TW463057B - Compact illumination system providing improved field of view for virtual display applications - Google Patents

Abstract

The invention provides a newly designed head mounted virtual image display that is dramatically less in weight than is known in the art by virtue of a unique beam folding design, making possible wearable computer systems of significantly greater convenience and acceptability to a wide range of users. The unit may be used comfortably in conjunction with eyeglasses. Optical systems according to the invention are provided that are advantageous for use with emissive, transmissive and reflective microdisplays, and which provide high optical performance, compact design and clear see-through properties. Also, the invention provides an improved method of illumination for reflection liquid crystal microdisplays. This makes possible optical systems for virtual image displays of improved field of view, compactness, and shorter image path combined with good efficiency.

Description

4 63 05 7 V. Description of the invention (1) 'One---- Reciprocal of the related two applications This application claims U.S. Patent Application No. 60/1 2 8, 89 9 ^ such as and D " Dc ^ ve) priority, the application was filed on April 12, 1999. The name of the application is 11 small optical design and display device for virtual image display. The disclosure of this case is cited as For reference, and the second agent: US patent No. Y099 9—88: Please name 2 "Used in virtual image display applications ^ i Xianyu You", whose disclosure is here 彖The main body of the invention is the small optical system, especially the lighting system in the small optical system of the SI, for example, using personal devices such as ί. The chopped display is not beneficial, and the portable phone invents the back f virtual image display system. The magnifying optical instrument is lifted up to provide a two-level panel that can display a large amount of information. It is known that it is used in the so-called head-mounted display industry, and the staff can use it in a variety of different applications without coordination. Models include processing and display drivers. _It is known that the computer-type device board generates a shadow to be displayed ^ Signal ^ by optical instruments and image planes. However, this kind of conventional virtual image shows crying qi. This—the display has 5 midnight shortcomings for portable °. For example, it seems clumsy, non- •, even = too heavy, and the shape is too large and the disadvantage is due to the confusion of the user wearing the headset 2. In addition ’these _… large optical systems are used in the settings, and

Page 5/4 63 05 7 V. Description of the invention ¢ 2) ~ ----— The shape design cannot take into consideration important factors such as size, shape, weight and body dryness. '_ _ Some head-mounted virtual images Examples of displays are shown in FIGS. 1 and 2. Figure f and 7 'are worn on the user's head and are presented in a manner similar to a pair of glasses. The weekly person is displayed through the nose bridge portion 14 and the side branches so that 1 is supported on the user's head and face. 1 set 10 can be used, T ^ Γ, unjustified ^ This kind of conventional device is quite troublesome, that is, the user is able to see other things directly. That is, @ @ Γ, the clothing environment at jin. The head-mounted virtual image display is disclosed in International Patent Application No. WO 95/1 1 473, the contents of which are incorporated herein by reference. FIG. T shows a head-mounted monocular virtual image display 20. The support structure 12 is positioned on the user's head, and the display portion 14 is arranged below the user's field. This practice is also quite troublesome, and it will hinder the use of the field of vision. This head-mounted single-eye virtual image display is also disclosed in International Patent Application No. WO 95/1 1 473. Other examples of conventional small display systems and head-mounted displays are disclosed in U.S. Patent No. 5,771,124 (Kintz et al.); U.S. Patent No. 5,757,339 (WiUiams et al.), And U.S. Patent No. 5,844,6 5 6 No. (Ronzani et al.), The contents disclosed in these patents can be cited for the purpose of explanation. Furthermore, it is known that Sony Corporation has introduced a head-mounted virtual image display called G1 a s s t r η η ". However, all of these examples have more or less the design flaws described above.

05 7 Five 'invention description ¢ 3) Therefore, these flaws have seriously affected the public acceptance of these devices. -Therefore, there is a need for a small optical system used in display devices of personal devices such as wearable computers, head mounted displays, portable phones, etc., which can actually reduce or eliminate these and other imperfections = Abstract of the Invention The present invention provides various optical system designs *, which are used in display devices such as head-mounted virtual image displays, which can improve the disadvantages of the conventional technology, such as excessive size and weight, obstructed vision, and the like. The optical system is relatively miniaturized and has the advantage of light weight, so that when a head-mounted support is used to fix the display near the eye, its weight is only about 1 to 2 pans. This display system can have excellent optical characteristics. A special advantage of the present invention is that it can obtain a certain field of view with an optical system with a smaller thickness, and therefore has the advantages of light weight and small volume. With a light-weight computer-type device, this display is portable and compatible with wearable computer systems. In one feature of the present invention, a miniaturized optical system can be used to guide an image signal that can be viewed by a user. The image signal is generated by a microdisplay and includes: (i) a first frame , Which is positioned near the microdisplay; (ii) a quarter wave plate, which is positioned near the first frame; (iii) a reflective layer, which is located near the quarter wave plate Position; and (iv) — the second frame, which is positioned close to the first frame; wherein the first frame, the quarter-wave plate, the reflective layer, and the second frame are configured to make the image signal The system enters the first ridge, and reflects on the air gap between the first ridge and the quarter wave plate.

