CN2547079Y - scanning projection device - Google Patents

Abstract

A scanning projection device for reconstructing and projecting an image frame on a screen according to an input signal, the image frame having a two-dimensional pixel array formed by a plurality of pixels, each pixel corresponding to a specific position on the screen having an address coordinate and a scan line coordinate, the scanning projection device comprising: the scanning type projection device synchronously outputs a plurality of light beams which are consistent with the pixel number in the extending direction of the address coordinate to be sequentially projected on the positions of the address coordinate on different scanning line coordinates so as to form an image frame by scanning one by one.

Description

scanning projection device

(1) Technical field

The utility model relates to a projection device, in particular to a scanning projection device for forming image frames by scanning one by one.

(2) Background technology

Display devices currently on the market for displaying pictures can be roughly divided into direct-view displays and projection displays. CRT for short) display, plasma display (Plasma Display Panel, PDP), liquid crystal display (Liquid Display Panel, LCD), etc. are directly displayed for people to watch. When displaying a large screen (such as 40 o'clock to 200 o'clock), the manufacturing technology of large-sized panels has its upper limit. Even within the manufacturable range, the cost is still too high, so projection displays are mainly used, including cathode ray displays. Tube projection display, liquid crystal projection display and shutter display, such as digital microlens (Digital MicromirrorDevice, DMD), etc., and no matter what kind of projection display, it includes an image electrical signal processing circuit and an image The signal forms the projection device of the image frame.

FIG. 1 shows a conventional cathode ray tube projection display 1 . The display 1 is composed of three single-color (red, green, blue) cathode ray tubes 111, and the output of each cathode ray tube 111 is respectively provided with a lens 112, which originally scattered the output light of the cathode ray tube 111 to a certain direction forward. In the range of angles, it is projected onto the screen 12 intensively. However, the cathode ray tube projection display 1 is limited by the volume of the cathode ray tube 111 , so there is a lack of a large overall volume, which is contrary to the trend of today's electronic products tending to be short and thin. In addition, in this cathode ray tube projection display 1, the surfaces of the cathode ray tubes 111 and the surfaces adjacent to the lens 112 are respectively coated with phosphors of corresponding colors, and the output light is emitted by using an electron gun to excite the phosphors to emit light indirectly. The lens 112 is projected on the screen 12, so that the cathode ray tube projection display 1 has the disadvantage of low conversion efficiency of indirect light emission, and because each cathode ray tube 111 emits light in all directions, it can really be collected by the lens 112 and output to the screen 12 The above part needs to be discounted again, during which the energy loss is greater, so that the utilization rate of the light source is lower.

Therefore, in order to ensure that the reconstructed image frame can be viewed clearly, the screen 12 must be limited to structures such as directional aluminum foil or glass beads, and it is best to turn off the light when in use to reduce the interference of other light sources. Restricted.

Furthermore, in the conventional liquid crystal projection display 2 (called a liquid crystal projector) as shown in FIG. The light source 211 is a point light source, so it can be reflected by a parabolic mirror 212, and the light from the light source 211 can be output in parallel. After the light is split by the dichroic mirrors 213, 214, and 215, it is respectively incident on the corresponding liquid crystal panels 216, 217, and 218, and the light of each color After being modulated by the corresponding liquid crystal panels, they are integrated and projected onto the screen 22 through a projection lens 219 .

Therefore, in fact, the beam intensity of each pixel projected on each frame image needs to be modulated by the liquid crystal panels 216, 217, 218, so that the size of the liquid crystal panels 216, 217, 218 needs to match the resolution of the conventional liquid crystal projection display 2, for example For example, the resolution of the liquid crystal projection display 2 is 1024×768 pixels, and each liquid crystal panel 216, 217, 218 needs at least 1024×768 unit cells to correspond to each pixel respectively, but as we all know, the liquid crystal panel The prices of 216, 217, and 218 increase significantly with increasing size, so that this liquid crystal projection display 2 has the advantage of being smaller than the cathode ray tube projection display 1, but its price remains high. In addition, because the light emitted by the actually used light source 211 cannot be regulated by a parabolic mirror to a parallel output, the frequency limitation of the dichroic mirrors 213, 214, 215 and the multiple losses of the light through the liquid crystal panel screening, etc., cause this The energy utilization rate of the projection device 2 is extremely low, so that the luminous intensity of the matching light source 211 must be extremely high to produce clear images. However, the luminescence of the light source 211 is not only accompanied by high heat, but also high-intensity light beams incident, resulting in a large amount of light energy absorbed by each optical path element, which is converted into heat and damages the life of the element, so the luminescence of the light source cannot be enhanced without limit.

