JP3777434B2 - 3D display using light emitting diodes - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a stereoscopic display that is mainly used outdoors and can view a stereoscopic image without wearing glasses.
[0002]
[Prior art]
The light emitting diode has a feature that it can be used outdoors because of its high emission luminance. An LED flat display in which RGB light emitting diodes are arranged in a plane is used for outdoor use. In this LED flat display, a lenticular lens is disposed on the front surface, and images of the right eye and the left eye can be displayed on the LED flat display to form a three-dimensional display. The three-dimensional display having this structure has a feature that three-dimensional display can be performed without using glasses. FIG. 1 shows a principle diagram of this stereoscopic display. In this stereoscopic display, as shown in the figure, a right eye image and a left eye image of a light emitting diode are imaged by the lenticular lens 3 to the right and left eyes of the observer.
[0003]
[Problems to be solved by the invention]
The three-dimensional display having this structure requires the lenticular lens 3 to be separated from the LED flat display 1 as the observer looks farther away, in other words, as the observation distance becomes longer. For example, if the pixel pitch of the LED flat display 1 is 8 mm, the observation distance is 20 m, and the distance between both eyes is 65 mm, the distance between the LED flat display 1 and the lenticular lens 3 is about 2 meters. As shown in FIG. 2, the pixel pitch of the LED flat display 1 can be reduced to narrow the distance between the lenticular lens 3 and the LED flat display 1. However, since the LED flat display 1 has a structure in which one pixel 2 is formed by three light emitting diodes of RGB, the pixel pitch is limited by the size of the light emitting diodes and cannot be reduced.
[0004]
The distance between the LED flat display 1 and the lenticular lens 3 is the depth of the stereoscopic display. Therefore, a stereoscopic display with a depth of 2 meters cannot be installed on the wall of a building, for example. Since the stereoscopic display used outdoors is often fixed to the wall of the building, the application of the stereoscopic display that cannot be installed on the wall of the building is extremely limited.
[0005]
A three-dimensional display that observes a three-dimensional image by wearing glasses of a polarizing plate can be shallow because it does not use a lenticular lens. However, a stereoscopic display using glasses has a drawback that no one can see a stereoscopic image when used outdoors. Instead of the lenticular lens, a three-dimensional display can be realized by providing a slit on the front surface of the LED flat display. However, the three-dimensional display with this structure also has a long interval between the slit and the LED flat display, and the depth cannot be reduced.
[0006]
The present invention has been developed for the purpose of solving such drawbacks of conventional LED stereoscopic displays. An important object of the present invention is to provide a stereoscopic display using light-emitting diodes that can be stereoscopically displayed with a shallow depth without using glasses.
[0007]
[Means for Solving the Problems]
In the three-dimensional display of the present invention, a lenticular lens 3 is arranged in parallel with the LED flat display 1 on the front surface of the LED flat display 1 in which a large number of RGB light emitting diodes are arranged in a plane. Further, an auxiliary lenticular lens 4 that forms an image by reducing the pixel pitch of the LED flat display 1 is disposed between the lenticular lens 3 and the LED flat display 1, and an image formed by the auxiliary lenticular lens 4. Is formed on the position of the observer's eyes by the lenticular lens 3.
[0008]
The pitch of the auxiliary lenticular lens 4 can be set to 0.3 to 3 mm. Furthermore, the focal length of the auxiliary lenticular lens 4 can be set to 2 to 10 mm.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. However, the example shown below illustrates the three-dimensional display for embodying the technical idea of the present invention, and the present invention does not specify the three-dimensional display as described below.
[0010]
Further, in this specification, in order to facilitate understanding of the scope of claims, the numbers corresponding to the members shown in the embodiments are referred to as “claims” and “means for solving the problems”. It is added to the member shown by. However, the members shown in the claims are not limited to the members in the embodiments.
