JPH1091125A - Driving method for display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce power consumption by varying limit resolution in accordance with a displayed picture. SOLUTION: Low pass filters(LPF) 2a-2d have frequency characteristics respectively as shown in a figure. A switch 3 switches connection to a display screen 1 of the LPFs 2a-2d conforming to instruction from a selecting circuit 4. A scanning frequency variable circuit 5 changes a scanning frequency of the display screen 1 conforming to instruction from the selecting circuit 4. A desired LPF is selected by the switch 3, and sent to the display screen. Plural pixels are arranged in a matrix state, and plural block pictures constituted with plural pixels and frame pictures constituted with plural block pictures are temporarily continuously displayed. Then, limit resolution of one frame or one block of a picture which can be displayed on a display device is different. Also, the number of blocks which can be rewritten simultaneously is different depending on a frame. Therefore, limit resolution can be varied in accordance with a displayed picture.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for driving a display device.

[0002]

2. Description of the Related Art In recent years, the power consumption of a liquid crystal display device has been reduced by reducing the driving voltage and the driving frequency. As a method for further reducing the power consumption, a device having a memory for each pixel has been proposed. (Eg, Japanese Patent Application Laid-Open No. 58-1)
96582, JP-A-3-77922).

[0003] In the case where the memory is provided for each pixel as described above, for a still image, once a display signal is transferred to each pixel, the held signal may be constantly displayed. If done, the power consumption is theoretically only that consumed for polarity reversal. However, as multimedia becomes more advanced and displays moving images, power consumption increases significantly.

Here, what factors determine the power consumption of the liquid crystal panel will be examined. A scanning line (gate line) and a signal line in the liquid crystal panel have a capacitance C, and power of CfV ² is consumed to drive the capacitance C. Therefore, in order to reduce power consumption, it is necessary to reduce the capacitance C, the frequency f, and the voltage V. In the case of a still image, the frequency f can be set to zero, but in the case of a moving image, the frequency f needs to be increased, and power consumption increases.

On the other hand, in order to prevent flicker from occurring when a refresh operation is performed, it is necessary to increase the frequency, but this increases power consumption. Therefore, a multi-field driving method (for example, Japanese Unexamined Patent Publication No.
271795) has been proposed, but when displaying a moving image or a scroll image (hereinafter referred to as a quasi-moving image),
Due to the interlace driving, a jagged feeling like an image lag occurs.

[0006]

As described above, in a liquid crystal panel having a memory for each pixel, it is possible to reduce power consumption for a still image, but it is possible to reduce the driving frequency for a moving image and a quasi-moving image. And the conventional liquid crystal display device has a problem that power consumption increases. An object of the present invention is to provide a display device capable of reducing power consumption even when a moving image or a quasi-moving image is displayed.

[0007]

According to a first aspect of the present invention, a plurality of pixels are arranged in a matrix, and a plurality of block images composed of the plurality of pixels and a frame image composed of the plurality of block images are arranged. In a method for driving a display device that is displayed continuously in time, a limit resolution of one frame or one block image of an image that can be displayed on the display device is different.

Further, in the above driving method, the number of blocks to be simultaneously rewritten differs depending on the frame. According to the above driving method, the limit resolution can be changed according to the image to be displayed, and the power consumption can be reduced. For example, if the display is performed so that the limit resolution gradually increases, display information can be quickly checked on a low-resolution screen, while high-definition display can be carefully viewed on a high-resolution screen.

According to a second aspect of the present invention, an image is displayed by A (A is a positive integer) pixels or scanning lines, and one frame image is divided into n subfields sequentially displayed along a time axis. , The subfield is defined by A ÷ n × m (n is a positive integer of 3 or more and A or less, m is a positive integer of n or less) A × n × m pixels or scanning lines in the A pixels or scanning lines. In the driving method of the display device thus configured, after selecting a first scanning line provided with a pixel displaying an image according to an image signal, a second scanning line provided with a pixel displaying an image according to an image signal is next selected Until you select the first
And for a pixel connected to a third scanning line disposed between the first and second scanning lines, there is a correlation between respective image signals to the pixels connected to the first and second scanning lines, respectively. A signal is supplied from a signal line.

