JPWO2020145332A1 - Electronic mirror device - Google Patents

Abstract

An object of the present invention is to make it possible to switch between displaying an image around a vehicle by an image and displaying an image around the vehicle by reflecting light from a real landscape with a simpler configuration. The electronic mirror device (1) of the present invention emits a display (200) that emits display light indicating a peripheral image captured by imaging the periphery of the vehicle (A), and the display light emitted from the display (200). It is provided with a reflective concave mirror (300) and a liquid crystal panel (100) arranged between the display (200) and the concave mirror (300) and capable of switching between a transmission state and a reflection state according to the application of a voltage. ..

Description

The present invention relates to an electronic mirror device.

Patent Document 1 discloses an electronic mirror for an automobile in which a display element is arranged behind the concave mirror at a distance shorter than the focal length thereof and a virtual image is displayed behind the concave mirror. According to this, it is possible to give depth to the virtual image and reduce the distance for switching the focus of the eyes to the distant image as in the conventional mirror type, and to make the rear and side images easier to see.

Japanese Unexamined Patent Publication No. 2018-55075

This type of electronic mirror device displays an image of the surroundings of the vehicle by an image and an image of the surroundings of the vehicle by reflecting external light from the conventional peripherals of the vehicle in order to select the image display device according to the user's preference or when the image display device fails. It is desirable that and can be switched. Patent Document 1 describes that a plane mirror is placed on the back surface of the concave mirror as a switching method, or the back surface of the concave mirror is used as a plane mirror to invert the front and back sides. There is a problem in inviting.

The present disclosure has been made in view of the above circumstances, and is an electron that enables switching between the display of an image around a vehicle by an image and the display of an image around the vehicle by reflection of light from an actual landscape by a simpler configuration. It is an object of the present invention to provide a mirror device.

In order to achieve the above object, the electronic mirror device according to the present disclosure includes a display that emits display light indicating a peripheral image captured by imaging the periphery of the vehicle.
A concave mirror that reflects the display light emitted from the display, and
A switching panel arranged between the display and the concave mirror and capable of switching between a transmission state and a reflection state according to the application of a voltage.
To prepare for.

According to the electronic mirror device according to the present disclosure, it is possible to switch between the display of the image around the vehicle by the image and the display of the image around the vehicle by the reflection of light from the actual landscape with a simpler configuration.

It is a schematic diagram of the vehicle equipped with the electronic mirror device which concerns on embodiment of this disclosure. It is a block diagram which shows the function of the electronic mirror apparatus shown in FIG. FIG. 3 is a schematic cross-sectional view showing a liquid crystal panel of the electronic mirror device shown in FIG. 1. It is a figure which shows the positional relationship between the concave mirror of the electronic mirror apparatus shown in FIG. 1 and a liquid crystal panel. It is a figure which shows the transmission state of the electronic mirror apparatus shown in FIG. It is a figure which shows the reflection state of the electronic mirror apparatus shown in FIG. It is a figure which shows the liquid crystal panel in the transmission state shown in FIG. 5A. It is a figure which shows the liquid crystal panel in the reflection state shown in FIG. 5B. It is a side view which shows the display | display of the electronic mirror apparatus which concerns on other embodiment of this disclosure.

The embodiments of the present disclosure will be described with reference to the drawings.

FIG. 1 is a schematic view of a vehicle A equipped with the electronic mirror device 1 according to the embodiment of the present disclosure, and shows a state in which the vehicle A is viewed from the right side. FIG. 2 is a block diagram showing the functions of the electronic mirror device 1. Hereinafter, the front-rear direction of the vehicle A in FIG. 1 is the X direction (the front direction is the + X direction, the rear direction is the −X direction), the left-right direction is the Y direction (the left direction is the + Y direction, and the right direction is the −Y direction). ), The vertical direction is the Z direction (the upward direction is the + Z direction, and the downward direction is the −Z direction).

