JP5228747B2 - Integrated circuit device, electro-optical device and electronic apparatus - Google Patents

Description

  The present invention relates to an integrated circuit device (IC), an electro-optical device (a liquid crystal display device, an organic EL display device, other display devices, a projector, etc.), an electronic device, and the like.

  In recent years, high-definition video technology such as high-definition video has become widespread, and along with this, display devices (electronic devices) such as liquid crystal projectors have become higher definition and multi-gradation. In such a multi-gradation display device, a highly accurate analog circuit is required for a driver for driving a liquid crystal panel (electro-optical panel).

  Specifically, since the gradation voltage per gradation decreases as the number of gradations increases, the gradation is not correctly expressed only by a slight error in the driving voltage of the driver. For example, when there is an offset difference between operational amplifiers that drive adjacent data line drive voltage supply lines (data lines, source lines), a difference occurs in the voltage of adjacent data line drive voltage supply lines, resulting in a vertical shift on the display image. Looks like a line. As described above, a driver used in a multi-gradation display device has a problem of accurately outputting a data line driving voltage.

  For example, Patent Document 1 discloses a technique for improving the accuracy of the data line driving voltage by driving the data line driving voltage supply line with an operational amplifier and then driving with a DAC output. According to this method, by driving the data line drive voltage supply line with the DAC output, it is possible to prevent an error in the data line drive voltage due to the offset of the operational amplifier.

On the other hand, Patent Document 2 discloses a technique for correcting display unevenness of a liquid crystal projector by performing interpolation calculation on correction data stored in a RAM and adding it to video data. According to this method, by correcting video data by digital processing, it is possible to output a data line driving voltage with high accuracy and to drive at high speed with an operational amplifier having high driving power.
Japanese Patent No. 3405333 JP 2002-108298 A

  The higher the resolution of the liquid crystal panel, the faster the data line drive voltage supply line needs to be driven. In the method of Patent Document 1, since a DAC output having a higher output impedance than that of an operational amplifier is used, there is a problem that it takes time until the data line driving voltage reaches a desired gradation voltage.

  In addition, the characteristics of the liquid crystal panel and driver deteriorate with time after shipment. Further, the characteristics change due to heat generated by a display device such as a projector lamp. In the method of Patent Document 2, since correction is performed using correction data adjusted at the time of manufacturing a liquid crystal panel or the like, there is a problem that it is not possible to cope with such a change in characteristics after shipment.

  In order to be able to respond to changes in the characteristics of liquid crystal panels and drivers over time, the actual deviation of the drive output between multiple data lines is measured when the liquid crystal panel (electro-optical panel) is actually used. However, a technique that enables adaptively generating correction data based on the measured data is desired.

  In other words, in order to realize a higher-definition, multi-output, multi-gradation electro-optic panel, correction data is calculated based on the measured deviation of the drive output, and the image data is corrected using the correction data. Therefore, a novel technique capable of driving the data line at high speed based on the corrected image data is desired.

  In addition, when calculating correction data based on actually measured data, a certain amount of time is required for acquiring the correction data. Therefore, for example, if the measurement of the deviation data of the drive output and the calculation of the correction data based on the measured deviation data are performed after the power is turned on, the image may not be corrected during that time.

  Therefore, it is desirable to eliminate such inconvenience and correct the image data in real time immediately after the power is turned on so that proper image display (image formation) can be performed.

  According to some aspects of the present invention, for example, correction data is calculated based on an actual measurement value of drive output deviation, image data is corrected using the correction data, and high-speed is calculated based on the corrected image data. In addition, an integrated circuit device capable of driving the data line can be realized. Further, for example, an integrated circuit device is realized that enables real-time correction of image data immediately after an electronic device equipped with an electro-optical device is turned on.

(1) One aspect of the integrated circuit device of the present invention is an integrated circuit device that drives each of a plurality of data lines, and the data is based on a result of comparing a data line driving voltage to be corrected with a reference voltage. A correction data calculation unit for calculating correction data for correcting line drive voltage variation;
A correction data storage unit that stores the correction data, a correction circuit that corrects image data based on the correction data output from the correction data storage unit, an interface unit for inputting the image data, and the interface A control unit that controls a transfer operation of the image data input via a unit, a storage operation of the correction data in the correction data storage unit, and a correction operation of the image data by the correction circuit, and When the control unit receives the image data including the correction data or the image data to which the correction data is added and is transferred via the interface unit, the control unit extracts the correction data and extracts the correction data. Is stored in the correction data storage unit.

  In this aspect, when an electro-optical device (liquid crystal panel, organic EL panel, etc.) is actually used, the deviation of the drive output between a plurality of data lines is measured, and adaptively based on the measured data. A novel technique for generating correction data (digital correction data) and correcting an image at high speed using the correction data is employed.

  That is, for example, the correction data calculation unit calculates correction data based on a result of comparing the drive voltage of the data line to be corrected with the reference voltage, and the correction circuit corrects the image data based on the correction data. Therefore, variation in the data line driving voltage can be accurately corrected. Even when there is a manufacturing variation in the data line driving circuit, the data line driving voltage corresponding to the image data can be output with high accuracy. Thereby, even pixels driven by different data line drivers can display image data of the same gradation with the same luminance accurately, and the image quality can be improved. In addition, since the image can be corrected in real time, even when the output characteristics of each of the plurality of data line drivers change due to an external factor such as heat, it is possible to prevent image quality deterioration. Therefore, for example, it is possible to appropriately cope with a change with time of the characteristics of the liquid crystal panel and the driver.

  Further, in this aspect, in addition to the above basic function, correction data can be input from the higher-level device or the like to the integrated circuit device, and the input correction data can be written in the correction data storage unit. For example, when the power is turned off, the correction data is read from the correction data storage unit and saved outside the integrated circuit. Then, at the next power-on, the saved correction data (but not limited to this, may be newly created correction data) is accumulated from the host device via the interface unit. Input to the circuit device. The correction data is separated from the image data by the control unit, transferred to the correction data storage unit, and written.

  Here, the correction data is input to the interface unit in a form included in the image data or in a form added to the image data. In this case, the correction data is separated from the image data by the control unit, transferred to the correction data storage unit, and written. When the correction data is input to the integrated circuit device alone, it is necessary to newly construct a transfer path for inputting the correction data. However, the correction data is transmitted together with the image data via the input line of the image data. If the input is made to the integrated circuit device, a new transfer path is unnecessary, and therefore the circuit configuration is not complicated.

  As an aspect in which the correction data is included in the image data, for example, there is an aspect in which the correction data is embedded instead of a part of the image data. As an aspect in which correction data is added to image data, for example, m-bit correction data is added to k-bit image data, and (k + m) -bit data is interfaced via an image data input line or the like. There is a mode to input to the part.

  By providing a function for writing correction data to the integrated circuit device, for example, when the power is turned on, the saved correction data can be transferred to the integrated circuit device together with the image data, and in real time immediately after the power is turned on. The image can be corrected. Therefore, an extremely high quality image display and image formation can be performed without being affected by the deviation of the drive voltage characteristics of the data line drive circuit immediately after the power is turned on.

  (2) In another aspect of the integrated circuit device of the present invention, the image data including the correction data or the image data to which the correction data is added in a period during which an on sequence for power-on is executed. Input to the interface unit.

  In this aspect, the correction data and the image data are written into the correction data storage unit in the integrated circuit device via the interface unit during the period when the on sequence for power-on is executed.

  (3) In another aspect of the integrated circuit device of the present invention, the image data including the correction data or the image data to which the correction data is added is displayed by an electro-optical device during the on-sequence execution period. This is image data for the initial screen.

  In the on-sequence period, generally, an initial screen showing a manufacturer name, a computer operating system name, and the like is generally displayed short. Therefore, in this aspect, in the on-sequence period, for example, a host device (such as a host computer or an image display controller) inputs correction data together with image data for displaying the initial screen to the integrated circuit device. In this way, it is possible to input (write) correction data into the integrated circuit device without difficulty.

  (4) In another aspect of the integrated circuit device of the present invention, the correction data included in the image data is embedded in lower bits of the image data, and the control unit is embedded in the lower bits. The correction data is taken out and stored in the correction data storage unit.

  Thereby, the image data and the correction data can be transferred without increasing the bit width of the image data input line for transferring the image data. In addition, for example, the initial screen displayed during the on-sequence period usually does not require high image quality. Therefore, no problem occurs even if the image quality of the initial screen or the like is somewhat deteriorated as a result of the correction data being embedded in the lower bits of the image data.

  (5) In another aspect of the integrated circuit device of the present invention, the correction data included in the image data or the correction data added to the image data includes correction data for positive polarity and correction for negative polarity. The correction data storage unit includes a first correction data storage unit that stores the correction data for positive polarity, and a second correction data storage unit that stores the correction data for negative polarity The control unit refers to a polarity signal supplied from a host device provided outside the integrated circuit device, and stores the correction data for positive polarity in the first correction data storage unit. The correction data for negative polarity is stored in the second correction data storage unit.

  For example, in a liquid crystal display device, line inversion driving, dot inversion driving, and the like are executed in order to prevent liquid crystal burn-in. Then, it may be desirable to finely adjust the value of the correction data depending on whether the image data supplied to the data line is image data for positive polarity or image data for negative polarity. In addition, a host device (such as a host computer or an image display controller) may output a polarity control signal for controlling the inversion driving described above.

  Therefore, in this aspect, as the correction data storage unit, a first correction data storage unit that stores correction data for positive polarity and a second correction data storage unit that stores correction data for negative polarity are prepared. To do. Then, the control unit refers to the polarity control signal supplied from the host device, transfers the positive correction data to the first correction data storage unit, and stores the negative correction data in the second correction data. Are transferred to and stored in the correction data storage unit. In this way, the correction data can be properly used according to the polarity. Therefore, it is possible to correct image data more accurately according to the polarity.

  (6) In another aspect of the integrated circuit device of the present invention, the corrected image data output from the correction circuit is supplied in time division to n (n is an integer of 2 or more) data lines. When multiplex driving is performed, a data set including n image data to be supplied to each of the n data lines is input to the interface unit, and the n images included in the data set are input. The correction data is included in one image data of the data, or the correction data is added to the one image data.

  Multiplex driving in which one driver (unit driver) drives n data lines in a time-sharing manner may be executed. In this case, a data set including n image data to be supplied to each of the n data lines is input to the interface unit.

  There is only one correction data for correcting fluctuations in driving characteristics of one data line driver (unit driver) used for driving n data lines. Therefore, one correction data is embedded in one image data out of n image data included in the data set, or one correction data is added to one image data. This makes it possible to write correction data into the integrated circuit device even when multiplex driving is performed.

  (7) In another aspect of the integrated circuit device of the present invention, the corrected image data output from the correction circuit is supplied to n (n is an integer of 2 or more) data lines in a time division manner. When multiplex driving is executed, a data set including n image data corresponding to each of the n data lines is input to the interface unit, and the n image data included in the data set is input. The correction data for positive polarity is included in one of the image data, or the correction data for positive polarity is added to the one image data, and the other one of the n pieces of image data. The negative correction data is included in one image data, or the negative correction data is added to the other image data.

