JPH09134135A - Laser projection display - Google Patents

Abstract

(57) Abstract: A laser projection display device capable of displaying a high-luminance and high-definition image. An image signal from an image information source 1 is divided into a plurality of pieces by an image controller 2. The laser light oscillated by the laser oscillators 11 to 13 corresponding to the divided number is
Amplitude modulation is performed by the modulators 21 to 29 based on the image signal. The plurality of modulated laser beams are horizontally scanned by the horizontal scanning device 44 and vertically scanned by the vertical scanning device 54, and are combined and displayed on one screen for projection display. By dividing the image signal, the time axis of the image signal can be divided by the number of times,
The amplitude modulation frequency of the image is reduced in inverse proportion to the number of divisions of the image.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser projection display device which scans a laser beam to display a television screen, a computer screen or the like on the screen.

[0002]

2. Description of the Related Art FIG.
l. 68, no. FIG. 4 is a configuration diagram showing a conventional laser projection display device shown on pages 4, 387 to 394. In the figure, 11, 12, and 13 are laser oscillators 61, 62, and 63 that generate red, green, and blue laser lights, respectively.
Is a three-color laser light, 1 is an image information source, 2 is an image controller, 21, 22 and 23 are modulators for amplitude-modulating the three-color laser lights, and 3 is a three-color laser light on one optical axis. A light combining optical system for combining, 7 is amplitude-modulated and three-color combined laser light, 4 is a horizontal scanning element, 111 is a collimating / condensing lens that collimates the horizontally scanned laser light and condenses it on a vertical scanning element, Reference numeral 5 is a vertical scanning element, 121 is a projection lens, and 110 is a screen.

The conventional laser projection display apparatus is configured as described above, and the image information source 1 outputs an image signal of a system such as NTSC (television broadcasting standard) which is a conventional television system. The image controller 2 outputs an image amplitude signal of the three primary colors, a vertical scanning (synchronization) signal, and a horizontal scanning (synchronization) signal based on the image signal output from the image information source 1. The image amplitude signal is a modulator 21 or 2 for each color.
2 and 23 are input. On the other hand, laser oscillators 11, 1
Laser light 61, 62 of three colors extracted from Nos. 2 and 13,
63 are input to the modulators 21, 22, and 23, respectively.
The laser light 61, 62, and the modulator 21, 22, 23,
63 is amplitude-modulated according to the image amplitude signal from the image controller 2, and is combined with the laser light 7 by the light combining optical system 3 including a dichroic mirror. The laser light 7 is incident on the horizontal scanning element 4 including a rotating mirror or an acoustic deflection element, and is scanned in the horizontal direction of the screen according to the horizontal scanning (synchronization) signal from the image controller 2. The scanned laser light is collimated / condenser lens 11
1 is focused on the vertical scanning element 5 and
The image is scanned in the vertical direction of the screen according to the vertical scanning (synchronization) signal from the image controller 2. As described above, the beam scanned in the horizontal / vertical directions is projected onto the projection lens 121.
Screen size and focus with
The image is projected onto 10 and an image is projected and displayed.

[0004]

Since the conventional laser projection display device is constructed as described above, the definition, brightness, etc. of the image are determined by the frequency band of modulators 21, 22, 23 (hereinafter, simply referred to as band). Note), light resistance, horizontal scanning element 4
Limited by the scanning speed of HD, EWS (EWS (E
It is difficult to reproduce a high-definition image, such as a digital imaging work station. Further, in order to realize a large screen, a long projection distance is required, and a large installation location in the depth direction is required.

Although acousto-optic modulators and electro-optic modulators are used as the modulators 21, 22, and 23, it is difficult to practically cover a band of 10 MHz or more. For example, the band of the acousto-optic modulator is inversely proportional to the beam diameter of the incident laser light. Tellurium oxide, which is a typical material, has a band of 15 MHz for a beam diameter of 0.2 mm, but the light resistance is 250 W / mm ^2. It is a degree. Therefore, considering the case of modulating a laser beam of 10 W, the beam diameter is limited to 0.23 mm when calculated backward from the light resistance strength, and the band becomes about 13 MHz at most.
Both frequency bands are insufficient. If the output of the laser is increased for higher brightness, the band will be further reduced.

A rotating mirror or an acoustic deflection element is often used as the horizontal scanning element 4. The performance of the acoustic deflection element is limited by the physical properties of the material, and the resolution is about 500 and the horizontal scanning frequency is about 15 kHz, and it is the best to support the NTSC signal which is the conventional television system.
On the other hand, the rotating mirror is a polygon mirror with 25 faces and 81000.
By using a motor of rpm, there is a track record up to 30 kHz horizontal scanning frequency for high definition. However, as the number of rotations increases, the size of the apparatus becomes significantly large and the reliability decreases, so that the horizontal scanning frequency up to about 16 kHz is currently used stably. For these reasons, it is impossible for the current apparatus to support the horizontal scanning frequency of 64 kHz to 100 kHz currently used in EWS and the like.

The present invention has been made to solve the above problems, and an object thereof is to obtain an inexpensive laser projection display device capable of displaying a high-luminance and high-definition image.

[0008]

A laser projection display apparatus according to a first structure of the present invention comprises a laser light source for each of the three colors and a set of modulators for amplitude-modulating the laser light of each of the three colors. Laser projection including a combination optical system for combining the modulated laser lights of three colors and a scanning device for two-dimensionally scanning the combined laser light on a plane, and displaying an image on a screen based on an image signal The display device includes an image signal processing device that divides an image signal into a plurality of parts, a plurality of modulation devices, and a scanning device that scans a plurality of combined laser beams into respective image areas divided into the same number on the screen. Is displayed in each of the divided image areas on the screen based on the same number of image signals, and the amplitude modulation frequency of the image is reduced in inverse proportion to the number of divided images. .

Further, in the laser projection display apparatus according to the second configuration of the present invention, in the first configuration, when the number of divisions of the image area is N (N is an integer larger than 1),
It is characterized in that the division is made up of a set of scanning lines selected for every N lines.

