WO2021017981A1 - 投影显示设备 - Google Patents

投影显示设备 Download PDF

Info

Publication number
WO2021017981A1
WO2021017981A1 PCT/CN2020/103562 CN2020103562W WO2021017981A1 WO 2021017981 A1 WO2021017981 A1 WO 2021017981A1 CN 2020103562 W CN2020103562 W CN 2020103562W WO 2021017981 A1 WO2021017981 A1 WO 2021017981A1
Authority
WO
WIPO (PCT)
Prior art keywords
brightness
light
image
period
display device
Prior art date
Application number
PCT/CN2020/103562
Other languages
English (en)
French (fr)
Inventor
胡飞
陈晨
余新
郭祖强
李屹
Original Assignee
深圳光峰科技股份有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 深圳光峰科技股份有限公司 filed Critical 深圳光峰科技股份有限公司
Publication of WO2021017981A1 publication Critical patent/WO2021017981A1/zh
Priority to US17/588,146 priority Critical patent/US12003896B2/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N9/00—Details of colour television systems
    • H04N9/12—Picture reproducers
    • H04N9/31—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM]
    • H04N9/3141—Constructional details thereof
    • H04N9/315—Modulator illumination systems
    • H04N9/3155—Modulator illumination systems for controlling the light source
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N13/00—Stereoscopic video systems; Multi-view video systems; Details thereof
    • H04N13/30—Image reproducers
    • H04N13/363—Image reproducers using image projection screens
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N13/00—Stereoscopic video systems; Multi-view video systems; Details thereof
    • H04N13/30—Image reproducers
    • H04N13/332—Displays for viewing with the aid of special glasses or head-mounted displays [HMD]
    • H04N13/339—Displays for viewing with the aid of special glasses or head-mounted displays [HMD] using spatial multiplexing
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N13/00—Stereoscopic video systems; Multi-view video systems; Details thereof
    • H04N13/30—Image reproducers
    • H04N13/398—Synchronisation thereof; Control thereof
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N9/00—Details of colour television systems
    • H04N9/12—Picture reproducers
    • H04N9/31—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM]
    • H04N9/3102—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM] using two-dimensional electronic spatial light modulators
    • H04N9/312—Driving therefor
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N9/00—Details of colour television systems
    • H04N9/12—Picture reproducers
    • H04N9/31—Projection devices for colour picture display, e.g. using electronic spatial light modulators [ESLM]
    • H04N9/3141—Constructional details thereof
    • H04N9/317—Convergence or focusing systems

