JP2007079087A - Image display apparatus and its control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image display apparatus and the like that scan a plurality of light beams and that enable uneven light quantity to be reduced through a simple and manufacturing-cost-reducible structure. <P>SOLUTION: This is an image display apparatus that displays an image by scanning a plurality of light beams. The apparatus is provided with a light source section 121R for supplying a plurality of light beams and a scanning section 200 for scanning the plurality of light beams from the light source section 121R, in the X direction of a first direction in a region to be irradiated and in the Y direction of a second direction nearly orthogonal to the first direction. The light source section 121R is designed to array in parallel the plurality of light beams at least in one of the X and Y directions. Among the spot positions and their in-between positions, formed in the region to be irradiated by the plurality of light beams, at least one position is made a reference point. On the basis of the position of the reference point moving with the scanning of the plurality of light beams, in the region to be irradiated, the light source section is driven in a manner adjusting the light quantity of the two or more light beams among the plurality of light beams. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image display device and a method for controlling the image display device, and more particularly to a technique of an image display device that displays an image by scanning a laser beam modulated according to an image signal.

  In recent years, a laser projector that displays an image by scanning laser light has been proposed as an image display device that displays an image. Since the laser light has a single wavelength, the color purity is high, the coherence is high, and shaping is easy. For this reason, the laser projector has an advantage that good color reproducibility and a high-resolution image can be obtained. In order to display an image with little flicker by raster scanning of laser light, it is necessary to scan the laser light at high speed. In order to modulate the laser beam scanned at high speed according to the image signal, it is necessary to make the modulation frequency for modulating the laser beam very high. Further, in order to display a bright image, a very large amount of laser light is required. In recent years, the feasibility of laser projectors is increasing due to the improvement of the modulation frequency due to the development of the modulation circuit and the significant increase in the amount of light due to the development of the manufacturing technology of the laser light source.

  When a single laser beam is scanned over the entire screen, there is an advantage that the image display device can be configured simply and at low cost. On the other hand, although the manufacturing technology of the laser light source has been developed, the laser light from a single laser light source is insufficient to cover the light amount necessary for displaying an image. Particularly in recent years, since the screen of the image display device tends to be enlarged, a larger amount of laser light is required. Thus, since it is extremely difficult to display an image by scanning a single laser beam, a technique for displaying an image by scanning a plurality of laser beams has been proposed (for example, Patent Documents). 1). When scanning a plurality of laser beams, the amount of light per laser beam can be reduced in inverse proportion to the number of laser beams.

Japanese National Patent Publication No. 8-509067

  For example, when the laser beam is scanned by resonating a reflection mirror that reflects the laser beam, the scanning speed of the laser beam is higher as it is closer to the center of the irradiated region and is lower as it is closer to the outer edge. In this case, even if the laser beam is scanned with a substantially uniform light amount, unevenness in the light amount is generated such that the irradiated region is darker at the center and brighter as it is closer to the outer edge. In order to reduce such unevenness in the amount of light, it is conceivable to adjust the amount of laser light according to the position where the laser light is scanned. However, when a plurality of laser beams are scanned, if the amount of light is adjusted for each laser beam, a circuit for adjusting the amount of laser light is provided by the number of laser beams. There arises a problem that it is difficult to make the configuration capable of reducing the cost. The present invention has been made in view of the above-described problems, and an image display device capable of reducing unevenness in light quantity by scanning a plurality of light beams and capable of reducing the manufacturing cost with a simple configuration capable of reducing manufacturing costs, and an image display An object is to provide a method for controlling an apparatus.

  In order to solve the above-described problems and achieve the object, according to the present invention, an image display device that displays an image by scanning a plurality of light beams, the light source unit supplying a plurality of light beams; And a scanning unit that scans a plurality of light beams from the light source unit in a first direction in a region to be irradiated and a second direction substantially orthogonal to the first direction. A plurality of light beams are arranged in parallel with respect to at least one of the first direction and the second direction, and at least one of the positions of the spots and the positions between the spots formed in the irradiated region by the plurality of light beams is provided. It is driven to adjust the light quantity of two or more of the plurality of light beams based on the position of the reference point in the irradiated region as the reference point and moving with the scanning of the plurality of light beams. Toss It is possible to provide an image display device.

