RU2347254C2 - Device for formation of bright images on screen - Google Patents

Abstract

FIELD: physics; processing of images.

SUBSTANCE: device for formation of images on the screen in which the shone image shaped by a file of light sources is designed on the screen by means of an objective. Thus the device is executed with travel possibility on the screen of the image designed on the screen in such a manner that the image of each light source periodically moves on the closed trajectory, thus the file of light sources and an objective are executed with travel possibility from each other on the closed trajectory.

EFFECT: obtaining of high-quality image on the screen.

10 cl, 10 dwg

Description

Technical field

The present invention relates to the formation of bright large-format images on a screen using brightness-modulated light sources and can be used in various information display devices, in particular in cinema, in street screens, in advertising.

State of the art

The most widely used projectors are those in which a film or a liquid crystal matrix is illuminated by a powerful beam of light. Using a lens consisting of a lens system, a film frame or matrix is projected onto a reflective screen. This method of forming an image on the screen has fundamental disadvantages associated with the fact that a significant part of the light flux is absorbed by the film frame or matrix. This leads to a limitation of the maximum power of the luminous flux and, as a result, to restrictions on the brightness of the screen and its size.

In connection with the recent appearance of powerful small-sized light sources capable of high-frequency modulation in brightness, it became possible to significantly increase the brightness of the image formed on the screen and its area. These light sources are powerful LEDs. The total luminous flux generated by the matrix of LEDs can significantly exceed the maximum luminous flux that can pass through a film frame or a liquid crystal matrix. As a result, an image can be formed on the screen, the brightness of which greatly exceeds the brightness of the currently existing images.

Unfortunately, at present, the technology for manufacturing LEDs has not reached a level at which it would be possible to produce a matrix of LEDs with high resolution. However, in many applications this is not required. A high-quality image on the screen can be obtained using a matrix with a relatively small number of LEDs in the event that the image of each LED on the screen moves along some closed path. When the LED is turned on at specified times, the LED forms a fragment of the image, the area of which is significantly larger than the area formed by the fixed LED.

SUMMARY OF THE INVENTION

The essence of the invention lies in the fact that a matrix of powerful light sources, consisting of N lines, each of which contains M sources, is projected on the screen. Each of the sources can be modulated in brightness. An image of size M * N pixels may be formed on the screen.

To increase the resolution of the resulting image, the lens performs a translational motion in such a way that all its points move around a circle of the same radius. At the same time, the image on the screen of each LED moves in a circle and each LED illuminates a ring, the area of which is L / S times the area illuminated by the LED with a stationary lens, where L is the circumference on the screen, S are the transverse dimensions of the image on the screen of the stationary LED. For example, with M * N = 1000 and L / S = 1000, you can form an image with a resolution of 1,000,000 pixels.

An increase in image resolution can also be achieved by introducing into the device a mirror that performs vibrational-rotational movements. Rays from modulated light sources, reflected from such a mirror, move along a certain closed path, thereby increasing the area illuminated by one light source.

Using the proposed device for the viewer can be formed stereo image. At the same time, the viewer is equipped with glasses that transmit light of one polarization into the left eye of the viewer, and orthogonal into the right eye. In another modification of the device, the viewer is equipped with glasses that transmit light into the left (right) eye when applying voltage to the left (right) glass of the glasses.

List of drawings

Figure 1 shows the relative position of the screen, lens and matrix of modulated light sources.

Figure 2 shows the image on the screen of the LED matrix projected through the lens, provided that all the LEDs emit light.

Figure 3 shows a special case when the lens 2 performs a circular motion.

Figure 4 shows a device for moving the lens.

Figure 5 shows the path of the rays in the installation with a fixed lens and a matrix of LEDs, in which the image of the LEDs on the screen is moved using a movable mirror.

Figure 6 shows a device that provides rotational-vibrational motion of the mirror.

7 shows a device that provides rotationally oscillatory motion of the mirror and minimizes dynamic reactions to the base of the device.

On Fig shows a top view of a device that provides the movement of the mirror so that the image of the LED on the screen describes the ring.

Figure 9 shows the means for dynamically balancing the device shown in Fig. 8.

Figure 10 shows the shape of the mirror, performing a rotationally oscillatory motion and adapted to display stereo images.

Information confirming the possibility of carrying out the invention

Figure 1 shows a top view of the relative position of the matrix of LEDs 1, lens 2 and reflective screen 3. Figure 2 shows the screen image of the LED matrix projected through the lens, provided that all the LEDs emit light. As can be seen from these figures, the design of the LEDs on the screen does not differ in this case from the traditional one, in which a luminous film or a luminous liquid crystal matrix is projected on the screen.

