JP4528289B2 - Head-mounted image display device - Google Patents

Description

  The present invention relates to a head-mounted image display device, and more specifically, predetermined image display means, an optical system for projecting an image by the image display means, and the image display means and the optical system on an observer's head. The present invention relates to a head-mounted image display device including a structure for holding at an observation position that is close to or touching.

  As a head-mounted display (hereinafter referred to as HMD) as a conventional head-mounted image display device, for example, there is a head-mounted display that is an HMD disclosed in Japanese Patent Laid-Open No. 8-160348. The HMD incorporates two liquid crystal displays (LCD) for left and right eyes as video display means, and an optical system for left and right eyes for projecting video. The observer can observe the image projected on the LCD with both eyes by wearing the HMD on the head. The shape of the HMD is a goggle shape, but it is quite large and may be heavy in weight. Further, folding and the like cannot be performed.

  In addition, the HMD disclosed in JP-T-8-509075 can be observed with both eyes by similarly mounting the head on the head, so that the image displayed on the LCD can be observed. This HMD has a configuration in which the goggle portion is supported by a band-like member and is mounted on the head, is quite large, and cannot be folded.

  The HMD can be used for many purposes, such as when an image is easily enlarged and observed, or when it is used for a long period of time such as watching a movie or playing a game. However, the conventional HMD or the like has a large shape, so that the mounting work on the head is troublesome, and it is inconvenient when observing an image easily. Further, since the shape of the HMD itself is large and heavy, when it is necessary to observe continuously for a long time, fatigue increases and it is difficult to withstand long-time use.

  Also, when the HMD is used for observation in virtual reality, if the head to which the HMD is attached needs to be moved in accordance with the observation state, the movement of the head when the shape of the HMD is large and heavy Is unnatural and unwell. In addition, the large shape of the HMD means that the storage space is large and it is difficult to carry it easily.

  The present invention has been made to solve the above-mentioned problems. It is easy to mount on the head, is light in weight, is compact in shape, and has a small storage space. An object of the present invention is to provide a type image display device.

  The head-mounted image display device of the present invention includes a predetermined image display means, an optical system for projecting an image projected by the image display means onto the retina in the eyeball of the observer, the image display means, A head-mounted image display device comprising a structure for holding the optical system in an observation position close to or in contact with the head of the observer, wherein the image display means is based on the supplied image signal A display element for projecting an image; a case for protecting the display element; and a light source for emitting light to the back of the display element. The case is made of a transparent material. It is characterized by being configured.

  According to the present invention, the case on the light source side that protects the display element is made of a transparent material, the number of components is reduced, and the assembly can be simplified and made compact.

  Furthermore, since the case for protecting the display element also serves as a light guide plate for the irradiation light of the light source, it can be used as a surface light source using a tubular light source other than the surface light source, for example, as a light source. In addition, it is advantageous in terms of space.

  Furthermore, since the irradiation area by the light emitted from the light source is enlarged, a light source having a small light emitting surface can be applied as the light source, which is advantageous in terms of cost and space.

  Furthermore, since the case for protecting the display element is configured with a portion that also serves as an optical low-pass filter for an image projected on the display element, there is no need to separately provide an optical low-pass filter, which is costly. Also, space is advantageous.

  Furthermore, since the case for protecting the display element also serves as a predetermined optical element involved in the observation of the image projected on the display element, it is advantageous in terms of cost and space.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a perspective view showing an external appearance of an HMD device that is a head-mounted image display device according to an embodiment of the present invention. This HMD apparatus is composed of an HMD 1 and a controller 2.

  The HMD 1 is a goggle type HMD, and includes a display main body 11 having left and right observation windows 12L and 12R, a nose pad member 13, and the like, and left and right frames 41L and 41R.

