WO2014068830A1

WO2014068830A1 - Information display device and information display method

Info

Publication number: WO2014068830A1
Application number: PCT/JP2013/005339
Authority: WO
Inventors: 塩田　奈津子; 木戸　稔人
Original assignee: コニカミノルタ株式会社
Priority date: 2012-10-30
Filing date: 2013-09-09
Publication date: 2014-05-08

Abstract

In this information display device and information display method, back brightness is determined by weighting back brightness distribution with a weight that is set according to a direction of display of information displayed in a display section, and display brightness of the display section is controlled according to illuminance of a display face in the display section and the back brightness.

Description

Information display apparatus and method

The present invention relates to an information display device and an information display method capable of controlling the display brightness of a display unit.

In recent years, for example, information display devices represented by smartphones, tablets, e-books, and the like have been improved in portability along with progress in downsizing, thinning, and weight reduction, and maintenance of wireless LANs and data communication networks, for example. And mobility is greatly improved. For this reason, such an information display device is used in various places, times, and situations (such as a living room in a home, a study, a bedroom, a commuting to work, a commuting destination, a commuting to school, a school, and a vacation destination). Used in the aspect).

Under these usage conditions, the light environment around the information display device is diverse, and good visibility is not always obtained. For example, a display device disclosed in Patent Literature 1 has been proposed as a countermeasure against the various light environments.

The display device disclosed in Patent Document 1 is provided on the front surface of the display device, displays a display surface, and is provided on the back surface of the display device, and first measurement means for measuring illuminance on the back surface, The second measuring means provided on the front surface of the display device and displaying on the display surface according to a measurement result in at least one of the second measuring means for measuring the illuminance on the front face and the first and second measuring means. First control means for controlling the brightness of the image. With such a configuration, according to Patent Document 1, the display device can accurately grasp the influence of ambient light and perform control in response thereto.

By the way, information display devices represented by the above-described smartphones and tablets can change the display direction of information displayed on the display surface of the display device, such as vertical display and horizontal display.

Furthermore, from the portability and mobility of the information display device, the user's posture in the usage situation varies, such as standing, sitting, lying, etc., and information is displayed accordingly. The posture of the device, more specifically, the posture of the display surface of the display device has also changed variously.

However, the display device disclosed in Patent Document 1 only considers the influence of ambient light, does not consider the display direction and the attitude, and can handle such usage situations. Can not. In particular, due to improvements in portability and mobility, the usage time of the user in the information display device tends to increase, and if the brightness of the information display device is not controlled more according to the usage situation, the user is tired of eyes. End up.

JP 2010-181763 A

The present invention has been made in view of the above-described circumstances, and an object thereof is to provide an information display device and an information display method capable of controlling the display luminance in accordance with the usage situation.

In the information display device and the information display method according to the present invention, the back surface luminance is obtained by weighting the back surface luminance distribution by the weight set based on the display direction of the information displayed on the display unit. The display brightness of the display unit is controlled based on the illuminance of the display surface and the back surface brightness. In such an information display device and information display method, since at least one of the display direction and orientation of the display unit is taken into consideration, the display luminance can be controlled more in accordance with the usage situation.

The above and other objects, features and advantages of the present invention will become apparent from the following detailed description and the accompanying drawings.

1 is a schematic external view illustrating a configuration of an information display device according to a first embodiment. It is a block diagram which shows the electrical structure of the information display apparatus shown in FIG. It is a figure for demonstrating the display surface illumination intensity detection part and back surface luminance distribution detection part in the information display apparatus shown in FIG. It is a flowchart which shows operation | movement of the information display apparatus shown in FIG. It is a figure for demonstrating how to obtain | require back luminance in the information display apparatus shown in FIG. It is a block diagram which shows the electric constitution of the information display apparatus in 2nd Embodiment. It is a flowchart which shows operation | movement of the information display apparatus shown in FIG. FIG. 7 is a diagram for explaining the relationship between the display direction and posture (the display direction is vertical and the posture is vertical) and the weight in the information display device shown in FIG. 6. FIG. 7 is a diagram for explaining the relationship between the display direction and posture (the display direction is vertical and the posture is horizontal) and the weight in the information display device shown in FIG. 6. FIG. 7 is a diagram for explaining the relationship between the display direction and posture (the display direction is horizontal and the posture is horizontal) and the weight in the information display device shown in FIG. 6. FIG. 7 is a diagram for explaining the relationship between the display direction and posture (the display direction is horizontal and the posture is vertical) and the weight in the information display device shown in FIG. 6. It is a flowchart which shows operation | movement of the information display apparatus in 3rd Embodiment. It is a figure which shows the other aspect of the back surface luminance distribution detection part in the information display apparatus of 1st thru | or 3rd embodiment.

Hereinafter, an embodiment according to the present invention will be described with reference to the drawings. In addition, the structure which attached | subjected the same code | symbol in each figure shows that it is the same structure, The description is abbreviate | omitted suitably. In this specification, when referring generically, it shows with the reference symbol which abbreviate | omitted the suffix, and when referring to an individual structure, it shows with the reference symbol which attached the suffix.

(First embodiment)
FIG. 1 is a schematic external view illustrating the configuration of the information display device according to the first embodiment. 1A is a front view, FIG. 1B is a side view, and FIG. 1C is a rear view. FIG. 2 is a block diagram showing an electrical configuration of the information display device in the first embodiment. FIG. 3 is a diagram for explaining a display surface illuminance detection unit and a back luminance distribution detection unit in the information display device of the first embodiment.

The information display device Da in the first embodiment is a device that displays information, and can control the display luminance according to the display direction of information displayed on the display surface of the display unit and the surrounding ambient light. Device. In the information display device Da according to the first embodiment, the direction and posture of the user's face are considered to match the display direction of the information displayed on the display surface 111 of the display unit 11, and the information display according to the first embodiment is performed. The device Da determines the direction and posture of the user's face based on the display direction of information displayed on the display surface 111 of the display unit 11. The information display device Da according to the first embodiment includes, for example, a display unit 11, a display surface illuminance detection unit 12, a back luminance distribution detection unit 13, and a display direction detection unit 14 as shown in FIGS. A control value calculation unit 15a, a display control unit 16, and a housing H that houses these units 11-16.

The housing H is a plate-like box member that is a thin, substantially rectangular parallelepiped shape that is substantially rectangular in plan view. On one main surface (front surface) Hf of the housing H, the display surface 111 of the display unit 11 is arranged so as to face the outside, and an arbitrary position on the one main surface Hf and in the vicinity of the periphery of the display surface 111 ( In the example illustrated in FIG. 1A, the light receiving surface of the display surface illuminance detection unit 12 is disposed at the one end in the vertical direction of the display surface 111 so as to face the outside. Then, the other main surface (back surface) Hb of the housing H facing the one main surface Hf is arranged so that the light receiving surface of the back luminance distribution detecting unit 13 faces the outside together at one central portion. ing.

The display unit 11 is a device that displays predetermined information on the display surface 111, and is a device that has a function of adjusting display luminance, such as a liquid crystal display and an organic EL display. As will be described later, the display unit 11 is driven by the display control unit 16 and displays information with a display luminance corresponding to the control value given to the display control unit 16 from the control value calculation unit 15a. The display surface 111 of the display unit 11 is obtained, for example, by the information display device Da accessing a network such as the Internet by a communication card (not shown) for transmitting and receiving communication signals and downloading from a server in the network. Information is displayed by the browser. For example, information such as images (still images and moving images) and documents stored in a storage element (not shown) is displayed on the display surface 111 of the display unit 11. Further, for example, on the display surface 111 of the display unit, for example, images (still images and moving images) recorded on a recording medium (for example, a CD-ROM, a USB memory, a memory card, etc.) mounted on a drive device (not shown) from the outside. ) Or document information is displayed.

