TWI701498B - LCD projector - Google Patents

Abstract

The liquid crystal projector 10 is equipped with: a light source 11, which generates light; a condenser lens 12, which is arranged on the light path; a liquid crystal panel 13, which has a polymer dispersed liquid crystal layer or a polymer mesh liquid crystal Any one of the layers reflects the light emitted by the condenser lens 12 corresponding to the display pattern and emits reflected light; the scattered light elimination section 14, which eliminates the scattered light emitted by the liquid crystal panel 13; and the projection lens 15, which will pass The reflected light of the scattered light elimination unit 14 is projected.

Description

LCD projector

The invention relates to a liquid crystal projector using a liquid crystal panel.

Conventional liquid crystal projectors having color filters have, for example, the following configuration. The liquid crystal projector has a liquid crystal panel as an image display unit. The liquid crystal panel is a transmissive type that transmits light, for example, and has a structure in which a liquid crystal layer is sandwiched between two glass substrates. A color filter is formed on one of the glass substrates, and a TFT (Thin Film Transistor) element is formed on the other glass substrate. In addition, polarizing plates are respectively arranged on the outer sides of the two glass substrates (for example, Patent Document 1).

However, if a polarizing plate is arranged on the glass substrate, the light system from the light source is absorbed along the absorption axis of the polarizing plate, and the intensity of the light becomes 50% or less (actually 40% or less). In addition, the polarizing plate generates heat due to the absorption of light along the absorption axis of the polarizing plate. Therefore, the liquid crystal in the liquid crystal panel tends to stand up, and the contrast of the displayed image is lowered, and the image display characteristics may deteriorate.

Prior art literature Patent literature

Patent Document 1 Japanese Patent Laid-Open No. 6-160854

Patent Document 2 International Publication No. 2014/069484

The purpose of the present invention is to provide a liquid crystal projector with high light utilization efficiency and improved image display characteristics.

One aspect of the liquid crystal projector of the present invention is characterized by: a light source, which generates light; a condenser lens, which is arranged on the optical path of the aforementioned light; and a liquid crystal panel, which has a polymer dispersed liquid crystal layer or Any layer of the polymer mesh type liquid crystal layer reflects the light emitted by the aforementioned condenser lens corresponding to the display pattern and emits reflected light; the scattered light elimination part eliminates the scattered light emitted by the aforementioned liquid crystal panel; and the projection lens, This is to project the reflected light that has passed through the scattered light elimination part.

With the present invention, a liquid crystal projector with high light utilization efficiency and improved image display characteristics can be provided.

10‧‧‧LCD projector

11‧‧‧Light source

12‧‧‧Condenser lens

13‧‧‧LCD Panel

14‧‧‧Scattered light elimination part

14A‧‧‧Cylinder-shaped member

14B‧‧‧Scattered light

14C‧‧‧Reflected light

15‧‧‧Projection lens

16‧‧‧Drive circuit

17‧‧‧Control circuit

21‧‧‧TFT substrate

22‧‧‧Common substrate

23‧‧‧Liquid crystal layer

23A‧‧‧Polymer layer

23B‧‧‧LCD

23C‧‧‧Liquid crystal molecules

24‧‧‧TFT

25‧‧‧Insulation layer

26‧‧‧Reflective film

27‧‧‧Color filter

27-R‧‧‧Red filter

27-G‧‧‧Green filter

27-B‧‧‧Blue filter

28‧‧‧Pixel electrode

29‧‧‧Common electrode

30‧‧‧LCD projector

31‧‧‧Scattered light elimination part

31A: Cylindrical member

31B: Scattered light elimination part

31C: Flat member

100: screen

Fig. 1 is a diagram showing the configuration of a liquid crystal projector according to the first embodiment.

Fig. 2 is a cross-sectional view showing the liquid crystal panel in the first embodiment when the display is in an OFF state.

Fig. 3 is a cross-sectional view showing the liquid crystal panel in the first embodiment when the display is in an ON state.

Fig. 4 is a diagram showing the structure of a scattered light eliminating section in the first embodiment.

Fig. 5 is a diagram showing scattered light and reflected light incident on the scattered light eliminating section.

FIG. 6 is a diagram showing the operation of the optical system of the display and the scattered light elimination section of the liquid crystal panel in the first embodiment.

FIG. 7 is a diagram showing the operation of the optical system of the display and the scattered light elimination section of the liquid crystal panel in the first embodiment.

