JP2009192977A - Display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display device capable of suppressing display of interference light due to interference between light beams reflected by a pixel electrode or common electrode on an image display unit. <P>SOLUTION: In the display device (headup display system 100), a liquid crystal display panel 13 is disposed in an inclined state such that the projection direction of light emitted from a back light 12 to a concave mirror 14 and a normal direction of a surface of the liquid crystal display panel 13 includes a predetermined angle, and a slit 321 is formed extending substantially in parallel to a direction obtained by tilting the normal direction of the surface of the liquid crystal display panel 13 to the light projection direction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a display device, and more particularly to a display device including a liquid crystal display panel.

  Conventionally, a display device including a liquid crystal display panel is known (see, for example, Patent Document 1).

Patent Document 1 discloses a head-up display system (display device) including a backlight, a liquid crystal display panel, a mirror, and a windshield glass.
In the head-up display system disclosed in Patent Document 1, light emitted from the backlight is transmitted through the liquid crystal display panel and reflected by the mirror, and the light reflected by the mirror is windshield glass (image display unit). The image displayed on the liquid crystal display panel is displayed on the windshield glass.

JP 2007-52383 A

However, in the head-up display system described in Patent Document 1, it is conceivable that light enters from the windshield glass due to sunlight or the like, and this light enters the liquid crystal display panel via a mirror. When a slit is provided on one of the pixel electrode or the common electrode of the pixel of the liquid crystal display panel as in the horizontal electric field mode in which an electric field is generated in a horizontal direction with the electrode sandwiching the liquid crystal, the liquid crystal display panel There may be a problem in that light interference occurs between the light incident and reflected by the pixel electrode or the common electrode, and the interference light is displayed on the windshield glass.

The present invention has been made to solve the above-described problems, and one object of the present invention is that interference light resulting from light interference between lights reflected by a pixel electrode or a common electrode is an image. It is an object of the present invention to provide a display device capable of suppressing display on a display unit.

Means for Solving the Problems and Effects of the Invention

A display device according to an aspect of the present invention includes a liquid crystal display panel including a plurality of pixels, a light source disposed to face the liquid crystal display panel, and a side opposite to the side on which the light source of the liquid crystal display panel is disposed. An optical member disposed, and an image display unit on which an image displayed on the liquid crystal display panel is projected. The pixel includes a pixel electrode and a common electrode disposed on the same substrate side that applies a voltage to the liquid crystal and the liquid crystal. The electrode on the liquid crystal layer side of the pixel electrode or the common electrode is provided with a slit, and the liquid crystal display panel has a light emission direction in which light is emitted from the light source toward the optical member, and a surface of the liquid crystal display panel. The slit is arranged so as to be inclined with respect to the normal direction, and the slit extends substantially parallel to the direction in which the normal direction of the surface of the liquid crystal display panel is inclined with respect to the light emitting direction. Formed There.

In the display device according to this aspect, as described above, the light emission direction in which light is emitted from the light source toward the optical member of the liquid crystal display panel and the normal direction of the surface of the liquid crystal display panel are a predetermined angle. By tilting and arranging so that light incident on the liquid crystal display panel from the optical member side (for example, sunlight) can be reflected with a predetermined angle shifted from the direction from the liquid crystal display panel toward the optical member, It is possible to suppress the light (regular reflection light) reflected from the liquid crystal display panel from being displayed on the image display unit. In addition, by providing a slit in one of the pixel electrode and the common electrode, light reflected on one of the pixel electrode and the common electrode causes light interference between the reflected lights. This interference light appears in a direction perpendicular to the direction in which the slit is formed. The interference light is displayed on the image display unit together with the specular reflection light, and the slit extends substantially parallel to the direction in which the normal direction of the surface of the liquid crystal display panel deviates from the light emission direction (for example, downward). The interference light is generated in a direction perpendicular to the direction in which the liquid crystal display panel is tilted (for example, in the lateral direction). Then, the liquid crystal display panel is disposed so as to be inclined such that a light emitting direction in which light is emitted from the light source toward the optical member and a normal direction of the surface of the liquid crystal display panel are shifted by a predetermined angle (for example, downward). Thus, for example, the interference light generated in the horizontal direction can be reflected with a predetermined angle shifted from the direction from the liquid crystal display panel toward the optical member, so that the interference light is displayed on the image display unit via the optical member. Can be suppressed. In the case where the slit is formed so as to extend substantially perpendicular (for example, lateral direction) to a direction (for example, the lower side) in which the normal direction of the surface of the liquid crystal display panel deviates from the light emission direction, the interference light is transmitted to the liquid crystal display panel Occurs in a direction (for example, up and down direction) along the direction in which is tilted. At this time, even if the liquid crystal display panel is tilted downward, the interference light is formed in the vertical direction, so that the interference light cannot be suppressed from being reflected by the optical member. As a result, the interference light is displayed on the image display unit.

