WO2012147642A1

WO2012147642A1 - Image display device

Info

Publication number: WO2012147642A1
Application number: PCT/JP2012/060685
Authority: WO
Inventors: 健太郎今村; 嶋谷　貴文
Original assignee: シャープ株式会社
Priority date: 2011-04-27
Filing date: 2012-04-20
Publication date: 2012-11-01

Abstract

An image display device (102) comprises: a display unit group (1) which includes one or more display units for emitting an image as light; an optical element (2) for receiving light generated by a first display unit (11) as a light source, the first display unit being any display unit of the display unit group (1), and emitting a first light (81) in a first polarization state; and a reflection-type polarizing plate (3) designed to transmit light that is in the first polarization state and reflect light that is in a second polarization state. The reflection-type polarizing plate (3) emits a second light (82) in the second polarization state by receiving and reflecting light generated by a second display unit (12) as a light source that is any display unit of the display unit group (1) and that is integrated with or separate from the first display unit (11). The image display device (102) displays an image (4) by combining the second light (82) and the first light (81) that has been emitted from the optical element (2) and transmitted through the reflection-type polarizing plate (3).

Description

Video display device

The present invention relates to a video display device.

A general mirror generates an image of an object placed in front of the mirror on the back side of the mirror when viewed from an observer. An image generated in this way is called a “virtual image”. Since the virtual image appears beyond the mirror, the observer cannot reach to the virtual image. On the other hand, an optical element that generates an image of an object placed on the back side of a plate-like optical element on the near side has been proposed. An image generated in this way is called a “real image”. In the case of a real image, the viewer feels as if an object is present in the air in front of the optical element. If there is nothing else to block, the observer can reach to the position of the real image. Such a real image is also called “aerial image”.

An optical element that generates an aerial image is described in International Publication WO2007 / 116639A1 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2009-276699 (Patent Document 2).

On the other hand, an optical element that can generate a real image of an object placed in front of the mirror in the air in front of the mirror has been proposed, and is described in Japanese Patent Application Laid-Open No. 2009-42337 (Patent Document 3).

Furthermore, Japanese Patent Application Laid-Open No. 2009-300623 (Patent Document 4) describes a configuration in which an aerial image and another flat display image are combined.

In the display device described in Patent Document 4, a plurality of square holes are formed in a flat base, and smooth mirror surface processing is performed on two inner wall surfaces that are adjacent and orthogonal to each other inside each hole. What is functioning as a corner reflector, that is, a two-sided corner reflector array is provided. As a result, the display device is configured to form a real image of the observation object disposed below the two-surface corner reflector array at an upper plane-symmetric position. In this two-sided corner reflector array, a reflective surface is formed by applying a smooth mirror surface treatment to the upper surface of the base. In this display device, a virtual image can be observed from the same side as the real image by specularly reflecting light emitted from another observation object arranged above the two-surface corner reflector array on the reflecting surface. . Therefore, for the observer, the two images appear to overlap.

International Publication WO2007 / 116639A1 JP 2009-276699 A JP 2009-42337 A JP 2009-300623 A

In paragraph 0042 of Patent Document 4, a half mirror is formed by a method such as attaching a thin reflective film to the upper surface of the two-sided corner reflector array instead of forming a reflective surface by performing a smooth mirror surface treatment on the upper surface of the base. It is described that it is good. It also describes that a large number of two-surface corner reflectors may be formed on the lower surface of the half mirror.

However, when a half mirror is used, loss of light intensity occurs. For example, when the half mirror transmits 50% of the incident light and reflects 50%, half of the light is surely lost. In particular, when a display device is configured using an optical element such as a two-surface corner reflector array, the light use efficiency is inevitably lowered to some extent due to circumstances such as the aperture ratio of the optical element. It is not preferable that the amount of light is already greatly reduced by a half mirror that is different from the above.

Therefore, an object of the present invention is to provide an image display device with improved light utilization efficiency.

