JP4572569B2 - Display device - Google Patents

Description

  The present invention relates to a display device that captures an object image with a light receiving element while observing the object image, displays the captured image on a display device, and enables observation with the object image.

Conventionally, there has been proposed a display device that has an imaging device that receives and images an object image of an observation optical system, and that can display an electronic image captured in the optical path of the observation optical system and observe it together with the object image of the observation optical system (For example, refer to Patent Document 1).
JP 11-174367 A

  However, in the above disclosed example, the half-mirror is used as the optical path separating unit provided in the optical path of the observation optical system. Therefore, the amount of light from the object image reaching the observer's eyes is attenuated and the object image is dark. There is a problem of becoming.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a display device having an optical system that hardly attenuates the amount of light from an object image (observed image).

In order to achieve the above object, the present invention provides:
A first wavelength-selective optical member and a second wavelength-selective optical member, which are arranged in order from the incident side of the background light along the incident optical axis;
A wavelength-selective polarization separation mirror that is sandwiched between the first wavelength-selective optical member and the second wavelength-selective optical member and is inclined with respect to the incident optical axis;
It has a display means and an imaging device that are arranged to face the incident optical axis and sandwich the wavelength selective polarization separation mirror,
The wavelength selective polarization separation mirror reflects the light of the first specific wavelength and the light of the second specific wavelength, transmits the light of the first polarization direction, and is different from the first polarization direction by 90 degrees. Reflects light in two polarization directions,
The first wavelength selective optical member has a substantial refractive power focusing on the display surface of the display means, reflects the light of the first specific wavelength among the display light of the display means, and Transmits light other than light of the first specific wavelength,
The second wavelength selective optical member has a substantial refractive power focusing on the imaging surface of the imaging device, and directs the light of the second specific wavelength out of the background light to the wavelength selective polarization separation mirror. And transmits light other than the second specific wavelength,
The first wavelength selective optical member includes a first wavelength selection element and a first quarter wavelength plate,
The second wavelength selective optical member includes a second wavelength selection element and a second quarter wavelength plate,
A reflective surface that reflects light from the display means and directs it to the wavelength selective polarization separation mirror between the display means and the wavelength selective polarization separation mirror;
The display light is reflected by the reflecting surface and then enters the wavelength selective polarization separation mirror, and the wavelength selective polarization separation mirror emits light having the second polarization direction and the first specific wavelength in the display light. Reflected toward the first wavelength selective optical member, and the reflected light is transmitted through the first quarter wavelength plate of the first wavelength selective optical member and reflected by the first wavelength selective element. Then, the light is again transmitted through the first quarter-wave plate, converted from the second deflection direction to the light in the first polarization direction, and emitted, and then the wavelength selective polarization separation mirror and the second wavelength selective optics. Through the member and entering the observer's pupil,
Light in the background light other than the first specific wavelength is transmitted through the first wavelength selective optical member, and light in the first polarization direction among the transmitted light is transmitted through the wavelength selective polarization separation mirror. Heading to the second wavelength selective optical member, light other than the second specific wavelength among the transmitted light passes through the second wavelength selective optical member and enters the observer's pupil,
Of the light incident on the second wavelength-selective optical member, the light having the second specific wavelength is transmitted through the second quarter-wave plate and reflected by the second wavelength selection element, and then the second wavelength again. And is converted from the first polarization direction to the light having the second polarization direction, emitted from the second wavelength selective optical member, and incident on the wavelength selective polarization separation mirror. Provided is a display device characterized by being reflected toward the imaging device by a wavelength selective polarization separation mirror and forming an image on the imaging device .

In the display device of the present invention, it is preferable that the first wavelength selection element and the second wavelength selection element are formed of a diffractive optical element.

Further, in the display device of the present invention, on the side where the background light of the first wavelength selective optical element is first incident, it is preferable to have a light control means for adjusting the amount of pre-Symbol background light.

