Image display device and electronic device

Abstract

This image display device includes a first display panel and second display panel in which the transmissivity and reflectivity of light are controlled on the basis of an image signal, and a light radiation unit that irradiates the first display panel and the second display panel with light, the first display panel and the second display panel being driven in sequence by the image signal in accordance with each of a plurality of colored lights, and switching of the image signal for driving the first display panel and / or the second display panel being performed during a period in which the other of the first display panel and the second display panel is driven by the image signal in accordance with any one colored light among the plurality of colored lights.

Description

[Technical field]

[0001] The present disclosure relates to an image display device and an electronic device. [Background technology]

[0002] In a so-called field sequential color image display device, a color image is separated based on color components, and the separated red, green, and blue images are sequentially displayed at high speed. This type of image display device has the advantage that the number of display panels can be reduced and the scale of the optical system can be made smaller.

[0003] On the other hand, the field sequential color method performs an operation of sequentially switching the display colors of an image, which causes a phenomenon called color breakup. For example, when an object moves within the display screen and the viewpoint of the image observer moves, a phenomenon occurs in which colors are perceived as separated. Color breakup can be improved by speeding up the switching of images. For this reason, an image display device has been proposed that uses, for example, two display panels to speed up the switching of images (see, for example, Reference 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2003-241164 A Summary of the Invention [Problem to be solved by the invention]

[0005] For example, the image display device disclosed in the cited document 1 performs an operation of displaying an image based on one display panel, and then displaying an image based on the other display panel. Therefore, only one of the display panels contributes to the display at any given time. For this reason, the image display device can only ensure the same brightness as an image display device using one display panel.

[0006] In view of the above, an object of the present disclosure is to provide an image display device capable of improving color breaking and also improving luminance, and an electronic device including such an image display device. [Means for solving the problem]

[0007] In order to achieve the above object, an image display device according to the present disclosure comprises: A first display panel and a second display panel whose light transmittance or reflectance is controlled based on an image signal; and a light irradiation unit that irradiates light onto the first display panel and the second display panel; Contains The first display panel and the second display panel are sequentially driven by image signals corresponding to the respective colors of light, During a period in which one of the first display panel and the second display panel is driven by an image signal corresponding to one of the plurality of color lights, an image signal for driving the other display panel is switched. An image display device.

[0008] In order to achieve the above object, an electronic device according to the present disclosure includes: A first display panel and a second display panel whose light transmittance or reflectance is controlled based on an image signal; and a light irradiation unit that irradiates light onto the first display panel and the second display panel; Contains The first display panel and the second display panel are sequentially driven by image signals corresponding to the respective colors of light, During a period in which one of the first display panel and the second display panel is driven by an image signal corresponding to one of the plurality of color lights, an image signal for driving the other display panel is switched. The electronic device is equipped with an image display device. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram for explaining the configuration of an image display device according to a first embodiment of the present disclosure. [Diagram 2] Fig. 2 is a diagram for explaining the operation of the image display device. Fig. 2A is a schematic timing chart for explaining the relationship between a first image displayed based on the operation of a first display panel etc. and a second image displayed based on the operation of a second display panel etc. Fig. 2B is a schematic timing chart for explaining the relationship between the drive timing of the first display panel and the switching timing of the light irradiated to the first display panel, and the relationship between the drive timing of the second display panel and the switching timing of the light irradiated to the second display panel. [Diagram 3] FIG. 3 is a schematic diagram for explaining the operation of the image display device in the first half of the period TP11 shown in FIG. 2A. [Figure 4] FIG. 4 is a schematic diagram for explaining the operation of the image display device in the latter half of the period TP11 shown in FIG. 2A. [Diagram 5] FIG. 5 is a schematic diagram for explaining the operation of the image display device in the first half of the period TP12 shown in FIG. 2A. [Figure 6] FIG. 6 is a schematic diagram for explaining the operation of the image display device in the latter half of the period TP12 shown in FIG. 2A. [Figure 7] FIG. 7 is a schematic diagram for explaining the operation of the image display device in the first half of the period TP13 shown in FIG. 2A. [Figure 8] FIG. 8 is a schematic diagram for explaining the operation of the image display device in the latter half of the period TP13 shown in FIG. 2A. [Figure 9] FIG. 9 is a schematic timing chart for explaining a driving example in which a black display is inserted. [Figure 10] FIG. 10 is a schematic diagram for explaining the configuration of an image display device according to a second embodiment of the present disclosure. [Figure 11] FIG. 11 is a schematic diagram for explaining the operation of the image display device in the first half of the period TP11 shown in FIG. 2A. [Figure 12]FIG. 12 is a schematic diagram for explaining the operation of the image display device in the latter half of the period TP11 shown in FIG. 2A. [Figure 13] FIG. 13 is a schematic diagram for explaining the operation of the image display device in the first half of the period TP12 shown in FIG. 2A. [Figure 14] FIG. 14 is a schematic diagram for explaining the operation of the image display device in the latter half of the period TP12 shown in FIG. 2A. [Figure 15] FIG. 15 is a schematic diagram for explaining the operation of the image display device in the first half of the period TP13 shown in FIG. 2A. [Figure 16] FIG. 16 is a schematic diagram for explaining the operation of the image display device in the latter half of the period TP13 shown in FIG. 2A. [Figure 17] FIG. 17 is a schematic timing chart for explaining a driving example in which the display period of a predetermined display color is set long. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the present disclosure will be described based on the 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 examples. In the following description, the same elements or elements having the same functions will be designated by the same reference numerals, and duplicated descriptions will be omitted. The description will be given in the following order. 1. General Description of Image Display Device and Electronic Device According to the Present Disclosure 2. First embodiment 3. Second embodiment 4.Other 5. Configuration of the Disclosure

