JP4635431B2 - Driving method and driving device for simple matrix display device, and display system using simple matrix display device - Google Patents

Description

  INDUSTRIAL APPLICABILITY The present invention utilizes a self-luminous simple matrix display device driving method and device, and a simple matrix display device in which light emitting elements are formed at intersections of a plurality of anode lines and cathode lines arranged in a matrix. Related to the display system.

  FIG. 8 shows a method as disclosed in Patent Document 1 as an example of a driving method of a simple matrix display device. FIG. 8 shows an example in which an organic EL display device in which light emitting elements (pixels) are formed at intersections between the anode lines A1 to AN and the cathode lines B1 to BM arranged in a matrix is a driving target. In this case, one of the anode lines A1 to AN and the cathode lines B1 to BM (the cathode lines B1 to BM in the example of FIG. 8) is sequentially selected and scanned at a fixed time interval, and the other is synchronized with this scanning cycle. (Anode lines A1 to AN in the example of FIG. 8) are driven by outputs from current sources 1-1 to 1-N as drive sources, thereby causing the light emitting element at a desired intersection position to emit light. .

  The cathode lines B1 to BM are connected to scanning switches 2-1 to 2-M for selecting a power supply voltage (+ Vcc) or a ground potential (0 V) which is a reference potential in order to perform the sequential scanning. By scanning these scanning switches 2-1 to 2-M while sequentially switching them from the power supply terminal side to the ground terminal side at a constant cycle, a ground potential (0 V) is sequentially applied to the cathode lines B1 to BM. . On the other hand, the anode switches A1 to AN are connected to current sources 1-1 to 1-N fed from the power supply terminals or drive switches 3-1 to 3-N for selecting a ground potential (0 V). . These drive switches 3-1 to 3 -N are selectively turned on / off in synchronization with the scanning cycle of the scan switches 2-1 to 2 -M, so that the anode lines A 1 to 1 corresponding to the turned on drive switches A N is connected to current sources 1-1 to 1-N. As a result, a drive current is supplied to the light emitting element at the desired intersection position.

For example, when the light emitting elements E1,1 and E1,2 are caused to emit light, as shown in FIG. 8, only the scanning switch 2-1 is switched to the ground terminal side to scan the cathode line B1 to the ground potential. The drive switches 3-1 and 3-2 are switched to the current source side, and the anode lines A2 and A3 are connected to the current sources 1-1 and 1-2, respectively. Then, as indicated by the arrows in the figure, only the light emitting elements E1,1 and E1,2 are supplied with drive current to emit light. By repeating such scanning and driving operations at high speed, it is possible for the human eye to recognize that the light emitting elements E1,1 and E1,2 are simultaneously emitting light due to the afterimage phenomenon. Incidentally, by applying a reverse bias voltage (+ Vcc) having the same potential as the power supply voltage to the non-selected cathode lines B2 to BM, erroneous light emission of the light emitting elements corresponding to the cathode lines B2 to BM is prevented. Then, by selectively performing such scanning and driving control for the scanning switches 2-1 to 2-N and the driving switches 3-1 to 3-M, the light emitting elements at arbitrary positions are caused to emit light in the same manner. Can do.
Japanese Patent Application Laid-Open No. 9-232074

In an organic EL display device, when displaying the wave of a wave front or the brightness of a jewel, only a part of the display screen is extremely bright with respect to the background, that is, the dynamic range of light emission luminance is wide. Display is required. However, in the conventional driving method described with reference to FIG. 8, even when only a part of the display screen emits light with high brightness, it is necessary to supply a high level of current according to the light emission brightness. In addition, the power supply capability of the current sources 1-1 to 1-N, the scanning line side drivers (scanning switches 2-1 to 2-M), and the signal line side drivers (driving switches 3-1 to 3-N) is increased. Thus, in accordance with the given image data, the light emitting element corresponding to the brightness and brightness is driven with high brightness. For this reason, in the conventional method,
・ Increases the cost of circuit components required for driving.
-The light emitting element driven with high brightness requires a large instantaneous light emitting brightness, and its deterioration over time is increased, so that a decrease in the brightness of the light emitting element is promoted.
・ In order to suppress the deterioration of display quality even during high-luminance display, it is necessary to apply a high reverse bias voltage, which may lead to the destruction of the light emitting element.
There were problems such as.

