WO2020039954A1 - Dispositif d'affichage - Google Patents

Dispositif d'affichage Download PDF

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Publication number
WO2020039954A1
WO2020039954A1 PCT/JP2019/031307 JP2019031307W WO2020039954A1 WO 2020039954 A1 WO2020039954 A1 WO 2020039954A1 JP 2019031307 W JP2019031307 W JP 2019031307W WO 2020039954 A1 WO2020039954 A1 WO 2020039954A1
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WIPO (PCT)
Prior art keywords
light source
bit
gradation
output
display device
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PCT/JP2019/031307
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English (en)
Japanese (ja)
Inventor
真一郎 田尻
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ソニー株式会社
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Publication of WO2020039954A1 publication Critical patent/WO2020039954A1/fr

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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B21/00—Projectors or projection-type viewers; Accessories therefor
    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B21/00—Projectors or projection-type viewers; Accessories therefor
    • G03B21/14—Details
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G—PHYSICS
    • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
    • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
    • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
    • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
    • G09G3/34—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters by control of light from an independent source
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/74—Projection arrangements for image reproduction, e.g. using eidophor
    • 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]

Definitions

  • the present disclosure relates to a display device that displays an image using a light modulation element.
  • gradation control is performed by a PWM (Pulse Width Modulation) method.
  • PWM Pulse Width Modulation
  • the brightness of the light source is kept constant and the width of the light emission time of the light source is changed according to the brightness, thereby enabling a multi-step gradation expression.
  • a technique has been proposed in which one frame is divided into a plurality of subframes, and the luminance of the light source is variably controlled in subframe units (see Patent Document 1).
  • image data for each gradation is transferred to the light modulation element prior to a display period for each gradation.
  • a display device includes a light source that outputs light that is a source of illumination light and a bit plane for each gradation bit within a display period allocated to each of the plurality of gradation bits.
  • a light modulation element for modulating the illumination light based on the data; a display period of the lowest gradation bit of the plurality of gradation bits as T1; and a display period of the gradation bit one stage higher than the lowest as T2.
  • a period control unit that variably controls a display period for each gradation bit in the light modulation element so that T2 ⁇ T1> T2 ⁇ 1/2, and a light source at least in a display period of the lowest gradation bit.
  • a light source output controller for variably controlling the output.
  • the display period of the lowest gradation bit of the plurality of gradation bits is T1
  • the display period of the gradation bit one step higher than the lowest is T2.
  • the display period for each gradation bit in the light modulation element is variably controlled so that T2 ⁇ T1> T2 ⁇ 1/2, and at least the output of the light source in the display period of the least significant gradation bit is variably controlled.
  • FIG. 9 is an explanatory diagram illustrating an example of light emission control of a light source in a display device according to a comparative example.
  • 1 is a configuration diagram schematically illustrating a configuration example of a projector as a display device according to a first embodiment of the present disclosure.
  • FIG. 3 is an explanatory diagram schematically illustrating an example of a frame configuration of an image in the display device according to the first embodiment.
  • FIG. 2 is a block diagram schematically illustrating a configuration example of a control system of the display device according to the first embodiment.
  • 9 is a timing chart illustrating an example of light emission control of a light source in a display device according to a comparative example.
  • FIG. 9 is a timing chart illustrating an example of a transfer timing of data transfer for each gradation bit in a display device according to a comparative example. 5 is a timing chart illustrating an example of a transfer timing of data transfer for each gradation bit in the display device according to the first embodiment.
  • FIG. 9 is an explanatory diagram illustrating an example of light emission control of a light source in a display device according to a first modification of the first embodiment.
  • FIG. 11 is an explanatory diagram illustrating an example of light emission control of a light source in a display device according to a second modification of the first embodiment.
  • FIG. 3 is an explanatory diagram illustrating an example of an ideal output waveform and an actual output waveform of a light source in the display device according to the first embodiment.
  • 9 is a timing chart illustrating an example of light emission control of a light source in a display device according to a second embodiment.
