US 6,151,007 A · Analog interface display apparatus with color display control

Abstract

In a liquid crystal display apparatus having a liquid crystal display panel, an input analog display data is converted to a digital display data, a data portion is selected from the digital display data, and display status information is displayed on the display panel in the form of an overlay display data over the digital display data, so that display adjustment on the display panel is possible. The display adjustment may be automatically performed by use of a minimum value data and a maximum value data, found among the digital display data, for an automatic offset level adjustment and for an automatic gain level adjustment, respectively.

Drawings

Drawings are temporarily unavailable. Open the PDF at USPTO

Drawings

Claims29

Dependent claims

A liquid crystal display apparatus comprising:

a liquid crystal display section having a liquid crystal display panel;
an A/D converting section for receiving an input analog display data and converting said input analog display data to a digital display data, said input analog display data having a black level and a brightest level, said A/D converting section including a black level controller for adjusting said black level of said input analog display data to generate a black level-adjusted analog display data and an A/D converter for converting said black level-adjusted analog display data to said digital display data using first reference level and a second reference level lower than said first reference level;
a minimum value storing section connected to said A/D converter for storing a minimum value of said black level-adjusted analog display data;
and
an automatic offset adjusting section connected to said minimum value storing section for detecting a minimum value corresponding to said black level of said input analog display data and producing an adjusted offset level, said adjusted offset level being fed to said black level controller, whereby said black level of said input analog display data is shifted to said adjusted offset level, said adjusted offset level being such that a black level of said black level-adjusted analog display data is lower than said second reference level,
said digital display data from said A/D converting section being supplied to said liquid crystal display panel.

3 more elements

A liquid crystal display apparatus comprising:

a liquid crystal display section having a liquid crystal display panel;
an A/D converting section for receiving an input analog display data and converting said input analog display data to a digital display data, said input analog display data having a black level and a brightest level, said A/D converting section including a black level controller for adjusting said black level of said input analog display data to generate a black level-adjusted analog display data and an A/D converter for converting said black level-adjusted analog display data to said digital display data using first reference level and a second reference level lower than said first reference level;
a minimum value storing section connected to said A/D converter for storing a minimum value of said black level-adjusted analog display data;
a maximum value storing section connected to said A/D converter for storing a maximum value of said black level-adjusted analog display data;
an automatic offset adjusting section connected to said minimum value storing section for detecting a minimum value corresponding to said black level of said input analog display data and producing an adjusted offset level, said adjusted offset level being fed to said black level controller, whereby said black level of said input analog display data is shifted to said adjusted offset level, said adjusted offset level being such that a black level of said black level-adjusted analog display data is lower than said second reference level;
and
an automatic gain adjusting section connected to said maximum value storing section for detecting a maximum value corresponding to said brightest level of said input analog display data and producing an adjusted gain level, said adjusted gain level being fed as said first reference level to said A/D converter, whereby said first reference level for said A/D converter is changed to said adjusted gain level, said adjusted gain level being such that a brightest level of said input black level-adjusted analog display data is lower than said adjusted gain level,
said digital display data from said A/D converting section being supplied to said liquid crystal display section panel.

5 more elements

A liquid crystal display apparatus comprising:

a liquid crystal display section having a liquid crystal display panel;
an A/D converting section for receiving an input analog display data and converting said input analog display data to a digital display data, said A/D converting section including a black level controller for adjusting a black level of said input analog display data to generate a black level-adjusted analog display data and an A/D converter for converting said black level-adjusted analog display data to said digital display data using first reference level and a second reference level lower than said first reference level;
means connected to said A/D converter for selecting, from said digital display data, first and second data portions each concerning a predetermined point on said display panel, said first and second data portions being representative of a brightest level and a black level of said input analog display data, respectively;
automatic offset adjusting section connected to said selecting means for comparing said second data portion with a second reference data representative of said second reference level for said A/D converter and producing an adjusted offset level, said adjusted offset level being fed to said black level controller, whereby said black level of said input analog display data is shifted to said adjusted offset level, said adjusted offset level being such that comparison of said second data portion with said second reference data by said automatic offset adjusting section results in a coincidence therebetween;
and
automatic gain adjusting section connected to said selecting means for comparing said first data portion with a first reference data representative of a level higher than said first reference level for said A/D converter and producing an adjusted gain level, said adjusted gain level being fed as said first reference level to said A/D converter, whereby said first reference level for said A/D converter is changed to said adjusted gain level, said adjusted gain level being such that comparison of said first data portion with said first reference data by said automatic offset adjusting section results in a coincidence therebetween.

