WO2017213165A1

WO2017213165A1 - Display device and electronic apparatus

Info

Publication number: WO2017213165A1
Application number: PCT/JP2017/021066
Authority: WO
Inventors: 卓天野; 笠井　一郎; 諭姫田
Original assignee: コニカミノルタ株式会社
Priority date: 2016-06-10
Filing date: 2017-06-07
Publication date: 2017-12-14

Abstract

Provided are an electronic apparatus and a display device provided with a transmission-type display whereby an external environment and a display image can be clearly distinguished and recognized even when the luminance or contrast of the external environment is reduced. A display control device in the display device according to the present invention adjusts the luminance of an image displayed in the transmission-type display so that when A ≤ 500 (1) and B/A ≥ α (2) (where α is an arbitrary value) are satisfied, A (cd/m²) being the maximum luminance of the external environment and B (cd/m²) being the minimum luminance of the external environment detected by a luminance sensor, the expression α < (B + C)/(A + C) ≤ 0.9 (3) is satisfied, C (cd/m² being the luminance of the image displayed in the transmission-type display.

Description

Display device and electronic device

The present invention relates to a display device and an electronic apparatus provided with a transmissive display.

Head mounted display (hereinafter referred to as HMD), which is a type of wearable terminal, and in-vehicle head-up display (hereinafter referred to as HUD) allow an observer to observe the outside world through a transmissive display, and at the same time, to such a transmissive display. The displayed information image can be visually recognized. Therefore, the observer can obtain necessary information without taking his eyes off the transmissive display or with little eye movement, which is useful for an observer who wants to continue observation of the outside world with the displayed information. is there.

By the way, in the early morning, dusk, or rainy weather, the outside scene is low in brightness and contrast, and the contrast is reduced. However, such an outside scene is displayed together with the display image through the transmissive display. When observed, there is a possibility that display light that does not adjust the brightness overlaps and cannot be clearly identified.

Here, Patent Document 1 discloses a virtual image display device that has an external light sensor that detects the intensity of external light and changes the transmittance of the optical element based on the output of the external light sensor. According to the technique of Patent Document 1, it is possible to observe an image adjusted according to a change in the brightness of the outside world.

JP2015-96982A JP 2013-174708 A

However, the technique of Patent Document 1 adjusts the transmittance of the light control plate based on the detection signal from the external light sensor to appropriately shield external light, thereby reducing the contrast of the virtual image formed by the image forming apparatus. This is to prevent difficulty in seeing. Therefore, when the brightness and contrast of the outside world are reduced, the technique of Patent Document 1 cannot cope with it.

On the other hand, in Patent Document 2, the brighter the external illuminance detected by the illuminance detection means, the wider the luminance interval between the luminance levels, and the darker the external illuminance is, the narrower the luminance interval between the luminance levels. In addition, a technique is disclosed in which the luminance of the backlight is determined for each luminance level so that the ratio of the luminance of the light source to the external illuminance is always constant at the same luminance level.

According to the technique of Patent Document 2, the luminance of the backlight can be determined so that the luminance interval between luminance levels becomes narrower as the illuminance of the outside world becomes darker. However, when the contrast of the outside world is lowered, the technique of Patent Document 2 cannot cope with the problem and remains a problem.

The present invention has been made in view of the above circumstances, and includes a transmissive display that can clearly identify and visually recognize the outside world and a display image even when the brightness and contrast of the outside world are reduced. It is an object to provide a display device and an electronic device.

In order to achieve at least one of the above-described objects, a display device reflecting one aspect of the present invention is provided.
A transmissive display capable of displaying an image and allowing an observer to visually recognize the outside world together with the displayed image;
A display control device for displaying an image on the transmissive display;
A brightness sensor that detects the brightness of the outside world that the viewer visually recognizes through the transmissive display,
When the maximum brightness of the external environment detected by the brightness sensor is A (cd / m ² ) and the minimum brightness of the external environment is B (cd / m ² ),
A ≦ 500 (1)
B / A ≧ α (2)
(However, α is an arbitrary value)
When the brightness of the image displayed on the transmissive display is C (cd / m ² ),
α <(B + C) / (A + C) ≦ 0.9 (3)
The brightness of the image displayed on the transmissive display is adjusted so as to satisfy the above condition.

