JP2000089687A - Non-speckle laser diode projection display system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the coherence of radiation light and to obtain non-speckle high-resolution images by arranging a phase modulation layer between a light source and a display screen and randomly modulating the phase of the light passing the same. SOLUTION: An image source includes a silicon wafer 12 and a cantilever portion 14 is formed as part thereof. Deflection arises in this cantilever portion 14 and the scan operation of laser diodes 18 to 20 is executed in response with the change in the voltage impressed from a voltage source 41. The phase modulation layer 28 is arranged on the uppermost surface 26 of the cantilever portion 14. The phase modulation layer 28 includes plural conductive layers and an interconnection 41 electrically connected to an external power source for sending a signal thereto. Irregular signals are sent by randomly changing the amplitude or frequency of the input signal during the operation. The phase of the phase modulation material of the phase modulation layer 28 is randomly modulated, by which the coherence of the light rays 32 to 34 passing the same is annihilated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a visual display system, and more particularly, to a display system that uses a phase modulation material to produce a high resolution image in a viewer's field of view.

[0002]

2. Description of the Related Art The human visual system is a complex system with a high capacity to absorb the vast amount of information transmitted in a variety of formats, including visual displays. In today's world, visual displays come in a variety of sizes and shapes, from large visual displays that show and take off schedule information, such as those found at airports, to small visual displays, such as those built into calculators. , Displaying a wide variety of information. Such visual displays include direct-view displays, including projection displays. When using a projection display, emphasis is placed on the quality of the display resolution, the maintenance of minimum power requirements and low manufacturing costs.

[0003] Maintaining resolution quality is the ability of the human visual system to process and integrate information and the speed at which the visual system can do so. One of the biggest problems with laser projection displays is the "speckle" in the image that is caused by light reflecting off the screen and interfering with each other, causing "speckle" to the human eye It is. In theory, "speckle" is defined as a random change in intensity caused by random interference of light. Therefore, a common solution to the "speckle" problem in displays is to vibrate the screen at a high frequency to rapidly change and smooth the speckle pattern so that it is not visible to the naked eye. This type of display is complicated and expensive to operate because of the mechanical movement of the display screen.

In theory, only coherent light causes interference, resulting in "speckle" on the display. By eliminating the coherence of the light emitted from the image source,
Light interference can be eliminated. Therefore, if the phase of the emitted light is randomly modulated at frequencies above 60 Hz, interference will be eliminated and "speckle" will not be observed. This process can be used in the field of display technology, and more specifically, in the development of high resolution visual displays, including projection displays, by modifying the image source to include a phase modulation layer.

[0005] Therefore, there is a need for a laser projection display system that eliminates the need for mechanical motion of the screen so that high resolution images without speckle can be viewed. Accordingly, a display system that includes a phase-modulating material disposed in the path of the emitted light, wherein the coherence of the light is diminished in order to eliminate the normally observed "speckle", thereby reducing the interference of the light. Disclosed is a display system that enables a high-resolution display to be generated by vanishing.

[0006]

Accordingly, there is provided a laser projection display system comprising a light source, more specifically, a plurality of laser diodes, and a display screen capable of eliminating coherence of emitted light. It would be highly desirable to provide a laser projection display system that includes an intervening phase modulation material, thereby eliminating "speckle" when viewing the display.

It is another object of the present invention to provide a new and improved non-speckle laser projection display system that does not require mechanical movement to produce a projection display.

Another object of the present invention is to provide a non-speckle high-resolution image in which a plurality of laser diodes and a phase modulation layer disposed based on the laser diodes eliminate coherence of emitted light. To provide a new and improved non-speckle laser display system.

Yet another object of the present invention is to provide a non-speckle high resolution image for generating a laser image source;
Including a phase modulation layer that can withstand random changes in phase,
A new and improved non-speckle laser display system is provided.

It is also an object of the present invention to include a plurality of laser diodes and a phase modulation layer intended for use in videoconferencing systems, cellular phones, personal digital assistants (PDAs), pagers, portable computers, and the like. A new and improved projection display system is provided.

[0011]

SUMMARY OF THE INVENTION The above and other problems and objects are to provide a plurality of laser diodes for emitting coherent light in a path, a display screen for receiving the emitted light, and a random phase for passing light. A non-speckle laser diode projection display system including a phase modulation layer disposed between the plurality of laser diodes and the display screen to modulate the light, i.e., in the path of the emitted light. And realized. By randomly modulating the phase of the light passing through the phase modulation layer in this way, the coherence of the light is lost and interference is eliminated, resulting in a high-resolution, speckle-free image . A high frequency, low voltage random signal is input to the phase modulation layer, which randomly modulates the phase at a frequency of 60 Hz or more.