The display surface illuminance detection unit 12 is a device that detects the illuminance on the display surface 111 of the display unit 11. As described above, the display surface illuminance detection unit 12 detects the illuminance on the display surface 111 of the display unit 11 and, as described above, in the example shown in FIG. It is arranged at one end of the display surface 111 in the vertical direction. The display surface illuminance detection unit 12 outputs the detection result to the control value calculation unit 15a.

In the present embodiment, for example, as shown in FIG. 3A, the display surface illuminance detection unit 12 includes a photoelectric conversion element 121 such as a photodiode and a hemispherical shell-shaped diffusion member 122 that covers the light receiving surface of the photoelectric conversion element 121. I have. In such a display surface illuminance detection unit 12, incident light is diffused by the diffusion member 122, and the diffused incident light is incident on the light receiving surface of the photoelectric conversion element 121. For example, the incident light of the ambient light shown in FIG. 3B is diffused by the diffusing member 122, and the substantially uniform amount of incident light shown in FIG. 3C is incident on the light receiving surface of the photoelectric conversion element 121. The photoelectric conversion element 121 photoelectrically converts the diffuse incident light received by the light receiving surface, and outputs an output having a level corresponding to the amount of diffuse incident light as display surface illuminance (display surface illuminance value). In the present embodiment, the display surface illuminance is detected with such a relatively simple configuration.

The rear luminance distribution detector 13 is a device that detects the luminance distribution of the rear surface facing the display surface 111. As described above, the rear luminance distribution detection unit 13 detects the luminance distribution behind the display surface 111 of the display unit 11 and, as described above, the light receiving surface faces the outside so that the other main surface ( (Back) Located on Hb. The back luminance distribution detector 13 outputs the detection result to the control value calculator 15a.

In the present embodiment, for example, as shown in FIG. 3A, the back luminance distribution detection unit 13 is configured to detect a distribution, for example, a plurality of photoelectric conversion elements 131 such as photodiodes, and a light receiving surface of the photoelectric conversion element K. And an incident optical system 132 for guiding ambient light on the entire back surface. As shown in FIG. 1C, the plurality of photoelectric conversion elements 131 are arranged in a two-dimensional array in two linearly independent directions. In the example shown in FIG. 1C, the back luminance distribution detector 13 includes nine photoelectric conversion elements 131-11 to 131-13, 131-21 to 131-23, and 131-13 to 131-33. The nine photoelectric conversion elements 131-11 to 131-33 are arranged in a two-dimensional array with three rows and three columns in two directions orthogonal to each other. Incident light imaged by the incident optical system L is incident on the light-receiving surfaces formed by these nine photoelectric conversion elements 131-11 to 131-33, and these nine photoelectric conversion elements 131-11 to 131-131. Each of −33 photoelectrically converts incident light incident on the photoelectric conversion element 131, and outputs an output of a level corresponding to the amount of incident incident light as luminance (luminance value) at the position of the photoelectric conversion element 131 To do. As a result, a luminance distribution of 3 rows and 3 columns is obtained. For example, the incident light of the ambient light shown in FIG. 3D is imaged on the light receiving surface formed by the nine photoelectric conversion elements 131-11 to 131-33 by the incident optical system L, and the nine photoelectric conversion elements 131- Light is received in nine divisions with 11 to 131-33 as pixels. Each of the photoelectric conversion elements 131-11 to 131-33 photoelectrically converts incident light incident on the pixel, and outputs an output at a level corresponding to the amount of incident light incident on the pixel. Output as (luminance value). FIG. 3E shows an image of the luminance level of each pixel (each photoelectric conversion element 131-11 to 131-33). In the present embodiment, the back luminance distribution is detected with such a relatively simple configuration.

The display direction detection unit 14 detects the display direction of information displayed on the display surface 111 of the display unit 11. Information is arranged in order so that each element (character, word, sentence, paragraph, figure, table, image, etc.) constituting this information represents this information content, but the display direction depends on the arrangement order of these elements. The vertical direction of the information display device Da that is arranged in order from top to bottom along the vertical direction of the information display device Da (the longitudinal direction of the housing H in plan view), and the information display device Da that is orthogonal to the vertical direction. There are horizontal directions that are arranged in order from left to right (or from right to left) along the horizontal direction. The display direction detection unit 14 outputs the detection result to the control value calculation unit 15a.

In this embodiment, for example, the display direction detection unit 14 detects the display direction by detecting how the application software displaying information on the display surface 111 of the display unit 11 displays each element of the information. Is detected by software. For example, the display direction is detected by searching for the display order in which the application software displays each element of information. Further, for example, the display direction is detected by detecting the direction of the element (for example, the character direction). For example, when the application software includes a setting input unit for setting a character direction such as vertical writing or horizontal writing, the display direction is detected by referring to the setting of the setting input unit. For example, when the application software is transmitting image information from the origin of the display unit 11 as information to be displayed on the display unit 11, when the information display device Da rotates, the application software displays the rotated image information. This is communicated to the display unit 11. In such application software, since the application software has display direction information, the display direction is detected by acquiring the display direction information from the application software. Further, for example, the information display device Da may include a hardware switch or a software switch that receives an input of the display direction, and the display direction detection unit 14 may detect the display direction represented by such a switch.

The control value calculator 15a obtains the back luminance (back luminance value) by weighting the luminance distribution detected by the back luminance distribution detector 13 with the weight set based on the display direction detected by the display direction detector 14. Is. This weight is stored in advance in the control value calculator 15a. This weight may be appropriately set so that the display brightness is adjusted so that the user feels easy to see the display surface 111 when the display direction of the display surface 111 is taken into consideration. For example, in the display direction detected by the display direction detection unit 14, the weight used for one of the display directions may be set larger than the weight used for the other display direction.

For example, when the display direction is the vertical direction from top to bottom, the weight used for the upper side of the display direction may be set larger than the weight used for the lower side. For example, in the present embodiment, the back luminance distribution detection unit 13 has the photoelectric conversion elements 131-11 to 131-33 of 3 rows and 3 columns, so that, for example, as shown in FIG. The weights used for the upper part of the display direction are 1, 1, 1, and the weights used for the center of the display direction are 1, 1, 1, and the weights used for the lower part of the display direction. Is 0, 0, 0 (1 row and 1 column weight M11 = 1 row and 2 column weight M12 = 1 row and 3 column weight M13 = 2 rows and 1 column weight M21 = 2 rows and 2 columns weight M22 = 2 rows and 3 columns weight M23 = 1, 3 rows and 1 column weight M31 = 3 rows and 2 columns weight M32 = 3 rows and 3 columns weight M33 = 0). A user who uses the information display device Da is generally considered to be watching the upper part of the display when the information is displayed from substantially upward to downward in the display direction. As well as its surroundings. For this reason, in order to improve the visibility of the information displayed on the display surface 111, it is preferable to weight the upper part of the display direction relatively heavily with respect to the lower part.

Also, for example, when the display direction is a horizontal direction from left to right along the horizontal direction of the information display device Da, the weight used for the left side of the display direction is used for the right side. It may be set larger than the weight. Further, for example, the weight may be set so as to decrease in order from one display direction to the other in the display direction detected by the display direction detection unit 14.

Then, the control value calculation unit 15a generates a control value for controlling the display luminance of the display unit 11 based on the obtained back surface luminance and the illuminance detected by the display surface illuminance detection unit 12. The control value calculation unit 15 a outputs this control value to the display control unit 16. The display control unit 16 drives and controls the display unit 11 with the display luminance of the control value, so that the display luminance of the display unit 11 is controlled based on the back surface luminance and the illuminance detected by the display surface illuminance detection unit 12.

More specifically, in this embodiment, for example, the control value calculation unit 15a converts the illuminance detected by the display surface illuminance detection unit 12 into luminance as illuminance conversion luminance (illuminance conversion luminance value), and this illuminance conversion luminance. And a control value for controlling the display luminance of the display unit 11 based on the ratio of the calculated rear luminance. For example, when the ratio of the illuminance converted luminance to the back luminance is within a predetermined range set in advance (lower limit value ≦ ratio ≦ upper limit value), the control value calculation unit 15a When a control value for controlling the display brightness of the display unit 11 is generated with a bright brightness, and the ratio is not within a predetermined range set in advance (ratio <lower limit value, upper limit value <ratio), the rear brightness and illuminance A control value for controlling the display brightness of the display unit 11 is generated by multiplying the bright brightness of the converted brightness by a predetermined correction value set in advance.