  One data line driver (unit) used for driving n data lines when multiplex driving is executed and a correction value for positive polarity and a correction value for negative polarity are used as correction data There may be two correction data for correcting fluctuations in the drive characteristics of the driver (that is, there may be correction data for positive polarity and correction data for negative polarity).

  Therefore, one correction data is embedded in one image data of n image data included in the data set, or one correction data is added to one image data. The correction data for negative polarity is embedded in the other one of the image data, or the correction data for negative polarity is added to the other one image data.

  As a result, even when multiplex driving is performed, it is possible to write correction data for positive polarity and correction data for negative polarity into the integrated circuit device.

  (8) In another aspect of the integrated circuit device of the present invention, a plurality of correction data registers as the correction data storage unit, a correction data bus for transferring the correction data to each of the plurality of correction data registers, A correction shift register for designating a latch timing of the correction data in the correction data register, a plurality of image data registers for storing the image data, and a transfer for transferring the image data to each of the plurality of image data registers. An image data bus; and an image shift register for designating a latch timing of the image data in the image data register, and the control unit includes the correction data transferred via the interface unit The image data or the image data to which the correction data is added is received. The correction data is taken out, and the correction data is transferred via the correction data bus in synchronization with the transfer timing of the image data via the image data bus, and the image data is transferred to the image data register. The correction data is latched in the correction data register in synchronization with the latched timing.

  In this aspect, the correction data is transferred to the correction register via the correction data bus, and the image data is transferred to the image data register via the image data bus. A correction shift register is used to sequentially latch the correction data in the correction data register, and an image shift register is used to sequentially latch the image data in the image data register.

  Then, the control unit controls the timing of transfer and latching of correction data and image data using, for example, a common clock. For example, the control unit transfers the correction data and image data synchronously and latches them synchronously.

  Thus, for example, immediately after the power is turned on, each of the image data and the correction data can be simultaneously set (written) in each of the image data register and the correction data register. Therefore, when display of a regular image is started, the image data can be corrected in real time from the first image data.

  (9) In another aspect of the integrated circuit device of the present invention, the control unit stores the correction data when image data corrected using the correction data is input from the host device to the interface unit. The corrected image data is supplied to each of the plurality of data lines in a state where the section is initialized.

  In some cases, a host device (for example, an image display controller) corrects image data using correction data instead of writing correction data to the integrated circuit device, and inputs the corrected image data to the integrated circuit device. possible. It is desirable that the integrated circuit device can cope with this case.

  Therefore, in this aspect, in the above case, the integrated circuit device directs the input corrected image data as it is to the data line in a state where the correction data is not set in the correction data register (initialized state). Output.

  (10) According to one aspect of the electro-optical device of the invention, any one of the integrated circuit devices, an image display unit including a plurality of data lines driven by the integrated circuit device, and a host device of the integrated circuit device And at least one of a host computer and an image display controller.

  By using any of the integrated circuit devices described above, it is possible to correct image data following changes in the characteristics of the driving unit of the integrated circuit device over time, and therefore, higher-definition, multi-output / multi-story Toning electro-optic device. Further, for example, when the power is turned on, the saved correction data can be transferred together with the image data to the integrated circuit device. Therefore, an electro-optical device (liquid crystal device) that can correct an image in real time immediately after the power is turned on. Display devices, organic EL display devices, other display devices and projectors) can be realized.

(11) One aspect of the electronic apparatus of the present invention includes the electro-optical device described above.
This improves the display performance of the electronic device.

  Hereinafter, preferred embodiments of the present invention will be described in detail. The present embodiment described below does not unduly limit the contents of the present invention described in the claims, and all the configurations described in the present embodiment are indispensable as means for solving the present invention. Not necessarily.

(First embodiment)
The first embodiment will be described below with reference to FIGS. In the integrated circuit device (IC) of the present invention, when an electro-optical device (a liquid crystal panel, an organic EL panel, etc.) is actually used, the drive output deviation between a plurality of data lines is measured, and the actual measurement is performed. A novel technique for adaptively generating correction data based on the data and correcting the image at high speed using the correction data is employed. In this embodiment, the novel image correction technique will be described.

1. Data line drive voltage correction circuit 1.1. Configuration Example Hereinafter, as an application example of this embodiment, a case where a liquid crystal panel (electro-optical panel in a broad sense) is driven according to this embodiment will be described. As the liquid crystal panel, for example, an active matrix type panel using a switching element such as a TFT (Thin Film Transistor) or a TFD (Thin Film Diode) or a simple matrix type panel can be used. However, the present invention can also be applied when driving an electro-optical panel other than the liquid crystal panel. For example, the present invention can be applied to a case where a display panel using a self-luminous element such as an organic EL (Electro Luminescence) element or an inorganic EL element is driven.

  FIG. 1 shows a configuration example of this embodiment. The configuration example of this embodiment includes first to nth data line driving circuits 140-1 to 140-n (a plurality of data line driving circuits), first to nth correction circuits 160-1 to 160-n ( A plurality of correction circuits), a comparator 180, a control unit 100, and a selection circuit 120. The control unit 100 includes a correction data calculation unit 102. Various modifications may be made such as omitting some of these components, adding other components, and changing the connection relationship.

  In the present embodiment, variations (deviations and errors) of the first to nth data line drive voltages SV1 to SVn (a plurality of data line drive voltages) are corrected in the correction data calculation mode and the normal operation mode. Specifically, in the correction data calculation mode, the correction data calculation unit 102 measures variations in the data line drive voltages SV1 to SVn to obtain correction data CD1 to CDn. In the normal operation mode, the correction circuits 160-1 to 160-n correct the image data PD1 to PDn using the correction data CD1 to CDn, and the data line drive circuits 140-1 to 140-n correct the image data after the correction processing. In response to PCD1 to PCDn, data line drive voltages SV1 to SVn are output. Accordingly, the present embodiment can drive an electro-optical panel such as a liquid crystal panel in a state where output variations of the data line driving circuits 140-1 to 140-n are corrected.

  For example, variations in the data line drive voltages SV1 to SVn are caused by offsets of operational amplifiers OP1 to OPn, which will be described later with reference to FIG. 8, and variations in output characteristics of the D / A conversion circuits DAC1 to DACn. At this time, even if the same gradation data is input to the data line driving circuits 140-1 to 140-n, the data line driving voltages SV1 to SVn are not uniform due to an offset or the like. In this embodiment, the correction data CD1 to CDn are used to cancel these offsets, etc., and the data line drive voltages SV1 to SVn corresponding to the same gradation data are made uniform so that the variations in the data line drive voltages SV1 to SVn are reduced. to correct.

  Specifically, the correction data calculation unit 102 receives the comparison result CPQ from the comparator 180 and obtains correction data corresponding to the correction target data line driving circuit (hereinafter, correction target correction data). For example, a part of the correction data CD1 to CDn as correction data to be calculated is obtained in one correction data calculation, and this correction data calculation is repeated to obtain correction data CD1 to CDn.

  More specifically, in the correction data calculation mode, the correction data calculation unit 102 sequentially changes the measurement data MD within a predetermined range and outputs the measurement data MD to the correction circuits 160-1 to 160-n. The data line drive circuits 140-1 to 140-n output data line drive voltages corresponding to the measurement data MD as data line drive voltages SV1 to SVn. Then, the comparator 180 compares the data line driving voltage output from the correction target data line driving circuit (hereinafter referred to as the correction target data line driving voltage) with the comparator reference voltage VP and outputs a comparison result CPQ. The unit 102 receives the comparison result CPQ and obtains correction data to be calculated.

  For example, the correction data calculation unit 102 sequentially outputs the measurement gradation data MGD1 to MGDk (k is a natural number) one by one as the measurement data MD, and the correction target data line driving circuit outputs the measurement gradation data MGD1 to MGD1. Data line drive voltages corresponding to MGDk are sequentially output. Then, the comparator 180 outputs a comparison result CPQ corresponding to each of the measurement gradation data MGD1 to MGDk. The correction data calculation unit 102 detects an edge (change point) of the comparison result CPQ as will be described later with reference to FIG. 2 and the like, and obtains correction data to be calculated using the measurement gradation data when the edge is detected. .

  The correction circuits 160-1 to 160-n receive the measurement data MD, the correction data CD1 to CDn, and the image data PD1 to PDn, and send the measurement data MD or the corresponding data line drive circuits 140-1 to 140-n. The corrected image data PCD1 to PCDn are output. Specifically, in the correction data calculation mode, the correction circuits 160-1 to 160-n output the measurement data MD. In the normal operation mode, the correction circuits 160-1 to 160-n correct the image data PD1 to PDn with the correction data CD1 to CDn and output the image data PCD1 to PCDn. For example, AD1 to ADn described later in FIG. 8 perform correction processing by adding image data PD1 to PDn and correction data CD1 to CDn.

  The data line driving circuits 140-1 to 140-n receive the measurement data MD or the image data PCD1 to PCDn from the correction circuits 160-1 to 160-n and receive the first to nth data line driving voltage supply lines. S1 to Sn (a plurality of data line drive voltage supply lines) are driven. Specifically, in the correction data calculation mode, the data line drive circuits 140-1 to 140-n output data line drive voltages SV1 to SVn corresponding to the measurement data MD. In the normal operation mode, the data line driving circuits 140-1 to 140-n output data line driving voltages SV1 to SVn corresponding to the corrected image data PCD1 to PCDn.

  The selection circuit 120 selects the data line drive voltage to be corrected from the data line drive voltages SV1 to SVn, and outputs it as the input voltage CPI of the comparator 180. For example, the selection circuit 120 receives the selection signal SL from the control unit 100 and selects the data line driving voltage as shown in FIG.

  Comparator 180 receives input voltage CPI (data line drive voltage to be corrected) and comparator reference voltage VP, and outputs comparison result CPQ. Specifically, based on the magnitude relationship between the data line drive voltage to be corrected and the comparator reference voltage VP, the H level (first logic level) or the L level (second logic level) is output as the comparison result CPQ. . As described in FIG. 2, the comparator reference voltage VP is within the range of the data line drive voltage corresponding to the measurement data MD when the correction data calculation unit 102 changes the measurement data MD within a predetermined range. Voltage. For example, the comparator reference voltage VP may be supplied from the power supply circuit 50 shown in FIG. 3, or may be a voltage obtained by dividing the voltage supplied from the power supply circuit 50 with a resistor.

  The control unit 100 controls the operation of the components of this embodiment, and controls the operation timing in the correction data calculation mode and the normal operation mode. For example, the control unit 100 outputs a selection signal SL to the selection circuit 120, and outputs a correction enable signal C_Enable to the correction circuits 160-1 to 160-n. Further, as will be described later with reference to FIG. 9, the calculation timing of the correction data CD1 to CDn is controlled using the sequencer 240, the counter unit 200, and the like.

1.2. Explanation of Operation of Correction Data Calculation The operation in the correction data calculation mode will be described in detail with reference to FIGS. 2 (A) and 2 (B). FIG. 2A schematically shows an example of the waveform of the data line drive voltage to be corrected in the correction data calculation unit mode. FIG. 2B schematically shows a waveform example of the comparison result CPQ of the comparator 180 in the correction data calculation unit mode.

