Three-dimensional image display apparatus

Abstract

A three-dimensional image display apparatus includes a liquid crystal display panel, a variable focus lens unit, and a controller. The liquid crystal display panel displays a first image and a second image which are sequentially displayed by scanning line by line, and emits display light of the first image and display light of the second image. The variable focus lens unit switches a focal length of the display light to form a first image and a second image as virtual images on the first display surface and the second display surface, respectively. The controller configures each of the display periods to have a plurality of frame periods during which the first image or the second image is displayed in each of the display periods, and controls a brightness of a pixel of the liquid crystal display panel to a minimum brightness of the pixel in a last frame period.

Description

[0001] This application claims priority to Japanese Patent Application No. 2024-108758, filed on July 5, 2024, the entire disclosure of which is incorporated herein by reference. Technical Field

[0002] This disclosure generally relates to three-dimensional image display devices. Background Technology

[0003] In related technologies, depth-fused 3D (DFD) type three-dimensional image display devices are referred to as display devices that display three-dimensional images (3D images) visible to the naked eye. For example, unexamined Japanese Patent Application Publication No. 2005-129983 describes a three-dimensional display device that includes a display device that alternately displays two two-dimensional images, a polarizing plate that emits outgoing light emitted from the display device as polarized light, a polarization switching device that switches the polarization direction of the outgoing light emitted from the polarizing plate, and a polarized bifocal lens.

[0004] In the three-dimensional display device described in unexamined Japanese Patent Application Publication No. 2005-129983, from the observer's perspective, two two-dimensional images are alternately formed on corresponding display surfaces located at different depths, and the brightness or transmittance of the two two-dimensional images is independently changed. In this way, the three-dimensional display device displays a three-dimensional image.

[0005] When a display device (such as a liquid crystal display device, an organic electroluminescence (EL) display device, or the like) that performs display operations continuously within a single frame period via line-by-line scanning is used in the three-dimensional display apparatus included in unexamined Japanese Patent Application Publication No. 2005-129983, the brightness of the pixels perceived by the observer (the brightness of the pixels forming the two-dimensional image) is the average brightness of the pixels of the display device within the single frame period. In this case, the brightness perceived by the observer is essentially equal to the brightness of the display device at the pixel located at the beginning of the line-by-line scan. Conversely, the pixel located at the end of the line-by-line scan emits display light corresponding to the image signal for a shorter time within the single frame period; therefore, the brightness perceived by the observer is significantly different from the brightness of the display device.

[0006] In other words, pixel signals (pixel data) are rewritten at different times within a single frame period, depending on the position of the display device (two-dimensional image) in the line-by-line direction. Therefore, even if the pixels of the display device have the same brightness, the brightness perceived by the observer (the average brightness of the pixels of the display device within a single frame period) will differ depending on the position of the display device in the line-by-line direction. In the three-dimensional display device included in the unexamined Japanese Patent Application Publication No. 2005-129983, if pixels of the display device with the same brightness are perceived by the observer as pixels with different brightness depending on the position of the display device in the line-by-line direction, then a three-dimensional image with a shape different from the shape of the three-dimensional image to be displayed will be perceived by the observer.

[0007] This disclosure is made in view of the above circumstances, and the purpose of this disclosure is to provide a three-dimensional image display device that can control the average brightness of pixels during a display period, regardless of the position of the pixels in the line-by-line direction. Summary of the Invention

[0008] The three-dimensional image display device according to the first aspect of this disclosure includes:

[0009] A liquid crystal display panel is used to sequentially display a first image and a second image, and to emit display light for the first image and display light for the second image;

[0010] A variable-focus lens unit for switching between the focal length of the display light of the first image and the focal length of the display light of the second image; and

[0011] The controller is used to control the display on the LCD panel, wherein...

[0012] The first and second images are two-dimensional images, obtained by projecting the display target from the observer's side onto a corresponding one of a first and second display surfaces, which are located at different positions in the depth direction from the observer's perspective.

[0013] The liquid crystal display panel displays each of the first and second images by scanning the lines line by line.

[0014] The variable focus lens unit forms a first image and a second image as virtual images on the first display surface and the second display surface respectively, and

[0015] Controller:

[0016] Each display period in the display time slot is configured to have multiple frame periods, during which either the first image or the second image is displayed in each display period, and

[0017] In the last frame of the multiple frame periods included in the display period, the brightness of the pixels of the liquid crystal display panel is controlled to the minimum brightness.

[0018] The three-dimensional image display device according to the second aspect of this disclosure includes:

[0019] A self-emissive display panel is used to sequentially display a first image and a second image, and to emit display light for the first image and display light for the second image;

[0020] A variable-focus lens unit for switching between the focal length of the display light of the first image and the focal length of the display light of the second image; and

[0021] The controller is used to control the display of the self-emissive display panel, wherein...

[0022] The first and second images are two-dimensional images, obtained by projecting the display target from the observer's side onto a corresponding one of a first and second display surfaces, which are located at different positions in the depth direction from the observer's perspective.

[0023] The self-emissive display panel displays each of the first and second images by scanning lines sequentially.

[0024] The variable focus lens unit forms a first image and a second image as virtual images on the first display surface and the second display surface respectively, and

[0025] Controller:

[0026] Each display period in the display time slot is configured to have multiple frame periods, during which either the first image or the second image is displayed in each display period, and

[0027] In the last frame of the multiple frame periods included in the display period, the brightness of the pixels of the self-emissive display panel is controlled to the minimum brightness.

[0028] It should be understood that the foregoing general description and the following detailed description are both exemplary and explanatory, and do not limit this disclosure.

[0029] According to this disclosure, each display period for displaying the first or second image is configured to have multiple frame periods, and the brightness of the pixel is controlled to the minimum brightness of the pixel in the last frame period. Therefore, the average brightness of the pixel within the display period can be controlled regardless of its position in the line-by-line direction. Attached Figure Description

[0030] Figure 1 This is a schematic diagram illustrating a three-dimensional image display device according to Embodiment 1;

[0031] Figure 2 This is a plan view showing the liquid crystal display panel according to Embodiment 1;

[0032] Figure 3 This is a cross-sectional view showing the polarization switch according to Embodiment 1;

[0033] Figure 4 This is a cross-sectional view showing the polarizing bifocal lens according to Embodiment 1;

[0034] Figure 5 This is a block diagram showing the controller according to Embodiment 1;

[0035] Figure 6 This is a diagram illustrating the hardware configuration of the controller according to Embodiment 1;

[0036] Figure 7 This is a diagram showing a first image according to Embodiment 1;

[0037] Figure 8 This is a diagram showing a second image according to Embodiment 1;