The display control unit 16 drives the display unit 11 and controls the display unit 11 so that the display luminance is in accordance with the control value generated by the control value calculation unit 15a.

Next, the operation of this embodiment will be described. FIG. 4 is a flowchart showing the operation of the information display apparatus in the first embodiment. FIG. 5 is a diagram for explaining how to obtain the back luminance in the information display apparatus according to the first embodiment. FIG. 5A is a diagram for explaining a case where the display direction is a vertical direction, and FIG. 5B is a diagram for explaining a weight when the display direction is a horizontal direction from right to left. .

In FIG. 4, when controlling the display luminance, first, in process S1, the display surface illuminance is acquired by the display surface illuminance detection unit 12, and the acquired display surface illuminance is output to the control value calculation unit 15a.

Next, in process S2, the display direction of the information on the display surface 111 of the display unit 11 is acquired by the display direction detection unit 14, and the acquired display direction is output to the control value calculation unit 15a.

Next, in the process S3, the back light detection area is set based on the display direction detected by the display direction detection unit 14 by the control value calculation unit 15a. More specifically, the control value calculation unit 15a associates each preset weight Mmn with each photoelectric conversion element 131-ij of the back luminance distribution detection unit 13. In the present embodiment, since the photoelectric conversion element 131 of the back luminance distribution detection unit 13 has 3 rows and 3 columns (i = 1, 2, 3; j = 1, 2, 3), the weight Mmn is also 3 rows and 3 columns. (M = 1, 2, 3; n = 1, 2, 3). Since the display direction is the vertical direction from the top to the bottom, as shown in FIG. 5A, the 1-row 1-column photoelectric conversion element 131-11 is associated with the 1-row 1-column weight M11. A 1-row, 2-column weight M12 is associated with the 2-column photoelectric conversion element 131-12, and a 1-row 3-column weight M13 is associated with the 1-row 3-column photoelectric conversion element 131-13. The photoelectric conversion element 131-21 is associated with a weight M21 of 2 rows and 1 column, and the photoelectric conversion element 131-22 of 2 rows and 2 columns is associated with a weight M22 of 2 rows and 2 columns. A weight M23 of 2 rows and 3 columns is associated with the conversion element 131-23, a weight M31 of 3 rows and 1 column is associated with the photoelectric conversion element 131-31 of 3 rows and 1 column, and a photoelectric conversion element of 3 rows and 2 columns 131-32 is associated with a weight M32 of 3 rows and 2 columns, and 3 rows 3 The weight M33 of 3 rows and 3 columns is associated with the photoelectric conversion element 131-33 (the weight Mmn of m rows and n columns is associated with the photoelectric conversion element 131-ij of i row and j column with i = m and j = n. ). In this way, each weight Mmn set in advance is associated with each photoelectric conversion element 131-ij of the back luminance distribution detecting unit 13, and each weight Mmn is associated with the output Kij of each photoelectric conversion element 131-ij. .

Next, in process S4, the rear luminance distribution is acquired by the rear luminance distribution detector 13, and the acquired rear luminance distribution is output to the control value calculator 15a. The control value calculator 15a obtains the back luminance value Lb by weighting the luminance distribution detected by the back luminance distribution detector 13 with the weight set based on the display direction detected by the display direction detector 14. .

More specifically, since the correspondence is made as described above, the output Kij of the 3 × 3 photoelectric conversion element 131-ij is multiplied by the weight Mmn of 3 × 3 (Kij × Mmn, i = m), respectively. , J = n), the sum is obtained (Σ (Kij × Mij)), and the average value (Σ (Kij × Mij)) / (3 × 3) is obtained as the back luminance value Lb (Lb = (M11 × K11 + M12 × K12 + M13 × K13 + M21 × K21 + M22 × K22 + M23 × K23 + M31 × K31 + M32 × K32 + M32 × K33) / 9 = (K11 + K12 + K13 + K21 + K22 + K23) (1 × K11 + 1 × K12 + 1 × K13 + 1 × K21 + 1 × K22 + 1 × K23 + 1 × K0 × 3 K11 + K12 + K13 + K21 + K22 + K23) / 9).

In the above description, the case where the display direction is the vertical direction has been described. However, when the display direction is the horizontal direction from right to left, the weight is set to the right of the display direction as shown in FIG. 5B. The weights M13, M23, M33 used for the display direction are 1, 1, 1, the weights M12, M22, M32 used for the center of the display direction are 1, 1, 1, and the display direction The weights M11, M21, M31 used for the left side may be 0, 0, 0, and the back luminance Lb is Lb = (M11 × K11 + M12 × K12 + M13 × K13 + M21 × K21 + M22 × K22 + M23 × K23 + M31 × K31 + M32 × K32 + M32). × K33) / 9 = 0 × K11 + 1 × K12 + 1 × K13 + 0 × K21 + 1 × K22 + 1 × K23 + 0 × K31 + 1 × K32 + 1 × K33) / 9 Good me.

Next, in process S5, the illuminance detected by the display surface illuminance detection unit 12 is converted by the control value calculation unit 15a by using a predetermined conversion coefficient set in advance as the illuminance conversion luminance. And the back luminance obtained by the control value calculator 15a. More specifically, the ratio of the illuminance converted luminance to the back luminance is obtained by the control value calculation unit 15a. Then, in order to control the display brightness of the display unit 11 based on the obtained ratio, the control value calculation unit 15a determines whether or not the obtained ratio is within a predetermined range set in advance. To do. In other words, the control value calculation unit 15a determines whether or not the obtained ratio is greater than or equal to a preset lower limit value and less than or equal to a predetermined upper limit value. As a result of this determination, when the obtained ratio is within a predetermined range set in advance (in other words, when the ratio is not less than a predetermined lower limit value and not more than a predetermined upper limit value), control is performed. The value calculation unit 15a performs the process S7. On the other hand, if the determined ratio is not within a predetermined range set in advance as a result of this determination (in other words, the ratio is less than a predetermined lower limit value or exceeds a predetermined upper limit value). In the case), the control value calculation unit 15a executes the process of the process S6.

In this process S6, the control value calculation unit 15a controls the display luminance of the display unit 11 to the luminance obtained by multiplying the bright luminance of the back luminance and illuminance conversion luminance by a predetermined correction value set in advance. Is generated, this control value is output to the display control unit 16, and the process returns to the process S1. In such a case, since the brightness in the field of view feels dark, the brightness of the back luminance and the luminance converted luminance is less than 1, for example, a predetermined value such as 0.8, 0.7, or 0.6. Since the display brightness of the display unit 11 is matched with the brightness multiplied by the correction value, the display surface 111 of the display unit 11 is not dazzled and visibility is improved.

In this process S <b> 7, the control value calculation unit 15 a generates a control value for adjusting the display luminance of the display unit 11 to the bright luminance of the back surface luminance and the illuminance conversion luminance, and sends this control value to the display control unit 16. Output, and the process returns to the process S1. Since the display brightness of the display unit 11 is adjusted to the bright brightness of the back surface brightness and the illuminance conversion brightness in this way, the display surface 111 of the display unit 11 is not dazzled and the visibility is improved.

The upper limit value, lower limit value, and correction value are statistically set in advance appropriately based on empirical results obtained by a plurality of trials.

The display control unit 16 to which the control value is input controls the display unit 11 to drive the display unit 11 so that the display luminance according to the control value is obtained, and the display unit 11 thereby controls the display value. The display surface 111 is displayed with the display brightness.