[0011]
The three-dimensional display of FIG. 3 has a lenticular lens 3 disposed in parallel with the LED flat display 1 on the front surface of the LED flat display 1 in which a large number of RGB light emitting diodes are arranged in a plane. Further, between the lenticular lens 3 and the LED flat display 1, an auxiliary lenticular lens 4 that forms an image by reducing the pixel pitch of the LED flat display 1 is disposed.
[0012]
The LED flat display 1 has a right-eye pixel array and a left-eye pixel array arranged vertically. Each of the right-eye and left-eye pixels 2 is provided with RGB light emitting diodes to form full-color pixels 2. The right-eye and left-eye pixel columns are alternately arranged in the horizontal direction. The LED flat display 1 displays an image viewed with the right eye with a pixel array for the right eye, and displays an image viewed with the left eye with the pixel array for the left eye. The three-dimensional display displays the image three-dimensionally as a slightly different image for the right eye and the left eye. The LED flat display 1 is an RGB display that configures each pixel 2 so that a viewer can view a right-eye image with the right eye and a left-eye image with the left eye to form a stereoscopic image. The light emitting diode blinks.
[0013]
The lenticular lens 3 and the auxiliary lenticular lens 4 are arranged so that the observer can view the pixel array for the right eye on the right side of the observer so that the observer can see the LED flat display 1 from a predetermined position and view it as a stereoscopic image. A pixel row for the left eye is imaged on the left eye of the observer. In particular, the stereoscopic display according to the present invention has an auxiliary depth lenticular lens 4 disposed between the LED flat display 1 and the lenticular lens 3 so that the distance between the LED flat display 1 and the lenticular lens 3 is close to the entire depth. Is shallow.
[0014]
The auxiliary lenticular lens 4 and the lenticular lens 3 have a convex lens shape in the horizontal section and a lens shape in the vertical section, and are made of transparent glass, plastic, or a composite material thereof. The pitch and focal length of the auxiliary lenticular lens 4 and the lenticular lens 3 specify the depth of the entire stereoscopic display. The pitch and focal length of the auxiliary lenticular lens 4 and the lenticular lens 3 can be optimally designed by the method described in detail below, and the depth of the stereoscopic display can be minimized. However, the three-dimensional display of the present invention does not necessarily require the depth of the three-dimensional display to be a minimum value.
[0015]
In the conventional stereoscopic display in which the lenticular lens 3 is disposed on the front surface of the LED flat display 1 without providing the auxiliary lenticular lens, the distance between the lenticular lens 3 and the LED flat display 1 increases as the observer looks away. It needs to be wide. However, as shown in FIGS. 1 and 2, the three-dimensional display having this structure can narrow the interval between the LED flat display 1 and the lenticular lens 3 by narrowing the pitch of the pixel rows of the LED flat display 1. However, since the LED flat display 1 comprises one pixel 2 with RGB light emitting diodes, the pixel pitch cannot be made smaller than the size of the light emitting diodes. That is, it is difficult to reduce the pixel pitch of the LED flat display 1 due to restrictions on the size of the light emitting diode. In particular, a three-dimensional display for outdoor use is a type having a condensing lens in order to cause a light emitting diode to emit light with high brightness. This type of light-emitting diode has a large external shape, and at least three of the light-emitting diodes are used to form one pixel 2 with RGB light-emitting diodes, so it is extremely difficult to reduce the pixel pitch.
[0016]
The auxiliary lenticular lens 4 is disposed in front of the LED flat display 1 in parallel with the LED flat display 1 to reduce the pixel pitch of the LED flat display 1. That is, the auxiliary lenticular lens 4 forms an image of a pixel row with a pixel pitch narrowed to 1 / M of the pixel row of the LED flat display 1 on the front surface thereof.
[0017]
When the reduction ratio at which the auxiliary lenticular lens 4 reduces the pixel row is M, the reduction ratio M is calculated by the following equation.