In the display device according to the above aspect, preferably, the predetermined angle at which the liquid crystal display panel is tilted is at least light incident on the liquid crystal display panel from the optical member side and reflected by the surface of the liquid crystal display panel on the optical member side. The angle does not enter the optical member. If comprised in this way, since it can suppress that the light reflected on the surface by the side of the optical member of a liquid crystal display panel injects into an optical member, it suppresses that interference light is displayed on an image display part. Can do.

In the display device according to the above aspect, the angle formed between the longitudinal direction of the slit and the direction in which the normal direction of the surface of the liquid crystal display panel is inclined with respect to the light emitting direction may be 10 degrees or less. Good.

In the display device according to the above aspect, preferably, the optical member is a concave mirror, the liquid crystal display panel and the concave mirror are arranged on a straight line parallel to the light emission direction, and the image display unit is emitted from the light source, It is arranged in the reflection direction of the light reflected by the concave mirror. If comprised in this way, the light (image) radiate | emitted from the liquid crystal display panel can be easily displayed on an image display part via a concave mirror.

In this case, preferably, the light emitted from the light source is reflected upward by the concave mirror, and the liquid crystal display panel is arranged such that the normal direction of the surface of the liquid crystal display panel is shifted downward by a predetermined angle with respect to the light emission direction. Tilted. With this configuration, light incident from the outside is reflected by the concave mirror, and even if this reflected light is incident on the liquid crystal display panel, the liquid crystal display panel is tilted so as to shift downward by a predetermined angle. The incident light is reflected so as to deviate downward from the concave mirror by a predetermined angle. Thereby, it is possible to suppress the light reflected on the liquid crystal display panel from being reflected by the concave mirror and displaying the reflected light on the image display unit.

In the display device in which the optical member is a concave mirror, preferably, the light emitted from the light source is reflected upward by the concave mirror, and the liquid crystal display panel has a normal direction of the surface of the liquid crystal display panel with respect to the light emission direction. It is inclined so as to be displaced by a predetermined angle in the lateral direction. If configured in this way, the light incident from the outside is reflected on the concave mirror, and even if this reflected light is incident on the liquid crystal display panel, the liquid crystal display panel is tilted so as to be displaced by a predetermined angle in the lateral direction. The incident light is reflected from the concave mirror so as to be shifted in the lateral direction by a predetermined angle. Thereby, it is possible to suppress the light reflected on the liquid crystal display panel from being reflected by the concave mirror and displaying the reflected light on the image display unit.

In the display device according to the one aspect, preferably, the optical member includes a convex lens,
The liquid crystal display panel and the convex lens are arranged on a straight line parallel to the light emitting direction in which light is emitted from the light source, and the image display unit is arranged in a direction in which the light emitted from the light source is transmitted through the convex lens. . If comprised in this way, the light radiate | emitted from the liquid crystal display panel can be easily permeate | transmitted to an image display part via a convex lens.

In this case, the liquid crystal display panel is preferably tilted so that the normal direction of the surface of the liquid crystal display panel is deviated by a predetermined angle with respect to the light emission direction emitted toward the convex lens. With this configuration, even when light incident from the outside passes through the convex lens and the incident light enters the liquid crystal display panel, the liquid crystal display panel is tilted so as to deviate by a predetermined angle with respect to the light emitting direction. Therefore, the incident light is reflected so as to be shifted by a predetermined angle with respect to the optical member. Thereby, it is possible to suppress the light reflected by the liquid crystal display panel from being transmitted through the convex lens and displaying the reflected light on the image display unit.

In the display device according to the above aspect, the liquid crystal display panel includes a polarizing plate on a side facing the optical member, and the transmission axis of the polarizing plate is inclined with respect to the light emitting direction in the normal direction of the surface of the liquid crystal display panel. You may comprise so that it may become a direction orthogonal to a given direction.

