JP3080374B2 - Display device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device using a plurality of light transmission displays.

[Conventional technology]

In recent years, a display is required to have a large screen and a thin shape, and various devices to which a light transmission type display such as a liquid crystal display device which is optimal for the thinning are applied have been proposed. For example,
National Technical Report Vol.33 No.1 Feb.198
FIG. 7 proposes a configuration as shown in FIG. In FIG. 2, 1 is a light source and 3 is a light transmission type display. In this proposal, a light transmissive display 3 for displaying a screen by light from the light source 1 is arranged in close contact with the light-transmitting display 3,
A thin, large-screen display device has been obtained.

Further, Japanese Patent Application Laid-Open No. 61-138288 proposes a configuration as shown in FIG. In FIG. 3, 1 is a light source, 3 is a light transmission type display, and 5 is a screen. In this proposal, the divergent light from the light source 1 is radiated to the light transmission type display 3 and the enlarged screen of the light transmission type display 3 is projected on the screen 5. Has obtained a large screen display device.

[Problems to be solved by the invention]

The above National Technical Report Vol.33 No.1 F
In the prior art proposed in eb.1987, there is a problem that an unnatural screen is formed because a seam is formed between the light transmission displays. For example, 64 AZ-5 (8 vertical, 8 horizontal) light-transmitting displays described in this proposal are connected to obtain a large screen with a screen size of 1.6 m and 2.1 m.
At 100, the seam between the light transmissive displays is about 10 mm. This is equivalent to seven lines each of 10 mm in width being drawn in a screen of 1.6 m in length and 2.1 m in width, 7 lines each in the vertical and horizontal directions. In the method of simply connecting the light-transmitting displays as in the present proposal, such mechanical joints are inevitably generated, and it is impossible to eliminate them.

Further, in the prior art proposed in Japanese Patent Application Laid-Open No. 61-138288, the screens on the light transmission type display are enlarged and connected, so that there is no mechanical joint. However, since the divergent light from the light source enters the light transmission type display, the angle of the incident light varies depending on the height of the light transmission type display. As a result, color unevenness and brightness unevenness occur on the screen of the light transmission type display, and as a result, color unevenness and brightness unevenness also occur on the enlarged screen on the screen.

SUMMARY OF THE INVENTION It is an object of the present invention to improve the disadvantages of the prior art and to provide a display device which is thin and can be enlarged and displayed, and which suppresses seams due to graphic distortion.

[Means for solving the problem]

In order to achieve the above object, the present invention provides a unit display comprising a light source, a light transmission type display, and a lens group having a negative refractive power and at least one surface having an aspherical surface in both vertical and horizontal directions. A plurality of unit display groups arranged side by side, and a screen arranged at a predetermined distance on the front side of the unit display group, comprising at least one of images projected from each unit display of the unit display group. In order to display a part of the images on the screen by joining them, the lens group enlarges the display image of the light transmission type display with its negative refractive power and corrects the graphic distortion on the aspherical surface. And

[Action]

The divergent light from the light source passes through the first lens group, the light transmission display, and the second lens group in this order, and reaches the screen. The first lens group has a positive refractive power, and the light source is arranged near a focal position on the light source side of the first lens group. As a result, the divergent light from the light source becomes a parallel light beam after passing through the first lens group and irradiates the light transmissive display, so that the screen of the light transmissive display has no color unevenness or luminance unevenness. Since the second lens group has a negative refractive power and enlarges the display screen of the light transmission display, an enlarged screen of the light transmission display free from color unevenness and luminance unevenness is obtained on the screen. According to the present invention, a unit display is constituted by a light source, a first lens group, a light transmission type display, and a second lens group, and a plurality of unit displays are arranged side by side by coupling means for arranging the unit displays adjacent to each other. Since a screen is arranged on the front side and the display images of the unit displays are joined on the screen to obtain a large screen, no mechanical joint occurs. Further, the first lens group, the second lens group, or both of them have an operation of correcting distortion of a display image of the unit display. As a result, since the display images on each unit display have no distortion, when these display images are connected to form a large screen, a natural large screen having no joint between the display images and a sense of incompatibility can be obtained.

