Method of detecting a position indicated by an electronic pen in a display-integrated panel for multilevel image display

• US 6,091,030 A
• Filed: 11/13/1997
• Issued: 07/18/2000
• Est. Priority Date: 11/14/1996
• Status: Expired due to Fees

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Shibazaki, Shigeru, Tagawa, Takao, Taga, Shiro, Katagiri, Masayuki
• Primary Examiner(s): Hjerpe, Richard A.
• Assistant Examiner(s): Tran, Henry N.
• Application Number:
  US08/969,893
• Time in Patent Office: 978 Days
• Field of Search: 345/173, 345/174, 345/179, 345/63, 345/68, 345/55, 345/89, 345/104, 345/147, 178/18.01, 178/18.03, 178/18.07, 178/19.01, 178/19.03
• US Class Current: 178/18.01
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/04184 Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally
• CPC Class Codes: G06F 3/0441 using active external devices, e.g. active pens, for receiving changes in electrical potential transmitted by the digitiser, e.g. tablet driving signals
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes

Abstract

In a display-integrated panel having first and second electrodes crossing each other and being operable to display a gray scale image, a position indicated by an electronic pen is detected by a method including the step of displaying information on a display panel by repeating a step of displaying one frame. This step of displaying one frame includes the step of applying to the second electrodes second direction drive signals of predetermined waveforms in accordance with a predetermined order at timings shifted from each other, applying to the first electrodes first direction drive signals of waveforms corresponding to display intensities of pixels, respectively, thereby performing gray scale image display on each pixel, and simultaneously detecting the position of the electronic pen in the first direction based on a waveform of an induced voltage induced at the electronic pen by the second electrode located near the electronic pen; and the step of applying a voltage for position detection to the first electrodes in accordance with the predetermined second order, and detecting a position of the electronic pen in the second direction based on an induced voltage induced at the electronic pen by the voltage for the position detection.

Claims

1. A method of detecting a position of an electronic pen on a display-intergrated panel while displaying a gray scale image display on the display panel, the display panel having a plurality of first electrodes each extending in a first direction and aligned to each other in a second direction crossing the first direction, a plurality of second electrodes each extending in the second direction and aligned to each other in the first direction, and a plurality of pixels arranged correspondingly to crossings between the plurality of first electrodes and the plurality of second electrodes, the electronic pen for electrostatically coupling the plurality of first electrodes and the plurality of second electrodes for outputting an induced voltage, wherein said method comprises the steps of:

displaying information on the display panel by repeating the step of displaying one frame, said step of displaying said one frame including the steps of;

performing gray scale image display on each of the pixels by applying to the plurality of second electrodes second direction drive signals of predetermined waveforms for achieving gray scale image display in accordance with a predetermined first order at timings shifted from each other, respectively

applying to the first electrodes first direction drive signals of waveforms corresponding to the display intensities of the pixels, respectively, the first order being equal to the order of alignment of the second electrodes in the first direction, and

simultaneously detecting a position of the electronic pen in the first direction based on a waveform of an induced voltage induced at the electronic pen by the second electrode located near the electronic pen;

applying a voltage for position detection to the first electrodes in accordance with a predetermined second order, and detecting the position of the electronic pen in the second direction based on an induced voltage induced at the electronic pen by the voltage for said position detection;

wherein said step of detecting the position in the first direction includes the steps of;

performing the gray scale image display on the plurality of pixels by applying to the plurality of second electrodes the second direction drive signals of the predetermined waveforms for achieving the gray scale image display in accordance with the first electrodes the first direction drive signals of the waveforms corresponding to the display intensities of the pixels, respectively, and

detecting the position of the electronic pen in the first direction based on the timing of appearance of a predetermined feature of the waveform of the induced voltage output from the electronic pen;

wherein said one frame is divided into a plurality of sub-fields and a period for detecting the position in the second direction, and said plurality of sub-fields of the second direction drive signal include a scanning pulse and a preselected number of sustaining pulses following the scanning pulse and provided for each of said sub-fields for achieving the gray scale image display; and

wherein said step of detecting the position in the first direction further includes the steps of;

starting time counting from a point of time predetermined in each frame,

a first measuring step of measuring the time count at a point of time when the induced voltage issued from the electronic pen exceeds a predetermined threshold in the predetermined sub-field,

a second measuring step of measuring a point of time after said induced voltage falls below said threshold after exceeding said threshold and when said induced voltage exceeds said threshold in the following sub-field within the same frame, and

obtaining an average between the result of said first measuring step and the result of said second measuring step, and effecting a predetermined arithmetic operation to obtain the position in said first direction.

