throbber
(11) Japanese Unexamined Patent Application Publication No.
`6-003526
`(43) Publication Date: January 14, 1994
`(21) Application No. 4-159403
`(22) Application Date: June 18, 1992
`(71) Applicant: Fujitsu Limited
`(72) Inventor: Nagatani et al.
`(74) Agent: Patent Attorney, Aoki et al.
`
`(54) [Title of the Invention] ILLUMINATION APPARATUS
`
`(57) [Abstract]
` [Object] An object of the invention, which relates to an
`illumination apparatus, is to provide a plane illumination
`apparatus that realizes high brightness and high
`productivity.
` [Construction] An illumination apparatus at least
`includes a light-guiding plate 11 and a light source 12
`provided along and next to a side edge of the light-guiding
`plate. The apparatus is characterized in that, a light-
`diffusing plate 21 is provided on an outgoing-light emission
`surface of the light-guiding plate 11; a concave portion 14
`having a substantially triangular cross-sectional shape is
`formed in an opposite surface of the light-guiding plate 11
`as a line pattern or a dot pattern; a transparent layer 16
`
`- 1 -
`
`Sony Corp. Exhibit 1020
`
`SONY_000750
`
`

`
`is formed on the opposite surface of the light-guiding plate
`11, in which the concave portion 14 is formed, by using a
`material that has an index of refraction that is greater
`than that of the light-guiding plate 11, said transparent
`layer being formed in such a way that the concave portion 14
`is filled in by said material; and a reflection sheet 18 is
`either provided on or formed integrally on an outer surface
`of the transparent layer 16.
`
`- 2 -
`
`SONY_000751
`
`

`
`[Claims]
`[Claim 1] An illumination apparatus that at least includes
`a light-guiding plate (11) and a light source (12) that is
`provided along and next to a side edge of the light-guiding
`plate,
`
`characterized in that,
`
`a light-diffusing plate (21) is provided on an
`outgoing-light emission surface of the light-guiding plate
`(11);
`
`a concave portion (14) that has a substantially
`triangular cross-sectional shape is formed in an opposite
`surface of the light-guiding plate (11) as a line pattern or
`a dot pattern;
`
`a transparent layer (16) is formed on the opposite
`surface of the light-guiding plate (11), in which the
`concave portion (14) is formed, by using a material that has
`an index of refraction that is greater than an index of
`refraction of the light-guiding plate (11), said transparent
`layer being formed in such a way that the concave portion
`(14) is filled in by said material; and
`
`a reflection sheet (18) is either provided on or formed
`integrally on an outer surface of the transparent layer (16).
`[Claim 2] An illumination apparatus that at least includes
`a light-guiding plate (11) and a light source (12) that is
`provided along and next to a side edge of the light-guiding
`
`- 3 -
`
`SONY_000752
`
`

`
`plate,
`
`characterized in that,
`
`a concave portion (34) that has a substantially
`triangular cross-sectional shape is formed in an outgoing-
`light emission surface of the light-guiding plate (11) as a
`line pattern or a dot pattern;
`
`a transparent layer (36) is formed on the outgoing-
`light emission surface of the light-guiding plate (11) by
`using a material that has an index of refraction that is
`greater than an index of refraction of the light-guiding
`plate (11), said transparent layer being formed in such a
`way that the concave portion (34) is filled in by said
`material;
`
`a light-diffusing plate (38) is provided on an outer
`surface of the transparent layer (36); and
`
`a reflection sheet (32) is provided on an opposite
`surface of the light-guiding plate (11).
`[Claim 3] An illumination apparatus that at least includes
`a light-guiding plate (11) and a light source (12) that is
`provided along and next to a side edge of the light-guiding
`plate,
`
`characterized in that,
`
`a concave portion (34) that has a substantially
`triangular cross-sectional shape is formed in an outgoing-
`light emission surface of the light-guiding plate (11) as a
`
`- 4 -
`
`SONY_000753
`
`

