USRE39858EExpiredUtility

Infrared absorption filter

32
Assignee: TOYO BOSEKIPriority: May 15, 1998Filed: May 17, 1999Granted: Sep 25, 2007
Est. expiryMay 15, 2018(expired)· nominal 20-yr term from priority
Inventors:Tetsuo ShimomuraShinya OnomichiMasanori KobayashiYozo YamadaSeiichiro Yokoyama
G02B 5/208G02B 5/22
32
PatentIndex Score
2
Cited by
26
References
27
Claims

Abstract

The infrared absorption filter of the present invention has a transmittance of not higher than 30% in the near-infrared region in the wavelength range of 800 to 1100 nm; a difference of 10% or less between a maximum value and a minimum value of transmittance in the visible light region in the wavelength range of 450 to 650 nm; and a transmittance of not lower than 50% at a wavelength of 550 nm, the filter being so excellent in environmental stability that after being left to stand in the air atmosphere at a temperature of 60° C. and a humidity of 95% for 1000 hours, the filter can maintain said spectral property in said range. Consequently, when used for a plasma display or the like, the filter can absorb the unwanted infrared rays radiated from the display, resulting in preventing erroneous operation of a remote control using infrared radiation even in such a high-temperature and high-humidity environment. The filter is gray in color so that when placed in front of a display, the color originated in the display can be seen without discoloration.

Claims

exact text as granted — not AI-modified
1. An infrared absorption filter which has a transmittance of not higher than 30% in the near-infrared region in the wavelength range of 800 to 1100 nm;
 a difference of 10% or less between a maximum value and a minimum value of transmittance in the visible light region in the wavelength range of 450 to 650 nm; and  
 a transmittance of not lower than 50% at a wavelength of 550 nm,  
 said filter, after being left to stand in the air atmosphere at a temperature of 60° C. and a humidity of 95% for 1000 hours, having  
 a transmittance of not higher than 30% in the near-infrared region in the wavelength range of 800 to 1100 nm, and  
 a difference of 10% or less between a maximum value and a minimum value of transmittance in the visible light region in the wavelength range of 450 to 650 nm,  
 said filter having an infrared-absorbing layer on a transparent substrate,  
 the infrared-absorbing layer being composed of a coloring matter, dye or pigment absorbing infrared radiation and a polymer serving as a dispersing medium and  
 the transparent substrate having a total light transmittance of not lower than 89%, a haze of not higher than 1.6%, a coefficient of static friction of not higher than 0.6 and a coefficient of dynamic friction of not higher than 0.6.  
 
     
     
       2. The infrared absorption filter according to  claim 1 , wherein after being left to stand in the air atmosphere at a temperature of 80° C. for 1000 hours, the filter has a transmittance of not higher than 30% in the near-infrared region in the wavelength of 800 to 1100 nm and has a difference of 10% or less between a maximum value and a minimum value of transmittance in the visible light region in the wavelength of 450 to 650 nm. 
     
     
       3. The infrared absorption filter according to  claim 1 , wherein the amount of a solvent remaining in the infrared-absorbing layer is 5.0 wt. % or less. 
     
     
       4. The infrared absorption filter according to  claim 1 , wherein the transparent substrate is a polyester film. 
     
     
       5. The infrared absorption filter according to  claim 1 , wherein the polymer constituting the infrared-absorbing layer has a glass transition temperature of not lower than 80° C. 
     
     
       6. The infrared absorption filter according to  claim 5 , wherein the polymer constituting the infrared-absorbing layer is a polyester resin. 
     
     
       7. The infrared absorption filter according to  claim 1 , wherein the filter has an electroconductive layer of metal mesh having an aperture ratio of not less than 50% on the same side as the infrared-absorbing layer of the filter or on the opposed side thereof. 
     
     
       8. The infrared absorption filter according to  claim 1 , wherein the filter has a transparent electroconductive layer on the same side as the infrared-absorbing layer of the filter or on the opposed side thereof. 
     