  The present invention has been made in view of the above circumstances, and a driving method and a driving device for a simple matrix display device capable of realizing partial high-luminance light-emitting display without increasing instantaneous light-emitting luminance and applied current, and An object of the present invention is to provide a display system using a simple matrix display device.

In the driving method of the matrix type display device according to claim 1, one of a plurality of anode lines and cathode lines is a scanning line, and the other is a signal line. By applying a current signal to a desired signal line while scanning, a light emitting element formed at the intersection of the scanning line and the signal line is caused to emit light. In this case, control is performed to increase the luminance of the light emitting elements that emit light in accordance with the scanning by relatively extending the scanning period of some scanning lines. In other words, control is performed to increase the drive duty ratio for some of the scanning lines, so that the luminance of the light emitting element to be driven can be increased without increasing the instantaneous light emission luminance and the applied current. Become.
In addition, when there is a scanning line in which there is no light emitting element to be driven in one scanning cycle of the scanning line, scanning of the scanning line in which the light emitting element does not exist is prohibited and the scanning period of the other scanning lines has a scanning period. The period is proportional to the maximum gradation level of the light emitting element to be driven existing on the scanning line. For this reason, for the scanning line in which the light emitting element to be driven exists, the scanning period is controlled to be extended in proportion to the maximum gradation level of the light emitting element to be driven. The luminance of the light emitting element to be driven can be increased without increasing the brightness.
In addition, it is possible to prevent a situation in which the luminance varies between the frame images constituting the moving image.

According to the drive device of the matrix type display device according to claim 2 , the control means provides a current signal to a desired signal line while periodically scanning the scan line, thereby intersecting the scan line and the signal line. Control is performed to cause the light-emitting elements formed in the substrate to emit light. In this case, the control unit performs control to increase the luminance of the light emitting element that emits light according to the scanning by relatively extending the scanning period of some of the scanning lines. In other words, control is performed to increase the drive duty ratio for some of the scanning lines, so that the luminance of the light emitting element to be driven can be increased without increasing the instantaneous light emission luminance and the applied current. Become.
In addition, when there is a scanning line in which there is no light emitting element to be driven in one scanning cycle of the scanning line, the control unit prohibits scanning of the scanning line in which the light emitting element does not exist and The scanning period is controlled to be a period proportional to the maximum gradation level of the light emitting element to be driven existing on the scanning line. For this reason, for the scanning line in which the light emitting element to be driven exists, the scanning period is controlled to be extended in proportion to the maximum gradation level of the light emitting element to be driven. The luminance of the light emitting element to be driven can be increased without increasing the brightness.
In addition, it is possible to prevent a situation in which the luminance varies between the frame images constituting the moving image.

(First embodiment)
The first embodiment of the present invention will be described below with reference to FIGS.
FIG. 1 shows the overall electrical configuration by a combination of functional blocks. In FIG. 1, an organic EL panel 11 (corresponding to a simple matrix display device) is modularized together with a drive circuit 12, a control circuit 13 (corresponding to control means) and a power supply circuit 14. Although not specifically shown, the organic EL panel 11 has the same configuration as the organic EL display device shown in FIG. 8, and is arranged in a matrix (for example, M × N: M, N is 2 or more). A light emitting element is formed at each intersection of an anode line and a cathode line, and one of the anode line and the cathode line (for example, the cathode line) is a scanning line, and the other (for example, the anode line) is a signal line. At the time of driving the organic EL panel 11, the M scanning lines are periodically scanned by the row driver 12 a in the driving circuit 12, and the desired signal line among the N signal lines is transferred to the driving circuit 12. A current signal is supplied from the column driver 12b to cause the light emitting elements formed at the intersections of the scanning lines and the signal lines to emit light.

  The control circuit 13 includes an image data receiving unit 13a, an image memory 13b, a scanning duty calculating unit 13c, and a drive data generating unit 13d. The image data receiving unit 13a receives image data sent from an external device (such as an image processing circuit) and stores it in the image memory 13b. The image data is data for M rows × N columns corresponding to the organic EL panel 11, and in this embodiment, is data of on / off gradation for a binary image.