  Here, the two or more light beams among the plurality of light beams include a case where it is a part of the plurality of light beams and a case where it is all of the plurality of light beams. By adjusting the light quantity of two or more light beams based on the position of the reference point, the light source unit can be controlled more easily than when adjusting the light quantity for each light beam based on the position of each light beam. Further, by adjusting the light amount of two or more beam lights with the position of the reference point as a representative, the configuration for adjusting the light amount of the laser light can be reduced. For this reason, compared with the case where the circuit for adjusting light quantity for every beam light, etc. are provided, an image display apparatus can be made a simple structure, and manufacturing cost can be reduced. If the light amounts of two or more light beams are adjusted based on the position of the reference point, it is conceivable that an error in the adjusted light amount occurs depending on the distance from the reference point to the light beam. With regard to this, if the error is equal to or less than the light amount difference for one gradation for displaying an image, it can be considered that there is almost no influence on the image. As a result, an image display device capable of reducing the unevenness in the amount of light can be obtained with a configuration that can scan a plurality of light beams and can easily reduce the manufacturing cost.

  According to a preferred aspect of the present invention, it is desirable that the light source unit is driven so as to adjust the light amount for all of the plurality of light beams based on the position of one reference point. By adjusting the light amount of all of the multiple light beams with the position of one spot as the reference point, it is possible to adjust the light amount of all the light beams using a single configuration for adjusting the light amount of the light beams. is there. Thereby, it can be set as the structure which can be further simplified and can reduce manufacturing cost.

  According to a preferred aspect of the present invention, it is desirable that the light source unit is driven so as to divide a plurality of light beams into two or more light beam groups and adjust the light amount for each light beam group. For each light beam group, the amount of light beam is adjusted based on the position of the reference point. By adopting a configuration in which the light quantity of two or more light beams is adjusted based on the reference point for each light beam group, the light quantity of the light source unit is compared with the case where the light quantity is adjusted for each light beam based on the position of each light beam. Easy to control. In addition, by adjusting the amount of light for each light beam group, it is possible to reduce the error of the adjusted light amount, compared to the case of adjusting the light amount of all the light beams based on one reference point. Become. Thereby, the error of the light quantity of beam light can be reduced.

  As a preferred aspect of the present invention, it is desirable that the light source unit has a reference point at a substantially center position of a line in which spots formed by two or more light beams are arranged in parallel. When the approximate center position of a line in which two or more light beams are arranged in parallel is used as the reference point, the distance between the reference point and the light beam farthest from the reference point can be made the shortest. Therefore, by setting the approximate center position of the line in which two or more light beams are arranged in parallel as the reference point, the error of the adjusted light amount can be minimized without increasing the reference point. Thereby, the error of the light quantity of beam light can be reduced.

  Moreover, as a preferable aspect of the present invention, it is desirable that the light source unit is configured to parallel a plurality of light beams in the first direction and the second direction in the irradiated region. By modulating a plurality of light beams in the first direction and the second direction, the modulation frequency of each light beam can be changed as compared with the case where the light beams are paralleled in one of the first direction and the second direction. Can be reduced. Even when a plurality of light beams are juxtaposed in the first direction and the second direction, the light amount of the light beam is adjusted so as to reduce the light amount unevenness in at least one direction of the first direction and the second direction. It can be carried out.

  In a preferred aspect of the present invention, the light source unit includes two or more beams in the first direction and the second direction based on the position in the irradiated region of the reference point that moves together with the scanning of the plurality of light beams. It is desirable to be driven so as to adjust the amount of light. Thereby, the light amount of the beam light can be adjusted so as to reduce the unevenness of the light amount in both the first direction and the second direction.