M = (2P0 / P1) -1 …… (1)
In this equation, P0 is the pixel pitch of the LED flat display 1, and P1 is the pitch of the auxiliary lenticular lens 4. The pitch P1 of the auxiliary lenticular lens 4 is the center distance between adjacent lenses arranged vertically. The center distance between adjacent lenses is the width of each lens. When the reduction ratio M is specified from this equation, the interval a1 between the auxiliary lenticular lens 4 and the LED flat display 1 and the interval b1 between the auxiliary lenticular lens 4 and the imaging position are calculated by the following equations.
a1 = f1 (M + 1) ………… ▲ 2 ▼
b1 = f1 (M + 1) / M …… (3)
[0018]
In this equation, f1 is the focal length of the auxiliary lenticular lens 4.
When the reduction ratio M and the focal length f1 of the auxiliary lenticular lens 4 are specified from the equations (2) and (3), the distance a1 between the auxiliary lenticular lens 4 and the LED flat display 1 is specified. Further, the image position reduced by the auxiliary lenticular lens 4 is also specified by b1.
[0019]
When the above-described parameters of the auxiliary lenticular lens 4 are specified, the pitch P2, the position a2, and the focal length f2 of the lenticular lens 3 are specified by the following equations.
P2 = 2KP0 / (KM + P0) ...... (4)
a2 = b2P0 / KM ……………… ▲ 5 ▼
f2 = b2P0 / (KM + P0) ...... (6)
In the formulas (4) to (6), K is the distance between the observer's eyes and is generally about 65 mm, and b2 is the distance from the lenticular lens 3 to the observer.
[0020]
By the way, the depth (T) of a three-dimensional display is represented by the following formula.
T = a1 + b1 + a2 ………… ▲ 7 ▼
From this equation, dT / dM = 0 is calculated, and the value of the reduction ratio M that minimizes the depth (T) of the stereoscopic display is calculated. The value of the reduction ratio M is expressed by the following formula.
M = (1 + b2P0 / Kf1) ^1/2 ... (8)
[0021]
FIG. 4 is a graph showing the depth (T) of the stereoscopic display with respect to the pitch (P1) of the auxiliary lenticular lens 4. However, the curve A in this figure shows the characteristic that the focal length of the auxiliary lenticular lens 4 is 2 mm, the curve B shows the characteristic that the focal length of the auxiliary lenticular lens 4 is 3 mm, and the curve C is the focal point of the auxiliary lenticular lens 4. The characteristic which makes distance 10mm is shown. Further, the distance between the lenticular lens 3 and the observer is 20 m, the distance between the eyes of the observer is 65 mm, and the pixel pitch of the LED flat display 1 is 8 mm.
[0022]
From this figure, the stereoscopic display of the present invention can be made extremely thin with a minimum depth of only 14.4 cm by setting the focal length and pitch of the auxiliary lenticular lens 4 and the lenticular lens 3 to the following values.
f1 = 2mm
f2 = 69.9mm
P1 = 0.443mm
P2 = 0.454mm
[0023]
With the above configuration, the depth of the stereoscopic display can be made extremely shallow, but since the pitch between the auxiliary lenticular lens 4 and the lenticular lens 3 is extremely narrow as 1 mm or less, the pitch and the focal length of the auxiliary lenticular lens 4 and the lenticular lens 3 are as follows. The depth can be set to 44.3 cm.
f1 = 10mm
f2 = 346mm
P1 = 2mm
P2 = 2.25mm
[0024]
By the way, the stereoscopic display without the auxiliary lenticular lens 4 has the focal length and pitch of the lenticular lens 3 as follows, and the depth becomes extremely thick at 2.46 m.