  • FIG. 9 is an explanatory diagram illustrating an example of an output waveform of a light source in the display device according to the first embodiment and an output waveform of a light source in the display device according to the second embodiment.
  • FIG. 1 First Embodiment (Technique for lowering the light source output so as to lengthen the display period of LSB) 1.1 Configuration of Display Device According to First Embodiment (FIGS. 2 to 4) 1.2 Control Operation of Display Device According to First Embodiment (FIGS. 5 to 8) 1.3 Effects 1.4 Modifications of First Embodiment (FIGS. 9 to 11) 2. 2. Second Embodiment (Technique for shortening light emission time of light source so as to lengthen display period of LSB) (FIGS. 12 to 13) 3. Other embodiments
  • Comparative Example> (Overview and Issues of PWM Display Device According to Comparative Example)
  • a light source continuously emits light having a constant luminance to a light modulation element.
  • the light modulation element controls the modulation of light into two states of light and dark for each pixel according to the luminance of an image to be displayed.
  • the display device as light modulation control, on (light emission) / (non-light emission) off control of light reaching the image display surface is performed in a pulsed manner.
  • the light modulation element changes the pulse width of light by changing the on / off switching timing for each pixel, and performs gradation expression. By irradiating the light modulated in this manner on the image display surface, an image is displayed in multiple gradations.
  • an image of 16 gradations can be represented by combining at least four types of images having different luminances within a predetermined period (usually one frame). That is, when expressing 16 gradations, first, the luminance is quantized into, for example, four gradation bits for each pixel. Then, for example, one frame of image data is represented by a combination of four types of image data weighted by each gradation bit. At this time, a group of image data for each gradation bit is usually called a “bit plane”.
  • the bit plane is an information surface of luminance for each gradation bit.
  • the output of the light source is controlled to be constant.
  • a technique for variably controlling the output of a light source has been proposed in order to improve image quality and the like.
  • FIG. 1 illustrates an example of light emission control of a light source in a display device according to a comparative example.
  • Patent Document 1 Japanese Patent Application Laid-Open No. 2007-78866
  • one frame is divided into a plurality of subframes SF1, SF2, SF3, and SF4 having different lengths.
  • the display periods of R (red), G (green), and B (blue) are dispersed in one frame.
  • the display period is shortened in the order of the plurality of subframes SF1, SF2, SF3, and SF4.
  • a bit plane of gradation bits corresponding to the display period of each color is displayed for each subframe.
  • the emission intensity of each color is changed for each subframe in synchronization with the display period of each color. This makes it possible to express the gradation more precisely than in the case where the output of the light source is controlled to be constant, and particularly, the gradation expression on the dark side is improved.
  • the emission intensity of each color is changed for each subframe, but the display period of each gradation bit of each color and the emission The period is fixed.
  • the light emission intensity of each color of the sub-frames SF2, SF3, and SF4 changes, but FIG. 1B and FIG. 1C. There is no change in the light emission period of each color.
  • bit plane data for each gradation it is necessary to transfer bit plane data for each gradation to the light modulation element in advance before a display period for each gradation.
  • the data of the bit plane of the sub-frame SF4 in FIG. 1A needs to be transferred to the light modulation element within the display period of the sub-frame SF3 earlier than that. Therefore, the transfer period during which the data of the bit plane is transferred needs to be shorter than at least the display period of the least significant gradation bit (LSB).
  • LSB least significant gradation bit
  • FIG. 2 schematically illustrates a configuration example of the display device according to the first embodiment of the present disclosure.
  • FIG. 2 illustrates a single-panel projector 10 as an example of the display device.
  • the projector 10 includes a plurality of light sources, a plurality of condensing optical systems, a color combining unit 13, an illumination optical system 14, a TIR (Total Internal Internal Reflection) prism 15, a display panel 16, and a projection optical system 17.
  • a plurality of light sources a plurality of condensing optical systems
  • a color combining unit 13 an illumination optical system 14
  • a TIR (Total Internal Internal Reflection) prism 15, a display panel 16, and a projection optical system 17.
  • Each of the plurality of light sources outputs a color light which is a source of the illumination light.
  • the plurality of light sources include a red light source 11R, a green light source 11G, and a blue light source 11B.
  • Each of the plurality of light sources is composed of a solid-state light source such as a semiconductor laser (LD: Laser Diode) or an LED (Light Emitting Diode).
  • LD Laser Diode
  • LED Light Emitting Diode
  • the plurality of light-collecting optical systems include a red light-collecting optical system 12R, a green light-collecting optical system 12G, and a blue light-collecting optical system 12B.
