Pixel expansion device and projection display equipment

Abstract

The invention relates to a pixel expansion device and projection display equipment, and the device comprises a first optical wedge which is used for receiving an incident light beam; and the second optical wedge is opposite to the first optical wedge and is arranged at an interval, and any one of the second optical wedge and the first optical wedge reciprocates relative to the other one along the light path direction, so that the incident light beam passes through the second optical wedge, and then the emergent light beam generates a preset displacement in the direction perpendicular to the light path. Accurate pixel expansion can be achieved, the display resolution is improved, the structure is simple, and implementation is easy.

Description

Technical Field

[0001] The present application relates to the field of projection display technology, and in particular to a pixel expansion device and a projection display equipment. Background Art

[0002] In the projection display technology of Digital Light Procession (DLP), the Digital Micromirror Device (DMD) is a crucial optical component that directly determines the image resolution. At present, the display system with 4K resolution (the pixel value per row in the horizontal direction reaches or approaches 4096) has gradually become the mainstream display technology, but the price of DMD chips with 4K resolution is relatively high and is not applicable in many scenarios. Therefore, the Extended Pixel Resolution (XPR) technology can be used to expand the pixels. XPR technology achieves higher resolution image display than the original DMD chip by offsetting the pixels (such as directional movement of half a pixel), thereby using low-resolution dimming devices to achieve high-resolution display effects.

[0003] The XPR technologies in related technologies include galvanometer solutions and plane reflector solutions. The principle of both solutions is to use external force to drive flat glass or plane reflectors to make fixed movements at a fixed frequency and angle to displace pixels, thereby achieving the effect of enhancing pixels. However, the energy utilization rate of the galvanometer solution is relatively low, that is, a displacement of half a pixel requires a large power consumption to achieve. The plane reflector solution has a greater impact on the optical path layout in the optical machine because it is placed at a certain angle in the optical machine to reflect light, and a very small swing angle can produce a displacement of half a pixel, which requires extremely high control accuracy and manufacturing accuracy of the device. Summary of the invention

[0004] The purpose of the present application is to provide a pixel expansion device and a projection display device, which can achieve accurate pixel expansion, improve display resolution, and have a simple structure and are easy to implement.

[0005] In a first aspect, an embodiment of the present application provides a pixel expansion device, comprising: a first optical wedge for receiving an incident light beam; a second optical wedge, opposite to and spaced from the first optical wedge, wherein either the second optical wedge or the first optical wedge moves back and forth relative to the other along the direction of the optical path, so that an outgoing light beam after the incident light beam passes through the second optical wedge generates a preset displacement in a direction perpendicular to the optical path.

[0006] In a possible implementation, the first optical wedge has a first inclined surface and a first straight surface set at a first preset angle, the second optical wedge has a second inclined surface and a second straight surface set at a second preset angle, the second inclined surface is parallel to and opposite to the first inclined surface, and the first straight surface and the second straight surface are parallel to and opposite to each other; the incident light beam is incident from the first straight surface, and the outgoing light beam is emitted from the second straight surface.

[0007] In a possible implementation, a refractive index of the first optical wedge is the same as a refractive index of the second optical wedge.

[0008] In a possible implementation, the value range of the first preset angle and the second preset angle are both 0 to 20 degrees.

[0009] In a possible implementation, a driving mechanism is further included, and the driving mechanism is connected to the first optical wedge or the second optical wedge to drive the first optical wedge or the second optical wedge to reciprocate along the optical path direction.

[0010] In one possible implementation, the driving mechanism includes an annular coil, a plurality of magnetic parts arranged on the outer circumference of the annular coil, and a bracket connected to the plurality of magnetic parts, each magnetic part includes a pair of magnetic strips placed with opposite polarities, and the bracket is connected to the first optical wedge or the second optical wedge so that the first optical wedge or the second optical wedge moves back and forth along the optical path direction under the drive of electromagnetic force.

