Arrangement for improving visual detection of painted areas relative to surrounding material

Claim 1

A method for improving detectability of a predetermined area on a surface surrounded by surfaces that may contain specular reflecting regions, comprising the steps of: coating a predetermined area on a surface with material radiating energy in a frequency band other that that of a radiation source when irradiated by said source; irradiating said surface with said radiation source; imaging a first predetermined portion of reflected and reradiated energy from said surface onto an image detection surface after passing through a first filter having low attenuation in a frequency band of radiation from said predetermined area coating and high attenuation at least in the frequency band of said radiation source; imaging a second predetermined portion of reflected and reradiated energy from said surface onto an image detection surface after passing through a second filter having low attenuation for all frequencies except those of the radiation band of the coating; subtracting the second detected image from the first detected image and forming a difference image; and automatically detecting said predetermined surface area by said difference image; said two filters being in operation at the same frequency whereby one filter is a band pass filter and the other filter is a band reject filter, so that uncertainty is prevented due to unknown selectivity of reflectance of surfaces as wavelength is changed, said predetermined surface area being detected independent of any absorption band present in said radiation source.

Claim 2

A method for improving detectability of a predetermined area on a surface surrounded by surfaces that may contain specular reflecting regions, comprising the steps of: coating a predetermined area on a surface with material radiating energy in a frequency band other that that of a radiation source when irradiated by said source; irradiating said surface with said radiation source; imaging a first predetermined portion of reflected and reradiated energy from said surface onto an image detection surface after passing through a first filter having low attenuation in a frequency band of radiation from said predetermined area coating and high attenuation at least in the frequency band of said radiation source; imaging a second predetermined portion of reflected and reradiated energy from said surface onto an image detection surface after passing through a second filter having low attenuation for all frequencies except those of the radiation band of the coating; subtracting the second detected image from the first detected image and forming a difference image; and automatically detecting said predetermined surface area by said difference image; said two filters being in operation at the same frequency whereby one filter is a band pass filter and the other filter is a band reject filter, so that uncertainty is prevented due to unknown selectivity of reflectance of surfaces as wavelength is changed, said predetermined surface area being detected independent of any absorption band present in said radiation source.

Claim 9

A method for automatically detecting energy reflected from a predetermined area on a surface comprising the steps of: coating said predetermined area with a material having selective wavelength reflection characteristics, said material reflecting a narrow band of energy within a broadband radiation source, said narrow band forming a principal reflectance band; irradiating said surface with a broadband radiation source; imaging a portion of the reflected energy from said surface onto a first image detection surface after passing through a narrow bandpass filter having low attenuation at frequencies substantially encompassing said principal reflectance band of the coating, producing a first detected filtered image; imaging a portion of said reflected energy from said surface onto a second image detection surface after passing through a band reject filter having low attenuation for all frequencies except those of the principal reflectance band of the coating, producing a second detected filtered image; and comparing the detected outputs for automatically detecting said predetermined surface area.

Claim 10

A method for automatically detecting energy reflected from a predetermined area on a surface comprising the steps of: coating said predetermined area with a material having selective wavelength reflection characteristics, said material reflecting a narrow band of energy within a broadband radiation source, said narrow band forming a principal reflectance band; irradiating said surface with a broadband radiation source; imaging a portion of the reflected energy from said surface onto a first image detection surface after passing through a narrow bandpass filter having low attenuation at frequencies substantially encompassing said principal reflectance band of the coating, producing a first detected filtered image; imaging a portion of said reflected energy from said surface onto a second image detection surface after passing through a band reject filter having low attenuation for all frequencies except those of the principal reflectance band of the coating, producing a second detected filtered image; and comparing the detected outputs for automatically detecting said predetermined surface area.

Claim 13

A method for automatically detecting energy reflected from a predetermined area on a surface comprising the steps of: coating said predetermined area with a material having selective wavelength reflection characteristics, said material reflecting a narrow band of energy within a broadband radiation source, said narrow band forming a principal reflectance band; irradiating said surface with a broadband radiation source; imaging a portion of the reflected energy from said surface onto a suitable image detection surface after passing through a narrow bandpass filter having low attenuation at frequencies substantially encompassing said principal reflectance band of the coating, producing a first detected filtered image; storing the data related to signal strength; imaging all reflected energy from said surface onto said image detection surface after passing through a band reject filter having low attenuation for all frequencies except those of the principal reflectance band of the coating, producing a second detected filtered image; and comparing the data related to signal strength with said stored data for automatically detecting said predetermined surface area.