  In FIGS. 2A and 2B, the correction data calculation unit 102 obtains correction data CDi (1 ≦ i ≦ n, i is a natural number) as correction data to be calculated, and 8 as measurement data MD. An example of outputting the measurement grayscale data MGD1 to MGD8 (k = 8) will be described. However, the same applies when obtaining other correction data other than the correction data CDi. Further, the correction data calculation unit 102 may obtain a plurality of correction data as the correction data to be calculated, and may output the number of measurement gradation data other than eight as the measurement data MD.

  In the correction data calculation mode, the correction data calculation unit 102 outputs measurement gradation data MGD1 to MGD8. The correction circuit 160-i outputs the measurement gradation data MGD1 to MGD8 from the correction data calculation unit 102 to the data line driving circuit 140-i. Then, as indicated by LC1 in FIG. 2A, the data line drive circuit 140-i changes the data line indicated by C2 from the data line drive voltage indicated by C1 as the measurement grayscale data MGD1 to MGD8 sequentially change. The drive voltage is sequentially output as the data line drive voltage SVi. The selection circuit 120 selects the data line driving voltage SVi and outputs it as the comparator input voltage CPI to the comparator 180, and the comparator 180 outputs the comparison result CPQ.

  For example, the data line drive voltage SVi corresponding to the measurement gradation data MGD2 is smaller than the comparator reference voltage VP as indicated by C3 in FIG. 2A, and the data corresponding to the measurement gradation data MGD3 as indicated by C4. It is assumed that the line drive voltage SVi is larger than the comparator reference voltage VP. In this case, the comparison result CPQ indicated by LC3 in FIG. 2B corresponds to the L level corresponding to the measurement gradation data MGD2 as indicated by C5, and corresponds to the measurement gradation data MGD3 as indicated by C6. Becomes H level. Then, the correction data calculation unit 102 detects the edge that changes from the L level to the H level, and sets MGD3 that is the measurement gradation data when the edge is detected as the correction data CDi.

  In this way, this embodiment can obtain correction data for correcting variations in the data line drive voltage.

  Here, it is assumed that the data line drive voltage SVi does not vary due to an offset or the like. At this time, as indicated by LC2 in FIG. 2A, the data line driving voltage SVi sequentially changes from the data line driving voltage indicated by C7 to the data line driving voltage indicated by C8. This data line drive voltage SVi is an ideal data line drive voltage corresponding to the measurement gradation data MGD1 to MGD8. As described with reference to FIG. 1, the comparator 180 uses a voltage between the ideal minimum value (C7) and maximum value (C8) of the data line drive voltage as the comparator reference voltage VP. For example, a data line driving voltage corresponding to the measurement gradation data MGD5 is used as indicated by C9. Then, when it is assumed that there is no variation due to offset or the like, the comparison result CPQ changes as indicated by LC4 in FIG. 2B, and the correction data CDi becomes the measurement gradation data MGD5.

  As indicated by LC1 in FIG. 2A, the data line driving voltage SVi actually output from the data line driving circuit 140-i in the correction data calculation mode is the ideal data line indicated by LC2 in FIG. A variation VOFi (offset) is included with respect to the drive voltage SVi. According to the correction data calculation method, the actually measured correction data CDi = MGD3 and the correction data CDi = MGD5 for the ideal data line drive voltage are different correction data by the number of gradations corresponding to the variation VOFi. . Therefore, in the present embodiment, the variation VOFi of the data line drive voltage SVi can be corrected by correcting the image data PDi using the correction data CDi = MGD3.

  By the way, if the data line drive voltage varies, the display quality deteriorates because the luminance differs for each data line drive voltage supply line even though the same gradation is output. Therefore, there has been a problem that a data line driving voltage is output with high accuracy in a driver for driving a liquid crystal panel.

  In this regard, according to the present embodiment, the correction data calculation unit 102 outputs the measurement data MD in the correction data calculation mode, and the data line driving circuits 140-1 to 140-n correspond to the measurement data MD. The drive voltages SV1 to SVn are output, the comparator 180 compares the data line drive voltages SV1 to SVn with the comparator reference voltage VP, and outputs the comparison result CPQ. The correction data calculation unit 102 calculates the correction data CD1 to CDn from the comparison result CPQ. Is calculated. In the normal operation mode, the image data PD1 to PDn are corrected using the correction data CD1 to CDn.

  As a result, variations in the data line drive voltages SV1 to SVn can be corrected, and the data line drive voltages corresponding to the image data PD1 to PDn can be output with high accuracy. Therefore, even on pixels (subpixels, dots in a narrow sense) on different data line drive voltage supply lines, the same gradation data can be displayed with the same luminance, and the image quality can be improved. For example, a driver for a high-definition liquid crystal panel generally has a large number of gradations and a small gradation voltage per gradation, so that the image quality is likely to deteriorate due to variations in the data line drive voltage. Specifically, luminance unevenness such as vertical lines occurs in the display image. In the present embodiment, variations in the data line drive voltages SV1 to SVn can be corrected, so that deterioration of image quality can be prevented even when a high-definition liquid crystal panel is driven.

  For example, as another method for correcting the variation in the data line driving voltage, the data line due to the offset of the operational amplifier is directly driven by driving the data line driving voltage supply line with the output of the DAC that converts the gradation data into the gradation voltage. There has been a method of preventing variations in driving voltage. However, since the output impedance of the DAC is higher than that of the operational amplifier, there is a problem that driving time is insufficient in driving a high-definition liquid crystal panel or in multiplex driving that outputs a plurality of data line driving voltages in one horizontal period. .

  In this regard, in the present embodiment, the variations in the data line drive voltages SV1 to SVn are corrected by correcting the image data PD1 to PDn using the correction data CD1 to CDn. Therefore, output variations of the data line driving circuits 140-1 to 140-n can be corrected on the data. Thereby, as will be described later with reference to FIG. 8, for example, the data line drive voltage supply lines S1 to Sn can be driven at high speed using the operational amplifiers OP1 to OPn.

  Further, for example, as another method for correcting the variation in the data line driving voltage, the variation in the data line driving voltage is measured at the time of shipment, and the correction data is stored, and the variation in the data line driving voltage is determined using the correction data. There is also a method of correcting. However, this method has a problem that it cannot cope with characteristic changes after shipment.

  In this regard, according to the present embodiment, the comparator 180 compares the data line drive voltages SV1 to SVn with the comparator reference voltage VP, and the correction data calculation unit 102 receives the comparison result CPQ and calculates the correction data CD1 to CDn. Thereby, variations in the data line drive voltages SV1 to SVn can be measured and corrected in real time. Therefore, it is possible to prevent the image quality from being deteriorated even when the characteristics of the driver are changed after shipment or when the characteristics of the driver are changed by heat of the backlight or the like.

  For example, as will be described later with reference to FIG. 9 and the like, in this embodiment, the correction data CD1 to CDn may be calculated in the 1H mode in which the correction data is calculated in the non-display period of the frame (vertical scanning period). For example, correction data CD1 to CDn may be calculated in n frames by calculating one correction data as correction data to be calculated for each frame.

  As described above, by calculating the correction data CD1 to CDn for each frame, it is possible to correct variations in the data line drive voltages SV1 to SVn in real time while displaying an image. Therefore, it is possible to cope with a change in characteristics over time after shipment of the driver. Further, by calculating the correction data CD1 to CDn during the non-display period, it is possible to correct variations in the data line drive voltages SV1 to SVn without affecting the image display.

  Here, as will be described later with reference to FIG. 3 and the like, in this embodiment, multiplex driving may be performed. In multiplex driving, each of the data line driving circuits 140-1 to 140-n drives a plurality of data lines (for example, data lines S1i to S8i in FIG. 3) on the liquid crystal panel in one horizontal scanning period. At this time, the correction data calculation unit 102 may obtain a plurality of correction calculation data in one horizontal scanning period. Specifically, the correction calculation data is calculated by a method similar to the calculation method described in FIG. Then, correction data may be calculated from the plurality of correction calculation data.

  By the way, when the variation of the data line driving voltage cannot be measured accurately due to the influence of noise or the like, there is a problem that correction data in which the variation of the data line driving voltage is accurately reflected cannot be obtained.

  In this respect, in the present embodiment, a plurality of correction calculation data is obtained in one horizontal scanning period, and correction data is obtained using the plurality of correction calculation data. Thus, even when some correction calculation data becomes inaccurate due to the influence of noise or the like, accurate correction data can be obtained by using a plurality of correction calculation data.

  For example, the correction data calculation unit 102 may calculate correction data by averaging a plurality of correction calculation data. Specifically, the correction data calculation unit 102 may perform addition averaging as the averaging process, or may weight each correction calculation data and average it. Further, the correction data calculation unit 102 may add or subtract a constant in the averaging process.

  Accordingly, correction data can be calculated from a plurality of correction calculation data, and the influence of noise or the like can be prevented.

  For example, gradation data GD + ΔGD1 to GD + ΔGDk may be output as measurement gradation data MGD1 to MGDk to obtain a plurality of correction calculation data. Then, the correction data may be obtained by subtracting the gradation data GD from the average of the plurality of correction calculation data.

  Thereby, the variation in the data line drive voltage can be measured in the data line drive voltage corresponding to the gradation data GD. Then, by subtracting the gradation data GD from the average of the plurality of correction calculation data, correction data corresponding to the variation in the data line drive voltage can be extracted.

  Here, in the case of multiplex driving in which p data lines (p is an integer of 2 or more) are driven by one data line driving circuit as the plurality of data lines, the correction data calculation unit 102 sets the plurality of data as correction calculation data. p correction calculation data may be obtained.

  In this case, each of the data line driving circuits 140-1 to 140-n has a capability of driving p data lines in one horizontal scanning period in the normal operation mode. Therefore, in the correction data calculation mode, p data lines can be driven in the same horizontal scanning period to measure p correction calculation data. Although the accuracy of the data line drive voltage depends on the drive time, the data line drive equivalent to the normal operation mode can be obtained by making the drive time per data line equal in the normal operation mode and the correction data calculation mode. Correction data CD1 to CDn can be obtained with voltage accuracy. As a result, the data line drive voltages SV1 to SVn can be corrected accurately.

  However, in multiplex driving, a plurality of correction calculation data is obtained in one horizontal period, and a plurality of measurement gradation data are used when obtaining one correction calculation data. Therefore, when the driving capability of the operational amplifier is insufficient, there is a problem that the data line driving voltage corresponding to each measurement gradation data is not sufficiently driven and the variation in the data line driving voltage cannot be measured accurately.

  According to the present embodiment, as will be described later with reference to FIG. 7, correction data CD1 to CDn are multiplied by the correction coefficient in the correction data calculation mode to obtain correction data after coefficient multiplication, and correction data after coefficient multiplication is performed in the normal operation mode. The image data PD1 to PDn may be corrected based on the above.

  As described above, in the present embodiment, correction data that has not been accurately calculated due to a lack of operational capability of the operational amplifier is corrected using the correction coefficient. As a result, variations in the data line drive voltages SV1 to SVn can be accurately corrected.

  Here, in the present embodiment, when the correction data calculation unit 102 sequentially changes the measurement data MD within a predetermined range, the comparison result CPQ is L level (first level) or H level (second level). ) May be determined as overflow, and the overflow data may be used as the correction calculation data.

