JP2000020237A - Pen position detecting device in plasma display and electronic board using plasma display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pen position detecting device in plasma display which can detect the position of a touch pen without providing a touch panel. SOLUTION: The pen position detecting device in plasma display 1, which detects the position of the touch pen 2 to a plasma display driven by a subfield method, is equipped with a photodetecting device which is provided on the touch pen 2 and photodetects light from the plasma display 1, a pattern display means which switches such a pattern that the position detection area of the touch pen 2 is gradually narrowed down in subfield units according to the output of the photodetecting device and displays it on the plasma display 1, and a position detecting means which detects the position of the touch pen 2 according to the output of the photodetecting device of the touch pen 2 to the pattern displayed by the pattern display means.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting a pen position in a plasma display and an electronic board (electronic blackboard or white board) using the plasma display.
About.

[0002]

2. Description of the Related Art It is necessary to detect the position of a touch pen when drawing on a display by tracing the touch pen with the touch pen or when using the touch pen as a pointer. There are the following methods for detecting the position of the touch pen.

The first is a method of detecting the position of a touch pen by attaching a touch panel having a transparent position sensor to the entire display. Second,
When the display is a CRT, this method detects the position of the touch pen based on the timing at which the touch pen senses the raster light of the CRT.

However, in the case of a large-sized plasma display panel having a display exceeding 40 inches, if the first method is employed, there is a problem that the touch panel becomes very expensive.

In the case of a plasma display panel, the drive is performed in units of lines. Once driven, an afterimage occurs until the next drive. Therefore, based on the timing at which raster light is detected as in a CRT display. The second method, such as detecting the position of the touch pen, cannot be adopted.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a pen position detecting device in a plasma display which can detect the position of a touch pen without providing a touch panel.

An object of the present invention is to provide an electronic board using a plasma display.

[0008]

A pen position detecting device in a plasma display according to the present invention is provided in a touch pen in a pen position detecting device in a plasma display for detecting a position of a touch pen with respect to a plasma display driven by a subfield method. In addition, based on the output of the light receiving device that receives light from the plasma display and the light receiving device of the touch pen, a pattern that gradually narrows the position detection area of the touch pen is switched on a subfield basis and displayed on the plasma display. And a position detecting means for detecting the position of the touch pen based on the output of the light receiving device of the touch pen for the pattern displayed by the pattern displaying means.

An electronic board using a plasma display according to the present invention is based on a plasma display driven by a subfield method, a touch pen having a light receiving device for receiving light from the plasma display, and an output of a light receiving device of the touch pen. Pattern display means for switching the pattern in which the position detection area of the touch pen is gradually narrowed on a sub-field basis to be displayed on the plasma display, based on the output of the light receiving device of the touch pen for the pattern displayed by the pattern display means And a movement trajectory display means for displaying a movement trajectory of the touch pen on a plasma display based on the position of the touch pen detected by the position detection means. I do.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the configuration of an electronic whiteboard using a plasma display.

In FIG. 1, reference numeral 1 denotes a plasma display panel (hereinafter, referred to as PDP). 2 is PDP
1 is a touch pen having a function of detecting the light on the touch panel 1 and transmitting a signal corresponding to the detected light.

Reference numeral 11 denotes a receiving antenna for receiving a signal transmitted from the touch pen 2. Reference numeral 12 denotes a reception detector that converts a signal received by the reception antenna 11 into a digital signal.

A pattern signal generator 13 generates a pattern signal for detecting the position of the touch pen 2. 14 controls the pattern signal generator 13 and controls the touch pen 2 based on the signal from the reception detector 12.
This is a control device for detecting the position of.

Reference numeral 15 denotes a memory for storing data (position data) indicating the position of the touch pen 2 detected by the control device 14. A read circuit 16 is controlled by the control device 14 and reads position data from the memory 15.

Reference numeral 17 denotes a switch for switching between a video signal input and position data. 18 is switch 1
7 and a pattern signal from the pattern signal generator 13.

It is assumed that an AC PDP is used as the PDP 1. In the AC type PDP 1, a subfield method is adopted as a driving method for performing gradation expression.

For example, in order to experiment with 256 gradations using 8-bit video data, one field has 12 fields.
It is divided into eight subfields having a light emission period of a ratio corresponding to the weight of each bit such as 8: 64: 32: 16: 8: 4: 2: 1. Each subfield includes a writing period (address period) and a light emitting period (display period). In the writing period, wall charges are initially formed in the discharge cells to be displayed on the entire screen. In the light emission period, the sustaining pulse is applied to the entire screen simultaneously. As a result, the discharge continuously occurs only in the discharge cells in which the wall charges have been formed.

FIG. 2 shows the structure of the touch pen 2.

The touch pen 2 includes a light sensor 21 that detects light from the PDP 1 and converts the light into an electric signal, a modulator 22 that amplifies and modulates an output signal of the light sensor 21, and a transmitter that transmits an output of the modulator 22. 23 and an antenna 24.

Hereinafter, an outline of a method for detecting the position of the touch pen 2 will be described. For convenience of explanation, it is assumed that there is no video signal input. Therefore, the switch 17 is always
The position data read by the read circuit 16 is selected.

