Indication device

Abstract

To suppress the occurrence of moiré patterns in a display device in which two liquid crystal display panels are arranged so that they overlap when viewed from above. [Solution] The display device 1 includes a first polarizing plate 30 into which light from a light source device 10 is incident, a first liquid crystal display panel 20a into which transmitted light from the first polarizing plate 30 is incident, a second liquid crystal display panel 20b arranged separately from the first liquid crystal display panel 20a into which transmitted light from the first liquid crystal display panel 20a is incident, and a second polarizing plate 40 into which transmitted light from the second liquid crystal display panel 20b is incident. The first liquid crystal display panel 20a and the second liquid crystal display panel 20b include a first sub-pixel Sα having a first color filter CF1, a second sub-pixel Sβ having a second color filter CF2, and a third sub-pixel Sγ having a third color filter CF3, and are arranged such that at least the first color filter CF1 of the first liquid crystal display panel 20a and the second color filter CF2 of the second liquid crystal display panel 20b overlap in a plan view.

Description

Technical Field

[0001] The present invention relates to a display device.

Background Art

[0002] Patent Document 1 discloses, as an example of a display device, a wristwatch-type electronic apparatus such as a so-called smart watch. The display device of Patent Document 1 includes a first display panel and a second display panel arranged so as to overlap in plan view with an air layer interposed therebetween. The first display panel is capable of color display, and the second display panel is capable of monochrome display.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the display device of Patent Document 1, when both the first display panel and the second display panel have color filters to constitute a liquid crystal display panel capable of color display, moire may occur.

[0005] An object of the present disclosure is to suppress the occurrence of moire in a display device in which two liquid crystal display panels are arranged so as to overlap in plan view.

Means for Solving the Problems

[0006] A display device according to one aspect of the present disclosure comprises: a light source device; a first polarizing plate to which light from the light source device is incident and which transmits linearly polarized light having a first polarization direction; a first liquid crystal display panel to which the transmitted light from the first polarizing plate is incident; a second liquid crystal display panel disposed separately from the first liquid crystal display panel and to which the transmitted light from the first liquid crystal display panel is incident; and a second polarizing plate to which the transmitted light from the second liquid crystal display panel is incident and which transmits linearly polarized light having a second polarization direction different from the first polarization direction, wherein no polarizing plate is disposed between the first liquid crystal display panel and the second liquid crystal display panel, and the first liquid crystal display panel and the Each of the two liquid crystal display panels has a plurality of subpixels arranged in a matrix along the row and column directions, respectively, and the plurality of subpixels include a first subpixel having a first color filter, a second subpixel having a second color filter, and a third subpixel having a third color filter, and the first color filter, the second color filter and the third color filter have different colors from each other, and the first liquid crystal display panel and the second liquid crystal display panel are arranged such that at least the first color filter of the first liquid crystal display panel and the second color filter of the second liquid crystal display panel overlap in a plan view. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a schematic diagram showing the configuration of a display device according to the first embodiment of this disclosure. [Figure 2] Figure 2 is a plan view of the liquid crystal display panel shown in Figure 1. [Figure 3] Figure 3 shows the circuit configuration of the liquid crystal display panel shown in Figure 2. [Figure 4] Figure 4 is a cross-sectional view of the liquid crystal display panel shown in Figure 2. [Figure 5] Figure 5 shows the arrangement of subpixels in the second liquid crystal display panel shown in Figure 1. [Figure 6] Figure 6 shows the arrangement of subpixels in the first liquid crystal display panel shown in Figure 1. [Figure 7] Figure 7 is a schematic diagram of a comparative example display device used to illustrate moiré patterns. [Figure 8] Figure 8 shows the arrangement of subpixels of the first liquid crystal display panel and the second liquid crystal display panel when the user views the comparative example display shown in Figure 7 along the Z direction. [Figure 9] Figure 9 shows the arrangement of subpixels of the first liquid crystal display panel and the second liquid crystal display panel when the user views the comparative example display device shown in Figure 7 along the first tilt direction. [Figure 10] Figure 10 shows the arrangement of subpixels of the first liquid crystal display panel and the second liquid crystal display panel when the user views the comparative example display shown in Figure 7 along the second tilt direction. [Figure 11] Figure 11 shows the relationship between the amount of X-direction displacement between the subpixels of the first liquid crystal display panel and the subpixels of the second liquid crystal display panel when the display device is in a white display state, and the brightness of the transmitted light from the second polarizer. [Figure 12] Figure 12 shows the relationship between the amount of Y-direction displacement between the subpixels of the first liquid crystal display panel and the subpixels of the second liquid crystal display panel and the brightness of the transmitted light from the second polarizer, when the display device in Figure 1 and the comparative example display device are in a white display state. [Figure 13] Figure 13 shows the positional relationship between the subpixels of the first liquid crystal display panel and the subpixels of the second liquid crystal display panel in the display device shown in Figure 1. [Figure 14] Figure 14 shows the arrangement of subpixels in the first liquid crystal display panel of the display device according to the second embodiment of this disclosure. [Figure 15] Figure 15 is a diagram showing the positional relationship between the subpixels of the first liquid crystal display panel and the subpixels of the second liquid crystal display panel in the display device of the second embodiment. [Figure 16] Figure 16 shows the relationship between the amount of X-direction displacement between the subpixels of the first liquid crystal display panel and the subpixels of the second liquid crystal display panel and the brightness of the transmitted light from the second polarizer plate when the display device of the second embodiment is displaying white. [Figure 17]FIG. 17 is a diagram showing the relationship between the shift amount in the Y direction between the sub-pixels of the first liquid crystal display panel and the sub-pixels of the second liquid crystal display panel and the luminance of light transmitted through the second polarizing plate when the display device of the second embodiment performs white display. [Figure 18] FIG. 18 is a diagram showing an arrangement of sub-pixels in a first liquid crystal display panel included in a display device according to a third embodiment of the present disclosure. [Figure 19] FIG. 19 is a diagram showing a positional relationship between sub-pixels of a first liquid crystal display panel and sub-pixels of a second liquid crystal display panel in the display device of the third embodiment. [Figure 20] FIG. 20 is a diagram showing the relationship between the shift amount in the X direction between the sub-pixels of the first liquid crystal display panel and the sub-pixels of the second liquid crystal display panel and the luminance of light transmitted through the second polarizing plate when the display device of the third embodiment performs white display. [Figure 21] FIG. 21 is a diagram showing the relationship between the shift amount in the Y direction between the sub-pixels of the first liquid crystal display panel and the sub-pixels of the second liquid crystal display panel and the luminance of light transmitted through the second polarizing plate when the display device of the third embodiment performs white display. [Figure 22] FIG. 22 is a diagram showing an arrangement of sub-pixels in a first liquid crystal display panel included in a display device according to a fourth embodiment of the present disclosure. [Figure 23] FIG. 23 is a diagram showing a positional relationship between sub-pixels of a first liquid crystal display panel and sub-pixels of a second liquid crystal display panel in the display device of the fourth embodiment. [Figure 24] FIG. 24 is a diagram showing the relationship between the shift amount in the X direction between the sub-pixels of the first liquid crystal display panel and the sub-pixels of the second liquid crystal display panel and the luminance of light transmitted through the second polarizing plate when the display device of the fourth embodiment performs white display. [Figure 25] FIG. 25 is a diagram showing the relationship between the shift amount in the Y direction between the sub-pixels of the first liquid crystal display panel and the sub-pixels of the second liquid crystal display panel and the luminance of light transmitted through the second polarizing plate when the display device of the fourth embodiment performs white display. [Figure 26] FIG. 26 is a diagram showing an arrangement of sub-pixels in a first liquid crystal display panel included in a display device according to a fifth embodiment of the present disclosure. [Figure 27]FIG. 27 is a diagram illustrating a positional relationship between sub-pixels of a first liquid crystal display panel and sub-pixels of a second liquid crystal display panel in the display device according to the fifth embodiment. [Figure 28] FIG. 28 is a diagram illustrating a relationship between an X-direction shift amount between the sub-pixel of the first liquid crystal display panel and the sub-pixel of the second liquid crystal display panel and luminance of transmitted light through a second polarizing plate when the display device according to the fifth embodiment performs white display. [Figure 29] FIG. 29 is a diagram illustrating a relationship between a Y-direction shift amount between the sub-pixel of the first liquid crystal display panel and the sub-pixel of the second liquid crystal display panel and luminance of transmitted light through the second polarizing plate when the display device according to the fifth embodiment performs white display. [Figure 30] FIG. 30 is a diagram illustrating a configuration of a display device according to a modification of the embodiment of the present disclosure. [Mode for Carrying Out the Invention]

[0008] Hereinafter, each embodiment of the present disclosure will be described with reference to the drawings. The present disclosure is not limited by the contents described in the following embodiments. Furthermore, constituent elements described below include elements that can be easily assumed by those skilled in the art and elements that are substantially the same. Further, the constituent elements described below can be appropriately combined.