4 63 05 7 Description of the invention (4) Reflection on the boundary between the mirror and the second frame, the first pass through the quarter wave plate, the reflection on the $ lens lens, the second pass through the quarter wave plate, The user sees the image through the boundary between the first prism and the second frame and away from the second frame. It is best to design the boundary between the first frame and the second frame to reflect the polarized light related to the image signal generated by the 5H display. For example, the boundary may include- Multiple reflective coatings or a DBEF film. Furthermore, the reflecting lens preferably includes a concave curved surface on the surface facing the quarter wave plate. The reflective lens system may include a reflective coating, such as a total reflective metal coating, a total reflective multilayer dielectric coating, a portion of the reflective coating, or a full-image coating. Furthermore, the reflective coating preferably has a predetermined wavelength so that the image signal can be completely reflected or other images above or above can be completely penetrated, such as the image on the other side of the reflective lens, that is, , As opposed to the user-facing side. In this mode, the user can view the image signal, but can still see the image of the surrounding environment through the far optical system. Various embodiments of the present invention can be used with transmissive, diffuse, and / or reflective microdisplays. In another feature of the present invention, a head-mounted virtual image display includes a .a ^ display; (b)-an optical system, which can be used to guide an image signal that can be viewed by a user, the The image signal is generated by a micro, non-state: the optical system includes: (i) a first frame, which is located near the position of the micro-indicator; (ii) a quarter wave plate, 1 (Iil) a reflective layer, which is positioned close to the

Page 8 4 63 05 7 V. Description of the invention (5) Near the quarter-wave plate is close to the first layer and the second line of optics. First

After passing through the quarter wave plate, the second prism is used to make the structure, which is used in the area. Preferably, the ground is moved in or out and viewed from the opposite user's point of view to install the user; and (iv); wherein the first setting is such that the reflection lens on the second lens of the quarter wave plate is reflected. See the image with the second prism; The solid structure of the optical system is designed for the field of vision of the eye

The boundary between the image signals, the edge between the second, and (c) ~ are set to allow the range. Mirror 'and its position: Dividing the slope, and passing the ^ ~ times in reverse on the reflection gap of the system into the Chu, and the quarter boundary of the quarter, and the distance between the previous faculty. In another feature of this, A portable computer system is provided. Its spoon = (1) a head-mounted virtual image display. The display includes: (a) a micro-display; (b) an optical system. The optical system can be used for Guidance-an image signal that can be viewed by a user, the image signal is generated by a micro-display 'The optical system contains: (i)-the first-the mirror, which is positioned close to the micro-display; (ii) -A quarter-wave plate, which is positioned close to the first ridge; (iii) a reflective layer, which is located close to the quarter-wave plate; and (iv)-a second ridge, which is Positioned at the position near the first frame; wherein the first frame, the quarter wave plate, the reflection layer, and the second frame are configured so that the image signal system enters the first frame and is at the first edge; Reflected on the air gap between the mirror and the quarter-wave plate Reflected on the boundary between them, passed through the quarter wave plate for the first time, reflected on the reflection lens, passed through the quarter wave plate for the second time, through 463 05 7 V. Description of the invention (6) The boundary between the second frame, and leaving the second frame to allow the user to view the image; and (c) an optical system mounting structure for fixing the optical system within the field of vision of the user's eyes And (2) — a computer-type device connected to a head-mounted virtual image display for generating and providing an electronic signal to a microdisplay to generate an image signal that can be viewed by a user. In still another feature of the present invention, it provides an improved lighting system for a virtual image display, wherein the display is a reflective liquid crystal microdisplay. In detail, the function of the lighting system is: (i) to provide the convergence and dispersion of the light source, to polarize the light beam incident on the reflective microdisplay; (ii) to provide the path reflected by the microdisplay, so that Into the image forming optical device; and (iii) maintaining the efficiency of use of the amount of available light. The illumination method of the present invention is capable of providing a shortened imaging path while ensuring polarization efficiency and quality. This is particularly useful for the design of miniaturized virtual image displays. These and other objects, features, and advantages of the present invention can be obtained by a detailed description of the following exemplary embodiments and the accompanying drawings to gain a deeper understanding. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a conventional glasses-type head-mounted virtual image display; FIG. 2 shows a conventional monocular-type head-mounted virtual image display; FIG. 3A shows a head-mounted virtual image display according to an embodiment of the present invention; Computer-type device; FIG. 3B shows a head-mounted virtual image display of the present invention worn by a user