[0038] Figure 9 This is a diagram used to explain the display control and polarization switch control of the liquid crystal display panel according to Embodiment 1;

[0039] Figure 10 This is a diagram used to explain the display operation of the liquid crystal display panel according to the comparative example;

[0040] Figure 11 This is a diagram showing the recognition of the first image based on the comparison example;

[0041] Figure 12 This is a diagram showing the recognition of the second image based on the comparison example;

[0042] Figure 13 This is a diagram used to explain the display control of the liquid crystal display panel according to Embodiment 2;

[0043] Figure 14 This is a diagram used to explain the display control of the liquid crystal display panel according to Embodiment 3;

[0044] Figure 15 This is a schematic diagram illustrating a three-dimensional image display device according to Embodiment 4;

[0045] Figure 16 This is a plan view showing the self-emissive display panel according to Embodiment 4;

[0046] Figure 17 This is a graph showing the relationship between the luminance half-life and luminance of the organic EL element according to Example 4;

[0047] Figure 18 This is a graph showing the brightness reduction rate according to Example 4;

[0048] Figure 19 This is a graph showing the relationship between (i) the brightness of the organic EL element and the emission time of the organic EL element according to Example 4, and (ii) the brightness half-life of the self-emissive display panel; and

[0049] Figure 20 This is a diagram used to explain the display control of a liquid crystal display panel based on a modified example. Detailed Implementation

[0050] In the following description, a three-dimensional image display device according to various embodiments is illustrated with reference to the accompanying drawings.

[0051] Example 1

[0052] Reference Figures 1 to 12 A three-dimensional image display device 10 according to this embodiment is described. The three-dimensional image display device 10 is a display device that displays three-dimensional images using depth-fused 3D (DFD). In one example, the three-dimensional image display device 10 is combined with an eyepiece and used as a head-mounted display. In this embodiment, an example of a three-dimensional image display device 10 using a monochrome liquid crystal panel is described.

[0053] Overall configuration

[0054] First, the overall configuration of the 3D image display device 10 is described. For example... Figure 1 As shown, the three-dimensional image display device 10 includes a display unit 20, a variable focus lens unit 40, and a controller 80.

[0055] Display unit 20 displays a first image and a second image sequentially according to time division. In this embodiment, display unit 20 emits display light PL1 of the first image and display light PL1 of the second image as polarized light. The polarization direction of the polarized light is a predetermined first direction. Variable focus lens unit 40 switches between the focal length of the display light PL1 of the first image and the focal length of the display light PL1 of the second image to form the first image and the second image as virtual images respectively on the first display surface 102 and the second display surface 104. Variable focus lens unit 40 includes a polarization switcher 50 and a polarization bifocal lens 60. Polarization switcher 50 emits display light PL2 while simultaneously switching the polarization direction of the display light PL1 emitted from display unit 20 between a predetermined first direction and a predetermined second direction. Polarization bifocal lens 60 is a lens whose focal length varies depending on the polarization direction of the outgoing light emitted from polarization switcher 50. Controller 80 controls the display of display unit 20. The controller 80 provides the display unit 20 with a first image signal for displaying a first image, a second image signal for displaying a second image, and a minimum brightness signal, which will be described later. Furthermore, the controller 80 controls the switching of polarization direction by the polarization switch 50.

[0056] In this instruction manual, for ease of understanding, Figure 1 In the three-dimensional image display device 10, the left direction (left direction on the paper) is referred to as the "+Z direction", the top direction (top direction on the paper) is referred to as the "+Y direction", and the direction perpendicular to the +Y and +Z directions (front direction on the paper) is referred to as the "+X direction". Furthermore, the first image signal used to display the first image and the second image signal used to display the second image are collectively referred to as "image signals".

[0057] Display unit

[0058] The display unit 20 of the three-dimensional image display device 10 includes a liquid crystal display panel 22 and a light source 32. The liquid crystal display panel 22 of the display unit 20 modulates the light emitted from the light source 32 based on a first image signal, a second image signal, and a minimum brightness signal provided from a controller 80, thereby sequentially displaying a first image and a second image in a time-divided manner. The liquid crystal display panel 22 emits display light PL1 of the image (e.g., the first image and the second image) as polarized light. The polarization direction of the polarized light is a predetermined first direction. The display light PL1 emitted from the liquid crystal display panel 22 enters a polarization switch 50. In this embodiment, the predetermined first direction is the X-direction.

[0059] The first and second images are two-dimensional images, obtained by projecting the display target from the observer's side onto one of the corresponding first display surfaces 102 and 104, which, from the observer's perspective, are located at different positions in the depth direction (+Z direction). The first display surface 102 and the second display surface 104 will be described later.

[0060] In one example, the liquid crystal display panel 22 is implemented as a transmissive twisted nematic (TN) liquid crystal panel, which is an active matrix driven by line-by-line scanning of thin film transistor (TFT) lines. Figure 2 As shown, the liquid crystal display panel 22 includes pixels P arranged in a matrix, a gate driver 23G, and a data driver 23D. The gate driver 23G selects pixels P row by row and performs line-by-line scanning from the +Y side along the -Y direction. The data driver 23D provides a voltage corresponding to an image signal or a minimum brightness signal to each of the selected pixels P, thereby writing the image signal or minimum brightness signal into each of the pixels P. Note that... Figure 2 Only a portion of the pixels P arranged in a matrix is ​​shown. Furthermore, the liquid crystal display panel 22 includes a light-transmitting substrate (not shown), TFTs, liquid crystal, polarizing plates, etc.

[0061] The light source 32 of the display unit 20 is the light source of the liquid crystal display panel 22. In one example, the light source 32 is implemented as a direct-lit backlight disposed on the rear surface of the liquid crystal display panel 22. The light source (backlight) 32 includes light-emitting diodes (LEDs), reflective sheets, diffusers, etc. (not shown).

[0062] Variable focus lens unit

[0063] The polarization switcher 50 of the three-dimensional image display device 10 switches the polarization direction of the display light PL1 emitted from the display unit 20 between a predetermined first direction (X direction) and a predetermined second direction based on a switching signal synchronized with the image signal. In this embodiment, the predetermined second direction is the Y direction. Specifically, when a first image is being displayed on the liquid crystal display panel 22 of the display unit 20, the polarization switcher 50 maintains the polarization direction of the incident display light PL1 in the X direction and emits display light PL2. When a second image is being displayed on the liquid crystal display panel 22 of the display unit 20, the polarization switcher 50 switches the polarization direction of the incident display light PL1 to the Y direction to emit display light PL2.

