Head-up display

Abstract

A head-up display capable of projecting two virtual images having mutually different degrees of inclination is miniaturized. A head-up display (1) is provided with: a liquid crystal display device (10) that emits first light (L1) corresponding to a first image (G1) from a display surface (10a) toward a translucent body (2) in a first emission direction (W1), and that emits second light (L2) corresponding to a second image (G2) from the display surface (10a) in a second emission direction (W2) different from the first emission direction (W1); and a reflecting plate (40) having a reflecting surface (41) on which the second light (L2) is incident and which reflects the second light (L2) toward the translucent body (2) in the first emission direction (W1).

Description

Technical Field

[0001] This disclosure relates to head-up displays. Background Technology

[0002] As an example of a head-up display, Patent Document 1 discloses a vehicle display device that projects multiple virtual images to different positions. Patent Document 2 discloses a head-up display device that projects two virtual images with different tilt angles.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2004-168230

[0004] Patent Document 2: Japanese Patent Application Publication No. 2016-137746 Summary of the Invention

[0005] In the head-up display of Patent Document 1, multiple display panels (liquid crystal display devices) are provided to display multiple virtual images. Furthermore, in the head-up display of Patent Document 2, two display surfaces with different tilt angles are provided to display two virtual images. Thus, the head-up displays of Patent Documents 1 and 2 are relatively large because they have multiple display surfaces to project multiple virtual images.

[0006] The purpose of this disclosure is to achieve miniaturization in a head-up display capable of projecting two virtual images with different tilt angles.

[0007] The head-up display disclosed herein includes: a liquid crystal display device that emits first light corresponding to a first image from a display surface toward a light-transmitting body along a first emission direction, and emits second light corresponding to a second image from the display surface along a second emission direction different from the first emission direction; and a reflector having a reflective surface for the second light to be incident upon and for reflecting the second light toward the light-transmitting body and along the first emission direction.

[0008] Furthermore, the head-up display disclosed herein includes: a liquid crystal display device that emits first light corresponding to a first image from a display surface toward a light-transmitting body along a first emission direction, and emits second light corresponding to a second image from the display surface along a second emission direction different from the first emission direction; a quarter-phase retardation plate for incident on the second light emitted from the display surface; and a reflective plate having a reflective surface that reflects light transmitted through the quarter-phase retardation plate toward the display surface along the second emission direction via the quarter-phase retardation plate, wherein a first angle between an orthogonal direction orthogonal to the display surface and the first emission direction is equal to a second angle between the orthogonal direction and the second emission direction, and the liquid crystal display device includes a reflective polarizing plate that allows linearly polarized light having a first polarization direction orthogonal to the first emission direction and the second emission direction to pass through, and reflects linearly polarized light having a second polarization direction orthogonal to the first emission direction, the second emission direction, and the first polarization direction. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of a head-up display according to the first embodiment of this disclosure.

[0010] Figure 2 yes Figure 1 The diagram shown is a conceptual representation of a liquid crystal display device.

[0011] Figure 3 yes Figure 1 The top view of the liquid crystal display device shown.

[0012] Figure 4 yes Figure 3 The side view of the liquid crystal display device shown.

[0013] Figure 5 It is shown Figure 3 The diagram shows the configuration of the first and second sub-pixels.

[0014] Figure 6 It is shown Figure 3 The diagram shown illustrates the circuitry of the display panel.

[0015] Figure 7 yes Figure 3 The diagram shows a cross-sectional view of the display panel.

[0016] Figure 8 yes Figure 7 The top view of the parallax barrier shown.

[0017] Figure 9 Is Figure 1The head-up display shown depicts the first and second virtual images as perceived by the observer.

[0018] Figure 10 This is a schematic diagram of a head-up display according to the second embodiment of this disclosure.

[0019] Figure 11 This is a schematic diagram of a head-up display according to the third embodiment of this disclosure.

[0020] Figure 12 yes Figure 11 The diagram shows a cross-sectional view of the display panel of the liquid crystal display device.

[0021] Figure 13 Observed from a direction orthogonal to the reflecting surface Figure 11 The diagram shown is for a 1 / 4 phase difference plate.

[0022] Figure 14 Is Figure 11 The head-up display shown depicts the first and second virtual images as perceived by the observer.

[0023] Figure 15 This is a diagram illustrating the configuration of the first sub-pixel and the second sub-pixel in a liquid crystal display device included in a modified embodiment of the present disclosure.

[0024] Figure 16 This is a top view of a parallax barrier in a liquid crystal display device included in a modified embodiment of the present disclosure.

[0025] Explanation of reference numerals in the attached figures

[0026] 1. Head-up Display (HUD)

[0027] 2. Transparent body

[0028] 10. Liquid crystal display device

[0029] 10a display surface

[0030] 27 Parallax Barrier

[0031] 40 Reflector

[0032] 41 Reflective surface

[0033] 228 Reflective polarizing plate

[0034] 242 1 / 4 phase difference plate

[0035] D1 First Direction

[0036] D2 Second Direction

[0037] D3 Third direction (orthogonal direction)

[0038] DA display area

[0039] G1 First Image

[0040] G2 Second Image

[0041] L1 First Light

[0042] L2 Second Light

[0043] Lv vision

[0044] P pixel

[0045] P1 First pixel

[0046] P2 Second Pixel

[0047] SP1 first sub-pixel

[0048] SP2 second sub-pixel

[0049] W1 First firing direction

[0050] W2 Second firing direction

[0051] θ1 First angle

[0052] θ2 is the second angle. Detailed Implementation

[0053] Hereinafter, various embodiments of the present disclosure will be described with reference to the accompanying drawings. This disclosure is not limited to the contents described in the following embodiments. Furthermore, the constituent elements described below include elements that can be easily conceived by those skilled in the art, and substantially the same elements. Moreover, the constituent elements described below can be appropriately combined.