[0011] [General Description of Image Display Device and Electronic Device According to the Present Disclosure] In the image display device according to the present disclosure, or in the image display device used in the electronic device according to the present disclosure (hereinafter, these may be simply referred to as the image display device according to the present disclosure), the light irradiation unit irradiates the first display panel with color light corresponding to an image signal for driving the first display panel, and irradiates the second display panel with color light corresponding to an image signal for driving the second display panel; It can be configured as follows.

[0012] In this case, the light irradiation unit can be configured to stop irradiating light to the first display panel and the second display panel during a predetermined period that includes the time when the image signal driving the first display panel is switched, and during a predetermined period that includes the time when the image signal driving the second display panel is switched.

[0013] By stopping the light irradiation, the display image is made to display black at a predetermined interval. This can reduce color mixing that occurs when the screen is switched, and improve the color gamut of the display image. In some cases, the frequency of stopping the light irradiation can be reduced. For example, the first display panel may be configured to stop the light irradiation only during a predetermined period including when the image signal that drives the first panel is switched, and the second display panel may be configured to stop the light irradiation only during a predetermined period including when the image signal that drives the second panel is switched.

[0014] In the image display device of the present disclosure including the various preferred configurations described above, the first display panel and the second display panel are sequentially driven by image signals corresponding to red light, green light, and blue light, respectively; the light irradiation unit irradiates the first display panel with color light corresponding to an image signal for driving the first display panel, and irradiates the second display panel with color light corresponding to an image signal for driving the second display panel; It can be configured as follows.

[0015] The image display device of the present disclosure including the various preferred configurations described above may further include a projection unit that superimposes and projects a first image obtained by the first display panel and a second image obtained by the second display panel. The configuration of the projection unit is not particularly limited, and may be configured using well-known optical members such as lenses and prisms.

[0016] The image display device of the present disclosure including the various preferable configurations described above further includes a polarizing beam splitter having a first surface onto which light from the light irradiation unit is incident, second and third surfaces from which the incident light exits, and a fourth surface from which light via the first display panel and light via the second display panel exit, The first display panel is disposed so as to face the second surface, The second display panel is disposed so as to face the third surface. It can be configured as follows.

[0017] In this case, a configuration can be used in which a predetermined wave plate is disposed between the second surface of the polarizing beam splitter and the first display panel, and between the third surface of the polarizing beam splitter and the second display panel.

[0018] In this case, the light irradiation unit irradiates the first surface of the polarizing beam splitter with light in the first polarization state and light in the second polarization state, Light in the first polarization state exits the second surface of the polarizing beam splitter, Light having a second polarization state exits from a third surface of the polarizing beam splitter. It can be configured as follows.

[0019] In the image display device of the present disclosure having the above-mentioned preferable configuration, the light irradiation section may be configured to include a light source capable of emitting a plurality of color lights.

[0020] In this case, the light irradiation unit may include a first light source for irradiating light in a first polarization state and a second light source for irradiating light in a second polarization state. The light irradiation unit may further include a polarizing beam splitter for light irradiation having a first entrance surface into which light from the first light source is incident, a second entrance surface into which light from the second light source is incident, and an exit surface from which the light from the first light source and the second light source exit.

[0021] Alternatively, the light irradiation section may include a polarization adjustment element capable of switching light between a first polarization state and a second polarization state for each of a plurality of color lights.

[0022] As the display panel used in the image display device of the present disclosure including the preferred configuration described above (hereinafter, these may be simply referred to as the present disclosure), well-known display panels such as transmissive or reflective liquid crystal display panels and display panels using LCOS technology (Liquid Crystal On Silicon, LCOS is a registered trademark) can be used.

[0023] The polarizing beam splitter used in this disclosure has a function of splitting a light beam into two. The polarizing beam splitter is composed of a prism made of an optical material such as glass. In the case of a cube type, the slant faces of two right-angle prisms are joined together, and an optical thin film is formed on the slant face of one of the prisms to split the light into approximately half and half.