[0064] In one example, the polarization switch 50 is implemented as a TN liquid crystal element with a 90° twist angle. For example... Figure 3As shown, the polarization switcher (TN liquid crystal element) 50 includes liquid crystal 52, two light-transmitting substrates 54a and 54b, and an alignment film (not shown) for aligning the liquid crystal 52. Both light-transmitting substrates 54a and 54b include electrodes 53 for applying voltage to the liquid crystal 52. The light-transmitting substrates 54a and 54b are adhered to each other by a sealing material 56, thereby clamping the liquid crystal 52. When an OFF level switching signal is provided, the polarization switcher 50 rotates the polarization direction of the display light PL1 by 90° and emits display light PL2. The polarization direction of the display light PL2 is the Y direction. When an ON level switching signal is provided to the polarization switcher 50, the liquid crystal 52 is aligned perpendicular to the light-transmitting substrates 54a and 54b, and the polarization switcher 50 maintains the polarization direction of the display light PL1 in the X direction and emits display light PL2. The display light PL2 emitted from the polarization switcher 50 enters a polarizing bifocal lens 60. The switching signal will be described later.

[0065] The polarizing bifocal lens 60 of the three-dimensional image display device 10 is a lens whose focal length varies depending on the polarization direction (X and Y directions) of the display light PL2 emitted from the polarization switch 50. The polarizing bifocal lens 60 accordingly forms a first image and a second image on the first display surface 102 and the second display surface 104, serving as virtual images from the observer's perspective. The first display surface 102 and the second display surface 104 are imaginary display surfaces located at different positions in the depth direction (+Z direction) from the observer's perspective. In this embodiment, as... Figure 1 As shown, from the observer's perspective, the first display surface 102 and the second display surface 104 are positioned further away than the display unit 20. Furthermore, the first display surface 102 is closer to the observer's side (-Z side) than the second display surface 104.

[0066] An observer views a virtual image of a first image on a first display surface 102 and a virtual image of a second image on a second display surface 104, which are displayed sequentially according to time, and identifies the displayed target as located between the first display surface 102 and the second display surface 104. The position of the displayed target identified by the observer can be changed by adjusting the brightness (e.g., luminance) ratio of the first image to the second image. For example, when the luminance ratio of the first image to the second image is 1:1, the observer identifies the displayed target as located between the first display surface 102 and the second display surface 104.

[0067] In one example, the polarizing bifocal lens 60 is implemented as a liquid crystal lens. For example... Figure 4 As shown, the polarizing dual-focus lens (liquid crystal lens) 60 includes a first light-transmitting substrate 61, a second light-transmitting substrate 62, and a liquid crystal 64.

[0068] In one example, the first light-transmitting substrate 61 and the second light-transmitting substrate 62 are implemented as glass substrates. The first light-transmitting substrate 61 includes a resin Fresnel lens 66 on a first main surface 61a facing the second light-transmitting substrate 62. The first light-transmitting substrate 61 and the second light-transmitting substrate 62 are adhered to each other by a sealing material 67, thereby clamping the liquid crystal 64. In one example, the liquid crystal 64 is implemented as a nematic liquid crystal having positive refractive index anisotropy (Δn = ne - no > 0, where ne is the refractive index of the extraordinary ray and no is the refractive index of the ordinary ray). The liquid crystal 64 is aligned in the Y direction by an alignment film (not shown).

[0069] When the display light PL2 of the first image, polarized in the X direction, enters the polarizing bifocal lens 60, the nematic liquid crystal with positive refractive index anisotropy is aligned in the Y direction. Therefore, the focal length of the polarizing bifocal lens 60 for the display light PL2 is relatively long. Thus, the first image is formed on the first display surface 102. When the display light PL2 of the second image, polarized in the Y direction, enters the polarizing bifocal lens 60, the focal length of the polarizing bifocal lens 60 for the display light PL2 is relatively short. Therefore, the second image is formed on the second display surface 104.

[0070] controller

[0071] The controller 80 of the three-dimensional image display device 10 generates first image data representing a first image and second image data representing a second image based on three-dimensional object data representing a display target input from an external device. The three-dimensional object data includes coordinate data representing the position of the display target in the display space, color data representing the color of the display target, and brightness data representing the brightness of the display target.

[0072] The controller 80 provides the display unit 20 with a first image signal for displaying a first image on the liquid crystal display panel 22 (display unit 20), a second image signal for displaying a second image on the liquid crystal display panel 22 (display unit 20), and a minimum brightness signal, thereby controlling the display of the display unit 20. Furthermore, the controller 80 provides a switching signal to the polarization switch 50, thereby controlling the polarization switch 50. For example... Figure 5 As shown, the controller 80 includes a memory 82, an image generator 84, a display driver 86, and a polarization switching driver 88.

[0073] The memory 82 of the controller 80 stores programs that enable the image generator 84, the display driver 86, and the polarization switching driver 88 to operate. Furthermore, the memory 82 stores various types of data, such as display surface data, perspective data, the distance between the observer and the first display surface 102, the distance between the observer and the second display surface 104, and so on. Display surface data is coordinate data representing the positions of the first display surface 102 and the second display surface 104 in the display space (three-dimensional space) where the display target is displayed. Perspective data is coordinate data representing the position of the observer's angle in the display space.

[0074] The image generator 84 of the controller 80 calculates the brightness ratio of the first image to the second image based on three-dimensional object data, display surface data, and perspective data. Then, the image generator 84 generates first image data representing the first image and second image data representing the second image. The image generator 84 outputs the first image data and the second image data to the memory 82 (frame memory) to store the data. Hereinafter, the first image data and the second image data can be collectively referred to as "image data".

[0075] The display driver 86 of the controller 80 uses multiple frame periods FP to configure each of a first display period DP1 representing a first image and a second display period DP2 representing a second image. During the last frame period FP of the multiple frame periods FP included in the first display period DP1, the display driver 86 controls the brightness of pixel P of the liquid crystal display panel 22 to the minimum brightness Lmin of pixel P. During the last frame period FP of the multiple frame periods FP included in the second display period DP2, the display driver 86 controls the brightness of pixel P of the liquid crystal display panel 22 to the minimum brightness Lmin of pixel P. The minimum brightness Lmin of pixel P is pre-calculated and stored in the memory 82. Controlling the brightness of pixel P of the liquid crystal display panel 22 to the minimum brightness Lmin of pixel P is also represented as setting the grayscale of pixel P of the liquid crystal display panel 22 to zero grayscale.

[0076] In the following text, the first display period DP1 and the second display period DP2 can also be collectively referred to as the "display period". The minimum brightness Lmin of pixel P can also be referred to as the "minimum brightness Lmin".

[0077] The display driver 86 sequentially reads first image data and second image data from the memory 82, and generates a first image signal for displaying the first image and a second image signal for displaying the second image. Furthermore, the display driver 86 generates a minimum brightness signal to control the brightness of pixels P of the liquid crystal display panel 22 to a minimum brightness Lmin during the last frame period FP of the display period.

