Display device and display system

Abstract

A display device 1 comprises a display panel 10, a light source device 40 that emits first light of a first color, second light of a second color, and third light of a third color at the display panel 10 in the given order, a line-of-sight detection sensor 30 that detects the line of sight of a user, and a drive circuit 20. The drive circuit 20 displays a first color image G1 of the first color, a second color image G2 of the second color, and a third color image G3 of the third color in the given order, estimates a reference point of sight Pb for when the second color image G2 is displayed, a first point of sight Pg1 for when the first color image G1 is displayed, and a second point of sight Pg2 for when the third color image G3 is displayed on the basis of detection results from the line-of-sight detection sensor 30, and adjusts the positions of the first color image G1 and the third color image G3 relative to the second color image G2 on the basis of the positional relationship between the reference point of sight Pb, the first point of sight Pg1, and the second point of sight Pg2.

Description

Display device and display system

[0001] The present disclosure relates to a display device and a display system.

[0002] Patent Document 1 discloses an image display device (display device) that displays an image by a field sequential color method. The display device of Patent Document 1 controls the display order of a plurality of color field images for display by the field sequential color method based on the luminance distribution on the retina of an observer. Thereby, the occurrence of color breakup (so-called color breakup) in which field images are visually recognized as afterimages or the like is suppressed.

[0003] Japanese Patent Application Laid-Open No. 2010-276966

[0004] The above color breakup may occur, for example, when the observer's line of sight moves. In the display device, there is a desire to further suppress the occurrence of color breakup.

[0005] An object of the present disclosure is to suppress the occurrence of color breakup in a display device that displays an image by a field sequential color method.

[0006] The display device of this disclosure comprises a display panel having a display area, a light source device that emits a first light of a first color, a second light of a second color, and a third light of a third color in that order to the display panel within one frame, a gaze detection sensor that detects the user's gaze at a predetermined period, and a drive circuit that displays an image in the display area based on an image signal, wherein the drive circuit generates a first color image corresponding to the first color of the image, a second color image corresponding to the second color of the image, and a third color image corresponding to the third color of the image based on the image signal, displays the first color image when the first light is emitted, displays the second color image when the second light is emitted, and displays the third color image when the third light is emitted, and before displaying the first color image, the second color image, and the third color image in the display area, it displays a plurality of gaze detection results including the latest detection result of the gaze detection sensor Based on the detection result of the line detection sensor, a reference viewpoint, which is the user's viewpoint in the display area when the second color image is displayed, is estimated. A first viewpoint, which is the user's viewpoint in the display area when the first color image is displayed, is estimated based on the detection results of a plurality of gaze detection sensors, including the latest detection result of the gaze detection sensor since the time the reference viewpoint was estimated. Based on the positional relationship between the reference viewpoint and the first viewpoint, the position of the first color image relative to the second color image is adjusted. A second viewpoint, which is the user's viewpoint in the display area when the third color image is displayed, is estimated based on the detection results of a plurality of gaze detection sensors, including the latest detection result of the gaze detection sensor since the time the first viewpoint was estimated. Based on the positional relationship between the reference viewpoint and the second viewpoint, the position of the third color image relative to the second color image is adjusted.

[0007] The display device of this disclosure comprises a display panel having a display area, a light source device that emits a first light of a first color, a second light of a second color, and a third light of a third color in that order to the display panel within one frame, a gaze detection sensor that detects the user's gaze at a predetermined period, and a drive circuit that displays an image in the display area based on an image signal, wherein the drive circuit generates a first color image corresponding to the first color of the image, a second color image corresponding to the second color of the image, and a third color image corresponding to the third color of the image based on the image signal, displays the first color image when the first light is emitted, displays the second color image when the second light is emitted, and displays the third color image when the third light is emitted, and before displaying the first color image, the second color image, and the third color image in the display area, it detects the detection results of a plurality of gaze detection sensors Based on the results, a reference viewpoint, which is the user's viewpoint in the display area when the first color image is displayed, is estimated; a first viewpoint, which is the user's viewpoint in the display area when the second color image is displayed, is estimated based on the detection results of a plurality of gaze detection sensors, including the latest detection result of the gaze detection sensor since the time the reference viewpoint was estimated; the position of the second color image relative to the first color image is adjusted based on the positional relationship between the reference viewpoint and the first viewpoint; a second viewpoint, which is the user's viewpoint in the display area when the third color image is displayed, is estimated based on the detection results of a plurality of gaze detection sensors, including the latest detection result of the gaze detection sensor since the time the first viewpoint was estimated; and the position of the third color image relative to the second color image is adjusted based on the positional relationship between the first viewpoint and the second viewpoint.

[0008] Furthermore, the display system of this disclosure comprises the above-described display device and a lens, wherein the drive circuit corrects the first color image, the second color image, and the third color image based on either distortion aberration or chromatic aberration caused by the lens.

[0009] Figure 1 is a perspective view of a display device according to an embodiment of the present disclosure. Figure 2 is a cross-sectional view of the display device. Figure 3 is a diagram showing the circuit configuration of the display panel. Figure 4 is a cross-sectional view of the display panel. Figure 5 is a diagram showing an example of an input image. Figure 6 is a diagram showing a first color image corresponding to the input image shown in Figure 5. Figure 7 is a diagram showing a second color image corresponding to the input image shown in Figure 5. Figure 8 is a diagram showing a third color image corresponding to the input image shown in Figure 5. Figure 9 is a diagram showing the operation of the drive circuit and light source device when an image is displayed on the display panel. Figure 10 is a diagram showing an example of an image that the user sees when a color breakup occurs. Figure 11 is a flowchart executed by the image processing circuit. Figure 12 is a diagram showing an example of the position of a point of fixation. Figure 13A is a diagram showing the transition in the X direction for multiple points of fixation shown in Figure 12. Figure 13B is a diagram showing the transition in the Y direction for multiple points of fixation shown in Figure 12. Figure 14 is a diagram showing a first color image whose position has been adjusted relative to the second color image. Figure 15 is a diagram showing a second color image whose position has been adjusted. Figure 16 shows a third color image whose position has been adjusted relative to the second color image. Figure 17 is a flowchart of the image processing circuit of a display device according to a modified embodiment of the present disclosure. Figure 18 is a perspective view of a display system according to an embodiment of the present disclosure. Figure 19 is a schematic diagram showing the configuration of the display system. Figure 20 is a block diagram of the display system. Figure 21 is a flowchart of the image processing circuit of a display device provided in the display system when displaying a color image.

[0010] The embodiments of this disclosure will be described below with reference to the drawings. This disclosure is not limited to the embodiments described below. Furthermore, the components described below include those that are readily conceivable to those skilled in the art, and those that are substantially the same. In addition, the components described below can be combined as appropriate.

[0011] Furthermore, the disclosure is merely an example, and any modifications that a person skilled in the art could easily conceive of while maintaining the spirit of this disclosure are naturally included within the scope of this disclosure. In addition, drawings may schematically represent the width, thickness, shape, etc. of each part in order to clarify the explanation, but these are merely examples and do not limit the interpretation of this disclosure. In addition, in this specification and each drawing, elements similar to those described above in previously shown drawings are denoted by the same reference numerals, and detailed explanations may be omitted as appropriate.

[0012] The X and Y directions shown in the drawings correspond to directions parallel to the surface of the substrate included in the display device 1. The +X and -X sides in the X direction, and the +Y and -Y sides in the Y direction correspond to the sides of the display device 1. The Z direction corresponds to the thickness direction of the display device 1, the +Z side in the Z direction corresponds to the front side where the image is displayed in the display device 1, and the -Z side in the Z direction corresponds to the back side of the display device 1. In this specification, "plan view" means viewing the display device 1 along the Z direction from the +Z side to the -Z side. Furthermore, the X, Y, and Z directions are examples, and this disclosure is not limited to these directions.

[0013] <Display Device 1> Figure 1 is a perspective view of a display device 1 according to an embodiment of the present disclosure. Figure 2 is a cross-sectional view of the display device 1. Figure 3 is a diagram showing the circuit configuration of the display panel 10.

[0014] The display device 1 displays an image based on an image signal output from an external device (not shown) connected by wire or wireless. The display device 1 comprises a display panel 10, a drive circuit 20, a gaze detection sensor 30, and a light source device 40.

[0015] The display panel 10 is a transmissive liquid crystal display. The display panel 10 may also be, for example, a projection display using a reflective liquid crystal and a digital mirror device (DMD), an organic EL display, or an inorganic EL display. The display panel 10 is a rectangular plate in plan view and has a display area DA on its front surface for displaying images. The display area DA is rectangular in plan view and has a reference point Ds at its center. The reference point Ds may be located elsewhere, for example, at the periphery of the display area DA. The display panel 10 has a plurality of pixels P arranged in a matrix along the X and Y directions within the display area DA.

