JP2022103554A - Display - Google Patents

Abstract

To prevent the occurrence of displacement between a lenticular lens and pixels even when a display is used in a thermal shock environment.SOLUTION: A display has a liquid crystal display panel 25 that includes a pair of front and rear glass substrates 102F, 102R enclosing a liquid crystal layer 101; and a light source 21 that is provided in the rear of the liquid crystal display panel 25 and emits illumination light 4 performing transmitted illumination of the liquid crystal display panel 25. In the liquid crystal display panel 25, a lenticular lens 150 for spreading the illumination light 4 is applied onto a front face of the front glass substrates 102F, 102R with an adhesive AD therebetween, and a front polarizing plate 104F is provided in the front of the lenticular lens 150 and a rear polarizing plate 104R is provided in the rear of the rear glass substrate 102R.SELECTED DRAWING: Figure 4

Description

The present invention relates to a display device that displays a desired display to a viewer.

Conventionally, for example, the display device described in Patent Document 1 is known. In this display device, an anisotropic scattering sheet is attached to one surface of a liquid crystal display panel having a pixel pair consisting of left and right pixels, and further, the left is attached to one surface of the anisotropic scattering sheet. -A lenticular lens that separates the light from the right pixel is attached.

Japanese Unexamined Patent Publication No. 2008-134617

In the configuration of the display device of the prior art, a polarizing plate made of a resin material may be generally used instead of the anisotropic scattering sheet. In that case, the polarizing plate is attached to the one side surface of the liquid crystal display panel, and the lenticular lens is attached to the one side surface of the polarizing plate.
However, in this case, under the condition that the display device is placed in an environment where thermal shock is present, the polarizing plate made of a resin material shrinks permanently, and the amount of shrinkage is larger than that of the glass substrate of the liquid crystal display panel. Therefore, there is a problem that the positional relationship between the lenticular lens and the pixel is displaced due to the influence of the polarizing plate that shrinks greatly due to heat.

Therefore, the present invention has been made in view of the above problems, and provides a display device capable of preventing the occurrence of deviation between the lenticular lens and the pixel even when used in a thermal shock environment. The purpose is to do.

The present invention is provided with a liquid crystal display panel 25 having a pair of front and rear glass substrates 102F and 102R for enclosing the liquid crystal layer 101, and a liquid crystal display panel 25 provided behind the liquid crystal display panel 25 and transmitting through the liquid crystal display panel 25. A light source 21 that emits illumination light 4 to illuminate, and a lenticular lens 150 that spreads the illumination light 4 is attached to the front surface of the front glass substrate 102F in the liquid crystal display panel 25 via an adhesive AD. The front side polarizing plate 104F is provided on the front side of the lenticular lens 150, and the rear side polarizing plate 104R is provided on the rear side of the rear side glass substrate 102R.

According to the present invention, it is possible to provide a display device that prevents the occurrence of deviation between the lenticular lens and the pixel even when used in a thermal shock environment.

An explanatory view of the front part of an automobile equipped with a head-up display provided with a display device according to an embodiment of the present invention. FIG. 3 is a cross-sectional view showing an overall schematic structure of a head-up display provided with the display device shown in FIG. 1. The front view schematically showing the detailed structure of the liquid crystal display panel shown in FIG. The top view schematically shows the detailed structure of the liquid crystal display panel shown in FIG. A perspective view showing the detailed shape of a lenticular lens. The front view schematically shows the detailed structure of the liquid crystal display panel in the modified example in which the air layer is provided between the lenticular lens and the polarizing plate. Top view schematically showing the detailed structure of a liquid crystal display panel. The front view schematically shows the detailed structure of the liquid crystal display panel in the modification which uses the rectangular cylindrical lens part. Top view schematically showing the detailed structure of a liquid crystal display panel. The top view schematically shows the detailed structure of the liquid crystal display panel in the modified example in which the reinforcing member is provided on the front side of the front polarizing plate. Top view schematically showing the detailed structure of the liquid crystal display panel in another modification in which a reinforcing member is provided on the front side of the front polarizing plate.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The present embodiment is an embodiment when the display device of the present invention is applied to, for example, a head-up display that can be mounted on an automobile.