Further, in the display device of the present invention, the light control means includes light amount detecting means for detecting the amount of the background light, it is preferably made of a light-reducing or shielding dimming member the background light.

  The present invention can provide a display device having an optical system in which the amount of light from an object image (observation image) is hardly attenuated.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of a display device according to a first embodiment of the present invention. FIG. 2 shows an enlarged schematic view of portion A in FIG. FIG. 3 is a diagram schematically showing the spectral characteristics of the wavelength selective optical member used in the first embodiment. FIG. 4 is a diagram schematically showing the spectral characteristics of the wavelength selective polarization separation mirror used in the first embodiment. FIG. 5 is a schematic configuration diagram of a display device according to the second embodiment of the present invention.

(First embodiment)
In FIG. 1, a wavelength-selective polarization separation mirror 5 is formed on at least one of the opposed surfaces 1a and 3a of the substantially trapezoidal transparent first glass member 1 and second glass member 3, 1a and the surface 3a are bonded and formed integrally with an optical adhesive. The wavelength selective polarization separation mirror 5 is formed of a multilayer coating, and has a characteristic of reflecting only S-polarized light having a specific wavelength as shown in FIG .

  The first wavelength selective optical member 7 is disposed on the incident surface 1b side of the incident light beam (background light beam) of the first glass member 1, and the second wavelength is disposed on the emission surface 3b side of the second glass member 3. The selective optical members 9 are bonded with an optical adhesive. The first wavelength selective optical member 7, the wavelength selective polarization separation mirror 5, and the second wavelength selective optical member 9 are integrally configured via the first glass member 1 and the second glass member 3. These three optical members are arranged along the incident optical axis I.

  A display device 11 is disposed in the vicinity of the end surface 1 c of the first glass member 1, and an imaging device 13 is disposed in the vicinity of the end surface 3 c of the second glass member 3. The display device 11 and the imaging device 13 are disposed at a position substantially opposite to the incident optical axis I with the wavelength selective polarization separation mirror 5 interposed therebetween.

  The first wavelength-selective optical member 7 has a substantial refractive power with the display surface of the display device 11 as a focal point, and the light having a specific wavelength of the display light from the display device 11 is applied to the observer's pupil. Incident and display image can be observed. On the other hand, the second wavelength-selective optical member 9 has a substantial refractive power with the imaging surface of the imaging device 13 as a focal point, and has a specific wavelength among the background light fluxes incident along the incident optical axis I. Is picked up by the image pickup device 13, and light other than the specific wavelength is transmitted and incident on the observer's pupil to enable observation.

  In FIG. 2, the first wavelength selective optical member 7 is formed of a hologram 7 a and a quarter wavelength plate 7 b, and the quarter wavelength plate 7 b side is bonded to the incident surface 1 b of the first glass member 1. Yes. On the other hand, the second wavelength selective optical member 9 is formed of a hologram 9 a and a quarter wavelength plate 9 b, and the quarter wavelength plate 7 b side is bonded to the emission surface 3 b of the second glass member 3. A wavelength selective polarization separation mirror 5 is disposed between the first wavelength selective optical member 7 and the second wavelength selective optical member 9.

  The spectral characteristics of the hologram 7a and the hologram 9a have characteristics as shown in FIG. The hologram 7a has a specific wavelength in the incident light beam (in the background light beam), blue (hereinafter referred to as λ1B), green (hereinafter referred to as λ1G), and red (hereinafter referred to as λ1R). Only the light in the region is reflected, and the light having a wavelength other than the specific wavelength is transmitted.

  The hologram 9a reflects display light of a specific wavelength from the display device 11, only light in each limited wavelength region of blue (λ2B), green (λ2G), and red (λ2R), and transmits light of other wavelengths. To do.

  The hologram 7a has spectral characteristics having a wavelength width of about 10 nm on one side with respect to the peak wavelengths of wavelengths λ1B, λ1G, and λ1R. The same applies to the spectral characteristics of the hologram 9a. Further, the peak wavelength λ1B and the peak wavelength λ2B have characteristics in which the peak wavelengths are different by about 15 to 20 nm.

