JP2008046212A - Display device and display system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device, wherein NVIS adaptation is attained and the color rendering properties of display in three primary colors in the daytime is superior. <P>SOLUTION: The display device combines the image light from a red display element illuminated by a light source for red color, the image light from a blue display element illuminated by a light source for blue color, and the image light from a green display element illuminated by a light source for green color, and displays the composite image by the image light of the three primary colors. The light source for red color includes a first red light source 11 for irradiating the near-red light of a wavelength region on a wavelength side shorter than the boundary wavelength set based on the NVIS adaptation, and a second red light source 111 for irradiating the red light of a wavelength region on a wavelength side longer than at least the boundary wavelength, and further, includes a light source selection 70 which stops the irradiation light of the second light source section 111. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a display device and a display system for displaying an image, and more particularly to a display device and a display system that can visually recognize a subject using a night vision device at night or the like.

  The user of the display device may be wearing a night vision device in an aircraft or for special purposes such as security, crime prevention, and defense. (For example, refer patent document 1) Thereby, the user can also visually recognize the external world even under nighttime environments. A night vision device uses a faint amplification function of a photomultiplier tube. For example, it amplifies light in a wavelength region ranging from red visible light (red light) to near infrared light (infrared light). It is.

  Therefore, when the user of the display device observes the display device while wearing the night vision device, red light is included in the emission wavelength of the display device. May cause halation with infrared light. Therefore, a filter for blocking light having a wavelength longer than the wavelength causing halation is provided in the front stage of the night vision device, and light having a wavelength longer than a specific boundary wavelength (for example, 610 nm) is not emitted to the display device. By using the method, the light emitted from the display device is not amplified by the night vision device. As a result, the user of the display device can observe the display device while wearing the night vision device, and can also visually recognize the outside world in an environment such as at night.

  The details of such a method are stipulated in the US military standard MIL-STD-3009 (old standard MIL-L-85762). An apparatus conforming to this standard is called night vision apparatus compatibility or NVIS compatibility (Night Vision Imaging System Compatible). Specifically, in Class A (mainly targeted for rotary wing aircraft for examining the ground surface), the boundary wavelength is defined as approximately 610 nm, and in Class B (mainly targeted for fixed wing aircraft flying in the high sky), The boundary wavelength is defined as 635 nm, and in order to comply with NVIS, the total amount of light having a wavelength longer than the boundary wavelength (610 nm or 635 nm) (NVIS Radiance) must not exceed the specified value specified in the standard. .

  4 and 5 show the transmission characteristics of the optical filter that must be mounted inside the night vision apparatus corresponding to Class A and Class B, respectively. Since the wavelength range in which the night vision device performs light amplification is limited by this figure, the light emitted from the display device satisfying the NVIS conformity may be composed only of the wavelength region blocked by the filter in the night vision device. Desired.

  The reason why the boundary wavelength is generally described here is that MIL-STD-3009 is defined by a continuous weighting function (Table IV and V in the standard) and does not define a clear boundary wavelength. . Tables IV and V are shown as Table 1 and Table 2 below. In this document, the 5% point of the weight function value in Table I V and V is named as the prescribed boundary wavelength for the sake of convenience, and will be adopted thereafter.

  That is, the boundary wavelength (610 nm or 635 nm) belongs to a wavelength region from orange to red. Therefore, a pure red color cannot be expressed on a display device that is NVIS compatible. Therefore, since night vision devices are used only at night, a display device equipped with a light source capable of emitting light up to a long wavelength is used with the light source light as it is in the daytime, and when using a night vision device, it is longer than the boundary wavelength. A method of making a display device compatible with NVIS by inserting a filter that blocks light of a wavelength into the display device is generally performed.

  On the other hand, display devices are broadly classified into those using self-luminous elements typified by a plasma panel and those using elements that do not emit light themselves and use an illumination light source, such as liquid crystal panels. As a light source of a liquid crystal panel, a fluorescent lamp has been used so far. However, recently, an example using a light emitting diode has appeared.