[0009] Note that the present disclosure is merely an example, and appropriate modifications that can be easily conceived by those skilled in the art while maintaining the gist of the present disclosure are naturally included in the scope of the present disclosure. In addition, for clearer description, the drawings may schematically illustrate the width, thickness, shape, and the like of each part compared to actual aspects, but these are merely examples and do not limit the interpretation of the present disclosure. In the present specification and each drawing, elements similar to those described above with reference to the previously presented drawings are denoted by the same reference numerals, and detailed description thereof may be omitted as appropriate.

[0010] The X, Y, and Z directions shown in the drawings are orthogonal to each other and indicate the direction of the display device 1. The X and Y directions correspond to the sides of the display device 1. In the X direction, the side indicated by the arrow corresponds to the +X side, and the opposite side corresponds to the -X side. In the Y direction, the side indicated by the arrow corresponds to the +Y side, and the opposite side corresponds to the -Y side. In the Z direction, the side indicated by the arrow corresponds to the +Z side, and the opposite side corresponds to the -Z side. The Z direction also corresponds to the thickness direction of the display device 1. Note that the X, Y, and Z directions are examples, and this disclosure is not limited to these directions. Also, when "plan view" is simply described in this specification, it means viewing the display device 1 along the Z direction.

[0011] <First Embodiment> Figure 1 is a schematic diagram showing the configuration of a display device 1 according to the first embodiment of this disclosure. Examples of the display device 1 include a wristwatch-type electronic device such as a smartwatch, and an instrument panel installed in a vehicle such as an automobile.

[0012] The display device 1 comprises a light source device 10, a first liquid crystal display panel 20a, a second liquid crystal display panel 20b, a first polarizing plate 30, and a second polarizing plate 40. The light source device 10, the first polarizing plate 30, the first liquid crystal display panel 20a, the second liquid crystal display panel 20b, and the second polarizing plate 40 are arranged in this order from the -Z side to the +Z side.

[0013] The light source device 10 emits light toward the first polarizing plate 30. The light source device 10 is, for example, a direct-type backlight and has multiple light-emitting diodes (not shown). The light source device 10 is electrically connected to an external device 100 by wire or wireless means, and the timing and duration of light emission are controlled.

[0014] The first liquid crystal display panel 20a and the second liquid crystal display panel 20b are transmissive liquid crystal displays. In this first embodiment, the first liquid crystal display panel 20a and the second liquid crystal display panel 20b are configured similarly. Hereafter, when the first liquid crystal display panel 20a and the second liquid crystal display panel 20b are described without distinction from each other, they will simply be referred to as the liquid crystal display panel 20.

[0015] The first panel direction D1, the second panel direction D2, and the third panel direction D3 shown in the figure are orthogonal to each other and represent the direction of the liquid crystal display panel 20. The first panel direction D1 and the second panel direction D2 correspond to directions parallel to the main surface of the substrate included in the liquid crystal display panel 20. The third panel direction D3 corresponds to a direction perpendicular to the main surface of the substrate included in the liquid crystal display panel 20. Furthermore, the third panel direction D3 corresponds to the thickness direction of the liquid crystal display panel 20, and the side indicated by the arrow in the third panel direction D3 (+D3 side) corresponds to the front side of the liquid crystal display panel 20 where the image is displayed, and the opposite side (-D3 side) corresponds to the back side of the liquid crystal display panel 20. Note that the first panel direction D1, the second panel direction D2, and the third panel direction D3 are examples, and this disclosure is not limited to these directions.

[0016] The liquid crystal display panel 20 is arranged so that the third panel direction D3 and the Z direction are parallel. The liquid crystal display panel 20 is electrically connected to an external device 100 and displays an image based on an image signal transmitted from the external device 100. The first liquid crystal display panel 20a and the second liquid crystal display panel 20b are arranged so that they are spaced apart from each other in the Z direction and overlap in a plan view.

[0017] Figure 2 is a plan view of the liquid crystal display panel 20 shown in Figure 1. The front surface of the liquid crystal display panel 20 has a display area DA on which an image is displayed. The front surface of the liquid crystal display panel 20 is perpendicular to the Z direction. The display area DA is polygonal in plan view, but may also be rectangular. The display area DA of the first liquid crystal display panel 20a and the display area DA of the second liquid crystal display panel 20b overlap in plan view.

[0018] In the display area DA, multiple subpixels S are arranged in a matrix along the row direction W1 and the column direction W2. The row direction W1 and the column direction W2 are orthogonal to each other. The row direction W1 is parallel to the first panel direction D1, and the column direction W2 is parallel to the second panel direction D2. Each of the multiple subpixels S is rectangular in shape, having a longitudinal direction and a transverse direction in a plan view. The multiple subpixels S are arranged so that their longitudinal direction aligns with the column direction W2 and their transverse direction aligns with the row direction W1. Details of the arrangement of the subpixels S will be described later.

[0019] Figure 3 shows the circuit configuration of the liquid crystal display panel 20 shown in Figure 2. The liquid crystal display panel 20 includes a drive circuit 21, and each of the multiple sub-pixels S has a switching element SW, a sub-pixel electrode PE, a common electrode CE, a liquid crystal capacitance LC, and a retaining capacitance CS.

[0020] The drive circuit 21 displays an image in the display area DA. The drive circuit 21 includes a signal processing circuit 21a, a signal output circuit 21b, and a scanning circuit 21c.

[0021] The signal processing circuit 21a generates a plurality of sub-pixel signals, described later, based on the image signal output from the external device 100, and outputs the generated plurality of sub-pixel signals to the signal output circuit 21b. The signal processing circuit 21a also outputs a clock signal to the signal output circuit 21b and the scanning circuit 21c to synchronize the operation of the signal output circuit 21b and the operation of the scanning circuit 21c.

[0022] The signal output circuit 21b outputs each of the multiple sub-pixel signals to the corresponding sub-pixel S. The signal output circuit 21b and the multiple sub-pixels S are electrically connected via multiple signal lines Lb that extend along the column direction W2.

[0023] The scanning circuit 21c scans multiple sub-pixels S in synchronization with the output of the sub-pixel signal by the signal output circuit 21b. The scanning circuit 21c and the multiple sub-pixels S are electrically connected via multiple scan lines Lc that extend along the row direction W1.

[0024] In a plan view, a region demarcated by two adjacent signal lines Lb in the row direction W1 and two adjacent scan lines Lc in the column direction W2 corresponds to one sub-pixel S.

[0025] 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.

[0026] The sub-pixel electrode PE is connected to the drain electrode of the switching element SW. The common electrode CE is positioned corresponding to the sub-pixel electrode PE. Both the sub-pixel electrode PE and the common electrode CE are translucent.

[0027] The liquid crystal capacitance LC is the capacitance component of the liquid crystal material in the liquid crystal layer 23, which will be described later, located between the sub-pixel electrode PE and the common electrode CE. The retained capacitance CS is formed between the electrode at the same potential as the common electrode CE and the electrode at the same potential as the sub-pixel electrode PE.

[0028] Figure 4 is a cross-sectional view of the liquid crystal display panel 20 shown in Figure 2. The liquid crystal display panel 20 comprises a first substrate 22, a liquid crystal layer 23, and a second substrate 24.

[0029] The first substrate 22, the liquid crystal layer 23, and the second substrate 24 are all light-transmitting and are arranged in this order from the -D3 side to the +D3 side. The IC chip Ti that constitutes the drive circuit 21 is placed on the first substrate 22 (Figure 2).

[0030] A common electrode CE is placed on the main surface 22a, which corresponds to the front surface of the first substrate 22. An insulating layer IL is placed in front of the common electrode CE, and furthermore, a sub-pixel electrode PE and an alignment film AL are placed therein.

[0031] The sub-pixel electrode PE is positioned between the insulating layer IL and the alignment layer AL. Thus, the common electrode CE and the sub-pixel electrode PE are positioned on the first substrate 22. In other words, the liquid crystal display panel 20 is a transverse electric field type liquid crystal display. Signal lines Lb and scan lines Lc (not shown in Figure 4) are positioned on the main surface 22a of the first substrate 22.

[0032] The second substrate 24 is located on the +D3 side of the first substrate 22. On the back surface of the second substrate 24 are the first color filter CF1, the second color filter CF2, and the third color filter CF3, which are of different colors from each other, the light-shielding film SM, and the alignment film AL. The light-shielding film SM and the color filters CF are placed between the second substrate 24 and the alignment film AL. Hereafter, when the first color filter CF1, the second color filter CF2, and the third color filter CF3 are described without distinction, they will simply be referred to as color filters CF.