For example, each image signal to a pixel connected to each of the first and second scanning lines is stored in a line memory having a storage area for two lines, and based on this, the correlation is obtained. The signal can be configured. In this case, if only the upper bits of the image signal are referred to, the number of memories can be reduced.

When the multi-field driving method is used for displaying a moving image or a still image, jaggies may occur because there is no correlation between pixels to be written and pixels not to be written. For example, since the display is performed by correlating the lines, the image quality can be improved. In addition, although the scanning line driver circuit operates, transmission from the information device main body or the like can be reduced, so that total power consumption can be reduced. Further, an optimal image can be displayed by using or not using the driving method according to a display image.

According to another aspect of the present invention, an image is displayed by A (A is a positive integer) pixels or scanning lines, and one frame image is divided into n subfields sequentially displayed along a time axis. The subfield is defined as A ÷ n × m (n is a positive integer of 3 or more and A or less, m is a positive integer of n or less) of the A pixels or scanning lines. And a switching element (control means for controlling the supply of the image signal supplied to the pixel) is provided between the signal line for supplying the image signal to the pixel and the signal line driver. By controlling the supply of the signal to each pixel by the switching element, after selecting the first scanning line provided with the pixel for displaying the image according to the image signal, the pixel for displaying the image according to the image signal is selected. Equipped Until the selected second scanning line is selected, the first and second pixels are connected to the pixel connected to the third scanning line disposed between the first and second scanning lines. It is characterized in that a signal of a voltage intermediate between the respective image signals to the pixels connected to the scanning lines is supplied from the signal lines.

In the method of controlling the switching elements, all the switching elements may be controlled, the control may be performed in units of blocks, and the control may be performed in units of signal lines.

According to the above-described driving method, the same effect as that obtained by the second aspect of the invention can be obtained, for example, jaggedness can be reduced. In addition to the above driving methods, the following driving methods are also conceivable. This means that an image is displayed by A (A is a positive integer) pixels or scanning lines, pixels of the same scanning line are driven with the same polarity, and the same is applied to continuous scanning lines. In a method for driving a display device driven by polarity, B (B is A
For the pixels or scanning lines of the following (positive integers), the same display image is displayed continuously by changing the driving frequency within the same frame, and the driving method of inverting the polarity of writing (hereinafter referred to as sub This is referred to as a field inversion driving method), whereby driving can be performed in which surface flicker is not visually recognized.

In the above-mentioned driving method, when images are displayed continuously by changing the driving frequency within the same frame, a part of the displayed image can be changed and displayed. For an image such as a still image in which the image signal does not change between the previous frame and the next frame, a multi-field driving method which is a driving method for reducing power consumption is used. Method can be used. Furthermore, when a moving image and a still image are displayed on the same scanning line, surface flicker may occur in the still image depending on the driving frequency when the subfield inversion driving method is used. The image quality can be improved by making the region invisible in characteristics.

According to the above-mentioned driving method, a display image having a large number of rewrites, such as a moving image, is not subjected to interlace processing, but is subjected to field inversion driving by changing the driving frequency. In addition to reducing the power consumption in the unit, it is possible to display an optimal image quality. When a moving image and a still image are simultaneously displayed by window display or the like, and the moving image and the still image do not exist on the same scanning line, the multi-field driving method is used in the still image portion, and the subfield inversion driving method is used in the moving image portion. By using, power consumption can be reduced in each part. When a moving image and a still image are present on the same scanning line, the driving frequency at which flicker does not occur in the still image (normally 40 Hz
Above), power consumption can be reduced and image quality can be improved.

