JP2009217032A - Plasma display panel unit and display - Google Patents

Abstract

の関係を有する。
【選択図】図５A PDP unit and a display device that include a PDP and an optical sheet and can provide a high-quality image.
At least one of the plurality of layers of the optical sheet is formed of a material having a refractive index of N _{0 so} as to be able to transmit light, and is provided between the prism units and a prism unit arranged in parallel along the sheet surface. , A triangle having a hypotenuse with one sheet surface side as a base and an angle with respect to the normal of the sheet surface of θ ₀ and having a material with a refractive index N _b smaller than the refractive index N ₀ , and capable of absorbing light The optical function sheet layer 11 having a light absorbing portion is formed, and the thicknesses of the layers 4, A, and 5 provided between the image output side surface of the pixel and the optical function sheet layer are set to L _i , and the refractive index of the layer is set. N _i , where p is the size of the pixel in the direction in which the prism portions are arranged in parallel,

Have the relationship.
[Selection] Figure 5

Description

  The present invention relates to a plasma display panel unit used in a display device and a display device including the plasma display panel unit, and more particularly to a plasma display panel unit and a display device that can reduce ghosts.

  A display device such as a plasma television using a plasma display panel (hereinafter sometimes referred to as “PDP”) includes a PDP that is an image source and an optical sheet that is disposed closer to the viewer than the PDP. ing. A plasma display unit is composed of the PDP, the optical sheet, and other members having various functions. The plasma display unit is arranged to provide a display device such as a plasma television.

  The PDP is an image source and emits an image provided to an observer. On the other hand, the optical sheet has a role of providing a viewer with a higher quality image, and therefore, in many cases, layers having various functions are laminated.

Patent Document 1 discloses an example of a conventional optical sheet. According to this, the optical sheet is provided with an external light shielding layer having a transparent resin material substrate and a large number of wedge-shaped black stripes arranged in parallel to one surface of the substrate, thereby improving contrast and visible light transmittance. be able to.
JP 2006-189867 A

  However, in the conventional optical sheet described in Patent Document 1 or the like, the relationship with the image source on which the optical sheet is arranged has not been considered. Thereby, even if such an optical sheet is used, an appropriate image cannot always be emitted, and in particular, there may be a problem due to the occurrence of a ghost.

  In view of the above problems, it is an object of the present invention to provide a plasma display panel unit and a display device that include a plasma display panel and an optical sheet and can provide a high-quality image.

  The present invention will be described below. In order to facilitate understanding of the present invention, reference numerals in the accompanying drawings are appended in parentheses, but the present invention is not limited to the illustrated embodiment.

The invention according to claim 1 includes a plasma display panel (2) in which pixels (3a, 3a,...) Are arranged in parallel in the vertical and horizontal directions, a plurality of layers disposed on the image output side of the plasma display panel. An optical sheet (10, 30), and a plasma display panel unit (1, 21), wherein at least one of the plurality of layers of the optical sheet is short on one sheet surface side in the sheet thickness direction cross section. A prism portion (12, 12,...) Having a bottom, a trapezoid having a long lower bottom on the other sheet surface side, formed so as to be able to transmit light with a material having a refractive index N ₀ , and juxtaposed along the sheet surface When, is provided between the prism portions, one of the sheet surface side and bottom, triangular with oblique angle is theta ₀ with respect to the normal line of the sheet surface, a refractive index N ₀ is smaller than the refractive index N _b A light absorbing portion (13, 13,...) That is formed so as to be capable of absorbing light, and between the image output side surface of the pixel and the optical function sheet layer. when the thickness of the layer to be provided (4, a, 5) L i, the refractive index of the layer and N _i, the magnitude of the pixels in the direction of the prism portion is in parallel to the p to,

の関係を有することを特徴とするプラズマディスプレイパネルユニットを提供することにより前記課題を解決する。

The above problem is solved by providing a plasma display panel unit characterized by having the following relationship.

