Patent Grant
9697759
This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2013-211049 filed on Oct. 8, 2013.
The present invention relates to a drive device for a display medium, a non-transitory computer readable medium storing a program causing a computer to execute a process for a display medium, a process for display medium and a display apparatus.
According to an aspect of the invention, there is provided a drive device for a display medium, comprises: a control unit which controls density of a display color of a predetermined range in which glare may likely occur, of display colors of an image displayed on a reflective type display medium, based on brightness information indicating brightness of irradiation beams irradiated on the display medium so that occurrence of the glare as to the display color of the predetermined range can be suppressed.
Exemplary embodiments of the present invention will be described in detail based on the following figures, wherein:
(First Exemplary Embodiment)
The drive device 20 is provided with a voltage application portion 30, a control portion 40, and a brightness information acquisition portion 42. The voltage application portion 30 applies a voltage between a display-side electrode 3 and a back-side electrode 4 of the display medium 10. The control portion 40 controls the voltage application portion 30 in accordance with color information of an image displayed on the display medium 10. The brightness information acquisition portion 42 acquires brightness information indicating brightness of irradiation beams irradiated on the display medium 10.
In the display medium 10, a display substrate 1 having translucency and used as an image display surface, and a back substrate 2 used as a non-display surface are disposed to be opposed to each other at a distance from each other. In addition, a predetermined distance between the display substrate 1 and the back substrate 2 is kept, and a gap member 5 partitioning a space between the substrates into a plurality of cells is provided so as to prevent in-plane particle groups of the display medium from leaning. Incidentally, one cell is shown in
In addition, in the exemplary embodiment, the display-side electrode 3 is a common electrode formed on the whole surface of the display substrate 1 and the back-side electrode 4 is constituted by a plurality of isolated electrodes to thereby form an electrode configuration supporting so-called active matrix driving, by way of example. In addition, although pixels are formed correspondingly to the plurality of isolated electrodes respectively, the pixels and the cells may or may not correspond to each other.
For example, a transparent dispersion medium 6 made of an insulating liquid, and a cyan colored particle group 11C (hereinafter also referred to as cyan particles C), a magenta colored particle group 11M (hereinafter also referred to as magenta particles M), a yellow colored particle group 11Y (hereinafter referred to as yellow particles Y) and a white colored particle group 12W (hereinafter also referred to as white particles W) which are dispersed in the dispersion medium 6 are sealed inside the cell. Although the exemplary embodiment will be described in the case where three kinds of (i.e. cyan, magenta and yellow) colored particle groups are provided as the colored particle groups moving between the substrates, the kinds of colors are not limited thereto. In addition, the number of kinds of colored particle groups moving between the substrates may be two or may be four or more.
As shown in
For example, in the case where the pulse width (voltage application time) of the applied voltage is set to be constant, the particle quantity of yellow particles Y moved from the back substrate 2 side to the display substrate 1 side can be controlled (voltage value modulation) by changing the voltage value of the applied voltage. For example, when the pulse width of the applied voltage is set to be constant and the voltage value is set as a desired voltage value not lower than +V1a for controlling the particle quantity of yellow particles Y moved from the back substrate 2 side to the display substrate 1 side, the yellow particles Y having a particle quantity corresponding to the voltage value are moved to the display substrate 1 side. In this manner, gradation display of the yellow particles Y can be controlled. The same rule applies to the particle quantity in the case where the yellow particles Y on the display substrate 1 side are moved to the back substrate 2 side.
Incidentally, configuration may be made so that the voltage value of the applied voltage can be set to be constant and the pulse width can be changed to control the particle quantity of moving particles to thereby control the gradation display (pulse width modulation). For example, when the voltage value of the applied voltage is set as a predetermined voltage value not lower than +V1a for controlling the particle quantity of yellow particles Y moved from the back substrate 2 side to the display substrate 1 side, the particle quantity of yellow particles Y moving to the display substrate 1 side is larger as the pulse width of the voltage is longer. Accordingly, when the voltage value is fixed and the pulse width is set as a pulse width having a length corresponding to a gradation, the gradation display of the yellow particles Y can be controlled. The exemplary embodiment will be described in the case where the particle quantity of moving particles is controlled by voltage value modulation by way of example. Incidentally, the same rule will also apply to the cyan particles C and the magenta particles M which will be described as follows.
