JP3461361B2 - Display device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a capacitive flat matrix.
Display such as a screen display or plasma display
Related to the device. [0002] EL (electroluminescence) display
The device is a display device using a thin-film EL element as a display panel.
You. This thin film EL element is composed of a plurality of strips on a glass substrate.
Transparent electrodes are arranged in parallel with each other, and a dielectric material is
Stacked, and then an EL layer is further stacked thereon, and further
Is laminated with a dielectric material to form a three-layer structure, on which the transparent
A plurality of strip-shaped back electrodes extending in a direction orthogonal to the electrodes
They are arranged in parallel with each other. [0003] In an EL display device, a transparent electrode of a thin film EL element is used.
The pole is the data side electrode, and the back electrode of the thin film EL element
Are the scanning electrodes, and the data side electrode and the scanning side electrode
Each intersection becomes a picture element. [0006] The data side electrode has a pixel corresponding to display data.
A data voltage for performing a corresponding gray scale display is applied.
In addition, the scanning electrode has a scanning for sequentially specifying a row of picture elements.
A voltage is selectively applied. [0005] One of the conventional examples of such an EL display device is as follows.
And divide the display panel into two upper and lower display areas.
The result is known. In the case of this EL display device,
The data side electrode is in the upper half display area and lower half of the display panel.
Display area and the data display area
Pressure is applied. FIG. 5 is a schematic view of a conventional EL display device.
FIG. 2 is a block diagram showing a typical configuration. This EL display device
Is a display device using the thin-film EL element as the display panel 1.
The display panel 1 has an upper half display area (hereinafter referred to as “upper screen”).
Surface ". ) And the lower half of the display area (
Surface ". ). The upper screen includes data side electrodes UD1 to UDm.
Scanning side electrodes S1 to Sn, the lower screen is the data side
Electrodes LD1 to LDm and scanning-side electrodes S (n + 1) to S2n
It is composed of Two data-side switching circuits 11 and 12
1 corresponds to the upper screen and the lower screen, respectively.
Data side electrodes UD1 to UDm and LD1 to LDm
A modulation voltage V which is a data voltage corresponding to display data.
This is a circuit for applying MU and VML.
Individually connected to the electrodes UD1 to UDm and LD1 to LDm
Data side output port groups 12 and 22 and display data U
Data side output port groups 12, 22 according to D ', LD'
And logic circuits 13 and 23 for turning on / off. The scanning side switching circuit 2 includes a scanning side electrode.
S1 to S2n are write voltages which are scanning voltages in line sequence.
A circuit for applying pressure, and each scanning side electrode S1 to S
2n, a scanning-side output port group 3 connected to
The port group 3 is set in accordance with the line order of the scanning electrodes S1 to S2n.
And a logic circuit 4 for turning on / off. The scanning side
The electrodes S1 and S (n + 1) are output by one signal line on the scanning side.
Are connected to the input port group 3 and the other scan electrodes S2 to S
Similarly, two scans are performed for n, S (n + 2) to S2n.
The side electrodes are connected by one signal line. [0010] The drive circuit 5 is configured to output a constant reference voltage VD.
Circuit for generating a high voltage for driving the display panel,
A conversion circuit for supplying a modulation voltage to a modulation voltage control circuit 31 described later.
A write voltage is supplied to the grayscale drive circuit 6 and the scan-side output port group 3.
And a write drive circuit 7 for supplying the data. The modulation drive circuit 6 and the data-side switching circuit
Between the data output port groups 12 and 22 of the paths 11 and 21
, A modulation voltage control circuit 31 is interposed. Modulation voltage
The control circuit 31 controls the modulation power output from the modulation driving circuit 6.
The pressure is distributed to each data output port group 12 and 22 respectively.
To the upper screen data output port group 12
Modulation voltage VMU amplitude and lower screen data output port
The amplitude of the modulation voltage VML supplied to the group 22 can be individually varied
It is a circuit to adjust. The logic control circuit 8 operates according to the drive voltage VL.
Operate, upper screen display data UD, lower screen display data L
D, data transfer clock CK, horizontal synchronization signal HS, vertical
Based on an input signal such as a synchronization signal VS, the display panel 1
To generate the various timing signals required to drive the
Road. Basic display operation of the display device shown in FIG.