Further, in the laser projection display apparatus according to the third structure of the present invention, the scanning apparatus in the first or second structure is installed in the vicinity of the front of the screen portion corresponding to the divided screen, and a plurality of units are provided. A relay lens for guiding the laser light to the corresponding scanning device and a projection lens for projecting the laser light on the screen are provided.

Also, in the laser projection display apparatus according to the fourth structure of the present invention, a plurality of modulators in the first or second structure and the scanning device in the first or second structure are arranged near the laser light source. A collimator lens for guiding a plurality of laser beams to the vicinity of the front of a screen portion for projecting a corresponding screen, and a projection lens for projecting the laser beams on the screen. .

Further, in the laser projection display apparatus according to the fifth aspect of the present invention, the scanning apparatus according to any one of the first to fourth aspects is composed of a plurality of horizontal scanning apparatuses and a single vertical scanning apparatus. An optical system that amplitude-modulates the same number of combined laser beams as the number of image divisions by a modulator, horizontally scans by the horizontal scanning device, and makes incident on the vertical scanning device at an angle corresponding to each of the divided image signals. It is characterized by.

Further, in the laser projection display apparatus according to the sixth structure of the present invention, the scanning device in any one of the first to fourth structures comprises a plurality of horizontal scanning devices and a single vertical scanning device. , An optical system in which the same number of divided laser beams as the number of image divisions are amplitude-modulated by a modulation device, is incident on a vertical scanning device at an angle corresponding to each of the divided image signals, is vertically scanned, and is incident on each of the horizontal scanning devices. It is characterized by having a system.

Further, in the laser projection display apparatus according to the seventh structure of the present invention, the scanning device in any one of the first to fourth structures comprises a single horizontal scanning device and a single vertical scanning device. Then, the modulation device amplitude-modulates the same number of combined laser beams as the number of image divisions, and enters the horizontal scanning device at an angle corresponding to each of the divided image signals and horizontally scans the divided image signals. It is characterized in that it is provided with an optical system which is vertically incident upon a vertical scanning device at a corresponding angle.

Further, in the laser projection display apparatus according to the eighth structure of the present invention, the scanning device in any one of the first to fourth structures is composed of a single vertical scanning device and a single horizontal scanning device. Then, the modulation device amplitude-modulates the same number of combined laser beams as the number of image divisions, and enters the vertical scanning device at an angle corresponding to each of the divided image signals to perform vertical scanning, and to each divided image signal. It is characterized in that it is provided with an optical system for entering the horizontal scanning device at a corresponding angle and performing horizontal scanning.

Further, in the laser projection display apparatus according to the ninth configuration of the present invention, in any one of the first to eighth configurations, a time difference is provided in the blanking period between the plurality of divided image signals, and It is characterized in that a switching means for switching the laser light is provided so that the image signal which is not in the line period is inputted to the modulator for modulation.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. Hereinafter, a laser projection display apparatus according to Embodiment 1 of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a laser projection display apparatus according to Embodiment 1, in which 1 is an image information source, 2 is an image processing signal device, for example, an image controller, 11, 14, 17 are red, 1
2, 15, 18 are green, 13, 16 and 19 are laser oscillators that generate blue laser light, 61-69 are laser lights generated by the laser oscillators 11-19, respectively 21-29
Is a modulator for amplitude-modulating the laser beams 61 to 69, 31, 3
2, 33 are photosynthesis optical systems for synthesizing laser beams of three colors on one optical axis, 71, 72, 73 are laser beams which are amplitude-modulated and three-color synthesized, 41, 42, 43 are horizontal scanning elements, 1
Reference numerals 11, 112 and 113 denote collimating / condensing lenses that collimate the laser beam horizontally scanned and condense it on the vertical scanning element, 51, 52 and 53 denote vertical scanning elements, 121 and 12
Reference numerals 2 and 123 are projection lenses, and 110 is a screen.

Next, the operation will be described. The image controller 2 has a frame memory, and based on the image signal from the image information source 1, the image signal is horizontally divided into three as shown in FIG. 2A, and the time axis is tripled. Then, the blue, green, and red image amplitude signals of the divided image 1 are input to the modulators 21, 22, and 23, and the blue, green, and red image amplitude signals of the divided image 2 are modulated by the modulators 24, 25, and 25, respectively.
26, and the image amplitude signals of blue, green, and red of the divided image 3 are input to modulators 27, 28, and 29. here,
The horizontal scanning (synchronization) signal is output three times on the time axis, that is, the repetition frequency is ⅓, while the vertical scanning (synchronization) signal is output as the repetition frequency of the original image.

On the other hand, the three-color laser beams 61, 62 and 63 extracted from the laser oscillators 11, 12 and 13 are input to the modulators 21, 22 and 23, respectively, and are amplitude-modulated according to the image amplitude signal, The laser light 71 is combined by the light combining optical system 31 including a dichroic mirror. The laser light 71 is incident on the horizontal scanning element 41 including a rotating mirror or an acoustic deflection element, and is scanned in the horizontal direction of the screen according to the horizontal scanning signal output from the image controller 2. The scanned laser light is condensed on the vertical scanning element 51 by the collimator / condensing lens 111, and is scanned in the vertical direction of the screen according to the vertical scanning signal output from the image controller 2 by the vertical scanning element 51. . The beam that has been two-dimensionally scanned in the horizontal and vertical directions as described above is focused on the size of the screen by the projection lens 121, is irradiated onto the screen 110, and the divided image 1
Is projected and displayed.

Similarly, the laser oscillators 14, 15, 1
The laser lights 64, 65, 66 of the three colors extracted from 6 are amplitude-modulated by the modulators 24, 25, 26, and are combined into the laser light 72 by the light combining optical system 32 to be combined with the horizontal scanning element 42 and the collimating / condensing lens. 112, vertical scanning element 5
2. The split image 2 is projected and displayed on the screen 110 through the projection lens 121. Similarly, the divided images 3 are projected and displayed on the screen by the laser beams from the laser oscillators 27, 28 and 29. 3
By adjusting the positions of the two divided images, the divided screens are again combined on the screen into one image for viewing.