FIG. 8 is a diagram showing the operation of the optical system of the display and the scattered light elimination portion of the liquid crystal panel in the first embodiment.

9 is a diagram showing the operation of the optical system of the display of the liquid crystal panel and the scattered light elimination unit in the first embodiment.

FIG. 10 is a diagram showing the operation of the optical system of the display and the scattered light elimination portion of the liquid crystal panel in the first embodiment.

Fig. 11 is a diagram showing the configuration of a liquid crystal projector according to a second embodiment.

Fig. 12 is a diagram showing the structure of a scattered light elimination unit in the second embodiment.

Fig. 13 is a plan view showing a modified example of the scattered light eliminating section in the second embodiment.

Fig. 14 is a perspective view showing a modified example of the scattered light eliminating section in the second embodiment.

The embodiments are described below with reference to the drawings. However, it should be noted that the illustrations are modular or conceptual, and the sizes and ratios of the illustrations are not necessarily the same as the actual ones. In addition, when the figures show the same parts with each other, they may be presented in different dimensional relationships or ratios. In particular, the several embodiments shown below are examples of devices and methods for embodying the technical idea of the present invention, and are not intended to specify the technical idea of the present invention by the shape, structure, and arrangement of constituent parts. Among them, in the following description, elements having the same function and configuration are denoted with the same reference numerals, and the description is repeated only when necessary.

[1] The first embodiment

The liquid crystal projector of the first embodiment will be described below.

[1-1] Composition of LCD projector

Fig. 1 is a diagram showing the configuration of a liquid crystal projector according to a first embodiment of the present invention. The liquid crystal projector 10 includes a light source 11, a condenser lens 12, a liquid crystal panel 13, a scattered light elimination unit 14, a projection lens 15, a drive circuit 16, and a control circuit 17.

The light generated by the light source 11 passes through the condenser lens 12 and is irradiated to the liquid crystal panel 13. A condenser lens 12 is arranged on the optical path between the light source 11 and the liquid crystal panel 13. The liquid crystal panel 13 has a plurality of pixels, and takes an ON state or an OFF state for each pixel. The pixels in the ON state of the liquid crystal panel 13 specularly reflect the light (hereinafter referred to as incident light) emitted by the condenser lens 12, and emit reflected light. The pixels in the OFF state scatter incident light and emit scattered light. The reflection from the LCD panel 13 The incident light system passes through the scattered light elimination unit 14 and enters the projection lens 15. On the other hand, the scattered light system emitted from the liquid crystal panel 13 is blocked by the scattered light elimination unit 14 and does not enter the projection lens 15. A scattered light elimination unit 14 is arranged on the optical path between the liquid crystal panel 13 and the projection lens 15. Then, the light incident on the projection lens 15 is projected to the external screen 100 and the like through the projection lens 15.

The light source 11 generates light to the liquid crystal panel 13. The light source 11 is composed of, for example, a metal halide lamp. The metal halide lamp is a lamp that uses arc discharge in the mixed vapor of mercury and metal halide. The condenser lens 12 collects light from the light source 11 and emits parallel light to the liquid crystal panel 13. The condenser lens 12 may be composed of, for example, one lens, or may be composed of a plurality of lenses.

The liquid crystal panel 13 is a reflective liquid crystal panel using polymer dispersed liquid crystal (PDLC: Polymer Dispersed Liquid Crystal) or polymer network liquid crystal (PNLC: Polymer Network Liquid Crystal). The display panel 13 includes a pixel array in which a plurality of pixels are arranged in a matrix. The display panel 13 is provided with a plurality of scanning lines extending in a row direction (X direction), and a plurality of signal lines extending in a column direction (Y direction). Pixels are arranged in the intersection area of the scan line and the signal line. The liquid crystal panel 13 will be described in detail later.

The scattered light elimination unit 14 eliminates or blocks scattered light emitted from the liquid crystal panel 13 and transmits the reflected light emitted from the liquid crystal panel 13. The scattered light removing section 14 will be described in detail later. The projection lens 15 projects the light passing through the scattered light elimination unit 14 to, for example, an external screen 100. The projection lens 15 may be composed of, for example, one lens, or may be composed of a plurality of lenses.