[0033] A color filter CF is rectangular in plan view. A color filter CF is light-transmitting, and the peaks in the spectrum of the light it transmits are predetermined. The spectral peaks correspond to the colors of the color filter CF. The color of the first color filter CF1 is red, the color of the second color filter CF2 is green, and the color of the third color filter CF3 is blue.

[0034] Each sub-pixel S has one color filter CF. The sub-pixel S having the first color filter CF1 is designated as the first sub-pixel Sα, the sub-pixel S having the second color filter CF2 is designated as the second sub-pixel Sβ, and the sub-pixel S having the third color filter CF3 is designated as the third sub-pixel Sγ. In other words, the first sub-pixel Sα is the red sub-pixel S, the second sub-pixel Sβ is the green sub-pixel S, and the third sub-pixel Sγ is the blue sub-pixel S. When describing the first sub-pixel Sα, the second sub-pixel Sβ, and the third sub-pixel Sγ without distinguishing between them, they are simply referred to as sub-pixel S.

[0035] The light-shielding film SM has light-shielding properties. The light-shielding film SM overlaps with the signal line Lb and the scan line Lc in the third panel direction D3. In other words, the light-shielding film SM partitions multiple sub-pixels S. To put it another way, the light-shielding film SM overlaps with the boundary between two adjacent sub-pixels S in the row direction W1 and column direction W2 in the third panel direction D3.

[0036] The liquid crystal layer 23 contains multiple liquid crystal molecules LM. The liquid crystal layer 23 is located between two alignment films AL that face each other in the third panel direction D3. The orientation of the liquid crystal molecules LM is restricted by the two alignment films AL.

[0037] Figure 5 shows the arrangement of subpixels S in the second liquid crystal display panel 20b shown in Figure 1. The multiple subpixels S shown in the figure are indicated by a color filter CF and a light-shielding film SM. In a plan view of the liquid crystal display panel 20, the multiple subpixels S are separated by the light-shielding film SM, and the color filter CF is rectangular. As described above, the first subpixel Sα has a red first color filter CF1, the second subpixel Sβ has a green second color filter CF2, and the third subpixel Sγ has a blue third color filter CF3.

[0038] The arrangement of subpixels S in the second liquid crystal display panel 20b is a so-called stripe arrangement. Specifically, the multiple subpixels S are arranged such that in the row direction W1, the first subpixel Sα, the second subpixel Sβ, and the third subpixel Sγ are repeated in this order, and in the column direction W2, the first subpixel Sα, the second subpixel Sβ, and the third subpixel Sγ are arranged consecutively.

[0039] Furthermore, each of the multiple pixels G that make up the image is composed of one first sub-pixel Sα, one second sub-pixel Sβ, and one third sub-pixel Sγ, which are arranged consecutively along the row direction W1. The pixels G are square in shape when viewed from above the liquid crystal display panel 20. The multiple pixels G are arranged in a matrix along the row direction W1 and the column direction W2.

[0040] Furthermore, the second liquid crystal display panel 20b is positioned on the display device 1 such that the row direction W1 (first panel direction D1) is aligned with the X direction (corresponding to the "second direction") and the column direction W2 (second panel direction D2) is aligned with the Y direction (corresponding to the "first direction" in the first embodiment) (see Figures 1 and 5).

[0041] Figure 6 shows the arrangement of subpixels S in the first liquid crystal display panel 20a shown in Figure 1. The shape and size of the subpixels S in a plan view are the same for the first liquid crystal display panel 20a and the second liquid crystal display panel 20b. The arrangement of subpixels S in the first liquid crystal display panel 20a is a stripe arrangement, similar to that of the second liquid crystal display panel 20b.

[0042] The first liquid crystal display panel 20a is positioned on the display device 1 such that its row direction W1 (first panel direction D1) aligns with the Y direction and its column direction W2 (second panel direction D2) aligns with the X direction (see Figures 1 and 5). As a result, the angle between the row direction W1 of the first liquid crystal display panel 20a and the row direction W1 of the second liquid crystal display panel 20b is 90°.

[0043] Light from the light source device 10 is incident on the first polarizing plate 30 shown in Figure 1. The first polarizing plate 30 transmits linearly polarized light along the first polarization direction. The first polarization direction is perpendicular to the Z direction. The light transmitted through the first polarizing plate 30 is linearly polarized light along the first polarization direction. The light transmitted through the first polarizing plate 30 is incident on the first liquid crystal display panel 20a.

[0044] The second polarizer 40 is incident on the transmitted light from the second liquid crystal display panel 20b. The second polarizer 40 transmits linearly polarized light along the second polarization direction, which is different from the first polarization direction. The second polarization direction is perpendicular to the Z direction and the first polarization direction. The transmitted light from the second polarizer 40 (i.e., the light transmitted through the first polarizer 30, the first liquid crystal display panel 20a, the second liquid crystal display panel 20b, and the second polarizer 40: the same applies hereafter) is linearly polarized light along the second polarization direction. The transmitted light from the second polarizer 40 is visible to the user M of the display device 1.

[0045] Furthermore, no polarizing plate is placed between the first liquid crystal display panel 20a and the second liquid crystal display panel 20b. With the display device 1 configured in this way, when no voltage is applied to the second liquid crystal display panel 20b, the user M can view the image displayed on the first liquid crystal display panel 20a, and when no voltage is applied to the first liquid crystal display panel 20a, the user M can view the image displayed on the second liquid crystal display panel 20b (details will be described later).

[0046] Next, the operation of the display device 1 will be described. First, we will describe the case where the display method of the liquid crystal display panel 20 is the so-called normally black method, and no image signal is transmitted from the external device 100 to the display device 1, and the display device 1 displays black. In this case, in both the first liquid crystal display panel 20a and the second liquid crystal display panel 20b, the drive circuit 21 does not apply voltage to the sub-pixel S, and no electric field is generated in the liquid crystal layer 23. As a result, the orientation of the liquid crystal molecules LM is restricted to the initial orientation (horizontal orientation: direction perpendicular to the Z direction) by the alignment film AL.

[0047] Light from the light source device 10 is incident on the first polarizing plate 30. The transmitted light from the first polarizing plate 30 is incident on the liquid crystal layer 23 of the first liquid crystal display panel 20a.

[0048] When the orientation of the liquid crystal molecules LM is restricted to their initial orientation by the alignment film AL, the polarization axis of the light transmitted through the liquid crystal layer 23 does not rotate. The light transmitted through the liquid crystal layer 23 of the first liquid crystal display panel 20a passes through the first liquid crystal display panel 20a while maintaining its first polarization direction and is incident on the second liquid crystal display panel 20b.

[0049] In the liquid crystal layer 23 of the second liquid crystal display panel 20b, similar to the liquid crystal layer 23 of the first liquid crystal display panel 20a, the polarization axis of the light transmitted through the liquid crystal layer 23 does not rotate. The light transmitted through the liquid crystal layer 23 of the second liquid crystal display panel 20b passes through the second liquid crystal display panel 20b while maintaining the first polarization direction, and is incident on the second polarizing plate 40.

[0050] The first polarization direction of the light transmitted from the second liquid crystal display panel 20b is perpendicular to the second polarization direction of the second polarizing plate 40. Therefore, the light transmitted from the second liquid crystal display panel 20b does not pass through the second polarizing plate 40. As a result, the user M perceives black.

[0051] Next, the operation of the liquid crystal display panel 20 in display area DA will be described. The drive circuit 21 generates sub-pixel signals based on the image signal transmitted from the external device 100 and outputs the sub-pixel signals to a plurality of sub-pixels S via the signal output circuit 21b. The sub-pixel signals include sub-gradation data indicating the gradation of the sub-pixels S.

[0052] Furthermore, when the sub-pixel S is scanned by the scanning circuit 21c, the switching element SW is operated, and a sub-pixel signal is transmitted to the sub-pixel electrode PE. This creates a potential difference between the common electrode CE and the sub-pixel electrode PE, generating an electric field in the liquid crystal layer 23, which changes the orientation of the liquid crystal molecules LM. The orientation of the liquid crystal molecules LM corresponds to the sub-gradation data. As a result, the light transmitted through the liquid crystal layer 23 is modulated for each sub-pixel S. Also, the light transmitted through the color filter CF has the color of the color filter CF. In this way, the brightness and color of the light transmitted through the liquid crystal display panel 20 are adjusted for each sub-pixel S, and an image is displayed in the display area DA.

[0053] Next, we will describe the case where user M views the first image displayed on the first liquid crystal display panel 20a and then views the second image displayed on the second liquid crystal display panel 20b.

