JP2006301050A - Optical scanner, method of controlling optical scanner, and image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical scanner in which a plurality of color light beams are efficiently scanned according to the output balance of the respective color light beams. <P>SOLUTION: The optical scanner includes: a plurality of light source parts 101 which supply light beams; and a scanning part 200 which scans the light beams from the light source parts 101 in X-direction which is the first direction on a screen 110 which is a region to be irradiated and in Y-direction which is the second direction which is substantially perpendicular to the first direction. The light source part 101 is provided with at least a light source part 101R for first color light which supplies first color light beam and a light source part 101G for second color light which supplies second color light beam, and the light source part 101R for first color light and the light source part 101G for second color light are different in numbers from each other. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical scanning device, an optical scanning device control method, and an image display device, and more particularly, to a technique of an optical scanning device for displaying an image by scanning a laser beam modulated in accordance with an image signal.

  An optical scanning device that scans a laser beam is used as an image display device that displays an image by scanning the laser beam. The optical scanning device scans a laser beam modulated in accordance with an image signal in a two-dimensional direction. The image display device displays an image by causing laser light from the optical scanning device to enter a screen or the like. In order to display a color image using an optical scanning device, a plurality of color lights, for example, a red laser beam (hereinafter referred to as “R light”), a green laser beam (hereinafter referred to as “G light”), and blue. Laser light (hereinafter referred to as “B light”) is used. As a technique of an image display device that scans a plurality of color lights, for example, there is one proposed in Patent Document 1.

JP 2003-21804 A

  Laser light sources currently used, such as semiconductor lasers, often have a difference in maximum output for each color light. For example, in general, an R light source has a larger maximum output than other color light sources, whereas a G light source has a smaller maximum output than other color light sources. On the other hand, for example, the conventional technique proposed in Patent Document 1 is premised on using the same number of light sources for each color light. For example, if the same number of light sources are used for R, G, and B, in order to obtain a good white balance, it is necessary to reduce the output of the R light source to the same level as the outputs of the other color light sources. Will be wasted. Arranging useless light sources leads to an increase in the size and complexity of the optical system as well as the space of the light source itself, which raises the price and hinders downsizing. As described above, the conventional technique has a problem that it is difficult to efficiently scan a plurality of color lights according to the output balance of each color light. The present invention has been made in view of the above-described problems. An optical scanning device capable of efficiently scanning a plurality of color lights according to the output balance of each color light, a control method for the optical scanning device, and an image display An object is to provide an apparatus.

  In order to solve the above-described problems and achieve the object, according to the present invention, a plurality of light source units for supplying beam-shaped light, and beam-shaped light from the light source unit in the irradiated region And a scanning unit that scans in a second direction substantially orthogonal to the first direction, and the light source unit includes a first color light source unit that supplies first color light that is beam-shaped light, and A second color light source unit that supplies second color light that is beam-shaped light, and the first color light source units and the second color light source units are provided in different numbers. An optical scanning device can be provided.

  By providing different numbers of the first color light source units and the second color light source units, the output balance can be achieved when the first color light source units and the second color light source units have a difference in maximum output. The number of light sources for each color light can be determined according to the above. Therefore, it is not necessary to drop the output of the color light source unit with a large maximum output to the same level as the output of another color light source unit with a small maximum output, and the color light source unit with a large maximum output is wasted. You can avoid that. As a result, an optical scanning device capable of efficiently scanning a plurality of color lights according to the output balance of each color light can be obtained. In addition, since it is not necessary to provide a color light source unit having a large maximum output more than necessary, the optical scanning device can be configured simply and inexpensively.

  According to a preferred aspect of the present invention, the light source unit includes a red light source unit that supplies red light, and the red light source unit is the smallest number of light source units provided for each color light. It is desirable to be provided. Generally, the maximum output of the light source unit for R light is larger than that of other light source units for color light. For this reason, by reducing the number of R light source units among the light source units provided for each color light, the output of the R light source unit is reduced to the same level as the outputs of the other color light source units. There is no need to drop the light source unit, and it is possible to avoid the waste of the R light source unit. Thereby, each color light can be efficiently scanned according to the output balance.

  According to a preferred aspect of the present invention, the scanning unit is configured such that the frequency at which the beam-shaped light is scanned in the first direction is higher than the frequency at which the beam-shaped light is scanned in the second direction. It is desirable to drive and scan at least the first color light and the second color light at different frequencies in the first direction. Even if a light source having a different number for each color light is applied as it is to the conventional configuration that is premised on using the same number of light sources for each color light, it is very difficult to obtain an image according to the image signal. . In this aspect, the driving frequency of the scanning unit can be made different for the first color light and the second color light according to the number of the respective light source units. By scanning each color light at a different frequency according to the number of light source units, it is possible to scan each color light on the same number of scanning lines in the same frame period. Thereby, an image can be displayed using the first color light and the second color light.

  Further, as a preferred aspect of the present invention, the first color light source unit and the second color light source unit are configured to cause the spot of the first color light and the spot of the second color light in the irradiated region to be mutually in the second direction. The scanning units are arranged in parallel with each other, and the scanning unit scans the first color light from the first color light source unit and the second color light from the second color light source unit. And a scanning unit. Thereby, the first color light and the second color light can be scanned at different frequencies.

  In a preferred aspect of the present invention, the scanning unit is driven so that the frequency at which the beam-shaped light is scanned in the first direction is higher than the frequency at which the beam-shaped light is scanned in the second direction. In addition, it is desirable that the first color light and the second color light are scanned at the same frequency in the first direction. By scanning the first color light and the second color light at the same frequency, each color light can be scanned on the same number of scanning lines using one scanning unit in the same frame period. Thereby, it is possible to display an image using the first color light and the second color light with a simple configuration.

  Further, as a preferred aspect of the present invention, the first color light source unit and the second color light source unit are configured to cause the spot of the first color light and the spot of the second color light in the irradiated region to be mutually in the second direction. It is desirable that the same number be arranged in parallel. With this configuration, it is possible to scan the first color light and the second color light at the same frequency using one scanning unit. Thereby, the first color light and the second color light can be scanned at the same frequency.