In order to achieve the above object, an image display device according to the present invention is a display unit group including one or more display units that emit an image as light, and a first display unit of any one of the display unit groups. An optical element that receives light from the display unit as a light source and emits it as first light in the first polarization state, and reflective polarization having a property of transmitting the light in the first polarization state and reflecting the light in the second polarization state And the reflective polarizing plate emits light using a second display unit as a light source, which is one of the display units in the display unit group and the same or separate from the first display unit. The second light in the second polarization state is emitted by receiving and reflecting, and the first light transmitted from the optical element and transmitted through the reflective polarizing plate is combined with the second light as an image. indicate.

According to the present invention, it is possible to obtain a video display device that can suppress the loss of light amount and enhance the light utilization efficiency.

It is a conceptual diagram of the video display apparatus in Embodiment 1 based on this invention. It is a conceptual diagram of the video display apparatus in Embodiment 2 based on this invention. It is principle explanatory drawing of the video display apparatus in Embodiment 2 based on this invention. It is a figure of an example of the image | video displayed on the 1st display part of the video display apparatus in Embodiment 2 based on this invention. It is a figure of an example of the image | video displayed on the 2nd display part of the video display apparatus in Embodiment 2 based on this invention. It is a figure of an example of the image | video which an observer sees when it displays with the video display apparatus in Embodiment 2 based on this invention. It is a figure of the modification of the image | video displayed on the 2nd display part of the video display apparatus in Embodiment 2 based on this invention. It is a conceptual diagram of the video display apparatus in Embodiment 3 based on this invention. It is principle explanatory drawing of the video display apparatus in Embodiment 3 based on this invention. It is explanatory drawing of the 1st example of the common display part used with the video display apparatus in Embodiment 3 based on this invention. It is a 1st example of the common display part used with the video display apparatus in Embodiment 3 based on this invention, and is a figure of an example of the image | video displayed by a common display part. It is explanatory drawing of the 2nd example of the common display part used with the video display apparatus in Embodiment 3 based on this invention. It is a perspective view of an example of the reflective imaging mirror used with the video display apparatus in Embodiment 3 based on this invention. It is sectional drawing of an example of the reflective imaging mirror used with the video display apparatus in Embodiment 3 based on this invention.

(Embodiment 1)
With reference to FIG. 1, video display apparatus 101 according to the first embodiment of the present invention will be described. The video display device 101 according to the present embodiment uses a display unit group 1 including one or more display units that emit video as light, and a first display unit that is one of the display unit groups 1 as a light source. And a reflection type polarizing plate 3 having the property of transmitting the light in the first polarization state and reflecting the light in the second polarization state. With. The reflective polarizing plate 3 receives and reflects light having a light source of a second display unit that is the same or separate from the first display unit in the display unit group 1. To emit the second light 82 in the second polarization state. The video display device 101 displays the video 4 by combining the first light 81 emitted from the optical element 2 and transmitted through the reflective polarizing plate 3 and the second light 82.

Fig. 1 is a conceptual illustration only. The display unit group 1 is named “group”, but may include only one display unit or may include a plurality of display units. The display unit included in the display unit group 1 may be a liquid crystal display device or another type of display device. In the display unit group 1, the first display unit and the second display unit can be considered. The first display unit and the second display unit may serve as the same display unit, or may be separate display units. The display unit group 1 may include three or more display units.

The light emitted from the first display unit in the display unit group 1 reaches the optical element 2 through a certain path. The path | route until the light emitted from a 1st display part arrives at the optical element 2 is not limited. In FIG. 1, A, B, and C are shown as examples of paths through which light emitted from the display unit group 1 reaches the optical element 2. The path A exits the display unit group 1 and directly enters the optical element 2. The path B is incident on the optical element 2 after the light emitted from the display unit group 1 is reflected by the reflective polarizing plate 3. In the path C, the light emitted from the display unit group 1 enters the optical element 2 through some other situation. In the path C, the light emitted from the display unit group 1 may enter the optical element 2 after undergoing some other processing or element. Therefore, the middle of the path C is indicated by a broken line. Regardless of which path is passed, the light incident on the optical element 2 is emitted from the optical element 2 as light 81 in the first polarization state through some action. Here, the action caused by the optical element 2 may be reflection, transmission, or other.