  In addition to panel-type display devices, display devices such as rear-projection or front-projection projectors have begun to be introduced. Such a projector has an element called a micro display inside, and irradiates illumination light on the element, thereby forming an image and projecting it on a screen (display unit) with a projector optical system. Some microdisplays use non-self light emitting elements in addition to self light emitting elements such as EL (Electro-Luminescence) elements. Examples of non-self light emitting elements include transmissive liquid crystal elements, reflective LCOS (Liquid Crystal on Silicone), and reflective DMD (Digital Micromirror Device).

  In addition, as a light source used for a micro display of a non-self light emitting element, a discharge tube capable of condensing such as a metal halide lamp or an ultrahigh pressure mercury lamp has been used exclusively. In recent years, research on increasing the output of light emitting diodes and the development of laser light sources used for illumination light sources are progressing, and it is considered that they will replace discharge tubes in the future.

  FIG. 9 is a schematic configuration diagram showing an internal optical system of a conventional display device conforming to NVIS. The display device 101 includes a discharge tube 110 as a light source, a relay optical system including a dichroic mirror 121, transmissive liquid crystal elements 131, 132, and 133 corresponding to channels of each color, and a cross dichroic prism 140 that synthesizes video light of each color. A projection lens (projector optical system) 150 and a screen (display unit) 160. With such a configuration, first, the white light emitted from the discharge tube 110 is separated into three primary colors (red, green, and blue) by the dichroic mirror 121, and then a transmission type liquid crystal element that takes charge of each color channel. 131, 132, 133 are irradiated. Next, the image lights emitted from the transmissive liquid crystal elements 131, 132, and 133 are combined by the cross dichroic prism 140, and then projected onto the screen 160 via the projection lens 150, thereby displaying an image. Will be. At this time, by inserting a filter 107 at an appropriate location in the relay optical system at night, etc., the light having a wavelength longer than the boundary wavelength is blocked and the light having a wavelength longer than the boundary wavelength is removed from the image. is doing.

FIG. 10 is a schematic configuration diagram showing an internal optical system of another conventional display device conforming to NVIS. Unlike the display device 101 described above, the display device 151 changes the transmissive liquid crystal elements 131, 132, and 133 to reflective LCOS 181, 182, and 183. In addition, the same code | symbol is attached | subjected about the thing similar to the display apparatus 101. FIG. Even in such a configuration, in an environment such as nighttime, by inserting the filter 107 at an appropriate place in the relay optical system, light having a wavelength longer than the boundary wavelength is blocked, and the image having a wavelength longer than the boundary wavelength is blocked. The light is removed.
JP-A-7-151498

When the discharge tube 110 is used as a light source like the display devices 101 and 151, the discharge tube 110 generally emits white light. FIG. 6 is a diagram illustrating an example of emission spectrum intensity characteristics of the discharge tube 110. That is, as shown in FIG. 6, although there are unique peaks in some places, the wavelength distribution is spread over the entire visible light range.
On the other hand, when a light emitting diode is used as a light source in a display device, the light emitting diodes of the three primary colors are generally used separately, or they are collectively packaged and used as a white light source. FIG. 7 is a diagram showing emission spectrum intensity characteristics when the light emitting diodes of the three primary colors are combined. As shown in FIG. 7, the light emission distribution of the light emitting diodes of each color is a narrow region having a peak in each of the three primary colors, depending on the material and manufacturing method. Also, when a laser light source is used as a light source in a display device, generally, laser light sources of three primary colors are used separately, or they are packaged together and used as a white light source. FIG. 8 is a diagram showing emission spectrum intensity characteristics when the laser light sources of the three primary colors are combined. As shown in FIG. 8, the light emission distribution of the laser light source of each color becomes an extremely narrow region as it can be expressed as a single wavelength.

