JP5266526B2 - Video display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a visual field range intercepted by a frame in an image display device displaying an image over an external image. <P>SOLUTION: The image display device is formed in spectacles shape having two plate-like prisms, and a casing which holds a display is mounted to the periphery of the prism. The casing is shaped such that the length in one direction perpendicular to a direction to connect the eye to the casing is shorter than the length of the direction to connect the eye to the casing and that an angle intercepting the visual field is determined only by a portion closer to the eye than the center of the casing in a direction to connect the eye to the casing. The visual field range intercepted by the casing is thereby reduced, and a frame for holding the prism is dispensed with to eliminate the visual field range intercepted by the frame. A hologram element is provided inside the prism to use the prism as an ocular optical system, and light from the display is made incident to the prism from the end face and led to the hologram element while being reflected inside. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to an image display apparatus that is used in front of a face and provides an image superimposed on an image of the outside world.

  2. Description of the Related Art In recent years, a video display device that is mounted in front of the face and displays the displayed image light together with light from the outside world to the eyes and provides the image superimposed on the outside image has been proposed as a personal information supply means. . The user can use the device in every scene of daily life. For example, the user can observe images while walking.

  Such devices are typically shaped like glasses having a frame, a pair of lenses, a nose pad, and a pair of temples. A display for displaying an image is housed in a housing attached around the frame. In order to superimpose the image on the image of the outside world, it is necessary to guide the light from the side display located in front of the eyes and change the optical path so that the light enters the eyes from the front. In addition, it is preferable that an image displayed on a small display can be enlarged and observed. For these reasons, a hologram element is used.

  For example, Patent Document 1 discloses an apparatus including a hologram element on the front surface (a surface far from the eye) of a lens. Light from the display device is guided into the lens from the end face of the lens, directly enters the hologram element, is diffracted by the hologram element, and is guided to the eye. Patent Document 2 discloses an apparatus including a hologram element on the rear surface (surface close to the eye) of a lens. The light from the display is guided to the hologram element from the rear side of the lens, and is diffracted without being incident on the lens and guided to the eye.

The user observes the real image of the outside world together with the enlarged virtual image of the video. However, part of the light from the outside world is blocked by the frame, and the field of view is distorted.
Japanese Patent Laid-Open No. 11-64781 Japanese Patent Laid-Open No. 11-64782

  The fact that light from the outside world is blocked by the frame does not matter for the purpose of providing video. However, considering that it is used in various everyday situations, it is necessary for safety to secure a wide field of view by making the range where light is blocked by the frame as small as possible.

  However, in conventional devices, the frame is designed mainly to facilitate the arrangement of the optical system and increase the strength of the device, and their size and shape are not very suitable for securing a wide field of view. There wasn't. The present invention has been made in view of such problems, and an object of the present invention is to provide an image display device whose field of view is not blocked by a frame.

  In order to achieve the above object, a video display device according to a first aspect of the present invention includes a nose pad that touches the nose and a pair of temples that touches the ear, temporal region, or occipital region, and is mounted in front of the face for display. In a video display device that guides the light of the image together with light from the outside world to the eye and provides the image superimposed on the image of the outside world, the display device that displays the image, the housing that holds the display device, and the display device One or two display units including an eyepiece optical system that guides light to the eye and provides a virtual image of the image, and a pair of prisms positioned in front of the eye and transmitting light from the outside world to guide the left and right eyes The prism is attached to the nose pad, and the temple and the housing are attached to the prism.

  The video display device of a second invention is characterized in that, in the first invention, a part of the prism also serves as an eyepiece optical system and guides light from the display to the eye.

  According to a third aspect of the present invention, there is provided the video display device according to the second aspect, wherein the housing is positioned around the prism, the prism has a surface for guiding the light from the display inside, and the guided light is 1 inside. The eyepiece optical system includes a surface that reflects more than once and guides it to the front of the eye and a surface that directs the light guided to the front of the eye toward the eye.

  According to a fourth aspect of the present invention, there is provided the video display device according to the third aspect, wherein the surface that directs the light guided to the eye just before the eye is a hologram element.

  According to a fifth aspect of the present invention, there is provided the video display device according to the second aspect, wherein the prism has power for correcting diopter.

  The video display device according to a sixth aspect of the present invention is characterized in that, in any one of the first to fifth aspects, the casing is disposed at a peripheral portion of the user's visual field or outside the visual field.

