This application claims the benefit of Japanese Priority Patent Application JP 2014-031399 filed Feb. 21, 2014, the entire contents of which are incorporated herein by reference.
The present disclosure relates to a display device having current-driving-type display elements, a method of driving the display device, and an electronic apparatus having the display device.
Recently, display devices have been broadly used in not only televisions and monitors but also in various electronic apparatuses including portable electronic apparatuses such as tablet terminals and smartphones. For such display devices, various developments have been made in order to further improve image quality.
One of parameters representing image quality is a dynamic range. The dynamic range is defined as a ratio of the maximum luminance to the minimum luminance, and generally, it is preferable that a value of the ratio to be high. For example, Japanese Unexamined Patent Application Publication No. 2010-276968 discloses a display device capable of performing display (a so-called high dynamic range (HDR) display) based on a wide dynamic range that exceeds the representation performance of a display panel. In this display device, for example, from an input image, two images having grayscale ranges different from each other are generated, and thus the two images are displayed in a time-division manner.
As described above, in the display device, it is preferable to improve image quality, and thus it is expected that image quality is further improved.
According to the present disclosure, it is desirable to provide a display device, a method of driving a display device, and an electronic apparatus capable of improving image quality.
According to an embodiment of the present disclosure, a first display device includes a display section and a driving section. The display section has pixels. The driving section drives the display section on the basis of luminance information including a plurality of sub-luminance information pieces. The driving section drives the pixels in a time-division manner on the basis of each sub-luminance information piece during a single display period or a plurality of display periods which is set in each sub-luminance information piece. One or both of a timing of start of each display period and the number of the display periods are changeable.
According to another embodiment of the present disclosure, a second display device includes a display section, a light emitting section, and a driving section. The display section has pixels. The driving section drives the display section and the light emitting section on the basis of luminance information including a plurality of sub-luminance information pieces. The driving section drives the pixels in a time-division manner on the basis of each sub-luminance information piece, and drives the light emitting section during a single display period or a plurality of light emitting periods which is set in each sub-luminance information piece. One or both of a timing of start of each light emitting period and the number of the light emitting periods are changeable.
According to a further embodiment of the present disclosure, a method of driving a display device includes setting a single display period or a plurality of display periods in each of the plurality of sub-luminance information pieces included in luminance information, and driving pixels in a division manner on the basis of each sub-luminance information piece during the single display period or the plurality of display periods. One or both of a timing of start of each display period and the number of the display periods are changeable.
According to a still further embodiment of the present disclosure, an electronic apparatus includes the display device. For example, the electronic apparatus corresponds to a television apparatus, an electronic book, a smartphone, a digital camera, a notebook-size personal computer, a video camera, a head-mount display, and the like.
In the first display device, the method of driving the display device, and the electronic apparatus according to the embodiments of the present disclosure, the pixels are driven in a time-division manner on the basis of each sub-luminance information piece during the single display period or the plurality of display periods which is set in each sub-luminance information piece. One or both of the timing of start of each display period and the number of the display periods are changeable.
In the second display device according to the embodiment of the present disclosure, the pixels are driven in a time-division manner on the basis of each sub-luminance information piece, and the light emitting section is driven during the single display period or the plurality of light emitting periods which is set in each sub-luminance information piece. One or both of the timing of start of each display period and the number of the display periods are changeable.
According to the first display device, the method of driving the display device, and the electronic apparatus of the embodiments of the present disclosure, one or both of the timing of start of each display period and the number of the display periods are changeable. Therefore, it is possible to improve image quality.
According to the second display device of the embodiment of the present disclosure, one or both of the timing of start of each light emitting period and the number of the light emitting periods are changeable. Therefore, it is possible to improve image quality.
It should be noted that the effect described herein is not necessarily limited, and may be any one of the effects described in the present disclosure.
Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. It should be noted that description will be given in the following order: 1. Embodiments; and 2. Application Examples.
The display device 1 displays an image on the basis of an image signal Spic. The image signal Spic includes: various synchronization signals such as a vertical synchronization signal and a horizontal synchronization signal; luminance information IR of red (R); luminance information IG of green (G); and luminance information IB of blue (B). Hereinafter, luminance information I is appropriately used to indicate any of the luminance information pieces IR, IG, and IB. The image signal Spic has linear gamma characteristics, in this example. Further, a frame rate of the image signal Spic is 60 Hz, in this example.
The display device 1 includes a sub-frame generation section 11, an analysis section 14, a reference condition setting section 15, a control section 16, a correction section 12, a panel gamma conversion section 13, a driving section 20, and a display section 30.
