Electronic rearview mirror and control method thereof

Abstract

Provided is a structure for suppressing a reduction in visibility of a user in an electronic rearview mirror providing an anti-glare function. An electronic rearview mirror is provided with: a first polarizing plate (315); a liquid crystal layer (316) that is disposed on the rear surface side of the first polarizing plate and that controls the optical rotation of light by applying a voltage; a reflective polarizing plate (317) that is disposed on the rear surface side of the liquid crystal layer and reflects or transmits light from the liquid crystal layer on the basis of a polarization axis; a second polarizing plate (331) disposed on the rear surface side of the reflective polarizing plate; a liquid crystal cell (332) disposed on the rear surface side of the second polarizing plate; and a backlight (334) disposed on the rear surface side of the liquid crystal cell, in which the haze of the second polarizing plate is in the range of 3.0%-8.0%.

Description

Technical Field

[0001] The present disclosure relates to an electronic rearview mirror and a control method thereof. Background Art

[0002] During driving of a vehicle, etc., irradiated light from surrounding vehicles etc. is reflected by the vehicle-mounted rearview mirror, which may cause a phenomenon such as a decrease in the operability of the driver's vehicle. Conventionally, an anti-glare function is provided to the vehicle-mounted electronic rearview mirror to cope with such a phenomenon.

[0003] For example, Patent Document 1 discloses a structure that reduces transmission loss and provides a bright screen in a liquid crystal anti-glare rearview mirror that can be switched between anti-glare and non-anti-glare.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2009-8881 Summary of the invention

[0007] Problem that the invention aims to solve

[0008] In an electronic rearview mirror that provides an anti-glare function, a reduction in the user's visual confirmation may occur under certain circumstances.

[0009] The present disclosure has been made in view of the above-mentioned problems, and an object of the present disclosure is to provide a structure for suppressing a decrease in user's visual recognition in an electronic rearview mirror having an anti-glare function.

[0010] Solutions for solving problems

[0011] The present disclosure provides an electronic rearview mirror, comprising: a first polarizing plate; a liquid crystal layer, which is arranged on the back side of the first polarizing plate, and the optical rotation of light is controlled by applying a voltage; a reflective polarizing plate, which is arranged on the back side of the liquid crystal layer, and reflects or transmits light from the liquid crystal layer based on the polarization axis; a second polarizing plate, which is arranged on the back side of the reflective polarizing plate; a liquid crystal unit, which is arranged on the back side of the second polarizing plate; and a backlight source, which is arranged on the back side of the liquid crystal unit, wherein the haze of the second polarizing plate is in the range of 3.0% to 8.0%.

[0012] In addition, the present disclosure provides an electronic rearview mirror, comprising: a first polarizing plate; a liquid crystal layer, which is arranged on the back side of the first polarizing plate, and the optical rotation of light is controlled by applying a voltage; a reflective polarizing plate, which is arranged on the back side of the liquid crystal layer, and reflects or transmits light from the liquid crystal layer based on the polarization axis; a second polarizing plate, which is arranged on the back side of the reflective polarizing plate; a liquid crystal unit, which is arranged on the back side of the second polarizing plate; and a backlight source, which is arranged on the back side of the liquid crystal unit, wherein the reflective polarizing plate and the second polarizing plate are bonded to each other by an adhesive component.

[0013] In addition, the present disclosure provides an electronic rearview mirror comprising: a first polarizing plate; a liquid crystal layer, which is arranged on the back side of the first polarizing plate, and the optical rotation of light is controlled by applying a voltage; a reflective polarizing plate, which is arranged on the back side of the liquid crystal layer, and reflects or transmits light from the liquid crystal layer based on the polarization axis; a liquid crystal unit, which is arranged on the back side of the reflective polarizing plate; and a backlight source, which is arranged on the back side of the liquid crystal unit.

[0014] In addition, the present disclosure provides an electronic rearview mirror configured to be able to switch an anti-glare function, the electronic rearview mirror comprising: a display structure, the reflectivity of light of the display structure being controlled; an illuminance sensor, which obtains a first illuminance from a surface side of the display structure and a second illuminance from a back side of the display structure; and a control circuit, which adjusts an applied voltage to a liquid crystal layer of the display structure based on the first illuminance and the second illuminance, thereby controlling the anti-glare function, wherein when the anti-glare function is in operation, the control circuit adjusts the applied voltage so that the reflectivity of the display structure is within a specified range.

[0015] In addition, the present disclosure provides a control method for an electronic rearview mirror, wherein the electronic rearview mirror is configured to be able to switch an anti-glare function, the control method comprising: an acquisition process, acquiring a first illuminance from a surface side of a display structure of the electronic rearview mirror and a second illuminance from a back side of the display structure; and a control process, adjusting an applied voltage to a liquid crystal layer of the display structure of the electronic rearview mirror based on the first illuminance and the second illuminance to control the reflectivity of light of the display structure, thereby controlling the anti-glare function, wherein, when the anti-glare function is activated, the applied voltage is adjusted so that the reflectivity of the display structure is within a specified range.

[0016] Furthermore, any combination of the above-described constituent elements and any form of expression of the present disclosure in the form of a method, an apparatus, a system, a storage medium, a computer program, etc., may also be practiced as additional forms of the present disclosure.

[0017] Effects of the Invention

[0018] According to the present disclosure, it is possible to provide a structure for suppressing a decrease in visual confirmation of a user in an electronic rearview mirror providing an anti-glare function. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a block diagram showing an example of the functional configuration of the electronic rearview mirror according to the first embodiment of the present invention.

[0020] Figure 2 This is a schematic diagram for explaining white blur in an electronic rearview mirror.

[0021] Figure 3 This is a schematic diagram for explaining the layer structure of the electronic rearview mirror according to the first embodiment of the present invention.

[0022] Figure 4 A conceptual illustration of double reflections, rainbows, and white blur in electronic rearview mirrors.

[0023] Figure 5 This is a graph showing evaluation examples according to the first embodiment of the present invention.

[0024] Figure 6 This is a schematic diagram for explaining the layer structure of the electronic rearview mirror according to the second embodiment of the present invention.

[0025] Figure 7 This is a schematic diagram for explaining the layer structure of the electronic rearview mirror according to the third embodiment of the present invention.

[0026] Figure 8 This is a schematic diagram for explaining the layer structure of the electronic rearview mirror according to the fourth embodiment of the present invention.

[0027] Fig. 9 This is a graph for explaining the relationship between the voltage applied to the liquid crystal layer and the reflected light according to the fourth embodiment of the present invention.

[0028] Fig.10 This is a flowchart of a method for controlling an electronic rearview mirror according to a fifth embodiment of the present invention.

[0029] Fig.11 This is a graph for explaining control according to Embodiment 5 of the present invention. DETAILED DESCRIPTION

[0030] Below, with appropriate reference to the accompanying drawings, the electronic rearview mirror and the electronic rearview mirror control method involved in the present disclosure are specifically disclosed in detail. However, unnecessary detailed descriptions are sometimes omitted. For example, detailed descriptions of well-known matters or repeated descriptions of substantially the same structures are sometimes omitted. This is to avoid the following description from being unnecessarily lengthy and to make it easy for those skilled in the art to understand. In addition, the drawings and the following description are provided for those skilled in the art to fully understand the present disclosure, and it is not intended to limit the subject matter described in the present disclosure by these.

[0031] (Opinion of the inventor)

[0032] For example, the electronic rearview mirror is configured to be able to switch between a mode in which it functions as a normal mirror (hereinafter also referred to as "rearview mirror mode") and a mode in which an arbitrary image is displayed through a liquid crystal display (hereinafter also referred to as "display mode"). In addition, it is known to realize the anti-glare function as described above in the rearview mirror mode. When operating in the rearview mirror mode, the liquid crystal display of the electronic rearview mirror usually stops operating. Therefore, due to this structure, there is a tendency for the reflected light on the surface of the liquid crystal display to increase. Moreover, as such reflected light increases, sometimes the reflected light from the liquid crystal electronic rearview mirror is scattered due to the reflective characteristics of the components on the optical path in the electronic rearview mirror, and light with unclear contours (hereinafter also referred to as "white blur") will appear. In addition, unexpected reflected light may be generated due to the layer structure of the liquid crystal electronic rearview mirror, thereby generating double reflections, rainbows, etc. on the surface of the display structure. Such a phenomenon will reduce the visual confirmation of the driver, and as a result, it may lead to a reduction in the operability of the vehicle.