2. A method of detecting a position of an electronic pen on a display-intergrated panel while displaying a gray scale image display on the display panel, the display panel having a plurality of first electrodes each extending in a first direction and aligned to each other in a second direction crossing the first direction, a plurality of second electrodes each extending in the second direction and aligned to each other in the first direction, and a plurality of pixels arranged correspondingly to crossing between the plurality of first electrodes and the plurality of second electrodes, the electronic pen for electrostatically coupling the plurality of first electrodes and the plurality of second electrodes for outputting an induced voltage, wherein said method comprises the steps of:

displaying information on the display pane by repeating the step of displaying one frame, said step of displaying said one frame including the steps of;

displaying information on the display panel by repeating the step of displaying one frame, said step of displaying said one frame including the steps of;

performing gray scale image display on each of the pixels by applying to the plurality of second electrodes second direction drive signals of predetermined waveforms for achieving gray scale image display in accordance with a predetermined first order at timings shifted from each other, respectively,

applying to the first electrodes first direction drive signals of waveforms corresponding to the display intensities of the pixels, respectively, the first order being equal ot the order of alginment of the second electrodes in the first direction, and

simultaneously detecting a position of the electronic pen in the first direction based on a waveform of an induced of an induced voltage induced at the electronic pen by the second electronic located near the electronic pen;

applying a voltage for position detecting to the first electrodes in accordance with a predetermined second order, and detecting the position of the electronic pen in the second direction based on an induced voltage induced at the electronic pen by the voltage for said position detection;

wherein said step of detecting the position in the first direction includes the steps of;

performing the gray scale image display on the plurality of pixels by applying to the plurality of second electrodes the second direction drive signals of the predetermined waveforms for achieving the gray scale image display in accordance with the first order at timings shifted from each other, respectively, and applying to the first electrodes the first direction drive signals of the waveforms corresponding to the display intensities of the pixels, respectively, and

detecting the position of the electronic pen in the first direction based on the timing of appearance of a predetermined feature of the waveform of the induced voltage output from the electronic pen;

wherein said one frame is divided into a plurality of sub-fields and a period for detecting the position in the second direction, and said plurality of sub-fields of the second direction drive signal include a scanning pulse adn a preselected number of sustaining pulses following the scanning pulse and provided for each of said sub-fields for achieving the gray scale image display, the preselected number of the sustaining pulses for said sub-fields are different from each other; and

wherein said step of detecting the position in the first direction is performed within that one of said sub-fields in a field where the sustaining pulses are applied for the longest time in said field.

3. A method of detecting a position of an electronic pen on a display-intergrated panel while displaying a gray scale image display on the display panel, the display panel having a plurality of first electrodes each extending in a first direction and aligned to each other in a second direction crossing the first direction, a plurality of second electrodes each extending in the second direction and aligned to each other in the first direction, and a plurality of pixels arranged correspondingly to crossing between the plurality of first electrodes and the plurality of second electrodes, the electronic pen for electrostatically coupling the plurality of first electrodes and the plurality of second electrodes for outputting an induced voltage, wherein said method comprise the steps of:

displaying information on the display panel by repeating the step of displaying one frame, said said step of displaying said one frame including the steps of;

performing gray scale image display on each of the pixels by applying to the plurality of second electrodes second direction drive signals of predetermined waveforms for achieving gray scale image display in accordance with a predetermined first order at timings shifted from each other, respectively,

applying to the first electrodes first direction drive signal of waveforms correspondingly to the display intensities of the pixels, respectively, the first order being equal to the order of alignment of the second electrodes in the first direction, and

simultaneaously detecting a position of the electronic pen in the first direction based on a waveform of an induced voltage induced at the electronic pen by the second electrode located near the electronic pen;

applying a voltage for position detection to the first electrodes in accordance with a predetermined second order, and detecting the position of the electronic pen in the second direction based on an induced voltage induced at the electronic pen by the voltage for said position detection;

wherein said step of detecting the position in the first direction includes the steps of;

performing the gray scale image display on the plurality of pixels by applying to the plurality of second electodes the second direction drive signals of the predetermined waveforms for achieving the gray scale image display in accordance with the first order at timings shifted from each other, respectively, and applying to the first electrodes the first direction drive signals of the waveforms corresponding to the display intensities of the pixels, respectively, and

detecting the position of the electronic pen in the first direction based on the timing of appearance of a predetermined feature of the waveform of the induced voltage output from the electronic pen;

wherein said one frame is divided into a plurality of sub-fields and a period for detecting the position in the second direction, and said plurality of sub-fields of the second direction drive signal include a scanning pulse and a preselected number of sustaining pulses following the scanning pulse and provided for each of said sub-fields for achieving the gray scale image display; and

wherein said step of detecting the position in the first direction further includes the steps of;

starting time counting from a point of time predetermined in each frame,

a first measuring step of measuring the time count at a point of time when the induced voltage issued from the electronic pen exceeds a predetermined threshold in the predetermined sub-field,

a second measuring step of measuring a point of time after said induced voltage falls below said threshold after exceeding said threshold and when said induced voltage exceeds said threshold in the following sub-field within the same frame, and

obtaining an average between the result of said first measuring step and the result of said second measuring step, and effecting a predetermined arithmetic operation to obtain the position in the first direction; and

wherein a period for detecting the position in the second direction is located between the sub-field for performing said first measuring step and the sub-field for performing said second measuring step.