According to the present invention, it is possible to provide a display device and an electronic apparatus including a transmissive display that can clearly identify and visually recognize the outside world and a display image even when the brightness and contrast of the outside world are reduced. it can.

It is a perspective view of the head mounted display (HMD) concerning this embodiment. It is the figure which looked at HMD from the front. It is the figure which looked at HMD from the upper part. It is a schematic sectional drawing which shows the structure of a display unit. It is a block diagram of the main circuit of HMD. It is a front view when a user wears HMD. It is the figure which divided the display area DP of the display unit into 63, and showed it typically assigning a number for each area. (A) is a figure which shows the scenery of the external world which the user US visually recognizes via display area DP, (b) is a figure which shows an example of image IMG displayed on display area DP by 104 A of image formation parts. is there. It is a figure which shows the state which accumulated Fig.8 (a) and FIG.8 (b). It is a figure which shows image IMG displayed by the image formation part 104A on the division area of display area DP with the scenery of the external world. FIG. 11 is a diagram showing a luminance distribution in a range (regions 37 to 45) through which an X-X line in FIG. 10 passes, where the vertical axis represents the external brightness and the horizontal axis represents the external position. It is a figure which takes the brightness | luminance of a display image on a vertical axis | shaft and takes the position of the external field on a horizontal axis. 4 is a flowchart illustrating control performed by a control processing unit 121.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view of a head mounted display 100 that is an electronic apparatus according to the present embodiment. FIG. 2 is a front view of the HMD 100 according to the present embodiment. FIG. 3 is a view of the HMD 100 according to the present embodiment as viewed from above. Hereinafter, the right side and the left side of the HMD 100 refer to the right side and the left side for the user (observer) wearing the HMD 100.

As shown in FIGS. 1 to 3, the HMD 100 of this embodiment has a frame 101 as a support member. A frame 101 that is U-shaped when viewed from above has a front part 101a to which two spectacle lenses 102 are attached, and

side parts

101b and 101c extending rearward from both ends of the front part 101a. The two spectacle lenses 102 attached to the frame 101 may or may not have refractive power.

A cylindrical main body 103 as a support member is fixed to the front portion 101a of the frame 101 on the upper side of the spectacle lens 102 on the right side (which may be on the left side depending on the user's dominant eye). The main body 103 is provided with a display unit 104. In the main body 103, a display image / display luminance control unit 121a (see FIG. 6 described later) that controls display of the display unit 104 based on an instruction from the control processing unit 121 described later is disposed. If necessary, a display unit may be arranged in front of both eyes.

FIG. 4 is a schematic cross-sectional view showing the configuration of the display unit 104. The display unit 104 as a display device includes an image forming unit 104A and an image display unit 104B. The image forming unit 104A is incorporated in the main body unit 103, and includes a light source 104a, a unidirectional diffuser 104b, a condenser lens 104c, and a display element 104d. On the other hand, the image display unit 104B, which is a so-called see-through type display member (transmission type display), is arranged so as to extend downward from the main body unit 103 and in parallel with one eyeglass lens 102 (see FIG. 1). Further, it is generally plate-shaped and has an eyepiece prism 104f, a deflection prism 104g, and a hologram optical element 104h.

The light source 104a has a function of illuminating the display element 104d. For example, 462 ± 12 nm (B light), 525 ± 17 nm (G light), 635 ± 11 nm (R It is composed of RGB-integrated LEDs that emit light in three wavelength bands. Thus, the light source 104a emits light having a predetermined wavelength width, whereby the image light obtained by illuminating the display element 104d can have a predetermined wavelength width, and the hologram optical element 104h transmits the image light. When diffracted, the user can observe an image over the entire observation angle of view at the position of the pupil B ′. Further, the peak wavelength for each color of the light source 104a is set in the vicinity of the peak wavelength of the diffraction efficiency of the hologram optical element 104h, so that the light use efficiency is improved.

Further, since the light source 104a is composed of LEDs that emit RGB light, the cost of the light source 104a can be reduced, and a color image is displayed on the display element 104d when the display element 104d is illuminated. The color image can be visually recognized by the user. In addition, since each of the RGB LED elements has a narrow emission wavelength width, the use of a plurality of such LED elements enables high color reproducibility and bright image display.

The display element 104d displays an image by modulating the light emitted from the light source 104a in accordance with image data, and is configured by a transmissive liquid crystal display element having pixels that serve as light transmitting regions in a matrix. Has been. Note that the display element 104d may be of a reflective type.