[0033] <Implementation Method 1>

[0034] The structure example of the liquid crystal electronic rearview mirror (hereinafter also referred to as "electronic rearview mirror") involved in this embodiment is described. The electronic rearview mirror can be, for example, an interior rearview mirror or an exterior rearview mirror mounted on a vehicle. In addition, there is no particular limitation on the type of mobile body equipped with the electronic rearview mirror, and it can be a four-wheeled vehicle such as an ordinary passenger car or a two-wheeled vehicle such as a motorcycle.

[0035] [Functional structure]

[0036] Figure 1 1 is a diagram showing an example of the device structure of the electronic rearview mirror 1 according to the present embodiment. The electronic rearview mirror 1 is configured to include a display structure 10, a temperature sensor 11, an illuminance sensor 12, a control circuit 13, a storage device 14, and an external IF 15. In addition, the structure of the electronic rearview mirror 1 is an example, and it may also be, Figure 1A part of the parts shown is provided on the vehicle (not shown) side, and when mounted on the vehicle, the functions described below are achieved by cooperating with the parts on the vehicle side.

[0037] The display structure 10 has a layer structure described below, and functions by switching between a rearview mirror mode and a display mode. The temperature sensor 11 detects the ambient temperature of the electronic rearview mirror 1 as temperature information. The illuminance sensor 12 detects the illuminance of light received by the electronic rearview mirror 1 as illuminance information.

[0038] The control circuit 13 controls the operation of the electronic rearview mirror 1, especially the display structure 10, by reading out and executing various programs and data stored in the storage device 14. The storage device 14 is composed of a volatile / non-volatile storage device such as a random access memory (hereinafter referred to as "RAM") and a read-only memory (hereinafter referred to as "ROM"), and is used to store various programs and data required for executing the operation of the electronic rearview mirror 1. The RAM is, for example, a working memory used when the electronic rearview mirror 1 is in operation. The ROM, for example, stores and retains programs and data for controlling the electronic rearview mirror 1 in advance.

[0039] The external IF 15 is an interface for transmitting and receiving data with an external device (not shown), and is connected to a control device of a vehicle equipped with the electronic rearview mirror 1 in a communicative manner via, for example, a controller area network (hereinafter referred to as "CAN"), etc. In addition, the external IF 15 can also operate as an interface for supplying power to the electronic rearview mirror 1.

[0040] [white blur]

[0041] Next, use Figure 2 The "white blur" involved in this embodiment will be described. White blur is, for example, a phenomenon in which, when light is irradiated from another vehicle to the electronic rearview mirror 1, the outline of the light and its surroundings are unclear in the display structure 10 due to the structure of the electronic rearview mirror 1. Such white blur may be a major factor that reduces the visual confirmation of the driver of the vehicle using the electronic rearview mirror 1.

[0042] Figure 2 (a) is a diagram showing an example of the appearance structure of the electronic rearview mirror 1. Here, the electronic rearview mirror 1 is in the rearview mirror mode and operates as a normal mirror. Figure 2 In (a), the display structure 10 shows a dark state. Figure 2 In (b), light is irradiated to the center of the display structure 10, but blur occurs at the center 201 of the light, and the surrounding area 202 also becomes unclear. The surrounding area 203 is a dark area. In other words, a white blur occurs. Figure 2 In (c), Figure 2(b) irradiates light in the same way, but the center of the light 211 appears to be Figure 2 The center of (b) is clearer. The peripheral area 212 of the center 211 is blurred. In addition, the peripheral area 213 is a dark area. That is, Figure 2 The state of (c) is Figure 2 This is an example of a state in which the degree of white blurring is suppressed compared to the state of (b).

[0043] [Display structure of layers]

[0044] Figure 3 1 is a schematic diagram for explaining the layer structure of the display structure 10 according to the present embodiment. Figure 3 In the figure, the upper side (glass layer 311 side) corresponds to the front side of the electronic rearview mirror 1, and the lower side (backlight source 334 side) corresponds to the back side of the electronic rearview mirror 1. The front side here refers to the side where the driver using the electronic rearview mirror 1 is located, for example.

[0045] The electronic rearview mirror 1 according to the present embodiment is composed of a surface structure 310 and a display 330 , and an air gap 320 is present between the surface structure 310 and the display 330 .

[0046] The surface structure 310 is composed of a glass layer 311, an adhesive layer 312, a protective layer 313, an adhesive layer 314, a polarizing plate 315, a liquid crystal layer 316, and a reflective polarizing plate 317 stacked in order from the surface side. In this embodiment, the structure including the polarizing plate 315, the liquid crystal layer 316, and the reflective polarizing plate 317 is sometimes referred to as a reflectivity control mechanism. The adhesive layer 312 and the adhesive layer 314 are composed of, for example, Optical Clear Adhesive (hereinafter referred to as "OCA"). The glass layer 311 and the adhesive layer 312 are attached to the end region 312a of the adhesive layer 312, for example, by evaporation. The protective layer 313 is composed of, for example, polyethylene terephthalate (hereinafter referred to as "PET").

[0047] The liquid crystal layer 316 is composed of the well-known NT (Twisted Nematic) liquid crystal. The liquid crystal layer 316 is configured to switch the direction of the liquid crystal molecules by switching the applied voltage. By switching the direction of the liquid crystal molecules, the transmission / blocking of light is controlled according to the polarization direction of the polarizing plate 315 and the reflective polarizing plate 317. In the case of NT liquid crystal, light is transmitted through the polarizing plate located around the NT liquid crystal due to the optical rotation of light when no voltage is applied, and the light is blocked by the polarizing plate when a voltage is applied. The structure and characteristics of TN liquid crystal are well known, and a detailed description is omitted here.

[0048] The polarizing plate 315 and the reflective polarizing plate 317 located around the liquid crystal layer 316 are arranged so that the polarization axes are orthogonal to each other, so that the polarization components corresponding to the polarization axes are transmitted. In addition, in the reflective polarizing plate 317, the light orthogonal to the polarization axis is reflected at a high reflectivity, and the component parallel to the parallel axis is reflected at a low reflectivity. That is, it is configured so that the component parallel to the parallel axis is transmitted through the reflective polarizing plate 317. In other words, the reflection of light by the reflective polarizing plate 317 is adjusted by applying a voltage to the liquid crystal layer 316 constituting the reflectivity control mechanism, thereby adjusting the reflectivity by the reflectivity control mechanism.

[0049] In addition, the display 330 is configured as follows: an upper polarizing plate 331, a liquid crystal unit 332, a lower polarizing plate 333, and a backlight source 334 are stacked in order from the surface side. The upper polarizing plate 331 and the lower polarizing plate 333 are provided with polarization axes along a predetermined direction, and the components of light are transmitted by the polarization axes. In addition, the upper and lower polarizing plates 331 and the lower polarizing plates 333 are merely indicated relative positional relationships with respect to the liquid crystal unit 332, and are not intended to be interpreted in a limiting manner. In the liquid crystal unit 332, cells 332a, 332b, and 332c corresponding to R (red), G (green), and B (blue) are arranged according to a predetermined rule. The backlight source 334 functions as a light source, and is configured to include, for example, a light emitting diode (hereinafter referred to as "LED") and the like.

[0050] [Reflection principle]

[0051] Here, use Figure 4 The principle of reflection caused by the layer structure of the display structure will be described. Figure 4 (a) is Figure 3 An enlarged view of the vicinity of a liquid crystal unit in a display having a display structure as shown in FIG. An upper polarizing plate 401 and a liquid crystal unit 402 are shown in the display 400. In addition, in the liquid crystal unit 402, cells 402a, 402b, and 402c corresponding to RGB are arranged according to a prescribed rule. At this time, the upper polarizing plate 401 is a polarizing plate that has been subjected to a hard coating (HC) and an anti-reflection (AR) surface treatment to reduce diffuse reflection.

[0052] If used Figure 3As described above, the transmittance of light in the reflectivity control mechanism is controlled by applying a voltage to the liquid crystal layer 316. At this time, when the reflectivity control mechanism is controlled so that the light is reflected at the reflective polarizing plate 317, that is, when the reflectivity at the reflective polarizing plate 317 is made high reflective, the degree of light reaching the display 330 becomes small. On the other hand, when the reflectivity control mechanism is controlled so that the light passes through the reflective polarizing plate 317, that is, when the reflectivity at the reflective polarizing plate 317 is made low reflective, the degree of light reaching the display 330 becomes large.

[0053] In such a structure, double reflection of the reflected light generated by the reflective polarizing plate 317 of the surface structure 310 and the reflected light 404 generated by the upper surface of the upper polarizing plate 401 of the display 330 may occur on the surface of the display structure 10. The degree of the double reflection varies depending on the voltage applied to the liquid crystal layer 316, that is, the degree of anti-glare. In addition, there is a case where a phenomenon like a diffraction grating is generated for the incident light by each unit constituting the liquid crystal unit 402, and the reflected light 403 like a rainbow appears on the surface of the display structure 10. For convenience, the phenomena that appear on the surface of the display structure as described above are respectively referred to as "double reflection" and "rainbow" for explanation.

