Patent Application
20070274701
The objects and advantages of the present invention will be better understood from the following description, with reference to the accompanying drawings in which:
The present invention is described below with reference to the embodiments shown in the drawings.
In
The photographic optical system comprises a plurality of lenses, such as a focusing lens and a zooming lens (not depicted). The mirror 33 is attached in the housing 31 so that the mirror 33 can rotate on a straight line axis perpendicular to the optical axis of the photographic optical system 32. Before and after the release operation, the mirror 33 is held in the path of the optical axis and the angle between the surface of the mirror 33 and the optical axis is kept at 45 degrees.
The focusing screen 35, the transparent display 10, the condenser lens 36, and the pentaprism 37 are mounted above the mirror 33. The imaging device 34 is mounted behind the mirror 33. In addition, the eyepiece is mounted behind the pentaprism 37.
Before and after the release operation, the optical image of an object passes through the photographic optical system 31 and is reflected by the mirror 33. The reflected optical image is focused on the focusing screen 35. The focused optical image passes through the focusing screen 35, the transparent display 10, the condenser lens 36, the pentaprism 37, and the eyepiece 38, where the optical image is observable to the user.
When a release button (not depicted) is depressed, the release operation commences. During the release operation, the mirror 33 is raised above the optical axis, a shutter (not depicted) opens, and the imaging device 34 captures the optical image.
Next, the structure of the transparent display 10 is described below using
The display unit 20 is formed as a rectangular plate. The optical image is projected onto one side of the plate and then transmitted through and to the other side of the plate. The light source unit 11 is mounted at the side of the display unit 20. The light source unit 11 emits red, green, and blue light, separately. The red, green, and blue light emitted from the light source unit 11 is incident on the side face of the display unit 20.
The display unit 20 and the light source unit 11 are connected electrically to the display controller 12. The display controller 12 controls the display unit 20 and the light source unit 11 so that the required information is superimposed on a projected optical image of an object on the display unit 20.
As shown in
The first and second transparent electrodes 22a, 22b are mounted between the first and second glass substrates 21a, 21b, and adhered on the inside surface of the first and second glass substrates 21a, 21b, respectively.
As shown in
A lot of unit cells 24 are constructed on the areas where the first and second transparent electrodes 22a, 22b overlap.
A polymer dispersed crystal liquid layer 23 is fills the gap between the first and second transparent electrodes 22a, 22b. The polymer dispersed crystal liquid layer 23 is made by dispersing innumerable liquid crystal droplets 26 in a polymer medium 25.
The refractive index of the first and second glass substrates 21a, 21b are the same as each other. A p-type liquid crystal is used for the liquid crystal droplets 26. The specification of the liquid crystal is such that the refractive indexes of a liquid crystal molecule in the p-type liquid crystal against an ordinary ray and an extraordinary ray, respectively, are greater than that of the first and second glass substrates 21a, 21b. In addition, a material with a specification such that the refractive index of the material is nearly equal against the extraordinary ray to that of the liquid crystal molecules in the p-type liquid crystal, is used for the polymer medium 25.
Incidentally, an n-type liquid crystal can be adaptable for the liquid crystal droplet 26. However, in such a case, the refractive index against the ordinary ray of the polymer medium 25 must be nearly equal to that of the liquid crystal molecules in the n-type liquid crystal.
When voltage is applied on the first and second transparent electrodes 22a, 22b, the liquid crystal molecules, which are long molecules, turn so that the liquid crystal molecules are parallel to a theoretical line connecting the first transparent electrode 22a to the second transparent electrode 22b (see
On the other hand, when a voltage is ceased to be applied between the first and second transparent electrodes 22a, 22b, the liquid crystal molecules turn to various orientations (see
Each light source unit 11 is mounted so that the two light source units 11 face onto two edge surfaces of the first glass substrate 21a (see
A light source unit 11 comprises red, green, and blue light sources (not depicted) that emit red, green, and blue light, respectively. The red, green, and blue light sources are organo-electroluminescence devices. The red, green, and blue light emitted from the red, green, and blue light sources have directivity. The red, green, and blue light sources are mounted so that the red, green, and blue light is emitted in predetermined directions toward the edge surface of the first glass substrate 21a, respectively.
