JP4576080B2 - Video display device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image display device in which an eccentric free-form surface prism is positioned or held with reference to its ridgeline or vertex.
[0002]
[Prior art]
In general, in order to obtain good optical performance as an optical device using an optical element such as a prism, it is necessary to fix the optical element to the inside of the casing or other optical elements in a state of being accurately and accurately positioned.
[0003]
A representative example of this optical element is an eccentric free-form curved prism. This eccentric free-form surface prism enlarges an image displayed on a video display device and guides it to an observer's eyeball, and is often used in a head mounted display (HMD) or the like. Since this eccentric free-form surface prism has few standard planes, various fixing methods have been proposed.
[0004]
For example, in Japanese Patent Laid-Open No. 9-73005, positioning portions are projected on both side surfaces that are not optically affected, and the eccentric free curved surface portion rhythm is fixed in another member or housing with reference to the positioning portions. Technology is disclosed.
[0005]
[Problems to be solved by the invention]
However, if a positioning part is provided on the eccentric free-form curved prism, in addition to the original optical performance of the eccentric free-form curved prism, positioning accuracy for mounting this eccentric free-form prism is required. Dimensional accuracy is required, which not only complicates the manufacturing process but also increases the product cost.
[0006]
Recently, in order to reduce the weight and cost of the apparatus itself, plastic eccentric free-form curved prisms are often used. However, the positioning is integrally formed with such an eccentric free-form prism. When fixing the part to other members via screws or the like, if it is tightened too much, excessive stress will be applied to the eccentric free-form curved prism, and the optical characteristics will be significantly impaired. Careful attention is also required when attaching, which complicates manufacturing and assembly, and is an obstacle to improving productivity.
[0007]
Furthermore, if the positioning portion is formed on the eccentric free-form curved prism, it is necessary to form a receiving portion for supporting the positioning portion on another member or the casing, which increases the size of the entire product and realizes downsizing. There is a problem that causes trouble on the above.
[0008]
In view of the above circumstances, the present invention reduces the parts required for dimensional accuracy with respect to an eccentric free-form curved prism, achieves cost reduction of the product, and is relatively easy without affecting optical characteristics. It is an object of the present invention to provide a video display device that can be assembled to improve productivity, and that can reduce the size of the product.
[0009]
[Means for Solving the Problems]
  In order to achieve the above object, an image display device according to the present invention includes an image display element for displaying an image, at least one eccentric free-form curved prism for enlarging the image and guiding the image to an observer, and the image A holding member for holding the display element and the eccentric free-form curved prism;TheHaveThe holding member isUsing at least one ridge line or vertex of the eccentric free-form surface prism,Position or hold the eccentric free-form curved prismIt is characterized by that.
[0010]
  In this case, preferably 1) the aboveOf the eccentric free-form surface prism by the holding member.Positioning isThe eccentric free-form surface prismIt is performed at a ridge line or a vertex provided around a surface facing the image display surface of the image display element.
[0011]
  2) AboveEccentricity due to holding memberThe positioning of the free-form surface prism is performed by using a ridge line formed substantially parallel or substantially at right angles to the mold splitting direction when the eccentric free-form surface prism is formed.
[0012]
  3) The eccentric free-form surface prism isAn optical surface facing an observation window provided in an exterior member that houses the eccentric free-form surface prismRidge aroundIs held by the holding membersoFor the exterior memberIt is characterized by being positioned or held.
  4)The holding member is formed on an exterior member that houses the eccentric free-form curved prism.
  5)The ridge line is formed in a substantially straight line and a symmetrical position of the eccentric free-form surface prism.
  6)An exterior member for interiorly arranging the video display element and the eccentric free-form surface prism;
  The holding member is provided on the inner surface of the exterior member for positioning or holding the ridge line of the eccentric free-form curved prism, and the holding member is provided on the inner surface of the exterior member for positioning or apex of the eccentric free-form curved prism. It has the vertex holding member to hold | maintain.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 to 6 show a first embodiment of the present invention. 1 is a cross-sectional front view of the image display device, FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1, FIG. 3 is a cross-sectional view taken along the line III-III in FIG. FIG. 5 is an explanatory diagram for observing an enlarged image using an eccentric free-form curved prism, and FIG. 6 is an explanation for observing an enlarged image using an eccentric free-form curved prism according to another aspect. FIG.