`
`line pattern or a dot pattern;
`
`a transparent layer (36) is formed on the outgoing-
`light emission surface of the light-guiding plate (11) by
`using a material that has an index of refraction that is
`greater than an index of refraction of the light-guiding
`plate (11), said transparent layer being formed in such a
`way that the concave portion (34) is filled in by said
`material;
`
`a light-diffusing plate (38) is provided on an outer
`surface of the transparent layer (36);
`
`a concave portion (14) that has a substantially
`triangular cross-sectional shape is formed in an opposite
`surface of the light-guiding plate (11) as a line pattern or
`a dot pattern;
`
`a transparent layer (16) is formed on the opposite
`surface of the light-guiding plate (11), in which the
`concave portion (14) is formed, by using a material that has
`an index of refraction that is greater than an index of
`refraction of the light-guiding plate (11), said transparent
`layer being formed in such a way that the concave portion
`(14) is filled in by said material; and
`
`a reflection sheet (18) is either provided on or formed
`integrally on an outer surface of the transparent layer (16).
`[Claim 4] The illumination apparatus according to any of
`Claims 1, 2, and 3, further characterized in that either one
`
`- 5 -
`
`SONY_000754
`
`

`
`of two surfaces each having the largest area size among
`surfaces of the light-guiding plate (11) is, or both of said
`two surfaces are, sloped.
`[Claim 5] A liquid crystal display device, characterized by
`being assembled as a combination of the illumination
`apparatus (40) according to any of Claims 1, 2, 3, and 4 and
`a liquid crystal panel (41).
`[Detailed Description of the Invention]
`[0001]
`[Field of Industrial Application] The present invention
`relates to a plane illumination apparatus used for enhancing
`the display viewability of a display device such as a liquid
`crystal display device.
`[0002]
`
`Two popular types of plane illumination apparatuses are
`a direct lighting type, which is for illumination from below,
`and an edge-light type (light-guiding type). In an edge-
`light-type plane illumination apparatus, a diffusing
`reflection layer is formed on its back to cause light to go
`out. For the purpose of obtaining uniform brightness
`distribution throughout the area of a plane for light
`emission, in such a plane illumination apparatus, a light-
`diffusing reflection portion is formed in a dot pattern, a
`mesh pattern, etc. that has area-size percentage
`corresponding to a distance from a light source. The ratio
`
`- 6 -
`
`SONY_000755
`
`

`
`of the diffusing reflection portion to a non-diffusing
`reflection portion, that is, the percentage of a diffusing
`reflection amount, is pre-designed for realizing uniform
`brightness distribution irrespective of a position on the
`light emission plane.
`[0003]
`
`In prior art, a paint containing white pigments or a
`paint containing glass beads is used to form such a
`diffusing reflection layer by printing. Optical diffusion
`occurs due to the light-diffusing effects of the diffusing
`reflection layer, and light that propagates while meeting
`the conditions of total reflection, that is, perfect
`internal reflection, fails to meet said conditions due to
`the diffusion and, as a result, is taken out as outgoing
`light. To meet an increasing demand for an apparatus having
`a low-profile body, a light-guiding plate has recently been
`becoming thinner and thinner, as a component of the entire
`body structure. In the art, the lack of uniformity in
`brightness appears conspicuously on the light emission plane
`of a plane illumination apparatus due to an error in the
`percentage of area size, which is caused by the lack of
`precision in printing. In order to obtain a plane
`illumination apparatus that has excellent plane illumination
`characteristics, high-precision print technology is required.
`In the art, this is an obstacle to improved productivity and
`
`- 7 -
`
`SONY_000756
`
`

