WO2014002511A1

WO2014002511A1 - Rear-projection display device, rear-projection display system, and control method

Info

Publication number: WO2014002511A1
Application number: PCT/JP2013/050269
Authority: WO
Inventors: 藤男奥村
Original assignee: 日本電気株式会社
Priority date: 2012-06-25
Filing date: 2013-01-10
Publication date: 2014-01-03
Also published as: JPWO2014002511A1

Abstract

In the present invention, a laser projector engine (102) emits light. An angle switcher (103) alters the direction of progress of light and emits the result. Longitudinal scanning elements (105-107) scan incoming light, causing projection to a plurality of regions each differing at the rear surface of a screen (108). A control unit (109) switches the direction of progress of light altered by the angle switcher (103), and sequentially causes the light exiting the angle switcher (103) to enter each of the longitudinal scanning elements (105-107).

Description

Rear projection display device, rear projection display system, and control method

The present invention relates to a rear projection display device that projects light onto a screen from the back side and displays an image on the screen.

Projection-type display devices, unlike LCD (Liquid Crystal Display) and PDP (Plasma Display Panel), do not have a screen size determined by the size of the manufacturing equipment or panel substrate, so lowering the screen size is low. And can be done easily. For this reason, for example, by using a rear projection display device that projects light from the back of the screen, a large television or a large digital signage device can be easily manufactured at low cost.

Many of the projection display devices use an ultra-high pressure mercury lamp as a light source, such as a liquid crystal modulator such as a liquid crystal light valve, LCOS (Liquid Crystal on Silicon), or a DMD (Digital Micromirror Device) of TI. It has a configuration in which light from a light source is modulated and projected using a two-dimensional spatial modulator using MEMS technology.

In contrast, in recent years, a projection display device using a laser light source as a light source has been developed. Projection-type display devices that use laser light sources are attracting attention as future-proof display devices because they have better power efficiency and color reproducibility than projection-type display devices that use ultra-high pressure mercury lamps, LCDs, and PDPs. ing.

As a rear projection display device using a laser light source, for example, Mitsubishi Electric Corporation 75-LT1 (see Non-Patent Document 1), Prism Digital Signage Display Device (see Non-Patent Document 2), and Patents The rear projection display device described in Document 1 has been put to practical use or proposed.

The 75-LT1 projects a laser beam onto a screen using a DMD, and the digital signage display device and the rear projection display device described above use a scanning element such as a polygon mirror. It is scanned and projected onto the screen. In addition, the display device for digital signage is provided with a mechanism capable of configuring a large screen by assembling a plurality of devices so that blocks are stacked.

JP 2008-033039 A

The rear projection display device using a laser light source such as the 75-LT1, the digital signage display device, and the rear projection display device is configured to return the laser beam from the laser light source using a mirror or the like. The depth is narrowed as much as possible, but the depth is still not enough.

For example, in the case of an LCD or PDP of about 60 type, the depth of the panel body can be about 4 cm. However, when the LCD or PDP is placed on a TV stand or the like, a stand for holding the LCD or PDP is required, so that the entire apparatus has a depth of several tens of centimeters. In addition, when the LCD or PDP is installed on a wall or the like, it is necessary to create a gap between the wall and the panel body for heat dissipation, so that the entire apparatus has a depth of about 10 cm.

On the other hand, for example, 75-LT1 of Mitsubishi Electric Co., Ltd. is 75 type and has a depth of 38 cm, and the display device for digital signage of Primsm has a depth of 36 cm even if it is a small type of 29 type. Also become.

As described above, the rear projection type display device has a problem that the installation location is limited due to the deep depth. For this reason, LCDs and PDPs are employed in many large televisions and large digital signage instead of rear projection display devices that can be easily manufactured at low cost.

Hereinafter, with reference to FIG. 10, a description will be given of the cause of a common problem occurring in a rear projection display device using a laser light source that the depth cannot be sufficiently narrowed.

10 includes a casing 1001, a light source 1002, a DMD 1003, a projection lens 1004, a free-form curved mirror 1005, a mirror 1006, and a screen 1007.

As shown in FIG. 10, the rear projection type display device projects a laser beam emitted from the DMD twice using a free-form curved mirror 1005 and a mirror 1006 in order to project a laser beam from a small DMD 1003 to a large screen 1007. It is folded and projected on the screen 1007.

At this time, the laser beam is projected obliquely with respect to the screen 1007. However, if the depth is narrowed, the incident angle of the laser beam with respect to the screen 1007 increases, and the image is distorted.

The rear projection display device shown in FIG. 1 uses a free-form surface mirror 1005 as a mirror for folding the light beam, thereby reducing the incident angle of the laser beam on the screen 1007 and correcting image distortion. Note that the greater the image distortion, the greater the number of correction optical systems for correcting the distortion, such as the free-form curved mirror 1005. For example, for the projection lens 1004, a free-form surface lens or an aspheric lens that is a correction optical system may be used.

However, since there is a limit to distortion correction using the correction optical system, if the depth is narrowed to some extent, the incident angle of the laser beam with respect to the screen 1007 becomes too large and image distortion may not be eliminated. For this reason, in order to display an image without distortion, the depth of the 70-inch size can only be reduced to about 20 cm or less.