[0054] Furthermore, the disclosure is merely an example, and the scope of this disclosure naturally includes content that can be readily conceived by those skilled in the art with respect to appropriate modifications that maintain the spirit of this disclosure. Additionally, the accompanying drawings are provided to make the description clearer; therefore, compared to the actual solution, the width, thickness, shape, etc., of various parts are sometimes schematically shown, but are merely examples and do not limit the interpretation of this disclosure. Furthermore, in this specification and the various drawings, the same reference numerals are used for the same elements as described above, and detailed descriptions are sometimes appropriately omitted.

[0055] The X, Y, and Z directions shown in the accompanying drawings represent the depth, width, and height directions of the head-up display 1, respectively. The X, Y, and Z directions are orthogonal to each other. Furthermore, the X, Y, and Z directions are merely examples, and this disclosure is not limited to these directions.

[0056] <First Implementation>

[0057] Figure 1 This is a schematic diagram of a head-up display 1 according to the first embodiment of this disclosure. The head-up display 1 (hereinafter, sometimes referred to as HUD1) projects an image onto a light-transmitting body 2, enabling an observer to visually recognize a virtual image VG. The light-transmitting body 2 is plate-shaped and has light transmittance. The light-transmitting body 2 is, for example, the windshield and assembly of a vehicle, but is of course not limited to the windshield and assembly, as long as it is a component of the image output by the projected HUD1.

[0058] HUD1 includes a liquid crystal display device 10 and a reflector 40.

[0059] Figure 2 yes Figure 1 The diagram shows a concept of a liquid crystal display device 10. In the display area DA of the liquid crystal display device 10, a first image G1 and a second image G2 are simultaneously displayed on the entire display area DA from different viewing angles.

[0060] Figure 3 yes Figure 1 A top view of the liquid crystal display device 10 shown. Figure 4 yes Figure 3 The attached figure shows a side view of the liquid crystal display device 10. The first direction D1, the second direction D2, and the third direction D3 (equivalent to "orthogonal directions") shown in the figure are orthogonal to each other, corresponding to the depth, width, and height directions of the liquid crystal display device 10, respectively. Furthermore, in the first direction D1, the side indicated by the arrow corresponds to the +D1 side of the liquid crystal display device 10, and the opposite side corresponds to the -D1 side. In the second direction D2, the side indicated by the arrow corresponds to the +D2 side of the liquid crystal display device 10, and the opposite side corresponds to the -D2 side. In the third direction D3, the side indicated by the arrow corresponds to the +D3 side (upper side) of the liquid crystal display device 10, and the opposite side corresponds to the -D3 side (lower side). However, the first direction D1, the second direction D2, and the third direction D3 are just examples, and this disclosure is not limited to these directions. Additionally, in this specification, "top view" refers to viewing the liquid crystal display device 10 along the third direction D3.

[0061] The liquid crystal display device 10 displays images based on image signals output from an external device (e.g., a car navigation system) electrically connected via a flexible wiring substrate (not shown). In this first embodiment, the liquid crystal display device 10 is configured such that a third direction D3 is parallel to the Z direction. Furthermore, the liquid crystal display device 10 is configured such that a first direction D1 is parallel to the X direction and a second direction D2 is parallel to the Y direction.

[0062] like Figure 4As shown, the liquid crystal display device 10 includes a display panel 20 and a light source device 30.

[0063] The display panel 20 is a transmissive liquid crystal display. Alternatively, the display panel 20 can be, for example, an organic EL display or an inorganic EL display. Figure 3 As shown, the display panel 20 has a display area DA for displaying images on the display surface 10a. The display surface 10a is flat and planar. The display surface 10a is orthogonal to the third direction D3.

[0064] The display panel 20 has a plurality of pixels P arranged in a matrix when viewed from above. The row direction is parallel to the first direction D1. The column direction is parallel to the second direction D2. When viewed from above, the plurality of pixels P overlap with the display area DA. Each pixel P has a first pixel P1 and a second pixel P2.

[0065] The first pixel P1 is the pixel corresponding to the first image G1. The first pixel P1 has a first sub-pixel SP1a, a second first sub-pixel SP1b, and a third first sub-pixel SP1c. The first first sub-pixel SP1a is a red sub-pixel. The second first sub-pixel SP1b is a green sub-pixel. The third first sub-pixel SP1c is a blue sub-pixel. Hereinafter, when describing the first first sub-pixel SP1a, the second first sub-pixel SP1b, and the third first sub-pixel SP1c without distinguishing between them, they will simply be referred to as "first sub-pixel SP1".

[0066] The second pixel P2 is the pixel corresponding to the second image G2. The second pixel P2 has a first second sub-pixel SP2a, a second second sub-pixel SP2b, and a third second sub-pixel SP2c. The first second sub-pixel SP2a is a red sub-pixel. The second second sub-pixel SP2b is a green sub-pixel. The third second sub-pixel SP2c is a blue sub-pixel. Hereinafter, when describing the first second sub-pixel SP2a, the second second sub-pixel SP2b, and the third second sub-pixel SP2c without distinguishing between them, they will simply be referred to as "second sub-pixel SP2".

[0067] Thus, the first pixel P1 has three first sub-pixels SP1, and the second pixel P2 has three second sub-pixels SP2. The number and color of the first sub-pixels SP1 and the number and color of the second sub-pixels SP2 are, of course, not limited to those mentioned above.

[0068] Figure 5 It is shown Figure 3 A diagram showing the configuration of the first sub-pixel SP1 and the second sub-pixel SP2. Furthermore, in Figure 5 In the diagram, the first sub-pixel SP1 is labeled with a rectangular shape indicated by a dashed line, and the second sub-pixel SP2 is labeled with a rectangular shape indicated by a single-dot dashed line.

[0069] The first pixel P1 and the second pixel P2 are configured along the row direction (first direction D1). In addition, the first pixel P1 and the second pixel P2 are configured in a zigzag pattern along the column direction (second direction D2).

[0070] In the row direction, when focusing on the first pixel P1, the first first sub-pixel SP1a, the third first sub-pixel SP1c, and the second first sub-pixel SP1b are repeatedly configured in this order. Similarly, in the row direction, when focusing on the second pixel P2, the second second sub-pixel SP2b, the first second sub-pixel SP2a, and the third second sub-pixel SP2c are repeatedly configured in this order.