According to this structure, since the image is divided into three and the time axis is tripled, the band required by the modulator is 1/3 of the image input signal band, and as a result, the input image signal The band can be tripled. Further, if the laser light powers on the screen are the same, the laser light power input per modulator becomes 1/3, and as a result, the beam diameter at the modulator can be reduced, Further, it becomes possible to widen the band of the input image signal. In addition to this, the scanning frequency of the horizontal scanning element is 1 of the original image.
/ 3 is sufficient, so the horizontal scanning frequency of the original image is NT
It can support up to 3 times the SC system.

As described above, a small horizontal scanning element can be used by reducing the laser beam power input to one modulator to widen the signal band and reducing the horizontal scanning frequency. As a result, A high-definition and high-luminance image can be displayed, and the device can be inexpensive.

Although the image is divided into three in this embodiment, the number of divisions can be arbitrarily selected. For example, if the image is divided into four, the horizontal scanning frequency is 16k.
It is possible to select 64 kHz, which is four times the Hz, and it is possible to support EWS for high-definition images.

In the above embodiment, the image is displayed as shown in FIG.
Although it is divided horizontally as shown in FIG.
As shown in FIG. 2C, or may be divided into both horizontal and vertical directions as shown in FIG. However, in the case of division in the vertical direction, the band of the modulator can be widened in the same manner as in the case of horizontal division, but the horizontal and vertical scanning frequencies are the same as in the conventional system. In addition, as shown in the example of three divisions in FIG. 3, the number of divisions is N (N
Is an integer larger than 1), the division may be performed by a set of scanning lines selected for every N lines, that is, the scanning lines may be taken out every three lines to obtain one image. In this case, it is necessary to overlay a plurality of projected images on the screen. Further, the memory required for the image controller 2 can be several line memories instead of the frame memory. Further, when scanning the beams in the horizontal and vertical directions, usually, a blanking period, which is a time for returning the beam to the original position after the scanning, is required. On the other hand, since the image controller 2 reads the image once stored in the frame or line memory, it is not necessary to provide the blanking period depending on the type of the scanning element such as the polygon mirror. Therefore, in the conventional method,
The time lost as the flyback period can be used for image display.

The positional relationship between the direction of the light source and the viewer may be the same (front projection) or opposite (rear projection) with respect to the screen.

In the above embodiment, the projection lens 12 is used.
1, 122 and 123 were used to irradiate the screen 110 with the size and focus of the screen, but the projection lens may be omitted. Furthermore, in the above-described embodiment, a full-color image device using three primary color lasers has been described, but display may be performed using a single color laser. For example, a green laser can easily obtain a larger output than a red-blue laser and has high luminosity, so that a very high-luminance image can be obtained.

Embodiment 2. FIG. 4 is a configuration diagram showing a laser projection display apparatus according to Embodiment 2 of the present invention, and the vicinity of the screen is the same as in Embodiment 1 and is omitted here. In the figure, 8 is a laser oscillator 11, 12,
Laser light splitting devices 141, 142, and 143, which split the laser beams of three colors from 13 according to the number of split images, and extract the laser beams 61 to 69, 131, 13 are mirrors.
Reference numerals 2, 133 are relay lenses. Here, only the part that performs horizontal and vertical scanning is placed on the front of the screen,
A large part such as a laser oscillator is placed separately, and a mirror 141, 142, 143, a relay lens 131, 1 is provided between them.
32 and 133 are optically coupled.

That is, the three-color laser beams 61, 62, and 63 extracted from the laser oscillators 11, 12, and 13 are input to the modulators 21, 22, and 23, respectively, and are amplitude-modulated according to the image amplitude signal to be dichroic. The laser light 71 is combined by the light combining optical system 31 including a mirror and the like. The laser light 71 is guided to the front surface of the screen 110, and is reflected by the reflection mirror 141 in the optical path in the direction of irradiating the screen 110. Further, scanning is performed in the horizontal and vertical directions by the relay lens 131, the horizontal scanning element 41 including a rotating mirror or an acoustic deflection element, the collimating / condensing lens 111, and the vertical scanning element 51. The beam scanned in the horizontal and vertical directions is projected onto the projection lens 1.
The size and focus of the screen are adjusted by 21, and the divided image 1 is projected and displayed on the screen 110.
The same applies to the divided images 2 and 3.

According to this embodiment, the number of laser oscillators required in the first embodiment is nine, which is three, and therefore the device can be obtained at a lower cost. Further, since only the scanning portion is arranged in front of the screen, there is an advantage that a load applied to the ceiling can be reduced when the ceiling is hung.

Although the optical coupling is performed by the mirrors 31, 32 and 33 in the above embodiment, the optical coupling may be performed by using an optical fiber. In this case, the degree of freedom in arranging the device configuration is significantly improved.

Further, although the front projection has been described in the above embodiment, the rear projection may be used and the same effect can be obtained.

Although the projection lens is used in the above embodiment, the projection lens may be omitted.

Embodiment 3 FIG. 5 is a configuration diagram showing a laser projection display device according to a third embodiment of the present invention. This embodiment is the same as the projection lens 12 of the second embodiment.
1, 122 and 123 are collimating lenses 12 respectively
4, 125, 126 and condenser projection lenses 127, 128,
It is divided into 129, and only the condenser projection lenses 127, 128, 129 are arranged near the screen 110.

Amplitude modulation is performed by the modulators 21 to 29, the horizontal scanning elements 41, 42 and 43, the collimator / condensing lens 11
1, 112, 113 and the vertical scanning elements 51, 52, 53 two-dimensionally scanned in the horizontal and vertical directions to collimate lenses 124, 125, 126 into parallel light beams, and then use mirrors 141, 142, 143. Condensed projection lens 127, which is transmitted in space and placed in front of the screen,
Projected and displayed on the screen 110 at 128 and 129.

According to this embodiment, there is an advantage that the optical system arranged near the screen can be made extremely small.

In the above embodiment, the front projection has been described, but the rear projection may be used and the same effect can be obtained.

