JPH067372B2 - Touch panel and control method thereof - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a touch panel and a method for controlling the touch panel.

[Conventional technology]

In recent years, touch panels have been widely used in combination with video displays such as CRT screens and flat panel displays.

As one type of touch panel currently used,
A rectangular frame is attached to the front of the display, and a plurality of energy beam emitting devices are provided on the outer periphery thereof, and the energy beam emitted from the device is projected across a screen to a beam detector located oppositely. There is something like this.

When an indicator needle or other external object interrupts one or more beams, the analysis circuit senses the interrupted state and calculates the interrupted position on the screen surface. This information is then transferred to the host computer controlling the video display. Therefore, it is possible to write or mark on the screen by using a pointer or a human finger.

Although various types of energy beams are utilized, infrared beams are commonly used.

One problem with the use of infrared beams is that ambient light interferes with the device's ability to sense the interruption of a particular beam being emitted across the screen.

To prevent interference from ambient light, an infrared beam is modulated at a specific frequency so that an electronic circuit senses and analyzes the beam break condition as the beam is projected across a video screen. There is a way to make it possible.

An example of this type of device is disclosed in U.S. Pat. No. 4,868,912. However, the device described therein is designed to modulate the infrared beam with a light emitting diode (LED) modulator, which is another electronic device incorporated into the circuit. . The LED modulator produces an analog sine wave signal, which in the next stage,
It is adapted to be converted into a digital signal by another element inside the device.

[Problems to be Solved by the Invention]

A first object of the present invention is to provide an excellent touch panel and a method for controlling the touch panel.

A second object of the invention is to adjust the beam, as described in said US Pat. No. 4,868,912.
It is an object of the present invention to provide an excellent touch panel using a central processing unit for controlling the generation of various infrared beams without using another electric element.

A third object of the present invention is to provide an excellent touch panel and a control method of the touch panel which is easy to adjust and which can modulate the infrared beam in a special way.

A fourth object of the present invention is to provide an excellent touch panel using a simple electric circuit and a small number of electric elements, and a control method thereof, as compared with a conventional device.

A fifth object of the present invention is to provide an excellent touch panel which uses a central processing unit capable of generating a digital modulation signal at an early stage in order to adjust the energy beam.

A sixth object of the present invention is to provide an excellent touch panel which can be manufactured economically, can withstand long-term use, and can operate effectively.

[Means for Solving the Problems]

As a means for solving the problems, the present invention provides a touch panel connected to a host computer; (a) a display area having a determined outer edge; (b) at least one of the outer edges of the display area. A plurality of pairs of emitter detectors arranged in a section, each pair of emitter detectors operative to emit an energy beam, said pair of emitter detectors being located opposite the emitter across the display area, (C) a central processor means separate from a host computer connected to the emitter detector pair; and (d) integrated in the central processor. The computer program means, or the central processor means,
Computer program means for controlling activation and deactivation of the emitter-detector pair in time series to generate a plurality of energy signals comprising an actuating portion and a deactivating portion; (e) the computer program means; A modulation signal is generated in the central processor means to modulate the active portion of the energy signal at a predetermined frequency, such that the emitter emits a modulated energy beam while receiving the modulation signal. (F) The detector is adapted to sense the modulated energy beam and to generate a first electrical beam signal whenever the modulated beam is unimpeded from the emitter to the detector. And each of the detectors includes an emitter and a detector for a predetermined period. A second electrical beam signal different from the first beam signal is generated whenever there is an intervening modulated beam in between; and (g) connected to the detector and the central processor means. Disconnection detecting means for transmitting a disconnection signal to the central processor means in response to the disconnection detecting means for detecting the second signal: and (h) the computer program means for the central processor. And a touch panel including an element for causing the means to generate an output signal indicating the position of the obstruction in the display area in response to the interruption signal received from the interruption detection means.