The driving circuit 16 is connected to a plurality of scanning lines and a plurality of signal lines. The driving circuit 16 turns on or off the switching element included in the pixel according to the control signal transmitted by the control circuit 17. The driving circuit 16 sends the driving voltage to the display panel 13 according to the control signal. That is, the control circuit 17 sends the control signal to the drive circuit 16 based on the image data. Then, the control circuit 17 controls the display on the display panel 13 by the control signal.

[1-1-1] Configuration of display panel 13

Next, the structure of the display panel 13 in the first embodiment will be described.

2 and 3 are cross-sectional views of the panel 13. FIG. 2 shows a case where the display of the liquid crystal panel 13 is in an OFF state, and FIG. 3 shows a case where the display of the liquid crystal panel 13 is in an ON state.

The display panel 13 is provided with: a switching element, for example, a substrate on which TFT (Thin Film Transistor) is formed (hereinafter referred to as TFT substrate) 21, and a substrate on which common electrodes are formed and arranged opposite to the TFT substrate 21 (hereinafter referred to as common substrate) 22. And the liquid crystal layer 23 sandwiched between the TFT substrate 21 and the common substrate 22.

Each of the TFT substrate 21 and the common substrate 22 is composed of a transparent substrate (for example, a glass substrate). The TFT substrate 21 and the common substrate 22 are bonded with a sealing material (not shown) while maintaining a space. A liquid crystal material is sealed in the space surrounded by the TFT substrate 21, the common substrate 22, and the sealing material, and the liquid crystal layer 23 is formed. The specific configuration of the liquid crystal layer 23 will be described later.

On the side of the liquid crystal layer 23 on the TFT substrate 21, a plurality of switching elements such as TFT 24 are provided. The TFT 24 is provided with: for example, a gate electrode electrically connected to the scanning line; a gate insulating film provided on the gate electrode; a semiconductor layer (such as an amorphous silicon layer) provided on the gate insulating film; and Away from the source electrode and the drain electrode provided on the semiconductor layer. The source electrode is electrically connected with the signal line.

An insulating layer 25 is provided on the TFT substrate 21 and the TFT 24. A reflective film 26 is provided on the insulating layer 25. A color filter 27 is provided on the reflective film 26. The color filter 27 is provided with a plurality of color filters (coloring members). Specifically, it includes a plurality of red filters 27-R, a plurality of green filters 27-G, and a plurality of blue filters 27-B. Pixel electrodes 28 are provided on the plurality of red filters 27-R, green filters 27-G, and blue filters 27-B, respectively.

A general color filter is composed of the three primary colors of light, namely red (R), green (G), and blue (B). The set of adjacent R, G, and B colors becomes the display unit (pixel), and any monochromatic part of R, G, and B in a pixel is called the smallest subpixel (subpixel) Drive unit. The TFT 24 and the pixel electrode 28 are provided for each sub-pixel. In the following description, except for cases where it is necessary to distinguish between pixels and sub-pixels, sub-pixels are referred to as pixels.

The aforementioned common electrode 29 is provided on the liquid crystal layer 23 side of the common substrate 22. The common electrode 29 is formed in a planar shape on the entire display area of the display panel 13. The pixel electrode 28 and the common electrode 29 are composed of transparent electrodes. For the transparent electrode system, for example, ITO (Indium Tin Oxide) is used.

The liquid crystal layer 23 includes a polymer layer 23A and liquid crystal 23B. The liquid crystal 23B includes liquid crystal molecules 23C. In detail, the liquid crystal layer 23 is composed of polymer dispersed liquid crystal (PDLC: Polymer Dispersed Liquid Crystal) or polymer network liquid crystal (PNLC: Polymer Network Liquid Crystal). The PDLC system has a structure in which liquid crystal 23B is dispersed in a polymer layer (polymer network) 23A, that is, it has a structure in which liquid crystal 23B is phase-separated in the polymer layer 23A. Alternatively, the liquid crystal 23B in the polymer layer 23A may have a continuous phase.

For the polymer layer 23A, a light-curing resin can be used. For example, in PDLC, a solution in which liquid crystal is mixed with a photopolymerizable polymer precursor (monomer) is irradiated with ultraviolet rays to polymerize the monomer to form a polymer, and the liquid crystal is dispersed in the polymer network . For the liquid crystal 23B, for example, a nematic liquid crystal whose dielectric anisotropy is positive (positive type) is used. That is, when voltage is not applied to the liquid crystal layer 23, it is formed in a state where the liquid crystal molecules 23C are randomly arranged in the polymer layer 23A. When a voltage is applied to the liquid crystal layer 23, the liquid crystal molecules 23C are formed in a state where the liquid crystal molecules 23C stand up in the electric field direction (a state where the long axis of the liquid crystal molecules 23C faces the electric field direction). The thickness (cell gap) of the liquid crystal layer 23 is, for example, about 7 μm.