[0012]

Throughout this description, the same numbers in different figures illustrating the invention are used to identify the same elements. The invention is based on incorporating a phase modulation layer in the path of the light emitted by the plurality of laser diodes to modulate the phase of the light passing therethrough. The phase modulation layer receiving the high frequency, low voltage random signal performs a random modulation of the light passing therethrough, thereby eliminating the coherence of the light and eliminating interference. Such light modulation provides a non-speckle laser projection display.

Referring now to the accompanying drawings, and more specifically to FIG. FIG. 1 shows a first embodiment of an image source 10,
It includes an integrated phase modulation layer 28 according to the present invention. In this particular embodiment, image source 10 is a micro-electro-mechanical scanner (MEMS), which includes a minimum number of laser diodes in that scanning technology is utilized. Can be kept to a minimum. It is to be understood that image sources that include more visible semiconductor laser diodes are also contemplated by the present invention, and that MEMES image sources are disclosed only as preferred embodiments. Thus, the image source 10 operates using scanning techniques to produce high resolution images from a small number of light sources. Such a scanning operation forms what appears to the observer to be a high resolution integrated image. Those skilled in the art will appreciate that scanning can create an entire display from a small number of light sources.

The scanning process utilized is based on the "x" -axis and "y" -axis scanning principles, which change the path of emitted light for each part or element of the array. More specifically, in this particular embodiment, the image source 10 (which may refer to a microscanner with at least one light emitting device mounted on a cantilevered portion to which an external stimulus is applied) Scan in the “x” axis and / or “y” axis direction depending on the applied electrostatic charge. The resulting light scan can produce an integrated image that appears to be composed of many pixels, even with image source 10 having a minimum number of light sources (laser diodes).

The image source 10 includes a silicon wafer 12, the wafer of which is formed with a cantilever portion 14 as part thereof using standard cantilever fabrication methods, thereby defining the gap 13. Multiple laser diodes 1
6 is arranged in the center plane 15 of the cantilevered part 14, which is deflected in response to an applied electrostatic charge. In this embodiment, a plurality of laser diodes 1
6 includes a red laser diode 18, a green laser diode 19 and a blue laser diode 20.
To generate a full-color image. The arrangement of the laser diodes 18, 19, 20 is exemplary and other layouts are envisioned by the present invention and will vary from design to design depending on the scanning technology used and the desired image results. The plurality of cavities 22, 23,
24 are made in the cantilevered section 14 and are defined by a plurality of sidewalls. Laser diode 16 is mounted in cavities 22,23,24. As shown, the laser diodes 18, 19, 20
Emits light which is shown and referenced 32, 33, 34 in the figure.

A phase modulation layer 28 is disposed on top surface 26 of cantilevered portion 14. In a preferred embodiment,
The phase modulation layer 28 controls the light 32, 33, 34 passing therethrough.
Liquid crystal material for modulating the phase of the liquid crystal. Liquid crystal materials that can be used for this particular purpose include nematic liquid crystal materials,
Chiral smectic liquid crystal materials and ferroelectric liquid crystal materials are included. In an alternative embodiment, the phase modulation layer 28 comprises
PLZT (Pb _0.814 La _0.213 (Ti _0.6 Zr _0.4 ) O ₃
Base composition) or lithium niobate (LiNbO
₃ ), including a solid transparent phase modulating material such as KDP (KHH ₂ PO ₄ ).

During the scanning operation, an external electrical stimulus supplies a varying electrostatic charge to the image source 10, thereby causing the cantilevered portion 14 to move to the lower portion of the silicon wafer 12 , Along the “x” axis. Thus, by deflecting the cantilevered portion 14, the light emitted by the laser diodes 18, 19, 20 can be scanned in the "x" axis direction.

A plurality of electrical interconnects 36, 38, 40
Are shown as electrically connecting the laser diodes 18, 19, 20 to an external power supply (not shown). Also, a plurality of electrical contacts 37 and 39 are provided on the cantilevered portion 14 and the substrate 12 and are electrically connected to a voltage source 41 so as to respond to a change in the voltage applied from the voltage source 41. As a result, deflection of the cantilevered portion 14 occurs.
The voltage is applied to the cantilever portion 14 and the silicon wafer 12.
Over the gap 13 defined by the lower part of The generation of the electromagnetic field causes the cantilevered portion 14 to be attracted or repelled according to the electric charge in the gap 13. When the cantilever portion 14 is attracted or repelled in this way, the cantilever portion 14 is deflected, and the laser beam
The scan operation of the diodes 18, 19, 20 is performed.