[0054] To simplify the explanation, we will describe the case in the display device 1 shown in Figure 1 where the first image is visible in the first region R1 on the -X side of the boundary line Lr, and the second image is visible in the second region R2 on the +X side of the boundary line Lr.

[0055] An image signal containing information about the first image is transmitted to the first liquid crystal display panel 20a. Based on the image signal, a sub-pixel signal is generated in the first liquid crystal display panel 20a, applying a voltage to the sub-pixel S corresponding to the first region R1, while no voltage is applied to the sub-pixel S corresponding to the second region R2. In Figure 1, the liquid crystal layer 23 with hatching indicates that a voltage is applied to the sub-pixel S, and the liquid crystal layer 23 without hatching indicates that no voltage is applied to the sub-pixel S (the same applies to Figure 7, which will be described later).

[0056] Meanwhile, an image signal containing information about the second image is transmitted to the second liquid crystal display panel 20b. Based on the image signal, a sub-pixel signal is generated in the second liquid crystal display panel 20b, so no voltage is applied to the sub-pixel S corresponding to the first region R1, while a voltage is applied to the sub-pixel S corresponding to the second region R2.

[0057] In the first region R1, the transmitted light from the first liquid crystal display panel 20a is modulated, causing the first image to be displayed in the display area DA of the first liquid crystal display panel 20a. Furthermore, the transmitted light from the first liquid crystal display panel 20a is incident on the second liquid crystal display panel 20b. No voltage is applied to the sub-pixels S in the second liquid crystal display panel 20b, and therefore the transmitted light in the second liquid crystal display panel 20b is not modulated. Thus, the transmitted light from the second polarizer 40 in the first region R1 is perceived by the user M as the first image.

[0058] On the other hand, in the second region R2, no voltage is applied to the sub-pixel S in the first liquid crystal display panel 20a, and the transmitted light from the first liquid crystal display panel 20a is not modulated. Furthermore, the transmitted light from the first liquid crystal display panel 20a is incident on the second liquid crystal display panel 20b. In the second region R2, the transmitted light from the second liquid crystal display panel 20b is modulated, causing the second image to be displayed in the display area DA of the second liquid crystal display panel 20b. Therefore, the transmitted light from the second polarizer 40 in the second region R2 is perceived by the user M as the second image. Needless to say, the ranges of the first region R1 and the second region R2 are not limited to the range shown in Figure 1, and will vary depending on the shape, size, and range of the first and second images.

[0059] As described above, the first liquid crystal display panel 20a and the second liquid crystal display panel 20b are arranged to be separated in the Z direction. This allows the user M to view a three-dimensional image composed of the first image and the second image. However, as will be explained below, the arrangement of the first liquid crystal display panel 20a and the second liquid crystal display panel 20b may cause so-called moiré patterns.

[0060] Figure 7 is a schematic diagram of a comparative example display device 2 used to illustrate moiré patterns. Similar to the display device 1 described above, the comparative example display device 2 comprises a light source device 10, a first polarizing plate 30, a first liquid crystal display panel 20a, a second liquid crystal display panel 20b, and a second polarizing plate 40.

[0061] In the comparative example display device 2, the orientation of the first liquid crystal display panel 20a differs from that of the display device 1 described above. In the comparative example display device 2, the first liquid crystal display panel 20a is positioned on the display device 1 such that, like the second liquid crystal display panel 20b, the row direction W1 (first panel direction D1) is aligned with the X direction and the column direction W2 (second panel direction D2) is aligned with the Y direction. As a result, the row direction W1 of the first liquid crystal display panel 20a and the row direction W1 of the second liquid crystal display panel 20b are parallel to the X direction and are parallel to each other. In addition, the periphery of the sub-pixel S of the first liquid crystal display panel 20a and the periphery of the sub-pixel S of the second liquid crystal display panel 20b overlap in a plan view.

[0062] When a voltage is applied to the sub-pixels S of the first liquid crystal display panel 20a, a white image is displayed across the entire display area DA of the first liquid crystal display panel 20a. When no voltage is applied to the sub-pixels S of the second liquid crystal display panel 20b, and the display device 1 allows the user M to see a white image, this state is referred to as the white display state. When the display device 1 is in the white display state, the luminance of the transmitted light in each of the multiple sub-pixels S of the first liquid crystal display panel 20a is approximately equal to that of the others. The comparative example display device 2 shown in Figure 7 is in the white display state.

[0063] The first light L1, second light L2, and third light L3 shown in Figure 7 are transmitted light from the second polarizer 40. The first light L1 is directed towards the user M along the Z direction. The second light L2 is directed towards the user M along the first inclination direction T1, which is inclined with respect to the Z and X directions. The third light L3 is directed towards the user M along the second inclination direction T2, which is inclined more sharply with respect to the Z and X directions than the first inclination direction T1. In this case, as will be explained below, the brightness of subpixels S of the same color differs from one another among the first light L1, second light L2, and third light L3.

[0064] Figure 8 shows the arrangement of subpixels S of the first liquid crystal display panel 20a and the second liquid crystal display panel 20b when the user M views the comparative example display device 2 shown in Figure 7 along the Z direction. In Figure 8, only the second subpixel Sβ is shown among the multiple subpixels S (the same applies to Figures 9 and 10 described later).

[0065] As described above, the periphery of the sub-pixel S of the first liquid crystal display panel 20a and the periphery of the sub-pixel S of the second liquid crystal display panel 20b overlap in a plan view. Therefore, in the Z direction, the overlapping portion (hatched portion) of the second sub-pixel Sβ of the first liquid crystal display panel 20a and the second sub-pixel Sβ of the second liquid crystal display panel 20b extends to the entire second sub-pixel Sβ. Consequently, in the Z direction, the transmitted light from the second sub-pixel Sβ of the first liquid crystal display panel 20a is almost completely transmitted through the second sub-pixel Sβ of the second liquid crystal display panel 20b.

[0066] Figure 9 shows the arrangement of subpixels S of the first liquid crystal display panel 20a and the second liquid crystal display panel 20b when the user M views the comparative example display device 2 shown in Figure 7 along the first tilt direction T1. In Figure 9, the second subpixel Sβ of the first liquid crystal display panel 20a is shown by a dashed line, and the second subpixel Sβ of the second liquid crystal display panel 20b is shown by a solid line (the same applies to Figure 10, which will be described later).

[0067] As shown in Figure 9, the subpixel S of the second liquid crystal display panel 20b is offset in the X direction by half the short-side length of the subpixel S relative to the subpixel S of the first liquid crystal display panel 20a. Therefore, focusing on the second subpixel Sβ, the overlapping portion (hatched portion) of the second subpixel Sβ of the first liquid crystal display panel 20a and the second subpixel Sβ of the second liquid crystal display panel 20b in the first tilt direction T1 corresponds to half of the second subpixel Sβ. Consequently, in the first tilt direction T1, a portion of the transmitted light from the second subpixel Sβ of the first liquid crystal display panel 20a is transmitted through the second subpixel Sβ of the second liquid crystal display panel 20b in the first tilt direction T1. In other words, with respect to the brightness of the transmitted light from the second subpixel Sβ, the second light L2 is lower than the first light L1. This is also true for the first subpixel Sα and the third subpixel Sγ.

[0068] Figure 10 shows the arrangement of subpixels S of the first liquid crystal display panel 20a and the second liquid crystal display panel 20b when the user M views the comparative example display device 2 shown in Figure 7 along the second tilt direction T2.

[0069] As shown in Figure 10, the subpixel S of the second liquid crystal display panel 20b is offset in the X direction by the length of the shorter side of the subpixel S relative to the subpixel S of the first liquid crystal display panel 20a. Therefore, in the second tilt direction T2, the second subpixel Sβ of the first liquid crystal display panel 20a and the second subpixel Sβ of the second liquid crystal display panel 20b do not overlap. Consequently, in the second tilt direction T2, almost all of the transmitted light from the second subpixel Sβ of the first liquid crystal display panel 20a does not pass through the second subpixel Sβ of the second liquid crystal display panel 20b in the first tilt direction T1. In other words, with respect to the brightness of the transmitted light from the second subpixel Sβ, the third light L3 is lower than the second light L2. This is also true for the first subpixel Sα and the third subpixel Sγ.

[0070] Thus, the brightness of subpixels S of the same color decreases in the order of the first light source L1, the second light source L2, and the third light source L3. Therefore, the brightness of subpixels S of the same color changes depending on the degree of light gradient perceived by the user M. In other words, the brightness of subpixels S of the same color also changes when the subpixels S of the first liquid crystal display panel 20a and the subpixels S of the second liquid crystal display panel 20b are shifted in the X direction.