Such control of the display luminance is periodically performed at predetermined time intervals while the information display device Da is powered on, for example. Alternatively, such display luminance control may be performed when at least one of the illuminance on the display surface and the luminance on the back surface is larger than a predetermined threshold value set in advance. This makes it possible to cope with a change in the amount of light in the user's field of view due to a change in ambient light due to a change in usage status.

Thus, in the information display device Da according to the present embodiment, the back luminance Lb is the luminance distribution Kij detected by the back luminance distribution detecting unit 13 with the weight Mmn set based on the display direction detected by the display direction detecting unit 14. The display luminance of the display unit 11 is controlled based on the back luminance Lb and the illuminance detected by the display surface illuminance detection unit 12 thus obtained. Therefore, such an information display device Da can also control the display brightness in accordance with the usage situation because the display direction is taken into consideration when the display brightness of the display unit 11 is controlled. For this reason, even if the user uses the information display device Da for a long time, the fatigue can be reduced.

In addition, it is considered that the user who uses the information display device Da is generally gazing at the one on the display surface 111 of the display unit 11 when the information is displayed from approximately one of the display directions to the other. The visual field includes not only the information display device Da but also its periphery. In the information display device Da according to the present embodiment, when information is displayed on the display surface 111 in the vertical direction from the upper side to the lower side, the upper side of the display surface 111 is weighted relatively high above the display surface 111. The weight Mmn used for the lower side is set larger than the weight Mmn used for the lower side. For this reason, the information display device Da of the present embodiment can control the display luminance more in accordance with the usage situation.

Moreover, since the information display device Da in the present embodiment uses the ratio of the illuminance-converted luminance and the back luminance when controlling the display luminance of the display unit 11, it is possible to easily compare the other on the basis of one. The display surface illuminance and the back surface brightness can be easily evaluated. More specifically, in this embodiment, since the ratio of the illuminance-converted luminance to the rear luminance is used, the display surface illuminance can be easily compared based on the rear luminance, and the display surface illuminance and the rear luminance can be compared. Can be easily evaluated.

Further, in the information display device Da according to the present embodiment, when the ratio of the illuminance conversion luminance to the front-rear luminance is within a predetermined range, the display luminance of the display unit 11 is the brighter luminance of the front surface and the rear surface. Since it is controlled, the display brightness can be appropriately controlled even in a light environment where there is a difference in brightness between the front surface and the back surface. When the ratio is not within the predetermined range, the information display device Da displays the display luminance of the display unit 11 by multiplying the luminance of the brighter one of the front and back surfaces by a predetermined correction value. Therefore, the display brightness can be appropriately controlled even in a light environment where there is a relatively large difference in brightness between the front surface and the back surface.

In the information display device Da according to the present embodiment, since the display direction detection unit 14 can detect the display direction by software, no separate component is required to detect the display direction. For this reason, such information display device Da does not impair the reduction in size and weight.

Next, another embodiment will be described.

(Second Embodiment)
FIG. 6 is a block diagram illustrating an electrical configuration of the information display device according to the second embodiment. The information display device Da in the first embodiment sets the weight based on the display direction, but the information display device Db in the second embodiment further includes a posture detection unit 17 that detects the posture of the display unit 11 and displays the information. The weight is set based on the direction and the attitude of the display unit 11. In the information display device Db of the second embodiment, the direction of the user's face is considered to match the display direction of the information displayed on the display surface 111 of the display unit 11, and the information display device of the second embodiment Da determines the direction of the user's face based on the display direction of the information displayed on the display surface 111 of the display unit 11, and in the information display device Db of the second embodiment, the user's posture is displayed. The information display device Db according to the second embodiment determines the user's posture based on the posture of the display unit 11. Such an information display device Db in the second embodiment includes, for example, as shown in FIG. 6, a display unit 11, a display surface illuminance detection unit 12, a back luminance distribution detection unit 13, and a display direction detection unit 14. A posture detection unit 17; a control value calculation unit 15b; a display control unit 16; and a housing H that houses these units 11 to 17. That is, the information display device Db of the second embodiment includes a control value calculation unit 15b instead of the control value calculation unit 15a, and further includes an attitude detection unit 17 with respect to the information display device Da of the first embodiment. Yes.

In the information display device Db of the second embodiment, the display unit 11, the display surface illuminance detection unit 12, the back luminance distribution detection unit 13, the display direction detection unit 14, the display control unit 16, and the housing H are respectively the first implementation. Since the display unit 11, the display surface illuminance detection unit 12, the back luminance distribution detection unit 13, the display direction detection unit 14, the display control unit 16, and the housing H in the information display device Da of the embodiment are the same, description thereof is omitted. .

The posture detection unit 17 is a device that detects the posture of the display unit 11 (the posture of the information display device Db). The posture detection unit 17 outputs the detection result to the control value calculation unit 15b. For example, the posture detection unit 17 is, for example, a gyro sensor, and a roll angle that is a rotation angle about the longitudinal direction axis with the longitudinal direction of the display surface 111 as an axis (longitudinal axis), and the display surface 111 Using the short direction as an axis (short direction axis), a pitch angle that is a rotation angle around the short direction axis is detected, and the detected roll angle and pitch angle are output. The gyro sensor outputs each of the roll angle and the pitch angle when the display surface 111 of the display unit 11 faces upward and the display surface 111 is horizontal with respect to gravity (each reference state of the roll angle and the pitch angle). Is disposed in the housing H such that 0 is zero. For this reason, the normal direction of the plane composed of the long direction axis and the short direction axis coincides with the normal direction of the display surface 111. Note that the yaw angle that is the rotation angle around the normal direction axis with the normal direction of the display surface 111 as the axis (normal direction axis) is not used in the present embodiment and may be set arbitrarily. However, the initial setting may be performed so that, for example, magnetic north or the like becomes a reference.

The control value calculation unit 15b weights the luminance distribution detected by the back luminance distribution detection unit 13 with a weight set based on the display direction detected by the display direction detection unit 14 and the posture detected by the posture detection unit 17. The back luminance (back luminance value) is obtained. This weight may be set as appropriate so that the display brightness is adjusted so that the user feels easy to see the display surface 111 when the display direction and orientation of the display surface 111 are taken into consideration. This weight is stored in advance in the control value calculator 15b. Then, similarly to the control value calculation unit 15a, the control value calculation unit 15b generates a control value for controlling the display luminance of the display unit 11 based on the obtained back surface luminance and the illuminance detected by the display surface illuminance detection unit 12. To do. The control value calculation unit 15 b outputs this control value to the display control unit 16. The display control unit 16 drives and controls the display unit 11 with the display luminance of the control value, so that the display luminance of the display unit 11 is controlled based on the back surface luminance and the illuminance detected by the display surface illuminance detection unit 12.

Next, the operation of this embodiment will be described. FIG. 7 is a flowchart showing the operation of the information display apparatus in the second embodiment. FIG. 8 is a diagram for explaining the relationship between the display direction and posture (the display direction is vertical and the posture is vertical) and the weight in the information display apparatus according to the second embodiment. FIG. 9 is a diagram for explaining the relationship between the display direction and posture (the display direction is vertical and the posture is horizontal) and the weight in the information display device according to the second embodiment. FIG. 10 is a diagram for explaining the relationship between the display direction and posture (the display direction is horizontal and the posture is horizontal) and the weight in the information display apparatus according to the second embodiment. FIG. 11 is a diagram for explaining the relationship between the display direction and posture (the display direction is horizontal and the posture is horizontal) and the weight in the information display apparatus according to the second embodiment. 8 to 11, FIG. A shows the front surface of the display unit 11, and FIG. B shows the weighting direction. 8C and 9C show the first weight and FIG. 9D shows the second weight. Regardless of whether the orientation of the information display device Db (the orientation of the display unit 11) is portrait or landscape, the user is standing and using the information display device Db, or the user is sitting and sitting on the information display device Db. Or when the user is lying down and using the information display device Db.

In FIG. 7, the information display device Db according to the second embodiment controls the display unit 11 according to the usage situation, and similarly to the above-described processing S <b> 1 and processing S <b> 2, processing S <b> 11 and display for obtaining the display surface illuminance. A process S12 for detecting a direction is performed.