According to a second aspect of the present invention, there is provided a plasma display panel unit comprising: a plasma display panel in which pixels are provided in parallel in a vertical and horizontal direction; and an optical sheet that is disposed on a video emission side of the plasma display panel and includes a plurality of layers. And at least one of the plurality of layers of the optical sheet has a trapezoidal shape having a short upper base on one sheet surface side and a long lower base on the other sheet surface side in the sheet thickness direction cross section. A prism portion that is formed of a material of N _{0 so} as to transmit light and is arranged in parallel along the sheet surface, and is provided between the prism portions, and has a long lower bottom on one sheet surface side and a short on the other sheet surface side. and has a upper base, a trapezoid having a hypotenuse is ₀ angle θ relative to the normal of the sheet surface, the light absorption-friendly have a material that is a refractive index N ₀ is smaller than the refractive index N _b A light absorbing portion formed on an optical functional sheet layer comprising, a layer to be provided between the image exit surface and the optical functional sheet layer of the pixel thickness of the L _i, the refractive index of the layer N _{When i} is p and the pixel size in the direction in which the prism portions are arranged in parallel is p,

の関係を有することを特徴とするプラズマディスプレイパネルユニットを提供することにより前記課題を解決する。

The above problem is solved by providing a plasma display panel unit characterized by having the following relationship.

  According to a third aspect of the present invention, there is provided a light absorbing part (13, 13,...) In the plasma display panel unit (1, 21) according to the first or second aspect, wherein the light absorbing particles (13, 13,. 15, 15, ...) is contained.

  Here, “average particle size of 1 μm” in the case of “average particle size of 1 μm or more” is intended for particles having a particle size of 0.5 μm or more and smaller than 1.5 μm in the particle size measurement by the weight distribution method. In the particle size distribution, it means that the standard deviation is 0.3 or more.

  The invention according to claim 4 is characterized in that the light absorbing portion in the plasma display panel unit according to claim 1 or 2 contains a black pigment or a dye.

  The invention described in claim 5 is characterized in that the black pigment in the plasma display panel unit according to claim 4 is carbon black.

The invention according to claim 6 is the light absorption section (13, 13, ...) in the plasma display panel unit (1, 21) according to any one of claims 1 to 5.
) Is configured to have a light absorption performance such that the transmittance is 70% or less in the transmittance measurement of a sheet having a thickness of 6 μm formed only of the material constituting the light absorbing portion. Features.

  In the invention according to claim 7, the length of the short upper base of the prism portion (12, 12,...) In the plasma display panel unit (1, 21) according to any one of claims 1 to 6, The pitch is 50% to 90% of the parallel pitch of the prism portions.

The invention described in claim 8 is characterized in that θ ₀ in the plasma display panel unit (1, 21) according to any one of claims 1 to 7 is greater than 0 degree and equal to or less than 10 degrees.

In the ninth aspect of the present invention, in the plasma display panel unit (1, 21) according to any one of the first to eighth aspects, both N ₀ and N _b have a value of 1.49 to 1.56. It is characterized by being.

In a tenth aspect of the present invention, the difference between N ₀ and N _b in the plasma display panel unit (1, 21) according to any one of the first to ninth aspects is greater than ₀ and equal to or less than 0.07. It is characterized by that.

  An eleventh aspect of the present invention provides the display device (19) characterized in that the plasma display panel unit (1, 21) according to any one of the first to tenth aspects is provided. Solve the problem.

  According to the plasma display panel unit and the display device of the present invention, it is possible to suppress the occurrence of ghost particularly in a front view.

  Such an operation and gain of the present invention will be made clear from the best mode for carrying out the invention described below.

  Hereinafter, the present invention will be described based on embodiments shown in the drawings.

  FIG. 1 shows a cross section of a plasma display panel unit (hereinafter sometimes referred to as “PDP unit”) 1 according to the first embodiment of the present invention, and schematically shows the layer structure thereof. In FIG. 1, for the sake of easy understanding, a part of the repetitive symbols may be omitted (the same applies to the following drawings). The PDP unit 1 includes a plasma display panel (hereinafter sometimes referred to as “PDP”) 2, an electromagnetic wave shielding layer 5, and an optical sheet 10. Further, a gap is provided between the PDP 2 and the electromagnetic wave shielding layer 5, and this is an air layer A.