[0071] Figure 11 shows the relationship between the amount of X-direction displacement between the sub-pixel S of the first liquid crystal display panel 20a and the sub-pixel S of the second liquid crystal display panel 20b, and the brightness of the transmitted light from the second polarizing plate 40, when the display devices 1 and 2 are in a white display state.

[0072] The horizontal axis in the figure represents the displacement of the sub-pixel S. The displacement of the sub-pixel S corresponds to the displacement of the pixel G, with the displacement of one pixel G corresponding to 1. The vertical axis in the figure represents the luminance of the transmitted light from the second polarizer 40 (hereinafter sometimes simply referred to as luminance). The vertical axis in Figure 11 represents the luminance per sub-pixel S. The luminance is defined as 1 when all of the transmitted light from one sub-pixel S of the first liquid crystal display panel 20a passes through the second liquid crystal display panel 20b (the same applies to Figures 12, 16, and 17 described later).

[0073] In Figure 11, the luminance of the subpixel S in the comparative example display device 2 with respect to the X-direction displacement is shown by a dashed line. The luminance of the subpixel S with respect to the X-direction displacement fluctuates periodically. This is because the first subpixel Sα, the second subpixel Sβ, and the third subpixel Sγ are repeated in this order along the X-direction.

[0074] Figure 12 shows the relationship between the amount of Y-direction displacement between the sub-pixel S of the first liquid crystal display panel 20a and the sub-pixel S of the second liquid crystal display panel 20b, and the brightness of the transmitted light from the second polarizing plate 40, when the display device 1 in Figure 1 and the comparative example display device 2 are in a white display state.

[0075] In Figure 12, the luminance with respect to the amount of displacement in the Y direction of the subpixel S in the comparative example display device 2 is shown by a dashed line. The luminance with respect to the amount of displacement in the Y direction of the subpixel S fluctuates periodically. Furthermore, in the comparative example display device 2, the range of luminance fluctuation in Figure 12 is smaller than the range of luminance fluctuation in Figure 11. This is because subpixels S of the same color are arranged continuously along the Y direction. In addition, in the comparative example display device 2, when the subpixel S of the first liquid crystal display panel 20a and the subpixel S of the second liquid crystal display panel 20b are shifted in the Y direction, the luminance decreases as they cross the light-shielding film SM.

[0076] As described above, a change in the amount of displacement of the subpixels S is equivalent to a change in the degree of inclination of the transmitted light from the second polarizer 40 toward the user M. Furthermore, the luminance with respect to the amount of displacement of the subpixels S fluctuates periodically. Therefore, as the luminance of the transmitted light from the second polarizer 40 fluctuates periodically in relation to the degree of inclination of the transmitted light from the second polarizer 40 toward the user M, there is a possibility that moiré patterns will occur, causing the user M to perceive striped patterns. For this reason, in the display device 1 of this first embodiment, the arrangement of subpixels S in the first liquid crystal display panel 20a and the second liquid crystal display panel 20b is determined as described above (Figures 5 and 6).

[0077] Figure 13 shows the positional relationship between the sub-pixels S of the first liquid crystal display panel 20a and the sub-pixels S of the second liquid crystal display panel 20b in the display device 1 of Figure 1. In Figure 13, only the second sub-pixel Sβ of the first liquid crystal display panel 20a is shown with a dashed line. In the second liquid crystal display panel 20b, the second sub-pixel Sβ is shown with a thick solid line, and the first sub-pixel Sα and the third sub-pixel Sγ are shown with thin solid lines (the same applies to Figures 15, 19, 23, and 27 described later).

[0078] In the display device 1, the first liquid crystal display panel 20a and the second liquid crystal display panel 20b are arranged such that the angle between the row direction W1 of the first liquid crystal display panel 20a and the row direction W1 of the second liquid crystal display panel 20b is 90°.

[0079] Focusing on the second subpixel Sβ, in a plan view, the area where the second subpixel Sβ of the first liquid crystal display panel 20a and the second subpixel Sβ of the second liquid crystal display panel 20b overlap (the hatched area) corresponds to a part of the second subpixel Sβ. Also, in a plan view, the second subpixel Sβ of the first liquid crystal display panel 20a overlaps with both the first subpixel Sα and the third subpixel Sγ of the second liquid crystal display panel 20b. In other words, in a plan view, the second color filter CF2 of the first liquid crystal display panel 20a overlaps with the first color filter CF1, the second color filter CF2, and the third color filter CF3 of the second liquid crystal display panel 20b.

[0080] Similarly, in a plan view, the overlapping portion of the first sub-pixel Sα of the first liquid crystal display panel 20a and the first sub-pixel Sα of the second liquid crystal display panel 20b corresponds to a part of the first sub-pixel Sα. Also, in a plan view, the first sub-pixel Sα of the first liquid crystal display panel 20a overlaps with both the second sub-pixel Sβ and the third sub-pixel Sγ of the second liquid crystal display panel 20b. In other words, in a plan view, the first color filter CF1 of the first liquid crystal display panel 20a overlaps with the first color filter CF1, the second color filter CF2, and the third color filter CF3 of the second liquid crystal display panel 20b.

[0081] Similarly, in a plan view, the overlapping portion of the third sub-pixel Sγ of the first liquid crystal display panel 20a and the third sub-pixel Sγ of the second liquid crystal display panel 20b corresponds to a part of the third sub-pixel Sγ. Also, in a plan view, the third sub-pixel Sγ of the first liquid crystal display panel 20a overlaps with both the first sub-pixel Sα and the second sub-pixel Sβ of the second liquid crystal display panel 20b. In other words, in a plan view, the third color filter CF3 of the first liquid crystal display panel 20a overlaps with the first color filter CF1, the second color filter CF2, and the third color filter CF3 of the second liquid crystal display panel 20b.

[0082] Thus, in the display device 1, the first liquid crystal display panel 20a and the second liquid crystal display panel 20b are arranged such that at least the first color filter CF1 of the first liquid crystal display panel 20a and the second color filter CF2 of the second liquid crystal display panel 20b overlap in a plan view.

[0083] Next, we will explain how moiré patterns occur when the display device 1 is in a white display state.

[0084] In Figure 11, the relationship between the X-direction displacement of the sub-pixel S in display device 1 and the brightness is shown by a solid line. The brightness in display device 1 also fluctuates periodically with respect to the X-direction displacement of the sub-pixel S, similar to the comparative example display device 2. However, regarding the range of brightness fluctuation in Figure 11, the fluctuation range B1 of display device 1 is smaller than the fluctuation range B2 of the comparative example display device 2. Therefore, compared to the comparative example display device 2, display device 1 can suppress the occurrence of moiré patterns by suppressing the brightness fluctuation due to the X-direction displacement of the sub-pixel S.

[0085] Furthermore, in Figure 12, the relationship between the amount of Y-direction displacement of the sub-pixel S in the display device 1 and the brightness is shown by a solid line. The brightness in relation to the amount of Y-direction displacement of the sub-pixel S in the display device 1 also fluctuates periodically, similar to the comparative example display device 2. Regarding the range of brightness fluctuation in Figure 12, the range of fluctuation B3 of the display device 1 is larger than the range of fluctuation B4 of the comparative example display device 2.

[0086] However, the degree to which the fluctuation range B1 of display device 1 is suppressed compared to the fluctuation range B2 of display device 2 in the comparative example shown in Figure 11 is greater than the degree to which the fluctuation range B3 of display device 1 is increased compared to the fluctuation range B4 of display device 2 in the comparative example shown in Figure 12. Therefore, display device 1 can suppress the occurrence of moiré patterns more effectively than display device 2 in the comparative example.

[0087] Furthermore, the orientation of the liquid crystal display panels 20 in the display device 1 and the arrangement direction of the sub-pixels S in the liquid crystal display panels 20 may be changed so that the angle between the row direction W1 of the first liquid crystal display panel 20a and the row direction W1 of the second liquid crystal display panel 20b is 90°. For example, in the first liquid crystal display panel 20a, multiple sub-pixels S may be arranged such that the row direction W1 is aligned with the second panel direction D2 and the column direction W2 is aligned with the first panel direction D1. In this case, the first liquid crystal display panel 20a is arranged in the display device 1 such that the row direction W1 (second panel direction D2) is aligned with the Y direction and the column direction W2 (first panel direction D1) is aligned with the X direction.

[0088] <Second Embodiment> Next, the display device 1 of the second embodiment of this disclosure will be described, primarily in terms of its differences from the display device 1 of the first embodiment described above.

[0089] Figure 14 shows the arrangement of subpixels S in the first liquid crystal display panel 120a of the display device 1 according to the second embodiment of this disclosure.