An explanatory view of the front part of an automobile equipped with a head-up display provided with the display device of the present embodiment is shown in FIG. 1, and a sectional view showing an overall schematic structure of the head-up display provided with the display device of the present embodiment is shown in FIG. Shown in 2. In the following, in order to facilitate understanding of the configuration of the display device, the front side of the vehicle is "front (Fr.)", the opposite side is "rear (Re.)", And the left side of the vehicle is "left (". L) ”, the right side is“ right (R) ”, the upper side of the automobile is“ upper (U) ”), and the lower side of the automobile is“ lower (D) ”). reference).

<Arrangement of HUD in automobile>
In FIG. 1, the head-up display 1 (HUD1) is arranged inside the instrument panel 3 of the automobile 2. The HUD 1 reflects the display light (illumination light) 4 toward the driver 6 (viewer) of the automobile 2 by the windshield 5 of the automobile 2 which is a projection member, and displays the virtual image 7. As a result, the driver 6 can observe the virtual image 7 superimposed on the landscape.

<Overall configuration of HUD>
In FIG. 2, the HUD 1 mainly includes a display device 20 according to the present embodiment, a reflector unit 30, and a case 40.

The display device 20 includes an LED 21 (light source), a condenser lens (condensing lens) 22, a condensing lens 24, a liquid crystal display panel 25, a reflector 27, a display device case 28, and a heat sink 29. Have.

The LED 21 is mounted on the light source substrate 21a behind the liquid crystal display panel 25, and is arranged in thermal contact with the heat sink 29. The LED 21 emits display light 4 (illumination light 4a) for transmitting and illuminating the liquid crystal display panel 25.

The reflecting plate 27 is arranged on the optical path of the display light 4 between the LED 21 and the liquid crystal display panel 25, and the S-polarized light (S wave vibrating the surface perpendicular to the incident surface) of the display light 4 is applied to the liquid crystal display panel. It reflects toward 25 and transmits P-polarized light (P wave that vibrates a surface parallel to the incident surface). The reflector 27 is a transparent resin material (for example, polymethyl methacrylate resin (PMMA)).

The condenser lens 22 collects the display light 4 (reflected light 4b, S-polarized light in the reflecting plate 27) emitted from the LED 21 and reflected by the reflecting plate 27 so as to be parallel light having a substantially uniform light density.
The condenser lens 24 is, for example, a convex lens having a toroidal surface in which the curvature in the vertical direction and the curvature in the horizontal direction are different. The condenser lens 24 collects the reflected light 4b toward the liquid crystal display panel 25.

The display device case 28 fixes and supports and accommodates the condenser lens 22, the condenser lens 24, and the liquid crystal display panel 25 on the front side of the bent portion 28a. The display device case 28 fixes, supports, and accommodates the LED 21 on the rear side of the bent portion 28a.

The heat sink 29 is fixed to the rear end portion 28b of the display device case 28. The heat sink 29 has a large number of flat plate-shaped heat radiation fins 29a. The heat radiating fins 29a release the heat generated by the LED 21 to the outside of the head-up display 1.

The reflecting mirror unit 30 includes a concave mirror 31, a holding member 32, and a stepping motor 33.

The concave mirror 31 is composed of a substrate made of a resin (for example, polycarbonate) and a metal (for example, aluminum) vapor-deposited on the substrate to be a reflective surface 31a. The reflecting surface 31a is a concave surface, and enlarges and reflects the display light 4 (reflected light 4b in this example) emitted by the liquid crystal display panel 25. The holding member 32 is made of resin (for example, ABS) and is adhered to the concave mirror 31 with double-sided adhesive tape.

The holding member 32 has a gear 34 and a shaft portion 35. The shaft portion 35 is pivotally supported by the case 40. The stepping motor 33 has a gear 37 that meshes with the gear 34 of the holding member 32. The stepping motor 33 adjusts the projection direction of the display light 4 by supporting the concave mirror 31 in a state of being rotatable via the holding member 32. The stepping motor 33 adjusts the angle of the concave mirror 31 so that the display light 4 (reflected light 4b) is reflected at the position of the eyes (so that the virtual image 7 can be visually recognized) based on the operation of the driver 6.

