JP2606144Y2 - Video display device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image display device, and more particularly to an in-vehicle vehicle which has a plurality of (two systems) image inputs such as a television image and a computer image such as a map, and switches and displays them according to a user's request. The present invention relates to a video display device used in a navigation system for automobiles and the like.

[0002]

2. Description of the Related Art FIG. 5 schematically shows an example of an image display device 10 used in a vehicle-mounted navigation system in a simplified form together with main operation switches related to image display. In the figure, a display 11 is a liquid crystal display, particularly recently a TFT (thin film transistor).
s) A color liquid crystal display is used, which is used not only for displaying a map for navigation as described later, but also for displaying a television program as a normal television. The navigation system is started by turning on the power switch 12, but the image itself is not displayed immediately after the power switch 12 is turned on. Next, when one of the television (TV) switch 13 and the map switch 14 for navigation is depressed, an image corresponding to the switch is displayed on the display 1.
1 is displayed. The screen erase switch 15 is used when it is desired to erase the image display by manual operation. In addition,
As the display 11, a so-called touch panel type is used, and detailed function selection after selecting the video type is performed by touching a predetermined location displayed on a video screen. For example, pressing the TV switch 13 selects a television, and touching a channel selection touch key displayed on the television screen sets a reception channel.

FIG. 6 is a block diagram schematically showing the image display device 10 shown in FIG. In relation to FIG. 5, the display 11 in FIG. 5 is a TFT color liquid crystal display (LCD) 11 in FIG.
2 corresponds to the switch 12 in FIG. 6, and the TV switch 13, the map switch 14, and the screen blanking switch 15 in FIG. 5 correspond to the switches 13 to 15 in FIG. 6, respectively. In FIG. 6, when the power switch 12 is turned on, a DC power supply 26 controls a microprocessor (μP) 25 for controlling the entire image display device 10, and a liquid crystal power supply circuit (LPW) 23 for generating a power supply for operating the display 11. And a television signal output circuit (video 1) 21 for providing a television video signal to the display 11 via an RGB terminal or the like and a computer video signal such as a map via the RGB terminal or the like different from the above. Display 11
Signal output circuit (video 2) 2
2 and so on.

Next, when any one of the switches 13 to 15 is depressed, the microprocessor 25 detects a low-level signal corresponding to each switch-on, and accordingly the microprocessor 25 causes the display (LCD) 11 and the The backlight (BL) 24 and the like are controlled. For example, when the TV switch 13 is pressed, the microprocessor 25 selects a television signal from the television signal output circuit 21 as a video signal to be supplied to the display 11 by setting the display selection signal 30 to a low level, and at the same time, controls the backlight. By setting the signal 31 to a high level, the backlight 24 is turned on and the display 11 displays a television image. Similarly, when the map switch 14 is pressed, the display selection signal 30 is set to a high level to select the computer signal output circuit 22 and the backlight control signal 31 is set to a high level to turn on the backlight 24 to turn on the display 11. To display the map image. When the screen erase switch 15 is depressed, only the backlight 24 is turned off by setting the backlight control signal 31 to a low level while the selected video signal is input as it is, and the screen display is turned off. .

[0005]

However, the conventional video display device is required when the backlight 24 switches from off to on, that is, at the moment when the backlight control signal 31 rises from a low level to a high level, and at the same time. When the image displayed on the display 11 switches, that is, when the instant at which the display selection signal 30 switches to a level opposite to the current level overlaps, the image immediately ahead is displayed, and thereafter, the image originally selected is displayed. There was the inconvenience of switching to video.

The above will be described with reference to the operation timing chart of the conventional video display device shown in FIG. When the image display device 10 shown in FIG. 7A is turned on, that is, at the time of initialization, for example, a television image (image 1) is selected as an initial image ((c) in FIG. 9), and the backlight 24 is turned off. ((D) in the figure). At this stage, nothing is displayed on the display 11. Next, when a computer image (image 2) different from the initial image is selected by pressing the map switch 14 ((b) in the figure), the display selection signal 30 is switched from low level to high level, and At the same time, the backlight control signal 31 switches from a low level to a high level to turn on the backlight 24.