The electronic mirror device 1 is arranged in front of the vehicle interior of the vehicle A, and includes a liquid crystal panel 100, a display 200, and a concave mirror 300. In addition to these, the electronic mirror device 1 includes a control unit 400, a storage unit 500, and an I / O interface 600 as its functions. The electronic mirror device 1 has a peripheral image recognition mode in which a user D who is supposed to be a driver who is mainly seated in the driver's seat visually recognizes a peripheral image image of the surrounding area including the rear side and the side of the vehicle A. It is possible to switch between the actual landscape viewing mode, which mainly reflects the actual landscape behind and to the side of the vehicle A and makes the user visually recognize the actual landscape.

The liquid crystal panel 100 is arranged together with the concave mirror 300 in the vicinity of the front windshield A1 in the vehicle interior of the vehicle A, and is arranged between the display 200 and the concave mirror 300 in the front-rear direction of the vehicle A. Further, in terms of the positional relationship with the user D, it can be said that the liquid crystal panel 100 is arranged between the user D and the concave mirror 300. The liquid crystal panel 100 according to this embodiment is a twisted nematic (TN (Twisted Nematic)) type liquid crystal panel, and is configured as shown in FIG. 3 in a schematic cross-sectional view. The liquid crystal panel 100 is an example of the switching panel of the present disclosure, and is configured to be able to switch between a transmission state and a reflection state according to the application of voltage under the voltage application control of the control unit 400. The transmission state and the reflection state of the liquid crystal panel 100 will be described in detail later.

In the following, in order to facilitate the understanding of the explanation, the user D side (generally in the −X direction) of the liquid crystal panel 100 is referred to as the “front side”, and the opposite side (generally in the + X direction) is referred to as the “back side”. do. Further, in consideration of the legibility of the drawing, in FIG. 3, hatching showing a cross section is omitted as appropriate.

As shown in FIG. 3, the liquid crystal panel 100 includes a liquid crystal element 10, an absorption-type polarizing plate 21 located on the front side of the liquid crystal element 10, and a reflection-type polarizing plate 22 located on the back side of the liquid crystal element 10. Although not shown, the liquid crystal panel 100 in a plan view has, for example, a substantially rectangular shape.

As shown in FIG. 3, the liquid crystal element 10 includes a first substrate 11, a second substrate 12, and a liquid crystal layer 13.

The first substrate 11 and the second substrate 12 are a pair of transparent substrates facing each other, and are made of, for example, glass, plastic, or the like. The first substrate 11 and the second substrate 12 are arranged so as to face each other with the liquid crystal layer 13 interposed therebetween and so that their main surfaces (opposing surfaces) are parallel to each other. The first substrate 11 is located on the front side of the liquid crystal layer 13.

A transparent electrode 11a is provided on the liquid crystal layer 13 side of the first substrate 11. A transparent electrode 12a is provided on the liquid crystal layer 13 side of the second substrate 12. The transparent electrodes 11a and 12a are formed by known methods such as sputtering, vapor deposition, and etching. In this embodiment, the transparent electrodes 11a and 12a are each formed in a solid shape on the corresponding substrate surface and have a substantially rectangular shape in a plan view. The transparent electrodes 11a and 12a are made of an ITO (Indium Tin Oxide) film or the like containing indium oxide as a main component.

Further, an insulating film and an alignment film (not shown) are formed on each of the first substrate 11 and the second substrate 12. The insulating film is made of a silicon-based insulating film, and is formed so as to cover each of the transparent electrodes 11a and 12a from the liquid crystal layer 13 side. Further, an alignment film is formed between the insulating film and the liquid crystal layer 13. That is, the transparent electrode 11a, the insulating film, and the alignment film are laminated and formed on the first substrate 11. Further, a transparent electrode 12a, an insulating film, and an alignment film are laminated and formed on the second substrate 12.

The alignment film is in contact with the liquid crystal layer 13 and is for defining the alignment state of the liquid crystal molecules 13a (schematically represented in FIGS. 6A and 6B) contained in the liquid crystal layer 13. For example, a known method from polyimide. Formed by (eg, flexo printing). The alignment film is subjected to a rubbing treatment. In this embodiment, the rubbing direction of the alignment film on the front side (that is, the alignment film formed on the first substrate 11) and the rubbing direction of the alignment film on the back side (that is, the alignment film formed on the second substrate 12) are It is substantially orthogonal (including just orthogonal) when viewed from the substrate normal direction (the normal direction of the facing surfaces of the first substrate 11 and the second substrate 12). The orientation of the liquid crystal molecules 13a is regulated by the bidirectional film subjected to the rubbing treatment in this way. The alignment treatment applied to the alignment film is not limited to the rubbing treatment, but may be another known treatment such as a photo-alignment treatment or a protrusion alignment treatment.