[0017]

Embodiments of the present invention will be described below. FIG. 1 is an explanatory diagram showing a first embodiment of the present invention, and shows a scanning procedure on a display screen (for example, a TFT-LCD or the like, the same applies to the following embodiments).

For example, when displaying a moving image, FIG.
As shown in (a), six scanning lines are simultaneously scanned. When a moving image is always displayed, only a resolution of 1/6 can be obtained. However, in the case of a moving image, the sensitivity of the visual characteristics is low, so that the image quality deterioration due to the decrease in the resolution is not so noticeable. In the case of a still image, as shown in FIG. 1B, an interlaced image is displayed, and the number of scanning lines scanned simultaneously is reduced to three lines. Thereafter, the number of scanning lines scanned simultaneously is gradually reduced to two lines and one line, in other words, the limit resolution is gradually increased. In the example shown in FIG. 1, a screen of one frame is constituted by six fields, and an extremely high-definition image can be finally displayed.

When such a display is performed, in the case of a still image, the resolution is not degraded by displaying an interlaced image over a plurality of fields as in the case of MF driving. With a display image having a resolution of 6, it is possible to obtain an image with excellent motion tracking. Therefore,
Even if the driving frequency is reduced, the image quality is hardly degraded, and a significant reduction in power consumption can be realized. In addition, when displaying a moving image for a search, such as when scrolling images or switching between multiple screens, it is necessary to know what kind of image is as soon as possible. In the case of normal MF driving, It is difficult to quickly recognize the image because the image is lost in an interlace shape. On the other hand, according to the present driving method, since the display can be performed quickly although the resolution is low, it is determined whether or not the screen is being searched before the final high-definition image is completely displayed. And the power consumption can be reduced without impairing the human interface.

As described above, according to the present embodiment, the image is gradually changed from low resolution to high resolution with time.
That is, by displaying the image so that the limit resolution is gradually increased, it is possible to obtain an image which is easy to view even when the driving frequency for display is lowered. By lowering the driving frequency in this way, not only can the power consumption be significantly reduced, but also the information to be searched can be quickly displayed on a scroll screen or the like, while a high-definition display can be performed if the display screen is to be viewed carefully. be able to. That is, an appropriate display can be performed by changing the scanning conditions according to the image.

FIG. 2 is a diagram showing a second embodiment of the present invention. Hereinafter, the present embodiment will be described with reference to FIG. In FIG. 2A, reference numerals 2a to 2d denote low-pass filters (hereinafter, LPFs), each having a frequency characteristic as shown in FIG. 2B. Reference numeral 3 denotes a switch, and LPFs 2 a to 2 according to an instruction from the selection circuit 4.
The connection of d to the display screen 1 is switched. Reference numeral 5 denotes a scanning frequency variable circuit that changes the scanning frequency of the display screen 1 according to an instruction from the selection circuit 4.

The image signals are LPs having different characteristics.
The band is limited by F2a to F2d, the desired LPF is selected by the switch 3, and sent to the display screen 1. First, signals passing through the LPF 2a having the lowest cutoff frequency are selected as display data, and signals passing through the LPFs 2b, 2c, and 2d having sequentially higher cutoff frequencies are selected as display data. On the display screen 1, as the signal that has passed through the LPF with a higher cutoff frequency is selected as the display data, the display with a higher resolution, that is, a higher limit resolution is performed. The selection circuit 4 selects display data, and an instruction is given from the selection circuit 4 to the scanning frequency variable circuit 5 so that display is performed at a scanning frequency required for the selected display data. Scanning frequency variable circuit 5
Then, in low-resolution display, the scanning frequency is lowered, and the higher the resolution, the higher the scanning frequency.

By performing such driving, the transmission frequency and driving frequency of an image can be reduced as a whole, and power consumption can be reduced. For example, if the display using the display data with the lowest resolution is sufficient, the power consumption can be reduced most, and if a high resolution is required, the image quality is improved at the expense of the power consumption. The required resolution can be obtained as appropriate according to the image.