  Further, as a preferred aspect of the present invention, the first color light source unit and the second color light source unit are configured to cause the spot of the first color light and the spot of the second color light in the irradiated region to be mutually in the second direction. The scanning unit is arranged so as to be arranged in parallel with each other, and the scanning unit, for each number of rows equal to or less than the number of spots with the smaller number of spots arranged in parallel in the second direction, among the spots with the first color light and the spots with the second color light, It is desirable to scan the beam of light in the first direction. With this configuration, it is possible to scan the first color light and the second color light at the same frequency using one scanning unit. Thereby, the first color light and the second color light can be scanned at the same frequency.

  Furthermore, according to the present invention, at least the first color light and the second color light that are beam-shaped light are supplied, and the beam-shaped light supplied in the light supply process is the first in the irradiated region. 1 and a scanning step of scanning in a second direction substantially orthogonal to the first direction. In the light supply step, the first color light and the second color light are supplied so as to have different numbers. In the scanning step, the frequency at which the beam-shaped light is scanned in the first direction is higher than the frequency at which the beam-shaped light is scanned in the second direction, and at least the first color light in the first direction. It is possible to provide a method of controlling an optical scanning device characterized in that the second color light and the second color light are scanned at different frequencies. By supplying the first color light source units and the second color light source units in different numbers, it is possible to efficiently scan a plurality of color lights according to the output balance of each color light. In addition, for the first color light and the second color light, it is possible to vary the drive frequency of the scanning unit according to the number of the respective light source units. By scanning each color light at a different frequency according to the number of light source sections, each color light can be scanned on the same number of scanning lines in the same frame period. Thereby, an image can be displayed using the first color light and the second color light.

  Furthermore, according to the present invention, at least the first color light and the second color light that are beam-shaped light are supplied, and the beam-shaped light supplied in the light supply process is the first in the irradiated region. 1 and a scanning step of scanning in a second direction substantially orthogonal to the first direction. In the light supply step, the first color light and the second color light are supplied so as to be equal in number to each other. In the scanning step, the frequency at which the beam-shaped light is scanned in the first direction is higher than the frequency at which the beam-shaped light is scanned in the second direction, and at least the first color light in the first direction. And the second color light can be scanned at the same frequency, and a method for controlling the optical scanning device can be provided. By supplying the first color light source units and the second color light source units in different numbers, it is possible to efficiently scan a plurality of color lights according to the output balance of each color light. Further, by scanning the first color light and the second color light at the same frequency, it is possible to scan each color light on the same number of scanning lines using one scanning unit in the same frame period. Thereby, it is possible to display an image using the first color light and the second color light with a simple configuration.

  Furthermore, according to the present invention, there is provided an image display device for displaying an image by light from an optical scanning device, wherein the optical scanning device is the optical scanning device described above. Can do. By using the above optical scanning device, it is possible to efficiently scan a plurality of color lights according to the output balance of each color light. Thereby, an image display device capable of efficiently displaying a high-quality image according to the output balance of each color light can be obtained.

  Embodiments of the present invention will be described below in detail with reference to the drawings.

  FIG. 1 shows a schematic configuration of an image display apparatus 100 according to Embodiment 1 of the present invention. The image display device 100 is a so-called rear projector that supplies laser light to one surface of the screen 110 and observes an image by observing light emitted from the other surface of the screen 110. The image display device 100 displays an image by transmitting light from the optical scanning device 120 to the screen 110.

  The optical scanning device 120 includes a plurality of light source units 101 that supply laser light that is beam-like light. The laser light from the light source unit 101 passes through the projection optical system 102 and then enters the scanning unit 200. The scanning unit 200 scans the laser light from the light source unit 101 in the X direction that is the horizontal direction and the Y direction that is the vertical direction on the screen 110 that is the irradiated region. The X direction is the first direction, and the Y direction is the second direction substantially orthogonal to the first direction.

  The laser light from the optical scanning device 120 passes through the projection optical system 103 and then enters the reflection unit 105. The reflection unit 105 is provided on the inner surface of the housing 107 at a position facing the screen 110. The reflection unit 105 reflects the laser beam from the optical scanning device 120 toward the screen 110. The housing 107 seals the space inside the housing 107. The screen 110 is provided on a predetermined surface of the housing 107. The screen 110 is a transmissive screen that transmits laser light from the optical scanning device 120 modulated in accordance with an image signal. The light from the reflection unit 105 enters from the surface of the screen 110 on the inner side of the housing 107 and then exits from the surface on the viewer side. The observer observes the image by observing the light emitted from the screen 110.

  FIG. 2 shows a schematic configuration of the optical scanning device 120. The light source unit 101 includes an R light source unit 101R, a G light source unit 101G, and a B light source unit (not shown). As the R light source unit 101R and the B light source unit, for example, a semiconductor laser provided with a modulation unit for modulating laser light, or a solid-state laser can be used. As the G light source unit 101G, for example, a semiconductor laser pumped solid state (hereinafter referred to as “DPSS”) laser oscillator can be used. The DPSS laser is a laser that is supplied by exciting a solid crystal with laser light from a laser diode. The laser beam supplied from the solid crystal is emitted after being converted into a laser beam having a half wavelength, for example. The maximum output of each color light source unit is different for each color light. For example, the R light source unit 101R can supply up to 500 milliwatts, the G light source unit 101G can supply up to 60 milliwatts, and the B light source unit can supply up to 200 milliwatts of laser light.

  The image display apparatus 100 displays a color image by scanning R light, G light, and B light. Here, only the configuration for scanning R light and G light is illustrated and described. The R light source unit 101R is a first color light source unit that supplies R light as first color light. The light source unit for G light 101G is a light source unit for second color light that supplies G light that is second color light. As the light source units 101R and 101G for the respective color lights, either amplitude modulation or pulse width modulation may be used for modulation according to the image signal. While the R light source unit 101R is provided independently, the three G light source units 101G are provided in parallel. The R light source units 101R and the G light source units 101G are provided in different numbers according to the respective output balances.