[0011] In a possible implementation, after the driving mechanism drives the first optical wedge or the second optical wedge to move to a preset position along the optical path direction, the driving mechanism maintains the transient preset time and then moves in the opposite direction, wherein the duration of the transient preset time is greater than the duration of movement along the optical path direction.

[0012] In a possible implementation, the driving mechanism is an ultrasonic motor, which includes a piezoelectric ceramic component. The piezoelectric ceramic component is alternately powered on or off to drive the first optical wedge or the second optical wedge to move back and forth along the optical path.

[0013] In a possible implementation, the driving mechanism includes a first shape memory alloy wire and a second shape memory alloy wire, the first shape memory alloy wire is connected to one side of the incident surface of the first optical wedge, and the second shape memory alloy wire is connected to one side of the exit surface of the second optical wedge, and the first shape memory alloy wire and the second shape memory alloy wire are alternately powered on or off to drive the first optical wedge or the second optical wedge to move back and forth along the optical path direction.

[0014] In a possible implementation, the first optical wedge and the second optical wedge form a group of optical devices, the number of optical devices is two, the optical paths of the two groups of optical devices are in the same direction, and the second optical wedge of one group of optical devices moves synchronously with the first optical wedge of the other group of optical devices.

[0015] In a second aspect, an embodiment of the present application provides a projection display device, comprising: a light source for generating an incident light beam; and a pixel expansion device as described above, arranged on the light path of the light source.

[0016] The pixel expansion device and projection display device provided by the embodiment of the present application include: a first optical wedge for receiving an incident light beam; a second optical wedge, which is arranged opposite to and spaced from the first optical wedge, and either the second optical wedge or the first optical wedge moves back and forth relative to the other along the optical path, so that the outgoing light beam after the incident light beam passes through the second optical wedge generates a preset displacement in the direction perpendicular to the optical path. Thus, by the first optical wedge and the second optical wedge which are arranged opposite to and spaced from each other, and either the second optical wedge or the first optical wedge moves back and forth relative to the other along the optical path, the outgoing light beam can generate a preset displacement in the direction perpendicular to the optical path relative to the incident light beam, thereby achieving accurate pixel expansion and improving display resolution, and the structure is simple and easy to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In addition, in the drawings, the same parts are marked with the same reference numerals, and the drawings are not drawn according to the actual scale.

[0018] Figure 1 A schematic diagram showing the optical path of the pixel expansion device provided by an embodiment of the present application at time T0 is shown;

[0019] Figure 2 Show Figure 1 The optical path schematic diagram of the pixel expansion device at time T1 is shown;

[0020] Figure 3 Show Figure 1 A schematic structural diagram of a driving mechanism of the pixel expansion device shown;

[0021] Figure 4 Show Figure 1 A schematic structural diagram of another driving mechanism of the pixel expansion device shown;

[0022] Figure 5 Show Figure 1 A schematic structural diagram of another driving mechanism of the pixel expansion device shown;

[0023] Figure 6 A comparison diagram of driving current of an ultrasonic motor or SMA and an XPR in related art is shown.

[0024] Description of reference numerals:

[0025] 1. first optical wedge; 11. first inclined surface; 12. first flat surface; 2. second optical wedge; 21. second inclined surface; 22. second flat surface; θ, vertex angle; 3. driving mechanism;

[0026] 31. Ring coil; 32. Magnetic component;

[0027] 33. stator; 34. biasing elastic member; 35. piezoelectric ceramic member; 36. elastic body; 37. mover;

[0028] 38. a first shape memory alloy wire; 39. a second shape memory alloy wire;

[0029] 100, pixel expansion device; 200, light source; 201, incident light beam; 202, outgoing light beam. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0031] like Figure 1 and Figure 2 As shown, an embodiment of the present application provides a pixel expansion device, including a first optical wedge 1 and a second optical wedge 2 that are arranged opposite to and spaced apart from each other.