[0090] In this second embodiment, the first liquid crystal display panel 120a is positioned on the display device 1 such that the row direction W1 (first panel direction D1) is aligned with the Q direction (corresponding to the "first direction" in the second embodiment). The Q direction is perpendicular to the Z direction and inclined with respect to the X and Y directions. The angle between the Q direction and the X direction is 45°. The arrangement of subpixels S in the second liquid crystal display panel 20b of the second embodiment is the same as the arrangement of subpixels S shown in Figure 5. Therefore, the angle between the row direction W1 of the first liquid crystal display panel 120a and the row direction W1 of the second liquid crystal display panel 20b is 45°.

[0091] Figure 15 is a diagram showing the positional relationship between the sub-pixels S of the first liquid crystal display panel 120a and the sub-pixels S of the second liquid crystal display panel 20b in the display device 1 of the second embodiment. Hatching is applied to the area where the second sub-pixel Sβ of the first liquid crystal display panel 120a and the second sub-pixel Sβ of the second liquid crystal display panel 20b overlap in the Z direction.

[0092] The second sub-pixel Sβ of the first liquid crystal display panel 120a overlaps with the first sub-pixel Sα, second sub-pixel Sβ, and third sub-pixel Sγ of the second liquid crystal display panel 20b, respectively. In other words, in a planar view, the second color filter CF2 of the first liquid crystal display panel 120a overlaps with the first color filter CF1, second color filter CF2, and third color filter CF3 of the second liquid crystal display panel 20b, respectively.

[0093] Similarly, in a plan view, the first color filter CF1 and the third color filter CF3 of the first liquid crystal display panel 120a overlap with the first color filter CF1, the second color filter CF2, and the third color filter CF3 of the second liquid crystal display panel 20b, respectively.

[0094] Figure 16 shows the relationship between the amount of X-direction displacement between the sub-pixel S of the first liquid crystal display panel 120a and the sub-pixel S of the second liquid crystal display panel 20b, and the brightness of the transmitted light from the second polarizing plate 40, when the display device 1 of the second embodiment is displaying white.

[0095] In the second embodiment of the display device 1, the brightness with respect to the amount of displacement of the sub-pixel S in the X direction also fluctuates periodically, similar to the comparative example display device 2. However, with respect to the range of brightness fluctuation in Figure 16, the range B1 of the second embodiment of the display device 1 is smaller than the range B2 of the comparative example display device 2. As a result, the display device 1 of the second embodiment can suppress the occurrence of moiré patterns by suppressing the brightness fluctuation due to the displacement of the sub-pixel S in the X direction, compared to the comparative example display device 2.

[0096] Figure 17 shows the relationship between the amount of Y-direction displacement between the sub-pixel S of the first liquid crystal display panel 120a and the sub-pixel S of the second liquid crystal display panel 20b, and the brightness of the transmitted light from the second polarizing plate 40, when the display device 1 of the second embodiment is displaying white.

[0097] In the second embodiment of the display device 1, the luminance with respect to the amount of displacement in the Y direction of the subpixel S also fluctuates periodically, similar to the comparative example of the display device 2. Regarding the luminance fluctuation range in Figure 17, the fluctuation range B3 of the second embodiment of the display device 1 is larger than the fluctuation range B4 of the comparative example of the display device 2.

[0098] However, the degree to which the fluctuation range B1 of the display device 1 is suppressed relative to the fluctuation range B2 of the comparative example display device 2 shown in Figure 16 is greater than the degree to which the fluctuation range B3 of the display device 1 is increased relative to the fluctuation range B4 of the comparative example display device 2 shown in Figure 17. Therefore, the display device 1 of the second embodiment can suppress the occurrence of moiré patterns compared to the display device 2 of the comparative example.

[0099] Furthermore, the orientation of the liquid crystal display panel 20 in the display device 1 and the arrangement direction of the sub-pixels S in the liquid crystal display panel 20 may be changed so that the angle between the row direction W1 of the first liquid crystal display panel 120a and the row direction W1 of the second liquid crystal display panel 20b is 45°. For example, in the first liquid crystal display panel 120a, multiple sub-pixels S may be arranged such that the row direction W1 is aligned with the second panel direction D2 and the column direction W2 is aligned with the first panel direction D1. In this case, the first liquid crystal display panel 120a is arranged in the display device 1 such that the row direction W1 (second panel direction D2) is aligned with the Q direction and the column direction W2 (first panel direction D1) is aligned with a direction perpendicular to the Q direction and the Z direction.

[0100] Furthermore, it goes without saying that in the display device 1 of this second embodiment, the angle between the Q direction and the Y direction is not limited to 45°.

[0101] <Third Embodiment> Next, the display device 1 of the third embodiment of this disclosure will be described, primarily in terms of its differences from the display device 1 of the first embodiment described above.

[0102] Figure 18 shows the arrangement of subpixels S in the first liquid crystal display panel 220a of the display device 1 according to the third embodiment of this disclosure. The shape and size of the subpixels S in a plan view are the same for the first liquid crystal display panel 220a and the second liquid crystal display panel 20b. In addition, in the first liquid crystal display panel 220a of this third embodiment, three subpixels S arranged consecutively along the row direction W1 correspond to one pixel G.

[0103] In the first liquid crystal display panel 220a, the multiple subpixels S are arranged such that the first subpixel Sα, the second subpixel Sβ, and the third subpixel Sγ are repeated in this order in the row direction W1 and the column direction W2, respectively.

[0104] The first liquid crystal display panel 220a is positioned on the display device 1 such that its row direction W1 (first panel direction D1) aligns with the X direction and its column direction W2 (second panel direction D2) aligns with the Y direction. Therefore, the row direction W1 of the first liquid crystal display panel 220a and the row direction W1 of the second liquid crystal display panel 20b are parallel to the X direction and are parallel to each other.

[0105] Figure 19 shows the positional relationship between the sub-pixels S of the first liquid crystal display panel 220a and the sub-pixels S of the second liquid crystal display panel 20b in the display device 1 of the third embodiment. The arrangement of the sub-pixels S of the second liquid crystal display panel 20b is the same as that of the second liquid crystal display panel 20b in the first embodiment (Figure 5). Hatching is applied to the area where the second sub-pixel Sβ of the first liquid crystal display panel 220a and the second sub-pixel Sβ of the second liquid crystal display panel 20b overlap in the Z direction.

[0106] The second sub-pixel Sβ of the first liquid crystal display panel 220a overlaps with the first sub-pixel Sα, second sub-pixel Sβ, and third sub-pixel Sγ of the second liquid crystal display panel 20b, respectively. In other words, in a planar view, the second color filter CF2 of the first liquid crystal display panel 220a overlaps with the first color filter CF1, second color filter CF2, and third color filter CF3 of the second liquid crystal display panel 20b, respectively.

[0107] Similarly, in a planar view, the first color filter CF1 and the third color filter CF3 of the first liquid crystal display panel 220a overlap with the first color filter CF1, the second color filter CF2, and the third color filter CF3 of the second liquid crystal display panel 20b, respectively.

[0108] Figure 20 shows the relationship between the amount of X-direction displacement between the sub-pixel S of the first liquid crystal display panel 220a and the sub-pixel S of the second liquid crystal display panel 20b, and the brightness of the transmitted light from the second polarizing plate 40, when the display device 1 of the third embodiment is displaying white.

[0109] The vertical axis in Figure 20 represents the luminance per subpixel S in the first range H1 shown in Figure 18. The luminance is defined as 1 when all of the transmitted light from the six subpixels S of the first liquid crystal display panel 220a passes through the second liquid crystal display panel 20b (the same applies to Figure 21, which will be described later). The six subpixels S in the first range H1 correspond to two pixels G and include two first subpixels Sα, two second subpixels Sβ, and two third subpixels Sγ.

[0110] In the third embodiment of the display device 1, the brightness with respect to the amount of displacement of the sub-pixel S in the X direction also fluctuates periodically, similar to the comparative example display device 2. However, with respect to the range of brightness fluctuation in Figure 20, the range B1 of the third embodiment of the display device 1 is smaller than the range B2 of the comparative example display device 2. As a result, the display device 1 of the third embodiment can suppress the occurrence of moiré patterns by suppressing the brightness fluctuation due to the displacement of the sub-pixel S in the X direction, compared to the comparative example display device 2.

[0111] Figure 21 shows the relationship between the amount of Y-direction displacement between the sub-pixel S of the first liquid crystal display panel 220a and the sub-pixel S of the second liquid crystal display panel 20b and the brightness of the transmitted light of the second polarizing plate 40 when the display device 1 of the third embodiment is displaying white.

[0112] In the third embodiment of the display device 1, the luminance with respect to the amount of displacement in the Y direction of the subpixel S also fluctuates periodically, similar to the comparative example of the display device 2. Regarding the luminance fluctuation range in Figure 21, the fluctuation range B3 of the third embodiment of the display device 1 is larger than the fluctuation range B4 of the comparative example of the display device 2.