  Therefore, in a display device using a discharge tube or a broadband light emitting diode, light is emitted over a wide range of the red wavelength region, so even if light having a wavelength longer than the boundary wavelength is blocked, the display of the three primary colors is possible. It did not matter so much about color rendering. However, when using a laser light source or a narrow-band light emitting diode, for example, if a light source that emits only light having a light emission band longer than the boundary wavelength is used as a red light source, Almost all of the light emitted from the red light source is blocked by the filter, and the image cannot be expressed in the three primary colors. On the other hand, when using light that emits light having a wavelength shorter than the boundary wavelength, NVIS conformity can be achieved without being blocked by a filter. Since it is emitted, the color rendering properties of the three primary colors display in the daytime are inferior.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a display device that achieves NVIS conformity and has excellent color rendering properties for displaying three primary colors in the daytime.

The display device of the present invention, which has been made to solve the above problems, includes image light from a red display element illuminated by a red light source, image light from a blue display element illuminated by a blue light source, and a green light source. A display device that synthesizes image light from illuminated green display elements and displays a composite image of these three primary color image lights, wherein the red light source has a wavelength shorter than the boundary wavelength set based on NVIS compatibility A first red light source that irradiates near-red light in a wavelength region on the side, and a second red light source that irradiates red light in a wavelength region longer than the boundary wavelength, and further irradiates a second red light source A light source selection unit for stopping the light is provided.
Here, “NVIS conformity” is conformity with respect to the standard of the display device set to prevent halation from occurring when the display device is viewed using a night vision device. Of the light emitted from the display of the device, the total amount of light components having a wavelength longer than the boundary wavelength at which the low light amplification sensitivity of the night vision device occurs (referred to as NVIS Radiance) is defined by the standard (for preventing halation from occurring) It means adapting so as not to exceed the standard value. Specifically, for example, a display device conforming to the US military standard MIL-STD-3009 is a display device having NVIS compatibility. The boundary wavelength in this case is defined as 610 nm for Class A (mainly for rotary wing aircraft for examining the ground surface), and the boundary wavelength for Class B (mainly for fixed wing aircraft flying in the high sky). Is defined as 635 nm. Therefore, NVIS compatibility in this case means that the total amount of light (NVIS Radiance) longer than the boundary wavelength (610 nm or 635 nm) is zero or does not exceed the specified value defined in the standard. Say.

  As described above, “boundary wavelength set based on NVIS compatibility” is 610 nm or 635 nm when a display device conforming to MIL-STD-3009 is used. However, the present invention is not limited to this, and a value between 610 nm and 635 nm may be used as the boundary wavelength. In addition, when the standard is the same as MIL-STD-3009 and conforms to other NVIS compatibility standards, the boundary wavelength within the wavelength range from orange to red is determined by each standard. May be used.

  The “near red light” here is light whose emission wavelength is distinguished from “red light”, and is light in a wavelength region from orange to red emitted by a red light source. Light on the shorter wavelength side than the “boundary wavelength set based on the nature” is called “near red light”, and light on the longer wavelength side than the “boundary wavelength set based on the NVIS compatibility” is called “red light” (“ Also called “pure red light”.

According to the present invention, in the environment such as nighttime, only the first red light source, the blue light source, and the green light source are used by stopping the light emitted from the second red light source, and set based on NVIS compatibility. The display is performed by blocking light having a wavelength longer than the boundary wavelength defined in the wavelength range from the orange color to the red wavelength range, thereby preventing halation.
On the other hand, since the night vision device is not worn at daytime, the first red light source, the blue light source, and the green light source as well as the second red light source are turned on to display the three primary colors including pure red.

  According to the display device of the present invention, in the environment such as nighttime, by stopping the light emitted from the second light source, the color rendering property of the three primary colors display is secured while preventing halation from occurring in the night vision device. On the other hand, in the daytime, it is possible to achieve excellent color rendering of the three primary colors by emitting light from the second light source.

(Means and effects for solving other problems)
In the above invention, the boundary wavelength may be either 610 nm or 635 nm.
According to this, the display device conforms to the US military standard MIL-STD-3009 (610 nm conforms to Class A and 635 nm conforms to Class B), and the color rendering properties of the three primary colors are excellent during daytime use. A display device can be realized.