[0024] The light source used in the light irradiation unit is not particularly limited, and well-known light sources such as light-emitting diodes and lasers can be used. Since it is necessary to switch the light color quickly, it is basically preferable to use a light source made by semiconductor technology.

[0025] Examples of electronic devices equipped with an image display device according to the present disclosure include projectors used in display systems for large conference rooms, entertainment, and the like.

[0026] In the various conditions in this specification, the existence of various variations occurring in design or manufacturing is permitted. Also, the figures used in the following explanation are schematic. For example, Figure 1 described later shows the structure of an image display device, but does not show the ratio of width, height, thickness, etc.

[0027] [First embodiment] The first embodiment relates to an image display device according to the present disclosure.

[0028] FIG. 1 is a schematic diagram for explaining the configuration of an image display device according to a first embodiment of the present disclosure.

[0029] The image display device 1 includes a first display panel 21 and a second display panel 22, the light transmittance or reflectance of which is controlled based on an image signal, and a light irradiation unit 10 that irradiates the first display panel 21 and the second display panel 22 with light. The image display device 1 further includes a projection unit 30 that superimposes a first image obtained by the first display panel 21 and a second image obtained by the second display panel 22 and projects them. The superimposed image is projected onto a screen 40 that is installed on, for example, a wall surface. The operation of the entire image display device 1 is controlled by, for example, a control circuit (not shown) or the like.

[0030] As will be described in detail later with reference to Figures 2 to 8, the first display panel 21 and the second display panel 22 are sequentially driven by image signals corresponding to each of the multiple color lights. Then, during a period in which either the first display panel 21 or the second display panel 22 is driven by an image signal corresponding to any one of the multiple color lights, the image signal driving the other display panel is switched. Also, the light irradiating unit irradiates the first display panel 21 with color light corresponding to the image signal driving the first display panel 21, and irradiates the second display panel 22 with color light corresponding to the image signal driving the second display panel 22.

[0031] More specifically, the first display panel 21 and the second display panel 22 are sequentially driven by image signals corresponding to red light, green light, and blue light, respectively. The light emitting unit irradiates the first display panel 21 with color light corresponding to the image signal for driving the first display panel 21, and irradiates the second display panel 22 with color light corresponding to the image signal for driving the second display panel 22.

[0032] Continuing on, the configuration of the image display device 1 will be described. The image display device 1 further includes a polarizing beam splitter 25 having a first surface (indicated by reference symbol 25A) into which light from the light irradiation unit 10 is incident, a second surface (indicated by reference symbol 25B) and a third surface (indicated by reference symbol 25C) from which the incident light exits, and a fourth surface (indicated by reference symbol 25D) from which the light via the first display panel 21 and the light via the second display panel 22 exit. Reference symbol 25E indicates an interface formed by an optical thin film or the like in the polarizing beam splitter 25.

[0033] The first display panel 21 is disposed so as to face the second surface 25B, and the second display panel 22 is disposed so as to face the third surface 25C. The first display panel 21 and the second display panel 22 are each formed of a reflective display panel such as an LCOS.

[0034] Between the second surface 25B of the polarizing beam splitter 25 and the first display panel 21, and between the third surface 25C of the polarizing beam splitter 25 and the second display panel 22, λ / 4 wave plates 23 and 24 are disposed as predetermined wave plates. The projection unit 30 is disposed on the fourth surface side of the polarizing beam splitter 25.

[0035] The light irradiation unit 10 irradiates the first surface 25A of the polarizing beam splitter 25 with light in a first polarization state (hereinafter, sometimes referred to as P light) and light in a second polarization state (hereinafter, sometimes referred to as S light). The light in the first polarization state is reflected by the interface 25E, and the light in the second polarization state travels straight without being reflected. Therefore, the light in the first polarization state (P light) is emitted from the second surface 25B of the polarizing beam splitter 25, and the light in the second polarization state (S light) is emitted from the third surface 25C of the polarizing beam splitter 25.

[0036] The light emitted from the second surface 25B of the polarizing beam splitter 25 reaches the first display panel 21 through the wave plate 23. The first display panel 21 acts as a light valve, and the light whose luminance is controlled according to the video signal is incident on the second surface 25B of the polarizing beam splitter 25 through the wave plate 23. This reflected light travels straight through the polarizing beam splitter 25 and is emitted from the fourth surface 25D to form a first image. The light emitted from the third surface 25C of the polarizing beam splitter 25 reaches the second display panel 22 through the wave plate 24. The second display panel 22 acts as a light valve, and the light whose luminance is controlled according to the video signal is incident on the third surface 25C of the polarizing beam splitter 25 through the wave plate 24. This reflected light is reflected by the interface 25E and is emitted from the fourth surface 25D to form a second image. Therefore, an image in which the first image and the second image are superimposed is displayed on the screen 40.