Next, in process S13, the attitude of the display surface 111 of the display unit 11 (the attitude of the information display device Db) is acquired by the attitude detection unit 17, and the acquired attitude (roll angle and pitch angle in the present embodiment). Is output to the control value calculator 15b. The control value calculation unit 15b sets the positions according to the posture of the information processing device Db in the plurality of photoelectric conversion elements 131-11 to 131-33 of the back luminance distribution detection unit 13 to the postures acquired by the posture detection unit 17. Judgment and setting based on. That is, by changing the posture of the information processing device Db, even in the same photoelectric conversion element 131-ij disposed in the housing H, the arrangement position of the two-dimensional array differs depending on the posture. For example, when the information display device Db is used in the vertical orientation (in the case of the vertical orientation), the photoelectric conversion element 131-33 is in the position of 3 rows and 3 columns, but the information display device Db is in the horizontal orientation. In the case of being used for (in the case of the landscape mode), since it is rotated 90 degrees, it becomes a position of 3 rows and 1 column. Thus, it is necessary to associate the absolute position of the photoelectric conversion element 131 disposed in the housing H with the actual position generated by the change in the attitude of the information processing device Db. Therefore, the actual positions according to the postures of the plurality of photoelectric conversion elements 131-11 to 131-33 of the back luminance distribution detecting unit 13 are determined and set based on the postures acquired by the posture detecting unit 17. Then, the photoelectric conversion element 131-ij at each set position is associated with each weight Mmn in the next process.

Next, in the process S14, as in the above-described process S3, the back light detection area is set based on the display direction detected by the display direction detection unit 14 by the control value calculation unit 15b. More specifically, the control value calculation unit 15a associates each preset weight Mmn with the output Kij of each photoelectric conversion element 131-ij of the back luminance distribution detection unit 13.

Next, in process S15, the back luminance distribution is acquired by the back luminance distribution detector 13, and the acquired back luminance distribution is output to the control value calculator 15b. Then, the back luminance value Lb is weighted by weighting the luminance distribution detected by the back luminance distribution detecting unit 13 with the weight set based on the display direction detected by the display direction detecting unit 14 and the posture detected by the posture detecting unit 17. Is obtained by the control value calculation unit 15b.

These processes S13 through S15 will be described more specifically with reference to FIGS.

For example, in the example shown in FIG. 8A, the roll angle is 0, the pitch angle is + α (0 <α <90 degrees), and the display surface 111 of the information display device Dc is in the vertical orientation (vertical orientation mode). ). That is, the orientation of the display surface 111 of the display unit 11 is vertical. The display direction is the vertical direction from the top to the bottom (upper to lower) in the usage mode in the vertical direction, and the vertical direction from the top to the bottom (upper to lower) for the display unit 11 disposed in the housing H. ). In such a case, the positions of the photoelectric conversion elements 131-11 to 131-33 disposed in the housing H coincide with the positions based on the posture by the process S13. That is, as shown in FIG. 8B, the photoelectric conversion element 131-ij disposed in the housing H in the i-th row and j-th column is the i-th row and j-th column position even based on the posture. Next, by processing S14, each preset weight is associated with each photoelectric conversion element Kij of the back luminance distribution detection unit 13, and as shown in FIG. 8B, i = m, j = n, A weight Mmn of m rows and n columns is associated with the photoelectric conversion element Kij of i rows and j columns at a position based on the posture (i = m = 1, 2, 3; j = n = 1, 2, 3). As shown in FIG. 8C, the weights M11, M12, and M13 used for the upper part of the display direction (first row) are 1, 1, 1, and the center of the display direction (second row). So that the weights M21, M22, M23 used are 1, 1, 1, and the weights M31, M32, M33 used for the lower part of the display direction (third row) are 0, 0, 0 It is set in advance. Therefore, in the process S15, the rear luminance Lb is Lb = M11 × K11 + M12 × K12 + M13 × K13 + M21 × K21 + M22 × K22 + M23 × K23 + M31 × K31 + M32 × K32 + M33 × K33) / 9 = 1 × K11 + 1 × K12 + 1 × K13 + 1 × K21 + 1 × K22 + 1 × K23 K31 + 0 × K32 + 0 × K33) / 9. When there is such a pitch angle, the weight changes along the row direction, and is set in advance so as to decrease as the number of rows increases. Thereby, the weight is set in advance so as to decrease from the upper side to the lower side of the display surface 111 in the vertical usage mode and the vertical display mode.

Further, for example, in the example shown in FIG. 9A, the roll angle is + β (0 <β <90 degrees), the pitch angle is 0, and the display surface 111 of the information display device Dc is oriented sideways (sideways Embodiment). That is, the posture of the display surface 111 of the display unit 11 is horizontal. The display direction is the left-to-right left-right direction (left → right) in the horizontal usage mode, but for the display unit 11 disposed in the housing H, the vertical direction from bottom to top (bottom → upper). ). In such a case, the position of each of the photoelectric conversion elements 131-1 to 131-33 disposed in the housing H is rotated 90 degrees in the clockwise direction by the process S13, so that each position based on the posture is changed. Match the position. That is, as shown in FIG. 9B, the photoelectric conversion elements 131-11 arranged in the housing H in the first row and the first column are in the first row and the third column in the position based on the posture, and in the first row and the second column. The photoelectric conversion element 131-12 disposed in the housing H is in a position of 2 rows and 3 columns in a position based on the posture, and the photoelectric conversion element 131- disposed in the housing H in 1 row and 3 columns. 13 is a position of 3 rows and 3 columns in the position based on the posture, and the photoelectric conversion element 131-21 disposed in the housing H in 2 rows and 1 column is a position of 1 row and 2 columns in the position based on the posture. The photoelectric conversion element 131-22 arranged in the housing H in 2 rows and 2 columns is located in 2 rows and 2 columns in the position based on the posture, and is arranged in the housing H in 2 rows and 3 columns. The photoelectric conversion element 131-23 is arranged in a position of 3 rows and 2 columns in a position based on the posture, and is arranged in the housing H in 3 rows and 1 column. The photoelectric conversion element 131-31 in the position based on the posture is in the position of 1 row and 1 column, and the photoelectric conversion element 131-32 arranged in the housing H in 3 rows and 2 columns is in the position based on the posture. The photoelectric conversion elements 131-33 that are located in the 2nd row and 1st column and are disposed in the housing H in the 3rd row and the 3rd column are located in the 1st row and the 3rd column in a position based on the posture. When the photoelectric conversion element 131-ij disposed in the housing H at the position of ij in the i row and j column is used in the horizontal direction, the position based on the posture is the position of j (4-i) Become. Next, by processing S14, each weight Mmn set in advance is associated with each output Kij of each photoelectric conversion element 131 of the back luminance distribution detection unit 13, and as shown in FIG. 9C, i = m, When j = n, the weight Mmn is associated with the output Kj (4-i) of the photoelectric conversion element 131-j (4-i) at the position of j (4-i) based on the posture (m = 1, 2, 3; n = 1, 2, 3). As shown in FIG. 9C, the weights M11, M12, and M13 used for the upper part of the display direction (first row) are 2, 2, 0, and the center of the display direction (second row) is used. So that the weights M21, M22, M23 used are 2, 2, 0, and the weights M31, M32, M33 used for the lower part of the display direction (third row) are 0, 0, 0 It is set in advance. Therefore, in the process S15, the rear luminance Lb is Lb = M13 × K11 + M23 × K12 + M33 × K13 + M12 × K21 + M22 × K22 + M23 × K23 + M11 × K31 + M21 × K32 + M31 × K33) / 9 = 0 × K11 + 0 × K12 + 0 × K13 + 2 × K21 + 2 × K2 K31 + 2 × K32 + 0 × K33) / 9. Alternatively, as shown in FIG. 9D, the weights M11, M12, and M13 used for the upper side of the display direction (first row) are 2, 2, 1, and the center of the display direction (second row). The weights M21, M22, M23 used for are 2, 2, 1, and the weights M31, M32, M33 used for the lower part of the display direction (third row) are 0, 0, 0. It may be preset as follows. In this case, in the processing S15, the back luminance Lb is Lb = M13 × K11 + M23 × K12 + M33 × K13 + M12 × K21 + M22 × K22 + M23 × K23 + M11 × K31 + M21 × K32 + M31 × K33) / 9 = 1 × K11 + 1 × K12 + 0 × K13 + 2 × K21 + 2 × K K23 + 2 × K31 + 2 × K32 + 0 × K33) / 9. Thus, even when there is a roll angle, by making the positions of the photoelectric conversion elements 131-1 to 131-33 arranged in the housing H coincide with the positions based on the posture, the weight can be set in the column direction. Is set in advance so as to decrease as the number of columns increases. Accordingly, the weight is set in advance so as to decrease from the lower side to the upper side of the display surface 111 in the horizontal usage mode and the vertical display mode.

