JP2008250241A - Video display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery-mounted video display device displaying an image with maximum screen illuminance while satisfying a use time that a user desires. <P>SOLUTION: The video display device mounted with a battery as a power source includes: a battery remaining amount detecting means 22 of detecting the remaining amount of the battery 18; a current calculating means 23 of finding a current consumption value maximizing the illuminance of a screen in the range satisfying the use time from the remaining amount of the battery 18 and the use time that the user desires; and a display unit 17 which adjusts luminance with the current value obtained by the current calculating means 23. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a projection video display apparatus equipped with a battery as a power source for driving the apparatus.

In recent years, along with the development of LED technology, projection video display devices equipped with LEDs as light sources have been realized. Compared with ultra-high pressure mercury lamp, LED light source has 1) long life, 2) wide color reproduction range, 3) instant lighting and relighting, 4) low power drive, and 5) driving current operation comparison There are many advantages such as being easy.

In such a projection image display device, as a power source for driving the device, there is a power source that is connected to an external power source and that can be driven by receiving a power supply from the battery. In the projection display device, the light source generally consumes the largest amount of power in the device, and thus the power used here greatly affects the usable time of the battery.

For this reason, many projection video display devices equipped with a battery have a function of detecting the remaining amount of the battery. On the other hand, when the remaining battery level is low, to prevent it from stopping during the usage time, when detecting that the remaining battery level is low, switch to the mode with less current consumption and display To be done (
For example, Patent Document 1).
JP 2006-154671 A

However, in the conventional configuration, driving is performed only at an output determined regardless of the “time that the user wants to use”. As a result, even if the remaining battery level is sufficient, a brighter image is not provided.On the other hand, if the remaining battery level is low, the device may stop during use time. It was.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an image display device that maximizes screen illuminance while satisfying a usage time desired by a user.

In order to achieve the above object, according to the present invention, in a video display device equipped with a battery as a power source, a battery remaining amount detecting means for detecting the remaining amount of the battery, the remaining amount of the battery and a usage time desired by the user, And a current calculation means for obtaining a current consumption value that maximizes the illuminance of the screen within a range that satisfies the usage time, and a display unit that adjusts the luminance with the current value obtained by the calculation means. And

By having such a configuration, it is possible to perform display with the maximum screen illuminance while satisfying the usage time desired by the user.

As described above, according to the present invention, since the brightness of the display device is controlled from the remaining amount of the battery and the usage time desired by the user, the present invention uses the desired usage in the video display device. The screen illumination can be maximized while satisfying the time.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The projection video display apparatus described here has a function of detecting a remaining battery level while mounting a battery as a power source for driving the apparatus. In the projection display device, the light source generally consumes the largest amount of power in the device, and thus the power used here greatly affects the usable time of the battery.

Example 1 of the present invention will be described.
FIG. 1 is a block diagram showing the overall configuration of the video display apparatus of this embodiment.
Reference numeral 11 denotes an input terminal to which an analog video signal is input. The analog video signal input to the input terminal 11 is supplied to an A / D (analog / digital) converter 12 and digitized, and then supplied to a video processor 13.

In FIG. 2, reference numeral 14 denotes an input terminal to which a digitally encoded video signal is input. The digitally encoded video signal input to the input terminal 15 is supplied to the video decoder unit 15 and subjected to digital decoding processing, and then supplied to the video processing unit 13.

The video processing unit 13 selects one of the digital video signal supplied from the A / D conversion unit 12 and the digital video signal supplied from the video decoder 15, for example, scaling processing or contour correction processing. After performing various processes necessary for video display, etc., the image is output to the optical control unit 16.

The LED drive current control unit 16 performs contrast adjustment processing on the video signals corresponding to the color components R, G, and B among the digital video signals supplied from the video processing unit 13, and then performs LED adjustment. It is supplied to the display unit 17.

The LED display unit 17 emits light based on a signal from the LED drive current control unit 16 to be diffused and projected onto the screen, and an image is displayed thereon.
On the other hand, a battery 18 is provided to supply power to each part in the apparatus. The battery 18 can be connected to an external power outlet (not shown). The battery 18 is charged when connected to an external power supply, and when the power supply from the external power supply is not received, the battery 18 supplies power to each part in the apparatus.

The video display apparatus performs all operations including the video processing operation described above by the control unit 1.
9 is centrally controlled. The control unit 19 includes a CPU (centralproc
essing unit), etc., and operation information from the operation unit 20 or
Each unit is controlled so that the operation information from the remote controller 22 input via the receiving unit 21 is reflected in the operation content. Further, the control unit 19 requires a remaining battery level detection unit 22 that detects the remaining battery level, a remaining battery level detected by the remaining battery level detection unit 22, and a usage time specified by the user. A current calculation unit 23 that calculates the LED drive current amount is provided.

The control unit 19 uses the memory unit 23. The memory unit 24 is mainly composed of
ROM (ready memory) that stores the control program executed by the CPU
RAM (random access memory) that provides a work area to the CPU
) And a non-volatile memory in which various setting information, control information, and the like are stored.

Next, the LED drive current determination process will be described.
FIG. 2 is a flowchart illustrating an LED driving current determination process.
In the video display device equipped with the battery 18, when an external power source is not connected,
The battery 18 is driven only by the power source. First, in step S31, when the apparatus is started up with no external power supply connected, or when the external power supply is cut off due to a power failure or disconnection of the power cord during use with the external power supply connected The control unit detects this and prompts the user to input “use time”. Here, as a notification method to the user, any method such as a method of displaying on a display unit (not shown) of the main body, a method of displaying on a screen projected on a screen, a method of notifying by sound or the like may be used.