In the above invention, the first red light source and the second red light source are each composed of a laser light source, the first red light source oscillates laser light having a wavelength shorter than the boundary wavelength, and the second red light source has a wavelength longer than the boundary wavelength. The laser beam may be oscillated.
According to this, since the laser light source is a monochromatic light source, the first red light source emits laser light having a shorter wavelength than the boundary wavelength, and the second red light source has an oscillation wavelength longer than the boundary wavelength. By oscillating the laser light, it is possible to realize NVIS compatibility during night use and excellent color rendering during daytime use only by controlling the wavelength.

In the above invention, the first red light source and the second red light source are each composed of a light emitting diode, and the light emitting diode for the first red light source emits near-red light only on the shorter wavelength side than the boundary wavelength. You may make it have a characteristic.
According to this, since the light emitting diode of the first red light source can emit only near red light having a wavelength shorter than the boundary wavelength, a display device having NVIS compatibility can be realized without using a filter or the like. can do.

In the above invention, the first red light source and the second red light source are each composed of a light emitting diode, and the light emitting diode for the first red light source is near-red light in a wavelength region on the short wavelength side across the boundary wavelength, and A broadband light emitting characteristic that emits red light in the wavelength region on the long wavelength side and a filter for shielding light so that the total amount of red light having a longer wavelength side component than the boundary wavelength satisfies NVIS compatibility is provided. It may be.
According to this, even if the light emitting diode of the first red light source includes red light having a wavelength longer than the boundary wavelength, the display device having NVIS compatibility is obtained by shielding the wavelength longer than the boundary wavelength with the filter. Can be realized.

Another aspect of the display system of the present invention is a display system including a display device and a night vision device, and the night vision device has a wavelength longer than a boundary wavelength set in a red wavelength region. Provided with night vision mechanism that amplifies red light, display device illuminates with image light from red display element illuminated by red light source, image light from blue display element illuminated by blue light source, and green light source The image light from the green display element to be synthesized is displayed, and a composite image by these three primary color image lights is displayed, and as a red light source, near red light in a wavelength region shorter than the boundary wavelength is irradiated. And a second red light source that emits red light in a wavelength region longer than the boundary wavelength, and the display device further includes a light source selection unit that stops the irradiation light of the second red light source. Prepare for use in dark spaces The night vision is mounted to stop the second red light source, in use in a bright space so that night vision device is not installed by irradiating a second red light source.
According to the present invention, when the night vision device is used in a dark space, the second red light source is stopped and the night vision device is mounted, so that the display device can be visually recognized without causing halation. Further, since the second red light source is irradiated when the night vision device is not used in a bright space, it is possible to perform three primary color display with excellent color rendering.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited to the following embodiment, It cannot be overemphasized that various aspects are included in the range which does not deviate from the meaning of this invention.

<First embodiment>
FIG. 1 is a diagram illustrating a use state of a display device according to an embodiment of the present invention. FIG. 2 is a schematic configuration diagram showing the internal optical system of the display device according to the present invention. The display device 1 is visually recognized as it is during the daytime, and is visually recognized through the night vision device at nighttime.

The night vision device 2 has a night vision function by amplifying the amount of captured infrared light (wavelength of 610 nm or more). Accordingly, the user can visually recognize a subject that emits or reflects external infrared light even in an environment such as at night.
As the night vision device, for example, an imaging lens that captures light from a subject, a light amount adjustment unit that adjusts the amount of light to be captured, and a microchannel plate type that receives light captured from the imaging lens and converts the light into an optical image Image indentifier (hereinafter also referred to as MCP type II), coupling mechanism, MCP type I.I. An optical image output from I. is formed, and an image sensor that converts the optical image into an image signal is used.