  FIG. 3 explains the arrangement of the G light source 101G. It is assumed that the a direction and the b direction substantially orthogonal to the a direction in the G light source unit 101G correspond to the X direction and the Y direction on the screen 110, respectively. The three G light source parts 101G are provided in parallel in the b direction. Three spots SP are arranged in the Y direction on the screen 110 by the G light from the three G light source sections 101G. The light source unit for R light 101R and the light source unit for G light 101G have different numbers of the spot SP by the R light and the spot SP by the G light in the Y direction that is the second direction on the screen 110 that is the irradiated region. Are arranged in parallel. Further, the G light source section 101G is provided at intervals such that the spots SP are arranged in parallel at the pixel pitch.

  Returning to FIG. 2, the scanning unit 200 includes an R light scanning unit 200R and a G light scanning unit 200G. The R light scanning unit 200R is a first scanning unit that scans the R light from the R light source unit 101R. The G light scanning unit 200G is a second scanning unit that scans the G light from the G light source 101G. The R light scanned by the R light scanning unit 200R and the G light scanned by the G light scanning unit 200G are superimposed on the screen 110.

  The projection optical system 102 provided between the R light source unit 101R and the R light scanning unit 200R and between the G light source unit 101G and the G light scanning unit 200G includes a convex lens 202 and a concave lens 203. It is configured by combining. A projection optical system 103 between the scanning unit 200 and the screen 110 forms an image of the laser light from the light source unit 101 on the screen 110. By using the projection optical systems 102 and 103, a high-definition image can be displayed on the screen 110.

  In addition, the projection optical system 102 provided between the G light source 101G and the G light scanning unit 200G uses the convergence action of the convex lens 202 and the diffusion action of the concave lens 203 to change the G light to the pixel pitch. It also plays a role in supplying the products with a corresponding interval. In addition, the projection optical system 102 is not limited to the case where the projection lens 202 and the concave lens 203 are configured, and other configurations capable of supplying G light at intervals corresponding to the pixel pitch, such as using a single lens or prism, are used. Also good.

  FIG. 4 shows a schematic configuration of the scanning unit 200. The scanning unit 200 has a so-called double gimbal structure that includes a reflection mirror 205 and an outer frame portion 204 provided around the reflection mirror 205. The outer frame portion 204 is connected to a fixed portion (not shown) by a torsion spring 206 that is a rotating shaft. The outer frame portion 204 rotates around the torsion spring 206 using the twist of the torsion spring 206 and the restoration to the original state. The reflection mirror 205 is connected to the outer frame portion 204 by a torsion spring 207 that is a rotation axis substantially orthogonal to the torsion spring 206. The reflection mirror 205 reflects the laser light from the light source unit 101. The reflection mirror 205 can be configured by forming a highly reflective member, for example, a metal thin film such as aluminum or silver.

  The reflection mirror 205 is displaced so that the laser beam is scanned in the Y direction (see FIG. 1) on the screen 110 when the outer frame portion 204 rotates around the torsion spring 206. Further, the reflection mirror 205 rotates around the torsion spring 207 using the twist of the torsion spring 207 and the restoration to the original state. The reflection mirror 205 is displaced so as to scan the laser beam reflected by the reflection mirror 205 in the X direction by rotating about the torsion spring 207. As described above, the scanning unit 200 emits the laser light from the light source unit 101 in the X direction, which is the first direction, in the screen 110 that is the irradiation region, and in the second direction substantially orthogonal to the first direction. Scan in the Y direction.

  FIG. 5 illustrates a configuration for driving the scanning unit 200. Assuming that the side on which the reflecting mirror 205 reflects the laser light is the front side, the first electrodes 301 and 302 are spaces on the back side of the outer frame portion 204 and are provided at substantially symmetrical positions with respect to the torsion spring 206. Yes. When a voltage is applied to the first electrodes 301 and 302, a predetermined force corresponding to the potential difference, for example, an electrostatic force, is generated between the first electrodes 301 and 302 and the outer frame portion 204. The outer frame portion 204 rotates about the torsion spring 206 by alternately applying a voltage to the first electrodes 301 and 302.

  Specifically, the torsion spring 207 includes a first torsion spring 307 and a second torsion spring 308. A mirror-side electrode 305 is provided between the first torsion spring 307 and the second torsion spring 308. A second electrode 306 is provided in the space behind the mirror side electrode 305. When a voltage is applied to the second electrode 306, a predetermined force according to the potential difference, for example, an electrostatic force, is generated between the second electrode 306 and the mirror side electrode 305. When a voltage having the same phase is applied to any of the second electrodes 306, the reflection mirror 205 rotates about the torsion spring 207. The scanning unit 200 rotates the reflection mirror 205 in this way, thereby scanning the laser light in a two-dimensional direction. The scanning unit 200 can be created by, for example, MEMS (Micro Electro Mechanical Systems) technology.

  For example, during one frame period of the image, the scanning unit 200 moves the reflection mirror 205 so as to reciprocate the laser light a plurality of times in the horizontal X direction while scanning the laser light once in the vertical Y direction. Displace. Thus, the scanning unit 200 is driven so that the frequency of scanning the laser beam in the X direction, which is the first direction, is higher than the frequency of scanning the laser beam in the Y direction, which is the second direction. The Note that the R light scanning unit 200R and the G light scanning unit 200G are different in only the reflected color light and have the same configuration.

  In order to scan the laser beam in the X direction at high speed, it is desirable that the scanning unit 200 is configured to resonate the reflection mirror 205 around the torsion spring 207. By resonating the reflection mirror 205, the amount of displacement of the reflection mirror 205 can be increased. By increasing the displacement amount of the reflection mirror 205, the scanning unit 200 can efficiently scan the laser beam with less energy. Note that the reflection mirror 205 may be driven without using resonance.

  The scanning unit 200 is not limited to a configuration that is driven by an electrostatic force corresponding to a potential difference. For example, the structure driven using an electromagnetic force and the structure driven using the expansion-contraction force of a piezoelectric element may be sufficient. When the electromagnetic force is used, the scanning unit 200 can be driven by generating an electromagnetic force between the reflection mirror 205 and the permanent magnet according to the current. The scanning unit 200 may include a reflection mirror that scans the laser light in the X direction and a reflection mirror that scans the laser light in the Y direction.

