CN111787296B

CN111787296B - Data superposition processing method of liquid crystal polarization invisible word-prompting DLP projector system

Info

Publication number: CN111787296B
Application number: CN202010723421.2A
Authority: CN
Inventors: 韩殿元; 戴长志; 赵加强; 曹连振
Original assignee: Weifang University
Current assignee: Weifang University
Priority date: 2020-03-11
Filing date: 2020-07-24
Publication date: 2021-09-28
Anticipated expiration: 2040-07-24
Also published as: CN111510695A; CN111225198A; CN111866479B; CN111866479A; CN111787296A

Abstract

The invention discloses a data superposition processing method of a liquid crystal polarization invisible word DLP projector system, which comprises a projector, a caption superimposer, a caption computer and polarization glasses, wherein the projector is used for projecting a caption image; the subtitle superimposer receives the video data and the subtitle data, then superimposes the two data to form video data containing the invisible subtitles, outputs the video data to a corresponding interface of a projector, and forms a projection area on an imaging plane through the projector; the invention has reasonable design and convenient use, can be used as a common projector, can realize the prompter function of a speaker and cannot influence the watching of audiences.

Description

Data superposition processing method of liquid crystal polarization invisible word-prompting DLP projector system

Technical Field

The invention relates to the technical field of projectors, in particular to a data superposition processing method of a liquid crystal polarization invisible word DLP projector system.

Background

The projector is widely applied at present, and is widely used in school lessons, company meetings, vocational training and product release meetings, images or videos such as PPT (Power Point) are projected onto a screen by the projector, a speaker needs to explain in combination with the projected images or videos, the PPT generally contains less characters, more content is spoken, most content cannot be seen in the PPT, and some content is not suitable for appearing in the PPT, and at this time, if the content is not mature, some prompting materials are needed, and some people hold lecture prompter cards and the like, so that lecture effect is influenced.

Disclosure of Invention

The invention aims to solve the technical problem of providing a data superposition processing method of a liquid crystal polarization invisible prompt DLP projector system, which has reasonable design and convenient use, can be used as a common projector, can realize the prompt function for a speaker at the same time, and cannot influence audiences.

In order to solve the technical problems, the technical scheme of the invention is as follows: a data superposition processing method of a liquid crystal polarization invisible word DLP projector system comprises the steps that the projector system comprises a projector, a caption superimposer, a caption computer and polarization glasses;

the projector comprises a light source, a first converging mirror, a color wheel, a second converging mirror, a digital micromirror, a lens, a liquid crystal panel and a liquid crystal panel control circuit,

the liquid crystal panel is arranged on a light path between the light source and the digital micromirror and comprises a polarizer layer, a first glass substrate layer, a first transparent electrode layer, a liquid crystal layer, a second transparent electrode layer and a second glass substrate;

the liquid crystal panel control circuit is connected with the liquid crystal panel, and the liquid crystal panel is switched between two states under the control of the liquid crystal panel control circuit: one is that the polarization direction of the light passing through the polarizer layer of the liquid crystal panel keeps the original polarization direction, the other is that the polarization direction of the light passing through the polarizer layer of the liquid crystal panel generates torsion 90 degrees, the conversion of the two states is synchronous with the color wheel, when the polarization direction of the light is changed once, the color wheel synchronously rotates through three color areas, namely, the video just passes through one frame;

the caption superposition device comprises an HDMI input port, a VGA input port, a composite video input port, an RS-232 serial port, an HDMI output port, a VGA output port and a caption superposition module;

the caption superposition module receives video data transmitted from an HDMI input port, a VGA input port or a composite video input port and caption data from an RS-232 serial port, then carries out superposition processing on the two data to form video data containing invisible captions, and outputs the video data to a corresponding interface of the projector through an HDMI output port or a VGA output port;

the caption computer is connected with the caption superimposer through an RS-232 serial port and internally comprises a caption data generation module for generating caption data;