  As shown in FIG. 4, the spectral characteristics of the wavelength selective polarization separation mirror 5 include the wavelength regions of the specific wavelengths of the hologram 7a and the hologram 9a (λ1B + λ2B, λ1G + λ2G, λ1R + λ2R). ing. As a result, the wavelength selective polarization separation mirror 5 reflects the specific wavelengths (λ1B, λ1G, λ1R) of the S-polarized light in the incident light beam and the specific wavelengths (λ2B, λ2G, λ2R) of the S-polarized light in the display light. Transmits light of wavelength. In this way, the display device according to the first embodiment is configured.

  Next, the operation of the display device according to the first embodiment will be described. First, imaging of a background light beam and observation by an observer will be described.

  In FIG. 1 and FIG. 2, an incident light beam (background light beam) incident from the right side in the drawing enters the first wavelength selection optical member 7. Since the hologram 7a has the reflection spectral characteristics shown in FIG. 3, light of specific wavelengths (λ1B, λ1G, λ1R) in the incident light beam is reflected on the surface on the incident side of the hologram 7a and returns to the background side.

  Light other than the specific wavelength in the incident light beam passes through the hologram 7 a and the quarter wavelength plate 7 b and enters the wavelength selective polarization separation mirror 5. The wavelength selective polarization separation mirror 5 reflects S-polarized light at the included wavelengths (λ1B + λ2B, λ1G + λ2G, λ1R + λ2R) as described above. The P-polarized light among the light transmitted through the wavelength selective polarization separation mirror 5 is converted into circularly polarized light by the quarter wavelength plate 9b of the second wavelength selective optical member 9, and the specific wavelength (λ2B, λ2G, The light of [lambda] 2R) is reflected, is incident again on the quarter wave plate 9b, and is converted to S-polarized light. The S-polarized light is reflected by the wavelength selective polarization separation mirror 5 and condensed on the imaging device 13, and a background image is captured by the imaging device 13. If the light receiving element becomes too large due to the distance relationship between the hologram 9a and the image pickup element 13, an adjustment imaging lens is disposed between the end face 3c of the second glass member 3 or the end face 3c and the image pickup apparatus 13. You may do it. Further, the light receiving element of the imaging device 13 may be a CCD or a CMOS. Since optical elements such as an optical low-pass filter placed in the optical path immediately before the imaging device 13 are not related to the present embodiment, description thereof is omitted.

  On the other hand, light having a wavelength other than the specific wavelength transmitted through the hologram 9a is incident on the observer's pupil and a background image in front of the eye is observed. Since the hologram 7a, the wavelength selective polarization separation mirror 5, and the hologram 9a have steep reflection spectral characteristics with respect to a specific wavelength, the brightness of the background image that is incident on the observer's pupil and observed It hardly affects the hue.

  Next, display light from the display device 11 will be described. The display device 11 is an LCD with a backlight, for example. The display light from the display device 11 corresponds to S-polarized light having a specific wavelength (λ1B, λ1G, λ1R) corresponding to the spectral characteristics of the holograms 7a and 9a and the wavelength selective polarization separation mirror 5 described above. . This is because the spectral characteristics of the holograms 7 a and 9 a and the wavelength selective polarization separation mirror 5 are created corresponding to the wavelength of the display light of the display device 11. The LCD may be a color filter method or a field sequential method. Further, if a color filter type LCD is used and the efficiency can be ignored, it may be illuminated with a white light source such as a cold cathode tube.