The optical element 2 may form an aerial image, but may not form an aerial image. However, the optical element 2 is not a half mirror.

In the display unit group 1, light emitted from the second display unit enters the reflective polarizing plate 3 through some path and is reflected. Since the reflective polarizing plate 3 has the property of reflecting the light in the second polarization state, the light that is reflected by the reflective polarizing plate 3 and becomes the second light is already second when it enters the reflective polarizing plate 3. It can be said that it is in a polarization state. The light emitted from the display unit group 1 may be in the second polarization state from the beginning, or may be subjected to some other process to be in the second polarization state.

In the present embodiment, the light emitted from the optical element 2 derived from the light from the display unit group 1 is the first light 81 in the first polarization state, so that it can be transmitted through the reflective polarizing plate 3. it can. On the other hand, there is also light that is derived from the light from the display unit group 1 and reflected by the reflective polarizing plate 3 and emitted as the second light 82 in the second polarization state. In the present embodiment, the first light and the second light are combined using the property of the reflective polarizing plate 3 that transmits the light in the first polarization state and reflects the light in the second polarization state. Since the video 4 is displayed, a plurality of videos can be combined and provided as one video 4 without using a half mirror. In this embodiment, since a half mirror is not used, loss of light amount can be suppressed, and a video display device with improved light use efficiency can be obtained.

In the present embodiment, the terms “first polarization state” and “second polarization state” are used. As an example of how to distinguish such states, the incident surface of the reflective polarizing plate 3 is used. On the other hand, the point is whether it is p-polarized light or s-polarized light. “P-polarized light” and “s-polarized light” are general technical terms, but to be noted, “p-polarized light” (also referred to as “p-wave”) is light on the surface of the reflective polarizing plate 3. Is an electromagnetic wave whose electric field component is parallel to the incident surface. “S-polarized light” (also referred to as “s-wave”) is an electromagnetic wave whose electric field component is perpendicular to the incident surface when light is incident on the surface of the reflective polarizing plate 3. The “incident surface” here is a general term in geometric optics, but to avoid misunderstanding, the “incident surface” is a plane defined by the surface of the reflective polarizing plate 3. It means not a reflection surface itself in terms of geometric optics, but a surface that is perpendicular to the reflection surface and includes incident rays and reflected rays.

For example, the state of p-polarized light with respect to the surface of the reflective polarizing plate 3 may be the first polarization state, and the state of s-polarized light may be the second polarization state. The reverse is also possible. Even if the light is not directly incident on the reflective polarizing plate 3, the geometrical relationship with the surface of the reflective polarizing plate 3 whose posture has already been determined is taken into consideration, and the light axis itself depends on the direction of the polarization axis of the light itself. It is possible to determine whether the polarization state is the first polarization state, the second polarization state, or neither.

The concept of “first polarization state” and “second polarization state” is not limited to the present embodiment, and the same applies to the following embodiments.

In this embodiment, the configuration of the present invention has been conceptually described, but in the following embodiment, a more specific configuration will be described.

(Embodiment 2)
With reference to FIG. 2 and FIG. 3, the video display apparatus 102 in Embodiment 2 based on this invention is demonstrated. The video display apparatus 102 in the present embodiment also basically includes the configuration described in the first embodiment. As shown in FIG. 2, in the video display device 102, the display unit group 1 includes two display units, that is, a first display unit 11 and a second display unit 12. In FIG. 2, the optical element 2 and the reflective polarizing plate 3 appear to be in contact with each other, but they do not necessarily have to be in contact with each other. The structure shown in FIG. 2 is disassembled and shown in FIG. In FIG. 3, the optical element 2 and the reflective polarizing plate 3 are separated from each other, and the entire optical system is rotated so that they are horizontal. In FIG. 3, the distinction whether the direction of hatching inside the arrow is parallel or perpendicular to the longitudinal direction of the arrow expresses two types of polarization states in a pseudo manner. In the following drawings, the same meaning is given when hatching is given inside the arrow.