The filtering process and the LPF selection process in the LPF are performed separately from the apparatus main body.
The scanning frequency for inputting the data obtained by filtering the image signal and the selection signal to the apparatus main body for display may be changed. In this case, the number of processing systems decreases,
It is suitable for constructing a system that carries only the display panel portion and receives the transmitted image signal.

FIGS. 3 to 5 are views showing a third embodiment of the present invention. Hereinafter, the present embodiment will be described with reference to FIGS. In the second embodiment shown in FIG. 2, a filter is provided on the side receiving an image signal to perform processing, but there is a method called sub-band coding as a method of compressing and transmitting the image itself, and the image itself is When the image signal is transmitted by this method, it is not necessary to provide a filter on the side receiving the image signal, and only the circuit for demodulation and the scanning method may be changed. The second embodiment relates to such a method.

FIG. 3 is a block diagram showing a configuration of an encoder provided on a signal sending side, and FIG. 4 is a block diagram showing a configuration of a decoder provided on a side receiving a signal sent from the encoder. It is. In FIG. 3, reference numerals 11a to 11c denote LPFs, and each of the LPFs 1 to 3 has different filter characteristics. Note that it is also possible to use a BPF (bandpass filter) instead of the LPF. 12b-1
2d is a subtractor, 13b to 13d are delay circuits,
Reference numeral 14 denotes a multiplexer for selecting one of the signals a to d. In FIG. 4, 15 is a demultiplexer, 16a to 16c are delay circuits, and 17b to 17e.
Is an adder.

In the above sub-band coding, as shown in FIG. 3, a signal a having the lowest frequency to a signal d having the highest frequency are transmitted in a time-division manner by the multiplexer 14, and this transmission signal is transmitted to the multiplexer shown in FIG. Combined. In this case, an initially blurred image is transmitted to the multifunction device. For example, as shown in FIG. 5, the number of scanning lines to be simultaneously scanned is 6 in the first frame (a).
All the scanning lines are rewritten in each frame, for example, four in the next frame (b), two in the next frame (c), and one in the next frame (d).
As described above, by gradually reducing the number of scanning lines that are simultaneously scanned, the initially blurred image becomes gradually clearer. Also, when displaying an originally blurred image, if the frequency band of the blurred image is fx,
If the image is displayed at twice or more the sampling frequency, a faithful image can be reproduced. Therefore, the display method of the present invention in which the pitch of a scanning line of a block to be sampled, that is, scanned simultaneously, is changed according to how much the image is blurred, the image quality can be prevented from deteriorating, and the power consumption can be reduced. .

In this embodiment, a plurality of scans are performed at the same time. However, as in the fourth and fifth embodiments to be described later, the scan may be performed by shifting the interpolated images. Next, a fourth embodiment of the present invention will be described. In the following embodiments, a multi-field driving method that lowers the driving frequency by dividing one frame (one frame image) into a plurality of subfields is included. Since this is a well-known driving method (for example, Japanese Patent Application Laid-Open No. 3-21795), a detailed description thereof will be omitted.

According to the fourth embodiment, in the multi-field driving method, a signal having a correlation with an image signal of a pixel to which an image signal is transmitted is supplied to a pixel to which an image signal is not transmitted in a subfield. It is.

FIG. 6 is a block diagram showing the overall configuration of the liquid crystal display device according to the fourth embodiment. 21 is a TFT
A display panel such as an LCD, 22 a scanning line for supplying a scanning signal to a switching element such as a TFT, 23 a signal line for supplying an image signal to each pixel, 24 a scanning line driving circuit, 25
Is a signal line driver, 26 is a scanning line selection signal generation circuit, 2
7 is an n counter circuit, 28 is an n: m interlace processing circuit, and 29 is a correlated image signal generation circuit.