The case 40 houses the front side portion of the display device 20 and the reflector unit 30. The case 40 has a cover 41 and a light-shielding wall 42. The cover 41 is made of a curved translucent resin (for example, acrylic) and emits the display light 4. The light-shielding wall 42 blocks external light such as sunlight, and prevents a phenomenon (washout) in which the external light is incident on the liquid crystal display panel 25 and the virtual image 7 is difficult to see.

<Detailed structure of liquid crystal display panel>
The detailed structure of the liquid crystal display panel 25, which is the main part of the present embodiment, is shown in FIGS. 3 and 4.

In FIGS. 3 and 4, the liquid crystal display panel 25 is, for example, a TFT (Thin Film Transistor) type normally black type (black display when no voltage is applied) liquid crystal display panel suitable for HUD1. The liquid crystal display panel 25 includes a pair of front and rear glass substrates 102F and 102R that enclose the liquid crystal layer 101. A transparent electrode (not shown) is formed on the pair of glass substrates 102F and 102R by ITO (Indium Tin Oxide) or the like.

A lenticular lens 150 that spreads the display light 4 (reflected light 4b) is attached to the front surface of the glass substrate 102F on the front side via the adhesive AD. A front polarizing plate 104F is provided on the front side of the lenticular lens 150. A rear polarizing plate 104R is provided on the rear side of the rear glass substrate 102R. The polarizing plates 104F and 104R have a polarizing axis parallel to the vibration axis of the display light 4 (reflected light 4b, S polarization in the reflecting plate 27) reflected by the reflecting plate 27.

The lenticular lens 150 has a base film 151 and a UV resin layer 152 provided on the front side of the base film 151 and having a predetermined uneven shape. The front polarizing plate 104F is attached to the front side of the UV resin layer 152 via the adhesive AD. As the adhesive AD, for example, a transparent optical adhesive, that is, OCA (Optical Clear Adhesive) can be used.

The UV resin layer 152 of the lenticular lens 150 is composed of a plurality of (16 in the example shown in FIG. 4) cylindrical lens portions 162, and displays the display light 4 focused by the condenser lens 24 in the vertical direction and the horizontal direction. Spread in the direction. FIG. 5 shows a perspective view showing the detailed shape of the lenticular lens 150. Note that FIG. 5 illustrates a case where the UV resin layer 152 of the lenticular lens 150 is composed of 11 cylindrical lens portions 162 in order to prevent the complexity of the illustration. As shown in FIG. 5, each cylindrical lens portion 162 has a convex cross-sectional shape, specifically, a cross-sectional shape that protrudes in a substantially semicircular shape in the left-right direction. Further, the axial direction of the semicircular shape at this time is the vertical direction. In reality, the width of one cylindrical lens unit 162 in the left-right direction (LR direction in the figure) is about 50 μm to 150 μm, and the height of one cylindrical lens unit 162 (before and after the cylindrical lens unit 162). The directional dimension x) is about 3 μm to 20 μm.

Returning to FIGS. 3 and 4, the liquid crystal display panel 25 is located on the outer edge side and is located inside the first region 25a and the first region 25a, which have a substantially square frame shape and are not used for display, and are used for display. (Represented by "Used Area" in FIG. 3) It has a second region 25b having a substantially quadrangular shape. In this example, the front polarizing plate 104F is not attached to the second portion 152b of the UV resin layer 152 corresponding to the second region 25b, and the first portion of the UV resin layer 152 corresponding to the first region 25a. It is attached to 152a.

The front polarizing plate 104F may be attached not to the entire circumference of the first portion 152a corresponding to the first region 25a of the UV resin layer 152, but to a part of the UV resin layer 152 (for example, only two opposing sides). .. Further, the first portion 152a may not be formed on the second region 25b side of the first region 25a but may be formed only on the outer peripheral side. The anteroposterior dimension x of the cylindrical lens portion 162 in the first portion 152a of the UV resin layer 152 is set so that the cylindrical lens portion 162 in the second portion 152b and the front polarizing plate 104F are in contact with each other. The front polarizing plate 104F may be attached to both the second portion 152b and the first portion 152a.