Are two fields, the first field and the second field.
The period over the field is one cycle, and the data side electrodes UD1 to UD1
For UDm, LD1 to LDm, emit or not emit light
The voltage VM is used as the modulation voltage corresponding to the display data to be determined.
give. Also, writing is performed on the scanning-side electrodes S1 to S2n.
Voltage -VW in the first field and
In two fields, apply voltage VW + VM line-sequentially
Done by FIG. 6 shows a display operation of the display device shown in FIG.
It is a timing chart for explaining. FIG. 6 (a)
FIG. 6B shows the upper screen logic circuit 13 and the lower screen.
Upper screen display data U respectively given to logic circuit 23
D ′ and lower screen display data LD ′. FIG. 6C shows an upper screen data side switch.
Circuit 11 outputs the data to the data-side electrodes UD1 to UDm.
The modulation voltage VMU corresponding to the display data UD 'to be displayed.
FIG. 6D shows the lower screen data side switching circuit 2.
1 to the data side electrodes LD1 to LDm
2 shows the pressure VML. FIG. 6E shows the first line and (n + 1) lines.
The scanning voltage output to the scanning electrodes S1 and S (n + 1) of the eye
And write voltages -VW and VW + VM. FIG. 6F shows the relationship between the first scanning side electrode S1 and the data.
Is applied to the portion of the picture element where the data-side electrode UD1 intersects
6 (g) shows the (n + 1) -th scanning side
Picture where electrode S (n + 1) intersects with data-side electrode LD1
It shows the effective voltage applied to the elemental part. The display device
The basic display operation of the first field A '
The period over two fields of two fields B 'is 1
Period. By this display operation, the data side electrode UD
1 to UDm, LD1 to LDm, and scanning electrodes S1 to S2
n, the write voltage −VW, VW
Superimposition effect of + VM and modulation voltage VM, or cancellation effect
Occurs. Thin-film EL device constituting display panel 1
Shows the applied voltage-luminance characteristics shown in FIG.
Superimposition effect of voltage −VW, VW + VM and modulation voltage VM
Due to the offset effect, the picture element emits light as effective voltage
Voltage VW + VM equal to or higher than threshold voltage Vth, or light emission threshold
A voltage VW equal to or lower than the value voltage Vth is applied, and each pixel emits light.
Alternatively, a non-light emitting state is obtained, and a predetermined display is obtained. [0018] The EL display device described above.
Consists of the display panel 1 divided into two upper and lower display areas.
Have been. The upper screen of the display panel 1 divided into upper and lower
When simultaneously driving the lower screen, the upper screen display data UD '
And the lower screen display data LD 'at the same time
To the data side switching circuits 11 and 21 corresponding to the screen
Data data according to each display data
The modulation voltage VM which is a voltage is applied to the data side electrodes UD1 to UD1.
m, LD1 to LD1 are generally applied to each of them.
Is being done. However, the input form of the display data is
CRT (cathode ray) generally used as a display device
The input form of display data for the tube) is the data transfer order
Is completely different, so the input form of the display data for CRT
When using it, change it including dedicated frame memory.
A replacement circuit must be provided, which increases product manufacturing costs
Is caused. An object of the present invention is to transform a frame memory or the like.
Input form of display data without providing a new conversion circuit
Display device that can display images using
Is to provide an installation. According to the present invention, a plurality of scanning devices are provided.
The electrode and the plurality of data side electrodes interpose a thin film EL element.
Are arranged in a direction intersecting with each other
Display area with picture elements at each intersection of
Connected to the lower two display panels and the scanning side electrodes
And a write voltage for designating a row of picture elements in a line-sequential manner.
The same timing is applied to the scanning electrodes in the upper and lower display areas.
Scanning-side driving means for outputting the data in the
Connected to the data-side electrode and modulates the modulation voltage corresponding to the display signal.
The modulation voltage is applied to each data side to apply to each column of picture elements.
An upper area data side driving means for outputting to the electrode,
The display signal is connected to the data side electrode of the lower display area.
In order to apply a modulation voltage corresponding to
For lower area that outputs modulation voltage to each data side electrode
Data side driving means, and the upper side data side driving means
And the lower area data side drive means
Data control means for outputting a display signal by
First field to which a display signal for the upper display area is given
Then, the data control means drives the data side for the upper area.