In this embodiment, the optical element 2 is a transmission imaging mirror 25. The transmission imaging mirror 25 has an imaging mirror first main surface 2a and an imaging mirror second main surface 2b that face each other. The transmission imaging mirror 25 generates an aerial image visible from the imaging mirror second main surface 2b side based on the light incident from the imaging mirror first main surface 2a side. Can be generated outside the side. The second display unit 12 is separate from the first display unit 11. The first display unit 11, the second display unit 12, the reflective polarizing plate 3, and the transmission imaging mirror 25 are connected by the light emitted from the first display unit 11 being incident on the imaging mirror first main surface 2 a. The first light 81 is emitted from the image mirror second main surface 2b as the first polarization state in the first polarization state, the aerial image 6 is formed after passing through the reflective polarizing plate 3, and the second display unit 12 is emitted. It arrange | positions so that the light of a 2nd polarization state may reflect with the reflective polarizing plate 3, and may advance as the 2nd light 82. FIG.

As the transmission imaging mirror 25, an optical element described in Patent Document 1 or Patent Document 2 can be used.

As the reflective polarizing plate 3, DBEF (registered trademark) series, which is a brightness enhancement film manufactured by Sumitomo 3M Limited, can be used. The DBEF series has a property of reflecting light having a specific polarization direction and transmitting light having another specific polarization direction.

Alternatively, as the reflective polarizing plate 3, an inorganic polarizing plate ProFlux (registered trademark) manufactured by Polatechno Co., Ltd. can also be used.

In the video display device 102 according to the present embodiment, the display unit group 1 includes a first display unit 11 and a second display unit 12 that are separate from each other. Video light is emitted from each of these two display units.

From the first display unit 11, which is one display unit in the display unit group 1, image light is emitted toward the transmission imaging mirror 25 as the optical element 2, and the imaging mirror of the transmission imaging mirror 25. It is incident on the first main surface 2a. Based on this light, the transmission imaging mirror 25 emits p-polarized light toward the reflective polarizing plate 3 as the first light 81. Since the first light 81 is in the first polarization state, that is, p-polarized light, it passes through the reflective polarizing plate 3. Since the first light 81 is originally light having the property of forming an aerial image by the action of the transmissive imaging mirror 25, the aerial image 6 is imaged after passing through the reflective polarizing plate 3.

On the other hand, light from the second polarization state, that is, s-polarized light is emitted from the second display portion 12, which is another display portion in the display portion group 1, and reflected by the reflective polarizing plate 3. This reflected light is naturally s-polarized light and travels as the second light 82. Since the video display device 102 displays the video 4 by combining the first light 81 and the second light 82, the virtual image of the second display unit 12 generated by the second light 82 that is reflected light is displayed. Then, a combination of the real image which is the aerial image 6 created by the first light 81 is seen as an image 4 to the observer.

The video teaching apparatus 102 according to the present embodiment creates the video 4 by combining the videos provided from a plurality of display units, but since a half mirror is not used, loss of light amount can be suppressed, A video display device with improved light utilization efficiency can be obtained.

In FIG. 3, a gap is provided between the reflective polarizing plate 3 and the optical element 2, but actually it is preferable that both are in close contact as shown in FIG. 2. However, a slight air layer can occur even if they are in close contact. When there is an air layer between the reflective polarizing plate 3 and the optical element 2, the light from the first display unit 11 is transmitted between the optical element 2 and the air layer or between the air layer and the reflective polarization. Interfacial reflection occurs between the plate 3 and a light amount loss occurs. In order to reduce this light loss as much as possible, it is preferable to arrange the reflective polarizing plate 3 and the optical element 2 in parallel as shown in the present embodiment.