[0014]
Reference numeral 1 in FIGS. 1 to 3 denotes a video display device, which is provided in the portable terminal 2 in the present embodiment. The mobile terminal 2 includes a mobile phone, a mobile device, and the like, but in the present embodiment, a mobile phone is shown as an example of the mobile terminal 2. Therefore, in the following, the mobile terminal 2 is referred to as a mobile phone. This will be described as “2”.
[0015]
  An image display element 4 for displaying an image and an image displayed on the image display element 4 are enlarged in a housing 3 as an exterior member of the image display device 1 fixed on the bottom surface of the mobile phone 2.BiasA core free-form curved prism 6 and the like are internally provided. The video display element 4 may be an EL (Electronic Luminescent) element, a plasma display, an LED (Light Emitting Diode) array, or the like in addition to the liquid crystal display element. In the present embodiment, a liquid crystal display element is adopted. Therefore, the illumination element 5 for allowing the image displayed on the liquid crystal display element to be observed with sufficient brightness is disposed on the rear surface. Further, an observation window 7 for emitting an image displayed on the video display element 4 and enlarged by the eccentric free-form curved prism 6 is provided on the front surface of the housing 3.
[0016]
As shown in FIG. 4, the eccentric free-form curved prism 6 is a plastic molded product, and is composed of a first optical surface 6a, a spherical surface, or a toric surface as a light incident surface composed of a flat surface or a curved surface such as a spherical surface or an aspheric surface. A second optical surface 6b that acts as a reflection and refracting surface utilizing total reflection at the part, a rotationally asymmetric aspherical surface having different curvatures depending on the azimuth angle of semi-transmission or specular reflection, ie, a surface only on one symmetric surface Three optical surfaces 6a to 6c having an optical action as a whole of the third optical surface 6c having a symmetric surface shape, and a pair of parallel side faces 6d facing each other that do not contribute to the optical action (reflection and refraction action). And have. Further, outer ridge lines L1, L1 ', L2 to L4 are formed by the optical surfaces 6a to 6c and the side surface 6d.
[0017]
Then, as shown in FIG. 5, when a light beam based on the image displayed on the video display element 4 is introduced from the first optical surface 6a of the eccentric free-form surface prism 6 into the element, the second optical surface After being totally reflected by 6b, it is reflected and condensed by the third optical surface 6c, is transmitted through the second optical surface 6b, and is guided to the eyeball Uey of the observer. At this time, a virtual image enlarged in front of the observer is displayed without forming an image displayed on the video display element 4 in the middle due to the curvature of the second optical surface 6b and the third optical surface 6c. Let
[0018]
In this case, as another embodiment, a light beam introduced from the first optical surface 6a to the inside of the element is guided to the third optical surface 6c as in the eccentric free-form surface prism 6 ′ shown in FIG. The first optical surface 6c is once totally reflected, the second optical surface 6b is totally reflected, the third optical surface 6c is further reflected and condensed, and then the eyeball of the observer is reflected from the second optical surface 6b. The light may be guided to Uey, that is, the light beam may be totally reflected twice by the third optical surface 6c.
[0019]
By the way, the eccentric free-form surface prism 6 has few planes as a reference surface, and it is difficult to fix the eccentric free-form surface prism 6 to the housing 3 in a predetermined position. By positioning or holding the external ridge line or apex of the eccentric free-form curved prism 6 as a reference, the conventional positioning portion protruding from the eccentric free-form curved prism 6 can be eliminated, and high-precision positioning is possible. I have to.
[0020]
In this case, which external ridge line or vertex of the eccentric free-form curved prism 6 is positioned with respect to the housing 3 is set based on the structure of the mold for molding the eccentric free-form curved prism 6.