It is also possible to obtain color images. For this purpose, instead of one matrix of LEDs, 3 matrixes of LEDs should be used, containing respectively red, green and blue LEDs. In this case, each matrix forms on the screen, respectively, red, green and blue images. The superposition of these images results in a color image. It is also possible to use LEDs that can emit at the same time and / or alternately red, green and blue light (RGB LEDs). The use of such LEDs allows to increase the maximum density of LEDs in the matrix. Finally, the use of semiconductor lasers is also possible. Unlike LEDs, semiconductor lasers emit light in an extremely small solid angle. This makes it possible to direct all the emitted light into the lens 2 in FIG. 1 and thus increase the brightness of the image formed on the screen 3.

The situation changes if the lens and the luminous object move relative to each other. Figure 3 shows a special case when the lens 2 performs a circular motion. As can be seen from the figure, in this case, each LED illuminates the ring on the screen and each point on the screen at one time or another is illuminated by one or another LED. In this case, the required number of LEDs is reduced by L / S times, where L is the circumference along which the LED image moves, S is the diameter of the image of the stationary LED. In this case, the maximum illumination of the screen is proportional to the number of LEDs used and, when using existing LEDs, it can be orders of magnitude higher than the illumination created by traditional projectors.

The same effect can be achieved if the lens is stationary and the matrix of LEDs moves relative to the lens.

The circular movement of the lens 2 in a circle can be carried out using the device shown in Fig.4. Here, on the axis of the stationary motor 5, a rotating lever 6 is fixed, to one of the ends of which the link 4. The link is also pivotally attached to the rotating levers 7, the axis of rotation of which are parallel to the axis of rotation of the motor 5. As a result, the link 4 moves parallel to itself and all points the scenes move in circles of the same radius. Rigidly connected to the wings, the lens 2 also moves in a circle.

Figure 5 shows the path of the rays in the installation with a fixed lens 2 and a matrix of LEDs 1. Moving the image of the LEDs on the screen 3 is carried out using a movable mirror 8, which performs rotational-vibrational movements around an axis perpendicular to the plane of the figure.

Figure 6 shows a device that provides rotational-vibrational motion of the mirror 8, which is mounted on the shaft of a DC motor 9, attached to the base 11. In addition, the mirror is connected to the base of the motor through an elastic mechanical system that seeks to return the mirror to the equilibrium position when turning the motor shaft from the equilibrium position. In the simplest case, a twisted spring 10 can be used as such a system. Rotational-vibrational motion of the mirror is excited when a periodic sequence of voltage pulses is applied to the motor, the repetition rate of which is equal to the natural frequency of the vibrational system formed by the mass of the mirror and the elastic mechanical system.

7 shows a device that provides rotational-vibrational motion of the mirror 8 and minimizes dynamic reactions to the base 11. In this case, the mechanical oscillatory system is formed by the mass of the mirror 8, the mass of the counterweight 12, which are interconnected by an elastic mechanical system, which can a coil spring 10 is used. Fluctuations in this system are excited by rotating magnets 14 attached to the shaft of the motor 9. In order to fix the equilibrium position of the mirror 8, the coil spring 10 is connected to the main aniem 11 at the location of the spring, in which the amplitude of its vibrations is minimal. A distinctive feature of this device is the fact that the rotational speed of the motor is automatically set equal to the frequency of oscillations of the mirror, provided that the motor power slightly exceeds the minimum required power.

On Fig shows a side view of a device that provides the movement of the mirror 8 in such a way that the normal to the mirror describes a cone whose axis coincides with the axis of the electric motor 9. The mirror 8 is mounted on the shaft of the electric motor so that the plane of the mirror makes an angle with the axis of the motor shaft π / 2-φ, where φ << π / 2. When the motor shaft rotates, the angle of inclination of the mirror relative to the horizontal and vertical axes changes by 2φ. The image of each LED in the LED matrix describes an ellipse. The major axis of the ellipse is determined by the expression 2Lφ, where L is the distance from the imaginary image of the fiber to the screen. The small axis of the ellipse in Cos is γ times smaller than the large, where γ is the angle between the normal to the plane of the mirror and the beam from the LED. Thus, by changing the angle φ, you can change the size of the ellipse, and by changing the angle γ, you can change the ratio of the axes of the ellipse. This allows you to choose a compromise between the brightness of individual pixels of the image and its resolution.

In order to provide dynamic balancing of the device, it is proposed to additionally introduce a plate 81, which is identical in size and weight to mirror 8 (Fig. 9). Instead of a plate, it is possible to use two identical weights located at the same distance from the motor axis, but at different distances from the shaft end.

