Projection device and projection display method

Abstract

The present invention discloses a projection device and a projection display method, relating to the field of projection technology. The present invention uses two scan drive devices to drive N rows of pixels of a liquid crystal display element row by row. During the driving process of a frame, when the first scan drive device begins driving the Xth row of pixels of the liquid crystal display element, the second scan drive device is controlled to begin driving the first row of pixels of the liquid crystal display element, so that the refresh rate of the liquid crystal display element matches the frame rate of the video data, thereby avoiding screen distortion.

Description

Technical Field

[0001] The present invention relates to the field of projection technology, and in particular to a projection device and a projection display method. Background Art

[0002] Currently, projection equipment is widely used in various scenarios, such as office briefings, film and television broadcasts, and art installations. Most projectors are based on spatial light modulators (SLMs), which mainly include transmissive LCD (Liquid Crystal Display) projectors, reflective LCoS (Liquid Crystal on Silicon) projectors, and reflective DMD (Digital Micro-Mirror Device) projectors.

[0003] In liquid crystal projection technology, the existing data processing process is usually as follows: the back buffer obtains data from the graphics card to read the image, and the image data in the back buffer is stored in the front buffer after reading. The liquid crystal display element is driven to refresh according to the data in the front buffer, such as Figure 1 However, when the refresh rate and frame rate do not match (not a multiple or at the same time), if a frame of the original image is divided into a first image and a second image, if the frame rate is greater than the refresh rate, the first image is cached in the back buffer area, and the liquid crystal display element is driven to refresh according to the first image in the front buffer area. When the second image is cached in the back buffer area, the liquid crystal display element will be refreshed according to the second image updated in the front buffer area, resulting in part of the display screen being the first image and part being the second image; when the frame rate is less than the refresh rate, the above problem also exists. Summary of the Invention

[0004] In view of this, the present invention provides a projection device and a projection display method to avoid the screen distortion problem caused by the mismatch between refresh rate and frame rate.

[0005] In a first aspect, the present invention provides a projection device, comprising:

[0006] A liquid crystal display element including N rows of pixels;

[0007] A first scanning driving device, configured to drive the N rows of pixels row by row;

[0008] a second scanning driving device, configured to drive the N rows of pixels row by row;

[0009] The scanning drive control unit is used to control the first scanning drive device and the second scanning drive device, and in the driving process of one frame of picture, when the first scanning drive device starts to drive the Xth row of pixels of the liquid crystal display element, the second scanning drive device is controlled to start driving the first row of pixels of the liquid crystal display element, so that the liquid crystal

[0010] In one possible implementation, the scan drive control unit is further used to control the first scan drive device and the second scan drive device to perform a reset after the second scan drive device drives the Nth row of pixels of the liquid crystal display element during the driving process of a frame of the picture.

[0011] A possible implementation also includes:

[0012] The margin factor calculation module is used to calculate the margin factor according to the frame rate of the video data and the resolution and refresh rate of the liquid crystal display element.

[0013] In a possible implementation, calculating the margin factor according to the frame rate of the video data and the resolution and refresh rate of the liquid crystal display element includes:

[0014] Obtaining the frame rate of the video data, and the resolution and refresh rate of the liquid crystal display element;

[0015] The margin factor is calculated based on the refresh rate, frame rate, and number of lines of resolution, and the calculation formula of the margin factor is as follows: X = (RefreshRate-y*FPS)*N / y*FPS, where RefreshRate is the refresh rate, FPS is the frame rate, N is the number of lines of resolution, y is the multiplication factor, and y = floor(RefreshRate / FPS), where the floor function means rounding down.

[0016] A possible implementation also includes:

[0017] An image division module, configured to divide an original frame into a first image and a second image;

[0018] The first scanning driving device drives the N rows of pixels row by row according to the first image; and the second scanning driving device drives the N rows of pixels row by row according to the second image.

[0019] In a possible implementation manner, the first image and the second image are different.

[0020] In a possible implementation, dividing an original picture frame into a first image and a second image includes:

[0021] A frame of original picture is divided into a global image and a local image, the first image is one of the global image and the local image, and the second image is the other of the global image and the local image.

