WO2002061492A1

WO2002061492A1 - Three-dimensional image display apparatus using aspherical mirrors

Info

Publication number: WO2002061492A1
Application number: PCT/KR2002/000130
Authority: WO
Inventors: Choong-Sun Park; Choul-Woo Park; Chang-Young Lee; Kyoung-Yong Kim
Original assignee: Dma Korea Co., Ltd.
Priority date: 2001-01-30
Filing date: 2002-01-29
Publication date: 2002-08-08
Also published as: KR20010044267A

Abstract

A three- dimensional image display apparatus using two aspherical (paraboloidal) mirrors for forming a three-dimensional image of an object is disclosed. The apparatus has two paraboloidal mirrors which face each other, and the optical axes of the mirrors are coincident with each other. The vertex of the second paraboloidal mirror is coincident with a focal point of the first paraboloidal mirror, and the object is placed around the vertex of the second paraboloidal mirror so that the real image of the object is viewed through the opening of the first paraboloidal mirror. When the focal length of the first paraboloidal mirror is the same as that of the second paraboloidal mirror, the real image is formed around the vertax of the first mirror. When a focal length of the mirror is shorter that of the second mirror, the real image of the object is formed farther than the vertex of the first paraboloidal mirror.

Description

THREE-DIMENSIONAL IMAGE DISPLAY APPARATUS USING ASPHERICAL MIRRORS

BACKGROUND OF THE INVENTION

(a) Field of the Invention

The present invention relates to a three-dimensional image display

apparatus, and more particularly, to such an apparatus which displays a real

image of an object using aspherical mirrors, specifically paraboloidal mirrors.

Further, the present invention allows a user to view the three-

dimensional image in various viewing angles so that it is applicable to

various applications including light fixtures, decoration articles, electronic and

electrical products for home or office, various optical instruments, as well as

scientific articles and playthings,

(b) Description of the Related Art

Recently, three-dimensional display apparatuses have been

developed, in which a real image of an object is formed so that a user may

view the image with a three-dimensional effect as if it were a real object.

However, the conventional three-dimensional display apparatuses display

images which are placed in a vertical direction to the object using a

beamsplitter, so that it is difficult to reduce the size of the apparatus.

Therefore, it is not suitable to embed the apparatus in a small article such as

scientific articles or playthings. SUMMARY OF THE INVENTION

It is an object of the present invention to provide a three-dimensional

display apparatus using aspherical mirrors including paraboloidal mirrors,

adaptable to various articles such as scientific articles, playthings, light

fixtures, decorating articles, electronic and electrical products for home or

office, and various optical instruments.

It is another object to provide a three-dimensional display apparatus

having various displaying effects, by rotating an object and/or the apparatus

itself.

It is still another object to provide a three-dimensional display

apparatus having various displaying effects, by inserting a light-emitting

device into an object or using an illuminating device.

To achieve these objects, as embodied and broadly described herein,

a three-dimensional image display apparatus according to the invention

comprises a first paraboloidal mirror having an opening formed at a vertex

thereof and a second paraboloidal mirror disposed facing the first

paraboloidal mirror, an optical axis of the second paraboloidal mirror being

coincident with that of the first paraboloidal mirror. The vertex of the second

paraboloidal mirror is coincident with a focal point of the first paraboloidal

mirror, and the object is placed around the vertex of the second paraboloidal

mirror, so that the real image of the object is viewed through the opening of the first paraboloidal mirror.

When the focal length of the first paraboloidal mirror is the same as

that of the second paraboloidal mirror, the real image is formed around the

vertex of the first mirror. When a focal length of the first mirror is shorter that

that of the second mirror, the real image of the object is formed farther than

the vertex of the first paraboloidal mirror.

The second paraboloidal mirror preferably has an opening formed at a

vertex thereof, and the apparatus further has a support, disposed behind the

opening of the second paraboloidal mirror, for supporting the object, so that

the object may be placed around the vertex of the second paraboloidal mirror.