Page 10 463 05 7 V. Description of the invention (7) When on the body; Figure 4 shows the virtual image display optical system of the first embodiment of the present invention; Figure 5 shows the virtual image display optical system of the second embodiment of the present invention; 6 is a virtual image display optical system according to a third embodiment of the present invention; FIG. 7 is a virtual image display optical system according to a fourth embodiment of the present invention; FIG. 8 is a virtual image display optical system according to a fifth embodiment of the present invention; Fig. 10 shows a virtual image display optical system of a sixth embodiment of the present invention; Fig. 10 shows a virtual image display optical system of a seventh embodiment of the present invention; Fig. 11 shows a virtual image display optical system of an eighth embodiment of the present invention; Fig. 1 2 shows an example of a conventional lighting method of a reflective microdisplay using a polarizing beam splitter; FIG. 13 shows an example of a conventional lighting method of a reflective microdisplay using a reflective film, such as a polarizing material of DBEF; and FIG. 14 shows an embodiment of the lighting method of the present invention, which uses a small chirp and folds the light path to provide an improved light for displaying a virtual image. Learn configuration. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Various optical system designs of the present invention will be described in the following with a head-mounted virtual image display and a wearable computer. However, it should be understood that the present invention is not limited to this or any particular display application. On the contrary, the present invention can be applied to any suitable display application, wherein the display can use a small optical system to display an image, and the small optical system can cooperate with a device used in this application. For example, such devices could be wearable computers, head mounted displays

4 63 05 7 V. Description of the Invention (8) Personal and other personal devices such as mobile phones and portable phones Please refer to FIG. 3A for details. It is preferable that the virtual image display 50 and the head-mounted device 70 according to an embodiment of the present invention include a binocular device 70. It should be understood that the computer meter has a light-weight < = shaped appearance design, for example, a pocket type device can be fastened so that the circumference 'of = L, it is best to have a-clip, and It ’s a wearable computer. ”Ye has f pockets. This computer-type device can be called a personal computer, a laptop ^ A wearable computer system can include all or most of the components, such as-^, personal Digital assistant (PDA), etc., removable memory: CPU, fixed memory network) connection device, ", unfavorable drive circuit, external network (such as the head Wearable virtual image display circles; 0 with software, etc. ° Slider 54; located on the wearer respectively:-display 52;-adjustable 56 and around the wearer's head next to the two: = side = left head Supporting parts-used to connect the computer-type device 70 and the first two: 60;-earphones 62 and-the electric delay 64. The device 5. The display portion 52 which is also electrically connected to the device 50 is a small size of the invention Light wind sounder 63. It will be described in this article. The display section 52 is: two cymbals, which will be pivoted on the lower part 56. On this side :: 54 and head wing "move in and out, for example, the right eye view; can also be converted to use in the left eye. Furthermore, ㈣. Yicheng includes two detachable display parts 52 … That is, one: use, and the other is used by the left eye. Have a general understanding of this technology | = to implement other different shape designs. T 'a 63 05 7 V. Description of the invention (9) Therefore The head-mounted virtual image display allows users to watch according to the device application software, web browser, etc. which can be provided to the user via the cable 64 to hear the user's input of sound instructions to the device according to the device 70. Therefore, Fig. 3 A series Display-a light-weight head-mounted display ^ system can be used with a pocket type, because the optical system is-on the user's head, so this is about 2 ounces or less. This-if you can The 52 series worn on a pair of glasses as a display by a user can be quite advantageous because the system is quite small, so the optical system does not get enough light from the outside world. In a fairly bright state, its 〇Can be used The display section 52 will be described as follows. However, it is possible to use a virtual image data generated by 70, which is different from that shown in FIG. The generated information. The virtual image information is a display. The headset 62 is a sound information that can be used. The loudspeaker 6 3 can make a brain. A wearable computer system that includes a small-sized display that includes a small The optical wearable computer is used in conjunction. As shown in the figure, a light weight slider or headband structure is connected to enable the overall weight of the head-mounted display-the design is multi-purpose and if necessary. Figure 3B shows the present invention Head-mounted virtual wear. As shown in the figure ', the display is moved into the field of view of the right or left eye of the user without blocking the external field of vision, or through a distorted field of view. The monitor is clearly visible when the monitor is activated. A shutter can be used to block external light sources. It is now understood that these optical systems can be used in other systems of wearable computer systems. And can clearly display high-quality optical shadows