Definitions

  • the present invention relates to the field of projection technology, in particular to a projection display device.
  • 3D projection display relies on the higher refresh rate of the projector, so that images along different angles can be projected within the display time of one frame of 3D picture.
  • One of the practical problems is that each angle of display needs to have enough Refresh rate.
  • PWM pulse width modulation
  • DMD digital micromirror device
  • the present invention provides a projection display device that can effectively increase the image refresh rate (frame rate) to project two-dimensional images from multiple angles and obtain stereoscopic images.
  • the present invention provides a projection display device, a period for displaying one frame of stereoscopic image is a first modulation period, and the projection display device includes:
  • Light source used to emit illuminating light
  • a spatial light modulator configured to modulate the illumination light according to multiple frames of two-dimensional images corresponding to the three-dimensional images to be displayed, and sequentially emit image lights corresponding to multiple frames of the two-dimensional images during the first modulation period;
  • An angle biasing device which is arranged in the exit light path of the image light, and is used to deflect the image light corresponding to the multiple frames of the two-dimensional image to different angles to exit;
  • the projection screen is used to display the image light deflected by the angle bias device.
  • the first modulation period includes a plurality of second modulation periods, and the spatial light modulator emits one frame of image light of the two-dimensional image during the second modulation period;
  • the projection display device further includes a control device configured to control the light source to emit illuminating light of varying brightness in the second modulation period;
  • the control device is also used for controlling the time length corresponding to the least significant bit of the spatial light modulator in the second modulation period and the time corresponding to each least significant bit of the modulation unit of the spatial light modulator. It is in an on or off state within the length, so that the spatial light modulator can modulate a set of set illumination brightness in the second modulation period.
  • the second modulation period includes a low-brightness period and a high-brightness period.
  • the light source emits a first level of brightness during the low-bright period and emits a second level of brightness during the high-bright period.
  • the first horizontal brightness Less than the second level of brightness.
  • the first horizontal brightness and the second horizontal brightness are both interval brightness, and any brightness of the first horizontal brightness is less than any brightness of the second horizontal brightness; or
  • the rated brightness of the first level of brightness is small and the average brightness is less than the rated brightness of the second level of brightness; or the luminous brightness of the light source is rated brightness when its rated current is continuously driven, and any brightness of the first level of brightness is less than
  • any brightness of the second horizontal brightness is not less than the rated brightness, and the difference between the rated brightness average brightness of the first horizontal brightness and the second horizontal brightness and the rated brightness is less than the set value Set threshold.
  • the first horizontal brightness and/or the second horizontal brightness change stepwise, and each level of brightness corresponds to at least one length of time corresponding to the least significant bit.
  • the low-bright period includes m least significant bits
  • the high-bright period includes n least significant bits
  • m and n are both positive integers
  • the illumination brightness in the low-bright period satisfies:
  • L 1i L/2m+1-i, 1 ⁇ i ⁇ m, i is an integer, where L 1i is the illumination brightness corresponding to the i-th least significant bit,
  • the illumination brightness of the high-brightness sub-period satisfies:
  • L 2j L*2j-1, 1 ⁇ j ⁇ n, j is an integer, where L 2j is the brightness of the illumination corresponding to the j-th least significant bit,
  • control device is configured to combine images of multiple frames of different imaging surfaces into a stereo image, and then split the stereo image through an algorithm to obtain two-dimensional images corresponding to different spatial angles;
  • the angle biasing device is used to deflect the image light corresponding to any one of the two-dimensional images emitted by the spatial light modulator to the corresponding spatial angle.
  • control device controls the spatial light modulator to modulate the two-dimensional images in different frames when the modulation unit is in the state according to the correspondence between the spatial angle and the stable state of the modulation unit. Deflection under different steady-state conditions.
  • the angle biasing device includes a plurality of guiding parts sequentially located in the image light path during the first modulation period, each of the guiding parts is used to transfer the two-dimensional image The image light is deflected to its associated spatial angle, and the time that each guided part stays in the optical path is the time corresponding to the second modulation period.
  • the projection screen is an angle expansion screen.
  • image light corresponding to multiple frames of two-dimensional images is emitted in each first modulation period, and the image light corresponding to different frames of two-dimensional images is deflected along different angles to improve the frame of the projection display device.
  • Rate image refresh rate
  • Figure 1 is a schematic structural diagram of a projection display device provided by the present invention.
  • Figure 2 is a schematic diagram related to the second modulation period
  • FIG. 3 is a schematic diagram of the correspondence between the illumination brightness and the least significant bit in the second modulation period provided in an embodiment of the present invention
  • FIG. 4 is a schematic diagram of the correspondence between the illumination brightness and the least significant bit in the second modulation period provided in another embodiment of the present invention.
  • Fig. 5 is a schematic structural diagram of the angle biasing device shown in Fig. 1 in an embodiment
  • Fig. 6 is a schematic structural diagram of the angle biasing device shown in Fig. 1 in another embodiment.
  • Projection display equipment 100 light source 110 Spatial light modulator 150 Angle offset device 170 Control device 190 Image light I, I1, I2, I3 Boot array W Guidance W1, W2, W3
  • the present invention provides a projection display device 100, which can be a projection display device for displaying stereoscopic images, such as a cinema projector, an engineering projector, a miniature projection projector, and a laser TV.
  • the projection display device 100 includes a light source 110, a spatial light modulator 150, an angle biasing device 170, a control device 190, a projection lens (not shown) and a projection screen (not shown).
  • the light source 110 is used to emit illuminating light
  • the spatial light modulator 150 is used to modulate the illuminating light according to multiple frames of two-dimensional images corresponding to one frame of stereoscopic image to obtain image light
  • the angle biasing device 170 is used to correspond to different frames of two-dimensional images.
  • the image light is deflected to different deflection angles, and the image light transmitted along the different deflection angles emitted by the angle biasing device 170 passes through the projection lens and is projected onto the projection screen; the projection screen is used to receive the image light with different deflection angles to display stereo image.
  • the period during which the projection display device 100 is used to display one frame of stereoscopic image is the first modulation period, and the first modulation period is determined by the refresh frequency of the stereoscopic video.
  • the presentation of the stereoscopic video needs to modulate multiple frames of the two-dimensional image during the time when the two-dimensional video modulates one frame of the two-dimensional image.
  • the present invention splits the first modulation period determined according to the refresh frequency into a plurality of second modulation periods.
  • the projection display device 100 shortens the modulation time of a single frame of two-dimensional image to achieve a smaller time period (second During the modulation period) the image light corresponding to the two-dimensional image is projected, and then the image light of multiple frames of the two-dimensional image is emitted along different deflection angles in the first modulation period, and multiple frames of the two-dimensional image transmitted in different directions are combined into a stereo image. Realize three-dimensional display.
  • the control device 190 is used to receive a video signal
  • the video signal is a stereoscopic image signal
  • each frame of the stereoscopic image signal includes multiple frames of two-dimensional original image signals, wherein each frame of the two-dimensional original image signal corresponds to one A two-dimensional image with a projection angle.
  • the projection angle corresponding to the two-dimensional original image signal received by the control device 190 may not be consistent with the fixed multiple projection angles provided by the projection display device 100, so the control device 190 receives the video
  • the signal first obtain the corresponding stereoscopic image data according to the two-dimensional original image data of multiple angles, and split the stereoscopic image data to obtain two corresponding spatial angles that can be offset by the angle offset device of the projection display device 100. And transmit the obtained two-dimensional image to the spatial light modulator 150.
  • the light source 110 may be a pure laser light source for emitting laser light as illumination light.
  • the light source 110 may include three primary color lasers, such as red, green, and blue lasers, to emit illumination light including three primary colors.
  • the light source 110 is a laser-fluorescence hybrid light source, which includes an excitation light source and a wavelength conversion device.
  • the excitation light source includes a luminous body for emitting laser light to emit laser light as excitation light, and the excitation light is used for excitation wavelength conversion.
  • the wavelength-converting material on the surface of the device generates the laser light whose color is different from the excitation light.
  • the received laser light and the unconverted part of the excitation light are emitted from the light source as illumination light.
  • the light source 110 emits illumination light of multiple primary colors sequentially, for example, emits red-green-blue illumination light sequentially.
  • the light source may also be an LED light source.
  • the control device 190 is used to issue a light source control signal, and the light source 110 is used to emit illumination light according to the light source control signal.
  • the first modulation period includes a plurality of second modulation periods, and the spatial light modulator 150 is used to emit image light corresponding to one frame of two-dimensional image in each second modulation period. It is equivalent to a traditional projection display device for projecting two-dimensional images.