In the display device according to the above aspect, the display device preferably further includes a thin film transistor disposed on the same substrate side as the pixel electrode and connected to the pixel electrode, and an insulating film sandwiched between the pixel electrode and the common electrode, The liquid crystal is configured to be driven by an electric field generated between the pixel electrode and the common electrode through the slit. According to this configuration, the liquid crystal can be driven in a lateral electric field mode in which an electric field is generated between the pixel electrode and the common electrode in a direction substantially parallel to the substrate, so that the viewing angle can be widened.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a diagram showing an overall configuration of a head-up display system according to a first embodiment of the present invention. FIG. 2 is a view showing a liquid crystal display panel and a backlight according to the first embodiment of the present invention. 3 to 7 are views for explaining the configuration of the liquid crystal display panel according to the first embodiment of the present invention. First, the structure of the head-up display system 100 according to the first embodiment of the present invention will be described with reference to FIGS. In the first embodiment,
A case where the present invention is applied to a head-up display system 100 which is an example of a display device will be described.

The head-up display system 100 according to the first embodiment, as shown in FIG.
For example, it is mounted on an automobile and is composed of a head-up display unit 1 and a windshield 2 on which light (image) emitted from the head-up display unit 1 is displayed. The windshield 2 is an example of the “image display unit” in the present invention.

The head-up display unit 1 includes a housing 11, a backlight 12, a liquid crystal display panel 13, and a concave mirror 14. Here, in the first embodiment, the backlight 1
2, the liquid crystal display panel 13, and the concave mirror 14 are arranged on a straight line parallel to the light emission direction of the light emitted from the backlight 12, and the windshield 2 is emitted from the backlight 12 and the concave mirror 14. The light is reflected in the reflection direction. Backlight 1
2 and the concave mirror 14 are examples of the “light source” and “optical member” of the present invention, respectively.
Thus, in 1st Embodiment, the concave mirror 14 is arrange | positioned on the optical path of the light radiate | emitted from the pack light 12 and displayed on the windshield 2. FIG. The backlight 12 and the concave mirror 14 are disposed so as to face each other with the liquid crystal display panel 13 interposed therebetween. In addition, the housing 11 includes
An opening 111 is provided, and light is emitted from the head-up display unit 1. For example, the distance L1 between the liquid crystal display panel 13 and the concave mirror 14 is about 1
. The distance L2 from the concave mirror 14 to the virtual image of the image described later is about 2 in plan view.
. 0 m. Here, in the first embodiment, as shown in FIG.
The light emission direction of the light emitted from the backlight 12 toward the concave mirror 14 and the normal direction of the surface of the liquid crystal display panel 13 are tilted so as to be shifted by 15 ° in the Z2 direction (downward). In FIG. 2, a slit 321 formed on the surface of one pixel electrode 32, which will be described later, is shown for the sake of simplicity. In the first embodiment, the angle at which the liquid crystal display panel 13 is tilted is at least an angle at which light is incident on the liquid crystal display panel 13 from the concave mirror 14 and light reflected by the pixel electrode 32 is not incident on the concave mirror 14. However, if the tilt angle is increased too much, the amount of light transmitted from the backlight 12 through the liquid crystal display panel 13 is reduced, so that the range of about 10 ° to 20 ° is preferable. It is preferable to set the size of the concave mirror 14 and the distance L1 between the liquid crystal display panel 13 and the concave mirror 14 and so on.

Further, as shown in FIG. 3, the liquid crystal display panel 13 includes a display unit 21, a drive IC 22, and V
A driver 23, an HSW (horizontal switch) 24, and a COM 25 are provided. Display unit 2
In FIG. 1, a plurality of pixels 26 are arranged in a matrix. The drive IC 22 has a function of driving the liquid crystal display panel 13 and a function of controlling a potential difference (gradation voltage) applied to the liquid crystal 35 described later. A plurality of gate lines 27 and data lines 28 are connected to the V driver 23 and the HSW 24, respectively, and the plurality of gate lines 27 and data lines 28 are arranged so as to be orthogonal to each other as shown in FIG. Has been.
Further, the V driver 23 has a function as a drive circuit for the gate line 27. HSW
24 has a switching function of dividing the signal supplied from the drive IC 22 by time division and outputting the divided signal to the corresponding data line 28 from the plurality of data lines 28. The COM 25 has a function of controlling the potential of the common electrode 33 of the pixel 26.

Each pixel 26 is configured to transmit light from the backlight 12 shown in FIG. 2 and display an image by the transmitted light.

As shown in FIG. 4, the pixel 26 includes a pixel transistor 31 composed of an n-type TFT, a pixel electrode 32, a common electrode 33, and a storage capacitor 34. The pixel transistor 31 is an example of the “thin film transistor” in the present invention. The drain region D of the pixel transistor 31 is connected to the data line 28. The source region S of the pixel transistor 31 is connected to the pixel electrode 32 and one electrode of the storage capacitor 34. The gate G of the pixel transistor 31 is connected to the gate line 27. The other electrode of the common electrode 33 and the other electrode of the storage capacitor 34 are connected to the COM 25 (see FIG. 3).