In addition, the free-form surface optical system used as the correction optical system has a problem that it is difficult to design and a problem that the price becomes very high.

Furthermore, in order to eliminate image distortion using a free-form surface optical system, there is a problem that an extra area called a skirt portion 1008 is generated under the screen 1007.

In the display device for digital signage, the skirt portion is configured behind the screen, so that the devices can be stacked. However, as a result, the depth is increased, and as described above, the 29-inch compact size is achieved. Regardless of the device, the depth is as high as 36 cm.

In the rear projection display device described in Patent Document 1, the depth is narrowed by lengthening the mirror 1006, but there is a limit to this, and the mirror 1006 is applied to a free-form surface optical system.

An object of the present invention is to provide a rear projection display device, a rear projection display system, and a projection method capable of easily reducing the depth at low cost.

A rear projection display device according to the present invention uses a screen, a light emitting unit that emits light, a deflecting unit that changes the traveling direction of the light, and the deflecting unit to change the traveling direction of the light into a plurality of predetermined directions. And a plurality of scanning units that scan each light emitted in each predetermined direction and project the light onto a plurality of different regions on the back surface of the screen.

The rear projection display system according to the present invention includes a plurality of rear projection display devices, and the rear projection display devices are arranged in parallel.

The projection method according to the present invention includes a screen, a light emitting unit that emits light, a deflecting unit that emits light by changing a traveling direction of the light, and a plurality of different regions on the back surface of the screen by scanning incident light. A rear projection display device having a plurality of scanning units that project light onto the rear projection type display device, wherein the deflection unit changes the traveling direction of the light, and the light emitted from the deflection units is transmitted to the plurality of scanning units. A control method that makes each incident in order.

According to the present invention, the depth can be easily reduced at low cost.

It is a figure which shows the structure of the rear projection type display apparatus which is related technology. It is a figure which shows the structure of the rear projection type display apparatus of the 1st Embodiment of this invention. It is a figure which shows an example of a rear projection type display system. It is a figure for demonstrating switching of the advancing direction of light. It is a timing chart for demonstrating the operation | movement which switches the advancing direction of light. It is a figure which shows the structure of the laser projector engine and angle switch of the 2nd Embodiment of this invention. It is a figure which shows the structure of the laser projector engine and angle switch of the 3rd Embodiment of this invention. It is a figure which shows the structure of the elongate scanning element of the 4th Embodiment of this invention. It is a timing chart for demonstrating the operation | movement which drives the elongate scanning element of the 4th Embodiment of this invention. It is a figure which shows the structure of the rear projection type display apparatus of the 5th Embodiment of this invention. It is a figure which shows the structure of the rear projection type display apparatus of the 6th Embodiment of this invention. It is a figure which shows the structure of the rear projection type display apparatus of the 7th Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, components having the same function may be denoted by the same reference numerals and description thereof may be omitted.

(First embodiment)
FIG. 2A is a diagram showing a configuration of a rear projection display device according to the first embodiment of the present invention. Specifically, FIG. 2A (a) is a front transparent view of the rear projection display device of the present embodiment, and FIG. 2A (b) is a longitudinal sectional view of the rear projection display device of the present embodiment. .

2A includes a housing 101, a laser projector engine 102, an angle switch 103, a magnifying optical system 104, a long scanning element 105 to a long scanning element 107, a screen 108, and the like. And a control unit 109.

The housing 101 houses a laser projector engine 102, an angle switch 103, a magnifying optical system 104, long scanning elements 105 to 107, a screen 108, and a control unit 109. Note that the front surface of the screen 108 is exposed from the housing 101.

The laser projector engine 102 is a light emitting unit that emits a laser beam as light. Specifically, the laser projector engine 102 emits a linear beam whose cross-sectional shape is a linear laser beam, or a point beam whose cross-sectional shape is a point-like laser beam as a resonance mirror. It has the structure which scans with a scanning element and radiate | emits.

As will be described later, the laser projector engine 102 emits a laser beam modulated according to the input video signal. Moreover, the arrow in a figure has shown the advancing direction which a laser beam advances.

The angle switch 103 is a deflection unit that changes the traveling direction of the laser beam emitted from the laser projector engine 102. For example, the angle switch 103 has a mirror, and reflects the laser beam with the mirror to change the traveling direction of the laser beam.

The magnifying optical system 104 is an optical system for magnifying the projection area on the screen 108, and is arranged on the optical path from the laser projector engine 102 to the screen 108.

Specifically, when the laser beam is a linear beam, the expansion optical system 104 expands the cross-sectional shape of the linear beam in the width direction. When the laser beam is a dot beam, the magnifying optical system 104 deflects the dot beam so that the scanning amplitude of scanning by the scanning element of the laser projector engine 102 is apparently enlarged.

In either case, as the magnifying optical system 104, an easy-to-design fθ lens used for a laser printer or the like can be used, and it is not necessary to use an expensive free-form surface lens that is difficult to design. In this embodiment, the magnifying optical system 104 is disposed on the optical path from the angle switch 103 to the long scanning elements 105 to 107.