As shown in
Similarly to the aforementioned yellow particles Y, the particle quantity of cyan particles C moved from the back substrate 2 side to the display substrate 1 side can be controlled by the voltage value modulation or the pulse width modulation. For example, assume that the particle quantity of cyan particles C moved from the back substrate 2 side to the display substrate 1 side is controlled by the voltage value modulation. When the pulse width of the applied voltage is set to be constant and the voltage value is set as a desired voltage value not lower than +V2a in this case, the cyan particles C having a particle quantity corresponding to the voltage value are moved to the display substrate 1 side. In this manner, gradation display of the cyan particles C can be controlled.
As shown in
As shown in
Similarly to the aforementioned yellow particles Y and the aforementioned cyan particles C, the particle quantity of magenta particles M moved from the back substrate 2 side to the display substrate 1 side can be controlled by the voltage value modulation or the pulse width modulation. For example, assume that the particle quantity of magenta particles M moved from the back substrate 2 side to the display substrate 1 side is controlled by the voltage value modulation. When the pulse width of the applied voltage is set to be constant and the voltage value is set as a desired voltage value not lower than +V3a in this case, the magenta particles M having a particle quantity corresponding to the voltage value are moved to the display substrate 1 side. In this manner, gradation display of the magenta particles M can be controlled.
As shown in
Although the exemplary embodiment has been described in the case where all the yellow particles Y, the cyan particles C and the magenta particles M are charged positively, the charging polarity is not limited thereto. For example, the yellow particles Y and the magenta particles M may be charged positively and the cyan particles C may be charged negatively. In this case, the relation between the applied voltage and the display density becomes a relation shown in
In addition, according to the exemplary embodiment, for example, each of the cyan particle C and the magenta particle M has a particle diameter which is smaller than the particle diameter of the yellow particle Y and which is small enough to pass through a gap between adjacent ones of some aggregated yellow particles Y when the yellow particles Y are deposited and aggregated on any one of the substrates. However, the invention is not limited thereto. The particle diameter of each of the cyan particle C and the magenta particle M may be set suitably in accordance with the charging polarity and responsiveness, etc. of the particle.
On the other hand, the white particles W are particles each with a smaller electric charge amount or with no electric charge amount, in comparison with the colored particles of the yellow particles Y, the magenta particles M and the cyan particles C. Therefore, even when the voltage by which the colored particles are made to migrate to one of the display substrate 1 and the back substrate 2 is applied between the display-side electrode 3 and the back-side electrode 4, the migration speed of the white particles W is slower than the migration speed of each of the colored particles so that the white particles W are not deposited on any one of the substrates but float in the dispersion medium 6. Therefore, when all the colored particles of the yellow particles Y, the magenta particles M and the cyan particles C are moved to the back substrate 2 side, the whole surface turns into white display. That is, the display medium 10 is a display medium whose base is white in color. Incidentally, the color of the base is not limited to white. That is, particles having another color than white may be used as the particles floating in the dispersion medium 6. In addition, a display medium having a configuration in which floating particles are not used may be used.
The drive device 20 (the voltage application portion 30 and the control portion 40) applies a voltage corresponding to color information of an image to be displayed, between the display-side electrode 3 and the back-side electrode 4 to move colored particles having a quantity corresponding to the color information. Thus, the image is displayed on the display medium 10.
The voltage application portion 30 is a voltage application device for applying a voltage to the display-side electrode 3 and the back-side electrode 4. The voltage application portion 30 is electrically connected to the display-side electrode 3 and the back-side electrode 4 and connected to the control portion 40. The voltage application portion 30 applies a voltage to the display-side electrode 3 and the back-side electrode 4 in accordance with an instruction issued from the control portion 40.
As shown in
The brightness information acquisition portion 42 acquires brightness information indicating brightness of irradiation beams irradiated on the display medium 10. The exemplary embodiment will be described in the case where an illuminance sensor detecting illuminance of irradiation beams irradiated on the display medium 10 is used as the brightness information acquisition portion 42 by way of example. In this case, the illuminance sensor detects illuminance (luxes) as brightness information of irradiation beams irradiated on the display medium 10. The illuminance sensor is disposed in the neighborhood of the display medium 10 so as to be able to detect the illuminance of the irradiation beams irradiated on the display medium 10.
