Liquid crystal display device and electronic device

Provided is a liquid crystal display device that includes a first substrate including a microlens corresponding to each pixel, a second substrate disposed to face the first substrate, and a liquid crystal material layer sandwiched between the first substrate and the second substrate. A first transparent material layer including a material having a first refractive index is formed in the first substrate, and a material having a second refractive index different from the first refractive index is disposed in a portion of the first transparent material layer corresponding to a region between adjacent pixels. A second transparent material layer including a material having a third refractive index is formed in the second substrate, and a material having a fourth refractive index different from the third refractive index is disposed in a portion of the second transparent material layer corresponding to the region between the adjacent pixels.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Phase of International Patent Application No. PCT/JP2021/012088 filed on Mar. 23, 2021, which claims priority benefit of Japanese Patent Application No. JP 2020-068095 filed in the Japan Patent Office on Apr. 6, 2020. Each of the above-referenced applications is hereby incorporated herein by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates to a liquid crystal display device and an electronic device.

BACKGROUND ART

There has been known a liquid crystal display device having a configuration in which a liquid crystal material layer is sandwiched between a pair of substrates. The liquid crystal display device displays an image by operating a pixel as an optical shutter (light valve).

In recent years, the liquid crystal display device has been required to have high definition and high luminance. Therefore, it has been proposed that a microlens corresponding to a pixel is provided to increase light utilization efficiency. Furthermore, it has also been proposed to stack a plurality of microlenses to further increase light utilization efficiency (for example, see Patent Document 1).

CITATION LIST

Patent Document

SUMMARY OF THE INVENTION

Problems to be Solved by the Invention

In a case where a liquid crystal display device is formed by stacking a plurality of microlenses, it is necessary to align the lenses with high accuracy in order to form an image with high accuracy. However, due to a misalignment caused in a lithography process and a shape variation caused in an etching process, it is not easy to align the microlenses having a three-dimensional shape with high accuracy. At this point, it is required to increase light utilization efficiency without stacking a plurality of microlenses having a three-dimensional shape.

Therefore, an object of the present disclosure is to provide a liquid crystal display device capable of improving light utilization efficiency, without stacking a plurality of microlenses having a three-dimensional shape, and an electronic device including the liquid crystal display device.

Solutions to Problems

A liquid crystal display device according to the present disclosure for achieving the above-described object includes: a first substrate including a microlens corresponding to each pixel; a second substrate disposed to face the first substrate; and a liquid crystal material layer sandwiched between the first substrate and the second substrate, in which a first transparent material layer including a material having a first refractive index is formed in the first substrate, and a material having a second refractive index different from the first refractive index is disposed in a portion of the first transparent material layer corresponding to a region between adjacent pixels, and a second transparent material layer including a material having a third refractive index is formed in the second substrate, and a material having a fourth refractive index different from the third refractive index is disposed in a portion of the second transparent material layer corresponding to the region between adjacent pixels.

The first transparent material layer is formed between the microlens and the liquid crystal material layer.

The second refractive index is smaller than the first refractive index.

The material having the second refractive index is arranged in a form of a lattice.

The material having the second refractive index is arranged to widen at an intersection portion of the lattice.

The material having the first refractive index is a silicon nitride or a silicon oxynitride.

The material having the second refractive index is a silicon oxide.

A multilayer laminate film including a high refractive index material film and a low refractive index material film is disposed between the microlens and the first transparent material layer.

The multilayer laminate film includes a silicon nitride film and a silicon oxide film.

The first transparent material layer includes a multilayer laminate film including a high refractive index material film and a low refractive index material film.

The fourth refractive index is smaller than the third refractive index.

The material having the fourth refractive index is arranged in a form of a lattice.

The material having the fourth refractive index is arranged to widen at an intersection portion of the lattice.

The material having the third refractive index is a silicon nitride or a silicon oxynitride.

The material having the fourth refractive index is a silicon oxide.

A transparent common electrode is formed in the first substrate, and a transparent pixel electrode corresponding to each pixel is formed in the second substrate.

The second substrate has a lattice-shaped light shielding region located in a portion corresponding to the region between adjacent pixels.

A plurality of transparent electrodes extending in a first direction is formed in the first substrate, and a plurality of transparent electrodes extending in a second direction different from the first direction is formed in the second substrate.

An electronic device according to the present disclosure for achieving the above-described object includes a liquid crystal display device, the liquid crystal display device including: a first substrate including a microlens corresponding to each pixel; a second substrate disposed to face the first substrate; and a liquid crystal material layer sandwiched between the first substrate and the second substrate, in which a first transparent material layer including a material having a first refractive index is formed in the first substrate, and a material having a second refractive index different from the first refractive index is disposed in a portion of the first transparent material layer corresponding to a region between adjacent pixels, and a second transparent material layer including a material having a third refractive index is formed in the second substrate, and a transparent material having a fourth refractive index different from the third refractive index is disposed in a portion of the second transparent material layer corresponding to the region between adjacent pixels.

A third transparent material layer including a material having a fifth refractive index higher than the second refractive index is formed on the first transparent material layer in the first substrate, and the material having the second refractive index is embedded in a first groove provided in portions of the first and third transparent material layers corresponding to the region between adjacent pixels.

A side wall of the first groove in the first transparent material layer is inclined at a first inclination angle from a direction perpendicular to an interface between the first transparent material layer and the third transparent material layer, and a side wall of the first groove in the third transparent material layer is inclined at a second inclination angle larger than the first inclination angle from the perpendicular direction.

The third transparent material layer has a film thickness of larger than 0 nm and smaller than 200 nm.

The first transparent material layer is a silicon oxynitride film, and the third transparent material layer is a silicon nitride film.

The third transparent material layer is etched or polished at a slower speed than the first transparent material layer.

A fourth transparent material layer including a material having a sixth refractive index higher than the fourth refractive index is formed on the second transparent material layer in the second substrate, and the material having the fourth refractive index is embedded in a second groove provided in portions of the second and fourth transparent material layers corresponding to the region between adjacent pixels.

A side wall of the second groove in the second transparent material layer is inclined at a third inclination angle from a direction perpendicular to an interface between the second transparent material layer and the fourth transparent material layer, and a side wall of the second groove in the fourth transparent material layer is inclined at a fourth inclination angle larger than the third inclination angle from the perpendicular direction.

The fourth transparent material layer has a film thickness of larger than 0 nm and smaller than 200 nm.

The second transparent material layer is a silicon oxynitride film, and the fourth transparent material layer is a silicon nitride film.

The fourth transparent material layer is etched or polished at a slower speed than the second transparent material layer.

In the electronic device according to the present disclosure for achieving the above-described object, a third transparent material layer including a material having a fifth refractive index higher than the second refractive index is formed on the first transparent material layer in the first substrate, and the material having the second refractive index is embedded in a first groove provided in portions of the first and third transparent material layers corresponding to the region between adjacent pixels.

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present disclosure will be described based on embodiments with reference to the drawings. The present disclosure is not limited to the embodiments, and various numerical values and materials in the embodiments are exemplary. In the following description, the same reference signs will be used for the same elements or elements having the same functions, and description thereof will not be repeated. Note that the description will be given in the following order.1. General Description of Liquid Crystal Display Device and Electronic Device According to Present Disclosure2. First Embodiment3. Second Embodiment4. Third Embodiment5. Fourth Embodiment6. Description of Electronic Device7. Application Example8. Others

[General Description of Liquid Crystal Display Device and Electronic Device According to Present Disclosure]

In the following description, a liquid crystal display device according to the present disclosure and a liquid crystal display device included in an electronic device according to the present disclosure may be simply referred to as [a liquid crystal display device of the present disclosure]. As described above, the liquid crystal display device of the present disclosure includes:a first substrate including a microlens corresponding to each pixel;a second substrate disposed to face the first substrate; anda liquid crystal material layer sandwiched between the first substrate and the second substrate,in which a first transparent material layer including a material having a first refractive index is formed in the first substrate, and a material having a second refractive index different from the first refractive index is disposed in a portion of the first transparent material layer corresponding to a region between adjacent pixels, anda second transparent material layer including a material having a third refractive index is formed in the second substrate, and a material having a fourth refractive index different from the third refractive index is disposed in a portion of the second transparent material layer corresponding to the region between adjacent pixels.

In the liquid crystal display device of the present disclosure, the first transparent material layer can be formed between the microlens and the liquid crystal material layer. The configuration of the microlens is not particularly limited. The microlens can be formed by a known lithography technique or a known etching technique.

In the liquid crystal display device of the present disclosure including the above-described preferable configuration, the second refractive index can be smaller than the first refractive index.

In the liquid crystal display device of the present disclosure including the above-described various preferable configurations, the material having the second refractive index may be discretely arranged, but is preferably arranged in the form of a lattice. In this case, the material having the second refractive index can be arranged to widen at an intersection portion of the lattice.

In the liquid crystal display device of the present disclosure including the above-described various preferable configurations, the material having the first refractive index and the material having the second refractive index can be appropriately selected from organic materials and inorganic materials. From the viewpoint of a process of manufacturing the liquid crystal display device and the like, the material having the first refractive index is preferably a silicon nitride or a silicon oxynitride. In this case, the material having the second refractive index can be a silicon oxide.

In the liquid crystal display device of the present disclosure including the above-described various preferable configurations, a multilayer laminate film including a high refractive index material film and a low refractive index material film can be disposed between the microlens and the first transparent material layer. The high refractive index material film and the low refractive index material film can be constituted by using, for example, inorganic insulating materials. Examples of the material constituting the high refractive index material film include a silicon nitride (SiNx), a tantalum oxide (Ta2O5), and a titanium oxide (TiO2). In addition, examples of the material constituting the low refractive index material film include a silicon oxide (SiOx) and a silicon oxynitride (SiOxNy). From the viewpoint of a process of manufacturing the liquid crystal display device and the like, the multilayer laminate film preferably includes a silicon nitride film and a silicon oxide film.

The multilayer laminate film described above usually functions as a C plate. In addition, the multilayer laminate film including a group of stacked layers, in which high refractive index oblique vapor deposition films and low refractive index oblique vapor deposition films having the same inclination direction with respect to a normal line of a surface on which the films are formed are alternately formed, optically functions as an inclined C plate. Such a multilayer laminate film can optically compensate for the influence of the refractive index anisotropy of the liquid crystal material layer and the pre-tilt of the liquid crystal molecules.

The film thickness or the number of stacked films of the multilayer laminate film may be appropriately set from the viewpoint of optical compensation. For example, the film thickness can be about 10 to 50 nanometers. The film thickness ratio between the high refractive index material films and the low refractive index material films may be about 1:1. The number of these stacked films may be, for example, about 10 to 200. The high refractive index material films and the low refractive index material films can be formed by a known film formation method such as a CVD method or a PVD method.