Next, the operation when light enters the liquid crystal panel 13 will be described using FIGS. 2 and 3.

If the display of the liquid crystal panel 13 is in the OFF state, if light enters the condenser lens 12, the incident light is scattered by the liquid crystal layer 23, or the scattered light is reflected by the reflective film 26, and part of the scattered light is directed upward by the common electrode 22 issue.

In detail, if no electric field is applied to the liquid crystal layer 23 (OFF state), that is, when the pixel electrode 28 and the common electrode 29 are formed at the same voltage (for example, 0V), the liquid crystal molecules 23C are randomly arranged. At this time, since the refractive index of the polymer layer 23A is different from the refractive index of the liquid crystal 23B, the incident light from the common substrate 22 side is scattered in the liquid crystal layer 23 (scattered state). The incident light in the scattered state is reflected by the reflective film 26 and the scattered light is radiated from the common substrate 22.

On the other hand, if the display of the liquid crystal panel 13 is in the ON state, if the light is incident from the condenser lens 12, the incident light will not pass through without being scattered by the liquid crystal layer 23, and the transmitted light will be positive on the reflective film 26. The reflected and regular reflection light is emitted upward from the common electrode 22.

In detail, if an electric field is applied to the liquid crystal layer 23 (ON state), that is, a voltage difference is applied to the pixel electrode 28 and the common electrode 29 (for example, a positive voltage is applied to the pixel electrode 28, and 0V is applied to the common electrode 29) At this time, the long axis of the liquid crystal molecules 23C is aligned in the direction of the electric field (that is, the vertical direction). At this time, since the refractive index of the polymer layer 23A and the refractive index of the liquid crystal 23B are roughly the same, the incident light from the common substrate 22 side passes through the liquid crystal layer 23. The incident light passing through the liquid crystal layer 23 is reflected by the reflective film 26, and is emitted as regular reflection light (mirror light) from the common substrate 22.

[1-1-2] Configuration of the scattered light elimination unit 14

Next, the structure of the scattered light elimination unit 14 will be described. The scattered light elimination unit 14 blocks the scattered light emitted by the liquid crystal panel 13 or the scattered light before entering the projection lens 15, and transmits the reflected light emitted by the liquid crystal panel 13.

FIG. 4 is a diagram showing the structure of the scattered light elimination unit 14 in the first embodiment. The scattered light elimination part 14 has a plurality of cylindrical members 14A. A plurality of cylindrical members 14A are arranged in a direction orthogonal to the optical path direction of the reflected light reflected on the liquid crystal panel 13. The cylindrical members 14A are preferably arranged in such a way that there is no gap between them as much as possible, for example, arranged in a matrix. The cylindrical direction of the cylindrical member 14A is formed parallel to the optical path direction of the reflected light from the liquid crystal panel 13. The cylindrical member 14A has, for example, a cylindrical shape. The cylindrical member 14A is made of, for example, metal, and a matt black paint is applied to the inner and outer surfaces. In other words, the inner surface and the outer surface of the cylindrical member 14A are black.

In FIG. 5, the scattered light 14B and the reflected light 14C incident on the cylindrical member 14A of the scattered light eliminating section 14 are shown. Here, four cylindrical members 14A are extracted and displayed.

As described above, the inner surface and outer surface of the cylindrical member 14A are black. Therefore, the light system that is not parallel to the cylindrical direction of the cylindrical member 14A is absorbed to the inner surface. On the other hand, the light system parallel to the cylindrical direction of the cylindrical member 14A passes through the cylindrical member 14A. That is, the scattered light 14B incident on the cylindrical member 14A is incident on the inner surface of the cylindrical member 14A, and is absorbed to the inner surface. On the other hand, the reflected light 14C incident on the cylindrical member 14A is not absorbed into the inner surface of the cylindrical member 14A, but advances parallel to the cylindrical direction and passes through the cylindrical member 14A.

Among them, the above shows an example in which the cylindrical member 14A has a cylindrical shape, but it is not limited to a circle. If it is cylindrical, it can also be triangular, quadrangular, or other polygonal shapes.