  Specifically, the correction data calculation unit 102 may use a predetermined constant as the overflow data. For example, gradation data between the maximum gradation data and the minimum gradation data of the measurement gradation data MGD1 to MGDk output from the correction data calculation unit 102 may be used as the predetermined constant.

  Thus, in this embodiment, when it is determined that the variation in the data line drive voltage exceeds the measurement range, the correction data is obtained using the overflow data. Thereby, even when the calculation of the correction calculation data overflows due to the influence of noise or the like, the correction data reflecting the variation in the data line drive voltage can be obtained as accurately as possible.

  The correction data calculation unit 102 overflows when obtaining the s-th correction calculation data (1 ≦ s ≦ t, where s and t are integers of 2 or more) among the first to t-th correction calculation data. The first to s-1th correction calculation data among the first to tth correction calculation data is averaged to obtain overflow data to obtain the sth correction calculation data. It may be used as

  As described above, in this embodiment, the correction calculation data for the times determined to be overflow are obtained from the correction calculation data obtained before the overflow is determined. As a result, it is possible to eliminate the influence of overflow due to noise or the like, obtain correction data that more reflects the variation in the actual data line drive voltage, and accurately correct the variation in the data line drive voltage.

  However, when it is continuously affected by noise or the like, inaccurate correction data may be calculated even when the overflow process is performed. For example, when calculating correction data repeatedly in 1H mode or the like, if inaccurate correction data is suddenly calculated for a data line for which correction data has been calculated accurately, the luminance of the pixels on the data line is increased. It changes suddenly and the vertical line blinks on the displayed image.

  In this regard, according to the present embodiment, the correction data calculation unit 102 uses the current correction data obtained for the correction target data line driving circuit and the previous correction data to perform correction corresponding to the correction target data line driving circuit. You may ask for data.

  For example, when the current correction data is larger than the previous correction data, the correction data may be obtained by adding a positive predetermined value to the previous correction data. When the correction data obtained this time is smaller than the previous correction data, the correction data may be obtained by adding a negative predetermined value to the previous correction data.

  As described above, in the present embodiment, in the correction data repeatedly calculated in the 1H mode or the like, the variation amount restriction is performed to limit the variation amount of the correction data within a predetermined value using the previously calculated correction data. Thereby, even when inaccurate correction data is suddenly calculated due to the influence of noise or the like, it is possible to prevent vertical lines from being displayed on the display image.

  Here, as will be described later with reference to FIG. 11 and the like, the correction data calculation unit 102 may include a measurement start register 224 and a measurement period register 226. Specifically, the measurement start register 224 sets the timing for starting the monitoring of the comparison result CPQ of the comparator 180, and the measurement period register 226 sets the period for monitoring the comparison result CPQ of the comparator 180.

  As a result, the timing for monitoring the comparison result CPQ used for the calculation of the correction calculation data can be adjusted. Specifically, the measurement start period shown in FIG. 2 can be adjusted by the measurement start register 224, and the measurement period can be adjusted by the measurement period register 226. The measurement start period is a period in which the comparison result CPQ is initialized to the L level as indicated by C10 in FIG. Then, the correction data calculation unit 102 starts monitoring the comparison result CPQ at the timing when the measurement start period ends. The measurement period is a period during which the correction data calculation unit 102 outputs one gradation of the measurement gradation data MGD1 to MGDk and monitors the corresponding comparison result CPQ.

2. Multiplex drive 2.1. Configuration Example of Liquid Crystal Display Device that Performs Multiplex Drive Hereinafter, a detailed operation and a detailed configuration of the present embodiment will be described by taking as an example a case where the present embodiment performs multiplex drive in the normal operation mode. In the following, a case where the present embodiment is applied to a monochromatic liquid crystal panel used in a liquid crystal projector (projection display device) or the like will be described as an example. Note that, as will be described later with reference to FIG. The present invention can also be applied to liquid crystal panels of a plurality of colors such as RGB used for PDA (Personal Digital Assistants), liquid crystal televisions, mobile phones, car navigation systems and the like.

  FIG. 3 shows a configuration example of a liquid crystal display device (electro-optical device) including a driver 60 (integrated circuit device) to which the present embodiment is applied. The configuration example illustrated in FIG. 3 includes a liquid crystal panel 12 (electro-optical panel), a driver 60, a display controller 40, and a power supply circuit 50.

  Specifically, the liquid crystal panel 12 can be constituted by, for example, an active matrix type liquid crystal panel. At this time, a plurality of scanning lines G1 to Gm (m is an integer of 2 or more) arranged in the Y direction in FIG. 3 and extending in the X direction on the liquid crystal substrate (active matrix substrate, for example, a glass substrate) of the liquid crystal panel 12; A plurality of data lines S11 to S81, S12 to S82,..., S1n to S8n (n is an integer of 2 or more) arranged in the X direction and extending in the Y direction are arranged. The liquid crystal substrate is provided with data line drive voltage supply lines S1 to Sn. Further, the liquid crystal substrate is provided with demultiplexers DMUX1 to DMUXn corresponding to the respective data line driving voltage supply lines.

  Further, on the liquid crystal substrate, for example, a position corresponding to an intersection of the scanning line Gj (1 ≦ j ≦ m, j is a natural number) and the data line S1i (data lines S2i to S8i) (1 ≦ i ≦ n, i is a natural number) In addition, a thin film transistor Tji-1 (thin film transistors Tji-2 to Tji-8) is provided.

  For example, the gate electrode of Tji-1 is connected to the scanning line Gj, the source electrode is connected to the data line S1i, and the drain electrode is connected to the pixel electrode PEji-1. Between the pixel electrode PEji-1 and the counter electrode CE (common electrode, common electrode), a liquid crystal capacitor CLji-1 (liquid crystal element, electro-optical element in a broad sense) is formed. And the transmittance | permeability of a pixel changes according to the applied voltage between pixel electrode PEji-1 and counter electrode CE.

  The demultiplexer DMUXi supplies the data line driving voltage SVi supplied to the data line driving voltage supply line Si in a time division manner, for example, by dividing it into eight data lines S1i to S8i. The demultiplexer DMUXi separates the data line drive voltage SVi of the data line drive voltage supply line Si into each data line based on the multiplex control signal from the data driver 20.

  Here, in FIG. 3, only the demultiplexer DMUXi and the data lines S1i to S8i corresponding to the data line driving voltage supply line Si are shown for the sake of simplicity. Further, only the thin film transistor provided at the position corresponding to the intersection of the data lines S1i to S8i and the scanning line Gj is shown. However, the same applies to demultiplexers and data lines corresponding to other data line driving voltage supply lines, and thin film transistors provided at positions corresponding to intersections between other data lines and scanning lines.

  The voltage level of the counter electrode voltage VCOM applied to the counter electrode CE is generated by a counter electrode voltage generation circuit included in the power supply circuit 50. For example, the counter electrode CE is formed on one surface on the counter substrate.

  The data driver 20 drives the data line driving voltage supply lines S1 to Sn of the liquid crystal panel 12 based on the gradation data. When the data driver 20 drives the data line driving voltage supply lines S1 to Sn, the data driver 20 is controlled by the demultiplexers DMUX1 to DMUXn as described above. .., S1n to S8n can be driven. On the other hand, the scanning driver 38 scans (sequentially drives) the scanning lines G1 to Gm of the liquid crystal panel 12.

  The display controller 40 controls the data driver 20, the scan driver 38, and the power supply circuit 50 according to the contents set by a host such as a central processing unit (CPU) (not shown). More specifically, the display controller 40 supplies the data driver 20 and the scan driver 38 with, for example, setting of an operation mode and supply of an internally generated vertical synchronization signal and horizontal synchronization signal.

  The power supply circuit 50 generates various voltage levels (reference voltages) necessary for driving the liquid crystal panel 12 and the voltage level of the counter electrode voltage VCOM of the counter electrode CE based on a reference voltage supplied from the outside.

  In the liquid crystal display device having such a configuration, under the control of the display controller 40, the data driver 20, the scan driver 38, and the power supply circuit 50 cooperate to drive the liquid crystal panel 12 based on gradation data supplied from the outside. To do.

  FIG. 3 illustrates an example in which one pixel is composed of one dot as a liquid crystal panel for monochrome display, and one data line drive voltage supply line supplies data line drive voltages to eight data lines. . In the present invention, in order to display each color component of RGB, one pixel is composed of 3 dots. For example, one data line driving voltage supply line is connected to six data lines with data line driving voltages (for example, R1, R2, G1). , G2, B1, and B2 data line driving voltages) may be supplied.

  In FIG. 3, the liquid crystal display device includes the display controller 40, but the display controller 40 may be provided outside the liquid crystal display device. Alternatively, the host may be included in the liquid crystal display device together with the display controller 40. Further, some or all of the data driver 20, the scan driver 38, the display controller 40, and the power supply circuit 50 may be formed on the liquid crystal panel 12.

  Further, in FIG. 3, the display driver 60 may be configured as a semiconductor device (integrated circuit, IC) by integrating the data driver 20, the scan driver 38, and the power supply circuit 50.

  FIG. 4 shows a configuration example of the data driver 20 of FIG. The data driver 20 includes a shift register 22, line latches 24 and 26, a multiplexing circuit 28, a correction circuit 70, a reference voltage generation circuit 30 (grayscale voltage generation circuit), and a DAC 32 (Digital-to-Analog Converter, data in a broad sense). Line drive voltage generation circuit), data line drive circuit 34, and multiplex drive control unit 36.

  The shift register 22 includes a plurality of flip-flops provided corresponding to the data line driving voltage supply lines and sequentially connected. When the shift register 22 holds the enable input / output signal EIO in synchronization with the clock signal CLK, the shift register 22 sequentially shifts the enable input / output signal EIO to the adjacent flip-flops in synchronization with the clock signal CLK. The clock signal CLK and the enable input / output signal EIO are input from the display controller 40, for example.

  The line latch 24 receives gradation data (DIO) from the display controller 40 in units of 64 bits (8 bits (gradation data) × 8 (multiple number)), for example. The line latch 24 latches the gradation data (DIO) in synchronization with the enable input / output signal EIO sequentially shifted by each flip-flop of the shift register 22.

  The line latch 26 latches the grayscale data for one horizontal scan latched by the line latch 24 in synchronization with the horizontal synchronization signal LP supplied from the display controller 40.

  The multiplexing circuit 28 time-division multiplexes the gradation data for the eight data lines latched corresponding to each source line in the line latch 26. When this multiplexing circuit 28 is applied to this embodiment, it is provided between the image data registers PDR1 to PDRn and the addition circuits AD1 to ADn in the detailed configuration example shown in FIG. 8, for example.

  The correction circuit 70 corrects the variation in the data line drive voltage using the correction data obtained by the correction data calculation method described with reference to FIG. Specifically, the correction data CD1 to CDn corresponding to the data line drive voltage supply lines S1 to Sn are obtained in the correction data calculation mode, and the gradation data from the multiplexing circuit 28 is obtained as the correction data CD1 to CDn in the normal operation mode. The correction processing is performed, and the gradation data after the correction processing is output.