Claim 14

A method for automatically detecting energy reflected from a predetermined area on a surface comprising the steps of: coating said predetermined area with a material having selective wavelength reflection characteristics, said material reflecting a narrow band of energy within a broadband radiation source, said narrow band forming a principal reflectance band; irradiating said surface with a broadband radiation source; imaging a portion of the reflected energy from said surface onto a suitable image detection surface after passing through a narrow bandpass filter having low attenuation at frequencies substantially encompassing said principal reflectance band of the coating, producing a first detected filtered image; storing the data related to signal strength; imaging all reflected energy from said surface onto said image detection surface after passing through a band reject filter having low attenuation for all frequencies except those of the principal reflectance band of the coating, producing a second detected filtered image; and comparing the data related to signal strength with said stored data for automatically detecting said predetermined surface area.

Claim 15

A method for improving the image contrast between the detected energy reflected from a predetermined area on a surface and the surrounding reflecting areas including specular reflecting areas, comprising the steps of: coating said predetermined area with a material having selective wavelength reflection characteristics, said material reflecting a narrow band of energy within a broadband radiation source, said narrow band forming a principal reflectance band; irradiating said surface with a broadband radiation source; imaging a portion of the reflected energy from said surface onto a first image detection surface after passing through a narrow bandpass filter having low attenuation at frequencies substantially encompassing said principal reflectance band of the coating, producing a first detected filtered image; and imaging at least a portion of the said reflected energy onto a suitable image detection surface after passing through a band-reject filter having low attenuation for all frequencies except those of the principal reflectance band of the coating, producing a second detected filtered image.

Claim 16

A method for improving the image contrast between the detected energy reflected from a predetermined area on a surface and the surrounding reflecting areas including specular reflecting areas, comprising the steps of: coating said predetermined area with a material having selective wavelength reflection characteristics, said material reflecting a narrow band of energy within a broadband radiation source, said narrow band forming a principal reflectance band; irradiating said surface with a broadband radiation source; imaging a portion of the reflected energy from said surface onto a first image detection surface after passing through a narrow bandpass filter having low attenuation at frequencies substantially encompassing said principal reflectance band of the coating, producing a first detected filtered image; and imaging at least a portion of the said reflected energy onto a suitable image detection surface after passing through a band-reject filter having low attenuation for all frequencies except those of the principal reflectance band of the coating, producing a second detected filtered image.

Claim 17

A method for automatically detecting energy reflected from a predetermined area on a surface comprising the steps of: coating said predetermined area with a material having selective wavelength reflection characteristics, said material reflecting a narrow band of energy within a broadband radiation source, said narrow band forming a principal reflectance band; irradiating said surface with a broadband radiation source; imaging all reflected energy from said surface onto a suitable image detection surface after passing through a narrow bandpass filter having low attenuation at frequencies substantially encompassing said principal reflectance band of the coating, producing a first detected filtered image; storing the data related to signal strength; imaging all reflected energy from said surface onto said image detection surface after passing through a band reject filter having a low attenuation for all frequencies except those of the principal reflectance band of the coating, producing a second detected filtered image; comparing the data related to signal strength with said stored data for automatically detecting said predetermined surface area; and indicating said predetermined surface to be present only where the signal derived from the energy filtered by the band pass filter is greater than the signal derived from the energy filtered by the band reject filter.

Claim 18

A method for automatically detecting energy reflected from a predetermined area on a surface comprising the steps of: coating said predetermined area with a material having selective wavelength reflection characteristics, said material reflecting a narrow band of energy within a broadband radiation source, said narrow band forming a principal reflectance band; irradiating said surface with a broadband radiation source; imaging all reflected energy from said surface onto a suitable image detection surface after passing through a narrow bandpass filter having low attenuation at frequencies substantially encompassing said principal reflectance band of the coating, producing a first detected filtered image; storing the data related to signal strength; imaging all reflected energy from said surface onto said image detection surface after passing through a band reject filter having a low attenuation for all frequencies except those of the principal reflectance band of the coating, producing a second detected filtered image; comparing the data related to signal strength with said stored data for automatically detecting said predetermined surface area; and indicating said predetermined surface to be present only where the signal derived from the energy filtered by the band pass filter is greater than the signal derived from the energy filtered by the band reject filter.