[0037] The configuration of the light irradiation unit 10 will now be described. The light irradiation unit 10 includes a light source capable of emitting a plurality of color lights. More specifically, the light irradiation unit 10 includes a first light source 11 for emitting light in a first polarization state and a second light source 12 for emitting light in a second polarization state. The first light source 11 includes a red light source 11. R , green light source 11 G , blue light source 11 B Similarly, the second light source 12 is composed of a red light source 12 R , green light source 12 G , blue light source 12 B It is composed of:

[0038] Red light source 11 constituting the first light source 11 R , green light source 11 G , and blue light source 11 B Similarly, the red light source 12 constituting the second light source 12 is configured to be capable of emitting / not emitting light individually. R , green light source 12 G , blue light source 12 BEach of the light emitting devices is configured so that it can be individually controlled to emit light or not. These devices are configured, for example, of semiconductor lasers or light emitting diodes.

[0039] Furthermore, the light irradiation unit 10 further includes a polarizing beam splitter 15 for light irradiation, which has a first incident surface 15A on which the light from the first light source 11 is incident, a second incident surface 15D on which the light from the second light source is incident, and an exit surface 15C on which the light from the first light source and the second light source is exited. The polarizing beam splitter 15 for light irradiation further has a surface 15B, which is not involved in the light irradiation. Also, the reference symbol 15E indicates an interface formed by an optical thin film or the like in the polarizing beam splitter 15 for light irradiation. Between the first light source 11 and the polarizing beam splitter 15 for light irradiation, a polarizing plate 13 that puts the irradiated light into a first polarization state is disposed. Also, between the second light source 12 and the polarizing beam splitter 15 for light irradiation, a polarizing plate 14 that puts the irradiated light into a second polarization state is disposed.

[0040] The light (P light) of the first light source 11 transmitted through the polarizing plate 13 travels straight through the light irradiation polarizing beam splitter 15 and is emitted from the emission surface 15C. On the other hand, the light (S light) of the second light source 12 transmitted through the polarizing plate 14 is reflected by the interface 15E and is emitted from the emission surface 15C.

[0041] Above is a description of the configuration of the image display device 1. Next, the operation of the image display device 1 will be described in detail.

[0042] Fig. 2 is a diagram for explaining the operation of the image display device. Fig. 2A is a schematic timing chart for explaining the relationship between a first image displayed based on the operation of a first display panel etc. and a second image displayed based on the operation of a second display panel etc. Fig. 2B is a schematic timing chart for explaining the relationship between the drive timing of the first display panel and the switching timing of the light irradiated to the first display panel, and the relationship between the drive timing of the second display panel and the switching timing of the light irradiated to the second display panel.

[0043] In the image display device 1, the frame frequency is set to, for example, 60 Hz. As shown in Fig. 2A, one frame is composed of six subframes. Basically, each subframe is composed of a repetition of a red image (represented by the symbol RP), a green image (represented by the symbol GP), and a blue image (represented by the symbol BP). The subframe frequency is 360 Hz. The display periods of the red image, green image, and blue image are all the same length.

[0044] As shown in Fig. 2B, the first display panel 21 and the second display panel 22 are sequentially driven by image signals corresponding to each of the plurality of color lights. Then, during a period in which either the first display panel 21 or the second display panel 22 is driven by an image signal corresponding to any one of the plurality of color lights, the image signal driving the other display panel is switched. Also, the light irradiation unit 10 irradiates the first display panel 21 with color light corresponding to the image signal driving the first display panel 21, and irradiates the second display panel 22 with color light corresponding to the image signal driving the second display panel 22.

[0045] In the example shown in Fig. 2B, the first display panel 21 and the second display panel 22 are driven so that their display timings are shifted by approximately half a subframe. Each display panel is driven so that the display colors do not overlap at a certain timing. Then, both the first display panel 21 and the second display panel 22 are continuously irradiated with colored light according to an image signal.

[0046] Hereinafter, the operation for each period based on the subframe of the first image shown in FIG. 2A will be described in detail with reference to the drawings.

[0047] [Period TP 11 ] (See Figure 3) The first display panel 21 is driven by a red image signal in the current frame. The second display panel 22 is driven by a green image signal in the previous frame. RIn the second light source 12, only the green light source 12 is in the light emitting state. G Only the first image is illuminated. The first image is a red image, and the second image is a green image.

[0048] [Period TP 11 ] (See Figure 4) The first display panel 21 continues to be driven by the red image signal in the current frame. The image signal to the second display panel 22 is switched, and the second display panel 22 is driven by the blue image signal in the current frame. The first light source 11 is the red light source 11. R The second light source 12 continues to emit light only from the blue light source 12. B The first image is a red image, and the second image is a blue image.