On the other hand, in step S32, the user operates the operation unit 20 or the remote controller 2.
The desired usage time is input via 2.
When the usage time is input from the user, the remaining battery level detection unit 22 of the control unit 19 detects the remaining battery level in step S33.
In step S34, the current calculation unit 23 calculates the maximum current value within the LED standard within the input “use time” and the current value within the LED standard from the detected remaining battery level, and drives the LED. A control signal is output to the current control unit 16. Then, the LED drive current control unit 16 controls the LED drive current.

According to the present embodiment, since the brightness of the LED is substantially proportional to the current value, the apparatus can project an image with the illuminance of the screen maximized within a range that satisfies the usage time desired by the user. Become.

Next, Example 2 will be described. In this embodiment, a battery remaining amount feedback process is further added to the first embodiment.
FIG. 3 is a flowchart illustrating a battery remaining amount feedback process. In addition,
Steps S31 to S34 are the same as in FIG.
In step S34, the battery 18 is operating at a maximum current value within the LED standard within a range where the capacity of the battery 18 does not run out within the “use time”. Next, in step S35,
The remaining time is calculated with respect to the usage time entered by the user. Here, when the remaining time becomes 0, the power is turned off and the process ends.

In step S35, if the remaining time is not 0 (there is a remaining time), step S35
In 36, the battery remaining amount detection unit 22 detects the remaining amount (W1) of the battery 18 at that time. In addition, the power consumption when the remaining time is used with the current power consumption (W2: W2 = current used power × remaining used time) is calculated. Then, W1 and W2 are compared.

If the remaining battery power W1 is greater than W2, the process returns to step S35. Conversely, when the remaining battery power W1 is smaller than W2, the process proceeds to step S37 and the current calculation unit 23
Calculates a new LED drive current, reduces the LED drive current amount, and returns to step S35. Here, it is desirable to limit the amount of current change when reducing the amount of LED drive current to a level at which the user does not feel uncomfortable. However, if the amount of change in current is limited, the subsequent decrease in the remaining amount of the battery 18 increases, so even if the user feels uncomfortable, a method of reducing the amount of current corresponding to the remaining amount of the battery may be used.

According to the present embodiment, the LED drive current calculated at the start of startup and the battery 18
Even if there is a discrepancy in how to reduce the remaining amount of LED, the LED drive current can be controlled appropriately, so the device maximizes the screen illuminance within the range that satisfies the usage time desired by the user. Can be continued.

The third embodiment is an embodiment in which a recording medium 24 such as a DVD is mounted in addition to the first and second embodiments. FIG. 4 is a block diagram showing the overall configuration of the third embodiment. In addition to the configuration of FIG. 1, a recording medium 24 is added.
FIG. 5 shows an LED drive current determination process when a recording medium such as a DVD is mounted. In FIG. 2, the user directly inputs “usage time”, but here, the playback time of the medium to be viewed is read from the recording medium 24 and set as the “usage time” of the user.

First, in step S41, when the apparatus is started up with no external power supply connected, or when the external power supply is cut off due to a power failure or disconnection of the power cord during use with the external power supply connected The control unit detects this and reads data relating to the reproduction time of the medium being reproduced from the recording medium 25.

In step S42, the usage time is set.
Subsequent battery remaining amount confirmation in step S43 and determination of the LED drive current in step S44 are the same as in FIG.
In this embodiment, since the usage time is automatically detected from the recording medium 25 even if the user does not input the usage time, it can be used more easily.
In each of the embodiments described above, an LED video display device using an LED as a display device has been described as an example. However, the present invention is not limited to this, and any video display device equipped with a battery 18 may be a laser, a liquid crystal, or the like. The present invention can also be applied to a video display device using a display element.

Further, the present invention is not limited to the above-described embodiment as it is, and can be embodied by variously modifying the constituent elements without departing from the scope of the invention in the implementation stage. Also,
By appropriately combining a plurality of constituent elements disclosed in the embodiment described above,
Various inventions can be formed. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements according to different embodiments may be appropriately combined.

1 is a block diagram showing an overall configuration related to Embodiment 1 of the present invention. The flowchart which shows the LED drive current determination process in Example 1 of this invention. The flowchart which shows the battery remaining charge feedback process in Example 2 of this invention. The block block diagram which shows the whole structure in connection with Example 3 of this invention. The flowchart which shows the LED drive current determination process in Example 3 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 13 ... Video processing part 16 ... LED drive current control part 17 ... LED display part 18 ... Battery 19 ... Control part 20 ... Operation part 22 ... Battery remaining charge detection part 23 ... Current calculation unit 24 ... Memory unit 25 ... Recording media

Claims (4)

In a video display device equipped with a battery as a power source,
Battery remaining amount detecting means for detecting the remaining amount of the battery;
From the remaining amount of the battery and the usage time desired by the user, current calculation means for obtaining a current consumption value that maximizes the illuminance of the screen within a range that satisfies the usage time;
An image display apparatus comprising: a display unit that adjusts luminance with a current value obtained by the calculation means. The said display apparatus is a video display apparatus which mounts LED or a laser as a light source, The said consumption current value calculated | required by the said calculation means is a drive current value of LED or a laser, The Claim 1 characterized by the above-mentioned. Video display device. The video display device
3. The video display device according to claim 2, wherein the remaining amount of the battery is monitored at any time, and the drive current of the LED or laser is adjusted so as to satisfy a desired usage time. The video display device is
2. The video display device according to claim 1, further comprising a recording medium, wherein the reproduction time of the recording medium is read, and the read data is set as the usage time.

Images