  • Each of the red light collecting optical system 12R, the green light collecting optical system 12G, and the blue light collecting optical system 12B includes a light collecting lens and the like.
  • the red light condensing optical system 12R is provided on the optical path of the red light emitted from the red light source 11R, and condenses the red light toward the color combining unit 13.
  • the green light condensing optical system 12G is provided on the optical path of the green light emitted from the green light source 11G, and condenses the green light toward the color combining unit 13.
  • the blue light condensing optical system 12B is provided on the optical path of the blue light emitted from the blue light source 11B, and condenses the blue light toward the color combining unit 13.
  • the color combining unit 13 has a first dichroic mirror 31 and a second dichroic mirror 32.
  • the first dichroic mirror 31 is provided on an optical path of blue light and green light.
  • the first dichroic mirror 31 has a property of transmitting blue light and reflecting green light, and combines the optical paths of blue light and green light.
  • the second dichroic mirror 32 is provided on an optical path of the blue light, the green light, and the red light after being combined by the first dichroic mirror 31.
  • the second dichroic mirror 32 has a property of transmitting blue light and green light and reflecting red light, and combines the optical paths of blue light and green light with the optical path of red light.
  • the illumination optical system 14 includes a light collecting optical system 41, a light pipe 42, and a light collecting optical system 43. Each color light from a plurality of light sources enters the illumination optical system 14 via the color synthesis unit 13.
  • the condenser optical system 41 and the condenser optical system 43 include a condenser lens and the like.
  • the condensing optical system 41 condenses each color light toward the light pipe 42.
  • the light pipe 42 equalizes each color light to generate illumination light of each color.
  • the condensing optical system 43 condenses the illumination light of each color from the light pipe 42 toward the TIR prism 15.
  • the display panel 16 is illuminated at a desired angle by the illumination light of each color generated by the illumination optical system 14 via the TIR prism 15.
  • the TIR prism 15 has a pair of prisms having a triangular cross section.
  • the TIR prism 15 deflects illumination light from the illumination optical system 14 toward the display panel 16 at a desired angle. Further, the TIR prism 15 emits a projection image from the display panel 16 toward the projection optical system 17.
  • the display panel 16 is a light modulation element such as a mirror array device having a plurality of mirrors.
  • the display panel 16 generates a projection image by modulating the illumination light for each color based on the image signal Vin.
  • the illumination light is deflected toward the projection optical system 17 via the TIR prism 15 by changing the tilt angle of each mirror based on the image signal Vin.
  • the mirror array device is a micromirror array device such as a DMD (Digital Micromirror Device) in which a plurality of micromirrors corresponding to pixels are arranged in an array (matrix).
  • the projection optical system 17 includes, for example, a plurality of lenses, and projects a projection image generated by the display panel 16 onto a projection surface such as a screen 18.
  • FIG. 3 schematically shows an example of a frame configuration of an image in the projector 10.
  • the projector 10 uses a single display panel 16 and is a so-called single-panel type, and performs full-color display in a time-division manner.
  • one frame is equally divided into R, G, and B sub-frames for display as shown in FIG.
  • Light of each wavelength of R, G, and B is emitted from the plurality of light sources in a time division manner in synchronization with the period of the subframe.
  • the display panel 16 is irradiated with illumination light of each color in a time-division manner.
  • the display panel 16 generates a projection image of each color in a time-division manner with respect to the illumination light of each color in synchronization with the timing of irradiation of each color light.
  • FIG. 4 schematically illustrates a configuration example of a control system of the projector 10.
  • the projector 10 includes a sub-frame control unit 51, a PWM sequence control unit 52, a bit plane generation unit 53, and a light source output control unit 54.
  • the sub-frame control unit 51 controls the period of each color sub-frame in one frame of the input image signal Vin.
  • the PWM sequence control unit 52 is a period control unit that controls a display period for each gradation bit of each color within a period of a subframe of each color. As shown in FIGS. 6 and 8 described later, the PWM sequence control unit 52 sets the display period of the lowest gradation bit of the plurality of gradation bits in the subframe period of each color to T1 and the display period of the lowermost gradation bit to be lower than the lowest. Assuming that the display period of the gradation bit of one higher order is T2, The display period of each gray scale bit on the display panel 16 is variably controlled so that T2 ⁇ T1> T2 ⁇ 1/2.
  • the display period T1 of the lowermost grayscale bit exceeds the display period T2 of the uppermost grayscale bit, the grayscale relationship between the lowermost grayscale bit and the upper grayscale bit is reversed.