Means for supplying a display signal to the lower area data side driving means.
A constant voltage signal, and the scanning side driving means
Scan-side electrode in the display area and scan-side electrode in the lower display area
And the write voltage -VW is line-sequential at the same timing.
And the upper area data side driving means outputs a display signal.
When the picture element emits light according to the signal, the modulation voltage VM is
When not emitting light, apply modulation voltage 0 to the data side electrode
And the lower area data side driving means comprises:
Timing of applying the modulation voltage by the
At the same timing, the modulation voltage 1 /
Apply 2VM to the data side electrode and display for lower display area
In a second field to which a signal is applied, the data control
Means for supplying a constant voltage signal to the upper area data side driving means.
And a display signal to the lower area data side driving means.
The scanning-side driving means includes a scanning-side electrode in an upper display area.
And writing voltage VW + V to the scanning side electrode in the lower display area.
M are applied line-sequentially at the same timing.
The data driving means for the partial area changes in accordance with the constant voltage signal.
An adjustment voltage of 1/2 VM is applied to the data side electrode, and
The area data side driving means is configured to drive the upper area data side.
Same timing as the modulation voltage application timing by means
When the picture element emits light according to the display signal,
When the voltage 0 is not emitted, the modulation voltage VM is applied to the data side when not emitting light.
A display device characterized by applying a voltage to a pole. When the display panel is realized by a thin film EL element,
The picture element that has been selectively illuminated again emits light again due to the polarization effect.
The picture element that has emitted light maintains the non-emission state. By this
As a result, more clear display luminance can be realized.
Generally, a double-insulation AC-driven thin-film EL device having a three-layer structure
Select light emission once by writing voltage of about 200V
Picture element is held with the internal polarization formed in the light emitting layer
However, non-luminescent picture elements have no polarization,
When a write voltage of about voltage is applied,
Due to the tatami mat effect, the previously selected picture element emits light again,
The non-light emitting picture element maintains the non-light emitting state. like this
Such a characteristic is called a polarization effect. In the present invention, this polarization effect
I use. According to the present invention, disposed above and below the display panel
Scanning-side electrodes constituting the two display areas are arranged on the scanning side.
Write electric power at the same timing line-sequentially by the driving means
Pressure is applied and specified. That is, in the upper display area
The first line and the first line in the lower display area are specified at the same time.
The same applies to the second and subsequent rows. Scanning driver
The column is a first filter to which a display signal for the upper display area is given.
Field, the scanning electrode in the upper display area and the lower display
The write voltage -VW is applied to the scanning electrodes of the
Display signal for lower display area
In the second field given by
The write voltage VW is applied to the side electrode and the scanning side electrode in the lower display area.
+ VM are applied line-sequentially at the same timing.
You. For the pixel row of the designated scanning electrode,
Area data side driving means and lower area data side driving means
The stage applies a modulation voltage corresponding to the display signal.
You. The display signal is output at the same timing by the data control means.
To the two data-side driving means. This and
When the data control means is displayed on one data side driving means
When outputting a signal, a constant
Output pressure signal. That is, the display signal for the upper display area
In the first field where the signal is given,
The data driving means causes the picture element to emit light in accordance with the display signal.
The modulation voltage VM when the light is emitted, and the modulation voltage when the light is not emitted.
0 is applied to the data side electrode, and the lower side data side drive is applied.
The driving means is a modulation by the upper area data side driving means.
At the same timing as the voltage application timing, the constant voltage
In accordance with the signal, a modulation voltage of 1/2 VM is applied to the data side electrode.
Add. Also, a display signal for the lower display area is given.
In the second field, the data driver for the upper area
Is a modulation voltage 1/2 which is a constant voltage according to a constant voltage signal.
VM is applied to the data side electrode, and the lower side data side
The driving means is a conversion by the upper area data side driving means.
At the same timing as the application timing of the adjustment voltage, the display signal
When the picture element is caused to emit light according to
When light is not emitted, the modulation voltage VM is applied to the data side electrode.
Add. In other words, the display signal to be displayed in the upper display area is
When given, the lower area data side drive means
Is supplied with a constant voltage signal and should be displayed in the lower display area.