The scanning duty calculation unit 13c reads the image data stored in the image memory 13b, and for each of M scanning lines in the image data for one scanning period (one frame),
<1> Whether any one or more of the light emitting elements on the scanning line is turned on (light emission),
<2> All light emitting elements on the scanning line are off (non-light emitting),
And the number m (≦ M) of scanning lines determined as <1> is obtained.

  The drive data generation unit 13d reads out image data (m rows × N columns, on / off gradation) corresponding to only the scanning line determined as <1> from the image memory 13b, and drives based on the image data. Drive data to be supplied to the circuit 12 is generated. At the time of data generation, the drive data generation unit 13d obtains the drive duty ratio of the scan line and the scan period by calculation as shown below.

a. The drive duty ratio of the scanning lines is set to 1 / m based on the number m of scanning lines determined by the scanning duty calculator 13c.
b. If the scanning period of each scanning line in a state where the driving duty ratio of the scanning lines is 1 / M (a state where all scanning lines are scanned: the same driving method as in the prior art) is T [seconds], the driving duty ratio is 1 / M. The scanning period T ′ of each scanning line at m is T × (M / m) [seconds]. Since M ≧ m, T ′ ≧ T.

When the instantaneous emission luminance when the scanning line is scanned with the applied current at the same level as in the conventional driving method with the drive duty ratio and the scanning period thus obtained is L [cd / m ² ], the organic EL panel The display surface luminance La ′ at 11 is L / m [cd / m ² ]. On the other hand, the display surface luminance La according to the conventional driving method is L / M [cd / m ² ], and in this case, there is a relationship of M ≧ m.
The relationship La ′ ≧ La is established, and the brightness can be increased as compared with the conventional case. For example, when the number of scanning lines of the organic EL panel 11 is 64 (M = 64) and the instantaneous light emission luminance L = 6400 [cd / m ² ] at the time of scanning, when an image is displayed by a conventional driving method. The display surface brightness La is 100 [cd / m ² ]. On the other hand, the display surface luminance La ′ when the image display with 32 scanning lines (m = 32) is performed in the drive duty ratio and the scanning period obtained as described above is 200 [cd / m ² ], so that the brightness can be increased twice.

  The drive data generation unit 13d transmits the drive data (scanning line drive duty ratio, scan period) generated as described above to the drive circuit 12, and the drive circuit 12 performs low-level operation according to the received drive data. A scanning signal is output from the driver 12a and a current signal is output from the column driver 12b. The organic EL panel 11 is driven by these outputs.

  According to this embodiment configured as described above, when there is a scanning line in which the light emitting element to be driven does not exist in the scanning cycle of the M scanning line group included in the organic EL panel 11, the scanning line to be scanned is detected. The number is reduced from the normal number M to the number m of scanning lines in which the light emitting elements to be driven exist. In other words, when there is a scanning line in which the light emitting element to be driven does not exist in the scanning cycle of the scanning line group, scanning for the scanning line in which the light emitting element does not exist is prohibited. Control is performed to reduce the number of scanning lines per scanning period and to relatively extend the scanning period for the scanning lines in which the light emitting elements to be driven are present. Therefore, the driving duty ratio of the scanning line that is scanned in a state in which such control is performed is increased, and thus the light emitting element to be driven can be driven without increasing the instantaneous light emission luminance and the applied current. High brightness can be achieved.

Here, in FIG. 2, in order to make it easy to understand the difference between the conventional driving method and the driving method of this embodiment, an example of an image displayed on the organic EL panel 11 (conventional: (a), this embodiment: ( d)), instantaneous light emission luminance of the light emitting element in each scanning period (conventional: (b), embodiment (e)), drive current I level (conventional: (c), embodiment: (f)) Is shown schematically.
In FIG. 2, in the case of displaying a figure C as shown in (a) and (d) on the organic EL panel 11 having M scanning lines (the number of scanning lines including light emitting elements to be driven is m), Conventionally, since scanning is also performed for scanning lines ((M−m) scanning lines that do not correspond to the shape C) in which there is no light emitting element to be driven, M scanning lines are scanned in one scanning cycle. Therefore, the scanning period T of each scanning line becomes relatively short as shown in FIG. 5B, and the driving duty ratio of the scanning line becomes 1 / M.