[0016] As shown in Figure 3, the display panel 10 includes a switching element SW, a pixel electrode PE, a common electrode CE, a liquid crystal capacitance LC, and a retaining capacitance CS for each of the multiple pixels P. Furthermore, an IC chip Ti is placed on the first substrate 11 of the display panel 10 shown in Figure 1 (details to be described later). A control board CPC is electrically connected to the first substrate 11 via a flexible printed circuit board (FPC). A drive circuit 20 is located on both the IC chip Ti and the control board CPC.

[0017] The drive circuit 20 displays an image in the display area DA based on an image signal transmitted from an external device. As shown in Figure 3, the drive circuit 20 includes an image processing circuit 21, a signal output circuit 22, and a scanning circuit 23. The image processing circuit 21 is located on the control board CPC (Figure 1). The signal output circuit 22 and the scanning circuit 23 are located on the IC chip Ti (Figure 1) of the first substrate 11.

[0018] The image processing circuit 21 generates multiple pixel signals, described later, based on the image signal, and outputs the generated multiple pixel signals to the signal output circuit 22. The image processing circuit 21 also outputs a clock signal to the signal output circuit 22 and the scanning circuit 23 to synchronize the operation of the signal output circuit 22 and the operation of the scanning circuit 23.

[0019] The signal output circuit 22 outputs each of the multiple pixel signals to the corresponding pixel P. As shown in Figure 3, the signal output circuit 22 and the multiple pixels P are electrically connected via multiple signal lines Lb extending along the Y direction.

[0020] The scanning circuit 23 scans multiple pixels P in synchronization with the output of pixel signals from the signal output circuit 22. The scanning circuit 23 and the multiple pixels P are electrically connected via multiple scan lines Lc extending along the X direction.

[0021] A switching element SW is composed of, for example, a thin-film transistor (TFT). In a switching element SW, the source electrode and the signal line Lb are electrically connected, and the gate electrode and the scan line Lc are electrically connected.

[0022] The pixel electrode PE is connected to the drain electrode of the switching element SW. Multiple common electrodes CE are arranged to correspond to multiple scan lines Lc. Both the pixel electrode PE and the common electrode CE are translucent.

[0023] The liquid crystal capacitance LC is the capacitance component of the liquid crystal material in the liquid crystal layer 13, which will be described later, located between the pixel electrode PE and the common electrode CE. The retained capacitance CS is located between an electrode at the same potential as the common electrode CE and an electrode at the same potential as the pixel electrode PE.

[0024] Figure 4 is a cross-sectional view of the display panel 10. The display panel 10 further comprises a first substrate 11, a second substrate 12, and a liquid crystal layer 13. The first substrate 11, the liquid crystal layer 13, and the second substrate 12 are all translucent and are arranged in this order from the -Z side to the +Z side along the Z direction. The first substrate 11 and the second substrate 12 are rectangular in plan view and are made of resin such as polyethylene terephthalate or glass.

[0025] A common electrode CE is placed on the front surface of the first substrate 11. An insulating layer IL is placed in front of the common electrode CE, and further in front of the insulating layer IL, a pixel electrode PE and a first alignment film AL1 are placed.

[0026] The pixel electrode PE is positioned between the insulating layer IL and the first alignment film AL1. Thus, the common electrode CE and the pixel electrode PE are positioned on the first substrate 11. In other words, the display panel 10 is a transverse electric field type liquid crystal display.

[0027] The second substrate 12 is located on the front side of the first substrate 11. A second orientation film AL2 is arranged on the back side of the second substrate 12. The orientation directions of the first orientation film AL1 and the second orientation film AL2 are parallel to each other. However, the orientation directions of the first orientation film AL1 and the second orientation film AL2 may be orthogonal to each other. Note that the signal line Lb and scan line Lc are not shown in Figure 4. The signal line Lb and scan line Lc are located on the front side of the first substrate 11.

[0028] The liquid crystal layer 13 is composed of multiple liquid crystal molecules LM. The liquid crystal layer 13 is located between the first substrate 11 and the second substrate 12 and overlaps with the display area DA in a plan view. Specifically, the liquid crystal layer 13 is located between the first alignment film AL1 and the second alignment film AL2. The orientation of the liquid crystal molecules LM is regulated by the first alignment film AL1 and the second alignment film AL2.

[0029] The display panel 10 further includes a first polarizing plate 14 positioned on the back of the first substrate 11, and a second polarizing plate 15 positioned on the front of the second substrate 12. The first polarizing plate 14 has a transmission axis perpendicular to the Z direction. The second polarizing plate 15 has a transmission axis perpendicular to the transmission axis of the first polarizing plate 14 and the Z direction. The front of the second polarizing plate 15 corresponds to the front of the display panel 10. The back of the first polarizing plate 14 corresponds to the back of the display panel 10.

[0030] The gaze detection sensor 30 shown in Figure 1 is located on the display panel 10. The gaze detection sensor 30 detects the user's gaze using eye-tracking technology. The detection result from the gaze detection sensor 30 is output to the image processing circuit 21. The gaze detection sensor 30 captures the user's eye movements at a predetermined frequency (e.g., 120 Hz). The captured data is output to the image processing circuit 21. The image processing circuit 21 detects the direction of the gaze at a predetermined period (e.g., 8.33 ms) and records the detection result as time-series data. The number of data points recorded in the image processing circuit 21 is the number of points for a predetermined time (e.g., 1 second) (e.g., 120 points). This data is overwritten starting with the oldest data each time data captured by the gaze detection sensor 30 is output to the image processing circuit 21. Therefore, the image processing circuit 21 always holds the latest number of data points for a predetermined time.

[0031] The light source device 40 shown in Figures 1 and 2 emits light toward the display panel 10. The light source device 40 comprises a light guide plate 41, a plurality of first light emitters 42a, a plurality of second light emitters 42b, a plurality of third light emitters 42c, a prism sheet 43, and a diffusion sheet 44. Hereafter, when the first light emitters 42a, the second light emitters 42b, and the third light emitters 42c are described without distinction, they may simply be referred to as "light emitters 42".

[0032] In the light source device 40, the light guide plate 41, prism sheet 43, and diffusion sheet 44 are arranged in this order along the Z direction from the -Z side to the +Z side. The light emitter 42 is positioned to the side of the light guide plate 41.

[0033] The light guide plate 41 is rectangular in plan view. As will be described later, light is emitted from the front surface 41a of the light guide plate 41. A reflective sheet (not shown) is placed on the back surface 41b of the light guide plate 41.

[0034] Multiple light emitters 42 emit light toward the side surface 41c of the light guide plate 41. The light emitters 42 are, for example, LEDs (Light Emitting Diodes). The light emitted by the light emitters 42 corresponds to the light from the light source device 40. The first light emitter 42a emits first light of the first color. The second light emitter 42b emits second light of the second color. The third light emitter 42c emits third light of the third color. The first, second, and third colors are distinct from each other, with the first color being red, the second color being green, and the third color being blue. It goes without saying that the first, second, and third colors are not limited to the above colors.

[0035] Multiple light-emitting elements 42 are arranged facing the side surface 41c of the light guide plate 41, which is perpendicular to the X direction. Multiple light-emitting elements 42 are arranged along the Y direction. Specifically, one first light-emitting element 42a, one second light-emitting element 42b, and one third light-emitting element 42c arranged along the Y direction constitute one light-emitting element set CL, and multiple light-emitting element sets CL are arranged along the Y direction.

[0036] Light emitted from the light-emitting element 42 enters the light guide plate 41 from the side 41c, is reflected inside the light guide plate 41 and by the reflective sheet, and is emitted from the front surface 41a.

[0037] The prism sheet 43 refracts the light emitted from the light guide plate 41 in a direction along the Z-axis. The prism sheet 43 has a plurality of prisms 43a with a triangular cross-section extending along the Y-axis, facing the light guide plate 41. The plurality of prisms 43a may also be arranged facing the diffusion sheet 44. The light emitted from the prism sheet 43 is incident on the diffusion sheet 44.

[0038] The diffusion sheet 44 diffuses the light emitted from the prism sheet 43. The light emitted from the diffusion sheet 44 is incident on the display panel 10. The diffusion of light by the diffusion sheet 44 increases the viewing angle of the display panel 10.

[0039] Next, the basic operation of the display device 1 when the display panel 10 displays an image will be described. The display panel 10 displays an image in the display area DA using a field sequential color method.

[0040] When the image processing circuit 21 acquires an image signal from an external device, it generates a color image by separating the image contained in the image signal (hereinafter sometimes referred to as the input image Gi) into colors emitted by the light emitter 42.

