JP2007508598A - Two-dimensional optical scanning device and video display device using the same - Google Patents

Abstract

  The two-dimensional optical scanning device has a rotating body that rotates or a moving body that rotates in a circulating manner. The apparatus has at least two linear light source units. The rotating body can also be formed in the shape of a cylindrical drum. The moving body may have at least two cylindrical drums and an endless belt connected between them. Each linear light source unit is disposed on a rotating body or a moving body, and alternately projects an image. Since the apparatus can project light in various directions, it can also be used for an image display apparatus using a plurality of screens.

Description

  The present invention relates to a two-dimensional optical scanning device and an image display device using the same, and more specifically, a two-dimensional optical scanning device that two-dimensionally scans a light beam using a rotating or moving linear light source, and The present invention relates to a video display device using this.

  Recently, the demand for large image display devices has increased, and large image display devices can be classified as direct view types such as CRT devices, projection types such as LCD devices, and optical scanning types.

  A CRT device, which is a direct-view image display device, generates a color image when a red / green / blue electron beam strikes a fluorescent surface. Since the CRT apparatus requires a long flow distance of the electron beam between the electron gun and the fluorescent surface, the size of the CRT apparatus increases and becomes heavy. Therefore, the CRT device is not suitable for a large screen image display device.

  The LCD projector of the projection type image display device has an advantage that it can be reduced in thickness, but there is a disadvantage that light loss is caused by the use of a polarizing plate.

  An image display device based on an optical scanning method was proposed in Korean Patent No. 0366155 of the present applicant. However, in the case of the above-mentioned patent, since two-dimensional polygon mirrors are used for two-dimensional scanning, The volume becomes relatively large. Also, when using a rotating polygon mirror, not only does the deviation of the reflecting surface move little by little with respect to the optical axis around the rotation axis, but also when the incident angle of the light incident on the reflecting surface of the rotating polygon mirror is large. However, there was a restriction that the reflecting surface had to be wide.

  An object of the present invention is to solve the above problems, and a two-dimensional optical scanning device capable of two-dimensional scanning by rotating or moving a linear light source itself without using a rotating polygon mirror, and the same It is to provide a video display device that uses the.

  Another object of the present invention is to provide an image display device capable of displaying separate images on a plurality of screens using one optical scanning device.

  In order to achieve the above object and other objects, a two-dimensional optical scanning device according to the first aspect of the present invention includes a rotating rotating body and at least two linear light source units arranged on the surface of the rotating body. Have. Each linear light source unit includes a plurality of light emitting elements arranged in a line, and emits red, green, and blue light modulated according to a displayed image. At this time, the rotating body can be formed in the shape of a cylindrical drum.

  The two-dimensional optical scanning device according to the second aspect of the present invention includes a moving body that rotates and rotates, and at least two or more linear light source units arranged on the moving body. Each light source unit includes a plurality of light emitting elements arranged in a row, and emits red, green, and blue light modulated according to a displayed image. At this time, the moving body may be formed as at least two cylindrical drums and an endless belt or chain connected between them.

  According to a third aspect of the present invention, there is provided an image display device comprising: a rotating rotator; at least two linear light source units disposed on a surface of the rotator; and at least one or more projected light scanned from the light source. Screen.

  According to a fourth aspect of the present invention, there is provided an image display device including a moving body that circulates and rotates, at least two or more linear light source units arranged on the moving body, and at least one or more projected light scanned from the light source. Screen. At this time, when two or more screens are included, the respective screens may be arranged in different directions.

  Since the two-dimensional optical scanning device according to the present invention uses a linear light source unit arranged on a rotating rotating body or a circulating moving body, there is an advantage that the size can be reduced as compared with the conventional two-dimensional scanning device. In addition, since the two-dimensional optical scanning device according to the present invention does not use a rotating polygon mirror, it can prevent optical aberration and distortion generated by the rotating polygon mirror. Furthermore, design difficulties due to on-axis movement caused by the rotating polygon mirror can be avoided.

  According to the present invention, the linear light source can be variously configured, can be scanned not only with the length of the light source but also enlarged, and can be used for a large-sized image display device.

  The image display device according to the present invention can display images on a plurality of screens using a single scanning device, and can be configured to have a separate screen on each screen.

  Hereinafter, a two-dimensional optical scanning device according to the present invention will be described in detail with reference to the accompanying drawings so as to be easily implemented by those having ordinary knowledge in the technical field to which the present invention belongs.