Page 13 4 63 05 7 V. Description of the invention (10) Applicable The academic department can be centered. Only by way of example, the light path of the path (fre can also have common advantages and special features are as follows.-Its center point lens is condensed on a straight line in the system of the example system; in a wide range of equipment to explain the light of the present invention The e-form of the device is for the purpose of understanding here. In passing one, the collection is included in this, including the bundle, which will be shaped, the hair, the department) " optics as described here as the spherical shape is defined as the axis Nearby cameras and light systems are "off-image" in the various optical systems of the present invention. An ergonomic system with a general understanding of this technology is applied to a variety of different devices and moreover, 'for example, the following will be provided for various optical systems with tortuous light " on-ax is M optical devices instead of "Self-installation. In this way, the advantages and characteristics of the optical system, and other terms that can be realized after reading the teachings of the present invention for this technology " coaxial " and " free type ", which defines the lens The light is perpendicular to the lens and passes through the optical axis. The beam of light can pass through it and be imaged by the lens. Such systems are microscopes, binoculars. In more complex cases, it may converge on an axis that is tilted relative to the mirror (0ff-ax is). It should be noted here that the typical spherical lens is symmetrical to the optical central axis. Other systems that are not radially symmetrical and do not have the obvious optical center axis described above, but still have imaging functions, I will call these systems "free-type" optical devices. Please refer to FIG. 4, which The optical system β of the virtual image display showing the first embodiment of the present invention. The light emitted from the light source 1000 is usually a set of red, green, and blue light-emitting diodes (LEDs). It illuminates a microdisplay 20 0. In this embodiment, the microdisplay 200 is a transmissive microdisplay. The microdisplay of the present invention can be used, for example,

Page 丨 4 4 63 〇 5 7 V. Description of the invention (11) ^ Produced by Kopin Company of the city. It can be understood that the penetrable display Is system can be replaced with an emission type micro display, wherein the light source is located inside the micro display. An emission type microdisplay in the present invention can be used, for example, a microdisplay produced by p_laT \ r company of iBeaverton, Oregon, USA. In any of the above examples, the microdisplay Is is an image corresponding to the electronic signal supplied to the display. For example, the electronic signal can be provided to the micro display by the computer-type device 70 (FIG. 3A). This image is viewed by the user through a first 300 ′ reflecting mirror 500 and a second 2600 ′. The light emitted by the display is polarized and enters the first 稜鏡 300 ', and is reflected in the air gap 340 between the first 一 300 and a quarter-wave plate 400. The reflected beam is reflected a second time at a boundary 360 between the first 300 and the first mirror 600. It is preferable that the boundary has a multilayer reflective coating layer 'which can reflect the so-called s-polarized light emitted from the microdisplay' and enters the mirror plate 500 through the quarter wave plate 400. As shown in the figure, a glass sheet or lens 4 2 0 separates the quarter wave plate 4 00 from the reflective lens 5 00. For example, the multilayer reflective coating 360 may be a DBEF film produced by 3M Company of Sao Paulo, Nylon. The DBEF is the abbreviation of Dual Brightness Enhancement Film. Furthermore, the multilayer reflective coating 360 can also be a thin film dielectric stack. The reflective lens 500 may be a reflector, a holographic reflector, a flat mirror, or a partial flat mirror having a high reflectance at a specific wavelength. In any kind of reflector, the reflective lens 500 has a reflective coating 5 50 on its curved surface, which can reflect light back to the first through the quarter wave plate 4 00