Alternatively, in the liquid crystal display device of the present disclosure including the above-described various preferable configurations, the first transparent material layer may include a multilayer laminate film including a high refractive index material film and a low refractive index material film. In this case, a mean refractive index of the multilayer laminate film may be set as the first refractive index. The configuration of the multilayer laminate film including the high refractive index material films and the low refractive index material films is similar to that described above, and thus, the description thereof will be omitted.

In the liquid crystal display device of the present disclosure including the above-described various preferable configurations, the fourth refractive index can be smaller than the third refractive index.

In the liquid crystal display device of the present disclosure including the above-described various preferable configurations, the material having the fourth refractive index may be discretely arranged, but is preferably arranged in the form of a lattice. In this case, the material having the fourth refractive index can be arranged to widen at an intersection portion of the lattice.

In the liquid crystal display device of the present disclosure including the above-described various preferable configurations, the material having the third refractive index and the material having the fourth refractive index can be appropriately selected from organic materials and inorganic materials. From the viewpoint of a process of manufacturing the liquid crystal display device and the like, the material having the third refractive index is preferably a silicon nitride or a silicon oxynitride. In this case, the material having the fourth refractive index can be a silicon oxide.

In the liquid crystal display device of the present disclosure including the above-described various preferable configurations, a transparent common electrode can be formed in the first substrate, and a transparent pixel electrode corresponding to each pixel can be formed in the second substrate. Furthermore, in order to operate the liquid crystal display device in a so-called active matrix type, a transistor for driving the transparent pixel electrode or a holding capacitor for holding a charge may be formed in the second substrate. In this case, the second substrate can have a lattice-shaped light shielding region located in a portion corresponding to a region between adjacent pixels The light shielding region is usually formed by shielding light using various wirings, electrodes, or the like for driving the transparent pixel electrode. The light shielding region usually has a lattice shape to be located between pixels.

Alternatively, in the liquid crystal display device of the present disclosure including the above-described various preferable configurations, a plurality of transparent electrodes extending in a first direction can be formed in the first substrate, and a plurality of transparent electrodes extending in a second direction different from the first direction can be formed in the second substrate. The liquid crystal display device having this configuration is a liquid crystal display device in a so-called passive matrix type, and a portion where a transparent electrode in the first direction and a transparent electrode in the second direction different from the first direction overlap each other functions as a pixel.

In a case where the liquid crystal display device is a transmissive liquid crystal display device, the transparent pixel electrode or the like formed in the second substrate can be formed using a transparent conductive material such as an indium tin oxide (ITO) or an indium zinc oxide (IZO). The same applies to the transparent common electrode formed in the first substrate. Note that, in some cases, it is also possible to use a metal thin film including silver (Ag), magnesium (Mg), or the like having a thickness of about 5 nm and transmitting light to some extent.

As a substrate used for the first substrate or the second substrate, a substrate including a transparent material such as plastic, glass, or quartz can be used. In addition, the transistors and various circuits driving the pixel electrodes provided in the second substrate can be configured by, for example, forming and processing a semiconductor material layer or the like on the substrate.

The material constituting various wirings, electrodes, or contacts is not particularly limited, and a metal material can be used, for example, aluminum (Al), an aluminum alloy such as Al—Cu or Al—Si, tungsten (W), or a tungsten alloy such as a tungsten silicide (WSi).

The material constituting an interlayer insulating layer, a planarization film, or the like is not particularly limited, and an inorganic material such as a silicon oxide, a silicon oxynitride, or a silicon nitride, or an organic material such as polyimide can be used.

A method for forming the semiconductor material layer, the wiring, the electrode, the insulating layer, the insulating film, or the like is not particularly limited, and a film can be formed using a known film formation method as long as it does not cause a problem in implementing the present disclosure. The same applies to a method for patterning the semiconductor material layer, the wiring, the electrode, the insulating layer, the insulating film, or the like.

The liquid crystal display device may be configured to display a monochrome image, or may be configured to display a color image. As a pixel value of the liquid crystal display device, some image resolutions can be exemplified, for example, (3840, 2160) and (7680, 4320) as well as U-XGA (1600, 1200), HD-TV (1920, 1080), and Q-XGA (2048, 1536), but the pixel value is not limited thereto.

Furthermore, as an electronic device including the liquid crystal display device of the present disclosure, various electronic devices each having an image display function can be exemplified as well as a direct view type display device or a projection type display device.

In the present specification, various conditions are considered satisfied not only when they are strictly satisfied but also when they are substantially satisfied. The presence of several variations caused by design or caused in a manufacturing process is allowed. In addition, the drawings used in the following description are schematic, and do not indicate actual dimensions or ratios therebetween.

First Embodiment

A first embodiment relates to a liquid crystal display device and an electronic device according to the present disclosure.

FIG.1is a schematic view for explaining the liquid crystal display device according to the first embodiment.

The liquid crystal display device according to the first embodiment is a liquid crystal display device in an active matrix type. As shown inFIG.1, the liquid crystal display device1includes pixels PX arranged in a matrix form and various circuits such as a horizontal drive circuit11and a vertical drive circuit12for driving the pixels PX. The liquid crystal display device1is a display device in which various circuits such as the horizontal drive circuit11and the vertical drive circuit12are integrated. Note that, in some cases, various circuits may be configured separately.

The reference sign SCL denotes a scanning line for scanning the pixels PX, and the reference sign DTL denotes a signal line for supplying various voltages to the pixels PX. The pixels PX are arranged in a matrix form, including, for example, M pixels PX in a horizontal direction and N pixels PX in a vertical direction, i.e. a total of M×N pixels PX. A common electrode shown inFIG.1is provided as an electrode common to all liquid crystal cells. Note that, in an example shown inFIG.1, each of the horizontal drive circuit11and the vertical drive circuit12is disposed on one end side of the liquid crystal display device1, but this is merely exemplary.

FIG.2Ais a schematic cross-sectional view for explaining a basic configuration of the liquid crystal display device.FIG.2Bis a schematic circuit diagram for explaining a pixel in the liquid crystal display device.

As shown inFIG.2A, the liquid crystal display device1includes a first substrate150, a second substrate100disposed to face the first substrate150, and a liquid crystal material layer140sandwiched between the first substrate150and the second substrate100. For convenience of illustration, the first substrate150and the second substrate100inFIG.2Aare illustrated in a simplified manner. The first substrate150and the second substrate100are sealed by a seal part180. The seal part180has an annular shape to surround the liquid crystal material layer140.

Although not shown inFIG.2A, the first substrate150includes a microlens corresponding to each of the pixels. In addition, the first substrate150includes a transparent common electrode including a transparent conductive material such as ITO. More specifically, the first substrate150includes a rectangular support substrate including a transparent material such as quartz, a microlens corresponding to each of the pixels, a transparent common electrode provided on a surface of the support substrate facing the liquid crystal material layer140, an alignment film provided on the transparent common electrode, etc. Furthermore, appropriate polarizing films or the like are disposed on the first substrate150and the second substrate100to satisfy the crossed Nicols or parallel Nicols condition.

As will be described later, the second substrate100is formed by stacking various components on a support substrate including, for example, quartz. The liquid crystal display device1is a transmissive liquid crystal display device. That is, light from a light source enters the first substrate150and exits the second substrate100after passing through the liquid crystal material layer.

As shown inFIG.2B, a liquid crystal cell constituting a pixel PX includes a transparent pixel electrode provided on the second substrate100, and a liquid crystal material layer and a transparent common electrode in a portion corresponding to the transparent pixel electrode. In order to prevent the deterioration of the liquid crystal material layer, a positive-polarity common potential Vcomand a negative-polarity common potential Vcomare alternately applied to the transparent common electrode while the liquid crystal display device1is driven. Note that the components of the pixel PX excluding the liquid crystal material layer and the transparent common electrode are formed on the second substrate100shown inFIG.2A.

As is clear from the connection relationship inFIG.2B, a pixel voltage supplied through the signal line DTL is applied to the transparent pixel electrode via a transistor TR brought into a conductive state by a scanning signal through the scanning line SCL. Since the transparent pixel electrode and one electrode of a capacitance structure CS are conductive, the pixel voltage is also applied to one electrode of the capacitance structure CS. Note that the common potential Vcomis applied to the other electrode of the capacitance structure CS. In this configuration, even after the transistor TR is brought into a non-conductive state, the voltage of the transparent pixel electrode is maintained by the capacitance of the liquid crystal cell and the capacitance structure CS.

As will be described in detail with reference toFIGS.3to13, in the display device1according to the first embodiment, a first transparent material layer including a material having a first refractive index is formed in the first substrate150, and a material having a second refractive index different from the first refractive index is disposed in a portion of the first transparent material layer corresponding to a region between adjacent pixels. Also, a second transparent material layer including a material having a third refractive index is formed in the second substrate100, and a material having a fourth refractive index different from the third refractive index is disposed in a portion of the second transparent material layer corresponding to a region between adjacent pixels.

FIG.3is a partial schematic cross-sectional view of a substrate, etc. for explaining the liquid crystal display device according to the first embodiment.

As described above, the liquid crystal display device1includes a first substrate150, a second substrate100, and a liquid crystal material layer140sandwiched between the first substrate150and the second substrate100.

The first substrate150includes a support substrate151including quartz and a microlens152formed on the support substrate151and disposed to correspond to each pixel. In addition, a first transparent material layer160including a material having a first refractive index is formed in the first substrate150, and a material161having a second refractive index different from the first refractive index is disposed in a portion of the first transparent material layer160corresponding to a region between adjacent pixels. Note that, for convenience of description, the material constituting the first transparent material layer160may be referred to as the material160.

An arrangement pitch, a height, and a width of the material161are denoted by the reference signs PH, H, and W, respectively. The pitch denoted by the reference sign PH is equal to a pixel pitch, and has a value of, for example, about 5 to 10 micrometers. In addition, the height denoted by the reference sign H has a value of about 0.2 to 1 micrometer, and the width denoted by the reference sign W has a value of 0.5 to 1 micrometer.

The material160having the first refractive index and the material161having the second refractive index are selected to satisfy the condition that the second refractive index is smaller than the first refractive index. Here, the material160having the first refractive index is a silicon nitride, and the material161having the second refractive index is a silicon oxide. The first transparent material layer160including the silicon nitride is formed between the microlens152and the liquid crystal material layer140. A transparent common electrode171and an alignment film172are stacked on a surface of the first transparent material layer160facing the liquid crystal material layer140.

The second substrate100disposed to face the first substrate150includes a support substrate101including quartz, a wiring layer120including various wirings and the like, and a pixel electrode131formed on the wiring layer120. A planarization film132and an alignment film133are stacked on an entire surface of the wiring layer including on the pixel electrode131. The pixel electrode131is connected to one source/drain region of a transistor122via a contact (not illustrated).