  Next, the configuration of the display device 1 will be described. The display device 1 includes four types of laser light sources 11, 12, 13, and 111 having different laser light wavelengths as light sources, a dichroic mirror 21, transmissive liquid crystal elements 31, 32, and 33 corresponding to channels of each color, A cross dichroic prism 40 that synthesizes image light, a projection lens (projector optical system) 50, a screen (display unit) 60, and a light source selection unit 70 are provided.

  Examples of the laser light sources 11, 12, 13, and 111 include those manufactured by Novalux of the United States. The laser light source originally oscillates monochromatic light, but four types of laser light sources can be packaged together and used as a white light source. At this time, it is necessary to include a process of separating the three primary colors in the relay optical system.

  Here, laser light sources 11, 12, 13, and 111 that oscillate light corresponding to the three primary colors are separately provided, and the first red laser light source 11 and the second red laser light source 111 are red transmissive liquid crystal corresponding to the red channel. The green laser light source 13 emits a green transmissive liquid crystal element 33 corresponding to a green channel, and the blue laser light source 12 irradiates a blue transmissive liquid crystal element 32 corresponding to a blue channel.

As shown in FIG. 8, the second red laser light source 111 oscillates light having a pure red wavelength (for example, 650 nm). That is, the second red laser light source 111 oscillates light having a wavelength longer than the boundary wavelength 610 nm for NVIS conformity. On the other hand, the first red laser light source 11 oscillates light having an orange (near red) wavelength (for example, 600 nm). That is, the first red laser light source 11 oscillates light having a wavelength shorter than the boundary wavelength 610 nm for NVIS conformity.
The dichroic mirror 21 transmits light having a wavelength longer than a certain threshold wavelength and reflects light having a wavelength shorter than the threshold wavelength, or reflects light having a wavelength longer than the threshold wavelength and light having a wavelength shorter than the threshold wavelength. Is transparent. Here, the dichroic mirror 21 reflects light having a wavelength close to red (for example, 600 nm) and transmits light having a pure red wavelength (for example, 650 nm).
Therefore, the second red laser light source 111, the first red laser light source 11, and the dichroic mirror 21 are arranged such that the first red laser light source 11 is in the transmission position and the second red laser light source 111 is in the reflection position, as shown in FIG. The light emitted from the second red laser light source 111 and the first red laser light source 11 both irradiates the red transmissive liquid crystal element 31.

  As shown in FIG. 8, the green laser light source 13 oscillates light having a pure green wavelength (for example, 540 nm). Further, as shown in FIG. 8, the blue laser light source 12 oscillates light having a pure blue wavelength (for example, 480 nm). Therefore, the green laser light source 13 and the blue laser light source 12 oscillate light having a wavelength shorter than the boundary wavelength for NVIS conformity.

  The red transmissive liquid crystal element 31 forms a pattern corresponding to red, and forms image light having a pattern by transmission of light emitted from the first red laser light source 11 and the second red laser light source 111. . The green transmissive liquid crystal element 33 forms a pattern corresponding to green, and forms image light having a pattern by transmission of light emitted from the green laser light source 13. The blue transmissive liquid crystal element 32 forms a pattern corresponding to blue, and forms image light having a pattern by transmission of light emitted from the blue laser light source 12.

  The cross dichroic prism 40 is a cube made of a light-transmitting material having a square shape in plan view, and includes reflection surfaces 40a and 40b along two diagonal lines having a square cross-sectional shape. The reflection surface 40b is a dichroic mirror that reflects light having a wavelength less than the blue wavelength and transmits light having a wavelength greater than that, and the reflection surface 40a reflects light having a wavelength greater than or equal to the red wavelength. It is a dichroic mirror that transmits light of a wavelength. Therefore, the blue image light incident on the cross dichroic prism 40 is reflected by the reflection surface 40b, the red image light is reflected by the reflection surface 40a, and the green image light is transmitted through the reflection surfaces 40a and 40b, thereby blue light. , Red video light and green video light are combined and emitted from the cross dichroic prism 40 as combined light.

  The projection lens (projector optical system) 50 enlarges and transmits the combined light.

