JP6591250B2 - Projection display mechanism - Google Patents

Description

  The present invention relates to a projection display mechanism.

  Conventional display devices include a CRT (Cathode Ray Tube) device using an electron beam and a fluorescent material, and a liquid crystal display device using a liquid crystal panel and a backlight. In any of these apparatuses, the same area as the display surface is illuminated in dot units to express an image.

  In the case of a projection-type device, a light source such as a high-intensity halogen lamp and a liquid crystal panel having a shutter function placed in front of the light source are used, and transmitted light is projected onto a screen to display an image. In this case, a screen larger than the apparatus can be displayed by projecting the transmitted light onto a distant screen by controlling the optical axis with an optical lens or the like. In addition, there is a feature that the size of the display screen can be varied depending on the refractive index of the optical lens and the distance to the screen (for example, Patent Document 1).

Japanese translation of PCT publication No. 2003-510624

  In recent years, there has been a small-sized projection device using an LED as a light source due to an improvement in the amount of light emitted from an LED (Light Emitting Diode). In Patent Document 1, a laser light source and a rotating polygon mirror are used. However, the structure of the rotating polygon mirror is complicated and the manufacturing process is complicated due to screen scanning control, and the resolution and screen size cannot be changed. There was a problem.

  In addition, display devices using a CRT or a liquid crystal display have a limitation that the area and resolution of the display screen depend on the physical size and accuracy of the display device. There was a problem that this device could not be made.

  In the case of a projection-type display device, a high-intensity halogen lamp or the like requires a large amount of power, generates a large amount of heat, and cannot be realized with a battery. When an LED light source with low power consumption is used, downsizing and power saving can be achieved. However, since the light that passes through the color filter and the liquid crystal panel with the shutter function is magnified by the lens, the amount of light that is transmitted through the panel is attenuated and the mechanical parts of the optical system are downsized. There was a problem that could not be screened. Therefore, there has been a demand for a display device that can realize a large-screen display that is small, power-saving, and has high brightness.

  In the above-mentioned Patent Document 1, as a solution to this, a projection display device using a laser light source and a rotating polygon mirror is disclosed. However, a precision is required for the structure of the rotating polygon mirror for screen scanning control, and the manufacturing process. There are problems such as complexity and fixed resolution and screen size.

  This invention is made | formed in view of the above, Comprising: It aims at solving this subject by using two rotary mirrors of a simple shape.

  In order to solve the above problems and achieve the object, a projection display mechanism according to the present invention includes a rotary mirror that reflects light emitted from a light source, a drive unit that rotates the rotary mirror, and the drive unit. And a rotation control unit that controls the rotation of the rotating mirror to control the optical axis of the reflected light, and is configured as a projection type display mechanism.

  ADVANTAGE OF THE INVENTION According to this invention, the projection type display mechanism which implement | achieved power saving, size reduction, and weight reduction can be provided.

Overall configuration diagram showing an embodiment Optical axis control example Example of display screen size control by optical axis control Example of resolution control by optical axis control and light emission control Example of display screen projection trajectory Optical axis tilt example Example of tilting mirror alone Example of combination of tilt and vertical mirror Screen data projection method corresponding to optical axis tilt

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram showing a configuration example of a display apparatus 1000 to which a projection display mechanism according to the present invention is applied. As shown in FIG. 1, a display apparatus 1000 includes a laser light source 1, a vertical optical axis control rotary mirror 2 having a horizontal rotation axis, and a horizontal optical axis control having a vertical rotation axis. A rotary mirror 3, a motor 4 that rotates the vertical optical axis control rotary mirror 2, a motor 5 that rotates the horizontal optical axis control rotary mirror 3, and a motor that controls the rotational speed of these rotary mirror motors The rotational speed control circuit 6, the image data input buffer 8 for temporarily storing image data constituted by the image data input signal 7 input from the outside, and the image data to be displayed on the screen 11 are temporarily stored. An image display buffer 9, a laser light emitting element control circuit 10, and a projection screen 11 are included. In the following description, the vertical optical axis control rotary mirror 2 and the horizontal optical axis control rotary mirror 3 are used. However, these rotary axes do not necessarily have to be horizontal and vertical. You may comprise by the rotary mirror which has a mutually different rotating shaft which provided the predetermined angle in the axis | shaft.

  When the laser beam generated by the laser light source 1 is reflected by the vertical optical axis control rotary mirror 2 rotated by the motor 4, the optical axis is changed in the vertical direction. Further, when the light is reflected by the horizontal optical axis control rotating mirror 3 rotated by the motor 5, the optical axis is changed in the horizontal direction to irradiate the far screen 11 to form a light spot P.