The processing performed by the correlation image signal generation circuit 29 may be any processing as long as the jaggedness is reduced in a moving image or a quasi-moving image.
As an example, as shown in FIG. 7, in multi-field driving in which one frame image is interlaced by 3: 1, the m-th scanning line and the (m +
3) It is assumed that an image signal is sent from an information device to a scanning line. Assume that the liquid crystal cell has a voltage-transmittance characteristic as shown in FIG. In this case, an image signal (strictly, a voltage applied to the liquid crystal associated with the pixel, but an image signal for simplicity of description here) and a transmittance to a pixel connected to the m-th scanning line. Vm and Tm respectively
And these values for the pixel connected to the (m + 3) th scanning line are Vm + 3 and Tm + 3, respectively. In each pixel connected to the (m + 1) th scanning line and the (m + 2) th scanning line located between these two scanning lines, the transmittances Tm + 1 and Tm +
2 is defined as Tm + 1 = (Tm × 2 + Tm + 3 × 1) / 3 Tm + 2 = (Tm × 1 + Tm + 3 × 2) / 3, and thus obtained transmittances Tm + 1 and Tm + Two
By calculating the voltages Vm + 1 and Vm + 2 corresponding to the above from the characteristics shown in FIG. 8, the luminance difference between the pixels can be made equal. In the above example, FIG. 9 shows the scanning signals supplied to the (m) to (m + 3) th scanning lines and the signals applied to the signal lines.

Next, a fifth embodiment of the present invention will be described. In the fifth embodiment, in a multi-field driving method, a signal supplied to a pixel to which an image signal is not transmitted in a subfield is controlled by a switching element provided between a signal line and a signal line driver. For example, when the 3: 1 multi-field driving method of FIG. 7 is used, after selecting a scanning line m provided with a pixel for displaying an image according to an image signal, a pixel for displaying an image according to an image signal is provided next. Until the scanning line m + 3 is selected, the scanning line m + arranged between these two scanning lines is selected.
For pixels connected to 1 and m + 2, scan lines m and m
That is, a signal voltage intermediate between the two image signal voltages sent to the pixel connected to +3 is supplied.

FIG. 10 is a diagram showing a configuration of a main part of a liquid crystal display device according to the fifth embodiment. 31 is a display panel unit, 32 is a scanning line, 33 is a signal line, 34 is a scanning line drive circuit, and 35 is a signal line driver. Reference numeral 36 denotes a switching element (control means). The on-resistance Rs of the switching element 36 is controlled by a control signal voltage Vgs (voltage applied between the gate and source of the switching element 36) supplied from the control line drive circuit 37 to the control line 38. Changes (see FIG. 11).

FIG. 12 is a diagram showing signal waveforms at various parts in FIG. The image signals are scanning lines G1 and G
4 during the selected period, and the signal line S1
Are Vs1 and Vs2, respectively. During the period in which the scanning lines G2 and G3 are selected, the on-resistance of the switching element 36 is changed by the control voltage supplied from the control line driving circuit 37 to the control line C1, and the potential of the signal line S1 becomes Vs1.
And Vs2. In this case, the potential of the signal line during the period in which the scanning lines G2 and G3 are selected is determined by the capacitance of the signal line, the resistance of the signal line, and the output impedance of the signal line driver. Has a small output impedance and can be ignored here. Therefore, the response speed of the signal line potential is determined by the function of the ON resistance Rs of the switching element, that is, the control signal voltage Vgs supplied to the control line.

When the present embodiment is used for the common inversion driving method, it is possible to respond by changing the method of selecting the scanning lines. For example, as shown in FIG.
Scanning is performed in the order of 4, m + 5, m + 9, and scanning lines m and m +
4 performs positive writing, and scanning lines m + 5 and m + 9 perform negative writing. The polarity inversion can be performed by performing the writing operation continuously in this manner. In this case, a bundle of lines having the same polarity (m to m + 4 is a bundle of a positive polarity, and m + 5 to m + 9 is a bundle of a negative polarity) is generated.
Although it is possible that line flicker may occur on the spatial frequency, in a moving image, the difference in luminance due to a change in the image is larger, so that the image is not visually recognized or is hardly visually recognized.