[0041] Specifically, the image processing circuit 21 generates a color image by color-separating the acquired input image Gi according to the colors of light emitted by the light emitter 42. In other words, the image processing circuit 21 generates a first-color image G1 corresponding to the first color (red) of the input image Gi, a second-color image G2 corresponding to the second color (green) of the input image Gi, and a third-color image G3 corresponding to the third color (blue) of the input image Gi. When explaining the first-color image G1, second-color image G2, and third-color image G3 without distinguishing between them, they are simply referred to as "color image G".

[0042] Figure 5 shows an example of an input image Gi. The input image Gi shown in Figure 5 is rectangular and has an input image point Di at its center. The image processing circuit 21 superimposes the reference point Ds (see Figure 1) of the display area DA with the input image point Di. In this embodiment, when the input image point Di and the reference point Ds coincide, the periphery of the input image Gi overlaps with the periphery of the display area DA.

[0043] The input image Gi has a circular line drawing portion Gia centered on the input image point Di. The input image Gi also has an inner region Gib inside the line drawing portion Gia and an outer region Gic outside the line drawing portion Gia. In the input image Gi, the color of the line drawing portion Gia is black, the color of the inner region Gib is white, and the color of the outer region Gic is gray. In this case, the gradation of the pixel P corresponding to the line drawing portion Gia is the minimum, the gradation of the pixel P corresponding to the inner region Gib is the maximum, and the gradation of the pixel P corresponding to the outer region Gic is smaller than the gradation corresponding to the inner region Gib.

[0044] When the image processing circuit 21 acquires the input image Gi shown in FIG. 5, it generates the following color image G.

[0045] FIG. 6 is a diagram showing a first color image G1 corresponding to the input image Gi shown in FIG. 5. The first color image G1 is rectangular in shape with the same size as the input image Gi and centered on the first image point Dg1 corresponding to the input image point Di and the reference point Ds. The first color image G1 corresponds to the first color (red) of the input image Gi and has a first line drawing portion G1a, a first inner region G1b, and a first outer region G1c corresponding to the line drawing portion Gia, the inner region Gib, and the outer region Gic of the input image Gi, respectively. The gradation of the pixel P corresponding to the first line drawing portion G1a is the minimum, the gradation of the pixel P corresponding to the first inner region G1b is the maximum, and the gradation of the pixel P corresponding to the first outer region G1c is smaller than the gradation corresponding to the first inner region G1b.

[0046] FIG. 7 is a diagram showing a second color image G2 corresponding to the input image Gi shown in FIG. 5. The second color image G2 is rectangular in shape with the same size as the input image Gi and centered on the second image point Dg2 corresponding to the input image point Di and the reference point Ds. The second color image G2 corresponds to the second color (green) of the input image Gi and has a second line drawing portion G2a, a second inner region G2b, and a second outer region G2c corresponding to the line drawing portion Gia, the inner region Gib, and the outer region Gic of the input image Gi, respectively. The gradation of the pixel P corresponding to the second line drawing portion G2a is the minimum, the gradation of the pixel P corresponding to the second inner region G2b is the maximum, and the gradation of the pixel P corresponding to the second outer region G2c is smaller than the gradation corresponding to the second inner region G2b.

[0047] FIG. 8 is a diagram showing a third color image G3 corresponding to the input image Gi shown in FIG. 5. The third color image G3 has the same rectangular shape as the input image Gi and has, as its center, a third image point Dg3 corresponding to the input image point Di and the reference point Ds. The third color image G3 corresponds to the third color (blue) of the input image Gi and has a third line drawing portion G3a, a third inner region G3b, and a third outer region G3c corresponding to the line drawing portion Gia, the inner region Gib, and the outer region Gic of the input image Gi, respectively. The gradation of the pixel P corresponding to the third line drawing portion G3a is the minimum, the gradation of the pixel P corresponding to the third inner region G3b is the maximum, and the gradation of the pixel P corresponding to the third outer region G3c is smaller than the gradation corresponding to the third inner region G3b.

[0048] The gradations of the pixels P corresponding to the first outer region G1c shown in FIG. 6, the gradations of the pixels P corresponding to the second outer region G2c shown in FIG. 7, and the gradations of the pixels P corresponding to the third outer region G3c shown in FIG. 8 are equal to each other.

[0049] Further, the image processing circuit 21 generates a pixel signal indicating the gradation of the pixel P. Information on the gradation of the pixel P corresponding to the input image Gi is included in the image signal. The image processing circuit 21 generates a first pixel signal indicating the gradation of the pixel P corresponding to the first color image G1, a second pixel signal indicating the gradation of the pixel P corresponding to the second color image G2, and a third pixel signal indicating the gradation of the pixel P corresponding to the third color image G3 for each of the plurality of pixels P. When the first pixel signal, the second pixel signal, and the third pixel signal are described without distinction, they are simply referred to as "pixel signals".

[0050] FIG. 9 is a diagram showing the operations of the drive circuit 20 and the light source device 40 when an image is displayed on the display panel 10. In FIG. 9, the horizontal axis represents time, and the vertical axis represents the Y-direction positions of the plurality of pixels P in the display area DA. FIG. 9 shows the operations of the drive circuit 20 and the light source device 40 per one frame F. The frame F has, in this order, a first sub-frame SF1, a second sub-frame SF2, and a third sub-frame SF3.

[0051] In the first subframe SF1, the first color image G1 corresponding to the first color (red) is displayed. Specifically, in the first scanning period TS1, the scanning circuit 23 scans multiple pixels P. The scanning circuit 23 scans sequentially along the Y direction from the pixel P furthest to the +Y side to the pixel P furthest to the -Y side. In the first scanning period TS1, the solid line moving from the +Y side to the -Y side as time progresses indicates that the scanning circuit 23 is scanning multiple pixels P (the same applies to the second scanning period TS2 and the third scanning period TS3, which will be described later). The signal output circuit 22 outputs a first pixel signal corresponding to the multiple pixels P. As a result, the voltage of the pixel P becomes the voltage corresponding to the first pixel signal, and an electric field corresponding to the first pixel signal is generated in the liquid crystal layer 13, causing the orientation of the liquid crystal molecules LM to change. As a result, the transmittance of the liquid crystal layer 13 is adjusted for each pixel P according to the gradation of the pixel P indicated by the first pixel signal. The voltage applied to pixel P is held until it is updated by the second pixel signal in the second subframe SF2, as will be described later.

[0052] Next, during the first light emission period TL1, the light source device 40 causes the first light emitter 42a to emit light. The first light from the first light emitter 42a is incident on the display panel 10 and emitted from the display area DA with an intensity corresponding to the light transmittance of the liquid crystal layer 13. As a result, the first color image G1 is displayed in the display area DA. In other words, the first color image G1 is displayed during the first light emission period TL1.

[0053] In the second subframe SF2, a second-color image G2 corresponding to the second color (green) is displayed. Specifically, during the second scanning period TS2, the scanning circuit 23 scans multiple pixels P. The signal output circuit 22 outputs a second pixel signal corresponding to the multiple pixels P. As a result, the voltage of the pixels P is updated to a voltage corresponding to the second pixel signal, and an electric field corresponding to the second pixel signal is generated in the liquid crystal layer 13, causing the orientation of the liquid crystal molecules LM to change. As a result, the transmittance of the liquid crystal layer 13 is adjusted for each pixel P according to the gradation of the pixel P indicated by the second pixel signal. The voltage applied to the pixels P is held until it is updated by the third pixel signal in the third subframe SF3, as will be described later.

[0054] Next, during the second light emission period TL2, the light source device 40 causes the second light emitter 42b to emit light. The second light from the second light emitter 42b is incident on the display panel 10 and emitted from the display area DA with an intensity corresponding to the light transmittance of the liquid crystal layer 13. As a result, the second color image G2 is displayed in the display area DA. In other words, the second color image G2 is displayed during the second light emission period TL2.

[0055] In the third subframe SF3, a third-color image G3 corresponding to the third color (blue) is displayed. Specifically, during the third scanning period TS3, the scanning circuit 23 scans multiple pixels P. The signal output circuit 22 outputs a third pixel signal corresponding to the multiple pixels P. As a result, the voltage of the pixels P is updated to a voltage corresponding to the third pixel signal, and an electric field corresponding to the third pixel signal is generated in the liquid crystal layer 13, causing the orientation of the liquid crystal molecules LM to change. As a result, the transmittance of the liquid crystal layer 13 is adjusted for each pixel P according to the gradation of the pixel P indicated by the third pixel signal. The voltage applied to the pixels P is held until it is updated by the first pixel signal in the first subframe SF1 of the next frame F.