  The light source selection unit 70 includes, for example, a switch circuit using a CPU and CPU peripheral components, and emits light from the second red laser light source 111, the first red laser light source 11, the green laser light source 13, and the blue laser light source 12, respectively. Alternatively, control for switching whether or not to emit light is performed. At this time, for example, the control is executed by instructing with an input device (for example, a keyboard) (not shown).

Here, an example of how to use the display device of the present invention will be described (see FIG. 1).
(1) Daytime (see Fig. 1 (a))
First, the light source selection unit 70 performs control to emit light from the second red laser light source 111, the first red laser light source 11, the green laser light source 13, and the blue laser light source 12, respectively. That is, light is emitted from all of the second red laser light source 111, the first red laser light source 11, the green laser light source 13, and the blue laser light source 12. At this time, the user does not wear the night vision device 2.
Thus, the first red laser light source 11 and the second red laser light source 111 irradiate the red transmissive liquid crystal element 31 that forms a pattern corresponding to red, and the green laser light source 13 forms a pattern corresponding to green. The green transmissive liquid crystal element 33 is irradiated, and the blue laser light source 12 irradiates the blue transmissive liquid crystal element 32 that forms a pattern corresponding to blue.
Thereafter, the blue image light, the red image light, and the green image light incident on the cross dichroic prism 40 are combined and emitted from the cross dichroic prism 40 as combined light.
Therefore, the synthesized light is magnified by the projection lens 50 and displayed on the screen 60 as an image in the three primary colors, so that it is observed by the user. At this time, since the outside world is bright under the daytime environment or the like, the user can also visually recognize the outside subject without using the night vision device 2.

(2) At night (see Fig. 1 (b))
First, the light source selection unit 70 performs control to emit light from the first red laser light source 11, the green laser light source 13, and the blue laser light source 12. That is, light is not emitted from the second red laser light source 111. Further, the user wears the night vision device 2.
Thus, the first red laser light source 11 irradiates the red transmissive liquid crystal element 31 that forms a pattern corresponding to red, and the green laser light source 13 irradiates the green transmissive liquid crystal element 33 that forms a pattern corresponding to green. The blue laser light source 12 irradiates a blue transmissive liquid crystal element 32 that forms a pattern corresponding to blue.
Thereafter, the blue image light, the red image light, and the green image light incident on the cross dichroic prism 40 are combined and emitted from the cross dichroic prism 40 as combined light.
Therefore, the combined light is magnified by the projection lens 50 and displayed on the screen 60 as the three primary colors as an image, and NVIS conformance is achieved, so that the user wearing the night vision device 2 does not cause visual impairment. . At this time, since the user uses the night vision device 2 even in an environment such as at night, the user can visually recognize a subject in the outside world. Since the display on the screen 60 is a wavelength region outside the amplification sensitivity of the night-vision device 2, it can be seen as it is without going through the night-vision device.

  As described above, according to the display device 1 of the first embodiment, even if the laser light sources 11, 12, 13, and 111 are used as light sources, the light is emitted from the second red laser light source 111 in an environment such as nighttime. By stopping the light beam, it is possible to ensure the color rendering properties of the three primary colors while preventing the night vision device 2 from causing halation with the infrared light from the outside. On the other hand, in the daytime, the second red laser light source By emitting light from 111, an excellent color rendering property of the three primary colors can be realized.

<Second Embodiment>
FIG. 3 is a schematic configuration diagram showing an internal optical system of another display device according to the present invention. In the present embodiment, unlike the display device 1 described above, the display device 51 changes the transmissive liquid crystal elements 31, 32, and 33 to the reflective LCOS 81, 82, and 83, and the laser light sources 11, 12, 13, and 111 are changed. The light emitting diode light sources 61, 62, 63, and 131 are used. That is, the display device 51 combines four types of light emitting diode light sources 61, 62, 63, 131 as light sources, a dichroic mirror 21, reflective LCOSs 81, 82, 83 corresponding to each color channel, and video light of each color. A cross dichroic prism 40, a projection lens (projector optical system) 50, a screen (display unit) 60, and a light source selection unit 70. In addition, the same code | symbol is attached | subjected about the thing similar to the display apparatus 1. FIG.