[0113] However, the degree to which the fluctuation range B1 of the display device 1 is suppressed relative to the fluctuation range B2 of the comparative example display device 2 shown in Figure 20 is greater than the degree to which the fluctuation range B3 of the display device 1 is increased relative to the fluctuation range B4 of the comparative example display device 2 shown in Figure 21. Therefore, the display device 1 of the third embodiment can suppress the occurrence of moiré patterns compared to the display device 2 of the comparative example.

[0114] <Fourth Embodiment> Next, the display device 1 of the fourth embodiment of this disclosure will be described, primarily in terms of its differences from the display device 1 of the first embodiment described above.

[0115] Figure 22 shows the arrangement of subpixels S in the first liquid crystal display panel 320a of the display device 1 according to the fourth embodiment of this disclosure.

[0116] Regarding the size of the subpixels S, the first liquid crystal display panel 320a is smaller than that of the second liquid crystal display panel 20b. The size of the subpixels S of the second liquid crystal display panel 20b is the same as that of the second liquid crystal display panel 20b in the first embodiment described above, with three subpixels S arranged consecutively along the row direction W1 corresponding to one pixel G. On the other hand, the size of the subpixels S of the first liquid crystal display panel 320a in this fourth embodiment is such that six subpixels S arranged in a matrix of two rows and three columns correspond to two pixels G.

[0117] Furthermore, the ratio of the longitudinal length to the transverse length of the sub-pixel S differs between the first liquid crystal display panel 320a and the second liquid crystal display panel 20b. Specifically, the longitudinal length of the sub-pixel S is shorter in the first liquid crystal display panel 320a than in the second liquid crystal display panel 20b, while the transverse length of the sub-pixel S is longer in the first liquid crystal display panel 320a than in the second liquid crystal display panel 20b.

[0118] Furthermore, in the first liquid crystal display panel 320a of this fourth embodiment, the multiple subpixels S are arranged such that in the row direction W1, the first subpixel Sα, the second subpixel Sβ, and the third subpixel Sγ are repeated in this order, and in the column direction W2, the first subpixel Sα, the third subpixel Sγ, and the second subpixel Sβ are repeated in this order.

[0119] The first liquid crystal display panel 320a is positioned on the display device 1 such that its row direction W1 (first panel direction D1) aligns with the X direction and its column direction W2 (second panel direction D2) aligns with the Y direction. Therefore, the row direction W1 of the first liquid crystal display panel 320a and the row direction W1 of the second liquid crystal display panel 20b are parallel to the X direction and are parallel to each other.

[0120] Figure 23 shows the positional relationship between the sub-pixels S of the first liquid crystal display panel 320a and the sub-pixels S of the second liquid crystal display panel 20b in the display device 1 of the fourth embodiment. The arrangement of the sub-pixels S of the second liquid crystal display panel 20b is the same as that of the second liquid crystal display panel 20b in the first embodiment (Figure 5). Hatching is applied to the area where the second sub-pixel Sβ of the first liquid crystal display panel 320a and the second sub-pixel Sβ of the second liquid crystal display panel 20b overlap in the Z direction.

[0121] The second sub-pixel Sβ of the first liquid crystal display panel 320a overlaps with the first sub-pixel Sα, second sub-pixel Sβ, and third sub-pixel Sγ of the second liquid crystal display panel 20b, respectively. In other words, in a planar view, the second color filter CF2 of the first liquid crystal display panel 320a overlaps with the first color filter CF1, second color filter CF2, and third color filter CF3 of the second liquid crystal display panel 20b, respectively.

[0122] Similarly, the first color filter CF1 and the third color filter CF3 of the first liquid crystal display panel 320a overlap with the first color filter CF1, the second color filter CF2, and the third color filter CF3 of the second liquid crystal display panel 20b, respectively.

[0123] Figure 24 shows the relationship between the amount of X-direction displacement between the sub-pixel S of the first liquid crystal display panel 320a and the sub-pixel S of the second liquid crystal display panel 20b and the brightness of the transmitted light of the second polarizing plate 40 when the display device 1 of the fourth embodiment is displaying white.

[0124] The vertical axis in Figure 24 represents the luminance per subpixel S in the second range H2 shown in Figure 22. The luminance is defined as 1 when all of the transmitted light from the six subpixels S of the first liquid crystal display panel 320a passes through the second liquid crystal display panel 20b (the same applies to Figure 25, which will be described later). The six subpixels S in the second range H2 are six subpixels S arranged consecutively along the row direction W1, and include two first subpixels Sα, two second subpixels Sβ, and three third subpixels Sγ.

[0125] In the display device 1 of the fourth embodiment, the brightness with respect to the amount of displacement of the sub-pixel S in the X direction also fluctuates periodically, similar to the display device 2 of the comparative example. However, with respect to the range of brightness fluctuation in Figure 24, the range B1 of the display device 1 of the fourth embodiment is smaller than the range B2 of the display device 2 of the comparative example. As a result, the display device 1 of the fourth embodiment can suppress the occurrence of moiré patterns by suppressing the brightness fluctuation due to the displacement of the sub-pixel S in the X direction, compared to the display device 2 of the comparative example.

[0126] Figure 25 shows the relationship between the amount of Y-direction displacement between the sub-pixel S of the first liquid crystal display panel 320a and the sub-pixel S of the second liquid crystal display panel 20b, and the brightness of the transmitted light from the second polarizing plate 40, when the display device 1 of the fourth embodiment is displaying white.

[0127] In the display device 1 of the fourth embodiment, the brightness with respect to the amount of displacement in the Y direction of the subpixel S also fluctuates periodically, similar to the display device 2 of the comparative example. Regarding the range of brightness fluctuation in Figure 25, the range B3 of the display device 1 of the fourth embodiment is approximately the same as the range B4 of the display device 2 of the comparative example. Therefore, the display device 1 of the fourth embodiment can suppress the occurrence of moiré patterns compared to the display device 2 of the comparative example.

[0128] <Fifth Embodiment> Next, the display device 1 of the fifth embodiment of this disclosure will be described, primarily in terms of its differences from the display device 1 of the first embodiment described above.

[0129] Figure 26 shows the arrangement of subpixels S in the first liquid crystal display panel 420a of the display device 1 according to the fifth embodiment of this disclosure. The shape and size of the subpixels S in a plan view are the same for the first liquid crystal display panel 420a and the second liquid crystal display panel 20b. In addition, in the first liquid crystal display panel 420a of this fifth embodiment, three subpixels S arranged consecutively along the row direction W1 correspond to one pixel G.

[0130] The plurality of subpixels S of the first liquid crystal display panel 420a in this fifth embodiment further include a fourth subpixel Sδ having a fourth color filter CF4 whose color is different from that of the first color filter CF1, the second color filter CF2, and the third color filter CF3. The color of the fourth color filter CF4 is white. The fourth color filter CF4 may also be colorless and transparent.

[0131] In the first liquid crystal display panel 420a, the multiple subpixels S are arranged such that in the row direction W1, the first subpixel Sα, second subpixel Sβ, third subpixel Sγ, and fourth subpixel Sδ are repeated in this order, and in the column direction W2, the first subpixel Sα and third subpixel Sγ are arranged alternately, and the second subpixel Sβ and fourth subpixel Sδ are arranged alternately in the column direction W2.

[0132] The first liquid crystal display panel 420a is positioned on the display device 1 such that its row direction W1 (first panel direction D1) aligns with the X direction and its column direction W2 (second panel direction D2) aligns with the Y direction. Therefore, the row direction W1 of the first liquid crystal display panel 420a and the row direction W1 of the second liquid crystal display panel 20b are parallel to the X direction and are parallel to each other.

[0133] Figure 27 shows the positional relationship between the sub-pixels S of the first liquid crystal display panel 420a and the sub-pixels S of the second liquid crystal display panel 20b in the display device 1 of the fifth embodiment. The arrangement of the sub-pixels S of the second liquid crystal display panel 20b is the same as that of the second liquid crystal display panel 20b in the first embodiment (Figure 5). Hatching is applied to the area where the second sub-pixel Sβ of the first liquid crystal display panel 420a and the second sub-pixel Sβ of the second liquid crystal display panel 20b overlap in the Z direction.

[0134] The second sub-pixel Sβ of the first liquid crystal display panel 420a overlaps with the first sub-pixel Sα, second sub-pixel Sβ, and third sub-pixel Sγ of the second liquid crystal display panel 20b, respectively. In other words, in a planar view, the second color filter CF2 of the first liquid crystal display panel 420a overlaps with the first color filter CF1, second color filter CF2, and third color filter CF3 of the second liquid crystal display panel 20b.