the polarization glasses are horizontally arranged, and the polarization direction of the polarization glasses is vertical to or parallel to the polarization direction of the polarizer layer in the liquid crystal panel;

the data superposition processing method comprises the following steps:

step one, the caption superimposer receives caption data transmitted by the caption computer and video data transmitted by an HDMI input port, a VGA input port or a composite video input port;

dividing video data into a subtitle stroke area, a subtitle background area and a non-subtitle area according to the position of subtitle data, wherein the subtitle stroke area is an area covered by subtitle strokes, the subtitle background area is an area formed by subtracting the subtitle stroke area from a rectangular area capable of covering the subtitle position, and the remaining area of an image is the non-subtitle area;

dividing the video data into odd frames and even frames, wherein the processing method of the video data of the current odd frames comprises the following steps: the pixel brightness value of the video data of the non-caption area is not changed; the pixel brightness value of the video data of the subtitle stroke area is increased by 10-30%; the pixel brightness value of the video data of the corresponding subtitle background area is reduced by 10-15%;

the processing method of the video data of the even frame after the current odd frame comprises the following steps: the pixel brightness value of the video data of the non-caption area is not changed; subtracting the brightness value increased by the corresponding pixels of the odd frames from the pixel brightness value of the video data of the caption stroke area on the basis of the original brightness value; the brightness value of the pixel of the video data of the corresponding caption background area is increased by the reduced brightness value of the pixel corresponding to the odd frame on the basis of the original brightness value;

and step four, taking the next odd frame as the current odd frame, repeating the step three, and sequentially processing the following odd frame and even frame.

As a preferable technical scheme, the lens of the polarized glasses is formed by interleaving polarized areas and non-polarized areas, and the area of each polarized area is less than 0.02 square millimeter.

Preferably, the light source is a laser light source, the light emitted by the laser light source is polarized light, and the polarization direction is the same as the polarization direction of the polarizer layer of the liquid crystal panel.

As a preferred technical solution, the method for processing video data of an odd frame currently further includes: if the current pixel brightness value plus the increased brightness value of the video data of the caption stroke area is greater than the maximum brightness value represented by the video pixel bit depth, then: if the current brightness value plus the added value is larger than the maximum brightness value, the pixel brightness value of the video data in the current odd frame subtitle stroke area is increased to the maximum brightness value;

if the absolute value of the current pixel brightness value plus the reduced brightness value of the video data of the caption background area is greater than the maximum brightness value represented by the video pixel bit depth, then: when the current luminance value + | reduction value | > is greater than the maximum luminance value, the pixel luminance value of the video data in the subtitle background region is reduced to the difference between the current luminance value minus the maximum luminance value and the current luminance value, that is, the pixel luminance value of the video data in the subtitle background region of the current odd frame is equal to (current luminance value- (maximum luminance value-current luminance value)).

As a preferred technical scheme, the following components are added in the third step: the caption superposition module compares the data of the current odd frame and the even frame behind the current odd frame, if the average value of the difference of the pixel brightness values corresponding to the two frames is more than 5% of the maximum brightness value which can be expressed by the pixel bit depth of the video data, the brightness increase and decrease processing is not carried out on the current odd frame and the even frame behind the current odd frame, the comparison between the next odd frame and the even frame behind the current odd frame is continued, otherwise, the next step is carried out.

As a preferred technical solution, the pixel brightness value processing method is: firstly, converting an RGB color mode corresponding to video data into an HSI mode, namely converting three numerical values of red, green and blue colors corresponding to the video data into three numerical values of hue, saturation and brightness, then independently increasing and decreasing the brightness numerical value, and then converting the processed HSI value into an RGB value.