[0078] The display driver 86 provides the generated image signal and the generated minimum brightness signal to the liquid crystal display panel 22. Furthermore, the display driver 86 provides a synchronization signal to the polarization switching driver 88 to synchronize with the display period. The display control of the liquid crystal display panel 22 will be described later.

[0079] The polarization switching driver 88 of the controller 80 generates a switching signal based on a synchronization signal provided from the display driver 86. Furthermore, the polarization switching driver 88 provides the generated switching signal to the polarization switcher 50. In this embodiment, when the first image is displayed on the liquid crystal display panel 22, the polarization switching driver 88 sets the switching signal to the ON level and provides the switching signal to the polarization switcher 50.

[0080] Figure 6 The hardware configuration of controller 80 is shown. Controller 80 includes a central processing unit (CPU) 92, read-only memory (ROM) 94, random access memory (RAM) 96, and an input / output interface 98. The CPU 92, ROM 94, RAM 96, and input / output interface 98 are connected via a bus 99. The CPU 92 performs various types of processing. The ROM 94 stores programs and data. The RAM 96 stores data. The input / output interface 98 inputs and outputs signals between the CPU 92 and the display unit 20 (liquid crystal display panel 22), the zoom lens unit 40 (polarization switcher 50), and external devices. The CPU 92 executes programs stored in the ROM 94 to implement the functions of controller 80.

[0081] The display control of the liquid crystal display panel 22 is described. In this embodiment, for ease of understanding, as... Figure 7 As shown, the first image is described as having the same high brightness throughout the entire image (a grayscale image closer to white), and as... Figure 8 As shown, the second image is described as an image with the same low brightness across the entire image (a grayscale image closer to black). Furthermore, the display driver 86 provides signals to the liquid crystal display panel 22 at a period of 240Hz (frame duration FP: 4.2ms), and the liquid crystal display panel 22 performs line-by-line scanning (i.e., writing pixels P) at a period of 240Hz.

[0082] Figure 9 This diagram illustrates the display control of the liquid crystal display panel 22 and the control of the polarization switch 50. Figure 9In the first layer, signals (first image signal, second image signal, and minimum brightness signal) provided from the display driver 86 of the controller 80 to the liquid crystal display panel 22 are shown. Figure 9 The second layer shows the brightness of the pixels P in the first row of the liquid crystal display panel 22 during line progressive scan. Figure 9 The third layer shows the brightness of the pixel P in the middle row of the liquid crystal display panel 22 during line progressive scan. Figure 9 The fourth layer shows the brightness of the pixel P in the last row of the liquid crystal display panel 22 during line progressive scan. Figure 9 The fifth layer shows the switching signal provided from the polarization switching driver 88 of the controller 80 to the polarization switcher 50. Figure 9 The sixth layer shows the polarization direction of the display light PL2 emitted from the polarization switch 50.

[0083] like Figure 9 As shown, the display driver 86 of the controller 80 configures each of the first display period DP1 representing the first image and the second display period DP2 representing the second image to have two frame periods FP. Figure 9 As shown in the first layer, the display driver 86 provides an image signal (first image signal or second image signal) to the liquid crystal display panel 22 during the first frame period FP of the two frame periods FP. The display driver 86 provides a minimum brightness signal to the liquid crystal display panel 22 during the last frame period FP (second frame) of the two frame periods FP. Specifically, the display driver 86 sequentially provides the first image signal, the minimum brightness signal, the second image signal, and the minimum brightness signal to the liquid crystal display panel 22 at a period of 240Hz (frame period FP: 4.2ms).

[0084] In the following text, the brightness of pixel P in the first image signal is referred to as La, and the brightness of pixel P in the second image signal is referred to as Lb. The brightness La of pixel P in the first image signal corresponds to the brightness of pixel P in the liquid crystal display panel 22 displaying the first image, and also corresponds to a predetermined brightness. The brightness Lb of pixel P in the second image signal corresponds to the brightness of pixel P in the liquid crystal display panel 22 displaying the second image, and also corresponds to a predetermined brightness.

[0085] During the first display period DP1, which displays the first image, the average brightness of pixels P of the liquid crystal display panel 22 is referred to as DL1av. During the second display period DP2, which displays the second image, the average brightness of pixels P of the liquid crystal display panel 22 is referred to as DL2av. The average brightness of pixels P of the liquid crystal display panel 22 during the display period refers to the brightness obtained by averaging the brightness of pixels P of the liquid crystal display panel 22 during the display period. The average brightness DL1av and the average brightness DL2av can also be collectively referred to as the average brightness.

[0086] The liquid crystal display panel 22 sequentially performs line-by-line scanning (writing pixels P) at a period of 240Hz according to signals sequentially provided from the display driver 86. The liquid crystal display panel 22 sequentially displays a first image and a second image.

[0087] Specifically, such as Figure 9 As shown in the second layer, the brightness of pixel P in the first row of the liquid crystal display panel 22 during line progressive scanning is luminance La near the beginning of the first frame period FP of the first display period DP1, and is at its minimum luminance Lmin near the beginning of the last frame period FP of the first display period DP1. Then, the brightness of pixel P in the first row of the liquid crystal display panel 22 during line progressive scanning is luminance Lb near the beginning of the first frame period FP of the second display period DP2, and is at its minimum luminance Lmin near the beginning of the last frame period FP of the second display period DP2.

[0088] Then, in the first display period DP1, which includes two frame periods FP, the brightness of pixel P of the liquid crystal display panel 22 in the first row of line progressive scan is luminance La in a single frame period FP, and minimum luminance Lmin in another single frame period FP. Furthermore, in the second display period DP2, which includes both frame periods FP, the brightness of pixel P of the liquid crystal display panel 22 in the first row of line progressive scan is luminance Lb in a single frame period FP, and minimum luminance Lmin in another single frame period FP. Therefore, in the first row of line progressive scan, the average luminance DL1av of pixel P of the liquid crystal display panel 22 in the first display period DP1 is represented by DL1av = (La + Lmin) / 2. The average luminance DL2av of pixel P of the liquid crystal display panel 22 in the second display period DP2 is represented by DL2av = (Lb + Lmin) / 2.

[0089] like Figure 9 As shown in the third layer, the brightness of the pixel P in the middle row of the liquid crystal display panel 22 during line progressive scanning is La near the center of the first frame FP of the first display period DP1, and Lmin near the center of the last frame FP of the first display period DP1. Then, the brightness of the pixel P in the middle row is Lb near the center of the first frame FP of the second display period DP2, and Lmin near the center of the last frame FP of the second display period DP2.