When the display signal is given, the upper area data
A constant voltage signal is supplied to the side driving means. Therefore,
Input format of serial data such as display signal for CRT
Can be displayed as it is without converting
it can. A display signal for an upper display area is given.
In one field, the picture elements in the upper area of the display panel include:
A voltage is applied according to the display signal. That is, the scanning side
When the write voltage -VW is applied to the electrode,
VM or 0 is applied to electrode as modulation voltage
At the intersection of the scanning electrode and the data electrode.
Pixel has a voltage equal to or higher than the light emission threshold voltage of the pixel − (VW +
VM) or a voltage VW equal to or lower than the light emission threshold voltage is applied.
You. As a result, the picture elements in the upper area of the display panel are displayed.
Light emission / non-light emission is selected according to the indication signal. Meanwhile, the lower part
In the second field where the display signal for the display area is given
The picture elements in the upper area of the display panel follow a constant voltage signal.
Voltage is applied. That is, the writing voltage is
When the voltage VW + VM is applied, the data side electrode
By applying 1/2 VM as a modulation voltage,
For the picture element at the intersection of the scanning electrode and the data electrode
Is applied with a voltage (VW + ／ VM). This voltage
(VW + ／ VM) is equal to or higher than the light emission threshold voltage of the picture element.
However, the polarity is opposite to the voltage applied to the pixel in the first field.
Sex. Therefore, the first field due to the polarization effect
The non-light emitting picture elements do not emit light, and the light emitting picture elements emit light again
I do. The picture elements in the lower area of the display panel are also
A voltage is applied in the same manner as the picture elements in the area. That is, below
In the second field where the display signal for the partial display area is given
The picture elements in the lower area of the display panel follow the display signal.
Voltage is applied. That is, the writing voltage is applied to the scanning side electrode.
When VW + VM is applied, data is not applied to the data side electrode.
0 or VM is applied as the
And the pixel at the intersection of the scanning electrode and the data electrode
Has a voltage equal to or higher than the light emission threshold voltage of the picture element− (VW + VM)
Alternatively, a voltage VW equal to or lower than the light emission threshold voltage is applied. this
The picture elements in the lower area of the display panel
Therefore, light emission / non-light emission is selected. Meanwhile, the upper display area
In the first field where the display signal for the
A voltage is applied to the picture element in the lower area of the panel according to the constant voltage signal.
Applied. That is, the writing voltage −VW is applied to the scanning electrode.
When applied, the data side electrode
When 1/2 VM is applied, the scanning side electrode and the
The voltage (VW +
1/2 VM) is applied. This voltage (VW + ／ V)
M) is higher than the light emission threshold voltage of the picture element,
The polarity is opposite to the voltage applied to the pixel in the field. But
Therefore, the non-luminous picture element in the second field due to the polarization effect
Does not emit light, and the emitted picture element emits light again. FIG. 1 shows a display device according to an embodiment of the present invention.
It is a block diagram which shows a schematic structure. This display device
Is an EL display device using the thin-film EL element as the display panel 41
The display panel 41 has a display area in the upper half (hereinafter, referred to as a display area).
Called “upper screen”. ) And the lower half of the display area (hereinafter,
Called "lower screen." ). Display panel 41
Then, the transparent electrode of the thin film EL element is changed to the data side electrode UD1 to UD1.
UDm, LD1 to LDm, and the back of the thin film EL element.
The surface electrodes are scanning electrodes S1 to Sn and S (n + 1) to S2n.
Have been. The upper screen shows the data side electrodes UD1 to UDm.
Scanning side electrodes S1 to Sn, the lower screen is the data side
Electrodes LD1 to LDn and scanning-side electrodes S (n + 1) to S2n
It is composed of Two data-side switching circuits 51 and 6
1 corresponds to the upper screen and the lower screen, respectively.
Are individually displayed on the data side electrodes UD1 to UDm and LD1 to LDm.
Modulation which is a data voltage corresponding to data DAU, DAD
A circuit for applying a voltage, the data side electrode UD1
To UDm and data to which LD1 to LDm are connected respectively
Side output port groups 52 and 62 and given display data D
Data-side output port groups 52 and 62 according to AU and DAD
And logic circuits 53 and 63 for turning on / off. The scanning side switching circuit 42 is connected to each scanning side.