Furthermore, the reflective polarizing plate 3 and the optical element 2 are arranged in parallel, and the refractive index of either the reflective polarizing plate 3 or the optical element 2 is between the reflective polarizing plate 3 and the optical element 2. It is preferably filled with a material having an equal refractive index. With such a configuration, the difference in refractive index can be reduced as compared with the case where there is an air layer, and the interface reflection can be reduced, so that the light quantity loss can be reduced. The same applies to the following embodiments.

Since either the p-polarization as the first polarization state or the s-polarization as the second polarization state is a concept determined by the relative posture with respect to the surface of the reflective polarizing plate 3, When assembling the video display device 102 in FIG. 5, the polarization axes of the first display unit 11 and the second display unit 12 may be adjusted in accordance with the posture of the reflective polarizing plate 3. The first display unit 11 and the second display unit 12 are preferably liquid crystal display devices. This is because, in a liquid crystal display device, the emitted image light is polarized. When the first display unit 11 or the second display unit 12 is a display unit other than the liquid crystal display device, only a specific polarized light may be emitted to the outside by overlapping a polarizing plate on the display surface.

(Example content)
An example of an image displayed on the image display apparatus 102 in this embodiment will be described. The first display unit 11 displays an image to be popped out. An example is shown in FIG. Here, an image of the earth is displayed. The second display unit 12 displays an image to be a background. An example is shown in FIG. Here, an image of the water surface in which ripples are generated is displayed. However, the earth is reflected on the surface of the water. 4 and 5 are combined as the video 4 in the video display device 102, the viewer sees it as shown in FIG. Since the earth is displayed as an aerial image, it appears to jump out from the surface of the water.

In this case, in order to realize the display of the video 4 on the video display device 102, in principle, two types of video signals, that is, a video to be displayed on the first display unit 11 and a video to be displayed on the second display unit 12 are used. It is necessary to prepare. However, it is possible to use only one type of video signal. In that case, a new signal X corresponding to each part of the video is added to the video signal. The signal X may be associated with each pixel, or may be associated with each block in the video. For example, when the content of the signal X is ON, the video is to be displayed on the first display unit 11. When the content of the signal X is OFF, the video is to be displayed on the second display unit 12. It shall be. With such a signal X, each part in the video is distinguished and assigned to which display part the video should be displayed, and the part to be displayed should be displayed as it is, and the part should not be displayed. The other display unit is dark. That is, the signal X is a display part distribution signal. As a result of adopting such a signal X and combining the images of the two display units into one type of video signal, the image displayed on the first display unit 11 is not different from that shown in FIG. The video to be displayed on the display unit 12 is shown in FIG. 7 instead of that shown in FIG. That is, the area corresponding to the earth displayed on the first display unit 11 is darkly displayed on the second display unit 12.

When this is organized, the video display device 102 preferably receives a video to be displayed on the first display unit 11 and the second display unit 12 as one video signal, and the video signal is a video that is a part of the video. For each video portion that includes a corresponding display portion distribution signal for each portion, and the corresponding display portion distribution signal is in the first signal state, the display portion displays the first display portion and the second display portion displays a dark display. The video part in which the corresponding display part distribution signal is in the second signal state is displayed on the second display part as a dark display on the first display part.

In this way, it is possible to display an image with a stereoscopic effect using only one type of signal.
(Embodiment 3)
With reference to FIG. 8 and FIG. 9, the video display apparatus 103 in Embodiment 3 based on this invention is demonstrated. The video display device 103 according to the present embodiment also basically includes the configuration described in the first embodiment. As shown in FIG. 8, in the video display device 103, the display unit group 1 includes one display unit, and this one display unit also serves as the first display unit 11 and the second display unit 12. In FIG. 8, the optical element 2 and the reflective polarizing plate 3 appear to be separated from each other, but they may be in close contact with each other. A part of the structure shown in FIG. 8 is disassembled and shown in FIG. In FIG. 9, the entire optical system is rotated so that the optical element 2 and the reflective polarizing plate 3 are horizontal.