  The multiplex drive control unit 36 generates multiplex control signals SEL1 to SEL8 that define the time division timing of the data line drive voltage of the data line drive voltage supply line. More specifically, the multiplex drive control unit 36 generates the multiplex control signals SEL1 to SEL8 so that one of the multiplex control signals SEL1 to SEL8 becomes active in order within one horizontal scanning period. The multiplexing circuit 28 multiplexes based on the multiplex control signals SEL1 to SEL8 so as to supply the data line driving voltage to the data line driving voltage supply line in a time division manner. The multiplex control signals SEL1 to SEL8 are also supplied to the demultiplexers DMUX1 to DMUXn of the liquid crystal panel 12.

The reference voltage generation circuit 30 generates 256 (= 2 ⁸ ) types of reference voltages (grayscale voltages). 256 types of reference voltages (gradation voltages) generated by the reference voltage generation circuit 30 are supplied to the DAC 32.

  The DAC 32 generates an analog gradation voltage to be supplied to each data line. Specifically, the DAC 32 selects one of the reference voltages (gradation voltages) from the reference voltage generation circuit 30 based on the digital gradation data from the correction circuit 70 and corresponds to the digital gradation data. An analog gradation voltage is output, and a time division multiplexed gradation voltage is output.

  The data line drive circuit 34 buffers the grayscale voltage from the DAC 32 and outputs the data as a data line drive voltage to the data line drive voltage supply lines S1 to Sn. The data lines S11 to S81, S12 to S82,. S1n to S8n are driven. For example, the data line drive circuit 34 includes a voltage follower-connected operational amplifier (impedance conversion circuit in a broad sense) provided for each data line drive voltage supply line. The impedance of the voltage is converted and output to the data line drive voltage supply lines S1 to Sn.

2.2. FIG. 5 is a diagram for explaining the operation of the multiplex drive circuit 36 shown in FIG.
FIG. 5 shows an operation example of the demultiplexer DMUXi that separates the data line drive voltages V1 to V8 (data line drive voltage SVi) supplied to the data line drive voltage supply line Si in a time division manner into the data lines S1i to S8i. The same applies to the other demultiplexers.

  As shown in FIG. 5, the data line driving circuit 34 outputs multiplexed data line driving voltages V1 to V8 corresponding to the multiplexed data multiplexed by the multiplexing circuit 28. First, the multiplexed data multiplexed by the multiplexing circuit 28 and the multiplexed gradation voltage output from the DAC 32 will be described.

  The gradation data for the first to eighth data lines (data lines S1i to S8i) latched by the line latch 26 are denoted by GD1 to GD8. The multiplex control signals SEL1 to SEL8 generated by the multiplex drive control unit 36 are signals that become active once, for example, once in one horizontal scanning period. When the multiplex control signal SEL1 becomes active, the multiplexing circuit 28 selectively outputs the gradation data GD1 for the first data line (data line S1i), and the multiplex control signal SEL2 becomes active. When the multiplex control signal SEL8 becomes active, the grayscale data GD2 for the second data line (for example, the data line S2i) is selectively output, and the eighth data line (for example, the data line S8i) is activated. Gradation data GD3 for use is selectively output. As a result, the multiplexing circuit 28 generates multiplexed data in which the grayscale data GD1 to GD8 for the first to eighth data lines are time-division multiplexed, and supplies this multiplexed data to the correction circuit 70. .

  The correction circuit 70 corrects the multiplexed data obtained by time-division multiplexing the gradation data GD1 to GD8 using the correction data CDi. For example, correction processing is performed by adding correction data CDi to each of the gradation data GD1 to GD8. Then, the corrected gradation data GD1 'to GD8' are output.

  Each decoder of the DAC 32 converts the first to eighth gradation voltages corresponding to the gradation data GD1 ′ to GD8 ′, which have been multiplexed and corrected, into a reference voltage (gradation voltage, for example, 256 gradations). ) To choose from. As a result, each decoder of the DAC 32 outputs a gradation voltage obtained by multiplexing the first to eighth gradation voltages with respect to the multiplexed data. That is, the DAC 32 generates first to eighth gradation voltages corresponding to each gradation data in which each gradation voltage is multiplexed by the multiplexing circuit 28.

  As shown in FIG. 5, the data line driving circuit 34 receives the multiplexed first to eighth grayscale voltages from the DAC and multiplexes the first to eighth data line driving voltages V1 to V1. V8 (for example, the data line driving voltage SVi) is output within one horizontal scanning period.

  The demultiplexer DMUXi uses the multiplex control signals SEL1 to SEL8 to separate the multiplexed data line drive voltages V1 to V8 of the data line drive voltage supply line Si, and converts the data line drive voltages to the data lines S1i to S1i. Output to S8i.

  More specifically, when the multiplex control signal SEL1 is active as shown by A1 in FIG. 5, the demultiplexer DMUXi uses the data line drive voltage V1 shown by A2 as the data line drive voltage V1 shown by A3. Output to S1i. Similarly, when the multiplex control signal SEL2 is active, the multiplexed data line drive voltage V2 is output to the data line S2i, and when the multiplex control signal SEL8 is active, the multiplexed data line drive voltage V8 is output as data. Output to line S8i.

  By doing so, the data line driving voltage can be supplied to the source of the TFT connected to the scanning line selected in the liquid crystal panel 12.

2.3. Correction Data Calculation in Multiplex Drive FIG. 6 shows an operation example of correction data calculation in multiplex drive. FIG. 6 shows a case where, in the correction data calculation mode, for example, correction data CDi for the data line drive voltage supply line Si is obtained as correction data to be calculated (correction data corresponding to the data line drive circuit to be corrected). However, the same applies when obtaining other correction data.

  For example, when the data line driving voltage supply line Si described with reference to FIG. 5 is multiplex driving for supplying data line driving voltages to eight data lines in one horizontal scanning period, the correction circuit 70 performs one horizontal scanning in the correction data calculation mode. The correction calculation data is measured eight times during the period. In other words, if the first to eighth correction calculation data measurements are defined as the first to eighth indexes, the correction calculation data described with reference to FIG. Eighth correction calculation data is obtained.

  Specifically, as indicated by B1, when the multiplex control signal SEL1 is active, the correction circuit 70 performs measurement at the first index. In the first index, the correction circuit 70 outputs, for example, measurement gradation data MGD1 to MGD8 (measurement data MD). The DAC 32 selects and outputs the gradation voltage corresponding to each measurement gradation data of the measurement gradation data MGD1 to MGD8 from the reference voltage (gradation voltage). Then, as shown in B2 of FIG. 5, the data line driving circuit 34 receives the gradation voltage from the DAC 32 and supplies the data line driving voltages CV1 to CV8 corresponding to the measurement gradation data MGD1 to MGD8. Output to line Si. At this time, as indicated by B3, the demultiplexer DMUXi outputs the data line drive voltages CV1 to CV8 to the data line S1i based on the multiplex signal SEL1. The correction circuit 70 compares the data line drive voltages CV1 to CV8 output to the data line drive voltage supply line Si with the comparator reference voltage VP using, for example, the comparator 180 in FIG. 1, and the comparison result CPQ is inverted (for example, L The first correction calculation data is obtained using the measurement gradation data when the level is changed to the H level.

  Similarly, the correction circuit 70 obtains the second to eighth correction calculation data at the second to eighth indexes, and averages the first to eighth correction calculation data, for example, to obtain the correction data CDi. Ask.

  Thus, according to the present embodiment, the output variation of the data line driving circuit is repeatedly measured in one horizontal scanning period. Thereby, the influence of the measurement mistake by noise etc. can be decreased. Further, according to the present embodiment, as described with reference to FIG. 6, the data for correction calculation is obtained by driving the data lines in a time division manner in the same manner as in the multiplex driving in one horizontal scanning period. Thus, the data line can be driven with the same accuracy in the normal operation mode and the correction data calculation mode, and the data line drive voltage can be corrected accurately.

  6 illustrates an example in which the correction circuit 70 outputs the measurement gradation data MGD1 to MGD8 (k = 8) as the measurement gradation data. However, the correction circuit 70 has another number of measurement floors. Tone data may be output, and the data line driving circuit 34 may output the same number of corresponding data line driving voltages.

2.4. Correction Coefficient FIG. 7 shows an explanatory diagram of a correction coefficient to be multiplied to the correction data. FIG. 7 shows the data line drive voltage SVi in one of the first to eighth indexes described in FIG.

  At this time, the data line driving circuit 34 outputs the data line driving voltage SVi to the data line driving voltage supply line Si to drive any of the data lines S1i to S8i. For example, one of the data lines S1i to S8i is driven by an operational amplifier OPi described later with reference to FIG.

  As shown in LD1 of FIG. 7, when the operational amplifier OPi has a sufficient capability (speed) for driving the data line, the data line becomes sufficient as the correction circuit 70 outputs the measurement gradation data MGD1 to MGD8. Driven to reach a desired data line drive voltage. As indicated by D1, for example, when the data line drive voltage corresponding to the measurement gradation data MGD5 is larger than the comparator reference voltage VP, the correction circuit 70 uses the measurement gradation data MGD5 as the correction gradation data. Here, for simplicity, it is assumed that the measurement gradation data MGD5 is measured as the correction gradation data in the other indexes, and the measurement gradation data MGD5 is obtained as the correction data CDi.

  On the other hand, in multiplex drive, it is necessary to measure a plurality of correction calculation data in one horizontal scanning period and drive the data lines with a data line drive voltage corresponding to a plurality of measurement gradation data in one measurement. Therefore, the operational amplifier OPi may not have sufficient ability (speed) to drive the data line. At this time, as indicated by LD2, the data line is not sufficiently driven as compared with the data line voltage indicated by LD1, and the desired data line driving voltage is not reached. As shown in D2, for example, when the data line drive voltage corresponding to the measurement gradation data MGD6 is larger than the comparator reference voltage VP, the measurement gradation data MGD5 is used as the correction gradation data. Similarly, in other indexes, the measurement gradation data MGD6 is measured as the correction gradation data, and the measurement gradation data MGD6 is obtained as the correction data CDi.

  Thus, when the driving power of the operational amplifier is insufficient, correction data having a value deviated from the correction data calculated in an ideal case where the driving power of the operational amplifier is sufficient is calculated. Therefore, the deviation from the correction data calculated in the ideal case of the operational amplifier driving force is corrected by multiplying the correction data actually calculated by the correction coefficient.

3. Detailed configuration example 3.1. Detailed Configuration Example of the Present Embodiment FIG. 8 shows a detailed configuration example of the present embodiment. In the following, each component such as the comparator described with reference to FIG. Further, the present embodiment is not limited to the configuration of FIG. 8, and various modifications such as omitting a part of the configuration (for example, a shift register, a data switching circuit, etc.) or adding other components are possible. is there.

  The configuration example of FIG. 8 includes switches SW1 to SWn, shift registers SR1 to SRn, operational amplifiers OP1 to OPn, D / A conversion circuits DAC1 to DACn (Digital to Analog Converter, data line drive voltage generation circuit in a broad sense), selector DS1. DSn (data switching circuit), addition circuits AD1 to ADn (correction processing circuit in a broad sense), correction data registers CDR1 to CDRn, image data registers PDR1 to PDRn, comparator 180, control unit 100, and correction data calculation unit 102 Including.

