Remote infrared audible signage

Ikimenyetso cya kure cya infragre yumvikana (RIAS) cyakozwe n'ikigo cy’ubushakashatsi cy’amaso cya Smith-Kettlewell (nk'ibimenyetso bivuga ^R ), abanyamahanga, cyangwa abafite ubumuga bwo kutabona, bazashobora kubona ubwoko bumwe bwamakuru aboneka binyuze mubimenyetso byanditse byanditse mubidukikije byubatswe.

Igizwe na infragre ya transmitteri yohereza inshuro nyinshi verisiyo ivugwa yibiri mu kimenyetso binyuze mu itumanaho ridafite umugozi . Inyandiko ya mbere mu 1979 yiswe "Amatara yo Kuvuga" yazamuwe neza / igurishwa mu bucuruzi nka "Ibimenyetso byo Kuvuga" biri gushyirwaho ku isi.

Ikirangantego gifatanye cyangwa ibirahuri byashizwemo na IR yakira ibyerekezo byunvikana kumurongo, umurongo-wo-kubona- urumuri rwumucyo urumuri kandi rutanga umuntu mugutanga ibitekerezo byiza mugihe ikimenyetso cyerekanwe neza kandi kiri hafi.

Sisitemu yageragejwe kandi ikora neza haba mumbere ndetse ninyuma kandi ntabwo ihungabanya ibidukikije kuko imirasire ya IR itagaragara kandi icecekeye.

Ihame rya fotofone ya Alexander Graham Bell ryatumye habaho iterambere ryibikoresho bishobora kohereza / gutobora imiraba ya infragre muri sisitemu kuva mu itumanaho rya gisirikare binyuze muri sisitemu yo kugenzura kure kuri televiziyo na mudasobwa.

Ibipimo ngenderwaho

Ibiranga RIAS muri kode yo muri Amerika 703.7. Ibi byavuzwe muri raporo y’ikigo cy’Amerika gishinzwe kwinjira ku buryo bukurikira:

* 703.7.1 General: Remote Infra red Audible Sign Systems shall comply with Section 703.7.

• 703.7.2 Transmitters: Where provided, Remote Infra red Audible Sign Transmitters shall be designed to communicate with receivers complying with Section 703.7.3.
• 703.7.3 Remote Infra red Audible Sign Receivers.
• 703.7.3.1 Frequency: Basic speech messages shall be frequency modulated at 25 kHz, with a +/– 2.5 kHz deviation, and shall have an infra red wave length from 850 to 950 nanometer (nm).
• 703.7.3.2 Optical Power Density: Receiver shall produce a 12 decibel (dB) signal–plus–noise–to–noise ratio with a 1 kHz modulation tone at +/– 2.5 kHz deviation of the 25 kHz subcarrier at an optical power density of 26 picowatts per square millimeter measured at the receiver photosensor aperture.
• 703.7.3.3 Audio Out-put: The audio out-put from an internal speaker shall be at 75 dBA minimum at 18 inches (455 mm) with a maximum distortion of 10%.
• 703.7.3.4 Reception Range: The receiver shall be designed for a high dynamic range and capable of operating in full sun background illumination.
• 703.7.3.5 Multiple Signals: A receiver provided for the capture of the stronger of two signals in the receiver field of view shall provide a received power ratio on the order of 20 dB for negligible interference.