In the wiring layer120, the reference sign121denotes a wiring that also serves to shield light, and the reference sign122denotes a transistor. The reference sign122A denotes a patterned semiconductor material layer, and the reference sign122B denotes a gate electrode. Note that, although not illustrated, the wiring121is connected to the gate electrode122B. The reference sign123schematically denote various other wirings. Note that the wirings123include wirings extending in an X direction and wirings extending in a Y direction, but only partial cross sections thereof are schematically shown inFIG.3. The reference sign124denotes an insulating layer for separating the wirings and the like from each other. Note that the wiring layer120is formed by stacking various elements, but is illustrated in a simplified manner for convenience of illustration.

A second transparent material layer110including a material having a third refractive index is formed between the support substrate101and the wiring layer120, and a material111having a fourth refractive index different from the third refractive index is disposed in a portion of the second transparent material layer110corresponding to a region between adjacent pixels. The reference sign111A denotes a base layer including, for example, the same material as the material111. Note that, for convenience of description, the material constituting the second transparent material layer110may be referred to as the material110. An arrangement pitch, a height, and a width of the material111are similar to the arrangement pitch, the height, and the width of the material161described above, respectively.

Note that the material110constituting the second transparent material layer may be formed over an entire area of the first substrate150, or may be formed only in a portion of the first substrate150corresponding to a display region.

For example, by not forming the material110in a region where the horizontal drive circuit11and the vertical drive circuit12shown inFIG.1are formed, it is possible to adjust a threshold of a transistor according to the characteristics of the peripheral circuit described above and the like. In addition, a material having a high refractive index generally has large stress, which may cause a film to be peeled off. However, by forming the material110only in a specific region, stress can be suppressed overall.

The material110having the third refractive index and the material111having the fourth refractive index are selected to satisfy the condition that the fourth refractive index is smaller than the third refractive index. Here, the material110having the third refractive index is a silicon nitride, and the material111having the fourth refractive index is a silicon oxide. The second transparent material layer110including the silicon nitride is formed between the wiring layer120and the support substrate101.

Note that polarizing films (not illustrated) are disposed on the first substrate150and the second substrate100to have a crossed Nicols or parallel Nicols relationship depending on the specifications of the liquid crystal display device1.

The liquid crystal material layer140is sandwiched between the second substrate100and the first substrate150. An initial alignment direction of liquid crystal molecules141of the liquid crystal material layer140is set by the alignment films133and172. In a state where no electric field is applied to the liquid crystal material layer140, the liquid crystal molecules141are aligned in a substantially vertical direction with a predetermined tilt angle. The liquid crystal display device1is a liquid crystal display device in a so-called vertical alignment type (VA mode).

The basic configuration of the liquid crystal display device1has been described above. Next, convergence of light transmitted through liquid crystal display device1will be described. For convenience of description, a planar shape of a light shielding region in the liquid crystal display device1will be described first.

FIG.4is a partial schematic plan view of the liquid crystal display device for explaining the planar shape of the light shielding region in the liquid crystal display device according to the first embodiment.

A light shielding region, which does not allow light to be transmitted therethrough, is formed in the liquid crystal display device1by the wiring121, the wirings123, or the like shown inFIG.3. The various wirings are basically arranged to be positioned between a pixel electrode131and another pixel electrode131. Therefore, the light shielding region BLK of the liquid crystal display device1is a lattice-like region indicated by the hatching inFIG.4. Basically, the material161having the second refractive index different from the first refractive index is disposed in a portion of the first transparent material layer160corresponding to the light shielding region BLK. Similarly, the material111having the fourth refractive index different from the third refractive index is disposed in a portion of the second transparent material layer110corresponding to the light shielding region BLK.

The planar shape of the light shielding region has been described above. Next, convergence of light by the first transparent material layer will be described.

FIG.5is a schematic cross-sectional view of a portion taken along line A-A ofFIG.3.FIG.6is a partial schematic cross-sectional view of a substrate, etc. for explaining how light transmitted through the first substrate converges.

As shown inFIG.5, in the cross section taken along the line A-A, the material161having the second refractive index is arranged in the form of a lattice. Then, the material160constituting the first transparent material layer160is arranged in an island shape with respect to the lattice shape formed by the material161. As shown inFIG.6, a direction of light incident on the first substrate150is first changed by the microlens152to propagate in a convergent direction. The direction of the light incident on the first transparent material layer160is changed to propagate in a more convergent direction near a boundary between the material160and the material161because the light propagates relatively fast in the material161having a relatively small refractive index. In other words, the first transparent material layer160in which the material161is embedded optically functions similarly to a convex lens.

Note that it has been described above that the material161is arranged in the form of a lattice in the cross section of the portion taken along the line A-A, but this is merely exemplary. For example, even in a configuration in which the material161is discretely arranged in a portion corresponding to the light shielding region BLK, a certain degree of effect can be obtained. The same applies to the material111in the second transparent material layer110.FIGS.7and8are schematic cross-sectional views for explaining other examples of the portion taken along the line A-A ofFIG.3. They illustrate examples in which the material161is arranged at an intersection portion of the light shielding region BLK.FIG.7illustrates an example in which a region where the material161is arranged falls within the light shielding region BLK.FIG.8illustrates an example in which a part of the region where the material161is disposed beyond the light shielding region BLK.

The convergence of light by the first transparent material layer has been described above. Next, convergence of light by the second transparent material layer will be described.

FIG.9is a schematic cross-sectional view of a portion taken along line B-B ofFIG.3.FIG.10is a partial schematic cross-sectional view of a substrate, etc. for explaining how light transmitted through the second substrate converges.

As shown inFIG.9, in the cross section taken along the line B-B, the material111having the fourth refractive index is arranged in the form of a lattice. Then, the material110constituting the second transparent material layer110is arranged in an island shape with respect to the lattice shape formed by the material111. As shown inFIG.10, the light incident on the second substrate100through the liquid crystal material layer140is diffracted by the wiring or the like of the wiring layer120, and a direction of the light is changed to propagate in a divergent direction. At this time, the light incident near a boundary between the material110and the material111propagates relatively fast in the material111having a relatively small refractive index, and thus, wraparound due to the diffraction is alleviated. In other words, the second transparent material layer110in which the material111is embedded optically functions similarly to a convex lens.

The convergence of light by the second transparent material layer has been described above.

In the liquid crystal display device1, the light convergence effect is enhanced by the microlens152and the first transparent material layer160in which the material161is embedded, without stacking a plurality of microlenses having a three-dimensional shape. In addition, the wraparound due to the diffraction by the wiring or the like is alleviated by the second transparent material layer110. In this way, the liquid crystal display device1is capable of improving light utilization efficiency, without stacking a plurality of microlenses having a three-dimensional shape.

Note that, since the planar shape of the light shielding region is determined by the arrangement and shape of wiring and the like, the light shielding region does not necessarily have a simple lattice shape. For example, as shown inFIG.11, the light shielding region may widen at an intersection portion of the lattice. In such a case, it is only required that the material161having the second refractive index in the first transparent material layer160be arranged to widen at an intersection portion of the lattice. Specifically, the material161may be embedded in the first transparent material layer160so that the portion taken along the line A-A of FIG.3has a cross section as shown inFIG.12. Similarly, it is only required that the material111having the fourth refractive index in the second transparent material layer110be arranged to widen at an intersection portion of the lattice. Specifically, the material111may be embedded in the second transparent material layer110so that the portion taken along the line B-B ofFIG.3has a cross section as shown inFIG.13.

Next, a method for manufacturing the liquid crystal display device1according to the first embodiment will be described.

FIGS.14A,14B,15A,15B,16A,16B,17A,17B,18A,18B,18C,19A,19B,19C,20A, and20Bare partial schematic cross-sectional views of substrates, etc. for explaining the method for manufacturing the display device according to the first embodiment.

[Process-100] (SeeFIGS.14A,14B, and15A) First, a process of manufacturing a first substrate150will be described. A support substrate151is prepared (seeFIG.14A), and an outer shape for a microlens is formed thereon using a known etching technique or the like (seeFIG.14B). Subsequently, a material152having a higher refractive index than the support substrate151is formed thereon, and then planarized to form a microlens152(seeFIG.15A).

Subsequently, a first transparent material layer160in which a material161having a second refractive index is embedded is formed on the microlens152. First, a layer including a material160having a first refractive index is formed on the microlens152(seeFIG.15B). Subsequently, an opening OP is formed in a portion corresponding to a region between a pixel electrode131and another pixel electrode131(seeFIG.16A). Thereafter, a layer including a material161having a second refractive index is formed on an entire surface (seeFIG.16B). Subsequently, planarization is performed to obtain a first transparent material layer160in which the material161is embedded in the opening OP (seeFIG.17A). Note that, although it is illustrated that the material161remains only in the opening OP, the material161may remain at a predetermined thickness on an upper surface of the material160after the planarization.

Thereafter, a transparent common electrode171and an alignment film172are sequentially stacked on the entire surface of the first transparent material layer160. Through the above-described processes, the first substrate150can be obtained.

Next, a process of manufacturing the second substrate100will be described. A support substrate101is prepared (seeFIG.18A), and a second transparent material layer110in which a material111having a fourth refractive index is embedded is formed thereon. First, a base film111A including the same material as the material111having the fourth refractive index is formed (seeFIG.18B). Subsequently, a layer including a material110having a third refractive index is formed thereon (seeFIG.18C).

Subsequently, an opening OP is formed in a portion corresponding to a region between a pixel electrode131and another pixel electrode131of the layer including the material110(seeFIG.19A). Thereafter, a layer including a material111having a third refractive index is formed on an entire surface (seeFIG.19B). Subsequently, planarization is performed to obtain a second transparent material layer110in which the material111is embedded in the opening OP (seeFIG.19C).

Thereafter, a wiring layer120is formed on the second transparent material layer110. A wiring121, a transistor122including a semiconductor material layer122A and a gate electrode122B, and wirings123can be formed by a known film formation technique, a known patterning technique, and the like. The configuration of the wiring layer120is not particularly limited as long as the implementation of the present disclosure is not hindered. For example, the transistor122can be a TFT formed by forming a semiconductor material layer on the second transparent material layer110and appropriately patterning the semiconductor material layer. Alternatively, the transistor122can be formed by a so-called SOI process.

In a case where the transistor122is a TFT, a high-quality oxide film may be further formed on the second transparent material layer110, and then the wiring layer120may be formed on the oxide film. By forming the high-quality oxide film, it is possible to reduce an influence of hydrogen desorbed from the second transparent material layer110on an interface between the semiconductor material layer122A and a gate insulating film.

Thereafter, a pixel electrode131is formed on the wiring layer120, and subsequently, a planarization film132and an alignment film133are sequentially stacked on an entire surface. Through the above-described processes, the second substrate100can be obtained.

