Yupo Corporation

Oji Yuka Goseishi Co., Ltd.

Hiroshi Koyama

Takahiko Ueda

Tomotsugu Takahashi

Akihiko Ohno

Harumitsu Asazuma

Tamio Shikano

Atsushi Ishige

Koichi Asami

Haruto Nagakusa

A light reflector including a multilayer film wherein the multilayer film includes a substrate layer and an emission line preventing layer including a scale-like light reflecting section, and the reflection angle light quantity ratio is from 1.5 to 6.5. The light reflector is capable of preventing generation of emission lines when it is incorporated in a planar light source device or an illuminating device.

Light reflector, and planar light source device and illuminating device using the light reflector

A light reflector of which the bidirectional reflectance Ris from 90 to 120% when the light entrance angle is 15&#xb0; and the light acceptance angle is 0&#xb0;, and the bidirectional reflectance Ris from 85 to 110% when the light entrance angle is 75&#xb0; and the light acceptance angle is 0&#xb0;. The light reflector has high reflectivity, and attains brightness improvement even in underlight-type backlights.

Light reflector and planar light source device

A light reflector comprising a resin film having a reflection angle peak ratio [i.e. (reflection peak value when a light ray is applied at an angle of 45&#xb0; to the perpendicular line of the reflection surface)/(reflection peak value when a light ray is applied at an angle of 15&#xb0; to the perpendicular line of the reflection surface)] of from 1.3 to 10, and a specular reflectance [i.e. (reflectance)&#x2212;(diffuse reflectance)] of from 1.4% to 10%. This light reflector can prevent generation of a bright line even when it is used in an illumination device having a plurality of light sources.

Light reflector, planar light source and illumination device using the same

A light reflector including a laminate film having a light-diffusive layer on one surface of a substrate layer, wherein the surface roughness index of the light-reflective surface is at least 1, the reflectance thereof is at least 95%, and the regular reflectance thereof is at most 3%. The light reflector has higher brightness and higher reflectivity.

Disclosed is a light reflector formed of a white polyolefin film which contains a polyolefin resin and a filler and is oriented at least monoaxially to have an areal draw ratio of from 1.3 to 80 times, which has a whole ray reflectance of at least 95% and undergoes a dimensional change of at most 1.5% when left at 70&#xb0; C. for 300 hours, and which has a melting-starting temperature of 70&#xb0; C. or higher. The light reflector hardly causes brightness unevenness of the planar light source when it is built in a planar light source device and used for a long period of time.

Optical reflector and planar light source device

Disclosed is a semitransparent reflector having a whole light transmittance (T) of 10-80%, a whole light reflectance (R) of 20-90%, (T+R) of 80-100%, and (R&#x2212;Rd) of 8-30% in which Ris the whole light diffusion reflectance. When installed in a display device, the semitransparent reflector ensures efficient light transmission and reflection, and attains a high transmittance and a high reflectance of the display device, therefore significantly improving the letter visibility of the device.

Semitransparent reflector

An optically semi-transmission reflection material comprises a resinous film comprising a thermoplastic resin, wherein the sum of total light ray transmittance, T %, and total light ray reflectance, R %, i.e., T+R, is 80 to 100%; an absolute value of their difference is |(T&#x2212;R)|&#x3c;50% when displayed value a and displayed value b in transmitted light are designated as aand b, respectively, and when in reflected light, displayed value b is designated as b, in the transmitted light, aand bare in the range of &#x2212;2&#x2266;a&#x2266;2, and &#x2212;2&#x2266;b&#x2266;1.3 and the difference between the displayed value b to the transmitted light and the reflected light is |(b&#x2212;b)|&#x3c;10.

Optically semi-transmission reflection material

Provided is a planar light source device, which comprises a light guide having at least one side end serving as a light incident side and having one surface serving as a light-emitting side, a light source disposed in the vicinity of the side end of the light guide, and a light reflector disposed on the other side opposite to the light-emitting side, and which is characterized in that the light guide is essentially formed of a polyolefin resin, the light reflector is also essentially formed of a polyolefin resin, and when a piece of the light reflector having a face size of 1.5 cm&#xd7;1.5 cm is prepared, and it is pressed against the surface of the light guide with its reflective face being in contact with the surface of the light guide under a load of 135 g/cmthereto, and, in that condition, when it is reciprocated 10 times on the surface of the light guide to a width of 5 cm every time at a speed of 2.5 cm/sec, then the surface of the light guide is not substantially scratched by it. The planar light source device is characterized in that the light guide therein is hardly scratched and the device is lightweight.

