1. A photosensitive composition comprising:
(a) an infrared absorbing agent represented by the following formula (I); and
(b) a polymer compound which is insoluble in water and soluble in an aqueous alkali solution, wherein;
the solubility of the photosensitive composition in an aqueous alkali solution is changed by radiation of an infrared laser;
wherein X1 and X2 independently represent \u2014CR7R8\u2014,\u2014S\u2014, \u2014Se\u2014, \u2014NR9\u2014, \u2014CH\u2550CH\u2014 or \u2014O\u2014R1 and R2 independently represent an alkyl group having 9to 30 carbon atoms, R3, R4, R5 and R6 independently represent a hydrogen atom or an alkyl group having 1 to 10 carbon atoms and may represent a plurality of atoms required for R3 and R4 or R5 and R6 to be combined with each other to form an aliphatic 5- or 6-membered ring, an aromatic 6-membered ring, an aromatic 10-membered ring, a substituted aromatic 6-membered ring or a substituted aromatic 10-membered ring, R7 and R8 independently represent an alkyl group having 1 to 18 carbon atoms or an aryl group having 6 to 18 carbon atoms, R9 represents an alkyl group having 1 to 18 carbon atoms oran aryl group having 6 to 18 carbon atoms, Z represents a heptamethine group which may have a substituent wherein the substituent is an alkyl group having 8 or less carbon atoms, a halogen atom or an amino group and the heptamethine group may include a cyclohexene ring or a cyclopentene ring which is formed by combining substituents on two methine carbons with each other and which may have a substituent where the substituent on the ring structure is selected from an alkyl group having 6 or less carbon atoms or a halogen atom and Q represents a counter ion.
2. A photosensitive composition according to claim 1, wherein the counter ion Q of the infrared absorbing agent represented by said formula (I) is represented by the following formula (III);
A\u2014(Y)\u0398\u2003\u2003(III)
wherein A represents an atom selected from the group consisting of B, P, As, Sb, Cl and Br, Y represents a halogen atom or an oxygen atom and m denotes an integer from 1 to 6.
3. A photosensitive composition according to claim 1, wherein the counter ion Q of the infrared absorbing agent represented by said formula (I) is a counter ion having a sulfonic acid structure.
4. A photosensitive composition according to claim 1, wherein said aqueous alkali solution-soluble polymer compound has an acid group structure on the principal chain or side chain thereof.
5. A photosensitive composition according to claim 1, wherein said acid group structure includes a phenolic hydroxyl group, a sulfonamide group and an activated imide group.
6. A photosensitive composition according to claim 1, wherein the infrared absorbing agent is added in a proportion of 0.01 to 50% by weight based on the total solid of the photosensitive composition.
7. A planographic printing plate comprising a photosensitive layer consisting of the photosensitive composition as claimed in claim 1, the photosensitive layer being provided on a substrate.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for detecting trace evidence materials on a surface, comprising the steps of:
irradiating the surface with radiation from at least first and second lasers the first and second lasers emitting radiation at respectively first and second wavelengths selected to stimulate luminescence in the trace evidence materials, and the first and second wavelength radiations being delivered repeatedly and sequentially to the surface; and
observing the surface through an optical filter arranged to transmit the luminescence, and essentially block transmission of the first and second laser radiation wavelengths.
2. The method of claim 1, wherein the first and second wavelengths are characteristic absorption wavelengths of a particular trace evidence material being detected.
3. The method of claim 2, further including the step of adjusting the power of the first and second wavelength radiations such that the brightness of the luminescence from the particular trace evidence material stimulated by each of the first and second wavelength radiations is substantially similar.
4. The method of claim 3, wherein the luminescence stimulated by each of the first and second wavelength radiations is observed in monochrome.
5. The method of claim 3, wherein the particular trace evidence material is seminal fluid and the first and second wavelengths are respectively about 532 nm and about 460 nm.
6. The method of claim 2, wherein the filter transmits luminescence at wavelengths between the first and second wavelengths.
7. The method of claim 1, wherein the illumination periods are selected to be longer than the response time at which the human eye perceives intensity changes.
8. A method for detecting trace evidence materials on a surface, comprising the steps of:
irradiating the surface with radiation from at least first and second lasers the first and second lasers emitting radiation at respectively first and second wavelengths selected to stimulate luminescence in the trace materials; and
observing the surface through an optical filter arranged to transmit the luminescence, and essentially block transmission of the laser radiation wavelengths.
9. The method of claim 8, wherein the surface is simultaneously irradiated by the first and second wavelength laser radiations.
10. The method of claim 8, wherein the surface is repeatedly sequentially irradiated by the first and second wavelength laser radiations.
11. The method of claim 10, wherein the first and second wavelengths are characteristic absorption wavelengths of a particular trace evidence material being detected, the particular trace evidence materials having first and second absorption coefficients at respectively the first and second wavelengths.
12. The method of claim 11, further including the step of adjusting the power of the first and second wavelength radiations corresponding to the first and second absorption coefficients such that the brightness of the luminescence from the particular trace evidence material stimulated by each of the first and second wavelength radiations is substantially similar.
13. The method of claim 12, wherein the illumination periods are selected to be longer than the response time at which the human eye perceives intensity changes.
14. The method of claim 13, wherein the luminescence stimulated by each of the first and second wavelength radiations is observed in monochrome.
15. The method of claim 8, wherein the first wavelength is selected to stimulate luminescence in a first range of materials and the second wavelength is selected to stimulate luminescence in a second range of materials with one or more of the materials in the second range of materials not being included in the first range of materials.
16. An apparatus for detecting trace material on a surface comprising:
a first laser generating a first beam having a first wavelength;
a second laser generating a second beam having a second wavelength different from the first wavelength, with the intensity of both said beams being adjustable to elicit a substantially similar level of luminescence in a selected trace material of interest;
optics for combining the beams along a common path towards the surface;
a camera for detecting and displaying the luminescence response; and
means for sequentially and repeatedly activating the first and second lasers with the illumination periods being selected so that the selected trace material will appear substantially flicker free in the display while other trace materials will appear to flicker in the display.
17. An apparatus as recited in claim 16, wherein the first and second wavelengths are both in the visible spectrum.
18. An apparatus as recited in claim 16, further including an optical filter positioned in front of the camera for blocking radiation emitted in the wavelength ranges of the first and second lasers.
19. An apparatus as recited in claim 18, wherein said optical filter transmits luminescence at wavelength between the first and second wavelengths.