[0071] Furthermore, the first sub-pixel SP1 and the second sub-pixel SP2 are alternately arranged along the row direction. That is, the first sub-pixel SP1 and the second sub-pixel SP2 are adjacent to each other in the row direction. Specifically, in the row direction, the first sub-pixel SP1a is adjacent to at least one of the second sub-pixel SP2b and the third sub-pixel SP2c. Additionally, in the row direction, the second sub-pixel SP1b is adjacent to at least one of the third sub-pixel SP2c and the first sub-pixel SP2a. Furthermore, in the row direction, the third sub-pixel SP1c is adjacent to at least one of the first sub-pixel SP2a and the second sub-pixel SP2b.

[0072] Furthermore, in the row direction, the first second sub-pixel SP2a is adjacent to at least one of the second first sub-pixel SP1b and the third first sub-pixel SP1c. Additionally, in the row direction, the second second sub-pixel SP2b is adjacent to at least one of the third first sub-pixel SP1c and the first first sub-pixel SP1a. Moreover, in the row direction, the third second sub-pixel SP2c is adjacent to at least one of the first first sub-pixel SP1a and the second first sub-pixel SP1b.

[0073] Furthermore, the first sub-pixel SP1 and the second sub-pixel SP2 are arranged alternately along the column direction. That is, the first sub-pixel SP1 and the second sub-pixel SP2 are adjacent to each other in the column direction. Specifically, the first first sub-pixel SP1a and the first second sub-pixel SP2a are arranged alternately along the column direction. The second first sub-pixel SP1b and the second second sub-pixel SP2b are arranged alternately along the column direction. The third first sub-pixel SP1c and the third second sub-pixel SP2c are arranged alternately along the column direction.

[0074] Figure 6 It is shown Figure 3The diagram shows the circuit configuration of the display panel 20. The display panel 20 includes a driving circuit 21, and switching elements SW, sub-pixel electrodes PE, common electrodes CE, liquid crystal capacitors LC, and holding capacitors CS, respectively, for the first sub-pixel SP1 and the second sub-pixel SP2. The first sub-pixel SP1 and the second sub-pixel SP2 are configured similarly.

[0075] The driving circuit 21 drives the display panel 20. The driving circuit 21 includes a signal processing circuit 21a, a signal output circuit 21b, and a scanning circuit 21c.

[0076] Based on the image signal sent from an external device, signal processing circuit 21a outputs a first sub-pixel signal showing the grayscale of the first sub-pixel SP1 and a second sub-pixel signal showing the grayscale of the second sub-pixel SP2 to signal output circuit 21b. Additionally, signal processing circuit 21a outputs a clock signal to both signal output circuit 21b and scanning circuit 21c to synchronize the operation of signal output circuit 21b with the operation of scanning circuit 21c.

[0077] The signal output circuit 21b outputs the first sub-pixel signal to the first sub-pixel SP1 and the second sub-pixel signal to the second sub-pixel SP2. The signal output circuit 21b is electrically connected to the first sub-pixel SP1 and the second sub-pixel SP2 via a plurality of signal lines Lb extending along the second direction D2.

[0078] The scanning circuit 21c scans the first sub-pixel SP1 and the second sub-pixel SP2 synchronously with the output of the first sub-pixel signal and the second sub-pixel signal from the signal output circuit 21b. The scanning circuit 21c is electrically connected to the first sub-pixel SP1 and the second sub-pixel SP2 via a plurality of scan lines Lc extending along the first direction D1.

[0079] When viewed from above, the area divided by two adjacent signal lines Lb in the first direction D1 and two adjacent scan lines Lc in the second direction D2 corresponds to one of the first sub-pixel SP1 and the second sub-pixel SP2.

[0080] The switching element SW is, for example, composed of a thin-film transistor (TFT). In the switching element SW, the source electrode is electrically connected to the signal line Lb, and the gate electrode is electrically connected to the scan line Lc.

[0081] The sub-pixel electrode PE is connected to the drain electrode of the switching element SW. Multiple common electrodes CE are configured corresponding to multiple scan lines Lc. Both the sub-pixel electrode PE and the common electrode CE are transparent.

[0082] The liquid crystal capacitor LC is the capacitive component of the liquid crystal material in the liquid crystal layer 23 (described later) located between the sub-pixel electrode PE and the common electrode CE. The holding capacitor CS is located between an electrode at the same potential as the common electrode CE and an electrode at the same potential as the sub-pixel electrode PE.

[0083] Figure 7 yes Figure 3 The diagram shows a cross-sectional view of the display panel 20. The display panel 20 also includes a first substrate 22, a liquid crystal layer 23, and a second substrate 24. The first substrate 22, the liquid crystal layer 23, and the second substrate 24 are each transparent and are arranged in this order along a third direction D3 from the -D3 side to the +D3 side. The first substrate 22 and the second substrate 24 are rectangular in shape when viewed from above. However, the shapes of the first substrate 22 and the second substrate 24 when viewed from above may also be shapes other than rectangular, such as circular or trapezoidal shapes.

[0084] A common electrode CE is disposed on the main surface 22a of the first substrate 22 on the +D3 side. In addition, an insulating layer IL is disposed on the +D3 side of the common electrode CE, and a sub-pixel electrode PE and an alignment film AL are also disposed thereon.

[0085] The sub-pixel electrode PE is disposed between the insulating layer IL and the alignment film AL. Thus, the common electrode CE and the sub-pixel electrode PE are disposed on the first substrate 22. In other words, the display panel 20 is a liquid crystal display using a lateral electric field method.

[0086] The second substrate 24 is located on the +D3 side of the first substrate 22. An outer coating OC, a first color filter CF1, a second color filter CF2, a light-shielding film SM, and an alignment film AL are disposed on the lower surface 24b side of the second substrate 24. The light-shielding film SM, the first color filter CF1, the second color filter CF2, and the outer coating OC are disposed between the second substrate 24 and the alignment film AL.

[0087] The outer coating OC is formed from a light-transmitting material.