Each of the long scanning elements 105 to 107 is a scanning unit that displays an image on the screen 108 by scanning incident light in the first scanning direction and projecting the incident light on a plurality of different areas on the back surface of the screen 108. is there.

The first scanning direction is a direction that intersects the second scanning direction (or the width direction of the linear beam) in which the scanning element of the laser projector engine 102 scans the dotted beam. For this reason, the magnifying optical system 104 enlarges the length of the projection region in the direction intersecting the first scanning direction.

In this embodiment, the first scanning direction is the vertical direction, and the long scanning elements 105 to 107 are arranged in parallel in the vertical direction. Therefore, the area of the screen 108 on which the laser beam is projected by each of the long scanning elements 105 to 107 is also arranged in the vertical direction.

Further, the long scanning elements 105 to 107 include, for example, a long mirror that is long in the second scanning direction (or the width direction of the linear beam), and the laser beam is emitted by swinging the long mirror. Scan.

The screen 108 displays an image corresponding to the laser beam projected from the long scanning elements 105 to 107, and is appropriately selected according to the laser beam or the like.

For example, when the laser beam includes light of three primary colors of red, green, and blue, the screen 108 is a normal screen that diffuses and transmits the laser beam. In addition, when the laser beam is light having a wavelength of about 405 nm used in an optical disk drive or the like, the screen 108 is a fluorescent light having phosphor regions that generate red, green, and blue light using the laser beam as excitation light. It becomes a screen. When the laser beam is blue light, the screen 108 may have a region that diffuses and transmits the laser beam and a phosphor region that generates red and green using the laser beam as excitation light.

The control unit 109 controls the entire rear projection display device.

For example, the control unit 109 drives the laser projector engine 102 in accordance with the input video signal input, and emits a laser beam modulated in accordance with the input video signal from the laser projector engine 102.

Further, the control unit 109 switches the traveling direction of the laser beam changed by the angle switch 103 according to the input video signal, and sequentially turns the light emitted from the angle switch 103 to each of the long scanning elements 105 to 107. To enter. Then, the control unit 109 drives the long scanning elements 105 to 107 in accordance with the input video signal to cause the long scanning elements 105 to 107 to scan with the laser beam.

At this time, the control unit 109 switches the traveling direction of the laser beam so that the laser beam is incident on all the long scanning elements 105 to 107 for each frame of the input video signal. One large screen can be formed by connecting the images displayed by each of 105 to 107. The position of the long scanning elements 105 to 107, the scanning amplitude of scanning by the long scanning elements 105 to 107, and the like are set in a space on the screen 108 where the laser beams are projected by the long scanning elements 105 to 107. It is desirable to design so that there is no.

Note that a plurality of rear projection display devices described above may be arranged in parallel to constitute a rear projection display system.

FIG. 2B is a diagram illustrating an example of a rear projection display system. 2B, the rear projection display system includes nine rear projection display devices 1, and the rear projection display devices 1 are arranged in a 3 × 3 matrix. Note that the number and arrangement of the rear projection display device 1 are not limited to those shown in FIG. 2B and can be changed as appropriate.

Next, the operation of the rear projection display device will be described.

First, the control unit 109 drives the laser projector engine 102 according to the input video signal, and causes the laser projector engine 102 to emit a laser beam modulated according to the input video signal. The traveling direction of the laser beam emitted from the laser projector engine 102 is changed by the angle switch 103 and is incident on one of the long scanning elements 105 to 107 via the magnifying optical system 104. The long scanning elements 105 to 107 on which the laser beam is incident scan the laser beam and project it onto the screen 108.

Here, the control unit 109 switches the traveling direction of the laser beam, which is changed by the angle switch 103, in stages, and causes the laser beam to enter each of the long scanning elements 105 to 107 in order.

Hereinafter, the switching timing for switching the traveling direction will be described in more detail with reference to FIGS. 3A and 3B.

FIG. 3A shows an example of the angle switch 103 and the magnifying optical system 104.

In FIG. 3A, the angle switch 103 is constituted by a mirror. The magnifying optical system 104 includes a plurality of optical systems 104A to 104C corresponding to the long scanning elements 105 to 107, respectively. Each of the optical systems 104A to 104C is disposed on the optical path from the angle switch 103 to the long scanning element corresponding to the own optical system.

The control unit 109 adjusts the direction of the mirror of the angle switch 103 so that the laser beam 201 reflected by the mirror is sequentially incident on each of the long scanning elements 105 to 107 via the optical systems 104A to 104C. Next, the traveling direction of the laser beam is switched.

FIG. 3A shows a state in which the traveling direction of the laser beam 201 faces the long scanning element 105 (optical system 104A). Hereinafter, for convenience, this state is referred to as state A, the state in which the traveling direction of the laser beam 201 faces the long scanning element 106 (optical system 104B) is referred to as state B, and the traveling direction of the laser beam 201 is the long scanning element 107. The state facing the (optical system 104C) is defined as state C.

In FIG. 3A, in order to make the relationship between the magnifying optical system 104 and the long scanning elements 105 to 107 easier to understand, the magnifying optical system 104 is separated into optical systems 104A to 104C. It may be composed of one continuous optical system.