Subsequently, sealing is performed in a state where the first substrate150and the second substrate100face each other with the liquid crystal material layer140sandwiched therebetween. As a result, the liquid crystal display device1shown inFIG.3can be obtained.

The liquid crystal display device1has been described above. In the liquid crystal display device1, the light convergence effect is enhanced by the microlens152and the first transparent material layer160in which the material161is embedded without stacking a plurality of microlenses having a three-dimensional shape. In addition, the wraparound due to the diffraction by the wiring or the like is alleviated by the second transparent material layer110. In this way, the liquid crystal display device1is capable of improving light utilization efficiency, without stacking a plurality of microlenses having a three-dimensional shape.

In addition, if a three-dimensional microlens is formed on the support101, a crack or the like occurs during high-temperature heat treatment in a process of manufacturing a transistor after the microlens is formed, resulting in a decrease in yield. In the liquid crystal display device1, since a flat structure, such as the second transparent material layer110in which the material111is embedded, is formed on the support101, an occurrence of a crack caused by heat treatment can be suppressed.

Second Embodiment

A second embodiment also relates to a liquid crystal display device and an electronic device according to the present disclosure.

FIG.21is a partial schematic cross-sectional view for explaining the liquid crystal display device according to the second embodiment. For a schematic view of the liquid crystal display device according to the second embodiment, the liquid crystal display device1ofFIG.1may be replaced with a liquid crystal display device2. For a schematic cross-sectional view for explaining the basic configuration of the liquid crystal display device, the liquid crystal display device1ofFIG.2Amay be replaced with a liquid crystal display device2, and the first substrate150ofFIG.2Amay be replaced with a first substrate250.

When compared to the liquid crystal display device1described in the first embodiment, the liquid crystal display device2further includes a multilayer laminate film263disposed between the microlens152and the first transparent material layer160, the multilayer laminate film263including high refractive index material films264and low refractive index material films265. The multilayer laminate film263includes a silicon nitride film as the high refractive index material film264and a silicon oxide film as the low refractive index material film265.

A vapor deposition direction of the multilayer laminate film263is, for example, a normal direction of a surface on which films are formed. The multilayer laminate film263functions as an optical compensation element constituting a C plate. The multilayer laminate film263has an abnormal axis orthogonal to a plane, and does not cause retardation with respect to normal incident light. The refractive index anisotropy of the liquid crystal material layer140is compensated for by the multilayer laminate film263.

Alternatively, the vapor deposition direction of the multilayer laminate film263may be the same inclination direction (vapor deposition direction) with respect to a normal line of a surface on which films are formed. Such a multilayer laminate film263has 0-plate characteristics together with C-plate characteristics. Therefore, not only the refractive index anisotropy of the liquid crystal material layer140but also the refractive index anisotropy due to the tilt angle of the liquid crystal molecules141is compensated for by the multilayer laminate film263.

Next, a method for manufacturing the liquid crystal display device2according to the second embodiment will be described.

FIGS.22A and22Bare partial schematic cross-sectional views for explaining the method for manufacturing the liquid crystal display device according to the second embodiment.

First, a process similar to [Process-100] described in the first embodiment is performed to form a microlens152on a support151(seeFIG.15A).

Subsequently, a multilayer laminate film263is formed on the microlens152. The multilayer laminate film263can be obtained, for example, by alternately and continuously forming high refractive index material films264and low refractive index material films265on the microlens152in a predetermined inclination direction by vapor deposition.

Subsequently, a first transparent material layer160in which a material161having a second refractive index is embedded is formed on the multilayer laminate film263. By performing a process similar to that described with reference toFIGS.15B,16A,16B, and17Ain the first embodiment, the first transparent material layer160in which the material161having the second refractive index is embedded can be formed.

Thereafter, a transparent common electrode171and an alignment film172are sequentially stacked on the entire surface of the first transparent material layer160. Through the above-described processes, the first substrate250can be obtained.

Subsequently, processes similar to [Process-130] to [Process-150] described in the first embodiment can be performed to obtain a second substrate100. Then, a process similar to [Process-160] described in the first embodiment is performed. As a result, the liquid crystal display device2shown inFIG.21can be obtained.

In the liquid crystal display device2as well, the light convergence effect is enhanced by the microlens152and the first transparent material layer160in which the material161is embedded, without stacking a plurality of microlenses having a three-dimensional shape. In addition, the wraparound due to the diffraction by the wiring or the like is alleviated by the second transparent material layer110. In this way, the liquid crystal display device2is capable of improving light utilization efficiency, without stacking a plurality of microlenses having a three-dimensional shape. In addition, in the liquid crystal display device2as well, since flat structures, such as the first transparent material layer160in which the material161is embedded and the second transparent material layer110in which the material111is embedded, are stacked, an occurrence of a crack can be suppressed.

Moreover, in the liquid crystal display device2, the multilayer laminate film functioning as an optical compensation element is included in a cell. Therefore, it is possible to increase a contrast of an image to be displayed without separately arranging an optical compensation element, and it is also possible to reduce the number of manufacturing processes and the number of parts. Furthermore, since the optical compensation element can be disposed in the liquid crystal display device, a highly reliable liquid crystal display device can be obtained.

Third Embodiment

A third embodiment also relates to a liquid crystal display device and an electronic device according to the present disclosure.

FIG.23is a partial schematic cross-sectional view for explaining the liquid crystal display device according to the third embodiment. For a schematic view of the liquid crystal display device according to the third embodiment, the liquid crystal display device1ofFIG.1may be replaced with a liquid crystal display device3. For a schematic cross-sectional view for explaining the basic configuration of the liquid crystal display device, the liquid crystal display device1ofFIG.2Amay be replaced with a liquid crystal display device3, and the first substrate150ofFIG.2Amay be replaced with a first substrate350.

In the liquid crystal display device3, a first transparent material layer360includes a multilayer laminate film including high refractive index material films and low refractive index material films. More specifically, the material160described in the first embodiment is replaced with the multilayer laminate film360. In this case, a mean refractive index of the multilayer laminate film360may be a first refractive index. The configuration of the multilayer laminate film360is basically similar to that of the multilayer laminate film263described in the second embodiment.

Next, a method for manufacturing the liquid crystal display device3according to the third embodiment will be described.

FIGS.24A and24Bare partial schematic cross-sectional views for explaining the method for manufacturing the liquid crystal display device according to the third embodiment.

First, a process similar to [Process-100] described in the first embodiment is performed to form a microlens152on a support substrate151(seeFIG.15A).

Subsequently, a first transparent material layer360in which a material161having a second refractive index is embedded is formed on the microlens152. First, a multilayer laminate film360constituting the first transparent material layer is formed on the microlens152(seeFIG.24A). The multilayer laminate film360can be obtained, for example, by alternately and continuously forming high refractive index material films264and low refractive index material films265on the microlens152in a predetermined inclination direction by vapor deposition.

Subsequently, by performing a process similar to that described with reference toFIGS.16A,16B, and17Ain the first embodiment, the first transparent material layer360in which the material161having the second refractive index is embedded can be formed (seeFIG.24B).

Thereafter, a transparent common electrode171and an alignment film172are sequentially stacked on the entire surface of the first transparent material layer360. Through the above-described processes, the first substrate350can be obtained.

Subsequently, processes similar to [Process-130] to [Process-150] described in the first embodiment can be performed to obtain a second substrate100. Then, a process similar to [Process-160] described in the first embodiment is performed. As a result, the liquid crystal display device3shown inFIG.23can be obtained.

In the liquid crystal display device3as well, the light convergence effect is enhanced by the microlens152and the first transparent material layer360in which the material161is embedded, without stacking a plurality of microlenses having a three-dimensional shape. In addition, the wraparound due to the diffraction by the wiring or the like is alleviated by the second transparent material layer110. In this way, the liquid crystal display device3is also capable of improving light utilization efficiency, without stacking a plurality of microlenses having a three-dimensional shape. In addition, in the liquid crystal display device3as well, since flat structures, such as the first transparent material layer360in which the material161is embedded and the second transparent material layer110in which the material111is embedded, are stacked, an occurrence of a crack can be suppressed.

In addition, in the liquid crystal display device3as well, the multilayer laminate film functioning as an optical compensation element is included in a cell. Therefore, it is possible to increase a contrast of an image to be displayed without separately arranging an optical compensation element, and it is also possible to reduce the number of manufacturing processes and the number of parts. Furthermore, since the optical compensation element can be disposed in the liquid crystal display device, a highly reliable liquid crystal display device can be obtained.

Fourth Embodiment

A fourth embodiment also relates to a liquid crystal display device and an electronic device according to the present disclosure.

FIG.25is a schematic view for explaining a liquid crystal display device according to the present disclosure.FIG.26is a partial schematic cross-sectional view for explaining the liquid crystal display device according to the fourth embodiment.

The liquid crystal display device according to the fourth embodiment is a liquid crystal display device in a passive matrix type. As shown inFIG.25, a liquid crystal display device4includes a plurality of transparent electrodes SCL extending in a first direction (an X direction in the drawing), a plurality of transparent electrodes DTL extending in a second direction (a Y direction in the drawing) different from the first direction, and various circuits such as a horizontal drive circuit11for driving the transparent electrodes SCL and a vertical drive circuit12for driving the transparent electrodes DTL. For a schematic cross-sectional view for explaining the basic configuration of the liquid crystal display device4, the liquid crystal display device1ofFIG.2Amay be replaced with a liquid crystal display device4, the first substrate150ofFIG.2Amay be replaced with a first substrate450, and the second substrate100ofFIG.2Amay be replaced with a second substrate400.

As shown inFIG.26, a transparent electrode SCL extending in the X direction is formed in the first substrate450, and a transparent electrode DTL extending in the Y direction is formed in the second substrate400. Then, a region where the transparent electrode SCL and the transparent electrode DTL face each other forms a pixel.

The configuration of the first substrate450is basically a configuration in which the common electrode of the first substrate150in the first embodiment is replaced with the above-described transparent electrode SCL. The configuration of the first transparent material layer160illustrated inFIG.26is similar to that described in the first embodiment.

The configuration of the second substrate400is basically a configuration in which the wiring121, the transistor122, and the various wirings123are omitted, and the pixel electrode131is replaced with the above-described transparent electrode SCL, when compared to the second substrate100in the first embodiment. The configuration of the second transparent material layer110is also similar to that described in the first embodiment.

In the liquid crystal display device4, no wiring or the like for shielding light is formed. Therefore, although the fourth embodiment does not include a light shielding region as shown inFIG.4in the first embodiment, the components in the first transparent material layer160and the second transparent material layer110are arranged in a similar manner to those described in the first embodiment.FIG.27is a schematic cross-sectional view of a portion taken along line C-C ofFIG.26.FIG.28is a schematic cross-sectional view of a portion taken along line D-D ofFIG.26.