[0022] In a second aspect, the present invention provides a projection display method, comprising:

[0023] During the driving process of a frame of an image, when the first scanning drive device starts to drive the Xth row of pixels of the liquid crystal display element, the second scanning drive device starts to drive the first row of pixels of the liquid crystal display element, so that the refresh rate of the liquid crystal display element matches the frame rate of the video data, wherein the liquid crystal display element includes N rows of pixels; the first scanning device and the second scanning device are used to drive the N rows of pixels row by row; and X is a margin factor.

[0024] In a possible implementation, during the driving process of the one frame of image, the process further includes:

[0025] After the second scan driving device drives the Nth row of pixels of the liquid crystal display element, the first scan driving device and the second scan driving device are controlled to perform a reset.

[0026] A possible implementation also includes:

[0027] The margin factor is calculated according to the frame rate of the video data, and the resolution and refresh rate of the liquid crystal display element.

[0028] The present invention uses two scanning drive devices to drive N rows of pixels of a liquid crystal display element row by row respectively. In the driving process of a frame of an image, when the first scanning drive device starts to drive the Xth row of pixels of the liquid crystal display element, the second scanning drive device is controlled to start driving the first row of pixels of the liquid crystal display element, so that the refresh rate of the liquid crystal display element matches the frame rate of the video data, thereby avoiding screen distortion. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of the display structure of an existing liquid crystal projection;

[0030] Figure 2 A schematic diagram of functional modules of a projection device provided by an embodiment of the present invention;

[0031] Figure 3 A schematic structural diagram of a projection device provided by an embodiment of the present invention;

[0032] Figure 4 A schematic diagram of the display structure of a projection device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the embodiments described are only a part of the embodiments of the present invention, rather than all the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Although the disclosure in the present invention is introduced according to one or more exemplary examples, it should be understood that each aspect of these disclosures can also constitute a complete technical solution independently. In the absence of conflict, the features in the following embodiments and embodiments can be combined with each other.

[0034] In order to fully understand the present invention, a detailed description will be provided below to illustrate the technical solution of the present invention. Preferred embodiments of the present invention are described in detail below, but in addition to these detailed descriptions, the present invention may also have other embodiments.

[0035] Figure 2 Schematic diagram of the functional modules of a projection device provided by an embodiment of the present invention. Figure 2 As shown, the projection device includes an image processor 101 and a projection optical engine 102.

[0036] Image processor 101 may be a microcontroller, a dedicated image processing chip, or the like. The microcontroller may be an ARM chip, a microcontroller unit (MCU), or the like. The dedicated image processing chip may be an image signal processor (ISP), a graphics processing unit (GPU), or an embedded neural network processing unit (NPU). Image processor 101 may be used for video decoding, image quality processing, and the like.

[0037] The projection engine 102 may include a driver chip, a spatial light modulator, and a light source. The light source may include a laser, LED, or fluorescent light source. The spatial light modulator may be a digital micromirror device (DMD), a liquid crystal display (LCD), or a liquid crystal on silicon (LCOS) device, and is used to modulate the light from the light source to produce image light. The driver chip corresponds to the spatial light modulator. For example, the digital micromirror device can be driven by a digital light processing (DLP). The projection engine 102 is used to project the image to be projected into a projection screen.

[0038] In some embodiments, the projection device further includes a central controller 103 with one or more processing cores. This central controller can be a CPU, ARM, MCU, or other controller. Central controller 103 serves as the control center of the projection device, connecting various components of the entire projection device using various interfaces and circuits. It can run or execute software programs and / or operating systems stored in storage module 104, as well as access data stored in storage module 104. Alternatively, image processor 101 and central controller 103 can be integrated into a single processor.

[0039] In some embodiments, the projection device further includes a storage module 104 of one or more computer-readable storage media, an input module 105, a communication module 106, a power supply 107 and other components. Those skilled in the art will understand that Figure 1 The structure of the projection device shown in the figure does not constitute a limitation on the projection device, and may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently.