The sub-frame generation section 11 generates two sub-frame images FS1 and FS2 on the basis of a frame image F indicated by the image signal Spic. Specifically, as described later, the sub-frame generation section 11 divides a range (grayscale range) of a value of the luminance information I into a low grayscale range and a high grayscale range. Then, the sub-frame generation section 11 generates the sub-frame image FS1 on the basis of a luminance information component in the low grayscale range of each luminance information I of the frame image F, and generates the sub-frame image FS2 on the basis of a luminance information component in the high grayscale range thereof. Then, the sub-frame generation section 11 outputs the sub-frame images FS1 and FS2 as an image signal Spic2.
Each of
The display device 1 displays the sub-frame images FS1 and FS2, which are generated in such a manner, in a time-division manner, and is thus able to perform display (a so-called HDR display) based on a wide dynamic range more than representability of the display section 30.
L1=k×IS1×DR1 (1)
L2=k×IS2×DR2 (2)
Here, k is a constant, and DR1 and DR2 are light emitting duty ratios. Here, the light emitting duty ratio DR1 is a value which is obtained by dividing a time length of the light emitting period relating to the sub-luminance information piece IS1 by a time length of a frame period T0 (to be described later). In addition, the light emitting duty ratio DR2 is a value which is obtained by dividing a time length of the light emitting period relating to the sub-luminance information piece IS2 by the time length of the frame period T0. As represented by Expressions (1) and (2), the display luminance L1 is in proportion to the sub-luminance information piece IS1, and the display luminance L2 is in proportion to the sub-luminance information piece IS2. In addition, the proportional constants (k×DR1) and (k×DR2) are equal to each other if the light emitting duty ratios DR1 and DR2 are equal to each other. Accordingly, in this case, as shown in
The analysis section 14 analyzes an image, which is indicated by the image signal Spic, on the basis of the image signal Spic. Specifically, the analysis section 14 determines, for example, whether the image is a moving image or a still image, and acquires information (for example, an average value or a maximum value of an amount of motion, or the like) relating to an amount of motion if the image is the moving image. Further, if both the moving image and the still image are simultaneously displayed in one screen, the analysis section 14 acquires a size of a still image region in which the still image is displayed, an area ratio of the still image region to the entire region of the frame image F, and the like. In addition, analytical contents are not limited to this, and for example, information (for example, the grayscale range and the like) relating to the grayscale of the luminance information I included in the image signal Spic may be further acquired. Then, the analysis section 14 is configured to supply the information as an analysis result AR to the control section 16.
The reference condition setting section 15 sets, for example, an environment condition such as ambient brightness of the display device 1, and a reference condition of an operation of the display device 1, on the basis of user setting and the like. Specifically, for example, the reference condition setting section 15 sets the reference condition so as to brighten the display image if the surrounding area of the display device 1 is bright, or sets the reference condition so as to darken the display image if the surrounding area of the display device 1 is dark. Further, the reference condition setting section 15 sets the reference condition so as to brighten or darken the display image, on the basis of, for example, the user setting. In addition, the reference condition setting section 15 is configured to supply the reference condition as the reference condition information IC to the control section 16.
The control section 16 controls the correction section 12 and the driving section 20, on the basis of the analysis result AR and the reference condition information IC. At this time, the control section 16 selects one of a plurality of operation modes (in this example, four operation modes M1 to M4), on the basis of the analysis result AR. As described later, in the operation modes M1 to M4, for example, the light emitting timings or the light emitting duty ratios DR1 and DR2 are different from one another. Then, on the basis of the selected operation mode, the control section 16 issues an instruction of the light emitting timing or the light emitting duty ratios DR1 and DR2 to the driving section 20 through a control signal CTL2. Further, the control section 16 instructs the correction section 12 to correct the sub-luminance information piece IS1 so as to keep the display luminance L1 constant, through a control signal CTL1, when changing the light emitting duty ratio DR1. In addition, the control section 16 instructs the correction section 12 to correct the sub-luminance information piece IS2 so as to keep the display luminance L2 constant, through the control signal CTL2, when changing the light emitting duty ratio DR2.