  Furthermore, according to the present invention, there is provided a control method for an image display device for displaying an image by scanning a beam of light, the beam light supplying step for supplying a plurality of light beams, and the irradiation with the plurality of light beams. A scanning step of scanning in a region in a first direction and a second direction substantially orthogonal to the first direction, and in the beam light supplying step, a plurality of at least one of the first direction and the second direction Of reference points that move with the scanning of a plurality of light beams, with at least one of the positions of the spots formed between the plurality of light beams and the positions between the spots as a reference point. A detection step for detecting a position in the irradiated region, and a light amount adjusting process for adjusting the light amount of two or more of the plurality of light beams based on the position of the reference point in the irradiated region. When the control method of the image display apparatus further comprising a can be provided. By adjusting the light quantity of two or more light beams based on the position of the reference point, the light source unit can be controlled more easily than when adjusting the light quantity for each light beam based on the position of each light beam. In addition, the image display device can have a simple configuration and the manufacturing cost can be reduced as compared with the case where a circuit for adjusting the amount of light for each light beam is provided. Thereby, a plurality of light beams can be scanned, and the unevenness in the amount of light can be reduced with a simple configuration that can reduce the manufacturing cost.

  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 apparatus 100 displays an image by scanning laser light, which is a plurality of light beams, in the X direction that is the horizontal direction and the Y direction that is the vertical direction.

  FIG. 2 shows a schematic configuration of the laser apparatus 101. The laser device 101 includes an R light source 121 </ b> R that supplies red laser light (hereinafter referred to as “R light”) that is beam light, and green laser light (hereinafter referred to as “G light”) that is a beam light. Light source unit 121G for supplying G light and B light source unit 121B for supplying blue laser light (hereinafter referred to as “B light”) which is beam light.

  Each of the color light source units 121R, 121G, and 121B supplies five laser beams modulated according to the image signal. Each color light source unit 121R, 121G, 121B includes, for example, five laser diode elements that supply laser light. The laser device 101 is provided with two dichroic mirrors 124 and 125. The dichroic mirror 124 transmits R light and reflects G light. The dichroic mirror 125 transmits R light and G light and reflects B light. The R light from the R light source unit 121 </ b> R passes through the dichroic mirrors 124 and 125 and is then emitted from the laser device 101.

  The G light from the G light source 121G is reflected by the dichroic mirror 124, whereby the optical path is bent by approximately 90 degrees. The G light reflected by the dichroic mirror 124 passes through the dichroic mirror 125 and is then emitted from the laser device 101. The B light from the B light source 121B is reflected by the dichroic mirror 125, so that the optical path is bent by approximately 90 degrees. The B light reflected by the dichroic mirror 125 is emitted from the laser device 101. In this way, the laser device 101 supplies R light, G light, and B light modulated according to the image signal.

  Returning to FIG. 1, the laser light from the laser device 101 enters the scanning unit 200 after passing through the illumination optical system 102. The light from the scanning unit 200 enters the reflection unit 105 after passing through the projection optical system 103. The illumination optical system 102 and the projection optical system 103 project the laser light from the laser device 101 onto the screen 110. The reflection unit 105 reflects the laser light from the scanning unit 200 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 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. 3 shows a schematic configuration of the scanning unit 200. The scanning unit 200 has a so-called double gimbal structure having a reflection mirror 202 and an outer frame portion 204 provided around the reflection mirror 202. 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 202 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 202 reflects the laser light from the laser device 101. The reflection mirror 202 can be configured by forming a highly reflective member, for example, a metal thin film such as aluminum or silver.

  The reflection mirror 202 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 about the torsion spring 206. The reflection mirror 202 rotates about the torsion spring 207 using the twist of the torsion spring 207 and the restoration to the original state. The reflection mirror 202 is displaced so as to scan the laser beam reflected by the reflection mirror 202 in the X direction by rotating about the torsion spring 207. Thus, the scanning unit 200 repeatedly scans the laser light from the laser device 101 in the X direction and the Y direction.