[0056] Next, during the third light emission period TL3, the light source device 40 causes the third light emitter 42c to emit light. The third light from the third light emitter 42c is incident on the display panel 10 and emitted from the display area DA with an intensity corresponding to the light transmittance of the liquid crystal layer 13. As a result, the third color image G3 is displayed in the display area DA. In other words, the third color image G3 is displayed during the third light emission period TL3.

[0057] The duration of one frame F is defined as the time it takes for the combined light of the first, second, and third light emitted from the display area DA in one frame F to be perceived by the human eye. In other words, the human eye perceives the light of the combined color and gradation of the first, second, and third colors. Therefore, when the first color image G1, second color image G2, and third color image G3 are displayed in this order as described above, the user sees an image that is a combination of the first color image G1, second color image G2, and third color image G3. In other words, the image seen by the user corresponds to the input image Gi.

[0058] In such a display device 1, the following color breakup may occur.

[0059] For example, when the image shown in Figure 5 is displayed in the display area DA, assume that the position of the user's viewpoint (hereinafter sometimes referred to as the point of focus) in the display area DA moves in the order of the first position Po1, the second position Po2, and the third position Po3 shown in Figure 5. The first position Po1 is located -X along the X direction from the second position Po2. The second position Po2 is assumed to coincide with the input image point Di. The third position Po3 is located +X along the X direction from the second position Po2. Hereinafter, the direction from the first position Po1 to the second position Po2 will be referred to as the first movement direction Wo1, the direction from the second position Po2 to the third position Po3 will be referred to as the second movement direction Wo2, the distance between the first position Po1 and the second position Po2 will be referred to as the first movement distance Lo1, and the distance between the second position Po2 and the third position Po3 will be referred to as the second movement distance Lo2.

[0060] Furthermore, suppose that when the first color image G1 is displayed, the point of gaze is at the first position Po1; when the second color image G2 is displayed, the point of gaze is at the second position Po2; and when the third color image G3 is displayed, the point of gaze is at the third position Po3 on the input image Gi. In this case, color breakup occurs, in which the user perceives afterimages of the first color image G1, the second color image G2, and the third color image G3.

[0061] Figure 10 shows an example of an image that a user might see when a color breakup occurs. In Figure 10, the first color image G1 is shown by a dashed line, the second color image G2 is shown by a solid line, and the third color image G3 is shown by a double-dotted line.

[0062] As described above, when the point of focus shifts, the position of the color image G is recognized as the position of the second image point Dg2, which corresponds to the average position of the eye movement during display. Specifically, the first color image G1 is perceived by the user with the first image point Dg1 shifted relative to the second image point Dg2 of the second color image G2 along the first displacement direction Wz1, which is in the same direction as the first movement direction Wo1 shown in Figure 5. Similarly, the third color image G3 is perceived by the user with the third image point Dg3 shifted relative to the second image point Dg2 of the second color image G2 along the second displacement direction Wz2, which is in the opposite direction to the second movement direction Wo2 shown in Figure 5.

[0063] The first shift amount Lz1, which is the amount of shift between the first color image G1 and the second color image G2 as seen by the user, is approximately equal to the first movement distance Lo1 shown in Figure 5, and the second shift amount Lz2, which is the amount of shift between the second color image G2 and the third color image G3 as seen by the user, is approximately equal to the second movement distance Lo2 shown in Figure 5. Furthermore, the second color image G2 is seen by the user when the second image point Dg2 coincides with the reference point Ds of the display area DA.

[0064] In this case, in areas where the three inner regions G1b, G2b, and G3b of the first color image G1, second color image G2, and third color image G3 do not overlap, the user will perceive colors other than white and gray that the input image Gi possesses (for example, the first color, second color, and third color, as well as colors obtained by combining two of the first, second, and third colors).

[0065] Therefore, the drive circuit 20 suppresses the occurrence of the above-mentioned color breakup. The operation of the drive circuit 20 that suppresses the occurrence of color breakup will be described below in the case where, in the current frame F, the drive circuit 20 acquires the input image Gi shown in Figure 5 above, and when the first color image G1, the second color image G2, and the third color image G3 are displayed, the position of the point of focus moves in the order of first position Po1, second position Po2, and third position Po3.

[0066] Figure 11 is a flowchart executed by the image processing circuit 21. The image processing circuit 21 repeatedly executes the flowchart in Figure 11 for each frame F.

[0067] In step S1, the image processing circuit 21 estimates the reference viewpoint Pb. The reference viewpoint Pb is the user's viewpoint (point of focus) in the display area DA when the image processing circuit 21 displays the second-color image G2 (specifically, at the start of the second emission period TL2 shown in Figure 9).

[0068] As described above, the image processing circuit 21 constantly holds a predetermined number of the latest data points (detection results from the gaze detection sensor 30) for a set period of time. The data held by the image processing circuit 21 corresponds to the point of gaze.

[0069] Figure 12 shows an example of the position of the point of focus Pv. Figure 12 shows the positions of multiple points of focus Pv from a predetermined time prior to the current time (time t0) to the current time, and an arrow A passing through the multiple points of focus Pv. Arrow A indicates the trajectory of the point of focus Pv. The position of the point of focus Pv at the current time corresponds to the most recent point of focus Pv. It goes without saying that the position of the point of focus Pv is not limited to the positions shown in Figure 12.

[0070] The image processing circuit 21 estimates the reference viewpoint Pb using multiple gaze points Pv up to the present time shown in Figure 12 (specifically, multiple gaze points Pv within a predetermined time period, including the most recent gaze point Pv).

[0071] Figure 13A shows the transition in the X direction for multiple gaze points Pv shown in Figure 12. In Figure 13A, the horizontal axis is time, and the vertical axis is the X coordinate of the display area DA. Figure 13B shows the transition in the Y direction for multiple gaze points Pv shown in Figure 12. In Figure 13B, the horizontal axis is time, and the vertical axis is the Y coordinate of the display area DA.

[0072] The image processing circuit 21 generates approximation curves Cx and Cy using the positions of multiple points of interest Pv for the transition of the point of interest Pv in the X direction shown in Figure 13A and the transition of the point of interest Pv in the Y direction shown in Figure 13B. In Figures 13A and 13B, the approximation curves Cx and Cy up to the present time (time t0) are shown as solid lines, and the approximation curves Cx and Cy after the present time are shown as dashed lines.

[0073] The image processing circuit 21 identifies (estimates) the reference viewpoint Pb as a point on the dashed approximation curve Cx, Cy corresponding to the time tb when the second color image G2 is displayed (corresponding to the start of the second light emission period TL2 shown in Figure 9). The image processing circuit 21 then obtains the X and Y coordinates of the reference viewpoint Pb.

[0074] Figure 12 shows the reference viewpoint Pb estimated as described above. The reference viewpoint Pb corresponds to the second position Po2 shown in Figure 5 and is in close agreement with the second position Po2.

[0075] Thus, before displaying the first color image G1, the second color image G2, and the third color image G3 in the display area DA, the image processing circuit 21 estimates the reference viewpoint Pb, which is the user's viewpoint in the display area DA when displaying the second color image G2, based on the detection results of the multiple gaze detection sensors 30.

[0076] In step S2 shown in Figure 11, the image processing circuit 21 acquires the input image Gi. Subsequently, in step S3, the image processing circuit 21 generates a color image G by color-separating the input image Gi as described above.

[0077] Furthermore, in step S4, the image processing circuit 21 estimates the first viewpoint Pg1. The first viewpoint Pg1 is the user's viewpoint (point of focus) in the display area DA when the image processing circuit 21 displays the first color image G1 (specifically, at the start of the first light emission period TL1 shown in Figure 9).

[0078] The image processing circuit 21 estimates the first viewpoint Pg1 based on the detection results of multiple gaze detection sensors 30, including the detection result of the most recent gaze detection sensor 30, from the time the reference viewpoint Pb was estimated onward. Specifically, the image processing circuit 21 estimates the first viewpoint Pg1 using multiple gaze points Pv within a predetermined time period, including the most recent gaze point Pv, in the same manner as when the reference viewpoint Pb was estimated.

[0079] The detection result of the gaze detection sensor 30 at the time the image processing circuit 21 estimates the first viewpoint Pg1 is updated to the latest detection result compared to the detection result of the gaze detection sensor 30 at the time the image processing circuit 21 estimates the reference viewpoint Pb in step S1. Note that the detection result of the gaze detection sensor 30 at the time the image processing circuit 21 estimates the first viewpoint Pg1 may be the same as the detection result of the gaze detection sensor 30 at the time the image processing circuit 21 estimates the reference viewpoint Pb in step S1.