[0054] Figure 4 (b) is also Figure 3 An enlarged view of the vicinity of a liquid crystal unit in a display having a display structure as shown. An upper polarizing plate 411 and a liquid crystal unit 412 are shown in the display 410. In addition, in the liquid crystal unit 412, units 412a, 412b, and 412c corresponding to RGB are arranged according to a prescribed rule. At this time, the upper polarizing plate 411 is a polarizing plate that has been treated with anti-glare (AG) to reduce diffuse reflection. In this structure, the upper polarizing plate 411 is configured to include a filler 411a. The filler 411a is used to suppress the incident light 413 from Figure 4 In the structure of (a), the reflection light like a rainbow may be generated. In addition, by making the filler 411a appear on the surface of the upper polarizing plate 411, the reflection of the incident light 414 is suppressed, thereby suppressing the occurrence of double reflection. The degree of diffuse reflection is affected by the particle size of the filler 411a. On the other hand, there is a case where diffuse reflection is generated by the filler 411a, thereby generating a rainbow like using Figure 2 The degree of white blurring as described above increases.

[0055] [evaluate]

[0056] Based on the above, the inventors of the present invention determined that: Figure 4In the structure (b), by adjusting the haze of the upper polarizing plate, it is possible to suppress the occurrence of any of the phenomena of double reflection, rainbow, and white blur. Figure 5 The evaluation example as the verification result is shown. In addition, the method for measuring the haze uses a known method, and the detailed description is omitted here. The haze is calculated based on the ratio of the diffuse transmitted light to the total light transmitted light. In addition, in this evaluation example, only the haze of the upper polarizing plate is switched, and the other structures are the same.

[0057] First, in this embodiment, in order to suppress the occurrence of double reflection and rainbow, anti-glare (AG) treatment is applied to the upper polarizing plate. On this basis, the occurrence of white blur is also suppressed by adjusting the haze of the upper polarizing plate.

[0058] exist Figure 5 In the evaluation examples shown, there are five structures 1 to 5, and the haze is changed respectively. In these structures, the generation of double reflection, rainbow, and white blur is sensory evaluated by human visual recognition. In the sensory evaluation, the evaluation is performed on five levels (1 to 5), "5" is the highest evaluation, and "1" is the lowest evaluation. Figure 4 As shown, due to the anti-glare (AG) treatment, it was evaluated that double reflection and rainbow generation were suppressed in all of Structures 1 to 5. On the other hand, white blurring occurred in the haze in Structures 3 to 5, resulting in low evaluation values.

[0059] In contrast, the occurrence of white blur can be suppressed at the haze in Structure 1 and Structure 2, resulting in a high evaluation value. Figure 5 In the structure shown, at least when the haze of the upper polarizing plate is in the range of 5.7[%] to 7.9[%], the generation of white blur can be suppressed, and a display structure with high display quality can be realized. The inventor of the present invention has confirmed through further verification that the generation of white blur can be suppressed when the haze is in the range of 3.0[%] to 8.0[%], and it is preferred to design the haze of the upper polarizing plate of the electronic rearview mirror within this range.

[0060] As described above, according to the present embodiment, the electronic rearview mirror (e.g., electronic rearview mirror 1) comprises: a first polarizing plate (e.g., polarizing plate 315); a liquid crystal layer (e.g., liquid crystal layer 316), which is disposed on the back side of the first polarizing plate, and the optical rotation of light is controlled by applying a voltage; a reflective polarizing plate (e.g., reflective polarizing plate 317), which is disposed on the back side of the liquid crystal layer, and reflects or transmits light from the liquid crystal layer based on the polarization axis; a second polarizing plate (e.g., upper polarizing plate 331), which is disposed on the back side of the reflective polarizing plate; a liquid crystal unit (e.g., liquid crystal unit 332), which is disposed on the back side of the second polarizing plate; and a backlight source (e.g., backlight source 334), which is disposed on the back side of the liquid crystal unit, wherein the haze of the second polarizing plate is in the range of 3.0% to 8.0%.

[0061] This can suppress the occurrence of white blur on the surface of the display structure of the electronic rearview mirror, thereby improving the visual recognition of the user.

[0062] In addition, an anti-glare treatment is applied to the second polarizing plate.

[0063] This can suppress the occurrence of double reflection and rainbow on the surface of the display structure of the electronic rearview mirror, thereby improving the visual recognition of the user.

[0064] In addition, an air gap is formed between the reflective polarizing plate and the second polarizing plate.

[0065] As a result, the cost in configuring the electronic rearview mirror, such as the bonding cost and the number of manufacturing steps, can be reduced, and the electronic rearview mirror can be manufactured at low cost.

[0066] <Implementation Method 2>

[0067] Embodiment 2 of the present invention will be described. Note that description of the same configuration as that of Embodiment 1 will be omitted, and description will be given focusing on differences.

[0068] In implementation mode 1 Figure 3 In the structural example of the electronic rearview mirror 1 shown, a structure in which an air gap 320 is present between the surface structure 310 and the display 330 is shown. The inventor of the present invention has determined that the air gap 320 affects the occurrence of double reflection. Therefore, in this embodiment, a structure in which the air gap is replaced in order to further suppress the occurrence of double reflection is described.

[0069] [Display structure of layers]

[0070] Figure 6 1 is a schematic diagram for explaining the layer structure of the display structure 10 according to the present embodiment. Figure 6In the figure, the upper side (glass layer 611 side) corresponds to the front side of the electronic rearview mirror 1, and the lower side (backlight source 634 side) corresponds to the back side of the electronic rearview mirror 1.

[0071] The electronic rearview mirror 1 according to the present embodiment is Figure 3 The structure of the embodiment 1 shown in the figure is similarly constituted by the surface structure 610 and the display 630, and these components are also the same. Figure 3 The difference is that an adhesive layer 620 is provided between the surface structure 610 and the display 630 to replace the air gap 320.

[0072] The adhesive layer 620 is configured to bond the surface structure 610 and the display 630 using a predetermined adhesive member. As the adhesive member here, for example, an acrylic adhesive, a silicone adhesive, etc. can be used. In addition, the adhesive member may also include a Figure 4 The filler 411a of (b) is a material having a diffusion function. As such a diffusion material, silicon dioxide particles, i.e., silicon-based particles, etc. can be used. In addition, as a structure without a diffusion component, the adhesive layer 620 can also use OCA, Optical Clear Resin (optically transparent resin, hereinafter referred to as "OCR").

[0073] In order to suppress the occurrence of double reflection and rainbow as described in Embodiment 1, the combination of the components of the adhesive member constituting the adhesive layer 620 and the structure of the upper polarizing plate 631 may be designed as follows.

[0074] (Combination 1)

[0075] Adhesive constituting the adhesive layer 620: no diffuse component

[0076] Upper polarizing plate 631: Hard coating (HC)

[0077] This can suppress the occurrence of double reflection.

[0078] (Combination 2)

[0079] Adhesive constituting the adhesive layer 620: no diffuse component

[0080] Upper polarizing plate 631: Anti-glare (AG)

[0081] This can suppress the occurrence of double reflection and rainbow.

[0082] (Combination 3)

[0083] Adhesive constituting the adhesive layer 620: having a diffusion component

[0084] Upper polarizing plate 631: Hard coating (HC) or anti-glare (AG)

[0085] This can suppress the occurrence of double reflection and rainbow.

[0086] As described above, according to the present embodiment, the electronic rearview mirror (e.g., electronic rearview mirror 1) comprises: a first polarizing plate (e.g., polarizing plate 615); a liquid crystal layer (e.g., liquid crystal layer 616), which is disposed on the back side of the first polarizing plate, and the optical activity of light is controlled by applying a voltage; a reflective polarizing plate (e.g., reflective polarizing plate 617), which is disposed on the back side of the liquid crystal layer, and reflects or transmits light from the liquid crystal layer based on the polarization axis; a second polarizing plate (e.g., upper polarizing plate 631), which is disposed on the back side of the reflective polarizing plate; a liquid crystal unit (e.g., liquid crystal unit 632), which is disposed on the back side of the second polarizing plate; and a backlight source (e.g., backlight source 634), which is disposed on the back side of the liquid crystal unit, wherein the reflective polarizing plate and the second polarizing plate are bonded to each other by an adhesive member (e.g., adhesive layer 620).