The eyepiece prism 104f totally reflects the image light from the display element 104d incident through the base end face PL1 by the opposed parallel inner side face PL2 and outer side face PL3, and passes through the hologram optical element 104h to the user's pupil. On the other hand, external light is transmitted and guided to the user's pupil, and is composed of, for example, an acrylic resin together with the deflecting prism 104g. The eyepiece prism 104f and the deflection prism 104g are joined by an adhesive with the hologram optical element 104h sandwiched between inclined surfaces PL4 and PL5 inclined with respect to the inner surface PL2 and the outer surface PL3.

The deflection prism 104g is joined to the eyepiece prism 104f, and becomes a substantially parallel flat plate integrated with the eyepiece prism 104f. By joining the deflecting prism 104g to the eyepiece prism 104f, it is possible to prevent distortion in the external image observed by the user through the display unit 104.

That is, for example, when the deflecting prism 104g is not joined to the eyepiece prism 104f, external light is refracted when passing through the inclined surface PL4 of the eyepiece prism 104f, so that an external image observed through the eyepiece prism 104f is distorted. . However, by joining the deflecting prism 104g having the inclined surface PL5 complementary to the eyepiece prism 104f to form an integral substantially parallel plate, external light is transmitted through the inclined surfaces PL4 and PL5 (hologram optical element 104h). The refraction at that time can be canceled by the deflecting prism 104g. As a result, it is possible to prevent distortion in the external image observed through the see-through. In addition, if the spectacle lens 102 (refer FIG. 1) is mounted | worn between the display unit 104 and a user's pupil, it will be possible for the user who normally uses spectacles to observe an image without a problem.

The hologram optical element 104h diffracts and reflects the image light (light having a wavelength corresponding to the three primary colors) emitted from the display element 104d to guide it to the pupil B ′, and enlarges the image displayed on the display element 104d by the user. It is a volume phase type reflection hologram guided as a virtual image to the pupil. The hologram optical element 104h has, for example, three wavelength ranges of 465 ± 5 nm (B light), 521 ± 5 nm (G light), and 634 ± 5 nm (R light) with a peak wavelength of diffraction efficiency and a wavelength width of half the diffraction efficiency. The light is diffracted (reflected). Here, the peak wavelength of diffraction efficiency is the wavelength at which the diffraction efficiency reaches a peak, and the wavelength width at half maximum of the diffraction efficiency is the wavelength width at which the diffraction efficiency is at half maximum of the diffraction efficiency peak. is there.

The reflection-type hologram optical element 104h has high wavelength selectivity, and only diffracts and reflects light having a wavelength in the above-mentioned wavelength range (near the exposure wavelength). The hologram optical element 104h is transmitted, and a high external light transmittance can be realized.

Next, the operation of the display unit 104 will be described. The light emitted from the light source 104a is diffused by the unidirectional diffusion plate 104b, condensed by the condenser lens 104c, and enters the display element 104d. The light incident on the display element 104d is modulated for each pixel based on the image data input from the display image / display luminance control unit 121a as a display control device, and is emitted as image light. As a result, a color image is displayed on the display element 104d.

Image light from the display element 104d enters the eyepiece prism 104f from its base end face PL1, is totally reflected a plurality of times by the inner side face PL2 and the outer side face PL3, and enters the hologram optical element 104h. The light incident on the hologram optical element 104h is reflected there, passes through the inner side surface PL2, and reaches the pupil B '. At the position of the pupil B ', the user can observe an enlarged virtual image of the image displayed on the display element 104d and can visually recognize it as a screen formed on the image display unit 104B. In this case, it can be considered that the hologram optical element 104h constitutes a screen, or it can be considered that a screen is formed on the inner surface PL2. In the present specification, “screen” may refer to an image to be displayed.

On the other hand, since the eyepiece prism 104f, the deflecting prism 104g, and the hologram optical element 104h transmit almost all of the external light, the user can observe an external field image (real image) through them. Therefore, the virtual image of the image displayed on the display element 104d is observed so as to overlap with a part of the external image. In this manner, the user of the HMD 100 can simultaneously observe the image provided from the display element 104d and the external image via the hologram optical element 104h. Note that when the display unit 104 is in the non-display state, the image display unit 104B is transparent, and only the external image can be observed. In this example, a display unit is configured by combining a light source, a liquid crystal display element, and an optical system. However, instead of a combination of a light source and a liquid crystal display element, a self-luminous display element (for example, an organic EL display) is used. Element) may be used. Further, instead of a combination of a light source, a liquid crystal display element, and an optical system, a transmissive organic EL display panel having transparency in a non-light emitting state may be used. In any case, when the screen is arranged so as to fall within the visual field of the user's eye facing the image display unit 104B, and preferably at least partially overlaps the effective visual field, the user can easily visually recognize the image. Can do.