[0032] The first optical wedge 1 is used to receive an incident light beam, and either the second optical wedge 2 or the first optical wedge 1 moves back and forth relative to the other along the optical path direction, so that the outgoing light beam after the incident light beam passes through the first optical wedge 1 and the second optical wedge 2 generates a preset displacement in a direction perpendicular to the optical path.

[0033] An optical wedge, also called a wedge mirror, refers to a prism with a very small vertex angle, which is generally less than 1 / 10 radian. When light is incident on the optical wedge vertically or nearly vertically, the deflection angle generated is very small and has nothing to do with the incident angle. In this embodiment, the first optical wedge 1 and the second optical wedge 2 are arranged opposite to each other and spaced apart, and either the second optical wedge 2 or the first optical wedge 1 moves back and forth along the optical path relative to the other. For example, the first optical wedge 1 remains stationary, and the second optical wedge 2 moves back and forth along the optical path relative to the first optical wedge 1, or the second optical wedge 2 remains stationary, and the first optical wedge 1 moves back and forth along the optical path relative to the second optical wedge 2. In this way, the outgoing light beam after the incident light beam passes through the first optical wedge 1 and the second optical wedge 2 generates a preset displacement in the direction perpendicular to the optical path. The preset displacement can be half a pixel, so that one pixel point can be converted into two pixel points with a spacing of half a pixel, and then a low-resolution dimming device is used to achieve a higher-resolution image display.

[0034] It is understandable that the preset displacement is not limited to half a pixel, but may also be 1 pixel or 1 / 4 pixel, etc., depending on the specific application scenario, which will not be elaborated herein.

[0035] In addition, since the working principle of the pixel expansion device in this embodiment is to make a linear displacement of the pixel point by reciprocating one of the second optical wedge 2 and the first optical wedge 1 relative to the other along the optical path direction, it will not cause distortion or other aberration effects on the imaging, and the first optical wedge 1 and the second optical wedge 2 have simple structures, and the external force only needs to drive the first optical wedge 1 or the second optical wedge 2 to make a reciprocating linear motion in one direction to complete the pixel displacement of two channels (2way), and the driving control is simple and easy to implement.

[0036] The pixel expansion device provided by the embodiment of the present application comprises a first optical wedge 1 and a second optical wedge 2 which are arranged relative to and spaced apart from each other, wherein the first optical wedge 1 is used to receive an incident light beam; either the second optical wedge 2 or the first optical wedge 1 moves back and forth relative to the other along the optical path direction, and the outgoing light beam after the incident light beam passes through the second optical wedge 2 generates a preset displacement in the direction perpendicular to the optical path, so as to expand the resolution of the incident light beam. Thus, by the first optical wedge 1 and the second optical wedge 2 which are arranged relative to and spaced apart from each other, and either the second optical wedge 2 or the first optical wedge 1 moves back and forth relative to the other along the optical path direction, the outgoing light beam generates a preset displacement in the direction perpendicular to the optical path relative to the incident light beam, thereby expanding the resolution of the incident light beam, achieving accurate pixel expansion, improving display resolution, and having a simple structure and being easy to implement.

[0037] In some embodiments, the first optical wedge 1 has a first inclined surface 11 and a first flat surface 12 set at a first preset angle, and the second optical wedge 2 has a second inclined surface 21 and a second flat surface 22 set at a second preset angle, the second inclined surface 21 is parallel to and opposite to the first inclined surface 11, and the first flat surface 12 and the second flat surface 22 are parallel to and opposite to each other; the incident light beam is incident from the first flat surface 12, and the outgoing light beam is emitted from the second flat surface 22.