The scanning voltage is applied to the electrodes S1 to S2n according to the line sequence.
A circuit for applying the write voltages VW + VM, -VW
Yes, scan-side output to which scan-side electrodes S1 to S2n are connected
The port group 43 and the scanning output port group 43 are connected to the scanning electrode
Theory of turning on / off according to the line sequence of S1 to S2n
And a logic circuit 44. The two scanning electrodes S1,
S (n + 1) is a scanning line output port with one signal line.
Group 43, and the other scanning-side electrodes S2 to Sn,
Similarly, for S (n + 2) to S2n, a set of two
Each is connected by one signal line. The drive circuit 45 operates from a fixed reference voltage VD.
This is a circuit for generating a high voltage for driving the display panel.
The modulation voltage VM is applied to the data side output port groups 52 and 62.
(Specifically, modulation for supplying voltage VMU, VML)
Write voltage is applied to the drive circuit 46 and the scan-side output port group 43.
Write drive circuit 47 for supplying VW + VM, -VW
And The modulation drive circuit 46 and the upper screen data output port
A modulation voltage control circuit 71 is interposed between the
The modulation drive circuit 46 and the lower screen data output port
A modulation voltage control circuit 72 is interposed between the
ing. These modulation voltage control circuits 71 and 72 are
Modulation voltage VMU supplied to plane data output port group 52
And the voltage supplied to the lower screen data output port group 62.
And the amplitude voltage of the modulation voltage VML to be individually adjusted.
Circuit for The logic control circuit 48 operates at the drive voltage VL.
Display data DA, data transfer clock CK, horizontal
Based on input signals such as the synchronization signal HS and the vertical synchronization signal VS.
And various timing signals necessary for driving the display panel 41.
This is a circuit for generating. Logic control circuit 48 and upper drawing
An upper screen data control circuit 82 is provided between the
, And the logic control circuit 48 and the lower screen logic
A lower screen data control circuit 81 is interposed between the
Have been. The lower screen data control circuit 81 and the upper screen data
The data control circuit 82 is provided from the logic control circuit 48.
Operate based on display data DA and control signal
Output the screen data at the timing. Upper screen data control
The circuit 82 stores data to be displayed on the upper screen of the display panel 41.
Data is given, the display data DA is
Should be output as upper screen data DAU and displayed on lower screen
If data is given, specific data
As the upper screen data DAU. Also, the lower screen data control circuit 81 displays
The data to be displayed on the upper screen of panel 41 is given.
When the predetermined data is set in the lower screen data D
Output as AD and given the data to be displayed on the lower screen
Display data DA, lower screen data DAD
Output as Basic display operation of the display device shown in FIG.
Are two fields, the first field and the second field.
The period over the field is one cycle, and the data side electrodes UD1 to UD1
UDm, determines whether to emit light or not for LD1 to LDm
The modulation voltage VM is applied to the scanning electrodes S1 to S2n.
Therefore, in the first field, the write voltage is −V
W, and in the second field, the voltage VW + VM
It is done by giving to. FIGS. 2 and 3 show the display device shown in FIG.
5 is a timing chart for explaining a display operation.
FIG. 2A shows display data input to the logic control circuit 48.
6 shows the data DA. In the first field A, the logic control circuit 48
Is input with the upper screen display data, and in the second field B
Indicates that the lower screen display data is input to the logic control circuit 48.
You. FIG. 2B is a diagram showing a lower part of the logic control circuit 48.
Surface data control circuit 81, upper screen data control circuit 82,
And modulation voltage control circuits 71 and 72, respectively.
Control signal. The upper screen display data is stored in the logic control circuit 48.
In the first field A to be input,
Is supplied with a control signal indicating the effective period of the upper screen display data.
It is. The lower screen display data is input to the logic control circuit 48.
In the second field B, each circuit described above includes a lower screen
A control signal indicating a display data valid period is provided. FIG. 2C shows the upper screen data control circuit 82.
Screen data DA given to upper screen logic circuit 53 from
U, and FIG.
The lower screen data DAD given to the lower screen logic circuit 63 is
Show. FIG. 2E shows a state in which the modulation voltage control circuit 71
Modulation voltage VM applied to screen data output port group 52
U, and FIG.