The device shown in FIG. 1 can be modified to produce stereo images on a screen. For this purpose, part of the LEDs 1 is coated with a polarizing film that transmits light of one polarization, and the other part of the LEDs is coated with a film that transmits light of orthogonal polarization. As screen 3, a screen is used that preserves the polarization of light when reflected from it. The viewer is equipped with glasses that transmit light of one polarization into the left eye, and the other into the right.

If using the first group of LEDs to form an image for the left eye, and using the second group of LEDs to form an image for the right eye at the same time and on the same screen, the viewer will perceive a three-dimensional image.

The stereo image can also be obtained if, in the installation shown in FIG. 5, the mirror 8 is made bilateral and rotating. In this case, one side of the mirror is covered with a film that transmits one polarization of light, and the other is covered with a film that transmits orthogonal polarization of light. The viewer is equipped with glasses with polarizers, transmitting light to the left eye with one polarization, and to the right - with orthogonal.

A brighter stereo image can be obtained if, instead of a rotating mirror, two mirrors that perform rotational-vibrational movements are used (Figure 10). In this case, the light from the matrix of LEDs enters the eyes of the observer for a longer time than when rotating one mirror. As a result, more light enters the eyes of the observer and the image is brighter.

A similar effect can be obtained if the viewer is equipped with glasses with glasses, the transmission of light through which is controlled by electrical signals. If you alternately display images for the left and right eyes on the screen and open the glasses transmitting light into the left and right eyes, respectively, then the viewer will see one image with the left eye and the other with the right eye. This is enough to form a three-dimensional image.

Claims (10)

1. A device for forming images on a screen in which a luminous image formed by an array of light sources is projected onto the screen using a lens, characterized in that the device is configured to move the image projected onto the screen in such a way that the image of each light source periodically moves along a closed path, while the array of light sources and the lens are made with the possibility of moving relative to each other along a closed path. 2. The device according to claim 1, characterized in that the lens makes periodic movements around the circumference using a device consisting of a link, to which the lens is attached, a motor, to the axis of which is attached a rotating lever pivotally connected to the link, and two additional levers, providing translational backstage movement, and rotating around axes parallel to the axis of the motor. 3. The device according to claim 1, characterized in that the array of light sources makes periodic movements around the circumference using a device consisting of a link, to which an array of light sources is attached, a motor, to the axis of which is attached a rotating arm pivotally connected to the link, and two additional levers, providing translational movement of the scenes and rotating around axes parallel to the axis of the motor. 4. The device according to claim 1, characterized in that a flat mirror is inserted in the path of the light rays from the array of light sources to the screen, performing rotational-vibrational movements in space. 5. The device according to claim 4, characterized in that the flat mirror is attached to the axis of the motor so that the angle between the axis of the motor and the plane of the mirror is in the range of 70-90 °. 6. The device according to claim 5, characterized in that means are introduced that provide static and dynamic balancing of a rotating flat mirror. 7. The device according to claim 1, characterized in that one part of the array of light sources is covered with a polarizing film that transmits light only of the first polarization, and the other part is covered with a polarizing film that transmits light of the second polarization, which is perpendicular to the first; the screen onto which the image is projected is adapted to maintain the direction of polarization of the light reflected from it, the viewer examines the screen through glasses that pass light into the left and right eyes of the viewer, respectively, of the first and second polarizations. 8. The device according to claim 1, characterized in that on the path of the light rays from the array of light sources to the screen, adapted to maintain the polarization of the light reflected from it, a two-sided flat mirror is inserted, rotating along an axis parallel to the plane of the screen; one surface of the mirror is covered with a polarizing film that transmits light of the first polarization, and the opposite surface is covered with a film that transmits light of the second polarization, which is perpendicular to the first, the viewer looks at the screen through glasses that pass the light of the first and second polarizations into the left and right eyes of the viewer. 9. The device according to claim 1, characterized in that on the path of the light rays from the array of light sources to the screen, adapted to maintain the polarization of the light reflected from it, two flat mirrors are inserted, located at an angle to each other so that the intersection line of the planes, passing through a mirror surface, parallel to the axis of rotation, around which these mirrors make rotational-vibrational motion; the mirror surface of one mirror is covered with a polarizing film that transmits light of the first polarization, and the mirror surface of another mirror is covered with a film that transmits light of the second polarization, which is perpendicular to the first, the viewer looks at the screen through glasses that pass the light of the first and second polarizations into the left and right eyes of the viewer, respectively . 10. The device according to claim 1, characterized in that on the path of the light rays from a flat array of light sources to the screen, a mirror with a non-zero curvature performing a rotational-vibrational movement is inserted.

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