JP2010117683A - Image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image display device having high safeness even when a laser is used. <P>SOLUTION: Laser light sources 7r, 7g, 7b comprise, for example, laser diodes and emit red (R), green (G) and blue (B) laser beams, respectively. Half mirrors 8r, 8g, 8b multiplex the laser beams emitted from the laser light sources 7r, 7g, 7b to produce a single laser beam W. A laser control unit 100 controls the laser light source 7 so as to display a sub-image in a horizontal blanking period and in a vertical blanking period. An optical scanner 9 comprises, for example, a two-dimensional optical scanner and subjects the laser beam W to two-dimensional scanning (raster scanning) to display an image on a screen 10. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image display apparatus that displays an image by scanning a laser beam.

  An optical scanner projector provided with a laser light source displays an image on a screen by modulating a laser beam with an image signal and performing two-dimensional optical scanning (raster scanning).

  Laser beams have enormous energy because the beam diameter is very small and the divergence angle is also very small. Therefore, when the laser beam is directly incident on the eye, there is a risk that the retina is burned and in some cases blinded. Also, if the laser beam hits the human body, there is a risk of burning the skin.

  For equipment using laser beams and LED light, international laser safety standards IEC 60825 and safety standards such as national standards in each country are defined. For example, IEC60825-1 classifies classes 1 to 4 according to the intensity of illuminance, and provides guidelines for manufacturers and users to follow for each class. Therefore, in the field of an apparatus that displays an image using a laser light source, a manufacturer and a user of the device need to comply with the safety standard.

  In an apparatus that displays an image by projecting a laser beam onto a screen, such as an optical scanner projector, the laser beam is diffused and reflected by the screen and diffused in all directions. The laser beam diffused and reflected at has been confirmed to be safe. However, even devices of class 3 and below have a risk of eye damage if the laser beam before it is projected onto the screen directly enters the eye.

  Therefore, the following techniques 1 to 3 are known as conventional techniques for avoiding these dangers.

  Technology 1 is to control the intensity of the laser beam so that the illuminance is safe even if the laser beam is directly incident on the eyes of the audience.

  Technology 2 is to install a shield for preventing the audience from entering the laser irradiation space and prevent the audience from seeing the laser beam directly.

Technology 3 monitors the spectator's intrusion into the laser irradiation space. When the spectator's intrusion is detected, the intensity of the laser beam is lowered to a level that is not harmful to the human body so that the spectator cannot see the laser beam directly. (For example, Patent Documents 1 and 2).
Japanese Patent No. 2994469 JP 2005-352172 A

  However, Techniques 1 and 3 have a problem that the image becomes dark because the intensity of the laser beam is lowered. In addition, the technique 2 has a problem that a space for arranging the shielding object must be ensured in addition to the obstruction of the audience. In any of the techniques 1 to 3, if the audience is obsessed with viewing an image, there is a high possibility that the laser light source is temporarily forgotten temporarily. As a result, the audience may unintentionally see the laser beam and damage the eyes.

  An object of the present invention is to provide an image display apparatus with high safety.

  (1) An image display apparatus according to an aspect of the present invention includes a laser light source that emits a laser beam, a laser control unit that modulates the intensity of the laser beam with image data of a main image, and a scanning unit that scans the laser beam. The laser control unit modulates the intensity of the laser beam with image data of a sub-image for raising the danger of the laser beam.

  According to this configuration, the laser beam is modulated with the image data of the sub-image for raising the danger of the laser beam. Therefore, the user can recognize the danger of the laser beam by viewing the sub-image. Further, since the risk of the laser beam is urged to the user by the sub-image displayed separately from the main image, it is not necessary to display the main image darkly, and deterioration of the image quality can be prevented. Therefore, it is possible to provide an image display device with high safety.

  (2) The laser control unit may control the laser light source so that the sub-image is displayed during at least one of a horizontal blanking period and a vertical blanking period of the image data of the main image. preferable.

  According to this configuration, since the sub image is displayed so as to surround the main image, even if the user is enamored of viewing the main image, the sub image constantly enters the user's field of view. . Therefore, the danger of the laser beam can be surely alerted to the user. Further, since the sub image is displayed using the horizontal blanking period and the vertical blanking period of the main image, the sub image can be displayed with a relatively simple configuration.