  • the display period T1 of the lowermost grayscale bit is less than half of the display period T2 of the grayscale bit of the next higher level, the display period T1 of the lowermost grayscale bit becomes the same as that of a general PWM type display device. It becomes equal to or less than that, and as shown in FIG. 7 described later, there is no room in the transfer time of the data to be transferred next, and a failure occurs in the data transfer.
  • the bit plane generation unit 53 generates bit plane data for each gradation bit corresponding to each of the plurality of gradation bits and displayed during the sub-frame of each color based on the image signal Vin.
  • the bit plane generation unit 53 transfers the generated bit plane data for each gradation bit to the display panel 16 for each gradation bit prior to the display period for each gradation bit.
  • the light source output control unit 54 determines the light source output control unit 54 based on the display period for each gradation bit of each color within the subframe period of each color determined by the PWM sequence control unit 52. , The output (light emission timing and light emission intensity) of each light source of the red light source 11R, the green light source 11G, and the blue light source 11B.
  • the light source output control unit variably controls the output of each light source in at least the display period of the lowest gradation bit.
  • the light source output control unit 54 outputs the output of each light source during the display period of the lowest gradation bit to the light source of each light source during the display period of the other gradation bits other than the lowest gradation bit among the plurality of gradation bits. Vary to output. As shown in FIGS. 6 and 8 described below, the light source output control unit 54 lowers the output of each light source during the display period of the lowest gradation bit than the output of the light source during the display period of the other gradation bits. Let it.
  • the display panel 16 modulates the illumination light based on the data of the bit plane for each gradation bit within the display period allocated to each of the plurality of gradation bits.
  • FIG. 5 is a timing chart illustrating an example of light emission control of a light source in a display device according to a comparative example.
  • FIG. 6 is a timing chart illustrating an example of light emission control of the light source in the display device (projector 10) according to the first embodiment.
  • FIG. 7 is a timing chart illustrating an example of a transfer timing of data transfer for each gradation bit in the display device according to the comparative example.
  • FIG. 8 is a timing chart illustrating an example of a transfer timing of data transfer for each gradation bit in the display device according to the first embodiment.
  • FIGS. 5 to 8 show timing charts in an arbitrary sub-frame period among the sub-frames of each color shown in FIG.
  • the same light emission control is performed for each color within the subframe period of each color.
  • FIG. 5A and FIG. 6A show the state of the brightness (gradation) of the display image (bit plane).
  • B shows the output state of the light source (red light source 11R, green light source 11G, or blue light source 11B) of a color corresponding to the color of the display image.
  • C shows the state of an arbitrary pixel of the display panel 16. The display panel 16 controls the display state of each pixel to two states of ON / OFF (light emission (bright) / non-light emission (dark)).
  • D shows the transfer timing of the bit plane data for each gradation bit transferred from the bit plane generation unit 53 to the display panel 16.
  • FIGS. 5 and 6 (A) and (D), and FIGS. Bit plane data is transferred in the order of b4, b3, b2, and b1, and the bit plane of each gradation bit is displayed.
  • the least significant gradation bit is b1
  • the gradation bit one stage higher than the gradation bit b1 is b2
  • the gradation bit one stage higher than the gradation bit b2 is b3
  • the gradation bit b3 is the same.
  • the gradation bit one step higher is b4.
  • FIG. 7 shows a more specific state of brightness (gradation) of a display image (bit plane) and a transfer timing of bit plane data in the display device according to the comparative example.
  • FIG. 7 shows, as a specific example, the state of the bit plane for each gray scale bit corresponding to the 16 gray scales, 15 gray scales, and 14 gray scales.
  • FIG. 8 shows a comparison between the display period of each gradation bit in the display device according to the comparative example and the display period of each gradation bit in the display device (example) according to the first embodiment.
  • FIG. 8 shows the output state of the light source and the transfer timing of bit plane data in the display device according to the first embodiment.
  • the display period T3 of the gradation bit b3 is 1 / of the display period T4 of the gradation bit b4,
  • the display period T2 of the gradation bit b2 is 1 / of the display period T3 of the gradation bit b3, and the display period T1 of the gradation bit b1 is ⁇ of the display period T2 of the gradation bit b2.
  • the display device in the display device according to the first embodiment, as shown in FIGS. 6A and 6B and FIG.
  • the output of the light source in the display period T1 of b1 is made lower than the output of the light source in the display period of another gradation bit.
  • the PWM sequence control unit 52 in order to maintain the original brightness of the image by the reduction in the output of the light source, the PWM sequence control unit 52 is more compared to the display device according to the comparative example.