The display main body 11 includes front and rear exterior bodies 14a and 14b in which the lens barrel device 20 is incorporated, and a nose pad member 13 that can be adjusted in height. Observation windows 12L and 12R are provided. The front exterior body 14 a and the rear exterior body 14 b are fastened with screws 15.
The lens frame device 20 holds image display means and an optical system. The image display means includes a backlight 33 and a display element which are flat fluorescent tubes as light sources as shown in a cross-sectional view of FIG. And an upper LCD frame 26 as a transparent case for holding the LCD. The optical system includes an optical prism 23 which is an optical element.

  The left and right frames 41L and 41R are respectively detachable and bendable with respect to the main body 11, left and right frame main bodies 42L and 42R, and position-adjustable occipital head holding parts 43L having ear hooks 44L and 44R. 43R, earphones 45L, 45R, and the like.

  Further, the controller 2 includes a connector section 4 for power supply connection, video / audio signal input and through signal, a slide switch section 5 for parallax and 2D and 3D switching, and adjustment for audio adjustment and contrast adjustment. A knob unit 6, a power switch unit 7, and the like are disposed, and the video, audio output signal, and drive power lines are connected to the display main body 11 via the connection cord 3.

  By attaching the display main body 11 to the head, the lens frame device 20 can be held at an observation position that is close to or in contact with the head, and the image projected by the LCD 25 is observed on the left and right sides. The image can be projected onto the retina in the eyeball of the observer through the windows 12L and 12R.

Next, the internal structure of the display main body 11 will be described in detail.
FIG. 2 is a longitudinal sectional view of the display main body 11, and FIG. 3 is an exploded perspective view of the lens barrel device 20 incorporated in the display main body 11. 4 is an exploded perspective view around the optical system prism 23 which is the lens frame portion 21 of the lens frame device 20. FIG. 5 is a cross-sectional view of the lens frame portion showing a fixed state of the optical system prism 23. is there.

As shown in FIGS. 2 and 3, the lens frame device 20 includes a printed circuit board portion 31 and a lens frame portion 21.
The printed circuit board 31 includes a printed circuit board 32 that is a circuit board, a backlight 33 that is a pair of left and right planar light sources mounted on the printed circuit board, a pair of left and right backlight drive circuits 35 that serve as a second circuit, and The backlight driving transformer 36, the LCD driving circuit 34 as the first circuit, the left / right flexible printed circuit board connector 38, the power source, and the video signal line connector 39 are configured.

  The pair of left and right backlights 33 are inserted with their outer peripheral edges facing the inner peripheral edges of the notched concave portions 32a and 32b provided on the printed circuit board 32, and soldered at the terminals 33a. And mounted on the printed circuit board 32. In this state, the backlight 33 and the main surface of the printed circuit board 32 are arranged at substantially the same level position (the same height).

  The LCD drive circuit 34 and the power source / video signal line connector 39 are disposed at the center between the concave portions 32a and 32b, and two sets of left and right backlight drive circuits 35 and backlight drive are provided. The transformer for transformer 36 is arranged separately at both outer ends of the concave portions 32a and 32b. Thus, the LCD drive circuit 34, which is a low noise source, the power source, the video signal line connector 39, and the board connector 38 are arranged in the center, and the backlight drive circuit 35, which is a high noise source, and a high-voltage backlight drive. By disposing the transformer 36 at both ends, it is made difficult for noise to ride on the LCD drive circuit 34, the power source, and the video signal line.

  Further, as shown in the exploded perspective view of FIG. 4, the lens frame portion 21 includes a lens frame 22 that is a structure, an optical prism 23 that is an optical element, a lower LCD frame 24 and an upper LCD frame 26 for LCD protection. And the LCD 25.

  The lens frame 22 has a recess 22j into which the lower LCD frame 24 can be inserted, an LCD opening 22k, four insertion holes 22m into which the projections 24c of the lower LCD frame 24 provided in the recess 22j can be inserted, and a lower LCD frame. 24 positioning pins 22q, mounting holes 22p, slide grooves 22a into which slide projections 23d of the optical prism 23 can be inserted on the lower surface side, and self-tapping screws for mounting printed circuit boards on the upper surface side (hereinafter referred to as tapping screws). A protrusion 22g and a positioning pin 22i provided with a pilot hole for use, a support protrusion 22f protruding at both ends, and a support portion 22b at the center.