  As the light emitting diode light sources 61, 62, 63, 131, those having narrow band emission characteristics are preferable. The light emitting diode light source originally oscillates light in a single color region, but four types of light emitting diode light sources can be packaged together and used as a white light source. At this time, it is necessary to include a process of separating the three primary colors in the relay optical system.

  Here, the light emitting diode light sources 61, 62, 63, and 131 that emit light corresponding to the three primary colors are separately provided, and the first red light emitting diode light source 61 and the second red light emitting diode light source 131 are red corresponding to the red channel. The reflective LCOS 81 is irradiated, the green light emitting diode light source 63 is irradiated with the green reflective LCOS 83 corresponding to the green channel, and the blue light emitting diode light source 62 is irradiated with the blue reflective LCOS 82 corresponding to the blue channel.

  The second red light emitting diode light source 131 emits light in an orange to pure red wavelength region (for example, 600 nm to 650 nm). That is, the second red light emitting diode light source 131 emits light including a wavelength longer than the boundary wavelength 610 nm for NVIS conformity. On the other hand, the first red light emitting diode light source 61 emits light in an orange (near red) wavelength region (for example, 580 nm to 620 nm). That is, the first red light emitting diode light source 61 emits light having a wavelength shorter than the boundary wavelength for NVIS conformity. When the element of the first red light emitting diode light source 61 includes a light component having a wavelength longer than the boundary wavelength of 610 nm, a filter capable of blocking light having a wavelength longer than the boundary wavelength is used in combination. As a result, it is possible to use even a light emission wavelength having a wide band and having a characteristic that crosses the boundary wavelength.

The dichroic mirror 21 reflects light in a near red wavelength region (for example, 580 nm to 620 nm) that is shorter than the boundary wavelength, and transmits light in a pure red wavelength region (for example, 620 nm to 650 nm). Is.
Therefore, the second red light-emitting diode light source 131, the first red light-emitting diode light source 61, and the dichroic mirror 21 are arranged as shown in FIG. All the light emitted from 61 irradiates the red reflective LCOS 81.

  As shown in FIG. 7, the green light emitting diode light source 63 emits light mainly in a green wavelength region (for example, 480 nm to 580 nm). In the case of a characteristic that crosses the boundary wavelength, a filter that cuts off the light on the long wavelength side may be used together as necessary. Further, as shown in FIG. 7, the blue light emitting diode light source 62 emits light in a pure blue wavelength region (for example, 425 nm to 480 nm). Therefore, the green light emitting diode light source 63 and the blue light emitting diode light source 62 emit light having a wavelength shorter than the boundary wavelength for NVIS conformity.

  The red reflection type LCOS 81 forms a pattern corresponding to red, and forms image light having a pattern by reflection of light emitted from the first red light emitting diode light source 61 and the second red light emitting diode light source 131. . The green reflective LCOS 83 forms a pattern corresponding to green, and forms image light having a pattern by reflection of light emitted from the green light emitting diode light source 63. The blue reflective LCOS 82 forms a pattern corresponding to blue, and forms image light having a pattern by reflection of light emitted from the blue light emitting diode light source 62.

  As described above, according to the display device of the second embodiment, even if the light-emitting diode light sources 61, 62, 63, 131 are used as the light source, the light is emitted from the second red light-emitting diode light source 131 in an environment such as nighttime. By stopping the light beam, it is possible to prevent halation in the night vision device. On the other hand, by emitting light from the second red light-emitting diode light source 131 in the daytime, excellent color rendering of the three primary colors is achieved. can do.