[0088] A first color filter CF1 and a second color filter CF2 are disposed between the second substrate 24 and the liquid crystal layer 23. The first color filter CF1 is a color filter included in the first sub-pixel SP1. The second color filter CF2 is a color filter included in the second sub-pixel SP2.

[0089] The first color filter CF1 and the second color filter CF2 are rectangular in shape when viewed from above. The first color filter CF1 and the second color filter CF2 are translucent, and the peaks of the transmitted light spectrum are predetermined. These spectral peaks correspond to the colors of the first color filter CF1 and the second color filter CF2. In other words, the light transmitted through the first color filter CF1 and the second color filter CF2 is colored. Furthermore, the shapes of the first color filter CF1 and the second color filter CF2 when viewed from above can also be changed to match the shapes of the first sub-pixel SP1 and the second sub-pixel SP2.

[0090] The color of the first color filter CF1 is the same as the color of the first sub-pixel SP1. The color of the second color filter CF2 is the same as the color of the second sub-pixel SP2. That is, the red first sub-pixel SP1a has the red first color filter CF1, the green second sub-pixel SP1b has the green first color filter CF1, and the blue third sub-pixel SP1c has the blue first color filter CF1. Furthermore, the red first second sub-pixel SP2a has the red second color filter CF2, the green second second sub-pixel SP2b has the green second color filter CF2, and the blue third second sub-pixel SP2c has the blue second color filter CF2.

[0091] The light-shielding film SM has light-shielding properties and, when viewed from above, overlaps with the boundaries of the first sub-pixel SP1 and the second sub-pixel SP2 that are adjacent to each other in the first direction D1 and the second direction D2. That is, when viewed from above, the light-shielding film SM overlaps with the signal line Lb and the scan line Lc. Furthermore, in Figure 7 The diagram of signal line Lb and scan line Lc is omitted. Signal line Lb and scan line Lc are disposed on the main surface 22a of the first substrate 22. Additionally, in... Figure 5 In the diagram, the solid line dividing the first sub-pixel SP1 and the second sub-pixel SP2 corresponds to the light-shielding film SM. Furthermore, the periphery of the first color filter CF1 and the periphery of the second color filter CF2 overlap with the light-shielding film SM when viewed from above.

[0092] like Figure 7 As shown, the liquid crystal layer 23 is located between the first substrate 22 and the second substrate 24. The liquid crystal layer 23 contains a plurality of liquid crystal molecules LM. When viewed from above, the liquid crystal layer 23 overlaps with the display area DA. Specifically, the liquid crystal layer 23 is located between two opposing alignment films AL. The initial orientation of the liquid crystal molecules LM is determined by the two opposing alignment films AL.

[0093] In addition, the display panel 20 also includes a first polarizing plate 25, a second polarizing plate 26, and a parallax barrier 27.

[0094] A first polarizing plate 25 is disposed on the lower surface 22b of the first substrate 22. The first polarizing plate 25 has a transmission axis orthogonal to the third direction D3. A second polarizing plate 26 is disposed on the upper surface 24a of the second substrate 24. The second polarizing plate 26 has a transmission axis orthogonal to both the transmission axis of the first polarizing plate 25 and the third direction D3. The upper surface of the second polarizing plate 26 corresponds to the display surface 10a.

[0095] A parallax barrier 27 is disposed between the second substrate 24 and the second polarizing plate 26. The parallax barrier 27 is plate-shaped. The parallax barrier 27 is disposed on the side (upper surface 24a) of the second substrate 24 opposite to the surface (lower surface 24b) opposite to the surface (lower surface 24b) of the first color filter CF1 and the second color filter CF2. The parallax barrier 27 has a plurality of openings 27a and light-blocking portions 27b.

[0096] The opening 27a allows light traveling along the first emission direction W1 from the light transmitted through the first color filter CF1 to pass through. The first emission direction W1 is... Figure 7 The solid line indicates the direction of inclination from the third side towards D3 to -D1. The first emission direction W1 is orthogonal to the second direction D2. The first emission direction W1 is the direction towards the light-transmitting body 2 (see reference). Figure 1 ).

[0097] Furthermore, the opening 27a allows light that has passed through the second color filter CF2 and travels along a second emission direction W2, which is different from the first emission direction W1, to pass through. The second emission direction W2 is... Figure 7 The direction shown by the dashed line is the inclination from the third direction D3 towards +D1. The second emission direction W2 is orthogonal to the second direction D2. The first angle θ1 between the first emission direction W1 and the third direction D3 is different from the second angle θ2 between the second emission direction W2 and the third direction D3.

[0098] Figure 8 yes Figure 7 A top view of the parallax barrier 27 shown. Figure 8 In the diagram, the first sub-pixel SP1 and the second sub-pixel SP2 are shown with dashed lines. For example... Figure 7 , Figure 8 As shown, multiple openings 27a overlap with the first color filter CF1 of the first sub-pixel SP1 and the second color filter CF2 of the second pixel P2, which are adjacent to each other in the row direction, when viewed from above. Figure 8 In the top view shown, multiple openings 27a overlap with the -D1 side of the first color filter CF1 and the +D1 side of the second color filter CF2, respectively.

[0099] In addition, such as Figure 8As shown, the plurality of openings 27a are arranged along the row direction when viewed from above. Furthermore, the plurality of openings 27a are arranged in a serrated pattern along the column direction when viewed from above.

[0100] Figure 7 , Figure 8 The light-shielding portion 27b shown is formed of a material with high light absorption (e.g., metallic chromium (Cr), chromium oxide (CrO2), resin, etc.). The light-shielding portion 27b blocks light traveling along the second emission direction W2 from the light transmitted through the first color filter CF1. Additionally, the light-shielding portion 27b blocks light traveling along the first emission direction W1 from the light transmitted through the second color filter CF2.

[0101] In addition, such as Figure 3 As shown, the first substrate 22 has an exposed portion E that protrudes from the second substrate 24 when viewed from above. The exposed portion E is located on the -D2 side relative to the second substrate 24 when viewed from above. Furthermore, an IC chip Ti containing a driving circuit 21 is disposed on the upper surface of the exposed portion E. The upper surface of the exposed portion E is part of the main surface 22a of the first substrate 22.