  The support portion 22b is provided with a tapping screw insertion hole 22c and positioning holes 22d and positioning long holes 22e at the left and right positions thereof. In addition to the support portion 22b of the lens frame 22, a pair of left and right recesses 22j, slide grooves 22a, protrusions 22g, support protrusions 22f, and the like are provided.

  The optical prism 23 has an upper incident surface 23a and a lower reflecting surface 23b, and has a half mirror surface 23c that is inclined toward the observation direction at the central joint. In addition, two sets of projections 23d are provided on each side 2 for attachment in the front-rear direction of the observation direction 51 on the incident surface 23a side.

  For the optical prism 23, a copolymer resin using norbornene monomers, which is an olefin monomer, is applied as a resin having good transparency and no water absorption and less cracking. .

  The lower LCD case 24 has a recess 24a and an opening 24b for mounting the LCD 25, four protrusions 24c that can be fitted into the fitting holes 22m of the lens frame 22, mounting holes 24f and 24e, and positioning pins 24d. ing. The internal dimensions of each of the two protrusions 24c forming the set are dimensions that can be fitted to the outside of the two protrusions 23d on the optical prism 23 side, as shown in the cross-sectional view of FIG.

  The upper LCD case 26 is a transparent case, and is provided with a recess 26a into which the LCD 25 can be inserted from below and a hole 26b for mounting and positioning.

  As shown in the exploded perspective view of FIG. 6, the front exterior body 14 a to which the lens frame device 20 is assembled is disposed at a position facing the tapping screw insertion hole 22 c and the positioning holes 22 d and 22 e of the lens frame 22 in the center of the interior. A mounting pilot hole 14c and positioning / rotation preventing pins 14d and 14e are provided. Further, a pair of U-shaped receiving portions 14f into which the support protrusions 22f of the lens frame 22 can be inserted are disposed at the left and right ends.

Next, a procedure for assembling the display main body 11 configured as described above will be described.
To assemble the lens frame portion 21, first, the LCD 25 is fixed with the tapping screw 17 in a state in which it is housed in the lower LCD frame 24 and the upper LCD frame 26, and an LCD assembled state is obtained. On the other hand, the projection 23d is slid into the guide groove 22a of the lens frame 22, and the optical prism 23 is mounted.

  The upper and lower LCD frames 24 and 26 incorporating the LCD 25 are inserted into the recesses 22j of the lens frame 22. At that time, the protrusion 24c of the lower LCD frame 24 is inserted through the insertion hole 22m and is inserted into the outside of the protrusion 23d of the optical prism 23, so that the optical prism 23 is fixed in place. In this state, the tapping screw 18 is screwed and the upper and lower LCD frames 24 and 26 are fixed to the lens frame 22. Note that the optical prism 23, the LCD 25, and the like each have a pair of left and right members mounted on the lens frame 22 at the same time.

  Further, the printed circuit board 31 on which the backlight 33, the LCD drive circuit 34, and the like are mounted is attached to the lens frame portion 21, positioned by the positioning pins 22i, and the tapping screws 16 are screwed into the pilot holes 22g and fixed. Furthermore, when the flexible printed circuit board 37 connected to the LCD 25 is connected to the connector 38 on the printed circuit board 31, the lens frame device 20 is completed. In this mounted state, the backlight 33 on the printed circuit board 31 side is located above the LCD 25.

  Next, the lens frame device 20 is attached to the front and rear exterior bodies 14a and 14b. When the lens frame device 20 is attached as shown in FIG. 6, the positioning hole 22d and the elongated hole 22e of the support portion 22b of the lens frame 22 are provided. The pins 14d and 14e of the exterior body 14a are inserted, and the screw 19 is inserted into the mounting hole 22c through the mounting hole 22c and fixed.