  FIG. 6 illustrates an aspect of scanning of R light on the screen 110. The R light from the R light source unit 101 </ b> R starts scanning from the upper left part of the screen 110 when viewed from the incident side of the screen 110. When the R light scanning unit 200R scans the R light in the plus X direction, the spot SP moves on the pixels P in the first row as counted from the plus Y side. When scanning of the first row by the spot SP is completed, the R light scanning unit 200R changes the scanning direction of the R light from the plus X direction to the minus X direction. While the R light scans in the plus X direction and further from the plus X direction to the minus X direction, the R light scanning unit 200R displaces the laser beam in the minus Y direction so that the spot SP is scanned in the second row. Let Then, the spot SP moves in the minus X direction on the pixel P in the second row. The R light scanning unit 200R scans the laser light in the X direction for each row.

  FIG. 7 is a diagram for explaining how the G light is scanned on the screen 110. Here, it is assumed that the three spots SP appearing on the screen 110 are assigned numbers 1, 2, and 3, respectively. When the G light scanning unit 200G scans each G light in the plus X direction, the spot SP1 moves on the pixels P in the first row. The spot SP2 moves on the pixel P in the second row. The spot SP3 moves on the pixel P in the third row. While each G light scans in the plus X direction and further from the plus X direction to the minus X direction, the G light scanning unit 200G has the spot SP1 in the fourth row, the spot SP2 in the fifth row, and the spot SP3 in the six rows. The laser beam is displaced in the negative Y direction so that the eye scans.

  The spot SP1 moves on the fourth row of pixels P, the spot SP2 moves on the fifth row of pixels P, and the spot SP3 moves on the sixth row of pixels P in the negative X direction. The G light scanning unit 200G scans the G light in the X direction for every three rows on the screen 110 that are the same as the number of spots SP arranged in parallel in the Y direction. Since the G light source 101G is provided so that the spots SP are arranged in parallel at the pixel pitch, an image corresponding to the image signal can be accurately displayed by scanning the G light every three rows. By repeating this, the optical scanning device 120 scans the R light and the G light on substantially the entire surface of the screen 110. For both the R light and the G light, the gradation of the pixel P is expressed by a single laser beam.

  The optical scanning device 120 causes the R light scanning unit 200R to scan the R light three times in the X direction while the G light scanning unit 200G scans the G light once in the X direction. The driving frequency of the G light scanning unit 200G is approximately one third of the driving frequency of the R light scanning unit 200R. As described above, the R light scanning unit 200R and the G light scanning unit 200G have different frequencies for the R light that is the first color light and the G light that is the second color light with respect to the X direction that is the first direction. Let it scan. By scanning each color light at a different frequency according to the number of light sources 101, each color light can be scanned on the same number of scanning lines in the same frame period.

  FIG. 8 illustrates a configuration for controlling scanning of G light. The image signal input unit 111 performs characteristic correction and amplification of the image signal input from the input terminal. The synchronization / image separation unit 112 separates the signal from the image signal input unit 111 into an image information signal, a vertical synchronization signal, and a horizontal synchronization signal for each of R light, G light, and B light, and outputs them to the control unit 113. To do. Of the control unit 113, the scanning control unit 123 generates a drive signal for driving each scanning unit 200 based on the vertical synchronization signal and the horizontal synchronization signal. At this time, the scanning control unit 123 drives the G light scanning unit 200G so that the driving frequency of the G light scanning unit 200G is approximately one third of the driving frequency of the R light scanning unit 200R. Generate a signal. The G light scanning drive unit 115G drives the G light scanning unit 200G in response to a drive signal from the control unit 113.

  The horizontal angle sensor 125 detects the swing angle of the reflection mirror 205 (see FIG. 4) that causes the screen 110 to scan the laser beam in the X direction. The vertical angle sensor 126 detects the swing angle of the reflection mirror 205 that causes the screen 110 to scan the laser beam in the Y direction. The signal processing unit 127 generates a frame start signal F_Sync from the displacement of the vertical angle sensor 126 and generates a line start signal L_Sync from the displacement of the horizontal angle sensor 125, and outputs them to the control unit 113.

  The image processing unit 121 divides the image information input to the control unit 113 into information for each scanning line and outputs the information to the frame memory 114. The frame memory 114 stores the image signal from the image processing unit 121 in units of frames. The light source control unit 122 outputs an image information signal for each row read from the frame memory 114. Further, the control unit 113 generates a pixel timing clock based on the frame speed calculated from the frame start signal F_Sync, the line start signal L_Sync, the vertical synchronization signal, and the horizontal synchronization signal. The pixel timing clock is a signal for knowing the timing at which the laser beam passes on each pixel, and is for causing the laser beam modulated in accordance with the image signal to enter an accurate position.

  The light source sharing control unit 116G determines the G light source unit 101G to be driven based on the image information signal input from the control unit 113. For example, the light source sharing control unit 116G assigns the spot SP2 to the pixel P in the first row, the spot SP2 to the pixel P in the second row, and the spot SP3 to the pixel P in the third row. The light source drive timing unit 117G determines the drive timing of the G light source unit 101G so that the G light source unit 101G is turned on in synchronization with the pixel timing clock. The G light source drive unit 118G drives the G light source unit 101G assigned by the light source sharing control unit 116G at the drive timing determined by the light source drive timing unit 117G. The configuration for controlling the scanning of the R light is the same as the configuration for controlling the scanning of the G light. However, since only one R light source unit 101R is used for the R light, a light source sharing control unit is not required. With this configuration, each color light can be scanned at a different frequency according to the number of light source units 101.