[0102] like Figure 4 As shown, the light source device 30 is disposed on the -D3 side of the display panel 20. The light source device 30 emits light toward the display panel 20. The light source device 30 is, for example, a direct-lit backlight and has multiple light-emitting diodes (not shown).

[0103] Next, the operation of the liquid crystal display device 10 when the first image G1 and the second image G2 are displayed in the display area DA will be described.

[0104] When the liquid crystal display device 10 acquires an image signal transmitted from an external device, it displays a first image G1 and a second image G2 on the display area DA. The image signal includes the grayscale of a first sub-pixel SP1 corresponding to the first image G1 and the grayscale of a second sub-pixel SP2 corresponding to the second image G2. As described above, a first sub-pixel signal showing the grayscale of the first sub-pixel SP1 is output to the first sub-pixel SP1, and a second sub-pixel signal showing the grayscale of the second sub-pixel SP2 is output to the second sub-pixel SP2.

[0105] A voltage corresponding to the grayscale indicated by the first sub-pixel signal is applied to the liquid crystal layer 23 corresponding to the first sub-pixel SP1, causing the liquid crystal molecules LM to tilt. The degree of tilting of the liquid crystal molecules LM varies according to the grayscale indicated by the first sub-pixel signal. Light transmitted through the light source device 30 of the liquid crystal layer 23 corresponding to the first sub-pixel SP1 is modulated to the grayscale indicated by the first sub-pixel signal. Furthermore, the light transmitted through the liquid crystal layer 23 corresponding to the first sub-pixel SP1 is colored by passing through the first color filter CF1. The light transmitted through the display panel 20 after passing through the first color filter CF1 corresponds to the first image G1.

[0106] The light traveling along the second emission direction W2 in the light transmitted through the first color filter CF1 is blocked by the light-shielding part 27b. Therefore, the light traveling along the second emission direction W2 in the light transmitted through the first color filter CF1 cannot be visually identified.

[0107] On the other hand, the light that travels along the first emission direction W1 in the light transmitted through the first color filter CF1 (hereinafter referred to as the first light L1: reference) Figure 1 The light L1 is emitted from the display surface 10a to the outside through the opening 27a of the parallax barrier 27. In other words, the first light L1 can be visually recognized as the first image G1.

[0108] Furthermore, a voltage corresponding to the grayscale indicated by the second sub-pixel signal is applied to the liquid crystal layer 23 corresponding to the second sub-pixel SP2, causing the liquid crystal molecules LM to tilt. The degree of tilting of the liquid crystal molecules LM varies according to the grayscale indicated by the second sub-pixel signal. Light transmitted through the liquid crystal layer 23 corresponding to the second sub-pixel SP2 is modulated to the grayscale indicated by the second sub-pixel signal. Moreover, the light transmitted through the liquid crystal layer 23 corresponding to the second sub-pixel SP2 is colored by passing through the second color filter CF2. The light transmitted through the display panel 20 via the second color filter CF2 corresponds to the second image G2.

[0109] The light traveling along the first emission direction W1 in the light transmitted through the second color filter CF2 is blocked by the light-shielding part 27b. Therefore, the light traveling along the first emission direction W1 in the light transmitted through the second color filter CF2 cannot be visually identified.

[0110] On the other hand, the light that travels along the second emission direction W2 in the light transmitted through the second color filter CF2 (hereinafter referred to as the second light L2: reference) Figure 1 The light L2 is emitted from the display surface 10a to the outside through the opening 27a of the parallax barrier 27. In other words, the second light L2 can be visually recognized as the second image G2.

[0111] Thus, depending on the parallax barrier 27, the viewing angles of the first image G1 and the second image G2 are different. Furthermore, as described above, the first sub-pixel SP1 and the second sub-pixel SP2 are arranged throughout the entire display area DA. Therefore, the first image G1 corresponding to the first light L1 and the second image G2 corresponding to the second light L2 are simultaneously displayed throughout the entire display area DA of the display surface 10a.

[0112] like Figure 1As shown, the first light L1 emitted from the display surface 10a travels toward the light-transmitting body 2 along the first emission direction W1 and is projected onto the light-transmitting body 2. An observer whose line of sight Lv is directed toward the first light L1 projected onto the light-transmitting body 2 will visually recognize the first image G1 as the first virtual image VG1.

[0113] The first virtual image VG1 is visually recognized by the observer when it is approximately perpendicular to the observer's line of sight Lv. The observer's line of sight Lv is approximately parallel to the X-direction. The first virtual image VG1 is orthogonal to the X-direction. The first image G1 displayed on the display surface 10a and the first virtual image VG1 are linearly symmetrical about the light-transmitting body 2 as the axis of symmetry. In other words, the tilt of the light-transmitting body 2, the tilt of the display surface 10a, and the first angle θ1 are determined so that the first virtual image VG1 is visually recognized when it is orthogonal to the X-direction.

[0114] On the other hand, the second light L2 emitted from the display surface 10a is incident on the reflector 40.

[0115] The reflector 40 is, for example, a mirror. The reflector 40 has a reflective surface 41 on which the second light L2 emitted from the display surface 10a of the liquid crystal display device 10 is incident. The reflective surface 41 reflects the second light L2 toward the light-transmitting body 2 in a manner that is in the first emission direction W1. In other words, the second angle θ2 and the tilt (or orientation) of the reflector 40 are determined such that the second light L2 reflected by the reflective surface 41 travels toward the light-transmitting body 2 in the first emission direction W1.

[0116] The second light L2, reflected by the reflector 40, travels along the first emission direction W1 and is projected onto the light-transmitting body 2. An observer whose line of sight Lv is directed toward the second light L2 projected onto the light-transmitting body 2 visually recognizes the second image G2 as the second virtual image VG2. The second virtual image VG2 is visually recognized by the observer in a state where it is adjacent to the first virtual image VG1 without overlapping. In addition, the second virtual image VG2 is visually recognized by the observer in a state where it is tilted relative to the first virtual image VG1.

