JP2002341286A - Display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device using a reflection type display panel equipped with a compact and stable lighting function. SOLUTION: Stable lighting quality which is efficient and free of the emission of unnecessary light can be obtained for a reflection type display module and the module is constituted compactly by effectively adopting a structure wherein a sub-prism 16, a rotary parabolic mirror, a micromirror which reflects the light from a light source nearly toward the center of an eyepiece lens, or a direct light source is arranged.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device having a function of enlarging a display surface of a moving image or a still image, which is stored or distributed as data, as a virtual image and presenting the display surface with high definition. It is.

[0002]

2. Description of the Related Art Various information devices, especially devices capable of handling visual information by means of liquid crystal or photoelectric image display means, have made remarkable progress.
In addition, there has been a remarkable progress in personal use information processing machines, which are so-called mobile devices that can be used anywhere or at any place. The performance required of this mobile device includes a compact form with good mobile performance, a high speed of information processing, a large number of processing functions, etc., as well as more information accurately in a limited space of a small device. Means for displaying to the user in an easy-to-understand manner are required. At present, display means such as liquid crystal, which occupy most of an arbitrary operation surface of the device, has become mainstream, but unfortunately, as the size of the device has decreased, the display area, characters, and charts have also become smaller and more difficult to see.

In view of the above, virtual image magnifying display devices such as a head-mounted display and a finder (check) display have recently attracted attention as one effective display method for solving this problem, and much research and development of related devices have been advanced. I have.

[0004] This is based on a small two-dimensional display device having a display screen of about 1 inch or less in diagonal width by photoelectric means such as liquid crystal or plasma, or a one-dimensional array light source such as an LED by an optical path such as a mirror. Optically enlarging means such as a convex lens or concave reflecting mirror for moving images or still images by means of forming an apparent two-dimensional image by scanning in the direction perpendicular to the array direction using a bending means. Is a method and apparatus for enlarging and projecting a virtual image as a virtual image using an image, and displaying an apparently larger screen than an actual display screen.

[0005] Enlarging a small display device as a virtual image has the advantages of downsizing the device, suppressing power consumption of the device, and reducing the price. In addition, the apparent display screen is enlarged regardless of the small display device, and the high It can be presented as a fine virtual image. In the future, the resolution, contrast, brightness, performance of magnifying optics, and the development of image processing technology, etc. of small display devices will be combined, and magnified display devices with good performance will be used in various devices and scenes. It seems to come.

In order to present a display image of a small display device brightly, an illumination device is required unless the small display device itself emits light. This lighting device is roughly classified into two methods. One is to install a light emitting source behind a small display device and project the transmitted light to a visual part,
That is, backlight illumination. The two methods include a method of installing a light emitting light source on the front of a small display device and projecting the reflected light to a visual part, that is, a front light illumination. In recent years, a small, high-definition, low power consumption, manufacturing facility, etc. Attention has been focused on a low-cost, reflective, small-sized display module including the entire system. The optical system of the latter virtual image magnifying display device by the epi-illumination method using the front light and illumination will be described with reference to FIGS. 9 and 10, and its structure and operation will be described. 9 and 10 are configuration diagrams of a conventional display device.

First, the configuration of a virtual image magnifying display device using the image magnifying action of a concave mirror will be described with reference to FIG. A light source unit 1 such as a small fluorescent tube, a light bulb, an electronic light emitting element, etc., a first half mirror 7 having a function of bending the light from the light source unit 1 by approximately 90 degrees, and a target display illuminated by the bent light Small display device 4 that forms a screen
A second half mirror 2 having a function of bending transmitted light of the reflected light from the small display device 4 by approximately 90 degrees;
A structure including a concave mirror 3 having a function of condensing the reflected light from the second half mirror 2 to the visual part 5 is adopted, and the optical path is bent twice in the optical system by the second half mirror 2 and the concave mirror 3. It has the feature that the optical system can be made relatively compact.

A display image (not shown) drawn on the small display device 4 installed outside the line of sight of the observer's visual section 5.
Part of the light of the second half mirror 2 is approximately 9
After being bent by 0 °, the reflected image is converged by the concave mirror 3, and then transmitted through the second half mirror 2 along the optical axis 6 of the concave mirror 3, and a virtual image of a display image (not shown) is enlarged. 5 can be projected. According to this method, a relatively wide viewing angle can be obtained, and the occurrence of aberration (such as chromatic aberration) can be suppressed to a relatively small value. Many products have been put to practical use.