[0090] Similar to the first row, even in the middle row of the liquid crystal display panel 22 during line-by-line scanning, the brightness of pixel P of the liquid crystal display panel 22 in the first display period DP1 is luminance La within a single frame period FP, and is at its minimum luminance Lmin within another single frame period FP. Furthermore, in the second display period DP2, the brightness of pixel P of the middle row of the liquid crystal display panel 22 is luminance Lb within a single frame period FP, and is at its minimum luminance Lmin within another single frame period FP. Therefore, the average luminance DL1av in the middle row is represented by DL1av = (La + Lmin) / 2. The average luminance DL2av is represented by DL2av = (Lb + Lmin) / 2.

[0091] like Figure 9 As shown in the fourth layer, the brightness of pixel P in the last row of the liquid crystal display panel 22 during line progressive scanning is La near the end of the first frame period FP of the first display period DP1, and Lmin near the end of the last frame period FP of the first display period DP1. Then, the brightness of pixel P in the last row is Lb near the end of the first frame period FP of the second display period DP2, and Lmin near the end of the last frame period FP of the second display period DP2.

[0092] Even in the last row of pixels P, the brightness of pixel P of the liquid crystal display panel 22 in the first display period DP1 is luminance La in a single frame period FP, and minimum luminance Lmin in another single frame period FP. Furthermore, in the second display period DP2, the brightness of pixel P in the last row of the liquid crystal display panel 22 is luminance Lb in a single frame period FP, and minimum luminance Lmin in another single frame period FP. The average luminance DL1av in the last row is represented by DL1av = (La + Lmin) / 2. The average luminance DL2av is represented by DL2av = (Lb + Lmin) / 2.

[0093] As described above, in this embodiment, the average brightness DL1av is represented by DL1av = (La + Lmin) / 2, and the average brightness DL2av is represented by DL2av = (Lb + Lmin) / 2, which is independent of the position of the liquid crystal display panel 22 in the progressive scan direction. That is, each display period (first display period DP1 and second display period DP2) includes multiple frame periods FP (two frame periods FP), and the brightness of pixel P of the liquid crystal display panel 22 is controlled to the minimum brightness Lmin in the last frame period FP (the second frame) of the multiple frame periods FP included in the display period. Therefore, the three-dimensional image display device 10 can control the average brightness (average brightness DL1av and average brightness DL2av) of pixel P of the liquid crystal display panel 22 within the display period, regardless of the position of the liquid crystal display panel 22 in the progressive scan direction.

[0094] In this embodiment, when the brightness of pixel P in the first image data is L1 and the brightness of pixel P in the second image data is L2, the display driver 86 sets the brightness La of pixel P in the first image signal and the brightness Lb of pixel P in the second image signal to satisfy the following formulas (1) and (2). Brightness La is the brightness of pixel P in the liquid crystal display panel 22 displaying the first image. Brightness Lb is the brightness of pixel P in the liquid crystal display panel 22 displaying the second image. Note that the brightness L1 of pixel P in the first image data and the brightness L2 of pixel P in the second image data are also represented as the brightness to be displayed by the liquid crystal display panel 22 or the target brightness of the liquid crystal display panel 22.

[0095]

[0096] In other words, the display driver 86 sets the brightness of pixel P (i.e., the brightness of pixel P in the liquid crystal display panel 22 displaying the image) to a brightness that matches the brightness of pixel P in the image data with the average brightness of pixel P in the liquid crystal display panel 22 during the display period. Due to this configuration, the three-dimensional image display device 10 enables the observer to identify the correct first image and the correct second image.

[0097] Meanwhile, if the display driver 86 configures each of the first display period DP1 representing the first image and the second display period DP2 representing the second image as a single frame period FP, as Figure 10 As shown, the average brightness (average brightness DL1av and average brightness DL2av) of pixel P of liquid crystal display panel 22 varies depending on the position of liquid crystal display panel 22 in the line-by-line direction during the display period. Hereinafter, this example is referred to as the comparative example. This allows an observer to identify the first image as... Figure 11 The image shown is used to identify the second image as follows. Figure 12The images shown. As a result, in the comparison example, the first and second images were not displayed correctly, and the observer identified a 3D image with a shape different from the 3D image to be displayed.

[0098] Refer again Figure 9 In the fifth layer, the polarization switching driver 88 of the controller 80 synchronously provides an ON-level switching signal to the polarization switcher 50 in sync with the first image signal provided by the display driver 86. Furthermore, the polarization switching driver 88 synchronously provides an OFF-level switching signal to the polarization switcher 50 in sync with the second image signal provided by the display driver 86. For example... Figure 9 As shown in the sixth layer, the polarization switch 50 switches the polarization direction of the display light PL2 according to the switching signal.

[0099] As described above, the display period includes multiple frame periods FP, and the brightness of pixel P of liquid crystal display panel 22 is controlled to the minimum brightness Lmin of pixel P in the last frame period FP among the multiple frame periods FP included in the display period. Therefore, the three-dimensional image display device 10 can control the average brightness of pixel P of liquid crystal display panel 22 within the display period, regardless of the position of liquid crystal display panel 22 in the line progressive direction. By setting the brightness of pixel P (that is, the brightness of pixel P of liquid crystal display panel 22 displaying the image) according to the pixel signal to a brightness that matches the brightness of pixel P in the image data with the average brightness of pixel P of liquid crystal display panel 22 within the display period, the three-dimensional image display device 10 enables the observer to identify the correct first image and the correct second image, and correctly displays the three-dimensional image.

[0100] Example 2

[0101] In Embodiment 1, the display period includes two frame periods FP, and the brightness of pixel P of liquid crystal display panel 22 is controlled to a minimum brightness Lmin in the last frame period FP of the two frame periods FP. It is sufficient for the display period to include multiple frame periods FP. The brightness of pixel P of liquid crystal display panel 22 can be controlled to a minimum brightness Lmin in all frame periods FP except the last frame period FP included in the multiple frame periods FP included in the display period.

[0102] Similar to the three-dimensional image display device 10 of Embodiment 1, the three-dimensional image display device 10 of this embodiment includes a display unit 20, a variable focus lens unit 40, and a controller 80. Except for the configuration of the display driver 86 of the controller 80, the configuration of the three-dimensional image display device 10 of this embodiment is similar to that of the three-dimensional image display device 10 of Embodiment 1. Therefore, the configuration of the display driver 86 of the controller 80 and the display control of the liquid crystal display panel 22 of this embodiment are described herein.

[0103] Similar to the display driver 86 in Embodiment 1, the display driver 86 in this embodiment is configured with a display period having multiple frame periods FP. Furthermore, the display driver 86 in this embodiment controls the brightness of pixel P of the liquid crystal display panel 22 to the minimum brightness Lmin of pixel P in the last frame period FP of the multiple frame periods FP included in the display period.