  The image data registers PDR1 to PDRn hold image data PD1 to PDn which are gradation data corresponding to pixels driven by the data line driving voltage supply lines S1 to Sn. For example, the image data PD1 to PDn may be collectively written to the image data registers PDR1 to PDRn from the image data stored in a storage unit such as a RAM (Random Access Memory), and stream data is received by the I / F circuit. The image data registers PDR1 to PDRn may be sequentially written.

  The correction data registers CDR1 to CDRn hold the measurement data MD and the correction data CD1 to CDn from the correction data calculation unit 102. For example, when correction data CDi is calculated in the correction data calculation mode, measurement data MD sequentially output from the correction data calculation unit 102 is set in the correction data register CDRi, and the correction data register CDRi selects the correction data MD as a selector. Output to DSi. Then, the correction data calculation unit 102 calculates correction data CDi by calculating correction data, and sets the correction data CDi in the correction data register CDRi. In the normal operation mode, the correction data register CDRi outputs the correction data CDi to the addition circuit ADi. Measurement data and correction data are set in the correction data registers CDR1 to CDRn, for example, when the outputs of the corresponding shift registers SR1 to SRn are active.

  Note that initial values may be set in the correction data registers CDR1 to CDRn. For example, as described in FIG. 10, the initial values of the correction data CD1 to CDn may be set by the burst mode, or the initial values of the correction data CD1 to CDn may be set from a host controller (not shown).

  The adder circuits AD1 to ADn add the correction data CD1 to CDn to the image data PD1 to PDn, perform correction processing, and output the corrected image data PCD1 to PCDn. The correction processing may be performed by adding correction data CD1 to CDn to the image data PD1 to PDn and performing correction processing, or by adding or multiplying other coefficients.

  The selectors DS1 to DSn receive the measurement data MD from the correction data registers CDR1 to CDRn and the image data PCD1 to PCDn from the adder circuits AD1 to ADn, select one of them and send it to the D / A conversion circuits DAC1 to DACn. Output. Specifically, the selectors DS1 to DSn select data based on the correction enable signal C_Enable from the control circuit 100. For example, in the correction data calculation mode, the control unit 100 activates the correction enable signal C_Enable, and the selectors DS1 to DSn select and output the measurement data MD. On the other hand, in the normal operation mode, the control unit 100 deactivates the correction enable signal C_Enable, and the selectors DS1 to DSn select and output the image data PCD1 to PCDn.

  The D / A conversion circuits DAC1 to DACn generate gradation voltages to be supplied to the data line drive voltage supply lines S1 to Sn. Specifically, based on the gradation data (measurement data MD or image data PCD1 to PCDn) from the selectors DS1 to DSn, one of the reference voltages is selected and the gradation voltage is output. More specifically, the gradation voltage corresponding to the measurement data MD is output in the correction data calculation mode, and the gradation voltage corresponding to the image data PCD1 to PCDn is output in the normal operation mode. When the present embodiment performs multiplex driving, the D / A conversion circuits DAC1 to DACn output grayscale data time-division multiplexed based on the image data PCD1 to PCDn in which the grayscale data is time-division multiplexed. To do. Note that the reference voltage is input from, for example, a reference voltage generation circuit 30 shown in FIG.

  The operational amplifiers OP1 to OPn buffer the grayscale voltages from the D / A conversion circuits DAC1 to DACn and output the data line driving voltages S1 to Sn to the data line driving voltage supply lines S1 to Sn. For example, as shown in FIG. 8, a voltage follower can be configured using operational amplifiers OP1 to OPn to buffer gradation voltages.

  Shift registers SR1 to SRn output switch control signals SRQ1 to SRQn for controlling on / off of switches SR1 to SRn. Specifically, switch control that takes in H_SR (first logic level) SR_Data from the control unit 100, sequentially shifts H_SR_Data based on SR_Clock from the control unit 100, and sequentially becomes active. Output a signal. For example, when calculating the correction data CDi in the correction data calculation mode, the shift register SRi outputs active as the switch control signal SRQi.

  The switches SW1 to SWn are turned on / off based on signals from the shift registers SR1 to SRn. Specifically, the switches SW1 to SWn are turned on when signals from the shift registers SR1 to SRn are active, and are turned off when inactive. For example, when the correction data CDi is obtained in the correction data calculation mode, the switch SWi is turned on and the data line driving voltage SVi output from the operational amplifier OPi is input to the comparator 180 as the comparator input voltage CPI.

  The control unit 100 includes shift data SR_Data, a reset signal SR_Reset for the shift registers SR1 to SRn, a clock SR_Clock for the shift registers SR1 to SRn to capture shift data, and an enable signal that determines a period during which the shift registers SR1 to SRn output active. SR_Enable and selectors DS1 to DSn output a correction enable signal C_Enable for outputting measurement data MD in the correction data calculation mode.

3.2.1 H Mode A detailed operation example of this embodiment will be described with reference to FIGS. 9 and 10. In the present embodiment, correction data calculation is performed in the 1H mode and the burst mode as the correction data calculation mode.
FIG. 9 shows a signal waveform example in the 1H mode.

  In the present embodiment, correction data calculation in the 1H mode is performed in one horizontal scanning period of the non-display period. Specifically, correction data calculation in the 1H mode is performed in each of the first to nth vertical scanning periods of the plurality of vertical scanning periods (frames).

  More specifically, as indicated by E1 in FIG. 9, the correction data calculation unit 102 calculates the correction data CD1 in one horizontal scanning period within the first vertical scanning period.

  At this time, the control unit 100 activates SR_Reset as indicated by E2 to reset the shift registers SR1 to SRn, and deactivates the outputs of the shift registers SR1 to SRn as indicated by E3.

  Next, the control unit 100 outputs an H level (first logic level) to SR_Data as indicated by E4, and the SR_Clock from the control unit 100 indicated by E5 causes the shift register SR1 to be at the H level of SR_Data as indicated by E6. Capture levels.

  As indicated by E7, the control unit 100 activates SR_Enable, and the shift register SR1 outputs active as the switch control signal SRQ1 in the active period of SR_Enable.

  Then, the switch SW1 is turned on in response to the active switch control signal SRQ1 as indicated by E8, and the data line driving voltage SV1 is input to the comparator 180 as the comparator input CPI as indicated by E9.

  The correction data calculation unit 102 sequentially outputs the measurement data MD in the 1H mode indicated by E1. As indicated by E 10, when the control unit 100 activates C_Enable, the data line driving voltage SV 1 corresponding to the measurement data MD is output to the data line driving voltage supply line S 1 and input to the comparator 180. The correction data calculation unit 102 receives the comparison result CPQ from the comparator 180, for example, performs edge detection with the edge detection unit 260 in FIG. 11, and obtains correction data CD1. The correction data calculation unit 102 sets the obtained correction data CD1 in the correction data register CDR1.

  In this way, the correction data calculation unit 102 obtains the correction data CD1 in the 1H mode in the first vertical scanning period indicated by E1. Similarly, the correction data CD2 is obtained and set in the correction data register CDR2 in the 1H mode in the subsequent second vertical scanning period as indicated by E11, and the correction data in the 1H mode in the nth vertical scanning period as indicated by E12. CDn is obtained and set in the correction data register CDRn. Then, in the subsequent (n + 1) th vertical scanning period, the correction data CD1 is obtained again and set in the correction data register CDR1, and the correction data CD1 to CDn held in the correction data registers CDR1 to CDRn are sequentially updated by repeating this.

  As shown in E13, the present embodiment performs image display in the normal operation mode between the 1H mode and the 1H mode. Specifically, in the present embodiment, image data is corrected with correction data obtained in the 1H mode, and image display is performed.

  As described above, by performing correction data calculation in the 1H mode for each vertical scanning period, variations in the data line driving voltages SV1 to SVn due to offsets of the operational amplifiers OP1 to OPn can be corrected in real time. Further, by performing correction data calculation during a non-display period within the vertical scanning period, correction data can be calculated without affecting image display.

  According to the present embodiment, the correction data calculation unit 102 can also limit the amount of change in the correction data. For example, as shown in FIG. 9, it is assumed that the correction data calculation unit 102 obtains one correction data in one vertical scanning period and sequentially obtains correction data CD1 to CDn. Then, when the correction data CDi (current correction data) is obtained in the 1H mode in the vertical scanning period with the correction data calculation unit 102, the correction data CDi (previous correction data) obtained in the 1H mode in the n-th vertical scanning period. ) Can be limited to a positive or negative predetermined value. Thereby, it is possible to prevent the image quality from deteriorating due to abrupt changes in correction data due to noise or the like.

  The non-display period in which the present embodiment executes the 1H mode is a period in which the data line driving circuits 140-1 to 140-n do not output the data line driving voltages SV1 to SVn corresponding to the image data PD1 to PDn. is there. For example, it is a period from the fall of the vertical synchronization signal Vsync to the start of input of the image data PD1 to PDn to the image data registers PDR1 to PDRn. Alternatively, it is a period from the fall of the vertical synchronization signal Vsync until the first scanning line (for example, the scanning line G1 in FIG. 3) of the liquid crystal panel (for example, the liquid crystal panel 12 in FIG. 3) is selected.

3.3. Burst Mode FIG. 10 shows a signal waveform example in the burst mode.
In the present embodiment, correction data calculation is performed in a burst mode in which initial values of the correction data CD1 to CDn are collectively obtained during the display preparation period. Specifically, as shown in F1 of FIG. 10, the initial values of the correction data CD1 to CDn are obtained in the burst mode, and the correction data CD1 to CDn are obtained in the 1H mode after the burst mode as shown in F2.

  For example, in the present embodiment, the burst mode is executed during a period in which image display is not performed when the system is started up. For example, the burst mode is executed when an electronic device (projector, car navigation system, PDA, etc.) is turned on or returned from a hibernation state, before the backlight or projector lamp is turned on. Or this embodiment performs burst mode in the period when the image display at the time of display mode switching is not performed. For example, the burst mode is executed when the resolution of image display is switched.

  In the burst mode shown in FIG. 10, the present embodiment obtains initial values of the correction data CD1 to CDn in the first to nth horizontal scanning periods among the plurality of horizontal scanning periods.

  Specifically, first, as indicated by F3, the control unit 100 activates SR_Reset to reset the shift registers SR1 to SRn.

  Next, the control unit 100 outputs an H level (first logic level) to SR_Data as indicated by F4, and the SR_Clock from the control unit 100 indicated by F5 causes the shift register SR1 to be H of SR_Data as indicated by F6. Capture levels.

  As indicated by F7, the control unit 100 activates SR_Enable, and the shift register SR1 outputs active as the switch control signal SRQ1 in the active period of SR_Enable.

  Then, the switch SW1 is turned on in response to the active switch control signal SRQ1 as indicated by F8, and the data line drive voltage SV1 is input to the comparator 180 as the comparator input CPI as indicated by F9.

  As indicated by F10, when the control unit 100 activates C_Enable, the data line drive voltage SV1 corresponding to the measurement data MD is output to the data line drive voltage supply line S1, and is input to the comparator 180. The correction data calculation unit 102 receives the comparison result CPQ from the comparator 180, obtains correction data CD1, and sets it in the correction data register CDR1 as an initial value.