Further, for example, in the example shown in FIG. 10A, the roll angle is + β (0 <β <90 degrees), the pitch angle is 0, and the display surface 111 of the information display device Dc is oriented sideways (sideways Embodiment). The display direction is a vertical direction from the top to the bottom (upper to lower) in the horizontal usage mode, but for the display unit 11 disposed in the housing H, the horizontal direction from the left to the right (left to right). It is. In such a case, the position of each of the photoelectric conversion elements 131-1 to 131-33 disposed in the housing H is rotated 90 degrees in the clockwise direction by the process S13, so that each position based on the posture is changed. Match the position. That is, as shown in FIG. 10B, when the photoelectric conversion element 131-ij disposed in the housing H at the position ij in the i row and the j column is used in the horizontal direction, The position is j (4-i). Next, by processing S14, each weight Mmn set in advance is associated with each output Kij of each photoelectric conversion element 131 of the back luminance distribution detection unit 13, and as shown in FIG. 10B, i = m, When j = n, the weight Mmn is associated with the output Kj (4-i) of the photoelectric conversion element 131-j (4-i) at the position of j (4-i) based on the posture (m = 1, 2, 3; n = 1, 2, 3). The weights are the same as those shown in FIG. 8C. Therefore, in the process S15, the rear luminance Lb is Lb = M13 × K11 + M23 × K12 + M33 × K13 + M12 × K21 + M22 × K22 + M23 × K23 + M11 × K31 + M21 × K32 + M31 × K33) / 9 = 1 × K11 + 1 × K12 + 0 × K13 + 1 × K21 + 1 × K22 + 0 × K31 + 1 × K32 + 0 × K33) / 9. Thus, even when there is a roll angle, by making the positions of the photoelectric conversion elements 131-1 to 131-33 arranged in the housing H coincide with the positions based on the posture, the weight can be set in the row direction. And is set in advance so as to decrease as the number of rows increases. Accordingly, the weight is set in advance so as to decrease from the upper side to the lower side of the display surface 111 in the horizontal usage mode and the horizontal display mode.

Further, for example, in the example shown in FIG. 11A, the roll angle is 0, the pitch angle is + α (0 <α <90 degrees), and the display surface 111 of the information display device Dc is oriented vertically (vertically placed). Embodiment). The display direction is the horizontal direction from left to right (left → right) in the vertical usage mode, but for the display unit 11 arranged in the housing H, the horizontal direction from left to right (left → right). Right). In such a case, the positions of the photoelectric conversion elements 131-11 to 131-33 disposed in the housing H coincide with the positions based on the posture by the process S13. That is, as shown in FIG. 11B, the photoelectric conversion element 131-ij disposed in the housing H in the i row and j column is also in the i row and j column position even based on the position. Next, by processing S14, each preset weight is associated with each photoelectric conversion element Kij of the back luminance distribution detecting unit 13, and as shown in FIG. 11B, i = m, j = n, A weight Mmn of m rows and n columns is associated with the photoelectric conversion element Kij of i rows and j columns at a position based on the posture (i = m = 1, 2, 3; j = n = 1, 2, 3). The weight is the same as the weight shown in FIG. 9C. Therefore, in the process S15, the rear luminance Lb is Lb = M11 × K11 + M12 × K12 + M13 × K13 + M21 × K21 + M22 × K22 + M23 × K23 + M31 × K31 + M32 × K32 + M33 × K33) / 9 = 2 × K11 + 2 × K12 + 0 × K13 + 2 × K21 + 2 × K0 + 2 × K0 K31 + 0 × K32 + 0 × K33) / 9. The weight may be the weight illustrated in FIG. 9D. Thus, the weight changes along the column direction and is set in advance so as to decrease as the number of columns increases. Accordingly, the weight is set in advance so as to decrease from the left side to the right side of the display surface 111 in the vertical usage mode and the horizontal display mode.

And next, each processing S12 of processing S16 thru / or processing 18 is performed like each processing of processing S5 thru / or processing S7 mentioned above.

As described above, in the information display device Db according to the present embodiment, the back luminance Lb is a weight set based on the display direction detected by the display direction detecting unit 14 and the posture detected by the posture detecting unit 17. The display luminance of the display unit 11 is controlled on the basis of the back luminance and the illuminance thus obtained. Therefore, the information display device Db according to the present embodiment takes into consideration the display direction and orientation of the display unit 11 when controlling the display luminance of the display unit 11, and therefore can control the display luminance more according to the usage situation. .

In the second embodiment described above, the weights used when obtaining the back luminance (back luminance value) are individually prepared in advance and stored in the control value calculation unit 15b for each combination of the display direction and the posture mode. May be. For example, the first weight (vertical-vertical aspect weight) when the display direction on the display surface 111 is the vertical direction and the posture of the display unit 11 is vertical, the display direction on the display surface 111 is the horizontal direction. The second weight when the orientation of the display unit 11 is vertical (horizontal-vertical aspect weight), and the third weight when the display direction on the display surface 111 is vertical and the orientation of the display unit 11 is horizontal. Weight of 4 patterns of weight (vertical-horizontal aspect weight) and fourth weight (horizontal-horizontal aspect weight) when the display direction on the display surface 111 is horizontal and the orientation of the display unit 11 is horizontal. May be prepared in advance and stored in the control value calculation unit 15b. In this case, the weight used for one of the display directions may be set in advance larger than the weight used for the other display direction, and when there is a roll angle, the weight is along the row direction. And may be preset to decrease as the number of columns increases, and when there is a pitch angle, the weight changes along the column direction and the number of rows increases. It may be set in advance so as to become smaller according to In such a case, a weight is required for each pattern, and a corresponding amount of memory capacity is required. In the second embodiment described above, as described above, by converting each position of the photoelectric conversion element 131 actually arranged in the housing H to each position according to the posture, FIG. 8C, FIG. 9C, and FIG. Each weight for the vertical orientation shown in 9D is used for each weight for the horizontal orientation and is shared.

Next, another embodiment will be described.

(Third embodiment)
The information display devices Da and Db in the first and second embodiments described above control the display luminance of the display unit 11. The information display device Dc in the third embodiment further controls the contrast of the display unit 11. Is.

The information display device Da of the first embodiment may be further configured to control the contrast of the display unit 11, but here, the information display device Db of the second embodiment further includes the display unit 11. A case where the contrast is controlled will be described. Note that the information display device Da of the first embodiment is also configured as described later, so that the information display device Dc that controls the contrast of the display unit 11 can be similarly configured.

Such an information display device Dd in the third embodiment includes a display unit 11, a display surface illuminance detection unit 12, a back luminance distribution detection unit 13, a display direction detection unit 14, a posture detection unit 17, and a control value. A calculation unit 15d, a display control unit 16, and a housing H that houses these units 11 to 17 are provided. In the information display device Dd of the third embodiment, the display unit 11, the display surface illuminance detection unit 12, the back luminance distribution detection unit 13, the display direction detection unit 14, the posture detection unit 17, the display control unit 16, and the housing H are The display unit 11, the display surface illuminance detection unit 12, the back luminance distribution detection unit 13, the display direction detection unit 14, the posture detection unit 17, the display control unit 16, and the housing H in the information display device Db of the second embodiment, respectively. Since it is the same, the description is omitted.

