KR20070064055A - Touch screen with capacitive switch - Google Patents

Abstract

The present invention provides a printed circuit board (PCB) having an array of capacitive switches for sensing a touch of a user, a display panel disposed on the PCB to receive an electrical signal and display the image and provide a contact with the user; The present invention relates to a touch screen using a capacitive switch including a control unit configured to sense a change in capacitance of each capacitive switch in a switch array and to sense a position at which the user's contact occurs.

According to the present invention, a conventional button switch or a capacitive switch is provided separately from the display device, thereby improving the disadvantage that the screen size of the display device is limited, particularly in the implementation of an in-vehicle media playback device. The present invention relates to a touch screen using a capacitive switch that removes the limitation of the screen size and reduces the probability of malfunction due to a poor environment inside the vehicle.

Description

Touch screen with capacitive switch {TOUCH SCREEN DEVICE USING CAPACITIVE SWITCH}

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing the appearance of a conventional vehicle media playback device.

2 is an exemplary configuration diagram of a front panel attached to a front side of a media player for a vehicle having a conventional capacitive touch switch.

3 is a diagram illustrating a configuration of a touch screen using a conventional sensor line.

4 is a block diagram of a touch screen using a capacitive switch according to the present invention.

5 is a view showing an embodiment of a touch screen using a capacitive switch according to the present invention.

<Description of the symbols for the main parts of the drawings>

100: front panel 110: button switch

120: display 130: DVD insertion / ejection tray

140: capacitive touch switch 150: display panel

160: transparent touch screen panel 163, 166: sensor line

210: PCB 215: capacitive switch

220: display panel 225: icon

240: control unit 250: protective film

The present invention relates to a touch screen using a capacitive switch, and more particularly, a conventional button switch or a capacitive switch is provided separately from the display device, so that the screen size of the display device can be improved. The present invention relates to a touch screen using a capacitive switch to reduce the limitation of the screen size and to reduce the probability of malfunction due to a poor environment inside a vehicle by improving the limitation.

In the case of a conventional automobile media player, such as a car audio or DVD player or a navigation device, it is configured to receive a user input using a button switch.

1 is a view showing the appearance of a conventional vehicle media reproducing apparatus.

The conventional automotive media player 100 shown in FIG. 1 illustrates an automobile DVD player, for example, and includes various button switches 110a to 110j, a display device 120 for displaying image information, and a DVD insertion. / Discharge tray 130 is included.

If car audio, the front panel may include a liquid crystal panel that displays the operation of the car audio, and may also include a configuration for insertion or ejection of the CC or cassette tape.

The button switches 110a to 110j are configured to allow the user to press a button to execute the operation of the car DVD player. For example, button switch 110a is DVD ejection, button switch 110b is DVD playback start, button switch 110c is DVD playback stop, button switch 110d is fast forward, button switch 110e is fast backward, button The switch 110f can be configured to execute each function such as pause.

By pressing each button switch (110a to 110i) generates a different electrical signal corresponding to each operation, which is interpreted by the signal detection device inside the car DVD player to provide an interface for performing a specific operation of the car DVD player do.

Interfaces via these button switches are vulnerable to the harsh environment inside the car and are likely to cause malfunctions. In other words, there is a high probability that the inside of the car will malfunction due to dust, heat, and humidity.In particular, due to the metallic conductor used for the operation of the button switch, it may be corroded by moisture or by direct contact with the human body. There is a possibility of breakage of circuits due to static electricity and the possibility of contaminants entering the switch gap, which increases the probability of such a malfunction.

Therefore, there is a growing need for a switch that is free from malfunctions even in the harsh environment inside the vehicle.

Accordingly, a product that employs a capacitive switch instead of a button switch has been released for an automotive media player 100 in an automobile.

For example, patent application No. 10-2004-91688 filed on November 11, 2004, filed by Applicant, entitled "Automobile Media Playback Device with Capacitive Touch Switch," Disclosed is a media player.

FIG. 2 is an exemplary configuration diagram of a front panel attached to a front portion of a media player for a vehicle having a capacitive touch switch disclosed in Patent Application No. 10-2004-91688.

As shown in FIG. 2, the front panel disclosed in Patent Application No. 10-2004-91688 has a capacitive touch switch whose switch is not a button switch 110a to 110j as compared to the front panel of a conventional vehicle media player. Replaced with (140a to 140j).