At this time, the backlight 24 is immediately turned on by the backlight control signal 31.
Is not switched to the selected computer image unless one frame time (approximately 33 ms) has elapsed from the television image of the initial image. Therefore,
During this time, there is a problem that the television image is displayed for a moment (afterimage on the left side of (e) in the figure). The same applies to the case where the screen erase switch 15 is depressed while the image is being displayed on the display 11 (corresponding to the backlight off on the right side of (d) in the figure), the screen is erased, and then another image is displayed. This also occurred when switching was performed (corresponding to the rising signal on the right side in (b) of the figure) (afterimage on the right side in (e) of the figure). The backlight 24 shown near the center of the figure
The switching of the video without on / off control of the video is a video switching intended for the user of the video display device 10 and is not a problem.

In view of the above-mentioned problems, the present invention considers the above-mentioned problems, and when the switching of the video display and the switching of the backlight 24 from off to on occur simultaneously, the display switching signal 30 changes the video display content of the display 11. Time to switch to new display content, ie 1
Alternatively, the backlight control signal is turned off for two frame times or a time at which a person does not feel the display delay to be uncomfortable, and the backlight control signal is turned on after the elapse of the time, so that the above-described momentary ahead can be achieved. It is an object of the present invention to provide an image display device that prevents an image from being seen.

[0009]

According to the SUMMARY for the present invention, the image display means 1 for displaying a video signal, the video display hand
A backlight 2 for illumination of the stage 1, a plurality of image output means 4 ₁ to 4 _n for outputting a video signal, one of the video signals from the plurality of image output means 4 ₁ to 4 _n and image selecting means 3 for outputting select and to said image display unit 1, when video is switched to, the one to output the video switching signal 6 for instructing image selection on the image selection unit 3 and a backlight Switch from off to on
Light On signal and image control unit 5 for outputting at least said predetermined time by the video switching signal 6 to the switched video from the image display means 1 changing, the La
Consists delay means 8 which delays the Itoon signal
An image display device is provided.

[0010]

The video control means 5 supplies a video switching signal 6 to the video selection means 3 to provide a plurality of video output means 4 _1.
Select one of to 4 _n, the image display unit 1 displays the selected video signal. In addition to the video switching signal 6, the video control means 5 supplies a backlight on / off signal 7 for enabling / disabling the video display of the video display means 1 to the delay means 8. The delay unit 8 turns off the backlight of the backlight on / off signal 7 from the off state to at least the time until the video output of the video display unit 1 is switched by the video switching signal 6.
Delays the write-on signal for switching to the on state . The light-on signal after the delay is applied to the backlight 2, whereby the backlight 2 turns off the irradiation of the video display means 1 during operation (during energization) from off to on.
Replace it .

[0011]

FIG. 2 is a block diagram showing an embodiment of the video display device 10 according to the present invention in comparison with a conventional example (FIG. 6). 2, the same components as those in the conventional example of FIG. 6 are denoted by the same reference numerals, and those already described in the conventional example will not be described again here. In the context of the present invention in FIG. 1, the television signal output circuit (video 1) 21 and the computer signal output circuit (video 2) 22 are a plurality of image output means 4 ₁ to 4 n _(n is an integer) in FIG. 1 ,
A liquid crystal power supply circuit (LPW) 23 and a TFT color liquid crystal display (LCD) 11 correspond to the image display means 1 and the image selection means 3 in FIG. 1, respectively. The display 11 in this example has a two-input type display 11 having an input terminal for the display selection signal 30 and capable of selecting one of the two video signals 21 and 22.
Is used. A delay circuit 32 according to the present invention, which will be described later, corresponds to the delay means 8 in FIG. 1, and the microprocessor 25 and the switches 13 to 15 correspond to the video control means 5 in FIG.

Next, the delay circuit 32 newly loaded in the conventional example (FIG. 6) according to the present invention will be described with reference to the operation timing chart of the video display device according to the present invention in FIG. The delay circuit 32 of FIG. 2 receives the backlight control signal 31 from the microcomputer 25 described above, and delays the input signal by a predetermined time until the display 11 is switched to a new video display by the display selection signal 30. And output it. As the delay circuit 32, a simple timer circuit including a normal simple CR circuit or the like can be used, and the entire ON signal of the backlight control signal 31 from the microcomputer 25 is delayed for a predetermined time (FIG. 4). (D)) and the backlight control signal 3
For example, one that delays only the rising edge portion (on start-up) and does not delay the falling edge (start-up stop) is used. In any case, the backlight signal 31 from the microcomputer 25 is required.
Is to output a new backlight control signal 33 delayed by the predetermined time, and the backlight 24 is turned on / off by using the new backlight control signal 33.
It is to control off. As a result, as shown in FIG.
Even when switching from OFF to ON at the same time, generation of the preceding image, which has conventionally been a problem, is prevented.