  As a result, in the conventional driving method, for example, when trying to display a whisper of a wave front or the shine of a jewel, that is, when only a part of the display screen is to be emitted with high brightness, the standard driving method is used. Since it becomes necessary to supply a current at a higher level than the driving current I, the problems described in the section “Problems to be solved by the invention” (an increase in the cost of circuit components and a decrease in luminance of the light emitting element) Problems such as promotion of

  On the other hand, in the driving method according to the present embodiment, the number of scanning lines per scanning period is reduced to m, so that the scanning period T ′ (= T × (M / m) [seconds] of those scanning lines. ]) Becomes longer than the conventional method as shown in (e), and the drive duty ratio of the scanning line is increased to 1 / m. As a result, when only the standard driving current I is supplied, the light emission luminance at the time of scanning of each light emitting element can be relatively increased, and only a part of the display screen emits light with high luminance. However, there is no risk of incurring the above problems.

(Second Embodiment)
3 and 4 show a second embodiment of the present invention. Hereinafter, only portions different from the first embodiment will be described.
In FIG. 3 showing the overall electrical configuration by a combination of functional blocks, in this embodiment, a control circuit 15 (corresponding to control means) is provided instead of the control circuit 13 in the first embodiment. The image data receiving unit 15a in the control circuit 15 receives image data (M rows × N columns, K gradation) sent from an external device and stores it in the image memory 15b. The drive data generation unit 15 c reads image data from the image memory 15 b according to a display mode designated from the outside, generates drive data, and provides the drive data to the drive circuit 12. The display mode need not be specified from the outside, and can be automatically determined based on the number of rows and columns of image data stored in the image memory 15b.

Here, as the display mode, a “low luminance full screen mode” (corresponding to a normal display mode in the present invention) in which all the scanning lines of the organic EL panel 11 are scanned to perform full screen display, a specific scan is performed. A “high luminance sub screen mode” (corresponding to a partial display mode in the present invention) in which only a group of lines is scanned to perform screen display using a sub display area within a predetermined range is set.
When the display mode is the low-luminance full screen mode, the drive data generation unit 15c sequentially reads all image data (M rows × N columns, K gradation) for one frame from the image memory 15b. In addition, when the display mode is the high luminance sub-screen mode, the drive data generation unit 15c reads image data (m rows × N columns, K gradation) corresponding to a specific scanning line group from the image memory 15b. Note that m <M. Here, when the scanning period of each scanning line in the low luminance full screen mode is T [second] and the scanning period of each scanning line in the high luminance sub screen mode is T ′ [second],
T ′ = T × (M / m), T ′> T
The relationship holds.

The drive data generation unit 15c generates drive data under the following conditions based on the read image data. That is, when the maximum instantaneous light emission luminance of each light emitting element during scanning line scanning in the low luminance full screen mode is L [cd / m ² ], each light emission during scanning line scanning in the high luminance sub screen mode. The maximum instantaneous light emission luminance of the element is also set to L [cd / m ² ]. Further, when the maximum driving current of each light emitting element during scanning line scanning in the low luminance full screen mode is I [A], the maximum driving of each light emitting element during scanning line scanning in the high luminance sub screen mode. The current is also set to I [A]. The drive circuit 12 that has received such drive data outputs a scanning signal from the row driver 12a and a current signal from the column driver 12b in accordance with the drive data.

According to this embodiment configured as described above, the display surface luminance Lf in the low luminance full screen mode is L / M [cd / m ² ], and the display surface luminance Ls in the high luminance sub screen mode is L / M. Since m [cd / m ² ], the relationship of Lf <Ls is established, and therefore, it is possible to realize partial but high luminance light emission in the high luminance sub-screen mode.
Here, FIG. 4 shows an example of a screen displayed on the organic EL panel 11 (low luminance full screen mode: (a), high luminance sub-mode) in order to explain the driving method of this embodiment in which two types of display modes are set. Screen mode: (d)), instantaneous light emission luminance of the light emitting element in each scanning period (low luminance full screen mode: (b), high luminance sub screen mode (e)), drive current level (low luminance full screen mode) : (C), high luminance sub-screen mode (f)) is schematically shown.