  On the other hand, the external image data input signal 7 is temporarily stored in the image data input buffer 8, converted into an image data format corresponding to the display method of the display device 1000, and stored in the image display buffer 9. The accumulated image data is sent to the laser light emitting element control circuit 10 in the order of display on the screen 11 and instructs the laser light source 1 to blink the light emitting elements.

  As described above, the image data input signal 7 from the outside blinks the laser light source 1, and the laser beam is reflected by the vertical optical axis control rotary mirror 2 and the horizontal optical axis control rotary mirror 3 and then the screen 11. Irradiated as a continuous light spot. By being recognized as an image by the collection of light spots and afterimages of human eyes, it functions as an image display device.

  As an example of the projection display device using the laser light source and the reflecting mirror as described above, there is a projection display device using a laser light source and a rotating polygon mirror as disclosed in JP-T-2003-510624. However, there are problems such as that the structure of the rotating polygon mirror is required to be accurate for screen scanning control, the manufacturing process is complicated, and the resolution and screen size are fixed. Specifically, in order to change the optical axis in the vertical direction of the screen, it is necessary to create a mirror having a plurality of reflection angles in the polygon mirror. In principle, it is technically possible to create mirrors having different reflection angles by the number of scanning lines in the same polygon mirror. However, since high accuracy is required for the work accuracy, the cost increases. Similarly, since the resolution of the display screen is determined by the number of mirrors, there are problems that it is difficult to physically reduce the size and that the resolution is fixed.

  In this embodiment, this problem is solved by using two rotary mirrors having a simple shape and having mirrors having the same reflection angle. First, a solution to the problem of the mirror accuracy and cost increases will be described below.

  As shown in FIG. 2, the laser beam blinked by the laser light source 201 is reflected by the vertical optical axis control rotary mirror 202 and the horizontal optical axis control rotary mirror 203, and is then incident on the screen 204 as the optical axis 205. Irradiated as a spot. Since the rotary mirrors 202 and 203 rotate at a constant speed, the reflection angle changes according to the number of rotations after a certain period of time and is irradiated to different positions on the screen 204 like the optical axis 206. At this time, since the laser beam is blinking, two light spots that are different in position according to the blinking interval can be realized. By controlling the blinking timing and the period of the rotary mirror, a light spot can be created at any position in the vertical and horizontal directions. The rotating mirror used in this case is a plurality of mirrors having the same reflection angle arranged on the same rotation axis, and does not depend directly on the number of mirrors and the number of scanning lines. The number obtained by multiplying the number is the number of scanning lines. For this reason, in order to cope with the number of scanning lines of a general PC (Personal Computer) display and the number of scanning lines of Hi-Vision, from several hundred to several 10,000, for example, a rotating mirror having ten mirrors is used every second. If the number of rotations is several tens to several hundreds, the necessary number of scanning lines can be secured. Creating about 10 mirrors having the same reflection angle is easy in terms of work accuracy and can be physically downsized.

  Next, in the conventional technique, the size of the display screen is changed according to enlargement / reduction by an optical lens or the distance between the projection device and the screen. For this reason, the solution to the problem that the use of an optical lens cannot physically reduce the size and the limitation of the distance between the projection apparatus and the screen will be described below.

  As shown in FIG. 3, the laser beam flashed by the laser light source 301 is reflected by the vertical optical axis control rotary mirror 302 and the horizontal optical axis control rotary mirror 303, and is then incident on the screen 304 as the optical axis 305. Irradiated as a spot. Next, after a certain period of time, the light axis 306 is irradiated as an adjacent light spot on the screen 304. At this time, by changing the rotation speed, it is possible to irradiate light spots at different positions as the optical axis 307 on the screen 304 even at the blinking interval of the same laser light source. That is, the display position intervals 308 and 309 between adjacent light spots can be enlarged or reduced. This makes it possible to change the size of the entire display screen only by changing the rotation speeds of the vertical optical axis control rotary mirror 302 and the horizontal optical axis control rotary mirror 303. Specifically, the size can be increased by increasing the rotation speed of the horizontal optical axis control rotary mirror 303, and the size can be reduced by decreasing the rotation speed of the horizontal optical axis control rotary mirror 303. can do.

  Next, the resolution of the display screen will be described. In the prior art disclosed in Japanese Patent Publication No. 2003-510624, it depends on the number of a plurality of mirrors each having a unique reflection angle as an element for determining the resolution of the screen. For this reason, there is a problem that the resolution of the display screen is fixed unless the rotating polygon is replaced. A solution to this problem will be described below.