[0021]
That is, as shown in FIG. 4B, the eccentric free-form curved prism 6 employed in the present embodiment is formed using a mold that is divided in three directions indicated by arrows A, B, and C. Yes. Among them, the dividing direction of the arrows A and B is set to a direction along the outer ridge line L3 formed by the first optical surface 6a and the side surface 6d, and the first optical surface 6a is Are set so as to be symmetric with respect to the dividing direction indicated by arrows A and B.
[0022]
Since the outer ridge line L3 formed on both sides of the first optical surface 6a is substantially straight and symmetrical, the two outer ridge lines L3 are substantially parallel to each other, and the vertices P1 and P2 have substantially the same height direction. I'm doing it. Therefore, the outer ridge line L3 or its apex P1. By setting P2 as a positioning portion for the housing 3, it becomes easy to obtain the accuracy of the holding member formed on the housing 3, and the eccentric free-form curved prism 6 can be positioned with high accuracy.
[0023]
For this reason, in the present embodiment, the eccentric free-form curved prism 6 is mounted on the basis of the outer ridge line L3 formed on both sides of the first optical surface 6a and the vertices P1 and P2 of the two outer ridge lines L3. It is fixed to the body 3.
[0024]
Specifically, as shown in FIGS. 1 to 3, the housing 3 is divided into a rear case 3 a and a front case 3 b, and the rear case 3 a has an outer ridge line L <b> 3 of the eccentric free-form curved prism 6. A rear vertex holding member 11 for positioning or holding the vertex P1 is integrally formed. On the other hand, the front case 3b is integrally formed with a front vertex holding member 12a that positions or holds the vertex P2 of the outer ridge line L3 of the eccentric free-form curved prism 6.
[0025]
Further, the front case 3b holds an external ridge line L2 (see FIG. 4) where the second optical surface 6b and the side surface 6d intersect on both sides of the second optical surface 6b of the eccentric free-form curved prism 6. The front ridge line holding member 12b is formed continuously with the front vertex holding member 12a, and the converging tips of the second optical surface 6b and the third optical surface 6c of the eccentric free-form curved prism 6 are fitted. A front end side holding member 13 having a concave portion to be joined is integrally formed.
[0026]
In such a configuration, the front ridge line holding member 12b and the front vertex holding member 12a formed on the front case 3b of the housing 3 are formed on both sides of the second optical surface 6b of the eccentric free-form curved prism 6. The outer ridge line L2 and the apex P2 formed at both ends of the outer ridge line L3 formed on both sides of the first optical surface 6a are mounted, and the second recess is formed in the recess formed in the distal end side holding member 13. The converging tip portions of the optical surface 6b and the third optical surface 6c are engaged. At this time, the eccentric free-form curved prism 6 is attached to each holding member 12a, 12b. 13 may be temporarily fixed.
[0027]
After that, when the front case 3b and the case 3a are fitted, the vertex P1 formed at the other end of the external ridge line L3 of the eccentric free-form curved prism 6 is retained at the rear vertex that is integrally formed with the rear case 3a. It is fitted to the member 11 and positioned or held.
[0028]
As a result, the first optical surface 6a of the eccentric free-form curved prism 6 is positioned by the rear vertex holding member 11 and the front vertex holding member 12a, and the outer ridge line L2 is further pressed against the front vertex holding member 12b. Fixed.
[0029]
As described above, according to the present embodiment, the external ridge line L3 of the first optical surface 6a processed with high accuracy of the eccentric free-form curved prism 6 is used as the positioning portion for the housing 3, and the external ridge line L3. Are formed in a substantially straight line shape along the mold dividing direction of the mold and have a bilaterally symmetric shape. Therefore, the height directions of the vertices P1 and P2 of the two outer ridge lines L3 coincide with each other. The rear apex holding member 11 and the front apex holding member 12a for positioning or holding P2 can be formed with high dimensional accuracy. Therefore, the eccentric free-form curved prism 6 is positioned with high accuracy with respect to the housing 3. Can be made.