  FIG. 4 illustrates a configuration for driving the scanning unit 200. Assuming that the side on which the reflection mirror 202 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 202 rotates about the torsion spring 207. The scanning unit 200 rotates the reflection mirror 202 in this way, thereby scanning the laser light in the 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 reflects the laser beam so as to reciprocate the laser beam a plurality of times in the X direction that is the main scanning direction while scanning the laser beam once in the Y direction that is the sub scanning direction. 202 is displaced. Assuming that the X direction is the first direction and the Y direction is the second direction substantially orthogonal to the first direction, the scanning unit 200 has a frequency at which the laser beam is scanned in the first direction. Driven to be higher than the frequency of scanning light. In order to scan the laser beam in the X direction at high speed, it is desirable that the scanning unit 200 be configured to resonate the reflecting mirror 202 around the torsion spring 207. By causing the reflection mirror 202 to resonate, the amount of displacement of the reflection mirror 202 can be increased. By increasing the displacement amount of the reflection mirror 202, the scanning unit 200 can efficiently scan the laser beam with less energy. The reflection mirror 202 may be driven by an operation other than the resonance operation.

  The scanning unit 200 is not limited to the configuration driven by the electrostatic force corresponding to the potential difference. For example, the structure driven using the expansion-contraction force or electromagnetic force of a piezoelectric element may be sufficient. 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. 5 illustrates the optical path of the laser light from the R light source unit 121R. Here, the configuration for supplying the laser light from the R light source unit 121R among the light source units for each color light will be described as a representative example, and illustrations of components unnecessary for the description are omitted. The R light source unit 121R includes five laser diode elements (LD) 501. Each laser diode element 501 supplies laser light modulated independently.

  The illumination optical system 102 provided between the R light source unit 121 </ b> R and the scanning unit 200 can be configured by combining a convex lens 502 and a concave lens 503. The illumination optical system 102 adjusts the interval between the five laser beams by the convergence effect of the convex lens 502 and the diffusion effect of the concave lens 503. A projection optical system 103 between the scanning unit 200 and the screen 110 projects the laser light from the R light source unit 121 </ b> R onto the screen 110. By using the illumination optical system 102 and the projection optical system 103, a high-definition image can be displayed on the screen 110. The five laser diode elements 501 are not limited to a configuration in which all of the laser diode elements 501 are integrally arranged, and may be arranged apart from each other according to a desired interval of the laser light. The R light source unit 121R is not limited to the configuration in which the five laser diode elements 501 are provided, and may be configured to use a surface-emitting type semiconductor laser that supplies laser light from a plurality of light emitting units.

  6 and 7 illustrate scanning of laser light from the R light source unit 121R. The spots SP1 to SP5 shown in FIG. 6 are formed in the irradiated region by the five laser beams from the R light source unit 121R. The spots SP1 to SP5 are arranged in the X direction in the irradiated region. The R light source unit 121R is configured to parallel five laser beams in the X direction. Further, one side of the pixel P formed in the irradiated region and the diameter of the spot SP are substantially the same, and the interval between the laser beams is adjusted so that the spots SP1 to SP5 are arranged in parallel without any gap. The image display apparatus 100 scans five laser beams for each row, and expresses gradation according to the image signal using the five laser beams. By using a plurality of laser beams in this way, the amount of light per laser beam can be reduced in inverse proportion to the number of laser beams.

  By using the above-described scanning unit 200, the five laser beams from the R light source unit 121R are scanned so as to draw a sinusoidal locus in the irradiated region of the screen 110 as shown in FIG. . During the scanning of the laser light in the X direction, the scanning speed of the laser light changes so that the center line N of the screen 110 is the fastest and the outer edges m1 and m2 are the slowest of the irradiated area. For example, in the case where 80% of the region in which the laser beam can be scanned in the X direction is an irradiated region, if the time required to pass over one pixel P at the outer edge portions m1 and m2 is 1, the center The time for passing over one pixel P on the line N is shortened to about 0.6. If the brightness of the laser light at the outer edge portions m1 and m2 is not reduced by a factor of 0.6 relative to the brightness of the laser light at the center line N, the outer edge portion is closer than the vicinity of the center line N as long as the laser light is turned on. An image in which m1 and m2 are brighter is displayed. Therefore, if the amount of laser light is not adjusted, the screen 110 will have unevenness in the amount of light that is darker as it is closer to the center line N and brighter as it is closer to the outer edge portions m1 and m2.