  As shown in FIG. 4, the laser beam flashed by the laser light source 401 is reflected by the vertical optical axis control rotary mirror 402 and the horizontal optical axis control rotary mirror 403, and is then reflected on the screen 404 as the optical axis 405. Irradiated as a light spot. As a light spot after a certain time, an optical axis 406 is irradiated at different positions on the screen 404. At this time, by changing the blinking emission interval of the laser light source 401, the number of light spots 407 and 408 irradiated within a certain time changes, so that the horizontal resolution per unit area can be changed. Become. Specifically, the horizontal resolution can be increased by reducing (shortening) the blinking emission interval of the laser light source 401, and the horizontal resolution can be increased by increasing (longening) the blinking emission interval of the laser light source 401. Can be lowered.

  The number of scanning lines in the vertical direction, which is another factor that determines the resolution, depends on the rotation speed of the vertical optical axis control rotating mirror 402. By controlling these two elements, it is possible to change the resolution without exchanging mechanical parts.

  Next, as described above, the reflection by the rotating mirror in the vertical and horizontal directions has a problem that the brightness of the display screen is lowered because there are invalid light spots. A solution to this problem will be described below.

  As shown in FIG. 5, the light spot irradiated on the screen moves like a plurality of light spots 503 by a moving direction 501 of the optical axis in the vertical direction and a moving direction 502 of the optical axis in the horizontal direction. As a result, it is irradiated as a continuous light spot. When enlarged, adjacent light spots such as a light spot 504 are irradiated with their positions shifted in the vertical and horizontal directions. By continuously irradiating this while shifting by one dot, the light spot for one screen is irradiated.

  In this case, when securing the light spot for the display screen 505, the light spot in the area twice as large as the area to be actually displayed is required. Since the area other than the display screen 505 is an invalid area, the laser light source is not turned on. That is, there is a problem that the irradiation efficiency becomes ½ and high luminance cannot be obtained. A solution to this problem will be described below.

  As shown in FIG. 6, the laser beam flashed by the laser light source 601 is reflected by the vertical optical axis control rotary mirror 602 and the horizontal optical axis control rotary mirror 603, and is reflected on the screen 604 as the optical axis 605. Irradiated as a spot. At this time, it is possible to change the moving direction of the optical axis from the horizontal direction to the oblique direction above the horizontal direction by tilting the rotation axis of the horizontal optical axis control rotary mirror 603.

  For example, when the vertical optical axis control rotary mirror 602 is rotated at a certain speed, the light emitted from the laser light source 601 is reflected by the vertical optical axis control rotary mirror 602, and then the upper side is reflected. The screen 604 is irradiated with the light reflected from the horizontal optical axis control rotary mirror 603 having a rotation axis inclined with respect to the screen 604, but is reflected by one mirror surface of the vertical optical axis control rotary mirror 602. The number of rotations of the rotary mirrors 602 and 603 may be controlled so that the reflected light irradiates the same surface of the horizontal optical axis control rotary mirror 603 while moving by one scanning line.

  Specifically, as shown in FIG. 7, when there is only one tilted horizontal optical axis control rotating mirror, the light emitted from the laser light source 701 is tilted by the tilted horizontal optical axis control rotating mirror 702. Reflected and applied to the screen 705. At this time, the light reflected first by the inclined optical mirror 702 for controlling the optical axis in the horizontal direction is irradiated onto the screen 705 as the optical axis 703. Since the tilted horizontal optical axis control rotary mirror 702 is then rotated, the light that is finally reflected by the same reflecting surface is irradiated onto the screen as the optical axis 704. By tilting the rotary mirror in this way, the moving direction of the optical axis can be changed from the horizontal direction to the upward oblique direction.

  Further, as shown in FIG. 8, when the vertical optical axis control rotary mirror 801 is combined, the light reflected by the vertical optical axis control rotary mirror 801 is tilted and the horizontal optical axis control rotary mirror 802 is tilted. , And is applied to the screen 804 as the optical axis 803. After that, the vertical optical axis control rotary mirror 801 and the inclined horizontal optical axis control rotary mirror 802 are rotated, respectively. The light reflected by the two rotating mirrors is applied to the screen 804 as the optical axis 805. At this time, the amount of movement in the upward oblique direction by the inclined horizontal optical axis control rotating mirror 802 and the amount of downward movement by the vertical optical axis control rotating mirror 801 are added, and the light trace is It becomes a horizontal direction like the bright mark 806.