[0040] The storage module 104 can be used to store software programs and an operating system. The central controller 103 executes various functional applications and data processing by running the software programs and operating system stored in the storage module 104. The storage module 104 may primarily include a program storage area and a data storage area. The program storage area may store the operating system and at least one application required for a function (such as a sound playback function or an image playback function); the data storage area may store data generated based on the use of the projection device. In addition, the storage module 104 may include high-speed random access memory and non-volatile memory, such as at least one disk storage device, flash memory device, or other volatile solid-state storage device. Accordingly, the storage module 104 may also include a memory controller to provide the central controller 103 with access to the storage module 104.

[0041] The projection device may further include an input module 105, which may be configured to receive input digital or character information and generate remote control, keyboard, mouse, joystick, optical or trackball signal input related to user settings and function control.

[0042] The projection device may also include a communication module 106. In some embodiments, the communication module 106 may include a wireless module. The projection device may use the wireless module of the communication module 106 to perform short-range wireless transmission, thereby providing the user with wireless broadband Internet access. For example, the communication module 106 may be used to help the user access streaming media, etc.

[0043] The projection device also includes a power supply 107 for supplying power to various components. In some embodiments, the power supply 107 can be logically connected to the central controller 103 via a power management system, thereby enabling the power management system to manage charging, discharging, and power consumption. The power supply 107 can also include one or more DC or AC power supplies, a recharging system, a power failure detection circuit, a power converter or inverter, a power status indicator, and other arbitrary components.

[0044] Figure 3 This is a schematic diagram of the structure of a projection device provided by an embodiment of the present invention. Figure 3 As shown, the projection device includes a light source device 201, an illumination optical system 202, and an imaging system 203. The light source device 201 includes one or more light sources; the illumination optical system 202 includes optical elements for collimating and combining the light from the light sources, and a homogenizing element, such as a light rod or a compound eye, for homogenizing the light from the light sources; the light beam emitted by the light source device 201 is irradiated by the illumination optical system 202 to a spatial light modulator (not shown in the figure), which then irradiates the incident light into the imaging system 203, ultimately imaging the image light onto a projected object such as a screen. The imaging system 203 is generally a lens system, such as a projection lens.

[0045] In addition, the projection device may further include a light source control module (not shown in the figure), which can control the operation of one or more light sources in the light source device 201 so that the light source device 201 emits light of a specified wavelength band required for generating an image. Furthermore, the light source device 201, the illumination optical system 202, and the imaging system 203 may all be included in the projection optical machine 102 (see Figure 2 )middle.

[0046] In the existing liquid crystal projection technology, a scanning driving device is usually used to drive the row pixels of the liquid crystal display element row by row. The embodiment of the present invention uses two scanning driving devices to drive N rows of pixels of the liquid crystal display element row by row, such as Figure 4As shown, the projection device includes a liquid crystal display element 301, a first scan driver 302, a second scan driver 303, and a scan driver control unit 304. The liquid crystal display element 301 includes N rows of pixels. The first scan driver 302 and the second scan driver 303 are respectively configured to drive the N rows of pixels of the liquid crystal display element 301 row by row. The scan driver control unit 304 is configured to control the first scan driver 302 and the second scan driver 303. During the driving process of a frame, when the first scan driver 302 begins driving the Xth row of pixels of the liquid crystal display element 301, the second scan driver 303 is controlled to begin driving the first row of pixels of the liquid crystal display element 301, so that the refresh rate of the liquid crystal display element matches the frame rate of the video data to avoid screen distortion. Wherein, X is a margin factor, which can be pre-set and stored in the projection device, or calculated by a margin factor calculation module (not shown) based on the frame rate of the currently playing video data, the resolution of the liquid crystal display element, and the refresh rate. An exemplary method for calculating the margin factor is provided below:

[0047] S1001. Obtain the frame rate FPS of the video data; and obtain the resolution M*N and refresh rate RefreshRate of the liquid crystal display element, where the resolution N represents the number of rows and M represents the number of columns.

[0048] S1002 : Calculate a margin factor X according to the refresh rate RefreshRate, the frame rate FPS, and the number of lines N of the resolution.

[0049] For example, the multiplication factor y may be calculated based on the refresh rate of the liquid crystal display element and the frame rate of the video data, where:

[0050] y=floor(RefreshRate / FPS), where the floor function represents rounding down.