FIG. 3B is a timing chart for explaining the switching timing of the traveling direction of the laser beam. Note that the control unit 109 switches the traveling direction of the laser beam in the order of states A, B, and C within one frame of the input video signal.

First, in the first period 202 of one frame of the input video signal, the control unit 109 adjusts the direction of the mirror of the angle switch 103 and sets the traveling direction of the laser beam to the state A. Subsequently, in the period 203, the control unit 109 drives the long scanning element 105 while keeping the traveling direction of the laser beam in the state A, and causes the long scanning element 105 to scan the laser beam, whereby the laser beam is scanned. Is projected onto the first area on the back of the screen 108.

Thereafter, in the period 204, the control unit 109 adjusts the direction of the mirror of the angle switch 103 to switch the traveling direction of the laser beam from the state A to the state B. Subsequently, in the period 205, the control unit 109 drives the long scanning element 106 while keeping the traveling direction of the laser beam in the state B, and causes the long scanning element 106 to scan the laser beam, whereby the laser beam is scanned. Is projected onto the second area of the back surface of the screen 108.

In the period 206, the control unit 109 adjusts the direction of the mirror of the angle switch 103 to switch the traveling direction of the laser beam from the state B to the state C. Subsequently, in the period 207, the control unit 109 drives the long scanning element 107 while keeping the traveling direction of the laser beam in the state C, and causes the long scanning element 107 to scan the laser beam, whereby the laser beam is scanned. Is projected onto the third area on the back of the screen 108.

Thereby, a large screen over the first area, the second area, and the third area can be formed.

As described above, according to the present embodiment, it is possible to divide and form a screen image using a plurality of scanning units, so that the incident angle of the laser beam with respect to the screen 108 can be reduced. . For this reason, an image without distortion can be realized by an apparatus having a small depth, and the depth can be reduced. In addition, since it is not necessary to use an expensive member that is difficult to design, such as a free-form curved mirror, the depth can be easily reduced at low cost.

Note that the depth of the depth depends on the size of the projection area formed by the long scanning elements 105 to 107, but it is possible to form a screen of about 60 inches with a depth of about 10 cm.

Also, the number of laser projector engines 102 is the same as that of the rear display device shown in FIG. Further, since the laser projector engine 102 can be provided at a position below the long scanning elements 105 to 107 behind the screen 108, an extra portion such as the skirt portion 1008 of the rear display device shown in FIG. There is no need to provide a region.

Therefore, when arranging a plurality of rear display devices side by side as shown in FIG. 2B, it is not necessary to consider the skirt portion in order to arrange the screens 108 of the respective rear display devices without gaps. Such restrictions can be reduced. For this reason, as long as the restrictions on the strength of the holding member that holds the rear display device are satisfied, a large number of rear display devices can be arranged side by side, and a large screen can be formed. At this time, a large screen common to the respective rear display devices may be used as the screen 108. In this case, it is possible to make the joints of the images displayed by the respective rear display devices more inconspicuous.

Further, in the present embodiment, since the magnifying optical system 104 is provided, the screen can be enlarged in the direction intersecting with the scanning direction of the scanning by the long scanning elements 105 to 107.

(Second Embodiment)
In the present embodiment, specific examples of the laser projector engine 102 and the angle switch 103 will be described.

FIG. 4 is a diagram showing the laser projector engine 102 and the angle switch 103 according to the present embodiment. In FIG. 4, the laser projector engine 102 includes a laser light source 301, a polarizing prism 302, and a one-dimensional spatial modulation element 303. In addition, the angle switch 103 includes a servo motor 304 and a mirror 305.

The laser light source 301 emits a linear beam. Note that when the rear projection display device has a large screen, the laser light source 301 requires a light source with a large output power. In this case, the laser light source 301 can be composed of a laser array in which a plurality of laser elements are arranged in parallel, and a shaping optical system that optically shapes the laser beam from each laser element and emits it as a linear beam. it can.

The polarizing prism 302 reflects the linear beam from the laser light source 301 and guides it to the one-dimensional spatial modulation element 303, and further transmits the linear beam from the one-dimensional spatial modulation element 303.

The modulation drive signal for modulating the linear beam is input from the control unit 109 to the one-dimensional spatial modulation element 303. The one-dimensional spatial modulation element 303 modulates and emits the linear beam from the polarizing prism 302 according to the input modulation drive signal.

The type of the one-dimensional spatial modulation element 303 is not particularly limited, but FIG. 4 shows a reflective one-dimensional spatial modulation element as the one-dimensional spatial modulation element 303. In this case, as the one-dimensional spatial modulation element 303, for example, a one-dimensional LCOS element is used. Although the optical characteristics of the one-dimensional spatial modulation element 303 are complicated, a grating light valve developed by Sony Corporation or a device developed by Aloes in the United States (D. Bloom, et. Al. "MEMS-Based Polarization Light Modulator Linear Array Microdisplay, IDW'09, pp.1497-1500, 2009) may be used. Further, the one-dimensional spatial modulation element 303 may be a transmission type one-dimensional spatial modulation element. In this case, as the one-dimensional spatial modulation element 303, for example, a one-dimensional liquid crystal element is used.