  • the display period T1 of the lower gradation bit b1 is lengthened. Further, in the display device according to the first embodiment, as shown in FIG.
  • the display period T1 of the lowermost gradation bit b1 is made longer.
  • the PWM sequence control unit 52 appropriately adjusts the display period of the other gradation bits.
  • the display periods T4 and T3 of the gradation bits b4 and b3 are adjusted to be shorter than in the display device according to the comparative example.
  • the light source output control unit 54 is compared with the display device according to the comparative example in order to maintain the original brightness of the image by shortening the display periods T4 and T3.
  • the output of the light source in the display periods T4 and T3 of the gradation bits b4 and b3 is increased.
  • the display period T4 of the gradation bit b4 is adjusted to be shorter than that of the display device according to the comparative example.
  • the light source output control unit 54 sets the gradation bit b4 to be smaller than that of the display device according to the comparative example. The output of the light source in the display period T4 is increased.
  • the display period T1 (PWM width) of the least significant gradation bit b1 is T_b1, as shown in FIGS. 5A and 5D, FIGS.
  • the display period T1 of the lowest gradation bit b1 the data of the bit plane of the first gradation bit (b4) in the next subframe is transferred.
  • the display period T1 of the least significant gradation bit b1 is too short, as shown in FIG. 7, there is no room in the transfer time of the next data to be transferred, and a failure occurs in the data transfer.
  • the actual gradation (brightness) is an integral of the brightness due to the PWM control. Therefore, if the output of the light source of the lowest gradation bit b1 is P_b1, P_b1 ⁇ T_b1.
  • the output (P_b1_new) of the light source of the lowest gradation bit b1 is changed by the light source output control unit 54 to the output (P_b1) of the display device according to the comparative example. ) Is controlled (P_b1> P_b1_new).
  • the display period T1 (PWM width) of the least significant gradation bit b1 in the display device according to the first embodiment is T_b1_new.
  • P_b1 ⁇ T_b1 P_b1_new ⁇ T_b1_new
  • the relationship becomes T_b1 ⁇ T_b1_new. Therefore, in the display device according to the first embodiment, with respect to the data transfer time T_d, T_b1_new> T_d, and as shown in FIG. 5D and FIG. 6D and at the bottom of FIG. 7 and FIG. As compared with the display device according to the example, a large margin is provided for the data transfer time.
  • the display device it is possible to extend the display period of the least significant gradation bit as compared with a general PWM type display device. It is possible to secure a long data transfer time. That is, high frame rate and high resolution data can be transferred within the display period of the lowest gradation bit without increasing the data transfer speed. As a result, it is possible to increase the frame rate and increase the number of pixels while maintaining a circuit configuration with a low data transfer speed.
  • FIG. 9 illustrates an example of light emission control of a light source in a display device according to a first modification of the first embodiment.
  • the light source output control unit 54 decreases the output stepwise as the output of the light source at the start of the subframe period is high and the end of the subframe period is approaching.
  • light emission control as illustrated in FIG. 9 may be performed in response thereto. That is, the light source output control unit 54 sets the plurality of light source outputs so that the output of the light source at the start of the sub-frame period and the output of the light source at the end of the sub-frame period are close to each other (to be substantially the same). The output of the light source in each display period of the gray scale bit may be changed.
  • the output of the light source at the start of the sub-frame period and the output of the light source at the end of the sub-frame period are substantially equal to each other, at the time of display transition between two adjacent sub-frames (For example, at the time of transition from the red sub-frame to the green sub-frame shown in FIG. 3), the change in luminance is small, so that flicker and other flickers are suppressed, and the image quality is improved.
  • FIG. 10 illustrates an example of light emission control of a light source in a display device according to a second modification of the first embodiment.
  • FIG. 11 illustrates an example of an ideal output waveform and an actual output waveform of the light source in the display device according to the first embodiment.
  • the light source output control unit 54 discretely changes the output control of the light source.
  • continuous light emission control as shown in FIG. 10 may be performed. That is, the light source output control unit 54 may continuously change the output of the light source in each display period of the plurality of gradation bits.
  • Second Embodiment> a display device according to a second embodiment of the present disclosure will be described.
  • portions that are substantially the same as the components of the display device according to the first embodiment are given the same reference numerals, and descriptions thereof will be omitted as appropriate.
  • FIG. 12 is a timing chart illustrating an example of light emission control of the light source in the display device according to the second embodiment.
