wave; a Bessel beam forming unit for generating a terahertz Bessel beam using the terahertz wave incident from the terahertz wave generating unit; a ring beam forming unit for forming a ring beam using the terahertz Bessel beam and concentrating the formed ring beam to an inspection target object; a scattered light detecting unit for detecting scattered light generated from the inspection target object; and a ring beam detecting unit for detecting a ring beam transmitted through the inspection target object.