The capacitive touch switches 140a to 140j may be external touch switches protruding out of the front panel, or may be internal touch switches mounted inside the front panel. However, in the case of external touch switches, as with the conventional button switches, the use of metallic conductors may cause corrosion by moisture, damage to circuits due to static electricity caused by direct contact with human bodies, and the possibility of contaminants entering into switch gaps. Therefore, it would be desirable to use a built-in capacitive touch switch.

However, even when the capacitive touch switches 140a to 140j are used, a space for the separate capacitive touch switches 140a to 140j is required in a portion other than the display 120, so that the installation space is limited. In particular, there is a limit to increase the size of the display 120 screen inside.

Meanwhile, the touch screen is a new input method that can replace an input device such as a mouse and a keyboard, and is currently applied to display devices such as PDAs, LCDs, and CRTs. When the touch screen touches the screen with a finger or a pen, the touch screen detects a portion in which the touch occurs and executes a command, moves a cursor, or inputs handwritten characters.

As the principle of the touch screen operation, the most representative method is to arrange the sensor lines responding to the pressure applied to the screen surface in the form of X and Y axes and to read the (x, y) coordinates when the corresponding pressure is applied.

3 is a diagram illustrating a configuration of a touch screen using a conventional sensor line.

As shown, the transparent touch screen panel 160 is attached to the display panel 150. In the transparent touch screen panel 160, the sensor lines 163a to 163e and 166a to 166d are arranged to form X and Y axes. The display panel 150 is a panel for implementing a display such as an LCD or an LED, for example, and the transparent touch screen panel 160 is attached to the display panel 150 to detect the touch of the user. The sensor lines 163a to 163e and 166a may be used. To 166d).

The detection of the contact may be performed by measuring a change in resistance values of the X and Y axes when the user's finger or the like touches the transparent touch screen panel 120.

This method is sometimes referred to as a "pressure sensitive" and is applied to various fields, but has a disadvantage of low precision.

As described above, a method of arranging a touch screen on a display device inside the vehicle is also attempted so that there is no fear of malfunction even in a poor environment inside the vehicle. However, when directly applying such a conventional touch screen, a separate touch screen panel should be attached to the display device, and a module for interpreting signals generated from the touch screen panel should also be added. In addition, when the touch screen panel is attached on the display device, there is a high possibility of breakage, and in particular, accurate touch detection is difficult in a poor environment inside the vehicle.

Therefore, the present invention can provide a touch screen that can be configured to maximize the display screen size in a display device, particularly in a media playback device mounted inside a vehicle, without requiring such additional components. The need for it is growing.

An object of the present invention is to provide a conventional button switch or capacitive switch separately from the display device to improve the disadvantage that the screen size of the display device is limited in particular in the implementation of a multimedia playback device for automobiles to provide a capacitive switch to the display device The present invention provides a touch screen using a capacitive switch that removes the limitation of the screen size and reduces the probability of malfunction due to the harsh environment inside the vehicle.

In order to achieve the above technical problem, the present invention is a PCB having an array of capacitive switches for detecting a user's touch, and disposed on the PCB to receive an electrical signal to display an image and to provide a contact with the user According to an aspect of the present invention, there is provided a touch screen including a display panel and a control unit configured to sense a change in capacitance of each of the capacitive switches in the capacitive switch array, and to sense a position at which the user's contact occurs.

In the touch screen using the capacitive switch according to the present invention, it is preferable that at least one capacitive switch is disposed corresponding to an image displayed in the form of an icon on the display panel.

In addition, in the touch screen using the capacitive switch according to the present invention, it is preferable that at least one capacitive switch is disposed corresponding to each pixel of the display panel screen.

In addition, in the touch screen using the capacitive switch according to the present invention, it is preferable that the display panel is an OLED display panel. Alternatively, the display panel may be implemented as an LCD display panel.

In addition, in the touch screen using the capacitive switch according to the present invention, the display panel is replaceable and may further include a protective film for protecting the display panel from contamination.

In addition, in the touch screen using the capacitive switch according to the present invention, the touch screen using the capacitive switch is preferably a display device provided in the media playback device mounted inside the vehicle.

Hereinafter, a touch screen using the capacitive switch of the present invention will be described in more detail with reference to the accompanying drawings.

4 is a configuration diagram of a touch screen using a capacitive switch according to the present invention.

As shown in FIG. 4, the touch screen using the capacitive switch according to the present invention includes a PCB 210, a display panel 220, and a controller 240. In addition, the touch screen using the capacitive switch according to the present invention may further include a protective film 250.

PCB 210 has an array of capacitive switches 215a through 215e for sensing a user's touch. Although a plurality of capacitive switches 215a to 215e exist, only five of the capacitive switches 215a to 215e will be described for convenience of description.