  As shown in FIG. 9, the moving direction 901 of the optical axis in the vertical direction is the same as that in FIG. 5, but the moving direction of the optical axis in the horizontal direction is 902 as shown in FIG. In addition to the horizontal direction, a vertical movement direction is added. As a result, it moves like a plurality of light spots 903 and is irradiated as light spots that are horizontally continuous. When enlarging, adjacent light spots such as the light spot 904 are irradiated with the movement component in the vertical direction canceled out and shifted in the horizontal direction only as a result. In accordance with the inclination angle of the rotation axis of the horizontal optical axis control rotary mirror 603 in FIG. 6, the rotational speed of the vertical optical axis control rotary mirror 602 and the rotation axis of the horizontal optical axis control rotary mirror 603 are adjusted. By controlling the rotation speed, irradiation is continuously performed while correcting for one dot and shifting vertically, and as a result, it is possible to irradiate light spots for one screen. In this case, the area of the display screen 905 and the area of the illuminated light spot are the same, and therefore there is no invalid area compared to the method of FIG. That is, in the case of FIG. 5, it is necessary to recognize the effective light spot or the invalid light spot and to control light emission so as to select only the effective light spot or to block the light to the invalid area. However, in the case of FIG. 9, such selection control becomes unnecessary, and it is possible to irradiate the light spots for the entire display screen by simply outputting all the light spots. The processing method of the program can be simplified and the performance can be improved.

  Thus, according to the above-described embodiment, it is possible to realize power saving, size reduction, and weight reduction by using the laser light source. By using two simple-shaped rotary mirrors, the mechanical parts can be reduced, the size can be reduced, and the manufacturing cost can be reduced. In addition, by providing a rotation speed control circuit for the rotating mirror, it is possible to change the size of the display screen only by changing the rotation speed without using an optical lens or changing the distance to the display screen. . Since no optical lens is used, it is possible to reduce the size, and since it does not depend on the distance between the apparatus and the screen, restrictions on the installation location of the apparatus are reduced. Furthermore, the resolution of the display screen can be easily changed by changing the rotation speed of the rotary mirror and changing the blinking cycle of the laser light source. As described above, it is possible to realize a projection display device having high brightness, power saving, small size, light weight, and high functionality.

  As another example, the display luminance may be improved by using a light source that does not diffuse into the light emitter. Furthermore, visual luminance and color tone on the display surface may be realized by using light sources of a plurality of colors and making each light emission time and light emission pattern variable. Further, high luminance may be realized by not using color composition using light transmitted by a liquid crystal panel having a color filter and a shutter function. Furthermore, it can be configured as a display screen that is characterized by reducing the volume and weight during storage by expanding it during use, or it can be used for both front projection and rear projection by using a removable expansion screen. .

  It can be used for projection display devices such as data terminals including personal computers and image display devices including televisions that are portable, compact, power-saving, high-intensity, and capable of freely changing the screen display size and display resolution. It is. Conversely, if a function of receiving the reflected light of the laser beam is provided, a small scanner can be realized using the same mechanism. Furthermore, by using the display screen as a transfer drum, it can be used for forming a latent image of a printer.

1 .... Laser light source 2 .... Rotating mirror for vertical optical axis control 3 .... Rotating mirror for horizontal optical axis control 4 .... Motor for rotating the rotating mirror of 2 5 .......... Motor for rotating the rotating mirror of 3. 6 .... Motor rotation speed control circuit for the rotating mirror. 7 .... External Image data input signal from 8... Image data input buffer 9... Image display buffer 10... Laser emitting element control circuit 11. screen.

Claims (3)

A plurality of mirrors having a plurality of mirrors having the same angle of reflection and having different rotation axes for reflecting light emitted from the light source;
A drive unit for rotating the rotating mirror;
A rotation control unit that controls rotation of the rotating mirror by the driving unit to control an optical axis of reflected light;
With
Wherein the plurality of rotating mirror is a vertical direction perpendicular optical axis control for rotating mirror having a rotation axis of the scanning line direction and the horizontal direction of the screen, with respect to the rotational axis of the vertical optical axis control for rotating mirror A rotating mirror for horizontal optical axis control having a rotation axis inclined with respect to the screen ,
The rotation control unit, the in accordance with the inclination angle of the rotation axis of the horizontal optical axis control revolution mirror, the axis of rotation of the vertical optical axis control for the rotational speed of the rotating mirror and the horizontal optical axis control for rotating mirror To control the rotation speed of the
A projection type display mechanism characterized by that. The rotation control unit enlarges or reduces a display screen for displaying the reflected light by controlling a rotation speed of the vertical optical axis control rotary mirror and the horizontal optical axis control rotary mirror.
The projection type display mechanism according to claim 1. The projection display mechanism includes a light emission control unit that controls a light emission interval of light emitted from the light source,
With
The resolution of the display screen that displays the reflected light is controlled by controlling the rotation speed by the rotation control unit and controlling the light emission interval by the light emission control unit.
The projection type display mechanism according to claim 1, wherein the projection type display mechanism is provided.

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