As mentioned above, the cathode ray tube projection display 1 in the past projection device has the disadvantage of being too large, and the liquid crystal projection display 2 has the disadvantage of high cost. Reconstructing the image frame with a low-cost structure has become the focus of the industry's efforts. Furthermore, conventional projection devices use an indirect method to reconstruct image frames, resulting in low energy utilization efficiency. Therefore, if the output intensity of the light source can be directly controlled without the loss of secondary light emission or absorption by other components, the energy utilization efficiency will be improved, the energy required for the light source will be greatly reduced, and the problems of heat generation and heat dissipation will be reduced, which will reduce the cost of raw materials and use. Decrease, component life increases accordingly.

(3) Contents of utility model

In the utility model, by controlling the luminous intensity of the light source assembly, several light beams in one dimension of the image frame are output, and the reflective unit is used to drive the light beams to reflect sequentially and scan column by column, so that they are sequentially projected to the corresponding The pixel position, so the light source component does not need to match the resolution of the overall image frame, but only needs to match one dimension of the image frame, effectively reducing the volume of the light source component.

Therefore, an object of the present invention is to provide a scanning projection device capable of reducing volume.

Another object of the present invention is to provide a scanning projection device capable of reducing costs.

Another object of the present invention is to provide a scanning projection device capable of improving the efficiency of light source utilization.

Another object of the present invention is to provide a scanning projection device that can prolong the service life of components.

The scanning projection device of the present invention is used to reconstruct and project an image frame on a screen according to an input signal. The image frame has a two-dimensional pixel array composed of a plurality of pixels, and each pixel is in the The screen corresponds to a specific position with an address coordinate and a scan line coordinate respectively. The scanning projection device includes a synchronous signal generating unit, a light source assembly and a reflection unit; wherein, the synchronous signal generating unit is used to Generate a synchronous control signal synchronous with the input signal; the light source component synchronously outputs pixels with a number consistent with the address coordinate extension direction of the pixel array and corresponding to each of the pixels with different address coordinates on the screen several light beams at positions, and the light source assembly is controlled by the input signal so that the light beams respectively have a visible light wavelength and relative intensity corresponding to a projected pixel in the pixel of the corresponding image frame; and the reflection unit is used so that the light beams from the light source assembly are respectively projected on the positions of the corresponding address coordinates on the same scan line coordinates of the screen, so as to display that the projected pixels in the image frame form a scan line, and the reflection unit The synchronous signal generating unit is further coupled to receive the synchronous control signal, so that the projected light beam can be projected on corresponding positions of different scanning line coordinates on the screen according to the synchronous control signal, thereby forming the image frame.

In order to further illustrate the purpose, structural features and effects of the utility model, the utility model will be described in detail below in conjunction with the accompanying drawings.

(4) Description of drawings

FIG. 1 is a schematic diagram of a conventional cathode ray tube projection display.

FIG. 2 is a schematic diagram of a conventional liquid crystal projection display.

FIG. 3 is a schematic block diagram of a preferred embodiment of the scanning projection device of the present invention.

FIG. 4 is a schematic diagram of the light source assembly in FIG. 3 .

FIG. 5 is a schematic diagram of a two-dimensional array of image frames in this embodiment.

FIG. 6 is a side view of the embodiment of FIG. 3 .

FIG. 7 is a schematic diagram of the reflection unit in FIG. 3 .