In the present invention, the first lens group or the second lens group is used.
By including a lens group of at least one lens is an aspheric surface, or by using a Fresnel lens,
The effect of reducing the number of lenses or reducing the weight can be obtained.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to FIG. FIG. 1 shows an embodiment of a large-screen display device according to the present embodiment. In FIG. 1 (a), 1 is a light source, 2 is a first lens group, 3 is a light transmissive display, 4 is a second lens group, 5 is a screen, and a light source 1 to a second lens group. The unit display (6) is constituted by up to four. As the light source 1, a halogen lamp or a xenon lamp is used. The first lens group includes two lenses having positive refractive power. Light-transmitting display has an effective screen size of 5 inches (diagonal length 125 mm)
Liquid crystal display panel. The second lens group 4 is composed of one lens having a negative refractive power. The screen 5 has a screen size of 100 inches (diagonal length 2.5 m).

The light source 1 is arranged in the vicinity of the principal point of the first lens group 2 on the light source side, so that the divergent light emitted from the light source 1 becomes a substantially parallel light beam after passing through the first lens group 2 and is a light transmission type display. Irradiate 3 Therefore, a screen free from color unevenness and luminance unevenness is obtained. The parallel light flux after passing through the light transmission type display 3 is deflected by the second lens group 4 and reaches the screen 5. Thereby, an enlarged screen of the light transmission display 3 is obtained on the screen 5. In the unit display 6 of this embodiment, a liquid crystal display panel having a diagonal screen size of 5 inches is used for the light transmission type display 3.
The image is magnified about twice by the second lens group 4 to obtain a 10-inch screen. Further, in this embodiment, ten unit displays 6 are arranged vertically and ten units horizontally, so that 10 units as a whole are arranged.
A 100-inch large-screen display device has been obtained with zero unit displays.

FIG. 1 (b) shows the appearance of the large screen display device of the present embodiment, in which a large screen of 100 inches is shown in depth.
It is realized in an ultra-thin form of 0.3 to 0.5m.

FIG. 4 shows a lens configuration of the unit display 6 of the present embodiment. Hereinafter, numerical examples corresponding to FIG. 4 will be described.

In the numerical examples, Ri is the radius of curvature of the i-th lens surface Si in order from the light source side, and Di is the lens surface S from the lens surface Si.
The distance on the optical axis between _{i + 1} , Nj and Vj are the refractive index and the number of the j-th lens in order from the light source side, L is the distance between the light source 1 and the screen 5, and M is the second. The magnification, h ₀ , of the lens group 4 is the diagonal size of the light transmission display.

Numerical Example Corresponding to FIG. 4 L = 236 mm, M = 1.96 times, h ₀ = 5 inches S R D N V 1 ∞ 53.0 2 −140.000 21.0 1.67270 32.10 3 −66.802 1.0 4 1270.000 21.0 1.67270 32.10 5 −130.98 10.0 6 ∞ 20.0 7 -212.79 5.0 1.84666 23.88 8 324.28 105.0 9 ∞ where S ₁ is a light source, S ₆ is a light transmitting display, and S ₉ is a dummy surface corresponding to a screen.

Next, the color unevenness of the present embodiment will be described. FIG. 5 shows angles of light rays emitted from the light source 1 and incident on the light transmission type display 3 through the first lens group 2;
The height in the diagonal direction of the light transmission display 3 is shown. As shown in the figure, in this embodiment, the angle of the incident light beam of the light transmission type display is 3 degrees or less, which is a substantially parallel light beam, and color unevenness and brightness unevenness do not occur on the light transmission type display 3. As a result, a large screen without color and luminance unevenness is obtained.

Next, the joint of the unit display 6 due to the graphic distortion will be described. FIGS. 6A and 6B show the distortion of the screen on the screen 5, in which FIG. 6A shows the graphic distortion with respect to the height on the vertical light transmission display 3, and FIG. 6B shows the horizontal light transmission display. 3 is the figure distortion with respect to the height above. (C) schematically shows a state in which short screens of the four unit displays are connected on the screen 5 to form one screen. In this embodiment, the figure distortion of the screen on the screen 5 corresponding to the outermost periphery of the light transmission display 3 in both the vertical and horizontal directions is 0.01%,
At this time, the shift amount between the respective screens is about 0.1 mm. For this reason, in this embodiment, a large seamless screen is obtained due to the graphic distortion of the unit display 6.