Next, as an effect of the exemplary embodiment, control executed by the CPU 401 of the control portion 40 will be described with reference to a flow chart shown in
First, in Step S10, color information of an image to be displayed on the display medium 10, that is, color information of each of respective colors, i.e. yellow, magenta and cyan is acquired from a not-shown external device, for example, through the I/O 405.
In Step S12, illuminance as brightness information detected by the brightness information acquisition portion 42 is acquired.
In Step S14, determination is made as to whether the illuminance acquired in Step S12 is at least a predetermined threshold or not. The threshold is set as a value based on which it can be determined that glare may likely occur as to a display color of a predetermined range in which glare may likely occur when the illuminance is not smaller than the threshold. Accordingly, when the illuminance is at least (not smaller than) the predetermined threshold, that is, when glare may likely occur as to the display color of the predetermined range in which glare may likely occur, the flow of processing shifts to Step S16. On the other hand, when the illuminance is smaller than the predetermined threshold, that is, when glare may unlikely occur as to the display color of the predetermined range in which glare may likely occur, the flow of processing shifts to Step S20. Incidentally, for example, white as the color of a base of the display medium 10 and a bright color close to white are also included in the display color of the predetermined range in which glare may likely occur.
In Step S16, a contrast correction process is executed on the color information (pixel values) of the three colors acquired in Step S10 based on the illuminance of the irradiation beams irradiated on the display medium 10, which illuminance is acquired in Step S12. For example, the color information of the respective colors CMY is subjected to contrast correction so that the image density increases as the detected illuminance increases. That is, the contrast correction is performed so that as the detected illuminance increases, the image density increases so as to decrease the reflection quantity of the color of the base with respect to the irradiation beams. Thus, occurrence of glare can be suppressed.
Specifically, as shown in
In the example of
Although the first correspondence between the illuminance and the shift quantity 64 may be set to be the same for all the colors yellow, magenta and cyan as described above, the first correspondence may be set in accordance with each color. That is, the first correspondence may be set in accordance with each color so that occurrence of glare as to the display color of the predetermined range in which glare may likely occur can be suppressed effectively.
In addition, as to the color information Cin on the low density side, color information Cout subjected to the correction may be set as a predetermined fixed value, for example, as shown in
In Step S18, a gamma correction process is executed on the color information (pixel values) of the three colors after the contrast correction of Step S16 based on the illuminance of the irradiation beams irradiated on the display medium 10, which illuminance is acquired in Step S12. For example, gamma correction is applied to the color information of each of the colors CMY so that the image density increases as the detected illuminance increases. That is, the gamma correction is performed so that as the detected illuminance increases, the image density increases so as to decrease the reflection quantity of the color of the base with respect to the irradiation beams. In this manner, occurrence of glare can be suppressed.
Specifically, as shown in
Incidentally, although the second correspondence between the illuminance and the shift quantity 74 may be set to be the same for all the colors yellow, magenta and cyan as described above, the second correspondence may be set in accordance with each color. That is, configuration may be made in such a manner that the second correspondence can be set in accordance with each color so that occurrence of glare as to the display color of the predetermined range in which glare may likely occur can be suppressed effectively.
In addition, as to the color information Cin on the low density side, color information Cout subjected to the correction may be set as a predetermined fixed value similarly to the contrast correction, for example, as shown in
Incidentally, the first correspondence in the contrast correction and the second correspondence in the gamma correction are set to have an optimal combination so that occurrence of glare as to the display color of the predetermined range in which glare may likely occur can be suppressed effectively.
In the case where the contrast correction and the gamma correction have been performed in the Steps S16 and S18, the color information subjected to the corrections is outputted to the voltage application portion 30 in Step S20. When these corrections are not performed, the color information acquired in Step S10 is outputted directly to the voltage application portion 30.
In this manner, when the detected illuminance is not smaller than the threshold based on which it can be determined that glare may likely occur in the exemplary embodiment, the image density is increased in accordance with the illuminance to thereby decrease the brightness of the color in which glare occurs easily, such as white which is the color of the base. Incidentally, the brightness means brightness, for example, defined based on JIS8715, JIS8148 and ISO2470, etc.