  The PDP 2 includes a light emitting unit 3 and a glass layer 4. The light emitting unit 3 includes pixels 3a, 3a,... Arranged in parallel in the vertical and horizontal directions (up and down and back / front direction), and image light is emitted from the pixels 3a, 3a,. The glass layer 4 is disposed so that a light-transmitting thin plate-like glass is laminated on the image emission side surface of the light emitting unit 3.

  The electromagnetic wave shielding layer 5 is a layer laminated on the PDP 2 side of the optical sheet 10 and is a layer having a function of shielding electromagnetic waves. The electromagnetic wave shielding layer 5 is a layer in which a film having translucency and having a role of shielding electromagnetic waves generated from the PDP 2 is disposed. The type of the film is not particularly limited as long as it is such a film. Examples of the film that can be usually obtained include a metal mesh and a transparent conductive film.

  The optical sheet 10 includes an optical function sheet layer 11, a PET film layer 16 as a base material layer, and an adhesive layer 17. Each of the layers extends in the back / front direction of the paper while maintaining the cross section shown in FIG. FIG. 2 shows a cross section of only the optical sheet 10 and schematically shows the layer structure. Each layer will be described below.

  The optical function sheet layer 11 has a substantially trapezoidal cross section in a cross section orthogonal to the sheet surface of the optical sheet 10, and the prism portions 12, 12,... Arranged in parallel along the sheet surface and the prism portions 12, 12,. It has light absorption parts 13, 13,. FIG. 3 shows an enlarged view focusing on one light absorbing portion 13 and the prism portions 12 and 12 adjacent thereto. The optical function sheet layer 11 will be described with reference to FIGS.

The prism parts 12, 12,... Are elements having a substantially trapezoidal cross section having an upper base on the side where the PDP 2 is arranged and a lower base on the opposite side of the sheet surface. The prism portions 12, 12, ... has a refractive index is composed of a light transmissive resin is N _0. Thereby, the image light is transmitted through the prism portions 12, 12,..., And the image light is provided to the observer. This is usually formed of, for example, epoxy acrylate having a characteristic of being cured by ionizing radiation, ultraviolet rays or the like. It is preferred size of N ₀ is not particularly limited but is 1.49 to 1.56 from the viewpoint of material availability. Further, the length of the upper base of the prism parts 12, 12,... (The distance indicated by B in FIG. 2) is the pitch (the distance indicated by C in FIG. 2) at which the prism parts 12, 12,. 50% to 90% is preferable.

The light absorbing parts 13, 13,... Are elements arranged between the prism parts 12, 12,. Therefore, the light absorbing parts 13, 13,... Are substantially triangular with the upper base side of the prism parts 12, 12,. The hypotenuse (two sides extending in the sheet thickness direction) in the triangle is formed with an angle of θ ₀ with respect to the normal of the sheet surface as shown in FIG. Light absorbing portions 13, ... includes a binder 14 which translucent with a substance filled a refractive index N _b, the binder portion 14 light-absorbing particles 15 and 15 are dispersed and mixed in, ... And.

The binder material filled in the binder part 14 is not particularly limited. While having translucency as described above, pigments and dyes may be mixed and colored. Examples of the pigment include carbon black. Although the material is not particularly limited, it is preferably formed of urethane acrylate having a characteristic of being cured by ionizing radiation, ultraviolet rays, or the like from the viewpoint of productivity. Moreover, the binder material is preferably a refractive index N _b is configured prism portions 12, by ... refractive index N ₀ less material. The size of N _b is not particularly limited, but is preferably 1.49 to 1.56 from the viewpoint of material availability, and the difference in refractive index between N ₀ and N _b is greater than 0. More preferably, it is 0.07 or less.

  Depending on the relationship between the refractive index difference and the incident angle of the image light, a part or all of the image light can be reflected at the interface without entering the light absorbing portions 13, 13,. Therefore, a bright image can be provided.