The correction section 12 corrects the sub-luminance information pieces IS1 and IS2 included in the image signal Spic2, on the basis of the control signal CTL1. Specifically, the correction section 12 corrects the sub-luminance information piece IS1 so as to keep the display luminance L1 constant when changing the light emitting duty ratio DR1, and corrects the sub-luminance information piece IS2 so as to keep the display luminance L2 constant when changing the light emitting duty ratio DR2. That is, for example, when increasing the light emitting duty ratio DR1, the correction section 12 corrects the value of the sub-luminance information piece IS1 to a small value, thereby keeping the display luminance L1 constant. In addition, when decreasing the light emitting duty ratio DR1, the correction section 12 corrects the value of the sub-luminance information piece IS1 to a large value, thereby keeping the display luminance L1 constant. It is the same for the case of changing the light emitting duty ratio DR2. The correction section 12 is configured to correct the sub-luminance information pieces IS1 and IS2 in such a manner, and to output the corrected sub-luminance information pieces IS1 and IS2 as an image signal Spic3.
The panel gamma conversion section 13 converts (panel gamma conversion) the image signal Spic3, which has linear gamma characteristics supplied from the correction section 12, into an image signal Spic4 which has non-linear gamma characteristics corresponding to characteristics of the display section 30. The panel gamma conversion section 13 is configured to have, for example, a look-up table, and to perform the gamma conversion by using the look-up table.
The driving section 20 drives the display section 30, on the basis of the image signal Spic4 and the control signal CTL2. The display section 30 displays an image on the basis of the driving performed by the driving section 20.
The writing transistor WSTr and the driving transistor DRTr are formed as, for example, N-channel metal oxide semiconductor (MOS) thin film transistors (TFT). A gate of the writing transistor WSTr is connected to the scanning-line WSL, a source thereof is connected to the data line DTL, and a drain thereof is connected to one end of the capacitance element Cs and a gate of the driving transistor DRTr. A gate of the driving transistor DRTr is connected to the drain of the writing transistor WSTr and one end of the capacitance element Cs, a drain thereof is connected to the power line PL, and a source thereof is connected to the other end of the capacitance element Cs and an anode of the light emitting element 49.
One end of the capacitance element Cs is connected to the gate of the driving transistor DRTr and the like, and the other end thereof is connected to the source of the driving transistor DRTr. The light emitting element 49 is a light emitting element formed by using an organic EL element. An anode thereof is connected to the source of the driving transistor DRTr and the other end of the capacitance element Cs, and a cathode thereof is supplied with a cathode voltage Vcath by the driving section 20. In addition, in this example, the light emitting element 49 is formed by using the organic EL element, but the present technology is not limited to this, and any light emitting element may be used if the type of the element is a current driving type.
With such a configuration, in the sub-pixel 9, the writing transistor WSTr is turned on so as to thereby perform a writing operation, and an electric potential difference corresponding to the pixel voltage Vsig (to be described) is set between both ends of the capacitance element Cs. Then, the driving transistor DRTr makes driving current corresponding to the electric potential difference between both ends of the capacitance element Cs flow to the light emitting element 49. Thereby, the light emitting element 49 is configured to emit light at a luminance corresponding to the pixel voltage Vsig.
The scanning-line driving section 21 sequentially selects the sub-pixels 9 by sequentially applying the scanning signals WS to the plurality of scanning-lines WSL in accordance with the control signals CTL2 supplied from the control section 16.
The power line driving section 22 controls light emitting operations and quenching operations of the sub-pixels 9 by sequentially applying the power supply signals DS to the plurality of power lines PL in accordance with the control signals CTL2 supplied from the control section 16. In this example, the power supply signal DS shifts between three voltages Vccp, Vext, and Vini. As described later, the voltage Vccp makes current flow into the driving transistor DRTr, and is a voltage for causing the light emitting element 49 to emit light and is a voltage higher than voltages Vext and Vini. The voltage Vext is a voltage for quenching the light emitting element 49, and is a voltage higher than the voltage Vini. The voltage Vini is a voltage for initializing the sub-pixel 9.
The data line driving section 23 generates the signal Sig in accordance with the image signal Spic4 supplied from the panel gamma conversion section 13 and the control signal CTL2 supplied from the control section 16, and applies the signal Sig to each data line DTL. The data line driving section 23 generates the pixel voltage Vsig, which indicates the light emitting luminance of each sub-pixel 9, on the basis of the image signal Spic4, and generates the signal Sig by alternately arranging the pixel voltage Vsig and a voltage Vofs for performing Vth correction to be described later.
With such a configuration, as described later, the driving section 20 is configured to initialize the sub-pixel 9, to perform correction (Vth correction and μ (mobility) correction) for suppressing the effect of element variation of the driving transistor DRTr onto image quality, and to record the pixel voltage Vsig.