Modulation voltage VM applied to screen data output port group 62
L. A control signal indicating the upper screen data valid period is:
Upper screen data control circuit 82 and lower screen data control circuit
81, the upper screen data control circuit 8
2 is the display data DA given from the logic control circuit 48
As the upper screen data DAU, the upper screen logic circuit 5
Give to 3. The lower screen data control circuit 81 displays the display data
All output of lower screen data output port group 62 regardless of DA
Lower data DAD
To the lower screen logic circuit 63. A control signal indicating the effective period of the upper screen data
Are applied to modulation voltage control circuits 71 and 72, respectively.
And the modulation voltage control circuit 71 is an upper screen data output port group.
52, the voltage VM is given as the modulation voltage VMU. Also strange
The voltage adjustment control circuit 72 includes a lower screen data output port group 62.
Is given a voltage 1/2 VM as a modulation voltage VML. A control signal indicating the lower screen data valid period is:
Upper screen data control circuit 82 and lower screen data control circuit
81, the lower screen data control circuit 8
1 is the display data DA given from the logic control circuit 48.
The lower screen logic circuit 63 is directly used as the lower screen data DAD.
Give to. The upper screen data control circuit 82 displays the display data D
All outputs of upper screen data output port group 52 regardless of A
Is the high screen data DAU.
To the upper screen logic circuit 53. A control signal indicating a lower screen data valid period.
Is applied to the modulation voltage control circuits 71 and 72,
The voltage control circuit 71 supplies a signal to the upper screen data output port group 52.
A voltage of 1/2 VM is given as a modulation voltage VMU. Also modulation
The voltage control circuit 72 is connected to the lower screen data output port group 62.
The voltage VM is given as a modulation voltage VML. FIG. 2 (g) shows an upper screen data switch.
Output to the data side electrodes UD1 to UDm from the
The upper screen data output port waveform by the modulation voltage VM
FIG. 2H shows the data switching circuit 6 for the lower screen.
1 to the data side electrodes LD1 to LDm
5 shows a lower screen data output port waveform by a pressure VM. As described above, the upper screen data valid period is
In the first field A, the upper screen logic circuit 53
The display data DA from the screen data control circuit 82 remains unchanged
Upper screen logic circuit 5 provided as upper screen data DAU
3 is an upper screen data output port according to the upper screen data DAU.
The port group 52 is turned on / off. Also, the upper screen data output port
The voltage group VM receives a voltage VM from the modulation voltage control circuit 71.
It is provided as a modulation voltage VMU. Therefore, FIG.
As shown in (g), the data side electrodes UD1 to UDm include:
The modulation voltage VM is applied corresponding to the display data DA. The lower screen logic circuit 63 stores lower screen data.
From the data control port 81 to the lower screen data output port group 62.
Data for which all outputs are high level is lower screen data DA
D is given. This makes the first field
In A, the lower screen data output port group 62 is always on.
State. The lower screen data output port group 62 includes:
The modulation voltage control circuit 72 outputs the voltage 1/2 VM as the modulation voltage V
ML, and is therefore shown in FIG.
As shown in FIG.
Modulation voltage clamped to a constant voltage, regardless of DA
1/2 VM is applied. Second field, which is the lower screen data validity period
In B, the upper screen logic circuit 53 includes upper screen data control.
All outputs of the upper screen data output port group 52 from the circuit 82
The data that is all high level is the upper screen data DAU.
Has been given. As a result, the second field B
And the upper screen data output port group 52 is always on.
You. The upper screen data output port group 52 has a modulation voltage
The control circuit 71 determines that the voltage 1/2 VM is the modulation voltage VMU.
Therefore, as shown in FIG. 2 (g)
The data electrodes UD1 to UDm are connected to the display data DA.
Modulation voltage 1 / 2VM clamped to a constant voltage regardless
Is applied. The lower screen logic circuit 63 stores lower screen data.
Display data DA from the data control circuit 81
Data DAD, and the lower screen logic circuit 63
Lower screen data output port group 6 according to screen data DAD
Turn 2 on / off. To lower screen data output port group 62
Is the voltage VM from the modulation voltage control circuit 72.