4. A method of detecting a position of an electronic pen on a display-intergrated panel while displaying a gray scale image display on the display panel, the display panel having a plurality of first electrodes each extending in a first direction and aligned to each other in a second direction crossing the first direction, a plurality of second electrodes each extending in the second direction and aligned to each other in the first direction, and a plurality of pixels arranged correspondingly to crossings between the plurality of first electrodes and the plurality of second electrodes, the electronic pen for electrostatically coupling the plurality of first electrodes and the plurality of second electrodes for outputting an induced voltage, wherein said method comprising the steps of:

displaying information on the display panel by repeating the step of displaying one frame, said step of displaying said one frame including the steps of;

performing gray scale image display on each of the pixels by applying to the plurality of second electrodes second direction drive signals of predetermined waveforms for achieving gray scale image display in accordance with a predetermined first order at timings shifted from each other, respectively,

applying to the first electrodes first direction drive signals of waveforms corresponding to the display intensities of the pixels, respectively, the first order being equal to the order of alignment of the second electrodes in the first direction, and

simultaneously detecting a position fo the electronic pen in the first direction based on a waveform of an induced voltage induced at the electronic pen by the second electrode located near the electronic pen;

applying a voltage for position detection to the first electrodes in accordance with a predetermined second order, and detecting the position of the electronic pen in the second direction based on an induced voltage induced at the electronic pen by the voltage for said position detection;

wherein said step of detecting the position in the first direction includes the steps of;

performing the gray scale image display on the plurality of pixels by applying to the plurality of second electrodes the second direction drive signals of the predetermined waveforms for achieving the gray scale image display in accordance with the first order at timings shifted from each other, respectively, and applying to the first electrodes the first direction drive signals of the waveforms correspondingly to the display intensities of the pixels, respectively, and

detecting the position of the electronic pen in the first direction based on the timing of appearance of a predetermined feature of the waveform of the induced voltage output from the electronic pen;

wherein said one frame is divided into a plurality of sub-fields and a period for detecting the position in the second direction, and said plurality of sub-fields of the second direction drive signal include a scanning pulse and a preselected number of sustaining pulses following the scanning pulse and provided for each of said sub-fields for achieving the gray scale image display;

wherein the second order is equal to the order of alignment of the first electrodes in the second direction; and

wherein said detection of the position in the first direction is performed within said sub-field nearest on the time basis to the period form performing said detection of the position in the second direction.

5. A method of detecting a position of an electronic pen on a display-intergrated panel while displaying a gray scale image display on the display panel, the display panel having a plurality of first electrodes each extending in a first direction and aligned to each other in a second direction crossing the first direction, a plurality of second electrodes each extending in the second direction and aligned to each other in the first direction, and a plurality of pixels arranged correspondingly to crossings between the plurality of first electrodes and the plurality of second of second electrodes, the electronic pen for electrostatically coupling the plurality of first electrodes and the plurality of second electrodes for outputting an induced voltage, wherein said method comprises the steps of:

displaying information on the display panel by repeating the step of displaying one frame, said step of displaying said one frame including the steps of;

performing gray scale image dispaly on each of the pixels by applying to the plurality of second electrodes second direction drive signals of predetermined waveforms for achieving gray scale image display in accordance with a predetermined first order at timings shifted from each other, respectively,

applying to the first electrodes first direction drive signals of waveforms corresponding to the display intensities of the pixels, respectively, the first order being equal to the order of alignment of the second electrodes in the first direction, and

simultaneously detecting a position of the electronic pen in the first direction based on a waveform of an induced voltage induced at the electronic pen by the second electrode located near the electronic pen;

applying a voltage for position detection to the first electrodes in accordance with a predetermined second order, and detecting the position of the electronic pen in the second direction based on an induced voltage induced at the electronic pen by the voltage for said position detection;

wherein said step of detecting the position in the first direction includes the steps of;

performing the gray scale image display on the plurality of pixels by applying to the plurality of second electrodes the second direction drive signals of the predetermined waveforms for achieving the gray scale image display in accordance with the first order at timings shifted from each other, respectively, and applying to the first electrodes the first direction drive signals of the waveforms corresponding to the display intensities of the pixels, respectively, and

detecting the position of the electronic pen in the first direction based on the timing of appearaned of a predetermined feature of the waveform of the induced voltage output from the electronic pen;

wherein said one frame is divided into a plurality of sub-fields and a period for detection the position in the second direction, and said plurality of sub-fields of the second direction drive signal include a scanning pulse and a preselected number of sustaining pulses following the scanning pulse and provide for each of said sub-fields for achieving the gray scale image display; and

wherein detection of the position of the electronic pen in the first direction is performed during one of a first, second and third sub-fields of said plurality of sub-fields and wherein detection of the position of the electronic pen in the second direction is performed prior to the first sub-field of said plurality of sub-fields.