  • FIG. 13 shows the output waveform of the light source in the display device according to the first embodiment (FIG. 13A) and the output waveform of the light source in the display device according to the second embodiment (FIG. 13B). ) Is shown.
  • (A) shows the state of the brightness (gradation) of the display image (bit plane).
  • (B) shows the output state of the light source (red light source 11R, green light source 11G, or blue light source 11B) of a color corresponding to the color of the display image.
  • (C) shows the state of an arbitrary pixel of the display panel 16.
  • (D) shows the transfer timing of the bit plane data for each gradation bit transferred from the bit plane generation unit 53 to the display panel 16.
  • the light source output control unit 54 controls the sub-color of each color similarly to the display device according to the comparative example (FIG. 5) except for the display period T1 of the lowest gradation bit b1. Light emission control is performed so that the output of the light source is constant during the frame period. However, in the display device according to the second embodiment, the light source output control unit 54 partially controls the output of the light source during the display period T1 of the lowest gradation bit b1 to display another gradation bit. The output of the light source during the period.
  • the display period T1 of the lowermost gradation bit b1 is set to a period of switching between subframes of each color.
  • the PWM sequence control unit 52 has the lowermost gradation bit.
  • the display period T1 of b1 is extended from T_b1 to T_b1_new.
  • the light source output control unit 54 according to the comparative example uses the light source output control unit 54 according to the comparative example in order to maintain the original brightness of the image by the length of the display period T1 of the lowest gradation bit b1.
  • the output of the light source in the display period T1 of the lowest gradation bit b1 is reduced in the middle of the display period T1.
  • the display period T_b1_new of the lowest gradation bit b1 in the display device according to the second embodiment is set to the lowest gradation bit in the display device according to the comparative example. It is about twice as long as the display period T_b1 of b1. For this reason, the light source output control unit 54 controls the output of the light source to be turned off when about half of the display period T1 has elapsed.
  • the light emission time of the light source is shortened only within the display period T1 of the lowest gradation bit b1, so that the display device is compared with a general PWM type display device.
  • the display period T1 of the lowest gradation bit b1 can be lengthened.
  • light emission adjustment is performed only in the display period T1 of the lowest gradation bit b1, and light emission in other display periods is performed. No adjustments need to be made.
  • the display device of the present disclosure is applied to a projector, but the display device of the present disclosure can be applied to devices other than the projector.
  • the present technology can also have the following configurations.
  • the present technology having the following configuration, at least the display period of the lowest gradation bit and the output of the light source are optimized, so that it is possible to increase the frame rate and increase the number of pixels.
  • a light source that outputs light that is a source of illumination light, Within a display period allocated to each of the plurality of gradation bits, a light modulation element that modulates the illumination light based on bit plane data for each gradation bit, T2 ⁇ T1> T2 ⁇ 1/2, where T1 is the display period of the lowermost grayscale bit of the plurality of grayscale bits and T2 is the display period of the grayscale bit one level higher than the lowermost grayscale bit.
  • a period control unit that variably controls a display period for each of the gradation bits in the light modulation element,
  • a light source output control unit that variably controls an output of the light source during a display period of at least the least significant gradation bit.
  • the light source output control unit outputs the output of the light source during the display period of the least significant grayscale bit during a display period of another grayscale bit other than the least significant grayscale bit of the plurality of grayscale bits.
  • the display device according to (1) wherein the display device changes the output of the light source.
  • the period control unit controls a display period for each of the grayscale bits within a period of one subframe,
  • the light source output control unit so that the output of the light source at the start of the period of the sub-frame and the output of the light source at the end of the period of the sub-frame approach each other, each of the plurality of gradation bits
  • the light source output control unit partially lowers the output of the light source during the display period of the least significant gray scale bit than the output of the light source during the display period of the other gray scale bit.
  • the display device according to (1).
  • a bit for generating bit plane data for each gradation bit based on an image signal and transferring the bit plane data to the light modulation element for each gradation bit prior to a display period for each gradation bit The display device according to any one of (1) to (6), further including a plane generation unit.
  • a projection optical system that projects an image generated by the light modulation element,