  The image display apparatus 100 uses the position of the spot SP3 among the spots SP1 to SP5 as the reference point S, and changes the light quantity of the five laser beams based on the position of the reference point S that moves by scanning of the five laser beams in the irradiated region. Adjust. The position of the spot SP3, which is the reference point S, is approximately the center position of a line in which the five spots SP1 to SP5 are parallel. Based on the position of one reference point S, by adjusting all the light amounts of the five laser beams with the reference point S as a representative, the light amount for R light is more than when adjusting the light amount for each beam light based on the position of each beam light. Control of the light source unit 121R can be simplified.

  The speed at which the laser beam scans changes according to the position of the laser beam in the irradiated region. When a plurality of laser beams are arranged in parallel as in the present embodiment, the laser beams forming the spots SP1, 2, 4, 5 are always at positions different from the reference point S. For this reason, when the light amounts of the five laser beams are adjusted using one reference point S as a reference, a slight error occurs in the light amounts of the laser beams forming the spots SP1, 2, 4, and 5.

  For example, if there are 1920 pixels P arranged in parallel in the X direction, the difference in the amount of light due to the difference in the positions of 5 pixels with respect to 1920 is only 0.2 percent. When an image is expressed with 256 gradations, a light amount difference of about 0.2 percent is about half of a light amount difference of about 0.4 percent corresponding to one gradation. Therefore, even if a light amount error occurs according to the distance from the reference point S to the spot SP, it can be considered that there is almost no influence on the image. Further, the reference point S is the most distant from the reference point S by setting the position of the spot SP3, which is the approximate center position of the line where the five spots SP1 to 5 are arranged in parallel, as in this embodiment. It is possible to make the distance from the spot SP1 or 5 as short as 2 pixels. Therefore, the error of the adjusted light amount can be minimized without increasing the reference point S.

  FIG. 8 shows a block configuration for controlling the image display apparatus 100. The image signal input unit 711 performs characteristic correction and amplification of the image signal input from the input terminal. For example, the image signal input unit 711 converts an analog image signal into a digital light source modulation intensity signal and outputs it. In addition, the image signal input unit 711 may output a digital image signal as a digital light source modulation intensity signal. The synchronization / image separation unit 712 separates the signal from the image signal input unit 711 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 713. To do. The image processing unit 721 in the control unit 713 divides the image information into information for each frame and outputs the information to the frame memory 714. The frame memory 714 stores the image signal from the image processing unit 721 in units of frames.

  The scanning control unit 723 of the control unit 713 generates a drive signal for driving the scanning unit 200 based on the vertical synchronization signal and the horizontal synchronization signal. The scan driver 715 drives the scanner 200 in response to a drive signal from the controller 713. In the scanning process, with this configuration, the laser beam is scanned in the X direction and the Y direction in the irradiated region. The horizontal angle sensor 716 detects the swing angle of the reflection mirror 202 (see FIG. 3) that scans the laser beam in the X direction on the screen 110. The vertical angle sensor 717 detects the swing angle of the reflection mirror 202 that causes the screen 110 to scan the laser beam in the Y direction. The signal processing unit 718 generates a frame start signal F_Sync from the displacement of the vertical angle sensor 717 and a line start signal L_Sync from the displacement of the horizontal angle sensor 716, and outputs them to the control unit 713.

  The control unit 713 generates a pixel timing clock based on the linear velocity 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 R light source driving unit 732R drives the R light source unit 121R based on the light source driving pulse signal from the light source control unit 722. The R light source driving unit 732R controls the five LDs of the R light source unit 121R according to the light source driving pulse signal. The G light source driving unit 732G also drives the G light source unit 121G in the same manner as the R light source driving unit 732R. Similarly to the R light source driving unit 732R, the B light source driving unit 732B drives the B light source unit 121B. In the beam light supplying step, a plurality of laser beams are supplied with this configuration.

  FIG. 9 illustrates a configuration for adjusting the amount of laser light from the five LDs 501. The counter 903 counts the clock generated by the clock generation unit 904. The light amount adjustment unit 902 recognizes the position of the reference point S based on the number of clocks counted from when the line start signal L_Sync is input. In the detection step, the position of the reference point S in the irradiated region is detected with this configuration.