  (3) It is preferable that the image data of the sub-image includes image data indicating an operation state of the laser light source.

  According to this structure, the danger of a laser beam can be alerted to a user by displaying the image which shows the operation state of a laser light source.

  (4) It is preferable that the image data of the sub-image includes image data indicating an operation state of the scanning unit.

  According to this configuration, it is possible to alert the user to the danger of the laser beam by displaying an image indicating the operating state of the scanning unit.

  (5) The operating state of the laser light source is preferably the intensity of the laser beam.

  According to this configuration, it is possible to alert the user to the danger of the laser beam by indicating the intensity of the laser beam.

  (6) It is preferable that the operation state of the scanning unit is at least one of a horizontal scanning amplitude and a vertical scanning amplitude of the laser beam.

  According to this configuration, it is possible to alert the user to the danger of the laser beam by indicating the horizontal scanning amplitude or the vertical scanning amplitude of the laser beam.

  (7) It is preferable that the image data of the sub-image includes at least one of a character, a symbol, and a pattern.

  According to this structure, the danger of a laser beam can be alerted to a user using a character, a symbol, or a pattern.

  According to the present invention, the laser beam is modulated with the image data of the sub-image for raising the danger of the laser beam. Therefore, the user can recognize the danger of the laser beam by viewing the sub-image. Further, since the risk of the laser beam is urged to the user by the sub-image displayed separately from the main image, it is not necessary to display the main image darkly, and deterioration of the image quality can be prevented. Therefore, it is possible to provide an image display device with high safety.

  FIG. 1 is a block diagram showing an overall configuration of an image display apparatus 1 according to an embodiment of the present invention. The image display device 1 is mounted on, for example, an optical scanner projector, and includes a laser light source 7 (7r, 7g, 7b), a laser control unit 100, a half mirror 8 (8r, 8g, 8b), an optical scanner 9 (scanning unit), a phase. A detection unit 110 and a synchronization signal output unit 120 are provided.

  The laser control unit 100 includes a frame memory 2, a character memory 3, a line buffer memory 4, a display controller 5, a modulator 6 (6r, 6g, 6b), an operation state detection unit 13, and a system controller 13, and includes horizontal blanking. The laser light source 7 is controlled so that the image data of the sub-image is displayed during the period and the vertical blanking period.

  The frame memory 2 temporarily stores image data of the main image (hereinafter referred to as “main image data”) in units of one frame based on the horizontal synchronization signal and the vertical synchronization signal. Here, the main image is an image that is appreciated by the audience. Examples of main images include movies and TV programs. The main image data is, for example, color image data composed of R, G, and B color components, but may be monochrome image data.

  The character memory 3 stores sub-image data for raising the danger of the laser beam.

  Here, the sub-image is displayed in at least one of the horizontal blanking period and the vertical blanking period of the main image data. As the sub image, an image indicating the operating state of the laser light source 7 and the optical scanner 9 and an image indicating the class to which the image display device 1 belongs are employed.

  As an image showing the operating state of the laser light source 7, for example, an image showing the intensity of the laser beam is employed. Further, as an image indicating the operation state of the optical scanner 9, for example, an image indicating a horizontal scanning amplitude of a laser beam or an image indicating a vertical scanning amplitude is employed.

  Therefore, the character memory 3 preliminarily stores digital sub-image image data (hereinafter referred to as “sub-image data”) such as characters, symbols, and patterns (patterns) representing the operating states of the laser light source 7 and the optical scanner 9. The character memory 3 stores in advance digital image data such as characters, symbols, and patterns (patterns) representing the class to which the image display device 1 belongs as sub-image data. The image data of the blue back image displayed on the screen 10 when the main image data is not input is stored in advance, and the sub image data is color image data composed of R, G, B color components, for example. Monochrome image data may also be used.

  The line buffer memory 4 stores main image data for one line sequentially output from the frame memory 2 in units of one line in the horizontal direction. The line buffer memory 4 stores sub-image data for one line that is sequentially output from the character memory 3 in units of one line in the horizontal direction.

