Footwear sanitizing and deodorizing system exposing light-activated photocatalytic oxidation coating
Introducing ultraviolet (UV) light to activate a photocatalytic oxidation coating applied to interior portions of footwear alters the environment inside a shoe or other footwear to destroy microorganisms or inhibit their growth. Visible light can also be used to prevent further microorganism growth. Introducing forced air flow through the footwear removes dampness in and thereby deodorizes the footwear. A preferred embodiment comprises an adjustable shoe tree equipped with a UV germicidal light source and electronic safeguards that prevent appreciable leakage of UV radiation outside the shoe.
1. Apparatus for sanitizing human footwear having an opening through which a person inserts his foot for placement inside a footwear interior region to put on the footwear, comprising:
a light source emitting radiation in a wavelength range that sanitizes the footwear by inhibiting growth of or destroying microorganisms present in the footwear interior region;
a hollow forepart shaped to pass through the opening in the footwear and fit inside the footwear interior region, the hollow forepart configured in the form of a skeletal structure that includes multiple windows;
a heel part positioned behind the hollow forepart and configured to deliver electrical power from a power source to activate the light source and generate emission of the radiation;
a support for the light source to set it in a sanitization position to direct the radiation through the multiple windows of the hollow forepart to the footwear interior region;
safety switch circuitry operable to prevent unwanted exposure to the radiation and operatively connected to a sensor, the safety switch circuitry enabling application of electrical power to the light source when there is no unwanted exposure to the radiation detected by the sensor; and
control circuitry providing a temporal operational sequence of sanitizing the footwear,
the control circuitry operatively connected to a user-actuated power-on control that initiates a preliminary period defined from user-actuation of the power-on control to activation of the light source, the preliminary period being of sufficient duration to ensure no unwanted exposure to the radiation, and
the control circuitry providing a specified operating time window during which the radiation sanitizes the footwear and being responsive to the safety switch circuitry to deactivate the light source upon detection, within the specified operating time window, of unwanted exposure to the radiation.
2. The apparatus of claim 1 , further comprising an ambient light sensor configured for placement within the footwear interior region and operatively associated with the safety switch circuitry to detect a presence of light leakage into the footwear interior region and thereby cause nonactivation of the light source to inhibit radiation emission.
3. The apparatus of claim 1 , in which the footwear interior region has surfaces to which a photocatalytic oxidation coating comprising titanium dioxide has been applied, and in which the wavelength range of radiation emitted by the light source activates the titanium dioxide.
4. The apparatus of claim 1 , in which the footwear interior region has surfaces to which a liquid photocatalytic oxidation coating has been applied, and in which the wavelength range of radiation emitted by the light source activates the photocatalytic oxidation coating.
5. The apparatus of claim 1 , in which the footwear interior region has surfaces to which an aerosol photocatalytic oxidation coating has been applied, and in which the wavelength range of radiation emitted by the light source activates the photocatalytic oxidation coating.
6. The apparatus of claim 1 , in which the light source emits ultraviolet (UV) light.
7. The apparatus of claim 1 , in which the light source emits visible light.
8. The apparatus of claim 1 , in which the light source includes a light-emitting diode (LED).
9. The apparatus of claim 1 , further comprising a blower fan producing forced air output and positioned in fluid communication with the hollow forepart to direct the forced air output through the multiple windows to dry the footwear interior region.
10. The apparatus of claim 1 , in which the hollow forepart contains component parts having outer surfaces located in proximity to the light source, and in which the outer surfaces of the component parts are coated with titanium dioxide.
11. The apparatus of claim 1 , further comprising a material in which a scent is incorporated.
12. The apparatus of claim 11 , in which the scent is carried by a solid material.
13. The apparatus of claim 11 , in which the scent is carried by a liquid material.
14. The apparatus of claim 1 , in which the sensor is a light sensing device.
15. The apparatus of claim 14 , in which the light sensing device comprises an infrared detector.
16. The apparatus of claim 14 , in which the light sensing device comprises a CCD.
17. The apparatus of claim 1 , in which the sensor is a motion detecting device.