The contacts and contacts 37, 39 with the laser diodes 18, 19, 20 are formed by conventional vapor deposition and / or etching techniques, for example, a conventional bus contact consisting of rows and columns is commonly used in the art. As is known, each laser diode 18, 19, 20 is formed to correspond individually. It has a data input terminal, and further has a control signal output terminal connected to the laser diodes 18, 19, 20 via a plurality of connection pads (not shown).
A plurality of driver / control circuits (not shown) for activating and controlling each of the terminals 9 and 20; and a plurality of drivers / control circuits having an input terminal and an output terminal connected to the contacts 37 and 39. Control circuit (not shown)
Are provided, and are combined to generate an image using a scanning technique in accordance with a signal input to an input terminal.

The phase modulating layer 28 is an interconnect 42 that electrically connects a plurality of conductive layers (not shown) manufactured as part of the phase modulating layer 28 to an external power supply that sends signals therethrough.
including. In operation, an irregular signal is sent by randomly varying the amplitude or frequency of the input signal.
In the preferred embodiment, this random signal is generated utilizing a digital signal processing chip (DSP). By randomly modulating the phase of the phase modulating material of the phase modulating layer 28, the coherence of the light 32, 33, 34 passing therethrough disappears. Eliminating the coherence of the light 32, 33, 34 in this manner eliminates interference patterns, thereby providing a projection display without speckle effects.

Since the present invention utilizes scanning technology, the number of interconnects is small in that the number of light emitting devices to be defined, ie, the number of laser diodes, is small. Because of this small number of interconnects, the manufacturing yield of image source 10 is high, and thus the manufacturing cost is low. In addition to serving as a means of laying out electrical interconnects, the silicon wafer 12 further includes a diode 1
8, 19, and 20 protection elements, more specifically, heat sinks.

During the image generation process, a changing external voltage is applied to the image source 10, more specifically the cantilever portion 14 and the phase modulation layer 28. Diodes 18, 19, 20
Is scanned in response to a change in the applied voltage, relative to the degree of deflection of the cantilever portion 14, and undergoes a phase change by the phase modulation layer 28, thereby resulting in a Non-coherent light is emitted. Generally speaking, the resulting non-coherent light is
In response to the change in the "x" axis direction, the moving distance for filling a certain area of the projection display with a specific part of the image is changed. The scanning operation operates to scan image data information.

Referring now to FIG. FIG. 2 shows an alternative embodiment of an image source utilized in the display system of the present invention. Note that all components similar to those shown in FIG. 1 are numbered similarly and have a prime added to indicate that they are different embodiments.
In this specific embodiment, image source 10 'is a laser diode chip that includes a plurality of visible semiconductor laser diodes. Image source 10 'does not incorporate a scanning device as disclosed in the first embodiment. The scanning technique is implemented separately from the image source. This scanning operation forms what the observer sees as a high-resolution integrated image. One skilled in the art will appreciate that scanning can create an entire display from a small number of light sources. In yet another alternative embodiment, the image source includes an array of laser diodes, which eliminates the need for including a scanner and the need for scanning technology to produce high resolution images.

As shown, the image source 10 'includes a silicon wafer 12' in which a plurality of cavities 22 ', 23', 24 'are formed as part thereof. The plurality of laser diodes 16 ′ are connected to the cavities 22 ′, 2
It is arranged on the center plane of each of 3 ′ and 24 ′. In this embodiment, the plurality of laser diodes 16 '
It includes a red laser diode 18 ', a green laser diode 19' and a blue laser diode 20 ', which can produce a full-color image. The arrangement of the laser diodes 18 ', 19', 20 'is exemplary and other layouts are contemplated by the present invention and will vary from design to design depending on the scanning technique used and the desired image results. As shown, the laser diodes 18 ', 19', 20 'are 32', 33 ', 3'.
Emit the light shown and referenced as 4 '.