[0038] like Figure 1 and Figure 2 As shown, the first optical wedge 1 has a first inclined surface 11, and the second optical wedge 2 has a second inclined surface 21. The second inclined surface 21 is parallel to the first inclined surface 11 and is arranged at an interval. The first optical wedge 1 also includes a first flat surface 12. The first inclined surface 11 and the first flat surface 12 form a first preset angle, which is the vertex angle of the first optical wedge 1. The incident light beam enters the flat surface vertically or nearly vertically, and is deflected from the first inclined surface 11 and then emitted. The second optical wedge 2 also includes a second flat surface 22. The second inclined surface 21 and the second flat surface 22 form a second preset angle, which is the vertex angle of the second optical wedge 2. The second inclined surface 21 is parallel to the first inclined surface 11 and is arranged opposite to each other. The first flat surface 12 and the second flat surface 22 are parallel to each other. That is, the first optical wedge 1 and the second optical wedge 2 are placed in different directions. The incident light beam is incident from the first flat surface 12, emerges from the first inclined surface 11, enters the second inclined surface 21 and is deflected, and finally emerges from the second flat surface 22 in a direction parallel to the incident light beam, and the emergent light beam is offset by half a pixel in a direction perpendicular to the optical path.

[0039] It is understandable that the vertex angle of the first optical wedge 1 and the vertex angle of the second optical wedge 2 can be the same or different. Optionally, the vertex angle of the first optical wedge 1 and the vertex angle of the second optical wedge 2 are the same. In this case, the structures and geometric dimensions of the first optical wedge 1 and the second optical wedge 2 are the same, and only the placement directions are different, thereby saving design costs and material storage costs. In addition, the incident light beam can be incident on the first straight surface or the first inclined surface vertically, or on the first straight surface or the first inclined surface at a certain angle. Correspondingly, the outgoing light beam can be emitted from the second straight surface or the second inclined surface. When the incident light beam is incident on the first straight surface vertically and emitted from the second straight surface, the structure is more compact and the volume is smaller.

[0040] In some embodiments, the refractive index of the first optical wedge 1 is the same as the refractive index of the second optical wedge 2. When the first optical wedge 1 and the second optical wedge 2 are made of the same material, the refractive index is also the same. Optionally, the material of the first optical wedge 1 and the second optical wedge 2 can both be K9 glass or ultraviolet fused quartz, thereby saving material storage costs.

[0041] Further, the movement amount of either the second optical wedge 2 or the first optical wedge 1 relative to the other along the optical path direction is Δx, the preset displacement amount of the outgoing light beam in the direction perpendicular to the optical path direction is Δy, and the following conditions are satisfied:

[0042] Δy=(n-1)*θ*Δx, wherein n is the refractive index of the first optical wedge 1 or the second optical wedge 2 , and θ is the first preset angle or the second preset angle.

[0043] The first preset angle or the second preset angle is the vertex angle θ, and the value range is 0 to 20°. When the vertex angle is small, the angle is approximately equal to the sine value. Optionally, the first preset angle and the second preset angle are any one of 5°, 10° and 15°. The displacement of either the second optical wedge 2 or the first optical wedge 1 along the optical path relative to the other is Δx, which is a known design value, and θ is a known design value. When the preset displacement Δy is half a pixel, the refractive index of the first optical wedge 1 and the second optical wedge 2 can be solved; or, the refractive index of the first optical wedge 1 and the second optical wedge 2 is a known design value. When the preset displacement Δy is half a pixel, the displacement Δx of the second optical wedge 2 along the optical path relative to the first optical wedge 1 can be solved, so that the internal optical path layout of the pixel expansion device can be designed.

[0044] In some embodiments, the pixel expansion device further includes a driving mechanism 3, which is connected to the second optical wedge 2 to drive the first optical wedge 1 or the second optical wedge 2 to reciprocate along the optical path. The driving mechanism 3 can be any one of an electromagnetically driven linear motor, an ultrasonic motor, and a shape memory alloy (Shape Memory Alloys, SMA for short), which will be described below in conjunction with specific embodiments.

[0045] In some embodiments, the driving mechanism 3 includes an annular coil 31, a plurality of magnetic members 32 arranged on the outer peripheral side of the annular coil 31, and a bracket connected to the plurality of magnetic members 32, each magnetic member 32 includes a pair of magnetic strips placed with opposite polarities, and the bracket is connected to the first optical wedge 1 or the second optical wedge 2 so that the first optical wedge 1 or the second optical wedge 2 moves back and forth along the optical path direction under the drive of electromagnetic force.