Here, the analysis section 14, the control section 16, and the driving section 20 correspond to one specific example of the “driving section” in the present disclosure. The sub-frame generation section 11 corresponds to one specific example of the “signal generation section” in the present disclosure. The sub-luminance information piece IS1 corresponds to one specific example of the first sub-luminance information piece” in the present disclosure, and the sub-luminance information piece IS2 corresponds to one specific example of the “second sub-luminance information piece” in the present disclosure.
Operations and Effects
Subsequently, operations and effects of the display device 1 of the present embodiment will be described.
Overall Operation Overview
First, referring to
In the display device 1, the analysis section 14 analyzes the image, which is indicated by the image signal Spic, on the basis of the image signal Spic. Specifically, the analysis section 14 determines, for example, whether the image is a moving image or a still image, and acquires information (for example, an average value or a maximum value of an amount of motion, or the like) relating to an amount of motion if the image is the moving image. Further, if both the moving image and the still image are simultaneously displayed in one screen, the analysis section 14 acquires a size of a still image region in which the still image is displayed, an area ratio of the still image region to the entire region of the frame image F, and the like. Then, the control section 16 selects one of a plurality of operation modes (in this example, the four operation modes M1 to M4), of which the light emitting timings and the light emitting duty ratios DR1 and DR2 are different from one another, on the basis of the analysis result AR, and controls the correction section 12 and the driving section 20, on the basis of the selected operation mode. Hereinafter, operations of the respective operation modes M1 to M4 will be described in detail.
Operation Mode M1
The operation mode M1 is an operation mode which is selected if the image indicated by the image signal Spic is a still image. Hereinafter, the operation mode M1 will be described in detail.
The display device 1 displays the sub-frame image FS1 and the sub-frame image FS2 in a time division manner, in the period corresponding to the frame period T0. Here, the frame period T0 is, for example, about 16.7 [msec] (= 1/60 [Hz]). That is, the frame period T0 corresponds to an inverse of the frame rate indicated by the image signal Spic supplied to the display device 1, and the display device 1 displays the two sub-frame images FS1 and FS2 in this period in a time division manner. Then, the display device 1 repeats the display operation for each frame period T0. Hereinafter, the specific operation will be described.
First, in response to a pulse of the vertical synchronization signal Vsync at the timing t21, the driving section 20 performs line-sequential scanning from the top of the display section 30 to the bottom thereof in the period of the timings t21 to t23, and sequentially starts the display driving based on the sub-frame image FS1 ((B) of
Next, in response to a pulse of the vertical synchronization signal Vsync at the timing t23, the driving section 20 performs line-sequential scanning from the top of the display section 30 to the bottom thereof in the period of the timings t23 to t25, and sequentially starts the display driving based on the sub-frame image FS2 ((B) of
Next, the light emitting operation of the sub-pixel 9 will be described in detail.
In a single horizontal period (1H), the driving section 20 initializes the sub-pixel 9 (initialization period P1), performs Vth correction for suppressing the effect of element variation of the driving transistor DRTr onto image quality (Vth correction period P2), records the pixel voltage Vsig into the sub-pixel 9, and performs the μ (mobility) correction different from the Vth correction (writing μ-correction period P3). Then, thereafter, the light emitting element 49 of the sub-pixel 9 emits light at the luminance corresponding to the written pixel voltage Vsig (light emitting period P4). Hereinafter, the detailed description will be given.
First, before the initialization period P1, the power line driving section 22 sets the power supply signal DS as the voltage Vini ((B) of
Next, in the period (initialization period P1) of the timings t2 and t3, the driving section 20 initializes the sub-pixel 9. Specifically, at the timing t2, the data line driving section 23 sets the signal Sig as the voltage Vofs ((C) of
Next, the driving section 20 performs the Vth correction in the period of the timings t3 and t4 (Vth correction period P2). Specifically, the power line driving section 22 changes the power supply signal DS from the voltage Vini to the voltage Vccp, at the timing t3 ((B) of
Next, the scanning-line driving section 21 changes the voltage of the scanning signal WS from the high level to the low level, at the timing t4 ((A) of
Next, the driving section 20 performs recording of the pixel voltage Vsig and μ-correction on the sub-pixel 9 in the period (writing μ-correction period P3) of the timings t6 and t7. Specifically, the scanning-line driving section 21 changes the voltage of the scanning signal WS from the low level to the high level, at the timing t6 ((A) of
Next, in the period (light emitting period P4) after the timing t7, the driving section 20 causes the sub-pixel 9 to emit light. Specifically, at the timing t7, the scanning-line driving section 21 changes the voltage of the scanning signal WS from the high level to the low level ((A) of
Thereafter, the driving section 20 changes the power supply signal DS from the voltage Vccp to the voltage Vini after the period corresponding to the light emitting duty ratios DR1 and DR2 has passed, and then the light emitting period P4 ends.