1 and 2, the right sub-body portion 107 is attached to the right side portion 101b of the frame 101, and the left sub-body portion 108 is attached to the left side portion 101c of the frame 101. The right sub-main body portion 107 and the left sub-main body portion 108 have an elongated plate shape, and have elongated

protrusions

107a and 108a on the inner side, respectively. By engaging the elongated protrusion 107 a with the elongated hole 101 d of the side portion 101 b of the frame 101, the right sub-body portion 107 is attached to the frame 101 in a positioned state, and the elongated protrusion 108 a is attached to the side of the frame 101. By engaging with the long hole 101e of the portion 101c, the left sub-main body portion 108 is attached to the frame 101 in a positioned state.

In the right sub-body 107, a temperature sensor 114 and a geomagnetic sensor 109 for detecting geomagnetism (see FIG. 6 to be described later), and a gyro and acceleration sensor 110A for generating an output corresponding to the posture (see FIG. 6 to be described later). And a speaker / earphone 111 </ b> C and a microphone 111 </ b> B (see FIG. 6 described later) are provided in the left sub-main body 108. The main body 103 is provided with an illuminance sensor 112 (see FIG. 6 described later). The main main body 103 and the right sub main body 107 are connected so as to be able to transmit signals through a wiring HS, and the main main body 103 and the left sub main body 108 are connected so as to be able to transmit signals through a wiring (not shown). Yes. As schematically illustrated in FIG. 3, the right sub-main body 107 is connected to the control unit CTU via a cord CD extending from the rear end. A 6-axis sensor in which an angular velocity sensor and an acceleration sensor are integrated may be used. Further, the HMD can be operated by sound based on an output signal generated from the microphone 111B according to the input sound. Further, the main main body 103 and the left sub main body 108 may be configured to be wirelessly connected. In the present embodiment, the camera 106 provided in the main body 103 serves also as a luminance distribution detection sensor. The camera 106 as the luminance distribution detection sensor preferably has its optical axis facing the line of sight of the user US, and is preferably provided near the eyes of the user US. However, a luminance distribution detection sensor separate from the camera may be provided.

FIG. 5 is a block diagram of main circuits of the HMD 100. The control unit CTU generates a control signal for the display unit 104 and other functional devices, a control processing unit 121, an operation unit 122, a GPS receiving unit 123 that receives radio waves from GPS satellites, and external and data. A communication unit 124 that exchanges information, a storage unit 129 that stores a program, image data, and the like, and a power supply circuit 130 that converts a voltage applied from the battery 127 into an appropriate voltage for each unit. The control processing unit 121 having the display image / display luminance control unit 121a and the luminance distribution data detection processing unit 121b can use an application processor used in a smartphone or the like, but the type of the control processing unit 121 is not limited. . For example, if an application processor includes hardware necessary for image processing such as GPU or Codec as a standard, it can be said that the processor is suitable for a small HMD.

Furthermore, when invisible light as detection light emitted from the human body from the proximity sensor 105 is detected, the control processing unit 121 receives the signal. For example, when the user US moves his / her hand or finger in front of his / her eyes, the proximity sensor 105 outputs a signal accordingly. Therefore, so-called gesture detection can be performed using the output signal.

The control processing unit 121 receives power from the power supply circuit 130, operates in accordance with a program stored in the storage unit 129, and inputs image data from the camera 106 in accordance with an operation input such as power-on from the operation unit 122. The data can be stored in the storage unit 129 and communicated with the outside via the communication unit 124 as necessary. Furthermore, when the control processing unit 121 executes control according to the output from the proximity sensor 105, the user can perform screen control of the HMD 100 or execute an application by a gesture operation using a hand or a finger. it can. Examples of screen control include page turning, scrolling, selection, and determination.