  In this way, the correction data calculation unit 102 obtains the initial value of the correction data CD1 in the first horizontal period in the burst mode. Similarly, the initial value of the correction data CD2 is obtained and set in the correction data register CDR2 in the subsequent second horizontal scanning period, and the initial value of the correction data CDn is obtained and set in the correction data register CDRn in the nth horizontal scanning period. To do. Then, after obtaining the initial values of the correction data CD1 to CDn in the burst mode, the correction data CD1 to CDn are sequentially updated every vertical scanning period in the 1H mode.

  Note that the control unit 100 does not reset the shift registers SR1 to SRn and outputs an L level (second logic level) to SR_Data during the horizontal scanning period in which the correction data CD2 to CDn are calculated.

  By the way, when the initial values of the correction data CD1 to CDn are not set, the variation in the data line voltage is not corrected until the correction data CD1 to CDn is calculated in the 1H mode, so that the display image immediately after the power is turned on or the like. There is a problem that image quality deteriorates.

  In this regard, according to the present embodiment, the initial values of the correction data CD1 to CDn are set in the correction data registers CDR1 to CDRn before the 1H mode is executed. Thus, the variation in the data line voltage can be corrected by the initial value until the first correction data CD1 to CDn are updated in the 1H mode. For example, as shown in F11 of FIG. 10, when the correction data CD1 is obtained in the first 1H mode (F2) after the burst mode, the correction data obtained in the 1H mode in the normal operation mode after the first 1H mode. Correction can be made with the initial values CD2 to CDn obtained in CD1 and burst mode.

  Further, according to the present embodiment, the burst mode is executed during a display preparation period such as when the power is turned on or before the backlight is turned on. Thereby, it is possible to improve the image quality by correcting the variation in the data line driving voltage immediately after the start of the image display without affecting the image display.

  In this embodiment, in the display preparation period or the non-display period, the data line driving voltage supply lines S1 to Sn are set to a predetermined data line driving voltage in the first horizontal scanning period among the plurality of horizontal scanning periods. In the subsequent second horizontal scanning period, the correction data calculation unit 102 may obtain the correction data CD1 to CDn.

  For example, after the data line drive voltage supply lines S1 to Sn are set to a predetermined data line drive voltage in one horizontal scanning period in the non-display period shown in E14 of FIG. 9, the 1H mode shown in E1 may be executed. The burst mode shown in F1 may be executed after the data line drive voltage supply lines S1 to Sn are set to a predetermined data line drive voltage in one horizontal scanning period in the display preparation period shown in F12 of FIG.

  As the predetermined data line drive voltage, for example, when the correction data calculation unit 102 sequentially changes the measurement data MD, a voltage within a range in which the corresponding data line drive voltage changes is set. For example, the operational amplifiers OP1 to OPn may output the predetermined data line driving voltage by setting the gradation data corresponding to the predetermined data line driving voltage in the correction data registers CDR1 to CDRn.

  As described above, according to the present embodiment, the data line driving voltage supply lines S1 to Sn to which various data line driving voltages are output according to the data line driving voltage of the display image, etc., are one horizontal before the correction data calculation. It is set to a constant voltage during the scanning period. Thereby, it is possible to measure the variation in the data line driving voltage by starting from the same data line driving voltage every time the correction data calculation is started. Therefore, the variation in the data line driving voltage can be measured with the same accuracy every time, and correction data that accurately reflects the variation in the data line driving voltage can be obtained.

3.4. Detailed Configuration Example of Control Unit and Correction Data Calculation Unit FIG. 11 shows a detailed configuration example of the control unit and the correction data calculation unit. 11 includes a correction data calculation unit 102 and a sequencer 240, and the correction data calculation unit 102 includes a counter unit 200, a register unit 220, an edge detection unit 260, and a processing unit 280. The correction data calculation unit 102 according to the present embodiment is not limited to the configuration shown in FIG. 11, and various modifications such as omitting some of the configuration requirements (index register 222, interval register 228, etc.) are possible.

  The counter unit 200 includes an index counter 202, a measurement start counter 204, a measurement period counter 206, an interval counter 208, and a measurement data counter 210.

  The index counter 202 counts an index that is the number of times correction correction data is measured in one horizontal scanning period. For example, the index counter 202 increments the index according to an instruction from the sequencer 240.

  The measurement start counter 204 counts the measurement start period from the horizontal synchronization signal to the start of correction data calculation. For example, the measurement start counter 204 counts the measurement start period using the dot clock Dclk.

  The measurement period counter 206 is a period in which the comparator 180 compares the data line driving voltage corresponding to one measurement data when the correction data calculation unit 102 sequentially outputs the measurement data MD (measurement gradation data). Count. For example, the measurement period counter 206 counts the measurement period based on the dot clock Dclk.

  The interval counter 208 counts the interval period from the end of one index to the start of the next index. The interval period is a period for initializing the output of the comparator 180 (comparison result CPQ) (for example, initializing to L level). For example, the interval counter 208 counts the interval period using the dot clock Dclk.

  The measurement data counter 210 generates measurement data MD based on the count value. For example, the measurement data counter 210 increments the count value every measurement period in accordance with an instruction from the sequencer 240.

  The register unit 220 includes an index register 222, a measurement start register 224, a measurement period register 226, an interval register 228, and a correction calculation data register 230.

  The index register 222 sets the number of indexes counted by the index counter 202.

  The measurement start register 224 sets a measurement start period counted by the measurement start counter 204.

  The measurement period register 226 sets the measurement period counted by the measurement period counter 206.

  The interval register 228 sets an interval period counted by the interval counter 208.

  For example, register values are set in the index register 222, the measurement start register 224, the measurement period register 226, and the interval register 228 from a host controller (CPU) (not shown).

  The correction calculation data register 230 holds correction calculation data calculated at each index. For example, the correction calculation data register 230 receives the edge detection pulse from the edge detection unit 260 and holds the measurement gradation data from the measurement data counter 210. Alternatively, the correction calculation data register 230 holds the correction calculation data subjected to the correction exception process from the processing unit 280.

  The edge detector 260 receives the comparison result CPQ from the comparator 180 and outputs an edge detection pulse. For example, as described with reference to FIG. 2, a rising edge (falling edge) of the comparison result CPQ is detected and an edge detection pulse is output.

  The processing unit 280 calculates correction data CD1 to CDn from the correction calculation data of each index held in the correction calculation data register 230, and sets the correction data in the correction data registers CDR1 to CDRn. For example, the processing unit 280 calculates correction data by averaging the correction calculation data of each index.

  Further, the processing unit 280 performs correction exception processing on the correction calculation data. The processing unit 280 can multiply the correction coefficient as the correction exception process. Specifically, as described with reference to FIG. 7 and the like, the measured correction calculation data is multiplied by a predetermined correction coefficient and set in the correction calculation data register 230. Further, the processing unit 280 can perform overflow processing as correction exception processing. Specifically, the processing unit 280 sets the overflow data in the correction calculation data register 230 when it is determined that overflow has occurred in the measurement of the correction calculation data. Further, the processing unit 280 can limit the amount of change as the correction exception process. Specifically, for example, the amount of change in the correction data is limited using the previous correction data held in the correction data registers CDR1 to CDRn in FIG.

  When the present embodiment alternately drives the data lines in the positive polarity period and the negative polarity period in the normal operation mode, the processing unit 280 corrects the correction data for the positive polarity and the correction for the negative polarity from the correction calculation data. You can also ask for data. For example, the processing unit 280 may use the 2's complement of the positive polarity correction data as the negative polarity correction data, or may use a 1's complement.

  The sequencer 240 receives the vertical synchronization signal Vsync, the horizontal synchronization signal Hsync, and the dot clock Dclk, controls the correction data calculation unit 102, the shift data SR_Data described in FIGS. 8 to 10, the reset signal SR_Reset of the shift register, and the shift The register clock SR_Clock, the shift register output enable signal SR_Enable, and the correction enable signal C_Enable are output.

  The correction data calculation unit 102 and the sequencer 240 may be configured using, for example, a gate array, and are realized by a CPU (not shown) executing a program in which the functions of the correction data calculation unit 102 and the sequencer 240 are described. May be.

  FIG. 12 shows an example of a processing flow of the correction data calculation unit 102. In FIG. 12, the operation in the 1H mode in the correction data calculation mode will be described as an example. In the burst mode, the process starts from the correction data calculation mode wait (step SA1) in FIG. 12 and stores the correction data (step SA22) in the same manner as in the 1H mode. Every time HSYNC wait (step SA3) to correction data storage (step SA22), this is repeated until correction data CD1 to CDn are obtained.

  The correction data calculation unit 102 waits for a correction data calculation start instruction from the sequencer 240 in the correction data calculation mode wait (SA1). If No, the correction data calculation mode wait (SA1) is repeated, and if Yes, the VSYNC wait (SA2) is performed.

  In the VSYNC wait (SA2), it waits for the edge (falling edge or rising edge) of the vertical synchronization signal Vsync. If No, the VSYNC wait (SA2) is repeated, and if Yes, the HSYNC wait (SA3) is performed.

  In the HSYNC wait (SA3), it waits for an edge (falling edge or rising edge) of the horizontal synchronization signal Hsync. If No, the HSYNC wait (SA3) is repeated, and if Yes, the measurement start counter is reset, the measurement data counter is reset, and the index counter is reset (SA4).

  Next, in the measurement start wait (SA5), it is determined whether or not the count value of the measurement start counter matches the measurement start period set in the measurement start register 224. If they do not match (No), the measurement start counter is incremented (SA6) and the measurement start wait (SA5) is repeated. If they match (Yes), the measurement period counter is reset (SA7), and a correction level match determination (SA8) is performed.

  In the correction level match determination (SA8), based on the comparison result CPQ from the comparator 180, it is determined whether the data line drive voltage output from the data line drive circuit to be corrected matches the comparator reference voltage VP. If they match (Yes), the correction calculation data is stored in the correction calculation data register 230 in the correction calculation data storage (step SA9), the index counter is incremented (SA16), and steps SA17 to SA22 are performed. If they do not match (No), the measurement period counter is incremented (SA10), and the measurement period end wait (SA11) is performed.

  In the measurement period end wait (SA11), it is determined whether or not the count value of the measurement period counter 206 matches the measurement period set in the measurement period register 226. If they do not match (No), a correction level match determination (SA8) is performed. If they match (Yes), the measurement data counter is incremented (SA12), and the measurement data maximum value determination (SA13) is performed.

  In the measurement data maximum value determination (SA13), it is determined whether or not the count value of the measurement data counter 210 exceeds a predetermined maximum value (or minimum value). If not exceeded (No), the measurement period counter is reset (SA7) and steps SA8 to SA13 are performed. When it exceeds (Yes), correction exception processing (SA14) is performed.

  In the correction exception processing (SA14), overflow processing, correction coefficient multiplication, and change amount limitation are performed, and in the correction calculation data storage (SA15), the correction calculation data is set in the correction calculation data register 230.

  Next, the index counter is incremented (SA16).

  Subsequently, the interval counter is reset (SA17) and waits for the end of the interval (SA18).