Fig. 8 is a side view of the embodiment of Fig. 3 with the light beam shown enlarged.

Fig. 9 is a side view of the second preferred embodiment of the present invention.

Fig. 10 is a side view of the third preferred embodiment of the present invention.

Fig. 11 is a side view of the fourth preferred embodiment of the present utility model.

(5) specific implementation

As shown in FIG. 3 , the scanning projection device of the preferred embodiment of the present invention is suitable for reconstructing and projecting an image frame on a screen (not shown in the figure) according to an input signal. As shown in FIG. 5 , the image frame has a two-dimensional pixel array composed of a plurality of pixels, and each pixel has a corresponding specific position with an address coordinate and a scan line coordinate on the screen. The scanning projection device of this embodiment includes a synchronous signal generating unit 3 , a light source unit 4 and a reflecting unit 5 .

The synchronous signal generating unit 3 is used for generating a synchronous control signal synchronous with the input signal to the reflecting unit 5 .

The light source assembly 4 is used to generate a number of light beams corresponding to the number of pixels in the direction in which the address coordinates of the pixel array extend and respectively corresponding to positions with different address coordinates on the screen, and can operate according to input signals The wavelength and relative intensity of each beam are controlled by the input signal to output these beams synchronously.

In this embodiment, as shown in FIG. 4 , the light source assembly 4 has a number corresponding to the number of pixels in the direction in which the address coordinates of the pixel array extend and corresponds to several positions on the screen with different address coordinates. The light source units 41, each of the light source units 41 can be operated to generate a plurality of light beams respectively having different wavelengths. Each light source unit 41 includes a diode matrix composed of several light emitting diode (LED) dies. Each of the light source units 41 is adapted to be controlled by an input signal fed through a signal line 7 to enable emitting a plurality of light beams, so as to respectively have a relative intensity corresponding to a projected pixel in the corresponding image frame. The light emitting diodes include a first set of diodes capable of generating red light, a second set of diodes capable of generating green light and a third set of diodes capable of generating blue light. Each diode set includes at least one LED. In this embodiment, each diode set includes a light-emitting diode, and by controlling the input voltage and/or current of each light-emitting diode, the color brightness output by each set is regulated, so that the three light-emitting diode sets jointly emit beam signals, In other words, by controlling the luminous intensity of each diode set in each light source unit 41 , the color and brightness of the light beam output by the light source unit 41 can be defined. It should be noted that in this embodiment, these light source units 41 are controlled by the input signal and are simultaneously activated to output light beams respectively to form a row of several light beams arranged along the extending direction of the address coordinates, thereby forming a scanning line , and when the number of the light source units 41 is 1024, the light source assembly 41 outputs scan lines with 1024 pixels. Referring to FIG. 6 together, in this embodiment, the light source assembly 4 also includes a focusing mirror 42 arranged on the light emitting direction of the light source unit 41. The focusing mirror 42 is an arc cylindrical mirror, and makes the light source unit 41 Set on a plane mirror surface 421 of the focusing mirror 42, so that the light beam is emitted from the arc mirror surface 422 of the focusing mirror 42. In addition, as shown in FIG. Like this, then all light source units 41 output light beams converge and focus through this focusing lens 42 and will make the fall of the light beams

The dots become smaller and the resolution increases simultaneously, and the image frame of the same height can be divided into more scan lines, and the same scan line can also be composed of more pixels, making the image more detailed.

In addition, the number of diodes included in each diode set in each light source unit 41 can be increased or decreased according to actual design requirements. For example, the third diode set can also include two blue light-emitting diodes due to the high demand for blue light in general screen display. . Since the currently used red, green, and blue LEDs emit light whose color is closer to the limit of human vision, the colors that can be combined and displayed through the LED light source are also richer and the range that can be adjusted is wider. Of course, besides being directly used as light emitting diodes in the foregoing disclosed embodiments, the light emitting diodes here may also be replaced by laser diodes (Laser Diode, hereinafter referred to as LD) included in the light emitting diodes.