3 more elements

A liquid crystal display apparatus comprising:

a liquid crystal display section having a liquid crystal display panel;
an A/D converting section for receiving an input analog display data and converting said input analog display data to a digital display data, said input analog display data having a black level and a brightest level, said A/D converting section including a black level controller for adjusting said black level of said input analog display data to generate a black level-adjusted analog display data and an A/D converter for converting said black level-adjusted analog display data to said digital display data using first reference level and a second reference level lower than said first reference level;
a minimum value storing section connected to said A/D converter for storing a minimum value of said black level-adjusted analog display data;
a maximum value storing section connected to said A/D converter for storing a maximum value of said black level-adjusted analog display data;
an automatic offset level calculating section connected to said minimum value storing section for detecting a minimum value corresponding to said black level of said input analog display data and producing an adjusted offset level, said adjusted offset level being fed to said black level controller, whereby said black level of said input analog display data is shifted to said adjusted offset level, said adjusted offset level being such that a black level of said black level-adjusted analog display data is lower than said second reference level;
and
an automatic gain level calculating section connected to said maximum value storing section for detecting a maximum value corresponding to said brightest level of said input analog display data and producing an adjusted gain level, said adjusted gain level being fed as said first reference level to said A/D converter, whereby said first reference level for said A/D converter is changed to said adjusted gain level, said adjusted gain level being such that said white level of said input analog display data is lower than said adjusted gain level,
said digital display data from said A/D converting section being supplied to said liquid crystal display section panel.

5 more elements

Dependencies are inferred from the claim text.

Description20,975 words

Summary869 words

#The present invention relates to a liquid crystal display apparatus having an analog interface.

#In a conventional liquid crystal display apparatus having an analog interface, for example, as described in the JP-A-2-245793 (Laid-Open Dec. 1, 1990), there are provided a liquid crystal panel including a liquid crystal display section, an analog-to-digital (A/D) converter circuit connected via an analog interface to an external device for converting input analog data having a plurality of signal levels into digital data, a voltage generator circuit for generating voltages having a plurality of levels according to gradation, a serial-to-parallel converter circuit for converting an input serial signal into a parallel signal, and latch means for simultaneously latching parallel outputs.

#However, in the liquid crystal display apparatus of the conventional technology, since the digital data transformed from the analog data is invisible to the user, it is impossible, for example, to appropriately adjust the luminance, contrast, and color levels.

Brief description of the drawings35 figures

#The objects and features of the present invention will become more apparent from the consideration of the following detailed description taken in conjunction with the accompanying drawings in which:

#FIG. 1 is a block diagram showing an analog interface liquid crystal display apparatus in an embodiment according to the present invention;

#FIG. 2 is a block diagram showing an example of constitution of an A/D converter of FIG. 1;

Detailed description19,391 words

#Embodiment 1

#FIG. 1 shows in a block diagram a simplified structure of an analog interfaced liquid crystal display apparatus in an embodiment according to the present invention.