  The display controller 5 controls writing of main image data of one frame to the frame memory 2 and writing control of image data from the frame memory 2 and the character memory 3 to the line buffer memory 4 based on the horizontal synchronizing signal and the vertical synchronizing signal. And control for sequentially outputting the image data from the line buffer memory 4 to the modulator 6 in units of one pixel. Here, in the image data stored in the live buffer memory 4, the R color component is output to the modulator 6r, the G color component is output to the modulator 6g, and the B color component is output to the modulator 6b.

  Specifically, the display controller 5 stores main image data for one frame in the frame memory 2 when a vertical synchronization signal is input from the synchronization signal output unit 120. The line buffer memory 4 stores the first one line of the sub-image data stored in the character memory 3. Then, the sub image data stored in the line buffer memory 4 is sequentially output to the modulator 6 in units of one pixel.

  When the horizontal synchronizing signal is input, the sub-image data for the next line is stored in the line buffer memory 4, and the sub-image data for the next line is sequentially stored in units of one pixel from the line buffer memory 4. The signal is output to the modulator 6.

  Thereafter, until the vertical blanking period ends, the line buffer memory 4 is caused to repeatedly execute the above operation, and the sub image is displayed on the screen 10.

  When the vertical blanking period ends and a horizontal synchronization signal is input, main image data for one horizontal line in the main image data stored in the frame memory 2 is stored in the line buffer memory 4. Further, the sub-image data for one horizontal line from the character memory 3 is stored in the line buffer memory 4. Then, the line buffer memory 4 sequentially outputs image data for one line to the modulator 6 in units of one pixel.

  Thereafter, the above operation is repeated until all the main image data of one frame is output. As a result, the laser beam whose intensity is modulated by the main image data and the sub image data is raster-scanned on the screen 10, and the main image and the sub image are displayed.

  The modulator 6 (6r, 6g, 6b) is emitted from the laser light sources 7r, 7g, 7b using the R, G, B components of the image data sequentially output from the line buffer memory 4 in units of one pixel. R, G, and B laser beam intensities are modulated.

  The laser light sources 7r, 7g, and 7b are configured by, for example, laser diodes, and emit red (R), green (G), and blue (B) laser beams, respectively.

  The half mirror 8 (8r, 8g, 8b) combines the laser beams emitted from the laser light sources 7r, 7g, 7b into a single laser beam W.

  The optical scanner 9 is constituted by a two-dimensional optical scanner, for example, and scans the laser beam W two-dimensionally (raster scanning) based on the horizontal synchronization signal and the vertical synchronization signal, and displays an image on the screen 10. The screen 10 projects a raster-scanned laser beam W to display an image.

  The photodiode 11 (11r, 11g, 11b) is provided in the laser light source 7 (7r, 7g, 7b), monitors the intensity of the laser beam emitted from the laser light source 7r, 7g, 7b, and modulates the monitor signal. To the devices 6r, 6g, 6b and the operation state detector 13. The modulators 6r, 6g, and 6b perform APC (auto power control) control of the laser light sources 7r, 7g, and 7b from the monitor signal so that the time average value of the intensity of the laser beam becomes a predetermined value. Thereby, the oscillation intensity of the laser beam is stabilized and the laser light source 7 is prevented from being damaged.

  The position detection unit (PR) 12 is configured by a photo reflector including a light emitting element such as an infrared light emitting diode and a light receiving element such as a phototransistor, for example, and the light output from the light emitting element is a mirror unit 16 (FIG. 2), the reflected light is detected by the light receiving element, and detection signals indicating the horizontal and vertical inclination angles of the mirror unit 16 are output to the operation state detection unit 13 and the phase detection unit 110.

  The operation state detection unit 13 detects the operation state of the laser light sources 7r, 7g, and 7b using the monitor signals output from the photodiodes 11r, 11g, and 11b.

  Here, when the intensity of the laser beam indicated by the monitor signal exceeds the reference intensity, the operation state detection unit 13 determines that the laser light source 7 is abnormal and sends a signal indicating the abnormality of the laser light source 7 to the system controller 14. Output. As the reference intensity, a laser beam safety reference value predetermined by the class to which the image display device 1 belongs can be used. Moreover, as a class, the class defined by international laser safety standard IEC60825 or Japanese Industrial Standard can be adopted. The signal indicating the abnormality of the laser light source 7 includes data indicating the intensity of the laser beam.