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • Theoretical Computer Science (AREA)
  • Multimedia (AREA)
  • Signal Processing (AREA)
  • Control Of Indicators Other Than Cathode Ray Tubes (AREA)
  • Liquid Crystal Display Device Control (AREA)

Abstract

La présente invention concerne un dispositif d'affichage comprenant : une source de lumière destinée à émettre de la lumière qui devient une source de lumière d'éclairage ; un élément de modulation optique qui module la lumière d'éclairage sur la base de données de plan binaire pour chaque bit de gradation au sein d'une période d'affichage attribuée à chacun des bits de gradation ; une unité de régulation de période qui régule de manière variable la période d'affichage pour chacun des bits de gradation dans l'élément de modulation optique de façon à obtenir T2≥T1>T2·1/2, où T1 désigne une période d'affichage pour un bit de gradation d'ordre le plus bas parmi les bits de gradation, et T2 désigne une période d'affichage pour un bit de gradation supérieur d'un ordre au bit de gradation d'ordre le plus bas ; et une unité de régulation de sortie de source de lumière qui régule de manière variable une sortie de la source de lumière au moins dans la période d'affichage du bit de gradation d'ordre le plus bas.
PCT/JP2019/031307 2018-08-20 2019-08-08 Dispositif d'affichage WO2020039954A1 (fr)

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CN115810320A (zh) * 2023-02-08 2023-03-17 山东云海国创云计算装备产业创新中心有限公司 灰度图像显示的协同控制方法、系统、设备及存储介质

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Publication number Priority date Publication date Assignee Title
WO1992012506A1 (fr) * 1991-01-04 1992-07-23 Rank Brimar Limited Dispositif d'affichage
JPH07212686A (ja) * 1993-12-24 1995-08-11 Texas Instr Inc <Ti> 階調表現方法
JPH08146934A (ja) * 1994-11-24 1996-06-07 Texas Instr Inc <Ti> パルス幅変調ディジタル表示画素の強度調節方法及びこの方法を適用される表示システム
WO2001069584A1 (fr) * 2000-03-14 2001-09-20 Mitsubishi Denki Kabushiki Kaisha Afficheur d'image et procede d'affichage d'image
US20110128607A1 (en) * 2007-08-16 2011-06-02 Silicon Quest Kabushiki-Kaisha Display system for higher grayscale with a varying light source
WO2014112032A1 (fr) * 2013-01-15 2014-07-24 Ｎｅｃディスプレイソリューションズ株式会社 Dispositif d'affichage d'image et procédé d'affichage d'image

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1992012506A1 (fr) * 1991-01-04 1992-07-23 Rank Brimar Limited Dispositif d'affichage
JPH07212686A (ja) * 1993-12-24 1995-08-11 Texas Instr Inc <Ti> 階調表現方法
JPH08146934A (ja) * 1994-11-24 1996-06-07 Texas Instr Inc <Ti> パルス幅変調ディジタル表示画素の強度調節方法及びこの方法を適用される表示システム
WO2001069584A1 (fr) * 2000-03-14 2001-09-20 Mitsubishi Denki Kabushiki Kaisha Afficheur d'image et procede d'affichage d'image
US20110128607A1 (en) * 2007-08-16 2011-06-02 Silicon Quest Kabushiki-Kaisha Display system for higher grayscale with a varying light source
WO2014112032A1 (fr) * 2013-01-15 2014-07-24 Ｎｅｃディスプレイソリューションズ株式会社 Dispositif d'affichage d'image et procédé d'affichage d'image

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115810320A (zh) * 2023-02-08 2023-03-17 山东云海国创云计算装备产业创新中心有限公司 灰度图像显示的协同控制方法、系统、设备及存储介质
CN115810320B (zh) * 2023-02-08 2023-05-05 山东云海国创云计算装备产业创新中心有限公司 灰度图像显示的协同控制方法、系统、设备及存储介质

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