  The S-polarized display light of the image displayed on the display device 11 is incident from the end face 1c of the first glass member 1, is incident on the wavelength selective polarization separation mirror 5, and is reflected on the first wavelength selective optical member 7 side. Is done. The P-polarized display light passes through the wavelength selective polarization separation mirror 5 and enters the image pickup device 13, but this light is stray light and does not form an image on the light receiving element of the image pickup device 13. In order to eliminate the influence of the stray light on the captured image, the display device 11 is turned off at the time of imaging, or the specific wavelength (λ2B, λ2G) of the display light between the wavelength selective polarization separation mirror 5 and the imaging device 13 is used. , Λ2R) may be provided.

  The light reflected by the wavelength selective polarization separation mirror 5 is transmitted through the quarter wavelength plate 7b to be converted into circularly polarized light, incident on the hologram 7a, reflected, and again transmitted through the quarter wavelength plate 7b to become P polarized light. After being converted, the light passes through the wavelength selective polarization separation mirror 5, and further passes through the second wavelength selective optical member 9 to enter the pupil of the observer. Since the hologram 7a has a substantial refractive power such that it has a focal position on the display surface of the display device 11, the display light reflected from the hologram 7a becomes a light beam substantially parallel to the incident optical axis I. It is incident on the pupil and observed.

  In the first embodiment, the background light beam and the display light are transmitted to the observer by the wavelength selective optical member that reflects or transmits the incident light beam (background light beam) and the light having the specific wavelength of the display light and the wavelength selective polarization separation mirror. It is possible to enter the pupil of the image and observe it, and it is possible to image the background light flux having a specific wavelength incident on the imaging device.

  In addition, the background image in front of the eye imaged by the imaging device 13 is subjected to image processing by an image processing unit (not shown), and then displayed on the display device 11, and the image processed background image and the background image in front of the eye are superimposed and observed. Is possible. At this time, various processes can be applied to the image displayed on the display device 11 to cause the observer to observe, and various information can be given.

  It is also possible to display and observe images, characters, and the like that are different from the background image in front of the display device 11.

  Moreover, it is also possible to use it as a digital camera by storing an image captured by the imaging device 13 in a memory (not shown).

  With such a configuration, a see-through wearable display can be configured. In addition, it is possible to reduce the thickness of the optical member used by adhering the wavelength selective polarization separation mirror, LCD, and light receiving element using a hologram or multilayer coating to a transparent optical member. A lightweight wearable display can be configured. Further, since the background light beam is directly incident on the pupil of the observer, problems such as parallax between the observation system and the imaging system can be avoided. Further, since the wavelength-selective optical member is used, the influence on the background light beam observed by the observer can be minimized, and the deterioration of the contrast of the background image can be prevented.

(Second Embodiment)
Next, a display device according to a second embodiment of the present invention will be described with reference to the drawings. The second embodiment is different from the display device of the first embodiment in that a dimming means for adjusting the amount of incident light of the background light beam is provided. The same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.

  In FIG. 5, an electrochromic film 21 is provided on the surface of the first wavelength selective optical member 7 on the side on which the background light beam is incident to adjust or block the amount of incident light (background light beam). The electrochromic film 21 adjusts the amount of incident light and controls light shielding by adjusting the density of the electrochromic film 21 based on information from the light quantity detection means 23 and the light quantity detection means 23 for detecting the peripheral light quantity of the display device. Control means 25 is connected. In this way, the display device of the second embodiment is configured.

  In the display device according to the second embodiment, the density of the electrochromic film 21 is adjusted when a captured image or an image irrelevant to the background image in front of the eye is displayed on the display device 11 for observation. Thus, the incident light quantity of the background light beam can be attenuated or shielded, so that a sharp and high-contrast display image can be observed. In addition, if it has the effect | action similar to the electrochromic film | membrane 21 as a light control film | membrane, it can be used as a light control member. Other operations and effects are the same as those in the first embodiment, and a description thereof will be omitted.

  The above-described embodiment is merely an example, and is not limited to the above-described configuration or shape, and can be appropriately modified and changed within the scope of the present invention.