[0049] [Period TP 12 ] (See Figure 5) The second display panel 22 continues to be driven by the blue image signal in the current frame. The image signal to the first display panel 21 is switched, and the first display panel 21 is driven by the green image signal in the current frame. The first light source 11 is the green light source 11. G The second light source 12 is in a light emitting state, and the blue light source 12 G The first image will be a green image and the second image will be a blue image.

[0050] [Period TP 12 ] (See Figure 6) The first display panel 21 continues to be driven by the green image signal in the current frame. The image signal to the second display panel 22 is switched, and the second display panel 22 is driven by the red image signal in the current frame. The first light source 11 is changed to the green light source 11. G The second light source 12 continues to emit light only from the red light source 12. R The first image is a green image and the second image is a red image.

[0051] [Period TP 13 ] (See Figure 7) The second display panel 22 continues to be driven by the red image signal in the current frame. The image signal to the first display panel 21 is switched, and the first display panel 21 is driven by the blue image signal in the current frame. The first light source 11 is a blue light source 11. B The second light source 12 is in a light emitting state only. R The first image will be a blue image and the second image will be a red image.

[0052] [Period TP 13 ] (see Figure 8) The first display panel 21 continues to be driven by the blue image signal in the current frame. The image signal to the second display panel 22 is switched, and the second display panel 22 is driven by the green image signal in the current frame. The first light source 11 is a blue light source 11. B The second light source 12 continues to emit light only from the green light source 12. G The first image is a blue image and the second image is a green image.

[0053] [Period TP 14 ] or [Period TP 16 The operation of the period TP 11 ] or [Period TP 13 ], so the explanation will be omitted.

[0054] As described above, the image in which the first image and the second image are superimposed changes display color at a high frequency (720 Hz in the above example) that exceeds the frame frequency, so color breakup can be improved. Also, since colored light corresponding to the image signal is continuously irradiated onto both the first display panel 21 and the second display panel 22, brightness can also be improved.

[0055] In some cases, the light irradiation unit may be configured to stop irradiating the first display panel 21 and the second display panel with light during a predetermined period including when the image signal driving the first display panel 21 is switched and during a predetermined period including when the image signal driving the second display panel is switched. By stopping the light irradiation, the display image is made to be in a black display state for a predetermined interval.

[0056] FIG. 9 is a schematic timing chart for explaining a driving example in which a black display is inserted.

[0057] By inserting the black display, it is possible to reduce color mixing caused by screen switching, etc., and therefore improve the color gamut of the displayed image. In some cases, it is also possible to configure the display device so that the frequency of stopping the light irradiation is reduced. For example, the first display panel may be configured to stop the light irradiation only during a predetermined period including the time when the image signal driving the first display panel is switched, and the second display panel may be configured to stop the light irradiation only during a predetermined period including the time when the image signal driving the second display panel is switched.

[0058] [Second embodiment] The second embodiment also relates to an image display device according to the present disclosure.

[0059] The image display device according to the second embodiment has the same configuration as the image display device according to the first embodiment, except for the configuration of the light irradiation unit.

[0060] FIG. 10 is a schematic diagram for explaining the configuration of an image display device according to a second embodiment of the present disclosure.

[0061] The light emitting unit 110 in the image display device 2 also includes a light source 11 capable of emitting a plurality of color lights. The light source 11 has a configuration similar to that of the first light source in the first embodiment, and includes a red light source 11. R , green light source 11 G , blue light source 11 BThe light irradiation unit 110 further includes a polarization adjustment element 16 capable of switching the light of each of the plurality of color lights between a first polarization state and a second polarization state. The polarization adjustment element 16 is R , green light source 11 G , blue light source 11 B The above-mentioned reference numbers are provided individually in correspondence with the above-mentioned respective items.

[0062] The polarizing plate 13 is disposed so as to change the light of the light source 11 into, for example, a first polarization state. The polarization adjustment element 16 is set so as to be controllable as to whether it transmits the light in the first polarization state as is, or transmits the light in the first polarization state after converting it into a second polarization state.

[0063] In the image display device 2, as shown in Fig. 2 referred to in the first embodiment, the first display panel 21 and the second display panel 22 are sequentially driven by image signals corresponding to each of the plurality of color lights. Then, during a period in which either the first display panel 21 or the second display panel 22 is driven by an image signal corresponding to any one of the plurality of color lights, the image signal driving the other display panel is switched. Also, the light irradiation unit 110 irradiates the first display panel 21 with color light corresponding to the image signal driving the first display panel 21, and irradiates the second display panel 22 with color light corresponding to the image signal driving the second display panel 22.

[0064] Hereinafter, the operation of the image display device 2 for each period based on the subframe of the first image shown in FIG. 2A will be described in detail with reference to the drawings.