One or more rotating units are preferably constructed to rotate the object

and/or the mirrors.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings provide a further understanding of the

invention, and together with the Detailed Description, explain the principles

of the invention. In the drawings:

Figs. 1 -2 show a three-dimensional image display apparatus

according to a first preferred embodiment of the present invention;

Fig. 3 illustrates the characteristics of a paraboloidal mirror;

Fig. 4 illustrates optical principles of the present invention;

Fig. 5 shows a three-dimensional image display apparatus according to a second preferred embodiment of the present invention;

Fig. 6 shows the three-dimensional image display apparatus of Fig. 5

when an object is an imaging screen;

Fig. 7 shows a three-dimensional image display apparatus according

to a third preferred embodiment of the present invention; and

Figs. 8-10 show a three-dimensional image display apparatus

according to a fourth preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will be described in detail with reference to the

accompanying drawings. The same reference numerals indicate the same

elements herein.

Referring to Figs. 1 -2, a three-dimensional image display apparatus

according to a first preferred embodiment will be described. As shown in Fig.

1 , the three-dimensional image display apparatus has a first paraboloidal

mirror 120 in an upper position and a second paraboloidal mirror 130 in a

lower position. The mirrors 120, 130 are disposed facing each other and the

optical axes thereof are coincident with each other. A vertex A of the second

paraboloidal mirror 130 is positioned at a focal point of the first paraboloidal

mirror 120. An object to be displayed is placed around the vertex A of the

second paraboloidal mirror 130, in the lower position.

The first paraboloidal mirror 120 has an opening which is formed at a vertex of the first paraboloidal mirror 120, so that a user can see a real

image 150 of the object, which is formed by the first and second paraboloidal

mirrors 120, 130.

The operation of the first preferred embodiment of the present

invention is as follows.

Referring to Fig. 3, the characteristics of a paraboloidal mirror will be

described. When rays enter into the paraboloidal mirror in parallel to an

optical axis O of the mirror, they are reflected and then all brought to a focal

point F of the mirror. Rays emitted from the focal point F are reflected and

then propagate in parallel to the optical axis O of the mirror.

The three-dimensional display apparatus of the present invention

uses this principle of the paraboloidal mirror. A three-dimensional image is

formed by two paraboloidal mirrors disposed facing each other such that the

focal point F1 of the first paraboloidal mirror 120 is coincident with the

position of the vertex A of the second paraboloidal mirror 130.

Referring to Fig. 4, two paraboloidal mirrors are used to form a real

image of the object. Let us assume that a point source of light lies on the

focal point F1 of the first paraboloidal mirror. A ray R1 emitted from the point

source is reflected from the first paraboloidal mirror 120 to be a ray R2 that is

parallel to the optical axis O. The ray R2 is then reflected from the second

paraboloidal mirror 130 through a focal point F2 of the second paraboloidal mirror 130 to be a ray R3. Therefore, the real image of the object is formed

around the focal point F2 of the second mirror 130 when the object is laid on

either the focal point F1 of the first paraboloidal mirror 120 or the vertex A of

the second paraboloidal mirror 130.

When a focal length of the first mirror 120 is the same as that of the

second mirror 130, the real image 150 of the object is formed at the vertex of

the first paraboloidal mirror 120. When a focal length of the first mirror 120 is

shorter that that of the second mirror 130, the real image 150 of the object is

formed farther than the vertex of the first paraboloidal mirror 120. That is,

the real image 150 is formed away from the vertex of the first mirror 120

towards a user. When a focal length of the first mirror 120 is longer than

that of the second mirror 130, the real image 150 of the object is formed

nearer than the vertex of the first paraboloidal mirror 120 within the two

mirrors 120, 130. Therefore, it is possible to determine a desirable image

position by selecting the focal lengths of the two mirrors. The user may view

the real image 150 at an oblique angle such as 45° with respect to the

optical axis O.