L. Therefore, as shown in FIG.
The display electrodes DA1 to LDm are connected to the display data DA.
Are applied to the modulation voltage VM. Next, a description will be given with reference to FIG. FIG.
FIG. 2A shows the same display data DA as in FIG.
3 (b) shows the same control signal as in FIG. 2 (b). FIG.
(C) is the same upper screen data output port wave as in FIG.
Fig. 3 (d) shows the same lower screen data as Fig. 2 (h).
3 shows an output port waveform. As described with reference to FIG. 2, the upper screen display data is valid.
The control signal indicating the period is the lower screen data control circuit 81 and
The first field provided to the upper screen data control circuit 82
In the field A, the data side electrode UD1 constituting the upper screen
To UDm are display data provided to the upper screen logic circuit 53.
The modulation voltage VM is applied according to the data. Also, the lower screen
The data side electrodes LD1 to LDm constituting
A modulation voltage 1/2 VM clamped to the pressure is applied. Control signal indicating valid period of lower screen display data
Are the lower screen data control circuit 81 and the upper screen data control.
In the second field B provided to the circuit 82
Indicates that a specific voltage is applied to the upper screen data side electrodes UD1 to UDm.
A modulation voltage 1/2 VM clamped to the pressure is applied.
The lower screen data side electrodes LD1 to LDm have a lower screen theory.
The modulation voltage V according to the display data given to the logical circuit 63
M is applied. FIG. 3E shows the first and (n + 1) th lines.
Scan applied to scan electrodes S1 and S (n + 1), respectively
Write voltages -VW and VW + VM are shown. FIG.
(F) shows the first scan electrode S1 and the data side electrode UD1.
Indicates the effective voltage applied to the portion of the picture element where
FIG. 3G shows the (n + 1) -th scan electrode S (n + 1).
It is applied to the picture element where the data side electrode LD1 intersects.
The effective voltage. By this display operation, the data side electrode UD
1 to UDm and the picture elements where the scanning side electrodes S1 to Sn intersect.
In the first field A, the write voltage −
A superimposition effect of VW and modulation voltage VM or an offset effect is produced.
I will. The thin-film EL elements constituting the display panel 41 include:
Since the applied voltage-luminance characteristics shown in FIG.
−VW and the modulation voltage VM due to the superimposition effect and the cancellation effect.
Therefore, each pixel has an emission threshold voltage Vt as an effective voltage.
h or more-(VW + VM) or light emission threshold voltage
A voltage VW equal to or lower than Vth is applied, and each pixel emits light or
No light is emitted, and a predetermined display is obtained. In the second field B, each of the picture elements
Is the overlap between the write voltage VW + VM and the modulation voltage 1/2 VM.
Applied in the first field A due to the tatami effect
An effective voltage (VW + 1/2) having a polarity opposite to the effective voltage
VM) is applied. At this time, the polarization effect described above
In the first field A, non-light emitting picture elements emit light.
The emitted picture element emits light again. Data side electrodes LD1 to LDm and scanning side electrodes
The same applies to the parts of each picture element where S (n + 1) to S2n intersect
In the second field B, the write voltage VW + VM
And the modulation voltage VM have a superimposing effect and a canceling effect.
Therefore, the write voltage VW + VM overlaps with the modulation voltage VM.
Due to the tatami effect and the offset effect, each pixel has an effective
As the voltage (VW + V
M) or a voltage VW equal to or lower than the light emission threshold voltage Vth is applied
Each picture element is in a light emitting or non-light emitting state,
The display is obtained. Immediately after the above-mentioned second field B,
In the first field A repeated, each of the picture elements
Is the superposition effect of the write voltage -VW and the modulation voltage 1 / 2VM.
As a result, the actual applied in the second field B is
Effective voltage having a polarity opposite to the effective voltage− (VW + ／)
VM) is applied. At this time, the polarization effect described above
In the second field B, non-light-emitting picture elements emit light.
The emitted picture element emits light again. Therefore, for each picture element, the first
Field A and second field B alternately have opposite polarities.
An effective voltage is applied, and the first field A and the second field
In this case, the alternating voltage driving of the thin-film EL element is
Done. Therefore, given from logic control circuit 48,
Of the display data DA in the first field A
The display data is given to the upper screen logic circuit 53, and the second field
In the mode B, the lower screen display data is given to the lower screen logic circuit 63.