`
`low cost.
`[0004]
`
`Moreover, for the purpose of increasing brightness, it
`is necessary to improve the optical characteristics of each
`portion. For example, for this purpose, it is necessary to
`improve a reflection factor and a transmission factor.
`Improved optical characteristics are required for the
`diffusing reflection layer mentioned above, too. That is,
`the development of a novel means for increasing brightness
`is awaited.
`[0005]
`[Description of the Related Art] The structure of an edge-
`light-type illumination apparatus according to prior art is
`illustrated in Fig. 9. In this drawing, the reference
`numeral 1 denotes a light-guiding plate. The light-guiding
`plate 1 is mainly made of transparent acrylic resin. A
`diffusing reflection layer 2, which has dots 2a as
`illustrated in Fig. 9(b), is formed on the reverse surface
`of the light-guiding plate 1. Each of the dots 2a is
`printed with the use of a paint having light-diffusing
`property such as a light-diffusing white paint. The method
`of screen printing, etc. is used for dot printing. As
`illustrated in Fig. 9(a), a reflector plate is provided on
`the diffusing reflection layer 2. On the opposite surface
`of the light-guiding plate 1, a diffusing plate 4 is
`
`- 8 -
`
`SONY_000757
`
`

`
`provided.
`[0006]
`
`The reference numeral 5 denotes a light source (light
`sources) using a fluorescent tube. For the purpose of
`causing light emitted from the light source 5 to go into the
`light-guiding plate 1 efficiently, a reflection cover 6,
`which is made of Al, Ag, or the like, is provided around the
`light source 5. The reflection cover 6 reflects light
`emitted from the light source 5 in such a way as to condense
`the emitted light onto an end face of the light-guiding
`plate 1. The condensed light goes into the light-guiding
`plate 1 as incident light. By the law of total reflection,
`the light having gone into the light-guiding plate 1
`propagates inside the light-guiding plate 1 within a
`critical angle. The propagation light does not turn into
`outgoing light, which goes out of the light-guiding plate 1,
`until a failure to meet the conditions of total reflection
`occurs. Due to the diffused reflection of the propagation
`light by the diffusing reflection layer 2 explained above,
`this failure occurs, and the propagation light turns into
`outgoing light.
`[0007]
`
`When going out, the outgoing light is further diffused
`at the diffusing plate 4, which enhances uniformity in
`brightness for use as plane illumination light. At the
`
`- 9 -
`
`SONY_000758
`
`

`
`reverse-surface side of the light-guiding plate 1, the
`reflector plate 3 reflects, toward a light emission surface
`1a, light coming from the diffusing plate 4 and leaking
`through the diffusing reflection layer 2 at the back,
`thereby increasing brightness. As a general tendency, the
`closer to the light source 5 on the light emission surface
`1a, the higher the brightness. For the purpose of avoiding
`this tendency, as well known in the art, the diffusing
`reflection layer 2 described above is formed in such a way
`as to have a pattern determined depending on various
`conditions.
`[0008]
`[Problems to be Solved by the Invention] In an edge-light-
`type illumination apparatus according to prior art such as
`one described above, a diffusing reflection layer that
`diffuses light originating from a light source is formed
`with the use of a printing method. Therefore, the area size
`of the diffusing reflection layer, which has an influence on
`the degree of uniformity in brightness, is susceptible to an
`error. In the art, this area-size error is a cause of low
`productivity (yield). In addition, optical absorption by
`the paint used for the printing increases due to multiple
`reflections inside a light-guiding plate. This makes it
`difficult to realize high brightness.
`[0009]
`
`- 10 -
`
`SONY_000759
`
`

`
`Ideally, 100% of light originating from a light source
`
`should turn into outgoing light after going into a light-
`guiding plate. This is advantageous from the viewpoint of
`efficiency in the use of light. In this respect, in
`diffusion by a diffusing reflection layer according to prior
`art, it is not possible to control the amount of light
`propagating inside a light-guiding plate because it is not
`possible to control the direction of reflected light. For
`this reason, either the returning of light to the light-
`source side or, if plural light sources are provided, the
`reaching of light to the opposite light-source side occurs,
`which makes it difficult to realize high brightness.
`[0010]
`
`An object of the present invention is to provide a
`plane illumination apparatus that realizes high brightness
`and high productivity.
`[0011]
`[Means for Solving the Problems] An illumination apparatus
`according to an aspect of the present invention at least
`includes a light-guiding plate 11 and a light source 12 that
`is provided along and next to a side edge of the light-
`guiding plate, characterized in that, a light-diffusing
`plate 21 is provided on an outgoing-light emission surface
`of the light-guiding plate 11; a concave portion 14 that has
`a substantially triangular cross-sectional shape is formed
`
`- 11 -
`
`SONY_000760
`
`

