JP2013037264A - Image display apparatus, image display terminal, and control method for controlling display of image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image display apparatus which suppresses color bleeding and crosstalk when a 3-dimensional image is displayed.SOLUTION: When a mobile phone as an embodiment of an image display apparatus displays an image three-dimensionally, light of some of pixels is turned off. Specifically, light of pixels 630, 631, 632, 633, 634, 635 is turned off. Light of a group of pixels 610, 620, 611, 612, 621, 622 is turned on.

Description

  The present invention relates to a technique for displaying an image in three dimensions, and more specifically to a technique for displaying an image using a parallax barrier.

  2. Description of the Related Art Conventionally, a liquid crystal display device capable of displaying a three-dimensional image distributes dots composed of red, blue, and green (RGB) for the right eye and the left eye for each column when displaying a two-dimensional image. When the liquid crystal display device displays an image in three dimensions, the right eye is shielded from light when the right eye image is displayed by the parallax barrier, and the right eye is displayed when the left eye image is displayed. By shielding the dots for use, an image can be displayed in three dimensions.

  Regarding a technique for displaying an image in three dimensions, for example, Japanese Patent Application Laid-Open No. 8-110495 (Patent Document 1) states, “Even if a liquid crystal panel having a horizontal aperture ratio of 50% or more is used for a stereoscopic display device, a pixel is used. A “stereoscopic display device capable of stereoscopic viewing with maximum illuminance at the observation position without increasing the crosstalk area” is disclosed (see “Summary”).

  Japanese Patent Laying-Open No. 2005-164916 (Patent Document 2) discloses a “stereoscopic display device capable of suppressing crosstalk within the range of the performance of existing displays and enabling good three-dimensional observation” (“Summary”). "reference).

  Japanese Patent Laying-Open No. 2010-109414 (Patent Document 3) discloses a technique for “combining parallax image data” (see “Summary”).

JP-A-8-110495 JP 2005-164916 A JP 2010-109414 A

  However, in the case of displaying an image in a three-dimensional manner using a parallax barrier, if the slit width of the parallax barrier is set to the full dot width, the gap between dots is very small, so the viewing angle, depth, position of the parallax barrier, Due to the width error, the color of adjacent pixels may wrap around and crosstalk may occur.

  In this case, if the slit width is reduced as a countermeasure, depending on the angle, the amount of light of the pixels on the outer edge of the slit (for example, the pixels R and B when the pixels R, G, and B are arranged) In some cases, the color balance is lost due to a dimensional error or the like, resulting in “color blur”.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an image display device in which deterioration in image quality such as crosstalk and color bleeding is suppressed. .

  According to a certain aspect, an image display device for displaying an image in two dimensions or three dimensions is provided. The image display device includes a forming unit for forming a parallax barrier, a display unit having pixels for displaying each of RGB (Red Green Blue), and a driving unit for controlling display by each pixel. Is provided. When the image display device displays an image in three dimensions, the driving unit includes a pixel between the RGB pixels for displaying the left-eye image and the RGB pixels for displaying the right-eye image. At least one pixel is turned off as a pixel that is not lit.

  Preferably, the driving unit controls display of an image by each pixel by repeating lighting of three pixels and extinguishing of one pixel.

  Preferably, each pixel includes a fourth color pixel in addition to RGB. The driving means turns off the fourth color pixel.

Preferably, the width of the slit formed by the parallax barrier exceeds the width of one pixel.
When another aspect is followed, an image display terminal provided with the image display apparatus in any one of said is provided.

  According to yet another aspect, a control method for controlling display of an image by an image display device having pixels for displaying each of RGB (Red Green Blue) is provided. This control method includes a step of forming a parallax barrier and a step of controlling display by each pixel. When the image display device displays an image in three dimensions, the controlling step is performed between RGB pixels for displaying a left-eye image and RGB pixels for displaying a right-eye image. The step of turning off at least one pixel as a pixel that is not lit is included.

  Preferably, the controlling step includes a step of controlling display of an image by each pixel by repeating lighting of three pixels and extinguishing of one pixel.

  Preferably, each pixel includes a fourth color pixel in addition to RGB. The controlling step includes a step of turning off the fourth color pixel.

According to a certain aspect, deterioration in image quality such as crosstalk and color blur is suppressed.
The above and other objects, features, aspects and advantages of the present invention will become apparent from the following detailed description of the present invention taken in conjunction with the accompanying drawings.

1 is a diagram illustrating an appearance of a mobile phone 100. FIG. 2 is a block diagram showing a hardware configuration of mobile phone 100. FIG. It is a figure showing the one aspect | mode of the output of the image data in the pixel which comprises a liquid crystal panel. It is a figure showing the case where the width | variety of the barrier which forms a slit is larger than the liquid crystal dot width of a liquid crystal panel. It is a figure for demonstrating the problem which may arise when a barrier is smaller than the dot width of a liquid crystal. 4 is a flowchart showing a part of a series of processes executed by CPU 110 of mobile phone 100. It is a figure showing lighting and extinction of a pixel in the case of switching from 2D display to 3D display. It is a figure showing the data structure 700 in case the mobile telephone 100 displays an image in two dimensions. It is a figure showing the control data at the time of turning off some pixels when the mobile telephone 100 displays an image in three dimensions. It is a figure showing the definition of the area | region used when CPU110 performs three-dimensional display. It is a flowchart showing a part of a series of processes which CPU110 performs. It is a figure explaining the aspect which switches a display from 2D display to 3D display using 4 color filter liquid crystal. It is a figure showing the relationship between a user and a display apparatus in the case of displaying an image in two dimensions. It is a figure for demonstrating the visual recognition distance at the time of applying the technical thought which concerns on this invention. It is a figure showing the relationship between a user and a display apparatus in case the display apparatus using a color filter of 4 colors displays an image in three dimensions. It is a figure showing the aspect which sets a barrier per subpixel.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

  A mobile phone 100 according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a diagram illustrating an appearance of the mobile phone 100. The mobile phone 100 includes a display 150 capable of displaying a three-dimensional image and a button 160.

  In the present embodiment, the cellular phone 100 is exemplified, but the present invention can also be applied to other portable terminals such as a PDA, an electronic dictionary, and other information processing terminals.

[Hardware configuration]
With reference to FIG. 2, a hardware configuration of mobile phone 100 according to the present embodiment will be described. FIG. 2 is a block diagram showing a hardware configuration of mobile phone 100.

  The cellular phone 100 includes a communication device 102, a tuner 104, antennas 106 and 108, a CPU (Central Processing Unit) 110, an audio signal processing circuit 111, a positioning processing unit 112, and a positioning signal receiving front end unit 114. , GPS (Global Positioning System) antenna 116, camera 120, flash memory 144, RAM (Random Access Memory) 146, ROM (Read Only Memory) 148, backlight 151, button 160, LED (Light Emitting Diode) 176, a memory card driving device 180, a data communication I / F (Interface) 178, and a vibrator 184. A memory card 182 can be attached to the memory card driving device 180.

  In one aspect, the antenna 106 receives a television broadcast signal. The tuner 104 selects a program in accordance with an instruction from the CPU 110 and transmits a video signal and an audio signal to the CPU 110.

  The signal received by the antenna 108 is subjected to front-end processing by the communication device 102, and the processed signal is sent to the CPU 110. CPU 110 executes processing for controlling the operation of mobile phone 100 based on a command given to mobile phone 100. The CPU 110 executes a predetermined process based on the signal sent from the communication device 102, and sends the processed signal to the audio signal processing circuit 111. The audio signal processing circuit 111 performs predetermined signal processing on the signal, and sends the processed signal to the speaker 140. The speaker 140 outputs sound based on the signal.

  The microphone 170 receives an utterance from the mobile phone 100 and sends a signal corresponding to the uttered voice to the voice signal processing circuit 111. The audio signal processing circuit 111 executes a predetermined process for a call based on the signal, and sends the processed signal to the CPU 110. CPU 110 converts the signal into data for transmission, and sends the converted data to communication device 102. Communication device 102 generates a signal for transmission using the data, and transmits the signal to antenna 108.

  The flash memory 144 stores data sent from the CPU 110. In addition, the CPU 110 reads data stored in the flash memory 144 and executes a predetermined process using the data.

  The RAM 146 temporarily holds data generated by the CPU 110 based on an operation performed on the button 160. ROM 148 stores a program or data for causing mobile phone 100 to execute a predetermined operation. CPU 110 reads the program or data from ROM 148 and controls the operation of mobile phone 100.

  The memory card drive device 180 reads data stored in the memory card 182 and sends it to the CPU 110. Conversely, the memory card driving device 180 writes the data output by the CPU 110 into the free area of the memory card 182.

  The audio signal processing circuit 111 executes signal processing for a call as described above. In the example shown in FIG. 3, the CPU 110 and the audio signal processing circuit 111 are shown as separate configurations. However, in other aspects, the CPU 110 and the audio signal processing circuit 111 may be configured as an integral unit. Good.

  The display 150 can display images in two dimensions or in three dimensions. In one aspect, the display 150 is realized by a liquid crystal display device capable of forming a parallax barrier. The display 150 displays an image based on data output from the CPU 110. For example, the display 150 displays the attributes (still file name, performer, performance time, etc.) of still images, moving images, and music files stored in the flash memory 144.

  The backlight 151 emits light to the display 150. In one aspect, the backlight 151 can increase or decrease the amount of light based on a control signal from the CPU 110.

  The LED 176 realizes a predetermined light emission operation based on a signal from the CPU 110. The data communication I / F 178 accepts attachment of a data communication cable. The data communication I / F 178 sends a signal output from the CPU 110 to the cable. Alternatively, the data communication I / F 178 sends data received via the cable to the CPU 110.

  Vibrator 184 performs an oscillating operation at a predetermined frequency based on a signal output from CPU 110.

  The GPS antenna 116 receives a signal transmitted from a GPS satellite and sends the received signal to the positioning signal reception front end unit 114. The positioning signal reception front end unit 114 performs pattern matching based on each signal received from at least three (preferably four or more) GPS satellites, and a code pattern included in each signal and a code held by the mobile phone 100 When the pattern matches, the signal is sent to the positioning processing unit 112.

  The positioning processing unit 112 executes positioning processing using the signal, and calculates the position of the mobile phone 100 that has received the signal. CPU 110 displays the calculation result on display 150.

  With reference to FIG. 3, pixel data for displaying a three-dimensional image will be described. FIG. 3 is a diagram illustrating an aspect of output of image data in pixels constituting the liquid crystal panel. As shown in FIG. 3, when a two-dimensional image is displayed, for example, red, green, and blue pixels are lit for each column (eg, 1r, 1g, 1b, etc.).

  When displaying a three-dimensional image, the liquid crystal panel outputs a right-eye image and a left-eye image. For example, as shown in FIG. 3, the pixels 210, 211, 212, and 213 for displaying the image for the left eye and the pixels 220, 221, 222, and 223 for displaying the image for the right eye are separately provided. Lighting control is performed by the CPU 110.

  Here, with reference to FIG. 4 and FIG. 5, the problem which may arise when displaying an image in three dimensions is demonstrated. FIG. 4 is a diagram illustrating a case where the width of the barrier forming the slit is larger than the liquid crystal dot width of the liquid crystal panel 330.

  As shown in FIG. 4, for example, the barrier liquid crystal 310 may be larger than the liquid crystal dots (L1r, L1g, L1b). In this case, the width of the slit formed by the barrier liquid crystals 310 and 320 decreases. As a result, some of the pixels 340 and 342 are blocked by the barrier liquid crystals 310 and 320, respectively. For this reason, the output corresponding to the regions 350 and 351 is lowered, and the color balance is deteriorated.

  FIG. 5 is a diagram for explaining a problem that may occur when the barrier is smaller than the dot width of the liquid crystal. As shown in FIG. 5, the widths of the barrier liquid crystals 310 and 320 may be smaller than the liquid crystal dot width (L1r, L1g, L1b). In this case, since the width of the slit formed by the barrier liquid crystal 310 and the barrier liquid crystal 320 becomes large, in addition to the image based on the pixels 340, 341, and 342, the image from the pixel 400 can be visually recognized by the user through the slit. . Specifically, images corresponding to the areas 410 and 420 are visually recognized. As a result, crosstalk occurs.

  With reference to FIG. 6, a control structure of mobile phone 100 according to the present embodiment will be described. FIG. 6 is a flowchart showing a part of a series of processes executed by CPU 110 of mobile phone 100.

  In step S510, CPU 110 detects a three-dimensional display command. This detection is performed, for example, based on an operation on the button 160 or based on control data associated with image data to be displayed. That is, when the control data includes data indicating that the data to be output is a target for 3D display, the CPU 110 detects a 3D display command.

  In step S520, CPU 110 forms a parallax barrier by sending a command to the barrier liquid crystal.

  In step S530, CPU 110 turns off the pixel between the pixel for displaying the left-eye image and the pixel for displaying the right-eye image, and displays the pixel for displaying the left-eye image, The pixels for displaying the image for lighting are turned on. As a result, three-dimensional display in which color bleeding and crosstalk are suppressed is realized.

  In step S540, CPU 110 increases the amount of light emitted from backlight 151. Thereby, a decrease in luminance due to the extinction of some pixels is suppressed.

  In step S550, CPU 110 detects a two-dimensional display command. This detection is performed based on, for example, an operation on the button 160 or control data associated with image data to be displayed.

  In step S560, CPU 110 releases the formed parallax barrier in response to detection of the command.

  In step S570, CPU 110 lights all images. Thereby, a two-dimensional display is realized.

  With reference to FIG. 7, one mode of pixel driving in three-dimensional display will be described. FIG. 7 is a diagram illustrating lighting and extinguishing of pixels when switching from two-dimensional display to three-dimensional display.

  When the mobile phone 100 displays an image in two dimensions, as shown in the state (A), all the pixels are lit.

  On the other hand, as shown in the state (B), when the mobile phone 100 displays an image in three dimensions, some pixels are turned off. Specifically, the pixels 630, 631, 632, 633, 634, and 635 are turned off. The remaining pixel groups 610, 620, 611, 612, 621, and 622 are turned on.

  A data structure for displaying an image will be described with reference to FIGS. 8 and 9. FIG. 8 is a diagram showing a data structure 700 when the mobile phone 100 displays an image in two dimensions. When the mobile phone 100 displays an image two-dimensionally, the CPU 110 stores the pixel values to be output in the registers that store data for displaying the image on the display 150 (R1, G1, B1). Such).

  FIG. 9 is a diagram illustrating a data structure when some pixels are turned off when the mobile phone 100 displays an image in three dimensions. The data structure 800 stores an instruction for instructing to turn off pixels at some addresses. Specifically, in one embodiment, data for turning off the pixels at addresses 3, 7, and 3n−1 is stored. As a result, the pixels corresponding to these addresses are extinguished, and as a result, the above-described image degradation (color blur) or crosstalk is suppressed.

  A control structure for three-dimensional display of the mobile phone 100 will be described with reference to FIGS. 10 and 11. FIG. 10 is a diagram showing the definition of regions when CPU 110 performs three-dimensional display. FIG. 11 is a flowchart showing a part of a series of processes executed by CPU 110.

  In step S1110, CPU 110 creates data for displaying an image in three dimensions based on detecting a three-dimensional display command. Specifically, the CPU 110, the input variable indat [], the variable width (number of dots in the horizontal direction) representing the width in the three-dimensional display direction of the display area, and the vertical length height (vertical direction height) of the display area. Dot number) and output variable outdat [].

  In step S1015, CPU 110 initializes internal variables i, j, k, and l, respectively.

  In step S1020, CPU 110 executes operation outdat [k] = indat [i].

  In step S1025, CPU 110 increments internal variables i, j, and k by 1, respectively.

  In step S1030, CPU 110 determines whether internal variable k is equal to three times variable width or not. When CPU 110 determines that internal variable k is equal to three times the variable width (YES in step S1030), control is switched to step S1060. If not (NO in step S1030), CPU 110 switches control to step S1035.

  In step S1035, CPU 110 determines whether internal variable j is equal to 3. When CPU 110 determines that internal variable j is equal to 3 (YES in step S1035), CPU 110 switches control to step S1040. If not (NO in step S1035), CPU 110 returns the control to step S1020.

  In step S1040, CPU 110 executes the operation “output variable outdat“ k ”= 00h”.

In step S1045, CPU 110 increments internal variable k by one.
In step S1050, CPU 110 determines whether internal variable k is equal to 3 × width. When CPU 110 determines that internal variable k is equal to 3 × width (YES in step S1050), CPU 110 switches control to step S1060. If not (NO in step S1050), CPU 110 switches control to step S1055.

In step S1055, CPU 110 initializes internal variable j.
In step S1060, CPU 110 increments internal variable l by one.

  In step S1065, CPU 110 determines whether internal variable l is equal to vertical length height or not. When CPU 110 determines that internal variable l is equal to vertical length height (YES in step S1065), control ends. If not (NO in step S1065), CPU 110 switches control to step S1070.

  In step S1070, CPU 110 executes operation “i = 3 × l”. CPU110 returns control to step S1055.

  As described above, when displaying an image in three dimensions, the mobile phone 100 according to the embodiment of the present invention turns off some pixels. Thereby, “crosstalk” and “color blur” with respect to the visually recognized image can be suppressed.

<Modification>
Hereinafter, modifications of the embodiment of the present invention will be described. A case where the liquid crystal display device includes four color filter (RGBY) liquid crystals will be described with reference to FIG. FIG. 12 is a diagram for explaining a mode in which the display is switched from the two-dimensional display to the three-dimensional display using the four-color color filter liquid crystal.

  As shown in the state (A), when the mobile phone 100 displays an image in two dimensions, each pixel corresponding to the four color filters is turned on.

  On the other hand, as shown in the state (B), when the mobile phone 100 displays an image in three dimensions, the pixels corresponding to the three color filters among the four color filters are turned on and the fourth color is displayed. The pixels corresponding to the color filter are turned off. Specifically, the CPU 110 lights up the pixel groups 1110, 1111, 1112, 1120, 1121, 1122. Then, the CPU 110 turns off the pixels 1130, 1131, 1132, 1133, 1134, 1135.

  With reference to FIGS. 13 and 14, the positional relationship between the user and the display device when the pixels are turned on and off will be described. FIG. 13 is a diagram illustrating a relationship between a user and a display device when an image is displayed two-dimensionally. A display device 1200 including the mobile phone 100 includes a barrier liquid crystal 1210, glass 1220, and a color filter 1230. In this case, the viewing distance D of the user of the display device 1200 is calculated as follows, for example.

D = E × S / (n × P)
Here, D is a viewing distance (mm). E is the distance (mm) between the eyes of the user. S is the distance (mm) between the color filter 1230 and the barrier liquid crystal 1210. n is the refractive index of the glass 1220. P is the width (mm) of a pixel (pixel).

  For example, if E = 62, S = 0.6, n = 1.5, and P = 0.1, then D = (62 × 0.6) / (1.5 × 0.1) = 248 (Mm).

  FIG. 14 is a diagram for explaining the viewing distance when the technical idea according to the present invention is applied.

  The same symbols as those shown in FIG. 13 apply to FIG. Here, if E = 62, S = 0.6, n = 1.5, and P ′ = P × 1.33 = 0.133, the viewing distance D = (62 × 0.6) / (1.5 × 0.133) = 186.5 (mm). At this distance, the mobile phone or other display device according to this aspect can withstand normal use by the user even when some pixels are lit.

  The case where four color filters are used will be further described with reference to FIG. FIG. 15 is a diagram illustrating the relationship between the user and the display device when the display device 1500 using four color filters displays an image in three dimensions. Display device 1500 includes barrier liquid crystal 1510, glass 1520, and color filter 1530.

  In one aspect, a display device that uses four color filters has R, G, B, and Y filters when displaying an image in two dimensions and when displaying an image in three dimensions in the vertical direction. Light up. On the other hand, when the image is displayed three-dimensionally in the horizontal direction, the fourth color filter Y is turned off. Specifically, the display device 1400 includes a barrier liquid crystal 1410, glass 1420, and a color filter 1430. In this case, for example, by turning off the pixel corresponding to the color filter Y, increasing the parallax barrier, and narrowing the slit, it is possible to prevent crosstalk and a decrease in color balance when displaying an image in three dimensions. . In this case, since the cell pitch does not change, the viewing distance D does not change. Also, the resolution does not change.

  With reference to FIG. 16, another method for solving the problem to be solved by the present invention will be described. FIG. 16 is a diagram illustrating a mode in which a barrier is set in units of subpixels.

  In the barrier method in units of subpixels, it is possible to reduce crosstalk and color blur at the same time due to the characteristic that the luminance of each subpixel is reduced evenly by providing a slit width slightly smaller than that of the subpixel. Therefore, it is possible to suppress a decrease in resolution and a decrease in brightness due to having the extinguished pixel as shown in the present invention. However, it can be difficult to mount the product for the following reasons. For example, when the distance between the eyes E = 62, S = 0.6, n = 1.5, and P ′ = P / 3 = 0.33, the viewing distance D = (62 × 0.6) / (1.5 × 0.33) = 744 (mm). This viewing distance is not a realistic distance. Therefore, for example, it can be said that it is desirable to triple the distance S between the color filter 1530 and the barrier liquid crystal 1510. However, an increase in the thickness of the display panel also increases the thickness of the product main body, so that the product power is impaired according to such another method. On the other hand, according to the above-described embodiment, deterioration in image quality can be suppressed without increasing the thickness of the image display device.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  The present invention is applied to a mobile phone, a smartphone, a tablet computer, a notebook computer, an electronic book terminal, or other information processing apparatus that can display an image three-dimensionally using a parallax barrier. be able to.

  100 cellular phone, 102 communication device, 104 tuner, 106, 106, 108, 108, 116 antenna, 111 audio signal processing circuit, 112 positioning processing unit, 114 positioning signal receiving front end unit, 120 camera, 140 speaker, 144 flash memory 146 RAM, 148 ROM, 150 display, 151 backlight, 160 button, 170 microphone, 180 memory card drive, 182 memory card, 184 vibrator, 210, 211, 212, 213, 220, 221, 222, 223, 340 , 341, 342, 340, 342, 400, 630, 631, 1130, 1131, 1132, 1133, 1134, 1135 pixels, 310, 320, 310, 320 Barrier liquid crystal, 350, 3 1,410,420 region, 610,620,611,612,621,622,1110,1111,1112,1120,1121,1122 pixel group, 700,800 data structure, 1200 display device, 1210,1410,1510 barrier, 1220, 1420, 1520 glass, 1230, 1430, 1530, color filter.

Claims (8)

An image display device for displaying an image in two or three dimensions,
Forming means for forming a parallax barrier;
Display means having each pixel for displaying each of RGB (Red Green Blue);
Driving means for controlling display by each of the pixels,
When the image display device displays an image in three dimensions, the driving means includes an RGB pixel for displaying a left-eye image and an RGB pixel for displaying a right-eye image. An image display device in which at least one pixel is turned off as a pixel that is not lit.   The image display device according to claim 1, wherein the driving unit controls display of an image by each of the pixels by repeating lighting of three pixels and turning off of one pixel. Each pixel includes a fourth color pixel in addition to RGB,
The image display apparatus according to claim 1, wherein the driving unit turns off the pixels of the fourth color.   The image display device according to claim 1, wherein a width of the slit formed by the parallax barrier exceeds a width of one pixel.   An image display terminal comprising the image display device according to claim 1. A control method for controlling display of an image by an image display device having each pixel for displaying each of RGB (Red Green Blue),
Forming a parallax barrier;
Controlling display by each of the pixels,
In the controlling step, when the image display device displays an image in three dimensions, RGB pixels for displaying an image for the left eye, and RGB pixels for displaying an image for the right eye, A control method including a step of turning off at least one pixel as a pixel that is not lit during   The control method according to claim 6, wherein the controlling step includes a step of controlling display of an image by each of the pixels by repeating lighting of three pixels and extinguishing of one pixel. Each pixel includes a fourth color pixel in addition to RGB,
The control method according to claim 6, wherein the controlling step includes a step of turning off the pixels of the fourth color.

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