[0080] The image processing circuit 21, similar to step S1, generates approximation curves Cx and Cy using the positions of multiple gaze points Pv, and identifies (estimates) the point on the approximation curves Cx and Cy corresponding to the time when the first color image G1 is displayed (corresponding to the start of the first emission period TL1 shown in Figure 9) as the first viewpoint Pg1. The image processing circuit 21 obtains the X and Y coordinates of the first viewpoint Pg1.

[0081] Figure 12 shows the first viewpoint Pg1. The first viewpoint Pg1 corresponds to the first position Po1 shown in Figure 5 and is approximately coincident with the first position Po1.

[0082] Next, in step S5, the image processing circuit 21 adjusts the position of the first color image G1. Specifically, the image processing circuit 21 determines the position of the first color image G1 relative to the second color image G2 based on the positional relationship between the reference viewpoint Pb and the first viewpoint Pg1.

[0083] The image processing circuit 21 first derives the positional relationship between the reference viewpoint Pb and the first viewpoint Pg1. Specifically, the image processing circuit 21 uses the X and Y coordinates of the reference viewpoint Pb and the first viewpoint Pg1, respectively, to derive a first estimated direction Wg1, shown in Figure 12, with the first viewpoint Pg1 as the starting point and the reference viewpoint Pb as the ending point. Furthermore, the drive circuit 20 calculates a first estimated distance Lg1, which is the distance between the reference viewpoint Pb and the first viewpoint Pg1.

[0084] Figure 14 shows the first color image G1 with its position adjusted relative to the second color image G2. In Figure 14, the periphery of the first color image G1 before position adjustment is shown by a dashed line, and the periphery of the first color image G1 after position adjustment is shown by a solid line.

[0085] The image processing circuit 21 adjusts the position of the first color image G1 such that the direction from the second image point Dg2 to the first image point Dg1 (first adjustment direction Wt1 shown in Figure 14) is the same as the opposite direction from the direction from the first viewpoint Pg1 to the reference viewpoint Pb (first estimation direction Wg1 shown in Figure 12).

[0086] As described above, by estimating the reference viewpoint Pb and the first viewpoint Pg1, the first estimated direction Wg1 shown in Figure 12 substantially aligns with the first movement direction Wo1 shown in Figure 5 and the first displacement direction Wz1 shown in Figure 10. Therefore, the first adjustment direction Wt1 shown in Figure 14 substantially aligns with the opposite direction of the first displacement direction Wz1 shown in Figure 10.

[0087] Furthermore, the image processing circuit 21 adjusts the position of the first color image G1 so that the distance between the second image point Dg2 and the first image point Dg1 is equal to the distance between the reference viewpoint Pb and the first viewpoint Pg1.

[0088] As described above, by estimating the reference viewpoint Pb and the first viewpoint Pg1, the first estimated distance Lg1 shown in Figure 12 is approximately equal to the first movement distance Lo1 shown in Figure 5 and the first displacement amount Lz1 shown in Figure 10. Therefore, the first adjustment distance Lt1 shown in Figure 16 is approximately equal to the first displacement amount Lz1 shown in Figure 10.

[0089] In this way, the position of the first color image G1 is adjusted so that the direction from the second image point Dg2 toward the first image point Dg1 is the first adjustment direction Wt1, and the distance between the second image point Dg2 and the first image point Dg1 is the first adjustment distance Lt1. In other words, the position of the first color image G1 is adjusted to be shifted relative to the second color image G2.

[0090] As will be described later, the image processing circuit 21 displays the second color image G2 in a state where the second image point Dg2 coincides with the reference point Ds of the display area DA. In other words, in step S5, the image processing circuit 21 adjusts the position of the first color image G1 so that the direction from the reference point Ds toward the first image point Dg1 is the first adjustment direction Wt1, and the distance between the reference point Ds and the first image point Dg1 is the first adjustment distance Lt1.

[0091] As described above, the periphery of the second color image G2 coincides with the periphery of the display area DA. Therefore, the first color image G1 is displayed offset from the display area DA. If the position of the first color image G1 is adjusted and a region without an image occurs between the periphery of the display area DA and the periphery of the first color image G1, the image processing circuit 21 may generate an image identical to the periphery of the first color image G1 adjacent to the region without an image and add it to the first color image G1. The same applies to the second color image G2 and the third color image G3, which will be described later.

[0092] Next, in step S6, the image processing circuit 21 displays the first color image G1. Specifically, the image processing circuit 21 generates a first pixel signal of the first color image G1 with the position adjusted as shown in Figure 14, and outputs the first pixel signal. As a result, the first color image G1 with the position adjusted as shown in Figure 14 is displayed in the display area DA during the first light emission period TL1 shown in Figure 9.

[0093] Furthermore, in step S7, the image processing circuit 21 adjusts the position of the second color image G2.

[0094] Figure 15 shows the second color image G2 after its position has been adjusted. The image processing circuit 21 determines the position of the second color image G2 such that the second image point Dg2 coincides with the reference point Ds of the display area DA. In this case, the periphery of the second color image G2 overlaps with the periphery of the display area DA. In other words, the position of the second color image G2 coincides with the position of the input image Gi and corresponds to the reference position when adjusting the position of the color image G.

[0095] Next, in step S8, the image processing circuit 21 displays the second-color image G2.

[0096] Specifically, the image processing circuit 21 generates a second pixel signal of the second color image G2 whose position has been adjusted as shown in Figure 15, and outputs the second pixel signal. As a result, the second color image G2 whose position has been adjusted as shown in Figure 15 is displayed in the display area DA during the second light emission period TL2 shown in Figure 9.

[0097] Next, in step S9, the image processing circuit 21 estimates the second viewpoint Pg2. The second viewpoint Pg2 is the user's viewpoint (point of focus) in the display area DA when the image processing circuit 21 displays the third-color image G3 (specifically, at the start of the third light emission period TL3 shown in Figure 9).

[0098] The image processing circuit 21 estimates the second viewpoint Pg2 based on the detection results of multiple gaze detection sensors 30, including the detection result of the most recent gaze detection sensor 30, from the time the first viewpoint Pg1 is estimated onward. Specifically, the image processing circuit 21 estimates the first viewpoint Pg1 using multiple gaze points Pv within a predetermined time period, including the most recent gaze point Pv, similar to when the reference viewpoint Pb was estimated.

[0099] The detection result of the gaze detection sensor 30 at the time the image processing circuit 21 estimates the second viewpoint Pg2 is updated to the latest detection result compared to the detection result of the gaze detection sensor 30 at the time the image processing circuit 21 estimates the first viewpoint Pg1 in step S4. Note that the detection result of the gaze detection sensor 30 at the time the image processing circuit 21 estimates the second viewpoint Pg2 may be the same as the detection result of the gaze detection sensor 30 at the time the image processing circuit 21 estimates the first viewpoint Pg1 in step S4.

[0100] The image processing circuit 21, similar to step S1, generates approximation curves Cx and Cy using the positions of multiple gaze points Pv, and identifies (estimates) the point on the approximation curves Cx and Cy corresponding to the time when the third-color image G3 is displayed (corresponding to the start of the third emission period TL3 shown in Figure 9) as the second viewpoint Pg2. The image processing circuit 21 obtains the X and Y coordinates of the second viewpoint Pg2.

[0101] Figure 12 shows the second viewpoint Pg2. The second viewpoint Pg2 corresponds to the third position Po3 shown in Figure 5, and is approximately coincident with the third position Po3.

[0102] Next, in step S10, the image processing circuit 21 adjusts the position of the third color image G3. Specifically, the image processing circuit 21 determines the position of the third color image G3 relative to the second color image G2 based on the positional relationship between the reference viewpoint Pb and the second viewpoint Pg2.

[0103] The image processing circuit 21 first derives the positional relationship between the reference viewpoint Pb and the second viewpoint Pg2. Specifically, the image processing circuit 21 uses the X and Y coordinates of the reference viewpoint Pb and the second viewpoint Pg2, respectively, to derive a second estimated direction Wg2, as shown in Figure 12, with the reference viewpoint Pb as the starting point and the second viewpoint Pg2 as the ending point. Furthermore, the drive circuit 20 calculates a second estimated distance Lg2, which is the distance between the reference viewpoint Pb and the second viewpoint Pg2.

[0104] Figure 16 shows a third-color image G3 whose position has been adjusted relative to the second-color image G2. In Figure 16, the periphery of the third-color image G3 before position adjustment is shown by a dashed line, and the periphery of the third-color image G3 after position adjustment is shown by a solid line.

[0105] The image processing circuit 21 adjusts the position of the third color image G3 so that the direction from the second image point Dg2 to the third image point Dg3 is the same as the direction from the reference viewpoint Pb to the second viewpoint Pg2.