The liquid crystal layer 13 is formed by enclosing the liquid crystal material in a sealed space formed by a sealing material (not shown) for joining the first substrate 11 and the second substrate 12 and both substrates. The thickness (cell gap) of the liquid crystal layer 13 is defined by a spacer (not shown) provided between the first substrate 11 and the second substrate 12. The direction of the long axis of the liquid crystal molecule 13a of the liquid crystal layer 13 is twisted by 90 ° between the end portion of the liquid crystal layer 13 on the first substrate 11 side and the end portion on the second substrate 12 side due to the orientation restricting force of the alignment film (the orientation of the liquid crystal layer 13 is twisted by 90 °. With a twist angle of 90 °), it is oriented so as to rotate (turn) little by little from one substrate side to the other substrate side (chiral structure). In this way, the liquid crystal layer 13 has chirality when no voltage is applied.

The absorption-type polarizing plate 21 has a transmission axis (hereinafter, also referred to as a first transmission axis) and an absorption axis orthogonal to the first transmission axis. The absorption type polarizing plate 21 transmits the incident light in the polarization direction parallel to the first transmission axis.

The reflective polarizing plate 22 has a transmission axis (hereinafter, also referred to as a second transmission axis) and a reflection axis orthogonal to the second transmission axis. The reflective polarizing plate 22 transmits the incident light in the polarization direction parallel to the second transmission axis, and reflects the light in the polarization direction parallel to the reflection axis.

In this embodiment, the first transmission axis of the absorption-type polarizing plate 21 and the second transmission axis of the reflection-type polarizing plate 22 are substantially parallel to each other (including just parallel) when viewed from the normal direction of the substrate. Both polarizing plates are arranged (parallel Nicol arrangement). Further, the rubbing direction of the alignment film on the front side (that is, the alignment film formed on the first substrate 11) and the direction along the absorption axis of the absorption type polarizing plate 21 are set to be parallel.

The absorbent polarizing plate 21 is attached to the front surface of the first substrate 11 via the first transparent adhesive film 31. The reflective polarizing plate 22 is attached to the back surface of the second substrate 12 via the second transparent adhesive film 32. An optical element such as a retardation plate may be provided between the liquid crystal element 10 and each polarizing plate. In this case, the polarizing plate may be attached to an optical element located between the liquid crystal element 10 and the polarizing plate.

The first transparent adhesive film 31 and the second transparent adhesive film 32 are each composed of, for example, an acrylic transparent adhesive (acrylic polymer) or the like. The first transparent pressure-sensitive adhesive film 31 is formed by applying a transparent pressure-sensitive adhesive to the surface of the absorbent polarizing plate 21 to be attached to the first substrate 11. The second transparent pressure-sensitive adhesive film 32 is formed by applying a transparent pressure-sensitive adhesive to the surface of the reflective polarizing plate 22 to be attached to the second substrate 12.

The display 200 is arranged near the roof A2 in the vehicle interior of the vehicle A, and is located on the rear side (-X direction) and the upper side (+ Z direction) of the vehicle A with respect to the liquid crystal panel 100 and the concave mirror 300. Is. The display 200 is a display capable of displaying the peripheral image captured under the image display control of the control unit 400 and emitting the display light L1 (see FIG. 5A) indicating the peripheral image toward the concave mirror 300. be. Specific examples thereof include a TFT (Thin Film Transistor) type liquid crystal display and an organic EL (Electro-Luminescence) display. Further, the display 200 may be a projector.