Due to the adoption of the technical scheme, the invention has the beneficial effects that: the subtitle superimposer receives the video data and the subtitle data, then superimposes the two data to form video data containing the invisible subtitles, outputs the video data to a corresponding interface of a projector, and forms a projection area on an imaging plane through the projector; after the polarized glasses are worn, hidden subtitles can be observed on an imaging plane, but audiences without the polarized glasses cannot observe the hidden subtitles on the imaging plane, the video data on the imaging plane under the visual angle of the audiences has the same effect as that projected by a common projector, and the display contrast of the hidden subtitles can be improved by a reverse processing method of a subtitle background area and a subtitle stroke area; the invention has reasonable design and convenient use, can be used as a common projector, can realize the prompter function of a speaker and does not influence the watching of audiences.

Drawings

The drawings are only for purposes of illustrating and explaining the present invention and are not to be construed as limiting the scope of the present invention. Wherein:

FIG. 1 is a schematic structural diagram of an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a projector according to an embodiment of the invention;

FIG. 3 is a schematic diagram of a liquid crystal panel according to an embodiment of the invention;

FIG. 4 is a data processing diagram according to an embodiment of the present invention;

FIG. 5 is a schematic view of polarizing glasses according to an embodiment of the invention;

FIG. 6 is an enlarged schematic view at I of FIG. 5;

in the figure: 100-a projector; 110-a light source; 120-a first converging mirror; 130-color wheel; 140-a second converging mirror; 150-digital micromirror; 160-lens; 170-liquid crystal panel; 171-a polarizer layer; 172-a first glass substrate layer; 173 — first transparent electrode layer; 174-a liquid crystal layer; 175-a second transparent electrode layer; 176-a second glass substrate; 180-liquid crystal panel control circuit; 200-a subtitle superimposer; 201-HDMI input port; 202-VGA input port; 203-composite video input port; 204-RS-232 serial port; 205-HDMI output port; 206-VGA output port; 300-caption computer; 400-polarized glasses; 401-a polarization region; 402-a non-polarizing region; 500-imaging plane; 600-subtitle stroke area; 700-subtitle background region; 800-non-subtitle region.

Detailed Description

The invention is further illustrated below with reference to the figures and examples. In the following detailed description, certain exemplary embodiments of the present invention are described by way of illustration only. Needless to say, a person skilled in the art realizes that the described embodiments can be modified in various different ways without departing from the spirit and scope of the present invention. Accordingly, the drawings and description are illustrative in nature and not intended to limit the scope of the claims.

As shown in fig. 1 and 5, the DLP projector system includes a projector 100, a caption superimposer 200, a caption computer 300, and polarized glasses 400, where the caption computer 300 is connected to the caption superimposer 200, and the caption superimposer 200 is connected to the projector 100; the caption computer 300 is configured to generate caption data and transmit the caption data to the caption superimposer 200, and the caption superimposer 200 performs data superimposition processing to superimpose the caption data and the video data together, so that the video projected onto the imaging plane 500 has hidden captions, and after wearing the polarization glasses 400, the captions can be seen on the imaging plane 500, but the polarization glasses 400 are not worn, and only normal video or images can be seen on the imaging plane 500.

Referring to fig. 2, the projector 100 includes a light source 110, a first converging mirror 120, a color wheel 130, a second converging mirror 140, a digital micromirror 150(DMD), a lens 160, a liquid crystal panel 170, and a liquid crystal panel control circuit 180; the light source 110, the first converging lens 120, the color wheel 130, the second converging lens 140, the digital micromirror 150, and the lens 160 all belong to a part of the existing projector, and belong to the prior art, and are not described herein again.

The liquid crystal panel 170 is disposed on the light path between the light source 110 and the digital micromirror 150, and in this embodiment, the liquid crystal panel 170 is disposed between the first converging mirror 120 and the color wheel 130, but may also be disposed between the light source 110 and the first converging mirror 120, or between the color wheel 130 and the second converging mirror 140, or between the second converging mirror 140 and the digital micromirror 150.

The liquid crystal panel 170 includes a polarizer layer 171, a first glass substrate layer 172, a first transparent electrode layer 173, a liquid crystal layer 174, a second transparent electrode layer 175, and a second glass substrate 176, see fig. 2; the liquid crystal panel 170 in the present embodiment is different from the liquid crystal panel in the related art in that: the polarizer layer is absent on the outer surface of the second glass substrate 176, and other structures are well known in the art and will not be described herein.