In the liquid crystal display device4as well, the light convergence effect is enhanced by the microlens152and the first transparent material layer160in which the material161is embedded, without stacking a plurality of microlenses having a three-dimensional shape. In addition, the second transparent material layer110also optically functions similarly to a convex lens. Therefore, the liquid crystal display device4is also capable of improving light utilization efficiency, without stacking a plurality of microlenses having a three-dimensional shape. In addition, in the liquid crystal display device4as well, since flat structures, such as the first transparent material layer160in which the material161is embedded and the second transparent material layer110in which the material111is embedded, are stacked, an occurrence of a crack can be suppressed.

[Description of Electronic Device]

The above-described liquid crystal display device according to the present disclosure can be used as a display unit (display device) for an electronic device in any field that displays a video signal input to the electronic device or a video signal generated in the electronic device as an image or a video. As an example, the above-described liquid crystal display device according to the present disclosure can be used as a display unit of a television set, a digital still camera, a notebook personal computer, a mobile terminal device such as a mobile phone, a video camera, a head mounted display, or the like.

The liquid crystal display device of the present disclosure also includes a module-type liquid crystal display device having a sealed configuration. As an example, the module-type liquid crystal display device may be a display module formed by attaching a counterpart including a transparent glass material or the like to a pixel array unit. Note that the display module may be provided with a circuit unit for inputting and outputting signals or the like from the outside to the pixel array unit, a flexible printed circuit (FPC), and the like. Hereinafter, as specific examples of the electronic device using the liquid crystal display device of the present disclosure, a projection display device, a digital still camera, and a head mounted display will be described. However, the specific examples described here are merely exemplary, and the present disclosure is not limited thereto.

Specific Example 1

FIG.29is a conceptual diagram of a projection display device using the liquid crystal display device of the present disclosure. The projection display device includes a light source unit500, an illumination optical system510, a liquid crystal display device1, an image control circuit520that drives the liquid crystal display device, a projection optical system530, a screen540, etc. Examples of the light source unit500can include various lamps, such as a xenon lamp, and semiconductor light emitting elements, such as a light emitting diode. The illumination optical system510is used to guide light from the light source unit500to the liquid crystal display device1, and includes an optical element such as a prism or a dichroic mirror. The liquid crystal display device1acts as a light valve, and an image is projected on screen540through projection optical system530.

Specific Example 2

FIGS.30A and30Bare external views of a lens-interchangeable single-eye reflex type digital still camera, andFIG.30Ashows a front view thereof andFIG.30Bshows a rear view thereof. The lens-interchangeable single-eye reflex type digital still camera includes, for example, an interchangeable imaging lens unit (interchangeable lens)612on the right of a front side of a camera main body (camera body)611, and a grip portion613to be held by a photographer on the left of the front side of the camera main body611.

A monitor614is provided substantially at the center of the back side of the camera main body611. A viewfinder (eyepiece window)615is provided above the monitor614. By looking into the viewfinder615, the photographer can visually recognize an optical image of a subject guided from the imaging lens unit612and determine a composition of the image.

In the lens-interchangeable single-eye reflex type digital still camera having the above-described configuration, the liquid crystal display device of the present disclosure can be used as the viewfinder615. That is, the lens-interchangeable single-eye reflex type digital still camera according to the present example is manufactured by using the liquid crystal display device of the present disclosure as the viewfinder615.

Specific Example 3

FIG.31is an external view of a head mounted display. The head mounted display includes ear-hook portions712to be worn on a user's head, for example, on both sides of an eyeglass-shaped display unit711. In this head mounted display, the liquid crystal display device of the present disclosure can be used as the display unit711. That is, the head mounted display according to the present example is manufactured by using the liquid crystal display device of the present disclosure as the display unit711.

Specific Example 4

FIG.32is an external view of a see-through head mounted display. The see-through head mounted display801includes a main body802, an arm803, and a lens barrel804.

The main body802is connected to the arm803and the glasses800. Specifically, an end of the main body802in a long side direction is coupled to the arm803, and one portion of a side surface of the main body802is coupled to the glasses800via a connecting member. Note that the main body802may be directly mounted on a human body's head.

A control board for controlling an operation of the see-through head mounted display801and a display unit are embedded in the main body802. The arm803connects the main body802and the lens barrel804to each other to support the lens barrel804. Specifically, the arm803is coupled to the end of the main body802and the end of the lens barrel804to fix the lens barrel804. Furthermore, a signal line is embedded in the arm803to communicate data related to an image provided from the main body802to the lens barrel804.

The lens barrel804projects image light provided from the main body802via the arm803toward eyes of the user wearing the see-through head mounted display801through ocular lenses. In the see-through head mounted display801, the liquid crystal display device of the present disclosure can be used as the display unit of the main body802.

The technology according to the present disclosure can be applied to various products. For example, the technology according to the present disclosure may be realized as a device mounted on any type of mobile body such as a vehicle, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, a personal mobility, an airplane, a drone, a ship, a robot, a construction machine, or an agricultural machine (tractor).

FIG.33is a block diagram depicting an example of schematic configuration of a vehicle control system7000as an example of a mobile body control system to which the technology according to an embodiment of the present disclosure can be applied. The vehicle control system7000includes a plurality of electronic control units connected to each other via a communication network7010. In the example depicted inFIG.33, the vehicle control system7000includes a driving system control unit7100, a body system control unit7200, a battery control unit7300, an outside-vehicle information detecting unit7400, an in-vehicle information detecting unit7500, and an integrated control unit7600. The communication network7010connecting the plurality of control units to each other may, for example, be a vehicle-mounted communication network compliant with an arbitrary standard such as controller area network (CAN), local interconnect network (LIN), local area network (LAN), FlexRay (registered trademark), or the like.

Each of the control units includes: a microcomputer that performs arithmetic processing according to various kinds of programs; a storage section that stores the programs executed by the microcomputer, parameters used for various kinds of operations, or the like; and a driving circuit that drives various kinds of control target devices. Each of the control units further includes: a network interface (I/F) for performing communication with other control units via the communication network7010; and a communication I/F for performing communication with a device, a sensor, or the like within and without the vehicle by wire communication or radio communication. A functional configuration of the integrated control unit7600illustrated inFIG.33includes a microcomputer7610, a general-purpose communication I/F7620, a dedicated communication I/F7630, a positioning section7640, a beacon receiving section7650, an in-vehicle device I/F7660, a sound/image output section7670, a vehicle-mounted network I/F7680, and a storage section7690. The other control units similarly include a microcomputer, a communication I/F, a storage section, and the like.

The driving system control unit7100controls the operation of devices related to the driving system of the vehicle in accordance with various kinds of programs. For example, the driving system control unit7100functions as a control device for a driving force generating device for generating the driving force of the vehicle, such as an internal combustion engine, a driving motor, or the like, a driving force transmitting mechanism for transmitting the driving force to wheels, a steering mechanism for adjusting the steering angle of the vehicle, a braking device for generating the braking force of the vehicle, and the like. The driving system control unit7100may have a function as a control device of an antilock brake system (ABS), electronic stability control (ESC), or the like.

The driving system control unit7100is connected with a vehicle state detecting section7110. The vehicle state detecting section7110, for example, includes at least one of a gyro sensor that detects the angular velocity of axial rotational movement of a vehicle body, an acceleration sensor that detects the acceleration of the vehicle, and sensors for detecting an amount of operation of an accelerator pedal, an amount of operation of a brake pedal, the steering angle of a steering wheel, an engine speed or the rotational speed of wheels, and the like. The driving system control unit7100performs arithmetic processing using a signal input from the vehicle state detecting section7110, and controls the internal combustion engine, the driving motor, an electric power steering device, the brake device, and the like.

The body system control unit7200controls the operation of various kinds of devices provided to the vehicle body in accordance with various kinds of programs. For example, the body system control unit7200functions as a control device for a keyless entry system, a smart key system, a power window device, or various kinds of lamps such as a headlamp, a backup lamp, a brake lamp, a turn signal, a fog lamp, or the like. In this case, radio waves transmitted from a mobile device as an alternative to a key or signals of various kinds of switches can be input to the body system control unit7200. The body system control unit7200receives these input radio waves or signals, and controls a door lock device, the power window device, the lamps, or the like of the vehicle.

The battery control unit7300controls a secondary battery7310, which is a power supply source for the driving motor, in accordance with various kinds of programs. For example, the battery control unit7300is supplied with information about a battery temperature, a battery output voltage, an amount of charge remaining in the battery, or the like from a battery device including the secondary battery7310. The battery control unit7300performs arithmetic processing using these signals, and performs control for regulating the temperature of the secondary battery7310or controls a cooling device provided to the battery device or the like.

The outside-vehicle information detecting unit7400detects information about the outside of the vehicle including the vehicle control system7000. For example, the outside-vehicle information detecting unit7400is connected with at least one of an imaging section7410and an outside-vehicle information detecting section7420. The imaging section7410includes at least one of a time-of-flight (ToF) camera, a stereo camera, a monocular camera, an infrared camera, and other cameras. The outside-vehicle information detecting section7420, for example, includes at least one of an environmental sensor for detecting current atmospheric conditions or weather conditions and a peripheral information detecting sensor for detecting another vehicle, an obstacle, a pedestrian, or the like on the periphery of the vehicle including the vehicle control system7000.

The environmental sensor, for example, may be at least one of a rain drop sensor detecting rain, a fog sensor detecting a fog, a sunshine sensor detecting a degree of sunshine, and a snow sensor detecting a snowfall. The peripheral information detecting sensor may be at least one of an ultrasonic sensor, a radar device, and a LIDAR device (light detection and ranging device, or laser imaging detection and ranging device). Each of the imaging section7410and the outside-vehicle information detecting section7420may be provided as an independent sensor or device, or may be provided as a device in which a plurality of sensors or devices is integrated.

FIG.34depicts an example of installation positions of the imaging section7410and the outside-vehicle information detecting section7420. Imaging sections7910,7912,7914,7916, and7918are, for example, disposed at at least one of positions on a front nose, sideview mirrors, a rear bumper, and a back door of the vehicle7900and a position on an upper portion of a windshield within the interior of the vehicle. The imaging section7910provided to the front nose and the imaging section7918provided to the upper portion of the windshield within the interior of the vehicle obtain mainly an image of the front of the vehicle7900. The imaging sections7912and7914provided to the sideview mirrors obtain mainly an image of the sides of the vehicle7900. The imaging section7916provided to the rear bumper or the back door obtains mainly an image of the rear of the vehicle7900. The imaging section7918provided to the upper portion of the windshield within the interior of the vehicle is used mainly to detect a preceding vehicle, a pedestrian, an obstacle, a signal, a traffic sign, a lane, or the like.