Further, the present invention for solving the problem is a method for controlling a touch panel which is connected to a host computer and determines the position of an object close to the display surface; At least a portion of the periphery comprises an emitter operative to emit an energy beam, and a pair of detectors that are positioned opposite the emitter across the display area and that receive the energy beam. Installing a plurality of beam emitter-detector pairs; (b) connecting a microprocessor separate from the host computer to the emitter-detector pairs; (c) to the microprocessor, To scan the emitter-detector pair and send an energy signal to the emitter In the computer program to
Programming the microprocessor; (d) using the computer program to cause the microprocessor to modulate a portion of the energy signal at a predetermined frequency and simultaneously transmit the energy signal to the emitter. Causing the emitter to emit a modulated energy beam having the predetermined frequency to the detector; (e) a first detector signal responsive to receiving the modulated energy beam using the detector. Generating a second detector signal whenever the object interrupts the modulated energy beam; (f) using an interrupt sensing means connected to the detector, the microprocessor Sending a shutoff signal to (g) using the computer program Connecting to a host computer and proximate to a display surface, comprising: analyzing the blocking signal and generating an output signal in response to the blocking signal shape, the output signal indicating a position of an object in the display area. It is a method of controlling a touch panel that indicates the position of an object.

The emitter produces a plurality of infrared beams that traverse the display panel and are received by the detector.

The detector examines the light it receives and produces an electrical signal that is sent to a comparator. The comparator analyzes the signal to determine whether the beam is blocking. If an interruption occurs, the comparator will
The cutoff signal is sent to the central processing unit, which examines the cutoff signal and calculates the cutoff position on the screen.

The central processing unit is also connected to the emitter-detector pairs and controls the scanning of the emitter-detector pairs one at a time. As the scan is being performed, the central processing unit produces a digital signal which modulates each projection during actuation.

The modulation of this beam is done at some frequency which can be changed by choice. Satisfactory results are obtained at frequencies in the range of 10 to 500 KHz. Suitable frequencies are in the range of 60-90 KHz.

The central processing unit is programmed to be able to modulate the frequency of the infrared beam, as mentioned above. Also,
The particular beam produced is a square wave. That is, the beam alternates on and off at some frequency determined by the program in the CPU device.

Although conventional devices have also been used which modulate the infrared beam, these devices are adapted to generate a sinusoidal waveform for the infrared beam.

The present invention utilizes a square wave rather than a sine waveform. Also, in the conventional device, the device for modulating the beam consists of a separate electrical element, unlike the central processing unit of the circuit.

The program in the CPU element according to the present invention is not the hardware of the conventional device, but rather controls the modulation.

〔Example〕

 Hereinafter, preferred embodiments of the present invention will be described in detail.

As shown, reference numeral (10) is a touch panel assembly according to the present invention. This Touch Panel Assembly (10)
Is the display surface (14) and the display frame (1
6), and a display panel (12) having a pair of side mounting flanges (18).

The mounting hole (20) penetrates the mounting flange and enables mounting of the display on a housing or other device mounted on the touch panel.

An electrically insulating gasket (22) is fixed to the frame (16), and the touch frame (24) is attached to the gasket (22).

The touch frame (24) includes a rectangular printed wiring board frame (26). The frame (26) has a plurality of lower light emitting diodes (LEDs) (28) along one side and a plurality of right side LEDs (30) on the right side.

The LED is oriented inward and when electrically energized, emits infrared radiation into the space within the frame (24).

A plurality of upper light converter (32) and the left light converter (34), respectively, to receive the infrared beam from the LED (28) (30),
It is mounted above and to the left of the frame.

On the left side of the device, a detector cable (36) connected to each optical converter (32) (34) is attached.

The LED cable (38) includes a cable connected to the bottom of the frame and led to each LED (28) (30).

Bezel frame (4
0) has four inwardly inclined lenses (42), and elongated grooves (44) are formed behind the lenses.

As shown in FIG. 2, the groove (44) accommodates the LEDs (28) (30) and the optical converters (32) (34). Therefore, LED (28) (3
The light emitted from (0) passes through the lens (42) and spreads across the screen.

The filter plate (46) is superposed on the display surface (14) of the display panel (12).

A control board (48) is attached to the back surface of the display panel (12). The control board (48) includes a plurality of electric elements described later.

Various elements are bezel frame (40), touch frame (2
4), gasket (22), display panel (12), and screws (5 through the matching holes in the control board (48).
They are stuck together by 0).

The detector cable (36) and LED cable (38) are
Each has a connector (39), and this connector (39)
As shown in FIG. 2, it can be connected to a control board (48).

FIG. 3 is a block diagram showing various elements on the control board (48). These elements include a central processing unit (CPU) (52). A suitable model of the CPU (52) is Motorola (Mo
trola) manufactured as model number MC68701S.