[0030]
Further, the apexes P1 and P2 of the outer ridge line L3 formed on both sides of the first optical surface 6a of the eccentric free-form curved prism 6 are positioned or held by the apex holding members 11 and 12a of the housing 3. Since the tip is held by the tip-side holding member 13, the eccentric free-form curved prism 6 is positioned in the housing 3 by mounting the front case 3b on the rear case 3a. This makes it easy to reduce the assembly man-hours.
[0031]
Furthermore, since there is no need to project a positioning portion as in the prior art on the eccentric free-form curved prism 6, the manufacture of the eccentric free-form curved prism 6 can be simplified and the weight can be reduced.
[0032]
Furthermore, in the assembly, it is not necessary to fix the eccentric free-form curved prism 6 using screws or the like, so that an excessive stress is not applied to the eccentric free-form curved prism 6 and the optical characteristics are improved. It is not damaged, the assembly quality is improved, the reliability of the product is improved, screws are not required, the number of parts can be reduced, and the entire device can be reduced in size and weight. .
[0033]
7 to 9 show a second embodiment of the present invention. 7 is a front view of the observation apparatus with the front case removed, FIG. 8 is a sectional view taken along the line VIII-VIII in FIG. 7, and FIG. 9 is a sectional view taken along the line IX-IX in FIG.
[0034]
In the present embodiment, the apex P1 of the outer ridge line L3 formed on both sides of the first optical surface 6a of the eccentric free-form curved prism 6 (see FIG. 4) shown in the first embodiment on the inner surface of the rear case 3a. The rear-side vertex holding member 11 is integrally formed, while the front-side holding member 14 that receives the other vertex P2 of the outer ridge line L3 is integrally formed on the inner surface of the front case 3b. This extends to the joint surface between the rear case 3a and the front case 3b.
[0035]
That is, at the time of assembling, the apex P1 or P2 of the eccentric free-form curved prism 6 is placed on one of the rear apex holding member 11 formed on the rear case 3a and the front holding member 14 formed on the front case 3b. At the same time, the outer ridge line L3 connecting the two apexes P1 and P2 is brought into contact, and positioned or held using an adhesive or the like.
[0036]
Next, when both cases 3a and 3b are closed, 4 of the first optical surface 6a provided on the eccentric free-form curved prism 6 between the holding members 11 and 14 formed on the inner surfaces of both cases 3a and 3b. Vertex P1. P2 is sandwiched and further positioned or held at the outer edge L3.
[0037]
As described above, according to the present embodiment, it is only necessary to close the rear case 3a and the front case 3b so that the four apexes P1. P2 is sandwiched and fixed by holding members 11 and 14 projecting from the inner surfaces of the rear case 3a and the front case 3b, and the apex P1. Since the outer ridge line L3 connecting between P2 contacts the inner surfaces of the holding members 11 and 14 and is positioned or held, the structure is further simplified as compared with the first embodiment, and the manufacturing and assembly is further facilitated. become.
[0038]
Furthermore, since the outer ridge line L3 of the eccentric free-form curved prism 6 is substantially linear and symmetrical, it can be positioned with high accuracy with respect to the holding members 11 and 14 formed on the housing 3. .
[0039]
10 to 12 show a third embodiment of the present invention. 10 is a front view corresponding to the XIII-XIII cross section of FIG. 12 of the observation device, FIG. 11 is a XI-XI cross sectional view of FIG. 10, and FIG. 12 is a XX cross sectional view of FIG.
[0040]
In the present embodiment, the outer ridge line L2 and the apex P2 of the eccentric free-form curved prism 6 are formed by the front ridge line holding member 12b formed on the front case 3b and the front vertex holding member 12a continuous to the front ridge line holding member 12b. In this state, it is fixed to the front case 3b while being positioned or held.
[0041]
That is, on the inner surface of the front case 3b, the front ridge line holding member 12b and the front vertex holding member 12a for positioning or holding the external ridge line L2 of the eccentric free-form curved prism 6 and positioning or holding the vertex P2 are integrally formed.
[0042]
When assembling, the external ridge line L2 of the eccentric free-form curved prism 6 is attached to the front ridge line holding member 12b formed on the inner surface of the front case 3b, and the vertex P1 is brought into contact with the front vertex holding member 12a. The top and bottom and left and right directions of the paper 10 are positioned or held and fixed using an adhesive or the like.