  • a projection display device for stereoscopic image display needs to modulate more image frames within the preset display time of one frame of image, that is, projection The display device has a higher image refresh frequency.
  • the control device 190 controls the non-constant illumination light emitted by the light source 110, and at the same time controls the spatial light modulator 150 to correspond to the least significant bit in the second modulation period
  • the purpose is to ensure the image quality of the modulated two-dimensional image (which can meet the bit depth requirement) under the combined action of the light source with changing brightness and the modulation mechanism of the spatial light modulator, and the modulation time occupied is shorter. That is to say, the spatial light modulator can modulate a brightness set or gray scale set that meets the bit depth requirement in the second modulation period.
  • Bit depth refers to the number of bits required by the computer to represent the gray information of a certain pixel in a gray image. The larger the bit depth, the more the number of bits required, the smaller the difference between adjacent gray values, the less obvious the numerical sampling of analog information, the more natural and smooth the transition of gray differences in the image, The greater the contrast.
  • the light source control signal can change the luminous brightness of the corresponding luminous body in the light source 110 by adjusting the driving current or driving voltage of the light source 110.
  • the brightness of the illuminating light increases as the driving current/driving voltage of the light source 110 increases.
  • the driving current/driving voltage exceeds the rated current/rated voltage, when the luminous body is continuously driven for a long time, the luminous body is more likely to be damaged.
  • the luminous brightness of the light source under the continuous drive of its rated current is the rated brightness of the light source.
  • the spatial light modulator adopts the PWM modulation method, and the light source works in a continuous driving mode, that is, the light source emits constant brightness illumination light.
  • the driving current of the light source is its rated current
  • the brightness of the illuminating light is its rated brightness.
  • the brightness of the illumination light is a variable brightness.
  • the second modulation period includes a low-bright period and a high-bright period.
  • the lighting brightness in the low-bright period is the first horizontal brightness
  • the lighting brightness in the high-bright period is the second horizontal brightness
  • the first horizontal brightness and the second horizontal brightness It can be a constant value or interval brightness, that is, the illumination brightness in the low-bright period includes multiple brightness values, and the illumination brightness in the high-bright period includes multiple brightness values.
  • the constant value corresponding to the first horizontal brightness is smaller than the constant value corresponding to the second horizontal brightness.
  • any brightness of the first horizontal brightness is less than any brightness of the second horizontal brightness; or, the luminous brightness of the light source is rated brightness under the continuous driving of its rated current, Any brightness of the first horizontal brightness is less than the rated brightness, any brightness of the second horizontal brightness is not less than the rated brightness, and the average brightness of the first horizontal brightness and the second horizontal brightness is divided by the sum of the first horizontal brightness plus the second horizontal brightness Take 2)
  • the difference with the rated brightness is less than the set threshold.
  • the spatial light modulator 150 is configured to modulate the illumination light according to the two-dimensional image corresponding to each spatial angle to obtain image light corresponding to each two-dimensional image.
  • the spatial light modulator 150 is a DMD as an example for description.
  • the DMD is provided with a modulation area that receives and modulates the illuminating light.
  • the modulation area is provided with a modulation unit arranged in pixels.
  • Each modulation unit is specifically a reflective micromirror, and each reflective micromirror can be in an "on” state or “Off” state, when the reflective micromirror is in the "on” state, the reflective micromirror is used to reflect a beam of illuminating light to the angle offset device 170 so that it can be emitted from the projection lens and displayed on the projection screen; When the micromirror is in the “off” state, the reflective micromirror is used to reflect a beam of illuminating light to the outside of the angle offset device 170, so that it will not enter the projection lens, and the light will not be emitted from the projection display device 100.
  • the light emitted by a reflective micromirror corresponds to a pixel in the image to be displayed.
  • the least significant bit refers to the smallest gray scale unit that the spatial light modulator can achieve.
  • the LSB corresponds to the duration of the smallest brightness unit that can be modulated by the spatial light modulator lighting sequence.
  • the second modulation period includes a plurality of least significant bits, and the sum of the time lengths corresponding to the plurality of least significant bits constitutes the second modulation period.
  • the time length corresponding to the least significant bit corresponds to one turn cycle of the modulation unit, which is recorded as response
  • the time t LSB is shown in Figure 2.
  • the played frame rate is preset or set according to actual needs, that is, the time corresponding to the first modulation period is determined, and the control device parses out based on the three-dimensional image data
  • the number of two-dimensional images is determined according to the actually set algorithm and is predetermined. Therefore, when the first modulation period is determined, the time corresponding to the second modulation period is also determined. For example, if the frame rate is 60 Hz, the modulation time of one frame of stereoscopic image, that is, the time length corresponding to the first modulation period is: the time corresponding to each color is 1/60Hz ⁇ 16.67ms.
  • the control device algorithm can change a The frame stereo image is split into 3 two-dimensional images, and the time length corresponding to the second modulation period is: 16.67/3 ⁇ 5.56 ms.
  • control device 190 controls the inversion period of the modulation unit of the spatial light modulator 150 in the determined second modulation period, that is, t LSB , and controls the change in the brightness of the illumination light emitted by the light source to achieve the second modulation period. It can modulate a set of set gray levels.
  • bit plane is on the other, according to the above laws, at the time of the DMD variable bit planes 5 Up to 32 gray-scale states, 5 bit depth image display can be realized.
  • the shortest time needed to implement a 5-bit deep image time using a binary PWM timing modulation method with constant illumination light is the time corresponding to 31 LSBs. Therefore, when the bit depth of the two-dimensional image is i bits, the length of time required to modulate one frame of the two-dimensional image in the PWM modulation mode is: (2 i -1)*t LSB . However, this time cannot meet the time of the second modulation period in 3D video display. That is, when the three-dimensional video that needs to be displayed requires a high frame rate, the traditional PWM timing modulation method will not be able to display high-bit-depth two-dimensional images in a relatively short time.
  • the present invention realizes higher bit depth image display in a shorter time by adjusting the length of time corresponding to the LSB, the brightness of the time illuminating light corresponding to each LSB, and the on-off state of the modulation unit.
  • the number of LSBs included in the second period can be adjusted according to the actual length of the second modulation period and the bit depth of the two-dimensional image to be displayed, that is, the time length corresponding to each LSB, and the setting
  • the length of time corresponding to one or more LSBs corresponds to one illumination brightness, and the time length corresponding to each illumination brightness may be the same or different.
  • each modulation unit in each second modulation period, that is, within the display time of each frame of the two-dimensional image, the brightness of the illumination light is not fixed, that is, the brightness in the low-bright period and the high-bright period in the second modulation period And the light brightness is not equal, compared to the PWM modulation mode, it is beneficial for each modulation unit to emit the illumination light corresponding to the pixel gray level to the angle bias device 170 in a relatively short time length, which is beneficial to the projection display
  • the device 100 shortens the duration of the second modulation period, and more second modulation periods can be set in the fixed first modulation period, that is, within the display time of one frame of stereoscopic image, the projection display device provided by the present invention is beneficial to more output Image light corresponding to multiple frames of two-dimensional images can be combined into one frame of stereo image after multiple frames of two-dimensional images are angularly polarized, thereby realizing the display of stereo images.
  • the time length corresponding to the least significant bit and the brightness of the illuminating light are adjusted, so that the time length of one or more LSBs corresponds to the brightness of one illuminating light, and finally realized in the second modulation period.
  • the rated brightness of the changed illuminating light is close to the rated brightness of the light source at the rated current or in the second modulation period, the ratio of the average brightness of the changed illuminating light to the rated brightness is (0.8 ⁇ 1.2) .
  • the second modulation period includes a low-bright period and a high-bright period.
  • the average brightness in the high-bright period is higher than the rated brightness, and the average brightness in the low-bright period is lower than the rated brightness.
  • the ratio of average brightness to rated brightness is (0.8 to 1.2).
  • the horizontal axis in FIG. 4 represents time, and the length of the horizontal axis in the figure is a second modulation period, including (m+n) response times t LSB , where m
  • Each response time corresponds to m low-brightness sub-periods, which are the first low-brightness sub-period, the second low-brightness sub-period, ..., the mth low-brightness sub-period, where n response times correspond to n high-brightness sub-periods, which are respectively the first high Bright sub-period, second high-bright sub-period, ..., nth low-bright sub-period.
  • the vertical axis in Figure 4 represents the brightness of the illuminating light.
  • the illuminating light has the lowest brightness in the first low-bright sub-period, and the n-th high-bright sub-period has the highest brightness.
  • the illuminating light has the highest brightness in each sub-period.
  • the illumination brightness is constant.
  • the brightness of the illumination light increases stepwise from low to high in different sub-periods, or more specifically, the change in the brightness of the illumination light between different sub-periods is exponential.
  • the brightness of the illumination light in the first low-bright sub-period is L/2 m
  • the brightness of the illuminating light increases to twice the brightness of the previous sub-period. That is, the brightness of the illumination light in multiple low-bright sub-periods is L/2 m , L/2 m-1 , L/2 m-2 ,..., L/2, respectively, and the brightness of the illuminating light in multiple high-bright sub-periods are respectively Is L, L*2,...L*2 n-1 .