[0087] This can suppress the occurrence of double reflection and rainbow in the display structure of the electronic rearview mirror, thereby improving the visual recognition of the user.

[0088] In addition, the adhesive member is an acrylic adhesive or a silicone adhesive. In addition, the adhesive member includes a diffusion material for diffusing light. In addition, the diffusion material is silicone particles.

[0089] Thus, by bonding the reflective polarizing plate and the upper polarizing plate using an arbitrary bonding member, it is possible to suppress the occurrence of double reflection and rainbow in the display structure of the electronic rearview mirror.

[0090] <Implementation Method 3>

[0091] Embodiment 3 of the present invention will be described. Note that description of the same configuration as that of Embodiment 1 will be omitted, and description will be given focusing on differences.

[0092] In implementation mode 1 Figure 3 In the structural example of the electronic rearview mirror 1 shown, a structure in which an air gap 320 exists between the surface structure 310 and the display 330 is shown. In Embodiment 2, a structure in which the air gap that affects the occurrence of double reflection is removed is described. On the other hand, in this embodiment, a structure in which the position of the air gap is changed in order to further suppress the occurrence of double reflection is described.

[0093] [Display structure of layers]

[0094] Figure 7 1 is a schematic diagram for explaining the layer structure of the display structure 10 according to the present embodiment. Figure 7In the figure, the upper side (glass layer 711 side) corresponds to the front side of the electronic rearview mirror 1, and the lower side (backlight source 733 side) corresponds to the back side of the electronic rearview mirror 1.

[0095] The electronic rearview mirror 1 according to the present embodiment is Figure 3 The structure of the first embodiment shown is similarly constituted by the surface structure 710 and the display 730 , and the components are also the same. In addition, an air gap 720 exists between the surface structure 710 and the display 730 .

[0096] As Figure 3 The difference from the embodiment 1 shown is that the upper polarizing plate provided on the display is moved to the surface structure. Therefore, the surface structure 710 is composed of: a glass layer 711, an adhesive layer 712, a protective layer 713, an adhesive layer 714, a polarizing plate 715, a liquid crystal layer 716, a reflective polarizing plate 717, an adhesive layer 718, and an upper polarizing plate 719 are stacked in sequence from the surface side. As in the embodiment 1, as a reflectivity control mechanism, it is composed of a polarizing plate 715, a liquid crystal layer 716, and a reflective polarizing plate 717. The adhesive layer 712, the adhesive layer 714, and the adhesive layer 718 are composed of, for example, OCA. The glass layer 711 and the adhesive layer 712 are attached to the end area 712a of the adhesive layer 712, for example, by evaporation. The protective layer 713 is composed of, for example, PET. The upper polarizing plate 719 is composed of, for example, hardening coating (HC).

[0097] The display 730 is configured such that a liquid crystal cell 731 , a lower polarizing plate 732 , and a backlight 733 are stacked in this order from the front surface side.

[0098] According to the above-mentioned structure, it is possible to suppress Figure 4 As a result, the occurrence of double reflection can be suppressed by the reflected light generated by the upper polarizing plate as shown in (a).

[0099] As described above, according to the present embodiment, the electronic rearview mirror (e.g., electronic rearview mirror 1) includes: a first polarizing plate (e.g., polarizing plate 715); a liquid crystal layer (e.g., liquid crystal layer 716) disposed on the back side of the first polarizing plate, and the optical rotation of light is controlled by applying a voltage; a reflective polarizing plate (e.g., reflective polarizing plate 717) disposed on the back side of the liquid crystal layer, and light from the liquid crystal layer is reflected or transmitted based on the polarization axis; a second polarizing plate (e.g., upper polarizing plate 719) disposed on the back side of the reflective polarizing plate; a liquid crystal unit (e.g., liquid crystal unit 731) disposed on the back side of the second polarizing plate; and a backlight source (e.g., backlight source 733) disposed on the back side of the liquid crystal unit, wherein the reflective polarizing plate and the second polarizing plate are bonded to each other by a bonding member (e.g., bonding layer 718). In addition, there is an air gap (e.g., air gap 720) between the second polarizing plate and the liquid crystal unit.

[0100] This can suppress the occurrence of double reflection and rainbow in the display structure of the electronic rearview mirror, thereby improving the visual recognition of the user.

[0101] <Implementation Method 4>

[0102] Embodiment 4 of the present invention will be described. Note that description of the same configuration as that of Embodiment 1 will be omitted, and description will be given focusing on differences.

[0103] If used Figure 4 As described in the above, double reflection occurs due to the reflected light from the reflective polarizing plate 317 of the surface structure 310 and the reflected light from the upper polarizing plate 331 of the display 330. Therefore, in this embodiment, a structure is described in which these components are combined into one component to suppress the occurrence of double reflection.

[0104] [Display structure of layers]

[0105] Figure 8 1 is a schematic diagram for explaining the layer structure of the display structure 10 according to the present embodiment. Figure 8 In the figure, the upper side (glass layer 811 side) corresponds to the front side of the electronic rearview mirror 1, and the lower side (backlight source 833 side) corresponds to the back side of the electronic rearview mirror 1.

[0106] The electronic rearview mirror 1 according to the present embodiment is Figure 3 The structure of the first embodiment shown is similarly constituted by the surface structure 810 and the display 830 , and the components are also the same. In addition, an air gap 820 exists between the surface structure 810 and the display 830 .

[0107] As Figure 3 The difference from the embodiment 1 shown in the figure is that the upper polarizing plate provided in the display is removed. Therefore, the display 830 is configured as follows: a liquid crystal unit 831, a lower polarizing plate 832, and a backlight 833 are stacked in order from the surface side. That is, in this embodiment, the functions of the reflective polarizing plate 317 of the surface structure 310 shown in the embodiment 1 and the upper polarizing plate 331 of the display 330 are realized by the reflective polarizing plate 817 of the surface structure 810.

[0108] According to this embodiment, it is possible to suppress Figure 4 As a result, the occurrence of double reflection can be suppressed by the reflected light generated by the upper polarizing plate as shown in (a).

[0109] As described above, according to the present embodiment, the electronic rearview mirror (e.g., electronic rearview mirror 1) comprises: a first polarizing plate (e.g., polarizing plate 815); a liquid crystal layer (e.g., liquid crystal layer 816), which is disposed on the back side of the first polarizing plate, and the optical rotation of light is controlled by applying a voltage; a reflective polarizing plate (e.g., reflective polarizing plate 817), which is disposed on the back side of the liquid crystal layer, and reflects or transmits light from the liquid crystal layer based on the polarization axis; a liquid crystal unit (e.g., liquid crystal unit 831), which is disposed on the back side of the reflective polarizing plate; and a backlight source (e.g., backlight source 833), which is disposed on the back side of the liquid crystal unit.

[0110] This can suppress the occurrence of double reflection in the display structure of the electronic rearview mirror, thereby improving the visual confirmation of the user.

[0111] In addition, there is an air gap between the reflective polarizing plate and the liquid crystal cell.

[0112] As a result, the cost in configuring the electronic rearview mirror, such as the bonding cost and the number of manufacturing steps, can be reduced, and the electronic rearview mirror can be manufactured at low cost.

[0113] <Implementation method 5>

[0114] Embodiment 5 of the present invention will be described. In this embodiment, control of the electronic rearview mirror having the above-described structure will be described. The control method described in this embodiment can also be applied to the structure of any of the electronic rearview mirrors shown in the above-described embodiments.

[0115] Fig. 9 is a graph for explaining the relationship between the voltage applied to the liquid crystal layer and the reflected light. Fig. 9 In the figure, the horizontal axis represents the voltage applied to the liquid crystal layer [V], and the vertical axis represents SCI (Specular Component Include: including specular reflected light) [%]. Figure 3 The electronic rearview mirror 1 shown is an example of the structure of the embodiment 1. In consideration of double reflection and rainbow, the upper polarizing plate 331 is configured to be anti-glare (AG).

[0116] The solid line 901 shows the change of the SCI of the electronic rearview mirror 1, that is, the display structure 10, when the applied voltage is changed. In addition, the dotted line 902 shows the change of the diffuse reflection component of the upper polarizing plate 331 when the applied voltage is changed. As shown by the solid line 901, if the applied voltage is increased, the reflectivity at the reflective polarizing plate 317 is reduced, so there is a tendency for the SCI of the electronic rearview mirror 1 to decrease. In addition, as shown by the dotted line 902, if the applied voltage is increased, the transmittance is increased, so there is a tendency for the diffuse reflection component of the upper polarizing plate 331 of the light that has passed through the surface structure 310 to increase.