<Effect of embodiment>
As described above, in the display device 20 of the present embodiment, the liquid crystal display panel 25 is illuminated by the display light 4 emitted from the LED 21. In the liquid crystal display panel 25, the liquid crystal layer 101 is enclosed in a pair of front and rear glass substrates 102F and 102R. A rear polarizing plate 104R is provided on the rear side of the rear glass substrate 102R.

Here, in the display device 20, a thermal shock due to a high temperature may occur due to a change in the environmental temperature, heat generation in the liquid crystal display panel 25, radiant heat from the LED 21, and the like.
At this time, if the structure is such that the lenticular lens 150 is attached to the front surface of the front polarizing plate 104F located in front of the front glass substrate 102F, the front polarizing plate 104F made of a resin material is permanently attached in a thermal shock environment. Shrink. Since the amount of shrinkage of the front polarizing plate 104F at that time is larger than that of the front glass substrate 102F, the positional relationship between the lenticular lens 150 and the pixel may be displaced due to the influence. As a result, X-talk (crosstalk phenomenon of three-dimensional image) may be deteriorated.

Correspondingly, in the present embodiment, the wrenchular lens 150 (specifically, the base film 151) is attached to the front surface of the front glass substrate 102F via the adhesive AD, and the wrenchular lens 150 (specifically, the base film 151) is attached. A front polarizing plate 104F is provided on the front side of the UV resin layer 152) by sticking with the adhesive AD in this example. As a result, as described above, the influence of the front polarizing plate 104F of the resin material, which shrinks more than the front glass substrate 102F, can be suppressed. Therefore, it is possible to maintain the positional relationship between the lenticular lens 150 and the pixels of the glass substrate 102F on the front side, and prevent misalignment from occurring between them. As a result, the generation of X-talk can be prevented.

Further, in the present embodiment, in particular, the liquid crystal display panel 25 having the base film 151 and the UV resin layer 152 includes a first region 25a on the outer edge side not used for display and an inner second region 25b used for display. ing. The front polarizing plate 104F is not attached to the second portion 152b corresponding to the second region 25b of the UV resin layer 152, but is attached only to the first portion 152a corresponding to the first region 25a. ..

As a result, the second portion 152b of the UV resin layer 152 corresponding to the second region 25b that contributes to the display on the liquid crystal display panel 125 has a structure specialized for a display function that does not consider fixing to the front polarizing plate 104F. The first portion 152a of the UV resin layer 152 corresponding to the first region 25a, which does not contribute to the display on the liquid crystal display panel 25, has a structure specialized for the fixing function with the front polarizing plate 104F. be able to.

Further, in the present embodiment, in particular, the front-back direction of the cylindrical lens portion 162 of the first portion 152a of the UV resin layer 152 so that the cylindrical lens portion 162 of the second portion 152b of the UV resin layer 152 and the front polarizing plate 104F are in contact with each other. The dimension x is set. This makes it possible to prevent the lenticular lens 150 and the pixels from being displaced in a configuration in which the UV resin layer 152 of the lenticular lens 150 and the front polarizing plate 104F are in contact with each other.

The present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit and technical idea. Hereinafter, such modification examples will be described step by step. The same reference numerals are given to the parts equivalent to those in the above embodiment, and the description thereof will be omitted or simplified as appropriate.

(1) When an air layer is provided between the lenticular lens and the polarizing plate The overall schematic structure of the liquid crystal display panel 25, which is the main part of the display device 20 of this modified example, is shown in FIGS. 3 and 4, respectively. 6 and FIG. 7.

In FIGS. 6 and 7, in the liquid crystal display panel 25 in this modification, of the 16 cylindrical lens portions 162 provided in the UV resin layer 152 in FIG. 4, the two cylindrical lens portions 162 on the left end side ( The front-rear dimension x) and the two cylindrical lens portions 162 (front-back dimension x) on the right end side are omitted, respectively. Then, instead of the four cylindrical lens portions 162, one large cylindrical lens portion 162'having a dimension y (> x) in the front-rear direction is provided on the left end side and the right end side, respectively. As a result, the anteroposterior dimension (= y) of the first portion 152a of the UV resin layer 152 becomes larger than the equidirectional dimension (= x) in the above embodiment, and the cylindrical lens portion of the second portion 152b of the UV resin layer 152. 162 and the front polarizing plate 104F are separated from each other via the air layer AR. The front polarizing plate 104F is attached to the cylindrical lens portion 162'of the first portion 152a via the adhesive AD.