[0043]
As described above, in the present embodiment, since the eccentric free-form curved prism 6 is adhered to the front ridge line holding member 12b and the front vertex holding member 12a formed on the front case 3b and positioned or held, the manufacturing is performed. It becomes easy and the assemblability is further improved.
[0044]
FIGS. 13 to 15 show a fourth embodiment of the present invention. 13 is a front view corresponding to the XIII-XIII cross section of FIG. 15 of the observation apparatus, FIG. 14 is a XIV-XIV cross sectional view of FIG. 13, and FIG. 15 is a XV-XV cross sectional view of FIG.
[0045]
In the present embodiment, the holding member 15 that contacts or contacts the side surface 6d of the eccentric free-form curved prism 6 on the inner surfaces of the rear case 3a and the front case 3b and positions or holds the side surface 6d of the eccentric free-form curved prism 6 , 16 project from each other, and the rear vertex holding member 15a and the front vertex holding member 16a holding the vertices P1, P2 formed at both ends of the outer ridge line L3 on the opposing surfaces of the holding members 15, 16 respectively. And a flange portion that is formed so that the third optical surface 6c and the side surface 6d of the eccentric free-form curved prism 6 intersect each other inwardly from the holding members 15 and 16, and abuts against the outer ridge line L4. 15b and a flange portion 16b that is formed by intersecting the second optical surface 6b and the side surface 6d and abuts against the outer ridge line L2.
[0046]
When the rear case 3a and the front case 3b are closed, the decentering free-form curved prism is formed by the holding members 15 and 16, the apex holding members 15a and 16a, and the flange portions 15b and 16b formed in the cases 3a and 3b. 6, the apexes P1 and P2 formed at both ends of the side surface 6d and the outer edge line L3, and the outer edge lines L2 and L4 are positioned or held, and further, the second optical surface 6b and the third optical surface 6c The converging tip is brought into contact with the tip holding member 13 and positioned or held.
[0047]
As a result, in this embodiment, the eccentric free-form curved prism 6 can be positioned or held by simply closing the rear case 3a and the front case 3b without using an adhesive or the like. Remarkably improved. Of course, when assembling, the eccentric free-form curved prism 6 may be temporarily fixed to one case 3a or 3b using an adhesive.
[0048]
FIGS. 16 to 18 show a fifth embodiment of the present invention. 16 is a front view corresponding to the XVI-XVI cross section of FIG. 17 of the video display device, FIG. 17 is a XVII-XVII cross section of FIG. 16, and FIG. 18 is a XVIII-XVIII cross section of FIG.
[0049]
In the present embodiment, the housing 3 is integrally formed in a bag shape, and a wall surface portion that receives the four apexes P1 and P2 of the first optical surface 6a of the eccentric free-form curved prism 6 and the outer ridge line L1 therein. The prism housing chamber 3c is formed in the housing 3 by integrally forming a holding member 17 having a side wall 17b that abuts on the side surface 6d of the eccentric free curved prism 6 and positions or holds the side surface 6d. In addition, the side surface of the prism accommodating chamber 3c is opened in the housing 3, and the opening is closed with a lid 17c.
[0050]
At the time of assembly, the eccentric free-form curved prism 6 is attached to the prism accommodating chamber 3c from the opening opened on the side surface of the housing 3. Then, the side surface 6d of the eccentric free-form curved prism 6 is guided in a state where the position is regulated by the side wall 17b, and when inserted to the deepest part, the four vertices P1, P2 formed on the first optical surface 6a, The outer ridge line L1 is positioned or held by contacting the rear wall surface 17a. Therefore, the eccentric free-form curved prism 6 can be positioned or held by adhering the four apexes P1 and P2 and the outer ridge line L1 to the wall surface 17a.
[0051]
Then, after the eccentric free-form curved prism 6 is properly positioned or held in the prism accommodating chamber 3c, the opening portion opened on the side surface of the housing 3 is closed with the lid 17c, and an adhesive or the like is used. And stick.