  The lookup table (LUT) 901 stores information about the correspondence relationship between the position of the reference point S and the adjustment amount of the laser light amount. The light amount adjusting unit 902 reads the adjustment amount of the light amount of the laser light from the lookup table 901 according to the position information of the reference point S, and determines the light amount that becomes the maximum gradation for each position of the reference point S. The light source control unit 722 generates a modulation signal corresponding to the image information signal so that the light amount determined by the light amount adjustment unit 902 becomes the maximum light amount. Further, the light source control unit 722 outputs a modulation signal for each laser beam to the five laser diode drivers (LDD) 905 provided in the R light source driving unit 732R. Each laser diode driver 905 drives the laser diode element 501. In the light quantity adjustment step, the light quantity of the five laser beams can be adjusted based on the position of the reference point S with this configuration.

  Since the image display apparatus 100 adjusts all the light amounts of the five laser beams based on the position of one reference point S, all the image display devices 100 use the output from the single light amount adjustment unit 902 that adjusts the light amount of the laser beams. A configuration in which the amount of laser light is adjusted is possible. For this reason, compared with the case where the light quantity is adjusted for each laser beam by using a circuit or the like for adjusting the light quantity for each laser beam, the image display device 100 has a simple configuration and the manufacturing cost is reduced. Can do. Thereby, a plurality of light beams are scanned, and there is an effect that unevenness in the amount of light can be reduced with a simple configuration capable of reducing the manufacturing cost.

  The image display apparatus 100 may adjust the amount of each laser beam with the position of the spot SP other than the spot SP3 as a reference point S. For example, as shown in FIG. 10, the position of the rightmost spot SP1 among the five spots SP1 to SP5 may be used as the reference point S. In this case, the distance between the reference point S and the spot SP5 farthest from the reference point S is a distance of 4 pixels. For this reason, compared with the case shown in FIG. 6, the error of the light quantity to be adjusted is slightly increased.

  The image display device 100 is not limited to the configuration in which the five spots SP1 to SP5 are arranged in parallel in the X direction to scan with laser light. For example, as shown in FIG. 11, it is good also as a structure which scans six laser beams so that six spots SP1-6 may be paralleled to a X direction. In this case, the approximate center position of the line where the six spots SP1 to 6 are arranged in parallel is an intermediate position between the spot SP3 and the spot SP4. Thus, the position between the spots SP may be used as the reference point S. By setting the reference point S as the position between the spots SP, it is possible to set the reference point S at a substantially central position of a line where the spots SP are arranged in parallel even when scanning an even number of laser beams. When the position between the spots SP is set as the reference point S, the position of the reference point S can be detected in the same manner as when the position of the spot SP is set as the reference point S.

  The image display apparatus 100 is not limited to a configuration that adjusts the light amounts of all the laser beams based on one reference point S. For example, as shown in FIG. 12, six laser beams may be divided into two laser beam groups g1 and g2, and the amount of light may be adjusted for each of the laser beam groups g1 and g2. The first laser beam group g1 is three laser beams that form the spots SP1, 2, and 3. The second laser beam group g2 is three laser beams that form the spots SP4, 5, and 6.

  The amount of light of the three laser beams of the first laser beam group g1 is adjusted with the position of the spot SP2 as the reference point S1. The position of the reference point S1 is a substantially central position of the spots SP1 to SP3 formed by the three laser beams of the first laser beam group g1. The amount of light of the three laser beams of the second laser beam group g2 is adjusted with the position of the spot SP5 as the reference point S2. The position of the reference point S2 is a substantially central position of the spots SP4 to SP6 formed by the three laser beams of the second laser beam group g2. In order to independently adjust the light amount for each of the laser light groups g1 and g2, two light amount adjustment units are provided corresponding to the laser light groups g1 and g2.