[1-2] The display of the liquid crystal panel 13 and the operation of the optical system in the scattered light elimination section 14

Next, the operation of the optical system in the display of the liquid crystal panel 13 of the first embodiment and the scattered light elimination unit 14 will be described. The display of the liquid crystal panel 13 is controlled by the control circuit 17. The control circuit 17 controls the voltage between the pixel electrode 28 and the common electrode 29 on the red filter 27-R, the green filter 27-G, and the blue filter 27-B through the driving circuit 16.

FIGS. 6 to 10 are diagrams showing the display of the liquid crystal panel 13 and the operation of the optical system in the scattered light elimination unit 14, and Table 1 is a diagram showing the relationship between the ON/OFF state of pixels and the color display.

For example, if the pixel of the red filter 27-R (red pixel), the pixel of the green filter 27-G (green pixel), and the pixel of the blue filter 27-B (blue pixel) are in the ON state, That is, if a voltage difference is applied between the three pixel electrodes 28 of the red pixel, the green pixel, and the blue pixel and the common electrode 29 (for example, a positive voltage is applied to the pixel electrode 28, and 0V is applied to the common electrode 29), As shown in FIG. 6, the long axes of the liquid crystal molecules 23C between the three pixel electrodes 28 and the common electrode 29 are aligned in the direction of the electric field (that is, the direction perpendicular to the electrode surface).

At this time, the refractive index of the polymer layer 23A is roughly the same as the refractive index of the liquid crystal layer 23B, so the incident light from the common substrate 22 side passes through the liquid crystal layer 23. The incident light passing through the liquid crystal layer 23 is reflected by the reflective film 26, and is emitted as regular reflection light (mirror light) from the common substrate 22. The specular reflection light system emitted from the common substrate 22 passes through the scattered light elimination unit 14 and enters the projection lens 15. Here, through the red filter 27-R, The regular reflection light from the green filter 27 -G and the blue filter 27 -B is incident on the projection lens 15. Thereby, the display system projected on the screen 100 by the projection lens 15 becomes a white display with a mixture of red, green, and blue light. Table 1(a) shows the ON/OFF conditions of the pixels when performing this white display.

In addition, for example, if the red pixel, the green pixel, and the blue pixel are in the OFF state, that is, if the three pixel electrodes 28 of the red pixel, the green pixel, and the blue pixel and the common electrode 29 are formed at the same voltage (for example, 0V) As shown in FIG. 7, the liquid crystal molecules 23C between the three pixel electrodes 28 and the common electrode 29 are randomly arranged.

At this time, since the refractive index of the polymer layer 23A and the refractive index of the liquid crystal layer 23B are different, the incident light from the common substrate 22 side is scattered in the liquid crystal layer 23 (scattered state). The incident light in the scattered state is reflected by the reflective film 26 and the scattered light is radiated from the common substrate 22. The scattered light system radiated from the common substrate 22 is eliminated by the scattered light elimination unit 14 and therefore does not enter the projection lens 15. Here, there is no regular reflection light. As described above, the scattered light does not enter the projection lens 15, so the display system projected onto the screen 100 by the projection lens 15 becomes a black display. Table 1(b) shows the ON/OFF conditions of the pixels when performing this black display.

In addition, for example, if the red pixel is in the ON state and the green pixel and the blue pixel are in the OFF state, that is, if a voltage difference is applied between the pixel electrode 28 and the common electrode 29 of the red pixel, the two pixels of the green pixel and the blue pixel When the electrode 28 and the common electrode 29 are formed at the same potential, as shown in FIG. 8, the long axis of the liquid crystal molecules 23C between the pixel electrode 28 and the common electrode 29 of the red pixel are aligned in the electric field direction. On the other hand, green pixels The liquid crystal molecules 23C between the two pixel electrodes 28 and the common electrode 29 of the blue pixel are randomly arranged.

At this time, incident light from the side of the common substrate 22 facing the red filter 27 -R passes through the liquid crystal layer 23. The incident light passing through the liquid crystal layer 23 is reflected by the reflective film 26 under the red filter 27-R, and is emitted from the common substrate 22 as regular reflection light. The specular reflection light system emitted from the common substrate 22 passes through the scattered light elimination unit 14 and enters the projection lens 15. On the other hand, incident light from the side of the common substrate 22 facing the green filter 27-G and the blue filter 27-B is scattered in the liquid crystal layer 23 (scattered state). The incident light in the scattered state is reflected by the reflective film 26 and the scattered light is radiated from the common substrate 22. The scattered light system radiated from the common substrate 22 is eliminated by the scattered light elimination unit 14 and therefore does not enter the projection lens 15. Here, the regular reflection light passing through the red filter 27-R enters the projection lens 15, and the scattered light does not enter the projection lens 15. Therefore, the display system projected on the screen 100 by the projection lens 15 becomes a red display. Table 1(c) shows the ON/OFF conditions of the pixels when performing this red display.