The liquid crystal panel control circuit 180 is connected to the liquid crystal panel 170, and the liquid crystal panel 170 is switched between two states under the control of the liquid crystal panel control circuit 180: one is that the polarization direction of the light passing through the polarizer layer 171 of the liquid crystal panel 170 is kept as the original polarization direction, the other is that the polarization direction of the light passing through the polarizer layer 171 of the liquid crystal panel 170 is twisted by 90 °, the two states are switched synchronously with the color wheel 130, and after the polarization direction of the light is changed once, the color wheel 130 synchronously rotates through three color regions, that is, the video just passes through one frame.

Polarization glasses 400 through which a caption image or video can be observed on the imaging plane 500; when the polarization glasses 400 are placed horizontally (corresponding to a state where a person wears the glasses while standing), the polarization direction is perpendicular to or parallel to the polarization direction of the polarizer layer 171 in the liquid crystal panel 170. When the polarization direction of the polarization glasses 400 is parallel to the polarization direction of the polarizer layer 171 in the liquid crystal panel 170, the light whose polarization direction is not twisted can smoothly pass through the polarization glasses 400 to reach the human eyes, and the light whose polarization direction is twisted can be blocked by the polarization glasses 400, so that the caption information can be seen after wearing the polarization glasses 400; when the polarization direction of the polarization glasses 400 is perpendicular to the polarization direction of the polarizer layer 171 in the liquid crystal panel 170, the principle of subtitle display is the same as that when the polarization direction is parallel, and thus the description thereof is omitted. The polarization glasses 400 in this embodiment are equivalent to the polarizer layer 171 on the outer surface of the second glass substrate 176 on the liquid crystal panel 170 in the prior art, and thus it can be seen that the polarization glasses 400 and the liquid crystal panel 170 in this embodiment constitute a liquid crystal panel structure in the prior art.

Referring to fig. 5 and 6, the lens of the polarized glasses 400 is composed of a plurality of polarized areas 401 and non-polarized areas 402 in an interlaced manner, in this embodiment, the polarized areas 401 are rectangular polarized blocks, the non-polarized areas 402 are rectangular blocks, and the rectangular polarized blocks of the polarized areas 401 are uniformly distributed in the non-polarized areas 402 in an interlaced manner, see fig. 5 and 6; the area of each polarized region 401 is less than 0.02 square millimeters and the transparency of the rectangular block of unpolarized regions 402 is high. By arranging the polarization areas 401 and the non-polarization areas 402 on the lenses of the polarization glasses 400 in a staggered manner, after the user wears the polarization glasses 400, the hidden cue words can be observed on the imaging plane 500 through the polarization areas 401, but the hidden cue words cannot be observed on the imaging plane 500 when the user passes through the non-polarization areas 402, but the transparency of the non-polarization areas 402 is higher, the non-polarization areas 402 are the same as common glasses or myopia glasses, and the purpose of arranging the polarization areas 401 and the non-polarization areas 402 in a staggered manner is to improve the transparency of the glasses, so that the contrast of the cue words is reduced to a certain extent, but the prompter cannot be viewed. After the user wears the polarized glasses 400, the hidden cue words can be observed, and other people who do not wear the polarized glasses 400 can not find that the cue words exist on the imaging plane 500 at all.

The polarized glasses 400 can be formed by a polarized film attached to ordinary glasses, and can be conveniently used by people who wear the glasses at ordinary times.