As shown in FIGS. 5 and 6, a common electrode 33 made of ITO or the like is formed on the surface of the substrate 41, and an insulating film 42 is formed on the surface of the common electrode 33. Also,
A pixel electrode 32 made of ITO or the like is formed on the surface of the insulating film 42. here,
In the first embodiment, as shown in FIGS. 2 and 5, the pixel electrode 32 is provided with a slit 321, and the slit 321 emits light emitted from the liquid crystal display panel 13 shown in FIG. 1. The liquid crystal display panel 13 is formed so as to extend substantially parallel to a direction (Z direction) in which the normal direction of the surface of the liquid crystal display panel 13 is deviated from the direction. Note that the pixel transistor 31 shown in FIG. 4 is connected to the pixel electrode 32.

A substrate 43 is provided so as to face the substrate 41, and the liquid crystal 35 is sandwiched between the substrate 43 and the pixel electrode 32 (insulating film 42). In the first embodiment, the polarizing plate 44 is provided on the surface of the substrate 43, and the transmission axis of the polarizing plate 44 is the surface of the liquid crystal display panel 13 with respect to the light emission direction of the light from the backlight 12. The normal direction is configured to be a direction (Y direction) orthogonal to the tilted direction (Z2 direction). In the first embodiment, as shown in FIGS. 6 and 7, the pixel electrode 32 and the common electrode 33 are arranged on the substrate 41 side, and the liquid crystal 35 aligned in parallel with the substrate 41 is formed on the surface of the substrate 41. When an electric field (in the direction of arrow A in FIG. 7) substantially parallel to the substrate is applied, the substrate rotates in a plane substantially in parallel with the substrate 41 (in the direction of arrow B in FIG. 5), by an FFS (Fringe-Field-Switching) method. It is configured. As described above, both the pixel electrode 32 and the common electrode 33 are attached to one substrate 4.
A configuration in which an electric field is applied to the liquid crystal 35 in a direction substantially parallel to the surface of the substrate 41 by being arranged on one side is referred to as a transverse electric field mode.

8 to 10 are views for explaining reflected light reflected from the liquid crystal display panel according to the first embodiment of the present invention. Next, the operation of the head-up display system 100 according to the first embodiment of the present invention will be described with reference to FIGS. 1 and 8 to 10.

First, as shown in FIG. 1, light is emitted from the backlight 12 toward the liquid crystal display panel 13. The light transmitted through the liquid crystal display panel 13 enters the concave mirror 14. The concave mirror 14 is
The light is transmitted at an angle with respect to the light emission direction (X1 direction) of the backlight 12, and the light transmitted through the liquid crystal display panel 13 is reflected upward (Z1 direction). Then, the light (image) reflected by the concave mirror 14 is displayed on the surface of the windshield 2. At this time, the driver can view the image displayed on the surface of the windshield 2. Actually, the driver sees a virtual image that appears away from the windshield 2 by an amount corresponding to the length of the path (optical path) from the liquid crystal display panel 13 to the windshield 2.

Next, as shown in FIG. 8, when sunlight or the like enters the windshield 2, the incident light is
Reflected by the concave mirror 14 and incident on the liquid crystal display panel 13, the liquid crystal display panel 13
Is reflected by. The reflected light (regularly reflected light 50) is transmitted from the liquid crystal display panel 13 to
As shown in FIG. 10, the specularly reflected light 50 is reflected below the concave mirror 14 by being arranged so as to be shifted by 15 ° in the Z2 direction (downward). The regular reflected light 50 is not displayed on the windshield 2 through the concave mirror 14. When the liquid crystal display panel 13 is arranged so that the light emission direction of the backlight 12 and the normal direction of the surface of the liquid crystal display panel 13 coincide (the liquid crystal display panel 13a indicated by the dotted line in FIG. 8). The regular reflection light 50a is reflected by the concave mirror 14 and displayed on the surface of the windshield 2 as shown in FIG.

Further, as shown in FIG. 9, the light incident on the liquid crystal display panel 13 is reflected on the surface of the pixel electrode 32 of the pixel 26 provided with the slits 321, and the reflected light interferes with the reflected light. appear. As shown in FIG. 10, a plurality of interference lights 51 are generated in the Y direction perpendicular to the Z direction (see FIG. 5) in which the slits 321 are formed.