f2 = 2.16mm
P2 = 14.2mm
[0025]
As described above, the three-dimensional display of the present invention can be made extremely thin by disposing the auxiliary lenticular lens 4 between the lenticular lens 3 and the LED flat display 1. The stereoscopic display according to the present invention has an auxiliary lenticular lens 4 disposed between the lenticular lens 3 and the LED flat display 1 to reduce the depth, but the focal length and pitch of the auxiliary lenticular lens 4 are lenticular. It affects the pitch and focal length of the lens 3 and also affects the depth of the stereoscopic display. Therefore, the focal length and pitch of the auxiliary lenticular lens 4 are determined to be values that allow both the lenticular lens 3 and the auxiliary lenticular lens 4 to be easily manufactured and make the stereoscopic display as thin as possible. From FIG. 4, the value of the reduction ratio M that makes the stereoscopic display the minimum depth is specified, but the stereoscopic display of the present invention does not necessarily specify the reduction ratio M to this value. This is because by changing the value of the reduction ratio M, it is possible to make the auxiliary lenticular lens 4 and the lenticular lens 3 simpler, while making the increase in depth relatively small.
[0026]
From the above, the auxiliary lenticular lens 4 has a minimum pitch of 0.3 mm or more so that it can be easily manufactured while making the stereoscopic display as thin as possible. Although the auxiliary lenticular lens 4 can be easily manufactured by increasing the pitch, it is necessary to increase the focal length of the auxiliary lenticular lens 4 and the lenticular lens 3 when the pitch is increased. Since the lenticular lens 3 has a longer focal length than the pitch, it becomes difficult to manufacture as the focal length increases. Therefore, the pitch of the auxiliary lenticular lens 4 is preferably 3 mm or less. Further, the focal length of the auxiliary lenticular lens 4 is preferably 2 to 10 mm in order to facilitate the production of the auxiliary lenticular lens 4 and the lenticular lens 3. Further, the pitch of the lenticular lens 3 is preferably designed to be 0.3 to 3 mm.
[0027]
【The invention's effect】
The three-dimensional display of the present invention has an advantage that three-dimensional display can be performed with a shallow depth without using glasses. In the stereoscopic display of the present invention, an auxiliary lenticular lens that forms an image by reducing the pixel pitch of the LED flat display is disposed between the LED flat display and the lenticular lens. This is because the image is formed on the observer's eye position with a lenticular lens. The stereoscopic display having this structure can change the depth of the stereoscopic display to be small by changing the value of the reduction ratio by changing the pitch and focal length of the auxiliary lenticular lens. Therefore, the stereoscopic display of the present invention can be ideally stereoscopically displayed with a reduced depth even if it is an LED flat display that is composed of RGB light emitting diodes and is limited by the pixel pitch. Thus, the three-dimensional display which can make depth small can be used very conveniently for various uses.
[Brief description of the drawings]
FIG. 1 is a schematic plan view showing the principle of a conventional stereoscopic display. FIG. 2 is a schematic plan view showing the principle of another conventional stereoscopic display. FIG. 3 is a schematic exploded perspective view of a stereoscopic display according to an embodiment of the present invention. [Fig.4] Graph showing depth of stereoscopic display with respect to pitch of auxiliary lenticular lens [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... LED flat display 2 ... Pixel 3 ... Lenticular lens 4 ... Auxiliary lenticular lens

Claims (3)

A lenticular lens (3) is arranged in parallel with the LED flat display (1) on the front surface of the LED flat display (1) in which a large number of RGB light emitting diodes are arranged in a plane.
Furthermore, an auxiliary lenticular lens (4) is formed between the lenticular lens (3) and the LED flat display (1) to reduce the pixel pitch of the LED flat display (1) and form an image. A three-dimensional display using a light-emitting diode that forms an image formed by the lenticular lens (4) at the position of the observer's eye using the lenticular lens (3). The three-dimensional display using a light emitting diode according to claim 1, wherein the pitch of the auxiliary lenticular lens (4) is 0.3 to 3 mm. The stereoscopic display using a light emitting diode according to claim 1, wherein the focal length of the auxiliary lenticular lens (4) is 2 to 10 mm.

Images