The predetermined directions are decided so that the light, which is emitted from each of the light sources, is made incident to the first glass substrate 21a and intersects the inside surface, which is facing the second glass substrate 21b, or an outside surface opposite to the inside surface. In addition, the predetermined direction is decided so that a beam incident to the first glass substrate 21a is reflected totally on the outside surface (see
The transparent display 10 is mounted in the single lens reflex camera 30 so that the second glass substrate 21b faces the pentaprism 37. The light progressing through the first glass substrate 21a is not completely reflected, but partially passes through the outside surface even if the light is incident on the outside surface at an angle of incidence more than the critical angle. Consequently, it is preferable that the second glass substrate 21b faces the pentaprism 37 to prevent light from entering the pentaprism 37.
The operation of displaying a required image on the transparent display 10 is explained below.
The light emitted from the light source unit 11 is made incident on the first glass substrate 21a. As the incident light progresses through the inside of the first substrate 21a, the incident light is substantially and almost totally reflected on the outside surface of the first glass substrate 21a and partially reflected on the inside surface. A part of the incident light passes through the inside surface and enters the polymer dispersed crystal liquid layer 23 through the first transparent electrode 22a.
When a voltage is applied between the first and second transparent electrodes 22a, 22b, the refractive index of the entire polymer dispersed liquid crystal layer 23 is uniform. Consequently, an optical image incident to the transparent display 10 from a side of the first glass substrate 21a passes through the polymer dispersed crystal liquid layer 23 and is emitted from the second glass substrate 21b. In addition, a beam incident on the first glass substrate 21a goes straight and is made incident on the second glass substrate 21b (see
The refractive indexes of the first and second glass substrates 21a, 21b are the same, so the angle of incidence from the first glass substrate to the polymer dispersed liquid crystal layer 23 through the first transparent electrode 22a is the same as the angle of incidence from the polymer dispersed liquid crystal layer 23 to the second glass substrate 21b through the second transparent electrode 22b. Consequently, the light incident on the second glass substrate 21b is reflected totally on the outside surface of the second glass substrate 21b. The totally reflected light from the outside surface of the second glass substrate 21b progresses through the inside of the second glass substrate 21b as the progressing light is reflected totally on the outside surface of the second glass substrate 21b and partially reflected on the inside surface, similar to the first glass substrate 21a.
Consequently, when a voltage is applied between the first and second transparent electrodes 22a, 22b, an optical image projected to the transparent display 10 is displayed on the transparent display 10.
On the other hand, while no voltage is applied between the first and second transparent electrode 22a, 22b, the incident light is scattered by the polymer dispersed liquid crystal layer 23 (see
The light incident on the polymer dispersed liquid crystal layer 23 from the light source unit 11 is scattered in numerous directions in the polymer dispersed liquid crystal layer 23. A part of the scattered light which progresses in the direction of the second glass substrate 21b becomes incident on the second glass substrate 21b. Light which is incident on the second glass substrate 21b by an angle of incidence more than the critical angle is reflected on the outside surface of the second glass substrate 21b. On the other hand, light which is incident on the second glass substrate 21b by an angle of incidence less than the critical angle passes through the second glass substrate 21b and is emitted therefrom. Consequently, while voltage is not applied between the first and second transparent electrodes 22a, 22b, the light emitted from the light source unit 11 is emitted from the second glass substrate 21b.
Incidentally, the magnitude of light which passes through the second glass substrate 21b can be controlled according to the voltage which is applied between the first and second transparent electrodes 22a, 22b.
When a required image is to be displayed on the transparent display 10, a plurality of the first transparent electrodes 22a are selected one by one. When one first transparent electrode 22a is selected, voltage data corresponding to the magnitudes of light which are required to be emitted at unit cells 24, arranged in a line corresponding to the selected first transparent electrodes 22a, is sent to all of the second transparent electrodes 22b. Each cell 24, which is located at the intersection point of the selected first transparent electrode 22a and the second transparent electrode 22b, emits colored light according to the received voltage data. A similar operation is carried out for all the all first transparent electrodes 22a, selected one by one.