[0051] Then, the margin factor X is calculated based on the frame rate FPS of the video data, the resolution M*N of the LCD element, the refresh rate RefreshRate, and the multiplication factor y. Specifically, X is calculated based on the refresh time being equal to the time corresponding to the frame rate, that is, (1 / RefreshRate+X / (N*RefreshRate))=1 / (y*FPS). The calculation formula for X is as follows:

[0052] X=(RefreshRate-y*FPS)*N / y*FPS.

[0053] In some other embodiments, the calculation formula of the multiplication factor may also be y=floor(FPS / RefreshRate), in which case the calculation formula of X is as follows:

[0054] X=(RefreshRate-FPS / y)*N / (FPS / y).

[0055] Furthermore, during the driving process of a frame of picture, after the first scanning driving device 302 drives the Nth row of pixels of the liquid crystal display element 301, no reset is performed. After the second scanning driving device 303 drives the Nth row of pixels of the liquid crystal display element 301, the scanning driving control unit 304 controls the first scanning driving device 302 and the second scanning driving device 303 to perform a reset, thereby avoiding the problem that the driving device is started according to the originally set V-BLANK, resulting in display confusion.

[0056] In some embodiments, an image division module (not shown) can be used to divide an original image frame into a first image and a second image. The first scan driver 302 drives N rows of pixels of the liquid crystal display element 301 according to the first image, and the second scan driver 303 drives N rows of pixels of the liquid crystal display element 301 according to the second image. Compared to existing projection display methods that use a single scan driver, this method can reduce refresh time and improve refresh efficiency.

[0057] For example, in a high dynamic range imaging (HDRI or HDR) scene, the high dynamic range image to be displayed can be divided into a standard part (global image) and a detail part (local image), that is, a frame of original picture can be divided into a global image and a local image, the first scanning driving device 302 drives N rows of pixels of the liquid crystal display element 301 according to the global image, and the second scanning driving device 303 drives N rows of pixels of the liquid crystal display element 301 according to the local image, or the first scanning driving device 302 drives N rows of pixels of the liquid crystal display element 301 according to the local image, and the second scanning driving device 303 drives N rows of pixels of the liquid crystal display element 301 according to the local image. The liquid crystal display element 301 is driven in N rows of pixels according to the global image. During the driving process of one frame, when the first scan driver 302 starts driving the Xth row of pixels of the liquid crystal display element 301, the second scan driver 303 starts driving the first row of pixels of the liquid crystal display element 301. After the first scan driver 302 completes scanning, no reset is performed. After the second scan driver 303 completes scanning, it notifies the scan driver control unit 304. At this time, the scan driver control unit 304 controls the first scan driver 302 and the second scan driver 303 to perform reset.

[0058] For example, in a resolution enhancement scenario, the original image can be divided into the same first pixel image and second pixel image, represented as Image1 and Image2. The first scan drive device 302 drives N rows of pixels of the liquid crystal display element 301 according to Image1, and the second scan drive device 303 drives N rows of pixels of the liquid crystal display element 301 according to Image2. During the driving process of a frame of the picture, when the first scan drive device 302 starts to drive the Xth row of pixels of the liquid crystal display element 301, the second scan drive device 303 starts to drive the first row of pixels of the liquid crystal display element 301. After the first scan drive device 302 completes the scan, no reset is performed. After the second scan drive device 303 completes the scan, the scan drive control unit 304 is notified. At this time, the scan drive control unit 304 controls the first scan drive device 302 and the second scan drive device 303 to perform reset.

[0059] It should be noted that the embodiment of the present invention may not divide the original image. In this case, both the first scan driving device 302 and the second scan driving device 303 drive N rows of pixels of the liquid crystal display element 301 according to the original image.