Page 15 ^ 63 〇 5 7 V. Description of the invention (12)-Brother 3 0 〇. Rong can convert the polarized light from s to P through the action of the quarter wave plate 400 twice. The light beam passes through the multilayer reflective coating 3 6 and enters the viewer's naked eye 7 0. It can be understood that the miniaturization of the optical system can be achieved by 'bending' the light path several times. It can be understood that the reflective coating 5 50 can be composed of a total reflective metal or a multilayer dielectric coating, or a partially reflective coating that allows a viewer to see through the device. The reflective layer can also be a type with a specific wavelength, which can enhance perspective or transparency, and at the same time can reflect light of an appropriate wavelength or light of a specific ethnic group wavelength to the eyes. This is quite advantageous when the light source consists of relatively narrow red, green and blue wavelengths, such as in the example of LEDs. By way of example, it is known that the YG, G, and B light have wavelengths of 625'525 and 460 nanometers (nm), respectively. X In the preferred embodiment, the red, green, and blue images are transmitted through the optical system in a closely connected continuous manner (also continued), and the average effect of a normal color image is provided to the viewer. Reachable: η; The image is transmitted to the naked eye ". This is achieved by the continuous beating on the red and the bits, and then the red and green technologies are known and understood by the industry; second, the rate is also ... there is a full-image coating or other coatings to achieve The required shot is = Yu, the naked eye: You: Guang, Fa: This: The characteristics of the optical system design are in the-miss: I: I, when you see the external image, you will see the-spoon image. This is achieved in accordance with the above design, which was designed by

4 6305 7 V. Description of the invention (13) oa The shape of the entrance surface of the second 稜鏡 600 and the exit surface behind the mirror moon 5 00 is achieved. For example, as shown in FIG. 4, the external surfaces are all flat, so the optical device can be clearly seen through. This feature is present in all the embodiments mentioned in this specification. Fig. 5 shows a virtual image display optical system according to a second embodiment of the present invention. In detail, the design of Fig. 5 is similar to the design of Fig. 4 'except that a one-way field lens 650 is added to improve optical characteristics. The field lens 650 is preferably a field flat lens, as known in the industry. It should be understood, however, that the addition of one or more smaller lenses or other elements to improve overall optical characteristics, such as the flatness or color convergence of a field lens, should be considered a change within the scope of the present invention. FIG. 7 shows a virtual image display optical system according to a fourth embodiment of the present invention. In detail, Fig. 7 shows a variation of the design of Fig. 4 in which a reflective microdisplay such as a reflective liquid crystal display is used. Fig. 6 is a diagram showing a virtual image display optical system according to a third embodiment of the present invention. In detail, FIG. 6 is a design similar to that of FIG. 4 except that the surface is curved, except for the optical system. An undistorted view of the image seen through the optical device is retained, but it is allowed to Changes in text appearance. As shown in the figure, the outer surface A is formed into a concave curved shape, and the outer surface b is formed into a convex curved shape. In addition, this design has the advantage that it requires fewer components than that of Fig. 4 »» -t 'and therefore its manufacturing cost is lower. That is, in the design shown in FIG. 6, the ′ 亥 reflective coating 5 50 can be applied to the outer surface of the lens 4 2 0 to form a flat mirror. In this manner, a separate mirror 500 is not required. Of course, if necessary, a field lens can also be used. Words

Page 17_4 63 05 7 ~~~ -——__________ 5. Description of the invention (⑷ " Reflective microdisplay used in the present invention, for example, can be used by '', '隹 拉 夕 州Micro display manufactured by C 〇 〇 〇rad ο Micr disp 1 ay company in Boulder city. In the case of reflective micro display, it can be used-a kind of lighting method. The light source in the lighting system 7 500 is directed to the micro display, and then the reflected light is allowed to enter the optical system shown in FIG. 4. The lighting method can be achieved by a lighting system 750. The following will be directed to FIG. 12 Various conventional lighting methods will be described with reference to FIG. 13. The preferred lighting method which can be implemented in the lighting system 75o according to the present invention will be described later with reference to FIG. 4. In any of the above cases 'The light emitted by the lighting system 75 is then moved along the path of the design shown in Figure 4. In this way, the advantage of the design of Figure 4 is that it can be used with reflective microdisplays. Figure 8 shows the this invention The virtual image display optical system of the fifth embodiment. Specifically, FIG. 8 shows another method using a penetrating microdisplay. The light emitted by the light source 100 passes through an illumination system 400, which may include an illumination Lenses and diffusers. The light then moves through the transmissive microdisplay 200 and enters a first foldable light that can be tightly folded. This can be achieved by reflecting on the first surface, where The first surface is provided with a flat mirror coating and is achieved by internal reflection, as shown in the figure. The internal reflection is achieved by designing that the light can be internally reflected ', wherein the internal reflection is achieved by a It is formed by an incident angle larger than the critical angle, which is a method known in the industry. The light emitted by the first 稜鏡 1 500 can then penetrate the imaging beam splitting 稜鏡 and lens design, as shown above for FIG. 4 Details.

