KR20050029899A - Apparatus and method for changeover display mode - Google Patents

Abstract

A display mode conversion device and a method therefor are provided to reduce diffused reflection generated in a color LCD(Liquid Crystal Display) by incident light from a light source, and indirectly reduce the consumption of a battery by converting a display mode of the color LCD into a black and white or a gray tone. A storing unit(24) stores a threshold value used for converting a color mode of a color LCD(25) into a black and white mode or a gray tone mode. A camera unit(27) acquires an image signal of an object according as a photographing mode is set up. A light sensing unit(21) senses light, and acquires the strength of an optical signal. The color LCD(25) displays the image acquired through the camera unit as a color, a black and white, or a gray tone. A color adjusting unit(26) converts a color image displayed on the color LCD into a black and white image or a gray tone image according to the control of a control unit(28). When the strength of the optical signal acquired in the light sensing unit is greater than the threshold value stored in the storing unit, the control unit controls the color adjusting unit to convert the color image into the black and white image or the gray tone image.

Description

Apparatus and method for changeover display mode

The present invention relates to a display mode switching device and a method thereof, and more particularly, to a display mode of a color display unit according to an intensity of light incident to prevent diffuse reflection generated in a color display unit by light incident from a strong light source such as the sun. The present invention relates to a display mode switching device and method for converting the color from color to black and white or gray tone.

In the present invention, the wireless communication terminal is a mobile communication terminal, a personal communication service (PCS) terminal, a personal digital assistant (PDA), a smart phone, a next generation mobile communication (IMT-2000) terminal, a wireless LAN terminal and the like through wireless communication Refers to a portable wireless communication terminal capable of transmitting and receiving text and image data. In the following example, a color liquid crystal display (LCD) will be described as a color display unit.

Currently, liquid crystal displays, in particular, thin film transistor-liquid crystal displays (TFT-LCDs), are mostly applied to wireless communication terminals. TFT-LCD has better visibility than cathode ray tube (CRT), average power consumption is about 30-40% compared to cathode ray tube of the same screen size, and heat generation is also smaller than cathode ray tube. have. In the following example, a color liquid crystal display (LCD) will be described as a color display unit.

TFT is a type of MOS (Metal Oxide Semiconducter) FET which is a Field Effect Transistor (FET). A TFT is formed by forming a semiconductor thin film such as amorphous silicon on a glass substrate. Say. The thin film formation technology is a technique for forming a thin film by vacuum deposition of a thin film of several hundred angstroms to thousands of angstroms on an insulating substrate. The silicon film is mainstream.

Liquid crystal is a liquid at first glance, but is an organic compound called thermotropic liquid crystal, which is an optically specific substance exhibiting anisotropy such as crystal. There are two types of liquid crystal display: reflective type and transmissive type. Reflective type is a type that reflects and displays the light incident from the front of the liquid crystal display panel on the reflective plate attached to the back of the panel. It is a type that represents an image.

Initially, liquid crystal displays supported only black and white, but as the application range of liquid crystal displays expanded and the display market became colored, liquid crystal displays also evolved to support color.

In the liquid crystal display, a color filter corresponding to three primary colors of red, green, and blue light is used to implement color. That is, the three primary color filters are arranged adjacent to each other, and color is expressed by applying a corresponding color signal to each color filter to control brightness. At this time, the brightness is adjusted by adjusting the voltage applied to the device, and eventually various colors are expressed.

Looking more closely at the principle of expressing colors, assuming that the liquid crystal can only do two things to completely block or pass light (when red, green and blue are 1 bit each), the number of colors that can be represented Is the number of eight cases, which is a power of two. In other words, as long as the filter is fully open and closed, it can control red, green, and blue with 1 bit of data. If each of red, green, and blue has two bits of data to control the unit color, then there are 64 cases of powers of two.

As a result, it can be said that the number of colors that can be expressed in the liquid crystal display device is determined by the number of bits of the image data used. That is, the amount of light passing through the color filter is controlled using a liquid crystal, and the voltage required to operate the liquid crystal is supplied through a pixel TFT.

In this way, the voltage supplied to the liquid crystal changes the transmittance of the liquid crystal. In this case, the number of colors that can be expressed is determined by how many steps the liquid crystal can be controlled. That is, when the liquid crystal is twisted, it becomes white, and when the liquid crystal is unwound, it becomes black, and various colors are expressed by combining gray scales therebetween.

However, such a color liquid crystal display device has a disadvantage in that diffuse reflection is severe. For example, when shooting a subject using a camera or camera phone with a color liquid crystal display, avoid normal backlighting (when the lens of the camera is looking at the sun, and in this case, the photograph is blurred). As shown in FIG. 1, the subject faces the sun, the camera lens faces the sun, and the color liquid crystal display faces the sun.