In the present embodiment, the optical element 2 is the reflective imaging mirror 27. The reflective imaging mirror 27 has an imaging mirror main surface 2c. The reflective imaging mirror 27 generates an aerial image 6 that is visible from the imaging mirror main surface 2c side, outside the imaging mirror main surface 2c side, based on light incident from the imaging mirror main surface 2c side. can do. The first display unit 11 and the second display unit 12 are the same body, and are the common display unit 10 that emits both the light in the first polarization state and the light in the second polarization state. In the common display unit 10, the reflective polarizing plate 3 and the reflective imaging mirror 27, the light in the first polarization state emitted from the common display unit 10 is transmitted through the reflective polarizing plate 3 and reaches the imaging mirror main surface 2c. Most of the incident light is reflected in the first polarization state to be emitted as the first light 81, passes through the reflective polarizing plate 3, forms an aerial image 6, and is emitted from the common display unit 10. The second polarization state light is reflected by the reflective polarizing plate 3 and travels as the second light 82.

As the reflective imaging mirror 2, an optical element described in Patent Document 3 can be used.
As the reflective imaging mirror 2, BEF series which is a brightness enhancement film manufactured by Sumitomo 3M Limited can be used. The BEF series is an optical element having a prism pattern with 90 ° irregularities formed on the surface. For example, BEF2 90/24 can be used in the BEF series. The BEF series may be used as it is, but it is more preferable that a metal is deposited on the surface of the BEF series so that the metal can be reflected. For example, aluminum is preferably deposited as the metal.

As the reflective polarizing plate 3, the same one as described in the second embodiment can be used.

Here, it has been described that light in the first polarization state enters the optical element 2 and then exits from the optical element 2 in the first polarization state. Strictly speaking, however, due to the nature of the optical element 2 When reflected by the optical element 2, it can be said that the polarization state of the incident light changes slightly. However, it is assumed that this slight change is negligible, and light is treated as being in the first polarization state before and after reflection. Here, the “first polarization state” has a meaning with such a width.

In the video display device 103 according to the present embodiment, since the common display unit 10 that is one display unit also serves as the first display unit 11 and the second display unit 12, the common display unit 10 starts the first polarization state. And the light in the second polarization state are emitted. Since the light in the first polarization state emitted from the common display unit 10 can pass through the reflective polarizing plate 3, it passes through the reflective polarizing plate 3 and enters the imaging mirror main surface 2 c of the reflective imaging mirror 27. To do. Since this light is reflected in the first polarization state and travels as the first light 81, it can be transmitted through the reflective polarizing plate 3 again, and after passing through the reflective polarizing plate 3, an aerial image 6 is formed. To do.

On the other hand, since the light in the second polarization state emitted from the common display unit 10 is reflected by the reflective polarizing plate 3, it does not reach the reflective imaging mirror 27. The light in the second polarization state reflected by the reflective polarizing plate 3 travels as the second light 82 and is recognized as an image 4 by the observer when combined with the first light 81.

In the present embodiment, since a half mirror is not used in superimposing a plurality of images, a loss of light amount can be suppressed and a video display device with improved light use efficiency can be obtained.

The common display unit 10 used in the present embodiment is required to emit both the light in the first polarization state and the light in the second polarization state, and a specific example for realizing the same. Will be described.

(First example)
A first example will be described. For example, as shown in FIG. 10, the common display unit 10 includes a band-shaped first region 31 that emits light in the first polarization state, that is, p-polarized light, and a band-shaped first region that emits light in the second polarization state, that is, s-polarized light. It is preferable that the display area is arranged so that the two areas 32 are alternately arranged in the width direction of the band shape. This can be realized by alternately arranging strip-shaped polarizing plates having absorption axes different by 90 ° every one to several pixel lines.

With such a configuration, both light in the first polarization state and light in the second polarization state can be emitted from one display region. For example, when displaying the video 4 as shown in FIG. 6 to the observer, the common display unit 10 displays the content corresponding to the video to be popped out, that is, the video as shown in FIG. The video corresponding to the background, that is, the video as shown in FIG. 5 or 7 may be displayed in the second area 32. As a result, an image displayed as the common display unit 10 is as shown in FIG. If such display is performed, the common display unit 10 can simultaneously display the first polarization state, that is, p-polarized light and the second polarization state, that is, s-polarized light, and these two types of light are reflected. Since the light is filtered and reflected by the polarizing plate 3 and reaches the observer as a combination of the first light 81 and the second light following the above-described path, an image as shown in FIG. 6 can be displayed. it can.