In this modification, the front-rear dimension y of the first portion 152a of the UV resin layer 152 is set so that the second portion 152b of the UV resin layer 152 and the front polarizing plate 104F are separated from each other. As a result, the air layer AR can be interposed between the second portion 152b of the UV resin layer 152 and the front polarizing plate 104F, and deterioration of display quality can be suppressed.

(2) When a rectangular cylindrical lens portion is used The overall schematic structure of the liquid crystal display panel 25, which is the main part of the display device 20 of this modified example, is shown in FIGS. 8 and 9 corresponding to FIGS. 6 and 7, respectively. ..

In FIGS. 8 and 9, in the liquid crystal display panel 25 in this modification, each cylindrical lens portion 162'(front-rear direction) provided in the first portion 152a of the UV resin layer 152 with one left and one right in FIG. 7 above. Instead of the dimension y), a cylindrical lens portion 162 ″ having a rectangular cross section is provided. As a result, the first portion 152a of the UV resin layer 152 has a rear surface in contact with the base film 151 and a front plate plate 104F. The front surface to which the is attached is composed of planes that are substantially parallel to each other.

In the illustrated example, the front-rear dimension z of the cylindrical lens portion 162 ″ is larger than the above-mentioned dimension x, and as a result, the UV resin layer 152 is similar to the liquid crystal display panel 25 of FIGS. 6 and 7. The cylindrical lens portion 162 of the second portion 152b and the front polarizing plate 104F are separated from each other via the air layer AR. The front polarizing plate 104F attaches the adhesive AD to the cylindrical lens portion 162 ″ of the first portion 152a. It is pasted through. The dimension z may be the same as the dimension x so that the air layer AR does not intervene.

In this modification, in the cylindrical lens portion 162 ″ arranged in the first portion 152a of the UV resin layer 152, the rear surface in contact with the base film 151 and the front surface to which the front polarizing plate 104F is attached are substantially parallel to each other. In other words, the first portion 152a of the UV resin layer 152 has a substantially rectangular cross-sectional shape. The first portion 152a of the UV resin layer 152 has such a shape, so that the front polarizing plate 104F is formed. It can be stably fixed, and the distance between the second portion 152b and the front polarizing plate 104F (corresponding to the anteroposterior dimension of the air layer AR) can be set to a desired value with high accuracy.

In the above-mentioned modifications (1) and (2), the cylindrical lens portion 162 ′, 162 ″ is arranged in the first portion 152a of the UV resin layer 152 corresponding to the first region 25a of the liquid crystal display panel 25. The cylindrical lens portion 162 was arranged in the second portion 152b corresponding to the two regions 25b. That is, the shape of the cylindrical lens portion was clearly different between the first portion 152a and the second portion 152b, but this was limited. That is, the cylindrical lens portion 162 is arranged from the second portion 152b to the boundary position between the first portion 152a and the second portion 152b (see the position of the square frame shown by the broken line in FIGS. 6 and 8). Therefore, the cylindrical lens portion 162 ′, 162 ″ may be arranged only on the left end side or the right end side of the cylindrical lens portion 162 located at the boundary.

Further, as described above, each of the two cylindrical lens portions 162 on the left end side and the right end side is replaced with one large cylindrical lens portion 162', 162 ″, respectively, but the present invention is not limited to this, that is, the left end side and the right end. By replacing each of three or more cylindrical lens portions 162 on the side, the portion for fixing the front polarizing plate 104F may be enlarged. Further, the cylindrical lens portions 162', 162 "and the cylindrical lens portion 162 are combined with the base film 161. It may be integrally molded.

(3) When a Reinforcing Member is Provided on the Front Side of the Front Polarizing Plate The overall schematic structure of the liquid crystal display panel 25, which is the main part of the display device 20 of this modified example, is shown in FIG. 10 corresponding to FIG. 7.