Fourth Embodiment FIG. 6 is a configuration diagram showing a laser projection display device according to a fourth embodiment of the present invention, and the configuration in the vicinity of the screen is the same as that of the first embodiment, and will be omitted here. In the figure, 114, 115 and 116 are collimating lenses for collimating the laser light beams horizontally scanned by the horizontal scanning elements 41, 42 and 43, respectively.
Reference numeral 17 is a condenser lens for condensing the horizontally scanned and collimated laser light beam on an element for vertical scanning, and 54 is a rotary reflection optical system such as a galvano mirror for vertical scanning.

In this embodiment, the split and horizontally scanned beams are incident on the rotary reflection optical system 54 at different angles, and the split beams are vertically scanned at once. Since the vertically scanned beams have different emission angles, they pass through the collimator lens 124 and then propagate to different positions, and can be separated by using the reflection mirrors 144, 145, and 146. The images 128 and 129 are projected and displayed on the screen 110.

According to this embodiment, all the beams after the division and the horizontal scanning can be vertically scanned at once by one vertical scanning element 54, and the beams after the vertical scanning can be separated by the emission angle. So it ’s easy to configure,
The device becomes cheaper.

In the above embodiment, the beams are incident on the rotary reflection optical system at different angles, but the respective beams may be incident on different positions on the rotary reflection optical system, and the same effect can be obtained.

Embodiment 5. FIG. 7 is a configuration diagram showing a laser projection display device according to a fifth embodiment of the present invention. In the figure, 147, 148 and 149 are reflection mirrors, 44,
45 and 46 are polygon rotating mirrors. In this embodiment, the laser light 7 modulated corresponding to the divided images is used.
Reference numerals 1, 72, 73 denote reflection mirrors 141, 142, 143.
The three laser beams that are incident on the rotary reflection optical system 54 at different positions or at different angles and are vertically scanned (scanning in the direction vertical to the paper surface in the figure) are converted into parallel light beams by the collimator lens 114. The parallel light fluxes generated by scanning the laser light 71, 72, 73 propagate at different positions or angles. Therefore, the reflection mirrors 144, 14
5, 146, and reflecting mirrors 147, 148, 149 and condenser lens 11 respectively.
Polygon rotary mirrors 44, 4 via 7, 118, 119
The light is focused and irradiated on 5, 46. Polygon rotating mirrors 44, 4
Laser beams horizontally scanned by the scanning lenses 5 and 46 (scanning in the horizontal direction on the paper in the figure) are projected lenses 121 and 12 respectively.
2, 123 is projected on the screen, and the images are combined and displayed.

According to this embodiment, the polygon rotating mirrors 44, 45 and 46 for horizontal scanning are provided on the screen 11.
Since it is arranged in front of 0, there is an advantage that it becomes easy to align the optical axes when the images are combined.

In the above embodiment, the vertical scanning element 5
Although the rotary reflection optical system is used for 4 and the polygon rotary mirror is used for the horizontal scanning elements 44, 45, and 46, the present invention is not limited to this, and other scanning elements such as a photoacoustic deflector may be used.

Embodiment 6 FIG. 8 is a block diagram showing a laser projection display device according to a sixth embodiment of the present invention. As shown in FIG. 3, the image controller 2 in this embodiment takes out every few scanning lines and divides the image. The laser beams 71, 72, 73 modulated corresponding to the divided images are reflected by the reflection mirrors 141, 14
2,143 different angles at the same point of the polygonal rotation mirror 44 (different angles in the direction perpendicular to the paper surface in the figure)
Is incident at. The three laser beams horizontally scanned (scanning in the horizontal direction on the paper surface in the figure) are converted by the collimator lens 114 into three sheet-like laser light beams. That is, three sheet-like light fluxes parallel to the paper surface are distributed perpendicularly to the paper surface. The three laser light fluxes are condensed and emitted to the rotary reflection optical system 54 by the condenser lens 117 via the reflection mirror 150. The rotary reflection optical system 54 scans in the direction perpendicular to the paper surface and projects it on the screen 110 by the projection lens 121. At this time, the three laser beams are projected as three parallel lines on the screen 110, and as a result, three horizontal scanning lines are simultaneously drawn by one horizontal scanning, so that an image is combined and displayed. It

According to this embodiment, the vertical scanning element 5
Since the device can be configured with one element for each of the horizontal scanning element 44 and the horizontal scanning element 44, the configuration is simplified and the number of devices in the vicinity of the screen 110 can be reduced. Furthermore, if even the incident angle to the horizontal scanning element 44 is adjusted accurately, there is the effect that the optical axis adjustment when combining a plurality of images is not necessary, which is extremely advantageous from the standpoint of maintenance of the apparatus. There are great advantages. Also, in this scanning optical system, the image division angle in the vertical direction corresponds to one scanning line, but if this is made 1/3 of the vertical direction and the vertical scanning angle is reduced to 1/2, It can also be used for the split display shown in 2 (a).

As shown in FIG. 9, the three-color laser oscillators 11, 12, and 13 may be used for the number of divided images without using the laser beam dividing device 8. Where 11 is red,
Reference numeral 12 is a laser oscillator that generates a green laser beam, and 13 is a laser oscillator that generates a blue laser beam. With this configuration, even if the laser output of one laser oscillator is small, a high-luminance display screen can be easily obtained by using a large number of lasers.

Embodiment 7 FIG. FIG. 10 is a configuration diagram showing a laser projection display device according to a seventh embodiment of the present invention,
Reference numerals 151, 152, 153, and 154 are reflection mirrors.
Laser lights 71 and 7 modulated corresponding to the divided images
The reflection mirrors 141, 142, and 143 cause the reflection mirrors 2, 73 to enter the rotary reflection optical system 54 at different positions or angles. The three laser beams vertically scanned by the rotary reflection optical system 54 (scanning in the direction perpendicular to the paper surface in the figure) are converted into parallel light beams by the collimator lens 114. Laser light 71,7
The parallel light fluxes generated by scanning 2, 73 propagate at different positions or angles. Therefore, they can be separated by the reflection mirrors 144, 145, 146, and are incident on the same surface of the polygon rotary mirror 44 via the reflection mirrors 147, 148, 149 and the condenser lenses 117, 118, 119, respectively. Focused and illuminated at an angle.
Laser beams horizontally scanned by the polygonal rotary mirror 44 (horizontal scanning in the drawing in the figure) are emitted in different directions, and the collimator lenses 124 and 12 are respectively emitted.
The collimated light beams are collimated by 5, 126. After this, through the reflection mirrors 151, 152, 153, 154 or directly, the condenser projection lenses 127, 128, 12 are used.
9 is projected on the screen 110, and the images are combined and displayed.