FIG. 6 is a front view when the user US wears the HMD 100 of the present embodiment. On the image display unit 104B arranged in front of the right eye EY of the user US, the range indicated by the alternate long and short dash line is the display area DP for displaying an image, and the range indicated by the dotted line is the detection area DT that can be detected by the camera 106. When viewed with the right eye EY of the user US, it is desirable that the display area DP and the detection area DT overlap.

Here, the control processing unit 121 divides the display area DP into seven rows and nine columns at equal intervals, and assigns numbers in ascending order from the upper left to the right. FIG. 7 schematically shows such a display area DP, but the ruled lines and area numbers of the display area DP are shown for easy understanding and are actually visually recognized by the user US. is not. Here, it is assumed that the brightness distribution data detection processing unit 121b can acquire the brightness of the outside world corresponding to the divided areas.

FIG. 8A is a diagram illustrating an external scene viewed by the user US via the display area DP, and FIG. 8B is an example of an image IMG displayed on the display area DP by the image forming unit 104A. FIG. FIG. 9 is a diagram illustrating a state in which FIGS. 8A and 8B are overlapped, that is, the image IMG displayed by the image forming unit 104A is visually recognized by the right eye EY of the user US together with the scenery of the outside world. Indicates the state.

By the way, in an environmental condition where the brightness of the outside scene is low and the contrast is low, when the user US observes the outside scene together with the display image IMG via the display area DP of the image display unit 104B, the two scenes overlap each other. There is a risk that the scenery and the display image IMG cannot be clearly identified. In such a case, the control processing unit 121 performs the following processing.

Specifically, the luminance distribution data detection processing unit 121b of the control processing unit 121 receives the image signal from the camera 106 and detects the luminance distribution data. Here, since the display area DP is divided into 63 areas, the luminance value can be obtained corresponding to each area. However, if an adjustment area for adjusting the luminance is defined, the luminance value can be obtained within that area. It ’s fine. The luminance distribution data detection processing unit 121b only needs to obtain the maximum luminance value and the minimum luminance value by processing the image signal from the camera 106. The camera 106 and the luminance distribution data detection processing unit 121b constitute a luminance sensor.

FIG. 10 is a diagram in which the image IMG displayed by the image forming unit 104A and the scenery of the outside world are superimposed on the divided area of the display area DP. FIG. 11 is a diagram showing the brightness of the outside world on the vertical axis and the position of the outside world on the horizontal axis in the range (division areas 37 to 45) through which the XX line of FIG. 10 passes. In the example of FIG. 11, the divided areas 37 to 45 are selected as the adjustment areas for adjusting the luminance, and the maximum luminance value and the minimum luminance value are set for each divided area based on the pixel value of the image sensor of the camera 106. Looking for.

Here, when the detected maximum brightness of the outside world is A (cd / m ² ) and the minimum brightness of the outside world is B (cd / m ² ),
A ≦ 500 (1)
B / A ≧ α (2)
(Where α is any value, preferably α is greater than 0.5 and less than 1, more preferably α is greater than 0.6 and less than 0.9)
When the condition is satisfied, the brightness of the displayed image IMG is adjusted. Conversely, when the expression (1) or (2) is not satisfied, the brightness of the displayed image IMG is not adjusted. . Specific examples will be shown below.

In FIG. 11, the minimum luminance distribution and the maximum luminance distribution of the outside world in the range of the divided regions 37 to 45 are shown by graphs. Here, the maximum luminance of the external field in the adjustment region occurs in the divided region 43, and the maximum luminance value A = 500 (cd / m ² ), while the minimum external luminance in the adjustment region occurs in the divided region 40, Assume that the minimum luminance value B = 350 (cd / m ² ). At this time,
A ≦ 500 (1)
When the above condition is satisfied, the brightness of the scenery in the outside world is low, so that the display image / display brightness control unit 121a determines that the display image is difficult to see. In this example, since A = 500, the expression (1) is satisfied.

However, when the maximum luminance value A is considerably low, it is considered that the environment of the outside world is at night or indoors where light is shielded, and it is inherently difficult to visually recognize the outside world. Therefore, the luminance adjustment may be executed only when the following expression (4) is satisfied.
20 ≦ A (4)
In this example, since A = 500, the expression (4) is satisfied.

Furthermore,
B / A ≧ α (2)
If the condition is satisfied, the contrast of the scenery in the outside world is low, so that the display image / display brightness control unit 121a can determine that the display image is difficult to see. In this example, when 0.7 is selected as α, for example, B / A = 0.7, which satisfies Expression (2).