Just do it. This makes it possible to convert the frame memory
Input of display data for CRT without newly providing
Using the two-screen split type table
The display device can be driven. In the display operation, the clamped variable
Modulation voltage of 1/2 VM is used as the adjustment voltage
However, the voltage is not necessarily limited to this potential.
No. To the required level such as the contrast of the display panel 41
Depending on which potential between ground potential GND and VM
Can also be used. As described above, according to the present invention, the frame
Generally displayed without any conversion circuit such as memory
Input form of display data for CRT used in the device
It is possible to drive a split screen display device
Wear. As a result, inexpensive and high-quality display devices are brought to the market.
Can be paid.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a schematic configuration of a display device according to one embodiment of the present invention. FIG. 2 is a timing chart showing a display operation of the display device shown in FIG. FIG. 3 is a timing chart showing a display operation of the display device shown in FIG. 1; FIG. 4 is a graph showing applied electrode-luminance characteristics of a thin film EL element included in the display panel 41 of the display device shown in FIG. FIG. 5 is a block diagram illustrating a schematic configuration of a conventional display device. 6 is a timing chart showing a display operation of the display device shown in FIG. 7 is a graph showing an applied voltage-luminance characteristic of a thin film EL element constituting a display panel of the display device shown in FIG. DESCRIPTION OF SYMBOLS 41 Display panel 42 Scanning side switching circuit 45 Drive circuit 46 Modulation drive circuit 47 Write drive circuit 48 Logic control circuit 51, 61 Data side switching circuit 52 Upper screen data output port group 62 Lower screen data output port group 71, 72 Modulation voltage control circuit 81 Lower screen data control circuit 82 Upper screen data control circuit

Claims (1)

(1) A plurality of scanning electrodes and a plurality of data electrodes are arranged in a direction intersecting each other with a thin-film EL element interposed therebetween. And a display panel in which two display areas having picture elements are arranged vertically at each intersection with the scanning electrodes, and a write voltage for specifying a row of picture elements in a line-sequential manner. Scanning-side driving means for outputting to the scanning-side electrodes of the display area at the same timing, connected to the data-side electrodes of the upper display area, and applying a modulation voltage corresponding to a display signal to each column of picture elements; An upper area data-side driving unit that outputs the modulation voltage to each data-side electrode; and a data-side electrode in the lower display area that is connected to the data-side electrode to apply a modulation voltage corresponding to a display signal to each column of picture elements. The modulation voltage is A lower-region data-side driving unit that outputs to the electrode, and a data control unit that outputs a display signal at the same timing to the upper-region data-side driving unit and the lower-region data-side driving unit, In a first field to which a display signal for an upper display area is provided, the data control means provides a display signal to the data drive means for the upper area, and a constant voltage signal to the data drive means for the lower area, The scanning-side driving unit applies a write voltage -VW to the scanning-side electrode of the upper display region and the scanning-side electrode of the lower display region in line sequence at the same timing, respectively, and the upper-region data-side driving unit includes: The modulation voltage VM is applied to the data-side electrode according to the display signal when the picture element is caused to emit light, and the modulation voltage 0 is applied to the data-side electrode when the picture element is not caused to emit light. The same timing as the application timing of the modulation voltage by the upper region data side drive means, in response to the constant voltage signal, the modulation voltage 1 / 2V
M is applied to the data side electrode, and in the second field where the display signal for the lower display area is given, the data control means applies a constant voltage signal to the upper area data side drive means, The drive means supplies a display signal, and the scan-side drive means applies a write voltage VW + VM line-sequentially to the scan-side electrode in the upper display area and the scan-side electrode in the lower display area at the same timing, respectively. The area data-side drive means applies a modulation voltage of 1/2 VM to the data-side electrode in response to the constant voltage signal, and the lower area data-side drive means adjusts the modulation voltage by the upper area data-side drive means. At the same timing as the application timing, a modulation voltage 0 is applied to the data side electrode according to the display signal when the picture element is caused to emit light, and a modulation voltage VM is applied to the data side electrode when the picture element is not caused to emit light. The display device according to symptoms.