4 63 05 7 5 'Explanation of the invention (15) FIG. 9 shows a virtual image display optical system according to a sixth embodiment of the present invention. In detail, Fig. 9 shows how the design of Fig. 8 is used in conjunction with a reflective microdisplay. In this example, another configuration is used to provide illumination for a reflective display. The light emitted by the LEDs 1000 is focused or scattered as needed 'to form an appropriate illumination beam. This can be achieved with a lens and diffuser combination 1400. The light beam enters a lower chirp or light pipe 1600 and undergoes the first internal reflection. On the second surface below it, the light is reflected by a flat mirror coating. These rays are incident on the air gap ', where the air gap is between the illuminating lens and what is referred to as the first compound mirror 1 500, as described with respect to FIG. 8, and by making the incident angle smaller than Critical angle, these rays can be transmitted to the first imaging 稜鏡 150 0 °. These rays constituting the illumination beam are reflected back to the first imaging 0150 0 by the reflective microdisplay 2 ◦ 〇, and Imaging can be performed in the manner illustrated in FIG. 8. In addition, the surface 3600 of 01 500 can also include a DBEF film ' to selectively reflect the s or P-type polarized light returned by the microdisplay 2000. It can also be understood that the '稜鏡 1500' series includes '稜鏡 300' as shown in FIG. 4 and thus can constitute a single-piece glass lens as shown in FIG. FIG. 10 shows a 7F virtual image display optical system according to a seventh embodiment of the present invention. In detail, Fig. 10 shows another method for illuminating the reflective microdisplay in the optical design shown in Fig. G. In this setting, the lower lighting 稜鏡 16 0 0 series has been replaced by a simple flat mirror 1 700. Emitted by the LED lighting system = the light is directed onto a suitably placed plane mirror, so that the light is directed to the first imaging prism 150, and is incident on the microdisplay 2000 in a forward direction. The reflected light enters the first imaging unit 1500, and according to FIG. 4

if

Page 19 4 63 05 7 V. Description of the invention (16) Imaging in the manner described in the following. It can be understood that it can have various different configurations, which may differ in details, but it can still be implemented within the scope of the present invention. FIG. 11 shows a virtual image display optical system according to an eighth embodiment of the present invention. In detail, FIG. 11 shows another optical system, which can fold light by complex reflection to form a small, long and thin optical configuration. The light emitted by a lighting system 14 00 enters a lighting guide 1800, where the light is reflected twice internally, as shown in the figure. These reflections are used to direct the illumination beam forward to a reflective microdisplay 2000. This light beam is reflected by the micro-display 2 0 0 and enters the light guide 1800 ', but by the light guide 1 800 and a first imaging 1 900 At the incident angle on the air gap between the two, the beam can enter the first imaging unit 190, instead of being guided back to the lighting system 1800. As shown in the figure, before the light beam is introduced into the imaging beam splitter 0600 and the lens configuration 4 2 0, 5 0 0 (its function has been detailed in the content of Figure 4), a flat mirror type Reflected from the surface 1950. It can be understood that the 稜鏡 1900 series includes the 稜鏡 300 in FIG. 4, thus forming a single-piece glass as shown in FIG. Illumination system Please recall the embodiment of the optical system design in FIG. 7, which uses an illumination device 750 to guide a light emitted by a light source inside the illumination system 75 onto the microdisplay, and then makes the reflection The light enters the optical system shown in FIG. 4. In this way, a reflective microcomputer can be used in conjunction with the optical system. ~Do not