  By adopting a configuration in which the light quantity of two or more laser lights is adjusted based on the reference points S1 and S2 for each of the laser light groups g1 and g2, the light quantity is adjusted for each laser light based on the position of each laser light. The control of the R light source unit 121R can be simplified. Further, by adjusting the light amount for each of the laser light groups g1 and g2, the error of the adjusted light amount can be reduced as compared with the case where the light amount of all the laser beams is adjusted based on one reference point. Is possible. Thereby, the error of the light quantity of a laser beam can be reduced. Note that the present invention is not limited to a configuration in which a plurality of laser beams are divided into two laser beam groups and the light amount is adjusted. The amount of light may be adjusted by dividing into three or more laser light groups. However, the number of laser beam groups needs to be smaller than the number of laser beams supplied by the R light source unit 121R.

  The image display apparatus 100 may have a configuration in which spots SP by a plurality of laser beams are arranged in parallel in the X direction that is the main scanning direction and the Y direction that is the sub scanning direction. For example, as shown in FIG. 13, 25 laser beams may be arranged in an array of five in the X direction and five in the Y direction. The R light source unit 121R is configured to parallel 25 laser beams in the X direction and the Y direction in the irradiated region. The image display apparatus 100 displays an image by scanning 25 laser beams for each row from 1 to 5. By paralleling a plurality of laser beams in the X direction and the Y direction, the modulation frequency of each laser beam can be reduced as compared with the case of paralleling the laser beams in the X direction.

  The image display apparatus 100 uses, as the reference point S, the position of the spot SP33 located substantially at the center among the spots SP arranged in an array, and the light amount of 25 laser beams based on the position of the reference point S in the irradiated region. Adjust. Thereby, the light quantity of each laser beam can be adjusted so as to reduce the unevenness of the light quantity in the X direction.

  Here, the scanning unit 200 (see FIG. 3) reciprocates the laser beam in the X direction, but scans the laser beam in only one direction in the Y direction. Since the laser beam is also scanned in the Y direction by the displacement of the reflection mirror 202, it is conceivable that the brightness of the laser beam changes not only in the X direction but also in the Y direction according to the position in the irradiated region. The image display device 100 may adjust the amount of each laser beam based on the position of the reference point S in the Y direction as well as in the X direction. As a result, the amount of laser light can be adjusted so as to reduce unevenness in the amount of light in both the X and Y directions. The reference point S is not limited to the position of the spot SP33, and may be a position of another spot SP or a position between spots SP.

  As described above, the present invention can be applied to any configuration that changes the speed at which the laser beam is scanned for each position in the irradiated region regardless of whether the laser beam is reciprocated or travels in only one direction. . For example, the present invention can also be applied to a case where a polygon mirror that rotates a rotating body including a plurality of mirror pieces is used as the scanning unit.

  Further, the image display device 100 is not limited to the configuration in which the spots SP are arranged in parallel in the irradiated region without a gap. For example, as shown in FIG. 14, the spots SP may be arranged in parallel so as to provide an interval d between the spots SP. The interval d has a length corresponding to the width of the pixel P, for example. In this case, the distance between the reference point S and the spot SP1 or 5 farthest from the reference point S is longer than when the spots SP are arranged in parallel without a gap. Therefore, as compared with the case shown in FIG. 6, the error of the adjusted light amount is slightly increased.

  FIG. 15 shows a schematic configuration of an image display apparatus 1700 according to the second embodiment of the present invention. The image display device 1700 is a so-called front projection projector that supplies laser light to a screen 1705 provided on the viewer side and observes an image by observing light reflected by the screen 1705. 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 scanning unit 200 passes through the projection optical system 103 and then enters the screen 1705. In the case of the present embodiment as well, unevenness in the amount of light can be reduced with a simple configuration that can reduce the manufacturing cost.

  In the above-described embodiments, each color light source unit uses a laser diode element. However, the present invention is not limited to this as long as it can supply beam-like light. For example, each color light source unit may be configured to use a liquid laser or a gas laser in addition to a solid-state light emitting element such as a solid-state laser and a light-emitting diode element (LED).

  As described above, the image display device according to the present invention is suitable for displaying an image using a plurality of light beams.