[0065] [Period TP 11 ] (See Figure 11) The first display panel 21 is driven by a red image signal in the current frame. The second display panel 22 is driven by a green image signal in the previous frame. R and green light source 11 GThe red light is kept in the first polarization state and the green light is set to the second polarization state by the polarization adjustment element 16. The first image is a red image and the second image is a green image.

[0066] [Period TP 11 ] (See Figure 12) The first display panel 21 continues to be driven by the red image signal in the current frame. The image signal to the second display panel 22 is switched, and the second display panel 22 is driven by the blue image signal in the current frame. R and blue light source 11 B The red light is kept in the first polarization state and the blue light is set to the second polarization state by the polarization adjustment element 16. The first image is a red image and the second image is a blue image.

[0067] [Period TP 12 ] (See Figure 13) The second display panel 22 continues to be driven by the blue image signal in the current frame. The image signal to the first display panel 21 is switched, and the first display panel 21 is driven by the green image signal in the current frame. G and blue light source 11 B The green light is kept in the first polarization state and the blue light is set to the second polarization state by the polarization adjustment element 16. The first image is a green image and the second image is a blue image.

[0068] [Period TP 12 ] (See Figure 14) The first display panel 21 continues to be driven by the green image signal in the current frame. The image signal to the second display panel 22 is switched, and the second display panel 22 is driven by the red image signal in the current frame. R and green light source 11 GThe green light is kept in the first polarization state and the red light is set to the second polarization state by the polarization adjustment element 16. The first image is a green image and the second image is a red image.

[0069] [Period TP 13 First half of ] (see Figure 15) The second display panel 22 continues to be driven by the red image signal in the current frame. The image signal to the first display panel 21 is switched, and the first display panel 21 is driven by the blue image signal in the current frame. R and blue light source 11 B The blue light is kept in the first polarization state and the red light is set to the second polarization state by the polarization adjustment element 16. The first image is a blue image and the second image is a red image.

[0070] [Period TP 13 ] (See Figure 16) The first display panel 21 continues to be driven by the blue image signal in the current frame. The image signal to the second display panel 22 is switched, and the second display panel 22 is driven by the green image signal in the current frame. G and blue light source 11 B The blue light is kept in the first polarization state and the green light is set to the second polarization state by the polarization adjustment element 16. The first image is a blue image and the second image is a green image.

[0071] [Period TP 14 ] or [Period TP 16 The operation of the period TP 11 ] or [Period TP 13 ], so the explanation will be omitted.

[0072] As described above, in the image display device according to the second embodiment, the image in which the first image and the second image are superimposed changes display color at a frequency higher than the frame frequency, so that color breakup can be improved. Moreover, since colored light corresponding to the image signal is continuously irradiated on both the first display panel 21 and the second display panel 22, brightness can also be improved.

[0073] [others] In the above-mentioned various image display devices, the lengths of the display periods of the red, green, and blue images are all the same. Since the reflectance of light also changes depending on the wavelength, it may be desirable to secure a relatively long display period for an image of a certain color in some cases. In such a case, a driving method that allows different subframe frequencies or different duties for the display periods may be used for the first and second display panels.

[0074] The example shown in FIG. 17 shows a driving example in which a red image is displayed continuously for the entire period of one frame. Normally, the reflectance decreases as the wavelength of light becomes longer. By displaying a red image continuously, the decrease in luminance caused by the decrease in reflectance is reduced. In addition, the image can be displayed while making the most of the capabilities of the light source.

[0075] [Configuration of this disclosure] The present disclosure may also be configured as follows.