  • L/2 m is the lowest brightness that the illuminating light can achieve in a pulsed state
  • the amount of light emitted by a modulation unit in the spatial light modulator 150 in the first low-bright sub-period (light brightness multiplied by the duration of the first low-bright sub-period)
  • L*2 n-1 is the highest brightness that the light source 110 can achieve in the pulse state.
  • the total amount of light emitted by each modulation unit corresponds to the gray value of the modulation unit.
  • the brightness of the illumination light changes exponentially. In other embodiments, the brightness of the illumination light decreases exponentially in each modulation period, or Show other numerical law changes.
  • the time required to modulate a frame of two-dimensional image in the traditional PWM modulation method is about (2 m+n -1)*t LSB
  • the modulation method shown in the embodiment only needs (m+n)*t LSB , that is, within the time of modulating one frame of two-dimensional image in the traditional PWM modulation method
  • the present invention can modulate approximately (2 m+n -1)/(m+n) frames.
  • the solution of the present invention cooperates with the brightness adjustment of the illuminating light to quickly realize the grayscale adjustment, and therefore has a high frame rate, which is beneficial to realize projected images from multiple angles to realize 3D display.
  • the second modulation period is a time length of 8 response times t LSB . Assuming that the minimum duration of the response time t LSB is about 22 us, if the scheme in this embodiment is adopted, the minimum second modulation period is about 176 us, and about 5682 frames can be displayed in 1 second. If the projection display device 100 sets the frame rate of the multi-angle 3D display as 60 Hz, each frame can be subdivided into 5682/60 ⁇ 95 angles for projection display.
  • the multi-angle image data of the stereoscopic image of each pixel input to the control device 190 may include a plurality of two-dimensional original image data, and each original image data corresponds to a projection angle. Since the multiple angles corresponding to the input multi-angle image data may be inconsistent with the multiple angles projected by the projection display device 100, the control device 190 obtains corresponding stereo image data according to the multiple angle original image data of each pixel. , And split each frame of stereoscopic image data through an algorithm to obtain a two-dimensional image corresponding to each projection angle of the projection display device 100. In each two-dimensional modulation period, the spatial light modulator 150 is used to modulate the illumination light according to the two-dimensional image corresponding to each projection angle to obtain image light corresponding to each projection angle.
  • the control device 190 is also used to send a deflection control signal.
  • the projection display device 100 also includes an angle biasing device 170.
  • the angle biasing device 170 is used for emitting multiple frames of the spatial light modulator 150 in the first modulation period according to the deflection control signal.
  • the two-dimensional image light is respectively guided to different spatial angles, and multiple frames of two-dimensional image light with different spatial angles are projected on the projection screen, which will present a stereoscopic display effect relative to the human eye.
  • the deflection control signal sent by the control device 190, the light source control signal, and the control signal of the on-off state of the modulation unit realize the synchronization control of the brightness adjustment of the illumination light, the control of the control unit, and the adjustment of the spatial angle of the emitted light.
  • I1, I2, and I3 are Three different steady states of the modulation unit of the spatial light modulator.
  • the spatial light modulator modulates and emits different two-dimensional images
  • the modulation unit is stabilized in an unused stable state.
  • the steady-state angle of the modulation unit is the same, thereby ensuring a complete gray-scale image is emitted.
  • the modulation unit in the first second modulation period of the first modulation period, the modulation unit is stabilized at I1 so that the two-dimensional image emitted in this period is deflected to the space angle corresponding to I1, and in the second second modulation period of the first modulation period Period, the modulation unit is stabilized at I2, so that the two-dimensional image emitted in this period is deflected to the spatial angle corresponding to I2.
  • the modulation unit is stabilized at I3, making the period The internally emitted two-dimensional image is deflected to the spatial angle corresponding to I3.
  • the MEMS can also be used to time-division and deflect the image light to more than three projection directions.
  • the angle biasing device 170 includes a plurality of guide parts located on the optical path of the image light according to the timing of the deflection signal, and different guide parts are used to guide the image light to different projection angles for transmission.
  • the angle biasing device 170 is a guide array W, which is used to deflect the image light I at the same incident angle to different angles and obtain the image light I1, I2, I3 transmitted along different angles.
  • the guide array W includes at least a guide part W1, a guide part W2, and a guide part W3. Each guide part in the guide array W vibrates repeatedly.
  • one guide part in the guide array W is located in the spatial light modulation
  • the guide part is used to refract the image light
  • different guide parts are used to refract the incident image light to different deflection angles, and at least obtain the image light I1, I2, and transmitted along the different deflection angles.
  • the guide array W guides the image light I to multiple deflections in a time-division manner by reflection.
  • the guiding part may be a designed polygonal scanning lens or the like.
  • the image light emitted along a plurality of different angles emitted by the angle biasing device 170 is projected onto a projection screen, and the projection screen is used to receive image light with different deflection angles to display a stereoscopic image.
  • the projection screen is an angle expansion screen to increase the angle between the transmission directions of the image light incident at different angles, so that the image light incident at different angles is more divided.
  • the present invention also provides a control method, which is applied to the above-mentioned projection display device 100.
  • the period during which the projection display device 100 displays one frame of stereoscopic image is the first modulation period.
  • One frame of stereoscopic image consists of two frames transmitted in different directions.
  • the period during which the projection display device 100 is used to display one frame of two-dimensional images in one frame of stereoscopic images is the second modulation period.
  • the control method provided by the present invention specifically includes the following steps:
  • the light source 110 is used to emit illumination light.
  • the light source 110 controls the brightness of the illumination light emitted by the light source 110 to change from a first level of brightness to a second level of brightness in each second modulation period.
  • the first horizontal brightness is less than the second horizontal brightness, where the first horizontal brightness and the second horizontal brightness are both in the brightness range, and during the second modulation period, the brightness of the illuminating light can exhibit multiple horizontal brightness.
  • Each second modulation period includes a low-bright period and a high-bright period.
  • the brightness of the illuminating light in the low-bright period is the first level
  • the brightness of the illuminating light in the high-bright period is the second level.
  • the light source 110 is continuous at its rated current.
  • the luminous brightness under driving is the rated brightness
  • the brightness of the control illuminating light in the low-bright period is lower than the rated brightness
  • the brightness in the high-bright period is not lower than the rated brightness.
  • the light source 110 is used to emit illumination light with different brightness in at least two periods of the second modulation period, which is beneficial to shorten the second modulation period and increase the frame rate.
  • the brightness of the illumination light in the low-bright period is lower than the rated brightness, and the brightness in the high-bright period is not lower than the rated brightness, so that while ensuring the image contrast, the frame rate is increased and the brightness of the image light emitted by the projection display device 100 is ensured.
  • the control device 190 obtains a corresponding frame of three-dimensional image data according to the two-dimensional original image data of multiple angles of each pixel, and splits one frame of the three-dimensional image data to obtain two corresponding spatial angles that the angle offset device can offset. Dimensional image.
  • the stereoscopic image data of one frame of stereoscopic image for each pixel input to the control device 190 may include multiple frames of two-dimensional original image data, and each frame of original image data corresponds to a projection angle. Since the multiple angles corresponding to the input multi-angle original image data may be inconsistent with the multiple angles projected by the projection display device 100, the control device 190 obtains the two-dimensional original image data from multiple angles of each pixel. Corresponding stereoscopic image data, or directly based on the received stereoscopic image data, split the stereoscopic image data through an algorithm to obtain two-dimensional original image data corresponding to each projection angle of the projection display device 100.
  • a two-dimensional image can correspond to a two-dimensional image of a single primary color, such as a red, green or blue primary color image, and multiple images of different primary colors are combined into a color two-dimensional image.
  • the spatial light modulator 150 is used to modulate the illumination light according to the two-dimensional image corresponding to each projection angle to obtain image light corresponding to each projection angle.
  • the low-brightness period includes m low-brightness sub-periods
  • the high-brightness period includes n high-brightness sub-periods, and both m and n are positive integers.
  • the light-emitting brightness of the control light source 110 changes exponentially.
  • the light-emitting brightness of the control light source in the i-th low-bright sub-period is L/2 m+1-i , 1 ⁇ i ⁇ m, and i is an integer; the light-emitting brightness of the control light source in the j-th low-bright sub-period is L*2 j-1 , 1 ⁇ j ⁇ n, j is an integer.
  • the spatial light modulator 150 is controlled to modulate the illumination light with one data bit in the two-dimensional image of the corresponding pixel in each sub-period, and the duration of each modulation period is (m+n)*t LSB .
  • the angle biasing device is controlled to deflect the image light corresponding to the two-dimensional images of different frames to different spatial angles.
  • the present invention provides two implementations of the angle biasing device 170. It is understood that other devices not provided by the present invention can also be used to realize the angle deflection function.
  • S4 Use the screen to receive image light with different deflection angles to display a stereoscopic image.