<Other embodiments>
The oscillation or emission wavelength of the laser light source or light emitting diode light source for the blue and green channels, which are the three primary color elements other than red, is arbitrary. The selection of the oscillation or emission wavelength of the red laser light source or the light emitting diode light source is only intended from the viewpoint of whether the wavelength is longer or shorter than the boundary wavelength, and is not particularly limited. Further, two or more types of red light sources may be used as red.
Of course, a front projection display may be used, and for example, a similar configuration may be used as a backlight light source of a liquid crystal panel.

  INDUSTRIAL APPLICABILITY The present invention can be used for a display device and a display system that can visually recognize a subject with a night vision device.

It is a figure which shows the use condition of the display apparatus (display system) which is one Embodiment of this invention. It is a schematic block diagram which shows the internal optical system of the display apparatus which concerns on this invention. It is a schematic block diagram which shows the internal optical system of the other display apparatus which concerns on this invention. It is a figure for demonstrating Class A of US military standard MIL-STD-3009. It is a figure for demonstrating Class B of US military standard MIL-STD-3009. It is a figure which shows the emission spectrum intensity | strength characteristic of a discharge tube. It is a figure which shows the emission spectrum intensity | strength characteristic of the light emitting diode of each of three primary colors. It is a figure which shows the oscillation spectrum intensity | strength characteristic of the laser light source of each of the three primary colors. It is a schematic block diagram which shows the internal optical system of the display apparatus made into the conventional NVIS conformity. It is a schematic block diagram which shows the internal optical system of the display apparatus made into another conventional NVIS conformity.

Explanation of symbols

1: Display device 2: Night vision device 11: First red laser light source 12: Blue laser light source 13: Green laser light source 21: Dichroic mirror 31, 32, 33: Transmission type liquid crystal element 40: Cross dichroic prism 50: Projection lens ( Projector optics)
70: Light source selection unit 60: Screen (display unit)
111: Second red laser light source

Claims (6)

These three primary colors are composed of image light from a red display element illuminated by a red light source, image light from a blue display element illuminated by a blue light source, and image light from a green display element illuminated by a green light source. A display device for displaying a composite image by the image light of
The red light source includes a first red light source that irradiates near red light in a wavelength region shorter than a boundary wavelength set based on NVIS compatibility, and red in a wavelength region that is at least longer than the boundary wavelength. A second red light source for irradiating light,
Furthermore, the display apparatus characterized by including the light source selection part which stops the irradiation light of a 2nd red light source. The display device according to claim 1, wherein the boundary wavelength is either 610 nm or 635 nm. The first red light source and the second red light source are each composed of a laser light source, the first red light source oscillates laser light having a wavelength shorter than the boundary wavelength, and the second red light source oscillates laser light having a wavelength longer than the boundary wavelength. The display device according to claim 1, wherein the display device is a display device. The first red light source and the second red light source are each composed of a light emitting diode, and the light emitting diode for the first red light source has a light emission characteristic of emitting near red light only on a shorter wavelength side than the boundary wavelength. Item 3. The display device according to Item 2. The first red light source and the second red light source are each composed of light emitting diodes, and the light emitting diodes for the first red light source are near red light in the short wavelength region and the long wavelength region with the boundary wavelength in between. A filter is provided for shielding light so that the total amount of red light having a longer wavelength component than the boundary wavelength satisfies NVIS compatibility. Or the display apparatus of Claim 2. A display system comprising a display device and a night vision device,
The night vision device includes a night vision mechanism that amplifies red light having a wavelength longer than the boundary wavelength,
The display device combines the image light from the red display element illuminated by the red light source, the image light from the blue display element illuminated by the blue light source, and the image light from the green display element illuminated by the green light source. And displaying a composite image of the image light of these three primary colors, and as a red light source, a first red light source that irradiates near red light in a wavelength region shorter than the boundary wavelength, and at least the boundary wavelength A second red light source that emits red light in the wavelength region on the long wavelength side, and the display device further includes a light source selection unit that stops the irradiation light of the second red light source,
A display system characterized in that when used in a dark space, the second red light source is stopped and the night vision device is mounted, and when used in a bright space, the second red light source is irradiated and the night vision device is not mounted.

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