The time at which the red, green, and blue light are emitted are separated. For example, first, the red light source is ordered to emit a fixed magnitude of red light. While red light is emitted, all voltage data corresponding to the red light is sent to all the unit cells 24 and each cell 24 emits red light, of which the magnitude is controlled. After ordering all the unit cells 24 to emit red light, the red light source is switched off.
Next, the green light source is ordered to emit a fixed magnitude of green light. While green light is emitted, all voltage data corresponding to the green light is sent to all the unit cells 24 and each cell 24 emits green light, of which the magnitude is controlled. After ordering all the unit cells 24 to emit green light, the green light source is switched off.
Next, the blue light source is ordered to emit a fixed magnitude of blue light. While blue light is emitted, all voltage data corresponding to the blue light is sent to all the unit cells 24 and each cell 24 emits blue light, of which the magnitude is controlled. After ordering all the unit cells 24 to emit blue light, the blue light source is switched off.
After ordering the blue light source to emit, the supply of red, green, and blue light to the display unit 20 is repeated, one by one. A full-color image can be displayed on the display unit 20 by repeating the above operation.
According to the above embodiment, a full-color required image can be displayed on the transparent display 10 so a user can observe the optical image of an object by ordering the optical image to pass through the transparent display 10.
In the above embodiment, the light source unit 11 is mounted on a side of the first glass substrate 21a and the light which is emitted by the light source unit 11 is incident on the side of the first glass substrate 21a. However, the light source unit 11 may be mounted on a side of the second glass substrate 21b and the light can be incident on the side of the second glass substrate 21b.
Alternatively, the light source unit 11 may be mounted on a side of the polymer dispersed liquid crystal layer 23 and the light may be incident on the side of the polymer dispersed liquid crystal layer 23. If the light source unit 11 is mounted on a side of the polymer dispersed liquid crystal layer 23, it is preferable to decide the direction in which the light source unit 11 emits red, green, and blue light so that the light incident on the first and second glass substrates 21a, 21b from the polymer dispersed liquid crystal layer 23 is reflected totally on their outside surfaces. Or, the direction in which the light source unit 11 emits light can be decided so that the incident light on the polymer dispersed liquid crystal layer 23 cannot enter the first and second glass substrates 21a, 21b, for example, the incident light progresses along a straight line which is parallel to the interfaces between the polymer dispersed liquid crystal layer 23 and the first and second transparent electrodes 22a, 22b. Even if the incident light is emitted by the light source unit 11 in the above direction, light is scattered at a unit cell 24 when voltage is not applied, and the unit cell 24 can emit the scattered light from the second glass substrate 21b.
In the above embodiment, the edge surfaces of the first glass substrate 21a are perpendicular to the inside and outside surfaces of the first glass substrate 21a. However, the angle between the side surfaces and the inside/outside surfaces can be an angle different from 90 degrees. By adjusting the angle, the angle of incidence of the light progressing inside the first glass substrate 21a, on the inside and outside surfaces can be adjusted.
In the above embodiment, by separately deciding the directions in which the red, green, and blue light source emits red, green, and blue light, the angle of incidence of the light hitting the inside and outside surfaces of the first glass substrate 21a can be adjusted. However, the directions in which the red, green, and blue light source emits red, green, and blue light are fixed in the light source unit 11, and by deciding the direction in which the light source unit 11 faces, the angle of incidence of the light hitting the inside and outside surfaces of the first glass substrate 21a can be adjusted.
In the above embodiment, the light source unit 11 and the first glass substrate 21a are mounted so that the light source unit 11 and the first glass substrate 21a are apart from each other. However, the light source unit 11 and the first glass substrate 21a can be adhered together.
In the above embodiment, fixed magnitudes of red, green, and blue light are emitted from the red, green, and blue light sources. However, the magnitude of the red, green, and blue light can be adjusted for each unit cell 24. If the magnitude of the emitted light is adjusted, it is unnecessary to adjust the voltage applied between the first and second transparent electrodes 22a, 22b. Of course, both the magnitude of the emitted light, and the voltage applied can be adjusted.