The light-absorbing particles 15, 15,... Are preferably particles having an average particle size of 1 μm or more from the viewpoint of availability and handling, and this is a predetermined concentration with pigments such as carbon or dyes such as black, red, blue, and yellow. Is colored. For this, for example, commercially available colored resin fine particles can be used. The light-absorbing particles 15 and 15, the refractive index N _r of ... is not particularly limited. A part of the external light incident on the light absorbing portions 13, 13,... Is absorbed by the light absorbing particles 15, 15,.

  Here, the light absorption performance of the light absorbing portions 13, 13,... Can be adjusted as appropriate depending on the purpose. However, in the transmittance measurement of a sheet having a thickness of 6 μm formed only from the material constituting the light absorbing portion, It is preferable that the optical absorption performance is such that the rate is 70% or less. The means for setting the transmittance to 70% or less is not particularly limited, and for example, it can be applied by adjusting the content of light absorbing particles and the light absorbing performance.

The size of the angle θ ₀ of the hypotenuse of the light absorbing portions 13, 13,... Is set within an angle that satisfies the formula described later. Thereby, a ghost is suppressed especially in the front view of a screen, and it becomes possible to provide a high quality image. The magnitude of θ ₀ is preferably greater than 0 degree and 10 degrees or less while satisfying the above requirements.

As shown in FIGS. 1 to 3, the optical functional sheet layer 11 has prism portions 12, 12,... Having a substantially trapezoidal cross section, and light absorbing portions 13, 13 formed between them. ... has a triangular cross-section. However, if the light can be controlled appropriately, these shapes are not particularly limited, and appropriate shapes are appropriately adopted. For example, the shape may be a trapezoid. FIG. 4 shows the light absorbing portion 13 ′ of the optical function sheet layer 11 ′ and the prism portions 12 ′ and 12 ′ adjacent thereto in an example in which the light absorbing portion is trapezoidal. In this embodiment, the light absorbing portion 13 'has a trapezoidal shape as shown in FIG. 4. At this time, the long base (lower base) of the trapezoid is on the PDP2 (see FIG. 1, left side of the drawing) side, and the short base is the side opposite to the PDP2. (See FIG. 1, right side of the page). Here, the length of the upper base shown by D in FIG. 4 is preferably in the range of 2 to 25 μm. Even in this case, the hypotenuse of the trapezoid (the two sides arranged between the upper base and the lower base) is formed with an angle of θ ₀ with respect to the normal to the sheet surface.

  Returning to FIG. 2, the configuration of the other part of the optical sheet 10 will be described. The PET film layer 16 is a film layer serving as a base for forming the optical functional sheet layer 11 on the PET film layer 16 and is formed mainly of PET. The PET film layer 16 only needs to contain PET as a main component, and may contain other resins. Here, the main component means a component contained in an amount of 50% by mass or more based on the entire PET film layer. Various additives may be added in appropriate amounts. Examples of general additives include phenol-based antioxidants, lactone-based stabilizers, and the like.

  As will be described later, the pressure-sensitive adhesive layer 17 is a layer in which a pressure-sensitive adhesive for adhering the optical sheet 10 to another sheet or member disposed on, for example, the plasma television 19 (see FIG. 8) is disposed. The material of the pressure-sensitive adhesive used for the pressure-sensitive adhesive layer 17 is not particularly limited as long as it transmits light and can appropriately adhere another optical sheet 10. Examples thereof include an acrylic copolymer, and the adhesive strength thereof is, for example, about several N / 25 mm to 20 N / 25 mm.

  The optical sheet 10 is manufactured as follows, for example. On the one surface side of the PET film layer 16, a liquid material serving as a material for the prism portion is applied. Next, the prism portions 12, 12,... Are formed by irradiating with ultraviolet rays in a state where the material to be the prism portion is sandwiched between the roll mold for forming the prism portion shape and the PET film. . Then, a liquid material in which black light-absorbing particles are added to the resin serving as the material of the binder portion is filled between the prism portions 12, 12,... Are cured by irradiating and forming the light absorbing portions 13, 13,... Thereby, the optical function sheet layer 11 is manufactured. The pressure-sensitive adhesive layer 17 is laminated on the optical function sheet layer 11 thus manufactured.