`
`in an opposite surface of the light-guiding plate 11 as a
`line pattern or a dot pattern; a transparent layer 16 is
`formed on the opposite surface of the light-guiding plate 11,
`in which the concave portion 14 is formed, by using a
`material that has an index of refraction that is greater
`than an index of refraction of the light-guiding plate 11,
`said transparent layer being formed in such a way that the
`concave portion 14 is filled in by said material; and a
`reflection sheet 18 is either provided on or formed
`integrally on an outer surface of the transparent layer 16.
`[0012]
`
`An illumination apparatus according to another aspect
`of the present invention at least includes a light-guiding
`plate 11 and a light source 12 that is provided along and
`next to a side edge of the light-guiding plate,
`characterized in that, a concave portion 34 that has a
`substantially triangular cross-sectional shape is formed in
`an outgoing-light emission surface of the light-guiding
`plate 11 as a line pattern or a dot pattern; a transparent
`layer 36 is formed on the outgoing-light emission surface of
`the light-guiding plate 11 by using a material that has an
`index of refraction that is greater than an index of
`refraction of the light-guiding plate 11, said transparent
`layer being formed in such a way that the concave portion 34
`is filled in by said material; a light-diffusing plate 38 is
`
`- 12 -
`
`SONY_000761
`
`

`
`provided on an outer surface of the transparent layer 36;
`and a reflection sheet 32 is provided on an opposite surface
`of the light-guiding plate 11.
`[0013]
`
`An illumination apparatus according to still another
`aspect of the present invention at least includes a light-
`guiding plate 11 and a light source 12 that is provided
`along and next to a side edge of the light-guiding plate,
`characterized in that, a concave portion 34 that has a
`substantially triangular cross-sectional shape is formed in
`an outgoing-light emission surface of the light-guiding
`plate 11 as a line pattern or a dot pattern; a transparent
`layer 36 is formed on the outgoing-light emission surface of
`the light-guiding plate 11 by using a material that has an
`index of refraction that is greater than an index of
`refraction of the light-guiding plate 11, said transparent
`layer being formed in such a way that the concave portion 34
`is filled in by said material; a light-diffusing plate 38 is
`provided on an outer surface of the transparent layer 36; a
`concave portion 14 that has a substantially triangular
`cross-sectional shape is formed in an opposite surface of
`the light-guiding plate 11 as a line pattern or a dot
`pattern; a transparent layer 16 is formed on the opposite
`surface of the light-guiding plate 11, in which the concave
`portion 14 is formed, by using a material that has an index
`
`- 13 -
`
`SONY_000762
`
`

`
`of refraction that is greater than an index of refraction of
`the light-guiding plate 11, said transparent layer being
`formed in such a way that the concave portion 14 is filled
`in by said material; and a reflection sheet 18 is either
`provided on or formed integrally on an outer surface of the
`transparent layer 16. In addition, said apparatus is
`further characterized in that either one of two surfaces
`each having the largest area size among surfaces of the
`light-guiding plate 11 is, or both of said two surfaces are,
`sloped.
`[0014]
`
`A liquid crystal display device according to an aspect
`of the present invention is characterized by being assembled
`as a combination of the illumination apparatus 40 mentioned
`above and a liquid crystal panel 41. With the structure
`described above, an illumination apparatus that realizes
`high brightness and high productivity, and a liquid crystal
`display device that includes said illumination apparatus,
`can be obtained.
`[0015]
`[Operation] In the present invention, a concave portion(s)
`that has a substantially triangular cross-sectional shape is
`formed in a surface(s) of a light-guiding plate 11 as a line
`pattern or a dot pattern, and a layer that has a relatively
`high index of refraction is formed on a concave-formed
`
`- 14 -
`
`SONY_000763
`
`