FIG. 14 shows a sixth embodiment of the present invention. In the fourth and fifth embodiments, when a moving image or a quasi-moving image is displayed by the window display, it is not necessary to rewrite the screen in the still image portion. Therefore, as shown in FIG. 14, a liquid crystal cell configuration in which scanning lines are provided in a horizontal direction and a vertical direction is used.

In FIG. 14, reference numeral 42a denotes a horizontal scanning line, 42b denotes a vertical scanning line, 43 denotes a signal line, and 44a
Is a row address line driving circuit for driving the scanning line 42a;
b denotes a column address line driving circuit for driving the scanning line 42b;
Reference numeral 5 denotes a signal line driver; 46, a switching element; 47, a control line driving circuit for driving a control line 48;
A signal is written from the signal line 42 only to the pixel at the intersection selected by 2a and 42b. With such a configuration, the driving method of the above embodiment is used for the pixels in the region displaying the moving image or the quasi-moving image, and the conventional driving method or the multi-field driving method is used for the pixels in the region displaying the still image. Can be used.

Incidentally, in addition to the above embodiments, the following embodiments are also conceivable. This is because A in the display area
Subfield inversion driving is performed for B (B is a positive integer equal to or less than A) pixels or scanning lines out of (A is a positive integer) pixels or scanning lines.

In the subfield inversion, one frame image is divided into a plurality of subfield images,
In the subfield, the B pixels or the scanning lines are driven with the same polarity. For other pixels or scanning lines (AB pixels or scanning lines), signal line inversion, common inversion, dot inversion, or the like is used. Further, since the normal frame period is 60 Hz, flicker occurs in the case where the plus writing and the minus writing are performed and the luminance difference differs depending on the writing polarity as in a liquid crystal display device.
Therefore, when the frame inversion for inverting the polarity for each frame is used, 30 Hz surface flicker occurs. Since this flicker enters a region where visual characteristics are visually recognized, it appears as image quality deterioration. However, it is possible to prevent the frame inversion by setting the frequency of the frame inversion outside the visible region.

FIG. 15 is a block diagram showing the overall configuration of the liquid crystal display device according to this embodiment. 61 is a TFT-
A display panel such as an LCD, 62 is a scanning line, 63 is a signal line,
A 64 scanning line drive circuit and 65 are signal line drivers. 6
A drive selection processing circuit 6 selects a drive method and sends a scan line selection signal and a clock signal converted in accordance with the drive method to the scan line drive circuit 64,
The clock signal converted for each driving method is sent to the signal line driver 63. 67 is an n: m interlace processing circuit, 68 is a subfield inversion drive processing circuit, and the subfield inversion drive processing circuit may have a frame memory.

When a still image and a moving image are simultaneously displayed on the same scanning line, subfield inversion driving can be performed in the moving image portion. However, surface flicker may occur in the still image portion depending on the subfield inversion cycle. There is.
Here, it is assumed that one frame period is constant, and a limit subfield frequency is obtained according to the number of pixels for which subfield inversion is performed. It is assumed that the frame period is Tf and the subfield inversion period is 2Ts (because two writing operations of plus writing and minus writing are required).

For example, as shown in FIG. 16, in a display image having a moving image portion and a still image portion, the ratio of pixels (region S) for which subfield inversion is performed on all pixels is r.
In addition, a multi-field driving method is used for pixels (region M) for which subfield inversion is not performed.
In this case, the period of a pixel that performs n: m multi-field driving can be converted to m / n. The above relationship can be expressed by the following equation: r × 2Ts + (1-r) × Tf × m / n = Tf Here, when m / n is obtained as a parameter,
For example, when the 3: 1 multi-field driving method is used, 2r / (1- (1-r) / 3) = Tf / Ts.