[0106] As described above, by estimating the reference viewpoint Pb and the second viewpoint Pg2, the second estimated direction Wg2 shown in Figure 12 is approximately aligned with the second movement direction Wo2 shown in Figure 5, and approximately aligned in the opposite direction to the second displacement direction Wz2 shown in Figure 10. Therefore, the second adjustment direction Wt2 shown in Figure 16 is approximately aligned in the opposite direction to the second displacement direction Wz2 shown in Figure 10.

[0107] Furthermore, the image processing circuit 21 adjusts the position of the third color image G3 so that the distance between the second image point Dg2 and the third image point Dg3 is equal to the distance between the reference viewpoint Pb and the second viewpoint Pg2.

[0108] As described above, by estimating the reference viewpoint Pb and the second viewpoint Pg2, the second estimated distance Lg2 shown in Figure 12 is approximately equal to the second movement distance Lo2 shown in Figure 5 and the second displacement amount Lz2 shown in Figure 10. Therefore, the second adjustment distance Lt2 shown in Figure 16 is approximately equal to the second displacement amount Lz2 shown in Figure 10.

[0109] In this way, the position of the third color image G3 is adjusted so that the direction from the second image point Dg2 towards the third image point Dg3 is the second adjustment direction Wt2, and the distance between the second image point Dg2 and the third image point Dg3 is the second adjustment distance Lt2. In other words, the position of the third color image G3 is adjusted to be shifted relative to the second color image G2.

[0110] As described above, the image processing circuit 21 displays the second color image G2 in a state where the second image point Dg2 coincides with the reference point Ds of the display area DA. In other words, in step S10, the image processing circuit 21 adjusts the third color image G3 so that the direction from the reference point Ds toward the third image point Dg3 is the second adjustment direction Wt2, and the distance between the reference point Ds and the third image point Dg3 is the second adjustment distance Lt2.

[0111] Next, in step S11, the image processing circuit 21 displays the third-color image G3. Specifically, the image processing circuit 21 generates a third pixel signal of the third-color image G3 with the position adjusted as shown in Figure 16, and outputs the third pixel signal. As a result, the third-color image G3 with the position adjusted as shown in Figure 16 is displayed in the display area DA during the third light emission period TL3 shown in Figure 9.

[0112] Thus, the first color image G1 shown in Figure 14, the second color image G2 shown in Figure 15, and the third color image G3 shown in Figure 16 are displayed in the display area DA in this order.

[0113] When the point of focus Pv moves in the order of the first position Po1, the second position Po2, and the third position Po3 shown in Figure 5, the second color image G2 shown in Figure 15 is viewed with the second image point Dg2 and the reference point Ds coinciding, as described above. In other words, the second color image G2 shown in Figure 15 is viewed without any displacement relative to the display area DA.

[0114] In this case, the first color image G1 shown in Figure 14 is viewed with a first displacement amount Lz1 along the first displacement direction Wz1 shown in Figure 10 relative to the second color image G2, as described above. As described above, the first adjustment direction Wt1 is approximately in the opposite direction to the first displacement direction Wz1 shown in Figure 10, and the first adjustment distance Lt1 is approximately equal to the first displacement amount Lz1 shown in Figure 10. Therefore, the first color image G1 shown in Figure 14 is viewed with the first image point Dg1 and the reference point Ds approximately overlapping.

[0115] Furthermore, in this case, the third color image G3 shown in Figure 16 is perceived as being shifted by a second displacement amount Lz2 along the second displacement direction Wz2 shown in Figure 10 relative to the second color image G2, as described above. As described above, the second adjustment direction Wt2 is approximately in the opposite direction to the second displacement direction Wz2 shown in Figure 10, and the second adjustment distance Lt2 is approximately equal to the second displacement amount Lz2 shown in Figure 10. Therefore, the third color image G3 shown in Figure 16 is perceived as being in a state where the third image point Dg3 and the reference point Ds are approximately overlapping.

[0116] Therefore, the user views the first color image G1 shown in Figure 14, the second color image G2 shown in Figure 15, and the third color image G3 shown in Figure 16 with the first image point Dg1, the second image point Dg2, and the third image point Dg3 overlapping. In other words, the image viewed by the user is in a state where the first line drawing section G1a, the second line drawing section G2a, and the third line drawing section G3a overlap, which corresponds to the input image Gi shown in Figure 5.

[0117] When the image processing circuit 21 completes step S11 shown in Figure 11, it returns the program to step S1.

[0118] In this way, the image processing circuit 21 adjusts the position of the color image G relative to the display area DA, thereby suppressing the occurrence of color breakup in the display device 1 that displays images using the field sequential color method.

[0119] Furthermore, as described above, the drive circuit 20 aligns the reference point Ds with the second image point Dg2 with respect to the display area DA of the second color image G2, so that the adjusted second color image G2 (Figure 15) has no misalignment with respect to the display area DA. In this case, the adjusted first color image G1 (Figure 14) and third color image G3 (Figure 16) have misalignment with respect to the display area DA as described above. In this state, the image viewed by the user corresponds to the image in which the input image Gi is not misaligned with respect to the display area DA.

[0120] If the image processing circuit 21 aligns the reference point Ds with the first image point Dg1 relative to the display area DA of the first color image G1, then the adjusted first color image G1 will have no displacement relative to the display area DA, while the adjusted second color image G2 and third color image G3 will have displacement relative to the display area DA. However, the amount of displacement of the third color image G3 relative to the display area DA when the reference point Ds and the first image point Dg1 coincide is greater than the amount of displacement of the third color image G3 relative to the display area DA when the reference point Ds and the second image point Dg2 coincide, and the image viewed by the user corresponds to an image where the input image Gi is shifted relative to the display area DA. Therefore, if the image processing circuit 21 aligns the reference point Ds with the second image point Dg2 as described above, the user can view the input image Gi more appropriately in the display area DA.

[0121] Furthermore, as mentioned above, the second color corresponding to the second-color image G2 is green. Humans can perceive green more easily than red and blue. Also, the second-color image G2 (Figure 15), whose position has been adjusted as described above, is not misaligned with the display area DA. Therefore, by viewing the second-color image G2, which corresponds to the easily visible green, without any misalignment with the display area DA, the user can perceive the input image Gi more appropriately in the display area DA compared to viewing either the first-color image G1, which corresponds to red, or the third-color image G3, which corresponds to blue, without any misalignment with the display area DA.

[0122] The image processing circuit 21 may, instead of making the second image point Dg2 coincide with the reference point Ds, make the reference point Ds coincide with the first image point Dg1 in relation to the display area DA of the first color image G1, as described above.

[0123] Figure 17 is a flowchart of the image processing circuit 21 of the display device 1 according to a modified embodiment of the present disclosure. In this modified embodiment, the image processing circuit 21 executes the flowchart of Figure 17 instead of the flowchart of Figure 11.

[0124] In step S21, the image processing circuit 21 estimates the reference viewpoint Pb. In this modified example, the reference viewpoint Pb is the user's viewpoint (point of focus) in the display area DA when the image processing circuit 21 displays the first color image G1 (corresponding to the start of the first light emission period TL1 shown in Figure 9).

[0125] Similar to step S1 described above, the image processing circuit 21 estimates the reference viewpoint Pb, which is the user's viewpoint in the display area DA when displaying the first color image G1, based on the detection results of the multiple gaze detection sensors 30, before displaying the first color image G1, the second color image G2, and the third color image G3 in the display area DA.

[0126] Next, in step S22, the image processing circuit 21 acquires the input image Gi in the same manner as in step S2 above, and in step S23, it generates a color image G in the same manner as in step S3 above.

[0127] Furthermore, in step S24, the image processing circuit 21 adjusts the position of the first color image G1. The image processing circuit 21 determines the position of the first color image G1 such that the first image point Dg1 coincides with the reference point Ds of the display area DA.

[0128] Next, in step S25, the image processing circuit 21 displays the first color image G1 in the same manner as in step S6 above. As a result, the first color image G1 is displayed in a state where the first image point Dg1 coincides with the reference point Ds of the display area DA.

[0129] Furthermore, in step S26, the image processing circuit 21 estimates the first viewpoint Pg1. In this modified example, the first viewpoint Pg1 is the user's viewpoint (point of focus) in the display area DA when the image processing circuit 21 displays the second-color image G2 (corresponding to the start of the second light emission period TL2 shown in Figure 9). Similar to step S4 above, the image processing circuit 21 estimates the first viewpoint Pg1 based on the detection results of multiple gaze detection sensors 30, including the detection result of the most recent gaze detection sensor 30, after the time the reference viewpoint Pb has been estimated.

[0130] Next, in step S27, the image processing circuit 21 adjusts the position of the second color image G2. Specifically, based on the positional relationship between the reference viewpoint Pb and the first viewpoint Pg1, the image processing circuit 21 determines the position of the second color image G2 relative to the first color image G1, similar to step S5 above. As a result, similar to the embodiment described above, the position of the first color image G1 is such that the direction from the second image point Dg2 toward the first image point Dg1 is the first adjustment direction Wt1, and the distance between the second image point Dg2 and the first image point Dg1 is the first adjustment distance Lt1.