  According to a seventh aspect of the present invention, in the video display device according to any one of the first to sixth aspects, at least one of the pair of prisms includes a first prism constituting an eyepiece optical system; And a second prism having a shape complementary to the first prism, wherein the first prism and the second prism are joined so that there is no gap and the surface is continuous. .

  In the video display device according to an eighth aspect of the present invention, in any one of the first to seventh aspects, the eyepiece optical system has a distance from an eye to a virtual image set to 1 to 3 m. .

  As described above, according to the first invention, a connecting member such as a frame for integrating the housing, the nose pad and the temple is unnecessary. Therefore, the visual field is not obstructed by the connecting member, and the device is highly safe. In addition, it is lightweight and can be used comfortably.

  According to the second invention, it is possible to avoid distortion and discontinuity in the image of the outside world due to the influence of the eyepiece optical system, and to provide a natural image to the user.

  According to the third invention, since the light from the display is reflected in the prism and guided to the front of the eye, it is possible to arrange the housing in the peripheral part of the visual field or outside the visual field, and the visual field is widened. Safety is further increased. In addition, the prism can be made thin, resulting in a lightweight device.

  According to the fourth invention, although it is a simple configuration, both the light from the display and the light from the outside can be guided to the eyes without loss, and the image and the image of the outside that overlaps the image become dark. There is no. Therefore, it is possible to provide a bright image and an entire image of the outside world. Moreover, since it is a simple structure, manufacture is also easy.

  According to the fifth aspect, since the function as glasses for correcting vision can be obtained, even a user with low vision can clearly observe the outside world without using other correcting means.

  Hereinafter, embodiments of a video display device of the present invention will be described with reference to the drawings. FIG. 1 shows the appearance of the video display device 1 of the first embodiment. The video display device 1 includes one display unit 10, a pair of left and right prisms 20L and 20R, a nose pad 31, and a pair of left and right temples 32L and 32R. The prisms 20L and 20R are positioned in front of the left and right eyes. So that it is worn in front of the user's face.

  The nose pad 31 is attached to the prisms 20L and 20R and connects them. The temples 32L and 32R are attached to the ends of the prisms 20L and 20R, respectively. At the time of wearing, the nose pad 31 hits the nose and the temples 32L and 32R hit the ear, temporal region or occipital region, and the video display device 1 is supported by these three parts. The temples 32L and 32R can be rotated around a vertical axis (not shown) provided in the vicinity of the prisms 20L and 20R, and can be folded inward when not in use.

  The display unit 10 is attached to the right prism 20R. A cross section including the display unit 10 is shown in FIG. The display unit 10 includes a transmissive liquid crystal display (LCD) 11, a housing 12, a prism 13, a light emitting diode (LED) 14, and a lens 15. The LCD 11 displays an image to be provided to the user, and modulates illumination light by the displayed image. The housing 12 accommodates and holds the LCD 11, the LED 14, and the lens 15. The LED 14 is a light source for illuminating the LCD 11, and the lens 15 is an illumination optical system for uniformly guiding light emitted from the LED 14 to the entire surface of the LCD 11.

  The display of the image on the LCD 11 and the light emission of the LED 14 are controlled by a control device (not shown) provided outside the image display device 1. As shown in FIG. 1, the control device is connected to the housing 12 via a cable 40, and supplies power and video signals via the cable 40.

  The prism 13 has a flat plate shape and is made of transparent glass or resin. The prism 13 guides the light from the LCD 11 to the user's eye E and provides a virtual image of the image displayed on the LCD 11. The upper end portion of the prism 13 has a wedge shape whose edge is thicker than the inner side, and the housing 12 is attached to the prism 13 so as to sandwich the upper end portion of the wedge shape.

  The prism 20L has a flat plate shape and is composed of a single member. The prism 20R is also flat, but is not a single member but is composed of a prism 13 and a prism 21. The prism 20L and the prism 21 are made of the same material as the prism 13, and there is no difference in refractive index between these three. The prism 13 and the prism 21 constituting the prism 20R have complementary shapes, and are joined so that there is no gap and the surface is continuous. The prisms 20L and 20R are symmetrical except that the prism 13 has a wedge-shaped upper end. A user wearing the image display device 1 in front of his / her face observes the outside through the prisms 20L and 20R.