Fig. 1 shows the apparatus in the case that the focal length of the

first mirror 120 is the same as that of the second mirror 130, while Fig. 2

shows the apparatus in the case that the focal length of the first mirror 120 is

shorter than that of the second mirror 130. Referring now to Fig. 5, a second preferred embodiment of the

present invention will be described. A three-dimensional display apparatus

of Fig. 5 is similar to the apparatus of Fig. 1 according to the first preferred

embodiment, but the apparatus of Fig. 5 has a second paraboloidal mirror

140 having an opening 131 around the vertex of the second mirror 140. The

object 110 is laid on a support 140 through the opening 131. The support

140 is placed behind the second mirror 130. That is, the three-dimensional

image display apparatus according to the second preferred embodiment has

a first paraboloidal mirror 120 in an upper position and a second paraboloidal

mirror 130 in a lower position. The first and second paraboloidal mirrors 120,

130 have openings 121 , 131 at their vertexes, respectively. The mirrors 120,

130 are disposed facing each other and with coincident optical axes. The

apparatus has a support 140 placed behind the opening 131 of the second

mirror 130 for supporting the object.

A vertex A of the second paraboloidal mirror 130 is positioned at a

focal point of the first paraboloidal mirror 120, similar to the first preferred

embodiment. The object is laid on the support 140 through the opening 131 .

The operation of the second preferred embodiment is similar to the

first preferred embodiment except for the support 140 on which the object is

laid. When the object is a light bulb, the apparatus is applicable to

illumination devices such as floor lamps. Fig. 6 illustrates the object which is an imaging screen such as a

liquid crystal device (LCD) monitor. The object is a plane of a two-

dimensional article, so that the image 151 becomes a two-dimensional plane.

Referring now to Fig. 7, a third preferred embodiment of the present

invention will be described. A three-dimensional display apparatus of Fig. 7

is similar to the apparatus of Fig. 5 according to the second preferred

embodiment. Further, the apparatus of Fig. 7 has one or more lamps 160

inside the support. In the third preferred embodiment, the lamps 160 are

mounted inside the support 140. A translucent shading sheet 161 is placed

between the lamp 160 and the object and prevents the lamps 160 from being

formed into an image. The lamps 160 are preferably used in the case that

the object is not light-emitting itself.

When the object 1 10 cannot emit light itself, a light emitting device

such as a light bulb or a light emitting diode is mounted under the object 1 10

on the support 140 and then fits into the object, thereby facilitating clear

viewing.

The object 1 10, the light-emitting device, or the auxiliary lamp 160, if

any, may be adjusted to be brighter or darker so that the image 160 also

becomes brighter or darker, resulting in various displaying effects. Further,

sound facilities (not shown) may be used in the apparatus. For example,

suitable sound effects from the sound facilities may be used in accordance with variations of the brightness of the image, resulting in maximization of the

displaying effects.

Referring next to Figs. 8-10, a fourth preferred embodiment of the

present invention will be described. A three-dimensional display apparatus

according to the fourth preferred embodiment has rotating members which

may rotate the object and/or the first and second paraboloidal mirrors,

thereby obtaining various displaying effects.

First, the apparatus as shown in Fig. 8 is similar to the apparatus of

Fig. 5 according to the second preferred embodiment, and it further has a

rotating member 170 to rotate the object 1 10. The real image 150 is also

rotated in accordance with the rotation of the object. The rotating member

170 has a driving motor 171 mounted inside the support 140, with a turntable

172 connected to the driving motor 171. The object 1 10 is disposed on the

turntable 172 and is then rotated according to the driving motor 171 , thereby

rotating the real image 150.

A three-dimensional display apparatus as shown in Fig. 9 uses a

rotating member 170 to rotate both the object and the two mirrors 120, 130,

resulting in displaying effects in which the mirrors as well as the object are

rotated. The rotating member 170 has a driving motor 171 mounted inside

the support 140, and a turntable 172 connected to the driving motor 171 .

The two mirrors 120, 130 as well as the object 1 10 are disposed on the turntable 172 and then rotated according to the driving motor 171 , thereby

rotating the real image 150 and the entire mirrors 120, 130. In this

embodiment, the external appearance of the two mirrors 120, 130 may be

designed as a flying saucer and the like, making the best use of their own

shape, so that the apparatus provides users with displaying effects of the

flying saucer as well as the rotation.