Planar light source device and liquid-crystal display device

A light reflector formed of a biaxially-stretched film which contains a thermoplastic resin and a filler and has an opacity of at least 95%, a whiteness of at least 90%, a reflectance Rof at least 92%, and an areal draw ratio of from 22 to 80 times, wherein the color difference &#x394;E, after irradiated with a metal halide lamp spaced from the light reflector by 10 cm under an environmental condition of 83&#xb0; C. and a relative humidity of 50% and at an intensity of radiation of 90 mW/cmfor 10 hours, is at most 10. The reflector is free from the trouble of yellowing as in white polyester films heretofore used in reflectors and is stable against color change for a long period of time.

Light reflector

A support which contains a base layer (B) composed of a biaxially stretched film of a thermoplastic resin containing an inorganic fine powder; and a surface layer (A) provided at least on one side of such base layer (B), which is composed of a biaxially stretched film of a thermoplastic resin having a three dimensional center plane average roughness of about 0.3 &mgr;m or below and a 60 degrees surface glossiness of about 80% or above is disclosed. A thermal transfer image-recording material using such support can produce a clear image having an excellent glossiness and no external waviness.

Support and thermal transfer image-recording material

A light reflector comprising a biaxially stretched film containing a polyolefinic resin and a filler, wherein said filler is an inorganic filler having an average grain size of 0.1 to 8 &mgr;m and/or an organic filler having a mean dispersion grain size of 0.1 to 8 &mgr;m, and said biaxially stretched film has an area stretched factor of 16 to 80, and having a luminance of 1,200 cd/m or above is disclosed. A specific feature of such light reflector of the present invention resides in that improvement in the luminance achieved at low cost is ascribable to the structural feature thereof rather than to the composition.

An illuminated sign board which comprises a film having printing, a frame, and a light source is described. The film is a semi-transparent film made of a stretched resin film containing a finely divided powder of a white inorganic material. The semi-transparent film satisfies the following requirements (1) to (4):

Illuminated signboard

A synthetic paper with a multi-layer structure comprising a biaxially stretched film of an olefinic polymer having a melting point (the peak temperature of the DSC curve) of from 130.degree. C. to 210.degree. C. containing from 5 to 40% by weight inorganic fine powders having a mean particle size of from 0.01 to 10 .mu.m as a base material layer (A) having adhered to at least one surface thereof a uniaxially stretched layer (B) having a surface roughness of from 0.3 to 1.5 .mu.m, with the uniaxially stretched layer (B) comprising a propylene .alpha.-olefin copolymer or a high-density polyethylene having a melting point (the peak temperature of the DSC curve) of from 120.degree. C. to 160.degree. C. which is at least 5.degree. C. lower than the melting point of the olefinic polymer of the base material layer (A) and from 8 to 65% by weight inorganic fine powders having a mean particle size of from 0.01 to 5 .mu.m, wherein the surfaces of the inorganic fine powders contained in the uniaxially stretched layer (B) are coated with the propylene .alpha.-olefin copolymer or the high-density polyethylene.

Synthetic paper with multi-layer structure and excellent printing

A thermal recording material comprising (1) a synthetic paper support having on one side thereof (2) a thermal color forming layer, the support comprising (B) a biaxially stretched resin film as a base layer having (A) a uniaxially stretched thermoplastic resin film containing from 1 to 8% by weight calcium carbonate powder as a calcium carbon powder containing layer on one side thereof, and (C) a uniaxially stretched thermoplastic resin film containing from 15 to 55% by weight inorganic fine powder as a back surface layer on the other side thereof, the thermal color forming layer being provided on the calcium carbon powder containing layer (A), in which (i) the support has an opacity of not more than 45% as measured according to JIS P-8138, (ii) the calcium carbon powder containing layer (A) has a Bekk's index of from 1,000 to 3,500 seconds and a center-line average roughness (Ra) of not more than 0.5 .mu.m, (iii) the back surface layer (C) has a Bekk's index of from 100 to 900 seconds and a center-line average roughness (Ra) of from 0.6 to 1 .mu.m, and (iv) the support has a density of from 0.91 to 1.1 g/cm.sup.3 as measured according to JIS P-8118. The thermal recording material has improved image definition, including dot reproducibility, is suitable for diazo copying and high-speed printing, and can be written on with a pencil.

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Ibaraki, Japan

Hiroshi Koyama