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 a laser apparatus. The figure which shows schematic structure of a scanning part. The figure explaining the structure for driving a scanning part. The figure explaining the optical path of the laser beam from the light source part for R light. The figure explaining the scanning of the laser beam from the light source part for R light. FIG. 10 is another diagram illustrating scanning of laser light from the R light source unit. The figure which shows the block structure for controlling an image display apparatus. The figure explaining the structure for adjusting the light quantity of a laser beam. The figure explaining the example which uses the position of the rightmost spot as a reference point. The figure explaining the example which uses the position between spots as a reference point. The figure explaining the example which adjusts light quantity for every laser beam group. The figure explaining the example which makes a laser beam parallel in a X direction and a Y direction. The figure explaining the example which provides a space | interval between spots and makes a laser beam parallel. FIG. 5 is a diagram illustrating a schematic configuration of an image display device according to a second embodiment of the invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 100 Image display apparatus, 101 Laser apparatus, 102 Illumination optical system, 103 Projection optical system, 105 Reflection part, 107 Housing | casing, 110 Screen, 200 scanning part, 121RR Light source part for 121R G light source part, 121B B Light source section for light, 124, 125 Dichroic mirror, 202 Reflective mirror, 204 Outer frame section, 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, 501 laser diode element, 502 convex lens, 503 concave lens, S reference point, SP spot, P pixel, m1, m2 outer edge part, N center line, 711 image signal input part, 712 synchronization / Image separation unit, 713 control unit, 714 frame Memory, 715 Scan driver, 716 Horizontal angle sensor, 717 Vertical angle sensor, 718 Signal processor, 721 Image processor, 722 Light source controller, 723 Scan controller, 732R R light source driver, 732G G light source driver, 732B B light source drive unit, 901 look-up table, 902 light amount adjustment unit, 903 counter, 904 clock generation unit, 905 laser diode driver, g1, g2 laser light group, S1, S2 reference point, 1700 image display device, 1705 screen

Claims (7)

An image display device that displays an image by scanning a plurality of light beams,
A light source unit for supplying the plurality of light beams;
A scanning unit that scans the plurality of light beams 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 is configured to parallel the plurality of light beams in at least one of the first direction and the second direction,
At least one of the positions of the spots formed in the irradiated region by the plurality of light beams and the position between the spots is used as a reference point, and the target of the reference point moving with the scanning of the plurality of light beams is used. An image display device that is driven so as to adjust the light quantity of two or more of the plurality of light beams based on a position in an irradiation region.   The image display apparatus according to claim 1, wherein the light source unit is driven so as to adjust a light amount for all of the plurality of light beams based on a position of the one reference point.   The image display apparatus according to claim 1, wherein the light source unit is driven to divide the plurality of light beams into two or more light beam groups and adjust the light amount for each of the light beam groups.   4. The image display according to claim 1, wherein the light source unit uses a substantially center position of a line in which spots formed by the two or more light beams are arranged in parallel as the reference point. 5. apparatus.   The said light source part is comprised so that the said some light beam may be paralleled about the said 1st direction and the said 2nd direction in the said to-be-irradiated area | region. The image display device described in 1.   The light source unit has a light quantity of the two or more light beams based on a position of the reference point in the irradiated area that moves with the scanning of the plurality of light beams in the first direction and the second direction. The image display device according to claim 1, wherein the image display device is driven so as to adjust the frequency. A method for controlling an image display device that displays an image by scanning a beam of light,
A light beam supplying step for supplying the plurality of light beams;
A scanning step of scanning the plurality of light beams in a first direction in a region to be irradiated and in a second direction substantially orthogonal to the first direction;
In the beam light supplying step, the plurality of beam lights are arranged in parallel in at least one of the first direction and the second direction,
At least one of the positions of the spots formed in the irradiated region by the plurality of light beams and the position between the spots is used as a reference point, and the target of the reference point moving with the scanning of the plurality of light beams is used. A detection step for detecting a position in the irradiation region;
A light amount adjusting step of adjusting a light amount of two or more of the plurality of light beams based on a position of the reference point in the irradiated region. Method.

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