  In general, the R light source unit 101R has a larger maximum output than other color light source units, whereas the G light source unit 101G has a smaller maximum output than other color light source units. In order to obtain a good white balance, it is desirable to adjust the intensity of R light, G light, and B light to, for example, 2: 1: 1 or 3: 1: 1. The optical scanning device 120 can determine the number of light source units 101R and 101G necessary for each color light in order to obtain a good white balance in accordance with the output balance of the light source units 101R and 101G. In the present embodiment, the necessary number of B light source units can be determined according to the output balance. In this embodiment, the first color light is R light and the second color light is B light. However, the first color light and the second color light can be appropriately selected from R light, G light, and B light.

  In addition, it may be difficult for the G light source unit 101G to perform high-speed modulation as compared with other color light source units. In the present embodiment, by increasing the number of light sources for G light 101G, the light source for G light 101G can be driven at a slow driving frequency. Accordingly, accurate display can be performed according to the image signal even when the light source unit 101, which is difficult to perform high-speed modulation, is used.

  Further, it is desirable that the light source unit for R light 101R is provided in the smallest number among the light source units 101 provided for each color light. In general, the R light source unit 101R has a larger maximum output than other color light source units. For this reason, it is not necessary to drop the output of the light source unit for R light 101R to the same level as the output of other light source units for color light, and the situation where the light source unit for R light 101R is wasted can be avoided. As described above, there is an effect that a plurality of color lights can be efficiently scanned according to the output balance of each color light, and a high-quality image can be efficiently displayed. The optical scanning device 120 can have a simple and inexpensive configuration because it is not necessary to provide a color light source unit with a large maximum output more than necessary.

  The scanning unit 200 may provide a unique B light scanning unit for the B light. When the number of B light source units is different from that of the R light source unit 101R and the G light source unit 101G, the G light can be scanned according to the number of the B light source units. Further, when the number of light sources for B light is the same as that for the light sources for R light 101R or the light source for G light 101G, the B light uses the R light scanning unit 200R or the G light scanning unit 200G. Scanning may be performed. The image display apparatus 100 according to the present embodiment displays an image using R light, G light, and B light, but may be configured to display an image using another color light. In this case, the necessary number of light source units that supply color light other than R, G, and B can be determined according to the output balance.

  FIG. 9 is a diagram for explaining an optical scanning device according to the first modification of the present embodiment, and shows a scanning mode of G light on the screen 110. The optical scanning device according to this modification is characterized in that a G light source 101G is provided so that the spot SP by G light is arranged in parallel in the X direction, which is the first direction. When attention is paid to the pixel P in the first row, the gradation of the pixel P is expressed by three spots SP3, 2, 1 that continuously irradiate the position of the pixel P. The three G light source sections 101G perform modulation for expressing the gradation of the pixel P at the timing when the spots SP1, 2, 3 pass the position of the pixel P. In the optical scanning device 120 described above, the gradation of the pixel P is expressed by a single laser beam. In the present modification, the gradation of the pixel P is expressed using three laser beams for the G light. Yes.

  The three G light source units 101G, for example, perform gradation expression by sharing 64, 64, and 128 gradations, respectively. For example, when displaying 250 gradations, the G light forming the spot SP1 displays 58 gradations, the G light forming the spot SP2 displays 64 gradations, and the G light forming the spot SP3 displays 128 gradations. Modulated. Since the gradation is expressed using the G light from the three G light source sections 101G, it is possible to reduce the power required to express the gradation. For this reason, it can be set as the structure suitable for the light source part 101G for G light with a small maximum output. The number of light source units 101 corresponding to the output balance can also be provided by arranging a plurality of laser beams in parallel in the X direction.

  When a plurality of light source units that supply the same color light are used, the spots may be juxtaposed in the Y direction as in the optical scanning device 120 described above, or the spots may be juxtaposed in the X direction as in this modification. . Furthermore, in the case of this modification, since the G light is also scanned for each row, it is possible to scan all the color lights using one scanning unit 200. As a result, the optical scanning device can have a simple configuration.

  FIG. 10 shows a characteristic part of the optical scanning device according to the second modification of the present embodiment. The optical scanning device according to this modification has two polygon mirrors 210R and 210G. The polygon mirror 210R is a first scanning unit that scans the R light from the R light source unit 101R. The polygon mirror 210G is a second scanning unit that scans the G light from the G light source unit 101G. The polygon mirror 210R scans the R light by rotating around the axis X and moving the six mirror pieces 211R. The polygon mirror 210G scans the G light by rotating around the axis X and moving the four mirror pieces 211G. The polygon mirrors 210R and 210G are both provided so that the axes X coincide with each other.

  Two R lights enter the polygon mirror 210R from the R light source 101R. When the polygon mirror 210R rotates once, the two R lights scan 12 rows by the six mirror pieces 211R. Further, three G lights are incident on the polygon mirror 210G from the G light source unit 101G. When the polygon mirror 210G makes one rotation, the three G lights scan 12 rows by the four mirror pieces 211G. In this way, even when the polygon mirrors 210R and 210G are rotated integrally with each other, the R light and the G light can be scanned at different driving frequencies. Further, by varying the driving frequencies of the R light scanning unit 200R and the G light scanning unit 200G according to the numbers of R light and G light, the R light and G light are scanned on the same number of scanning lines in the same frame period. The light can be scanned.

  FIG. 11 is a diagram for explaining an optical scanning device according to the second embodiment of the present invention, and shows an arrangement of spots SP of each color light on the screen 110. The optical scanning apparatus according to the present embodiment can be applied to the image display apparatus 100 according to the first embodiment. The same parts as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted. The optical scanning device of the present embodiment is characterized in that each color light is scanned at the same frequency in the X direction which is the first direction by the scanning unit.

  In the screen 110, two spots SPR are arranged in the Y direction by the R light from the two light sources for R light. For the B light, two spots SPB are arranged in the Y direction. For G light, two spots SPG in the Y direction and four spots SPG in the X direction are arranged in an array. As described above, in the present embodiment, the light sources for the respective color lights are arranged so that the spots SP by the respective color lights on the screen 110 that is the irradiated area are all arranged in parallel in the Y direction that is the second direction. Yes.