[0076] [A1] A first display panel and a second display panel whose light transmittance or reflectance is controlled based on an image signal; and a light irradiation unit that irradiates light onto the first display panel and the second display panel; Contains The first display panel and the second display panel are sequentially driven by image signals corresponding to the respective colors of light, During a period in which one of the first display panel and the second display panel is driven by an image signal corresponding to one of the plurality of color lights, an image signal for driving the other display panel is switched. Image display device. [A2] the light irradiation unit irradiates the first display panel with color light corresponding to an image signal for driving the first display panel, and irradiates the second display panel with color light corresponding to an image signal for driving the second display panel; The image display device according to the above [A1]. [A3] the light irradiation unit stops emitting light to the first display panel and the second display panel during a predetermined period including a time when an image signal for driving the first display panel is switched and during a predetermined period including a time when an image signal for driving the second display panel is switched; The image display device according to the above [A2]. [A4] the first display panel and the second display panel are sequentially driven by image signals corresponding to red light, green light, and blue light, respectively; the light irradiation unit irradiates the first display panel with color light corresponding to an image signal for driving the first display panel, and irradiates the second display panel with color light corresponding to an image signal for driving the second display panel; The image display device according to any one of the above [A1] to [A3]. [A5] The image display device further includes a projection unit that projects a first image obtained by the first display panel and a second image obtained by the second display panel in a superimposed manner. The image display device according to any one of the above [A1] to [A4]. [A6] the image display device further includes a polarizing beam splitter having a first surface onto which light from the light irradiation unit is incident, second and third surfaces from which the incident light exits, and a fourth surface from which the light passing through the first display panel and the light passing through the second display panel exit; The first display panel is disposed so as to face the second surface, The second display panel is disposed so as to face the third surface. The image display device according to any one of the above [A1] to [A5]. [A7] a predetermined wave plate is disposed between the second surface of the polarizing beam splitter and the first display panel, and between the third surface of the polarizing beam splitter and the second display panel; The image display device according to the above [A6]. [A8] the light irradiation unit irradiates the first surface of the polarizing beam splitter with light in the first polarization state and light in the second polarization state; Light in the first polarization state exits the second surface of the polarizing beam splitter, Light having a second polarization state exits from a third surface of the polarizing beam splitter. The image display device according to the above [A6] or [A7]. [A9] The light emitting unit is provided with a light source capable of emitting a plurality of color lights. The image display device according to the above [A8]. [A10] The light emitting section includes a first light source for emitting light in a first polarization state, and a second light source for emitting light in a second polarization state. The image display device according to the above [A9]. [A11] the light irradiation unit further includes a polarizing beam splitter for light irradiation having a first incident surface into which light from the first light source is incident, a second incident surface into which light from the second light source is incident, and an exit surface from which the light from the first light source and the light from the second light source exit. The image display device according to the above [A10]. [A12] The light irradiation unit includes a polarization adjustment element capable of switching the light between a first polarization state and a second polarization state for each of the plurality of color lights. The image display device according to the above [A9].

[0077] [B1] A first display panel and a second display panel whose light transmittance or reflectance is controlled based on an image signal; and a light irradiation unit that irradiates light onto the first display panel and the second display panel; Contains The first display panel and the second display panel are sequentially driven by image signals corresponding to the respective colors of light, During a period in which one of the first display panel and the second display panel is driven by an image signal corresponding to one of the plurality of color lights, an image signal for driving the other display panel is switched. An electronic device equipped with an image display device. [B2] the light irradiation unit irradiates the first display panel with color light corresponding to an image signal for driving the first display panel, and irradiates the second display panel with color light corresponding to an image signal for driving the second display panel; The electronic device described in [B1] above. [B3] the light irradiation unit stops emitting light to the first display panel and the second display panel during a predetermined period including a time when an image signal for driving the first display panel is switched and during a predetermined period including a time when an image signal for driving the second display panel is switched; The electronic device described in [B2] above. [B4] the first display panel and the second display panel are sequentially driven by image signals corresponding to red light, green light, and blue light, respectively; the light irradiation unit irradiates the first display panel with color light corresponding to an image signal for driving the first display panel, and irradiates the second display panel with color light corresponding to an image signal for driving the second display panel; The electronic device according to any one of [B1] to [B3] above. [B5] The electronic device further includes a projection unit that projects a first image obtained by the first display panel and a second image obtained by the second display panel in a superimposed manner. An electronic device according to any one of [B1] to [B4] above. [B6] the electronic device further includes a polarizing beam splitter having a first surface onto which light from the light irradiation unit is incident, second and third surfaces from which the incident light exits, and a fourth surface from which the light passing through the first display panel and the light passing through the second display panel exit; The first display panel is disposed so as to face the second surface, The second display panel is disposed so as to face the third surface. An electronic device according to any one of [B1] to [B5] above. [B7] a predetermined wave plate is disposed between the second surface of the polarizing beam splitter and the first display panel, and between the third surface of the polarizing beam splitter and the second display panel; The electronic device described in [B6] above. [B8] the light irradiation unit irradiates the first surface of the polarizing beam splitter with light in the first polarization state and light in the second polarization state; Light in the first polarization state exits the second surface of the polarizing beam splitter, Light having a second polarization state exits from a third surface of the polarizing beam splitter. The electronic device described in [B6] or [B7] above. [B9] The light emitting unit is provided with a light source capable of emitting a plurality of color lights. The electronic device described in [B8] above. [B10] The light emitting section includes a first light source for emitting light in a first polarization state, and a second light source for emitting light in a second polarization state. The electronic device described in [B9] above. [B11] the light irradiation unit further includes a polarizing beam splitter for light irradiation having a first incident surface into which light from the first light source is incident, a second incident surface into which light from the second light source is incident, and an exit surface from which the light from the first light source and the light from the second light source exit. The electronic device according to [B10] above. [B12] The light irradiation unit includes a polarization adjustment element capable of switching the light between a first polarization state and a second polarization state for each of the plurality of color lights. The electronic device described in [B9] above. [Explanation of symbols]