The control unit 109 outputs a linear beam modulated according to the input video signal to the one-dimensional spatial modulation element 303 by inputting the modulation drive signal corresponding to the input video signal to the one-dimensional spatial modulation element 303. I am letting.

The servo motor 304 of the angle switch 103 is connected to the mirror 305, and changes the direction of the mirror 305 by rotating the mirror 305 according to the drive signal from the control unit 109.

In the example of FIG. 4, the control unit 109 uses the servo motor 304 to adjust the direction of the mirror 305 to switch the traveling direction of the linear beam emitted from the angle switch 103. Specifically, the control unit 109 sends a drive signal to the servo motor 304 so that the traveling direction of the linear beam is sequentially switched to the states A to C at the switching timing shown in FIG. 3B according to the input video signal. The direction of the mirror 305 is adjusted by inputting.

In the example of FIG. 4, the servo motor 304 is illustrated as a drive unit that changes the direction of the mirror 305 of the angle switch 103. However, instead of the servo motor 304, a galvanometer or a DC drive type is used as the drive unit. A driving device that drives the scanning mirror may be used.

In the laser projector engine 102 and the angle switch 103 configured as described above, the linear beam output from the laser light source 301 is reflected by the polarizing prism 302 and enters the one-dimensional spatial modulation element 303. The linear beam incident on the one-dimensional spatial modulation element is modulated and reflected, passes through the polarizing prism 302, and enters the mirror 305 whose direction is adjusted by the servo motor 304. The traveling direction of the linear beam is changed by the mirror 305 and is incident on the long scanning elements 106 to 109 via the magnifying optical system 104.

(Third embodiment)
In the present embodiment, another specific example of the laser projector engine 102 and the angle switch 103 will be described.

FIG. 5 is a diagram showing the configuration of the laser projector engine 102 and the angle switch 103 according to this embodiment. In FIG. 5, the laser projector engine 102 includes laser elements 401 to 403, a mirror 404,

dichroic prisms

405 and 406, and a resonant scanning element 407. Further, the angle switch 103 includes a servo motor 408 and a lens 409.

Laser elements 401 to 403 emit red, green, and blue dot beams, respectively. More specifically, the control unit 109 inputs a light emission control signal indicating the intensity and period of the dotted beam emitted from the laser elements 401 to 403 to the laser elements 401 to 403 in accordance with the input video signal. The laser elements 401 to 403 emit red, green, and blue dot beams corresponding to the input light emission control signal, thereby emitting dot beams modulated according to the input video signal.

The mirror 404 reflects the red dot beam from the laser element 401. The dichroic prism 405 transmits the red dot beam reflected by the mirror 404 and reflects the green dot beam from the laser element 402. The dichroic prism 406 transmits the red and green dot beams from the dichroic prism 405 and reflects the blue dot beam from the laser element 403.

Note that the laser elements 401 to 403, the mirror 404, and the

dichroic prisms

405 and 406 are arranged so that the optical axes of the dot beams of the respective colors emitted from the dichroic prism 406 coincide. As a result, the dichroic prism 406 emits one dot beam in which the red, green, and blue dot beams are combined.

The resonant scanning element 407 scans and emits the point beam from the dichroic prism 406 in the second scanning direction. Note that, as described above, the second scanning direction is a direction that intersects the first scanning direction of scanning by the long scanning elements 105 to 107, and is, for example, a horizontal direction.

The laser projector engine 102 described above has the same configuration as a general scanning projection display device.

Further, as described in the first embodiment, a phosphor that generates red, green, and blue light for each pixel is provided on the screen 108 using a monochromatic laser beam (for example, wavelength 405 nm). It is also possible to use a blue laser beam or a phosphor provided with a phosphor that generates only red and green. In such a case, there is no need to use a plurality of laser elements that emit light of different colors, such as the laser elements 401 to 403, or a synthetic optical system such as the mirror 404 and the

dichroic prisms

405 and 406. It is only necessary to provide a monochromatic laser element.

The servo motor 408 of the angle switch 103 is connected to the lens 409 and changes the direction of the lens 409 by rotating the lens 409 in accordance with a drive signal from the control unit 109.

In the example of FIG. 5, the control unit 109 uses the servo motor 408 to adjust the direction of the lens 409 to switch the traveling direction of the point beam emitted from the angle switch 103. Specifically, the control unit 109 sends a drive signal to the servo motor 408 according to the input video signal so that the traveling direction of the dotted beam is sequentially switched to the states A to C at the switching timing shown in FIG. 3B. The direction of the lens 409 is adjusted by inputting.

In the example of FIG. 5, the servo motor 408 is illustrated as a lens driving unit that changes the direction of the lens 409 of the angle switch 103. However, instead of the servo motor 408, a galvanometer or DC driving is used as the lens driving unit. A driving device for driving a type of scanning mirror may be used.

Further, the laser projector engine 102 described in the third embodiment may be combined with the angle switch 103 described in the second embodiment, the laser projector engine 102 described in the second embodiment, The angle switch 103 described in the third embodiment may be combined.