  FIG. 12 shows a schematic configuration of the optical scanning device 220 of the present embodiment. The G light source sections 101G are arranged in a 4 × 2 array. In the figure, among the eight G light source sections 101G, only four on the front side of the sheet are shown. Two each of the R light source unit 101R and the B light source unit 101B are provided. The R light source unit 101R and the B light source unit 101B are arranged in a direction substantially orthogonal to the direction in which the G light source unit 101G supplies G light. The position where the G light from the G light source unit 101G and the B light from the B light source unit 101B intersect, and the G light from the G light source unit 101G and the R light from the R light source unit 101R Dichroic mirrors 213 and 214 are provided at the positions where the two intersect. The dichroic mirror 213 transmits G light and reflects B light. The dichroic mirror 214 transmits G light and B light and reflects R light.

  The G light from the G light source unit 101 </ b> G passes through the projection optical system 102 and the two dichroic mirrors 213 and 214 and then enters the scanning unit 200. The B light from the B light source unit 101B is reflected by the dichroic mirror 213 and travels in the direction of the dichroic mirror 214 after the optical path is bent 90 degrees. The B light traveling in the direction of the dichroic mirror 214 passes through the dichroic mirror 214 and then enters the scanning unit 200. The R light from the R light source unit 101R is reflected by the dichroic mirror 214 and is incident on the scanning unit 200 after the optical path is bent 90 degrees.

  The eight G light beams from the G light source unit 101G enter the scanning unit 200 after being narrowed down by the projection optical system 102. The G light is emitted at substantially the same interval as the pixel pitch by using the projection optical system 102. On the other hand, the R light from the R light source unit 101R enters the scanning unit 200 with the interval emitted from the two R light source units 101R. In this way, R light, G light, and B light are incident on the scanning unit 200 through substantially the same optical path. Since each color light is scanned by one scanning unit 200, the optical scanning device 220 scans each color light at the same frequency. Thereby, in the same frame period, each color light can be scanned on the same number of scanning lines using one scanning unit 200.

  The two light sources for R light 101R are arranged so that the two R lights are supplied at intervals corresponding to the pixel pitch. The two light sources for B light 101B are also arranged so that the two B lights are supplied at intervals corresponding to the pixel pitch. In this way, if the laser light can be supplied at intervals corresponding to the pixel pitch, an optical system for adjusting the interval between the laser beams is unnecessary, and the optical scanning device can be simplified. For the G light, the G light source 101G may be provided so that eight G lights are emitted at substantially the same interval as the pixel pitch without using the projection optical system 102. Further, the interval between the R light and the B light may be narrowed using the projection optical system 102.

  FIG. 13 illustrates a scanning mode of each color light on the screen 110. Here, the spots SP1 and SP2 for each color light arrayed in the Y direction are illustrated and described. Of each color light, the laser light forming the spot SP1 moves on the pixels P in the first row. The laser beam forming the spot SP2 moves on the pixels P in the second row. When the movement on the pixels P in the first row and the second row is finished, each laser beam then moves on the pixels P in the third row and the fourth row. The scanning unit 200 scans the laser beam in the X direction every two rows that are the same as the number of spots SP arranged in parallel in the Y direction on the screen 110. Further, since the spot SP of the G light is also arranged in the X direction, the gradation of the G light is expressed by using four G lights in which the spot SP is arranged in the X direction. For R light and B light, gradation is expressed using a single laser beam.

  FIG. 14 illustrates a configuration for controlling scanning of R light, G light, and B light. Of the control unit 113, the scanning control unit 123 generates a drive signal for driving the scanning unit 200 based on the vertical synchronization signal and the horizontal synchronization signal. The scan driving unit 115 drives the scanning unit 200 in response to a drive signal from the control unit 113.

  The R intensity control signal generation unit 241R generates an intensity control signal corresponding to the number of R light source units 101R based on the R light image information signal input from the control unit 113. The light source sharing control unit 116R determines the R light source unit 101R to be driven based on the intensity control signal from the R intensity control signal generation unit 241R. For example, the light source sharing control unit 116R assigns the spot SP1 to the pixels P in the first row and the spot SP2 to the pixels P in the second row. The light source drive timing unit 117R determines the drive timing of the R light source unit 101R so that the R light source unit 101R is lit in synchronization with the pixel timing clock. The R light source drive unit 118R drives the R light source unit 101R assigned by the light source sharing control unit 116R at the drive timing determined by the light source drive timing unit 117R.

  The G intensity control signal generation unit 241G generates an intensity control signal corresponding to the number of G light source units 101G based on the G light image information signal input from the control unit 113. The light source sharing control unit 116G determines the G light source unit 101G to be driven based on the intensity control signal from the G intensity control signal generation unit 241G. For example, the light source sharing control unit 116G assigns the spot SP1 to the pixel P in the first row and the spot SP2 to the pixel P in the second row, and further assigns the gradation to the four G lights. The light source drive timing unit 117G determines the drive timing of the G light source unit 101G so that the G light source unit 101G is turned on in synchronization with the pixel timing clock. The G light source drive unit 118G drives the G light source unit 101G assigned by the light source sharing control unit 116G at the drive timing determined by the light source drive timing unit 117G.

  The B intensity control signal generation unit 241B generates an intensity control signal according to the number of B light source units 101B based on the image information signal for B light input from the control unit 113. The light source sharing control unit 116B determines the B light source unit 101B to be driven based on the intensity control signal from the B intensity control signal generation unit 241B. For example, the light source sharing control unit 116B assigns the spot SP1 to the pixels P in the first row and the spot SP2 to the pixels P in the second row. The light source drive timing unit 117B determines the drive timing of the B light source unit 101B so that the B light source unit 101B is turned on in synchronization with the pixel timing clock. The light source drive unit for B light 118B drives the light source unit for B light 101B assigned by the light source sharing control unit 116B at the drive timing determined by the light source drive timing unit 117B.

  In the present embodiment, similarly to the first embodiment, it is possible to efficiently scan a plurality of color lights according to the output balance of each color light. Further, in the present embodiment, since each color light is scanned by one scanning unit 200, the optical scanning device 220 can have a simple configuration. Thereby, a high-quality image can be efficiently displayed with a simple configuration. In the present embodiment, the same number of spots SP are arranged in parallel for all color lights, but the same number of spots SP for at least two color lights, for example, R light as the first color light and G light as the second color light. Any configuration may be used as long as they are arranged in parallel. Thereby, at least R light and G light can be scanned at the same frequency by using one scanning unit 200.