  The operation state detection unit 13 detects the operation state of the optical scanner 9 using the detection signal output from the position detection unit 12. Here, as the operation state of the optical scanner 9, the horizontal and vertical scanning widths of the laser beam are employed. Then, the operation state detection unit 13 obtains the horizontal and vertical scanning widths of the laser beam from the amplitudes of the horizontal and vertical tilt angles of the mirror unit 16, and the horizontal and vertical scanning widths are respectively determined. If it is larger than the reference scanning width, it is determined that the optical scanner 9 is abnormal, and a signal indicating the abnormality of the optical scanner 9 is output to the system controller 14. This signal includes data indicating the scanning width of the laser beam in the vertical and horizontal directions.

  Further, the operation state detection unit 13 stores in advance class data indicating a class to which the image display device 1 belongs.

  When the signal indicating the abnormality of the laser light source 7 or the signal indicating the abnormality of the optical scanner 9 is output from the operation state detection unit 13, the system controller 14 displays a sub-image indicating the operation state of the laser light source 7 or the optical scanner 9. The display controller 5 is instructed to do so. Further, the system controller 14 instructs the display controller 5 to display a blue background image when the main image is not displayed.

  The phase detection unit 110 detects the horizontal and vertical tilt angles of the mirror unit 16 using the detection signal detected by the position detection unit 12.

  The synchronization signal output unit 120 outputs a horizontal synchronization signal and a vertical synchronization signal to the display controller 5 based on the tilt angle of the mirror unit 16 detected by the phase detection unit 110. Here, the synchronization signal output unit 120 may output a horizontal synchronization signal when the horizontal inclination angle detected by the phase detection unit 110 becomes an angle at which scanning of one line starts. In addition, the synchronization signal output unit 120 may output a vertical synchronization signal when the phase detection unit 110 sets the vertical inclination angle to the angle at which scanning of the first line of one frame starts.

  Next, the operation of the optical scanner 9 will be described. FIG. 2 is a plan view showing a detailed configuration of the optical scanner 9. The optical scanner 9 includes a two-dimensional scanning mirror 15, a fixed frame 70 that fixes the two-dimensional scanning mirror 15 to a housing (not shown), and a movable frame that is formed in a frame shape as a movable part inside the fixed frame 70. 30 and a square mirror 16 formed inside the movable frame 30.

  The mirror unit 16 is elastically supported by the movable frame 30 from both sides in the Y-axis direction via torsion bars 21 and 22 that extend outward along the Y-axis passing through the center of the mirror unit 16. In addition, the movable frame 30 is bent beams 41, 42, 43, 44 having one end connected to each of the end portions 30a, 30b, 30c, 30d in the vicinity of the X axis that are orthogonal to the Y axis and pass through the center of the mirror portion 16. Thus, the fixing frame 70 is elastically supported from both sides of the X axis. The fixed frame 70, the bending beams 41 to 44, the movable frame 30, the mirror portion 16, and the torsion bars 21 and 22 are integrally formed by anisotropic etching of the silicon substrate.

  In addition, a reflection film made of a metal thin film such as gold or aluminum is formed on the surface of the mirror portion 16, and the reflectance of incident light is increased. In addition, piezoelectric elements 51, 52, 53, and 54, which are electro-mechanical conversion elements, are attached to the surfaces of the bending beams 41, 42, 43, and 44 by bonding or the like, and the four unimorph portions 61, 62, 63, 64 is formed. The bending beams 41 to 44 cause the movable frame 30 to rotate about the Y axis and the X axis independently by bending deformation of the piezoelectric elements 51 to 54, and rotate the movable frame 30 about the Y axis and the X axis. Move.

  Here, the rotation operation of the movable frame 30 will be described with reference to FIG. 3A to 3E are cross-sectional views of the two-dimensional scanning mirror 15 from the direction 3-3 in FIG. 3A shows the stationary state, and FIGS. 3B to 3E show the driving state.

  As shown in FIG. 3A, upper plus (+) electrodes 511 and 521 and lower minus (−) electrodes 512 and 522 are provided on the front and back of the piezoelectric elements 51 and 52, respectively, and the upper (+). By applying an AC voltage between the electrode 511 (521) and the lower (−) electrode 512 (522) in a range that does not cause polarization reversal, the piezoelectric elements 51 and 52 are expanded and contracted, and the unimorph portions 61 and 62 are thickened. Displace in the direction. Similarly, upper (+) electrodes 531 and 541 (not shown) and lower (−) electrodes 532 and 542 (not shown) are provided on the front and back surfaces of the piezoelectric elements 53 and 54, respectively.