[0046] like Figure 3As shown, the shape of the annular coil 31 is rectangular or square, and a magnetic member 32 is respectively arranged on the outer peripheral side of its four sides. One end of the bracket (not shown in the figure) is connected to the multiple magnetic members 32, and the other end is connected to the second optical wedge 2. Each magnetic member 32 includes a pair of magnetic strips placed with opposite polarities, in which the N pole of one magnetic strip is adjacent to the S pole of the other magnetic strip, and the N poles of a pair of magnetic strips in the two magnetic members 32 corresponding to the two opposite sides are respectively arranged corresponding to the S poles of the other pair of magnetic strips. According to Ampere's law, when a current in a certain direction is passed through the annular coil 31, the electromagnetic forces generated by the two magnetic members 32 corresponding to the two opposite sides are in the same direction, that is, Figure 3 In the direction perpendicular to the paper, the combined electromagnetic force generated by the four magnetic members 32 corresponding to the four sides jointly drives the second optical wedge 2 to move along the optical path direction; when the annular coil 31 is supplied with current in the opposite direction, the combined electromagnetic force is opposite, thereby driving the second optical wedge 2 to move in the opposite direction along the optical path direction.

[0047] In the related art, multiple coils are formed into a ring shape, and a magnetic member 32 is correspondingly arranged on the inner circumference of each coil, so that the two ends of the coil do not play a role in the magnetic field and increase the resistance. In this embodiment, since the ring coil 31 is a ring structure, multiple magnetic members 32 are arranged on the outer circumference of the ring coil 31, and the entire ring coil 31 basically plays a role in the magnetic field, so that the overlapping area of ​​the magnetic member 32 and the ring coil 31 is large, and the electromagnetic utilization efficiency is high.

[0048] In some embodiments, after the driving mechanism 3 drives the first optical wedge 1 or the second optical wedge 2 to move to a preset position along the optical path, the wedge is kept in a transient state for a predetermined time and then moves in the opposite direction, wherein the duration of the transient state is greater than the duration of the movement along the optical path. This arrangement can greatly reduce power consumption.

[0049] According to the visual persistence characteristics of the human eye, when a pixel moves from left to right, if it moves very slowly, the human eye can see it as moving, and if it moves very quickly, the human eye sees a straight line. When enhancing pixels, the human eye cannot see it moving or as a straight line, so it is necessary to reduce the time of the moving process to a very short time, so that the stay time at the left and right ends is relatively long, so that the human eye can neither see the pixel moving nor a straight line, but can only see one pixel on each side, thus turning one pixel into two pixels, achieving the effect of enhancing the pixel. Therefore, the first optical wedge 1 or the second optical wedge 2 is in a transient state for 90% of the time in a motion cycle, and then the first optical wedge 1 or the second optical wedge 2 moves in the opposite direction to the initial position, and completes a motion cycle after staying for a preset time. Since the time that the pixel stays at the left and right ends accounts for 90% of the time in a motion cycle, power consumption can be greatly reduced.

[0050] In one example, the driving mechanism 3 is an ultrasonic motor, which includes a piezoelectric ceramic member 35, which is alternately powered on or off to drive the first optical wedge 1 or the second optical wedge 2 to move back and forth along the optical path. For ease of description, the embodiment of the present application is described by taking the example of the driving mechanism 3 driving the second optical wedge 2 to move back and forth relative to the first optical wedge 1 along the optical path.

[0051] Specifically, the ultrasonic motor also includes a stator 33, a biasing elastic member 34, an elastic body 36 and a mover 37. The biasing elastic member 34 is arranged between one side of the stator 33 and the piezoelectric ceramic member 35, the elastic body 36 is arranged between the piezoelectric ceramic member 35 and the mover 37, and the mover 37 is connected to the second optical wedge 2. When the piezoelectric ceramic member 35 is energized, ultrasonic vibration is generated to drive the second optical wedge 2 to move back and forth along the optical path direction.