[0060] It should be understood that the term "module" in the embodiments of the present invention may refer to an application-specific integrated circuit (ASIC), an electronic circuit, a processor (e.g., a shared processor, a dedicated processor, or a group processor, etc.) and memory for executing one or more software or firmware programs, a combined logic circuit, and / or other suitable components that support the described functions. Modules described as separate components may or may not be physically separate, and components displayed as modules may or may not be physical modules, i.e., they may be located in one place or distributed across multiple network modules. Some or all of the modules may be selected based on actual needs to achieve the purpose of the embodiments of the present invention. The division of modules is merely a logical functional division, and in actual implementation, there may be other division methods, such as a module or component may be divided into multiple modules or components, or multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed. In addition, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device, or module, which may be electrical, mechanical, or other forms.

[0061] Those skilled in the art will appreciate that the modules and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present invention.

[0062] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A projection device, characterized in that: include: A liquid crystal display element including N rows of pixels; A first scanning driving device, configured to drive the N rows of pixels row by row; a second scanning driving device, configured to drive the N rows of pixels row by row; a scan drive control unit, configured to control the first scan drive device and the second scan drive device, and to control the second scan drive device to start driving the first row of pixels of the liquid crystal display element when the first scan drive device starts driving the Xth row of pixels of the liquid crystal display element during a driving process of a frame of an image, so that a refresh rate of the liquid crystal display element matches a frame rate of video data, where X is a margin factor; Also includes: A margin factor calculation module, configured to calculate a margin factor based on a frame rate of the video data and a resolution and a refresh rate of the liquid crystal display element; The calculating of the margin factor according to the frame rate of the video data and the resolution and refresh rate of the liquid crystal display element includes: Obtaining the frame rate of the video data, and the resolution and refresh rate of the liquid crystal display element; The margin factor is calculated according to the refresh rate, frame rate and number of lines of resolution, and the calculation formula of the margin factor is as follows: X = (RefreshRate-y*FPS)*N / y*FPS or X = (RefreshRate-FPS / y)*N / (FPS / y), where RefreshRate is the refresh rate, FPS is the frame rate, N is the number of lines of resolution, y is the multiplication factor, and y = floor(RefreshRate / FPS), or y = floor(FPS / RefreshRate), and the floor function means rounding down.

2. A projection device according to claim 1, characterized in that: The scan drive control unit is further configured to control the first scan drive device and the second scan drive device to reset after the second scan drive device drives the Nth row of pixels of the liquid crystal display element during the driving process of one frame of picture.

3. The projection device according to claim 1, wherein: Also includes: An image division module, configured to divide an original frame into a first image and a second image; The first scanning driving device drives the N rows of pixels row by row according to the first image; and the second scanning driving device drives the N rows of pixels row by row according to the second image.

4. The projection device according to claim 3, characterized in that: The first image and the second image are different.

5. The projection device according to claim 3, characterized in that: The dividing of an original picture frame into a first image and a second image comprises: A frame of original picture is divided into a global image and a local image, the first image is one of the global image and the local image, and the second image is the other of the global image and the local image.

6. A projection display method, characterized in that: include: During the driving process of a frame of an image, when the first scanning driving device starts driving the Xth row of pixels of the liquid crystal display element, the second scanning driving device starts driving the first row of pixels of the liquid crystal display element, so that the refresh rate of the liquid crystal display element matches the frame rate of the video data, wherein the liquid crystal display element includes N rows of pixels; the first scanning device and the second scanning device are used to drive the N rows of pixels row by row; X is a margin factor; Also includes: Calculating a margin factor according to a frame rate of the video data and a resolution and a refresh rate of the liquid crystal display element includes: Obtaining the frame rate of the video data, and the resolution and refresh rate of the liquid crystal display element; The margin factor is calculated according to the refresh rate, frame rate and number of lines of resolution, and the calculation formula of the margin factor is as follows: X = (RefreshRate-y*FPS)*N / y*FPS or X = (RefreshRate-FPS / y)*N / (FPS / y), where RefreshRate is the refresh rate, FPS is the frame rate, N is the number of lines of resolution, y is the multiplication factor, and y = floor(RefreshRate / FPS), or y = floor(FPS / RefreshRate), and the floor function means rounding down.

7. A projection display method according to claim 6, characterized in that: The driving process of the one frame of picture further includes: After the second scan driving device drives the Nth row of pixels of the liquid crystal display element, the first scan driving device and the second scan driving device are controlled to perform a reset.

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