Incidentally,FIG.34depicts an example of photographing ranges of the respective imaging sections7910,7912,7914, and7916. An imaging range a represents the imaging range of the imaging section7910provided to the front nose. Imaging ranges b and c respectively represent the imaging ranges of the imaging sections7912and7914provided to the sideview mirrors. An imaging range d represents the imaging range of the imaging section7916provided to the rear bumper or the back door. A bird's-eye image of the vehicle7900as viewed from above can be obtained by superimposing image data imaged by the imaging sections7910,7912,7914, and7916, for example.

Outside-vehicle information detecting sections7920,7922,7924,7926,7928, and7930provided to the front, rear, sides, and corners of the vehicle7900and the upper portion of the windshield within the interior of the vehicle may be, for example, an ultrasonic sensor or a radar device. The outside-vehicle information detecting sections7920,7926, and7930provided to the front nose of the vehicle7900, the rear bumper, the back door of the vehicle7900, and the upper portion of the windshield within the interior of the vehicle may be a LIDAR device, for example. These outside-vehicle information detecting sections7920to7930are used mainly to detect a preceding vehicle, a pedestrian, an obstacle, or the like.

Returning toFIG.33, the description will be continued. The outside-vehicle information detecting unit7400makes the imaging section7410image an image of the outside of the vehicle, and receives imaged image data. In addition, the outside-vehicle information detecting unit7400receives detection information from the outside-vehicle information detecting section7420connected to the outside-vehicle information detecting unit7400. In a case where the outside-vehicle information detecting section7420is an ultrasonic sensor, a radar device, or a LIDAR device, the outside-vehicle information detecting unit7400transmits an ultrasonic wave, an electromagnetic wave, or the like, and receives information of a received reflected wave. On the basis of the received information, the outside-vehicle information detecting unit7400may perform processing of detecting an object such as a human, a vehicle, an obstacle, a sign, a character on a road surface, or the like, or processing of detecting a distance thereto. The outside-vehicle information detecting unit7400may perform environment recognition processing of recognizing a rainfall, a fog, road surface conditions, or the like on the basis of the received information. The outside-vehicle information detecting unit7400may calculate a distance to an object outside the vehicle on the basis of the received information.

In addition, on the basis of the received image data, the outside-vehicle information detecting unit7400may perform image recognition processing of recognizing a human, a vehicle, an obstacle, a sign, a character on a road surface, or the like, or processing of detecting a distance thereto. The outside-vehicle information detecting unit7400may subject the received image data to processing such as distortion correction, alignment, or the like, and combine the image data imaged by a plurality of different imaging sections7410to generate a bird's-eye image or a panoramic image. The outside-vehicle information detecting unit7400may perform viewpoint conversion processing using the image data imaged by the imaging section7410including the different imaging parts.

The in-vehicle information detecting unit7500detects information about the inside of the vehicle. The in-vehicle information detecting unit7500is, for example, connected with a driver state detecting section7510that detects the state of a driver. The driver state detecting section7510may include a camera that images the driver, a biosensor that detects biological information of the driver, a microphone that collects sound within the interior of the vehicle, or the like. The biosensor is, for example, disposed in a seat surface, the steering wheel, or the like, and detects biological information of an occupant sitting in a seat or the driver holding the steering wheel. On the basis of detection information input from the driver state detecting section7510, the in-vehicle information detecting unit7500may calculate a degree of fatigue of the driver or a degree of concentration of the driver, or may determine whether the driver is dozing. The in-vehicle information detecting unit7500may subject an audio signal obtained by the collection of the sound to processing such as noise canceling processing or the like.

The integrated control unit7600controls general operation within the vehicle control system7000in accordance with various kinds of programs. The integrated control unit7600is connected with an input section7800. The input section7800is implemented by a device capable of input operation by an occupant, such, for example, as a touch panel, a button, a microphone, a switch, a lever, or the like. The integrated control unit7600may be supplied with data obtained by voice recognition of voice input through the microphone. The input section7800may, for example, be a remote control device using infrared rays or other radio waves, or an external connecting device such as a mobile telephone, a personal digital assistant (PDA), or the like that supports operation of the vehicle control system7000. The input section7800may be, for example, a camera. In that case, an occupant can input information by gesture. Alternatively, data may be input which is obtained by detecting the movement of a wearable device that an occupant wears. Further, the input section7800may, for example, include an input control circuit or the like that generates an input signal on the basis of information input by an occupant or the like using the above-described input section7800, and which outputs the generated input signal to the integrated control unit7600. An occupant or the like inputs various kinds of data or gives an instruction for processing operation to the vehicle control system7000by operating the input section7800.

The storage section7690may include a read only memory (ROM) that stores various kinds of programs executed by the microcomputer and a random access memory (RAM) that stores various kinds of parameters, operation results, sensor values, or the like. In addition, the storage section7690may be implemented by a magnetic storage device such as a hard disc drive (HDD) or the like, a semiconductor storage device, an optical storage device, a magneto-optical storage device, or the like.

The general-purpose communication I/F7620is a communication I/F used widely, which communication I/F mediates communication with various apparatuses present in an external environment7750. The general-purpose communication I/F7620may implement a cellular communication protocol such as global system for mobile communications (GSM (registered trademark)), worldwide interoperability for microwave access (WiMAX), long term evolution (LTE), LTE-advanced (LTE-A), or the like, or another wireless communication protocol such as wireless LAN (referred to also as wireless fidelity (Wi-Fi (registered trademark)), Bluetooth (registered trademark), or the like. The general-purpose communication I/F7620may, for example, connect to an apparatus (for example, an application server or a control server) present on an external network (for example, the Internet, a cloud network, or a company-specific network) via a base station or an access point. In addition, the general-purpose communication I/F7620may connect to a terminal present in the vicinity of the vehicle (which terminal is, for example, a terminal of the driver, a pedestrian, or a store, or a machine type communication (MTC) terminal) using a peer to peer (P2P) technology, for example.

The dedicated communication I/F7630is a communication I/F that supports a communication protocol developed for use in vehicles. The dedicated communication I/F7630may implement a standard protocol such, for example, as wireless access in vehicle environment (WAVE), which is a combination of institute of electrical and electronic engineers (IEEE) 802.11p as a lower layer and IEEE 1609 as a higher layer, dedicated short range communications (DSRC), or a cellular communication protocol. The dedicated communication I/F7630typically carries out V2X communication as a concept including one or more of communication between a vehicle and a vehicle (Vehicle to Vehicle), communication between a road and a vehicle (Vehicle to Infrastructure), communication between a vehicle and a home (Vehicle to Home), and communication between a pedestrian and a vehicle (Vehicle to Pedestrian).

The positioning section7640, for example, performs positioning by receiving a global navigation satellite system (GNSS) signal from a GNSS satellite (for example, a GPS signal from a global positioning system (GPS) satellite), and generates positional information including the latitude, longitude, and altitude of the vehicle. Incidentally, the positioning section7640may identify a current position by exchanging signals with a wireless access point, or may obtain the positional information from a terminal such as a mobile telephone, a personal handyphone system (PHS), or a smart phone that has a positioning function.

The beacon receiving section7650, for example, receives a radio wave or an electromagnetic wave transmitted from a radio station installed on a road or the like, and thereby obtains information about the current position, congestion, a closed road, a necessary time, or the like. Incidentally, the function of the beacon receiving section7650may be included in the dedicated communication I/F7630described above.

The in-vehicle device I/F7660is a communication interface that mediates connection between the microcomputer7610and various in-vehicle devices7760present within the vehicle. The in-vehicle device I/F7660may establish wireless connection using a wireless communication protocol such as wireless LAN, Bluetooth (registered trademark), near field communication (NFC), or wireless universal serial bus (WUSB). In addition, the in-vehicle device I/F7660may establish wired connection by universal serial bus (USB), high-definition multimedia interface (HDMI (registered trademark)), mobile high-definition link (MHL), or the like via a connection terminal (and a cable if necessary) not depicted in the figures. The in-vehicle devices7760may, for example, include at least one of a mobile device and a wearable device possessed by an occupant and an information device carried into or attached to the vehicle. The in-vehicle devices7760may also include a navigation device that searches for a path to an arbitrary destination. The in-vehicle device I/F7660exchanges control signals or data signals with these in-vehicle devices7760.

The vehicle-mounted network I/F7680is an interface that mediates communication between the microcomputer7610and the communication network7010. The vehicle-mounted network I/F7680transmits and receives signals or the like in conformity with a predetermined protocol supported by the communication network7010.

The microcomputer7610of the integrated control unit7600controls the vehicle control system7000in accordance with various kinds of programs on the basis of information obtained via at least one of the general-purpose communication I/F7620, the dedicated communication I/F7630, the positioning section7640, the beacon receiving section7650, the in-vehicle device I/F7660, and the vehicle-mounted network I/F7680. For example, the microcomputer7610may calculate a control target value for the driving force generating device, the steering mechanism, or the braking device on the basis of the obtained information about the inside and outside of the vehicle, and output a control command to the driving system control unit7100. For example, the microcomputer7610may perform cooperative control intended to implement functions of an advanced driver assistance system (ADAS) which functions include collision avoidance or shock mitigation for the vehicle, following driving based on a following distance, vehicle speed maintaining driving, a warning of collision of the vehicle, a warning of deviation of the vehicle from a lane, or the like. In addition, the microcomputer7610may perform cooperative control intended for automated driving, which makes the vehicle to travel automatedly without depending on the operation of the driver, or the like, by controlling the driving force generating device, the steering mechanism, the braking device, or the like on the basis of the obtained information about the surroundings of the vehicle.

The microcomputer7610may generate three-dimensional distance information between the vehicle and an object such as a surrounding structure, a person, or the like, and generate local map information including information about the surroundings of the current position of the vehicle, on the basis of information obtained via at least one of the general-purpose communication I/F7620, the dedicated communication I/F7630, the positioning section7640, the beacon receiving section7650, the in-vehicle device I/F7660, and the vehicle-mounted network I/F7680. In addition, the microcomputer7610may predict danger such as collision of the vehicle, approaching of a pedestrian or the like, an entry to a closed road, or the like on the basis of the obtained information, and generate a warning signal. The warning signal may, for example, be a signal for producing a warning sound or lighting a warning lamp.

The sound/image output section7670transmits an output signal of at least one of a sound and an image to an output device capable of visually or auditorily notifying information to an occupant of the vehicle or the outside of the vehicle. In the example ofFIG.33, an audio speaker7710, a display section7720, and an instrument panel7730are illustrated as the output device. The display section7720may, for example, include at least one of an on-board display and a head-up display. The display section7720may have an augmented reality (AR) display function. The output device may be other than these devices, and may be another device such as headphones, a wearable device such as an eyeglass type display worn by an occupant or the like, a projector, a lamp, or the like. In a case where the output device is a display device, the display device visually displays results obtained by various kinds of processing performed by the microcomputer7610or information received from another control unit in various forms such as text, an image, a table, a graph, or the like. In addition, in a case where the output device is an audio output device, the audio output device converts an audio signal constituted of reproduced audio data or sound data or the like into an analog signal, and auditorily outputs the analog signal.