In the above embodiment, times when the red, green, and blue light are emitted are separated. However, a plurality of light sources can be ordered to emit light simultaneously. Of course, it is preferable to order the light sources to emit at separate times in order to express various colors. Incidentally, a similar effect can be achieved even if all the light sources are ordered to emit light simultaneously, as long as the magnitude of each light emitted by the light sources is adjusted.
In the above embodiment, the direction in which the light sources emit light is decided so that the incident light in the first glass substrate 21a is reflected totally on the outside surface of the first glass substrate 21a. However, it is not necessary to reflect totally the light on the outside surface of the first glass substrate 21a. If the transparent display 10 is mounted on the viewfinder of a camera as the above embodiment, the transparent display 10 is seen only directly from the front. Consequently, without total reflection, light which is not required to emit from a unit cell 24 and which passes through the outside surface of the second glass substrate 21b rarely reaches a user. Of course, it is preferable that the incident light is reflected on the outside surfaces of the first and second glass substrates 21a, 21b to prevent the luminance of the unit cells 24 from dropping.
In the above embodiment, an organo-electroluminescence device is used as a light source in the light source unit 11. However, the same effect can be achieved even if other kinds of light source, such as an LED, are used. Especially, if the voltage to be applied between the first and second transparent electrodes 22a, 22b is controlled, any kind of light source are adaptable for use. However, if the magnitudes of the emitted light are controlled, a light source where the magnitude of the light can be altered quickly, such as an organo-electroluminescence device, is preferable. In addition, a light source which can supply light uniformly to the entire incident surface of the first glass substrate 21a, such as an organo-electroluminescence device which is a surface-emitting device, is preferable.
In the above embodiment, the voltage data sent to each unit cell 24 is controlled according to the passive matrix method. However, the active matrix method is also adaptable for use.
In the above embodiment, a plurality of unit cells 24 are arranged according to the dot matrix system. However, the unit cells 24 may be arranged according to the segment system by forming the first and second transparent electrodes into a predetermined shape.
In the above embodiment, the first transparent electrodes 22a are arranged so that the first transparent electrodes 22a are parallel lengthwise to the shorter side of the first glass substrate 21a and the second transparent electrodes 22b are arranged so that the second transparent electrodes 22b are perpendicular to the first transparent electrode 22a. However, any arrangement of the first and second transparent electrodes 22a, 22b is acceptable as long as the polymer dispersed liquid crystal layer 23 is mounted between the first and second transparent electrodes 22a, 22b.
In the above embodiment, a reflection material is mounted on the first glass substrate 21a. However, the same effect can be achieved even if a reflection material is not mounted. It is preferable to mount the reflection material to fully utilize the light emitted from the light source unit 11.
In the above embodiment, the light source units 11 are mounted on two sides of the first glass substrate 21a, which is shaped as a rectangular. However, the light source unit 11 can be mounted on one, three, or all sides of the first glass substrate 21a.
In the above embodiment, one light source unit 11 comprises red, green, and blue light sources. However, a single light source unit 11 may comprise one kind of light source. For example, the same effect can be achieved by mounting a red light source unit 11r, which comprises only a red light source, a green light source 11g, which comprises only a green light source, and a blue light source 11b, which comprises only a blue light source, separately on one side of the first glass substrate 21a, as shown in
In the above embodiment, light sources which emit three primary colors are used. However, light sources which emit any other color light are also acceptable.
In the above embodiment, the first and second glass substrates 21a and 21b are used. However, any kind of substrate that is a transparent plate is acceptable.
In the above embodiment, the transparent display 10 is mounted in the single lens reflex camera 30. However, the transparent display 10 may be mounted in any kind of camera. Furthermore, the transparent display 10 may be used for any apparatus, such as binoculars.
Although the embodiments of the present invention have been described herein with reference to the accompanying drawings, obviously many modifications and changes may be made by those skilled in this art without departing from the scope of the invention.
The present disclosure relates to subject matter contained in Japanese Patent Application No. 2006-148021 (filed on May 29, 2006), which is expressly incorporated herein, by reference, in its entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2006-148021 | May 2006 | JP | national |