  FIG. 15 illustrates an optical scanning device according to the first modification of the present embodiment, and illustrates a scanning mode of each color light. This modification is the same as the optical scanning device 220 described above in that the light sources for each color light are arranged so that two spots SP by each color light are arranged in parallel in the Y direction. In this modification, the scanning unit scans the laser beam in the X direction for each row that is smaller than the number of spots SP arranged in parallel in the Y direction.

  When the scanning unit scans each laser beam in the plus X direction at the start of scanning, first, the laser beam forming the spot SP2 moves on the pixels P in the first row. The laser beam forming the spot SP2 finishes scanning the first row and starts scanning the second row. At the same time, the laser beam forming the spot SP1 starts scanning the first row. Since the light sources for the respective color lights are provided so that the spots SP are arranged in parallel at the pixel pitch, an image corresponding to the image signal can be accurately displayed by scanning the laser beam for each row. Focusing on one pixel P in the first row, for the R light and B light, the laser light forming the spot SP1 passes after the laser light forming the spot SP2 passes. The gradation expression of R light and B light is performed using two laser beams.

  As for the G light, after the four laser beams forming the spot SP1 pass, the four laser beams forming the spot SP1 pass through. The gradation expression of the G light is performed using eight laser beams. The gradation expression using a plurality of laser beams can be performed in the same manner as the modification of the first embodiment described with reference to FIG. Also according to this modification, it is possible to scan a necessary number of laser beams according to the output balance. The present modification may be configured to scan the laser beam for each row smaller than the number of spots SP arranged in parallel in the Y direction. For example, four spots SP are arranged in parallel in the Y direction and the laser beam is emitted every two rows. It is good also as making it scan.

  FIG. 16 illustrates an optical scanning device according to the second modification of the present embodiment, and illustrates a scanning mode of each color light. The present modification is characterized in that each color light is scanned on the screen 110 for each of the irradiated areas AR1 and AR2 divided into two in the Y direction. Of each color light, the laser light forming the spot SP1 scans the irradiated area AR1. In addition, laser light for forming the spot SP2 among the color lights scans the irradiated area AR2. Thus, in this modification, the irradiated region is shared for each spot SP arranged in parallel in the Y direction. Both the laser beam that scans the irradiated area AR1 and the laser beam that scans the irradiated area AR2 perform scanning for each row.

  In this way, in order to disperse the laser light into the irradiated area AR1 and the irradiated area AR2, for example, the color light source sections that form the spots SP1 and the color light source sections that form the spots SP2 are separated. It can be set as the structure provided. In addition, it is possible to change the optical path of the laser beam for forming the spot SP1 in the direction of the irradiated area AR1, and the laser beam for forming the spot SP2 in the direction of the irradiated area AR2. In the case of this modification, it is possible to scan the required number of laser beams according to the output balance, and there is an advantage that the scanning width in the Y direction can be reduced. Note that the irradiated region may be divided into three or more according to the number of spots SP arranged in parallel in the Y direction.

  FIG. 17 illustrates an optical scanning device according to the third modification of the present embodiment, and illustrates a scanning mode of G light among the respective color lights. Similar to the first embodiment, the present modification is characterized in that the spot SP by the R light and the spot SP by the G light are juxtaposed in different numbers in the Y direction that is the second direction. For G light, three spots SP are arranged in parallel in the Y direction. For the R light, one spot SP is formed as in the case of the first embodiment described with reference to FIG.

  In this modification, out of the number of spots SP that are smaller in number in the Y direction, which is the second direction, of the spots SP by the R light that is the first color light and the spots SP by the G light that is the second color light. For each number of rows, scanning in the X direction, which is the first direction, is performed. The optical scanning device performs scanning in the X direction for each row of the same number as the number of R light spots SP that are few in the Y direction among the R light and the G light. Also in this modification, R light and G light can be scanned at the same frequency by using one scanning unit as in the case of other modifications.

  The G light scans in the order of spot SP3, spot SP2, and spot SP1. The gradation expression of G light is performed using three laser beams. The R light is scanned in the same manner as that shown in FIG. The gradation expression of R light is performed using one laser beam. Also according to this modification, it is possible to scan a necessary number of laser beams according to the output balance. In this modification, for example, when two spots SP are arranged in parallel in the Y direction for the R light and four spots SP in the Y direction for the G light, the laser light can be scanned every two rows or one row. As in the case of the optical scanning device 220 described above, the spot SP may be arranged in parallel in the X direction as well as in the Y direction.

  FIG. 18 shows a schematic configuration of an image display apparatus 1700 according to the third embodiment of the present invention. The image display device 1700 is a so-called front projection type projector that supplies laser light to a screen 1705 provided on the viewer side and observes an image by observing light reflected on the screen 1705. The image display device 1700 includes the optical scanning device 120 as in the first embodiment. The same parts as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted. Laser light from the optical scanning device 120 passes through the projection optical system 103 and then enters the screen 1705. Also in this embodiment, a plurality of color lights can be efficiently scanned according to the output balance of each color light, and a high-quality image can be displayed efficiently.

  In each of the above embodiments, each color light source unit of the optical scanning device is configured to supply laser light. However, the present invention is not limited to this as long as beam-shaped light can be supplied. For example, each color light source unit may be configured to use a solid light emitting element such as a light emitting diode element (LED). Further, the optical scanning device of the present invention may be used in an electronic apparatus that scans laser light, such as a laser printer, in addition to the image display device.

  As described above, the optical scanning device according to the present invention is suitable for use in an image display device that scans light according to an image signal.