The concave mirror 300 is arranged together with the liquid crystal panel 100 in the vicinity of the front windshield A1 in the vehicle interior of the vehicle A, and is arranged on the front side (+ X direction) of the vehicle A with respect to the liquid crystal panel 100 and the display 200. The liquid crystal panel 100 and the concave mirror 300 are housed in a common case (housing) (not shown). FIG. 4 shows the positional relationship between the liquid crystal panel 100 and the concave mirror 300 in the front-rear direction (X direction) of the vehicle A. The liquid crystal panel 100 is tilted more downward (−Z direction) as compared with the concave mirror 300. That is, the horizontal first length DS1 between the upper end 110 of the liquid crystal panel 100 and the upper end 310 of the concave mirror 300 is the horizontal second length between the lower end 120 of the liquid crystal panel 100 and the lower end 320 of the concave mirror 300. Length is greater than DS2 (DS1> DS2). The reason why the liquid crystal panel 100 and the concave mirror 300 are arranged in such a positional relationship will be described later.

The control unit 400 includes one or more arithmetic processing circuits such as a microcomputer, peripheral circuits, and programs. More specifically, the control unit 400 includes a CPU that actually performs processing (control of the entire electronic mirror device 1, etc.) executed by the control unit 400 as hardware, a RAM that functions as the main memory of the CPU, and a control unit. A ROM that stores various programs that cause the 400 to execute processing described later, and various converters that digitally convert information (signals) input to and output from the control unit 400 for the CPU and analog for output. To prepare for. In addition to the CPU, the control unit 400 may include various dedicated circuits (for example, an image processing circuit, etc.) for executing a part of the processing performed by the control unit 400 on behalf of the CPU. Further, the control unit 400 includes a program for performing processing executed by the control unit 400 as software.

The storage unit 500 stores a program used when the control unit 400 executes the process, data used for the process, and the like. The storage unit 500 includes a non-volatile storage medium such as a flash memory in which data can be rewritten. The storage unit 500 may include a memory card or the like that is easily attached and detached.

The I / O interface 600 is a hardware interface for inputting / outputting information to / from the operation unit 2, the image pickup unit 3, and other devices in the vehicle A provided in the vehicle A by a wired connection or a wireless connection. And software interface. Through communication, the I / O interface 600 acquires various information such as the operation of switching between the transmission state and the reflection state of the electronic mirror device 1 from the operation unit 2 and the peripheral image captured from the image pickup unit 3, and transmits the information to the control unit 400. do. The operation unit 2 is, for example, a push button switch or a touch panel, and accepts the operation of the user D. The operation unit 2 may be capable of operating various devices in the vehicle A including the electronic mirror device 1, or may be dedicated to operating the electronic mirror device 1. The image pickup unit 3 is a camera provided in the vehicle interior of the vehicle A and / or in the vehicle body of the vehicle A, and images the surroundings including the rear and sides of the vehicle A to obtain the peripheral image.

As described above, the electronic mirror device 1 is configured.

Next, FIG. 5A describes switching between the transmission state and the reflection state of the liquid crystal panel 100 for switching between the peripheral image viewing mode of the electronic mirror device 1 and the actual landscape viewing mode and switching between these modes. , FIG. 5B, FIG. 6A, and FIG. 6B. FIG. 5A shows the electronic mirror device 1 in the peripheral image viewing mode, and FIG. 5B shows the electronic mirror device 1 in the real landscape viewing mode. FIG. 6A shows the liquid crystal panel 100 in the transmissive state, and FIG. 6B shows the liquid crystal panel 100 in the reflective state. In FIGS. 6A and 6B, hatching showing a cross section was omitted as appropriate, and appropriate members were omitted.

(Peripheral image viewing mode)
In the peripheral image viewing mode shown in FIG. 5A, the display 200 displays the peripheral image under the image display control of the control unit 400, and directs the display light L1 indicating the peripheral image toward the concave mirror 300. (Approximately + X direction).
The display light L1 emitted from the display 200 reaches the liquid crystal panel 100. At this time, the liquid crystal panel 100 is put into a transmissive state under the voltage application control of the control unit 400. The liquid crystal panel 100 transmits the display light L1 of the display 200 in the transmitted state. The display light L1 transmitted through the liquid crystal panel 100 reaches the concave mirror 300, is magnified and reflected by the concave mirror 300. The display light L1 reflected by the concave mirror 300 passes through the liquid crystal panel 100 again and reaches the eye box EB. The eyebox EB is a region in the vertical and horizontal directions (YZ plane) set as a range of the viewpoint position of the user D in a state of being seated in the driver's seat. As a result, the user D places the viewpoint position in the eyebox EB in the peripheral image viewing mode, so that the peripheral image is placed in a deep (generally located far away in the + X direction) virtual image V. Can be visually recognized as. According to this, the user D can easily adjust the focus of the eyes even when the line of sight is shifted from the distant view such as the landscape in front of the vehicle A to the peripheral image captured image (virtual image V).