For example, as shown in
In addition, as shown in
Incidentally, the exemplary embodiment has been described in the case where both the contrast correction and the gamma correction are executed. However, configuration may be made so that either of the contrast correction and the gamma correction is executed. In this case, when only the contrast correction is executed, the first correspondence is set optimally so that occurrence of glare as to the display color of the predetermined range where glare may likely occur can be suppressed effectively. When only the gamma correction is executed, the second correspondence is set optimally so that occurrence of glare as to the display color of the aforementioned range in which glare may likely occur can be suppressed effectively.
In addition, the exemplary embodiment has been described in the case where the input/output characteristic of the color information is corrected so that the contrast correction and the gamma correction are performed to suppress occurrence of glare. However, configuration may be made so that, for example, occurrence of glare can be suppressed based on an analysis result of an image displayed on the display medium 10. For example, a region of a display color of a predetermined range in which glare may likely occur, i.e. a region (for example, a background region) having an area in which glare may likely occur is extracted from the image displayed on the display medium 10, and the density of pixels in the extracted region is increased. In this manner, the image in the region having the area where glare may likely occur is darkened so that occurrence of glare can be suppressed.
In addition, although the exemplary embodiment has been described in the case where illuminance of irradiation beams is detected as brightness information, configuration may be made so that any other physical quantity indicating brightness such as the light quantity or intensity of irradiation light can be detected.
In addition, configuration may be made so that weather information can be acquired as the brightness information. In this case, for example, the brightness information acquisition portion 42 is configured to have a function of making connection to the Internet etc. to thereby acquire weather information corresponding to the place where the display medium 10 is located. The control portion 40 corrects the color information based on the acquired weather information. For example, in the case where the acquired weather is fine weather, the control portion 40 shifts the input/output characteristic 60 to the input/output characteristic 62 in the contrast correction to correct the color information, and shifts the input/output characteristic 70 to the input/output characteristic 72 in the gamma correction to correct the color information. In this manner, even in an environment in which the weather is fine and glare occurs easily, occurrence of glare can be suppressed.
Incidentally, the configuration (see
(Second Exemplary Embodiment)
A second exemplary embodiment of the invention will be described below. A display apparatus according to the second exemplary embodiment is different from the display apparatus 100 according to the first exemplary embodiment in the point that the brightness information acquisition portion 42 is configured to include a plurality of (four in
As shown in
In addition, as shown in
As an effect of the exemplary embodiment, control executed by the CPU 401 of the control portion 40 will be described below with reference to a flow chart shown in
The flow chart shown in
Step S10 is the same as Step S10 of the flow chart shown in
In Step S11, the voltage application portion 30 is controlled so that, for example, a white image (solid image) with a density of 100% is displayed on each of the regions 44A to 44D of the display medium 10.
In Step S12, illuminances of the reflected beams of the irradiation beams irradiated on the regions 44A to 44D, which illuminances are detected by the illuminance sensors 42A to 42D are acquired respectively.
In Step S13, an average value of the illuminances of the reflected beams detected by the illuminance sensors 42A to 42D is calculated.
In Step S14, determination is made as to whether the average value of the illuminances of the reflected beams calculated in Step S13 is at least a predetermined threshold or not. Processes after Step S14 are the same as those in the first exemplary embodiment so that description thereof will be omitted.
In this manner, in the exemplary embodiment, the white images are displayed in the four corners of the display medium 10 and the illuminances of the reflected beams on the regions are directed directly by the illuminance sensors 42A to 42D so that contrast correction etc. is performed. Accordingly, occurrence of glare can be suppressed more accurately.
Further, in the exemplary embodiment, the illuminance sensors 42A to 44A detect the reflected beams from the directions different from one another and determination is made as to whether glare occurs or not based on the average value of the thus detected reflected beams. Accordingly, occurrence of glare can be suppressed accurately in comparison with the case where, for example, reflected beams in the same direction are detected.
Incidentally, although the exemplary embodiment has been described in the case where four illuminance sensors are provided, the number of illuminance sensors is not limited thereto. One to three illuminance sensors or five or more illuminance sensors may be used alternatively. In addition, the regions where the white images are displayed are also not limited to the four corners of the display medium 10. The white images may be placed in any other places as long as the places are peripheral portions of the display medium 10.
(Third Exemplary Embodiment)
A third exemplary embodiment of the invention will be described below. A display apparatus according to the third exemplary embodiment is the same as the display apparatus according to the second exemplary embodiment so that description thereof will be omitted.