     
       9. The infrared absorption filter according to  claim 8 , wherein the transparent electroconductive layer is formed of a metal oxide. 
     
     
       10. The infrared absorption filter according to  claim 8 , wherein the transparent electroconductive layer has a repeatedly laminated structure in which at least three layers are laminated in the order of metal oxide/metal/metal oxide. 
     
     
       11. The infrared absorption filter according to  claim 10 , wherein the constituent metal layer of the transparent electroconductive layer is formed of silver, gold or a compound containing any of them. 
     
     
       12. The infrared absorption filter according to  claim 1 , wherein a hard coat-treated layer is formed as an outermost layer of the filter. 
     
     
       13. The infrared absorption filter according to  claim 1 , wherein an antireflection layer is formed as an outermost layer of the filter. 
     
     
       14. The infrared absorption filter according to  claim 1 , wherein an antiglare-treated layer is formed as an outermost layer on the filter. 
     
     
       15. The infrared absorption filter according to  claim 1 , wherein the filter is disposed in front of a plasma display. 
     
     
       16. An infrared absorption filter which has a transmittance of not higher than  30 % in the near-infrared region in the wavelength range of  800  to  1100  nm;
 a difference of  10 % or less between a maximum value and a minimum value of transmittance in the visible light region in the wavelength range of  450  to  650  nm; and    a transmittance of not lower than  50 % at a wavelength of  550  nm,    said filter, after being left to stand in the air atmosphere at a temperature of  60 ° C. and a humidity of  95 % for  1000  hours, having    a transmittance of not higher than  30 % in the near-infrared region in the wavelength range of  800  to  1100  nm, and    a difference of  10 % or less between a maximum value and a minimum value of transmittance in the visible light region in the wavelength range of  450  to  650  nm,    said filter comprising a transparent substrate and an infrared-absorbing layer formed thereon,    the filter being prepared by coating the transparent substrate with a coating solution comprising an infrared-absorbing material, a binder resin and at least one solvent, and    the transparent substrate having a total light transmittance of not lower than  89 %, a haze of not higher than  1 . 6 %, a coefficient of static friction of not higher than  0 . 6  and a coefficient of dynamic friction of not higher than  0 . 6 .   
     
     
       17. The infrared absorption filter according to  claim 16 , wherein the amount of the solvent remaining in the infrared-absorbing layer is  5 . 0  wt. % or less. 
     
     
       18. The infrared absorption filter according to  claim 16 , wherein the transparent substrate is a polyester film. 
     
     
       19. The infrared absorption filter according to  claim 16 , wherein the filter has an electroconductive layer of metal mesh having an aperture ratio of not less than  50 % on the same side as the infrared-absorbing layer of the filter or on the opposed side thereof. 
     
     
       20. The infrared absorption filter according to  claim 16 , wherein the filter has a transparent electroconductive layer on the same side as the infrared- absorbing layer of the filter or on the opposed side thereof.   
     
     
       21. The infrared absorption filter according to  claim 20 , wherein the transparent electroconductive layer is formed of a metal oxide. 
     
     
       22. The infrared absorption filter according to  claim 20 , wherein the transparent electroconductive layer has a repeatedly laminated structure in which at least three layers are laminated in the order of metal oxide/metal/metal oxide. 
     
     
       23. The infrared absorption filter according to  claim 20 , wherein the constituent metal layer of the transparent electroconductive layer is formed of silver, gold or a compound containing any of them. 
     
     
       24. The infrared absorption filter according to  claim 16 , wherein a hard coat-treated layer is formed as an outermost layer of the filter. 
     
     
       25. The infrared absorption filter according to  claim 16 , wherein an antireflection layer is formed as an outermost layer of the filter. 
     
     
       26. The infrared absorption filter according to  claim 16 , wherein an antiglare-treated layer is formed as an outermost layer of the filter.  
     
     
       27. The infrared absorption filter according to  claim 16 , wherein the filter is disposed in front of a plasma display.

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