Computer graphics processing and selective visual display system – Plural physical display element control system – Display elements arranged in matrix
Reexamination Certificate
2000-05-12
2004-02-10
Nguyen, Chanh (Department: 2675)
Computer graphics processing and selective visual display system
Plural physical display element control system
Display elements arranged in matrix
C345S204000
Reexamination Certificate
active
06690344
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to display devices having significant screen brightness (i.e., luminance) which consume a small amount of electric power, and in particular, to a display driving device which controls a variation of contact/separation directions of an actuator with respect to an optical wave guide plate in response to an input image signal input.
BACKGROUND OF THE INVENTION
Cathode ray tubes (CRT), liquid crystal devices and plasma display devices are known in the art. Cathode ray tubes are known as normal television receiving devices and monitor devices for computers. Although the screens are bright, they consume much electric power, and the overall depth of the display device relative to the size of the screen is great. In addition there are other problems such as diminished resolution in the peripheral portions of the display image, distorted images and graphics, lack of memory feature and an inability to achieve large scale displays. The reason for this is that the light emission point (beam spot) is broadened where electron beams reach the fluorescent face of the CRT diagonally because the electron beam is significantly deflected when fired from the electron gun that images are displayed obliquely. In addition, there are limits to maintaining vacuum in the large spaces of CRT's.
While liquid crystal displays have certain advantages such as being reduced in size and consuming little power, the brightness of the screen is inferior and the screen viewing angle is narrow. In addition, they have an additional disadvantage in that the configuration of the drive circuits has become very complex due to the fact that gradation expression (gray scale) is accomplished by changes in the voltage level. For example, when a digital data line is used, the drive circuit is configured to have a latch circuit which holds component RGB data (each 8 bits) for a specified period of time, a voltage selector, a multiplexer which switches the voltage level in response to the gradation number, and an output circuit for adding the data output from this multiplexer to a digital data line. In this case, if the gradation number increases, there is a need for the multiplexer to act to switch many levels, thus making the configuration more complex.
When an analog data line is used, the drive circuits are configured to have a shift register for aligning component RGB data (each 8 bits) successively input in a horizontal direction, a latch circuit which holds parallel data from the shift register a designated period of time, a level shifter which takes the voltage level adjustment, a digital to analog (D/A) converter which converts the data output from the level shifter to an analog signal, and an output circuit for adding the signal output for this D/A analog converter to an analog data stream. In this case, while a designated voltage is obtained in response to gradation by using an operating amplifier in the D/A converter, the use of an operating amplifier which outputs highly precise voltages becomes necessary as the range of gradation expands. This has the disadvantage that construction is more complex and more expensive.
Plasma displays are similar to liquid crystal display devices in that the display does not take up much space. In addition, since the plasma display is a flat surface, it has the advantage of being easy to view. In particular, with an alternating type plasma display, there is the added advantage that there is no need to have a refresh memory due to the cell memory function. However, there is a need to alternately switch the polarity of the voltage and have a continuous discharge in order to maintain the memory function in cells. Because of that, a first pulse generator that generates a sustained pulse in the X direction and a second pulse generator that generates a sustained pulse in the Y direction must be provided in the drive circuits. Thus there is a problem that the configuration of the drive circuits is more complex.
A recently developed display device, shown in
FIG. 66
, includes an actuator
1000
. Actuator
1000
is configured with an actuator unit
1008
that has a piezoelectric/electrostriction layer
1002
sandwiched between an upper electrode
1004
and a lower electrode
1006
formed respectively on the upper and lower surfaces of piezoelectric/electrostriction layer
1002
. A substrate
1014
includes a vibrator
1010
and a securing portion
1012
. Vibrator
1010
is disposed on a lower part of actuator unit
1008
. Lower electrode
1006
contacts vibrator
1010
such that actuator unit
1008
is supported by vibrator
1010
.
Substrate
1014
is composed of ceramic. A concave portion
1016
is formed in substrate
1014
and of a size so that vibrator
1010
is relatively thin. A displacement transfer portion
1020
makes the area of contact with optical wave guide plate
1018
a designated size. Displacement transfer portion
1020
is connected to upper electrode
1004
of actuator unit
1008
, and in the example in
FIG. 66
, displacement transfer portion
1020
is located close to optical wave guide plate
1018
when actuator
1000
is in a normal state (unmoved) and is disposed so that it contacts optical wave guide plate
1018
at a distance equal to or less than the wave length of light when in a state of excitation.
Then, for example, light
1022
is introduced from the end of optical wave guide plate
1018
. In this case, all of light
1022
is totally reflected in the interior without passing the front face and back face of optical wave guide plate
1018
due to the index of refraction of optical wave guide plate
1018
. In this state, a voltage signal corresponding to an image signal is selectively applied to actuator
1000
via upper electrode
1004
and lower electrode
1006
. By performing the displacement due to normal and excited states of actuator
1000
, the contact and separation of optical wave guide plate
1018
with displacement transfer portion
1020
is controlled. By virtue of this, the scattered light (leakage light)
1024
of optical wave guide plate
1018
is controlled and an image corresponding to the image signal is displayed on optical wave guide plate
1018
.
This display device has the following advantages: (1) it reduces power consumption, (2) it increases screen brightness, and (3) when using a color screen, there is no need to increase the number of pixels as compared to a black and white screen.
The peripheral circuits of the display device as described above, shown in
FIG. 67
, are configured to have a display
1030
which has multiple arranged pixels, a vertical shift circuit
1034
which deduces the number of rows necessary for vertical selection line
1032
(which are common to the pixels comprising one column), and a horizontal shift circuit
1038
which deduces the number of columns necessary for signal line
1036
, which are common to the pixels comprising one column. Because of that, the display information (output voltage) output for the pixel groups of a selected row from horizontal shift circuit
1038
is also applied to the pixel groups related to non-selected rows, thus driving unnecessary pixels. Thus, unnecessary power consumption occurs, which is a disadvantage in reducing the consumption of electric power.
In addition, in endeavoring to improve brightness and contrast with such things as memory effect while increasing the row selection number during the vertical scanning interval, there is a need to supply high voltage to the vertical shift circuit. Moreover, there is a necessity to supply at least three levels of voltage, thus making customization of an IC for the vertical shift circuit more difficult. Reducing the size of the IC's and making them have many outputs becomes difficult, and making displays thinner is hindered by the packaging space of driver IC.
SUMMARY OF THE INVENTION
Briefly stated, a display driving device drives a display which includes an optical wave guide plate and a drive section disposed opposite one face of the optical wave guide plate. The d
Akao Takayoshi
Nanataki Tsutomu
Ohwada Iwao
Takeuchi Yukihisa
Burr & Brown
NGK Insulators Ltd.
Nguyen Chanh
LandOfFree
Method and apparatus for driving device and display does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for driving device and display, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for driving device and display will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3295285