Although the description has been given here of alternately arranging the strip-shaped polarizing plates, the above-described display portion distribution signal method may be employed instead of adopting such a polarizing plate arrangement.

(Second example)
A second example will be described. For example, as shown in FIG. 12, the common display unit 10 preferably has a display region 16 a that is entirely covered with the polarization control element 15. However, the polarization control element 15 can determine whether the light transmitted and emitted is in the first polarization state or the second polarization state by a signal input to the polarization control element 15. The common display unit 10 includes a liquid crystal display device 16 and a polarization control element 15. The liquid crystal display device 16 has a display area 16a. As the polarization control element 15, for example, a TN (Twisted Nematic) liquid crystal layer including a TFT can be used. If such polarization control element 15 is used to switch the presence / absence of voltage application for each line in the display region 16a, the first polarization state, that is, the band-shaped first region 31 that emits p-polarized light and the first region 31 A band-shaped second region 32 that emits light in a two-polarized state, that is, s-polarized light, can be created.

Alternatively, the voltage application to the polarization control element 15 may be continuously switched at high speed over the entire display area 16a. For example, the liquid crystal display device 16 is driven at 120 Hz, 60 s-polarized pictures and 60 p-polarized pictures are alternately displayed per second, and the TN liquid crystal layer as the polarization control element 15 is either driven at 60 Hz. The voltage may be applied only during the display period of the polarization picture.

(Third example)
A third example will be described. The common display unit 10 may rotate the liquid crystal display device itself that continues displaying in a certain polarization state at a high speed. This is because if the orientation of the liquid crystal display device itself is changed by rotating, the emitted light is switched between the first polarization state, that is, p-polarization state, and the second polarization state, that is, s-polarization state.

(Reflection imaging mirror)
As described above, the reflection imaging mirror 27 can use the optical element described in Patent Document 3, but will be described in more detail.

As shown in FIGS. 13 and 14, the imaging mirror main surface 2 c of the reflective imaging mirror 27 is formed such that peaks 33 and valleys 34 extending linearly in parallel are alternately arranged in the width direction. When the imaging mirror main surface 2c is viewed in cross section, it is preferable that the uppermost part of the peak and the lowermost part of the valley are both at right angles. FIG. 14 shows a cross section of the reflective imaging mirror 27 shown in FIG. As described above, as the reflective imaging mirror 27, the BEF series, which is a brightness enhancement film manufactured by Sumitomo 3M Limited, can be used.

As shown in FIG. 14, the incident light 85 is reflected once by the inclined surfaces forming 90 ° with respect to the valley 34, and then emitted as reflected light 86 to form an image in the air. As shown in FIG. 13, the light emitted from the object 17 disposed on the near side of the imaging mirror main surface 2c is reflected by the imaging mirror main surface 2c, whereby the near side of the imaging mirror main surface 2c. An aerial image is formed on the screen.

Even if the metal film is not formed on the surface, incident light that satisfies the total reflection condition can be reflected to form an aerial image. When a metal film such as aluminum is attached to the surface by vapor deposition or the like, it can be easily reflected by metal reflection not only when the total reflection condition is satisfied, so that an aerial image can be formed more reliably. ,preferable.

It should be noted that the above-described embodiment disclosed herein is illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

The present invention can be used for a video display device.

DESCRIPTION OF SYMBOLS 1 Display part group, 2 Optical element, 2a Imaging mirror 1st main surface, 2b Imaging mirror 2nd main surface, 2c Imaging mirror main surface, 3 Reflective polarizing plate, 4 images, 6 Aerial images, 10 Common display Unit, 11 first display unit, 12 second display unit, 15 polarization control element, 16 liquid crystal display device, 16a display region, 17 object, 18 real image, 25 transmission imaging mirror, 27 reflection imaging mirror, 31 first Area, 32 second area, 33 mountain part, 34 valley part, 81 first light, 82 second light, 85 incident light, 86 outgoing light, 100 observer, 101, 102, 103 video display device.