1 is a schematic configuration diagram of a display device according to a first embodiment of the present invention. The enlarged schematic of the A section of FIG. 1 is shown. It is a figure which shows typically the reflection spectral characteristic of the wavelength selective optical member used for 1st Embodiment. It is a figure which shows typically the reflective spectral characteristic of the wavelength selection polarization separation mirror used for 1st Embodiment. The schematic block diagram of the display apparatus concerning 2nd Embodiment of this invention is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st glass member 3 2nd glass member 5 Wavelength selective polarization separation mirror 7 1st wavelength selective optical member 7a Hologram 7b 1/4 wavelength plate 9 2nd wavelength selective optical member 9a Hologram 9b 1/4 Wave plate 11 Display device 13 Imaging device 21 Electrochromic film 23 Light quantity detection means 25 Control device I Incident optical axis

Claims (4)

A first wavelength-selective optical member and a second wavelength-selective optical member, which are arranged in order from the incident side of the background light along the incident optical axis;
A wavelength-selective polarization separation mirror that is sandwiched between the first wavelength-selective optical member and the second wavelength-selective optical member and is inclined with respect to the incident optical axis;
It has a display means and an imaging device that are arranged to face the incident optical axis and sandwich the wavelength selective polarization separation mirror,
The wavelength selective polarization separation mirror reflects the light of the first specific wavelength and the light of the second specific wavelength, transmits the light of the first polarization direction, and is different from the first polarization direction by 90 degrees. Reflects light in two polarization directions,
The first wavelength selective optical member has a substantial refractive power focusing on the display surface of the display means, reflects the light of the first specific wavelength among the display light of the display means, and Transmits light other than light of the first specific wavelength,
The second wavelength selective optical member has a substantial refractive power focusing on the imaging surface of the imaging device, and directs the light of the second specific wavelength out of the background light to the wavelength selective polarization separation mirror. And transmits light other than the second specific wavelength,
The first wavelength selective optical member includes a first wavelength selection element and a first quarter wavelength plate,
The second wavelength selective optical member includes a second wavelength selection element and a second quarter wavelength plate,
A reflective surface that reflects light from the display means and directs it to the wavelength selective polarization separation mirror between the display means and the wavelength selective polarization separation mirror;
The display light is reflected by the reflecting surface and then enters the wavelength selective polarization separation mirror, and the wavelength selective polarization separation mirror emits light having the second polarization direction and the first specific wavelength in the display light. Reflected toward the first wavelength selective optical member, and the reflected light is transmitted through the first quarter wavelength plate of the first wavelength selective optical member and reflected by the first wavelength selective element. Then, the light is again transmitted through the first quarter-wave plate, converted from the second deflection direction to the light in the first polarization direction, and emitted, and then the wavelength selective polarization separation mirror and the second wavelength selective optics. Through the member and entering the observer's pupil,
Light in the background light other than the first specific wavelength is transmitted through the first wavelength selective optical member, and light in the first polarization direction among the transmitted light is transmitted through the wavelength selective polarization separation mirror. Heading to the second wavelength selective optical member, light other than the second specific wavelength among the transmitted light passes through the second wavelength selective optical member and enters the observer's pupil,
Of the light incident on the second wavelength-selective optical member, the light having the second specific wavelength is transmitted through the second quarter-wave plate and reflected by the second wavelength selection element, and then the second wavelength again. And is converted from the first polarization direction to the light having the second polarization direction, emitted from the second wavelength selective optical member, and incident on the wavelength selective polarization separation mirror. A display device, wherein the image is reflected on the imaging device by a wavelength selective polarization separation mirror and imaged on the imaging device. The display device according to claim 1 , wherein the first wavelength selection element and the second wavelength selection element are diffractive optical elements. 3. The display device according to claim 1, further comprising a light control unit that adjusts a light amount of the background light on a surface side on which the background light of the first wavelength selective optical member first enters . 4. The display device according to claim 3 , wherein the light control unit includes a light amount detection unit that detects a light amount of the background light and a light control member that reduces or blocks the background light.

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