FIG. 17 shows the minimum value of the subfield inversion frequency for the display area (display ratio r) in which the subfield inversion drive is performed. For example, if the display area where the subfield inversion drive is performed is 50% of the whole (display ratio 0.5), the subfield inversion frequency is 7
It is possible up to 2 Hz. However, in this case, since the surface flicker component is 36 Hz, in a still image, the flicker is within an area where the flicker is visually recognized. Although it depends on the brightness of the panel surface, if the surface flicker component is set to be 45 Hz or more, when the subfield inversion frequency is 90 Hz, 2/3 of the display area is set to subfield inversion drive,
The remaining area can be 3: 1 multi-field driven. This is a condition when a still image is driven by subfield inversion driving. In the case of a moving image, the frequency can be further reduced. If the region S in FIG. Can be lowered further.

When the subfield inversion driving method is used, a part of a display image can be displayed by changing a part of the display image in order to correct the luminance difference depending on the polarity or to improve the image quality. The present invention is not limited to the embodiments described above, and can be implemented with various modifications without departing from the spirit thereof.

[0045]

According to the first and second aspects of the present invention, the limit resolution can be changed according to the image to be displayed, and the power consumption can be reduced. According to the third aspect of the present invention, it is possible to improve image quality such as reduction of jaggedness and to reduce power consumption.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a display method according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a second embodiment of the present invention.

FIG. 3 is a block diagram showing a third embodiment of the present invention.

FIG. 4 is a block diagram showing a third embodiment of the present invention.

FIG. 5 is an explanatory diagram showing a display method according to a third embodiment of the present invention.

FIG. 6 is a block diagram showing a fourth embodiment of the present invention.

FIG. 7 is an explanatory diagram showing a scanning state for a 3: 1 interlace process.

FIG. 8 is a diagram showing a voltage-transmittance characteristic of a liquid crystal cell.

FIG. 9 is a diagram showing waveforms of respective units according to a fourth embodiment.

FIG. 10 is a view showing a fifth embodiment of the present invention.

FIG. 11 is a view showing the on-resistance with respect to the gate voltage of the switching element of FIG. 10;

FIG. 12 is a diagram showing waveforms of respective units according to a fifth embodiment.

FIG. 13 is an explanatory diagram showing a scanning state when a common inversion driving method is used in the fifth embodiment.

FIG. 14 is a block diagram showing a sixth embodiment of the present invention.

FIG. 15 is a block diagram showing another embodiment.

FIG. 16 is a diagram showing an example of a display area according to another embodiment.

FIG. 17 is a diagram illustrating a relationship between a display ratio and a subfield inversion frequency according to another embodiment.

[Explanation of symbols]

 22, 32: scanning line 23, 33: signal line 29: correlation image signal generating unit 36: switching element (control means)

Claims (3)

[Claims] 1. A display in which a plurality of pixels are arranged in a matrix, and a plurality of block images composed of the plurality of pixels and a frame image composed of the plurality of block images are temporally and continuously displayed. A method of driving a display device, wherein one frame or one block image of an image that can be displayed on the display device has a different limit resolution. 2. The method according to claim 1, wherein the number of blocks to be simultaneously rewritten differs from frame to frame. 3. An image is displayed by A (A is a positive integer) pixels or scanning lines, and one frame image is divided into n subfields to be sequentially displayed along a time axis. A display device composed of A ÷ n × m (n is a positive integer of 3 or more and A or less, m is a positive integer of n or less) of the A pixels or the scanning lines. In the driving method of (1), for a pixel connected to a scanning line located between the first scanning line and the second scanning line, an image signal for a pixel connected to the first scanning line and a second signal A method for driving a display device, comprising supplying a signal correlated with an image signal for a pixel connected to a scanning line.