[0131] Furthermore, in step S28, the image processing circuit 21 displays the second-color image G2 in the same manner as in step S8 described above. The positional relationship between the second-color image G2 and the first-color image G1 in the display area DA is the same as the positional relationship in the above embodiment.

[0132] Next, in step S29, the image processing circuit 21 estimates the second viewpoint Pg2. The second viewpoint Pg2 is the user's viewpoint (point of gaze) in the display area DA when the image processing circuit 21 displays the third color image G3 (corresponding to the start of the third light emission period TL3 shown in Figure 9), similar to the embodiment described above. The image processing circuit 21 estimates the second viewpoint Pg2 based on the detection results of multiple gaze detection sensors 30, including the detection result of the most recent gaze detection sensor 30 since the time the first viewpoint Pg1 was estimated, similar to step S4 described above.

[0133] Furthermore, in step S30, the image processing circuit 21 adjusts the position of the third color image G3. Specifically, based on the positional relationship between the first viewpoint Pg1 and the second viewpoint Pg2, the image processing circuit 21 determines the position of the third color image G3 relative to the second color image G2, similar to step S10 above. As a result, similar to the embodiment described above, the position of the third color image G3 is such that the direction from the second image point Dg2 toward the third image point Dg3 is the second adjustment direction Wt2, and the distance between the second image point Dg2 and the third image point Dg3 is the second adjustment distance Lt2.

[0134] Next, in step S31, the image processing circuit 21 displays the third-color image G3 in the same manner as in step S11. The positional relationship between the second-color image G2 and the third-color image G3 in the display area DA is the same as the positional relationship in the above embodiment. When step S31 is completed, the image processing circuit 21 returns the program to step S21.

[0135] In this modified example, as in the above embodiment, the user views the first color image G1, the second color image G2, and the third color image G3 with the first image point Dg1, the second image point Dg2, and the third image point Dg3 overlapping. In other words, the image viewed by the user is in a state where the first line drawing section G1a, the second line drawing section G2a, and the third line drawing section G3a overlap, which corresponds to the input image Gi shown in Figure 5. By adjusting the position of the color image G relative to the display area DA in this way, the display device 1 that displays an image using the field sequential color method can suppress the occurrence of color breakup.

[0136] <Display System 2> Next, a display system 2 according to an embodiment of this disclosure will be described.

[0137] Figure 18 is a perspective view of a display system 2 according to an embodiment of the present disclosure. Figure 19 is a schematic diagram showing the configuration of the display system 2. The images displayed by the display system 2 include, for example, computer graphics and 360-degree live-action video.

[0138] Display system 2 has a built-in video signal source Sg. Alternatively, display system 2 may acquire an input image Gi from an external device.

[0139] The output image of the video signal source Sg has two distinct output images that utilize the parallax between the user's two eyes. These two output images are the input image for the user's right eye and the input image for the user's left eye.

[0140] As shown in Figures 18 and 19, the display system 2 comprises a mounting unit 150, two lenses 160, the display device 1 described above, and a video signal source Sg.

[0141] The mounting unit 150 is attached to the user's head in a manner that covers both of the user's eyes. The mounting unit 150 may be, for example, a headset, goggles, helmet, or mask. Two lenses 160 and two display devices 1 are fixed to the mounting unit 150. The mounting unit 150 may further include an output unit (not shown) that outputs sound signals output from a video signal source Sg.

[0142] The two lenses 160 are positioned opposite the user's eyes E. The lenses 160 are, for example, convex lenses made of glass. The two lenses 160 correspond to both of the user's eyes. The lenses 160 are positioned between the display device 1 and the user's eyes E.

[0143] Due to the lens action of the lens 160, the light emitted from the display device 1 is focused towards the user's eye E, and the user sees an enlarged image of the image displayed in the display area DA.

[0144] The display device 1 is positioned on the opposite side of the user's eyes E, with two lenses 160 in between. The gaze detection sensor 30 is located on the mounting part 150 and is electrically connected to the control board CPC.

[0145] Figure 20 is a block diagram of the display system 2. The display system 2 comprises two display devices 1. That is, the display system 2 comprises a first display device 1a and a second display device 1b. The first display device 1a and the second display device 1b are configured in the same way as the display device 1 described above. In other words, the first display device 1a and the second display device 1b are equipped with a display panel 10, a drive circuit 20, a gaze detection sensor 30, and a light source device 40, similar to the display device 1 described above. That is, in the subframes SF1, SF2, and SF3 of frame F shown in Figure 9, the first color image G1 is displayed during the first light emission period TL1, the second color image G2 is displayed during the second light emission period TL2, and the third color image G3 is displayed during the third light emission period TL3.

[0146] The first display device 1a acquires an input image for the left eye. The display area DA of the first display device 1a faces the user's left eye. The display area DA of the second display device 1b acquires an input image for the right eye. The second display device 1b faces the user's right eye. Hereafter, when the first display device 1a and the second display device 1b are described without distinction, they will simply be referred to as "display device 1". The control board CPC of the first display device 1a and the control board CPC of the second display device 1b are integrated, but they may be separate.

[0147] The display system 2 may also include one display device 1. In this case, in the display area DA, the image for the left eye is displayed in the area corresponding to the left eye, and the image for the right eye is displayed in the area corresponding to the right eye.

[0148] Next, we will explain the operation of the display device 1 that displays an image in the display area DA, focusing on the differences from the operation of the display device 1 described above.

[0149] Figure 21 is a flowchart showing the actions taken by the image processing circuit 21 of the display device 1 in the display system 2 when displaying a color image G. In the display system 2, the image processing circuit 21 executes the flowchart shown in Figure 21 instead of the flowchart in Figure 11.

[0150] The flowchart in Figure 21 differs from the flowchart in Figure 11 in that it further includes steps S101, S102, and S103. The image processing circuit 21 executes step S101 between steps S5 and S6, step S102 between steps S7 and S8, and step S103 between steps S10 and S11. Below, the flowchart in Figure 12 will be explained, mainly focusing on the differences from the flowchart in Figure 11.

[0151] In step S101, the image processing circuit 21 performs lens correction on the first color image G1 whose position was adjusted in step S5. Lens correction is a process that corrects the color image G based on the distortion aberration of the lens 160.

[0152] The image viewed by the user through the lens 160 is distorted. In other words, distortion aberration occurs due to the lens 160. Specifically, the image viewed by the user through the lens 160 has a distortion (so-called pincushion distortion) in which the edges of the image appear to be widened compared to the image displayed in the display area DA. That is, with respect to the image displayed in the display area DA, the degree of distortion from the center of the color image G outwards in the radial direction increases as you move radially outwards from the center of the image.

[0153] Therefore, the image processing circuit 21 suppresses distortion aberration caused by the lens 160 by correcting the color image G. Specifically, the image processing circuit 21 corrects the color image G so that it has a distortion that makes the central part appear bulging (so-called barrel distortion). In other words, in the corrected color image G, the further you are from the center of the color image G, the greater the degree of distortion towards the center of the image.

[0154] In other words, the image processing circuit 21 corrects the color image G to have distortion in the opposite direction to the distortion of the image seen by the user, which is caused by the distortion aberration of the lens 160. Thus, in step S101, the first color image G1, whose position has been adjusted, is corrected based on the distortion aberration of the lens 160. In step S6, the image processing circuit 21 displays the first color image G1 that has been lens-corrected in step S101.

[0155] Furthermore, in step S102, the image processing circuit 21 corrects the second-color image G2 whose position was adjusted in step S7. In step S102, the second-color image G2 whose position has been adjusted is corrected based on the distortion aberration of the lens 160, similar to step S101. In step S8, the image processing circuit 21 displays the second-color image G2 whose lens correction was performed in step S102.

[0156] Furthermore, in step S103, the image processing circuit 21 performs lens correction on the third-color image G3 whose position was adjusted in step S10. In step S103, the third-color image G3 whose position has been adjusted is corrected based on the distortion aberration of the lens 160, similar to step S101. In step S11, the image processing circuit 21 displays the third-color image G3 whose lens correction was performed in step S103.

[0157] Therefore, the lens-corrected first color image G1, the lens-corrected second color image G2, and the lens-corrected third color image G3 are displayed in the display area DA in this order.

[0158] As described above, by adjusting the position of the color image G, the user views the first color image G1, the second color image G2, and the third color image G3 with the first image point Dg1, the second image point Dg2, and the third image point Dg3 overlapping. Furthermore, as described above, by correcting the color image G to have a distortion opposite to that caused by the lens 160, the user views the first color image G1, the second color image G2, and the third color image G3 with suppressed distortion aberration. In other words, the image viewed by the user corresponds to the input image Gi.