Operation Mode M2
The operation mode M2 is an operation mode which is selected if the image indicated by the image signal Spic is a moving image. Hereinafter, the operation mode M2 will be described in detail.
In the operation mode M2, in a manner similar to that of the operation mode M1, the display device 1 displays the sub-frame image FS1 and the sub-frame image FS2 in a time division manner, in the period corresponding to the frame period T0. At this time, the control section 16 delays the light emitting period P4 relating to the sub-frame image FS1, in the operation mode M2. Hereinafter, the specific operation will be described.
First, in response to a pulse of the vertical synchronization signal Vsync at the timing t31, the driving section 20 sequentially starts the display driving based on the sub-frame image FS1, in the period of the timings t32 to t34, and sequentially terminates the display driving based on the sub-frame image FS1, in the period of the timings t33 to t35 ((B) of
Next, in response to a pulse of the vertical synchronization signal Vsync at the timing t33, the driving section 20 sequentially starts the display driving based on the sub-frame image FS2, in the period of the timings t33 to t35, and sequentially terminates the display driving based on the sub-frame image FS2, in the period of the timings t34 to t36 ((B) of
In addition, the sub-pixel 9 terminates the light emitting in the light emitting period P4 relating to the sub-frame image FS1, as shown in
In such a manner, the display device 1 alternately displays the sub-frame image FS1 and the sub-frame image FS2 in a time division manner. At this time, in the operation mode M2, the control section 16 delays the light emitting period P4 relating to the sub-frame image FS1, thereby making the period adjacent to the light emitting period P4 relating to the subsequent sub-frame image FS2. In other words, in the display device 1, a time length between the timing of middle of the light emitting period P4 relating to the sub-frame image FS1 and the timing of middle of the light emitting period P4 relating to the sub-frame image FS2 is set to be shorter than a half of the time length of the frame period T0. Thereby, as described below, it is possible to reduce image blurring and ghost images when the moving image is displayed.
In the operation mode M1, as shown in (C) of
In contrast, in the operation mode M2, as shown in (C) of
Operation Mode M3
The operation mode M3 is an operation mode which is selected when an area ratio of the still image region is approximately 50% of the entire region of the frame image F in the case where both the moving image and the still image are simultaneously displayed in one screen. Hereinafter, the operation mode M3 will be described in detail.
In the operation mode M3, the display device 1 divides the light emitting period P4 relating to the sub-frame image FS1 into two pieces, divides the light emitting period P4 relating to the sub-frame image FS2 into two pieces, and displays the sub-frame images FS1 and FS2. Hereinafter, the specific operation will be described.
First, in response to a pulse of the vertical synchronization signal Vsync at the timing t41, the driving section 20 sequentially starts first display driving based on the sub-frame image FS1 in a predetermined period starting from the timing t41, and sequentially terminates the first display driving based on the sub-frame image FS1 in a predetermined period starting from the timing t42 ((B) of
Next, in response to a pulse of the vertical synchronization signal Vsync at the timing t44, the driving section 20 sequentially starts first display driving based on the sub-frame image FS2 in a predetermined period starting from the timing t44, and sequentially terminates the first display driving based on the sub-frame image FS2 in a predetermined period starting from the timing t45 ((B) of
As described above, the driving section 20 performs the display driving based on the sub-frame image FS1 twice, and thereafter performs the display driving based on the sub-frame image FS2 twice. At this time, in the second display driving based on the sub-frame image FS1 and the second display driving based on the sub-frame image FS2, as described below, it is possible to cause the sub-pixel 9 to emit light without performing the initialization, the Vth correction, the recording of the pixel voltage Vsig, and the μ-correction.
In the second display driving, the voltage of the scanning signal WS is constantly at the low level. Thereby, the writing transistor WSTr is kept turned off. Hence, the voltage Vgs between the gate and the source of the driving transistor DRTr keeps the voltage Vemi which is set in the writing μ-correction period P3 in the first display driving.