  First, the rotation operation around the X axis will be described. When a voltage in the extending direction is applied to the piezoelectric element 51, and a voltage in a direction in which the phase opposite to that of the piezoelectric element 51 is contracted is applied to the piezoelectric element 52, one end of the unimorph portions 61 and 62 is fixed and held on the fixed frame 70. Therefore, as shown in FIG. 3B, the unimorph portion 61 bends downward, while the unimorph portion 62 bends upward. Similarly, when voltages having the same phase as the piezoelectric elements 51 and 52 are applied to the piezoelectric elements 53 and 54, the unimorph part 63 bends downward, while the unimorph part 64 bends upward.

  As a result, rotational torque about the X axis acts on the movable frame 30, and the movable frame 30 tilts in the direction of arrow P about the X axis. Further, when a voltage having a phase opposite to that in the case of FIG. 3B is applied to the piezoelectric elements 51 to 54, the movable frame 30 has an X axis as shown in FIG. Rotation torque centering on the axis acts and tilts in the direction of arrow Q about the X axis. When an AC voltage maintaining such a phase relationship is applied to the piezoelectric elements 51 to 54, the unimorph parts 61 to 64 follow the AC voltage and repeat vertical vibrations so that the movable frame 30 rotates like a seesaw. Torque is applied, and the movable frame 30 rotates and vibrates up to a predetermined displacement angle about the X axis.

  Next, the rotation operation around the Y axis will be described. When a voltage in the extending direction is applied to both of the piezoelectric elements 51 and 52, one end of each of the unimorph portions 61 and 62 is fixed and held on the fixed frame 70. Therefore, as shown in FIG. Both bend downwards. On the other hand, when a voltage in the direction in which the phase opposite to that of the piezoelectric elements 51 and 52 contracts is applied to the piezoelectric elements 53 and 54, the unimorph parts 63 and 64 both bend upward as shown in FIG. As a result, rotational torque about the Y axis acts on the movable frame 30, and the movable frame 30 tilts about the Y axis.

  When an AC voltage maintaining such a phase relationship is applied to the piezoelectric elements 51 to 54, the unimorph parts 61 to 64 follow the AC voltage and repeat vertical vibrations so that the movable frame 30 rotates like a seesaw. Torque acts, and the movable frame 30 rotates and vibrates up to a predetermined displacement angle around the Y axis.

  As described above, by applying predetermined voltages to the four unimorph parts 61 to 64, the inclination of the mirror part 16 supported by the movable frame 30 around the X axis and the Y axis can be arbitrarily controlled. . Further, the bending beams 41 to 44 are arranged symmetrically across the Y axis and the X axis, and the piezoelectric elements 51 to 54 provided on the bending beams 41 to 44 have the same phase or opposite phases that are 180 degrees different from each other. Since it is driven by the drive signal, the movable frame 30 can be independently rotated about the Y axis and the X axis without any swing.

  Next, a method for deflecting the laser beam W using the two-dimensional scanning mirror 15 will be described with reference to FIG. The laser beam W emitted from the laser light source 7 is raster scanned by the two-dimensional scanning mirror 15 to generate an image.

  Here, the horizontal scanning frequency is, for example, 10 kHz, and the vertical scanning frequency is, for example, about 60 Hz. Further, the horizontal and vertical inclination angles of the mirror section 16 are each about ± 10 degrees. Further, since the horizontal scanning of the mirror unit 16 performs mechanical resonance vibration using a sinusoidal drive voltage, the horizontal scanning speed is extremely reduced in the left and right peripheral portions of the horizontal scanning region. Therefore, as shown in FIG. 4, the horizontal area of the image display area 17 is a slightly inner area without using all of the scanning area 18.

  Since the vertical scanning is performed using a sawtooth drive voltage, only the region with good scanning linearity of the mirror unit 16 is used for normal image display. The vertical region of the region 17 is a region slightly inside without using the entire scanning region 18.