Since an image frame can be divided into several pixels with two-dimensional coordinates as shown in FIG. Driven by the synchronous signal, the output scanning line of the light source assembly 4 is projected to the specific coordinate position of each pixel step by step in a sequential scanning manner, and a round of scanning is completed in the visual persistence period of the human eye to form a Information about an image frame.

In order to control the projection direction positioning of the light beam, as shown in FIG. 6 , the reflection unit 5 is a mirror for controlling the projection direction of the light beam in the extension direction of the scanning line coordinates. Of course, as those skilled in the art can easily understand, the aforementioned so-called sequential scanning does not necessarily completely scan every pixel position constituting the image frame plane, and can also use such as interlaced scanning to reduce the number of scans per pixel. The time required for one frame. In other words, the scanning projection device disclosed in the present invention can select the number of sampling points in a picture by means of the conventional control circuit, and thereby change the number of vertical and horizontal scanning lines, providing users with a choice of high-resolution (high-resolution) image quality), or shorten the time period required for scanning each frame (fast response rate, increased number of display frames per unit time).

For illustration, as shown in FIG. 7 , the reflecting unit 5 of this embodiment is a cylindrical polygonal mirror. As shown in Figure 5, if the X-axis coordinates are used as the address coordinates, and the Y-axis coordinates represent the scan line coordinates, the light source unit 4 will synchronously output the input signal fed in according to the signal line 7 corresponding to the first position in the frame. The image frame light beams of each pixel position (1, 1), (2, 1), (3, 1)..., (1024, 1) on a scan line (that is, located at the same scan line coordinate position), the The light beam is composed of different intensity beams of different wavelength bands (red, green, blue), as shown in Figure 7, the light beam is projected on the corresponding coordinate position on the screen 8 through the reflection of the reflection unit 5, so that the light source One action of unit 4 will display the pixels on the same scanning line on the screen 8, and then the light source unit 4 will continue to operate to output the pixels of the next scanning line according to the input signal and cooperate with the rotation of the reflection unit 5, so that the beams are sequentially projected to the next The height of one scanning line, repeating this cycle, completes the scanning of the entire screen and the reproduction of the image frame. In other words, each light beam is determined by the output from which light source unit 41 in the light source unit 4. The rotation angle can determine the scanning line coordinates (ie, the Y axis) of the relevant position of the light beam displayed on the screen 8, and the reflective unit 5 deflects a mirror to form an image frame.

At present, the switching frequency of light-emitting diodes used for communication can reach 0.5GHz, and the fastest switching frequency of laser diodes can reach above 10GHz (such as Vertical-Cavity Surface Emitting Laser, vertical resonant cavity surface emitting laser, referred to as VCEL or VCSEL), which is suitable for human eyes. Persistence of vision phenomenon, it is sufficient to only provide about 30 image frames per second, and if the reflection unit 5 of the present embodiment is a cylindrical hexagonal mirror, it needs to rotate 5 times per second (30/6 =5), and in terms of 1024×768 pixels of the current high-definition display, the total amount of information that each light-emitting diode needs to provide per second is equal to 768×30=230400.023G. In this way, the current light-emitting diode technology can fully support the high-quality display of the present invention.

As mentioned above, due to the progress of semiconductor technology, light-emitting diodes can be made of semiconductor grains, and the light source assembly 4 can be formed in a very small volume, and the manufacturing cost is also very low, so that the overall volume and price of the projection device are more competitive. force. In addition, unlike previous projection devices that used an indirect method to control the image brightness of each pixel position, resulting in low light source utilization, this embodiment directly controls the luminous intensity of multiple light source units, so that the light beams of different wavelength bands can be directly emitted. Projected on the corresponding pixel position without shading and attenuation, the utilization rate of the light source is higher than that of the previous technology, and the cost is greatly reduced. Moreover, since the scanning projection device of this embodiment scans line by line, the requirements for switching the light emitting diodes are reduced and the frame forming speed can be increased as required without limitation. Furthermore, according to this embodiment, the light source only needs to emit an intensity of 1800 lumens, and can easily project an image frame with an intensity of 1500 lumens. In this way, the viewer will be provided with the convenience of not having to turn off the light or screen when using it. That is to say, the miniaturized projection device only needs to be placed in a small box-shaped casing, and the user only needs to hold the small box, select a blank wall, and then project onto the wall to watch the reconstructed image frame . In particular, the resolution of image frame reconstruction can also be determined according to the size of the desired projection, or the color distribution of the light source can be further adjusted as compensation according to the color of the light source in the environment. Such a usage mode can completely change the current usage habits.