(Transparent state of LCD panel)
Here, the transmission state of the liquid crystal panel 100 will be described in detail with reference to FIG. 6A. When the drive voltage is applied, the liquid crystal molecules 13a of the liquid crystal panel 100 are oriented along the voltage application direction (board normal direction), and the chirality is lost. In this state, when the display light L1 is incident from the front side (generally in the −X direction) of the liquid crystal panel 100, it is transmitted through the absorption type polarizing plate 21 and becomes linearly polarized light parallel to the first transmission axis, but is transmitted through the liquid crystal layer 13. However, since the polarization direction is not changed, the reflective polarizing plate 22 having the second transmission axis parallel to the first transmission axis also transmits. In this way, the liquid crystal panel 100 transmits the display light L1. The display light L1 reflected by the concave mirror 300 passes through the reflective polarizing plate 22, the liquid crystal layer 13, and the absorption type polarizing plate 21 again, and causes the user D to visually recognize the virtual image V of the peripheral image reflected by the concave mirror 300. ..

When external light is incident from the front side of the liquid crystal panel 100, it passes through the absorption type polarizing plate 21 and passes through the liquid crystal layer 13 with linearly polarized light parallel to the first transmission axis. It passes through the reflective polarizing plate 22 having two transmission axes and is reflected by the concave mirror 300. However, since the reflecting surface shape and the installation angle of the concave mirror 300 are designed to reflect the display light L1 from the display 200 toward the eyebox EB of the user D, most of the external light incident on the concave mirror 300 is present. Does not reach the eye box EB of the user D, and hardly reduces the visibility of the peripheral image.

(Real landscape viewing mode)
In the actual landscape viewing mode shown in FIG. 5B, the light L2 from the actual landscape behind or beside the vehicle A reaches the liquid crystal panel 100. At this time, the liquid crystal panel 100 is set to the reflection state under the voltage application control of the control unit 400. The liquid crystal panel 100 reflects the light L2 from the actual landscape in the reflected state. The light L2 from the actual landscape reflected by the liquid crystal panel 100 reaches the eye box EB. As a result, the user D can visually recognize the actual landscape as a deep virtual image by placing his / her viewpoint position in the eyebox EB in the actual landscape viewing mode.

(Reflective state of LCD panel)
Here, the reflection state of the liquid crystal panel 100 will be described in detail with reference to FIG. 6B. In a state where no drive voltage is applied, the liquid crystal molecules 13a of the liquid crystal panel 100 are substantially parallel to the substrate surface, and the liquid crystal layer 13 still has chirality. In this state, when the light L2 from the actual landscape is incident from the front side of the liquid crystal panel 100, it is transmitted through the absorption type polarizing plate 21 to become linearly polarized light parallel to the first transmission axis, and when it is transmitted through the liquid crystal layer 13, the liquid crystal layer 13 is transmitted. The 90 ° polarization direction is converted by the chirality of the above to obtain linearly polarized light along the reflection axis of the reflective polarizing plate 22, so that the polarized light is reflected by the reflective polarizing plate 22. This reflected light passes through the liquid crystal layer 13, and the polarization direction is changed by 90 ° again, so that the reflected light passes through the absorption type polarizing plate 21. In this way, the liquid crystal panel 100 functions as a mirror in the reflective state. Hereinafter, the portion of the liquid crystal panel 100 in the reflective state that functions as a mirror is referred to as an active area.

In the actual landscape viewing mode, the display 200 is basically in a non-display state, but if the display light L1 is incident from the front side of the liquid crystal panel 100, it passes through the absorption type polarizing plate 21 and becomes the first transmission axis. When it becomes parallel linearly polarized light and passes through the liquid crystal layer 13, the 90 ° polarization direction is converted to linearly polarized light along the reflection axis of the reflective polarizing plate 22, so that it is reflected by the reflective polarizing plate 22. However, since the installation angle of the liquid crystal panel 100 is designed to reflect the light L2 from the actual landscape toward the eyebox EB of the user D, the display light L1 reflected by the liquid crystal panel 100 is the user D. It does not reach the eyebox EB and does not reduce the visibility of the actual landscape.