In addition, for example, if the green pixel is in the ON state and the red pixel and the blue pixel are in the OFF state, that is, if a voltage difference is applied between the pixel electrode 28 and the common electrode 29 of the green pixel, the two pixels of the red pixel and the blue pixel When the electrode 28 and the common electrode 29 are formed at the same potential, as shown in FIG. 9, the long axis of the liquid crystal molecule 23C between the pixel electrode 28 and the common electrode 29 of the green pixel is aligned in the electric field direction. On the other hand, the liquid crystal molecules 23C between the two pixel electrodes 28 of the red pixel and the blue pixel and the common electrode 29 are randomly arranged.

At this time, incident light from the side of the common substrate 22 facing the green filter 27 -G passes through the liquid crystal layer 23. The incident light passing through the liquid crystal layer 23 is reflected by the reflective film 26 under the green filter 27-G, and is formed by the common substrate 22 so that the regular reflection light is emitted. The specular reflection light system emitted from the common substrate 22 passes through the scattered light elimination unit 14 and enters the projection lens 15. On the other hand, incident light from the side of the common substrate 22 facing the red filter 27-R and the blue filter 27-B is scattered in the liquid crystal layer 23 (scattered state). The incident light in the scattered state is reflected by the reflective film 26 and the scattered light is radiated from the common substrate 22. The scattered light system radiated from the common substrate 22 is eliminated by the scattered light elimination unit 14 and therefore does not enter the projection lens 15. Here, the regular reflection light passing through the green filter 27-G is incident on the projection lens 15, and the scattered light is not incident on the projection lens 15. Therefore, the display system projected on the screen 100 by the projection lens 15 becomes a green display. Table 1(d) shows the ON/OFF conditions of the pixels when performing this green display.

In addition, for example, if the blue pixel is in the ON state and the red pixel and the green pixel are in the OFF state, that is, if a voltage difference is applied between the pixel electrode 28 and the common electrode 29 of the blue pixel, the two pixels of the red pixel and the green pixel When the electrode 28 and the common electrode 29 are set at the same potential, as shown in FIG. 10, the long axis of the liquid crystal molecule 23C between the pixel electrode 28 and the common electrode 29 of the blue pixel is aligned in the electric field direction. On the other hand, the liquid crystal molecules 23C between the two pixel electrodes 28 of the red pixel and the green pixel and the common electrode 29 are randomly arranged.

At this time, incident light from the side of the common substrate 22 facing the blue filter 27-B passes through the liquid crystal layer 23. Through the liquid crystal layer 23 The reflected light is reflected by the reflective film 26 under the blue filter 27-B, and the common substrate 22 is formed so that regular reflection light is emitted. The specular reflection light system emitted from the common substrate 22 passes through the scattered light elimination unit 14 and enters the projection lens 15. On the other hand, incident light from the side of the common substrate 22 facing the red filter 27-R and the green filter 27-G is scattered in the liquid crystal layer 23 (scattered state). The incident light in the scattered state is reflected by the reflective film 26 and the scattered light is radiated from the common substrate 22. The scattered light system radiated from the common substrate 22 is eliminated by the scattered light elimination unit 14 and therefore does not enter the projection lens 15. Here, the regular reflection light passing through the blue filter 27-B enters the projection lens 15, and the scattered light does not enter the projection lens 15. Therefore, the display system projected to the screen 100 by the projection lens 15 becomes a blue display. Table 1(e) shows the ON/OFF conditions of the pixels when performing the blue display.

[1-3] Effects of the implementation form

According to the first embodiment, it is possible to provide a liquid crystal projector with high light utilization efficiency and improved image display characteristics.

The effects of the first embodiment will be described in detail below.