[0104] Specifically, such as Figure 13 As shown, in this embodiment, the display driver 86 configures each of the first display period DP1 representing the first image and the second display period DP2 representing the second image as three frame periods FP. Figure 13 As shown in the first layer, the display driver 86 of this embodiment provides an image signal (first image signal or second image signal) to the liquid crystal display panel 22 during the first frame period FP of the three frame periods FP. Furthermore, the display driver 86 of this embodiment provides a minimum brightness signal to the liquid crystal display panel 22 during the second frame period FP and the last frame period FP (third frame) of the three frame periods FP.

[0105] The liquid crystal display panel 22 sequentially performs line-by-line scanning (writing pixels P) according to signals sequentially provided from the display driver 86. The liquid crystal display panel 22 sequentially displays the first image and the second image.

[0106] Specifically, such as Figure 13 As shown in the second layer, in the first display period DP1, which includes three frame periods FP, the brightness of pixel P in the first row of the liquid crystal display panel 22 during line progressive scanning is luminance La within a single frame period FP, and is at its minimum luminance Lmin within the other two frame periods FP. Furthermore, in the second display period DP2, which also includes three frame periods FP, the brightness of pixel P in the first row of the liquid crystal display panel 22 during line progressive scanning is luminance Lb within a single frame period FP, and is at its minimum luminance Lmin within the other two frame periods FP. Therefore, in the first row of line progressive scanning, the average luminance DL1av of pixel P of the liquid crystal display panel 22 during the first display period DP1 is represented by DL1av = (La + 2 × Lmin) / 3, and the average luminance DL2av of pixel P of the liquid crystal display panel 22 during the second display period DP2 is represented by DL2av = (Lb + 2 × Lmin) / 3.

[0107] like Figure 13As shown in the second and third layers, during the first display period DP1, the brightness of pixels P in the middle and last rows of the liquid crystal display panel 22 is luminance La within a single frame period FP, and is at its minimum luminance Lmin within the other two frame periods FP. Furthermore, during the second display period DP2, the brightness of pixels P in the middle and last rows of the liquid crystal display panel 22 is luminance Lb within a single frame period FP, and is at its minimum luminance Lmin within the other two frame periods FP. Therefore, even in the middle and last rows of line progressive scanning, the average luminance DL1av is represented by DL1av = (La + 2 × Lmin) / 3, and the average luminance DL2av is represented by DL2av = (Lb + 2 × Lmin) / 3.

[0108] As described above, in this embodiment, the average brightness DL1av is represented by DL1av = (La + 2 × Lmin) / 3, and the average brightness DL2av is represented by DL2av = (Lb + 2 × Lmin) / 3, regardless of the position of the liquid crystal display panel 22 in the progressive scan direction. Similarly, in this embodiment, the display period is configured as multiple frame periods FP (three frame periods FP), and the brightness of pixel P is controlled to the minimum brightness Lmin in the last frame period FP (the third frame) included in the multiple frame periods FP included in the display period. Therefore, the three-dimensional image display device 10 can control the average brightness of pixel P within the display period, regardless of the position of the liquid crystal display panel 22 in the progressive scan direction.

[0109] Similarly, in this embodiment, the display driver 86 sets the brightness of pixel P according to the pixel signal to a brightness that matches the brightness of pixel P in the image data with the average brightness of pixel P in the liquid crystal display panel 22 during the display period. More specifically, the brightness La of pixel P in the first image signal and the brightness Lb of pixel P in the second image signal are set to satisfy the following formulas (3) and (4). Due to this configuration, the three-dimensional image display device 10 enables the observer to identify the correct first image and the correct second image.

[0110]

[0111] As described above, also in this embodiment, the three-dimensional image display device 10 can control the average brightness of pixels P of the liquid crystal display panel 22 during the display period, regardless of the position of the liquid crystal display panel 22 in the line-by-line direction. Furthermore, the three-dimensional image display device 10 according to this embodiment enables the observer to identify the correct first image and the correct second image, and correctly displays the three-dimensional image.

[0112] Example 3

[0113] In Embodiments 1 and 2, the display driver 86 controls the brightness of pixel P of liquid crystal display panel 22 to brightness La in one of the multiple frame periods FP included in the first display period DP1, and controls the brightness of pixel P of liquid crystal display panel 22 to brightness Lb in one of the multiple frame periods FP included in the second display period DP2. The display driver 86 can control the brightness of pixel P of liquid crystal display panel 22 to brightness La or brightness Lb in multiple frame periods FP.

[0114] Similar to the three-dimensional image display device 10 of Embodiment 1, the three-dimensional image display device 10 of this embodiment includes a display unit 20, a variable focus lens unit 40, and a controller 80. Except for the configuration of the display driver 86 of the controller 80, the configuration of the three-dimensional image display device 10 of this embodiment is similar to that of the three-dimensional image display device 10 of Embodiment 1. Therefore, the configuration of the display driver 86 of the controller 80 and the display control of the liquid crystal display panel 22 of this embodiment are described herein.

[0115] Specifically, such as Figure 14 As shown, in this embodiment, the display driver 86 configures each of the first display period DP1 representing the first image and the second display period DP2 representing the second image as three frame periods FP. Figure 14 As shown in the first layer, the display driver 86 of this embodiment provides image signals (first image signal or second image signal) to the liquid crystal display panel 22 during the first frame period FP and the second frame period FP of the three frame periods FP. In addition, the display driver 86 of this embodiment provides a minimum brightness signal to the liquid crystal display panel 22 during the last frame period FP (third frame) of the three frame periods FP.

[0116] The liquid crystal display panel 22 sequentially performs line-by-line scanning (writing pixels P) according to signals sequentially provided from the display driver 86. The liquid crystal display panel 22 sequentially displays the first image and the second image.

[0117] Specifically, such as Figure 14As shown in the second layer, in the first display period DP1, which includes three frame periods FP, the brightness of pixel P in the first row of the liquid crystal display panel 22 during line progressive scanning is brightness La within two frame periods FP, and minimum brightness Lmin within a single frame period FP. Furthermore, in the second display period DP2, which also includes three frame periods FP, the brightness of pixel P in the first row of the liquid crystal display panel 22 during line progressive scanning is brightness Lb within two frame periods FP, and minimum brightness Lmin within a single frame period FP. Therefore, in the first row of line progressive scanning, the average brightness DL1av of pixel P of the liquid crystal display panel 22 during the first display period DP1 is represented by DL1av = (2 × La + Lmin) / 3. Furthermore, in the second display period DP2, the average brightness DL2av of pixel P of the liquid crystal display panel 22 is represented by DL2av = (2 × Lb + Lmin) / 3.