When the above expressions (1) and (2) are satisfied, the display image / display brightness control unit 121a
α <(B + C) / (A + C) ≦ 0.9 (3)
The luminance of the image displayed in the divided areas 37 to 45 is set to C (cd / m ² ) so as to satisfy the condition, and an adjustment signal is transmitted to the image forming unit 104A. Accordingly, the image forming unit 104A emits image light whose display luminance is adjusted, for example, by changing the light emission intensity of the backlight LED. The display image / display brightness control unit 121a may include a calculation circuit for calculation.

If (B + C) / (A + C) in equation (3) exceeds 0.9, the brightness of the display image IMG is too high with respect to the outside scene, and the outside scene is buried in the display image IMG. You may not be able to see the scenery. On the other hand, if (B + C) / (A + C) is less than or equal to α = 0.7, the brightness of the display image IMG is too low with respect to the outside scene, and the display image IMG is visible even though the outside scene can be seen. There is a risk that it will not be possible. That is, by satisfying the expression (3), when the outside scene has low brightness and low contrast, both the outside scene and the display image IMG can be clearly seen.

In the example shown in FIG. 12, C = 350 (cd / m ² ). As a result, B + C = 700 (cd / m ² ) in the minimum luminance division area 40 of the outside world, and A + C = 850 (cd / m ² ) in the maximum luminance division area 43 of the outside world, and 700/850 = 0. .82, the expression (3) is satisfied. The above is an example in which common luminance adjustment is performed for each row. However, the present invention is not limited to this, and common luminance adjustment may be performed for each column. Further, after the display area DP is divided into 63, the minimum luminance value and the maximum luminance value are obtained in each divided area, and further, the minimum luminance value and the maximum luminance value in the entire display area DP are obtained, and the expression (3) is obtained. After the fitting, adjustment may be performed using the obtained value C as a uniform common value in all divided regions.

Hereinafter, the control performed by the control processing unit 121 will be described with reference to the flowchart of FIG. In this example, it is determined for each of the divided areas 1 to 63 whether or not to adjust the image brightness. When α is assumed to be 0.7, in step S101, the luminance distribution data detection processing unit 121b inputs an image signal from the camera 106 as a luminance distribution detection sensor, and corresponds to the divided areas 1 to 63 in the external environment. The brightness distribution data of is detected. Next, in step S102, N = 1, and in step S103, the display image / display luminance control unit 121a determines whether or not the maximum luminance value A of the divided region N is 500 (cd / m ² ) or less. If it is determined that the maximum luminance value A of the divided area N exceeds 500 (cd / m ² ), the display image can be clearly distinguished from the scenery of the outside world regardless of the display luminance, and the process proceeds to step S106. The display image / display brightness control unit 121a does not adjust the brightness of the divided region N, that is, uses a reference brightness value.

On the other hand, if it is determined that the maximum luminance value A of the divided area N is 500 (cd / m ² ) or less, the process proceeds to step S104, and the display image / display luminance control unit 121a is the minimum area (minimum). It is determined whether (luminance value B) / (maximum luminance value A) is 0.7 or more. If (minimum luminance value B) / (maximum luminance value A) is determined to be less than 0.7 in the divided area N, the display image can be clearly distinguished from the scenery of the outside world regardless of the display luminance. The display image / display brightness control unit 121a does not adjust the brightness of the divided area N, that is, uses the reference brightness value.

On the other hand, when it is determined that (minimum luminance value B) / (maximum luminance value A) is 0.7 or more in the divided area N, the display image / display luminance control unit 121a determines that 0.7 or more in step S105. The display luminance C is set so as to satisfy <(B + C) / (A + C) ≦ 0.9. After that, it is determined whether or not N = 63 in step S107. If N is less than 63, an undetermined divided area remains. Therefore, N = N + 1 is set in step S108, and the step is performed in the next divided area. The processes of S103 to S107 are performed. On the other hand, if N = 63, all 63 divided areas have been determined, and thus the flow ends.

When (B / A) = 70% or more and less than 80%, it is desirable to adjust the display luminance C so as to satisfy α + 0.05 <(B + C) / (A + C) ≦ 0.9. When (B / A) = 80% or more and 89% or less, it is desirable to adjust the display luminance C so as to satisfy α + 0.01 <(B + C) / (A + C) ≦ 0.9.