`
`surface. Light having gone into the light-guiding plate 11
`from a light source 12 causes refraction and reflection, and
`goes out within a substantially constant angular range due
`to prismatic effects irrespective of an angle of incidence.
`In addition, since reflection effects arise from reflection
`caused due to a refractive index difference and reflection
`by a reflector/reflection plate, it is possible to suppress
`optical absorption and therefore increase brightness.
`[0016]
`[Embodiments] Fig. 1 is a set of diagrams of a first
`embodiment of the present invention, wherein (a) is a
`sectional view; (b) is an enlarged view of a part B
`illustrated in (a); (c) is an enlarged view of a part C
`illustrated in (a); and (d) is an enlarged view of a part D
`illustrated in (a). In Fig. 1, the reference numeral 11
`denotes a light-guiding plate, and the reference numeral 12
`denotes a light source provided along and next to each of
`two side edges of the light-guiding plate 11. For example,
`a cold-cathode tube that has a tube diameter of 4 mm is used
`as the light source 12. A reflection cover 13 is provided
`around the light source 12. The reflection cover 13 is made
`of an Al plate that has a thickness of 0.5 mm. As
`illustrated in Fig. 1(b), a thin reflection layer 13a, which
`is an Ag film that has a thickness of 1,000 angstrom, is
`formed on the inner surface of the reflection cover 13, and
`
`- 15 -
`
`SONY_000764
`
`

`
`a protection layer 13b, which is a PET resin coat that has a
`thickness of 100 m, is formed on the thin reflection layer
`13a. The thin reflection layer 13a gives high reflection
`property to the reflection cover 13. The protection layer
`13b increases its durability. The reflection cover 13
`reflects light emitted from the light source 12 in such a
`way as to condense the emitted light onto an end face of the
`light-guiding plate 11, and the condensed light goes into
`the light-guiding plate 11 efficiently.
`[0017]
`
`A plate that is made of transparent acrylic resin and
`has a thickness of 4 mm is used as the light-guiding plate
`11. As illustrated in Fig. 1(c), grooves 14, each of which
`extends as a line pattern (or a pattern of aligned dots) in
`a direction parallel to the linear cold-cathode-tube
`direction of the light source 12, are formed as concave
`portions in one surface (reverse face) of the light-guiding
`plate 11. As illustrated therein, each of the concave
`portions 14 has a substantially triangular cross-sectional
`shape with a vertex angle  of 90. The concave portions 14
`are arranged in such a way that the ratio of the area size
`of a concave-present region, which is recessed, to the area
`size of a concave-absent region, which is not recessed,
`satisfies the following formula. Note that the formula
`shown below is an empirical equation that has conventionally
`
`- 16 -
`
`SONY_000765
`
`

`
`been used in the art.
`Area-size percentage = [(-2.42  10-5  L2 + 4.42  10-3  L +
`0.4)2]-1
`, where L: Distance from the light source
`The formula shown above is adapted to a range from the end
`of the light-guiding plate 11 to the center thereof. A
`range from the center to the respective two ends is set
`symmetrically.
`[0018]
`
`A transparent plate 16, on one surface of which convex
`portions 15 are formed, is bonded to the light-guiding plate
`11 at its concave-formed surface, that is, a surface in
`which the concave portions 14 are formed, with the use of a
`transparent acrylate ultraviolet ray curing adhesive 17.
`Each of the convex portions 15 has a shape for mating with
`the corresponding one of the concave portions 14. The index
`of refraction of the ultraviolet ray curing adhesive 17 is
`substantially equal to that of the light-guiding plate 11.
`A thin reflection layer 18, which is an Ag film that has a
`thickness of approximately 1,000 angstrom, is formed on the
`outer surface of the transparent plate 16. A protection
`layer 19, which is a PET resin coat that has a thickness of
`approximately 100 m, is formed on the thin reflection layer
`18.
`[0019]
`
`- 17 -
`
`SONY_000766
`
`