Next, an example in which an aspheric lens is applied to the first lens group or the second lens group will be described. FIG.
FIG. 2 is a lens configuration of an embodiment in which the lens group of FIG. 2 is configured by a single lens having negative refractive power and both surfaces being aspherical;
Reference numeral 4 'denotes a first lens group using an aspheric lens. Hereinafter, numerical examples corresponding to FIG. 7 will be described. In the numerical examples, Di, Di, Nj, Vj, L, and M are the same as the definitions of the numerical examples corresponding to FIG.

Numerical Example L = 210 corresponding to FIG. 7 (mm), M = 2.0 [times], h ₀ = 5 [inch] S R D N V 1 ∞ 55.0 2 -197.10 19.0 1.84666 23.88 3 -74.21 1.0 4 - 1096.0 17.0 1.84666 23.88 5 -132.70 10.0 6 ∞ 14.0 7 -145.81 ^* 5.0 1.84666 23.88 8 252.76 ^* 89.0 9 ∞ In addition, the lens surface with an asterisk (*) attached to the radius of curvature is an aspheric surface, and the shape is the aspheric coefficient of the following formula. Is shown as follows.

Z: distance from the tangent plane of the apex of the aspheric surface on the aspheric surface at height Y from the optical axis C: curvature of the reference sphere (1 / r) K: conical constant Y: height from the optical axis A _{4 to} A ₁₀ : 7 aspherical surfaces K = 0.1750 A ₄ = −1.2341 × 10 ⁻⁷ A ₆ = 4.2798 ×
10 ^-11 A ₈ = 1.6446 x 10 ^-15 A ₁₀ = 3.2262 x
10 ^-19 8 surface _{K = 1.3789 A 4 = -1.3979 ×} 10 -8 A 6 = -1.2810
× 10 ^-11 A ₈ = 3.7944 × 10 ^-15 A ₁₀ = 4.9950 ×
10 ^-19 The vertical direction, graphic distortion of the unit display outermost periphery of the horizontal direction in the present embodiment is 0.01%, respectively, large-screen display device with no seams by graphic distortion can be obtained according to the present unit display.

Next, an example in which a Fresnel lens is applied to the first lens group or the second lens group will be described. FIG. 8 shows a lens configuration of an embodiment in which the first lens group is composed of one Fresnel lens having a positive refractive power, and the second lens group is composed of one Fresnel lens having a negative refractive power. ′ Is a first lens group using a Fresnel lens, and 4 ″ is a second lens group using a Fresnel lens.

Next, an embodiment in which a lens having the color temperature conversion effect or the heat absorption effect and a lens having any of these effects is attached to the lens in the first lens group 2 will be described.

In the embodiment shown in FIG. 9, reference numeral 7 denotes a laminated lens having a color temperature conversion effect or a heat absorption effect, and both effects. A display using a halogen lamp or a xenon lamp as a light source often requires a color temperature conversion filter or a heat absorption filter. In this embodiment, since some lenses of the first lens group 2 have a color temperature conversion effect or a heat absorption effect and any of these effects, a color temperature conversion filter,
Alternatively, since it is not necessary to newly install a heat absorption filter, the configuration can be simplified.

Next, an embodiment in which the surface of the lens in the first lens group 2 is subjected to a thin film treatment having a color temperature conversion effect or a heat absorption effect and any of these effects will be described.

In the embodiment shown in FIG. 10, reference numeral 8 denotes a thin film having a color temperature conversion effect or a heat absorption effect, and any of these effects. According to this embodiment, since a part of the first lens group 2 is subjected to a color temperature conversion effect or a heat absorption effect and a thin film treatment having any of these effects, a color temperature conversion filter and a heat absorption filter are newly provided. A simple configuration can be achieved without the need for installation.

Next, an embodiment in which the unit displays are arranged differently in the vertical direction and the horizontal direction to form a special screen such as a vertical screen and a horizontal screen will be described.