First, when the first display driving is terminated, the power line driving section 22 sets the power supply signal DS as the voltage ext ((B) of
Then, in the period (light emitting period P4) after the timing t13, the driving section 20 causes the sub-pixel 9 to emit light. Specifically, the power line driving section 22 changes the power supply signal DS from the voltage Vext to the voltage Vccp, at the timing t13 ((B) of
Thereafter, the driving section 20 changes the power supply signal DS from the voltage Vccp to the voltage Vini after the predetermined period has passed, and then the light emitting period P4 ends.
In the operation mode M3, the control section 16 divides the light emitting period P4 relating to the sub-frame image FS1 into two pieces, and divides the light emitting period P4 relating to the sub-frame image FS2 into two pieces. At this time, as shown in (C) of
That is, for example, if both the moving image and the still image are simultaneously displayed in one screen, the operation mode M2 may be selected. In this case, in the moving image part in the screen, it is possible to reduce the image blurring and the like, but there is a concern about occurrence of flicker in the still image part. That is, in the operation mode M2, as shown in
In contrast, in the operation mode M3, the light emitting period P4 relating to the sub-frame image FS1 is divided into two pieces, and the light emitting period P4 relating to the sub-frame image FS2 is divided into two pieces. Thus, the first light emitting period P4 relating to the sub-frame FS1 and the second light emitting period P4 relating to the previous sub-frame image FS2 are made to be adjacent. Thereby, the quenching period can be divided into a period between the first light emitting period P4 and the second light emitting period P4 relating to the sub-frame image FS1 and a period between the first light emitting period P4 and the second light emitting period P4 relating to the sub-frame image FS2. Thus, it is possible to decrease the length of each quenching period. As a result, a user is less likely to feel flicker particularly in the still image part in the screen.
Operation Mode M4
The operation mode M4 is an operation mode which is selected when the area ratio of the still image region is equal to or greater than, for example, approximately 80% of the entire region of the frame image F in the case where both the moving image and the still image are simultaneously displayed in one screen. Hereinafter, the operation mode M4 will be described in detail.
In the operation mode M4, the display device 1 divides the light emitting period P4 relating to the sub-frame image FS1 into three pieces, divides the light emitting period P4 relating to the sub-frame image FS2 into three pieces, and displays the sub-frame images FS1 and FS2. Hereinafter, the specific operation will be described.
First, in response to a pulse of the vertical synchronization signal Vsync at the timing t51, the driving section 20 sequentially starts first display driving based on the sub-frame image FS1 in a predetermined period starting from the timing t51, and sequentially terminates the first display driving based on the sub-frame image FS1 in a predetermined period starting from the timing t52 ((B) of
Next, in response to a pulse of the vertical synchronization signal Vsync at the timing t56, the driving section 20 sequentially starts first display driving based on the sub-frame image FS2 in a predetermined period starting from the timing t56, and sequentially terminates the first display driving based on the sub-frame image FS2 in a predetermined period starting from the timing t57 ((B) of
In the operation mode M4, the control section 16 divides the light emitting period P4 relating to the sub-frame image FS1 into three pieces, and divides the light emitting period P4 relating to the sub-frame image FS2 into three pieces. At this time, as shown in (C) of
Advantages
As described above, in the present embodiment, the image is analyzed, and on the basis of the analysis result, the light emitting timing or the light emitting duty ratio is changed. Therefore, it is possible to set the light emitting timing appropriate for a feature of the image, and thus it is possible to improve image quality.
In the present embodiment, in the operation mode M2, the light emitting periods relating to the two sub-frame images, which are generated from a single frame image, are made to be adjacent to each other. Therefore, it is possible to reduce image blurring and ghost images when the moving image is displayed.
In the present embodiment, in the operation modes M3 and M4, each of the light emitting periods relating to the two sub-frame images is divided into a plurality of periods. Therefore, it is possible to decrease the length of each quenching period, and it is possible to correct flicker particularly in the still image part in the screen.
In the embodiment, in the operation mode M2, as shown in
In the embodiment, the length (light emitting duty ratio DR1) of the light emitting period P4 relating to the sub-frame image FS1 is set to be equal to the length (light emitting duty ratio DR2) of the light emitting period P4 relating to the sub-frame image FS2. However, the present technology is not limited to this. Instead of this, the length of the light emitting period P4 relating to the sub-frame image FS1 may be set to be different from the length of the light emitting period P4 relating to the sub-frame image FS2.