  In this fixed support state, as shown in FIG. 7, the support protrusion 22f provided at the end of the lens frame 22 is inserted into the receiving portion 14f of the front exterior body 14a with a gap 22n in the vertical direction 53. is there. Since the lens frame 22 is supported in this way, if a strong impact force is applied to the lens frame 22 due to a drop or the like in terms of yield strength in the up and down direction, which is a relatively weak direction, both ends of the lens frame 22 are applied. There is room for the portion to be elastically deformed by the gap 22n. The impact force is absorbed by this elastic deformation.

Thereafter, the rear exterior body 14b is screwed to the front exterior body 14a to complete the assembly of the display main body 11, and the left and right frames 41L and 41R and the nose pad member 13 are attached to the display main body 11. Further, when the controller 2 is connected, the HMD 1 is completed.
When the HMD 1 is mounted on the head and the power and video signal are supplied to the controller 2, the video displayed on the LCD 25 is observed as a virtual image enlarged a predetermined distance in front of the viewer's eyes, for example, 2 m ahead. become.

  According to the HMD 1 of the present embodiment described above, since the display main body 11 is light and compact as described above, there is no feeling of fatigue even when used for a long time, and for virtual reality use. Even when used, there is no resistance to moving the head.

Further, the internal structure of the device 1 has the following characteristics.
That is, of the upper and lower LCD frames 24 and 26 that hold the LCD 25, a transparent member is applied to the upper LCD frame 26 on the backlight 33 side so that both the LCD holding member and the light guide member are used. Is summarized in a compact.

In the printed board 31, a pair of left and right backlights 33 is inserted into the two notched concave portions 32 a and 32 b of the printed board 32, so that there is no useless space.
In addition, an LCD drive circuit 34 and a connector 38, 39 such as a video line and a power source, which generate relatively little noise, are arranged in the central portion between the two notched concave portions 32a, 32b. Further, by disposing the backlight driving circuit 35 and the backlight driving transformer 36 that generate a relatively large amount of noise on the outer both end sides of the concave portions 32a and 32b, an arrangement in which noise is hardly applied to the video signal line as much as possible. It has become.

  In the lens frame device 20, the lens frame 22 is fixedly supported at the center by the front exterior body 14a and supported at the end with a vertical gap 22n. When a strong impact force is applied, the end of the lens frame 22 has a margin for elastic deformation by the gap 22n, and the impact force is absorbed. Misalignment and destruction of the positioning pins 14d and 14e can be prevented.

  The optical prism 23 is accurately positioned with respect to the lens frame 22 by the projection 24c of the lower LCD frame 24, and can be easily mounted without being fixed with a dedicated screw or the like.

Next, a modified example of the optical prism mounting structure will be described as a first modified example of the HMD 1 of the above-described embodiment.
FIG. 8 is an exploded perspective view of the optical prism 72 and the lens frame 71 of the modified example, and FIG. 9 is a longitudinal sectional view in a state where the lens frame 71 is attached to the optical system prism 72. The optical prism 72 of this modification is a resin having good transparency and no water absorption as in the case of the first embodiment, and is less likely to crack and can be fixed with a tapping screw. As the resin, a copolymer resin using a norbornene monomer that is an olefin monomer is used.

  As shown in FIGS. 8 and 9, the optical prism 72 is provided with a concave surface 72 b which is a surface that is one step lower than the upper incident surface 72 a at the left and right positions in the observation direction 51. On the left and right concave surfaces 72b, there are provided a projection 72c and a positioning pin 72e provided with a pilot hole 72d for a tapping screw for attaching the lens frame 71, respectively. In addition, the protrusion direction of the protrusion 72c and the positioning pin 72e is a direction orthogonal to the incident surface 72a.

  The protrusion 72c is disposed on the concave surface 72b and is disposed away from the effective diameter region 72f of the effective optical path of the optical system prism 72. A tapping screw 73 is screwed into the lower hole 72d. The distortion that occurs sometimes is not transmitted to the effective diameter region 72f.