In this embodiment, since a polymer dispersion liquid layer or a polymer network liquid crystal is used that does not require the use of a polarizing plate, the heat generated by the polarizing plate can be eliminated and the temperature rise of the liquid crystal panel can be prevented. Thereby, it is possible to reduce the degradation of image characteristics caused by the temperature rise of the liquid crystal layer. In addition, since no polarizing plate is used, there is no light absorption due to the absorption axis of the polarizing plate. Therefore, the use efficiency of light irradiated by the light source can be improved.

In addition, if polymer dispersed liquid crystal or polymer mesh liquid crystal is used in the liquid crystal panel, the liquid crystal layer corresponding to the pixel in the OFF state generates scattered light. However, the scattered light is eliminated by the scattered light eliminating section, so there is no possibility that the scattered light will degrade the image display characteristics.

[2] The second embodiment

Next, the liquid crystal projector of the second embodiment will be described. In the first embodiment, the scattered light canceling unit 14 is arranged near the projection lens 15, but in the second embodiment, an example in which the scattered light canceling unit 31 is arranged near the liquid crystal panel 13 will be described. The other structure including the liquid crystal panel is the same as that of the aforementioned first embodiment. The following describes the differences from the first embodiment.

[2-1] The composition of the LCD projector

Fig. 11 is a diagram showing the configuration of a liquid crystal projector according to a second embodiment of the present invention. In the liquid crystal projector 30, on the optical path between the liquid crystal panel 13 and the projection lens 15, a scattered light elimination unit 31 is arranged directly above the liquid crystal panel 13.

[2-1-1] Configuration of scattered light elimination unit 31

The scattered light elimination unit 31 passes the light emitted by the condenser lens 12 to block the scattered light emitted by the liquid crystal panel 13 and transmits the reflected light emitted by the liquid crystal panel 13.

FIG. 12 is a diagram showing the structure of the scattered light elimination unit 31 in the second embodiment. The structure of the scattered light eliminating unit 31 is substantially the same as that of the scattered light eliminating unit 14 in the first embodiment described above. The scattered light elimination part 31 has a plurality of cylindrical members 31A. The cylindrical member 31A is tied to the The optical path direction of the reflected light reflected by the liquid crystal panel 13 is arranged in a plurality of orthogonal directions. The cylindrical direction of the cylindrical member 31A is parallel to the optical path direction of the reflected light from the liquid crystal panel 13. The inner surface and the outer surface of the cylindrical member 31A are black. The diameter of the cylinder and the length of the cylinder in the cylindrical member 31A of the scattered light elimination part 31 are appropriately changed in accordance with the situation of elimination of scattered light. The other structure is the same as that of the scattered light elimination unit 14 in the first embodiment.

[2-1-2] Configuration of modified example of scattered light elimination unit 31

The scattered light elimination unit 31 of the modification of the second embodiment has the following configuration. This modified example is referred to as the scattered light elimination part 31B.

FIG. 13 and FIG. 14 are diagrams showing the structure of the scattered light elimination unit 31B. FIG. 13 is a plan view of the scattered light elimination part 31B, and FIG. 14 is a perspective view of the scattered light elimination part 31B.

As shown in FIG. 13 and FIG. 14, the scattered light elimination part 31B has a structure in which the plate-shaped member (or thin-plate-shaped member) 31C is arrange|positioned in a lattice. A plurality of plate-shaped members 31C are arranged in a direction orthogonal to the optical path direction of the reflected light from the liquid crystal panel 13. The plate-shaped member 31C is arranged so that its plate surface becomes parallel to the optical path direction of the reflected light.

The plate surface of the flat member 31C has a black color. Therefore, light systems that are not parallel to the plate surface of the plate-shaped member 31C are absorbed by the plate surface. On the other hand, the light system parallel to the plate surface of the plate-shaped member 31C passes through the plate-shaped member 31C. That is, the scattered light incident on the scattered light eliminating portion 31B is incident on the plate surface of the flat member 31C, and is absorbed by the plate surface. Close. On the other hand, the reflected light incident on the scattered light elimination portion 31B does not reach the plate surface of the plate-shaped member 31C, but advances parallel to the plate surface and passes between the plate-shaped members 31C.

For the scattered light elimination part 31B, for example, a louver film in which a plurality of flat members are arranged in an orthogonal manner can be used.

[2-2] Effects of the second embodiment

According to the second embodiment, it is possible to provide a liquid crystal projector with high light utilization efficiency and improved image display characteristics. The other effects and functions are the same as in the first embodiment described above.