Claims

A display unit group (1) including one or more display units for emitting an image as light;
An optical element (2) that receives light using the first display unit (11), which is one of the display units in the display unit group, as a light source and emits the first light (81) in a first polarization state;
A reflective polarizing plate (3) having a property of transmitting light in the first polarization state and reflecting light in the second polarization state;
The reflective polarizing plate receives light using a second display unit (12) which is a display unit of the display unit group and is the same as or separate from the first display unit as a light source. The second light (82) in the second polarization state is emitted by reflecting,
An image display device that displays the image (4) by combining the first light emitted from the optical element and transmitted through the reflective polarizing plate, and the second light.
The optical element has an imaging mirror first main surface (2a) and an imaging mirror second main surface (2b) facing each other, and is based on light incident from the imaging mirror first main surface side. A transmission imaging mirror (25) capable of generating an aerial image visible from the imaging mirror second main surface side to the outside of the imaging mirror second main surface side;
The second display unit is separate from the first display unit,
The first display unit, the second display unit, the reflective polarizing plate, and the transmission imaging mirror are configured such that light emitted from the first display unit is incident on the first main surface of the imaging mirror. The first light emitted from the second main surface of the imaging mirror as the first light in the first polarization state, imaged in the air after passing through the reflective polarizing plate, and emitted from the second display unit The video display device according to claim 1, wherein the two-polarized light is arranged so that the light is reflected by the reflective polarizing plate and travels as the second light.
The video to be displayed on the first display unit and the second display unit is received as one video signal, and the video signal includes a display unit distribution signal corresponding to each video part which is a part of the video. The video portion in which the display portion distribution signal is in the first signal state is displayed on the first display portion and is darkly displayed on the second display portion, and the corresponding display portion distribution signal is in the second signal state. The video display device according to claim 2, wherein a certain video portion is displayed on the second display unit as a dark display on the first display unit.
The optical element has an imaging mirror main surface (2c) and forms an aerial image visible from the imaging mirror main surface side based on light incident from the imaging mirror main surface side. A reflective imaging mirror (27) that can be generated outside the mirror main surface side;
The first display unit and the second display unit are the same body, and are a common display unit (10) that emits both the light in the first polarization state and the light in the second polarization state,
In the common display unit, the reflective polarizing plate, and the reflective imaging mirror, the light in the first polarization state emitted from the common display unit is transmitted through the reflective polarizing plate and is incident on the main surface of the imaging mirror. The second light that is incident and reflected as the first polarization state is emitted as the first light, is transmitted through the reflective polarizing plate, forms an aerial image, and is emitted from the common display unit. The video display device according to claim 1, wherein the light is polarized so that the light is reflected by the reflective polarizing plate and travels as the second light.
The common display section has a band-shaped first region (31) that emits light in the first polarization state and a band-shaped second region (32) that emits light in the second polarization state. The video display device according to claim 4, further comprising display regions arranged so as to be alternately arranged in the width direction.
The common display unit has a display area whose entire surface is covered with a polarization control element (15), and the polarization control element sets light transmitted and emitted to the first polarization state or the second polarization state. The video display apparatus according to claim 4, wherein whether or not to do so can be determined by a signal input to the polarization control element.
The imaging mirror main surface is formed such that peaks (33) and valleys (34) extending linearly in parallel are alternately arranged in the width direction, and the imaging mirror main surface is shown in cross section. The video display device according to claim 4, wherein when viewed, the uppermost part of the peak and the lowermost part of the valley are both perpendicular.
The reflective polarizing plate and the optical element are arranged in parallel, and a refractive index equal to the refractive index of either the reflective polarizing plate or the optical element is between the reflective polarizing plate and the optical element. The image display device according to claim 1, wherein the image display device is filled with a material having