  First, a two-dimensional optical scanning device for a video display device according to a first embodiment of the present invention will be described with reference to FIGS.

  The two-dimensional optical scanning device 10 shown in FIGS. 1 and 2 includes a cylindrical drum 300 that rotates by being connected to a motor (not shown), and two linear light source units disposed on the cylindrical surface of the drum. That is, the first linear light source unit 100 and the second linear light source unit 100 ′ are configured.

Each of the linear light source units 100 and 100 ′ preferably includes a plurality of light emitting elements 110, for example, laser diodes or light emitting diodes (LEDs) arranged in a line, and red, green, and blue corresponding to the displayed image. Emitting modulated light. As the linear light source 100, as shown in FIG. 3a, a light source in which a large number of light emitting elements 110 are arranged in one row can be used. If one row cannot obtain a sufficient resolution, or If the amount of light is insufficient, light sources arranged in two or more arrays can be used. (See Figure 3b)
Further, in order to maximize the efficiency of the intensity of light emitted from each light emitting element, a wedge prism 210 or a wedge reflecting surface can be used as shown in FIG.

  The wedge-shaped prism 210 shown in FIG. 4 includes an inclined surface 211 that is reflectively coated, a total reflection surface 212 that is parallel to the optical axis, and a lens surface 213. When the lens surface 213 is appropriately formed, it is not necessary to separately provide the collimator lens 200. Each time the light emitted from each light emitting element 110 is reflected by the inclined surface 211 and then reflected by the total reflection surface 212, the diverging angle of the diverging light emitted from the light emitting element decreases in proportion to the inclination angle. Can be used efficiently.

  In front of each light emitting element 110 of the linear light source unit, a collimator lens for converting light generated from each light emitting element 110 into each substantially parallel beam is disposed. As shown in FIGS. 4A to 4C, the collimator lens is a small rod lens 120 and / or a ball lens attached to the light emitting element 110 of each of the linear light source units 100 and 100 ′. 130 and an aspherical lens 140. On the other hand, the rod lens shown in FIGS. 4A to 4C and the cylindrical lens (or trick lens) may be used together.

  In addition, each light emitting element can be formed with an epoxy molded lens surface on the LED chip in order to focus, diffuse or convert light into a parallel light beam. At this time, the lens surface may be a spherical surface or an aspherical surface including a Cartesian oval surface.

  On the other hand, a surface-emitting LED can be used for each light-emitting element of the linear light source. In this case, it is desirable to coat the remaining surface excluding a part of the surface of the LED with a metal film to limit the light emitting part. This is because in the case of a surface emitting LED, light is emitted from the side surface and the surface of the light emitting layer, so that it is difficult to produce accurate and effective parallel light or convergent light due to a decrease in coupling efficiency when coupled with an external optical system. is there. Therefore, by limiting the light emitting part so that it can be reflected inside the LED by the metal film except for the predetermined light emitting part of the LED, the performance of the optical system can be improved and the structure of the optical system can be simplified. it can.

  Although two linear light source units 100 and 100 'are arranged in FIGS. 1 and 2, two or more linear light source units 100 and 100' can be formed by appropriate design. At this time, when the number of the linear light source units is n, it is preferable that the linear light source units are arranged on the drum 300 at an angle of 360 ° / n. Further, the linear light source units 100 and 100 ′ are arranged so that the length direction of the linear light source units 100 and 100 ′ and the rotation axis of the drum 300 are parallel to each other.

  The operation of the two-dimensional optical scanning apparatus according to the first embodiment of the present invention is as follows.

  The first and second linear light source units 100 and 100 ′ are arranged on the rotating drum 300 to rotate. At this time, first, when the first linear light source unit 100 faces the screen 500, the first When the light from the linear light source unit 100 is scanned onto the screen 500 and the second linear light source unit 200 is directed to the screen, the light from the second linear light source unit 100 ′ is irradiated onto the screen 500. Are scanned. That is, the first and second linear light source units 100 and 100 ′ are rotated to alternate with each other while scanning.

  On the other hand, although not shown, the screen size scanned using the magnifying lens between the drum 300 and the screen 500 can be enlarged, and various optical errors can be corrected with an appropriate correction lens to improve the screen quality. Can be improved.