While the above-described embodiment of FIG. 2 realizes the present invention by simple hardware means called a delay circuit 32, the control flow shown in FIG. This is an implementation of the inventive delay means 8. Therefore, in this case, the delay circuit 32 in FIG. 2 is unnecessary, and the device configuration is the same as the conventional example (FIG. 6). FIG. 3 is a functional drawing of a switch input routine that is periodically determined to implement the present invention among software for controlling the microcomputer 25 (FIG. 2).

In the figure, in step S101, the presence or absence of an input from each of the switches 13 to 15 in FIG. 2 is determined, and if any of them is input (low level is detected), it is determined that a switch input is present and the next step (S102 to S104). ), And if it is determined that there is no switch input, the routine is skipped and the switch input determination (S101) is performed again in the next program cycle in this routine.
When it is determined that the switch input is present, the type of the input switch is determined, and corresponding to the detection of the television switch 13, the map switch 14, and the screen blanking switch 15, the respective steps S102, 103 and S10 are performed.
4 are executed respectively.

When it is determined that the screen erase switch 15 has been pressed (S104), the backlight control signal 31 is set from the high level to the low level, and the backlight 24 is turned off and the display 11 is turned on. Screen disappears (S107). However, even in this case, the video signal before the extinguishing is still input to the display 11. When it is determined that the television switch 13 has been pressed (S102), the display selection signal 30 is set to a low level (S105), and when it is determined that the map switch 14 has been pressed (S10).
3) The display selection signal 30 is set to a high level (S
106). At this time, the display content of the video signal on the display 11 starts to change to the next video according to the selection. Next, in step S108, it is determined whether the backlight 24 is on or off. If the backlight 24 is on, the image is simply switched as shown near the center of FIG. 4, and this routine ends. In this case, the above-described problem does not occur. If the backlight 24 is off, the predetermined time timer corresponding to the delay circuit 32 in FIG. 2 is set by software (S109), and after the lapse of the predetermined time (S110), the backlight control signal is turned on (high level). ) And the backlight 24 is (S111).
Light. Therefore, in this embodiment, the display 11 and the backlight 2 are also provided as in the previous embodiment (FIG. 2).
4 is controlled, and the operation is performed at the timing shown in FIG.

[0016]

As described above, according to the present invention, the time until the video display content of the display is switched to the new display content, that is, one or two frame times, or the human being does not feel the display delay uncomfortable. Since the backlight is turned on after the elapse of a certain time, the image which has already disappeared when the backlight is turned on is not displayed again. Further, the present invention can be easily realized by hardware means such as the above-described simple CR timer or simple software means by a microcomputer, so that the conventional apparatus can be easily improved without increasing the cost and the like.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a basic configuration of a video display device according to the present invention.

FIG. 2 is a block diagram schematically illustrating an embodiment of the image display device according to the present invention;

FIG. 3 is a flowchart showing one embodiment of the delay means of the present invention by software.

FIG. 4 is an operation timing diagram of the image display device according to the present invention;

FIG. 5 is a front view schematically showing an example of the appearance of the video display device.

FIG. 6 is a block diagram schematically showing an example of a conventional video display device.

FIG. 7 is a diagram showing an example of operation timing of a conventional video display device.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 image display means 2 backlight 3 image selection means 4 ₁ to 4 _n image output means 5 image control means 8 delay means 11 liquid crystal display 12 power switch 13 television switch 14 map switch 15 ... Screen switch 21 ... Television signal output circuit 22 ... Computer signal output circuit 24 ... Backlight 25 ... Microcomputer 32 ... Delay circuit

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G09G 3/36 G02F 1/133

Claims (1)

(57) [Scope of request for utility model registration] 1. A video display means for displaying a video signal (1), a backlight to illuminate the image display means (1)
And (2), a plurality of image output means for outputting a video signal (4 ₁ -
4 _n) and the video signal from the plurality of image output means (4 ₁ ~4 _n)
Wherein the image selecting means for outputting to said image display means by selecting one (1) (3), when the image is switched to the video switching signal for instructing said one video select (6) of the Output to the image selection means (3) and switch the backlight from off to on
Video control means for outputting a change-on signal (5)
When the delay means at least the video switching signal (6) a predetermined time until the image is switched from the video display unit (1) by delaying the write-on signal (8)
A video display apparatus characterized by comprising consist.