In the embodiment, in the operation mode M3, as shown in
In the embodiment, the sub-frame generation section 11 generates the two sub-frame images FS1 and FS2 on the basis of the frame image F which is indicated by the image signal Spic. However, the present technology is not limited to this. Instead of this, three or more sub-frame images may be generated. Hereinafter, display devices 1D and 1E, which generate the three sub-frame images FS1 to FS3, will be described in detail.
The display device 1D displays the three sub-frame images FS1 to FS3 in a time division manner, in the period corresponding to the frame period T0. Hereinafter, the specific operation will be described.
First, in response to a pulse of the vertical synchronization signal Vsync at the timing t71, the driving section 20 sequentially starts the display driving based on the sub-frame image FS1, in the period of the timings t72 to t74 ((B) of
Next, in response to a pulse of the vertical synchronization signal Vsync at the timing t73, the driving section 20 sequentially starts the display driving based on the sub-frame image FS2, in the period of the timings t73 to t75 ((B) of
Next, in response to a pulse of the vertical synchronization signal Vsync at the timing t75, the driving section 20 sequentially starts the display driving based on the sub-frame image FS3, in the period of the timings t75 to t77 ((B) of
As described above, in the display device 1D, the control section 16 delays the light emitting period P4 relating to the sub-frame image FS1, thereby making the period adjacent to the light emitting period P4 relating to the subsequent sub-frame image FS2. Thereby, it is possible to reduce image blurring and the like when the moving image is displayed.
In the display device 1D, the light emitting duty ratios DR1 to DR3 are set to be equal to one another, but the present technology is not limited to this. Hereinafter, a display device 1E, of which the light emitting duty ratio DR2 is set to be large, will be described in detail.
First, in response to a pulse of the vertical synchronization signal Vsync at the timing t81, the driving section 20 sequentially starts the display driving based on the sub-frame image FS1, in the period of the timings t82 to t84 ((B) of
Next, in response to a pulse of the vertical synchronization signal Vsync at the timing t83, the driving section 20 sequentially starts the display driving based on the sub-frame image FS2, in the period of the timings t83 to t85 ((B) of
Next, in response to a pulse of the vertical synchronization signal Vsync at the timing t85, the driving section 20 sequentially starts the display driving based on the sub-frame image FS3, in the period of the timings t85 to t87 ((B) of
As described above, in the display device 1E, the control section 16 elongate the light emitting period P4 relating to the sub-frame image FS2, thereby making the light emitting period P4 relating to the sub-frame image FS1 and the light emitting period P4 relating to the sub-frame image FS2 adjacent and making the light emitting period P4 relating to the sub-frame image FS2 and the light emitting period P4 relating to the sub-frame image FS3. In such a manner, it is also possible to reduce image blurring and the like when the moving image is displayed.
In the embodiment, the image signal Spic including the frame image F is supplied, and the sub-frame generation section 11 generates the sub-frame images FS1 and FS2 on the basis of the frame image F. However, the present technology is not limited to this. Instead of this, for example, in a manner similar to that of the display device 1F shown in
Next, application examples of the display device according to the above-mentioned embodiment will be described. The display device according to the embodiment can be applied to display devices of electronic apparatuses in all fields for displaying an image signal, which is input from the outside, or an image signal, which is generated from the inside, as an image. The electronic apparatuses correspond to a television apparatus, an electronic book, a smartphone, a digital camera, a notebook-size personal computer, a video camera, a head-mount display, and the like.
The display device according to the embodiment may be provided as, for example, such a module shown in
The display device described in the above-mentioned embodiment can be applied to various electronic apparatuses. According to the present technology, it is possible to set the light emitting timing appropriate for the feature of the displayed image while increasing the dynamic range, and thus it is possible to improve image quality. The present technology greatly contributes to reduction in image blurring and ghost images in the display device, such as a floor-standing type television apparatus, having a large screen size.
The present technology has been hitherto described with reference to embodiments, the modification examples, and the application examples for the electronic apparatus, but the present technology is not limited to the embodiments and the like, and may be modified into various forms.
For example, in the embodiment, one capacitance element Cs is provided in each sub-pixel 9. However, the present technology is not limited to this. Instead of this, for example, similarly to the sub-pixel 7 shown in
Further, in the embodiment, an organic EL element is used as the light emitting element. However, the present technology is not limited to this. Instead of this, for example, various light emitting elements such as inorganic EL element may be employed. Further, in this example, the present technology has been applied to the self-light-emitting-type display device, but is not limited this. Instead of this, for example, the present technology may be applied to a non-light-emitting-type display device such as a liquid crystal display device.