Referring now to Fig. 10, a three-dimensional display apparatus uses

a rotating member 170 to rotate the two mirrors 120, 130 only, resulting in

displaying effects that the mirrors are rotated while the real image 150 is

stationary. The rotating member 170 has a driving motor 171 mounted inside

the support 140, a driving gear 175 connected to the driving motor 171 , a

turntable 172, a dependent gear 177 connected to the turntable 172, and a

prop 177 on which the object lies. When the driving motor 171 is operated,

the object 1 10 remains stationary on the prop 177 while the mirrors 120, 130

on the turntable 172 are rotated through the dependent gear 177 and the

driving gear 175 by the driving motor 171.

In this case, when the outside of the two mirrors 120, 130 is designed

as a flying saucer, it provides users with displaying effects of the flying

saucer rotating and the real image 150 remaining stationary.

The apparatus according to the fourth preferred embodiment may

have auxiliary light devices such as lamps, light-emitting diodes, and sound facilities to maximize the displaying effects, as described in the third

preferred embodiment.

It will be apparent to those skilled in the art that various modifications

and variations can be made to the apparatus of the present invention without

departing from the spirit and scope of the invention. The present invention

covers the modifications and variations of this invention provided they come

within the scope of the appended claims and their equivalents.

A three-dimensional display apparatus according to the present

invention displays a real image which causes the illusion that a real object

exists in space by using two aspherical mirrors. The real object mounted

inside the apparatus provides a real image viewed from the outside.

Using the present invention, a three-dimensional real image is viewed

with vaπous displaying effects, so that the apparatus may be adaptable to

various intricate articles such as scientific articles, playthings, light fixtures,

decoration articles, electronic and electrical products for home or office, and

vaπous optical instruments. Further, the appearance of the apparatus may

be designed as a flying saucer shape, thereby facilitating application to

various fancy articles.

The image display unit according to the present invention has

various three-dimensional effects such as rotating effects of the image

and/or the apparatus itself, lighting effects, and sound effects.

Claims

WHAT IS CLAIMED IS:

1. A three-dimensional image display apparatus for forming a three-

dimensional image of an object, comprising:

a first paraboloidal mirror having an opening formed at a vertex

thereof; and

a second paraboloidal mirror disposed facing the first paraboloidal

mirror, an optical axis of the second paraboloidal mirror being coincident

with that of the first paraboloidal mirror,

wherein a vertex of the second paraboloidal mirror is coincident with

a focal point of the first paraboloidal mirror, and the object is placed

around the vertex of the second paraboloidal mirror.

2. A three-dimensional display apparatus as recited in claim 1 ,

wherein the second paraboloidal mirror has an opening formed at a vertex

thereof, and the apparatus further comprises a support placed behind the

opening of the second paraboloidal mirror for supporting the object, so that

the object is placed around the vertex of the second paraboloidal mirror.

3. A three-dimensional display apparatus as recited in claim 2,

further comprising:

a first rotating unit, connected to the second paraboloidal mirror, for

rotating both the first and second paraboloidal mirrors.

4. A three-dimensional display apparatus as recited in claim 2 or 3, further comprising:

a second rotating unit, connected to the object, for rotating the object.

5. A three-dimensional display apparatus as recited in claim 1 ,

wherein a focal length of the first paraboloidal mirror is the same as that of

the second paraboloidal mirror.

6. A three-dimensional display apparatus as recited in claim 1 ,

wherein a focal length of the first paraboloidal mirror is shorter than that of

the second paraboloidal mirror.

7. A three-dimensional display apparatus as recited in claim 1 ,

further comprising sound facilities for producing sound effects.

8. The three-dimensional image display apparatus as recited in

claim 2, wherein the image display unit further comprises:

a lamp, placed inside the support, for illuminating the object; and

a shading sheet, placed between the lamp and the object, for

shading the lamp to prevent the mirrors from forming an image of the lamp.

9. The three-dimensional image display apparatus as recited in

claim 2, further comprising:

a light-emitting device, placed under the object, so that the light-

emitting device fits into the object.

10. The three-dimensional image display apparatus as recited in

claim 8 or claim 9, wherein the brightness of the lamp or the light-emitting device is adjustable.

11. The three-dimensional image display apparatus as recited in

claim 1 , 2, 3, 5, 6, 7, 8, or 9, wherein the apparatus is formed with a specific

article, the specific articling being a scientific article, a plaything, a light

fixture, a decoration article, an electronic or electrical product for home or

office, or an optical instrument.