  In FIG. 4, since each scanning period T ′ of m scanning lines is extended in the high luminance sub-screen mode, high emission luminance can be obtained even with the same drive current I as in the low-luminance full screen mode. I understand that.

(Third embodiment)
FIGS. 5 to 7 show a third embodiment of the present invention. Hereinafter, only portions different from the first and second embodiments will be described.
FIG. 5 shows an organic EL panel drive device formed by modularizing the organic EL panel 11, drive circuit 12, power supply circuit 14 and control circuit 15 in the second embodiment, and an image data generation module 16 (data conversion module) as an external device. The electrical configuration of the display system that is a combination of functional blocks is shown. In FIG. 5, the image data generation module 16 can also be configured by a personal computer, for example. The image data input including the gradation level data of the display image is received through the input interface 17 and stored in the image memory 18. The stored data is converted into image data (M rows × N columns, K gradation) for the organic EL panel 11 by the image data conversion unit 19 and then given to the image data reception unit 15 a in the control circuit 15.

Here, when an image is displayed on the organic EL panel 11 based on the image data given to the control circuit 15, light emission when the applied current during scanning line scanning is set to the maximum value (at full gradation). When the instantaneous light emission luminance of the element is L [cd / m ² ], in the conventional driving method, the scanning duty is 1 / M, and the maximum value of the display surface luminance is expressed by L / M [cd / m ² ]. The The scanning period at this time is fixed at T [seconds], and one frame period is T × M [seconds].

If the maximum value of gray level in each pixel of the m scanning line and k _m (m = 1 to M), the surface luminance L _m of the light emitting elements corresponding to the maximum grayscale level, the following equation (1) expressed.

In this embodiment, characterized in that the scanning period of the m scanning lines is controlled so that T '[sec] that is proportional to k _m. However, one frame period is equal to T × M [seconds] in the conventional method.
That is, the scanning period T _m ′ of the mth scanning line is a value determined by the following equation (2).

Incidentally, in this equation (1), when k _m = 0, T _m ′ = 0. That is, when the gray level of all the light emitting elements on the mth scanning line is zero, in other words, when all the light emitting elements are in the black display, the scanning line is not scanned.

Further, the surface luminance L _m ′ of the light emitting element corresponding to the maximum gradation level of the mth scanning line is expressed by the following equation (3).

Here, comparing the equations (1) and (3), k ₁ = k ₂ = k ₃ ... = K _M = K, that is, only when the maximum gradation level of all the scanning lines is K. It can be seen that L _m ′ = L _m , and L _m ′> L _m is always obtained at other times. Therefore, in most cases, high brightness can be realized. The magnification η for increasing the brightness at this time does not depend on m, and is obtained by the following equation (4).

The above-described increase in luminance will be described below with specific numerical examples.
For example, the image size of the organic EL panel 11 is M × N = 64 rows × 128 columns, and the gradation display capability is K = 64 gradations. Also, the maximum gradation level k _m of each scan line of the display image (m = 1 to 64) is 32 at the beginning (the display area by which the A) is 1/4 of the full tone k _m = 16 (m = 1~32), 16 present followed k _m = 32 (which by the display area and a B) is 1/2 of the full tone (m = 33 to 48), the remaining 16 ( the display area by which the C) is to k _m = 64 is a full gradation (m = 49~64).

If the scanning period T _m ′ of the m-th scanning line in each display area A, B, C is calculated according to equation (2),
Display area A: T _m '= 1 / 2T (m = 1 to 32)
Display area B: T _m ′ = T (m = 33 to 48)
Display area C: T _m ′ = 2T (m = 49 to 64)
It becomes. Further, if the surface luminance L _m ′ of the light emitting element corresponding to the maximum gradation level of the mth scanning line in each display area A, B, C is calculated according to the equation (3),
Display area A: L _m ′ = L / 128 (m = 1 to 32)
Display area B: L _m ′ = L / 64 (m = 33 to 48)
Display area C: L _m ′ = L / 32 (m = 49 to 64)
It becomes. That is, in the conventional driving method, only the surface luminance (L / 64) corresponding to the display area B can be obtained, but according to the driving method of this embodiment, the display area C has a high luminance up to twice that of the conventional driving method. Can be realized.