It should be noted that the effects described in the present specification are just examples and are not limited to this. Further, the present technology may have other effects.
It should be noted that the present technology may adopt the following configurations.
(1) A display device including:
a display section that has pixels; and
a driving section that drives the display section on the basis of luminance information including a plurality of sub-luminance information pieces,
in which the driving section drives the pixels in a time-division manner on the basis of each sub-luminance information piece during a single display period or a plurality of display periods which is set in each sub-luminance information piece, and
in which one or both of a timing of start of each display period and the number of the display periods are changeable.
(2) The display device according to (1),
in which the driving section has a first operation mode of setting one display period in each sub-luminance information piece,
in which the luminance information includes a predetermined number of sub-luminance information pieces which includes a first sub-luminance information piece and a second sub-luminance information piece, and
in which in the first operation mode, a first timing difference between a timing of middle of the display period, which is set in the first sub-luminance information piece, and a timing of middle of the display period, which is set in the second sub-luminance information piece, is shorter than a divided time length which is obtained by dividing a time length of a frame period by the predetermined number.
(3) The display device according to (2),
in which the driving section has a second operation mode of setting one display period in each sub-luminance information piece, and
in which the first timing difference in the second operation mode is longer than the first timing difference in the first operation mode.
(4) The display device according to (2) or (3),
in which the luminance information further includes third sub-luminance information pieces.
(5) The display device according to (4),
in which a display period, which is set in the second sub-luminance information piece, is longer than a display period, which is set in the first sub-luminance information piece, and a display period which is set in the third sub-luminance information piece.
(6) The display device according to any one of (2) to (5),
in which in the first operation mode, the first timing difference is smaller than a second timing difference between a timing of middle of a final period among a plurality of display periods, which is set in a single luminance information piece, and a timing of middle of a first period among a plurality of display periods which is set in a subsequent single luminance information piece to the single luminance information piece.
(7) The display device according to any one of (2) to (6),
in which the driving section further has a third operation mode of setting a plurality of display periods in each sub-luminance information piece,
in which in the third operation mode,
(8) The display device according to (7),
in which the driving section sets two display periods in each sub-luminance information piece, in the third operation mode.
(9) The display device according to (7) or (8),
in which in the third operation mode,
(10) The display device according to (7) or (8),
in which in the third operation mode,
(11) The display device according to any one of (2) to (10),
in which the driving section determines the operation mode on the basis of an amount of motion of a frame image.
(12) The display device according to any one of (2) to (11),
in which the driving section determines the operation mode on the basis of a proportion of an image part with motion in a frame image.
(13) The display device according to any one of (1) to (12), further including
a correction section that corrects the corresponding sub-luminance information piece on the basis of a length of each display period.
(14) The display device according to any one of (1) to (13), further including
a signal generation section that divides a range of a value of input luminance information into a plurality of grayscale ranges and acquires a luminance information component in each grayscale range of the input luminance information, as each sub-luminance information piece.
(15) A display device including:
a display section that has pixels;
a light emitting section; and
a driving section that drives the display section and the light emitting section on the basis of luminance information including a plurality of sub-luminance information pieces,
in which the driving section drives the pixels in a time-division manner on the basis of each sub-luminance information piece, and drives the light emitting section during a single display period or a plurality of light emitting periods which is set in each sub-luminance information piece, and
in which one or both of a timing of start of each light emitting period and the number of the light emitting periods are changeable.
(16) The display device according to (15),
in which the display section is a liquid crystal display section,
in which the light emitting section is a backlight, and
in which the driving section has a plurality of operation modes, and changes one or both of the timing of start of each light emitting period and the number of the light emitting periods, in accordance with the operation modes.
(17) A method of driving a display device including:
setting a single display period or a plurality of display periods in each of the plurality of sub-luminance information pieces included in luminance information; and
driving pixels in a division manner on the basis of each sub-luminance information piece during the single display period or the plurality of display periods,
in which one or both of a timing of start of each display period and the number of the display periods are changeable.
(18) An electronic apparatus including:
a display device; and
a control section that performs operation control on the display device,
in which the display device includes
in which the driving section drives the pixels in a time-division manner on the basis of each sub-luminance information piece during a single display period or a plurality of display periods which is set in each sub-luminance information piece, and
in which one or both of a timing of start of each display period and the number of the display periods are changeable.
It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof.
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2014-031399 | Feb 2014 | JP | national |
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Office Action from Japan Patent Office for JP2014-031399 issued Sep. 12, 2017. |
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