[0117] Regarding the anti-glare function provided by the electronic rearview mirror 1, as an example, consider controlling the liquid crystal layer 316 within a voltage range that minimizes the SCI value of the display structure 10. The voltage range for controlling the liquid crystal layer 316 to minimize the SCI value of the display structure 10 is, for example, a voltage range that makes the SCI of the display structure 10 13%. On the other hand, when the liquid crystal layer 316 is controlled within a voltage range that minimizes the SCI, as shown by the dotted line 902, the diffuse reflection component of the upper polarizing plate 331 increases. The increase in the diffuse reflection component of the upper polarizing plate 331 leads to an increase in the white blur in the electronic rearview mirror 1. About Figure 3 The structure of the electronic rearview mirror 1 shown in FIG. 1 has been verified by the inventors of the present invention and it has been confirmed that when the liquid crystal layer 316 is controlled in a voltage range such that the SCI value is in the range of about 17% to 20%, the SCI value can be lowered than the maximum value and the diffuse reflection component of the upper polarizing plate 331 can be reduced to about 70% or less of the maximum value, thereby reducing white blur. Therefore, in this embodiment, based on Fig. 9 By adjusting the applied voltage based on the relationship between the applied voltage and the reflected light as shown, the reflectance, that is, the transmittance, of the reflectance control mechanism during anti-glare is controlled, thereby reducing white blur.

[0118] In addition, the relationship between the applied voltage and the SCI can vary depending on the structure of the parts included in the layer structure of the electronic rearview mirror 1, such as the structure of the reflective polarizing plate. Therefore, the applied voltage is adjusted according to the structure of the electronic rearview mirror 1. In addition, the relationship between the applied voltage and the SCI can also vary depending on the surrounding environment of the electronic rearview mirror 1. As the surrounding environment, for example, the ambient temperature and ambient humidity of the electronic rearview mirror 1 are listed. Here, the ambient temperature is listed as an example for explanation.

[0119] [Processing Flow]

[0120] Fig.10 This is a flowchart of the control process of the electronic rearview mirror 1 according to the present embodiment. This process flow can also be realized by, for example, the control circuit 13 reading and executing the program and various data in the storage device 14. Here, for simplicity of description, the processing subject is collectively described as the control circuit 13.

[0121] The control circuit 13 receives a start signal of the electronic rearview mirror 1 from the vehicle (not shown) side (step S1001). The start signal may be, for example, a notification signal that the power supply to the electronic rearview mirror 1 has started, or a notification signal that the vehicle (not shown) equipped with the electronic rearview mirror 1 has become a drivable state (for example, the ignition is turned on ("ON")).

[0122] The control circuit 13 determines whether a setting of turning on the rearview mirror mode ("ON") is accepted (step S1002). The rearview mirror mode can be set arbitrarily by the driver of the vehicle or can be set automatically on the vehicle side. The electronic rearview mirror 1 involved in the present embodiment is configured to be able to switch between the rearview mirror mode and the display mode. In the case of accepting a setting of turning on the rearview mirror mode (step S1002: "Yes"), the processing of the control circuit 13 enters step S1005. On the other hand, in the case of accepting a setting of turning off the rearview mirror mode ("OFF"), that is, setting the display mode to turn on (step S1002: "No"), the processing of the control circuit 13 enters step S1003.

[0123] The control circuit 13 sets the display mode (step S1003 ). Then, the control circuit 13 proceeds to step S1004 .

[0124] The control circuit 13 performs a predetermined image output control in the display mode (step S1004). The displayed image may be, for example, an image of the surrounding area behind the vehicle captured by a camera (not shown) disposed at the rear of the vehicle. Then, the control circuit 13 proceeds to step S1021.

[0125] The control circuit 13 sets the rearview mirror mode (step S1005 ). Then, the control circuit 13 proceeds to step S1006 .

[0126] The control circuit 13 acquires illumination information indicating the illumination of light received by the electronic rearview mirror 1 by means of the illumination sensor 12 (step S1006). Here, the illumination information includes the illumination of light irradiated toward the vehicle from the front side of the vehicle (i.e., the back side of the electronic rearview mirror 1) (hereinafter referred to as "vehicle front illumination"), and the illumination of light irradiated toward the vehicle from the rear side of the vehicle (i.e., the surface side where the display structure 10 of the electronic rearview mirror 1 is located) (hereinafter referred to as "vehicle rear illumination").

[0127] The control circuit 13 determines whether the illuminance in front of the vehicle is below the first threshold value based on the illuminance information acquired in step S1006 (step S1007). The first threshold value is predetermined and stored in the storage device 14. When the illuminance in front of the vehicle is below the first threshold value (step S1007: "Yes"), the processing of the control circuit 13 enters step S1010. On the other hand, when the illuminance in front of the vehicle is greater than the first threshold value (step S1007: "No"), the processing of the control circuit 13 enters step S1008.

[0128] The control circuit 13 sets the anti-glare mode of the electronic rearview mirror to OFF (step S1008 ). The electronic rearview mirror 1 according to the present embodiment can switch between ON and OFF of the anti-glare mode when the rearview mirror mode is ON.

[0129] The control circuit 13 controls the voltage applied to the liquid crystal layer 316 in the reflectivity control mechanism to set the reflectivity to a fixed value (step S1009). The fixed value of the reflectivity used here can be predetermined, and here, control is performed so that the reflectivity of the reflective polarizing plate 317 is maximized. That is, it functions in the same way as a normal mirror. Then, the processing of the control circuit 13 enters step S1021.

[0130] The control circuit 13 determines whether the illumination behind the vehicle is below the second threshold value based on the illumination information obtained in step S1006 (step S1010). The second threshold value is predetermined and stored in the storage device 14. In addition, there is no particular limitation on each of the first threshold value and the second threshold value, but the value can be defined in consideration of the visual confirmation when the driver confirms the electronic rearview mirror 1. In the present embodiment, the second threshold value is defined in order to determine whether the electronic rearview mirror 1 receives light equivalent to the high beam. Regarding the specific example, the following uses Fig.11 When the illumination behind the vehicle is less than the second threshold value (step S1010: "Yes"), the control circuit 13 proceeds to step S1016. On the other hand, when the illumination behind the vehicle is greater than the second threshold value (step S1010: "No"), the control circuit 13 proceeds to step S1011.

[0131] The control circuit 13 controls the backlight source 334 to light up the backlight source 334 in such a way that the black image level is maximized (step S1011). That is, the control circuit 13 controls the light emission of the backlight source 334 to maximize the black image expression. In addition, the black image level that can be expressed by the backlight source 334 varies depending on the structure such as the dynamic range, for example.

[0132] The control circuit 13 sets the first anti-glare mode to on (step S1012). Here, the first anti-glare mode refers to a mode in which the reflectivity of the reflectivity control mechanism is controlled to be a fixed value so that the anti-glare function is activated. The first anti-glare mode is activated, for example, when the vehicle receives the light of the high beam from other vehicles behind, so as to prevent the visual confirmation of the electronic rearview mirror 1 from being reduced due to the high beam from the other vehicles behind.

[0133] The control circuit 13 acquires temperature information indicating the ambient temperature of the electronic rearview mirror 1 via the temperature sensor 11 (step S1013 ).

[0134] The control circuit 13 corrects the voltage applied to the liquid crystal layer 316 based on the temperature information acquired in step S1013 (step S1014 ). Fig. 9 The relationship between the applied voltage and SCI as shown may change depending on the ambient temperature of the electronic rearview mirror 1. It is conceivable that the change in the correlation caused by such a change in the ambient temperature may prevent the diffuse reflection component from being reduced to the target level under the applied voltage to the liquid crystal layer 316 before correction. Therefore, in this embodiment, the applied voltage is corrected based on the acquired temperature information, thereby achieving a reduction in the diffuse reflection component to the target level, thereby reducing white blur. There is no particular limitation on the correction method, for example, a predetermined table may be used to determine the correction amount, or a predetermined calculation formula may be used to determine the value of the applied voltage.

[0135] The control circuit 13 applies the applied voltage determined in step S1014 to the liquid crystal layer 316, and sets the reflectivity of the reflectivity control mechanism to a fixed value (step S1015). The fixed value of the reflectivity used here can be predetermined and is different from the fixed value in the process of step S1009. For convenience, the fixed value used in the process of step S1009 is also referred to as a "first fixed value", and the fixed value in this process is also referred to as a "second fixed value". Then, the processing of the control circuit 13 enters step S1021.