Here, FIG. 6 shows an example of dividing the display area of the organic EL panel 11 (conventional: (a), this embodiment: (D)), instantaneous light emission luminance of the light emitting element in each scanning period (conventional: (b), embodiment (e)), drive current level (conventional: (c), embodiment: (f)) Is shown schematically. In FIG. 6, the scanning period T _m ′ of the scanning line in this embodiment is as follows: display area A: T _m ′ = 1 / 2T (m = 1 to 32), display area B: T It can be seen that _m ′ = T (m = 33 to 48) and display area C: T _m ′ = 2T (m = 49 to 64). In addition, the surface luminance of each display area A, B, C obtained by instantaneous emission luminance × scanning period is L / 256, L / 128, L / 64, respectively, in the case of the conventional driving method. According to the driving method of this embodiment, L / 128, L / 64, and L / 32 are obtained, respectively, and it can be seen that the surface luminance is doubled in each of the display areas A, B, and C.

The image data generation module 16 shown in FIG. 5 performs an image data conversion operation as described below when image data as in the above-described example is supplied to the control circuit 15. That is, the image data generation module 16 an image memory 18 for storing image data, i.e. the original data, the maximum gradation level k _m of each scan line of the display image, 32 the beginning (corresponding to the display area A) is k _m = 16 is 1/4 of the full tone (m = 1~32), 16 present following (corresponding to the display region B) is k _m = 32 _(m = 33~ is 1/2 of the full tone 48) is data remaining 16 (corresponding to the display area C) is set to k _m = 64 is a full gradation (m = 49 to 64). This original data has a configuration as shown in FIG. Such original data is subjected to data conversion as described below in order to realize double high-luminance emission as described above. That is, as shown in FIG. 7, the scanning period information (1 / 2T, T, 2T) corresponding to each of the original data corresponding to the display areas A, B, C is added and the gradation of each light emitting element. The level is converted to a magnification (4 ×, 2 ×, 1 ×) set for each of the original data corresponding to the display areas A, B, and C. As a result of the provision of such an image data generation module 16, there is an advantage that it is not necessary to change the specifications on the control circuit 15 side.

(Other embodiments)
In addition, the present invention is not limited to the above-described embodiments, and can be modified or expanded as described below.
When handling image data of M rows × N columns and on / off gradation, scanning is performed on the one of the anode line group and the cathode line group of the organic EL panel 11 that has a smaller number of lines emitted by at least one light emitting element. By using the other as a signal line and the other as a signal line, it is also possible to perform control for relatively extending the scanning period of the scanning line.
Specifically, for every M scanning lines in the image data for one scanning cycle (one frame),
<1> Whether any one or more of the light emitting elements on the scanning line is turned on (light emission),
<2> All light emitting elements on the scanning line are off (non-light emitting),
And the number m (≦ M) of scanning lines determined as <1> is obtained. Next, for every N signal lines in the image data for one scanning period,
<3> Whether one or more of the light emitting elements on the signal line is turned on (light emission),
<4> All light emitting elements on the signal line are off (non-light emitting),
The number n (≦ N) of scanning lines determined as <3> is obtained.

Here, if m ≦ n, the driving duty ratio and scanning period of the scanning line are obtained by the same calculation as in the first embodiment, and the organic EL panel 11 is driven according to the driving data thus obtained. . In this case, if m <M, the scanning period is extended as compared with the conventional driving method, so that high luminance can be realized.
Contrary to the above, when m> n, the anode line which has been used as the signal line is scanned, and the signal current is applied to the cathode line which has been used as the scan line. Further, the driving duty ratio and scanning period of the scanning lines are calculated for the new scanning lines (n) by the same method as in the first embodiment, and the organic EL panel 11 is driven according to the driving data thus obtained. To do. In this case, since m> n, the one scanning period of the n scanning lines is further extended as compared with the case of scanning the m scanning lines as in the first embodiment. High brightness can be achieved.