According to this embodiment, the horizontal scanning element 4
Since the laser light horizontally scanned by 4 is emitted in different directions, the laser light can be easily separated with a simple configuration.

In the above arrangement, the vertical scanning by the rotary reflecting optical system 54 is performed before the horizontal scanning, but this order can be reversed.

Further, in the above structure, a plurality of laser beams are focused and irradiated on the same surface of the polygonal rotary mirror 44 at different incident angles to perform horizontal scanning. However, as shown in FIG.
It is also possible to perform a horizontal scan by converging and irradiating different surfaces of the polygonal rotary mirror 44 with a plurality of laser beams. In the configuration in which a plurality of laser beams are focused and irradiated on the same surface of the polygonal rotary mirror 44 as shown in FIG. 10, the laser power density on the surface of the polygonal rotary mirror 44 is increased, and the surface of the polygonal rotary mirror 44 is exposed. Risk of damage. On the other hand, in the configuration in which the different surfaces of the polygonal rotary mirror 44 are focused and irradiated as shown in FIG. 11, since the respective laser beams are incident on the different surfaces, the surface of the polygonal rotary mirror 44 is prevented from being damaged. It can be prevented, and a high brightness image can be obtained.

Embodiment 8 FIG. FIG. 12 is an explanatory diagram showing a part of the laser projection display device according to the eighth embodiment of the present invention. In this embodiment, the beam scanning portion will be described. As shown in the figure, the laser beams 71, 72, 73 whose amplitudes have been modulated corresponding to the divided images are incident on the same position of the galvano mirror 54 that performs vertical scanning at different angles in the horizontal direction. The laser beam 7 vertically scanned by rotating the galvanometer mirror 54 in the direction of arrow A
1, 72 and 73 are incident on the polygon mirror 44 that performs horizontal scanning at different angles in the vertical direction. Further, the laser beams 71, 72, 73 are horizontally scanned by the polygon mirror 44 rotating in the direction of the arrow B, and are projected on the screen. In this case, the galvano mirror 54 has 1/3 of the entire vertical direction of the screen 110.
Vertical scanning is performed with a deflection angle corresponding to. Further, the polygon mirror 44 horizontally scans at a deflection angle corresponding to the entire horizontal direction of the screen 110. As a result, on the screen 110, the images 110a and 110 which are horizontally divided into three by the laser beams 71, 72 and 73, respectively.
The entire image is displayed in the three areas b and 110c.

Further, in the above configuration, the case where the screen 110 is divided into three parts in the horizontal direction is shown, but FIG. 13 shows the beam scanning portion in the case where the screen 110 is divided into three parts in the vertical direction, which will be described. As shown in the figure, the laser beams 71, 72, amplitude-modulated corresponding to the divided images,
73 enter the galvano mirror 54 that performs vertical scanning at different positions in the horizontal direction. Galvano mirror 5
Laser light 71, 72, 73 vertically scanned by rotating 4 in the direction of arrow A is incident on the polygon mirror 44 that performs horizontal scanning at different angles in the horizontal direction. Further, the laser beams 71, 72, 73 are horizontally scanned by the polygon mirror 44 rotating in the direction of the arrow B, and are projected on the screen. In this case, the galvano mirror 54 performs vertical scanning at a deflection angle corresponding to the entire vertical direction of the screen 110. Also, the polygon mirror 4
In No. 4, horizontal scanning is performed at a deflection angle corresponding to 1/3 of the entire horizontal direction of the screen 110. As a result, on the screen 110, the images 110a and 110 which are vertically divided into three by the laser beams 71, 72 and 73, respectively.
The entire image is displayed in the three areas b and 110c.

Although not shown in FIGS. 12 and 13, the galvano mirror 54 and the polygon mirror 44 are connected to an image controller, and are scanned according to a vertical scanning signal and a horizontal scanning signal sent from the image controller, respectively. .

Further, in each of the above-mentioned embodiments, there is a description regarding one of horizontal and vertical screen division directions, but as shown in the present embodiment, the division directions are compatible with each other. It is a thing.

12 and 13 show an example in which a galvano mirror is used for vertical scanning and a polygon mirror is used for horizontal scanning, the scanning means used for vertical scanning and horizontal scanning is not limited to this combination. Alternatively, other combinations may be used. Further, an acoustic deflection element or the like may be used as the scanning means.

Embodiment 9 FIG. 14 is a configuration diagram showing a laser projection display device according to a ninth embodiment of the present invention,
Reference numerals 201 and 204 denote laser beams divided by the modulator 21, 202 and 205 laser beams divided by the modulator 22, and 203 and 206 laser beams divided by the modulator 23.

For example, in an ordinary CRT television, when scanning beams in the horizontal and vertical directions, it takes time to return the beams to their original positions after scanning. The period for returning the beam to its original position in the horizontal direction is called the horizontal blanking period, and the period for returning the beam to its original position in the vertical direction is called the vertical blanking period. If an image signal is present in each blanking period, it will be annoying when receiving an image, so the image signal is erased and used in the blanking period. For current Japanese standard TV signals,
The horizontal blanking period is about 17% of the horizontal scanning period, and the vertical blanking period is about 6.5% of the vertical scanning period.

The relation between the scanning period of the luminance signal of the image and the blanking period which are normally used is shown in FIGS. 15 (a) and 15 (b).
In the figure, the horizontal direction indicates time, and the vertical direction indicates luminance.
For example, in the case of horizontal scanning, as shown in FIG. 15A, after the beam is horizontally scanned while displaying an image, the beam is returned to its original position in the horizontal direction during the horizontal blanking period while the image signal is erased. The sum of the period for displaying an image and the horizontal blanking period is the horizontal scanning period. Further, when performing vertical scanning while performing horizontal scanning, as shown in FIG. 15B, a vertical blanking period is required as a period for performing horizontal scanning while moving vertically and returning to the original position in the vertical direction. Yes, the sum of horizontal scanning periods and vertical blanking periods for a plurality of times is called one field.