First, as shown in FIG. 3A, a pattern in which the left half is black and the right half is white is displayed on the PDP 1 for one subfield period, and based on the signal from the touch pen 2, the touch pen 2 Determine whether it is in the left half or the right half.

When it is determined that the touch pen 2 is located on the left half of the PDP 1, a pattern in which the upper half of the left half is white and the lower half is black as shown in FIG. Is displayed, and based on the signal from the touch pen 2, it is determined whether the touch pen 2 is in the upper half or the lower half of the left half of the PDP 1. In this way, the position detection area of the touch pen 2 is reduced by １ ／. The part shown in gray in FIG. 3B, that is, the right half of FIG. 3B is a part unrelated to position detection, and, for example, white is displayed. FIG.
In FIG. 3 (f), the part shown in gray is also a part unrelated to the position detection, and for example, white is displayed.

In the same manner, the positions of the touch pen 2 are narrowed down by sequentially displaying the patterns shown in FIGS. 3C, 3D, 3E, and 3F by the same operation. . When the position of the touch pen 2 is narrowed down until the size of the position detection area reaches a predetermined size, the narrowed position is stored in the memory 15 as the position of the touch pen 2 and displayed on the PDP 1.

Once the position of the touch pen 2 is specified, an area of a predetermined size centered on the position is
The next movement position of the touch pen 2 is detected as the first position detection area. The pattern display for detecting the position of the touch pen 2 and the touch pen 2 stored in the memory 15 are performed.
The display of the locus of the touch pen 2 based on the position data of
By controlling the switch 18, the operation is alternately performed every one or several fields.

FIG. 4 shows the operation procedure of the electronic whiteboard.

First, a pattern corresponding to the information on the position and size of the position detection area is generated from the pattern signal generator 13 so that the pattern is
One is displayed for one subfield period (step 1). A value corresponding to the entire panel of the PDP is set as the initial value of the information on the position and the size of the position detection area. In the first step 1, the pattern of FIG. 3A is displayed.

Based on the signal from the touch pen 2, the control device 14 detects the position of the touch pen 2 (step 2).

Next, it is determined whether or not the position of the touch pen 2 can be specified, that is, whether or not the size of the position detection area in step 1 is a predetermined size for specifying the pen position. (Step 3).

If the size of the position detection area in step 1 is not a predetermined pen position identifiable size, information on the position and size of the position detection area is obtained according to the position detection result in step 2. Updated (step 4).
Then, the process returns to step 1.

If it is determined in step 3 that the size of the position detection area in step 1 is a predetermined pen position identifiable size, the position detected in step 2 is used as the position data. Is stored in the memory 15 (step 5). Then, by reading out the data stored in the memory 15 and sending it to the PDP 1, for example, the movement locus of the touch pen 2 is displayed on the plasma display panel 1 for only one field period (step 6).

Next, the position information of the position detection area is set to information representing the position detected in step 2 and the size information of the position detection area is set to a predetermined size (step 7). . Then, the process returns to step 1.

Note that the touch pen 2 may be provided with an acceleration sensor so that information on the moving direction of the touch pen 2 is also transmitted from the touch pen 2. By doing so, each time the position of the touch pen is specified and stored (see step 5), the position and size of the first position detection area for the next position detection can be further limited, and the next position can be determined. The detection processing time can be reduced.

[0034]

According to the present invention, a pen position detecting device for a plasma display which can detect the position of a touch pen without providing a touch panel can be obtained.

According to the present invention, an electronic board using a plasma display can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an electronic whiteboard using a PDP.

FIG. 2 is a block diagram illustrating a configuration of a touch pen.

FIG. 3 is a schematic diagram showing a pattern for gradually narrowing the position of a touch pen.

FIG. 4 is a flowchart illustrating an operation procedure of the electronic whiteboard.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 PDP 2 Touch pen 12 Reception detector 13 Pattern signal generator 14 Control device 15 Memory 21 Optical sensor

Claims (2)

[Claims] 1. A pen position detecting device in a plasma display for detecting a position of a touch pen with respect to a plasma display driven by a subfield method, a light receiving device provided on the touch pen and receiving light from the plasma display, a light receiving device of the touch pen Pattern display means for switching a pattern in which the position detection area of the touch pen is gradually narrowed on a subfield basis based on the output of the touch pen to display the pattern on the plasma display, and a touch pen for the pattern displayed by the pattern display means. And a position detecting means for detecting the position of the touch pen based on the output of the light receiving device. 2. A plasma display driven by a subfield method, a touch pen having a light receiving device for receiving light from a plasma display, and a position detection area of the touch pen is gradually narrowed based on an output of the light receiving device of the touch pen. Pattern display means for switching various patterns in units of subfields to be displayed on the plasma display, position detection for detecting the position of the touch pen based on the output of the light receiving device of the touch pen with respect to the pattern displayed by the pattern display means An electronic board using a plasma display, comprising: means for moving the touch pen on a plasma display based on the position of the touch pen detected by the position detecting means.