`
`A light-diffusing plate 21, which is made up of two
`
`polycarbonate resin films (manufactured by GE, LEXAN 8B36)
`21a and 21b formed in layers, each with a crimp-treated
`irregular surface and with a thickness of 0.25 mm, is
`provided on the opposite surface (light emission plane 20)
`of the light-guiding plate 11. The purpose of providing the
`light-diffusing plate 21 thereon is to conceal the concave
`portions 14, which are arranged in the reverse surface, in
`such a way that these recesses cannot be seen from the
`outside through the surface 20, and, in addition, to enhance
`uniformity in brightness.
`[0020]
`
`Next, the operation of the present embodiment with the
`structure described above will now be explained. First,
`light originating from the light source 12 goes into the
`light-guiding plate 11. By the law of total reflection, the
`light having gone into the light-guiding plate 11 propagates
`inside the light-guiding plate 11 while repeating internal
`reflection as done in the prior-art structure. Since the
`concave portion 14 has the same structure as that of a prism
`held in the air, when propagation light goes into the
`concave portion 14, refraction/reflection occurs inside the
`concave portion 14. The light condensed within an angular
`range of approximately 45 as viewed from a direction
`perpendicular to the light emission plane 20 is outputted as
`
`- 18 -
`
`SONY_000767
`
`

`
`outgoing light that has characteristics illustrated in Fig.
`2. The angular range of the outgoing light does not exceed
`45 in relation to the surface 11a of the light-guiding
`plate 11, too. Therefore, as can be derived from the
`following conditions of total reflection of the present
`embodiment, most of the outgoing light is direct outgoing
`light, which goes to the light emission plane 20.
`c = sin-1 (N1 / N2)  42
`, where the index of refraction N1 of air = 1
`the index of refraction N2 of the light-guiding plate =
`1.491
`[0021]
`
`A part of incoming light does not turn into light
`outgoing to the light emission plane 20 because its angle
`falls within a critical angle. However, such a part has a
`function of enhancing uniformity in brightness by behaving
`as propagation light. Since the concave portions 14
`described above are arranged in such a way as to satisfy the
`area-size percentage formula expressed above, when viewed in
`a macro level, outgoing light obtained on the light emission
`plane 20 is almost constant, and does not vary from one
`position to another.
`[0022]
`
`Because of the prismatic effects of the concave portion
`14, most of light originating from the light source 12 goes
`
`- 19 -
`
`SONY_000768
`
`

`
`out from the light emission plane 20. Therefore, with the
`present embodiment described above, greater brightness as
`compared with that of prior art can be obtained. In
`addition, since an ordinary resin molding technique can be
`used mainly for the manufacturing of a light-guiding plate
`due to its structure, said manufacturing is easy, resulting
`in improved productivity.
`[0023]
`
`Fig. 3 is a sectional view of a second embodiment of
`the present invention. The present embodiment is basically
`the same as the foregoing embodiment. There are the
`following points of difference between the two: in the
`present embodiment, a single light source 12 is provided;
`and an aluminum-evaporated tape 22 is bonded or attached to
`the opposite end face of a light-guiding plate 11, that is,
`an end at which the light source 12 is not provided. The
`aluminum-evaporated tape 22 serves as a reflection plate,
`and light reflected by this reflection plate can be assumed
`as light originating from a pseudo light source. With the
`present embodiment, the same effects as those of the
`foregoing embodiment can be obtained.
`[0024]
`
`Fig. 4 is a set of diagrams of a third embodiment of
`the present invention, wherein (a) is a sectional view; (b)
`is an enlarged view of a part B illustrated in (a); and (c)
`
`- 20 -
`
`SONY_000769
`
`