  The image display apparatus using the two-dimensional optical scanning apparatus 10 according to the first embodiment can be used with one screen 500 installed in one direction with respect to the drum 300 as shown in FIGS. As shown in FIG. 6, two screens 500 and 500 'can be used to show an image. The number of screens to be used and the arrangement of the screens can be variously designed according to the purpose of use, and a separate screen can be configured for each screen.

  On the other hand, when the linear light source 100 is mounted on the rotator 300 and scanning is performed at a constant angular velocity, the image quality and resolution change on the screen 500 as far from the central axis. At this time, the image quality can be kept uniform on the screen 500 by changing the light emission time according to the scanning angle of the linear light source. With reference to FIG. 9, the change of the light emission time by the scanning angle of the linear light source 100 is demonstrated.

  As shown in FIG. 9, when the screen 500 is placed on the x-axis and the central axis of the scanning device is the z-axis, the average pixel size Dx of the screen can be defined by the following equation.

Dx = L tan θ _max / k (1)
Here, L is the scanning distance, θ _max is the maximum scanning angle, and (2k + 1) is the number of lines of the maximum pixel.

On the other hand, if θ _i is the scanning angle of the i-th line and θ _{i + 1} is the scanning angle of the (i + 1) -th line, the light scanned by the scanning means 300 scans one point x _i on the screen, and the next When x _{i + 1} is scanned during scanning, and the difference x _i -x _{i + 1} becomes the average pixel size Dx at an arbitrary point, the resolution becomes constant. That is, the pixel size must be constant (Dx) on the entire screen at an arbitrary point on the screen, and can be defined by the following equation.

x _i −x _{i + 1} = L (tan θ _i −tan θ _{i + 1} ) = Dx (2)
Therefore, when formulas 1 and 2 are rearranged, the following formula 3 can be obtained.

tan θ _max / k = (tan θ _i -tan θ _{i + 1} ) (3)
At this time, the scanning time interval Δt between the i-th point and the (i + 1) -th point is expressed by the following equation when the light source fixed to the rotator 300 rotates at a constant angular velocity ω.

Δt = (θ _i −θ _{i + 1} ) / 2ω (4)
Therefore, the scanning time interval Δt at the i-th point and the (i + 1) -th point can be obtained by the equations 3 and 4.

  That is, the light modulated and emitted from the linear light source 100 is scanned two-dimensionally by the rotating body 300 that rotates, and an image is displayed on the screen 500. As shown in Equations 3 and 4 for each scanning angle, By changing the light emission time, the pixel size Dx of the light finally scanned on the screen 500 becomes constant. That is, the image quality and resolution are uniform at all points on the screen.

  On the other hand, in addition to the method of adjusting the light emission time of the light source, the image quality and resolution of the image displayed on the screen can be maintained constant by using a correction prism block or the like, and an optical fiber bundle is attached in front of the screen 500 as shown in FIG. It can be used to make the image quality and resolution uniform.

  Next, a two-dimensional optical scanning device for an image display device according to a second embodiment of the present invention will be described with reference to FIG.

  The two-dimensional optical scanning device 10 shown in FIG. 7 is connected to a motor (not shown), and rotates between the first and second drums 310 and 310 ′ and the first and second drums 310 and 310 ′. Two linear light source units, that is, a first linear light source unit 100 and a second linear light source unit 100 ′ are arranged on a moving body configured as an endless belt 330 connected to the belt.

  At this time, the belt is connected between the first and second drums 310 and 310 ′, but the two drums may be connected by a chain or the like in addition to the belt. It is also possible to move the light source unit by using a linear (linear motor) with other moving means.

  Each of the linear light source units 100 and 100 'preferably outputs modulated light of red, green, and blue corresponding to an image displayed in a form in which a plurality of light emitting elements, for example, laser diodes or light emitting diodes are arranged in a line. discharge. The linear light source unit 100 can be variously formed as described with reference to FIGS. 3 to 5 in the first embodiment.

  Although two linear light source units 100 and 100 'are arranged in FIG. 7, two or more plural light source units can be formed by appropriate design. At this time, if the number of the linear light source units is n and the length of the belt 330 is s, it is desirable that the linear light source units are arranged on the belt 330 at intervals of s / n. Further, the linear light source units 100 and 100 ′ are arranged on the belt so that the length direction of the linear light source units 100 and 100 ′ is parallel to the rotation axis of the drums 310 and 310 ′.