  The lower end portion of the prism 13 is formed so that the front surface (surface farther from the eye E) approaches the rear surface (surface closer to the eye E) toward the edge, and has a wedge shape. The front surface of the wedge-shaped portion, that is, the joint surface with the prism 21 is a flat surface, and the hologram element 22 is formed on the flat surface. The hologram element 22 is located immediately in front of the eye E when worn. The prism 13 and the hologram element 22 constitute the eyepiece optical system 16.

  The prism 13 guides the light from the LCD 11 to the inside from the end face of the upper end, and guides the light to the hologram element 22 while being totally reflected a plurality of times on the front face and the rear face. The hologram element 22 diffracts the guided light to make it enter the eye E while making it a light beam close to parallel light. Thereby, the virtual image of the image displayed on the LCD 11 is provided to the user. The hologram element 22 hardly acts on the light from the outside world, and the virtual image is observed while overlapping the central portion of the outside world image.

  The hologram element 22 is set so that the distance from the eye E to the virtual image is about 1 to 3 m, and the size of the virtual image is several to several tens of times that of the real image displayed on the LCD 11. . Therefore, the video provided to the user is easy to see. Further, the user can clearly observe the image and the image of the outside world by slightly adjusting the focus of the eye E.

  In the video display device 1, since the light from the LCD 11 is guided to the hologram element 22 while being reflected inside the prism 13, the prism 20R can be enlarged. As a result, the housing 12 can be positioned at the periphery of the visual field of the eye E or outside the visual field, and the visual field range blocked by the housing is reduced. Further, most of the light from the outside world can be configured to pass through the prism 20R and enter the eye E, and the outside image is not disturbed except for a very peripheral part. Moreover, since the prism 20R can be made as thin as, for example, about 3 mm, the entire apparatus becomes light.

  Although the lower end of the prism 13 is wedge-shaped, it is joined to the prism 21 made of the same material, so that light from the outside that passes through the lower end of the prism 13 is not refracted. Therefore, the image display device 1 can provide a high-quality image without the central portion of the image of the outside world being distorted or discontinuous.

  The LCD 11 has a rectangular shape that is long in the left-right direction, and can display one to several lines of character strings in which dozen characters are arranged in the horizontal direction. Therefore, the user can obtain a lot of information from the video at a time.

  The housing 12 is set so that the length A in the direction connecting the eye E and the housing 12 is about twice the length B in the direction perpendicular to both the direction and the left-right direction. Therefore, the housing 12 is thin and has a small range that blocks the visual field. The LCD 11 is disposed such that its display surface is perpendicular to a straight line connecting the eye E and the center of the display surface, and the lens 15 and the LED 14 are disposed on an extension of the straight line. With this configuration, it is possible to easily dispose the LCD 11, the lens 15, and the LED 14 while making the housing 12 thin, and to include only the simple lens 15 as an illumination optical system.

  FIG. 3 shows an example of the range of the field of view of the eye E and the field of view blocked by the housing 12. This example shows a case where the entire housing 12 is located within the visual field V0, but the visual field range V1 blocked by the housing 12 is small. As described above, a part of the housing 12 can be positioned outside the visual field V0, and the visual field range blocked by the housing 12 can be further reduced.

  The housing 12 has a shape in which the angle α that blocks the visual field is determined only by a portion closer to the eye E than the center of the housing in the direction connecting the eye E and the housing 12. Although the range in which the housing 12 blocks the visual field is small because it is thin, this shape can further reduce the range that blocks the visual field and reduce the weight of the housing 12. If the angle at which the field of view is blocked is determined by both the part closer to the center and the part far from the center, the range of the field of view that is blocked is increased even with similar shapes, and the angle that blocks the field of view is determined only by the part far from the center. By doing so, the housing 12 is increased in size and weight.

  In the present embodiment, the video is provided to the right eye, but of course, the video may be provided to the left eye.

  The appearance of the video display device 2 of the second embodiment is shown in FIG. The video display device 2 is obtained by adding the frame 50 to the video display device 1 described above, and attaching the housing 12, the prisms 20L and 20R, the nose pad 31, and the temples 32L and 32R to the frame 50. In the video display device 1, the width of the prism 13 (the length in the left-right direction) is about １ ／ of the width of the prism 21. In the video display device 2, the width of the prism 13 is the same as the width of the prism 21. I have to. In addition, since the frame 50 for integrating the housing 12, the nose pad 31, and the temples 32L and 32R is used in the second embodiment, the second embodiment is a reference of the present invention in this respect. It is only one form for this and does not belong to this invention.