Landscapes

  • Engineering & Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Testing, Inspecting, Measuring Of Stereoscopic Televisions And Televisions (AREA)
  • Control Of Indicators Other Than Cathode Ray Tubes (AREA)
  • Projection Apparatus (AREA)

Abstract

本发明提供一种投影显示设备，用于显示一帧立体图像的时段为第一调制周期，所述投影显示设备包括：光源，用于出射照明光；空间光调制器，用于根据待显示的立体图像对应的多帧二维图像调制所述照明光，并在所述第一调制周期内，依次出射多帧所述二维图像对应的图像光；角度偏置装置，设置在所述图像光的出射光路中，用于将多帧所述二维图像对应的图像光偏转至不同角度出射；以及投影屏幕，用于显示经所述角度偏置装置偏转后的所述图像光。本发明提供的投影显示设备，有利于提高投影显示设备的帧率，进而有利于实现投影显示设备通过多个角度投射图像光显示立体图像。

Description

投影显示设备 技术领域
本发明涉及投影技术领域，尤其涉及一种投影显示设备。
背景技术
本部分旨在为权利要求书中陈述的本发明的具体实施方式提供背景或上下文。此处的描述不因为包括在本部分中就承认是现有技术。
一般3D投影显示的实现依赖于投影仪较高的刷新率，以使得在一帧3D画面的显示时间内可以投射出沿不同角度的图像，其中一个现实的问题是每个角度显示都需要有足够的刷新率。
然而，传统的数字微镜器件(DMD)的脉冲宽度调制(PWM)方式会限制单色8位位深显示的帧率在180Hz左右，如果每帧图像由三帧不同基色的图像合成，则每帧图像的帧率为60Hz，即每秒钟刷新60幅三基色图像，这对于多角度的3D投影显示是远远不够的。
发明内容
本发明提供一种能够有效提高图像刷新率(帧率)的投影显示设备，以从多个角度投射二维图像并得到立体图像。
本发明提供一种投影显示设备，用于显示一帧立体图像的时段为第一调制周期，所述投影显示设备包括：
光源，用于出射照明光；
空间光调制器，用于根据待显示的立体图像对应的多帧二维图像调制所述照明光，并在所述第一调制周期内，依次出射多帧所述二维图像对应的图像光；
角度偏置装置，设置在所述图像光的出射光路中，用于将多帧所述二维图像对应的图像光偏转至不同角度出射；以及
投影屏幕，用于显示经所述角度偏置装置偏转后的所述图像光。
在一个实施例中，所述第一调制周期包括多个第二调制周期，在 所述第二调制周期内所述空间光调制器出射一帧所述二维图像的图像光；
所述投影显示设备还包括控制装置，所述控制装置用于控制所述光源在所述第二调制周期出射亮度变化的照明光；
所述控制装置还用于控制所述空间光调制器在所述第二调制周期中最低有效位对应的时间长度以及所述空间光调制器的调制单元在每个所述最低有效位对应的时间长度内处于开启或者关闭状态，以使所述空间光调制器在所述第二调制周期内能够调制出设定的照明亮度集合。
在一个实施例中，所述第二调制周期包括低亮时段和高亮时段，所述光源在低亮时段出射第一水平亮度，在高亮时段出射第二水平亮度，所述第一水平亮度小于所述第二水平亮度。
在一个实施例中，所述第一水平亮度和所述第二水平亮度均为区间亮度，所述第一水平亮度的任一亮度均小于所述第二水平亮度的任一亮度；或所述第一水平亮度的额定亮度小平均亮度小于所述第二水平亮度的额定亮度；或所述光源在其额定电流连续驱动下发光亮度为额定亮度，所述第一水平亮度的的任一亮度小于所述额定亮度，所述第二水平亮度的任一亮度不小于所述额定亮度，所述第一水平亮度和所述第二水平亮度的额定亮度平均亮度与所述额定亮度的差值小于设定阈值。
在一个实施例中，所述第一水平亮度和/或所述第二水平亮度呈阶梯式变化，每一级阶段亮度对应至少一个所述最低有效位对应的时间长度。
在一个实施例中，所述低亮时段包括m个最低有效位，所述高亮时段包括n个最低有效位，m和n均为正整数，所述低亮时段的照明光亮度满足：
L 1i＝L/2m+1-i，1≤i≤m，i为整数，其中L 1i为第i个最低有效位对应的照明光亮度，
所述高亮子时段的照明光亮度满足：
L 2j＝L*2j-1，1≤j≤n，j为整数，其中L 2j为第j个最低有效位对应 的照明光亮度，
最低有效位对应的时间长度记为tLSB，则所述第二调制周期满足：T＝(m+n)*tLSB，其中T为所述第二调制周期。
在一个实施例中，2n-n≈m+(1/2m)。
在一个实施例中，所述控制装置，用于将多帧的不同成像面的图像组成立体图像，然后将所述立体图像通过算法拆分得到对应不同空间角度的二维图像；
所述角度偏置装置，用于将所述空间光调制器出射的任一所述二维图像对应的图像光偏转至对应的所述空间角度。
在一个实施例中，所述控制装置根据所述空间角度与所述调制单元的稳定状态的对应关系，控制所述空间光调制器在调制不同帧所述二维图像时，所述调制单元在不同的稳态状态下偏转。
在一个实施例中，所述角度偏置装置包括在所述第一调制周期内，依次位于所述图像光光路的多个引导部，每个所述引导部用于将所述二维图像的图像光偏转至其关联的空间角度，每个所引导部在光路中停留的时间为所述第二调制周期对应的时间。
在一个实施例中，所述投影屏幕是角度扩展屏幕。
本发明中提供的投影显示设备中，在每个第一调制周期中出射对应多帧二维图像的图像光，对应不同帧二维图像的图像光沿不同角度偏转提高所述投影显示设备的帧率(图像刷新率)，并且有利于从投影显示设备从多个角度发出图像光的方式实现立体投影显示。
附图说明
为了更清楚地说明本发明实施例/方式技术方案，下面将对实施例/方式描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图是本发明的一些实施例/方式，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他的附图。
图1为本发明提供的投影显示设备的结构示意图；
图2为第二调制周期相关的原理图；
图3为本发明的一个实施例中提供的第二调制周期内照明亮度与最低有效位的对应关系的原理图；
图4为本发明另一个实施例中提供的第二调制周期内照明亮度与最低有效位的对应关系的原理图；
图5为图1所示的角度偏置装置在一种实施方式中的结构示意图；
图6为图1所示的角度偏置装置在另一种实施方式中的结构示意图。
主要元件符号说明
投影显示设备 100
光源 110
空间光调制器 150
角度偏置装置 170
控制装置 190
图像光 I、I1、I2、I3
引导阵列 W
引导部 W1、W2、W3
如下具体实施方式将结合上述附图进一步说明本发明。
具体实施方式
为了能够更清楚地理解本发明的上述目的、特征和优点，下面结合附图和具体实施例对本发明进行详细描述。需要说明的是，在不冲突的情况下，本申请的实施例及实施例中的特征可以相互组合。
在下面的描述中阐述了很多具体细节以便于充分理解本发明，所描述的实施例仅是本发明一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本发明保护的范围。
除非另有定义，本文所使用的所有的技术和科学术语与属于本发明的技术领域的技术人员通常理解的含义相同。本文中在本发明的说 明书中所使用的术语只是为了描述具体的实施例的目的，不是旨在于限制本发明。
请参阅图1，本发明提供一种投影显示设备100，其可以是影院投影机、工程投影机、微型投影投、激光电视等用于显示立体图像的投影显示设备。投影显示设备100包括光源110、空间光调制器150、角度偏置装置170、控制装置190、投影镜头(图未示)与投影屏幕(图未示)。光源110用于发出照明光，空间光调制器150用于根据一帧立体图像对应的多帧二维图像调制照明光并得到图像光，角度偏置装置170用于将不同帧二维图像对应的图像光偏转至不同的偏转角度，角度偏置装置170出射的沿不同偏转角度传输的图像光穿过投影镜头后投射到投影屏幕上；投影屏幕用于接收具有不同偏转角度的图像光从而显示立体图像。
为了更清楚描述本发明的投影显示原理，将投影显示设备100用于显示一帧立体图像的时段为第一调制周期，第一调制周期是由立体视频的刷新频率确定的。同样刷新频率下，为呈现立体视频，在二维视频调制一帧二维图像的时间内，立体视频的呈现需要调制多帧二维图像。本发明将根据刷新频率确定的第一调制周期拆分成多个第二调制周期，投影显示设备100通过缩短单帧二维图像的调制时间的方式，实现在更小的时间周期内(第二调制周期内)投射出二维图像对应的图像光，然后在第一调制周期将多帧二维图像的图像光沿不同偏转角度出射，多帧不同方向传输的二维图像画面合成一帧立体图像实现三维立体显示。
在一个实施例中，控制装置190用于接收视频信号，该视频信号为立体图像信号，每帧立体图像信号中包括多帧二维的原始图像信号，其中每帧二维的原始图像信号对应一个带有投射角度的二维图像，然而，控制装置190接收到的二维的原始图像信号对应的投射角度与投影显示设备100提供的固定的多个投影角度未必一致，故控制装置190接收到视频信号之后，首先根据多个角度的二维的原始图像数据得到对应的立体图像数据，并将立体图像数据拆分得到分别与投影显示设备100的角度偏置装置可偏置的空间角度对应的二维图像，并将得到 的二维图像传输至空间光调制器150。
光源110可以为纯激光光源，用于发出激光作为照明光，光源110中可以包括三基色的激光器，比如红、绿、蓝色激光器，以出射包括三基色的照明光。在一种实施方式中，光源110为激光荧光混合光源，其包括激发光源与波长转换装置，激发光源中包括用于发出激光的发光体，以发出激光作为激发光，激发光用于激发波长转换装置表面的波长转换材料，从而产生颜色不同于激发光的受激光。受激光与未被转换的部分激发光作为照明光从光源出射。在一种实施方式中，光源110时序出射多种基色的照明光，比如时序出射红-绿-蓝色照明光。在一种实施例中，光源还可以是LED光源。