[0159] In this way, the image processing circuit 21 adjusts the position of the color image G relative to the display area DA and corrects the color image G to a state in which it has distortion, thereby suppressing the occurrence of color breakup and distortion aberration in a display system 2 equipped with a display device 1 that displays an image using a field sequential color method.

[0160] Furthermore, in steps S101, S102, and S103 described above, the image processing circuit 21 may correct the color image G based on the chromatic aberration of the lens 160 instead of the distortion aberration of the lens 160. That is, the image processing circuit 21 may correct the color image G by setting different distortion aberration magnitudes for each of the first color image G1, the second color image G2, and the third color image G3.

[0161] The wavelengths of light become shorter in the order of the first light (red), the second light (green), and the third light (blue). The general optical glass and resins that make up lens 160 have a wavelength-to-refractive index relationship called normal dispersion, and the refractive index of the first light, the refractive index of the second light, and the refractive index of the third light increase in this order.

[0162] Therefore, when the input image Gi is color-separated into the first, second, and third colors, the size of the image perceived by the user increases as the wavelength of light decreases, in the order of the first color image G1, the second color image G2, and the third color image G3. Consequently, the user perceives the image displayed in the display area DA with color shifts. In other words, chromatic aberration occurs due to the lens 160.

[0163] Therefore, the image processing circuit 21 suppresses chromatic aberration caused by the lens 160 by correcting the color image G. Specifically, the image processing circuit 21 corrects the color image G so that the size increases in the order of the third color image G3, the second color image G2, and the first color image G1. In other words, it corrects the size of the color image G so that it is the inverse relationship of the size relationship between the first color image G1, the second color image G2, and the third color image G3 caused by chromatic aberration.

[0164] The image processing circuit 21 uses the size of the second-color image G2 as a reference. In other words, the size of the second-color image G2 is equal to the size of the input image Gi.

[0165] In this way, the color image G is corrected to have the inverse relationship between the sizes of the first color image G1, the second color image G2, and the third color image G3 produced by the lens 160, so that the user can view the first color image G1, the second color image G2, and the third color image G3 with chromatic aberration suppressed. As the position of the color image G is adjusted as described above, the user can view the first color image G1, the second color image G2, and the third color image G3 with the first image point Dg1, the second image point Dg2, and the third image point Dg3 overlapping. In other words, the image viewed by the user corresponds to the input image Gi.

[0166] In addition, the image processing circuit 21 may correct the color image G in steps S101, S102, and S103 above based on both the distortion and chromatic aberration of the lens 160.

[0167] While preferred embodiments of this disclosure have been described above, this disclosure is not limited to such embodiments. The content disclosed in the embodiments is merely an example, and various modifications are possible without departing from the spirit of this disclosure. Any modifications made without departing from the spirit of this disclosure will naturally fall within the technical scope of this disclosure.

[0168] For example, one of the first and third colors corresponding to the first color image G1 and the third color image G3 may be green.

[0169] Furthermore, in the display system 2, the display panel 10 may be detachably attached to the mounting portion 150.

[0170] Furthermore, it goes without saying that the lens 160 is not limited to a convex lens. Also, the distortion aberration generated by the lens 160 may be aberration in which the image viewed by the user through the lens 160 exhibits so-called barrel distortion. In this case, the drive circuit 20 corrects the color image G so that it exhibits so-called pincushion distortion.

[0171] Furthermore, any other effects and advantages brought about by the embodiments described above that are obvious from this specification or that can be appropriately conceived by a person skilled in the art are naturally provided by this disclosure.

[0172] The drive circuit 20 includes, for example, a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), an internal storage unit (storage area), an input interface, and an output interface. The CPU, ROM, RAM, and internal storage unit are connected by an internal bus. The ROM stores programs such as the BIOS. The internal storage unit is, for example, an HDD (Hard Disk Drive) or flash memory, and stores operating system programs and application programs. The CPU realizes various functions by executing programs stored in the ROM or internal storage unit while using the RAM as a work area.

[0173] 1 Display device 2 Display system 10 Display panel 20 Drive circuit 30 Eye-line detection sensor 40 Light source device 160 Lens DA Display area Dg1 First image point Dg2 Second image point Dg3 Third image point Ds Reference point F Frame G1 First color image G2 Second color image G3 Third color image Gi Input image P Pixel Pb Reference viewpoint Pg1 First viewpoint Pg2 Second viewpoint

Claims

1. The system comprises a display panel having a display area, a light source device that emits a first light of a first color, a second light of a second color, and a third light of a third color in that order to the display panel within one frame, a gaze detection sensor that detects the user's gaze at a predetermined interval, and a drive circuit that displays an image in the display area based on an image signal, wherein the drive circuit generates a first-color image corresponding to the first color of the image, a second-color image corresponding to the second color of the image, and a third-color image corresponding to the third color of the image based on the image signal, displays the first-color image when the first light is emitted, displays the second-color image when the second light is emitted, and displays the third-color image when the third light is emitted, and before displaying the first-color image, the second-color image, and the third-color image in the display area, estimates a reference viewpoint, which is the user's viewpoint in the display area when displaying the second-color image, based on the detection results of a plurality of gaze detection sensors, including the latest detection result of the gaze detection sensor, A display device that estimates a first viewpoint, which is the user's viewpoint in the display area when displaying the first color image, based on the detection results of a plurality of gaze detection sensors, including the latest detection result of the gaze detection sensor since the time the reference viewpoint was estimated; adjusts the position of the first color image relative to the second color image based on the positional relationship between the reference viewpoint and the first viewpoint; estimates a second viewpoint, which is the user's viewpoint in the display area when displaying the third color image, based on the detection results of a plurality of gaze detection sensors, including the latest detection result of the gaze detection sensor since the time the first viewpoint was estimated; and adjusts the position of the third color image relative to the second color image based on the positional relationship between the reference viewpoint and the second viewpoint.

2. The display device according to claim 1, wherein the first color image, the second color image, and the third color image have a first image point, a second image point, and a third image point corresponding to a reference point of the display area, and the drive circuit adjusts the position of the first color image such that the direction from the second image point toward the first image point is the same as the opposite direction from the first viewpoint toward the reference viewpoint, and adjusts the position of the third color image such that the direction from the second image point toward the third image point is the same as the direction from the reference viewpoint toward the second viewpoint.

3. The display device according to claim 2, wherein the drive circuit displays the second color image in a state in which the second image point coincides with the reference point.

4. The display device according to claim 1, wherein the first color image, the second color image, and the third color image have a first image point, a second image point, and a third image point corresponding to a reference point of the display area, and the drive circuit adjusts the position of the first color image such that the distance between the second image point and the first image point is equal to the distance between the reference viewpoint and the first viewpoint, and adjusts the position of the third color image such that the distance between the second image point and the third image point is equal to the distance between the reference viewpoint and the second viewpoint.

5. The display device according to claim 1, wherein the second color is green.

6. The system comprises a display panel having a display area, a light source device that emits a first light of a first color, a second light of a second color, and a third light of a third color in that order to the display panel within one frame, a gaze detection sensor that detects the user's gaze at a predetermined interval, and a drive circuit that displays an image in the display area based on an image signal, wherein the drive circuit generates a first-color image corresponding to the first color of the image, a second-color image corresponding to the second color of the image, and a third-color image corresponding to the third color of the image based on the image signal, displays the first-color image when the first light is emitted, displays the second-color image when the second light is emitted, and displays the third-color image when the third light is emitted, and before displaying the first-color image, the second-color image, and the third-color image in the display area, estimates a reference viewpoint, which is the user's viewpoint in the display area when the first-color image is displayed, based on the detection results of a plurality of gaze detection sensors. A display device that estimates a first viewpoint, which is the user's viewpoint in the display area when displaying the second color image, based on the detection results of a plurality of gaze detection sensors, including the latest detection result of the gaze detection sensor since the time the reference viewpoint was estimated; adjusts the position of the second color image relative to the first color image based on the positional relationship between the reference viewpoint and the first viewpoint; estimates a second viewpoint, which is the user's viewpoint in the display area when displaying the third color image, based on the detection results of a plurality of gaze detection sensors, including the latest detection result of the gaze detection sensor since the time the first viewpoint was estimated; and adjusts the position of the third color image relative to the second color image based on the positional relationship between the first viewpoint and the second viewpoint.

7. A display system comprising the display device described in claim 1 and a lens, wherein the drive circuit corrects the first color image, the second color image, and the third color image based on either distortion aberration or chromatic aberration caused by the lens.

Images