  FIG. 5 is a diagram showing the distribution of the image area of the image displayed on the screen 10. As shown in FIG. 5, a frame-like region surrounding the image display region 17 obtained by removing the image display region 17 from the scanning region 18 is a blanking region BD. The blanking area BD includes a vertical blanking area BD1 and a horizontal blanking area BD2.

  The vertical blanking area BD1 is displayed in the vertical blanking period, and includes an upper vertical blanking area BD11 and a lower vertical blanking area BD12. The vertical blanking regions BD11 and BD12 are strip-like regions having a horizontal width that is the same as the horizontal width of the scanning region 18 and having the horizontal direction as the longitudinal direction.

  The horizontal blanking area BD2 is displayed during the horizontal blanking period, and includes a left horizontal blanking area BD21 and a right horizontal blanking area BD22. The horizontal blanking areas BD21 and BD22 are strip-shaped areas having a vertical width equal to the vertical width of the image display area 17 and having the vertical direction as a longitudinal direction.

  In the vertical image display period, the main image is displayed in the image display area 17 and the sub-image is displayed in the blanking area BD. In the vertical blanking period, the sub-image is displayed in the vertical blanking area BD1.

  Here, the vertical image display period is a period during which the laser beam is scanned from the upper left vertex of the horizontal blanking region BD21 to the lower right vertex of the horizontal blanking region BD22. The vertical blanking period includes a period during which the laser beam is scanned from the upper left vertex to the lower right vertex of the vertical blanking region BD11, and a laser beam from the upper left vertex to the lower right vertex of the vertical blanking region BD12. Scanning period.

  Next, the operation of the image display device 1 will be described. When the power is turned on, the system controller 14 instructs the display controller 5 to output the blue back image data from the character memory 3 to the line buffer memory 4. At the same time, the system controller 14 receives the class data indicating the class to which the image display device 1 belongs from the operation state detection unit 13, and sends the sub-image data indicating the class data from the character memory 3 to the line buffer memory 4. Instruct to output.

  For the writing of image data to the line buffer memory 4, the storage area of the line buffer memory 4 is divided into a main image storage area and a sub image storage area, and in the vertical image display period, blue background image data is stored in the main image storage area. And the sub image data is written in the sub image storage area. In the vertical blanking period, the sub image data is written in the entire area of the line buffer memory 4.

  The modulator 6 oscillates the laser light source 7, reads image data from the line buffer memory 4 in units of one pixel, and modulates the laser beam emitted from the laser light source 7 using the read image data.

  The three laser beams emitted from the laser light source 7 are combined into one laser beam W by the half mirror 8 and enter the mirror unit 16.

  The laser beam W is raster-scanned by the scanning-driven mirror unit 16 and projected onto the screen 10. As a result, the blue background image is displayed in the image display area 17, and the sub-image data is displayed in the blanking area BD.

  FIG. 6 is a diagram illustrating an example of a sub-image displayed on the screen 10. In the example of FIG. 6, a sub-image composed of characters “Class 3” indicating a class to which the image display device 1 belongs and a background image of the characters is displayed. As the background image, a solid image having a color different from the blue background image (for example, red) or a pattern image can be employed.

  Next, the frame memory 2 stores main image data for one frame. Next, in the vertical image display period, the display controller 5 sequentially writes the main image data stored in the frame memory 2 in the unit of one line in the main image storage area of the line buffer memory 4 instead of the blue back image data. As a result, the main image is displayed in the image display area 17. Similar to the vertical blanking period, the sub image data is sequentially written in the sub image storage area in units of one line. Thereby, a sub-image is displayed in the blanking area BD.

  Next, when a signal indicating abnormality of the laser light source 7 or a signal indicating abnormality of the mirror unit 16 is output from the operation state detection unit 13, the system controller 14 displays sub-image data to be displayed when the laser light source 7 is abnormal, Alternatively, the display controller 5 is instructed to read out the sub-image data to be displayed when the mirror unit 16 is abnormal from the character memory 3 and write it into the line buffer memory 4.

  Here, when an abnormality has occurred in the laser light source 7, for example, a wording “an abnormality has occurred in the laser light source” or data indicating the intensity of the laser beam is displayed in the blanking region BD. Is displayed. Further, when an abnormality has occurred in the optical scanner 9, the blanking area BD has, for example, the wording “A scanner has an abnormality” and the scanning width of the laser beam in the vertical and horizontal directions. Displayed data, data indicating the ratio of the scanning width in the vertical direction and the horizontal direction of the laser beam to the reference scanning width, and the like are displayed.