[0052] like Figure 4 As shown, the biasing elastic member 34 is a compressible spring, the material of the elastic body 36 can be silicone, rubber, etc., and the material of the mover 37 can be wear-resistant material, such as metal copper, etc. In one example, a micro-unit mass is arranged on the elastic body 36. Since the biasing elastic member 34 is arranged on one side of the stator 33, the piezoelectric ceramic member 35 generates ultrasonic vibration after being energized, which will drive the micro-unit mass on the elastic body 36 to make an elliptical motion, generating displacements in the X direction and the Y direction, wherein the displacement in the Y direction is absorbed by the elastic body 36, and the displacement in the X direction will drive the second optical wedge 2 to move along the optical path direction.

[0053] Further, after the second optical wedge 2 moves to the preset position along the optical path direction, the piezoelectric ceramic component 35 is powered off, and the biasing elastic component 34, the elastic body 36 and the friction component drive the second optical wedge 2 to maintain the preset position for a transient predetermined time, and then the piezoelectric ceramic component 35 is powered on to drive the second optical wedge 2 to move in the reverse direction.

[0054] After the second optical wedge 2 moves to the preset position along the optical path, the piezoelectric ceramic member 35 is powered off, and the pressure of the biasing elastic member 34 and the friction between the mover 37 and the elastic body 36 make the second optical wedge 2 remain relatively still in the power-off state, and a self-locking characteristic appears, so that the second optical wedge 2 remains motionless at the preset position for a predetermined time, and then the piezoelectric ceramic member 35 is powered on to drive the second optical wedge 2 to move in the opposite direction, completing a motion cycle. Such a cycle is repeated, and the second optical wedge 2 is in a transient state for 90% of the time in a motion cycle, so there is a long period of time in this process when the power consumption of the ultrasonic motor is zero, which can greatly reduce the power consumption of the ultrasonic motor.

[0055] Since the second optical wedge 2 is in a transient state for 90% of the time in a motion cycle to achieve the effect of enhancing resolution, the second optical wedge 2 is in a zero power consumption state for a large period of time during the overall reciprocating motion process. Compared with the XPR technical solution in the related art, the power consumption is much reduced.

[0056] In another example, the driving mechanism 3 includes a first shape memory alloy wire 38 and a second shape memory alloy wire 39, the first shape memory alloy wire 38 is connected to the incident surface side of the first optical wedge 1, and the second shape memory alloy wire 39 is connected to the exit surface side of the second optical wedge 2, and the first shape memory alloy wire 38 and the second shape memory alloy wire 39 are alternately powered on or off to drive the first optical wedge 1 or the second optical wedge 2 to move back and forth along the optical path direction.

[0057] Specifically, the driving mechanism 3 further includes a pair of stators 33 arranged at intervals, the pair of stators 33 are respectively arranged on one side of the incident surface of the first optical wedge 1 and on one side of the exit surface of the second optical wedge 2, the first shape memory alloy wire 38 is connected between the stator 33 and the incident surface of the first optical wedge 1, the second shape memory alloy wire 39 is connected between the stator 33 and the exit surface of the second optical wedge 2, and the first shape memory alloy wire 38 and the second shape memory alloy wire 39 are alternately powered on or off to drive the first optical wedge 1 or the second optical wedge 2 to reciprocate along the optical path direction. For ease of description, the embodiment of the present application is described by taking the example that the driving mechanism 3 drives the second optical wedge 2 to reciprocate relative to the first optical wedge 1 along the optical path direction.

[0058] Furthermore, after the second optical wedge 2 moves to the preset position along the optical path, the first shape memory alloy wire 38 is powered off, and after the second optical wedge 2 remains at the preset position for a transient predetermined time, the second shape memory alloy wire 39 is powered on to drive the second optical wedge 2 to move in the opposite direction.