(Fourth embodiment)
In the present embodiment, an example of the configuration of the long scanning elements 105 to 107 will be described. Since the long scanning elements 105 to 107 can all have the same configuration, the configuration of the long scanning element 105 is illustrated here.

FIG. 6 is a diagram showing a configuration of the long scanning element 105 of the present embodiment. In FIG. 6, the long scanning element 105 includes a servo motor 501 and a long mirror 502.

The servo motor 501 is connected to the long mirror 502, and scans the laser beam by vibrating the long mirror 502 in accordance with the scanning drive signal from the control unit 109.

FIG. 7 is a timing chart for explaining the control operation of the long scanning elements 105 to 107 by the control unit 109. In FIG. 7, it is assumed that the control unit 109 switches the traveling direction of the laser beam at the timing shown in FIG. 3B.

First, in the period 203, the control unit 109 inputs a scanning drive signal to the long scanning element 105 and changes the angle of the long mirror 502 of the long scanning element 105, whereby the long scanning element 105. Is scanned with a laser beam.

Thereafter, in the period 205, the control unit 109 inputs a scanning drive signal to the long scanning element 106 and changes the angle of the long mirror 502 of the long scanning element 106, whereby the long scanning element 106 is changed. Is scanned with a laser beam.

Then, in the period 206, the control unit 109 inputs a scanning drive signal to the long scanning element 107 and changes the angle of the long mirror 502 of the long scanning element 107, whereby the long scanning element 107. Is scanned with a laser beam.

In the operation described above, there is a return period 601 to 603 in which scanning is not performed after scanning the laser beam for each of the long scanning elements 105 to 107 until the next scanning with the laser beam. In the present embodiment, since there are three long scanning elements, the return periods 601 to 603 are almost twice as long as the scanning period in which scanning is performed, so the control unit 109 sets the long scan elements to the return periods 601 to 603. It is possible to ensure a sufficient time for accurately returning the angles of the scanning elements 105 to 107 to the starting angle when starting scanning.

In the example of FIG. 6, the servo motor 501 is illustrated as a scanning drive unit that vibrates the long mirror 502 of the long scanning element 105, but instead of the servo motor 501, a galvanometer or the like is used as the scanning drive unit. A driving device that drives a DC-driven scanning mirror may be used.

(Fifth embodiment)
FIG. 8 is a diagram showing the configuration of the rear projection display device of the present embodiment, and specifically, is a longitudinal sectional view of the rear projection display device of the present embodiment.

8 includes a folding mirror 701 to 704 in addition to the configuration of the rear projection display device of the first embodiment shown in FIG. 2A.

The folding mirrors 701 to 704 are reflection mirrors that reflect the laser beam emitted from the angle switch 103 and guide it to the long scanning elements 105 to 107.

The folding mirrors 701 and 702 are reflection mirrors for guiding the laser beam to the long scanning element 106. Specifically, the folding mirror 701 reflects the laser beam emitted in the first direction from the angle switch 103, and the folding mirror 702 reflects the laser beam reflected by the folding mirror 701, and is long. Incident on the scanning element 106.

The folding mirrors 703 and 704 are reflection mirrors for guiding the laser beam to the long scanning element 105. Specifically, the folding mirror 703 reflects the laser beam emitted in the second direction from the angle switch 103, and the folding mirror 704 reflects the laser beam reflected by the folding mirror 703, and is long. Incident on the scanning element 105.

According to this embodiment, since the folding mirrors 701 to 704 are provided, the switching angle for switching the angles of the mirror 305 and the lens 409 of the angle switch 103 in order to adjust the orientation of the mirror 305 and the lens 409 of the angle switch 103. Can be reduced.

For example, when the rear display device of the present embodiment is applied to a 60-inch display device having an aspect ratio of 16: 9, which is common in current televisions, the vertical length of the rear display device is about 75 cm. Become. At this time, assuming that the depth of the rear display device is 10 cm, when there are no folding mirrors 701 to 704, the difference in the incident angle of the laser beam with respect to the

long scanning elements

105 and 107 is about 23 °. On the other hand, when there are the folding mirrors 701 to 704, the difference in the incident angle can be about 15 °. Therefore, by providing the folding mirrors 701 to 704, the switching angle can be increased 2/3 times. It is assumed that the long scanning elements 105 to 107 are arranged at equal intervals.

Also, since the switching angle can be reduced, the switching operation time of the angle switch 103 for switching the traveling direction of the laser beam can be shortened. Therefore, as can be seen from FIG. 3B, it is possible to lengthen the display time for displaying an image and improve the luminance of the display image.

For example, in a general display device that refreshes the screen at 60 Hz, one frame time is 16.7 milliseconds. In the absence of the folding mirrors 701 to 704, the

image scanning periods

203, 205, and 207 in which the long scanning elements 105 to 107 display images are 4 milliseconds, respectively, and the

switching operation periods

202 and 204 of the angle switch 103 are performed. And 206 are each about 1.5 milliseconds. In this case, by providing the folding mirrors 701 to 704, the switching

operation periods

202, 204, and 206 can be set to about 1 millisecond, and the

image scanning periods

203, 205, and 207 can be set to 4.5 milliseconds. In this case, the luminance of the display image can be improved by about 11%.