  When the optical prism 72 having the above shape is attached to the lens frame 71, the positioning pin 72e of the optical prism 72 is inserted into the positioning hole 71a of the lens frame 71 with the incident surface 72a facing the LCD 25 that is an image element, The tapping screw 73 is inserted through the attachment hole 71b of the lens frame 71 and screwed into the prepared hole 72d to obtain an attachment state.

  As a structure for fixing the conventional optical prism to the lens frame, for example, as shown in the sectional view of the attached state in FIG. 14, the optical prism 101 protrudes from the effective area width to the outside in the direction orthogonal to the observation direction 52. A structure in which a protrusion 101a is provided and the pressing member 103 is brought into contact with the protrusion 101a and fixed to the lens frame 102 with a screw is applied, or a structure in which the protrusion 101a is fixed by adhesion is employed.

  However, in the mounting structure in this modification, as described above, the protrusion 72c having the pilot hole 72d for the tapping screw is disposed on the concave surface 72b provided within the width of the effective region 72f of the optical prism 72, and the pilot hole 72d is provided. A structure in which a tapping screw 73 is screwed in and attached is adopted. Therefore, the optical prism 72 can be fixed without affecting the effective diameter region 72f without providing a projecting portion in the width direction of the optical prism 72, that is, the direction orthogonal to the observation direction 52, and the lens frame device can be downsized. It becomes possible. Further, a tapping screw can be applied to fix the optical prism 72, and the screw machining of the prepared hole 72d is not necessary.

Next, a modified example around the display unit will be described as a second modified example of the HMD 1 of the above-described embodiment.
FIG. 10 is an exploded perspective view around the display unit of the modified example, and FIG. 11 is a longitudinal sectional view around the display unit. In this modification, the LCD 25 as a display unit is supported and protected by a backlight unit 81 including a transparent upper LCD frame 82 that also serves as a tubular light source 83 and a light guide plate, and a lower LCD frame 84 having an optical low-pass filter 84a. ing. The tubular light source 83 is held in a side recess 82 a of the upper LCD frame 82, and light from the light source 83 is transmitted through or reflected by the upper LCD frame 82 to irradiate the LCD 25. The light transmitted through the LCD 25 passes through the optical low-pass filter 84a of the lower LCD frame 84 and is emitted to an optical prism (not shown).

According to the structure of the display unit of the present modification configured as described above, it is not necessary to separately provide a backlight for the display unit, the occupied space is reduced, and the display unit can be compactly integrated. it can. In addition, the number of parts is reduced and the weight can be reduced. In addition, unitization is possible and assembly is simplified.
Japanese Laid-Open Patent Publication No. 9-43605 proposes a surface light source device using a fluorescent lamp for a backlight of a liquid crystal display. This device is a device as a single backlight, and the second light source described above. Unlike the modified example, the LCD 25 does not have both the support and protection functions of the LCD 25, and the effects of the modified example cannot be achieved.

Next, a modified example around the display unit will be described as a third modified example of the HMD 1 of the above-described embodiment.
In the display unit of this modification, a part of the upper and lower surfaces 92b, 92a of the transparent upper LCD frame 92, which is a member for holding the LCD 25, is partially shown as shown in the longitudinal sectional view around the display unit of this modification in FIG. A half mirror surface having an inclined surface of The light emitted from the backlight 91, which is a flat light emitting member, is reflected by the upper and lower surfaces 92b and 92a, and the irradiation range is expanded to the effective emission range 25a of the LCD 25. The LCD 25 is protected by being supported by the upper LCD frame 92 on the upper side and the lower LCD frame 93 on the lower side.

  According to the structure of the display unit of the present modification configured as described above, a backlight 91 having a small area can be applied. For example, in the case of the HMD 1 of the above-described embodiment, a backlight having a size of 0.7 inches is required as the backlight 33, but a backlight 91 having a size of 0.55 inches is applied as the backlight 91 of the above modification. Thus, the space occupied by the backlight is reduced, the display unit can be compactly packed, and the weight can be reduced.