Page 20

463 05 7 V. Description of the invention (17) There are several conventional lighting systems that can be used in conjunction with reflective displays. For example, Fig. 12 shows a conventional illumination method of a reflective microdisplay, wherein the microdisplay uses a polarized beam splitter. In Figure 2, the light emitted by a light source 2000, such as an LED, enters a polarizer cube 2100. This light beam can be shaped by the lens and the astigmatism benefit (2200) to provide uniform illumination on the microdisplay 2300. The so-called s-polarized light relative to the beam splitter cladding is reflected by the cladding, and the so-called p-polarized light is transmitted through it according to the existing nature of the polarizing beam splitter cube. The s polarized light system will hit a LCD cryo 2300. When the liquid crystal layer is reflected, the reflected light will rotate in the first direction. That is, an s-polarized light incident system is completely or partially converted into ρ-polarized light. In this example, on the other hand, 1 is P polarized light, which penetrates the polarizing beam splitter ^ beam device 24. . . The beam then passes through the overlay light and enters the eyes of the imaging optical user GD. In order to improve the optical contrast, U is set at 24㈣ and is oriented toward the =) system. It can be used to predict along the s direction; Residual light. As can be seen from the figure, proper illumination is provided on the part of the cover that is intended to exclude s. The light of the: part is the light of the image and the part of the shadow: the polarization control is used to In the benefit: = wear, and the lighting and imaging light. For contrast, effective; penetrating micro-display, you can understand the additional length on the path of a 。. This; Cheng; lighting method is the degree of magnification, and increased Overall imaging system = difficult to reach the appropriate size.

Page 21 4 63 05 7 V. Description of the invention (18) Generally, the micro-display with a field of view (F0V) is shown at a distance from the image forming lens approximately equal to the focal length of the lens. The field of view can be expressed by the following relationship: FOV = arctan (w / f), where wj is the width of the microdisplay, and f is the focal length of the imaging lens. For a given microdisplay, w is fixed, and for an appropriate 尺寸 size, the distance between the imaging lens and the microdisplay is also fixed. Therefore, there is a limit to the F0V that can be obtained. Larger values can be obtained by using a secondary optical system, where the second imaging lens is used to magnify the intermediate image, or a larger value can be obtained by a complex focus design of the imaging lens. However, it is best to avoid these costly methods. α, Fig. 13 shows the illumination method of the conventional reflective microdisplay, which uses a reflective film and the conventional DBEF (3M company, "" "The behavior of the material is similar to that of a polarizing beam splitter. Light Ϊ = ίconvenience: The P polarized light is transmitted through the beam splitter. In this polarized light, one can be used-a flat plate 2600 with a DBEF film, such as an image; two methods can reduce weight, but in the optical system : T I ~ even requires a larger path length. In addition, the slope of the plate is also "m like ...". The method of using this method is as shown in Figure 12:: In terms of shape, the half angle of f0v is about 8 Degree. As square, ·, two inventions-a preferred embodiment, which uses a small 00 it wind ^ folds the light path to provide a virtual image for displaying a virtual image '丈 可以 # ΐ + Figure shows a The novel imaging party'y, illumination system 750 (Figure 4), where the illumination light

Page 22 4 63 05 7 V. Description of the invention (19) The path can be folded to form a small configuration, which has the advantage of shortening the light path of the imaging optical device. In this example, half of the F 0V values in the illustrated geometry are 13 degrees, which is much larger than the example shown in FIG. 13. As shown, the lighting system includes a light source 300, a lens and a diffuser 3 100, and a pre-polarizer 3200 for shaping and guiding a light beam emitted by the light source. The illumination beam enters a folded shallow 稜鏡 33 〇 ^ The beam is first reflected in an air gap, where the air gap is located on the surface between 稜鏡 and the reflective microdisplay 3600 . The light beam is then incident on a beam splitting layer 3500 (e.g., DBEF), and the 's polarized light is reflected' and the p polarized light is transmitted through the light splitting layer. The penetrating light is reflected on the upper surface of the second unit 3700, and is guided to a black layer (not shown) and absorbed. The reflected light beam is incident on the lower surface of the MM ′ in a forward direction and penetrates and enters the reflective microdisplay 3600 in a forward direction. The light emitted by the micro display 3600 is converted into p-polarized light at the site to be imaged, and the p-polarized light beam then moves to the illumination mirror without hindrance. As shown in the figure, this embodiment may also include a rear polarizer 3800. However, it should be understood that 'the polarizer 3 8 0 0 is necessary only when the DBEF reflective layer 3 5 0 fails to sufficiently exclude improper S polarized light, in which case the polarizer 3 700 The system can be effectively used as a clear polarizer. The retro-theta layer 3 5 0 0 can also be a simpler spectroscopic method with some loss of efficiency. It should also be understood that the path length used in the lighting frame of FIG. Examples are shown in Figures 12 and 13. This is a major feature that can be achieved with a small optical device to achieve a virtual field with a larger field of view.