[0078] 1,2...Image display device, 10,110...Light irradiation unit, 11...Light source (first light source), 11 R ...red light source, 11 G ...green light source, 11 B ...Blue light source, 12...Second light source, 12 R ...Red light source, 12 G ...green light source, 12 B 15A···surface of the polarizing beam splitter for light irradiation (first entrance surface), 15B···surface of the polarizing beam splitter for light irradiation, 15C···surface of the polarizing beam splitter for light irradiation (exit surface), 15D···surface of the polarizing beam splitter for light irradiation (second entrance surface), 15E···interface of the polarizing beam splitter for light irradiation, 1···first display panel, 22···first display panel, 23, 24···wave plate, 25···polarizing beam splitter, 25A···first surface of polarizing beam splitter, 25B···second surface of polarizing beam splitter, 25C···third surface of polarizing beam splitter, 25D···fourth surface of polarizing beam splitter, 25E···interface of polarizing beam splitter, 30···projection unit, 40···screen

Claims

1. a first display panel and a second display panel whose light transmittance or reflectance is controlled based on an image signal; and a light irradiation unit including a light source capable of emitting a plurality of color lights for irradiating the first display panel and the second display panel with light, and a polarization adjustment element capable of switching the light between a first polarization state and a second polarization state for each of the plurality of color lights; Contains The first display panel and the second display panel are sequentially driven by image signals corresponding to the respective colors of light, during a period in which one of the first and second display panels is driven by an image signal corresponding to one of the plurality of color lights, an image signal for driving the other display panel is switched; a polarizing beam splitter having a first surface onto which light from the light irradiation unit is incident, second and third surfaces from which the incident light exits, and a fourth surface from which light passing through the first display panel and light passing through the second display panel exit, The first display panel is disposed so as to face the second surface, the second display panel is disposed so as to face the third surface; the light irradiation unit irradiates the first surface of the polarizing beam splitter with light in the first polarization state and light in the second polarization state; Light having a first polarization state exits from a second surface of the polarizing beam splitter; The light having the second polarization state exits from a third surface of the polarizing beam splitter. Image display device.

2. the light emitting unit irradiates the first display panel with color light corresponding to an image signal for driving the first display panel, and irradiates the second display panel with color light corresponding to an image signal for driving the second display panel; The image display device according to claim 1 .

3. the light irradiation unit stops emitting light to the first display panel and the second display panel during a predetermined period including a switching time of an image signal for driving the first display panel and during a predetermined period including a switching time of an image signal for driving the second display panel; The image display device according to claim 2 .

4. the first display panel and the second display panel are sequentially driven by image signals corresponding to red light, green light, and blue light, respectively; the light emitting unit irradiates the first display panel with color light corresponding to an image signal for driving the first display panel, and irradiates the second display panel with color light corresponding to an image signal for driving the second display panel; The image display device according to claim 1 .

5. The image display device further includes a projection unit that projects a first image obtained by the first display panel and a second image obtained by the second display panel in a superimposed manner. The image display device according to claim 1 .

6. a predetermined wave plate is disposed between the second surface of the polarizing beam splitter and the first display panel, and between the third surface of the polarizing beam splitter and the second display panel; The image display device according to claim 1 .

7. The light emitting section includes a first light source for emitting light in a first polarization state, and a second light source for emitting light in a second polarization state. The image display device according to claim 1 .

8. the light irradiation unit further includes a polarizing beam splitter for light irradiation having a first incident surface on which light from the first light source is incident, a second incident surface on which light from the second light source is incident, and an exit surface from which the light from the first light source and the light from the second light source exit; The image display device according to claim 7.

9. a first display panel and a second display panel whose light transmittance or reflectance is controlled based on an image signal; and a light irradiation unit including a light source capable of emitting a plurality of color lights for irradiating the first display panel and the second display panel with light, and a polarization adjustment element capable of switching the light between a first polarization state and a second polarization state for each of the plurality of color lights; Contains The first display panel and the second display panel are sequentially driven by image signals corresponding to the respective colors of light, during a period in which one of the first and second display panels is driven by an image signal corresponding to one of the plurality of color lights, an image signal for driving the other display panel is switched; a polarizing beam splitter having a first surface onto which light from the light irradiation unit is incident, second and third surfaces from which the incident light exits, and a fourth surface from which light passing through the first display panel and light passing through the second display panel exit, The first display panel is disposed so as to face the second surface, the second display panel is disposed so as to face the third surface; the light irradiation unit irradiates the first surface of the polarizing beam splitter with light in the first polarization state and light in the second polarization state; Light having a first polarization state exits from a second surface of the polarizing beam splitter; The light having the second polarization state exits from a third surface of the polarizing beam splitter. An electronic device equipped with an image display device.

Images