Anode driving means for LED (54), and cathode driving means for LED (56)
Are respectively connected to the LEDs (28) (30).

The CPU (52) is connected to the cathode driving means (56) via a modulation line (58) that modulates the operation of the LEDs (28) (30), as will be described later.

The control board (48) is also equipped with a detector decoder (60) and a detector multiplexer (62), which are respectively connected to the respective optical converters (32) (34).

The amplifier (64) is connected to the multiplexer (62) and also to the comparator (66), and beyond that CP.
It is connected to U (52).

A transceiver (68) is connected to the CPU (52) and is in communication with the host computer. The transceiver (68) enables the host computer to receive signals from the CPU (52) and to transmit signals to the CPU (52).

Reset control means (70) is connected to the CPU (52) to keep the unit operational. An oscillator or clock circuit (80) is connected to the CPU (52) in the usual manner.

As shown in Figure 4, a special series of low value resistors (82)
It is connected to the circuit between the multiplexer (62) and the connector (39).

Conventional devices use resistors as high as 1500 ohms for that purpose. However, it was found that excellent sharpness on the screen was obtained even though the resistor (82) had a much lower value of 200 ohms.

The CPU (52) is operated by the same program included in the appendix.

This program provides several functions. One of them controls the scanning of the anode and the cathode so that they can be performed one at a time in sequence.

The program stored in the CPU (52) also includes a modulation function so that, in operation, the signals generated by each LED (28) (30) are modulated.

6 and 7 show signals generated by a program in the CPU (52).

The optical signal is indicated by reference numeral (72). It consists of a working part (74) and a non-working part (76). As is apparent from FIG. 7, the operation part of the signal (72) is modulated into a plurality of square waves, and the square wave intermittently repeats the ON state and the OFF state.

The frequency at which this working part is modulated can be varied without substantially compromising the invention, but the preferred modulation range is (60) to 90 KHz.

The modulating portion of the circuit comprises approximately 0.8% of the total cycle of the signal (72), and the remaining portion of the cycle comprises 99.2% of the cycle period. The other LEDs 28, 30 are activated one at a time while the signal inactive portion 76 lasts.

The program in the CPU (52) contains the part that can receive the signals from the comparator (66), analyze them and send the output signal from the transceiver (68) to the host computer. .

During operation, the CPU (52) causes the LED anode drive means (54) and
The LED cathode driving means (56) sequentially activates the various LEDs (28) (30).

A program in the CPU (52) sends a digital modulation signal via the modulation line (58) so that the cathode of the LED can be turned on and off intermittently to modulate the LED. This produces an actuation modulator (74) of the signal (72) for each LED.

At the same time, the computer can either optical converter (32) (34)
Enables the sequential operation of the light converters (32) (34) such that each operates simultaneously with the corresponding LED (28) (30).

The optical signals detected by the optical converters (32) and (34) are transmitted to the multiplexer (62), from which they are further converted into electric signals to be transmitted to the amplifier (64) and the comparator (66).

The comparator compares the signal received from the light converter with predetermined signal characteristics to determine if the signal represents an interruption of the infrared beam across the video display panel (14).

If a blocking condition occurs, the comparator will detect the appropriate signal due to the nature of the signal sent to it from the amplifier (64).

Next, the comparator transmits the cutoff signal to the CPU (52). This cutoff signal indicates that a cutoff condition has occurred.
Notify U (52).

A program in the CPU (52) calculates the blocking position by analyzing the position where the infrared beam emitted from and crossing the LEDs (28) (30) is blocked. CPU
Sends an output signal to the host computer.

By modulating the light output of the LED, one can create a signal that is easily distinguishable from the signal originating from ambient light.

Ambient light is also detected by the optical converter, but the frequency of the modulated portion of the optical signal is easily identified by the comparator 66 so that the error caused by ambient light is minimized.

The advantage of modulating the optical signal by the CPU is that it is not necessary to separately provide an element for generating the modulated signal in the circuit.

Furthermore, the digital modulation signal generated by the CPU makes it possible to more easily control the specific timing of the optical signal, and the degree of modulation of the signal can be easily changed by reprogramming the CPU. .

The signal transmitted to the decoder drive means is not an analog signal, as is the case with a hardware drive signal,
It is a digital signal. This further improves accuracy and enables amplification of the modulated signal by the amplifier 64, improving the ratio of the modulated signal level to the noise level caused by ambient light. Therefore, a very good distinguishability is achieved.