(Sixth embodiment)
In the present embodiment, another configuration of the rear projection display device will be described.

FIG. 9 is a diagram showing a configuration of the rear projection type display device of the present embodiment, and specifically, a cross-sectional view of the rear projection type display device as seen from above.

The rear projection type display device shown in FIG. 9 has a concave curved surface type case 801 instead of the case 101, as compared with the rear projection type display device of the first embodiment shown in FIG. Instead of 108, a screen 803 having a concave curved surface shape is provided. In addition, the rear projection display device illustrated in FIG. 9 further includes a folding mirror 802.

In the first embodiment, the long scanning elements 105 to 107 are arranged in parallel in the vertical direction and scan the laser beam in the vertical direction. In the present embodiment, however, the long scanning elements 105 to 107 are These are arranged in parallel in the horizontal direction and scan the laser beam in the horizontal direction.

The folding mirror 802 is a reflection mirror that reflects the laser beam emitted from the angle switch 103 toward the long scanning element 105 and guides it to the long scanning element 105.

The rear projection type display device having the concave curved screen 803 described in the present embodiment is suitable as a monitor for a desktop PC (Personal computer), for example. For example, when the user wants to view each position of a wide screen from the front as much as possible, a plurality of monitors are arranged in a fan shape. In the rear projection display device of this embodiment, a single device is wide. The screen can be viewed from the front.

In the rear projection display device of this embodiment, there is no need for an extra area such as the skirt portion 1008 shown in FIG. 1, and therefore, a plurality of rear surfaces are provided as in the rear display system shown in FIG. 2B. A rear display system in which projection display devices are arranged side by side can be configured. In this case, it becomes possible for a person to enter the back-side display system configured in a cylindrical shape to visually recognize the image, and to make the person feel immersive.

(Seventh embodiment)
In the present embodiment, another configuration of the rear projection display device will be described.

FIG. 10 is a diagram showing a configuration of the rear projection type display device of the present embodiment, specifically, a cross-sectional view of the rear projection type display device as seen from above.

The rear projection display device shown in FIG. 10 has a convex curved housing 901 instead of the housing 101 as compared with the rear projection display device of the first embodiment shown in FIG. Instead of 108, a screen 905 having a convex curved surface shape is provided. Further, the rear projection type display device shown in FIG. 10 further includes folding mirrors 902 to 904.

In the present embodiment, as in the sixth embodiment, the long scanning elements 105 to 107 are arranged in parallel in the horizontal direction and scan the laser beam in the horizontal direction.

The folding mirrors 902 to 904 are reflection mirrors that reflect the laser beam emitted from the angle switch 103 and guide it to the long scanning elements 105 to 107.

The folding mirrors 902 and 903 are reflection mirrors for guiding the laser beam to the long scanning element 106. Specifically, the folding mirror 902 reflects the laser beam emitted in the third direction from the angle switch 103, and the folding mirror 903 reflects the laser beam reflected by the folding mirror 902, and is long. Incident on the scanning element 106.

The folding mirror 904 is a reflection mirror for guiding the laser beam to the long scanning element 105. Specifically, the folding mirror 904 reflects the laser beam emitted from the angle switch 103 in the fourth direction and enters the long scanning element 105.

9 and 10 is an example of a rear display device having a curved screen, and a folding mirror required for directing the laser beam to the long scanning elements 105 to 107. The number and the position of the display vary depending on specifications such as the shape and size of the rear display device. Further, in the rear display device having the convex curved screen 905, the switching angle of the angle switch 103 can be made extremely small as shown in FIG.

The rear display device of the present embodiment is suitable for a digital signage device disposed around a cylindrical column. In the rear projection display device of this embodiment, there is no need for an extra area such as the skirt portion 1008 shown in FIG. 1, and therefore, a plurality of rear surfaces are provided as in the rear display system shown in FIG. A rear display system in which projection display devices are arranged side by side can be configured. In this case, it is possible to configure a rear display system surrounding the cylinder.

In each of the embodiments described above, the illustrated configuration is merely an example, and the present invention is not limited to the configuration.

In addition, a part or all of each of the above embodiments can be described as in the following supplementary notes, but is not limited to the following.

[Appendix 1]
Screen,
A light emitting portion for emitting light;
A deflection unit that emits light by changing a traveling direction of the light;
A plurality of scanning units that scan incident light and project the light onto different areas on the back surface of the screen;
A rear projection type display device, comprising: a control unit that switches a traveling direction of light changed by the deflecting unit and causes light emitted from the deflecting unit to sequentially enter each of the plurality of scanning units.

[Appendix 2]
The rear projection type according to claim 1, further comprising a magnifying optical system that is disposed on an optical path from the light emitting unit to the screen and that expands the length of each region in a direction intersecting a scanning direction of scanning by the scanning unit. Display device.

[Appendix 3]
The light emitting part is
A light source that emits a linear beam whose cross-sectional shape is a linear light beam;
The rear projection display device according to appendix 1 or 2, further comprising: a one-dimensional spatial modulation element that modulates a linear beam emitted from the light source and emits the light as the light.