In addition, the type of the light source unit 4 is not limited by the ones disclosed in the foregoing embodiments, only a light source unit that can output several light beams with different wavelengths and intensities can be used. For example, as described below, a liquid crystal panel or a digital micromirror device (Digital Micromirror Device, DMD for short) can also be used to adjust the light intensity corresponding to the input signal. Elements in the following embodiments that have the same functions as those in the preceding embodiments will be denoted by the same reference numerals.

Fig. 9 is the second embodiment of the present utility model. In this embodiment, the difference from the previous embodiments is that the light source assembly 4' no longer controls the input voltage and/or current of each light-emitting diode to regulate the color brightness of each collective output, but is used in a reflective liquid crystal panel ( Liquid Crystal on Silicon, referred to as LCoS)44 to control the color brightness. Therefore, the reflective liquid crystal panel 44 of the present embodiment has the number of unit cells corresponding to the light source unit 41, and each unit cell has sub-unit cells respectively corresponding to the three primary colors, and the reflective liquid crystal panel 44 operates according to the input signal. Determine the light intensity (ie color brightness) reflected by each unit cell for the fed light beam. And because of the characteristics of the liquid crystal panel 44, it is better for the light to enter vertically and exit vertically, so the light source assembly 4' of this embodiment is also equipped with a polarized beam splitter (polarized beam splitter, PBS for short) that limits the direction of the light beam. )43. In this way, when the light source assembly 4' operates according to the input signal to output several light beams containing different wavelengths, the S component part of these light beams will be reflected by the PBS43 to the reflective liquid crystal panel 44, and then each unit cell will follow the The control of the input signal determines the ratio of the incident light beam from the S component to the P component, and then passes through the PBS43 to emit to the reflection unit 5, so as to sequentially project the modulated light beam on the screen 8 to form an image frame. In this way, due to this implementation The setting of the light source assembly 4' of the example makes the effect of this embodiment greatly reduced in size compared with the conventional cathode ray tube projection display 1, and even compared with the liquid crystal projection display 2, due to the area of the reflective liquid crystal panel 44 It only needs to correspond to the number of pixels in the direction of the extension of the address coordinates in the image frame, so that the required area is also greatly reduced compared with the prior art, so that this embodiment has the advantages of smaller size and lower size than the previous projection device. Advantages of cost reduction.

Figure 10 is the third embodiment of the present utility model. In this embodiment, the difference from the foregoing second embodiment is that the light source assembly 4″ uses a transmissive liquid crystal panel 45 to modulate the color intensity of the light beam output by the light source unit 41, so that the light intensity of the light beam is modulated by the transmissive liquid crystal panel 45. It can be output to the reflection unit 5. Because the quantity of the pass-through liquid crystal panel 45 in the present embodiment also only needs to correspond to the pixel quantity of the address coordinate extension direction in the image frame, it is the same as the foregoing embodiment, and also has the function of shrinking the volume. with the advantage of cost reduction.

As shown in Figure 11 is the fourth embodiment of the present utility model. The difference between this embodiment and the preceding embodiments is that the light source assembly 9 utilizes the DMD46 to modulate the brightness of the light. When this is done, the output light beam of the light source unit 41 hits the DMD46, and the DMD46 rotates the lens on the DMD46 according to the input signal to determine the reflected light. Then the reflected light beam with modulated brightness is projected to the reflection unit 5, and then reflected and projected on the screen 8 in sequence to form an image frame. Similarly, the DMD46 of this embodiment only needs to match the number of pixels in the direction of the extension of the address coordinates of the image frame, so compared with the conventional projection technology, it can also achieve the effect of reducing the size and cost.