When handling moving image data composed of a plurality of frame image data, a situation in which luminance varies between frames can be prevented by employing a driving method as described below. That is, for all frame images or a predetermined number of consecutive frame images, the magnification η _p for increasing the brightness is obtained according to the equation (4). Next, the minimum value minη _p of the high luminance magnification η _p for each frame image is obtained, and this is set as the high luminance magnification of the moving image, and the moving image data to be displayed is set to the set high luminance magnification. Then, the scanning line scanning period and gradation level of each frame image are calculated, and display control of moving image data is performed based on the calculation result.

  As an example of the simple matrix display device, the organic EL panel 11 has been described as an example. However, the organic EL panel 11 can be widely applied to other self-luminous simple matrix display devices such as a display panel using a light emitting diode as a light emitting element. .

Functional block diagram of electrical configuration showing a first embodiment of the present invention Operation explanation FIG. 1 equivalent view showing a second embodiment of the present invention. 2 equivalent diagram FIG. 1 equivalent view showing a third embodiment of the present invention. 2 equivalent diagram Schematic diagram for explaining an example of conversion of image data Equivalent circuit configuration diagram for explaining a conventional driving method

Explanation of symbols

Reference numeral 11 denotes an organic EL panel (simple matrix display device), 12 denotes a drive circuit, 13 and 15 denote control circuits (control means), 16 denotes an image data generation module (data conversion means), and 19 denotes an image data conversion unit.

Claims (2)

A light emitting element is formed at each intersection of a plurality of anode lines and cathode lines arranged in a matrix, and one of the anode lines and cathode lines is used as a scanning line, the other is used as a signal line, and the scanning line is scanned at a predetermined cycle. In the driving method of the simple matrix display device in which the light emitting element formed at the intersection position of the desired signal line is caused to emit light at a predetermined driving duty ratio,
When there is a scanning line in which there is no light emitting element to be driven in one scanning cycle of the scanning line, scanning of the scanning line in which the light emitting element does not exist is prohibited, and the scanning period of other scanning lines is Control to be a period proportional to the maximum gradation level of the light emitting element to be driven existing on the scanning line,
When a moving image composed of a plurality of frame images is displayed on the simple matrix display device, the brightness enhancement factor for the light emitting element corresponding to the maximum gradation level is set for all frame images or a predetermined number of consecutive frame images. At the same time, the minimum brightness enhancement magnification in each frame image is obtained and set as the high brightness magnification of the moving image, and each frame image is set to the above set high brightness magnification for the moving image data to be displayed. The scanning line scanning period and the gradation level are calculated, and display control of the moving image data is performed based on the calculation result, thereby performing control for increasing the luminance of the light emitting element that emits light according to the scanning. A driving method of a simple matrix type display device. A light emitting element is formed at each intersection of a plurality of anode lines and cathode lines arranged in a matrix, and a simple matrix type display device in which one of the anode lines and the cathode lines is a scanning line and the other is a signal line. A drive device comprising a control means for causing a light emitting element formed at an intersection position of a desired signal line to emit light at a predetermined drive duty ratio by scanning a scan line at a predetermined cycle.
When there is a scanning line in which no light emitting element to be driven exists in one scanning cycle of the scanning line, the control unit prohibits scanning of the scanning line in which the light emitting element does not exist and The scanning period is controlled to be a period proportional to the maximum gradation level of the light emitting element to be driven existing on the scanning line,
In the case where a moving image composed of a plurality of frame images is displayed on the simple matrix display device, the control unit is configured to control light emitting elements corresponding to the maximum gradation level for all frame images or a predetermined number of consecutive frame images. In addition to obtaining the high brightness magnification, the minimum brightness enhancement magnification in each frame image is obtained and set as the high brightness magnification of the moving image, and the above set high brightness magnification is obtained for the moving image data to be displayed. As described above, the scanning line scanning period and the gradation level of each frame image are calculated, and display control of the moving image data is performed based on the calculation result, thereby increasing the luminance of the light emitting element that emits light according to the scanning. A drive device for a simple matrix display device characterized by performing control.

Images