`
`is an enlarged view of a part C illustrated in (a). The
`structure of the present embodiment is directed to obtaining
`illumination light having high directivity. The basic
`feature of the structure of the present embodiment lies in
`the turning of the light-guiding plate of the first
`embodiment upside down. More specifically, in the present
`embodiment, the reverse surface of a light-guiding plate 11
`is formed as a flat surface. A thin reflection layer 32,
`which is an Ag film that has a thickness of approximately
`1,000 angstrom, is formed on this flat surface. A
`protection layer 33, which is a PET resin coat that has a
`thickness of approximately 100 m, is formed on the thin
`reflection layer 32.
`[0025]
`
`As in the first embodiment, in the present embodiment,
`grooves 34, each of which extends linearly, are formed as
`concave portions in the light emission plane 11a of the
`light-guiding plate 11. Each of the concave portions 34 has
`a substantially triangular cross-sectional shape. A
`transparent plate 36, on one surface of which convex
`portions 35 are formed, is bonded to the light-guiding plate
`11 at its concave-formed surface, that is, a surface in
`which the concave portions 34 are formed, with the use of a
`transparent acrylate ultraviolet ray curing adhesive 37.
`Each of the convex portions 35 has a shape for mating with
`
`- 21 -
`
`SONY_000770
`
`

`
`the corresponding one of the concave portions 34. The index
`of refraction of the ultraviolet ray curing adhesive 37 is
`substantially equal to that of the light-guiding plate 11.
`To slightly conceal the pattern of lines formed by the
`concave portions 34 and enhance uniformity in brightness, a
`light-diffusing plate 38, which is made of a polycarbonate
`resin film (manufactured by GE, LEXAN 8A13) with a crimp-
`treated irregular surface and with a thickness of 0.25 mm,
`is provided on the transparent plate 36. In the present
`embodiment, the vertex angle b of each of the concave
`portions 34 having a substantially triangular shape in cross
`section as illustrated in Fig. 4(b) is 70.
`[0026]
`
`The structure of the present embodiment described above
`produces prismatic effects, as in the first embodiment. In
`addition, with the present embodiment, it is possible to
`obtain high-directivity light, most of outgoing light of
`which is within an angular range of approximately 12 as
`viewed from a direction perpendicular to the light emission
`plane 11a of the light-guiding plate 11. It is easy to
`apply optical technology such as lens technology to the
`high-directivity light mentioned above. Especially when
`said high-directivity light is applied to a liquid crystal
`display device, it is possible to cause light condensed by
`means of a lens to go into the opening portion of each dot
`
`- 22 -
`
`SONY_000771
`
`

`
`on a display surface efficiently. By this means, it is
`possible to increase efficiency in the use of light inside a
`liquid crystal display device, realize high brightness, make
`the body of the device thinner, and achieve power savings.
`If a method of optical diffusion after the passing of high-
`directivity light through a liquid crystal panel, it is
`possible to obtain excellent display characteristics
`irrespective of visual sensation.
`[0027]
`
`Fig. 5 is a set of diagrams of a fourth embodiment of
`the present invention, wherein (a) is a sectional view; (b)
`is an enlarged view of a part B illustrated in (a); and (c)
`is an enlarged view of a part C illustrated in (a). In this
`drawing, the same reference numerals are assigned to
`components/portions that are the same as those illustrated
`in Fig. 1 or 4. The present embodiment is a combination of
`the first embodiment illustrated in Fig. 1 and the third
`embodiment illustrated in Fig. 4. That is, the same
`structure as that of the first embodiment is adopted at the
`reverse surface of the light-guiding plate 11, and the same
`structure as that of the third embodiment is adopted at the
`light-emission-side surface. Therefore, the present
`embodiment produces a combination of the effects of the
`first embodiment and the effects of the third embodiment.
`[0028]
`
`- 23 -
`
`SONY_000772
`
`