In FIG. 10, in the liquid crystal display panel 25 in this modification, in the structure shown in FIG. 7, a transmissive strength reinforcing member 171 attached to the front side of the front polarizing plate 104F is provided. As the strength reinforcing member 171, a glass plate similar to the glass substrates 102F and 102R may be used, or another appropriate member such as acrylic resin may be used provided that the desired hardness and optical characteristics can be secured.

In this modification, the transparent strength reinforcing member 171 is attached to the front side of the front polarizing plate 104F. As a result, as described above, the rigidity of the front polarizing plate 104F in a state where a gap (air layer AR) is interposed between the UV resin layer 152 and the second portion 152b and is not supported by the second portion 152b is improved. , Deterioration of display quality can be suppressed.

Although FIG. 10 shows an example in which the strength reinforcing member 171 is additionally provided in the structure shown in FIG. 7, as shown in FIG. 11, in the structure shown in FIG. 9, the front side of the front polarizing plate 104F is shown. The strength reinforcing member 171 may be provided in the. In this case as well, the same effect as described above is obtained.

In the above description, the case where the display device of the present invention is applied to a head-up display that can be mounted on an automobile has been described as an example, but the present invention is not limited to this. That is, it can be applied to other display devices for automobiles including meters, and further to display devices for motorcycles, ships, agricultural machines, construction machines, etc., not limited to automobiles, and the same effect can be obtained in this case as well. obtain.

1 Head-up display (HUD)
2 Automobile 4 Display light (illumination light)
4a Illumination light 4b Reflected light 5 Windshield 6 Driver 7 Virtual image 20 Display device 21 LED (light source)
21a Light source board 22 Condenser lens 24 Condensing lens 25 Liquid crystal display panel 25a 1st area 25b 2nd area 27 Reflector 28 Display device case 28a Bending part 28b Rear end 29 Heat dissipation fin 30 Reflecting mirror unit 31 Concave mirror 31a Reflection Surface 32 Holding member 33 Stepping motor 34 Gear 35 Shaft 37 Gear 40 Case 41 Cover 42 Shading wall 101 Liquid crystal layer 102F Front glass substrate 102R Rear glass substrate 104F Front polarizing plate 104R Rear polarizing plate 150 Wrenchular lens 151 Base film 152 UV resin layer 152a 1st part 152b 2nd part 162 Cylindrical lens part 162 ′ Cylindrical lens part 162 ″ Cylindrical lens part 171 Strength reinforcement member AD Adhesive AR Air layer x 1st part Cylindrical lens anteroposterior dimension y 1st Front-back dimension of the cylindrical lens of the part z Front-back dimension of the cylindrical lens of the first part

Claims (7)

A liquid crystal display panel with a pair of front and rear glass substrates that enclose the liquid crystal layer,
It has a light source that is provided behind the liquid crystal display panel and emits illumination light that transmits and illuminates the liquid crystal display panel.
In the liquid crystal display panel, a wrenchular lens that spreads the illumination light is attached to the front surface of the front glass substrate via an adhesive material, a front polarizing plate is provided on the front side of the wrenchular lens, and the rear glass substrate is provided. A display device characterized in that a rear polarizing plate is provided on the rear side. The liquid crystal display panel has a first region having a substantially square frame shape, which is located on the outer edge side and is not used for display.
It has a substantially quadrangular second region, which is located inside the first region and is used for display.
The lenticular lens includes a base film, a UV resin layer provided on the front side of the base film and having a predetermined uneven shape, and a UV resin layer.
Have,
The display device according to claim 1, wherein the front polarizing plate is attached to a first portion of the UV resin layer corresponding to the first region. The display device according to claim 2, wherein the front polarizing plate is not attached to a second portion of the UV resin layer corresponding to the second region. The display device according to claim 2 or 3, wherein the dimension in the anteroposterior direction of the first portion of the UV resin layer is set so that the second portion and the front polarizing plate are in contact with each other. .. 2. Item 3. The display device according to item 3. The display device according to claim 1, further comprising a transparent strength reinforcing member attached to the front side of the front polarizing plate. 4. The first portion of the UV resin layer is characterized in that a rear surface in contact with the base film and a front surface to which the front polarizing plate is attached are formed of substantially parallel surfaces. The display device according to any one of claims 6.

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