  On the other hand, FIG. 7 also shows two drums 310 and 310 ′ for rotating the belt 330, but it is possible to provide two or more such drums by an appropriate design.

  The operation of the two-dimensional optical scanning apparatus according to the second embodiment of the present invention is as follows.

  The first and second linear light source units 100 and 100 ′ are disposed on a belt 330 that is connected to two drums 310 and 310 ′ that rotate at the same speed, and rotate together when the belt 330 rotates. At this time, when the first linear light source unit 100 is directed toward the screen 500, the light is scanned on the screen 500 by the light emitted from the first linear light source unit 100 and the second linear light source unit 100 ′. Is directed to the screen, the screen 500 is scanned with light emitted from the second linear light source unit 100 '. That is, the first and second linear light source units 100 and 100 ′ are alternately scanned while moving on the rotating belt 330.

At this time, when the drum rotates at a constant angular velocity, the belt 330 moves substantially at the same speed. Therefore, if the length of the screen in the scanning direction is L and the number of screens per second is m, the speed is about L × m per second. For scanning, assuming that the radius of the drum 300 is r and the rotational angular velocity of the drum is ω, the linear velocity v is
v = ω × r = L × m
It comes to have the relationship.

  At this time, if the rotational angular velocity ω of the drum is made constant, the linear velocity v also becomes constant, so that the scanning time becomes constant. In addition, when only a section in which constant velocity linear motion is performed is used, a linear (linear) motor can be used instead of the belt 300.

  On the other hand, although not shown, various optical errors are corrected by an appropriate correction lens while enlarging the screen size scanned using the magnifying lens between the linear light source units 100 and 100 ′ and the screen 500. The screen quality can be improved.

  The image display apparatus using the two-dimensional optical scanning apparatus 10 according to the second embodiment can be used by installing one screen 500 in one direction with respect to the scanning apparatus 10 as shown in FIG. Depending on the purpose, the number of screens can be two or more.

  An image display apparatus having three screens is illustrated in FIG. The scanning device 10 used in such an image display device can use three rotating drums 310, 310 ′, and 310 ″, and a plurality of linear light source units are arranged on an endless belt 330 that connects the drums. 8 shows an arrangement in which three linear light source units 100, 100'100 "and three screens 500, 500 ', 500" are arranged. In this way, the video display device according to the present invention is shown. The number, arrangement or type (projection type or reflection type) of screens to be displayed can be designed in various ways according to the purpose of use, and a separate screen can be configured for each screen.

  In addition, the optical scanning device according to the second embodiment is capable of linear motion or rotational motion when the linear light source fixed to the belt moves, and when the linear light source performs linear motion or rotational motion. It is also possible to scan the image only, and there is an effect that the image can be scanned in various ways.

  The technical features of the present invention have been described above with reference to specific embodiments. However, if the person has ordinary knowledge in the technical field to which the present invention belongs, various modifications and changes can be made within the scope of the technical idea of the present invention. It is clear that modifications can be made. In particular, in the case of a rotating body in which a linear light source unit is arranged, it is naturally possible to make various changes other than those described in the first and second embodiments of the present invention.

1 is a perspective view schematically illustrating a two-dimensional optical scanning device according to a first embodiment of the present invention. 1 is a side view schematically showing a two-dimensional optical scanning device according to a first embodiment of the present invention; It is the figure which illustrated the linear light source. It is the figure which illustrated the linear light source. It is the figure which illustrated the collimator lens part. It is the figure which illustrated the collimator lens part. It is the figure which illustrated the collimator lens part. It is a figure which illustrates a wedge-shaped prism. It is another example of 1st Example of this invention. FIG. 5 is a side view schematically illustrating a two-dimensional optical scanning device according to a second embodiment of the present invention. It is another example of 2nd Example of this invention. It is a figure explaining changing light emission time in 1st Example. It is a figure which illustrates the screen using an optical fiber bundle.