The phase modulation layer 28 'is formed on the silicon wafer 1
Located on the top surface 26 'of the 2'. As in the above disclosure, the phase modulation layer 28 ′ has light 3 passing therethrough.
Includes a liquid crystal material that modulates the 2 ′, 33 ′, and 34 ′ phases. Liquid crystal materials that can be used for this particular purpose include nematic liquid crystal materials, chiral smectic liquid crystal materials, and ferroelectric liquid crystal materials. In an alternative embodiment, the phase modulation layer 28 may be PLZT (Pb _0.814 La _0.213 (Ti
_0.6 Zr _0.4 ) O ₃ -based composition), or a solid transparent phase modulation material such as lithium niobate (LiNbO ₃ ), KDP (KHH ₂ PO ₄ ).

The scanner 43 is provided with radiation 32 ', 33',
34 '. Scanner 43 is disclosed as any type of micro-mechanical scanner (MEMS) known in the art. Any type of scanning device can be used for the scanner 43, such as an electro-optic scanner, a polygon mirror scanner, a galvanometer mirror scanner, an acousto-optic scanner, or any combination thereof. During the scanning operation, an external electrical stimulus (not shown) supplies a varying electrostatic charge to the scanner 43, thereby causing the laser diode 1
The light emitted by 8 ', 19', 20 'is scanned in the "x" axis direction and / or in the "y" axis direction.

A plurality of electrical interconnects 36 ', 38', 4
0 'is the laser diode 18', 19 ', 20'
Shown for electrical connection to an external power supply (not shown). Further, an electrical interface, that is, an electrical contact electrically connected to a voltage source (not shown) is provided between the phase modulation layer 28 'and an irregular signal input to the phase modulation material.

Laser diodes 18 ', 19', 2
The contact with the 0 'is formed by conventional vapor deposition and / or etching techniques, for example, a bus contact consisting of ordinary rows and columns may be provided with laser diodes 18', 19 ', as is generally known in the art. , 20 '. A laser diode 1 having a data input terminal and a control signal output connected to the laser diodes 18 ', 19', 20 'via a plurality of connection pads (not shown).
A plurality of driver / control circuits (not shown) for activating and controlling 8 ', 19' and 20 'respectively
And a plurality of driver / control circuits (not shown) having an input terminal and further having an output terminal connected to the scanner 43. These are combined, and according to a signal input to the input terminal, The feature is that an image is generated using a scanning technique.

The phase modulation layer 28 '(to be mentioned here) comprises:
As previously described with respect to FIG. 1, it includes an interconnect (not shown) for electrically connecting an external power supply for transmitting signals and the phase modulation layer 28 '. In operation, an irregular signal is sent by randomly varying the amplitude or frequency of the applied irregular signal. As described above, this irregular signal is converted to a digital signal processing chip (DS).
P). By randomly modulating the phase of the phase modulating material, the light 32 ', 33', 34 '
Coherence disappears and interference is eliminated,
A projection display without speckle effects is obtained.

During the image generation process, the changing external voltage is
Image source 10 '(more specifically, laser diode 1)
8 ', 19' and 20 '), and are applied to the phase modulation layer 28 and the scanner 43. Diodes 18 ', 19', 20 '
Emits light that is phase modulated with respect to the random signal sent to the phase modulation material 28 ', resulting in the emission of non-coherent light 32', 33 ', 34'. Next, light 3 that undergoes a phase change to eliminate coherence of light 3
2 ′, 33 ′, 34 ′ are scanned in response to changes in the voltage applied to scanner 43. Generally speaking, the resulting non-coherent light undergoes a change in the "x" and / or "y" axis directions and travels to fill an area of the projection display with a particular portion of the image. To change.

Referring now to FIG. FIG. 3 is a simplified cross-sectional view of a phase modulation device 44 manufactured as an independent entity from an image source. The phase modulator (or layer) 44 includes a transparent substrate (or plate) 45.
And the conductive material 46 is formed on the surface thereof. The transparent plate 45 is generally formed from a transparent glass or plastic material. On the surface of the plate 45, in
A conductive material layer 46 such as dium-tin-oxide (ITO) is disposed. Next, a polymer film 47 into which the liquid crystal material is absorbed or which is manufactured to form a micro-encapsulation of a plurality of liquid crystal molecules is laminated on top of the conductive material layer 46. A second conductive material layer 48 is formed on the surface of the polymer film layer 47 and serves as a second electrical contact of the phase modulation material device 44. Driver source
49 is electrically connected to the conductive material layers 46 and 48 and provides a voltage during operation of the modulator 44.