[0136] The control circuit 13 controls the backlight source 334 to light up the backlight source 334 in such a manner that the black image level can be changed according to the illuminance behind the vehicle (step S1016). That is, the control circuit 13 controls the light emission of the backlight source 334 based on the detected illuminance behind the vehicle. Here, the lighting control of the backlight source 334 can also be performed based on a table predetermined corresponding to the illuminance behind the vehicle, for example.

[0137] The control circuit 13 sets the second anti-glare mode to on (step S1017). Here, the second anti-glare mode refers to a mode in which the anti-glare function is operated by controlling the reflectivity of the reflectivity control mechanism to be variable. The second anti-glare mode is operated, for example, in a state other than the high beam, and the visual confirmation of the electronic rearview mirror 1 is prevented from being reduced by switching the reflectivity in the reflectivity control mechanism according to the illumination behind the vehicle.

[0138] The control circuit 13 obtains temperature information indicating the ambient temperature via the temperature sensor 11 (step S1018 ).

[0139] The control circuit 13 corrects the voltage applied to the liquid crystal layer 316 based on the temperature information acquired in step S1018 (step S1019). The correction is not particularly limited and may be performed in the same manner as step S1014 or using other information (eg, a table or a calculation formula).

[0140] The control circuit 13 applies the applied voltage determined in step S1019 to the liquid crystal layer 316 to adjust the reflectivity of the reflectivity control mechanism (step S1020). Here, the reflectivity varies according to the illumination of the light received by the electronic rearview mirror 1 (particularly the illumination behind the vehicle). Then, the processing of the control circuit 13 enters step S1021.

[0141] The control circuit 13 determines whether a stop signal for the electronic rearview mirror 1 is received (step S1021). The stop signal may be, for example, a notification signal that the power supply to the electronic rearview mirror 1 is stopped, or a notification signal that the movement of the vehicle (not shown) equipped with the electronic rearview mirror 1 is stopped (for example, the ignition switch is turned off). If a stop signal is received (step S1021: "Yes"), the processing flow is terminated. On the other hand, if a stop signal is not received (step S1021: "No"), the processing of the control circuit 13 returns to step S1002 and the processing is repeated.

[0142] Fig.11 It is shown in Fig.10 A graph showing the relationship between reflectivity / applied voltage and illuminance involved in the control of the process flow shown in FIG. Fig.11 In FIG. 1 , the vertical axis represents reflectance / applied voltage, and the horizontal axis represents the illuminance behind the vehicle detected by the illuminance sensor 12 .

[0143] Fig.11 (a) is the case where the rearview mirror mode and the anti-glare mode are turned off, that is, Fig.10 The curves corresponding to the actions of the process of step S1008 to step S1009 are shown in FIG. 1101. Curve 1102 represents the applied voltage. In this mode, the reflectivity control mechanism controls the applied voltage to be constant regardless of the detected illumination behind the vehicle. In this embodiment, the reflectivity is a fixed value and is set to a maximum value.

[0144] Fig.11 (b) is a curve corresponding to the case where the rearview mirror mode and the anti-glare mode are turned on. As described above, in this embodiment, the first anti-glare mode and the second anti-glare mode are further used. Fig.10 The second threshold used in step S1010 corresponds to Fig.11The threshold value T shown in (b) of FIG. Therefore, when the detected vehicle rear illuminance is below the threshold value T, the second anti-glare mode is activated, and when the detected vehicle rear illuminance is greater than the threshold value T (for example, when the high beam is detected), the first anti-glare mode is activated.

[0145] Curve 1111 represents the reflectivity, and curve 1112 represents the applied voltage. In the second anti-glare mode, the reflectivity control mechanism is controlled so that the applied voltage becomes higher as the illumination behind the vehicle becomes larger. As a result, the reflectivity is controlled so that the reflectivity becomes smaller as the illumination behind the vehicle becomes larger. On the other hand, in the first anti-glare mode, the reflectivity control mechanism is controlled so that the applied voltage is fixed regardless of the change in the detected illumination behind the vehicle. As a result, the reflectivity is a fixed value.

[0146] As described above, the inventors of the present invention have determined that by controlling the SCI within the range of 17% to 20% in the anti-glare mode, the diffuse reflection component generated by the structure of the electronic rearview mirror 1 can be reduced to a target level, thereby achieving a reduction in white blur. Fig.11 In the curve (b) as well, control is performed so as to be within the above-mentioned parameter range.

[0147] In addition, Fig.11 In the embodiment, an example of a liquid crystal layer having a structure in which the reflectivity is reduced by increasing the applied voltage in the reflectivity control mechanism is shown, but the invention is not limited thereto. Therefore, even if the reflectivity control mechanism has a structure in which the reflectivity is increased by decreasing the applied voltage, the control can be performed in the same manner. In addition, an example in which the reflectivity is reduced in proportion to the increase in the illuminance behind the vehicle in the second anti-glare mode is shown. However, the reduction in this case is not limited to the above. Fig.11 For example, a structure in which the reduction in reflectivity is represented by a curve may be used.

[0148] As described above, according to the present embodiment, an electronic rearview mirror (e.g., electronic rearview mirror 1) configured to be able to switch the anti-glare function includes: a display structure (e.g., display structure 10) whose light reflectivity is controlled; an illuminance sensor (e.g., 12) that obtains a first illuminance (e.g., vehicle rear illuminance) from the surface side of the display structure and a second illuminance (e.g., vehicle front illuminance) from the back side of the display structure; and a control circuit (e.g., control circuit 13) that adjusts the applied voltage to the liquid crystal layer (e.g., liquid crystal layer 316) provided by the display structure based on the first illuminance and the second illuminance, thereby controlling the anti-glare function, wherein when the anti-glare function is in operation, the control circuit adjusts the applied voltage so that the reflectivity of the display structure is within a prescribed range. In addition, when the second illuminance is greater than the first threshold value, the control circuit stops the anti-glare function and adjusts the applied voltage to the liquid crystal layer so that the reflectivity of the display structure is at a maximum value (e.g., steps S1008 to S1009). In addition, when the second illuminance is less than the first threshold and the first illuminance is greater than the second threshold, the control circuit adjusts the applied voltage to the liquid crystal layer so that the reflectivity of the display structure is within a specified range (for example, step S1015). In addition, the display structure is configured to include: a reflective polarizing plate (for example, the reflective polarizing plate 317), which is located on the back side of the liquid crystal layer; and a polarizing plate (for example, the upper polarizing plate 331), which is located on the back side of the reflective polarizing plate, and the specified range is specified so that the diffuse reflection component of the polarizing plate for light incident from the surface side is less than 70% of the maximum value. In addition, the specified range is specified so that the reflectivity of the SCI (Specular Component Include: including specular regular reflection light) of the display structure is in the range of 17% to 20%. In addition, when the second illuminance is less than the first threshold and the first illuminance is less than the second threshold, the control circuit adjusts the applied voltage so that the reflectivity of the display portion decreases as the second illuminance increases (for example, step S1020).

[0149] This can suppress the occurrence of white blur in the display structure of the electronic rearview mirror, thereby improving the visual confirmation of the user.

[0150] In addition, a temperature sensor (eg, 11 ) is provided, which acquires the ambient temperature of the electronic rearview mirror, and the control circuit corrects the voltage applied to the liquid crystal layer based on the ambient temperature.

[0151] This can provide an anti-glare function that suppresses the occurrence of white blurring in response to changes in ambient temperature.

[0152] When the second illuminance is less than or equal to the first threshold and the first illuminance is greater than the second threshold, the control circuit adjusts so that the black image level of the backlight provided in the electronic rearview mirror becomes maximum (for example, step S1011).

[0153] Thus, when receiving light with a high illuminance of a certain level or higher, such as a high beam, the reflection of the upper polarizing plate can be made less noticeable. As a result, the visual confirmation of the user can be improved.

[0154] Furthermore, when the second illuminance is equal to or less than the first threshold value and the first illuminance is equal to or less than the second threshold value, the control circuit adjusts the black image level of the backlight provided in the electronic rearview mirror according to the first illuminance.

[0155] Therefore, by adjusting the black image level according to the detected illuminance, the visual confirmation of the user can be improved.

[0156] <Other Implementation Methods>

[0157] The above, while referring to the attached Figure 1 While various embodiments are described, the present disclosure is certainly not limited to such examples. Obviously, as long as one is skilled in the art, various modification examples, correction examples, substitution examples, addition examples, deletion examples, and equivalent examples can be thought of within the scope described in the claims, and it can be understood that these examples certainly also belong to the technical scope of the present disclosure. In addition, the various constituent elements in the above-mentioned various embodiments can also be arbitrarily combined within the scope of the main purpose of the invention.