[0059] like Figure 5 As shown, the length of the first shape memory alloy wire 38 or the second shape memory alloy wire 39 will shorten after being energized and heated, but will remain shortened after being de-energized and cooled. In this way, the second shape memory alloy wire 38 is energized and shortened, which will drive the second optical wedge 2 to move rightward to a preset position, and then the second shape memory alloy wire 38 is de-energized. At this time, the second optical wedge 2 is in a transient state (stopped motion state), and the first shape memory alloy wire 38 is stretched at the same time. After a certain period of time, the first shape memory alloy wire 39 is energized and shortened, which will drive the second optical wedge 2 to return to the initial position to the left, and the second shape memory alloy wire 38 is stretched at the same time. In this way, the first shape memory alloy wire 38 and the second shape memory alloy wire 39 are alternately moved. Since the second optical wedge 2 is in a transient state for 90% of the time in a motion cycle to achieve the effect of enhancing resolution, the second optical wedge 2 has a large amount of time in a zero power consumption state during the overall reciprocating motion process, and compared with the XPR technical solution in the related art, the power consumption is much reduced.

[0060] In some embodiments, the first optical wedge 1 and the second optical wedge 2 form a group of optical devices, the number of optical devices is two groups, the optical paths of the two groups of optical devices are in the same direction, and the second optical wedge 2 of one group of optical devices moves synchronously with the first optical wedge 1 of the other group of optical devices.

[0061] As mentioned above, the first optical wedge 1 and the second optical wedge 2 of a group of optical devices can complete the pixel displacement in one direction in a 2-way manner. Another group of optical devices is added in the direction of the optical path, so that the second optical wedge 2 of one group of optical devices keeps synchronous movement with the first optical wedge 1 of another group of optical devices. Then, when the second optical wedge 2 of one group of optical devices moves along the X direction relative to the first optical wedge 1 of the group, a pixel displacement will be generated in the Y direction. At the same time, the first optical wedge 1 of the other group of optical devices also keeps synchronous movement along the Y direction, that is, when the first optical wedge 1 of the other group of optical devices moves along the Y direction relative to the second optical wedge 2 of the group, a pixel displacement will be generated in the X direction, thereby realizing the pixel displacement in the other direction in a 2-way manner. Two 2-ways can be combined into a 4-way pixel displacement, that is, one pixel point can complete the displacement of four pixel points with a spacing of, for example, half a pixel, and the center points of the four pixels are connected to form a rectangle. As for whether to use 2-Way or 4-way, it is determined by the digital micromirror device (DMD) chip, the digital light processing (DLP) chip or the spatial light modulator chip.

[0062] Figure 6 The figure shows the driving current comparison of ultrasonic motor or SMA and XPR in related art. Figure 6 (b) It can be seen that in the XPR technical solution in the related art, the driving mechanism 3 always needs to output the driving current, which consumes a lot of power. Figure 6 In (a), when the ultrasonic motor or SMA is used as the driving mechanism 3, it only needs to output the driving current at certain moments when the preset position is reached, and it only needs to maintain the transient state most of the time, which greatly reduces the power consumption.

[0063] In addition, the embodiment of the present application further provides a projection display device, comprising: a light source 200 for generating an incident light beam 201; and the aforementioned pixel expansion device 100, which is arranged on the light path of the light source 200. The projection display device can be applied to a projector, a liquid crystal on silicon display system, a liquid crystal display system, and a micro-light emitting diode display system.

[0064] It should be noted that the phrases "one embodiment", "an embodiment", "an exemplary embodiment", "some embodiments", etc. mentioned in the specification indicate that the described embodiments may include certain features, structures or characteristics, but not every embodiment may include the certain features, structures or characteristics. In addition, such phrases do not necessarily refer to the same embodiment. In addition, when describing certain features, structures or characteristics in conjunction with an embodiment, it is within the knowledge of those skilled in the art to implement such features, structures or characteristics in conjunction with other embodiments, whether explicitly or not explicitly described.