[0052]
Thus, according to the present embodiment, the housing 3 is integrally formed in a bag shape, and even when it is difficult to attach from the outside, the eccentric free-form curved prism 6 can be easily externally Moreover, it can be mounted with high accuracy. Therefore, for example, it is possible to easily attach a product requiring a waterproof structure, and the application range of the product can be expanded.
[0053]
FIGS. 19 to 21 show a sixth embodiment of the present invention. Here, FIG. 19 is a front view of the image display device with the front case removed, FIG. 20 is a sectional view taken along line XX-XX in FIG. 19, and FIG. 21 is a sectional view taken along line XXI-XXI in FIG.
[0054]
In the present embodiment, the holding member 19 is formed in a frame shape, and the eccentric free-form curved prism 6 is housed in a holding member (hereinafter referred to as “frame body”) 19 formed in a frame shape. It is accommodated in the body 3. The frame 19 has an opening on the surface facing the first optical surface 6 a of the eccentric free-form curved prism 6, and the inner surface of the side wall 19 a positions or holds the side surface 6 d of the eccentric free-form curved prism 6. In addition, from the side wall 19a inward, the outer ridge line L4 formed by intersecting the third optical surface 6c and the side surface 6d, and the outer shape formed by intersecting the second optical surface 6b and the side surface 6d. Flange portions 19b and 19c for positioning or holding the ridge line L2 are formed.
[0055]
When the eccentric free-form curved prism 6 is inserted from the opening formed in the frame body 19, the outer ridge lines L4 and L2 are sandwiched and positioned or held by the flange portions 19b and 19c, and the side surface 6d is formed by the side wall 19a. Positioning or holding is performed, and further, the leading end is in contact with the inner surface of the frame body 19 to be positioned or held.
[0056]
As a result, the position is automatically fixed only by attaching the eccentric free-form curved prism 6 to the frame body 19.
[0057]
Then, after the eccentric free-form curved prism 6 is mounted on the frame 19 in a predetermined manner, the opening of the frame 19 is closed with a lid 17c and fixed using an adhesive or the like. The four vertices P1 and P2 and the outer ridge line L1 of the first optical surface 6a are positioned or held.
[0058]
A pair of opposing mounting portions 19e projecting outward is formed on the edges of the side walls 19a of the frame body 19 which are in contact with the inner surfaces of the front case 3b and the rear case 3a, and are attached to the mounting portions 19e. A hole 19f is formed.
[0059]
When the frame body 19 is assembled to the housing 3, first, a projection 3 d projecting on one inner surface of the rear case 3 a and the front case 3 b is drilled in one attachment portion 19 e of the frame body 19. The mounting hole 19f is inserted and positioned or held. Next, when the rear case 3a and the front case 3b are closed, the protruding portion 3d protruding from the inner surface of the other case 3a or 3b is inserted into the mounting hole 19f formed in the other mounting portion 19e. Positioning or holding.
[0060]
As described above, in the present embodiment, the eccentric free-form surface prism 6 is fixed to the housing 3 via the frame body 19, so that the eccentric free-form surface prism 6 can be assembled without being touched directly. In addition, by storing the eccentric free-form curved prism 6 in the frame 19 in advance, the eccentric free-form curved prism 6 can be effectively protected from scratches, defects, etc. during parts conveyance, etc. Get better. In particular, since the third optical surface 6c is subjected to a reflective coating process for total reflection, the reflective surface can be effectively protected from scratches and the product defect rate can be reduced.
[0061]
22 to 24 show a seventh embodiment of the present invention. Here, FIG. 22 is a front view of the image display device with the front case removed, FIG. 23 is a sectional view taken along line XXIII-XXIII in FIG. 22, and FIG. 24 is a sectional view taken along line XXIV-XXIV in FIG.
[0062]
In this embodiment, the eccentric free-form surface prism 6 is supported at three points from both sides.
[0063]
That is, a pair of inner surfaces of the rear case 3a and the front case 3b are parallel to the first optical surface 6a of the eccentric free-form curved prism 6 and are symmetrical with respect to the center of the eccentric free-form curved prism 6. Protrusions 20 a and 20 b are projected, and another projecting part 20 b is projected at the center of the tip of the eccentric free-form curved prism 6.