[0158] In addition, in this specification, the terms "first" and "second" are used only to distinguish from other elements and should not be construed as being limited to specific components. Therefore, these terms may be appropriately replaced according to the structure and relationship to which the present invention is applied.

[0159] (Note)

[0160] According to the description of the above embodiments, the following technology is disclosed.

[0161] (Technology 1)

[0162] An electronic rearview mirror comprises: a first polarizing plate; a liquid crystal layer, which is arranged on the back side of the first polarizing plate, and the optical rotation of light is controlled by applying a voltage; a reflective polarizing plate, which is arranged on the back side of the liquid crystal layer, and reflects or transmits light from the liquid crystal layer based on the polarization axis; a second polarizing plate, which is arranged on the back side of the reflective polarizing plate; a liquid crystal unit, which is arranged on the back side of the second polarizing plate; and a backlight source, which is arranged on the back side of the liquid crystal unit, wherein the haze of the second polarizing plate is within the range of 3.0% to 8.0%.

[0163] According to this configuration, the generation of white blur on the surface of the display structure of the electronic rearview mirror can be suppressed, and as a result, the visual confirmation of the user can be improved.

[0164] (Technique 2)

[0165] The electronic rearview mirror according to technology 1, wherein the second polarizing plate is subjected to anti-glare treatment.

[0166] According to this structure, it is possible to suppress the occurrence of double reflection and rainbow on the surface of the display structure of the electronic rearview mirror, thereby improving the visual confirmation of the user.

[0167] (Technique 3)

[0168] In the electronic rearview mirror according to the technique 1 or the technique 2, an air gap is formed between the reflective polarizing plate and the second polarizing plate.

[0169] According to this configuration, the cost when configuring the electronic rearview mirror, for example, the bonding cost and the manufacturing process, can be reduced, and the electronic rearview mirror can be manufactured at low cost.

[0170] (Technique 4)

[0171] An electronic rearview mirror comprises: a first polarizing plate; a liquid crystal layer, which is arranged on the back side of the first polarizing plate, and the optical rotation of light is controlled by applying a voltage; a reflective polarizing plate, which is arranged on the back side of the liquid crystal layer, and reflects or transmits light from the liquid crystal layer based on the polarization axis; a second polarizing plate, which is arranged on the back side of the reflective polarizing plate; a liquid crystal unit, which is arranged on the back side of the second polarizing plate; and a backlight source, which is arranged on the back side of the liquid crystal unit, wherein the reflective polarizing plate and the second polarizing plate are bonded to each other by an adhesive member.

[0172] According to this configuration, it is possible to suppress the occurrence of double reflection and rainbow in the display structure of the electronic rearview mirror, thereby improving the visual confirmation of the user.

[0173] (Technique 5)

[0174] In the electronic rearview mirror according to technology 4, the bonding member is an acrylic adhesive or a silicone adhesive.

[0175] According to this configuration, by bonding the reflective polarizing plate and the upper polarizing plate using an arbitrary bonding member, it is possible to suppress the occurrence of double reflection and rainbow in the display structure of the electronic rearview mirror.

[0176] (Technique 6)

[0177] In the electronic rearview mirror according to the fourth or fifth technique, the bonding member includes a diffusion material for diffusing light.

[0178] According to this configuration, by bonding the reflective polarizing plate and the upper polarizing plate using an arbitrary bonding member, it is possible to suppress the occurrence of double reflection and rainbow in the display structure of the electronic rearview mirror.

[0179] (Technique 7)

[0180] In the electronic rearview mirror according to technique 6, the diffusing material is silicon-based particles.

[0181] According to this configuration, by bonding the reflective polarizing plate and the upper polarizing plate using an arbitrary bonding member, it is possible to suppress the occurrence of double reflection and rainbow in the display structure of the electronic rearview mirror.

[0182] (Technology 8)

[0183] The electronic rearview mirror according to any one of Techniques 4 to 7, wherein an air gap exists between the second polarizing plate and the liquid crystal cell.

[0184] According to this configuration, by bonding the reflective polarizing plate and the upper polarizing plate using an arbitrary bonding member, it is possible to suppress the occurrence of double reflection and rainbow in the display structure of the electronic rearview mirror, thereby improving the visual recognition of the user.

[0185] (Technique 9)

[0186] An electronic rearview mirror comprises: a first polarizing plate; a liquid crystal layer, which is arranged on the back side of the first polarizing plate, and the optical rotation of light is controlled by applying a voltage; a reflective polarizing plate, which is arranged on the back side of the liquid crystal layer, and reflects or transmits light from the liquid crystal layer based on the polarization axis; a liquid crystal unit, which is arranged on the back side of the reflective polarizing plate; and a backlight source, which is arranged on the back side of the liquid crystal unit.

[0187] According to this configuration, it is possible to suppress the occurrence of double reflection in the display structure of the electronic rearview mirror, and as a result, it is possible to improve the visual confirmation of the user.

[0188] (Technology 10)

[0189] The electronic rearview mirror according to technology 9, wherein an air gap exists between the reflective polarizing plate and the liquid crystal cell.

[0190] According to this configuration, the cost when configuring the electronic rearview mirror, for example, the bonding cost and the manufacturing process, can be reduced, and the electronic rearview mirror can be manufactured at low cost.

[0191] (Technology 11)

[0192] An electronic rearview mirror is configured to be able to switch an anti-glare function, the electronic rearview mirror comprising: a display structure, the reflectivity of light of the display structure being controlled; an illuminance sensor, which obtains a first illuminance from the surface side of the display structure and a second illuminance from the back side of the display structure; and a control circuit, which adjusts an applied voltage to a liquid crystal layer of the display structure based on the first illuminance and the second illuminance, thereby controlling the anti-glare function, wherein when the anti-glare function is in operation, the control circuit adjusts the applied voltage so that the reflectivity of the display structure is within a specified range.

[0193] According to this configuration, the occurrence of white blur can be suppressed in the display structure of the electronic rearview mirror, and as a result, the visual confirmation of the user can be improved.

[0194] (Technology 12)

[0195] According to the electronic rearview mirror of technology 11, when the second illuminance is greater than a first threshold value, the control circuit stops the anti-glare function and adjusts the applied voltage to the liquid crystal layer so that the reflectivity of the display structure is maximized.

[0196] According to this configuration, the occurrence of white blur can be suppressed in the display structure of the electronic rearview mirror, and as a result, the visual confirmation of the user can be improved.

[0197] (Technology 13)

[0198] According to the electronic rearview mirror described in Technology 11 or Technology 12, when the second illuminance is below a first threshold value and the first illuminance is greater than a second threshold value, the control circuit adjusts the applied voltage to the liquid crystal layer so that the reflectivity of the display structure is within the specified range.

[0199] According to this configuration, the occurrence of white blur can be suppressed in the display structure of the electronic rearview mirror, and as a result, the visual confirmation of the user can be improved.

[0200] (Technology 14)

[0201] According to the electronic rearview mirror described in technology 13, the display structure is composed of: a reflective polarizing plate, which is located on the back side of the liquid crystal layer; and a polarizing plate, which is located on the back side of the reflective polarizing plate, and the specified range is specified so that the diffuse reflection component of the polarizing plate for light incident from the surface side becomes less than 70% of the maximum value.

[0202] According to this configuration, the occurrence of white blur can be suppressed in the display structure of the electronic rearview mirror, and as a result, the visual confirmation of the user can be improved.

[0203] (Technology 15)

[0204] In the electronic rearview mirror according to the thirteenth technique, the predetermined range is defined so that the reflectivity of SCI (Specular Component Include) of the display structure is within a range of 17% to 20%.

[0205] According to this configuration, the occurrence of white blur can be suppressed in the display structure of the electronic rearview mirror, and as a result, the visual confirmation of the user can be improved.

[0206] (Technology 16)

[0207] An electronic rearview mirror according to any one of technologies 11 to 15, wherein, when the second illuminance is below a first threshold and the first illuminance is below a second threshold, the control circuit adjusts the applied voltage so that the reflectivity of the display structure decreases as the second illuminance increases.

[0208] According to this configuration, the occurrence of white blur can be suppressed in the display structure of the electronic rearview mirror, and as a result, the visual confirmation of the user can be improved.

[0209] (Technology 17)

[0210] The electronic rearview mirror according to any one of Techniques 11 to 16, wherein the electronic rearview mirror has a temperature sensor that acquires a peripheral temperature of the electronic rearview mirror, and the control circuit corrects the voltage applied to the liquid crystal layer based on the peripheral temperature.

[0211] According to this configuration, it is possible to provide an anti-glare function that suppresses the occurrence of white blurring in response to changes in ambient temperature.