  Further, the following sub-image display modes may be employed. First, when the power is turned on, the screen 10 reads, “This device displays an image using a laser beam. It is dangerous if the laser beam directly enters the eye. A text such as “Displaying an image with a pattern or color” is displayed. Then, when the display of the main image is started, the danger of the laser beam may be urged to the audience by displaying a sub-image having a pattern in the blanking area BD.

  With the above operation, a spectator viewing the main image can view the main image without missing, and at the same time can always recognize the operation state of the image display device 1 from the sub-image displayed in the blanking area BD.

  The image display device 1 may adopt the following form.

  (1) In the above description, a mode in which a sub-image is displayed in the entire blanking area BD has been described. However, the present invention is not limited to this, and the sub-image may be displayed only in the horizontal blanking area BD2, or a vertical blanking area may be displayed. The sub image may be displayed only in the ranking area BD1.

  (2) In the above description, when an abnormality occurs in the laser light source 7 or the optical scanner 9, an image indicating the operating state of the laser light source 7 or the operating state of the optical scanner 9 is displayed. However, the present invention is not limited to this. . For example, the operating state of the laser light source 7 or the operating state of the optical scanner 9 may be always displayed regardless of whether the laser light source 7 or the optical scanner 9 is abnormal.

  (3) In the above description, the operating state of the laser light source 7 or the optical scanner 9 is displayed, but the present invention is not limited to this. For example, the audience may be informed only that an image is displayed by a laser beam. In this case, the operation state detection unit 13 may be omitted and a predetermined sub-image may be displayed in the blanking area BD.

  (4) As the modulator 6 shown in FIG. 1, an AOM (Acoustic Optical Modulator) may be adopted. In this case, the modulators 6r, 6g, and 6b may be installed between the laser light sources 7r, 7g, and 7b and the half mirrors 8r, 8g, and 8b.

  (5) In the blanking area BD, as described above, the horizontal scanning speed is extremely reduced at the end of the scanning area 18 and the linearity is lowered in the vertical scanning, so that an accurate display of characters and the like is possible. If it is difficult, an image consisting only of a pattern or a specific color may be displayed as a sub-image.

1 is a block diagram illustrating an overall configuration of an image display device according to an embodiment of the present invention. It is a top view which shows the detailed structure of an optical scanner. 3A to 3E are cross-sectional views of the two-dimensional scanning mirror from the direction 3-3 in FIG. It is the figure which showed a mode that a two-dimensional scanning mirror deflects a laser beam. It is the figure which showed distribution of the image area | region of the image displayed on a screen. It is the figure which showed an example of the subimage displayed on a screen.

Explanation of symbols

6, 6r, 6g, 6b Modulator 7, 7r, 7g, 7b Laser light source 8, 8r, 8g, 8b Half mirror 9 Optical scanner 10 Screen 14 System controller 15 Two-dimensional scanning mirror 16 Mirror unit 17 Image display area 18 Scanning area 100 Laser control unit 120 Synchronization signal output unit BD Blanking area BD1 Vertical blanking area BD2 Horizontal blanking area

Claims (7)

A laser light source for emitting a laser beam;
A laser controller that modulates the intensity of the laser beam with image data of a main image;
A scanning unit that scans the laser beam,
The laser control unit modulates the intensity of the laser beam with image data of a sub-image for raising the danger of the laser beam.   The laser control unit controls the laser light source so that the sub-image is displayed in at least one of a horizontal blanking period and a vertical blanking period of image data of the main image. The image display device according to claim 1.   The image display apparatus according to claim 1, wherein the image data of the sub-image includes image data indicating an operation state of the laser light source.   The image display device according to claim 1, wherein the image data of the sub-image includes image data indicating an operation state of the scanning unit.   The image display apparatus according to claim 3, wherein an operation state of the laser light source is an intensity of the laser beam.   The image display apparatus according to claim 4, wherein an operation state of the scanning unit is at least one of a horizontal scanning amplitude and a vertical scanning amplitude of the laser beam.   The image display device according to claim 1, wherein the image data of the sub-image includes at least one of a character, a symbol, and a pattern.

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