  Here, the base material layer provided in the optical sheet 10 of the PDP unit 1 is not necessarily made of PET, and other materials such as polybutylene terephthalate resin (PBT) or polytrimethylene terephthalate (PTT) resin, The “polyester resin” can be used. In the present embodiment, it has been described that a resin having PET as a main component is a preferable material from the viewpoint of mass productivity, price, availability, etc. in addition to performance.

  In addition to the above, the optical sheet 10 may be provided with functional film layers such as a film layer for preventing reflection, a film layer for preventing charging, and a film layer for anti-glare purposes.

  The PDP unit 1 is an example in which the glass layer 4, the air layer A, and the electromagnetic wave shielding layer 5 are provided between the light emitting unit 3 of the PDP 2 and the optical function sheet layer 11. Without being limited thereto, it can be increased or decreased as necessary. For example, a layer for correcting the color tone may be further provided here.

The configuration of the PDP unit 1 will be described in more detail. FIG. 5 is a view from the same viewpoint as FIG. 1 and is a view for explaining the relationship between the members arranged here. Here, a part of the reference numerals shown in FIG. 1 is omitted for easy viewing. As illustrated in FIG. 5, a description will be given by taking, as an example, a light ray E emitted from a certain pixel 3 a and emitted parallel to the sheet surface normal of the optical sheet 10. Here, the refractive index of the glass layer 4 is N ₁ , the thickness is L _1, and the light beam E passing through the inside of the glass layer 4 has an angle θ ₁ with respect to the normal line of the glass layer 4. . Further, the refractive index of the air layer A is N ₂ (= 1), the thickness is L _2, and the light ray E passing through the inside of the air layer A has an angle θ ₂ with respect to the normal of the air layer A. is doing. Further, the refractive index of the electromagnetic wave shielding layer 5 is N ₃ , the thickness is L _3, and the light beam E passing through the inner side of the electromagnetic wave shielding layer 5 has an angle θ ₃ with respect to the normal line of the electromagnetic wave shielding layer 5. Have.

In addition to moving in the thickness direction of the PDP unit 1 (left and right direction in FIG. 5), the light beam E is emitted from the pixel 3a of the light emitting unit 3 and reaches the observer, and the prism units 12, 12,. The distance x (see FIG. 5) also moves in the parallel direction (up and down direction in FIG. 5). The distance x can be generally represented by the sum of the moving distances in each layer (glass layer 4, air layer A, electromagnetic wave shielding layer 5), and is specifically represented by the following formula 1.
x = L ₁ tan θ ₁ + L ₂ tan θ ₂ + L ₃ tan θ ₃ (Formula 1)
Furthermore, not only the layers shown in FIG. 5 but also other layers may be laminated here, so that this can be taken into consideration as shown in Equation 2.

On the other hand, Snell's law
N ₁ sin θ ₁ = N ₂ sin θ ₂ = N ₃ sin θ ₃ = N ₀ sin (2θ ₀ ) (Formula 3)
The relationship is established. _Here, N ₀ sin (2θ 0) of (2 [Theta] _0), as shown in FIG. 6, light E is incident on the prism portion 12, is reflected by the hypotenuse of the light absorbing portion 13, of the optical sheet 10 since emitted as normal and parallel rays is by angle when entering into the prism section 12 is 2 [Theta] _0.
Therefore, for a certain refractive index N _i and angle θ _i ,
N _i sin θ _i = N ₀ sin (2θ ₀ ) (Formula 4)
Holds. And by transforming Equation 4,
θ _i = sin ⁻¹ ((N ₀ / N _i ) sin (2θ ₀ )) (Formula 5)
Get.

  Further, Expression 6 is obtained by substituting Expression 5 into Expression 2.

