Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
228 words
A process for the readout of coded symbols, the code being represented by the absence or presence in at least one level of photoluminescent materials which luminesce under ultraviolet illumination and which therefore permit a choice of symbols represented by Xn-1, where X is one more than the levels at which the components may be present, which comprises, a. illuminating a marking area containing the coded symbol with brief flashes of short wave radiation, b. optically imaging photoluminescence from the marking area onto at least one detector, transforming radiation striking the detector into an electrical signal, c. sequentially limiting radiation to the detector to that of a single code component, d. starting electrical readout by the occurrence of two signals, one in synchronism with sequential limitation of the whole number of different components and the second the first electrical signal from the detector above a predetermined low level, e. amplifying the signals from the detector in separate channels sequentially, the channel amplifying only the signals corresponding to its component, f. temporarily storing the amplified signals from each channel, and g. decoding the stored signals after a full sequence into forms corresponding to the symbols represented by the code and of suitable nAture for initiating at least one operation selected from the group consisting of visual display, printout, and other logical operations requiring the same type of electrical signal.
Claim 2
Dependent Claim
228 words
A process for the readout of coded symbols, the code being represented by the absence or presence in at least one level of photoluminescent materials which luminesce under ultraviolet illumination and which therefore permit a choice of symbols represented by Xn-1, where X is one more than the levels at which the components may be present, which comprises, a. illuminating a marking area containing the coded symbol with brief flashes of short wave radiation, b. optically imaging photoluminescence from the marking area onto at least one detector, transforming radiation striking the detector into an electrical signal, c. sequentially limiting radiation to the detector to that of a single code component, d. starting electrical readout by the occurrence of two signals, one in synchronism with sequential limitation of the whole number of different components and the second the first electrical signal from the detector above a predetermined low level, e. amplifying the signals from the detector in separate channels sequentially, the channel amplifying only the signals corresponding to its component, f. temporarily storing the amplified signals from each channel, and g. decoding the stored signals after a full sequence into forms corresponding to the symbols represented by the code and of suitable nAture for initiating at least one operation selected from the group consisting of visual display, printout, and other logical operations requiring the same type of electrical signal.
Claim 3
Dependent Claim
29 words
A process according to claim 1 in which the code is represented by the presence or absence of a photoluminescent component and the choice of symbols is, therefore, 2n-1.
Claim 4
Dependent Claim
59 words
A process according to claim 2 in which the components of the code have multimicrosecond decay half-lives and storage of the signals from the detectors takes place after a delay less than the decay half-life of the component but much longer than the decay half-life of organic fluorescers which have decay half-lives of a small fraction of a microsecond.
Claim 5
Dependent Claim
53 words
A process according to claim 3 in which there is a single detector and the sequential irradiation in the wavelength ranges of the photoluminescence of the different components is effected by filtering out luminescence in wavelength ranges outside that of the particular detector components the luminescence from which is to irradiate the detector.
Claim 6
Dependent Claim
27 words
A process according to claim 4 in which the photoluminescent components of the code are complexes containing different lanthanide ions having an atomic number greater than 57.
Claim 7
Dependent Claim
345 words
An apparatus for carrying out the process of claim 4 comprising in combination, a. a short-duration, intense, gaseous-discharge flash tube provided with a filter passing ultraviolet light but substantially opaque to visible light, b. means for imaging flashes from the flash tube onto the plane of a marking area containing a coded symbol, c. a single detector responsive to longer wave radiation at least through the visible range, d. means for imaging radiation from the marking area corresponding to coded components therein onto the detector, e. a filter wheel and means for rotating it, the wheel being located to interpose successive filters in the luminescent radiation, each filter passing a wavelength band including the wavelength range of only a single component, f. means driven in synchronism with the filter wheel to trigger flashes from the flash tube each time a filter is interposed in the luminescence beam, g. a plurality of electronic amplifying and processing circuits receiving inputs from the photodetector, the number of channels being equal to the number of components, h. means operated in synchronism with the filter wheel to open the electronic circuits for a single channel only each time a particular filter is interposed in the luminescence radiation, i. a plurality of temporary electronic signal storage means equal in number to the channels and responsive to input signals of at least one level, means for connecting the output of each channel to one of the electronic signal storage means, j. electronic decoding means for transforming stored signals into separate signals corresponding to particular coded symbols represented by one or more photoluminescent components, and k. means for initiating actuation of a full sequence of channels representing a full revolution of the filter wheel, said means being operated in synchronism with the filter wheel and including means controlled by the first filter receiving luminescence radiation to produce a signal from the photodetector of predetermined level and means for resetting the electronic circuits actuated by a full revolution of the filter wheel during which no signals of predetermined level are produced from any component.
Claim 8
Dependent Claim
52 words
An apparatus according to claim 6 in which the electronic processing circuits include an electronic time delay less than the half-life decay of photoluminescence from any components but more than a microsecond whereby very short life luminescence from organic fluorescent material, such as optical brighteners, do not reach the electronic signal storage.
Claim 9
Dependent Claim
53 words
An apparatus according to claim 7 in which the flash tube is movable to one of at least two positions and optical means moved by the same movement to image the flashes from the flash tube onto substrates at different distances and to image luminescent radiation from these different distances onto the photodetector.
Claim 10
Dependent Claim
14 words
An apparatus according to claim 8 in which the photodetector is a photomultiplier tube.
Claim 11
Dependent Claim
14 words
An apparatus according to claim 7 in which the photodetector is a photomultiplier tube.