As a modification, the user US may arbitrarily specify a divided area for brightness adjustment in the display area DP using the operation unit 122 or the like. For example, in the example shown in FIG. 10, the divided

areas

24, 25, 33, 34, 42, and 43 indicated by hatching are designated as the first adjustment area for performing the brightness adjustment, and the second adjustment area for performing the brightness adjustment is designated. The divided areas 29 to 32 and 38 to 41 indicated by different hatching are designated. Further, the user US adjusts the adjustment value so that (B + C) / (A + C) = 0.80 in the first adjustment area and (B + C) / (A + C) = 0.85 in the second adjustment area. You may make it differ for every area | region. Thereby, it is possible to customize the brightness adjustment so as to make it easier to visually recognize in accordance with characteristics of the right eye EY of the user US. The divided areas to be specified need not be continuous, and discontinuous divided areas may be designated by numbers. The number of divisions of the display area DP is not limited to 63, and may be smaller or larger. Further, when there is an extremely high luminance division region or an extremely low luminance division region in the designated division region, the luminance adjustment of the division region may not be performed.

The present invention is not limited to the embodiments described in the specification, and other embodiments and modifications are included for those skilled in the art from the embodiments and technical ideas described in the present specification. it is obvious. The description and the embodiments are for illustrative purposes only, and the scope of the present invention is indicated by the following claims. For example, in the above embodiment, the present invention has been described by taking the HMD as an example. However, the present invention is not limited to the HMD, and the present invention is not limited to an HUD for an airplane or a vehicle, and an electronic device such as an advertising panel attached to glass. It is applicable to. The information displayed on the transmissive display may be a menu that can be selected by a gesture operation.

100 Head Mount Display (HMD)
101 Frame 101a Front part

101b Side part

101c Side part 101d Long hole 101e Long hole 102 Eyeglass lens 103 Main body part 104 Display unit 104A Image forming part 104B Image display part 104DR Display control part 104a Light source 104b Unidirectional diffuser

104c Condensing lens

104d Display element

104f Eyepiece prism

104g Deflection prism 104h Hologram optical element 105 Proximity sensor 106 Camera 107 Right sub body 107a Protrusion 108 Left sub body 108a Protrusion 109 Geomagnetic sensor 110A Gyro & acceleration sensor 111B Microphone 111C Speaker / Earphone 112 Illuminance sensor 114 Temperature sensor 121 Control processing unit 121a Display image / display luminance control unit 121b luminance distribution data detection processing unit 122 operation unit 123 GPS reception unit 124 communication unit 127 battery 129 storage unit 130 power supply circuit B ′ pupil CD code CTU control unit DP display area DT detection area EY right eye HS wiring IMG display image US user

Claims

A transmissive display capable of displaying an image and allowing an observer to visually recognize the outside world together with the displayed image;
A display control device for displaying an image on the transmissive display;
A brightness sensor that detects the brightness of the outside world that the viewer visually recognizes through the transmissive display,
When the maximum brightness of the external environment detected by the brightness sensor is A (cd / m 2 ) and the minimum brightness of the external environment is B (cd / m 2 ),
A ≦ 500 (1)
B / A ≧ α (2)
(However, α is an arbitrary value)
When the brightness of the image displayed on the transmissive display is C (cd / m 2 ),
α <(B + C) / (A + C) ≦ 0.9 (3)
A display device that adjusts the luminance of an image displayed on the transmissive display so as to satisfy
The display device according to claim 1, wherein the display control device adjusts the luminance so as to satisfy the expression (3) in an image displayed in the adjustment region of the transmissive display.
The display device according to claim 1 or 2, wherein the display control device adjusts the luminance so that the expression (3) is satisfied in an image displayed in a range designated by the observer.
The brightness sensor detects the brightness of the outside world for each of a plurality of divided areas of the transmissive display where the observer visually recognizes the outside world, and the display control device displays for each of the plurality of divided areas. The display device according to any one of claims 1 to 3, wherein the brightness of the image to be adjusted is adjusted so as to satisfy the expression (3).
The display device according to any one of claims 1 to 5, wherein the display control device adjusts the luminance of an image displayed on the transmissive display only when the following expression is satisfied.
20 ≦ A (4)
An electronic device equipped with the display device according to any one of claims 1 to 5.