In this way, the electronic mirror device 1 arranges the concave mirror 300 so as to reflect the display light L1 of the display 200 arranged near the roof A2 of the vehicle A on the eyebox EB, and arranges the liquid crystal panel 100 from the display 200. The light L2 from the actual landscape below is arranged so as to be reflected by the eyebox EB. As a result, as shown in FIG. 4, the first horizontal length DS1 between the upper end 110 of the liquid crystal panel 100 and the upper end 310 of the concave mirror 300 is the lower end 120 of the liquid crystal panel 100 and the lower end 320 of the concave mirror 300. The horizontal second length between DS2 is greater than DS2 (DS1> DS2).

As described above, the electronic mirror device 1 does not require a complicated switching mechanism such as a rotation mechanism, and has a simpler configuration in which the liquid crystal panel 100 is arranged between the display 200 and the concave mirror 300. It is possible to switch between the display of the peripheral image (the peripheral image viewing mode) and the display of the image around the vehicle by the reflection of light from the actual landscape (the actual landscape viewing mode).

The scope of the present disclosure is not limited to the above embodiments and drawings. Of course, changes can be made to these (including the deletion of components).

Further, although the liquid crystal panel 100 is taken as an example of the switching panel of the present disclosure, the switching panel is not limited to this, and any switching panel may be used as long as it can switch between the transmission state and the reflection state depending on the voltage application state. As another example, an EC panel using an electrochromic (EC) material may be used.

Further, in another embodiment of the present disclosure, a liquid crystal panel 100 may be used as the switching panel to emit linearly polarized light parallel to the first transmission axis of the absorption type polarizing plate 21 as the display light L1 of the display 200. .. Further, in another embodiment of the present disclosure, the first transmission axis of the absorption-type polarizing plate 21 is set in the vertical direction so that the liquid crystal panel 100 transmits the linearly polarized light in the vertical direction in the transmission state, and the display 200. The linearly polarized light in the vertical direction may be emitted as the display light L1. According to this, even in a state where the user D wears a polarizing glass that mainly blocks the linearly polarized light in the horizontal direction, the visual recognition of the peripheral image is not hindered.

Further, as described above, in the peripheral image viewing mode, most of the external light does not reach the eyebox EB even if it is reflected by the concave mirror 300, but the external light passing near the periphery of the display 200 is the concave mirror 300. It may be reflected by and reach the eyebox EB. On the other hand, in another embodiment of the present disclosure, as shown in FIG. 7, the outside from the rear of the vehicle A (generally in the −X direction) so as to surround the emission unit 210 that emits the display light L1 of the display 200. A light-shielding portion 220 that blocks the light L3 may be provided. In FIG. 7, the light-shielding portion 220 is made of, for example, a brim-shaped member formed of a black resin material or a metal material, but its shape and the like are not limited thereto. According to this, the visibility of the peripheral captured image can be further improved.

Further, in the above description, in the liquid crystal panel 100, the first transmission axis of the absorption-type polarizing plate 21 and the second transmission axis of the reflection-type polarizing plate 22 are set in parallel, and reflection is performed when a driving voltage is not applied. An example (normal reflection) in which a state is established and a transmission state is obtained when a drive voltage is applied is shown, but the present invention is not limited to this. In the liquid crystal panel 100, the first transmission axis of the absorption-type polarizing plate 21 and the second transmission axis of the reflection-type polarizing plate 22 are set substantially orthogonal to each other, and when a drive voltage is applied, the liquid crystal panel 100 is in a reflective state, and the drive voltage is applied. The liquid crystal panel 100 may be configured so as to be in a transmissive state without being present (normally transmissive). In the example of normal transmission, the liquid crystal panel 100 can switch between the reflection state and the transmission state as follows.