[0117] When the image that is linearly symmetrical to the second image G2 displayed on the display surface 10a with the reflective surface 41 as the axis of symmetry is defined as the pseudo-virtual image TG, the second virtual image VG2 and the pseudo-virtual image TG are linearly symmetrical with the light-transmitting body 2 as the axis of symmetry. Furthermore, the pseudo-virtual image TG is tilted relative to the second virtual image VG2 displayed on the display surface 10a. Therefore, the second virtual image VG2 is tilted relative to the first virtual image VG1.

[0118] Figure 9 Is Figure 1 The head-up display 1 shown illustrates a diagram of the first virtual image VG1 and the second virtual image VG2, which are visually recognized by the observer. Figure 9In the example shown, the first image G1 contains text and symbols indicating the vehicle's speed or speed limit. Additionally, the second image G2 contains arrows indicating the vehicle's direction of travel and straight lines indicating lanes.

[0119] The first virtual image VG1 corresponding to the first image G1 is visually recognized by the observer in a state that is approximately perpendicular to the observer's line of sight Lv, as described above. Therefore, the observer can appropriately visually recognize text and symbols indicating the vehicle's speed or speed limit.

[0120] On the other hand, the second virtual image VG2, corresponding to the second image G2, is visually recognized by the observer in a state tilted relative to the first virtual image VG1, as described above. Thus, the arrow indicating the vehicle's direction of travel and the straight line indicating the lane, contained in the second virtual image VG2, are visually recognized by the observer in a state with depth. Therefore, the observer can appropriately grasp the vehicle's direction of travel based on the second virtual image VG2.

[0121] Thus, in the HUD1 described above, the first light L1 and the second light L2 are emitted from the planar display surface 10a in different directions, enabling the observer to visually identify the first virtual image VG1 and the second virtual image VG2 with different tilt degrees. Therefore, compared to the case where the observer visually identifies the first virtual image VG1 and the second virtual image VG2 with different tilt degrees through multiple display surfaces with different tilt degrees, the HUD1 can be miniaturized.

[0122] <Second Implementation>

[0123] Next, regarding the HUD1 according to the second embodiment of this disclosure, the differences from the HUD1 of the first embodiment described above will be explained.

[0124] Figure 10 This is a schematic diagram of a head-up display 1 according to a second embodiment of the present disclosure. In this second embodiment of the HUD1, the first angle θ1 between the third direction D3 and the first emission direction W1 is equal to the second angle θ2 between the third direction D3 and the second emission direction W2. In addition, the reflector 40 is arranged so that the reflective surface 41 is perpendicular to the display surface 10a (parallel to the third direction D3).

[0125] In this configuration, the pseudo-virtual image TG is parallel to the second image G2 displayed on the display surface 10a. As described above, the second virtual image VG2 and the pseudo-virtual image TG are linearly symmetrical about the light-transmitting body 2. Furthermore, the first image G1 displayed on the display surface 10a and the first virtual image VG1 are linearly symmetrical about the light-transmitting body 2. Therefore, the tilt angle of the first virtual image VG1 is equal to the tilt angle of the second virtual image VG2. Additionally, similar to the first embodiment described above, the second virtual image VG2 is visually recognized by the observer in a state where it is adjacent to the first virtual image VG1 without overlapping.

[0126] Thus, in the HUD1 of this second embodiment, a first light L1 and a second light L2 are emitted from a display surface 10a, and the first virtual image VG1 and the second virtual image VG2 are visually recognized by the observer in a state with equal tilt and adjacent to each other.

[0127] Compared to the case where light is emitted in only one direction (e.g., the first emission direction W1) instead of from one display surface 10a in two directions, and the virtual image corresponding to that light is visually recognized, HUD1 is able to visually recognize virtual images over a larger range.

[0128] <Third Implementation Method>

[0129] Next, regarding the HUD1 according to the third embodiment of this disclosure, the differences from the HUD1 of the first embodiment described above will be explained.

[0130] Figure 11 This is a schematic diagram of a head-up display 1 according to a third embodiment of the present disclosure. In the HUD1 of this third embodiment, the first angle θ1 between the first emission direction W1 and the third third direction D3 is equal to the second angle θ2 between the second emission direction W2 and the third third direction D3.

[0131] Figure 12 yes Figure 11 The diagram shows a cross-sectional view of the display panel 20 of the liquid crystal display device 10. In this third embodiment, the liquid crystal display device 10 replaces the second polarizing plate 26 of the first embodiment described above with a reflective polarizing plate 228. The upper surface 228a of the reflective polarizing plate 228 corresponds to the display surface 10a.

[0132] The reflective polarizing plate 228 has a polarizing axis through which linearly polarized light having a first polarization direction is transmitted. The polarizing axis of the reflective polarizing plate 228 is parallel to the transmission axis of the second polarizing plate 26 of the first embodiment described above. The first light L1 and the second light L2 emitted from the display surface 10a are transmitted through the polarizing axis of the reflective polarizing plate 228. That is, the first light L1 and the second light L2 emitted from the display surface 10a are linearly polarized light having a first polarization direction parallel to the polarizing axis of the reflective polarizing plate 228. The first polarization direction is orthogonal to the first emission direction W1 and the second emission direction W2. Furthermore, in Figure 11 The reference numerals for the first light L1 and the second light L2, which have a first polarization direction, are designated as "L1(S)" and "L2(S)".

[0133] Furthermore, the upper surface 228a of the reflective polarizer 228 reflects linearly polarized light having a second polarization direction orthogonal to the first polarization direction. The second polarization direction is also orthogonal to the first emission direction W1 and the second emission direction W2.

[0134] like Figure 11 As shown, the reflector 40 is arranged with the reflective surface 41 facing the display surface 10a and the reflective surface 41 orthogonal to the second emission direction W2. As a result, the second light L2 incident on the reflector 40 is reflected in the reflective surface 41 in a manner that faces the display surface 10a of the liquid crystal display device 10 and is along the second emission direction W2.