Then, the liquid crystal display panel 13 includes the light emission direction of the backlight 12 and the liquid crystal display panel 13.
10 is disposed so that the normal direction of the surface coincides with the liquid crystal display panel 13a indicated by the dotted line in FIG. 8, the interference light 51 is reflected by the concave mirror 14 as shown in FIG. Displayed on the surface of the glass 2. Here, in the first embodiment, the liquid crystal display panel 13 has the light emission direction of the backlight 12 and the normal direction of the surface of the liquid crystal display panel 13 downward (Z2 direction).
, The interference light 52 is reflected below the concave mirror 14 and is not displayed on the surface of the windshield 2 as shown in FIG.

In the first embodiment, as described above, the light emission direction of the light emitted from the backlight 12 toward the concave mirror 14 from the backlight 12 and the normal direction of the surface of the liquid crystal display panel 13 are 15 ° downward. The solar light incident from above is reflected by the concave mirror 14 and the light incident on the liquid crystal display panel 13 is transmitted from the liquid crystal display panel 13 to the concave mirror 1.
It can be reflected by shifting the direction toward 4 and 15 ° downward. Thereby, it can suppress that the light (regular reflection light 50) reflected from the liquid crystal display panel 13 is displayed on the windshield 2. FIG. Further, by forming the slit 321 so as to extend substantially parallel to the lower side (Z2 direction) in which the normal direction of the surface of the liquid crystal display panel 13 is shifted with respect to the light emitting direction, the interference light 52 is transmitted in the lateral direction (Y Direction). Then, the light emission direction of the light emitted from the backlight 12 toward the concave mirror 14 and the liquid crystal display panel 13 are displayed.
By tilting so that the normal direction of the surface of the surface deviates by 15 ° downward, the lateral direction (
The interference light 52 generated in the Y direction can be reflected below the concave mirror 14. Thereby, it can suppress that the interference light 52 is displayed on the windshield 2. FIG.

In the first embodiment, as described above, the angle at which the liquid crystal display panel 13 is tilted is such that at least the light incident on the liquid crystal display panel 13 from the concave mirror 14 side and the light reflected by the liquid crystal display panel 13 and reflected is the concave mirror 14. By making the angle not to be incident on the liquid crystal display panel, the light reflected by the liquid crystal display panel 13 is suppressed from entering the concave mirror 14, so that the specular reflection light and the interference light are prevented from being displayed on the windshield 2. Can do.

In the first embodiment, as described above, the concave mirror 14 is arranged on the optical path of light from the liquid crystal display panel 13 to the windshield 2, so that the light emitted from the liquid crystal display panel 13 is reflected by the concave mirror 14. The reflected light (image) can be displayed on the windshield 2.

In the first embodiment, as described above, the liquid crystal display panel 13 and the concave mirror 14 are arranged on a straight line parallel to the light emission direction, and the windshield 2 is emitted from the backlight 12.
By disposing in the reflection direction of the light reflected by the concave mirror 14, the light (image) emitted from the liquid crystal display panel 13 can be easily displayed on the windshield 2 via the concave mirror 14.

In the first embodiment, as described above, the viewing angle is widened by driving the liquid crystal 35 by a horizontal electric field generated between the pixel electrode 32 and the common electrode 33 via the slit 321. be able to.

(Second Embodiment)
FIG. 11 is a diagram showing an overall configuration of a head-up display system viewed from above according to the second embodiment of the present invention. FIG. 12 is a plan view of a pixel electrode of the liquid crystal display panel according to the second embodiment of the present invention. Referring to FIGS. 1, 11 and 12, in the second embodiment, unlike the first embodiment, the head-up display system in which the liquid crystal display panel 13 is disposed inclined in the horizontal direction (horizontal direction). 101 will be described.

The configuration of the head-up display system 101 according to the second embodiment is the same as that of the first embodiment shown in FIG. 1 except that the direction in which the liquid crystal display panel 13 is tilted is different. And in 2nd Embodiment, as shown in FIG. 11, as for the liquid crystal display panel 13, the normal line direction of the surface of the liquid crystal display panel 13 is 15 to a horizontal direction (horizontal direction) (Y direction) with respect to a light-projection direction. °
Tilt to shift.

In the second embodiment, as shown in FIG. 12, the pixel electrode 32a has a slit 321.
a is provided, and the slit 321a is substantially in a direction (Y direction) in which the normal direction of the surface of the liquid crystal display panel 13 deviates from the light emission direction of the light emitted from the liquid crystal display panel 13 shown in FIG. It is formed to extend in parallel.