When an image signal as shown in FIG. 15 is used, no image information appears on the screen during the horizontal and vertical blanking periods. Since no laser light is projected on the screen during this period, the time-averaged light amount in one screen is reduced by the blanking period. By the way, in this embodiment, the image signal is divided into a plurality of pieces, for example, two pieces, and the image is scanned by a plurality of laser beams as many as the number of the divided images. Even if the blanking period of each image signal is shifted, the same image is seen by human eyes. Therefore, if the blanking periods of a plurality of image signals are respectively shifted and the laser light of the image signal that has become the blanking period is used for the optical path of the image signal that is not the blanking period, it could not be used for the blanking period until now. Laser light can be used. In this embodiment, the utilization efficiency of the laser light is increased and the brightness of the projected image is increased.

In this embodiment, for example, a case where the image controller 2 separates the image signal into two will be described. Here, the image controller 2 divides the image signal into two and sets the ratio of the horizontal blanking period in the horizontal scanning period to 50% as shown in FIG. Further, among the image signals divided into two, in the first image signal and the second image signal, the timings of the horizontal blanking periods are shifted so that the horizontal blanking periods are interchanged with each other.

Modulators 21, 2 according to the first image signal
Amplitude modulation of the laser beams 61, 62 and 63 is carried out by 2 and 23.
Here, the laser light including the image signal modulated by the modulators 21, 22, and 23 is guided to the mirror 31 by the optical paths 201, 202, and 203, and is horizontally and vertically scanned to display an image on the screen 110. During the blanking period of the first image, the laser light 6 incident on the modulators 21, 22, 23
1, 62 and 63 are guided through the optical paths 204, 205 and 206 without being modulated by the modulators 21, 22 and 23 to the modulators 24, 25 and 26 which modulate the second image signal. First
In the blanking period of the image signal of, the other second image signal is a period for displaying an image, and the modulators 24, 25 and 26 use the second image signal to generate the laser beam 6 during this period.
1, 62, 63 are modulated and an image is displayed on the screen 110.

By the operation described above, the laser beams 61, 6
2, 63 can be used for image display over the entire horizontal scanning period without being invalidated during the blanking period. As a result, the output power of the laser light projected on the screen 110 can be increased, and the brightness of the screen can be increased.

Although the above embodiment has described the case where the image signal is divided into two, the same measure can be taken when the image signal is divided into three or more.
For example, when the image signal is divided into three, as shown in FIG. 17, the image controller 2 uses the first, second, and third image signals with respective blanking periods shifted. And
By utilizing the laser light of the image signal in the blanking period in the optical paths of the two image signals that are not in the blanking period, the utilization efficiency of the laser light can be increased and the brightness of the projected image can be increased. In this case, a switch may be provided in the optical path so that the laser light modulated by the image signal does not enter the laser optical path of the other image signal during the period other than the blanking period.
The same applies when each image signal is divided into n signals. If the blanking period is set to 1 / n of the horizontal scanning period, the image is projected by using the laser light of the image signal in the blanking period in the optical path of the n-1 image signal that is not in the blanking period. It is possible to make the input to the modulator uniform over the period of time, and suppress the temporal fluctuation of the light amount.

FIG. 18 shows an example of the configuration of a laser projection display device when the image signal is divided into three. In the figure, 2
Reference numerals 13, 214 and 215 denote red laser light, 216 and 21.
7, 218 are green laser lights, 219, 220 and 221 are blue laser lights, 207, 208 and 209 are light distributors, 2
Reference numerals 10, 211 and 212 denote light distribution control signals, 222 to 23.
3 is a mirror. Further, the screen portion is the same as in the above-mentioned embodiment and is omitted.

In the image controller 2, the image signal is divided into three, and the ratio of the horizontal blanking period to the horizontal scanning period is set to 1/3 as shown in FIG. Further, the timings of the horizontal blanking periods are adjusted so that the horizontal blanking periods of the first image signal, the second image signal, and the third image signal among the three divided image signals are interchanged with each other.

On the other hand, the laser beams emitted from the laser oscillators 11, 12 and 13 are distributed to the optical distributors 207, 208 and 209.
Is incident on. In the light distributor 207, the laser light is divided into three optical paths 213, 214, 215, and the divided laser light is guided to the optical modulators 21, 24, 27 via the respective optical paths. Here, the optical distributor 207 does not distribute the light to the optical path 215 during a period in which the image signal modulated by the optical modulator 27 corresponds to the horizontal blanking period, and to the modulators 21 and 24 not in the horizontal blanking period. To the optical paths 213 and 214. The amount of light to be distributed at this time is ½ of the input laser light to the light distributor 207. Similarly, the image signal modulated by the optical modulator 24 is distributed to the optical paths 213 and 215 to the modulators 21 and 27 that are not in the horizontal blanking period during the period corresponding to the horizontal blanking period. The image signal modulated by the optical modulator 21 is distributed to the optical paths 214 and 215 to the modulators 24 and 27 that are not in the horizontal blanking period during the period corresponding to the horizontal blanking period. The amount of light to be distributed at this time is ½ of the input laser light to the light distributor 207. The same applies to the light distributors 208 and 209. In addition, the timing of the light distribution is determined by the light distributor control signals 210 and 211 input from the image controller 2.
212.

As described above, while the image signal corresponds to the horizontal blanking period, the laser light is distributed to the other two optical paths for use, so that the laser light used for image projection in each optical path is laser light. It is possible to increase the amount of light emitted from the oscillator 11 from 1/3 to 1/2. As a result, the laser beam can be used for image display during the entire horizontal scanning period without being invalidated during the blanking period. As a result, the output power of the laser light projected on the screen can be increased and the brightness of the screen can be increased.