[0118] like Figure 14 As shown in the second and third layers, in the first display period DP1, the brightness of pixels P in the middle and last rows of the liquid crystal display panel 22 is luminance La within two frame periods FP, and is the minimum brightness Lmin within a single frame period FP. Furthermore, in the second display period DP2, the brightness of pixels P in the middle and last rows of the liquid crystal display panel 22 is luminance Lb within two frame periods FP, and is the minimum brightness Lmin within a single frame period FP. Therefore, even in the middle and last rows of line progressive scanning, the average brightness DL1av is represented by DL1av = (La + 2 × Lmin) / 3, and the average brightness DL2av is represented by DL2av = (Lb + 2 × Lmin) / 3.

[0119] As described above, the brightness of pixel P is controlled to a minimum brightness Lmin in the last frame period FP among the multiple frame periods FP included in the display period. Therefore, the three-dimensional image display device 10 can control the average brightness of pixel P during the display period, regardless of the position of the liquid crystal display panel 22 in the line progressive direction.

[0120] Similarly, in this embodiment, the display driver 86 sets the brightness of pixel P by the pixel signal to a brightness that matches the brightness of pixel P in the image data with the average brightness of pixel P in the liquid crystal display panel 22 during the display period. More specifically, the brightness La of pixel P in the first image signal and the brightness Lb of pixel P in the second image signal are set to satisfy the following formulas (5) and (6). Due to this configuration, the three-dimensional image display device 10 enables the observer to identify the correct first image and the correct second image.

[0121]

[0122] Furthermore, in this embodiment, the brightness of pixel P of liquid crystal display panel 22 is controlled to brightness La or brightness Lb during multiple frame periods FP. Therefore, when the average brightness DL1av of embodiments 1 and 2, in which the brightness of pixel P of liquid crystal display panel 22 is controlled to brightness La during one frame period FP, is the same as the average brightness DL1av of this embodiment, the brightness (brightness La) of pixel P of liquid crystal display panel 22 according to this embodiment can be less than the brightness (brightness La) of pixel P of liquid crystal display panel 22 according to embodiments 1 and 2. Furthermore, when the average brightness DL2av of embodiments 1 and 2 is the same as the average brightness DL2av of this embodiment, the brightness (brightness Lb) of pixel P of liquid crystal display panel 22 according to this embodiment can be less than the brightness (brightness Lb) of pixel P of liquid crystal display panel 22 according to embodiments 1 and 2.

[0123] As described above, also in this embodiment, the three-dimensional image display device 10 can control the average brightness of pixels P of the liquid crystal display panel 22 during the display period, regardless of the position of the liquid crystal display panel 22 in the line-by-line direction. Furthermore, the three-dimensional image display device 10 according to this embodiment enables the observer to identify the correct first image and the correct second image, and correctly displays the three-dimensional image.

[0124] Example 4

[0125] In embodiments 1-3, the display unit 20 of the three-dimensional image display device 10 includes a liquid crystal display panel 22 and a light source 32. However, the configuration of the display unit 20 is not limited to this.

[0126] Similar to the three-dimensional image display device 10 of Embodiment 1, the three-dimensional image display device 10 of this embodiment includes a display unit 20, a variable focus lens unit 40, and a controller 80. Except for the configuration of the display unit 20, the configuration of the three-dimensional image display device 10 of this embodiment is similar to the configuration of the three-dimensional image display device 10 according to Embodiments 1-3.

[0127] like Figure 15 As shown, the display unit 20 according to this embodiment includes a self-emissive display panel 24 and a polarizer 34. The self-emissive display panel 24 is implemented as an organic electroluminescence (EL) display panel, which is an active matrix driven by line-by-line scanning of TFTs. The polarizer 34 emits light from the self-emissive display panel 24 as display light PL1. The polarization direction of the display light PL1 is a predetermined first direction.

[0128] like Figure 16As shown, the self-emissive display panel 24 includes pixels P arranged in a matrix, a gate driver 23G, and a data driver 23D. The configuration of the gate driver 23G and the data driver 23D in this embodiment is similar to the configuration of the gate driver 23G and the data driver 23D according to embodiments 1 to 3. The self-emissive display panel 24 includes a light-transmitting substrate (not shown), a self-emissive element (organic EL element), a TFT, and the like.

[0129] Similar to the liquid crystal display panel 22 in Embodiments 1 to 3, the display of the self-emissive display panel 24 is controlled. Like the three-dimensional image display device 10 in Embodiments 1 to 3, the three-dimensional image display device 10 of this embodiment can control the average brightness of the pixels P of the self-emissive display panel 24 during the display period, regardless of the position of the self-emissive display panel 24 in the line-by-line direction. Furthermore, the three-dimensional image display device 10 according to this embodiment enables the observer to identify the correct first image and the correct second image, and correctly displays the three-dimensional image.

[0130] Similar to Example 3, in the display control of the self-emissive display panel 24, when the display driver 86 controls the brightness of the pixel P of the self-emissive display panel 24 to brightness La or brightness Lb in multiple frame periods FP, brightness La and brightness Lb can be reduced, thereby extending the time until the brightness of the self-emissive display panel 24 is halved (brightness half-life Th). This effect is illustrated below using an organic EL display panel (organic EL element) as an example.

[0131] The current density J (mA / cm) of an organic EL device is known. 2 The relationship between the current density J and the luminance half-life LT50 (hours) of the organic EL element is expressed by the following formula (7). In the case where the organic EL element emits light continuously, the current density J and luminance L (cd / m²) of the organic EL element are known. 2 The luminance half-life LT50 and luminance L of the organic EL element are proportional. Therefore, the luminance half-life LT50 and luminance L of the organic EL element are expressed by the following formula (8), and as shown in Figure 8. Figure 17 As shown. N and b in formula (7) vary depending on the configuration, materials, etc. of the organic EL element. Typically, N is about 1.3 to 1.5 and b is about 5. In addition, A in formula (8) is a proportionality constant.

[0132] Log(LT50) = -N×Log(J) + b (7)

[0133] Log(LT50) = -N×Log(A×L) + b (8)

[0134] When the initial brightness of the organic EL element is 1, and the rate at which the brightness of the organic EL element decreases with the emission time of the organic EL element is defined as the brightness reduction rate DR, the length of the display period in the embodiment is defined as T, and the emission time of the organic EL element in the embodiment during the display period is defined as t. Furthermore, when the change in the brightness reduction rate DR based on formula (8) is linearly approximated, the brightness reduction rate DR can be expressed as follows: Figure 18 As shown. In Figure 18 In this context, the time when the brightness reduction rate DR is 0.5 corresponds to the brightness half-life Th ​​of the self-emissive display panel 24 (organic EL display panel) in the embodiment.