The projection principle of the projector system is as follows:

the light generated by the light source 110 is irradiated to the first collecting mirror 120, and is collected after passing through the first collecting mirror 120, and is collected to the surface of the color area of the color wheel 130, when the light is irradiated to the surface of the color wheel 130 by the first collecting mirror 120, the light passes through the liquid crystal panel 170, and reaches the liquid crystal panel 170, the light first passes through the polarizer layer 171, the light becomes polarized light in the same direction, and then passes through the first glass substrate layer 172, the first transparent electrode layer 173, and reaches and passes through the liquid crystal layer 174, the liquid crystal layer 174 twists the polarization direction of the polarized light, and the twisting angle is determined by the voltage applied to the liquid crystal, that is, the liquid crystal panel 170 is switched between two states under the control of the liquid crystal panel control circuit 180: one is that the polarization direction of the light passing through the liquid crystal panel 170 keeps the original polarization direction, the other is that the polarization direction of the light passing through the liquid crystal panel 170 generates a twist of 90 degrees, the conversion of the two states is kept synchronous with the color wheel, when the polarization direction of the light is changed once, the color wheel synchronously rotates through three color areas, namely, the video just passes through one frame;

after passing through the color wheel 2, the light is diffused outward from the convergence point to the second converging mirror 140, and then passes through the second converging mirror 140 and then irradiates the digital micromirror 150; the digital micromirror 150 then reflects the video containing the closed captions onto the lens 160, and then enlarges and projects the video through the lens 160 onto the imaging plane 500, forming a projection area on the imaging plane.

The data superposition processing method of the liquid crystal polarization invisible word DLP projector system comprises the following steps:

step one, the caption superimposer 200 receives caption data transmitted from the caption computer 300 and video data transmitted from an HDMI input port 201, a VGA input port 202 or a composite video input port 203, see a) and b in fig. 4);

dividing video data into a subtitle stroke area 600, a subtitle background area 700 and a non-subtitle area 800 according to the position of subtitle data, wherein the subtitle stroke area 600 is an area covered by subtitle strokes, the subtitle background area 700 is an area formed by subtracting the subtitle stroke area from a rectangular area capable of covering subtitle positions, and the remaining area of an image is the non-subtitle area 800, which is shown in fig. 4 c);

dividing the video data into odd frames and even frames, wherein the processing method of the video data of the current odd frames comprises the following steps: the pixel brightness value of the video data of the non-subtitle area 800 is not changed; the pixel brightness value of the video data of the subtitle stroke area 600 is increased by 10-30%; the pixel brightness value of the video data of the corresponding subtitle background region 700 is reduced by 10-15%; the processing method of the video data of the even frame after the current odd frame comprises the following steps: the pixel brightness value of the video data of the non-subtitle area 800 is not changed; the pixel brightness value of the video data of the subtitle stroke area 600 is subtracted by the brightness value added by the corresponding pixel of the odd frame on the basis of the original brightness value; the brightness value of the pixel of the video data in the corresponding subtitle background region 700 is increased by the decreased brightness value of the pixel corresponding to the odd frame based on the original brightness value;

at this time, because the increasing and decreasing values of the corresponding areas of the two adjacent previous and next frames are the same, the visual effect is the same as that of the non-processed area due to the persistence of vision effect of human eyes, so that the viewer cannot see the subtitles superimposed on the video, for example, when the luminance value of the video pixel is 50%, the luminance value of the pixel of the video data in the current odd-frame subtitle stroke area 600 is 60% after increasing 20%, and the luminance value of the pixel of the video data corresponding to the even-frame subtitle stroke area 600 is 40% after decreasing 20%, and because the increasing and decreasing values of the corresponding areas of the adjacent previous and next frames are the same, the viewer cannot observe the subtitles on the imaging plane 500; similarly, when the pixel brightness value of the video data in the subtitle stroke area 600 of the current odd frame is increased, the pixel brightness value of the video data in the subtitle background area 700 corresponding to the current odd frame is decreased by 10%, the pixel brightness value of the video data in the subtitle background area 700 corresponding to the even frame is increased by 10%, and the increase and decrease values of the corresponding areas of the odd frame and the even frame are the same, so as to ensure that the viewer cannot observe the subtitle on the imaging plane 500; however, when the pixel brightness value of the subtitle stroke area 600 of the current odd frame is increased, the pixel brightness value of the subtitle background area 700 corresponding to the odd frame is decreased, and when the pixel brightness value of the subtitle stroke area 600 of the corresponding even frame is decreased, the brightness value of the subtitle background area 700 corresponding to the even frame is increased, such an increase-decrease or a decrease-increase between the subtitle stroke area 600 and the subtitle background area 700 is to make the difference between the pixel brightness values of the subtitle stroke area 600 and the subtitle background area 700 large, increase the contrast and the definition of the subtitle, and further highlight the subtitle data in the subtitle stroke area 600, see d) in fig. 4 as an effect map of a certain frame after data superposition processing;