本发明第一实施方式中，控制装置190用于发出光源控制信号，光源110用于根据光源控制信号出射照明光。第一调制周期包括多个第二调制周期，空间光调制器150用于在每个第二调制周期内出射对应一帧二维图像的图像光。相当于传统的显示用于投影二维图像的投影显示设备，用于立体图像显示的投影显示设备，需要在预设的一帧图像的显示时间内，调制出更多的图像帧，即需要投影显示设备具有更高的图像刷新频率，在每个第二调制周期内，控制装置190控制光源110出射的非恒定的照明光，同时控制空间光调制器150在第二调制周期内最低有效位对应的时间长度，其目的是在亮度变化的光源以及空间光调制器调制机制的共同作用下，保证调制的二维图像的图像质量(能够满足位深要求)下，所占用的调制时间更短。也就是说空间光调制器可以在第二调制周期内能够调制出满足位深要求的亮度集合或者灰度集合。
我们知道计算机之所以能够显示颜色，是采用了一种称作“比特”的记数单位来记录所表示颜色的数据。对于显示位深为8比特的图像而言，最小灰度值是0，最大灰度值为2 8-1＝255，在最小灰度值与最大灰度值之间还包括254个灰度状态，每个灰度状态对应不同的灰度值。
位深是指表示灰度图像中某个像素灰度信息时计算机所需要的位数。位深越大，即所需要的位数越多，相邻灰度值之间的差别越小， 对模拟信息的数值化采样越不明显，图像中灰度差别的过渡越自然顺滑，图像对比度越大。显示位深为8的图像可以有2 8＝256种灰度值。
故，假设要求投影设备出射的二维图像的位深为8，则需要空间光调制器能够在第二调制周期内能够出射2 8＝256种灰度状态(照明亮度)。
光源控制信号可以通过调节光源110的驱动电流或驱动电压来改变光源110中的对应发光体的发光亮度，一般地，照明光的亮度随着光源110的驱动电流/驱动电压的增大而增大。然而，在驱动电流/驱动电压超过额定电流/额定电压的情况下长时间连续驱动发光体时，发光体损坏的可能性较大。
一般地，光源在其额定电流连续驱动下发光亮度为光源的额定亮度，现有的投影设备中，空间光调制器采用PWM调制方式，光源工作在连续驱动模式，即光源发出恒定亮度的照明光至空间光调制器，光源的驱动电流为其额定电流，照明光的亮度为其额定亮度。本发明中，照明光的亮度是变化的亮度。具体的，第二调制周期包括低亮时段和高亮时段，低亮时段的照明亮度为第一水平亮度，高亮时段的照明亮度为第二水平亮度，其中第一水平亮度和第二水平亮度可以是一恒定值，也可以是区间亮度，即低亮时段照明亮度包括多个亮度值，高亮时段照明亮度包括多个亮度值。当第一水平亮度和第二水平亮度为恒定值时，第一水平亮度对应的恒定值小于第二水平亮度对应的恒定值。当第一水平亮度和第二水平亮度为区间亮度时，第一水平亮度的任一亮度均小于第二水平亮度的任一亮度；或，光源在其额定电流连续驱动下发光亮度为额定亮度，第一水平亮度的任一亮度小于额定亮度，第二水平亮度的任一亮度不小于额定亮度，第一水平亮度和第二水平亮度的平均亮度第一水平亮度加上第二水平亮度的和除以2)与额定亮度的差值小于设定阈值。
在每个第二调制周期中，空间光调制器150用于根据每个空间角度对应的二维图像调制照明光得到对应每个二维图像对应的图像光。本发明中以空间光调制器150为DMD为例进行说明。DMD设置有一接收并调制照明光的调制区域，调制区域中设置有像素排布的调制单 元，每个调制单元具体为一反射微镜，每个反射微镜可以处于“on(开启)”状态或“off(关闭)”状态，当反射微镜处于“on”状态时，反射微镜用于反射一束照明光至角度偏置装置170从而可以从投影镜头出射并显示在投影屏幕上；当反射微镜处于“off”状态时，反射微镜用于反射一束照明光至角度偏置装置170之外，从而不会进入投影镜头，进而该光线不会从投影显示设备100出射。一个反射微镜出射的光线对应待显示图像中的一个像素。
最低有效位(LSB)是指空间光调制器够实现的最小灰度单位，在本发明中，LSB对应空间光调制器照明时序能够调制的最小亮度单元所对应的时长。本申请中，第二调制周期包括多个最低有效位，多个最低有效位对应的时间长度之和构成了第二调制周期，最低有效位对应的时间长度对应调制单元一次翻转周期，记为响应时间t LSB，如图2所示。
需要说明的是，在进行立体视频播放时，播放的帧频是预先设定的或者根据实际需求设定的，也就是第一调制周期对应的时间是确定的，控制装置基于三维图像数据解析出的二维图像的数量是根据实际设定的算法确定的，是预先确定好的，因此在第一调制周期确定的情况下，第二调制周期对应的时间也是确定的。举例来说，若帧率为60Hz，则一帧立体图像的调制时间即第一调制周期对应的时间长度为：每种颜色对应的时间为1/60Hz≈16.67ms，若控制装置算法可将一帧立体图像拆分成3个二维图像，则第二调制周期对应的时间长度为：16.67/3≈5.56ms。
本申请中，控制装置190是通过控制空间光调制器150在确定的第二调制周期内调制单元的翻转周期，即t LSB，以及控制光源出射的照明光亮度的变化来实现在第二调制周期内能够调制出设定的灰度状态集合。
假设需要对由立体图像拆分得到的二维图像进行5位深的图像显示，若采用传统的照明光恒定的二进制PWM时序调制方法实现5位图像显示位深，需要划分出5个对应不同位阶的位平面，其中最低阶的位平面对应的权重为2 0，其对应一个最低有效位LSB对应的时间， 其他位阶的位平面对应的权重分别为2 1、2 2、2 3和2 4，最高阶的位平面对应的时间为2 4＝16个最低有效位LSB对应的时间，若某个像素的图像数据为二进制的01111，则DMD在最高位阶的位平面时间内为关闭状态，其他位平面时间内为开启状态。在若某个像素的图像数据为11010，则DMD在权重为2 0和2 2位平面为处于关闭状态，其他位平面处于开启状态，依据上述规律，DMD在该5个位平面的时间可调至出32种灰度状态，即可实现5位位深图像显示。采用照明光恒定的二进制PWM时序调制方法实现5位深图像时间所需要的最短时间为31个LSB对应的时间。因此在二维图像的位深为i位的情况下，PWM调制模式下调制一帧二维图像所需的时间长度为：(2 i-1)*t LSB。而该时间满足不了三维视频显示时第二调制周期的时间。也就是当需要显示的三维视频要求的帧频较高时，采用传统的PWM时序调制方式将不能在比较短的时间内显示高位深的二维图像。
本发明通过调整LSB对应的时间长度以及每个LSB对应的时间照明光的亮度以及调制单元的开闭状态现在更短的时间内实现更高的位深图像显示。
如图3所示，若实现5位位深图像的显示，最少只需5个LSB对应的时间，每个LSB对应的时间对应不同的照明光亮度，通过控制单个镜片在5个LSB时间内的开关，即可实现32个照明亮度，即32种灰度状态，分别是0、L1、L2、L3、L4、L5、L1+L2、L1+L3、L1+L4、L1+L5、L1+L2+L3、L1+L2+L4、L1+L2+L5、L1+L3+L4、L1+L3+L5、L1+L4+L5、L1+L2+L3+L4、L1+L2+L3+L5、L1+L2+L4+L5、L1+L3+L4+L5、L1+L2+L3+L4+L5、L2+L3、L2+L4、L2+L5、L2+L3+L4、L2+L3+L5、L2+L4+L5、L2+L3+L4+L5、L3+L4、L3+L5、L3+L4+L5、L4+L5。
当然在实际显示时，可根据第二调制周期的实际时长以及待显示的二维图像的位深，调整第二周期内包括的LSB的个数，也就是每个LSB对应的时间长度，以及设置一个或者多个LSB对应的时间长度对应一个照明亮度，每个照明亮度对应的时间长度可以相同也可以不相同。
由于本发明中在每个第二调制周期内，即每帧二维图像的显示时间内，照明光的亮度非定值，即在第二调制周期内的低亮时段与高亮时段中的亮度以及光亮度不等，相较于在PWM调制模式，有利于每个调制单元在相对较短的时间长度内出射符合像素灰度对应光量的照明光至角度偏置装置170，从而有利于投影显示设备100缩短第二调制周期的时长，在固定的第一调制周期内可以设置更多的第二调制周期，即在一帧立体图像的显示时间内，本发明提供的投影显示设备有利于出射更多帧二维图像对应的图像光，多帧二维图像角度偏振后可合成一帧立体图像，从而实现立体图像显示。
在一个实施例中，在第二调制周期中，调整最低有效位对应的时间长度以及调整照明光的亮度，以使一个或者多个LSB的时间长度对应一个照明光的亮度，最终实现在第二调制周期内能够调制出设定位深的二维图像外，还需要确保在第二调制周期内，照明光的平均亮度不小于设定的阈值，确保调制出的图像满足亮度的要求。如在第二调制周期内，变化的照明光的额定亮度接近光源在额定电流下的额定亮度或者在第二调制周期内，变化的照明光的平均亮度与额定亮度的比值为(0.8～1.2)。
一种实现方式为：第二调制周期包括低亮时段和高亮时段，高亮时段的平均亮度高于额定亮度，低亮时段的平均亮度低于额定亮度，高亮时段和低亮时段总体的平均亮度与额定亮度的比值为(0.8～1.2)。
在一个具体的实施例中，如图4所示，图4中的横轴表示时间，图中的横轴长度为一个第二调制周期，包括(m+n)个响应时间t LSB，其中m个响应时间对应m个低亮子时段，分别为第一低亮子时段、第二低亮子时段、……、第m低亮子时段，其中n个响应时间对应n个高亮子时段，分别为第一高亮子时段、第二高亮子时段、……、第n低亮子时段。图4中的纵轴表示照明光的亮度，在每个第二调制周期中，照明光在第一低亮子时段的亮度最低，在第n高亮子时段的亮度最高，照明光在每个子时段内照明光亮度恒定。照明光的亮度在不同的子时段由低到高呈阶梯式增长，或更具体地，不同子时段之间的照 明光亮度变化呈指数形式。本实施方式中，每个低亮子时段的照明光亮度满足：L 1i＝L/2 m+1-i，1≤i≤m，i为整数，其中L 1i为第i低亮子时段的照明光亮度，L为额定电流下光源出射的额定亮度；每个高亮子时段的照明光亮度满足：L 2j＝L*2 j-1，1≤j≤n，j为整数，其中L 2j为第j高亮子时段的照明光亮度，L为额定电压下光源出射的额定亮度。