As an effect of the exemplary embodiment, control executed by the CPU 401 of the control portion 40 will be described below with reference to a flow chart shown in
The flow chart shown in
Step S10 is the same as Step S10 of the flow chart shown in
In Step S10A, the voltage application portion 30 is controlled so that a particle color image (solid image) having a density 100% of a selected particle color (for example, cyan) selected from the respective particle colors CMY can be displayed on each of the regions 44A to 44D of the display medium 10.
In Step S10B, illuminances of reflected beams of irradiation beams irradiated on the regions 44A to 44D, which illuminances are detected by the illuminance sensors 42A to 42D, that is, densities of the selected particle color are acquired respectively.
In Step S10C, an average value of the illuminances of the reflected beams detected by the illuminance sensors 42A to 42D is calculated.
In Step S10D, color information of the selected particle color, of the color information acquired in Step S10 is corrected based on the average value of the illuminances of the reflected beams calculated in Step S10C. Specifically, the color information is corrected based on the average value of the illuminances of the reflected beams calculated in Step S10C, that is, a difference between the density of the selected particle color and the density of the particle color image display on each of the regions 44A to 44D. By this correction, color shift caused by the influence of the irradiation beams can be corrected.
In Step S10E, determination is made as to whether the processes of Steps S10A to S10D have been executed on all the particle colors CMY or not. When the processes of Steps S10A to S10D have been executed on all the particle colors CMY, the flow of processing shifts to Step S11. When there is an unprocessed particle color, the flow of processing returns to Step S10A so that the unprocessed particle color can be selected and the processes of Steps S10A to S10D can be executed.
In this manner, the solid images of the respective particle colors are displayed successively on the regions 44A to 44D in the four corners of the display medium 10 and the illuminances of the reflected beams on the regions 44A to 44D are detected so that densities of the respective particle colors can be detected and the color information can be corrected based on the detected densities. Accordingly, color shift caused by the influence of the irradiation beams can be suppressed.
Incidentally, even when the color information about each particle color is corrected, there may be a case where glare still occurs. To solve this problem, a process of suppressing occurrence of glare is executed in Steps S11 to S18. These processes are the same as Steps S11 to S18 in
Incidentally, although the exemplary embodiment has been described in the case where CMY solid images are displayed successively on the regions 44A to 44D and illuminances of reflected beams on the regions 44A to 44D are detected respectively, each of the regions 44A to 44D may be split into three regions and CMY solid images may be displayed simultaneously on these three split regions. In this case, configuration may be made so that illuminance sensors each having spectral sensitivity for the colors CMY are provided in the regions 44A to 44D respectively so as to detect illuminances of reflected beams on the regions 44A to 44D. In this case, as each of the illuminance sensors provided in the regions 44A to 44D, three illuminance sensors for the colors CMY may be provided or one single illuminance sensor which has sensitivity for all the colors CMY and which can detect illuminances of reflected beams of all the colors simultaneously may be used. When configuration is made thus, it is not necessary to display CMY solid images successively but the CMY solid images can be displayed simultaneously. Accordingly, the processing time can be shortened.
The foregoing description of the embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to understand the invention for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention defined by the following claims and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2013-211049 | Oct 2013 | JP | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 7109984 | Moon | Sep 2006 | B2 |
| 7737963 | Moon | Jun 2010 | B2 |
| 20030058235 | Moon | Mar 2003 | A1 |
| 20050017990 | Yoshida | Jan 2005 | A1 |
| 20060274006 | Moon | Dec 2006 | A1 |
| 20090040297 | Harada | Feb 2009 | A1 |
| 20110032227 | Miyaguchi | Feb 2011 | A1 |
| 20110122109 | Nose | May 2011 | A1 |
| 20140218345 | Matsuura | Aug 2014 | A1 |
| Number | Date | Country |
|---|---|---|
| 2003-186455 | Jul 2003 | JP |
| 2009-251066 | Oct 2009 | JP |
| 2011-53662 | Mar 2011 | JP |
| 2011-248060 | Dec 2011 | JP |
| Entry |
|---|
| Abstract and machine translation of JP 2009-251066. |
| Abstract and machine translation of JP 2011-248060. |
| Number | Date | Country | |
|---|---|---|---|
| 20150124010 A1 | May 2015 | US |