`
`Fig. 6 is a sectional view of a fifth embodiment of the
`
`present invention. In this drawing, the same reference
`numerals are assigned to components/portions that are the
`same as those illustrated in Fig. 1. The present embodiment
`is basically the same as the first embodiment. As the point
`of difference therebetween, in the present embodiment, the
`upper surface of the light-guiding plate 11 is formed as a
`sloped surface, thereby increasing efficiency in the use of
`light.
`[0029]
`
`Fig. 7 is a sectional view of a sixth embodiment of the
`present invention. In this drawing, the same reference
`numerals are assigned to components/portions that are the
`same as those illustrated in Fig. 4. The present embodiment
`is basically the same as the third embodiment. As the point
`of difference therebetween, in the present embodiment, the
`lower surface of the light-guiding plate 11 is formed as a
`sloped surface, thereby increasing efficiency in the use of
`light. In the present embodiment and the preceding
`embodiment, a surface in which no concave portion is formed
`is formed as a sloped surface. The opposite surface, in
`which concave portions are formed, may be formed as a sloped
`surface. Even with such a modification, it is possible to
`efficiently use light arriving at the opposite end face
`directly from the incident-side end face of a light-guiding
`
`- 24 -
`
`SONY_000773
`
`

`
`plate.
`[0030]
`
`Fig. 8 is a diagram that illustrates an example of the
`use of an illumination apparatus according to an exemplary
`embodiment of the present invention as the plane
`illumination unit of a liquid crystal display device. In
`the illustrated application example, an illumination
`apparatus 40, which is an illumination apparatus according
`to an exemplary embodiment of the present invention, and a
`liquid crystal panel unit 41 are assembled into one
`integrated component by means of exterior cover plates 42,
`which are made of steel plates. The illustrated application
`example realizes high brightness, a thin and lightweight
`body, and power savings. Note that circuitry, etc. for
`driving the panel of the liquid crystal panel unit 41 is not
`shown separately, and a detailed explanation of the
`circuitry, etc. is not given here. In the illustrated
`application example, an illumination apparatus according to
`the first embodiment is used as the illumination apparatus
`40. However, needless to say, an illumination apparatus
`according to any other embodiment may be used.
`[0031]
`
`Though specific materials of components/portions are
`mentioned in the foregoing embodiments, the scope of the
`invention is not limited thereto. For example, other
`
`- 25 -
`
`SONY_000774
`
`

`
`transparent member such as polystyrene, polycarbonate, etc.
`may be used as the material of a light-guiding plate. A
`white paint or a metal layer such as an Al, Au, Cr layer or
`the like may

This document is available on Docket Alarm but you must sign up to view it.


Or .

Accessing this document will incur an additional charge of $.

After purchase, you can access this document again without charge.

Accept $ Charge
throbber

Still Working On It

This document is taking longer than usual to download. This can happen if we need to contact the court directly to obtain the document and their servers are running slowly.

Give it another minute or two to complete, and then try the refresh button.

throbber

A few More Minutes ... Still Working

It can take up to 5 minutes for us to download a document if the court servers are running slowly.

Thank you for your continued patience.

This document could not be displayed.

We could not find this document within its docket. Please go back to the docket page and check the link. If that does not work, go back to the docket and refresh it to pull the newest information.

Your account does not support viewing this document.

You need a Paid Account to view this document. Click here to change your account type.

Your account does not support viewing this document.

Set your membership status to view this document.

With a Docket Alarm membership, you'll get a whole lot more, including:

  • Up-to-date information for this case.
  • Email alerts whenever there is an update.
  • Full text search for other cases.
  • Get email alerts whenever a new case matches your search.

Become a Member

One Moment Please

The filing “” is large (MB) and is being downloaded.

Please refresh this page in a few minutes to see if the filing has been downloaded. The filing will also be emailed to you when the download completes.

Your document is on its way!

If you do not receive the document in five minutes, contact support at support@docketalarm.com.

Sealed Document

We are unable to display this document, it may be under a court ordered seal.

If you have proper credentials to access the file, you may proceed directly to the court's system using your government issued username and password.


Access Government Site

We are redirecting you
to a mobile optimized page.





Document Unreadable or Corrupt

Refresh this Document
Go to the Docket

We are unable to display this document.

Refresh this Document
Go to the Docket