[0065] It should be easily understood that “on,” “above,” and “over” in the present disclosure should be interpreted in the broadest manner, so that “on” not only means “directly on something,” but also includes the meaning of “on something” with intervening features or layers therebetween, and “above” or “over” not only includes the meaning of “above” or “over,” but also may include the meaning of “above” or “over something” with no intervening features or layers therebetween (i.e., directly on something).

[0066] In addition, spatially relative terms, such as "below," "below," "beneath," "above," "above," etc., may be used herein for ease of description to describe the relationship of one element or feature relative to other elements or features as shown in the figures. Spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation shown in the figures. The device may have other orientations (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein may likewise be interpreted accordingly.

[0067] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A pixel expansion device, characterized in that: include: A first optical wedge, used for receiving an incident light beam; A second optical wedge is arranged opposite to and spaced from the first optical wedge, and either the second optical wedge or the first optical wedge moves back and forth relative to the other along the optical path so that an outgoing optical beam after the incident optical beam passes through the first optical wedge and the second optical wedge generates a preset displacement in a direction perpendicular to the optical path.

2. The pixel expansion device according to claim 1, characterized in that: The first optical wedge has a first inclined surface and a first flat surface set at a first preset angle, the second optical wedge has a second inclined surface and a second flat surface set at a second preset angle, the second inclined surface is parallel to and opposite to the first inclined surface, and the first flat surface is parallel to and opposite to the second flat surface; The incident light beam is incident from the first flat surface, and the outgoing light beam is outgoing from the second flat surface.

3. The pixel expansion device according to claim 2, characterized in that: The refractive index of the first optical wedge is the same as the refractive index of the second optical wedge.

4. The pixel expansion device according to claim 2, characterized in that: The value range of the first preset angle and the second preset angle are both 0 to 20 degrees.

5. The pixel expansion device according to claim 1, characterized in that: It also includes a driving mechanism, which is connected to the first optical wedge or the second optical wedge to drive the first optical wedge or the second optical wedge to move back and forth along the optical path direction.

6. The pixel expansion device according to claim 5, characterized in that: The driving mechanism includes a ring-shaped coil, a plurality of magnetic parts arranged on the outer peripheral side of the ring-shaped coil, and a bracket connected to the plurality of magnetic parts, each of the magnetic parts includes a pair of magnetic strips placed with opposite polarities, and the bracket is connected to the first optical wedge or the second optical wedge so that the first optical wedge or the second optical wedge moves back and forth along the optical path direction under the drive of electromagnetic force.

7. The pixel expansion device according to claim 5, characterized in that: After the driving mechanism drives the first optical wedge or the second optical wedge to move to a preset position along the optical path direction, the first optical wedge or the second optical wedge is kept in a transient preset time and then moves in the reverse direction, wherein the duration of the transient preset time is greater than the duration of movement along the optical path direction.

8. The pixel expansion device according to claim 7, characterized in that: The driving mechanism is an ultrasonic motor, and the ultrasonic motor includes a piezoelectric ceramic component. The piezoelectric ceramic component is alternately powered on or off to drive the first optical wedge or the second optical wedge to move back and forth along the optical path direction.

9. The pixel expansion device according to claim 7, characterized in that: The driving mechanism comprises a first shape memory alloy wire and a second shape memory alloy wire, wherein the first shape memory alloy wire is connected to one side of the incident surface of the first optical wedge, and the second shape memory alloy wire is connected to one side of the exit surface of the second optical wedge, and the first shape memory alloy wire and the second shape memory alloy wire are alternately powered on or off to drive the first optical wedge or the second optical wedge to move back and forth along the optical path direction.

10. The pixel expansion device according to any one of claims 1 to 9, characterized in that: The first optical wedge and the second optical wedge form a group of optical devices, the number of the optical devices is two groups, the optical path directions of the two groups of optical devices are the same, and the second optical wedge of one group of optical devices moves synchronously with the first optical wedge of the other group of optical devices.

11. A projection display device, characterized in that: include: a light source for generating an incident light beam; and The pixel expansion device according to any one of claims 1 to 10 is arranged in the light path of the light source.

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