  In addition, the other structure of 2nd Embodiment is the same as that of the said 1st Embodiment.

FIG. 13 is a view for explaining light reflected by the concave mirror according to the second embodiment of the present invention. Next, an operation of the head-up display system 101 according to the second embodiment of the present invention will be described with reference to FIGS.

The operation of displaying the image displayed on the liquid crystal display panel 13 on the windshield 2 is the same as in the first embodiment.

Next, as shown in FIG. 11, when sunlight or the like enters the windshield 2 from above in the Z2 direction, the incident light is reflected by the concave mirror 14 and is incident on the liquid crystal display panel 13. Then, the reflected light (regular reflection light 50) from the liquid crystal display panel 13 is arranged so that the liquid crystal display panel 13 is inclined so as to be shifted by 15 ° in the horizontal direction (Y direction). As shown in FIG. 13, the light is reflected to the side of the concave mirror 14 and is not displayed on the windshield 2. Note that the liquid crystal display panel 13 includes the light emission direction of the backlight 12 and the liquid crystal display panel 1.
3 is arranged so that the normal direction of the surface 3 coincides (the liquid crystal display panel 13a indicated by the dotted line in FIG. 11), the regular reflection light 50a is reflected by the concave mirror 14 as shown in FIG. Displayed on the surface of the windshield 2.

Further, the light incident on the liquid crystal display panel 13 is reflected on the surface of the pixel electrode 32a of the pixel 26 provided with the slits 321a shown in FIG. 12, and this reflected light causes light interference between the reflected lights. . As shown in FIG. 13, a plurality of interference lights are generated in the Z direction perpendicular to the Y direction (see FIG. 12) in which the slits 321a are formed.

Then, the liquid crystal display panel 13 includes the light emission direction of the backlight 12 and the liquid crystal display panel 13.
When the liquid crystal display panel 13a is arranged so that the normal direction of the surface coincides with the liquid crystal display panel 13a indicated by the dotted line in FIG. 11, the interference light 51 passes through the concave mirror 14 as shown in FIG. 2 is displayed in the Z direction on the surface. Here, in the second embodiment, the liquid crystal display panel 13 has a horizontal direction (Y that the light emission direction of the backlight 12 and the normal direction of the surface of the liquid crystal display panel 13 are
13, the interference light 52 is reflected in the lateral direction of the concave mirror 14 and is not displayed on the surface of the windshield 2.

In the second embodiment, as described above, the liquid crystal display panel 13 is incident from the outside by being tilted so that the normal direction of the surface of the liquid crystal display panel 13 is shifted by 15 ° in the lateral direction with respect to the light emitting direction. Even if the light is reflected by the concave mirror 14 and the reflected light is incident on the liquid crystal display panel 13,
Since the liquid crystal display panel 13 is tilted so as to be shifted by 15 ° in the horizontal direction, the incident light is reflected from the concave mirror 14 so as to be shifted in the horizontal direction by 15 °. Thereby, it is possible to suppress the light reflected by the liquid crystal display panel 13 from being reflected by the concave mirror 14 and displaying the reflected light on the windshield 2.

  The remaining effects of the second embodiment are similar to those of the aforementioned first embodiment.

(Third embodiment)
FIG. 14 is a diagram showing an overall configuration of a head-up display system viewed from the lateral direction according to the third embodiment of the present invention. Referring to FIG. 14, in the third embodiment, unlike the first embodiment, a head-up display system 102 that displays an image on the windshield 2 via the convex lens 15 will be described.

As shown in FIG. 14, the head-up display system 102 according to the third embodiment includes a head-up display unit 1 a and a windshield 2 on which light (image) emitted from the head-up display unit 1 a is displayed. ing.

The head-up display unit 1 a includes a backlight 12, a liquid crystal display panel 13, and a convex lens 15. The convex lens 15 is an example of the “optical member” in the present invention. Here, in the third embodiment, the backlight 12, the liquid crystal display panel 13, and the convex lens 15 are arranged on a straight line parallel to the light emission direction of the light emitted from the backlight 12. The head-up display unit 1a is provided with an opening 111a so that light is emitted from the head-up display unit 1a. Also,
The windshield 2 is arranged in the direction in which light is emitted from the convex lens 15. Also,
In the third embodiment, in the liquid crystal display panel 13, the light emission direction of light emitted from the backlight 12 toward the convex lens 15 and the normal direction of the surface of the liquid crystal display panel 13 are 15 ° in the X direction.
It is tilted so as to be displaced. The slits of the pixel electrode 32 are formed in parallel with the X direction.