Here, the relationship between the distance x and the length p (see FIG. 5) in the direction in which the light absorbing portions 13, 13,.
x ≦ p (Formula 7)
Therefore, ghost can be suppressed. If x> p, it means that light rays (image light) incident on the lens unit from other pixels increase, which is a factor in generating ghosts.
Therefore, Expression 8 can be obtained from Expression 6 and Expression 7.

  Generation of a ghost can be suppressed by the PDP unit 1 having the above relationship.

  FIG. 7 is a diagram schematically showing the layer structure of the PDP unit 21 of the present invention according to the second embodiment. The PDP unit 21 includes a PDP 2 and an optical sheet 30, and the optical sheet 30 is directly laminated on the PDP 2. Therefore, the PDP unit 21 does not have the air layer A (gap) provided in the above PDP unit 1.

  Since the PDP 2 of the PDP unit 21 is common to the PDP 2 provided in the PDP unit 1 described above, the description thereof is omitted. The optical sheet 30 includes an optical function sheet layer 31, a PET film layer 36 as a base material layer, and an adhesive layer 37. The optical sheet 30 differs from the optical sheet 10 in that the pressure-sensitive adhesive layer 37 is disposed on the PDP 2 side of the optical function sheet layer 31. Thereby, the optical sheet 30 can be directly laminated on the PDP 2. About each layer, since it is common with description of the optical function sheet | seat layer 11, the PET film layer 16, and the adhesive layer 17 of the optical sheet 10, description is abbreviate | omitted here.

  Here, an example in which the optical sheet 30 is directly laminated on the PDP 2 has been shown. However, the present invention is not limited thereto, and other film layers such as an electromagnetic wave blocking layer may be provided between the PDP and the optical sheet. Good.

  Next, a configuration when the PDP unit 1 is attached to a plasma television 19 that is a display device will be described. FIG. 8 is a cross-sectional view paying attention to a portion where the PDP unit 1 is disposed when the PDP unit 1 is provided in the plasma television 19. In FIG. 8, the right side of the drawing is the observer side.

  As shown in FIG. 8, when the PDP unit 1 is provided in the plasma television 19, various layers (6, 7) having, for example, AS and AR functions are provided on the viewer side of the adhesive layer 17. ing. Here, “AS” is an abbreviation of “anti-static” and means an antistatic function, and “AR” is an abbreviation of “anti-reflection” and means a function of suppressing light reflectance. An “AG (anti-glare)” layer that can prevent glare on the screen may be provided instead of AR.

  Here, various layers of AR and AS have been exemplified as other layers provided, but other layers having other functions can be provided as necessary. Examples thereof include a layer for correcting the color tone.

  Examples of the PDP unit having the above configuration will be described below in more detail. However, the present invention is not limited to the scope of the examples.

Four examples of PDP units shown in Table 1 were manufactured and examined for ghosting. “N ₁ , N ₂ , N ₃ , N ₀ , L ₁ , L ₂ , L ₃ , θ ₀ ” shown in Table 1 means the same symbols as those shown in FIG.

  Example 1 and Comparative Example 1 are examples having an air layer as shown in FIG. 1, and Example 2 and Comparative Example 2 are examples having no air layer as shown in FIG. The presence or absence of the ghost was visually observed.

  Table 2 shows the results. Here, “low” is described when the degree of ghost generation is small, and “high” is described when ghost generation is large.

According to this, when the actual θ ₀ is made smaller than θ ₀ in the case of p = x, the degree of occurrence of ghost can be suppressed low. Conversely, when θ ₀ is increased, the degree of ghost generation increases.

  Although the present invention has been described in connection with the most practical and preferred embodiments at the present time, the present invention is not limited to the embodiments disclosed herein, The invention can be changed as appropriate without departing from the scope or spirit of the invention that can be read from the claims and the entire specification, and a PDP unit and a display device accompanying such a change are also included in the technical scope of the present invention. Must be understood.