FIG. 11 is an embodiment of a screen when a multi-display is configured using the unit display shown in FIG. In FIG. 11 (a), three unit displays are arranged in each of the vertical direction and the horizontal direction, and as a whole, a screen corresponding to a normal broadcast standard of 18 inches by 24 inches and an aspect ratio of 3: 4 is displayed. It has gained. On the other hand, in Fig. 11 (b), three unit displays are arranged in the vertical direction and four unit displays are arranged in the horizontal direction, and as a whole, it corresponds to a high-definition television broadcast of 18 inches by 32 inches and an aspect ratio of 9:16. Obtained landscape screen.
Further, if the number of unit displays in the vertical and horizontal directions is increased, a larger screen having a larger size can be obtained.

Next, a plurality of lenses in the first lens group or the second lens group are simultaneously molded by a forming method such as molding or injection molding, and a joint portion of each lens is used as a coupling means when disposing the unit display. An example is shown.

FIG. 12 (a) has four unit displays shown in FIG. 1, and simultaneously molds four lenses of the first lens group and the second lens group, and joins the joint portion when the unit displays are arranged. Fig. 12 (b) shows a lens at the time of molding when the large-screen display device of the present invention is used as the coupling means.

According to this embodiment, when the unit displays are arranged adjacent to each other, there is no need for a means for coupling the lenses of the light focusing lens group and the light deflecting lens group.

〔The invention's effect〕

According to the present invention, since a unit display is constituted by at least the light source, the first lens group, the light transmission display, and the second lens group, uniform brightness and distortion correction are optically performed in each unit display. Therefore, a large-screen display can realize a large screen with high image quality without color unevenness and seamless connection, and has an effect that a screen size and a screen aspect ratio can be freely selected.

[Brief description of the drawings]

1 is a block diagram showing an embodiment of a large-screen display device according to the present invention, FIGS. 2 and 3 are block diagrams of a conventional large-screen display device, FIG. 4 is a lens configuration diagram of a unit display, FIG. FIG. 5 is a characteristic diagram showing the incident light ray angle of the unit display to the light transmission type display, FIG. 6 is a characteristic diagram showing the graphic distortion of the unit display, and FIG. 7 is a case where an aspheric lens is applied to the first lens group. FIG. 8 shows a lens configuration of an embodiment in which a Fresnel lens is applied to the first lens unit and the second lens unit, and FIG. 9 shows a color temperature conversion effect or heat applied to the first lens unit. FIG. 10 is a lens configuration diagram of an embodiment in which a lens having an absorption effect is bonded. FIG. 10 is a configuration diagram of an embodiment in which a thin film process having a color temperature conversion effect or a heat absorption effect is applied to the first lens group.
FIG. 11 is a view showing the configuration of a screen when the unit displays are arranged in different vertical or horizontal directions. FIG. 12 is a diagram showing a case where a plurality of lenses in the first lens group or the second lens group are simultaneously formed, and each lens is formed. FIG. 4 is a diagram showing a configuration of an embodiment in which a joining portion between them is used as a joining means when unit displays are arranged adjacent to each other. DESCRIPTION OF SYMBOLS 1 ... Light source, 2 ... 1st lens group, 2 '... 1st lens group using Fresnel lens, 3 ... Light transmission display, 4 ... 2nd lens group, 4' ... A second lens group using an aspherical lens, 4 ″: a second lens group using a Fresnel lens, 5: a screen, 6: a unit display, 7: a laminated lens, 8: a filter film .

Continuation of front page (56) References JP-A-61-183688 (JP, A) JP-A-55-110291 (JP, A) JP-A-62-195984 (JP, A) JP-A-62-236283 (JP, A) , A) JP-A-56-128914 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G09F 9/40

Claims (3)

(57) [Claims] 1. A unit in which a plurality of unit displays each comprising a light source, a light-transmitting display, and a lens group having a negative refractive power and at least one surface having an aspheric surface are arranged in both longitudinal and lateral directions. A display group, and a screen disposed at a predetermined distance on the front side of the unit display group, wherein at least a part of an image projected from each unit display of the unit display group is displayed on the screen. A display device, wherein the lens group enlarges a display image of the light transmission type display with its negative refractive power and corrects a graphic distortion on an aspherical surface in order to display the images together. . 2. The display device according to claim 1, wherein the unit display group includes a Fresnel lens having an aspheric surface and a negative refractive power. 3. The display device according to claim 1, wherein the unit display group has a configuration in which at least one lens of the lens group couples the unit displays.