Claims (21)

A rotating rotator; and a plurality of light emitting elements arranged on the surface of the rotator and arranged in a line, and at least two straight lines that emit red, green, and blue light modulated according to a displayed image. Mold light source;
A two-dimensional optical scanning device.   The two-dimensional optical scanning device according to claim 1, wherein the rotating body has a cylindrical drum shape.   3. The linear light source unit according to claim 2, wherein the number of the linear light source units is n, and the linear light source units are arranged on the surface of the rotating body at an angle of 360 ° / n. Two-dimensional optical scanning device. A moving body that circulates and rotates; and a plurality of light emitting elements that are arranged on the moving body and arranged in a row, and that emit at least two straight lines that emit red, green, and blue light modulated according to a displayed image. Mold light source;
A two-dimensional optical scanning device.   5. The two-dimensional optical scanning device according to claim 4, wherein the moving body includes at least two cylindrical drums and an endless belt or chain connected between the drums.   When the number of the linear light source units is n and the length of the belt or chain is s, the linear light source units are arranged on the belt or chain at intervals of s / n. The two-dimensional optical scanning device according to claim 5.   The two-dimensional optical scanning device according to claim 4, wherein there is a section in which the linear light source unit arranged on the moving body performs a linear motion.   The two-dimensional optical scanning device according to claim 1, wherein a length direction of the linear light source unit and a rotation axis of the rotating body are substantially parallel.   The two-dimensional optical scanning device according to claim 4, wherein a length direction of the linear light source unit and a moving direction of the moving body are substantially perpendicular to each other.   2. The apparatus according to claim 1, further comprising a collimator lens unit that converts light emitted from each light emitting element of each linear light source unit into a substantially parallel beam or a converging optical unit that converts the light into a convergent beam. The two-dimensional optical scanning device described.   5. The apparatus according to claim 4, further comprising a collimator lens unit that converts light emitted from each light emitting element of each linear light source unit into a substantially parallel beam or a converging optical unit that converts the light into a converging beam. The two-dimensional optical scanning device described.   Each light-emitting element of the linear light source unit includes a light-emitting diode chip and an epoxy mold unit, and a surface from which light is emitted from the epoxy mold unit is formed into a spherical surface or an aspheric surface, and functions as a lens. The two-dimensional optical scanning device according to claim 4.   2. The light emitting device according to claim 1, wherein each of the light emitting devices of the linear light source unit is a surface light emitting diode device, and a metal coating is applied to a surface of the diode device except for a predetermined portion. 2D optical scanning device. The linear light source is modulated between the i-th scanning angle θ _i and the (i + 1) -th scanning angle θ _{i + 1} by dividing the maximum scanning angle θ _max of the linear light source unit at a predetermined resolution. The time interval Δt for emitting light is expressed by the following equation: tan θ _max = k (tan θ _i -tan θ _{i + 1} )
Δt = (θ _i −θ _{i + 1} ) / 2ω
(Where (2k + 1) is the number of lines of maximum pixels;
θ _{i + 1} is the (i + 1) th scan angle;
ω is the rotational angular velocity of the scanning means)
The two-dimensional optical scanning device according to claim 1, wherein: Light obtained by modulating the linear light source between the i-th scanning angle θ _i and the (i + 1) -th scanning angle θ _{i + 1} by dividing the maximum scanning angle θ _max of the linear light source unit at a predetermined resolution. The time interval Δt for emitting light is expressed by the following equation: tan θ _max = k (tan θ _i -tan θ _{i + 1} )
Δt = (θ _i −θ _{i + 1} ) / 2ω
(Where (2k + 1) is the number of lines of maximum pixels;
θ _{i + 1} is the (i + 1) th scan angle;
ω is the rotational angular velocity of the scanning means)
The two-dimensional optical scanning device according to claim 4, wherein: Rotating rotating body;
At least two linear light source units arranged on the surface of the rotating body and including a plurality of light emitting elements arranged in a line and emitting red, green and blue light modulated according to a displayed image; and An image display apparatus comprising: at least one screen on which light scanned from the light source is projected. Circulating and rotating moving body;
At least two linear light source units arranged on the moving body and including a plurality of light emitting elements arranged in a line and emitting red, green and blue light modulated according to a displayed image; and the light source An image display device comprising: at least one screen on which light scanned from is projected.   The video display apparatus according to claim 17, wherein the moving body includes at least two cylindrical drums and an endless belt or chain connected between the drums.   The video display device according to claim 17, wherein there is a section in which the linear light source unit arranged on the moving body performs a linear motion.   The video display device according to claim 16, wherein when two or more screens are included, the screens are arranged in different directions. 18. The video display device according to claim 17, wherein when two or more screens are included, each screen is arranged in a different direction.

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