The capacitive switches 215a to 215e may be disposed in a pattern form on the PCB 210. In addition, one or more capacitive switches 215a to 215e may be disposed corresponding to each pixel of the screen of the display panel 220, for example. In this case, the capacitive switches 215a to 215e corresponding to each pixel may implement a character recognition or a mouse function through a handwriting input on the screen of the display panel 220.

Alternatively, one or more capacitive switches 215a to 215e may be disposed to correspond to an image displayed in the form of an icon on the display panel 220.

5 is a view showing an embodiment of a touch screen using a capacitive switch according to the present invention, in which the capacitive switches 215a to 215e are disposed corresponding to the icons 225a to 225e displayed on the display panel 220. An example is shown. That is, when an icon 225a corresponding to various functions, for example, a playback function, is displayed on the display panel 220, the user comes into contact with the icon 225a, and the contact is a capacitive switch corresponding to the icon 225a. At 215a, a change in capacitance is brought about. Therefore, the controller 240 may determine that the user selects a playback function corresponding to the icon 225a. In this case, when two or more capacitive switches are disposed to correspond to the icons 225a to 225e, even if a failure occurs in some capacitive switches, contact detection is possible when other capacitive switches operate normally. .

The display panel 220 is disposed on the PCB 220 and is a panel that receives an electrical signal and displays the image. The display panel 220 also provides contact with the user.

The display panel 220 is preferably an OLED display panel. That is, in the case of an OLED display panel, since the backlight unit used in the LCD display panel is not used, the thickness of the display panel can be reduced. Therefore, it can be used as a display panel of a vehicle media playback device or a portable media playback device. However, in the touch screen using the capacitive switch according to the present invention, the display panel 220 may be implemented as an LCD display panel.

The controller 240 detects a change in capacitance of each of the capacitive switches in the capacitive switch arrays 215a to 215e to detect a location where a user's contact occurs. That is, a case where a user's contact occurs with respect to the capacitive switch arrays 215a to 215e is sensed, and when a corresponding position is detected, it is transmitted to a control unit of various electronic devices including a display panel although not shown. The function corresponding to the contact is performed.

 In addition, the touch screen using the capacitive switch according to the present invention may further include a protective film 250. That is, when the user directly touches the display panel 220, the display panel 220 may be damaged, and the display panel 220 may be contaminated or foreign matter may deteriorate the display quality. Therefore, in order to improve such a disadvantage, it may be detachable and may further include a protective film 250 that can protect the display panel 220.

The touch screen using the capacitive switch according to the present invention described above is particularly preferably applied to automotive media playback devices such as car audio or automobile DVD players or navigation devices.

In other words, the interior of the car requires a durable switch configuration due to poor environment such as moisture, static electricity, dust, etc. In addition, it is preferable to implement a touch screen type due to space limitation, but the conventional touch screen is mainly mounted on the display panel. Therefore, there is a possibility of malfunction, but the touch screen according to the present invention detects the touch at the capacitive switch under the display panel, thereby increasing durability in a harsh environment and reducing the possibility of malfunction.

Although the present invention has been described in detail, this is for illustrative purposes only, and the protection scope of the present invention is not limited thereto, and the protection scope of the present invention is defined through the description of the claims.

As described above, according to the present invention, a conventional button switch or a capacitive switch is provided separately from the display device, thereby improving the disadvantage that the screen size of the display device is limited, particularly in the implementation of an in-vehicle media playback device. Can be incorporated in the display device to remove the limitation of the screen size and reduce the probability of malfunction due to the poor environment inside the vehicle.

Claims (7)

A PCB having an array of capacitive switches for detecting a user's touch; A display panel disposed on the PCB and configured to receive an electrical signal and display the image and provide contact with the user; A control unit for detecting a change in capacitance of each capacitive switch in the capacitive switch array to detect a position where the user's contact occurs Touch screen using a capacitive switch comprising a. The method of claim 1, The capacitive switch is one or more touch screen that is disposed corresponding to the image displayed in the form of an icon on the display panel. The method of claim 1, The capacitive switch is one or more touch screen is disposed corresponding to each pixel of the display panel screen. The method of claim 1, The display panel is a touch screen using a capacitive switch that is an OLED display panel. The method of claim 1, And the display panel is an LCD display panel. The method of claim 1, The touch screen using a capacitive switch is replaceable on the display panel and further comprises a protective film to protect the display panel from contamination. The method of claim 1, The touch screen using the capacitive switch is a display device provided in the media playback device mounted inside the vehicle.

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