It should be noted that, although the foregoing embodiments use a plurality of light source units 41 composed of three primary color light-emitting diodes to directly generate light beams containing different wavelengths, optical path elements such as optical filters and dichroic mirrors can also be used to The output beams of monochromatic light sources such as white light are distinguished into beams of three primary colors, so the number of light source units and output wavelengths are not limited to those disclosed in this embodiment.

Of course, those of ordinary skill in the art should recognize that the above embodiments are only used to illustrate the utility model, rather than as a limitation to the utility model, as long as within the spirit of the utility model, the above The changes and modifications of the embodiments will all fall within the scope of the claims of the present utility model.

Claims (10)

1. scan-type projection arrangement, in order to rebuild according to an input signal and to project an image frame on a screen, this image frame has a two-dimensional array that is made of a plurality of pixels, respectively this pixel is corresponding respectively one to have the ad-hoc location of an address coordinate and one scan line coordinate on this screen, its spy is that this scan-type projection arrangement comprises:

One synchronous signal generation unit, in order to produce one with the synchronous synchronous control signal of this input signal;

One light source assembly, output synchronously have that quantity conforms to the number of pixels of the address coordinate bearing of trend of this pel array and respectively on should screen respectively this has several light beams of the position of different address coordinates, and this light source assembly is to be subjected to the control of this input signal and to cause this light beam to have the visible wavelength and the correlation intensity of an a pair of projected pixel in should this pixel of image frame respectively; And

One reflector element, with so that from this light beam of this light source assembly be projected in respectively on the same scan line coordinate of this screen respectively should correspondence address coordinate the position, to show that this projected pixel in this image frame constitutes the one scan line, and this reflector element also is coupled this synchronizing signal generation unit to receive this synchronous control signal, this projected light beam can be incident upon on the correspondence position of the different scanning line coordinate on this screen, to constitute this image frame according to this synchronous control signal.

2. scan-type projection arrangement as claimed in claim 1 is characterized in that:

This light source assembly have that quantity conforms to the number of pixels of the address coordinate bearing of trend of this pel array and respectively on should screen respectively this has several light source cells of different address coordinate positions, respectively this light source cell is the light beam comprise several visible wavelengths for producing, this light source cell be can be subjected to this input signal control and by start synchronously to export several light beams.

3. scan-type projection arrangement as claimed in claim 2 is characterized in that:

Respectively this light source cell has several light-emitting diodes and causes this light beam to have this correlation intensity to the projected pixel in should this pixel of image frame respectively to be subjected to the control of this input signal.

4. scan-type projection arrangement as claimed in claim 3 is characterized in that:

Respectively this light-emitting diode in this light source cell comprises first diode set of a generation ruddiness, second diode set of a generation green glow and the 3rd diode set of a generation blue light.

5. scan-type projection arrangement as claimed in claim 2 is characterized in that:

This light source assembly also comprises a reflection liquid crystal, causes this light beam to have this correlation intensity to the projected pixel in should this pixel of image frame respectively to be subjected to the control of this input signal.

6. scan-type projection arrangement as claimed in claim 2 is characterized in that:

This light source assembly also comprises a penetration liquid crystal board, causes this light beam to have this correlation intensity to the projected pixel in should this pixel of image frame respectively to be subjected to the control of this input signal.

7. scan-type projection arrangement as claimed in claim 2 is characterized in that:

This light source assembly also comprises a digital micromirror elements, causes this light beam to have this correlation intensity to the projected pixel in should this pixel of image frame respectively to be subjected to the control of this input signal.

8. scan-type projection arrangement as claimed in claim 1 is characterized in that:

This light source assembly also comprises a condenser lens.

9. scan-type projection arrangement as claimed in claim 8 is characterized in that:

This condenser lens is a column globoidal mirror.

10. scan-type projection arrangement as claimed in claim 1 is characterized in that:

This reflector element is polygonal mirror of a column.

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