When a voltage is applied, the liquid crystal molecules contained in the polymer film 47 are modulated. This causes light to be emitted from an image source that includes a plurality of laser diodes (not shown) positioned to match modulator 44
4 undergoes a random change in phase, thereby eliminating the coherence of the light passing therethrough and eliminating the interference pattern of the light, resulting in a speckle effect in the generated display image. Is avoided. The phase modulator or phase modulation layer 44 is described as containing a liquid crystal material that is included in a polymer film that is manufactured as part of the device structure, but as previously disclosed with respect to FIGS.
A phase modulator having a phase modulating material sandwiched between two plates is also contemplated by the present invention.

Referring now to FIG. FIG. 4 shows a typical projection display system 50 referred to as prior art. As shown, the display system 50 includes a coherent image source 52 and a display screen 54. In operation, the coherent display source 52 provides a path 56 to a display screen 54.
Emit light into. One of the biggest problems with laser projection display systems, such as display system 50, is that light 58
Are "speckles" in the image that are reflected off the screen and interfere with each other to cause "speckles" to the naked eye 59. To eliminate the "speckle" problem in the display system 50, the screen 54 is typically vibrated at a high frequency, thereby causing the pattern of speckles to change rapidly and smooth, making it invisible to the naked eye 59. To This type of display system 50 requires mechanical movement of the display screen 54, which generally complicates operation and increases costs.

Referring now to FIG. FIG. 5 illustrates a non-speckle laser diode projection display system 60 according to the present invention. The display system 60 includes a route 64
An image source 62 for emitting coherent light therein is included. The image source 62 may be a phase modulation layer 66 incorporated into the image source as described with respect to FIGS.
An independent phase modulation layer in an alternative embodiment, or in the path of light emitted by a plurality of laser diodes, as described above with respect to FIG. 3, more specifically between the laser diode and the display screen Including the device arranged in the. Further, the display system 60 includes a display screen 68.
The display screen 68 is a book size screen (5 ″ ×
7 ″), folder size screen (8 ″ × 11 ″),
It includes a small screen such as a legal size screen (A4) and a large screen for use in theaters and movies. In a preferred embodiment, display screen 68 is disclosed as a flexible shape so that display screen 68 can be rolled up and stored when not in use.

During operation of the display system 60, the image source 62
Projects an image on the display screen 68. Light emitted by image source 62 passes through integrated phase modulation layer 66 and is emitted as non-coherent light. Therefore, as a result of eliminating the interference pattern, a high-resolution non-speckle generated image 70 is visible to the naked eye 72. Although the display system 60 is shown as including a transmissive display screen 68, and thus transmitting the light 70, in alternative embodiments the display screen 68 is constructed as a reflective screen,
It will be appreciated by the observer that the image generated by the display system will be visible on the same side of the display screen as the image source is located.

Referring now to FIG. FIG. 6 shows a block diagram of a display system 80 according to the present invention. here,
An imaging device, more specifically, an image source 82 is shown, which includes a vertical cavity surface emitting laser (VCSEL), a diode laser, a diode pump laser (diode).
It includes a light source 86 and an integrated phase modulation layer 87 that can be any of the well-known lasers, including solid state lasers, such as a pumped laser. The light source 86 sends the coherent light beam to the light intensity modulator 88. Light intensity modulator 88 generally imprints image information on the light beam by modulating the intensity of the light beam, for example, by changing the output level of laser 86. Depending on the application, this modulation can be simplified, such as turning the light source 86 on and off, which is essentially converted to a digital system. Although acousto-optic modulators are one of the preferred modulators for most applications, other techniques such as electro-optic and mechanical modulators are fully feasible. Electronic components 92 are included to control modulator 88 and scanner system 90.

The modulated light from modulator 88 is directed to scanner system 90. The lens system 94 includes a scanner
The light from the system 90 is used to focus and impinge on the projection display screen 84. Scanner system 90
Is to scan the modulated light beam onto the projection display screen 84. The scanner system 90 and the lens system 94 can take many configurations depending on the use of the display and the desired method of forming an image on the projection display screen 84.

As already mentioned, the display system 80 employs scanning technology to produce a high resolution image from a laser light source. This scanning operation forms what appears to the observer to be a high-resolution integrated image.
One skilled in the art will appreciate that scanning can create an entire display from a small number of light sources. With this particular system, the resulting integrated image looks like a projected image.

In a preferred embodiment, the use of a scanning technique that employs scanning of the light emitted by the laser 86 enables a display system that maintains a small size by including the scanning technique, which can be implemented in a personal digital assistant (PD).
A), and can be incorporated into small portable electronic devices such as cellular phones and pagers.

