A high-reliability invisible ink printing system (10) is provided which generates high-definition, lightfast images (210) that are easily read or otherwise detected using far red, infrared and/or ultraviolet light. The inks (32) contain an uncomplexed invisible metal phthalocyanine far red/infrared fluorophore (optimally chloroaluminum [III] phthalocyanine tetrasulfonic acid or salts thereof). An ultraviolet fluorophore can also be included. The inks (32) are invisible to the unaided eye. However, when exposed to far red or infrared light (wavelength = about 650 - 715 nm) they will fluoresce at a wavelength of about 670 - 720 nm. If an ultraviolet fluorophore is employed, the inks (32) can also be detected by applying ultraviolet light (wavelength = about 250 - 380 nm) which results in fluorescent emission at a wavelength of about 400 - 650 nm. The inks (32) are well suited for delivery using inkjet technology to efficiently form invisible images (210).
提供了一种高可靠性的隐形油墨印刷系统(10),该系统可生成高清晰度、光速快的图像(210),这些图像很容易用远红外线、红外线和/或紫外线读取或检测。油墨(32)含有未络合的隐形
金属
酞菁远红外/红外荧光体(最好是
氯铝[III]
酞菁四磺酸或其盐)。也可以包括紫外线荧光体。油墨(32)在肉眼下是不可见的。然而,当暴露在远红光或红外光(波长约为 650 - 715 纳米)下时,它们会在波长约为 670 - 720 纳米处发出荧光。如果使用紫外线荧光团,还可以通过紫外线(波长 = 约 250 - 380 nm)检测油墨(32),紫外线会在波长约 400 - 650 nm 处发出荧光。墨
水(32)非常适合于使用喷墨技术传送,以有效地形成不可见图像(210)。