  The remaining configuration of the third embodiment is similar to that of the aforementioned first embodiment.

Next, the operation of the head-up display system 102 according to the third embodiment of the present invention will be described with reference to FIG.

First, as shown in FIG. 14, light is emitted from the backlight 12 toward the liquid crystal display panel 13. The light transmitted through the liquid crystal display panel 13 enters the convex lens 15. Then, the light (image) transmitted through the convex lens 15 is displayed on the surface of the windshield 2. The driver
The image displayed on the surface of the windshield 2 can be viewed. Actually, the driver sees a virtual image that appears away from the windshield 2 by an amount corresponding to the length of the path (optical path) from the liquid crystal display panel 13 to the windshield 2.

Next, when sunlight or the like enters the windshield 2, the incident light passes through the convex lens 15 and enters the liquid crystal display panel 13. Here, in the third embodiment, the liquid crystal display panel 13 is used.
However, the light emission direction of the backlight 12 and the normal direction of the surface of the liquid crystal display panel 13 are in the horizontal direction (
(X direction) is inclined so as to be deviated by 15 °, so that the light incident from the windshield 2 and reflected by the liquid crystal display panel 13 and the interference light between the reflected lights are reflected on the windshield 2. It is not displayed on the surface.

In the third embodiment, as described above, the liquid crystal display panel 13 and the convex lens 15 are arranged on a straight line parallel to the light emission direction in which light is emitted from the backlight 12, and the windshield 2 is
By arranging the light emitted from the backlight 12 in a direction that transmits the convex lens 15, the light emitted from the liquid crystal display panel 13 can be easily transmitted to the windshield 2 through the convex lens 15.

In the third embodiment, the liquid crystal display panel 13 is replaced with the liquid crystal display panel 13 as described above.
The light incident on the liquid crystal display panel 13 from the outside is inclined with respect to the convex lens 15 by tilting so that the normal direction of the surface of the surface is shifted by 15 ° laterally with respect to the light emitting direction emitted toward the convex lens 15. Since the light is reflected so as to be shifted by 15 ° laterally, it is possible to suppress the light reflected on the liquid crystal display panel 13 from being transmitted through the convex lens 15 and displayed on the windshield 2.

  The remaining effects of the third embodiment are similar to those of the aforementioned first embodiment.

The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description of the embodiments but by the scope of claims for patent, and further includes all modifications within the meaning and scope equivalent to the scope of claims for patent.

For example, in the first to third embodiments, the example in which the pixel electrode is provided with the slit is shown.
The present invention is not limited to this, and a slit may be provided in the common electrode. In this case, a pixel electrode is formed above the substrate, and a common electrode is formed above the pixel electrode with an insulating film interposed therebetween.

In the first to third embodiments, the example in which the liquid crystal display panel is disposed to be inclined with respect to the Z direction, the Y direction, and the X direction has been described. However, the present invention is not limited thereto, and the liquid crystal display is provided. You may arrange | position a panel inclining in directions other than Z direction, Y direction, and X direction.

In the first embodiment, the slit is formed in parallel with the Z direction. However, the present invention is not limited to this, and the slit 322 of the pixel electrode 32b is formed as in the modification shown in FIG. , It may be inclined with respect to the Z direction within a range of 10 ° or less (for example, about 5 °). In this case, since the alignment direction of the liquid crystal can be the Y direction, the transmission axis of the polarizing plate disposed on the concave mirror side of the liquid crystal display panel can be parallel to the Y direction. Since it is arranged at an angle with respect to the image light from the concave mirror toward the windshield, it is incident as polarized light in a direction perpendicular to the tilted direction, and the image light incident on the windshield is efficiently used. Can reflect well.