Accordingly, a novel and improved non-speckle laser diode projection display system for use with a portable electronic device to produce a non-speckle projection image display is disclosed, the system comprising: The production is relatively easy and the production cost is low. The display system includes a phase modulation layer which, when subjected to irregular high frequency low voltages, modulates the phase of light passing through the phase modulation layer to provide a high resolution non-speckle projection image. Create a display.

Although specific embodiments of the present invention have been shown and described, those skilled in the art will perceive other modifications and improvements. Therefore, it is to be understood that the invention is not intended to be limited to the particular forms set forth herein. It is intended that the appended claims cover all such modifications that do not depart from the spirit and scope of the present invention.

[Brief description of the drawings]

FIG. 1 is a simplified cross-sectional view showing a portion of an image source including an integrated phase modulation layer according to the present invention.

FIG. 2 is a simplified cross-sectional view illustrating a portion of an alternative embodiment of an image source including an integrated phase modulation layer according to the present invention.

FIG. 3 is a simplified diagram of a phase modulation layer or device manufactured as a separate entity.

FIG. 4 is a simplified diagram of a prior art projection display system.

FIG. 5 is a simplified diagram of a non-speckle laser diode projection display system according to the present invention.

FIG. 6 is a block diagram of a non-speckle laser diode projection display system according to the present invention.

[Explanation of symbols]

 Reference Signs List 12 silicon wafer 13 gap 14 cantilever portion 15 center plane 16 laser diode 18 red laser diode 19 green laser diode 20 blue laser diode 22, 23, 24 cavity 26 top surface 28 phase modulation layer 32, 33 34 light 35 directional arrow 36, 38, 40 electrical interconnection 37, 39 electrical contact 41 voltage source 42 interconnection 43 scanner 44 phase modulator 45 transparent substrate 46 conductive material layer 47 polymer film 48 second conductive material layer 49 driver -Source 50 Projection display system 52 Coherent light source 54 Display screen 56 Path 58 Light 59, 72 eyes 60 Display system 62 Image source 64 Path 66 Phase modulation layer 68 Display screen 70 Generated image 80 Display system 82 Image source 84 Projection display image 86 light source 87 phase modulation layer 88 optical intensity modulator 90 scanner system 92 electronic member 94 the lens system

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Michael S. Levy North La Barge Road, Apache Junction, Arizona, U.S.A. 30 (72) Inventor Karen E. Jatimovic, Ravine, Arizona, U.S.A. Box 647, Earl R2

Claims (6)

[Claims] 1. A non-speckle laser diode projection display system; a light source (10, 52, 62, 86) for emitting coherent light into a path; and arranged to receive said emitted light. Display screen (54, 6
8, 84); a phase modulation layer (44, 8) disposed between the light source and the display screen, that is, in the path of the emitted light.
8) The display system according to 8), wherein the phase modulation layer includes a phase modulation layer that randomly modulates a phase of light passing therethrough. 2. The non-spec of claim 1, further comprising a voltage source (92) for sending a plurality of random signals of varying at least one of amplitude or frequency to said phase modulation material. Laser diode projection display system. 3. The non-speckle laser according to claim 1, wherein the phase modulation material includes one of a nematic liquid crystal material, a chiral smectic liquid crystal material, and a ferroelectric liquid crystal material.・ Diode projection display system. 4. A non-speckle laser diode projection display system comprising: a plurality of laser diodes for emitting coherent light; and an integrated type for randomly modulating the phase of the emitted coherent light. An image source (10, 52, 62,...) Including a phase modulation layer (44, 88) and consequently emitting non-coherent light;
82); a display system (54, 68, 84) arranged to receive the emitted non-coherent light. 5. The image source includes a voltage source electrically connected to the phase modulation layer, wherein the voltage source sends an irregular signal having at least one of a frequency and an amplitude that changes to the phase modulation layer. 5. The non-speckle laser diode projection display system according to claim 4, wherein said frequency is 60 Hz or more. 6. A non-speckle laser diode projection display system, comprising: a display screen (54, 68, 8);
4); and an image source (10, 52, 62, 82) for projecting an image on the display screen, the image source comprising a plurality of lasers for emitting coherent light.
A diode (16), an integrated phase modulation layer (44, 88) for randomly modulating the phase of the radiated coherent light, and thereby emitting non-coherent light, and an electrical connection to the phase modulation layer. An image source, comprising: a voltage source (92), wherein the voltage source sends an irregular signal of at least one of a frequency and an amplitude that changes to the phase modulation layer, wherein the frequency is 60 Hz or more. A display system comprising: