JP2006262031A - Image display device and image display method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image display device capable of displaying each of television broadcast program images and graphic user interface images (an electronic program guide, a variety of setting menus, etc.) in an easy-to-see and power-saving manner by controlling a screen luminance to an appropriate value in response to switching of a display mode. <P>SOLUTION: The image display device configured so as to switch between a mode of displaying the television image and a mode of displaying the graphic user interface image, controls variably luminance intensity of a backlight source 12 in response to the mode switching instruction, and thereby obtains a screen luminance appropriate for each mode. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image display device capable of switching and displaying a television program video screen and a graphic user interface video screen.

  2. Description of the Related Art Conventionally, a television receiver capable of displaying a television program guide and various setting menus as a graphic user interface (GUI) in addition to a normal television image is generally well known.

  For example, JP 2001-103388 A, JP 2001-186436 A, etc. acquire program information from digital data transmitted from a broadcasting station, analyze the program information, and analyze an electronic program guide (EPG; Electronic A digital television receiver capable of assisting a user in selecting a program by creating a program guide and displaying the program guide on an on-screen display (OSD) circuit is disclosed.

  Japanese Patent Laid-Open No. 2002-359789 and the like obtain program information from a television signal demodulated by a decoding circuit, analyze the program information, and create graphics data of a program information screen. Digital television capable of obtaining various explanations relating to, for example, a program before the start of broadcasting or a program being viewed by superimposing it on a television signal subjected to predetermined image processing and displaying it on an on-screen display (OSD). A broadcast receiver is disclosed.

  Further, Japanese Patent Application Laid-Open No. 2003-143433 describes that various television setting menus and electronic program guides are displayed as a GUI screen.

On the other hand, in recent years, instead of the cold cathode fluorescent lamp (CRT), a device that displays an image using a liquid crystal panel as a light receiving type light modulation means (hereinafter referred to as a liquid crystal display device) is a television receiver or a computer device. Have been widely used for image display. The liquid crystal display device controls the group and orientation of liquid crystal molecules by encapsulating liquid crystal between two transparent substrates provided with electrodes and controlling the voltage to drive electrode units arranged in a matrix. An image is displayed on the liquid crystal panel by changing the transmittance of the irradiation light from the backlight light source provided on the back surface of the transparent substrate.
JP 2001-103388 A JP 2001-186436 A JP 2002-359789 A JP 2003-143433 A

By the way, generally, in a personal computer (PC) monitor for displaying computer video, a screen luminance of about 250 cd / m ² is sufficient, whereas a television video mainly composed of natural shooting (actual shooting) images is displayed. In order to achieve this, a television receiver of 450 to 500 cd / m ² or more is required. Especially in a television receiver (liquid crystal television receiver) using a liquid crystal display device, the luminance is increased by improving the backlight. Is underway.

  Basically, the brightness level (light emission intensity) of the backlight light source is fixedly set to the content that the user manually adjusts (dimming), and the brightness level is constant regardless of the type of input video signal to be displayed. is there. Therefore, when a television receiver set to high brightness for displaying a television image and displaying a graphic user interface (GUI) image, which is similar to a computer image, such as an electronic program guide or various setting menus, There was a problem that the display was glaring because the luminance was too high, and the user's eyes were easily tired when viewed for a long time.

  In addition, the power consumption of large-screen liquid crystal display devices is largely occupied by the power consumption of the backlight unit, which also reduces unnecessary power consumption of the backlight unit from the viewpoint of reducing environmental impact. It is hoped to do.

  The present invention has been made in view of the above problems, and is easier to see for each of a television image and a graphic user interface (GUI) image by controlling to an appropriate screen luminance in conjunction with the display mode switching setting. An image display device capable of realizing image display and reducing power consumption is provided.

  According to a first aspect of the present invention, in an image display device configured to be able to switch between a mode for displaying a television image and a mode for displaying a graphic user interface image, the screen brightness can be changed according to the switching of the mode. Control means for controlling is provided.

  The second invention of the present application is characterized in that the control means changes the light emission intensity of a backlight light source that emits light from the back surface of the light receiving type light modulation means for displaying the input video signal.

  The third invention of the present application is characterized in that the control means slows down the change speed of the screen brightness when switching from the mode for displaying the television video to the mode for displaying the graphic user interface video.

  A fourth invention of the present application is characterized in that a mode for displaying the television video and a mode for displaying the graphic user interface video are switched based on a screen switching instruction from a user.

  The fifth invention of the present application is characterized in that the graphic user interface video is an electronic program guide display video.

  The sixth invention of the present application is characterized in that the graphic user interface video is various setting menu display video.

  A seventh invention of the present application includes a step of switching between a mode for displaying a television image and a mode for displaying a graphic user interface image, and a step of variably controlling the screen brightness in accordance with the switching of the mode. It is characterized by.

  According to the image display device of the present invention, control is performed so as to obtain an appropriate screen brightness in accordance with switching between a mode for displaying a television image and a mode for displaying a graphic user interface image. When displaying interface video, it is possible to achieve screen display that is easy to see and not tiring, and to reduce power consumption, by suppressing screen brightness compared to displaying television video. .

  Hereinafter, an image display device according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 9, for example, a liquid crystal digital television receiver (liquid crystal television). 1 is a block diagram showing a schematic configuration of the liquid crystal television of the present embodiment, FIG. 2 is an external view showing a remote control device in the liquid crystal television of the present embodiment, and FIG. 3 is an EPG display in the liquid crystal television of the present embodiment. FIG. 4 is an explanatory diagram showing a display example of a program information display screen on the liquid crystal television of the present embodiment, and FIG. 5 is a display example of a setting menu display screen on the liquid crystal television of the present embodiment. It is explanatory drawing.

  6 is a flowchart showing operation control in the liquid crystal television of the present embodiment, FIG. 7 is an explanatory diagram showing operation control in the liquid crystal television of the present embodiment, and FIG. 8 is a flowchart showing operation control in the liquid crystal television of the present embodiment. FIG. 9 is an explanatory diagram showing another operation control in the liquid crystal television of the present embodiment.

  As shown in FIG. 1, the liquid crystal television of the present embodiment demodulates a tuner 1 that selects a desired channel from a television broadcast wave received by an antenna, and a television signal that is selected by the tuner 1. Program information from the decoding unit 2 that performs processing, the image processing unit 3 that performs predetermined image processing on the television signal demodulated by the decoding unit 2, and the television signal that has been demodulated by the decoding unit 2 And a program information acquisition unit 4 for acquiring the program information.

  Further, a remote control light receiving unit 5 that receives an instruction signal input by a user from a remote control device (remote control), which will be described later with reference to FIG. 2, and an instruction signal received by the remote control light receiving unit 5 is detected and analyzed, and the tuner 1 decodes And a microcomputer 6 that outputs predetermined control signals to each unit such as the unit 2 and the image processing unit 3. Further, the microcomputer 6 controls the graphics generation unit 7 based on the program information acquired by the program information acquisition unit 4 to output graphics data related to the electronic program guide to the switching / synthesis processing unit 8. I am letting.

  The graphics generation unit 7 generates not only the electronic program guide based on the program information acquired by the program information acquisition unit 4 but also graphics data for OSD display of various setting menus under the control of the microcomputer 6. Is possible.

  Further, the television video signal output from the image processing unit 3 and the OSD display graphics data generated by the graphics generation unit 7 are selectively switched according to the switching / synthesis control signal from the microcomputer 6. Alternatively, the switching / compositing processing unit 8 that outputs the combined and output, and the source line and the gate line of the liquid crystal display panel 10 based on the R, G, and B signals (image display signals) output from the switching / compositing processing unit 8 And a light source drive unit 11 such as an inverter circuit for performing light emission drive control of the backlight light source 12 in accordance with a backlight control signal from the microcomputer 6.

  The liquid crystal television of this embodiment may be either a direct backlight type or a side edge type backlight system, and the light source 12 is a cold cathode fluorescent lamp (CCFL) that is generally used at present. In addition, a light emitting diode (LED) or the like can be used. Needless to say, the luminance control method of the light source 12 is not limited to voltage (or current) control, and may employ duty control.

  That is, the microcomputer 6 receives the television video signal output from the image processing unit 3 and the graphics data generated by the graphics generation unit 7 as the video to be displayed on the liquid crystal display panel 10 according to the user setting instruction. Are appropriately switched and output, and the light source drive unit 11 controls the brightness (light emission luminance) of the backlight light source 12.

  Next, as shown in FIG. 2, the remote controller used in the liquid crystal television of the present embodiment displays an electronic program guide (EPG) on the screen when searching for a desired program or making a reservation for viewing or recording a desired program. A program guide button 21 for displaying, a program information button 22 for displaying various information related to the program selected in the electronic program guide (EPG) and the program being viewed on the screen, adjustment of video and audio, and various functions A menu button 23 for displaying a setting menu screen for setting is provided.

  That is, when the user presses the program guide button 21 on the remote controller, a GUI screen of an electronic program guide (EPG) as shown in FIG. 3, for example, created based on the program information acquired from the received data, It can be displayed on the liquid crystal display panel 10. Then, the user searches for a desired program and sets viewing reservation or recording reservation by operating the up / down / left / right buttons and the enter button of the remote controller while viewing the GUI screen of the electronic program guide (EPG). be able to. At this time, excessive screen brightness is unnecessary, and thus the light emission brightness of the backlight light source 12 is lowered to reduce power consumption.

  Further, when the user presses the program information button 22, a GUI screen of program information, for example, as shown in FIG. 4 created based on the program information acquired from the received data is displayed on the liquid crystal display panel 10. can do. The user confirms the contents of the program while watching the GUI screen of the program information, and operates the up / down / left / right button, the decision button, the color button, etc. Settings such as cancellation and display of more detailed explanation information can be made. At this time, too much screen luminance is not necessary, so that the light emission luminance of the backlight light source 12 is lowered to reduce power consumption.

  Furthermore, when the user depresses the menu button 23 and the up / down / left / right buttons, a GUI screen of a setting menu related to a predetermined item as shown in FIG. 5 can be displayed on the liquid crystal display panel 10, for example. The user can adjust video and audio and make various function settings by operating the up / down / left / right buttons and the enter button of the remote controller while viewing the GUI screen of the setting menu. At this time, too much screen luminance is not necessary, so that the light emission luminance of the backlight light source 12 is lowered to reduce power consumption.

  Therefore, in the liquid crystal television of the present embodiment, switching between a mode for displaying a normal television image and a mode for displaying a graphic user interface image such as an electronic program guide and various setting menus is performed based on a user setting instruction. It is possible to variably control the light emission intensity of the backlight light source 12, that is, the screen luminance, by controlling the light source driving unit 11 in conjunction with the mode switching.

  Next, the screen brightness control operation in the liquid crystal television of this embodiment will be described with reference to the flowchart of FIG. First, when a user operates a remote control device (remote control) to give a display screen switching instruction (screen switching instruction = function switching instruction) (step 1), an image related to a normal television broadcast program is displayed. It is determined which one of the mode and the mode for displaying an image related to the graphic user interface (GUI) screen has been instructed.

  That is, whether the program guide button 21 of the remote controller is pressed to instruct the display of the electronic program guide (EPG) (step 2), or the program information button 22 is pressed to instruct the display of program information (step 2). Step 3) Alternatively, it is determined whether or not the menu button 23 has been pressed to instruct display of various setting menus (step 4).

If any of the determination results in Steps 2 to 4 is negative, it is determined that a mode for displaying an image related to a normal television broadcast program has been selected, and the light emission luminance level of the backlight light source 12 is A (A is preliminarily determined). A control signal is output from the microcomputer 6 to the light source driving unit 11 so that the set value becomes, for example, 10000 cd / m ² (step 5).

On the other hand, if it is determined in step 2 that display of an electronic program guide (EPG) is instructed, or if it is determined in step 3 that display of program information is instructed, display of various setting menus is instructed in step 4. If it is determined that the mode for displaying the graphic user interface (GUI) screen image has been selected, the light emission luminance level of the backlight light source 12 is B (B is a preset value smaller than A, For example, a control signal is output from the microcomputer 6 to the light source driving unit 11 so as to be 5000 cd / m ² ) (step 6).

  As described above, in the present embodiment, a mode for displaying a television image and a mode for displaying a graphic user interface image are switched according to a screen switching instruction (function selection setting) by a user, and the mode switching operation is performed. In order to control the light emission luminance (light emission intensity) of the light source 12 so as to obtain an appropriate screen luminance, particularly when displaying a GUI screen such as an electronic program guide (EPG, program information) and various setting menus, a normal television By suppressing the screen brightness as compared with the case of displaying a John image, it is possible to display a screen that is easy to see and not tired, and to reduce power consumption.

  By the way, when the screen brightness is changed abruptly at the same time as the display screen switching as described above, the screen brightness is sharply changed particularly when switching from the mode for displaying the television video to the mode for displaying the graphic user interface video. If this falls, the user will feel uncomfortable.

  Accordingly, in the present embodiment, as shown in FIG. 7, the screen brightness is actually started from the time T1 when the instruction to switch from the mode for displaying the television broadcast program video to the mode for displaying the video of the graphic user interface screen is made. It takes a sufficient amount of time t until the level reaches B to slow down the screen brightness change rate (by increasing the time constant and slowly changing the screen brightness), and the change in screen brightness gives the user a sense of incongruity. Has eased.

  It should be noted that even when the screen brightness increases when switching from the mode for displaying the graphic user interface screen to the mode for displaying the television broadcast program video, the user does not feel so uncomfortable. From the time T2 when an instruction to switch to the mode for displaying the television broadcast program video to the mode for displaying the television broadcast program video is made, the time until the screen brightness level actually reaches A is shortened, and the high brightness, It is desirable to present high contrast television images.

  Further, in the present embodiment, in addition to the automatic screen brightness control linked to the display screen mode, the user can also control the screen brightness adjustment. This will be described with reference to the flowchart of FIG. When a dimming key on a remote controller (not shown) is pressed and a dimming instruction is detected by the user (step 1), a dimming setting OSD (On Screen Display) is displayed on the edge of the screen. The user can instruct to increase or decrease the screen brightness by pressing the up / down direction key of the remote controller while looking at the light control setting OSD.

  When the up key of the remote control is pressed and an instruction to increase the luminance is given (step 2), the light emission luminance level of the backlight source 12 becomes a value obtained by adding one step to the light source luminance level at that time. Then, a control signal is output from the microcomputer 6 to the light source driving unit 11 (step 3). On the other hand, when the down key of the remote control is pressed to instruct a decrease in luminance (step 4), the emission luminance level of the backlight light source 12 is a value obtained by subtracting one step from the light source luminance level at that time. Thus, a control signal is output from the microcomputer 6 to the light source drive unit 11 (step 5).

  Thus, the user can arbitrarily adjust the screen brightness automatically set in each screen display mode according to the use environment, display video content, and the like, and the merchantability can be further improved.

Furthermore, an illuminance sensor that detects the brightness of the surrounding environment of the device may be provided, and the screen luminance may be determined from the detection result of the illuminance sensor and the video display mode. For example, as shown in FIG. 9, in the mode for displaying a television broadcast program image, the light emission luminance level of the light source 12 is A ₁ when the ambient illuminance is bright, and the light emission luminance of the light source 12 when the ambient illuminance is within the standard range. When the level is A ₂ and the ambient illuminance is dark, the light emission luminance level of the light source 12 is A ₃ (A ₁ > A ₂ > A ₃ ), while the ambient illuminance is bright in the mode for displaying the graphic user interface screen image. In this case, the light emission luminance level of the light source 12 is B ₁ , the light emission luminance level of the light source 12 is B ₂ when the ambient illuminance is within the standard range, and the light emission luminance level of the light source 12 is B ₃ when the ambient illuminance is dark (B _{1> B 2> B 3)} .

  As a result, it is possible to automatically control to the optimum screen brightness in each screen display mode in accordance with the brightness of the viewing environment, so that the merchantability can be further improved.

  In the above-described embodiment of the present invention, the EPG screen, the program information screen, or the menu screen has been described as the graphic user interface screen. However, the graphic user interface screen is not limited to this, and is generated by the microcomputer 6 and the graphic generation unit 7. Obviously, any display screen of various graphics data may be used.

  In the above-described embodiment of the present invention, the function switching instruction (screen switching instruction) by the user is performed by a one-touch operation of the remote controller, but an operation member (not shown) provided in the apparatus main body is used. It goes without saying that this may be configured by operation.

  Furthermore, when a graphic user interface image and a television image are displayed in a small screen with picture-in-picture or two screens with picture-by-picture, they are displayed in a larger screen area. The light emission luminance of the backlight light source may be controlled according to the video type. For example, when a television image is displayed on a small screen in a graphic user interface image, and the screen area displaying the graphic user interface image is larger, the back light intensity level B is set. What is necessary is just to control a light source.

  In addition, when a backlight light source that can change the light emission brightness for each screen area is used, the light emission brightness of the backlight light source corresponding to the screen area displaying the television image is increased to provide a graphic user interface. The light emission luminance of the backlight light source corresponding to the other screen area displaying the video may be lowered. For example, when a graphic user interface image is displayed on the left side of the screen and two television images are displayed on the right side of the screen, the emission intensity of the backlight light source corresponding to the area on the left side of the screen is controlled to become the luminance level B. The light emission intensity of the backlight light source corresponding to the area on the right side of the screen may be controlled to become the luminance level A. Such control can be easily realized by using, for example, a direct type LED backlight.

  Furthermore, in the above-described embodiment of the present invention, in order to realize a sharpness and a contrast when displaying a moving image, a backlight light source is used according to a screen feature amount such as an APL (average luminance level) of each video frame. The 12 light emission luminances may be dynamically variably controlled. In this case, the maximum light emission luminance of the backlight source 12 may be set depending on whether the video to be displayed is a graphic user interface video or a television video.

  In the embodiment of the present invention, the direct-view type liquid crystal display device has been described. However, the present invention may be applied to a projection type liquid crystal display device. It is obvious that the present invention may be applied to an image display device that displays an image using the image display device, or other image display devices. Furthermore, it goes without saying that a display panel other than the liquid crystal display panel may be used as the light receiving type light modulating means.

  However, the luminance signal level input to the display panel can be controlled by, for example, video signal processing by a luminance adjustment circuit in conjunction with switching between a mode for displaying television video and a mode for displaying graphic user interface video. In this case, although it is possible to display an image with an appropriate screen luminance that is easy for the viewer to see, an effect of reducing power consumption cannot be expected.

  In contrast, as in the above-described embodiment of the present invention, in the case where the light emission luminance (issue intensity) of the backlight light source is variably controlled according to the screen display mode, the image is always displayed with an appropriate screen luminance that is easy to see. Not only can the display be performed, but also a remarkable effect that wasteful power consumption can be reduced is achieved.

  In the above-described embodiment of the present invention, the television receiver including the television broadcast receiving means has been described. However, the present invention is not limited to this, and a personal computer (PC) capable of receiving and displaying television images. It can be applied to various image display devices such as mobile communication terminals.

It is a block diagram which shows schematic structure in one Embodiment of this invention. It is an external view which shows the remote control apparatus in one Embodiment of this invention. It is explanatory drawing which shows the example of a display of the EPG display screen in one Embodiment of this invention. It is explanatory drawing which shows the example of a display of the program information display screen in one Embodiment of this invention. It is explanatory drawing which shows the example of a display of the setting menu display screen in one Embodiment of this invention. It is a flowchart which shows the operation control in the liquid crystal television of one Embodiment of this invention. It is explanatory drawing which shows the operation control in the liquid crystal television of one Embodiment of this invention. It is a flowchart which shows the operation control in the liquid crystal television of one Embodiment of this invention. It is explanatory drawing which shows the other operation control in the liquid crystal television of one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tuner 2 Decoder part 3 Image processing part 4 Program information acquisition part 5 Remote control light-receiving part 6 Microcomputer 7 Graphic generation part 8 Switching / synthesis process part 9 LCD drive part 10 Liquid crystal display panel 11 Light source drive part 12 Light source

Claims (7)

In an image display device configured to be switchable between a mode for displaying a television image and a mode for displaying a graphic user interface image,
An image display apparatus comprising control means for variably controlling screen brightness in accordance with the mode switching.   2. The image display device according to claim 1, wherein the control unit is configured to vary a light emission intensity of a backlight light source that emits light from a back surface of a light receiving type light modulation unit that displays an input video signal. .   3. The control unit according to claim 1, wherein the control unit slows a change rate of screen brightness when switching from a mode for displaying a television image to a mode for displaying a graphic user interface image. Image display device.   4. The image according to claim 1, wherein a mode for displaying the television video and a mode for displaying the graphic user interface video are switched based on a screen switching instruction by a user. Display device.   The image display apparatus according to claim 1, wherein the graphic user interface video is an electronic program guide display video.   The image display device according to claim 1, wherein the graphic user interface video is a video for displaying various setting menus. Switching between a mode for displaying television images and a mode for displaying graphic user interface images;
And a step of variably controlling the screen brightness in accordance with the switching of the mode.