The method for processing the video data of the current odd frame is added in the third step and comprises the following steps: the pixel brightness value of the video data of the non-subtitle area 800 is not changed; the pixel brightness value of the video data in the subtitle stroke area 600 is increased by 10-30%, and the pixel brightness value of the video data in the corresponding subtitle background area 700 is decreased by 10-15%;

if the current pixel brightness value plus the increased brightness value of the video data of the subtitle stroke area 600 is greater than the maximum brightness value represented by the video pixel bit depth, then: if the current brightness value + added value > the maximum brightness value, the pixel brightness value of the video data of the current odd-frame subtitle stroke area 600 is the maximum brightness value;

if the absolute value of the current pixel brightness value plus the reduced brightness value of the video data in the caption background area 700 is greater than the maximum brightness value represented by the video pixel bit depth, then: when the current luminance value + | reduction value | > is greater than the maximum luminance value, the pixel luminance value of the video data in the subtitle background region 700 is reduced to the difference between the current luminance value minus the maximum luminance value and the current luminance value, i.e., the pixel luminance value of the video data in the subtitle background region 700 of the current odd frame is equal to (current luminance value- (maximum luminance value-current luminance value)). By adding this step, it is used to process the situation that the brightness value of the pixel of the video data is greater than the maximum brightness value represented by the bit depth of the video pixel after adding the added value. By the above improvement, the range of the hidden subtitle superimposition can be increased.

The broadcast PPT is the most commonly used mode of the projector 100, and the data superposition processing principle is described below by taking the PPT as an example:

if it is desired to overlay the closed captioning on the page of the PPT, the following process is required: the caption superimposing module 207 of the caption superimposer 200 receives the PPT information transmitted from the computer through the VGA input port 202, converts the PPT signal to generate video data that meets the resolution and frame frequency of the projector 100, and transmits the caption data generated by the caption computer 300 to the caption superimposing module 207 through the RS-232 serial port 204, where the resolution of the caption data generated by the caption computer 300 is the same as the resolution of the video data, see a) and b in fig. 4);

assuming that the caption of the cue word is a pattern of three 'T' words, the brightness value of the pixel of the video image is a gray image which is 40% of the highest brightness value; the caption superimposing module 207 divides the corresponding position of the video data into three regions, namely a caption stroke region 600, a caption background region 700 and a non-caption region 800, according to the patterns of the three T words of the caption data, wherein the caption stroke region 600 is a region covered by the patterns of the three T words, the caption background region 700 is a region formed by subtracting the caption stroke region from a rectangular region corresponding to the patterns of the three T words, and the other regions outside the rectangle are non-caption regions 800, which is shown in c in fig. 4);

the brightness value of the pixels of the subtitle stroke area 600 of the odd frame of the video data is increased by 52% after 30%, namely, the luminance value of the pixels of the corresponding region of the three "T" patterns is 52% of the highest luminance value, the luminance value of the pixels of the subtitle background region 700 of the odd frame of the video data is reduced by 15% to 34%, the luminance value of the pixels of the rectangular region outside the three "T" patterns is 34% of the highest luminance value, the luminance value of the pixels of the non-subtitle stroke region 600 of the video data is still 40% without change, i.e. the brightness value of the pixels in the other regions outside the rectangular region is 40% of the highest brightness value, see d in fig. 4), and the difference between the brightness values of the three "T" regions and the brightness value of the rectangular region outside is obvious, the brightness values of the pixels in the subtitle stroke region 600 and the subtitle background region 700 increase and decrease, the contrast and the definition of the subtitle are increased, the subtitle stroke area 600 can be seen only by adjusting the pixel brightness value of the video data to a small value;