[0064]
When the rear case 3a and the front case 3b are closed, the projecting portions 20a and 20b projecting from the cases 3a and 3b become the third optical surface 6c and the second optical surface 6b of the eccentric free-form curved prism 6, respectively. The two optical surfaces 6c and 6b are supported at three points. In this case, more accurate positioning can be performed by forming a concave portion at a position corresponding to the protrusions 20a and 20b of both the optical surfaces 6c and 6b.
[0065]
As described above in each embodiment, in this embodiment, the external ridge line of the eccentric free-form curved prism 6 and the apex thereof are used to position or hold the casing. It is possible to diversify the method, and it is possible to select an optimal mounting method for every housing, and not only the degree of freedom of design is increased, but also the space in the housing can be used effectively.
[0066]
FIG. 25 shows a perspective view of a main part of a head-mounted image display device (HMD) according to the eighth embodiment of the present invention.
[0067]
The optical system holding member 21 incorporated in the head-mounted image display device is provided with a pair of left and right optical system holding parts 21a, and both optical system holding parts 21a are connected via a connecting part 21b. .
[0068]
A step portion 6e is formed on the side surface 6d side of the first optical surface 6a of the eccentric free-form curved prism 6 attached to the optical system holding portion 21a. The step portion 6e is formed in a substantially linear shape along the mold dividing direction of the mold, and each optical system holding portion 21a is a recess that fits between the step portions 6e and is positioned or held. 22 is formed. Furthermore, a flange portion 21c protruding outward is bent at the lower end of the recess portion 22.
[0069]
In the eccentric free-form surface prism 6, the first optical surface 6a is fitted into the concave portion 22 formed in each optical system holding portion 21a, and the step portion 6e formed in a substantially linear shape is brought into contact with the flange portion 21c. By positioning, it is positioned or held, and in this state, it is fixed using an adhesive or the like.
[0070]
As described above, in this embodiment, the eccentric free-form curved prism 6 is fixed to the optical system holding portion 21a without using a screw or the like. In addition, the width W of the optical system holding member 21 can be reduced.
[0071]
Incidentally, FIG. 26 shows a perspective view of a main part of a head-mounted image display device (HMD) employing a conventional mounting method. As shown in the figure, the eccentric free-form curved prism 6 has a flange projecting outward from the step 6e to secure a hole 6g through which the screw 23 is inserted, while holding the optical system. The flange portion 21c of the member 21 must be extended outward in order to receive the flange portion protruded from the step portion 6e, and accordingly, the width W ′ of the optical system holding member 21 is increased, Enlargement is encouraged.
[0072]
Further, the flange portion 21c is provided with a receiving portion 21c for screwing, or a step 6e of the eccentric free-form curved prism 6 is formed with a positioning projection 6f. The structure is complicated, and manufacturing and assembly are complicated, and the weight of the entire apparatus is increased.
[0073]
The present invention is not limited to the above-described embodiments. For example, the surface of the third optical surface 6c of the eccentric free-form surface prism 6 is subjected to a rubber coating process, and the third optical surface 6c is formed. The reflective coating layer may be protected, or the periphery of the reflective coating surface may be protected by rubber coating.
[0074]
Further, a scratch preventing member may be interposed between the outer ridge line of the eccentric free-form curved prism 6 and the holding member that holds the outer ridge line. In this case, as the scratch preventing member, a buffer material applied to the holding member or a paint applied to the holding member may be used.
[0075]
【The invention's effect】
As described above, according to the present invention, it is possible to reduce the parts required for dimensional accuracy with respect to the eccentric free-form curved prism, to realize a cost reduction of the product, and to affect the optical characteristics. As a result, it is possible to assemble relatively easily without exerting an effect, and not only can the productivity be improved, but also the product can be reduced in size and weight.
[Brief description of the drawings]
FIG. 1 is a cross-sectional front view of a video display device according to a first embodiment.