  In this configuration, the range in which the field of view is blocked by the presence of the frame 50 increases, but a wide image can be provided. The shape of the housing 12, the configuration and function of the prism 13 and the hologram element 22 constituting the eyepiece optical system 16, and the prism 21 are the same as those of the video display device 1 as shown in the cross section in FIG. 5. The cable 40 for connecting to the control device is attached to the rear end portion of the temple 32L, and is connected to the housing 32R through the temple 32L and the inside of the frame 50.

  FIG. 6 shows the appearance of the video display device 3 of the third embodiment. The video display device 3 is provided with a pair of display units 10L and 10R to provide video to the left and right eyes and to give power to the prisms 20L and 20R so that the user's visual acuity can be corrected. is there. The configurations of the display units 10L and 10R are the same as those of the display unit 10 of the video display device 1 of the first embodiment, except that the prisms 13L and 13R have curvature. The housing 12R is connected to the control device by a cable 40, and the housing 12L is connected to the control device via the cable 40a, the housing 12R, and the cable 40.

  The power of the prisms 20L and 20R is set according to the visual acuity of the user. By giving negative power to the prisms 20L and 20R, myopia can be corrected, and by providing positive power, hyperopia can be corrected. The joint surfaces of the lower ends of the prisms 13L and 13R with the prisms 21L and 21R are flat, and the hologram elements 22L and 22R can be easily formed.

1 is a perspective view illustrating an appearance of a video display device according to a first embodiment. Sectional drawing containing the display part of the video display apparatus of 1st Embodiment. The figure which shows the example of the range of the visual field which the visual field of a user and the housing in the video display apparatus of 1st Embodiment block. The perspective view which shows the external appearance of the video display apparatus of 2nd Embodiment. Sectional drawing containing the display part of the video display apparatus of 2nd Embodiment. The perspective view which shows the external appearance of the video display apparatus of 3rd Embodiment.

Explanation of symbols

1, 2, 3 Video display device 10, 10L, 10R Display unit 11 Liquid crystal display device 12, 12L, 12R Housing 13, 13L, 13R Prism 14 Light emitting diode 15 Lens 20, 20L, 20R Prism 21, 21L, 21R Prism 22, 22L, 22R Hologram element 31 Nose pad 32L, 32R Temple 40, 40a Cable 50 Frame

Claims (4)

It has a nose pad that touches the nose and a pair of temples that touch the ear, the temporal region, or the back of the head, and is attached to the front, guiding the light of the displayed image together with the light from the outside world to the eye, In the video display device that is provided over the image of
One or two display units including a display that displays an image, a housing that holds the display, and an eyepiece optical system that guides light from the display to the eye and provides a virtual image of the image;
A pair of prisms located in front of the eyes and transmitting light from the outside world to guide the left and right eyes;
The prism is attached to the nose pad, the temple and the enclosure are attached to the prism, and the enclosure is located around the prism,
Of the pair of prisms, at least one of the prism, eye and first prism constituting the ocular optical system, to forming a shape complementary to the first prism, light from the outside world as an optical action And a second prism that only transmits light for guiding to the first prism, and the second prism supports the first prism in a state in which the first prism is fitted in the second prism, and the first prism The prism and the second prism are joined so that there is no gap and the surface is smoothly continuous.
The first prism has a surface that guides light from the display to the inside, a surface that reflects the introduced light at least once inside and guides it to the front of the eye, and light that is guided to the front of the eye. The surface to be directed as an eyepiece optical system, and the surface to direct the light guided to just before the eye to the eye is a plane made of a hologram element,
Nose pads and temples are attached to the second prism ,
Optical power to light from the outside world, a video display device comprising the same der Rukoto between other ranges and range of planes consisting of the hologram element.   The video display device according to claim 1, wherein the prism has power for correcting diopter.   The video display device according to claim 1, wherein the casing is arranged at a peripheral portion of the user's visual field or outside the visual field. The video display apparatus according to claim 1, wherein the eyepiece optical system has a distance from an eye to a virtual image set to 1 to 3 m.

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