如图4所示，照明光在第一低亮子时段的亮度为L/2 m，在后续的子时段中，照明光亮度增长为前一个子时段的亮度的2倍。即照明光在多个低亮子时段的亮度分别为L/2 m，L/2 m-1，L/2 m-2，……，L/2，照明光在多个高亮子时段的亮度分别为L，L*2，……L*2 n-1。其中L/2 m为照明光在脉冲状态下能够实现的最低亮度，空间光调制器150中的一个调制单元在第一低亮子时段出射的光量(光亮度乘以第一低亮子时段的时长)对应空间光调制器150能够调制实现的最低有效位为1时的灰度值，也是相邻灰度值之间的光量之间的差异。L*2 n-1为光源110在脉冲状态下能够实现的最高亮度。第二调制周期内，每个调制单元出射的总的光量对应该调制单元的灰度值。本实施方式中，每个调制周期中的连续两个子时段中，照明光的亮度变化呈指数规律，在其他实施方式中，在每个调制周期中，照明光的亮度呈指数规律减小，或呈其他数值规律变化。
照明光在一个调制周期中的平均亮度为L mean＝(2 n-1/2 m)*L/(m+n)，低亮子时段越多，平均亮度降低的越多。若要求在第二调制周期中的照明光的亮度接近光源在额定电流下的额定亮度或者在第二调制周期内，变化的照明光的平均亮度与额定亮度的比值为(0.8～1.2)，即L mean≈L，则控制装置控制低亮时段包括的最低有效位的数量m，高亮时段包括的最低有效位的数量n，满足如下关系：2 n-n≈m+(1/2 m)。当m＝1时，可取n＝2；当m＝2时，可取n＝2；当m＝3时，可取n＝3；……。
而要实现(m+n)的位深，传统PWM调制方式中调制一帧二维图像需要的时间约为(2 m+n-1)*t LSB，实施例所示的调制方式则仅需(m+n)*t LSB，即在传统PWM调制方式中调制一帧二维图像的时间内，本发明可以调制出约(2 m+n-1)/(m+n)帧。
与传统2D显示相比，本发明方案中配合照明光的亮度调节，可以快速实现灰度调节，因此具有高帧率，有利于实现多个角度出射投影图像从而实现3D显示。
在一种实施方式中，m＝5，n＝3，第二调制周期为8个响应时间t LSB的时间长度。假设响应时间t LSB的最小时长约为22us，如果采用本实施方式中的方案，第二调制周期最小约为176us，在1s内可以显示约5682帧。投影显示设备100若将多角度3D显示的帧率定为60Hz，每个帧内可以细分5682/60≈95个角度进行投影显示。
输入至控制装置190的每个像素的立体图像的多角度图像数据可以包括多个二维的原始图像数据，每个原始图像数据对应了一个投影角度。由于输入的多角度图像数据对应的多个角度与投影显示设备100投影出射的多个角度可能是不一致的，因此，控制装置190根据每个像素的多个角度原始图像数据得到对应的立体图像数据，并通过算法将每帧立体图像数据拆分得到分别与投影显示设备100的每个投影角度对应的二维图像。在每个二维调制周期中，空间光调制器150用于根据每个投影角度对应的二维图像调制照明光得到对应每个投影角度的图像光。
控制装置190还用于发出偏转控制信号，投影显示设备100还包括角度偏置装置170，角度偏置装置170用于根据偏转控制信号将空间光调制器150在第一调制周期内出射的多帧二维图像光分别引导至不同的空间角度，不同空间角度的多帧二维图像光投射到投影屏幕上，将呈现相对于人眼的立体显示效果。通过控制装置190发出的偏转控制信号，光源控制信号以及调制单元开关状态的控制信号实现从而照明光亮度调节、控制单元的控制以及出射光的空间角度的调节的同步控制。
在一个实施例中，通过调整空间光调制器的调制单元的在第二调制周期内的稳态状态，使得不同的图像帧具有不同的空间角度，如图5所示，I1、I2、I3为空间光调制器调制单元三种不同的稳态。空间光调制器调制出射不同的二维图像时，调制单元稳定在不用的稳定状态，在每个第二调制周期中，调制单元稳态角度相同，从而保证完整 出射一幅灰度图像。如在第一调制周期的第一个第二调制周期，调制单元稳定在I1处使得该周期内出射的二维图像偏转至I1对应的空间角度，在第一调制周期的第二个第二调制周期，调制单元稳定在I2处，使得该周期内出射的二维图像偏转至I2对应的空间角度，在第一调制周期的第三个第二调制周期，调制单元稳定在I3处，使得该周期内出射的二维图像偏转至I3对应的空间角度。可以理解的是，微机电***还可以用于将图像光分时偏转至多于三个投影方向上。
在另一个实施例中，如图6所示，角度偏置装置170包括根据偏转信号时序位于图像光光路上的多个引导部，不同引导部用于将图像光引导至不同的投影角度传输。如图6所示，角度偏置装置170为引导阵列W，引导阵列W用于将同一入射角度图像光I偏转到不同的角度上并得到沿不同角度传输的图像光I1、I2、I3。引导阵列W至少包括引导部W1、引导部W2与引导部W3，引导阵列W中的每个引导部反复振动，在每个第二调制周期中，引导阵列W中的一个引导部位于空间光调制器150出射图像光的光路上，该引导部用于折射图像光，不同引导部用于将入射的图像光折射至不同的偏转角度，并至少得到沿不同偏转角度传输的图像光I1、I2、I3。在其他实施方式中，引导阵列W通过反射的方式分时引导图像光I至多个偏转上。在一个实施例中，引导部可以是经过设计的多边形的扫描镜片等。
角度偏置装置170出射的沿多个不同角度出射的图像光投影到投影屏幕上，投影屏幕，用于接收具有不同偏转角度的图像光从而显示立体图像。在一种实施方式中，投影屏幕为角度扩展屏，以增大不同角度入射的图像光的传输方向之间的夹角，使得不同角度入射的图像光分的更开。
本发明还提供一种控制方法，应用于上述投影显示设备100中，投影显示设备100用于显示一帧立体图像的时段为第一调制周期，一帧立体图像由多帧沿不同方向传输的二维图像合成，投影显示设备100用于显示一帧立体图像中的一帧二维图像的时段为第二调制周期，本发明提供的控制方法具体包括以下步骤：
S1：控制光源出射照明光。
如图1所示，本发明中，利用光源110发光照明光，光源110在每个第二调制周期内，控制光源110出射的照明光的光亮度从第一水平亮度改变至第二水平亮度，第一水平亮度小于第二水平亮度，其中，第一水平亮度和第二水平亮度均为亮度范围，在第二调制周期，照明光的亮度可呈现出多个水平亮度。
每个第二调制周期包括低亮时段与高亮时段，照明光在低亮时段的光亮度为第一水平，照明光在高亮时段的光亮度为第二水平，光源110在其额定电流连续驱动下发光亮度为额定亮度，控制照明光在所述低亮时段的亮度低于所述额定亮度，在所述高亮时段中的亮度不低于所述额定亮度。
利用光源110在第二调制周期中的至少两个时段出射亮度不同的照明光，从而有利于缩短第二调制周期，提高帧频。照明光在低亮时段的亮度低于额定亮度，在高亮时段的亮度不低于额定亮度，从而在保证图像对比度的情况下，提高帧频并保证投影显示设备100出射图像光的亮度。
S2：在第一调制周期内，根据一帧立体图像对应的多帧二维图像控制空间光调制器调制照明光并得到图像光。
控制装置190根据每个像素的多个角度的二维的原始图像数据得到对应的一帧立体图像数据，并将一帧立体图像数据拆分得到角度偏置装置能够偏置的空间角度对应的二维图像。
输入至控制装置190的每个像素的一帧立体图像的立体图像数据可以包括多帧二维的原始图像数据，每帧原始图像数据对应了一个投影角度。由于输入的多角度原始图像数据对应的多个角度与投影显示设备100投影出射的多个角度可能是不一致的，因此，控制装置190根据每个像素的多个角度的二维的原始图像数据得到对应的立体图像数据，或直接根据接收到的立体图像数据，通过算法将立体图像数据拆分得到分别与投影显示设备100的每个投影角度对应的二维的原始图像数据。二维图像可以对应单一基色的二维图像，比如红、绿或蓝基色图像，不同基色的多幅图像合成一幅彩色的二维图像。在每个第二调制周期中，空间光调制器150用于根据每个投影角度对应的二维 图像调制照明光得到对应每个投影角度的图像光。
在一种实施方式中，低亮时段包括m个低亮子时段，高亮时段包括n个高亮子时段，m和n均为正整数。在每个调制周期中的不同子时段中，控制光源110的发光亮度变化呈指数规律。具体地，控制光源在第i个低亮子时段中的发光亮度为L/2 m+1-i，1≤i≤m，i为整数；控制光源在第j个低亮子时段中的发光亮度为L*2 j-1，1≤j≤n，j为整数。相应地，控制空间光调制器150在每个子时段利用对应像素的二维图像中的一个数据位调制照明光，每个调制周期的时长为(m+n)*t LSB。
S3：在第一调制周期内，控制角度偏置装置将不同帧二维图像对应的图像光偏转至不同的空间角度。
本发明中提供了两种角度偏置装置170的实施方式，可以理解的是，还可以采用本发明未提供的其他装置来实现角度偏转功能。
S4：利用屏幕接收具有不同偏转角度的图像光从而显示立体图像。
需要说明的是，在本发明的精神或基本特征的范围内，各个实施方式中的各具体方案可以相互适用，显示装置100与控制方法中的各种实施方式可以相互适用，节省篇幅及避免重复起见，在此就不再赘述。
对于本领域技术人员而言，显然本发明不限于上述示范性实施例的细节，而且在不背离本发明的精神或基本特征的情况下，能够以其他的具体形式实现本发明。因此，无论从哪一点来看，均应将实施例看作是示范性的，而且是非限制性的，本发明的范围由所附权利要求而不是上述说明限定，因此旨在将落在权利要求的等同要件的含义和范围内的所有变化涵括在本发明内。不应将权利要求中的任何附图标记视为限制所涉及的权利要求。此外，显然“包括”一词不排除其他单元或步骤，单数不排除复数。装置权利要求中陈述的多个装置也可以由同一个装置或***通过软件或者硬件来实现。第一，第二等词语用来表示名称，而并不表示任何特定的顺序。
最后应说明的是，以上实施例仅用以说明本发明的技术方案而非限制，尽管参照较佳实施例对本发明进行了详细说明，本领域的普通技术人员应当理解，可以对本发明的技术方案进行修改或等同替换， 而不脱离本发明技术方案的精神和范围。