[0135] Similarly, in a planar view, the first color filter CF1, third color filter CF3, and fourth color filter CF4 of the first liquid crystal display panel 420a overlap with the first color filter CF1, second color filter CF2, and third color filter CF3 of the second liquid crystal display panel 20b, respectively.

[0136] Figure 28 shows the relationship between the amount of X-direction displacement between the sub-pixel S of the first liquid crystal display panel 420a and the sub-pixel S of the second liquid crystal display panel 20b and the brightness of the transmitted light of the second polarizing plate 40 when the display device 1 of the fifth embodiment is displaying white.

[0137] The vertical axis in Figure 28 represents the luminance per 12 subpixels S in the third range H3 shown in Figure 26. The luminance is defined as 1 when all of the transmitted light from these 12 subpixels S of the first liquid crystal display panel 420a passes through the second liquid crystal display panel 20b (the same applies to Figure 29, which will be described later). The 12 subpixels S in the third range H3 are 12 subpixels S arranged consecutively along the row direction W1, and include 3 first subpixels Sα, 3 second subpixels Sβ, 3 third subpixels Sγ, and 3 fourth subpixels Sδ.

[0138] In the display device 1 of the fifth embodiment, the brightness with respect to the amount of displacement of the sub-pixel S in the X direction also fluctuates periodically, similar to the display device 2 of the comparative example. However, with respect to the range of brightness fluctuation in Figure 28, the range B1 of the display device 1 of the fifth embodiment is smaller than the range B2 of the display device 2 of the comparative example. As a result, the display device 1 of the fifth embodiment can suppress the occurrence of moiré patterns by suppressing the brightness fluctuation due to the displacement of the sub-pixel S in the X direction, compared to the display device 2 of the comparative example.

[0139] Figure 29 shows the relationship between the amount of Y-direction displacement between the sub-pixel S of the first liquid crystal display panel 420a and the sub-pixel S of the second liquid crystal display panel 20b, and the brightness of the transmitted light from the second polarizing plate 40, when the display device 1 of the fifth embodiment is displaying white.

[0140] In the display device 1 of the fifth embodiment, the luminance with respect to the amount of displacement in the Y direction of the subpixel S also fluctuates periodically, similar to the display device 2 of the comparative example. Regarding the luminance fluctuation range in Figure 29, the fluctuation range B3 of the display device 1 of the fifth embodiment is approximately the same as the fluctuation range B4 of the display device 2 of the comparative example. Therefore, the display device 1 of the fifth embodiment can suppress the occurrence of moiré patterns compared to the display device 2 of the comparative example.

[0141] <Other variations> 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.

[0142] For example, the above-mentioned liquid crystal display panel 20 may be a vertical electric field type liquid crystal display in which a common electrode CE is arranged on the second substrate 24 so as to face a plurality of sub-pixel electrodes PE.

[0143] Furthermore, the first liquid crystal display panel 20a and the second liquid crystal display panel 20b may be arranged in the display device 1 in an interchangeable state. In other words, the light source device 10, the first polarizing plate 30, the second liquid crystal display panel 20b, the first liquid crystal display panel 20a, and the second polarizing plate 40 may be arranged in this order from the -Z side to the +Z side.

[0144] Figure 30 shows the configuration of a display device 1 according to a modified embodiment of the present disclosure. The display device 1 may further include a diffusion sheet 550 disposed between a first liquid crystal display panel 20a and a second liquid crystal display panel 20b.

[0145] The diffusion sheet 550 diffuses the transmitted light from the first liquid crystal display panel 20a, further suppressing the occurrence of moiré patterns.

[0146] While preferred embodiments of this disclosure have been described above, this disclosure is not limited to such embodiments. The contents disclosed in the embodiments are merely examples, and various modifications are possible without departing from the spirit of this disclosure. For example, any appropriate modifications made without departing from the spirit of this disclosure naturally fall within the technical scope of the present invention. [Explanation of symbols]

[0147] 1 Display device 10 Light source device 20a First LCD display panel 20b Second LCD display panel 30. First polarizing plate 40. Second polarizing plate CF1 First Color Filter CF2 Second Color Filter CF3 Third Color Filter CF4 4th Color Filter S subpixel Sα (First Subpixel) Sβ Second Subpixel Sγ (third subpixel) SEO 4th subpixel W1 row direction W2 Column Direction

Claims

1. Light source device, A first polarizing plate is used to receive light from the aforementioned light source and transmit linearly polarized light having a first polarization direction, The first liquid crystal display panel into which the transmitted light from the first polarizing plate is incident, A second liquid crystal display panel is positioned separately from the first liquid crystal display panel, and transmitted light from the first liquid crystal display panel is incident on it. The second polarizing plate is set to receive transmitted light from the second liquid crystal display panel and transmits linearly polarized light having a second polarization direction different from the first polarization direction. A polarizing plate is not placed between the first liquid crystal display panel and the second liquid crystal display panel. The first liquid crystal display panel and the second liquid crystal display panel each have a plurality of subpixels arranged in a matrix along the row and column directions, respectively. The aforementioned plurality of sub-pixels are A first sub-pixel having a first color filter, A second sub-pixel having a second color filter, It includes a third sub-pixel having a third color filter, The first color filter, the second color filter, and the third color filter have different colors from each other. The first liquid crystal display panel and the second liquid crystal display panel are arranged such that at least the first color filter of the first liquid crystal display panel and the second color filter of the second liquid crystal display panel overlap in a plan view. Display device.

2. Each of the aforementioned subpixels is rectangular in shape with a longitudinal direction and a transverse direction in a plan view, and is arranged such that the longitudinal direction aligns with the column direction and the transverse direction aligns with the row direction. The plurality of subpixels in the first liquid crystal display panel are arranged such that, in a plan view, the row direction aligns with the first direction. The plurality of subpixels in the second liquid crystal display panel are arranged such that, in a plan view, the row direction aligns with a second direction different from the first direction. The display device according to claim 1.

3. In a plan view, the angle between the row direction of the first liquid crystal display panel and the row direction of the second liquid crystal display panel is 90°. The display device according to claim 2.

4. In a plan view, the angle between the row direction of the first liquid crystal display panel and the row direction of the second liquid crystal display panel is 45°. The display device according to claim 2.

5. In the first liquid crystal display panel and the second liquid crystal display panel, the plurality of sub-pixels are: In the row direction, the first sub-pixel, the second sub-pixel, and the third sub-pixel are arranged so as to be repeated in this order, and In the column direction, the first subpixel, the second subpixel, and the third subpixel are arranged in a continuous line. The display device according to claim 2.

6. The plurality of sub-pixels in the first liquid crystal display panel are In the row direction and the column direction, the first subpixel, the second subpixel, and the third subpixel are arranged so as to be repeated in this order. The plurality of sub-pixels in the second liquid crystal display panel are In the row direction, the first sub-pixel, the second sub-pixel, and the third sub-pixel are arranged so as to be repeated in this order, and In the column direction, the first subpixel, the second subpixel, and the third subpixel are arranged in a continuous line. The display device according to claim 1.

7. Each of the aforementioned subpixels is rectangular in shape, having a longitudinal direction and a transverse direction in a plan view. Regarding the ratio of the length in the longitudinal direction to the length in the short direction, the first liquid crystal display panel and the second liquid crystal display panel are different from each other. The plurality of sub-pixels in the first liquid crystal display panel are In the row direction, the first sub-pixel, the second sub-pixel, and the third sub-pixel are arranged in this order, and In the column direction, the first subpixel, the third subpixel, and the second subpixel are arranged in this order, and The plurality of sub-pixels in the second liquid crystal display panel are In the row direction, the first sub-pixel, the second sub-pixel, and the third sub-pixel are arranged so as to be repeated in this order, and In the column direction, the first subpixel, the second subpixel, and the third subpixel are arranged in a continuous line. The display device according to claim 1.

8. The plurality of subpixels further include a fourth subpixel having a fourth color filter whose color is different from that of the first color filter, the second color filter, and the third color filter. The plurality of sub-pixels in the first liquid crystal display panel are In the row direction, the first sub-pixel, second sub-pixel, third sub-pixel, and fourth sub-pixel are arranged in this order, and The first subpixel and the third subpixel are arranged alternately in the column direction, and the second subpixel and the fourth subpixel are arranged alternately in the column direction. The plurality of sub-pixels in the second liquid crystal display panel are In the row direction, the first sub-pixel, the second sub-pixel, and the third sub-pixel are arranged so as to be repeated in this order, and In the column direction, the first subpixel, the second subpixel, and the third subpixel are arranged in a continuous line. The display device according to claim 1.

9. The color of the fourth color filter is white. The display device according to claim 8.

10. The system further comprises a diffusion sheet disposed between the first liquid crystal display panel and the second liquid crystal display panel. The display device according to claim 1.

Images