1 is a diagram illustrating a schematic configuration of an image display apparatus according to Embodiment 1 of the present invention. The figure which shows schematic structure of an optical scanning device. The figure explaining arrangement | positioning of the light source part for G lights. The figure which shows schematic structure of a scanning part. The figure explaining the structure for driving a scanning part. The figure explaining the aspect of the scanning of R light in a screen. The figure explaining the aspect of the scanning of G light in a screen. The figure explaining the structure for controlling the scanning of G light. FIG. 6 is a diagram illustrating an optical scanning device according to a first modification of the first embodiment. FIG. 6 is a diagram illustrating a characteristic part of an optical scanning device according to a second modification of the first embodiment. FIG. 6 is a diagram illustrating an optical scanning device according to a second embodiment of the invention. The figure which shows schematic structure of an optical scanning device. The figure explaining the aspect of the scanning of each color light in a screen. The figure explaining the structure for controlling the scanning of R light, G light, and B light. FIG. 6 is a diagram illustrating an optical scanning device according to a first modification of the second embodiment. FIG. 6 is a diagram illustrating an optical scanning device according to a second modification of the second embodiment. FIG. 10 is a diagram illustrating an optical scanning device according to a third modification of the second embodiment. FIG. 9 is a diagram illustrating a schematic configuration of an image display device according to a third embodiment of the invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 100 Image display apparatus, 101 Light source part, 102, 103 Projection optical system, 105 Reflection part, 107 Housing | casing, 110 Screen, 120 Optical scanning apparatus, 200 scanning part, 101RR light source part, 101G light source part for G light, 200R R light scanning part, 200G G light scanning part, 202 convex lens, 203 concave lens, SP spot, 204 outer frame part, 205 reflecting mirror, 206 torsion spring, 207 torsion spring, 301, 302 first electrode, 305 mirror Side electrode, 306 second electrode, 307 first torsion spring, 308 second torsion spring, P pixel, 111 image signal input unit, 112 image separation unit, 113 control unit, 114 frame memory, 115 G G light scanning Drive unit, 116G light source sharing control unit, 117G light source drive timing 118G light source drive unit, 121 image processing unit, 122 light source control unit, 123 scanning control unit, 125G horizontal angle sensor, 126G vertical angle sensor, 127G signal processing unit, 210R, 210G polygon mirror, 211R, 211G Mirror piece, 213, 214 Dichroic mirror, 101B light source unit for B light, 220 optical scanning device, 115 scan drive unit, 116R, 116B light source assignment control unit, 117R, 117B light source drive timing unit, 118R light source drive unit for R light, 118B light source drive unit for B light, 125 horizontal angle sensor, 126 vertical angle sensor, 127 signal processing unit, 241R R intensity control signal generation unit, 241G G intensity control signal generation unit, 241BB B intensity control signal generation unit, AR1, AR2 Irradiated area, 1700 Image display device , 1705 screen

Claims (10)

A plurality of light source units for supplying beam-shaped light;
A scanning unit that scans the beam-shaped light from the light source unit in a first direction in a region to be irradiated and in a second direction substantially orthogonal to the first direction;
The light source unit includes at least a first color light source unit that supplies the first color light that is the beam-shaped light and a second color light source unit that supplies the second color light that is the beam-shaped light. And
The optical scanning device, wherein the first color light source units and the second color light source units are provided in different numbers. The light source unit has a red light source unit for supplying red light,
2. The optical scanning device according to claim 1, wherein the red light source unit is provided in the smallest number among the light source units provided for each color light.   The scanning unit is driven such that a frequency for scanning the beam-shaped light in the first direction is higher than a frequency for scanning the beam-shaped light in the second direction, and 3. The optical scanning device according to claim 1, wherein at least the first color light and the second color light are scanned at different frequencies in the first direction. 4. The light source unit for the first color light and the light source unit for the second color light are arranged in parallel so that the spots by the first color light and the spots by the second color light in the irradiated region are different from each other in the second direction. Arranged to let
The scanning unit includes: a first scanning unit that scans the first color light from the first color light source unit; and a second scanning unit that scans the second color light from the second color light source unit. The optical scanning device according to claim 3, further comprising:   The scanning unit is driven such that a frequency for scanning the beam-shaped light in the first direction is higher than a frequency for scanning the beam-shaped light in the second direction, and 3. The optical scanning device according to claim 1, wherein at least the first color light and the second color light are scanned at the same frequency in the first direction. 4.   The light source unit for the first color light and the light source unit for the second color light are arranged in parallel so that the spot by the first color light and the spot by the second color light in the irradiated region are equal to each other in the second direction. The optical scanning device according to claim 5, wherein the optical scanning device is arranged so as to cause the optical scanning device. The light source unit for the first color light and the light source unit for the second color light are arranged in parallel so that the spots by the first color light and the spots by the second color light in the irradiated region are different from each other in the second direction. Arranged to let
The scanning unit includes the first scanning unit for each number of rows equal to or less than the number of the spots that are smaller in number in the second direction among the spots by the first color light and the spots by the second color light. The optical scanning device according to claim 5, wherein the beam-shaped light is scanned in the direction of. A light supplying step for supplying at least a first color light and a second color light which are beam-shaped light;
A scanning step of scanning the beam-shaped light supplied in the light supply step in a first direction in a region to be irradiated and in a second direction substantially orthogonal to the first direction;
In the light supply step, the first color light and the second color light are supplied so as to have different numbers,
In the scanning step, the frequency at which the beam-shaped light is scanned in the first direction is higher than the frequency at which the beam-shaped light is scanned in the second direction, and in the first direction. A control method for an optical scanning device, wherein at least the first color light and the second color light are scanned at different frequencies. A light supplying step for supplying at least a first color light and a second color light which are beam-shaped light;
A scanning step of scanning the beam-shaped light supplied in the light supply step in a first direction in a region to be irradiated and in a second direction substantially orthogonal to the first direction;
In the light supply step, the first color light and the second color light are supplied so as to have different numbers,
In the scanning step, the frequency at which the beam-shaped light is scanned in the first direction is higher than the frequency at which the beam-shaped light is scanned in the second direction, and in the first direction. The method of controlling an optical scanning device, wherein the first color light and the second color light are scanned at the same frequency. An image display device that displays an image by light from an optical scanning device,
The image display device according to claim 1, wherein the optical scanning device is the optical scanning device according to claim 1.

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