[Appendix 4]
The light emitting part is
A light source that emits a point beam whose cross-sectional shape is a point beam;
The rear projection display device according to appendix 1 or 2, further comprising: a scanning element that scans the point beam emitted from the light source and emits the light as the light.

[Appendix 5]
The deflection unit is
A mirror that reflects the light;
A drive unit for changing the direction of the mirror,
5. The rear projection display device according to claim 1, wherein the control unit adjusts a direction of the mirror using the driving unit to switch a traveling direction of the light. 6.

[Appendix 6]
The deflection unit is
A lens for deflecting the light;
A lens driving unit that changes the direction of the lens,
5. The rear projection display device according to claim 1, wherein the control unit adjusts a direction of the lens using the driving unit to switch a traveling direction of the light. 6.

[Appendix 7]
The scanning unit
A scanning mirror that reflects the light;
The rear projection display device according to any one of appendices 1 to 6, further comprising: a scanning drive unit that changes a direction of the scanning mirror.

[Appendix 8]
The rear projection display device according to any one of appendices 1 to 7, further comprising a reflection mirror that reflects light emitted from the deflection unit and guides the light to the scanning unit.

[Appendix 9]
The rear projection display device according to any one of appendices 1 to 8, wherein the screen has a concave curved surface shape or a convex curved surface shape.
[Appendix 10]
A rear projection display system comprising a plurality of the rear projection display devices according to any one of appendices 1 to 9, wherein the rear projection display devices are arranged side by side.

[Appendix 11]
A screen, a light emitting unit that emits light, a deflecting unit that emits light by changing the traveling direction of the light, and a plurality of scanning units that scan incident light and project the incident light onto different areas on the back surface of the screen A control method for a rear projection display device comprising:
A control method, wherein the traveling direction of light changed by the deflecting unit is switched, and light emitted from the deflecting unit is sequentially incident on each of the plurality of scanning units.

This application claims priority based on Japanese Patent Application No. 2012-141810 filed on June 25, 2012, the entire disclosure of which is incorporated herein.

DESCRIPTION OF SYMBOLS 101 Case 102 Laser projector engine 103 Angle switch 104 Magnification optical system 105,106,107 Long scanning element 108 Screen 301 Linear beam laser light source 302 Polarizing prism 303 One-dimensional spatial modulation element 304 Servo motor 305

Mirror

401, 402, 403 Laser element 404

Mirror

405, 406 Dichroic prism 407 Resonant scanning element 408 Servo motor 409 Lens 501 Servo motor 502 Long mirrors 701, 702, 703, 704 Folding mirror 801 Concave surface type casing 802 Folding mirror 803 Concave surface shape of Clean 901 Screen convex

surface type housing

902, 903, 904 folding mirror 905 convex curved surface

Claims

Screen,
A light emitting portion for emitting light;
A deflection unit that emits light by changing a traveling direction of the light;
A plurality of scanning units that scan incident light and project the light onto different areas on the back surface of the screen;
A rear projection type display device, comprising: a control unit that switches a traveling direction of light changed by the deflecting unit and causes light emitted from the deflecting unit to sequentially enter each of the plurality of scanning units.
2. The rear projection according to claim 1, further comprising a magnifying optical system that is disposed on an optical path from the light emitting unit to the screen and that enlarges the length of each region in a direction intersecting a scanning direction of scanning by the scanning unit. Type display device.
The light emitting part is
A light source that emits a linear beam whose cross-sectional shape is a linear light beam;
The rear projection display device according to claim 1, further comprising: a one-dimensional spatial modulation element that modulates a linear beam emitted from the light source and emits the light as the light.
The light emitting part is
A light source that emits a point beam whose cross-sectional shape is a point beam;
The rear projection display device according to claim 1, further comprising: a scanning element that scans the point beam emitted from the light source and emits the light as the light.
The deflection unit is
A mirror that reflects the light;
A drive unit for changing the direction of the mirror,
5. The rear projection display device according to claim 1, wherein the control unit switches a traveling direction of the light by adjusting a direction of the mirror using the driving unit. 6.
The deflection unit is
A lens for deflecting the light;
A lens driving unit that changes the direction of the lens,
5. The rear projection display device according to claim 1, wherein the control unit adjusts a direction of the lens using the driving unit to switch a traveling direction of the light. 6.
The rear projection display device according to any one of claims 1 to 6, further comprising a reflection mirror that reflects light emitted from the deflecting unit and guides the light to the scanning unit.
The rear projection display device according to any one of claims 1 to 7, wherein the screen has a concave curved surface shape or a convex curved surface shape.
A rear projection display system comprising a plurality of rear projection display devices according to any one of claims 1 to 8, wherein the rear projection display devices are arranged side by side.
A screen, a light emitting unit that emits light, a deflecting unit that emits light by changing the traveling direction of the light, and a plurality of scanning units that scan incident light and project the incident light onto different areas on the back surface of the screen A control method for a rear projection display device comprising:
A control method, wherein the traveling direction of light changed by the deflecting unit is switched, and light emitted from the deflecting unit is sequentially incident on each of the plurality of scanning units.