[0135] Additionally, a quarter-phase retardation plate 242 is disposed on the reflective surface 41 of the reflector 40. Light transmitted through the quarter-phase retardation plate 242 is given a phase difference of 1 / 4 wavelength.

[0136] Figure 13 Viewed from a direction orthogonal to the reflecting surface 41 Figure 11 The diagram shows the 1 / 4 phase détachometer 242. The fast axis 242a and slow axis 242b of the 1 / 4 phase détachometer 242 are tilted at 45° relative to the second polarization direction.

[0137] like Figure 11 As shown, in this third embodiment, the first light L1, like in the first embodiment described above, travels towards the light-transmitting body 2 along the first emission direction W1 and is projected onto the light-transmitting body 2. The first virtual image VG1 is orthogonal to the X direction.

[0138] In this third embodiment, the second light L2 emitted from the display surface 10a travels along the second emission direction W2 and is incident on the quarter-phase difference plate 242 of the reflector 40. The second light L2 is given a phase difference of 1 / 4 wavelength by the quarter-phase difference plate 242 and is reflected by the reflector 41. The second light L2 reflected by the reflector 41 is then incident on the quarter-phase difference plate 242 and is further given a phase difference of 1 / 4 wavelength. That is, the second light L2 emitted from the display surface 10a is given a phase difference of 1 / 2 wavelength (=2×(1 / 4 wavelength)) by being reflected by the reflector 40.

[0139] As described above, the second light L2 emitted from the display surface 10a is linearly polarized light with a first polarization direction. Therefore, the second light L2 reflected by the reflector 40 is linearly polarized light with a second polarization direction orthogonal to the first polarization direction. Furthermore, in Figure 11 The reference numeral for the second beam L2 with a second polarization direction is designated as "L2(P)".

[0140] Furthermore, as described above, the reflective surface 41 is orthogonal to the second emission direction W2. Therefore, the second light L2 reflected by the reflector 40 travels along the second emission direction W2. Thus, the reflector 40 has a reflective surface 41 that reflects light transmitted through the quarter-phase plate 242 toward the display surface 10a along the second emission direction W2 via the quarter-phase plate 242.

[0141] The second light L2, reflected by the reflector 40, is incident on the upper surface 228a of the reflective polarizer 228 along the second emission direction W2. The second light L2 incident on the upper surface 228a of the reflective polarizer 228 has a second polarization direction and is reflected on the upper surface 228a of the reflective polarizer 228. Furthermore, the first angle θ1 and the second angle θ2 are equal. Therefore, the second light L2 reflected on the upper surface 228a of the reflective polarizer 228 travels towards the light-transmitting body 2 along the first emission direction W1 and is projected onto the light-transmitting body 2.

[0142] When the image that is linearly symmetrical with respect to the virtual image TG about the display surface 10a is defined as the second virtual image TG2, the second virtual image VG2 and the second virtual image TG2 are linearly symmetrical about the light-transmitting body 2. Therefore, the second virtual image VG2 is tilted relative to the first virtual image VG1.

[0143] Furthermore, the second virtual image VG2 is projected by the light-transmitting body 2 from the second light L2 reflected from the upper surface 228a of the reflective polarizing plate 228. Therefore, the observer performs visual recognition when the second virtual image VG2 overlaps with the first virtual image VG1. Moreover, the optical path length of the second light L2 is longer than that of the first light L1. Therefore, the second virtual image VG2 is located on the -X side compared to the first virtual image VG1.

[0144] Figure 14 Is Figure 11 The head-up display 1 shown presents a diagram of the first virtual image VG1 and the second virtual image VG2 for visual recognition by the observer.

[0145] exist Figure 14 In the example shown, the first image G1 includes text and symbols indicating the vehicle's speed or speed limit, as well as arrows indicating the vehicle's direction of travel. Additionally, the second image G2 includes arrows indicating the vehicle's direction of travel. The arrows indicating the vehicle's direction of travel in the first virtual image VG1 and the second virtual image VG2 are positioned so that they are not visually perceived as overlapping by the observer.

[0146] The second virtual image VG2 is tilted relative to the first virtual image VG1, and the observer visually recognizes the second virtual image VG2 while it has depth relative to the first virtual image VG1. Therefore, the observer perceives the arrow indicating the vehicle's direction of travel contained in the second virtual image VG2 as being located further forward of the vehicle's direction of travel than the arrow indicating the vehicle's direction of travel contained in the first virtual image VG1. Thus, the observer can appropriately determine the vehicle's direction of travel based on the first virtual image VG1 and the second virtual image VG2.

[0147] <Variation Example>

[0148] The above describes suitable embodiments of this disclosure, but this disclosure is not limited to such embodiments. The content disclosed in the embodiments is merely an example, and various modifications can be made without departing from the spirit of this disclosure. Appropriate modifications made without departing from the spirit of this disclosure are naturally within the technical scope of this disclosure.

[0149] For example, the liquid crystal display device 10 can be configured in a state where it is tilted in the third direction (D3) and the Z direction. In this case, the first virtual image VG1 may not be orthogonal to the X direction.

[0150] In addition, when viewed from above, the opening 27a may not overlap with at least one of the first color filter CF1 and the second color filter CF2.

[0151] Figure 15 This diagram illustrates the configuration of the first sub-pixel SP1 and the second sub-pixel SP2 in a liquid crystal display device 10 of a head-up display 1 according to a modified embodiment of the present disclosure.

[0152] In this modified example, the first pixel P1 and the second pixel P2 are configured along the row direction (first direction D1) and the column direction (second direction D2), respectively. In the row direction, when focusing on the first pixel P1, the first first sub-pixel SP1a, the third first sub-pixel SP1c, and the second first sub-pixel SP1b are repeatedly configured in this order. Similarly, in the row direction, when focusing on the second pixel P2, the second second sub-pixel SP2b, the first second sub-pixel SP2a, and the third second sub-pixel SP2c are repeatedly configured in this order.