#In FIG. 1, reference numerals 1 and 2 indicate a vertical synchronization signal and a horizontal synchronization signal supplied from an analog interface of, for example, a personal computer, numeral 3 denotes a clock generating section, numeral 4 designates a black level adjustment timing signal, and numeral 5 stands for a dot clock. The clock generating section 3 includes a phase-locked loop (PLL) circuit and generates the dot clock 5 and the black level adjustment timing signal 4 to generate a pulse during a fly-back period of time, which will be described later. Reference numeral 6 indicates analog display data inputted from the analog interface, numeral 7 denotes an offset level for the black level adjustment of analog display data, numeral 8 represents a gain level as a high-level reference voltage for the analog-to-digital conversion (to be abbreviated as A/D conversion herebelow), numeral 9 designates a reference low level as a low-level reference voltage for the A/D conversion, numeral 10 stands for an A/D converting section, and numeral 11 indicates digital display data. The A/D converting section 10 converts the analog display data 6 the into digital display data 11 according to the offset level 7, gain level 8, black level adjustment timing signal 4, reference low level 9, and dot clock 5. In the following description, it is assumed that the A/D converting section 8 has a precision of three bits and the digital display data 11 includes 3-bit data. Reference numeral 12 indicates a digital display data readout section and numeral 13 denotes readout data. The digital display data readout section 12 reads out the digital display data 11 at a particular display position (for example, selects a data portion related to a predetermined point on a liquid crystal panel 32, which will be described later) according to the dot clock 5, vertical synchronization signal 1, and horizontal synchronization signal 2 and then outputs the data 11 as readout data 13 (data portion 13). Reference numeral 14 designates a character information generating section and numeral 15 indicates readout data display information (display status indicator). To display on the display panel, which will be described later, the values of digital readout data 13 (values obtained as a result of the A/D conversion), the character information generating section 14 converts the readout data 13 into character information according to the dot clock 5 and vertical and horizontal synchronization signals 1 and 2 and then outputs the data 13 as readout data display information (conversion value information) 15. Reference numeral 16 represents an overlay display controlling section, numeral 17 indicates an A/D conversion value display control signal, which is disposed, for example, at an arbitrary position of the display apparatus and which is generated through an operation activated to display the conversion value information 15 for a color adjustment of the screen or the like, and numeral 18 designates overlay-controlled display data. The overlay display controlling section 16 achieves an operation responsive to the control signal 17 to achieved an overlay display of the readout data display information (conversion value information) on a screen in which the digital display data 11 is beforehand displayed so as to output overlay controlled display data (a combination of the digital display data 11 and the display status indicator 15). In this description, it is assumed that the A/D conversion value display control signal 17 is "1" when the digital data after the A/D conversion is to be displayed. Reference numeral 19 indicates a liquid crystal controller, numeral 20 denotes liquid crystal (LC) display data, numeral 21 represents a latch clock, numeral 22 designates a horizontal clock, and numeral 23 stands for a first line signal. The LC controller 19 re-arranges, as in the conventional technology, the overlay-controlled display data 18 in an array of pixels of the LC panel, which will be described later, to generate LC display data 20 in synchronism with the latch clock 21 generated according to the dot clock 5. Moreover, the LC controller 19 generates the horizontal clock as scan timing for each line and the first line signal 23 indicating the first position of one display period of time. Reference numeral 24 indicates a gradation voltage generating section, numeral 25 denotes a gradation voltage level signal, numeral 26 designates an X-driver to drive X signal lines, and numeral 27 stands for panel data. The X-driver 26 sequentially acquires, like in the case of prior art, one line of the LC display data 20 according to the latch clock 21, selects one of the gradation voltage level signals 25 generated from the gradation voltage generating section 24 according to data of each dot, and then outputs the data as panel data 27 in synchronism with a subsequent horizontal clock 22. In the description, it is assumed that the number of horizontal dots of the LC panel, which will be described later, is 640, the number of X signal lines is 1920 (=640.times.3 (one dot for red, green, and blue), and the gradation voltage level signals 25 have eighth levels. Reference numeral 28 indicates a Y-driver to drive Y-scan signal lines, numeral 29 designates a non-selection voltage signal, numeral 30 denotes a selection voltage signal, and numeral 31 stands for scan signal lines. The Y-driver 28 acquires the first line signal 23 and applies the selection voltage 30 to the first line of the group of scan signals lines 31 to thereby set the first signal line to the selection status. In synchronism with the horizontal clock 22 subsequent thereto, the scan signal lines 31 undergoes a shift operation such that the selection voltage 30 is sequentially applied to the second line, third line, etc. The non-selection voltage 29 is applied to the scan signal lines 31 other than those applied with the selection voltage signal 30. In this description, it is assumed that the number of vertical dots of the LC panel, which will be described later, is 480 and that of Y signal lines is 480. Reference numeral 32 indicates an LC panel, which displays thereon data on the scan signal lines 331 applied with the selection signal 30. In addition, as in the conventional case, the LC panel 32 includes a color filter for red (R), green (G), and blue (B) such that one dot includes three pixels to thereby achieve a color display through additive color mixture. As already described, it is assumed in this embodiment that the LC panel 32 has a resolution of 640.times.480 and eight gradation levels for each of red, green, and blue and can display 512 colors.

Facts

Application

08/837,822Filed 22 Apr 1997

Priority

JP 8-10088023 Apr 1996

Granted

21 Nov 2000

Term ended

22 Apr 2017

Estimated · how

20 years from earliest known nonprovisional domestic filing. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination. Patent term adjustment is unavailable; no adjustment was added.

Classification4 codes

G09G 5/222
Characterised by the display of characters or indicia using display control signals derived from coded signals representing the characters or…:…
G09G 3/3611
Using liquid crystals: control of matrices with row and column drivers
G09G 3/2007
For presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged…:…
G09G
Arrangements or circuits for control of indicating devices using static means to

Description20,975 words

Summary869 words

#The present invention relates to a liquid crystal display apparatus having an analog interface.

Brief description of the drawings35 figures

#The objects and features of the present invention will become more apparent from the consideration of the following detailed description taken in conjunction with the accompanying drawings in which:

#FIG. 1 is a block diagram showing an analog interface liquid crystal display apparatus in an embodiment according to the present invention;

#FIG. 2 is a block diagram showing an example of constitution of an A/D converter of FIG. 1;

Detailed description19,391 words

#Embodiment 1

#FIG. 1 shows in a block diagram a simplified structure of an analog interfaced liquid crystal display apparatus in an embodiment according to the present invention.

Analog interface display apparatus with color display control

Life of this patent

Analog interface display apparatus with color display control

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims29

Description20,975 words

Drawings

Classification4 codes

Life of this patent

Description20,975 words