FIG. 19 shows an example of the configuration of the optical distributor 207. The laser light emitted from the laser oscillator 11 is divided into ½ by the mirror 250. The two split laser beams are input to the light deflection elements 252 and 253. The light deflection elements 252 and 253 divide the laser light into light paths 255, 256, and 257, 258 by a light distribution control signal. For example, when the image signal modulated by the modulator connected to the optical path 215 corresponds to the horizontal retrace line period, the optical deflecting element 252 causes the optical deflecting element 2 to enter the optical path 255.
At 53, the laser light is passed through the optical path 257. Thus, while the image signal that modulates the laser light on the optical path 215 corresponds to the horizontal blanking period, the laser light is transmitted to the other two optical paths 21.
3, 214.

In the above embodiment, the red laser oscillator 11 is used.
However, the same operation is performed for the green laser oscillator 12 and the blue laser oscillator 13.

In the above embodiment, the case of the horizontal blanking period was described, but the same measures can be taken for the vertical blanking period and the same effect can be obtained.

[0071]

As described above, according to the laser projection display apparatus of the first configuration of the present invention, a laser light source for each of the three colors and a set of modulators for amplitude-modulating the laser light of each of the three colors. A combination optical system for combining the modulated laser lights of three colors and a scanning device for two-dimensionally scanning the combined laser lights on a plane, and an image is displayed on a screen based on an image signal. In the laser projection display device,
An image signal processing device that divides an image signal into a plurality, a plurality of modulators, and a scanning device that scans a plurality of combined laser light into each image region divided into the same number on the screen,
Since a plurality of combined laser beams are displayed in each divided image area on the screen based on the same number of image signals, and the amplitude modulation frequency of the image is reduced in inverse proportion to the number of divided images,
The laser beam power input to one modulator can be reduced to widen the signal band, and as a result, a high-definition and high-luminance image can be obtained.

According to the second structure of the present invention, the first
In addition to the above configuration, the number of divisions of the image area is N (N is 1
Larger integer), the division is made up of the set of scanning lines selected for every N lines, so that the laser beam power input to one modulator can be reduced and the signal band can be widened. An image with high definition and high brightness can be obtained.

According to the third aspect of the present invention, the first
The scanning device having the above configuration or the second configuration is installed near the front of the screen portion corresponding to the divided screen,
Since a relay lens for guiding a plurality of laser beams to the corresponding scanning devices and a projection lens for projecting the laser beams on the screen are provided, the laser beam power input to one modulator can be reduced. The signal band can be widened, and as a result, a high-definition and high-luminance image can be obtained.

According to the fourth aspect of the present invention, the first
Of the plurality of modulators in the above configuration or the second configuration and the scanning device in the first configuration or the second configuration are arranged in the vicinity of the laser light source, and a plurality of laser beams are projected on the corresponding screens in front of the screen portion. Equipped with a collimator lens for guiding light to the vicinity and a projection lens for projecting laser light on the screen, so that a high-definition and high-luminance image can be obtained and the device arranged near the screen can be made small. There is.

According to the fifth aspect of the present invention, the first
The scanning device according to any one of the above configurations to the fourth configuration is configured by a plurality of horizontal scanning devices and a single vertical scanning device, and the same number of combined laser beams as the number of image divisions is amplitude-modulated by the modulator to perform horizontal scanning. Since the system is equipped with an optical system that horizontally scans each device and makes incident on the vertical scanning device at an angle corresponding to each of the divided image signals, a high-definition and high-luminance image can be obtained and a single vertical image can be obtained. There is an effect that the device can be reduced in size by being configured with the operating element.

According to the sixth aspect of the present invention, the first
The scanning device according to any one of the above configurations to the fourth configuration is configured by a plurality of horizontal scanning devices and a single vertical scanning device, and the same number of divided laser beams as the number of image divisions are amplitude-modulated by the modulation device and divided. Since it has an optical system which is incident on the vertical scanning device at an angle corresponding to each of the image signals to perform vertical scanning and is incident on each of the horizontal scanning devices, a high-definition and high-luminance image can be obtained, and There is an effect that the device can be made compact by being constituted by a single vertical operation element.

According to the seventh aspect of the present invention, the first
The scanning device according to any one of the above configurations to the fourth configuration is configured by a single horizontal scanning device and a single vertical scanning device, and the same number of combined laser beams as the number of image divisions are amplitude-modulated by the modulation device and divided. Since it is equipped with an optical system that is incident on the horizontal scanning device at an angle corresponding to each of the divided image signals to perform horizontal scanning, and is incident on the vertical scanning device at an angle corresponding to each of the divided image signals to perform vertical scanning. In addition, it is possible to obtain a high-definition and high-luminance image, and to construct a single vertical and horizontal operation element, which is simple and small in size.

According to the eighth aspect of the present invention, the first
The scanning device according to any one of the above configurations to the fourth configuration is configured by a single vertical scanning device and a single horizontal scanning device, and the same number of image division laser beams is amplitude-modulated by the modulation device and divided. Since it has an optical system that is incident on the vertical scanning device at the angle corresponding to each of the divided image signals to perform vertical scanning, and is incident on the horizontal scanning device at the angle corresponding to each of the divided image signals to perform horizontal scanning. In addition, it is possible to obtain a high-definition and high-luminance image, and to construct a single vertical and horizontal operation element, which is simple and small in size.

According to the ninth aspect of the present invention, the first
In any one of the above configurations to the eighth configuration, a laser is provided so that a time difference is provided in the blanking period between the plurality of divided image signals, and the image signal that is not in the blanking period is input to a modulator for modulation. Since the switching means for switching the light is provided, the laser light during the blanking period that is not used for image display can be used as the light source of the optical path that is not in the blanking period, and the utilization efficiency of the laser light can be improved. As a result, there is an effect that a high-definition and high-luminance screen can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a laser projection display device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a method of dividing image information according to the first embodiment.

FIG. 3 is an explanatory diagram showing a method of extracting scanning lines at intervals of several lines among the methods of dividing image information according to the first embodiment.

FIG. 4 is a configuration diagram showing a laser projection display device according to a second embodiment of the present invention.

FIG. 5 is a configuration diagram showing a laser projection display device according to a third embodiment of the present invention.