Next, a modified example around the display unit will be described as a fourth modified example of the HMD 1 of the above-described embodiment.
In the display unit of this modification, a concave lens part 95a is provided at the center of a transparent upper LCD frame 95, which is a member for holding the LCD 25, as shown in the longitudinal sectional view around the display part of this modification in FIG. The light emitted from the backlight 91, which is a flat light emitting member, is transmitted through the lens portion 95a, and the irradiation range is expanded to the effective emission range 25a of the LCD 25. The LCD 25 is protected by being supported by the upper LCD frame 92 on the upper side and the lower LCD frame 93 on the lower side.

  According to the structure of the display unit of the present modification configured as described above, the space occupied by the backlight is reduced as in the display unit of the third modification, and the display unit can be compactly assembled. It is also possible to reduce the weight.

The perspective view which shows the external appearance of LMD which is a head mounted image display apparatus as one embodiment of this invention. The longitudinal cross-sectional view of the display main-body part of HMD of FIG. The disassembled perspective view of the lens-frame apparatus incorporated in the display main-body part of HMD of FIG. FIG. 2 is an exploded perspective view around the optical system prism and LCD of the HMD in FIG. 1. The cross-sectional view of the lens-frame part which shows the fixed state of the optical system prism of HMD of FIG. The disassembled perspective view of the lens-frame apparatus and front exterior body of HMD of FIG. Sectional drawing which shows the insertion state of the support protrusion of the lens barrel apparatus of FIG. 6, and the receiving part of a front exterior body. The disassembled perspective view around the optical prism mounting portion in the first modification of the HMD in FIG. The longitudinal cross-sectional view of the optical prism attachment part of FIG. The disassembled perspective view around the display part in the 2nd modification of HMD of FIG. FIG. 11 is a longitudinal sectional view around the display unit in FIG. 10. The longitudinal cross-sectional view around the display part in the 3rd modification of HMD of FIG. The longitudinal cross-sectional view around the display part in the 4th modification of HMD of FIG. The longitudinal cross-sectional view around the attaching part of the optical prism in a prior art example.

Explanation of symbols

22 ...... Mirror frame (structure)
23,72 …… Optical prism
(Optical element, optical system)
25 …… LCD (Video display means, display element)
26 …… Upper LCD frame
(Case for protecting display element)
32 …… Circuit board (video display means)
32a, 32b
... Concave part 33, 91, 83 of circuit board
...... Backlight (video display means)
34 ...... LCD drive circuit (first circuit)
35 ...... Backlight drive circuit
(Second circuit)
36 …… Backlight drive transformer
(Second circuit)
72b ...... Concave surface of optical prism
(Concave part of optical element)
72c ... Projection of optical prism
(Convex part of optical element)
72d: Tapping screw pilot hole
(Prepared holes for self-tapping screws)
73 …… Tapping screw
(Self-tapping screw)
82, 92, 95 …… Upper LCD frame
(Case protecting display element, light guide plate)
83 ...... Tubular light source (light source)
84 ...... Lower LCD frame
(Case for protecting display element,
Optical low-pass filter)

Claims (2)

Predetermined image display means, an optical system for projecting an image projected by the image display means onto the retina in the observer's eyeball, and the image display means and the optical system close to or near the head of the observer A head-mounted image display device provided with a structure for holding at an observation position in contact with the head,
The video display means includes a display element for Utsude video by the video signal supplied, and a case for protecting the upper Symbol display device, a light source that emits illumination light to the back surface of the display device, and
The case is made of a transparent material, and includes a portion that also serves as a light guide plate that guides light emitted from the light source so as to irradiate a predetermined area on the back surface of the display element.
The head-mounted image display device characterized in that the portion that also serves as the light guide plate of the case has a lens portion for enlarging an irradiation area by light emitted from the light source . The head-mounted image display device according to claim 1, wherein the case includes a portion that also serves as an optical low-pass filter for an image projected on the display element .

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