2 is a cross-sectional view taken along the line II-II in FIG.
3 is a sectional view taken along line III-III in FIG.
4A is a plan view, FIG. 4B is a side view, and FIG. 4C is a rear view of the eccentric free-form curved prism.
FIG. 5 is an explanatory diagram when observing an enlarged image using the eccentric free-form surface prism;
FIG. 6 is an explanatory diagram when observing an enlarged image using an eccentric free-form surface prism according to another embodiment;
FIG. 7 is a front view of the observation apparatus according to the second embodiment with the front case removed.
8 is a cross-sectional view taken along the line VIII-VIII in FIG.
9 is a cross-sectional view taken along the line IX-IX in FIG.
10 is a front view of the observation apparatus according to the third embodiment corresponding to the XIII-XIII cross section of FIG.
11 is a sectional view taken along line XI-XI in FIG.
12 is a sectional view taken along line XX in FIG.
13 is a front view corresponding to the XIII-XIII cross section of FIG. 15 of the observation apparatus according to the fourth embodiment.
14 is a cross-sectional view of XIV-XIV in FIG.
15 is a cross-sectional view taken along XV-XV in FIG.
16 is a front view corresponding to the XVI-XVI cross section of FIG. 17 of a video display device according to a fifth embodiment;
17 is a sectional view taken along line XVII-XVII in FIG.
18 is a sectional view taken along line XVIII-XVIII in FIG.
FIG. 19 is a front view of a video display device according to a sixth embodiment with a front case removed.
20 is a cross-sectional view taken along the line XX-XX in FIG.
21 is a cross-sectional view taken along XXI-XXI in FIG.
FIG. 22 is a front view of the image display device according to the seventh embodiment with the front case removed.
23 is a cross-sectional view taken along the line XXIII-XXIII in FIG.
24 is a sectional view taken along line XXIV-XXIV in FIG.
FIG. 25 is a perspective view of main parts of a head-mounted image display device according to an eighth embodiment.
FIG. 26 is a perspective view of a main part of a conventional head-mounted image display device.
[Explanation of symbols]
3 Housing (exterior material)
4 Video display element
6,6 'Eccentric free-form curved prism
6a First optical surface
6b Second optical surface
6c Third optical surface
11, 12a, 12b, 13, 14, 15, 16, 17, 19, 21 Holding member
L1, L1 ', L2, L3, L4 Outline ridgeline
P1, P2 vertex
Uey eyeball

Claims (7)

An image display element for displaying an image;
At least one eccentric free-form surface prism for enlarging the image and guiding the image to the observer;
A holding member for holding the image display element and the eccentric free-form curved prism ;
Have,
The holding member, using at least one ridge or apex of the upper Kihenshin free-form surface prism, a video display apparatus characterized by positioning or holding the polarizing core free-form surface prism. Positioning of the eccentric free-form surface prism by the holding member, and characterized in that is carried out by ridge or apex is provided around the surface facing the image display surface of the image display device of polarizing core free-form surface prisms The video display device according to claim 1. The positioning of the eccentric free-form surface prism by the holding member is performed using a ridge line formed substantially parallel or substantially perpendicular to the mold splitting direction of the mold when forming the eccentric free-form surface prism. The video display device according to claim 1 or 2. The eccentric free-form surface prism is positioned or held on the exterior member by holding the ridge line around the optical surface facing the observation window provided in the exterior member that houses the eccentric free-form surface prism with the holding member. The video display device according to claim 1, wherein: The video display device according to claim 1, wherein the holding member is formed on an exterior member that houses the eccentric free-form curved prism. The video display device according to claim 1, wherein the ridge line is formed at a substantially straight line and a symmetrical position of the eccentric free-form surface prism. An exterior member for interiorly arranging the video display element and the eccentric free-form surface prism;
The holding member is
A ridge line holding member provided on the inner surface of the exterior member for positioning or holding the ridge line of the eccentric free-form curved prism;
A vertex holding member provided on the inner surface of the exterior member for positioning or holding the vertex of the eccentric free-form curved prism;
The video display device according to claim 1, further comprising:

Images