Incidentally, at least two control units connected to each other via the communication network7010in the example depicted inFIG.33may be integrated into one control unit. Alternatively, each individual control unit may include a plurality of control units. Further, the vehicle control system7000may include another control unit not depicted in the figures. In addition, part or the whole of the functions performed by one of the control units in the above description may be assigned to another control unit. That is, predetermined arithmetic processing may be performed by any of the control units as long as information is transmitted and received via the communication network7010. Similarly, a sensor or a device connected to one of the control units may be connected to another control unit, and a plurality of control units may mutually transmit and receive detection information via the communication network7010.

The technology according to the present disclosure can be applied to, for example, a display unit of an output device capable of visually or auditorily notifying information among the above-described configurations.

FIG.35is a partial schematic cross-sectional view for explaining a liquid crystal display device according to a fifth embodiment. In the liquid crystal display device according to the fifth embodiment, the first substrate250further includes a third transparent material layer165. The third transparent material layer165includes a material having a refractive index (fifth refractive index) higher than the refractive index (second refractive index) of the material161, and is formed on the first transparent material layer160. Furthermore, the refractive index of the third transparent material layer165is higher than the refractive index (first refractive index) of the first transparent material layer160. That is, when the refractive indexes of the first transparent material layer160, the material161, and the third transparent material layer165are defined as n1, n2, and n3, respectively, they have a relationship of n2<n1<n3. For example, in a case where the material161is a silicon oxide film and the first transparent material layer160is a silicon oxynitride film, a high refractive index material such as a silicon nitride film is used for the third transparent material layer165. The third transparent material layer165has a film thickness of, for example, larger than 0 nm and smaller than 200 nm. Preferably, the film thickness of the third transparent material layer165is, for example, in the range of 100 nm to 200 nm.

As will be described later, the third transparent material layer165functions as an etching stopper or a polishing stopper when an etch-back process or a polishing process is performed with respect to the material161. Therefore, a surface of the material161can be made flat to be substantially flush with a surface of the third transparent material layer165. As a result, the transparent common electrode171and the alignment film172can be formed on the surfaces of the material161and the third transparent material layer165having high flatness. Accordingly, the liquid crystal material140can be aligned on the substantially flat alignment film172, and as a result, it is possible to suppress a decrease in contrast of a pixel.

FIG.36is a schematic cross-sectional view showing an example of a configuration in a broken-line frame B36ofFIG.35. The third transparent material layer165is provided on the first transparent material layer160. A first groove TR1is provided in the third transparent material layer165and the first transparent material layer160. Similarly to the material161in the first embodiment, the first groove TR1is provided in a portion of the first transparent material layer160corresponding to a region between adjacent pixels. In a plan view in a light incident direction (Z direction), the first groove TR1is provided between the adjacent pixels, for example, in the form of a lattice.

The material161is embedded in the first groove TR1. Therefore, the material161is also provided in a portion of the first transparent material layer160corresponding to a region between adjacent pixels, and for example, in the form of a lattice in a plan view in the Z direction.

Here, as will be described later, the third transparent material layer165is etched or polished at a slower speed than the first transparent material layer160. Therefore, in an etching process for forming the first groove TR1, it takes a relatively long time to process the third transparent material layer165, and accordingly, the third transparent material layer165is etched in a relatively large area in a transverse direction (X direction). On the other hand, it takes a relatively short time to process the first transparent material layer160, and accordingly, the first transparent material layer160is etched in a small area in the transverse direction (X direction). Therefore, an inclination angle of a side wall of the first groove TR1is different between the third transparent material layer165and the first transparent material layer160. For example, the inclination angle of the side wall of the first groove TR1is an angle at which the side wall of the first groove TR1is inclined with respect to a direction (Z direction) perpendicular to an interface IF between the first transparent material layer160and the third transparent material layer165. At this time, if the side wall of the first groove TR1in the first transparent material layer160is inclined at a first inclination angle θ1, then the side wall of the first groove TR1in the third transparent material layer165is inclined at a second inclination angle θ2larger than the first inclination angle θ1(θ2>θ1).

The other configurations in the fifth embodiment may be similar to the corresponding configurations in the second embodiment. Therefore, the fifth embodiment can obtain the same effects as the second embodiment.

Next, a method for manufacturing the liquid crystal display device according to the fifth embodiment will be described.

FIGS.37to42are cross-sectional views showing an example of a method for manufacturing the liquid crystal display device according to the fifth embodiment. First, a first transparent material layer160is formed on the multilayer laminate film263by performing the processes until the structure shown inFIG.22Ais obtained.

Next, as shown inFIG.37, a third transparent material layer165is formed on the first transparent material layer160.

Next, as shown inFIG.38, a resist film166is formed and patterned on the third transparent material layer165using a lithography technique. The resist film166is patterned to expose the third transparent material layer165in a region where a first groove TR1is to be formed.

Next, the third transparent material layer165and the first transparent material layer160are etched using an anisotropic etching method such as a reactive ion etching (RIE) method to form a first groove TR1. At this time, the third transparent material layer165is etched or polished at a slower speed than the first transparent material layer160. Therefore, as a processed state, the third transparent material layer165is etched in a relatively larger area in the X direction, and the side wall of the third transparent material layer165has a larger inclination angle (taper angle)02.

After the third transparent material layer165is etched, the first transparent material layer160is etched at a relatively high speed. Therefore, as a processed state, the first transparent material layer160is etched in a relatively small area in the X direction, and the side wall of the first transparent material layer160has a relatively small inclination angle (taper angle)01. In this way, the first groove TR1is formed to have a relatively large opening width at an upper end thereof, with an inclination angle of the first groove TR1gradually decreasing from the upper end to a bottom surface thereof.

Next, by removing the resist film166, the structure shown inFIG.40is obtained.

Next, as shown inFIG.41, a material161is formed on the third transparent material layer165and in the first groove TR1. As a result, the first groove TR1is filled with the material161. At this time, since the first groove TR1is formed to have a relatively large opening width at the upper end thereof as described above, the material161is easily filled in the first groove TR1. Even if a void or a seam is generated in the material161, the void or the seam is formed above the opening of the first groove TR1(an upper surface of the third transparent material layer165). Therefore, the void or the seam in the material161can be removed in a subsequent etch-back process or a polishing process.

Next, the material161is etched back or polished using a chemical mechanical polishing (CMP) method or the like. As a result, the material161and the third transparent material layer165are planarized as shown inFIG.42.

At this time, the third transparent material layer165is etched or polished at a lower speed than the material161. Therefore, the third transparent material layer165functions as an etching stopper or a polishing stopper, such that a surface of the material161can be substantially flush with a surface of the third transparent material layer165. As a result, flatness between the surface of the material161and the surface of the third transparent material layer165can be enhanced.

Next, a transparent common electrode171and an alignment film172are formed on the material161and the third transparent material layer165. At this time, the transparent common electrode171and the alignment film172are formed on the surfaces of the material161and the third transparent material layer165having high flatness. The flatness of the transparent common electrode171and the alignment film172is also improved.

In this way, a first substrate250is completed. A method for forming a second substrate100and a liquid crystal material layer140in the fifth embodiment may be the same as that in the second embodiment. In this way, the liquid crystal display device according to the fifth embodiment is completed.

Sixth Embodiment

FIG.43is a partial schematic cross-sectional view for explaining a liquid crystal display device according to a sixth embodiment. The liquid crystal display device according to the sixth embodiment further includes a material film162provided between the third transparent material layer165and the transparent common electrode171. For the material film162, for example, a silicon oxide film is used in the same manner as for the material161.

The material film162is formed on the material161and the third transparent material layer165after the material161is etched back or polished. Normally, film flatness achieved by a film forming process is better than that achieved by an etch-back process or a polishing process. Therefore, by forming the material film162, warpage and uneven polishing can be reduced throughout the entire first substrate250. That is, the surface of the material film162has further improved flatness than the surfaces of the material161and the third transparent material layer165. As a result, the flatness of the transparent common electrode171and the alignment film172is also improved, leading to an improvement in contrast.

The other configurations in the sixth embodiment may be similar to the corresponding configurations in the fifth embodiment. In addition, it is only required that the material film162be formed on the material161and the third transparent material layer165after the material161is etched back or polished. The other processes of the manufacturing method in the sixth embodiment may be the same as those in the fifth embodiment. Therefore, the sixth embodiment can obtain the same effects as the fifth embodiment.

Note that, although not illustrated, an antireflection film may be provided under the transparent common electrode171. The antireflection film may be, for example, a laminate film including a silicon oxide film and a silicon nitride film.

Seventh Embodiment

FIG.44is a partial schematic cross-sectional view for explaining a liquid crystal display device according to a seventh embodiment. In the liquid crystal display device according to the seventh embodiment, the second substrate100further includes a fourth transparent material layer168. The fourth transparent material layer168includes a material having a refractive index (sixth refractive index) higher than the refractive index (fourth refractive index) of the material111, and is formed on the second transparent material layer110. Furthermore, the refractive index of the fourth transparent material layer168is higher than the refractive index (third refractive index) of the second transparent material layer110. That is, when the refractive indexes of the second transparent material layer110, the material111, and the fourth transparent material layer168are defined as n4, n5, and n6, respectively, they have a relationship of n5<n4<n6. For example, in a case where the material111is a silicon oxide film and the second transparent material layer110is a silicon oxynitride film, a high refractive index material such as a silicon nitride film is used for the fourth transparent material layer168. The fourth transparent material layer168has a film thickness of, for example, larger than 0 nm and smaller than 200 nm. Preferably, the film thickness of the fourth transparent material layer168is, for example, in the range of 100 nm to 200 nm.

As will be described later, the fourth transparent material layer168functions as an etching stopper or a polishing stopper when an etch-back process or a polishing process is performed with respect to the material111. Therefore, a surface of the material111can be made flat to be substantially flush with a surface of the fourth transparent material layer168. As a result, accuracy is improved in finely processing the wirings121and123, the transistor122, and a contact (not illustrated).

FIG.45is a schematic cross-sectional view showing an example of a configuration in a broken-line frame B45ofFIG.35. The fourth transparent material layer168is provided on the second transparent material layer110. A second groove TR2is provided in the fourth transparent material layer168and the second transparent material layer110. Similarly to the first groove TR1, the second groove TR2is provided in a portion of the second transparent material layer110corresponding to a region between adjacent pixels. In a plan view in a light incident direction (Z direction), the second groove TR2is provided between the adjacent pixels, for example, in the form of a lattice.

The material111is embedded in the second groove TR2. Therefore, the material111is also provided in a portion of the second transparent material layer110corresponding to a region between adjacent pixels, and for example, in the form of a lattice in a plan view in the Z direction.