(Transparent state of LCD panel)
In a state where no drive voltage is applied, the liquid crystal molecules 13a of the liquid crystal panel 100 are substantially parallel to the substrate surface, and the liquid crystal layer 13 still has chirality. In this state, when the display light L1 is incident from the front side of the liquid crystal panel 100, it passes through the absorption type polarizing plate 21 and becomes linearly polarized light parallel to the first transmission axis, and when it passes through the liquid crystal layer 13, due to the chirality of the liquid crystal layer 13. The 90 ° polarization direction is converted to pass through the reflective polarizing plate 22 having a second transmission axis substantially orthogonal to the first transmission axis. In this way, the liquid crystal panel 100 transmits the display light L1.

(Reflective state of LCD panel)
When the drive voltage is applied, the liquid crystal molecules 13a of the liquid crystal panel 100 are oriented along the voltage application direction (board normal direction), and the chirality is lost. In this state, when the light L2 from the actual landscape is incident from the front side of the liquid crystal panel 100, it passes through the absorption type polarizing plate 21 and passes through the liquid crystal layer 13 with linearly polarized light parallel to the first transmission axis. It becomes linearly polarized light along the reflection axis of the reflection type polarizing plate 22 parallel to the transmission axis, and is reflected by the reflection type polarizing plate 22. This reflected light passes through the liquid crystal layer 13 again as it is, and passes through the absorption type polarizing plate 21 having a first transmission axis substantially orthogonal to the reflection axis. In this way, the liquid crystal panel 100 functions as a mirror in the reflective state.

Further, in another embodiment of the present disclosure, the active area of the liquid crystal panel 100 may be divided into a plurality of areas, and the transmission state and the reflection state may be switched for each divided area. For example, two divided areas on the left and right may be provided, one of which may be set to the actual landscape viewing mode as a reflection state, and the other may be set to the peripheral image viewing mode as a transmission state. Further, at this time, an image such as vehicle information may be appropriately displayed on the display 200 in addition to the peripheral captured image. Further, in order to divide the active area of the liquid crystal panel 100 into a plurality of areas, at least one of the transparent electrodes 11a and 12a is divided for each divided area. At this time, the voltage applied to the liquid crystal layer 13 via the transparent electrodes 11a and 12a may be a passive drive method or an active drive method.

Further, in the above, the liquid crystal element 10 is an example of a TN type liquid crystal having a twist angle of 90 °, but the present invention is not limited to this. The twist angle may be less than 90 ° or larger than 90 ° as long as the above-mentioned reflection state and transmission state can be realized by applying a voltage to the liquid crystal layer 13. For example, the liquid crystal element 10 may be an STN (Super Twisted Nematic) type. Further, if the reflection state and the transmission state can be realized by applying a voltage to the liquid crystal layer 13, the first transmission axis of the absorption-type polarizing plate 21 and the second transmission axis of the reflection-type polarizing plate 22 are , It does not have to be parallel or orthogonal, and it does not have to be parallel or orthogonal to the rubbing direction of these optical axes and the alignment film. It is also possible to appropriately shift each optical axis in consideration of the viewing angle characteristics in the transmission state and the reflection characteristics in the reflection state.

In the above description, in order to facilitate the understanding of the present invention, the description of known technical matters has been omitted as appropriate.

1 ... Electronic mirror device 100 ... Liquid crystal panel (switching panel)
200 ... Display 300 ... Concave mirror 400 ... Control unit 500 ... Storage unit 600 ... I / O interface A ... Vehicle L1 ... Display light L2 ... Light from the actual landscape

Claims (3)

A display (200) that emits display light (L1) indicating a peripheral captured image obtained by capturing the periphery of the vehicle (A), and a display (200).
A concave mirror (300) that reflects the display light (L1) emitted from the display (200), and a concave mirror (300).
A switching panel (100) arranged between the display (200) and the concave mirror (300) and capable of switching between a transmission state and a reflection state according to the application of a voltage.
An electronic mirror device equipped with. The first length (DS1) between the upper end (310) of the concave mirror (300) and the upper end (110) of the switching panel (100) is the lower end (320) of the concave mirror (300) and the switching panel. The electronic mirror device according to claim 1, which is larger than the second length (DS2) between the lower end (120) of (100). The switching panel (100) is a liquid crystal panel (100) that transmits polarized light in the vertical direction in the transmission state.
The electronic mirror device according to claim 1, wherein the display (200) emits polarized light in the vertical direction as the display light (L1).

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