It is the figure which showed the cross section of the PDP unit of this invention concerning 1st embodiment, and represented the layer structure typically. It is the figure which expanded and showed the optical sheet with which the PDP unit shown in FIG. 1 is equipped. It is the figure which expanded and showed a part of optical sheet shown in FIG. It is the figure which showed the example whose light absorption part of an optical sheet is trapezoid. It is a figure for demonstrating the relationship of each component. It is another figure for demonstrating the relationship of each component. It is the figure which showed the cross section of the PDP unit of this invention concerning 2nd embodiment, and represented the layer structure typically. It is a figure for demonstrating the example in which the PDP unit of this invention was attached to the plasma television.

Explanation of symbols

1,21 Plasma display panel unit (PDP unit)
2 Plasma display panel (PDP)
DESCRIPTION OF SYMBOLS 10, 30 Optical sheet 11, 31 Optical function sheet layer 12 Prism part 13 Light absorption part 14 Binder part 15 Light absorption particle 16, 36 PET film layer 17, 37 Adhesive layer 19 Plasma television (display apparatus)

Claims (11)

A plasma display panel in which pixels are provided in parallel in vertical and horizontal directions;
An optical sheet disposed on the image output side of the plasma display panel and having a plurality of layers, and a plasma display panel unit comprising:
At least one of the plurality of layers of the optical sheet is
In the sheet thickness direction cross section, a trapezoidal shape having a short upper base on one sheet surface side and a long lower base on the other sheet surface side is formed so that light can be transmitted by a material having a refractive index N ₀ , A prism portion juxtaposed along,
A triangle having a hypotenuse with an angle of θ ₀ with respect to the normal of the sheet surface, the refractive index N _b being smaller than the refractive index N _0. A light-absorbing part formed so as to be capable of absorbing light with a material, and an optical functional sheet layer,
The thickness L _i of the layer provided between the image exit side of the pixel and the optical functional sheet _layer, the refractive index of the layer and N _i, the size of the pixel in a direction in which the prism portion is parallel When p is

A plasma display panel unit having the following relationship: A plasma display panel in which pixels are provided in parallel in vertical and horizontal directions;
An optical sheet disposed on the image output side of the plasma display panel and having a plurality of layers, and a plasma display panel unit comprising:
At least one of the plurality of layers of the optical sheet is
In the sheet thickness direction cross section, a trapezoidal shape having a short upper base on one sheet surface side and a long lower base on the other sheet surface side is formed so that light can be transmitted by a material having a refractive index N ₀ , A prism portion juxtaposed along,
Provided between the prism portions, having a long lower base on the one sheet surface side, a short upper base on the other sheet surface side, and a hypotenuse whose angle with respect to the normal of the sheet surface is θ ₀ trapezoidal, and the light-absorbing part which is light absorbable form have the a refractive index N ₀ is smaller than the refractive index N _b material, an optical functional sheet layer comprising,
The thickness of a given layer that is provided between the image exit surface and the optical functional sheet layer of the pixel is L _i, the refractive index of the layer and N _i, the pixel of the direction in which the prism portion is parallel When the size of is p,

A plasma display panel unit having the following relationship:   The plasma display panel unit according to claim 1 or 2, wherein the light absorption part contains light absorption particles having an average particle diameter of 1 µm or more.   The plasma display panel unit according to claim 1, wherein the light absorbing portion contains a black pigment or a dye.   The plasma display panel unit according to claim 4, wherein the black pigment is carbon black.   The light absorption portion is configured to have a light absorption performance such that the transmittance is 70% or less in the transmittance measurement of a sheet having a thickness of 6 μm formed of only the material constituting the light absorption portion. The plasma display panel unit according to any one of claims 1 to 5, wherein:   The plasma display panel unit according to any one of claims 1 to 6, wherein a length of the short upper base of the prism portion is 50% to 90% of a parallel pitch of the prism portions. . The plasma display panel unit according to claim 1, wherein θ ₀ is greater than 0 degree and equal to or less than 10 degrees. 9. The plasma display panel unit according to claim 1, wherein both N ₀ and N _b have a value of 1.49 to 1.56. The plasma display panel unit according to any one of claims 1 to 9, wherein a difference between the N ₀ and the N _b is greater than 0 and 0.07 or less.   A display device comprising the plasma display panel unit according to claim 1.

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