[0135] Furthermore, the average brightness (L×t / T) of pixel P during the display period is 1000 cd / cm². 2 And if the display time period length T is 10ms, such as Figure 19 The image shows an example illustrating the relationship between (i) the luminance L of the organic EL element and the emission time t of the organic EL element and (ii) the luminance half-life Th ​​of the self-emissive display panel 24. Figure 19 As shown, the luminance half-life Th ​​can be extended by increasing the light emission time t of the organic EL element and decreasing the luminance L of the organic EL element. That is, similar to the display control in Embodiment 3, the luminance half-life Th ​​(lifetime) of the self-emissive display panel 24 can be extended by controlling the luminance of the pixel P of the self-emissive display panel 24 to luminance La or luminance Lb and decreasing luminance La and Lb in multiple frame periods FP.

[0136] Modify Example

[0137] Although embodiments have been described above, they may be modified in various ways without departing from the spirit of this disclosure.

[0138] In Embodiment 1, the light source 32 of the display unit 20 is implemented as a direct-lit backlight, but the light source 32 is not limited to a direct-lit backlight. For example, the light source 32 of the display unit 20 can be implemented as an edge-lit backlight.

[0139] The polarization switch 50 is not limited to TN liquid crystal elements. The polarization switch 50 can be implemented as a lead lanthanum zirconate titanate (PLZT) element, an element using the Faraday effect, or something similar.

[0140] Furthermore, the variable focus lens unit 40 may not necessarily include the polarization switcher 50 and the polarization bifocal lens 60. The variable focus lens unit 40 can be implemented as a liquid lens configuration in which the focal length changes based on the applied voltage. For example, an electrowetting liquid lens can be used as the liquid lens.

[0141] In this embodiment, an example of a three-dimensional image display device 10 using a monochrome display panel (liquid crystal display panel 22 and self-emissive display panel 24) is described; however, a configuration using a color display panel instead of a monochrome display panel may be adopted. In this case, pixel P may be configured to be divided into sub-pixels by color, such as red (R), green (G), blue (B), or similar.

[0142] When the 3D image display device 10 is used in a head-mounted display, it can be configured to include a right-eye variable focus lens unit 40 and a left-eye variable focus lens unit 40. Alternatively, the head-mounted display can be configured to include a right-eye 3D image display device 10 and a left-eye 3D image display device 10.

[0143] In this embodiment, the controller 80 generates first image data and second image data based on 3D object data input from an external device. The controller 80 can be configured to receive the first and second image data from the external device. In this case, the controller 80 does not need to include an image generator 84.

[0144] In embodiment 2, the display driver 86 controls the brightness of pixel P to a minimum brightness Lmin in two consecutive frame periods FP. In embodiment 3, the display driver 88 controls the brightness of pixel P to either brightness La or brightness Lb in two consecutive frame periods FP. The display driver 86 only needs to control the brightness of pixel P to the minimum brightness Lmin in the last frame period FP of the plurality of frame periods FP included in the display period, and control the brightness of pixel P to either brightness La or brightness Lb in at least one frame period FP of the plurality of frame periods FP. For example, as Figure 20 As shown, the display driver 86 can control the brightness of pixel P in the order of brightness La, minimum brightness Lmin, brightness La, and minimum brightness Lmin in the four frame periods FP included in the first display period DP1. The display driver 86 can also control the brightness of pixel P in the order of brightness Lb, minimum brightness Lmin, brightness Lb, and minimum brightness Lmin in the four frame periods FP included in the second display period DP2.

[0145] When the number of frame periods FP included in the display period is M (where M is a natural number) and the brightness of pixel P is controlled to be La or Lb for K (where K is a natural number), it is sufficient for the display driver 86 to set the brightness La and brightness Lb to satisfy the following formulas (9) and (10).

[0146]

[0147] For illustrative purposes, some exemplary embodiments have been described above. Although specific embodiments have been given in the foregoing discussion, those skilled in the art will recognize that changes in form and detail may be made without departing from the broader spirit and scope of the invention. Therefore, the specification and drawings should be regarded as illustrative rather than restrictive. Consequently, this detailed description should not be regarded as limiting, and the scope of the invention is defined only by the included claims and all their equivalents.

Claims

1. A three-dimensional image display device comprising: a liquid crystal display panel for sequentially displaying a first image and a second image and emitting display light of the first image and display light of the second image; a variable focus lens unit for switching between a focal distance of the display light of the first image and a focal distance of the display light of the second image; and a controller for controlling display of the liquid crystal display panel, wherein the first image and the second image are two-dimensional images and are obtained by projecting a display target from an observer side onto a corresponding one of a first display surface and a second display surface, the first display surface and the second display surface being located at different positions in a depth direction from an angle of view of the observer, the liquid crystal display panel displays each of the first image and the second image by line-by-line scanning, the variable focus lens unit forms the first image and the second image as virtual images on the first display surface and the second display surface, respectively, and the controller: configures each of display periods in the display period, during which the first image or the second image is displayed in each display period, to have a plurality of frame periods, and controls luminance of a pixel of the liquid crystal display panel to be minimum luminance in a last frame period among the plurality of frame periods included in the display period.

2. A three-dimensional image display device comprising: a self-emissive display panel for sequentially displaying a first image and a second image and emitting display light of the first image and display light of the second image; a variable focus lens unit for switching between a focal distance of the display light of the first image and a focal distance of the display light of the second image; and a controller for controlling display of the self-emissive display panel, wherein the first image and the second image are two-dimensional images and are obtained by projecting a display target from an observer side onto a corresponding one of a first display surface and a second display surface, the first display surface and the second display surface being located at different positions in a depth direction from an angle of view of the observer, the self-emissive display panel displays each of the first image and the second image by line-by-line scanning, the variable focus lens unit forms the first image and the second image as virtual images on the first display surface and the second display surface, respectively, and the controller: configures a display period to have a plurality of frame periods, during which the first image or the second image is displayed in each display period, and controls luminance of a pixel of the self-emissive display panel to be minimum luminance in a last frame period among the plurality of frame periods included in the display period.

3. The three-dimensional image display device according to claim 1 or 2, wherein the controller matches luminance of the pixel in pixel data representing each of the first image and the second image with average luminance of the pixel within the display period.

4. The three-dimensional image display device according to claim 1 or 2, wherein ​ ​ The controller controls luminance of the pixel to the minimum luminance in the plurality of frame periods.

5. The three-dimensional image display device according to claim 1 or 2, wherein The controller controls luminance of the pixel to a predetermined luminance in the plurality of frame periods.

Images