Page 23 4 6305 7 V. Description of the invention (20) Image display. The light emitted by the imaging system 75 0 can then be moved along a path directly through the imaging optics 2400 to the user's eye 250 0. < It is understood that the imaging optical device may include a design as shown in Fig. 4 and other designs described herein. In this way, the design advantage of FIG. 4 is that it can be used in conjunction with a reflective microdisplay. An advantageous feature of this folding chirped lighting system is that it is miniaturized and requires only a short distance between the display and the final polarizer 3700. Of course, if necessary, a field lens can also be used. As described above, the present invention can provide the following examples, features, and advantages with considerable advantages: (i) various virtual image display systems, such as can be used in head-mounted displays, which have a tough tongue, ... Light weight and can provide comfort reduction; (⑴- a kind of virtual image display that can be mounted to a slider-type head-mounted structure * easy to rectify and reduce fatigue 'and can synthesize clear virtual images-an improved head-mounted display Ｍ 由 本 与 么 "^; u mistakenly learn the transparency and feasibility of the system without hindering the user's horizon; (iv) an improved lens, which can be used with a pair of glasses, ' The virtual image, “'members do n’t wear comfortably while using it; (V) — improved head-mounted display writing car # ^ Λ 者 顼, 1 family ’s system' can be worn on a small ruler Qiu office products τ eight dimensions close to the eyes of the user's month < $ place without hindering the use of the design of a field of vision, without hindering the user's vision of the user ^ ^ Qi field of view; the specific value is Apricot and I 1 to achieve high optical performance

This heart is especially academic, which is based on the characteristics of A beam folding and light weight and 1 column AA * «Achieved by unique: indicator; (vii) has a specific value through teeth ~ micro-optical system, which is achieved by Reflects light and matches light weight and first gear = transparent

Brother page 24 4 63 05 7 V. Description of the invention (21) The light of nature is used to achieve '(viii) an optical system using a unique micro-display lighting method' wherein the micro-display is a flat reflective film; (i χ) shows Wide field of view, good eye pressure relief, and a wider view of the perforated hole; and (X)-a lighting method using a small chirp that uses a reflective microdisplay to fold the light path to provide enhanced Optical S has been set. When the present invention is combined with a lightweight wearable computer system 70 (shown in FIG. 3A), the above features and advantages can be achieved. It should also be understood that the optical design provided herein can be used with considerable advantage in any portable equipment that requires a miniaturized, lightweight virtual image display. For example, mobile phones, handheld facsimile browsers, and other devices using small displays. "Although the exemplary embodiments of the present invention have been described above with reference to the drawings, it can be understood that the present invention is not limited to the above. Detailed structure of the embodiment 'Without departing from the scope and spirit of the present invention, those skilled in the art can still make various changes and modifications to the embodiments of the present invention.

Claims (1)

r 4 63 05 6. Scope of patent application 1. A system for illuminating a microdisplay · used in conjunction with an imaging optical device, the illumination system includes: a first frame, which is positioned close to the microdisplay A reflective layer, which is positioned close to the first frame; and a second frame, which is positioned close to the first frame; wherein the first frame, the reflective layer, and the second frame Is configured so that the light emitted by a light source enters the first frame and reflects on the air gap between the first frame and the microdisplay, reflects on the reflective layer, and forms an image on the microdisplay The type of signal is reflected, wherein the imaging signal passes through the second frame and leaves the second frame so that the user can see the image through the imaging optical device. 2. The system according to item 1 of the patent application scope, wherein the reflective layer is a beam splitting layer 1 which can reflect s-polarized light and the p-polarized light penetrates. 3. The system according to item 1 of the patent application scope, further comprising a first polarizer disposed between the light source and the first chirp. 4. The system according to item 1 of the scope of patent application, further comprising a lens and a diffuser arranged between the light source and the first chirp. 5. The system according to item 1 of the scope of patent application, further comprising a second polarizer disposed between the second frame and the imaging optical device. 6. The system according to item 1 of the patent application scope, wherein the lighting system is used in a virtual image display. 7. The system according to item 6 of the patent application scope, wherein the virtual image display is a head-mounted display. Page 26