Thus, the device according to the invention can achieve at least all the above-mentioned objectives.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of the touch panel according to the present invention. FIG. 2 is a sectional view of the touch panel assembled to the panel display. FIG. 3 is a block diagram of a touch panel according to the present invention. 4 and 5 are circuit diagrams of the touch panel according to the present invention. FIG. 6 is a waveform diagram generated by a program in the CPU. FIG. 7 is an enlarged waveform diagram taken along line 7-7 of FIG. (10) Touch panel assembly (12) Display panel (14) Display surface, (16) Frame (18) Flange, (20) Mounting hole (22) Gasket, (24) Touch frame (26) Printed wiring board frame (28) (30) LED, (32) (34) Optical Converter (36) (38) Cable, (39) Connector (40) Bezel Frame, (42) Lens (44) Groove, (46) Filter Plate (48) Control Substrate, (50) Screw (52) CPU, (54) Anode driving means (56) Cathode driving means, (58) Modulation line (60) Decoder, (62) Multiplexer (64) Amplifier, (66) Comparator (68) Transceiver, (70) Reset control means (72) Optical signal, (74) Working part (76) Non-working part, (80) Clock circuit (82) Resistor

Claims (5)

[Claims] 1. A touch panel connected to a host computer; (a) a display area having a determined outer edge; and (b) an emitter disposed on at least a part of the outer edge of the display area. A plurality of pairs of detectors, each pair being positioned opposite the emitter with an emitter operative to emit an energy beam and the display region sandwiched therebetween, for receiving the energy beam, (C) central processor means separate from a host computer connected to the emitter-detector pair; and (d) computer program means embedded in the central processor. Alternatively, the central processor means is provided with a time sequence of activation and deactivation of the emitter-detector pair. Computer program means for controlling to generate a plurality of energy signals comprising an actuating portion and a deactivating portion; (e) said computer program means causing said central processor means to generate a modulation signal, said energy signal Is modulated by a predetermined frequency so that the emitter emits a modulated energy beam while receiving a modulated signal, and (f) the detector emits the modulated energy beam. It is adapted to generate a first electrical beam signal for sensing and whenever the modulated beam reaches the detector unimpeded from the emitter, and each detector is provided for the duration of a predetermined period. , Whenever there is something between the emitter and detector that interferes with the modulated beam, A second electrical beam signal different from the first beam signal is generated; (g) interruption detection means connected to the detector and the central processor means for providing the second signal Shutdown detection means for sending a shutoff signal to the central processor means in response to the sensed shutoff detection means: and (h) the computer program means is responsive to the shutoff signal received from the shutoff detection means to the central processor means. Generating an output signal indicating the position of the obstruction within the display area; a touch panel including the element. 2. The touch panel according to claim 1, wherein the predetermined frequency is in the range of 10 to 500 KHz. 3. The touch panel according to claim 1, wherein the predetermined frequency is in the range of 60 to 90 KHz. 4. The cut-off detection means is a comparator that determines whether the first electric beam signal or the second electric beam signal is present at an arbitrary time. The touch panel according to claim 1. 5. A method for controlling a touch panel which is connected to a host computer and determines the position of an object close to the display surface; (a) around at least a part of an outer edge of the display area; A plurality of beam emitter-detectors consisting of an emitter operative to emit an energy beam and a pair of detectors positioned opposite the emitter across the display area and receiving the energy beam. (B) connecting a microprocessor separate from the host computer to the emitter-detector pair; (c) scanning the emitter-detector pair with the microprocessor. And a computer program that enables it to send an energy signal to the emitter. In the absence of,
Programming the microprocessor; (d) using the computer program to cause the microprocessor to modulate a portion of the energy signal at a predetermined frequency and simultaneously transmit the energy signal to the emitter. Causing the emitter to emit a modulated energy beam having the predetermined frequency to the detector; (e) a first detector signal responsive to receiving the modulated energy beam using the detector. Generating a second detector signal whenever the object interrupts the modulated energy beam; (f) using an interrupt sensing means connected to the detector, the microprocessor Sending a shutoff signal to (g) using the computer program Connecting to a host computer and proximate to a display surface, comprising: analyzing the blocking signal and generating an output signal in response to the blocking signal shape, the output signal indicating a position of an object in the display area. A method for controlling a touch panel indicating the position of an object.