[3] Other

The present invention is not limited to the above-mentioned embodiment, and the constituent elements can be modified and embodied within a range that does not deviate from the gist. In addition, the above-mentioned embodiment includes inventions of various stages, and various inventions can be constituted by an appropriate combination of a plurality of components disclosed in one embodiment or an appropriate combination of components disclosed in different embodiments. For example, even if several constituent elements are deleted from all the constituent elements disclosed in the embodiment, the problem to be solved by the invention can be solved and the effect of the invention can be obtained, the embodiment in which these constituent elements have been deleted can be extracted as an invention .

10‧‧‧LCD projector

11‧‧‧Light source

12‧‧‧Condenser lens

13‧‧‧LCD Panel

14‧‧‧Scattered light elimination part

15‧‧‧Projection lens

16‧‧‧Drive circuit

17‧‧‧Control circuit

100‧‧‧Screen

Claims (9)

A liquid crystal projector, which is provided with: a light source, which generates light; a condenser lens, which is arranged on the optical path of the aforementioned light; a liquid crystal panel, which has a polymer dispersed liquid crystal layer or a polymer mesh liquid crystal Any one of the layers reflects the light emitted by the aforementioned condenser lens corresponding to the display pattern and emits reflected light; the scattered light elimination part eliminates the scattered light emitted by the aforementioned liquid crystal panel; and the projection lens, which will pass through the aforementioned scattering The reflected light of the light canceling portion is projected, the scattered light canceling portion has a cylindrical member, and the cylindrical direction of the cylindrical member is parallel to the optical path direction of the reflected light reflected on the liquid crystal panel, and the liquid crystal panel The system is provided with: a first substrate; a second substrate, which is arranged on the first substrate; any one of the polymer dispersed liquid crystal layer or the polymer network liquid crystal layer, which is provided on the first Between the substrate and the second substrate; the switching element is provided on the first substrate; the pixel electrode is electrically connected to the switching element; the color filter is provided corresponding to the pixel electrode The first substrate; the reflective film, which is provided on the first substrate and the color filter Between the sheets; and the common electrode, which is provided on the aforementioned second substrate. The liquid crystal projector according to claim 1, wherein the scattered light elimination unit is arranged on the optical path of the reflected light between the liquid crystal panel and the projection lens, and eliminates the scattered light incident on the projection lens. The liquid crystal projector according to claim 1, wherein the scattered light removing unit is disposed on the liquid crystal panel, and passes the light emitted by the condenser lens to remove the scattered light from the liquid crystal panel. The liquid crystal projector according to claim 1, wherein the cylindrical member has a black cylindrical surface. The liquid crystal projector of claim 1, wherein the pixel electrode includes a first pixel electrode and a second pixel electrode, and when a voltage is applied between the first pixel electrode and the common electrode, the The light system in the area of the first pixel electrode is reflected to form the reflected light, and when no voltage is applied between the second pixel electrode and the common electrode, the light system enters the area corresponding to the second pixel electrode It is scattered to form the aforementioned scattered light. A liquid crystal projector, which is provided with: a light source, which generates light; a condenser lens, which is arranged on the optical path of the aforementioned light; a liquid crystal panel, which has a polymer dispersed liquid crystal layer or a polymer mesh liquid crystal Any one of the layers reflects the light emitted by the aforementioned condenser lens corresponding to the display pattern and emits reflected light; the scattered light elimination part is the diffuser emitted by the aforementioned liquid crystal panel And a projection lens for projecting the reflected light passing through the scattered light canceling portion, the scattered light canceling portion having plate-shaped members arranged in a grid, and the plate surface direction of the plate-shaped member is relative to The optical path directions of the reflected light reflected on the liquid crystal panel are parallel, and the liquid crystal panel is provided with: a first substrate; a second substrate arranged on the first substrate; the polymer dispersed liquid crystal layer or Any one of the aforementioned polymer network type liquid crystal layer, which is provided between the aforementioned first substrate and the aforementioned second substrate; a switching element, which is provided on the aforementioned first substrate; a pixel electrode, which is similar to the aforementioned switching element For electrical connection; a color filter, which is provided on the first substrate corresponding to the pixel electrode; a reflective film, which is provided between the first substrate and the color filter; and a common electrode, which It is set on the aforementioned second substrate. The liquid crystal projector according to claim 6, wherein the scattered light elimination part is a louver film. The liquid crystal projector according to claim 6, wherein the flat member has a black surface. A liquid crystal projector according to claim 7, wherein the flat member has a black surface.

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