In this case, the photographer has a problem that the subject displayed on the liquid crystal display cannot be clearly identified because of the diffuse reflection caused by the light input from the light source such as the sun.

The present invention has been proposed to solve the above problems, and when photographing a subject using a device having a camera, according to the intensity of light in order to remove the diffuse reflection generated in the color display part by light incident from a strong light source such as the sun SUMMARY OF THE INVENTION An object of the present invention is to provide a display mode switching device and method for converting a display mode of a color display unit from color to black and white or gray tone.

An apparatus of the present invention for achieving the above object comprises: a display mode switching device comprising: storage means for storing a reference value (threshold value) used for switching a color mode of a color display means to a black and white or gray tone mode; Photographing means for obtaining an image signal of the subject as the photographing mode is set; Light intensity obtaining means for sensing light to obtain intensity of the optical signal; The color display means for displaying the image acquired through the photographing means in color or black and white or gray tone; Color adjusting means for converting a color image displayed through the color display means into a black and white or gray tone image under control of a control means; And converting the color image displayed on the color display means into black and white or gray tone image as the intensity of the optical signal acquired by the light intensity obtaining means exceeds a reference value (threshold value) previously stored in the storage means. And said control means for controlling the adjustment means.

On the other hand, the method of the present invention comprises: a display mode switching method, comprising: a first step of storing, in a storage means, a reference value used for switching a color mode of a color display means to a monochrome or gray tone mode; A second step of confirming the setting of the display mode switching function as the camera mode is set; A third step of sensing light incident on the color display means to obtain an intensity of an optical signal and to compare it with a reference value previously stored in the storage means; And a fourth step of controlling the color adjusting means as the obtained optical signal intensity (digital signal value) exceeds a reference value to switch the display mode of the color display means to black and white or gray tone. .

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a configuration diagram of an embodiment of a display mode switching device according to the present invention.

As shown in FIG. 2, the display mode switching device according to the present invention includes a light detector 21 for detecting light incident from a light source (sun or strong light emitting object) and outputting an optical signal according to the intensity of light. ), An amplifier 22 for amplifying the optical signal output from the light detector 21, an analog / digital converter for converting the optical signal (analog signal) amplified by the amplifier 22 into a digital signal ( 23) a storage unit 24 and a camera unit 27 which store a reference value (reference digital signal value) used for converting the color image of the color liquid crystal display unit 25 into black and white or gray tone. The color liquid crystal display 25 for displaying an image in color, black and white or gray tones, and the color image displayed through the color liquid crystal display 25 under the control of the controller 28 are converted into a black and white or gray tone image. Back End IC (26), a camera function is set to control the camera unit 27 and each of the components for receiving the image signal of the subject as the user photographs the subject, A reference value (reference digital signal value) pre-stored in the storage unit 24 by receiving the intensity (digital signal value) of the digital signal detected by the detector 21 and converted by the analog / digital converter 23. And a controller 28 for controlling the color adjusting unit 26 to convert a color image displayed on the color liquid crystal display unit 25 into a black and white or gray tone image when the digital signal value is larger than a reference value. do.

Here, since the optical signal output from the light detector 21 is electrically weak, the optical signal is amplified using the amplifier 22, but if the intensity of the optical signal is sufficient, it is not necessary to separately amplify the optical signal.

Further, the present invention can be applied not only to a wireless communication terminal, a digital camera or a camcorder, but also to any device to which a color display device is attached.

In addition, the light detector 21 may be implemented to be detachably attached to a wireless communication terminal or a digital camera. The light detector 21 may be located parallel to the color liquid crystal display 25 or embedded therein to receive the color liquid crystal display 25. It may be implemented to receive light of the same intensity as the light intensity.

3 is a flowchart illustrating a display mode switching method according to the present invention.

First, the storage unit 24 stores a reference value (reference digital signal value) used to convert a color image of the color liquid crystal display unit 25 into a black and white or gray tone image (301).

Thereafter, as the camera mode is set in a device (eg, a wireless communication terminal) having a display mode switching function (302), it is determined whether the display mode switching function is set (303).

As a result of the determination, if the display mode switching function is not set, the subject is photographed without switching the display mode (309). On the other hand, when the display mode switching function is set, the optical signal incident on the color liquid crystal display 25 is detected through the light detector 21 (304), and then detected by the analog / digital converter 23. The optical signal (analog signal) is converted into a digital signal (305).