In addition to the function of the control value calculation unit 15b in the information display device Db of the second embodiment, the control value calculation unit 15d further has the illuminance detected by the display surface illuminance detection unit 12 outside the preset threshold range. In this case, the display luminance is controlled so that the contrast is changed (adjusted) according to the illuminance detected by the display surface illuminance detection unit 12. The change in contrast is, for example, contrast enhancement or contrast suppression (reduction). The contrast enhancement is performed, for example, by increasing the number of luminance gradations. For example, when the number of gradations of luminance is 128 gradations from 0 to 127 by default, in order to enhance contrast, the difference between the black level and the white level is greatly expanded, and the number of gradations of luminance is 0. To 255 to 256 gradations. The contrast is suppressed by, for example, reducing the number of luminance gradations. For example, when the number of gradations of luminance is 128 gradations from 0 to 127 by default, the difference between the black level and the white level is further reduced to suppress the contrast, and the number of gradations of luminance is 0. To 63 to 64 gradations.

Next, the operation of this embodiment will be described. FIG. 12 is a flowchart showing the operation of the information display device in the third embodiment.

In FIG. 12, the information display device Dd according to the third embodiment performs processing S21, processing S22, processing S23, processing S24, processing S25, processing S26, processing S27 and the like in order to control the display unit 11 according to the usage situation. Processing S29 is performed. The processes S21 to S27 and S29 in the information display device Dd according to the third embodiment are the same as the processes S11 to S17 and S19 in the information display device Db according to the second embodiment, respectively. Omitted.

And after performing process S27, the information display apparatus Dd of 3rd Embodiment performs process S28, and returns a process to process S21. On the other hand, after performing process S29, it performs process S30 and processes a process S21. Return to.

In each of these processes S28 and S30, the control value calculator 15d first determines whether or not the illuminance detected by the display surface illuminance detector 12 is outside a preset threshold range. As a result of this determination, when the illuminance detected by the display surface illuminance detection unit 12 is outside the preset threshold range, the control value calculation unit 15d sets the illuminance detected by the display surface illuminance detection unit 12 to In response, a contrast control value for controlling the contrast to be changed is generated and output to the display control unit 16. The display control unit 16 to which the contrast control value is input controls the display unit 11 to drive the display unit 11 so as to obtain a contrast corresponding to the contrast control value, whereby the display unit 11 The display surface 111 is displayed by changing the contrast.

On the other hand, as a result of the determination, if the illuminance detected by the display surface illuminance detection unit 12 is not outside the preset threshold range, the control value calculation unit 15d maintains the current state without performing contrast enhancement. To do.

Such an information display device Dd according to the present embodiment changes (adjusts) the contrast according to the illuminance of the display surface 111 when the illuminance of the display surface 111 is relatively large, so that the visibility can be improved. . Further, when the illuminance of the display surface 111 is relatively small, it is possible to suppress eye fatigue by changing the contrast according to the illuminance of the display surface 111.

Note that in the information display devices D (Da to Dd) of the first to third embodiments described above, the control value calculation unit 15 (15a to 15d) calculates the maximum value and the minimum value in each value of the weighted luminance distribution. When the difference is equal to or greater than a predetermined threshold, the maximum value may be the back luminance value. That is, the control value calculation unit 15 obtains each value Kij × Mmn obtained by weighting each output Kij of the photoelectric conversion element 131-ij with a corresponding weight Mmn, and from these values, the maximum value Max (Kij × Mmn) is obtained. The minimum value Min (Kij × Mmn) is obtained, and it is determined whether or not the difference between the two is equal to or greater than a predetermined threshold value. If the difference is equal to or greater than the threshold value, the maximum value Max (Kij × Mmn) is determined as the rear luminance. Value. Such processing is performed in step S4 in the information display device Da of the first embodiment, in step S15 in the information display device Db of the second embodiment, and the information display device of the third embodiment. In Dd, it is performed in step S25.

When the difference between the maximum value and the minimum value is relatively large, if the minimum value is taken into consideration in the back luminance, the comparison is made between the back luminance actually recognized by the user and the back luminance calculated by the information display device D. Large deviation occurs, and good visibility cannot be obtained. Such an information display device D uses the maximum value as the back surface brightness in the predetermined case, so that the back surface brightness can be appropriately evaluated even when the back surface brightness distribution is biased. In addition, the display luminance can be controlled.

In addition, the back luminance distribution detector 13 in the information display device D of the first to third embodiments described above is arranged in close contact with each other so as to be adjacent to each other at the approximate center of the other main surface Hb of the housing H. Although (9 in this example) the photoelectric conversion elements 131-11 to 131-33 are provided, the present invention is not limited to this. For example, the back luminance distribution detecting unit 31 includes a plurality of photoelectric conversion elements K, and the plurality of photoelectric conversion elements K may be arranged so as to be distributed over the entire surface or the peripheral area of the other main surface Hb of the housing H. Good. More specifically, in the example shown in FIG. 13, the plurality of photoelectric conversion elements K include eight photodiodes 131-11 to 131-13; 131-21, 131-23; 131-31 to 131-33. The three photodiodes 131-11 to 131-13 in the rear luminance distribution detecting unit 31 are arranged so as to be distributed in the peripheral region on the other main surface Hb of the housing H. Two photodiodes 131-21 and 131- in the rear luminance distribution detector 31 are arranged in one end region in the longitudinal direction of Hb so as to be equally spaced from each other in the width direction perpendicular to the longitudinal direction. 32 is arranged in a substantially central region in the longitudinal direction on the other main surface Hb of the housing H, spaced apart at both ends in the width direction, and three photodiodes in the back luminance distribution detecting unit 31. De 131-31 ~ 131-33 are the other longitudinal end region of the other main surface Hb of the housing H, and is spaced apart so as to be equidistant from each other in the width direction. In this way, by being arranged so as to be distributed in the peripheral area on the other main surface Hb of the housing H, it is possible to detect the luminance distribution on the front surface of the back surface.

This specification discloses various modes of technology as described above, and the main technologies are summarized below.

An information display device according to an aspect includes a display unit for displaying information, a display surface illuminance detection unit for detecting illuminance on the display surface of the display unit, and a back surface for detecting a luminance distribution on the back surface facing the display surface. A luminance distribution detection unit, a display direction detection unit that detects a display direction of information displayed on the display unit, and the back luminance distribution detection with a weight set based on the display direction detected by the display direction detection unit A display unit based on the back luminance calculation unit that obtains the back luminance by weighting the luminance distribution detected by the unit, the illuminance detected by the display surface illuminance detection unit, and the back luminance obtained by the back luminance calculation unit. A control unit that controls display brightness of the unit.

In such an information display device, the rear luminance is obtained by weighting the luminance distribution detected by the rear luminance distribution detection unit with a weight set based on the display direction detected by the display direction detection unit, and the control The unit controls the display luminance of the display unit based on the back luminance obtained in this way and the illuminance detected by the display surface illuminance detection unit. Therefore, such an information display device can also control the display brightness in accordance with the usage situation because the display direction is taken into consideration when the display brightness of the display unit is controlled.

In another aspect, the information display device described above further includes a posture detection unit that detects a posture of the display unit, and the back luminance calculation unit detects the display direction and the posture detected by the display direction detection unit. The back luminance is obtained by weighting the luminance distribution detected by the back luminance distribution detecting unit with a weight set based on the posture detected by the unit.

In such an information display device, the luminance on the back surface weights the luminance distribution detected by the back luminance distribution detection unit with a weight set based on the display direction detected by the display direction detection unit and the posture detected by the posture detection unit. The control unit controls the display luminance of the display unit based on the back luminance and the illuminance detected by the display illuminance detection unit thus obtained. Therefore, such an information display device can control the display luminance more in accordance with the usage situation because the display direction and orientation of the display unit are taken into consideration when the display luminance of the display unit is controlled.