the brightness value of the pixels in the subtitle stroke area 600 of the even frame of the video data is reduced by 28% after 30%, that is, the brightness value of the pixels in the corresponding area of the three "T" words is 28% of the highest brightness value, the brightness value of the pixels in the subtitle background area 700 of the even frame of the video data is increased by 15% and is 46%, the brightness value of the pixels in the rectangular area outside the three "T" words is 46% of the highest brightness value, the brightness value of the pixels in the non-subtitle stroke area 600 of the video data is not changed and is still 40%, that is, the brightness value of the pixels in the other area outside the rectangular area is 40% of the highest brightness value, the increased and reduced brightness values of two adjacent frames are the same, due to the persistence of vision effect of human eyes, the visual effect is the same as that of the video data which is not processed, the frame frequency of the projector 100 is basically over 60 frames at present, so that no stroboscopic effect exists, so that the video data of the three "T" word positions seen by the common viewer through the imaging plane 500 is the same as that of the video data before being processed, the visual perception brightness value is still 40%; therefore, the video image seen by the common audience is the same as that before the caption is added, and has no change;

since the actual brightness values of the two processed frames at the three "T" positions are different, they are different from the 40% brightness of the non-caption stroke area 600, and further, due to the action of the liquid crystal panel 170 and the liquid crystal panel control circuit 180, the liquid crystal panel 170 is switched between two states under the control of the liquid crystal panel control circuit 180: one is that the polarization direction of the light passing through the liquid crystal panel 170 keeps the original polarization direction, the other is that the polarization direction of the light passing through the liquid crystal panel 170 generates a twist of 90 degrees, the conversion of the two states is kept synchronous with the color wheel, when the polarization direction of the light is changed once, the color wheel synchronously rotates through three color areas, namely, the video just passes through one frame; therefore, at this time, two adjacent frames correspond to two states of the liquid crystal panel 170, and thus the light formed by two adjacent frames after being processed is light with a polarization direction unchanged and light with a polarization direction twisted by 90 degrees;

the user can observe the subtitles on the imaging plane 500 through the polarized glasses 400; when the polarization direction of the polarization glasses 400 is parallel to the polarization direction of the polarizer layer 171 in the liquid crystal panel 170, the light whose polarization direction is not twisted, that is, the light whose polarization direction is not changed, can smoothly pass through the polarization glasses 400 to reach the human eyes, and the light whose polarization direction is twisted by 90 °, that is, the light whose polarization direction is twisted by 90 °, can be blocked by the polarization glasses 400, so that the caption information formed by the light whose polarization direction is not changed can be seen on the imaging plane after wearing the polarization glasses 400; when the polarization direction of the polarization glasses 400 is perpendicular to the polarization direction of the polarizer layer 171 in the liquid crystal panel 170, the light whose polarization direction is not twisted, that is, the light whose polarization direction is not changed, is blocked by the polarization glasses 400, and the light whose polarization direction is twisted by 90 ° reaches the human eyes through the polarization glasses 400, so that the subtitles formed by the light whose polarization direction is twisted by 90 ° can be seen on the image plane after wearing the polarization glasses 400;

that is, after wearing the glasses, no matter whether the polarized glasses 400 are horizontal or vertical, only even frames or odd frames of video can be observed on the imaging plane 500, and one frame of the two adjacent frames can not see subtitles without wearing the glasses. The invention can be used as a common projector, can realize the function of prompting the speaker at the same time, and can not influence the watching of the audience.