Here, the fourth transparent material layer168is etched or polished at a slower speed than the second transparent material layer110. Therefore, in an etching process for forming the second groove TR2, it takes a relatively long time to process the fourth transparent material layer168, and accordingly, the fourth transparent material layer168is etched in a relatively large area in a transverse direction (X direction). On the other hand, it takes a relatively short time to process the second transparent material layer110, and accordingly, the second transparent material layer110is etched in a small area in the transverse direction (X direction). Therefore, an inclination angle of a side wall of the second groove TR2is different between the fourth transparent material layer168and the second transparent material layer110. For example, the inclination angle of the side wall of the second groove TR2is an angle at which the side wall of the second groove TR2is inclined with respect to a direction (Z direction) perpendicular to an interface IF2between the second transparent material layer110and the fourth transparent material layer168. At this time, if the side wall of the second groove TR2in the second transparent material layer110is inclined at a third inclination angle θ3, then the side wall of the second groove TR2in the fourth transparent material layer168is inclined at a fourth inclination angle θ4larger than the third inclination angle θ3(θ4>θ3).

The other configurations in the seventh embodiment may be similar to the corresponding configurations in the fifth embodiment. Therefore, the seventh embodiment can obtain the same effects as the fifth embodiment.

A method for forming the fourth transparent material layer168, the second groove TR2, and the material film111in the seventh embodiment can be easily understood from the method for forming the third transparent material layer165, the first groove TR1, and the material film161in the fifth embodiment. Thus, the description thereof will be omitted.

Eighth Embodiment

FIG.46is a partial schematic cross-sectional view for explaining a liquid crystal display device according to an eighth embodiment. The liquid crystal display device according to the eighth embodiment further includes a material film112provided on the fourth transparent material layer168. For the material film112, for example, a silicon oxide film is used in the same manner as for the material111.

The material film112is formed on the material111and the fourth transparent material layer168after the material111is etched back or polished. Normally, film flatness achieved by a film forming process is better than that achieved by an etch-back process or a polishing process. Therefore, by forming the material film112, warpage and uneven polishing can be reduced throughout the entire second substrate100. That is, the surface of the material film112has further improved flatness than the surfaces of the material111and the fourth transparent material layer168. As a result, accuracy is improved in finely processing the wirings121and123, the transistor122, and a contact (not illustrated).

The other configurations in the eighth embodiment may be similar to the corresponding configurations in the seventh embodiment. In addition, it is only required that the material film112be formed on the material111and the fourth transparent material layer168after the material111is etched back or polished. The other processes of the manufacturing method in the eighth embodiment may be the same as those in the seventh embodiment. Therefore, the eighth embodiment can obtain the same effects as the seventh embodiment.

Note that the technology of the present disclosure can also have the following configurations.

A liquid crystal display device including:a first substrate including a microlens corresponding to each pixel;a second substrate disposed to face the first substrate; anda liquid crystal material layer sandwiched between the first substrate and the second substrate,in which a first transparent material layer including a material having a first refractive index is formed in the first substrate, and a material having a second refractive index different from the first refractive index is disposed in a portion of the first transparent material layer corresponding to a region between adjacent pixels, anda second transparent material layer including a material having a third refractive index is formed in the second substrate, and a material having a fourth refractive index different from the third refractive index is disposed in a portion of the second transparent material layer corresponding to the region between adjacent pixels.

The liquid crystal display device according to [A1], in which the first transparent material layer is formed between the microlens and the liquid crystal material layer.

The liquid crystal display device according to [A1] or [A2], in which the second refractive index is smaller than the first refractive index.

The liquid crystal display device according to any one of [A1] to [A3], in which the material having the second refractive index is arranged in a form of a lattice.

The liquid crystal display device according to [A4], in which the material having the second refractive index is arranged to widen at an intersection portion of the lattice.

The liquid crystal display device according to any one of [A1] to [A5], in which the material having the first refractive index is a silicon nitride or a silicon oxynitride.

The liquid crystal display device according to any one of [A1] to [A6], in which the material having the second refractive index is a silicon oxide.

The liquid crystal display device according to any one of [A1] to [A7], in which a multilayer laminate film including a high refractive index material film and a low refractive index material film is disposed between the microlens and the first transparent material layer.

The liquid crystal display device according to [A8], in which the multilayer laminate film includes a silicon nitride film and a silicon oxide film.

The liquid crystal display device according to any one of [A1] to [A9], in which the first transparent material layer includes a multilayer laminate film including a high refractive index material film and a low refractive index material film.

The liquid crystal display device according to any one of [A1] to [A10], in which the fourth refractive index is smaller than the third refractive index.

The liquid crystal display device according to any one of [A1] to [A11], in which the material having the fourth refractive index is arranged in a form of a lattice.

The liquid crystal display device according to [A12], in which the material having the fourth refractive index is arranged to widen at an intersection portion of the lattice.

The liquid crystal display device according to any one of [A1] to [A13], in which the material having the third refractive index is a silicon nitride or a silicon oxynitride.

The liquid crystal display device according to any one of [A1] to [A14], in which the material having the fourth refractive index is a silicon oxide.

The liquid crystal display device according to any one of [A1] to [A15], in which a transparent common electrode is formed in the first substrate, and a transparent pixel electrode corresponding to each pixel is formed in the second substrate.

The liquid crystal display device according to any one of [A1] to [A16], in which the second substrate has a lattice-shaped light shielding region located in a portion corresponding to the region between adjacent pixels.

The liquid crystal display device according to any one of [A1] to [A15], in which a plurality of transparent electrodes extending in a first direction is formed in the first substrate, anda plurality of transparent electrodes extending in a second direction different from the first direction is formed in the second substrate.

An electronic device including a liquid crystal display device, the liquid crystal display device including:a first substrate including a microlens corresponding to each pixel;a second substrate disposed to face the first substrate; anda liquid crystal material layer sandwiched between the first substrate and the second substrate,in which a first transparent material layer including a material having a first refractive index is formed in the first substrate, and a material having a second refractive index different from the first refractive index is disposed in a portion of the first transparent material layer corresponding to a region between adjacent pixels, anda second transparent material layer including a material having a third refractive index is formed in the second substrate, and a transparent material having a fourth refractive index different from the third refractive index is disposed in a portion of the second transparent material layer corresponding to the region between adjacent pixels.

The electronic device according to [B1], in which the first transparent material layer is formed between the microlens and the liquid crystal material layer.

The electronic device according to [B1] or [B2], in which the second refractive index is smaller than the first refractive index.

The electronic device according to any one of [B1] to [B3], in which the material having the second refractive index is arranged in a form of a lattice.

The electronic device according to [B4], in which the material having the second refractive index is arranged to widen at an intersection portion of the lattice.

The electronic device according to any one of [B1] to [B5], in which the material having the first refractive index is a silicon nitride or a silicon oxynitride.

The electronic device according to any one of [B1] to [B6], in which the material having the second refractive index is a silicon oxide.

The electronic device according to any one of [B1] to [B7], in which a multilayer laminate film including a high refractive index material film and a low refractive index material film is disposed between the microlens and the first transparent material layer.

The electronic device according to [B8], in which the multilayer laminate film includes a silicon nitride film and a silicon oxide film.

The electronic device according to any one of [B1] to [B9], in which the first transparent material layer includes a multilayer laminate film including a high refractive index material film and a low refractive index material film.

The electronic device according to any one of [B1] to [B10], in which the fourth refractive index is smaller than the third refractive index.

The electronic device according to any one of [B1] to [B11], in which the material having the fourth refractive index is arranged in a form of a lattice.

The electronic device according to [B12], in which the material having the fourth refractive index is arranged to widen at an intersection portion of the lattice.

The electronic device according to any one of [B1] to [B13], in which the material having the third refractive index is a silicon nitride or a silicon oxynitride.

The electronic device according to any one of [B1] to [B14], in which the material having the fourth refractive index is a silicon oxide.

The electronic device according to any one of [B1] to [B15], in which a transparent common electrode is formed in the first substrate, anda transparent pixel electrode corresponding to each pixel is formed in the second substrate.

The electronic device according to any one of [B1] to [B16], in which the second substrate has a lattice-shaped light shielding region located in a portion corresponding to the region between adjacent pixels.

The electronic device according to any one of [B1] to [B15], in which a plurality of transparent electrodes extending in a first direction is formed in the first substrate, anda plurality of transparent electrodes extending in a second direction different from the first direction is formed in the second substrate.

The liquid crystal display device according to [A1], in which a third transparent material layer including a material having a fifth refractive index higher than the second refractive index is formed on the first transparent material layer in the first substrate, and the material having the second refractive index is embedded in a first groove provided in portions of the first and third transparent material layers corresponding to the region between adjacent pixels.

The liquid crystal display device according to [A20], in which a side wall of the first groove in the first transparent material layer is inclined at a first inclination angle from a direction perpendicular to an interface between the first transparent material layer and the third transparent material layer, anda side wall of the first groove in the third transparent material layer is inclined at a second inclination angle larger than the first inclination angle from the perpendicular direction.

The liquid crystal display device according to [A20] or [A21], in which the third transparent material layer has a film thickness of larger than 0 nm and smaller than 200 nm.

The liquid crystal display device according to any one of [A20] to [A22], in which the first transparent material layer is a silicon oxynitride film, andthe third transparent material layer is a silicon nitride film.

The liquid crystal display device according to any one of [A20] to [A23], in which the third transparent material layer is etched or polished at a slower speed than the first transparent material layer.

The liquid crystal display device according to [A1], in which a fourth transparent material layer including a material having a sixth refractive index higher than the fourth refractive index is formed on the second transparent material layer in the second substrate, and the material having the fourth refractive index is embedded in a second groove provided in portions of the second and fourth transparent material layers corresponding to the region between adjacent pixels.

The liquid crystal display device according to [A25], in which a side wall of the second groove in the second transparent material layer is inclined at a third inclination angle from a direction perpendicular to an interface between the second transparent material layer and the fourth transparent material layer, and a side wall of the second groove in the fourth transparent material layer is inclined at a fourth inclination angle larger than the third inclination angle from the perpendicular direction.

The liquid crystal display device according to [A25] or [A26], in which the fourth transparent material layer has a film thickness of larger than 0 nm and smaller than 200 nm.

The liquid crystal display device according to any one of [A25] to [A27], in which the second transparent material layer is a silicon oxynitride film, and the fourth transparent material layer is a silicon nitride film.

The liquid crystal display device according to any one of [A25] to [A28], in which the fourth transparent material layer is etched or polished at a slower speed than the second transparent material layer.

The electronic device according to [A19], in which a third transparent material layer including a material having a fifth refractive index higher than the second refractive index is formed on the first transparent material layer in the first substrate, and the material having the second refractive index is embedded in a first groove provided in portions of the first and third transparent material layers corresponding to the region between adjacent pixels.

REFERENCE SIGNS LIST