Claims (11)

  1. 一种投影显示设备，用于显示一帧立体图像的时段为第一调制周期，其特征在于，所述投影显示设备包括：
    光源，用于出射照明光；
    空间光调制器，用于根据待显示的立体图像对应的多帧二维图像调制所述照明光，并在所述第一调制周期内，依次出射多帧所述二维图像对应的图像光；
    角度偏置装置，设置在所述图像光的出射光路中，用于将多帧所述二维图像对应的图像光偏转至不同角度出射；以及
    投影屏幕，用于显示经所述角度偏置装置偏转后的所述图像光。
  2. 如权利要求1所述的投影显示设备，其特征在于，所述第一调制周期包括多个第二调制周期，在所述第二调制周期内所述空间光调制器出射一帧所述二维图像的图像光；
    所述投影显示设备还包括控制装置，所述控制装置用于控制所述光源在所述第二调制周期出射亮度变化的照明光；
    所述控制装置还用于控制所述空间光调制器在所述第二调制周期中最低有效位对应的时间长度以及所述空间光调制器的调制单元在每个所述最低有效位对应的时间长度内处于开启或者关闭状态，以使所述空间光调制器在所述第二调制周期内能够调制出设定的照明亮度集合。
  3. 如权利要求2所述的投影显示设备，其特征在于，所述第二调制周期包括低亮时段和高亮时段，所述光源在低亮时段出射第一水平亮度，在高亮时段出射第二水平亮度，所述第一水平亮度小于所述第二水平亮度。
  4. 如权利要求3所述的投影显示设备，其特征在于，所述第一水平亮度和所述第二水平亮度均为区间亮度，所述第一水平亮度的任一亮度均小于所述第二水平亮度的任一亮度；或所述第一水平亮度的平均亮度小于所述第二水平亮度的额定亮度；或所述光源在其额定电流连续驱动下发光亮度为额定亮度，所述第一水平亮度的的任一亮度小 于所述额定亮度，所述第二水平亮度的任一亮度不小于所述额定亮度，所述第一水平亮度和所述第二水平亮度的平均亮度与所述额定亮度的差值小于设定阈值。
  5. 如权利要求3或4所述的投影显示设备，其特征在于，所述第一水平亮度和/或所述第二水平亮度呈阶梯式变化，每一级阶段亮度对应至少一个所述最低有效位对应的时间长度。
  6. 如权利要求5所述的投影显示设备，其特征在于，所述低亮时段包括m个最低有效位，所述高亮时段包括n个最低有效位，m和n均为正整数，所述低亮时段的照明光亮度满足：
    L 1i＝L/2 m+1-i，1≤i≤m，i为整数，其中L 1i为第i个最低有效位对应的照明光亮度，
    所述高亮子时段的照明光亮度满足：
    L 2j＝L*2 j-1，1≤j≤n，j为整数，其中L 2j为第j个最低有效位对应的照明光亮度，
    所述最低有效位对应的时间长度记为t LSB，则所述第二调制周期满足：T＝(m+n)*t LSB，其中T为所述第二调制周期。
  7. 如权利要求6所述的投影显示设备，其特征在于，2 n-n≈m+(1/2 m)。
  8. 如权利要求2所述的投影显示设备，其特征在于，所述控制装置，用于将多帧的不同成像面的图像组成立体图像，然后将所述立体图像通过算法拆分得到对应不同空间角度的二维图像；
    所述角度偏置装置，用于将所述空间光调制器出射的任一所述二维图像对应的图像光偏转至对应的所述空间角度。
  9. 如权利要求8所述的投影显示设备，其特征在于，所述控制装置根据所述空间角度与所述调制单元的稳定状态的对应关系，控制所述空间光调制器在调制不同帧所述二维图像时，所述调制单元在不同的稳定状态下偏转。
  10. 如权利要求8所述的投影显示设备，其特征在于，所述角度偏置装置包括在所述第一调制周期内，依次位于所述图像光光路的多个引导部，每个所述引导部用于将所述二维图像的图像光偏转至其关联 的空间角度，每个所引导部在光路中停留的时间为所述第二调制周期对应的时间。
  11. 如权利要求1所述的投影显示设备，其特征在于，所述投影屏幕是角度扩展屏幕。
PCT/CN2020/103562 2019-07-29 2020-07-22 投影显示设备 WO2021017981A1 (zh)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US17/588,146 US12003896B2 (en) 2019-07-29 2022-01-28 Projection display device

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201910691347.8A CN112312099B (zh) 2019-07-29 2019-07-29 投影显示设备
CN201910691347.8 2019-07-29

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US17/588,146 Continuation-In-Part US12003896B2 (en) 2019-07-29 2022-01-28 Projection display device

Publications (1)

Publication Number Publication Date
WO2021017981A1 true WO2021017981A1 (zh) 2021-02-04

Family

ID=74229136

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2020/103562 WO2021017981A1 (zh) 2019-07-29 2020-07-22 投影显示设备

Country Status (3)

Country Link
US (1) US12003896B2 (zh)
CN (2) CN116800939A (zh)
WO (1) WO2021017981A1 (zh)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113448234B (zh) * 2021-07-19 2022-05-17 北京航空航天大学 一种基于空间光调制器虚拟阵列拼接的全息3d显示***

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101398536A (zh) * 2007-09-24 2009-04-01 鸿富锦精密工业（深圳）有限公司 立体投影光学***
CN201576164U (zh) * 2009-11-13 2010-09-08 惠州市华阳多媒体电子有限公司 一种用于3d显示的微投影仪
CN102016695A (zh) * 2007-12-06 2011-04-13 石井房雄 彩色显示***
CN102768460A (zh) * 2011-05-05 2012-11-07 深圳市亿思达显示科技有限公司 投影机、立体影像***
US10306216B2 (en) * 2011-03-09 2019-05-28 Dolby Laboratories Licensing Corporation Projection display providing additional modulation and related methods

Family Cites Families (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5282121A (en) * 1991-04-30 1994-01-25 Vari-Lite, Inc. High intensity lighting projectors
US8061854B2 (en) * 2003-11-01 2011-11-22 Silicon Quest Kabushiki-Kaisha Projection display system with varying light source
JP4138677B2 (ja) * 2004-02-18 2008-08-27 セイコーエプソン株式会社 表示装置および表示方法、並びに投射型表示装置
US8432339B2 (en) * 2005-02-16 2013-04-30 Texas Instruments Incorporated System and method for increasing bit-depth in a video display system using a pulsed lamp
CN101256279B (zh) * 2005-02-23 2014-04-02 皮克斯特隆尼斯有限公司 显示方法和装置
US8643681B2 (en) * 2007-03-02 2014-02-04 Silicon Quest Kabushiki-Kaisha Color display system
US8581519B2 (en) * 2011-08-25 2013-11-12 Hong Kong Applied Science & Technology Research Institute Co., Ltd. Current-switching LED driver using DAC to ramp bypass currents to accelerate switching speed and reduce ripple
CN202975583U (zh) * 2012-10-09 2013-06-05 耿征 真三维图像显示***
CN206542530U (zh) * 2016-11-17 2017-10-03 深圳市绎立锐光科技开发有限公司 投影显示设备
CN110351539B (zh) * 2016-11-17 2021-07-20 深圳光峰科技股份有限公司 投影显示设备
KR102633622B1 (ko) * 2017-02-13 2024-02-02 시리얼 테크놀로지즈 에스.에이. 광 가이드 디바이스 및 장면을 표현하기 위한 디스플레이 디바이스
US10025174B1 (en) * 2017-03-07 2018-07-17 Disney Enterprises, Inc. Multi-theater light source
CN109388004B (zh) * 2017-08-04 2024-05-28 深圳光峰科技股份有限公司 投影***
CN110533662B (zh) * 2019-09-19 2022-05-20 京东方科技集团股份有限公司 一种成像质量分析方法及其装置
CN110596949B (zh) * 2019-10-28 2022-08-19 京东方科技集团股份有限公司 液晶空间光调制器以及三维显示装置

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101398536A (zh) * 2007-09-24 2009-04-01 鸿富锦精密工业（深圳）有限公司 立体投影光学***
CN102016695A (zh) * 2007-12-06 2011-04-13 石井房雄 彩色显示***
CN201576164U (zh) * 2009-11-13 2010-09-08 惠州市华阳多媒体电子有限公司 一种用于3d显示的微投影仪
US10306216B2 (en) * 2011-03-09 2019-05-28 Dolby Laboratories Licensing Corporation Projection display providing additional modulation and related methods
CN102768460A (zh) * 2011-05-05 2012-11-07 深圳市亿思达显示科技有限公司 投影机、立体影像***

Also Published As

Publication number Publication date
US12003896B2 (en) 2024-06-04
US20220224869A1 (en) 2022-07-14
CN116800939A (zh) 2023-09-22
CN112312099B (zh) 2023-08-29
CN112312099A (zh) 2021-02-02

Similar Documents

Publication Publication Date Title
US7147331B2 (en) Method of driving a spatial light modulator and projector
CN2893733Y (zh) 投影***中将发光器件排序的装置
US7773103B2 (en) Light source control device and method for a display apparatus using pulse width modulation
US8064125B2 (en) Color sequential illumination for spatial light modulator
JP4546499B2 (ja) 画像表示装置
US20090147154A1 (en) Color display system
US10281805B2 (en) Image display device and image display method
CN104541321A (zh) 显示器、显示控制方法、显示控制装置以及电子装置
US20180192013A1 (en) Image display device and image display method
US20090147033A1 (en) Color display system
US7969640B2 (en) Color display system
US7869115B2 (en) Display apparatus using pulsed light source
US11600238B2 (en) Display device having digital micromirror array with an increased display bit depth
WO2020057150A1 (zh) 投影***及投影显示方法
US20150279256A1 (en) Image display device and drive method therefor
CN110855968A (zh) 采用自发光像素阵列器件的投影显示装置
WO2020125301A1 (zh) 光源***及其控制方法与显示设备及其控制方法
WO2021017981A1 (zh) 投影显示设备
JP3710455B2 (ja) 画像表示装置及び画像表示装置用光源ユニット
WO2020168812A1 (zh) 光源***、光源组件与显示设备及其控制方法
CN210431678U (zh) 采用自发光像素阵列器件的投影显示装置
CN110753880A (zh) 激光投影仪中的激光功率管理
WO2020039954A1 (ja) 表示装置
JPWO2012147442A1 (ja) プロジェクタ
CN113885281A (zh) 光源以及投影装置

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 20848345

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 20848345

Country of ref document: EP

Kind code of ref document: A1