Thereafter, the controller 28 compares the intensity (digital signal value) of the converted digital signal with a reference digital signal value previously stored in the storage unit 24 (306). As a result of the comparison, if the intensity of the digital signal is greater, the subject is photographed after switching the display mode of the color liquid crystal display 25, which is currently set in color, to black and white or gray tone (308). Of course, if the reference digital signal value is not larger, the subject is photographed without switching the display mode (309).

Subsequently, it is determined whether the camera mode of the wireless communication terminal is terminated (310). If the camera mode is terminated, the display mode switching function is completed. If the camera is not terminated, the process proceeds to step “303” to perform the subsequent process. .

At this time, when the camera mode is terminated, the color liquid crystal display 25 operates in the color mode again.

In the above example, the control unit compares the intensity of the optical signal with a pre-stored reference value (threshold value) and describes the display mode automatic switching method of switching the display mode immediately when the intensity of the optical signal exceeds a threshold. When the intensity of the optical signal exceeds the threshold and outputs the user to select whether to switch the display mode when the intensity of the optical signal exceeds the threshold, the display mode is switched according to the input signal. It can also be implemented as a semi-automatic switch that controls no switching.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible in the art without departing from the technical spirit of the present invention. It will be clear to those of ordinary knowledge.

As described above, the present invention has an effect of reducing diffuse reflection (glare) generated in the color display part by light incident from a light source such as the sun when photographing a subject using a device having a camera.

In addition, the present invention switches the display mode of the color display unit to black and white or gray tone, thereby indirectly reducing battery consumption.

1 is a diagram illustrating a method of photographing a subject using a wireless communication terminal in general.

2 is a configuration diagram of an embodiment of a display mode switching device according to the present invention;

3 is a flowchart illustrating an embodiment of a display mode switching method according to the present invention;

* Explanation of symbols for the main parts of the drawings

21: light detecting unit 22: amplifying unit

23: analog / digital conversion unit 24: storage unit

25: color liquid crystal display 26: color adjustment unit

27: camera unit 28: control unit

Claims (7)

In the display mode switching device, Storage means for storing a reference value (threshold value) used for switching the color mode of the color display means to the monochrome or gray tone mode; Photographing means for obtaining an image signal of the subject as the photographing mode is set; Light intensity obtaining means for sensing light to obtain intensity of the optical signal; The color display means for displaying the image acquired through the photographing means in color or black and white or gray tone; Color adjusting means for converting a color image displayed through the color display means into a black and white or gray tone image under control of a control means; And Adjusting the color to convert the color image displayed on the color display means into black and white or gray tone image as the intensity of the optical signal acquired by the light intensity obtaining means exceeds the reference value (threshold) previously stored in the storage means Said control means for controlling the means Display mode switching device comprising a. The method of claim 1, The light intensity obtaining means, Light sensing means for sensing light to output an optical signal according to the intensity of the light; Amplifying means for amplifying an optical signal from the light sensing means; And Analog-to-digital conversion means for converting the optical signal (analog signal) amplified by the amplification means into a digital signal for transmission to the control means Display mode switching device comprising a. The method of claim 2, The light sensing means, The display mode switching device, characterized in that located in parallel to the periphery of the color display means detects the light of the same intensity as the intensity of the light incident on the color display means and outputs an optical signal accordingly. The method according to any one of claims 1 to 3, The control means, When the intensity of the optical signal is higher than the reference value, the display mode is not changed when the intensity of the optical signal is lower than the reference value, and the intensity of the optical signal exceeds the reference value. And the color adjusting means is directly controlled to convert the color image displayed on the color display means into a black and white or gray tone image. The method according to any one of claims 1 to 3, The control means, When the intensity of the optical signal is higher than the reference value, the display mode is not changed when the intensity of the optical signal is lower than the reference value, and the intensity of the optical signal exceeds the reference value. Outputting the user to select whether or not to switch the display mode and controlling the color adjusting means so as not to switch the display mode according to the input selection signal or to convert the color image displayed on the color display means into black and white or gray tone image Display mode switching device, characterized in that for switching the display mode. The method according to any one of claims 1 to 3, The display mode switching device, Display mode switching device, characterized in that integrated with a wireless communication terminal or a digital camera or camcorder. In the display mode switching method, A first step of storing, in the storage means, a reference value used to switch the color mode of the color display means to the monochrome or graytone mode; A second step of confirming the setting of the display mode switching function as the camera mode is set; A third step of sensing light incident on the color display means to obtain an intensity of an optical signal and to compare it with a reference value previously stored in the storage means; And A fourth step of controlling the color adjustment means to switch the display mode of the color display means to black and white or gray tone as the intensity (digital signal value) of the obtained optical signal exceeds a reference value; Display mode switching method comprising a.