[0153] Furthermore, the first sub-pixel SP1 and the second sub-pixel SP2 are alternately arranged along the row direction. That is, the first sub-pixel SP1 and the second sub-pixel SP2 are adjacent to each other in the row direction. Specifically, in the row direction, the first sub-pixel SP1a is adjacent to at least one of the second sub-pixel SP2b and the third sub-pixel SP2c. Additionally, in the row direction, the second sub-pixel SP1b is adjacent to at least one of the third sub-pixel SP2c and the first sub-pixel SP2a. Furthermore, in the row direction, the third sub-pixel SP1c is adjacent to at least one of the first sub-pixel SP2a and the second sub-pixel SP2b.

[0154] Furthermore, in the row direction, the first second sub-pixel SP2a is adjacent to at least one of the second first sub-pixel SP1b and the third first sub-pixel SP1c. Additionally, in the row direction, the second second sub-pixel SP2b is adjacent to at least one of the third first sub-pixel SP1c and the first first sub-pixel SP1a. Moreover, in the row direction, the third second sub-pixel SP2c is adjacent to at least one of the first first sub-pixel SP1a and the second first sub-pixel SP1b.

[0155] Furthermore, multiple first sub-pixels SP1 are arranged along the column direction. Specifically, multiple first sub-pixels SP1a are arranged in a state where they are adjacent to each other along the column direction. Multiple second first sub-pixels SP1b are arranged in a state where they are adjacent to each other along the column direction. Multiple third first sub-pixels SP1c are arranged in a state where they are adjacent to each other along the column direction.

[0156] Furthermore, multiple second sub-pixels SP2 are arranged along the column direction. Specifically, multiple first and second sub-pixels SP2a are arranged in a state where they are adjacent to each other along the column direction. Multiple second sub-pixels SP2b are arranged in a state where they are adjacent to each other along the column direction. Multiple third sub-pixels SP2c are arranged in a state where they are adjacent to each other along the column direction.

[0157] Figure 16 This is a top view of the parallax barrier 327 in the liquid crystal display device 10 of the head-up display 1 according to a modified embodiment of the present disclosure. The parallax barrier 327 of this modified embodiment is... Figure 15 The configurations of the first sub-pixel SP1 and the second sub-pixel SP2 shown correspond. The parallax barrier 327 has an opening 327a and a light-shielding portion 327b.

[0158] exist Figure 16 In the diagram, the first sub-pixel SP1 and the second sub-pixel SP2 are shown by dashed lines. In this modified example, the plurality of openings 327a overlap with a first color filter CF1 and a second color filter CF2 that are adjacent to each other in the row direction when viewed from above. Figure 16 In the top view shown, similar to the embodiment described above, the plurality of openings 327a overlap with the -D1 side of the first color filter CF1 and the +D1 side of the second color filter CF2, respectively.

[0159] The opening 327a has a shape that extends along the column direction (second direction D2). Multiple openings 327a overlap with multiple first sub-pixels SP1 arranged along the column direction and multiple second sub-pixels SP2 arranged along the column direction when viewed from above. Multiple openings 327a are arranged along the row direction (first direction D1).

[0160] like Figure 15 , Figure 16 As shown, by configuring the first sub-pixel SP1, the second sub-pixel SP2, and the opening 327a, similar to the embodiments described above, the viewing angles of the first image G1 and the second image G2 are different from each other. Furthermore, in this modified example, the first sub-pixel SP1 and the second sub-pixel SP2 are also configured to cover the entire display area DA. Therefore, the first image G1 and the second image G2 are simultaneously displayed throughout the entire display area DA.

[0161] In addition, Figure 16 In the parallax barrier 327 shown, the opening 327a can also be formed such that, when viewed from above, it overlaps with one first sub-pixel SP1 and one second sub-pixel SP2 in the column direction. In this case, multiple openings 327a are arranged along both the row direction (first direction D1) and the column direction (second direction D2).

[0162] Furthermore, other effects resulting from the solutions described in this embodiment are to be understood as being clearly stated in this specification, or as being to be reasonably conceived by those skilled in the art and thus to be derived from this disclosure.

Claims

1. A head-up display, characterized in that, have: The liquid crystal display device emits a first light corresponding to a first image from the display surface toward a light-transmitting body along a first emission direction, and emits a second light corresponding to a second image from the display surface along a second emission direction different from the first emission direction; as well as A reflector having a reflective surface that allows the second light to be incident on it and reflects the second light toward the light-transmitting body and along the first emission direction.

2. The head-up display according to claim 1, wherein, The first angle between the orthogonal direction orthogonal to the display surface and the first emission direction is equal to the second angle between the orthogonal direction and the second emission direction. The display surface is orthogonal to the reflective surface.

3. The head-up display according to claim 1, wherein, The liquid crystal display device includes: The display panel has multiple pixels arranged in a matrix when viewed from above; and The light source device emits light toward the display panel. The pixel has a first pixel corresponding to the first image and a second pixel corresponding to the second image. The first pixel contains multiple first sub-pixels. The second pixel contains multiple second sub-pixels. The display panel also features a parallax barrier. The parallax barrier allows light traveling along the first emission direction in the light source device transmitted through the first sub-pixel to pass through, and allows light traveling along the second emission direction in the light source device transmitted through the second sub-pixel to pass through. The parallax barrier blocks the light traveling along the second emission direction in the light source device that passes through the first sub-pixel and the light traveling along the first emission direction in the light source device that passes through the second sub-pixel.

4. A head-up display, characterized in that, have: The liquid crystal display device emits a first light corresponding to a first image from the display surface toward a light-transmitting body along a first emission direction, and emits a second light corresponding to a second image from the display surface along a second emission direction different from the first emission direction; A 1 / 4 phase difference plate is provided for the second light emitted from the display surface to be incident upon it; as well as A reflector having a reflective surface that reflects light transmitted through the quarter-phase retardation plate toward the display surface in a manner that follows the second emission direction. The first angle between the orthogonal direction orthogonal to the display surface and the first emission direction is equal to the second angle between the orthogonal direction and the second emission direction. The liquid crystal display device includes a reflective polarizing plate, which allows linearly polarized light with a first polarization direction to pass through and reflects linearly polarized light with a second polarization direction orthogonal to the first polarization direction.

Images