FIG. 6 is a configuration diagram showing a laser projection display device according to a fourth embodiment of the present invention.

FIG. 7 is a configuration diagram showing a laser projection display device according to a fifth embodiment of the present invention.

FIG. 8 is a configuration diagram showing a laser projection display device according to a sixth embodiment of the present invention.

FIG. 9 is a configuration diagram showing a laser projection display device according to another example of the sixth embodiment.

FIG. 10 is a configuration diagram showing a laser projection display device according to a seventh embodiment of the present invention.

FIG. 11 is a configuration diagram showing a laser projection display device according to another example of the seventh embodiment.

FIG. 12 is an explanatory diagram showing a part of a laser projection display device according to an eighth embodiment of the present invention.

FIG. 13 is an explanatory diagram showing a part of a laser projection display device according to an eighth embodiment.

FIG. 14 is a configuration diagram showing a laser projection display device according to a ninth embodiment of the present invention.

FIG. 15 is a diagram showing a relationship between a scanning period of an image signal and a blanking period which are generally used.

FIG. 16 is a diagram showing a relationship between an image signal scanning period and a blanking period according to a ninth embodiment of the present invention.

FIG. 17 is a diagram showing a relationship between another image signal scanning period and a blanking period according to the ninth embodiment of the present invention.

FIG. 18 is a configuration diagram showing another laser projection display device according to the ninth embodiment of the present invention.

FIG. 19 is a configuration diagram showing an example of an optical distributor used in Embodiment 9 of the present invention.

FIG. 20 is a configuration diagram showing a conventional solid-state laser device.

[Explanation of symbols]

1 image information source, 2 image controller, 8 laser beam splitting device, 11, 14, 17 red laser oscillator, 1
2,15,18 Green laser oscillator, 13,16,19
Blue laser oscillator, 21-29 modulator, 31, 3
2, 33 photosynthesis optical system, 41, 42, 43 horizontal scanning element, 44, 45, 46 polygonal rotary mirror, 51,
52, 53 vertical scanning element, 54 rotary reflection optical system, 6
1, 64, 67 red laser light, 62, 65, 68 green laser light, 63, 66, 69 blue laser light, 71,
72, 73 laser light, 110 screen, 111,
112,113 Collimating / Condensing lens, 114,1
15,116 Collimating lens 117,118,1
19 condensing lens, 121, 122, 123 projection lens, 124, 125, 126 collimating lens, 12
7,128,129 Projection condensing lens, 131,13
2,133 relay lens, 141-154 reflection mirror, 201-206 laser light, 207-209 light distributor, 210-212 light distributor control signal, 213-2
15 red laser light, 216 to 218 green laser light,
219 to 221 blue laser light, 250,251 mirror, 252,253 light deflecting element, 254 optical coupling element, 255 to 258 red laser light.

Claims (9)

[Claims] 1. A laser light source for each of the three colors,
A set of modulators for amplitude-modulating the three-color laser lights, a combining optical system for combining the modulated three-color laser lights, and a scan for two-dimensionally scanning the combined laser lights on a plane. A laser projection display device that displays an image on a screen based on an image signal, an image signal processing device that divides the image signal into a plurality, the plurality of modulators, and the plurality of combined lasers. A scanning device for scanning light into each of the image areas divided into the same number on the screen, and displaying the plurality of combined laser beams in each of the divided image areas on the screen based on the same number of image signals, and A laser projection display device characterized in that the amplitude modulation frequency of an image is reduced in inverse proportion to the number of divisions of the image. 2. The number of divisions of the image area is N (N
Is an integer greater than 1), the laser projection display device according to claim 1, wherein the division is made up of a set of scanning lines selected for every N lines. 3. A relay lens for installing the scanning device near the front of a screen portion corresponding to a divided screen, and a relay lens for guiding a plurality of laser beams to the corresponding scanning device, and on the screen. 3. The laser projection display apparatus according to claim 1, further comprising a projection lens that projects the laser light onto the laser. 4. A collimator lens for arranging the plurality of modulation devices and the scanning device in the vicinity of a laser light source, and guiding the plurality of laser lights to the vicinity of the front of a screen portion projecting a corresponding screen, and 3. The laser projection display device according to claim 1, further comprising a projection lens that projects the laser light on the screen. 5. The scanning device is composed of a plurality of horizontal scanning devices and a single vertical scanning device, wherein the modulator device amplitude-modulates the same number of combined laser beams as the number of image divisions, and each of the horizontal scanning devices horizontally. 5. The laser projection display apparatus according to claim 1, further comprising an optical system that is incident on the vertical scanning device at an angle corresponding to each of the scanned and divided image signals. 6. The scanning device comprises a plurality of horizontal scanning devices and a single vertical scanning device, amplitude-modulates the same number of combined laser beams as the number of image divisions by a modulator, and each of the divided image signals. 5. The laser according to claim 1, further comprising an optical system that is incident on the vertical scanning device at an angle corresponding to, vertically scans, and is incident on each of the horizontal scanning devices. Projection display device. 7. The scanning device is composed of a single horizontal scanning device and a single vertical scanning device, and the modulation device amplitude-modulates the same number of combined laser beams as the number of image divisions. An optical system is provided, which is incident on the horizontal scanning device at an angle corresponding to each of them and horizontally scans, and is incident on the vertical scanning device at an angle corresponding to each of the divided image signals to vertically scan. The laser projection display device according to any one of claims 1 to 4. 8. The scanning device is composed of a single vertical scanning device and a single horizontal scanning device, amplitude-modulates a combined laser beam of the same number as the number of image divisions by a modulator, and outputs the divided image signals. An optical system is provided, which is incident on the vertical scanning device at an angle corresponding to each of them to perform vertical scanning, and is incident on the horizontal scanning device at an angle corresponding to each of the divided image signals to perform horizontal scanning. The laser projection display device according to any one of claims 1 to 4. 9. A switching means for switching a laser beam so that a time difference is provided in a blanking period between a plurality of divided image signals and the image signal not in the blanking period is input to a modulator for modulation. Claim 1 characterized by the above-mentioned.
9. The laser projection display device according to claim 8.