Further, the light source unit 1 and the first half mirror 7 for illumination are mounted off the optical axis at a high position on the side surface of the small display device 4 as viewed from the visual unit 5 as shown in FIG. And illuminates the entire display section substantially perpendicular to the normal of the display surface of the small display device 4. This is referred to as coaxial epi-illumination, and is widely used in microscopes and precision optical instruments because it can realize stable illumination with relatively small unevenness in irradiation.

Next, an enlarged virtual image display apparatus using a simple off-axis oblique illumination method, which is the second illumination method, will be described with reference to FIG. In FIG.
The light source unit 1 is arranged on the side of the half mirror 2 outside the light beam of the small display device 4 and the half mirror 2 and the like are interposed from the outside of the optical axis of the small display device 4 at an angle θ with respect to the normal to the display surface of the small display device 4. Illuminate the whole directly without using The illuminated and reflected light is further reflected by the half mirror 2 as described above, and the concave mirror 3
And further transmits through the half mirror 2 to project an enlarged virtual image on the visual part 5. It has a simple structure with little loss of illumination light on the outward path of irradiation, is easy to manufacture, and is widely used.

Further, it is premised on that both types use a reflection type small display device which is configured so that reflected light can be adapted to display.

[0012]

However, there are the following problems in the display device and the illuminating device based on the virtual image enlargement method of the "coaxial incident illumination method and the oblique illumination method" described above.

First, in the coaxial epi-illumination method, a half mirror for guiding illumination light must be provided in front of the small display device, which increases the number of parts and further increases the number of parts by 4 with respect to the optical axis.
A relatively large half mirror inclined at 5 degrees is installed, and this space needs to be installed in the optical path of the small display device and the visual part, so that the optical path length becomes longer and the apparent display screen becomes smaller. In addition, the optical system of the display device and the housing itself become large.

Next, in the oblique illumination method, there is no loss of light in the middle, and it is not necessary to install an optical component such as a half mirror in the optical path. The angle of incidence on the display and the distance from the light source are uneven, that is, the brightness of the display surface differs in portions, and the display quality is greatly reduced. Furthermore, in order to make the incident angle closer to the vertical, the light source must be closer to the light flux. If the light source overlaps even a small amount of light, unnecessary light (stray light) overlapping the screen will result, further degrading the display quality. . The farther the light source is from the optical axis, the greater the decrease in brightness and unevenness, which further reduces the display quality.

Efficiently for the reflective display module,
It is another object of the present invention to provide a display device capable of obtaining stable illumination quality without generation of unnecessary light and having a relatively compact configuration.

[0016]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a liquid crystal or photoelectrically operated mainly small reflective image display section, an illumination section for illuminating the small image display section, An image enlarging unit that optically projects the image of the small image display unit illuminated by the illumination unit as an optically enlarged virtual image, and a first internal reflection for transmitting the image of the small image display unit to the image enlarging unit The surface, the small image display unit, and the image enlargement unit are adjacent to each other and perform a total internal reflection according to Snell's law, and a first internal reflection surface disposed immediately below the image enlargement unit. In a display device comprising a triangular prism having a structure similar to the inner reflection surface and a third inner reflection surface acting as a prism, or a prism having a polygonal prism shape, the illumination unit is disposed in proximity to the outside of the prism unit,
After the illumination light is made incident on the small image display unit from the third internal reflection surface or the second internal reflection surface, and further internally reflected by the second internal reflection surface and the first internal reflection surface, the image is displayed. Irradiating the illumination light from the off-axis with an optically substantially coaxial epi-illumination viewed from the enlarged portion or at an inclined angle, and illuminating the small image display portion, between the light source of the illumination portion and the prism portion,
According to another aspect of the present invention, there is provided a display device including a light introducing unit that prevents direct light from a light source from reaching a visual sense.

According to the present invention, there is provided a display device which can obtain a stable illumination quality without generating unnecessary light efficiently with respect to a reflection type display module and has a relatively compact configuration. be able to.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention described in claim 1 of the present invention is directed to a small-sized image display section mainly of a liquid crystal type or a photoelectrically operated type, an illuminating section for illuminating the small-sized image display section, and an illuminator. An image magnifying unit that projects an image of the small image display unit illuminated by the unit visually as an enlarged virtual image visually,
In order to propagate the image of the small image display unit to the image enlargement unit, the first internal reflection surface, the small image display unit, and the image enlargement unit come close to each other, and the total internal reflection according to Snell's law is performed. A prism having a triangular prism or a polygonal prism having a second internal reflection surface to be performed and a third internal reflection surface having a structure similar to the first internal reflection surface disposed immediately below the image enlarging portion and having an operation. In the display device consisting of the unit, the illumination unit is disposed in the vicinity of the outside of the prism unit, the illumination light from the third internal reflection surface, or from the second internal reflection surface to the small image display unit, Further, after being internally reflected by the second internal reflection surface and the first internal reflection surface, the illumination light is irradiated from the off-axis at an optically substantially coaxial incident angle or at an inclined angle when viewed from the image enlargement unit, It illuminates the small image display unit and Between the light source and the prism part, a display device characterized by being provided via light introducing means for avoiding direct light from the light source to reach the visual sense. In addition, the illumination light can be prevented from directly reaching the visual part as unnecessary light.

According to a second aspect of the present invention, the light introducing means may be an optical sub-prism, a triangular prism array, a hologram element, or an image magnifying section which is arranged in contact with or non-contact with the prism section. The light source device and the condenser lens incorporated in the image enlargement unit, or the concave reflection mirror installed outside the prism unit. 1. The display device according to item 1,
With such a configuration, the illumination light can be efficiently transmitted to the small-sized image display unit.

According to a third aspect of the present invention, in the optical sub-prism, the exit surface is in contact with the first inner reflection surface or the third inner reflection surface, and the optical axis of the image magnifying unit is reduced in size. The light source is installed outside the incident optical axis as viewed from the image display unit, and further on the sub-prism side in contact with the first internal reflection surface or the third internal reflection surface on an extension of the reflection optical axis. By adopting such a configuration, the entire display device can be made compact without increasing the thickness of the optical system in the line of sight.

According to a fourth aspect of the present invention, a surface of the first inner reflection surface or the third inner reflection surface which is in contact with the optical sub-prism reflects a part of light, A display device comprising a half mirror or an optical small-diameter hole for transmitting the rest, and by adopting such a configuration, distortion and unevenness of a propagating light beam are reduced and / or illumination is performed. The light propagation efficiency can be improved.

According to a fifth aspect of the present invention, there is provided an image magnifying device which is brought into close contact with or in contact with a first internal reflection surface comprising a triangular prism array, a half mirror, or an optically small hole. A display device in which corner mirrors having an internal angle of 90 degrees are continuously arranged with respect to that transmitted to the outside of the first internal reflection surface of the unit, and by adopting such a configuration, Alternatively, indirect unnecessary light can be prevented from propagating to the visual part.

According to a sixth aspect of the present invention, the concave reflecting mirror is installed near the first inner reflecting surface, converts illumination light from a substantially external light source into a substantially parallel light beam, and This is a display device that is illuminated by incident light from a reflecting surface to a small-sized image display unit. By adopting such a configuration, it is possible to realize high-quality illumination and to make the illumination device compact.

According to a seventh aspect of the present invention, the inside of the prism portion is made of a transparent material such as glass or resin which efficiently transmits light, or an internal reflection surface formed of a hollow structure by a flat semi-transmissive mirror. This is a display device comprising a prism-like member having the following characteristics. By adopting such a configuration, internal reflection by total reflection is realized, and an efficient and compact display optical system can be realized.

According to an eighth aspect of the present invention, a light source unit for illuminating a small image display unit is disposed substantially at the center of an image enlargement unit, or a light source is provided at a peripheral edge of the image enlargement unit. This is a display device in which a total reflection or semi-transmissive mirror that bends light from the camera to a small image display unit is arranged. With such a configuration, a compact and highly efficient illumination optical system can be realized. .

According to a ninth aspect of the present invention, there is provided a display device in which the total reflection or semi-transmission mirror has a smaller diameter than the pupil diameter of the observer. It is possible to transmit sufficient information of the small-sized image display unit to a user without impairing it.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1) FIG. 1 is a configuration diagram of a display device according to Embodiment 1 of the present invention, and shows a cross section of an optical system which is a main part of the display device of Embodiment 1. Things. In the figure, first, a lighting power is supplied from a power supply device 11 to a light source unit 13 in a lighting device 12 via a modulator 14 to cause the light source unit 13 to emit light. The light source section 13 is composed of red, green, and blue LED modules arranged in close proximity to each other, and emits modulated light at high speed independently and sequentially based on the field sequential display principle described later.

The emitted light of each color efficiently enters the sub-prism 16 by the condenser 15 and is reflected by the internal reflection surface 17 to pass through the joint surface 19 with the main prism 18 to the main prism 18 side. Incident. The joining surface 19 is formed with a half mirror that transmits a part of the light and reflects the rest, and the transmitted illumination light is reflected by the second internal reflection surface 20 while propagating inside the main body prism 18 (total reflection). After being reflected (reflected) and further reflected by the first internal reflection surface 21 (mirror internal reflection), the second internal reflection surface 2
Display module 2 emitted from the emission surface 20 which is the same as the surface 0
2 and illuminates the display surface 23.

The reflected light illuminated here and further including display information on the display surface 23 finally becomes a group of light rays necessary for projection to the visual part 24 as described later. Further, after this light group enters the main body prism 18 again, the first internal reflection surface 21, the second internal reflection surface 20, and the junction are so formed that they follow substantially the same path as the illumination light in the opposite direction. Propagation to surface 19. The joining surface 19 becomes a third inner reflection surface, and a part of the incident light passes through the emission surface 20 and the emission surface 20 to the eyepiece side which is the same surface as the second reflection surface 20 and passes through the eyepiece lens unit. As described above, the display image of the display module 22 is projected onto the visual section 24 by the enlarged imaging operation of 25.

The display module 22 is driven by a so-called field sequential driven by the image processing module 26 in synchronization with the illuminating device 12, or equivalent means. Here, the field sequential driving in the reflective display will be briefly described again. In the same method, the conventional N
Since the T panel has a slow response time and has a feeling of afterimage in moving image display and is unsuitable as a display method, a field sequential method having a high response performance is becoming mainstream in a reflection type method. Light source corresponding to each color of red, green and blue (LE
D) is synchronized with the display module 22 in a time-series manner, and is blinked at a high speed, which is invisible to the human eye, and visually superimposed, thereby enabling full-color display. High-speed performance, low power consumption, It has features such as high definition.

Next, the illumination unit will be described in more detail. In this figure, three LED arrays (not shown), which are the light source units 13 as described above, are arranged, and the inside of the sub-prism 16 is once inside the condensing unit 15 made of a convex lens or an optical member having the same function. After being reflected by the reflection surface 17,
The light is propagated to the joint surface 19 with the main body prism 18. The light beam transmitted and transmitted to the main body prism 18 is transmitted to the visual unit 24.
The display quality is not degraded due to unnecessary light (stray light) such as going to the right. This is because the light that reaches the second internal reflection surface 20 is incident on the second internal reflection surface 20 at an angle that satisfies the total reflection condition according to Snell's law, that is, from the second internal reflection surface 20. This is because there is no light transmitted directly to the eyepiece portion.

(Embodiment 2) FIG. 2 shows an optical system, which is a main part of a display device according to Embodiment 2 of the present invention, and peripheral parts thereof. This is an embodiment of a display device. In the first embodiment, the illumination light is introduced into the display module 22 by a third method.
Of the internal reflection surface (joining surface) 19,
The first inner reflection surface 21 closer to the small display unit is provided with a joint surface with the sub-prism, and has the following structure and operation.

In the figure, light emitted from a light source section 27 composed of three LED arrays is efficiently guided into a sub-prism 29 by a condenser 28, and two internal reflection surfaces 30 in the sub-prism 29. After being substantially totally reflected by the display module 2, the light passes through the joint surface 31 between the sub-prism 29 and the main prism 18, and further from the exit surface 20 of the main prism 18.
Illumination light is propagated to the second display surface 23.

The bonding surface 31 here is not completely bonded, but is larger than the wavelength of the LED but has a slight gap, and is strictly in a non-contact normal state. The previous two internal reflections satisfy the total reflection condition according to Snell's law described in the first embodiment, and all light is
9. However, the light arriving at the time of emission has an angle of about 30 degrees with respect to the normal of the bonding surface 31,
At this angle, since the total reflection condition (at least about 41 degrees or more) according to Snell's law cannot be satisfied, the light passes through the same surface and passes through the main body prism 18.

The first internal reflection surface 21 is constituted by a half mirror having the function applied to the bonding surface 19 of the first embodiment, and transmits a part of the light and transmits the remaining light. However, on the same surface on the side of the sub-prism 29, only a no-coat or an anti-reflection coat is provided, and has a function of transmitting most light that does not satisfy Snell's law.

The reflected return light including the display information reflected by the display module 22 is reflected by the first internal reflection surface 21, the second internal reflection surface 20, and the third internal reflection surface 19, respectively.
The light is transmitted from the exit surface 20 to the eyepiece lens unit 25, and the display of the display module 22 is projected as a virtual image on the visual unit 24 while being enlarged. However, the sub prism 29
There is a possibility that unnecessary light is generated by multiple reflection within the second internal reflection surface 20 and transmitted through the second internal reflection surface 20. Therefore, similarly to the first embodiment, the internal reflection surface 30 in the sub-prism 29 and the bonding surface 31
Light absorbing means 32 (anti-reflection treatment) is provided on the other surface. The basic configuration and operation of the light source unit 27, the modulator 14, the image processing module 26, and the power supply device 11 for driving them are the same as those in the first embodiment.

(Embodiment 3) FIG. 3 shows an optical system, which is a main part of a display apparatus according to Embodiment 3 of the present invention, and peripheral parts thereof. This is an embodiment of a display device. In the first embodiment, introduction of illumination light to the display module 22 is the first.
This is implemented by providing a joint surface between the inner reflection surface 21 and the sub-prism 34, and has the following structure and operation.

In the figure, light emitted from a light source unit 33 composed of three LED arrays is guided into the sub-prism 34 while diverging directly, and the light passes through a rotation axis passing through the light source position formed in the sub-prism 34. After being substantially totally reflected by the reflecting surface 35 which has been subjected to total reflection processing, such as a metal having a paraboloid or a dielectric multilayer film, the light passes through the joint surface 36 between the sub-prism 34 and the main body prism 18, and Illumination light is propagated from the exit surface 20 of the main body prism 18 to the display surface 23 of the display module 22.

The joining surface 36 is in contact with and joined to the main body prism without any gap. The joining surface 36 is formed with a half mirror that reflects part of incident light and transmits the rest. Further, the reflected return light including the display information reflected by the display module 22 is reflected by the first internal reflection surface 21, the second internal reflection surface 20, and the third internal reflection surface 19, respectively, and is reflected from the exit surface 20 by the eyepiece. The display module 2 is transmitted to the lens unit 25 and is transmitted to the visual unit 24 while being enlarged.
2 is projected as a virtual image.

However, since there is a possibility that multiple reflections occur in the sub-prism 34 and pass through the second internal reflection surface 20 to generate unnecessary light, light is partially transmitted between the light source 33 and the sub-prism 34. Absorbing means 37 (light transmission prevention processing) is provided.

The basic configuration and operation of the light source unit 33, the modulator 14, the image processing module 26, and the power supply device 11 for driving them are the same as in the first embodiment.

(Embodiment 4) FIG. 4 shows an optical system, which is a main part of a display device according to Embodiment 4 of the present invention, and peripheral parts thereof. This is an embodiment of a display device. In the first embodiment, the illumination light is introduced into the display module 22 by a third method.
Of the first internal reflection surface 21 closer to the display module 22, a prism array 40 for introducing illumination light and a relay lens 39 are provided. It has the following structure and operation.

In the figure, light emitted from a light source section 38 composed of three LED arrays is efficiently converted into a prism array 40 by a thin relay lens 39 having a positive power.
The light is guided to the side, passes through the relay lens 39, reaches the prism array 40, passes through the joint surface 41 between the prism array 40 and the main prism 18 under the action described later, and enters the main prism 18. , And the body prism 1
8, the display surface 2 of the display module 22 transmitted through the exit surface 20
Illumination light is propagated to 3.

The joining surface 41 here is a prism array 39
And the main body prism 18 are tightly joined without any gap, and a half mirror that reflects a part of the incident light and transmits the rest is formed on the joining surface 41.

Further, the reflected return light including the display information reflected by the display module 22 is reflected by the first internal reflection surface 21, the second internal reflection surface 20, and the third internal reflection surface 19, respectively, and is emitted. The display module 2 transmits through the eyepiece lens unit 25 to the eyepiece lens unit 25 and receives the magnifying effect to the visual unit 24.
2 is projected as a virtual image.

Here, a supplementary explanation of the structure of the prism array 40 will be given. One prism unit of the prism array 40 is composed of three planes, each of which is perpendicular to the paper surface. Two of the surfaces are the third internal reflection surface 19 and the second
About 45 degrees with respect to the optical axis turned back by the internal reflection surface 20,
And at an angle of approximately -45 degrees and in a roof shape. The remaining surfaces are parallel to the optical axis and are in contact with the main body prism 18.

When these three surfaces are viewed from the eyepiece lens portion 25 side, both of the two surfaces have an incident angle of approximately 45 degrees, that is, have a so-called corner mirror structure with an internal angle of 90 degrees, and the front (outside) of the main body prism 18. Can not be observed. To put it the other way around, the incident light from the opposite side of the main prism 18 does not reach the eyepiece lens portion 25. Furthermore, the other surface is invisible to an observer because it is parallel to the optical axis. However, when viewed from the display module 22 side, the illumination light is not limited to the above, and sufficient illumination light can reach.

However, two of the three surfaces in the prism array 40 that are in contact with the main prism 18 are subjected to multiple reflections in the prism array 40 to form the second internal reflection surface 2.
Since there is a possibility of transmitting unnecessary light and generating unnecessary light, a light absorbing means (light transmission preventing processing) is provided.

The basic structure and operation of the light source section 38, the modulator 14, the image processing module 26, and the power supply device 11 for driving them are the same as in the first embodiment.

(Embodiment 5) FIG. 5 shows an optical system, which is a main part of a display apparatus according to Embodiment 5 of the present invention, and peripheral parts thereof. This is an embodiment of a display device, in which a foldable parabolic mirror (concave reflecting mirror) is provided on a first inner reflection surface 21 close to a display module 22, and has the following structure and operation. Things.

In the same figure, light emitted from a light source section 42 composed of three LED arrays is thin and has a positive power, and is rotated by a rotating parabolic mirror 43 having a rotation axis with respect to the optical axis of the light source section 42. After being converted into a substantially parallel light beam, the light passes through the first reflection surface 21 of the main body prism 18 while being bent, enters the main body prism 18, further transmits through the exit surface 20 of the main body prism 18, and Illumination light is propagated to the display surface 23. In addition, a half mirror that reflects a part of the incident light and transmits the rest is formed on the first inner reflection surface 21 on which the illumination light is incident.

Further, the reflected return light including the display information reflected by the display module 22 is applied to the first internal reflection surface 21 and the second internal reflection surface 21.
Are reflected by the internal reflection surface 20 and the third internal reflection surface 19, respectively, are transmitted from the exit surface 20 to the eyepiece lens unit 25, and are projected on the display unit 22 as a virtual image to the visual unit 24 while being enlarged. I do.

FIG. 6 is a structural view of a mode in which the parabolic mirror of FIG. 5 is folded. As shown in FIG.
The 3 can be folded compactly, and is not bulky and convenient when not in use. This is because there is a space between the rotating parabolic mirror 43 and the main body prism 18, and such a configuration is employed for transmitting the illumination light via the prism member as in the above-described four embodiments. Is impossible. Furthermore, the basic configuration and operation of the light source unit 42, the modulator 14, the image processing module 26, and the power supply device 11 for driving them are the same as in the first embodiment.

(Embodiment 6) FIG. 7 shows an optical system, which is a main part of a display apparatus according to Embodiment 6 of the present invention, and its peripheral parts. The same virtual image enlargement as in the previous embodiment is shown. And the eyepiece lens unit 2 in the same manner as in the sixth embodiment.
5, and the illumination light from the second internal reflection surface 20 facing the display module 22 is realized, and has the following structure and operation.

In the same figure, a light beam emitted from a light source section 44 composed of three LED arrays and provided in the vicinity of the side face of the eyepiece lens section 25 is provided inside the eyepiece lens section 25 by a relay lens 45 having a positive power. , Approximately on the optical axis of the eyepiece lens unit 25, and
After being bent toward the main prism 18 by the micro-reflecting mirror 46 composed of a total reflection or a half mirror that is tilted by 5 degrees, the light enters the main prism 18 from the second incident surface 20 and further enters the third prism. Reflective surface 19,
It is bent by the second internal reflection surface 20 and the first internal reflection surface 21, emitted from the entrance surface 20 and the exit surface 20, and coaxially illuminates the display surface 23 of the display module 22 at a substantially right angle. .

The reflected return light reflected by the display surface 23 and containing the display information further enters the main body prism 18 and returns to the propagation route of the illuminating light in the opposite direction. The enlarged virtual image of the display unit can be projected on the visual unit 24. Further, the modulator 14 of the light source unit 44, the image processing module 26,
The basic configuration and operation of the power supply device 11 for driving them are the same as in the first embodiment.

(Embodiment 7) FIG. 8 shows an optical system, which is a main part of a display device according to Embodiment 7 of the present invention, and peripheral parts thereof. This is an aspect of a display device, which is intended to introduce illumination light from the first internal reflection surface 21 or the third internal reflection surface 19 to the display module 22 in the above embodiment. In the embodiment, the illumination light is introduced from the second internal reflection surface 20 facing the eyepiece lens unit 25 and the display module 22.
It has the following structure and operation.

In the figure, a light beam emitted from a light source unit 47 which is composed of three LED arrays and is provided on the optical axis of the eyepiece lens unit 25 or substantially at the center thereof is directly transmitted to a main body by a relay lens 48 having a positive power. After being incident and introduced on the prism 18 side, the incident light enters the inside of the main body prism 18 from the incident surface 20 which is the same as the second internal reflection surface 20 as in the previous embodiment, and further the third internal reflection The light is bent at the surface 19, the second internal reflection surface 20, and the first internal reflection surface 21, and is emitted from the entrance surface 20 and the exit surface 20 that is the same as the second internal reflection surface. This is for illuminating the display surface 23 coaxially at substantially right angles.

The reflected light reflected on the display surface and containing the display information further enters the main body prism 18 and returns to the propagation route of the illumination light in the opposite direction. Display surface 2 to 24
3 can project an enlarged virtual image.

Visual part 2 directly from eyepiece lens part 25
In order to remove unnecessary light emitted to
The light absorbing means 49 (light transmission preventing processing) is installed in the upper part of the drawing.

The basic configuration and operation of the modulator 14 of the light source unit 47, the image processing module 26, and the power supply device 11 for driving them are the same as in the first embodiment.

[0063]

As is clear from the above embodiments, the following effects are recognized according to the present invention. Efficiently employs a sub-prism, or an external concave mirror, or a micro-mirror that reflects light from a light source in the approximate center of an eyepiece lens, or a structure in which a direct light source is disposed, thereby effectively providing a reflective display module In addition, stable illumination quality without generation of unnecessary light can be obtained, and the configuration can be made relatively compact.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a display device according to a first embodiment of the present invention;

FIG. 2 is a configuration diagram of a display device according to a second embodiment of the present invention.

FIG. 3 is a configuration diagram of a display device according to a third embodiment of the present invention;

FIG. 4 is a configuration diagram of a display device according to a fourth embodiment of the present invention.

FIG. 5 is a configuration diagram of a display device according to a fifth embodiment of the present invention.

FIG. 6 is a configuration diagram of an embodiment in which the paraboloid of revolution shown in FIG. 5 is folded.

FIG. 7 is a configuration diagram of a display device according to a sixth embodiment of the present invention;

FIG. 8 is a configuration diagram of a display device according to a seventh embodiment of the present invention.

FIG. 9 is a configuration diagram of a conventional display device.

FIG. 10 is a configuration diagram of a conventional display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Power supply device 12 Illumination device (module) 13, 27, 33, 38, 42, 44, 47 Light source part 14 Modulator 15 Concentrator 16, 29, 34 Subprism 17 Internal reflection surface 18 Main body prism 19 Third Reflection surface, bonding surface 20 Second internal reflection surface, emission surface 21 First internal reflection surface 22 Display module 23 Display surface 24 Visual unit 25 Eyepiece lens unit 26 Image processing module 30 Internal reflection surface 31, 36, 41 Joint surface 32, 37, 49 Light absorbing means (anti-reflection treatment) 35 Reflecting surface 39, 45, 48 Relay lens 40 Prism array 43 Rotating parabolic mirror 46 Micro bending mirror

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) G02B 19/00 G02B 19/00 25/00 25/00 Z H04N 5/64 511 H04N 5/64 511A F-term (Reference) 2H042 AA02 AA03 AA04 AA09 AA15 AA26 CA12 CA18 DA20 DD06 DE04 2H052 BA02 BA03 BA09 BA14 2H087 KA14 KA24 TA01 TA05

Claims (9)

[Claims] 1. A small-sized image display unit mainly reflecting liquid crystal or photoelectric operation, an illuminating unit for illuminating the small-sized image display unit, and an image of the small-sized image display unit illuminated by the illuminating unit. An image magnifying unit that optically projects as a magnified virtual image visually, a first internal reflection surface, the small image display unit, and the image for transmitting an image of the small image display unit to the image magnifying unit A second internal reflection surface that is adjacent to the enlargement unit and performs total internal reflection according to Snell's law; and the first internal reflection surface that is disposed immediately below the image enlargement unit.
In a display device comprising a triangular prism having a structure similar to the inner reflection surface and a third inner reflection surface acting as a prism, or a prism having a polygonal prism shape, the illumination unit is close to the outside of the prism unit. Disposed, the illumination light is incident on the small image display unit from a third internal reflection surface, or the second internal reflection surface, and further, the second internal reflection surface,
And after being internally reflected by the first internal reflection surface, illuminating the illumination light from off-axis with an optically substantially coaxial epi-illumination viewed from the image enlarging unit, or at an inclined angle, A display device which illuminates and is provided between a light source of the illumination unit and the prism unit through a light introducing unit for preventing direct light from the light source from reaching the visual sense. 2. The image forming apparatus according to claim 2, wherein the light introducing means is an optical sub-prism, a triangular prism array, a hologram element, or an internal reflection surface incorporated in the image magnifying section, which is disposed in contact with or non-contact with the prism section. A light source device and a condenser lens incorporated inside the image enlargement unit, or a concave reflection mirror installed outside the prism unit.
The display device according to any one of the preceding claims. 3. The optical sub-prism has an exit surface in contact with the first internal reflection surface or the third internal reflection surface,
The optical axis of the image magnifying portion is in contact with the first internal reflection surface or the third internal reflection surface on the extension of the reflection optical axis, outside the incident optical axis as viewed from the small image display portion. The display device according to claim 2, wherein a light source is provided on the side of the sub-prism. 4. A half mirror that reflects a part of light and transmits the rest of the first internal reflection surface or the third internal reflection surface, the surface being in contact with the optical sub-prism. 4. The display device according to claim 3, wherein the display device comprises an optically small hole. 5. The first prism of the image enlarging section, wherein the triangular prism array is brought into non-contact with or in contact with the first internal reflection surface comprising a half mirror or an optically small hole. 3. The display device according to claim 2, wherein corner mirrors having an inner angle of 90 degrees are continuously arranged with respect to the light transmitted to the outside of the internal reflection surface. 6. The concave reflecting mirror is installed near the first inner reflecting surface, converts illumination light from a substantially external light source into a substantially parallel light beam, and displays the small image from the first inner reflecting surface. 3. The display device according to claim 2, wherein the portion is illuminated by incident light. 7. The inside of the prism portion is made of a transparent material such as glass or resin that efficiently transmits light, or a prism-like member having an internal reflection surface formed in a hollow structure by a flat semi-transmissive mirror. The display device according to claim 1, wherein: 8. A light source unit for illuminating the small image display unit is disposed at a substantially central portion of the image enlargement unit, or a light source is provided at a periphery of the image enlargement unit, and light from the light source is transmitted to the small image display unit. 2. The display device according to claim 1, wherein a total reflection or semi-transmission mirror to be bent to the display unit is arranged. 9. The display device according to claim 8, wherein the total reflection or semi-transmission mirror has a diameter smaller than a pupil diameter of an observer.