[0212] (Technology 18)

[0213] According to the electronic rearview mirror described in any one of Technology 11 to Technology 17, when the second illuminance is below a first threshold and the first illuminance is greater than a second threshold, the control circuit adjusts so that the black image level of the backlight source of the electronic rearview mirror becomes maximum.

[0214] According to this configuration, when receiving light having a high illuminance of a certain level or higher, such as a high beam, the reflection of the upper polarizing plate can be made less noticeable. As a result, the user's visual confirmation can be improved.

[0215] (Technology 19)

[0216] According to the electronic rearview mirror described in any one of Technology 11 to Technology 18, when the second illuminance is below a first threshold and the first illuminance is below a second threshold, the control circuit adjusts the black image level of the backlight source of the electronic rearview mirror according to the first illuminance.

[0217] According to this configuration, by adjusting the black image level according to the detected illuminance, it is possible to improve the visual confirmation of the user.

[0218] (Technology 20)

[0219] A control method for an electronic rearview mirror, wherein the electronic rearview mirror is configured to be able to switch an anti-glare function, the control method comprising: an acquisition step of acquiring a first illuminance from a surface side of a display structure of the electronic rearview mirror and a second illuminance from a back side of the display structure; and a control step of adjusting an applied voltage to a liquid crystal layer of the display structure of the electronic rearview mirror based on the first illuminance and the second illuminance to control the reflectivity of light of the display structure, thereby controlling the anti-glare function, wherein when the anti-glare function is in operation, the applied voltage is adjusted so that the reflectivity of the display structure is within a specified range.

[0220] According to this configuration, the occurrence of white blur can be suppressed in the display structure of the electronic rearview mirror, and as a result, the visual confirmation of the user can be improved.

[0221] Various embodiments have been described above, but the present invention is certainly not limited to such examples. Obviously, as long as one is skilled in the art, various variations or modifications can be thought of within the scope described in the claims, and it can be understood that these examples certainly also belong to the technical scope of the present invention. In addition, the various constituent elements in the above embodiments can also be arbitrarily combined within the scope of the gist of the invention.

[0222] In addition, this application is based on the Japanese patent application (Japanese Patent Application No. 2023-048162) filed on March 24, 2023, and its contents are incorporated herein by reference.

[0223] Industrial Applicability

[0224] The present disclosure is useful as an electronic rearview mirror and a control method of the electronic rearview mirror.

[0225] Description of Reference Numerals

[0226] 1: electronic rearview mirror; 10: display structure; 11: temperature sensor; 12: illumination sensor; 13: control circuit; 14: storage device; 15: external IF; 310: surface structure; 311: glass layer; 312, 314: adhesive layer; 313: protective layer; 315: polarizing plate; 316: liquid crystal layer; 317: reflective polarizing plate; 320: air gap; 330: display; 331: upper polarizing plate; 332: liquid crystal unit; 333: lower polarizing plate; 334: backlight source.

Claims

1. An electronic rearview mirror, comprising: a first polarizing plate; A liquid crystal layer disposed on the back side of the first polarizing plate, wherein the optical rotation of light is controlled by applying a voltage; a reflective polarizing plate disposed on the back side of the liquid crystal layer and reflecting or transmitting light from the liquid crystal layer based on a polarization axis; A second polarizing plate disposed on the back side of the reflective polarizing plate; a liquid crystal cell disposed on the back side of the second polarizing plate; and a backlight source, which is arranged on the back side of the liquid crystal unit, Wherein, the haze of the second polarizing plate is in the range of 3.0% to 8.0%.

2. The electronic rearview mirror according to claim 1, wherein: The second polarizing plate is subjected to an anti-glare treatment.

3. The electronic rearview mirror according to claim 1, wherein: An air gap is formed between the reflective polarizing plate and the second polarizing plate.

4. An electronic rearview mirror having: a first polarizing plate; A liquid crystal layer disposed on the back side of the first polarizing plate, wherein the optical rotation of light is controlled by applying a voltage; a reflective polarizing plate disposed on the back side of the liquid crystal layer and reflecting or transmitting light from the liquid crystal layer based on a polarization axis; A second polarizing plate disposed on the back side of the reflective polarizing plate; a liquid crystal unit disposed on the back side of the second polarizing plate; as well as a backlight source, which is arranged on the back side of the liquid crystal unit, Wherein, the reflective polarizing plate and the second polarizing plate are bonded to each other via an adhesive member.

5. The electronic rearview mirror according to claim 4, wherein: The bonding member is an acrylic adhesive or a silicone adhesive.

6. The electronic rearview mirror according to claim 4, wherein: The bonding member includes a diffusion material for diffusing light.

7. The electronic rearview mirror according to claim 6, wherein: The diffusion material is silicon-based particles.

8. The electronic rearview mirror according to claim 4, wherein: An air gap exists between the second polarizing plate and the liquid crystal cell.

9. An electronic rearview mirror, comprising: a first polarizing plate; A liquid crystal layer disposed on the back side of the first polarizing plate, wherein the optical rotation of light is controlled by applying a voltage; a reflective polarizing plate disposed on the back side of the liquid crystal layer and reflecting or transmitting light from the liquid crystal layer based on a polarization axis; a liquid crystal cell disposed on the back side of the reflective polarizing plate; and The backlight source is disposed on the back side of the liquid crystal unit.

10. The electronic rearview mirror according to claim 9, wherein: An air gap exists between the reflective polarizing plate and the liquid crystal cell.

11. An electronic rearview mirror, configured to be able to switch an anti-glare function, the electronic rearview mirror comprising: a display structure having a controlled reflectivity of light; an illuminance sensor that acquires a first illuminance from a front side of the display structure and a second illuminance from a back side of the display structure; and a control circuit that adjusts an applied voltage to a liquid crystal layer included in the display structure based on the first illuminance and the second illuminance, thereby controlling the anti-glare function; in, When the anti-glare function is activated, the control circuit adjusts the applied voltage so that the reflectivity of the display structure is within a predetermined range.

12. The electronic rearview mirror according to claim 11, wherein: When the second illuminance is greater than a first threshold, the control circuit stops the anti-glare function and adjusts the voltage applied to the liquid crystal layer so that the reflectivity of the display structure reaches a maximum value.

13. The electronic rearview mirror according to claim 11, wherein: When the second illuminance is less than or equal to a first threshold value and the first illuminance is greater than the second threshold value, the control circuit adjusts the voltage applied to the liquid crystal layer so that the reflectance of the display structure falls within the predetermined range.

14. The electronic rearview mirror according to claim 13, wherein: The display structure is configured to include: a reflective polarizing plate located on the back side of the liquid crystal layer; and a polarizing plate located on the back side of the reflective polarizing plate. The predetermined range is defined so that the diffuse reflection component of the polarizing plate with respect to the light incident from the front surface side becomes 70% or less of the maximum value.

15. The electronic rearview mirror according to claim 13, wherein: The predetermined range is defined so that the reflectance of the display structure including specularly reflected light (SCI) is within a range of 17% to 20%.

16. The electronic rearview mirror according to claim 11, wherein: When the second illuminance is less than or equal to a first threshold value and the first illuminance is less than or equal to a second threshold value, the control circuit adjusts the applied voltage so that the reflectivity of the display structure decreases as the second illuminance increases.

17. The electronic rearview mirror according to claim 11, wherein: The electronic rearview mirror has a temperature sensor, and the temperature sensor obtains the ambient temperature of the electronic rearview mirror. The control circuit corrects a voltage applied to the liquid crystal layer based on the ambient temperature.

18. The electronic rearview mirror according to claim 11, wherein: When the second illuminance is less than or equal to a first threshold and the first illuminance is greater than the second threshold, the control circuit performs adjustment so that a black image level of a backlight included in the electronic rearview mirror becomes maximum.

19. The electronic rearview mirror according to claim 11, wherein: When the second illuminance is less than or equal to a first threshold value and the first illuminance is less than or equal to a second threshold value, the control circuit adjusts a black image level of a backlight included in the electronic rearview mirror according to the first illuminance.

20. A method for controlling an electronic rearview mirror, wherein the electronic rearview mirror is configured to be able to switch an anti-glare function, the control method comprising: an acquisition step of acquiring a first illuminance from a front side of a display structure of the electronic rearview mirror and a second illuminance from a back side of the display structure; as well as a control step of adjusting a voltage applied to a liquid crystal layer provided in a display structure of the electronic rearview mirror based on the first illuminance and the second illuminance to control a reflectivity of light of the display structure, thereby controlling the anti-glare function; When the anti-glare function is activated, the applied voltage is adjusted so that the reflectivity of the display structure is within a predetermined range.

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