In another aspect, in the above-described information display device, the back luminance calculation unit, when a difference between a maximum value and a minimum value in each value of the weighted luminance distribution is equal to or greater than a predetermined threshold, The maximum value is the back luminance value.

When the difference between the maximum value and the minimum value is relatively large, if the minimum value is taken into consideration in the back luminance, the back luminance actually recognized by the user and the back luminance calculated by the information display device are relatively small. A large shift occurs and good visibility cannot be obtained. In such an information display device, the maximum value is used as the back luminance value in the predetermined case. Therefore, even when the back luminance distribution is biased, the back luminance can be appropriately evaluated, and the usage situation can be further improved. In addition, the display luminance can be controlled.

In another aspect, in the above-described information display device, the control unit, when the illuminance detected by the display surface illuminance detection unit is outside a preset threshold range, The display brightness is controlled so as to change the contrast according to the illuminance detected in step (b).

Such an information display device changes (adjusts) the contrast (changes the difference between the black level and the white level) in accordance with the illuminance on the display surface when the illuminance on the display surface is relatively large. Can be improved. Further, when the illuminance on the display surface is small, eye fatigue can be suppressed by changing the contrast according to the illuminance on the display surface.

In another aspect, the weight used for one of the display directions is set larger than the weight used for the other display direction in these information display devices described above.

A user who uses an information display device is generally considered to be watching one of the displays when information is displayed from one side of the display direction to the other side. The surrounding area is also included. For this reason, in such an information display device, the weight used for one of the display directions is set larger than the weight used for the other direction in order to weight one of the display directions relatively heavily. Therefore, it is possible to control the display brightness more according to the usage situation.

In another aspect, in the above-described information display device, the control unit converts the illuminance detected by the display surface illuminance detection unit into luminance as illuminance conversion luminance, and the illuminance conversion luminance and the back luminance calculation unit The display brightness of the display unit is controlled based on the ratio to the back face brightness obtained in step (1).

Such an information display device uses a ratio between the illuminance-converted luminance and the rear luminance, so that one can be easily compared with the other as a reference, and the display surface illuminance and the rear luminance can be easily evaluated. Can do.

In another aspect, in the above-described information display device, when the ratio of the illuminance-converted luminance to the back luminance obtained as the ratio is within a predetermined range, When the display brightness of the display unit is controlled to a bright brightness of the back brightness and the illuminance converted brightness, and the ratio is not within a predetermined range, the back brightness and the illuminance converted brightness The display brightness of the display unit is controlled by the brightness obtained by multiplying the bright brightness by a predetermined correction value set in advance.

Since such an information display device uses a ratio of the illuminance conversion luminance to the back luminance, the display surface illuminance can be easily compared based on the back luminance, and the display surface illuminance and the back luminance can be easily evaluated. can do. Further, in such an information display device, when the ratio is within the predetermined range, the display brightness of the display unit is controlled to the brighter brightness of the front face and the rear face. The display brightness can be appropriately controlled even in a light environment where there is a difference in brightness. When the ratio is not within the predetermined range, the information display device displays the display unit with a brightness obtained by multiplying the brightness of the brighter one of the front surface and the back surface by the predetermined correction value. Since the brightness is controlled, it is possible to appropriately control the display brightness even in a light environment where there is a relatively large difference in brightness between the front surface and the back surface.

The information display method according to another aspect includes a display surface illuminance detection step for detecting illuminance on the display surface of the display unit for displaying information, and a back surface brightness for detecting a luminance distribution on the back surface facing the display surface. A distribution detection step; a display direction detection step for detecting a display direction of information displayed on the display unit; and a back luminance distribution detection step with a weight set based on the display direction detected in the display direction detection step. The display unit based on the back luminance calculation step for obtaining the back luminance by weighting the luminance distribution detected in the step, the illuminance detected in the display surface illuminance detection step, and the back luminance obtained in the back luminance calculation step And a control step for controlling the display luminance of the display.

In such an information display method, the back luminance is obtained by weighting the luminance distribution detected in the back luminance distribution detection step with a weight set based on the display direction detected in the display direction detection step, and the control In the process, the display brightness of the display unit is controlled based on the back brightness and the illuminance detected in the display face illuminance detection process. Therefore, such an information display method can also control the display brightness in accordance with the usage situation because the display direction is taken into consideration when the display brightness of the display unit is controlled.

This application is based on Japanese Patent Application No. 2012-238980 filed on October 30, 2012, the contents of which are included in this application.

In order to express the present invention, the present invention has been properly and fully described through the embodiments with reference to the drawings. However, those skilled in the art can easily change and / or improve the above-described embodiments. It should be recognized that this is possible. Therefore, unless the modifications or improvements implemented by those skilled in the art are at a level that departs from the scope of the claims recited in the claims, the modifications or improvements are not covered by the claims. To be construed as inclusive.

According to the present invention, it is possible to provide an information display device and an information display method capable of controlling the display brightness of the display unit.

Claims

A display for displaying information;
A display surface illuminance detector that detects illuminance on the display surface of the display unit;
A back surface luminance distribution detecting unit for detecting a back surface luminance distribution facing the display surface;
A display direction detection unit for detecting a display direction of information displayed on the display unit;
A back luminance calculation unit for obtaining a back luminance by weighting the luminance distribution detected by the back luminance distribution detection unit with a weight set based on the display direction detected by the display direction detection unit;
An information display device comprising: a control unit that controls display luminance of the display unit based on the illuminance detected by the display surface illuminance detection unit and the rear luminance obtained by the rear luminance calculation unit.
A posture detecting unit for detecting the posture of the display unit;
The back luminance calculation unit weights the luminance distribution detected by the back luminance distribution detection unit with a weight set based on the display direction detected by the display direction detection unit and the posture detected by the posture detection unit. The information display device according to claim 1, wherein a rear luminance is obtained by
The back luminance calculation unit sets the maximum value as the back luminance value when a difference between a maximum value and a minimum value in each value of the weighted luminance distribution is equal to or greater than a predetermined threshold value. The information display device according to claim 1 or 2.
When the illuminance detected by the display surface illuminance detection unit is outside a preset threshold range, the control unit changes the contrast according to the illuminance detected by the display surface illuminance detection unit. The information display device according to any one of claims 1 to 3, wherein the display luminance is controlled.
5. The information according to claim 1, wherein the weight used for one of the display directions is set to be larger than the weight used for the other of the display directions. Display device.
The control unit converts the illuminance detected by the display surface illuminance detection unit into luminance as illuminance converted luminance, and displays the display based on a ratio between the illuminance converted luminance and the back luminance calculated by the back luminance calculation unit. The information display device according to any one of claims 1 to 5, wherein the display luminance of the unit is controlled.
When the ratio of the illuminance-converted luminance to the back-surface luminance obtained as the ratio is within a predetermined range set in advance, the control unit increases the brightness of the back-surface luminance and the illuminance-converted luminance to the bright luminance. When the display luminance of the display unit is controlled and the ratio is not within a predetermined range, the bright luminance of the back luminance and the illuminance-converted luminance is multiplied by a predetermined correction value. The information display device according to claim 6, wherein the display luminance of the display unit is controlled to a higher luminance.
A display surface illuminance detection step of detecting the illuminance on the display surface of the display unit for displaying information;
A backside luminance distribution detecting step for detecting a backside luminance distribution facing the display surface;
A display direction detecting step for detecting a display direction of information displayed on the display unit;
A back luminance calculation step for obtaining a back luminance by weighting the luminance distribution detected in the back luminance distribution detection step with a weight set based on the display direction detected in the display direction detection step;
A control step of controlling display luminance of the display unit based on the illuminance detected in the display surface illuminance detection step and the back luminance obtained in the back luminance calculation step.