1 is a diagram illustrating an overall configuration of a head-up display system according to a first embodiment of the present invention. It is a figure which shows the liquid crystal display panel and backlight by 1st Embodiment of this invention. It is a block diagram which shows the structure of the liquid crystal display panel by 1st Embodiment of this invention. FIG. 3 is an equivalent circuit diagram of a pixel portion of the liquid crystal display panel according to the first embodiment of the present invention. FIG. 3 is a plan view of a pixel electrode of the liquid crystal display panel according to the first embodiment of the present invention. FIG. 6 is a diagram for explaining an alignment state of liquid crystal when an off voltage is applied to an electrode in the pixel according to the first embodiment of the present invention. FIG. 5 is a diagram for explaining an alignment state of liquid crystal when an on-voltage is applied to an electrode in the pixel according to the first embodiment of the present invention. It is a figure for demonstrating a mode that sunlight injects into the liquid crystal display panel by 1st Embodiment of this invention. It is a figure for demonstrating interference of the reflected light reflected by the pixel electrode by 1st Embodiment of this invention. It is a figure for demonstrating the light reflected by the concave mirror by 1st Embodiment of this invention. It is a figure which shows the whole structure of the head-up display system seen from the upper direction by 2nd Embodiment of this invention. FIG. 6 is a plan view of a pixel electrode of a liquid crystal display panel according to a second embodiment of the present invention. It is a figure for demonstrating the light reflected by the concave mirror by 2nd Embodiment of this invention. It is a figure which shows the whole structure of the head-up display system seen from the horizontal direction by 3rd Embodiment of this invention. It is a top view of the pixel electrode of the liquid crystal display panel by the modification of 1st Embodiment of this invention.

Explanation of symbols

2 Windshield (image display part)
12 Backlight (light source)
13 Liquid crystal display panel 14 Concave mirror (optical member)
15 Convex lens (optical member)
26 pixels 31 pixel transistors (thin film transistors)
32, 32a, 32b Pixel electrode 33 Common electrode 41 Substrate 42 Insulating film 44 Polarizing plate 321, 321a, 322 Slit

Claims (10)

A liquid crystal display panel including a plurality of pixels;
A light source arranged to face the liquid crystal display panel;
An optical member disposed on the opposite side of the liquid crystal display panel from which the light source is disposed;
An image display unit on which an image displayed on the liquid crystal display panel is projected,
The pixel includes a liquid crystal and a pixel electrode and a common electrode disposed on the same substrate side that applies a voltage to the liquid crystal,
Of the pixel electrode or the common electrode, the electrode on the liquid crystal layer side is provided with a slit,
The liquid crystal display panel is disposed so that a light emitting direction in which light is emitted from the light source toward the optical member and a normal direction of the surface of the liquid crystal display panel are inclined at a predetermined angle. In addition, the slit is formed so as to extend substantially parallel to a direction in which a normal line direction of the surface of the liquid crystal display panel is inclined with respect to the light emitting direction. The predetermined angle at which the liquid crystal display panel is tilted is at least light incident on the liquid crystal display panel from the optical member side and reflected by the surface of the liquid crystal display panel on the optical member side,
The display device according to claim 1, wherein the display device is at least an angle not incident on the optical member. The display device according to claim 1, wherein an angle formed between a longitudinal direction of the slit and a direction in which a normal direction of the surface of the liquid crystal display panel is inclined with respect to the light emitting direction is 10 degrees or less. The optical member is a concave mirror,
The liquid crystal display panel and the concave mirror are arranged on a straight line parallel to the light emitting direction,
The display device according to claim 1, wherein the image display unit is arranged in a reflection direction of light emitted from the light source and reflected by the concave mirror. The light emitted from the light source is reflected upward by the concave mirror,
The display device according to claim 4, wherein the liquid crystal display panel is tilted so that a normal direction of a surface of the liquid crystal display panel is shifted downward by a predetermined angle with respect to the light emitting direction. The light emitted from the light source is reflected upward by the concave mirror,
The display device according to claim 4, wherein the liquid crystal display panel is tilted so that a normal direction of a surface of the liquid crystal display panel is shifted by a predetermined angle in a lateral direction with respect to the light emitting direction. The optical member comprises a convex lens,
The liquid crystal display panel and the convex lens are arranged on a straight line parallel to the light emitting direction in which light is emitted from the light source, and the image display unit transmits light emitted from the light source through the convex lens. The display device according to any one of claims 1 to 3, wherein the display device is disposed in a direction in which to perform the operation. The liquid crystal display panel is tilted so that a normal direction of a surface of the liquid crystal display panel is shifted by a predetermined angle with respect to the light emitting direction emitted toward the convex lens.
The display device described in 1. The liquid crystal display panel includes a polarizing plate on a side facing the optical member, and a transmission axis of the polarizing plate is in a direction in which a normal direction of a surface of the liquid crystal display panel is inclined with respect to the light emitting direction. The display device according to claim 1, wherein the display device is in an orthogonal direction. A thin film transistor disposed on the same substrate side as the pixel electrode and connected to the pixel electrode;
An insulating film sandwiched between the pixel electrode and the common electrode;
The display device according to claim 1, wherein the liquid crystal is configured to be driven by an electric field generated between the pixel electrode and the common electrode via the slit.

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