When designing courseware, if the caption is required to be displayed clearly, the content with the gray scale in the upper range is required to be used more on the picture, and the caption is hidden in the gray scale area, and the best effect is achieved when the gray scale value is 30% of the highest brightness, therefore, if the invisible prompting function is required to be used, the background with the gray scale of about 30% is preferably used when designing courseware, and the prompting word, namely the invisible caption is placed in the gray background area.

Adding the following components in the third step: the caption superimposing module 207 compares the data signals of the odd video frame and the even video frame, if the average value of the difference between the brightness values of the corresponding pixels of the two frames is greater than 5% of the maximum brightness value which can be represented by the pixel bit depth of the video data, the brightness increase and decrease processing is not performed on the current odd frame and the even video frame behind the current odd frame, the comparison between the next odd video frame and the even video frame behind the current odd frame is continued, otherwise, the next step is performed. Therefore, the defect that the original three-step processing method cannot realize complete complementation of the front frame and the rear frame when the brightness difference of the front frame and the rear frame of the video is large can be overcome, and the watching effect is improved.

The pixel brightness value processing method comprises the following steps: firstly, converting an RGB color mode corresponding to video data into an HSI mode, namely converting three numerical values of red, green and blue colors corresponding to the video data into three numerical values of hue, saturation and brightness, then independently increasing and decreasing the brightness numerical value, and then converting the processed HSI value into an RGB value. After the RGB value is converted into the HSI value, the brightness value is independently adjusted, so that the brightness value is increased and decreased more clearly, if the RGB value is directly adjusted, the red, green and blue color values need to be adjusted, the data operation is complex, the value adjustment is not visual, and when the HSI value is adjusted, only the brightness value is adjusted. The conversion method between the RGB color mode and the HSI mode is prior art and will not be described herein.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. The data superposition processing method of the liquid crystal polarization invisible word-lifting DLP projector system is characterized in that the projector system comprises a projector, a caption superimposer, a caption computer and polarization glasses;

the data superposition processing method comprises the following steps:

2. The data superposition processing method of the liquid crystal polarization invisible word DLP projector system as claimed in claim 1, characterized in that: the lens of the polarized glasses is composed of polarized areas and non-polarized areas in an interlaced mode, and the area of each polarized area is smaller than 0.02 square millimeter.

3. The data superposition processing method of the liquid crystal polarization invisible word DLP projector system as claimed in claim 1, characterized in that: the light source is a laser light source, light emitted by the laser light source is polarized light, and the polarization direction of the polarized light is the same as that of the polarizer layer of the liquid crystal panel.

4. The data superposition processing method of the liquid crystal polarization invisible word DLP projector system as claimed in claim 1, characterized in that: the current processing method for video data of odd frames further comprises the following steps: if the current pixel brightness value plus the increased brightness value of the video data of the caption stroke area is greater than the maximum brightness value represented by the video pixel bit depth, then: if the current brightness value plus the added value is larger than the maximum brightness value, the pixel brightness value of the video data in the current odd frame subtitle stroke area is increased to the maximum brightness value;

5. The data superposition processing method of the liquid crystal polarization invisible word DLP projector system as claimed in claim 4, characterized in that: adding the following components in the third step: the caption superposition module compares the data of the current odd frame and the even frame behind the current odd frame, if the average value of the difference of the pixel brightness values corresponding to the two frames is more than 5% of the maximum brightness value which can be expressed by the pixel bit depth of the video data, the brightness increase and decrease processing is not carried out on the current odd frame and the even frame behind the current odd frame, the comparison between the next odd frame and the even frame behind the current odd frame is continued, otherwise, the next step is carried out.

6. The data superposition processing method for the liquid crystal polarization invisible word DLP projector system as claimed in any one of claims 1 to 5, wherein: the pixel brightness value processing method comprises the following steps: firstly, converting an RGB color mode corresponding to video data into an HSI mode, namely converting three numerical values of red, green and blue colors corresponding to the video data into three numerical values of hue, saturation and brightness, then independently increasing and decreasing the brightness numerical value, and then converting the processed HSI value into an RGB value.