  In the interval end wait (SA18), it is determined whether or not the count value of the interval counter matches the interval period of the interval register 228. If they do not match (No), the interval counter is incremented (SA19) and the interval end wait (SA18) is repeated. If they match (Yes), the process waits for the specified number of times (SA20).

  In waiting for the end of the specified number of times (SA20), it is determined whether or not the count value of the index counter 202 matches the number of indexes set in the index register 222. If they do not match (No), the measurement period counter is reset (SA7), and steps SA8 to SA20 are performed. If they match (Yes), the correction calculation data is averaged (SA21) to obtain correction data, and correction data storage (SA22) is performed.

  In the correction data storage (SA22), for example, correction data from the processing unit 280 is set in the correction data registers CDR1 to CDRn in FIG.

  FIG. 13 shows a modification of the processing flow of the correction data calculation unit 102. The modification shown in FIG. 13 is an example of a processing flow when the present embodiment does not perform multiplex driving. Specifically, this embodiment is an example of a processing flow in the case where one data line is driven in one horizontal scanning period in the normal operation mode and one correction calculation data is obtained in one horizontal scanning period in the correction data calculation mode. is there.

  In the modification shown in FIG. 13, the index counter 202, interval counter 208, index register 222, and interval register 228 shown in FIG. 11 can be omitted.

  In the modification shown in FIG. 13, the correction data calculation unit 102 waits for a correction data calculation mode (SB1). If No, the correction data calculation mode wait (SB1) is repeated, and if Yes, the VSYNC wait (SB2) is performed.

  In the VSYNC wait (SB2), if No, the VSYNC wait (SB2) is repeated, and if Yes, the HSYNC wait (SB3) is performed.

  In the HSYNC wait (SB3), if No, the HSYNC wait (SB3) is repeated, and if Yes, the measurement start counter is reset and the measurement data counter is reset (SB4).

  Next, a measurement start wait (SB5) is performed. If No, the measurement start counter is incremented (SB6) and the measurement start wait (SB5) is repeated. In the case of Yes, the measurement period counter is reset (SB7), and the correction level coincidence determination (SB8) is performed.

  In the correction level match determination (SB8), if they match (Yes), correction calculation data storage (step SB9) is performed, and correction data calculation (SB16) is performed. If they do not match (No), the measurement period counter is incremented (SB10), and the measurement period end wait (SB11) is performed.

  In the measurement period end waiting (SB11), in the case of No, a correction level coincidence determination (SB8) is performed. In the case of Yes, the measurement data counter is incremented (SB12), and the measurement data maximum value determination (SB13) is performed.

  If the measurement data maximum value determination (SB13) is No, the measurement period counter is reset (SB7), and steps SB8 to SB13 are performed. In the case of Yes, correction exception processing (SB14) is performed, and correction calculation data storage (SB15) is performed.

  Next, in the correction data calculation (SB16), the processing unit 280 obtains correction data from the correction calculation data. For example, the processing unit 280 may use the correction calculation data stored in the correction calculation data register 230 as it is as correction data, and obtain correction data by adding or subtracting a predetermined constant to the correction calculation data. Also good.

  Then, the correction data is stored in the correction data register (SB17).

4). FIG. 14 schematically shows a layout arrangement example of the present embodiment. In FIG. 14, the layout arrangement is described using the first direction D1 to the fourth direction D4, the direction opposite to the first direction D1 is defined as the second direction D2, and the direction orthogonal to the first direction D1 is defined as the direction. Let it be the third direction D3 and the fourth direction D4.

  The layout arrangement example shown in FIG. 14 includes data line driving circuits 140-1 to 140-n (a plurality of data line driving circuits) and a comparator 180.

  As shown in FIG. 14, the data line driving circuits 140-1 to 140-n are arranged along the first direction D1. The comparator 180 is arranged in the first direction D1 (or the second direction D2) of the data line driving circuits 140-1 to 140-n. Specifically, the data line driving circuits 140-1 to 140-n are arranged at equal intervals without including other components such as the comparator 180 therebetween.

  Furthermore, the layout arrangement example shown in FIG. 14 can include a gate array GA. The gate array GA includes a control unit 100 including a correction data calculation unit 102. The gate array GA can also include, for example, an I / F circuit that receives stream data and digital cells of the scan driver 38. As shown in FIG. 14, the gate array GA may be arranged in the direction D1 of the data line driving circuits 140-1 to 140-n and the comparator 180, or may be arranged in the direction D2. Further, the gate array GA may be disposed in the direction D3 or the direction D4 of the data line driving circuits 140-1 to 140-n and the comparator 180.

  Here, if the data line driving circuits 140-1 to 140-n are arranged at unequal intervals, the process processing accuracy of each data line driving circuit is not uniform. For this reason, manufacturing variations tend to occur in the output characteristics of the data line driving circuit, and there is a problem that variations in data line voltages increase.

  For example, when the data line drive voltage is output using the operational amplifiers OP1 to OPn as shown in FIG. 8, if the processing accuracy of the differential pair of each operational amplifier is not uniform, the offset varies and the data line voltage varies. There is a problem that becomes larger.

  In this regard, according to the present embodiment, the data line driving circuit is arranged along the direction D1, and the comparator 180 is arranged in the direction D1 (or direction D2) of the data line driving circuit. As a result, the data line driving circuits can be arranged at equal intervals, and variations in the data line driving voltage due to manufacturing variations can be suppressed.

  Further, according to the present embodiment, the variation in the data line driving voltage is measured using one comparator. Thereby, it is not necessary to mix other components between the data line driving circuits, and the data line driving circuits can be arranged at equal intervals.

  As described above, according to the present embodiment, the variation in the data line driving voltage due to the manufacturing variation can be suppressed, and the correction accuracy of the data line driving voltage variation correction based on the correction data can be improved.

(Second Embodiment)
In the present embodiment, correction data saving will be described.

5. Saving (reading out) correction data
5.1. Outline of saving correction data (circuit configuration)
The correction data obtained by the calculation is valuable data indicating the characteristics of the electro-optical device. For example, the correction data can be used for verifying the degree of damage of the electro-optical device, or used for testing the driver characteristics. It is also possible. Therefore, in the present embodiment, correction data can be saved outside the integrated circuit device. As a result, for example, even when the power of an electronic device equipped with an electro-optical device is turned off, the correction data is left without being lost, and the correction data can be used for, for example, verification or testing of characteristics of the liquid crystal panel. Become available for such purposes.

  Further, for example, by comparing the current correction data with the past correction data, the degree of damage of the liquid crystal panel may be periodically checked, or the liquid crystal panel may be confirmed to have been changed. it can.

  In addition, for example, when vertical stripes are visible only in a part of the liquid crystal panel, correction data is obtained for a portion where the vertical stripes are visible and a plurality of data lines located in the peripheral portion, and the obtained correction data Is transferred to the outside of the integrated circuit device and the correction data is analyzed, so that the display defect portion can be accurately identified and the degree of the display defect can be confirmed.

  FIG. 15 is a diagram illustrating a circuit configuration of a portion related to saving correction data in the integrated circuit device according to the second embodiment. The integrated circuit device of FIG. 15 includes a correction sequencer 241 (including the correction data calculation unit 102), an image processing unit 243 that controls supply of image data, a command decoder 238, and an internal register group 245 (including a status register 247). ), The image data register 352 and the image shift register 350, the correction shift register 354, the correction data register 356, and the switches (first switches) SWQ (n−1), SWQn, SWQ ( n + 1), an adder circuit AD (358) functioning as an image data correction circuit, a read buffer RBF (for example, having a primary latch 237 and a secondary latch 239), and a host interface 300a (serial-parallel conversion shift register 311) And image interface And 300b, a second switch 251 provided between the read buffer RBF and host interface 300a, a.

  The correction sequencer 241 includes the correction data calculation unit 102 (not shown in FIG. 15) described above. The correction sequencer 241 controls an off sequence when the power is turned off and a transfer (save) sequence of correction data. The correction sequencer 241 can supply the correction shift register 354 with the correction shift start pulse SSP, the shift register clear pulse CLEAR, and the correction shift clock CCLK.

  The correction shift register 354 is used to select (specify) a correction data register 356 that is a target for reading (saving) correction data. When reading (saving) the correction data, the correction data register 356 is selected (designated) by the output signal of the correction shift register 354, and the first switch SWQ is turned on by the output signal, and the correction data read bus CDBUS and correction data register 356 are connected. As a result, a serial transfer path (but not limited to) for transferring the correction data CD in the integrated circuit device is formed.

  Serial data transferred via the correction data read bus is temporarily stored in the read buffer and then transferred to the host (CPU) 400 via the host interface 300a.

  In FIG. 15, a plurality of unit drivers LDR (LDR (n−1), LDRn, LDR (n + 1) are shown in FIG. 15) are arranged in the wiring direction of the word lines WL. Each unit driver LDR has the same internal configuration, and as components, an addition circuit AD that functions as a correction circuit, a first switch SWQ, a correction data register 356, a correction shift register 354, an image data register 352, and an image shift register 350 including. Note that an operational amplifier for amplifying the output signal of the adder circuit AD (reference numeral 358) is omitted in FIG. In FIG. 15, the save path (read path) for the correction data CD is indicated by a thick solid line.

(Correction data save operation)
The host (CPU) 400 transmits a correction data request command CMA to the integrated circuit device (IC). The correction data request command CMA is input to the control unit (gate array) 100 in the integrated circuit device via the host interface 300a. The correction data request command CMA is decoded by the command decoder 238, and the operation of the internal register group 245 (having the status register 247) is controlled by the decoded output. The status register 247 is a register in which an off sequence start flag, an end flag, and the like are set.

  When the internal register group 245 operates, a correction data transfer command P1 is supplied to the correction sequencer 241. Further, the second switch 251 is turned on at an appropriate timing.

  First, the correction sequencer 241 ends the correction of the image data using the correction data. For example, when image correction related to one data line is being performed at the time of input of the correction data request command, the correction for that data line can be completed after completion of the correction, and the correction data request command Is input, the correction can be immediately terminated without waiting for the image correction for the data line. Further, the correction of the image data is finished in synchronization with, for example, the rising or falling edge of the vertical synchronization signal (VSYNC).

  Next, the correction sequencer 241 clears the data in the correction shift register 354. This is because if the start pulse is input again while data remains in the correction shift register, there is a disadvantage that two data are transferred. In the case of FIG. 15, since the correction shift register 354 has a clear terminal, the correction shift register 354 can be cleared by inputting the shift register clear pulse CLEAR. When the correction shift register 354 does not have a clear terminal, the correction shift register 354 can be cleared by shifting data to the end of the correction shift register.

  Next, the correction shift register 354 is operated. For example, when reading correction data from each of all the correction data registers 354, each of the correction data registers 356 is sequentially selected by the output signal of the correction shift register 354.

  When the first switch SWQ is turned on by the output signal of the correction shift register 354, the correction data read bus CDBUS and the correction data register 356 are connected. As a result, a serial transfer path for transferring the correction data CD in the integrated circuit device is formed.

  The correction data CD output from each of the correction data registers 356 is transferred via the correction data read bus CDBUS in synchronization with the read clock, for example. The read clock can be generated, for example, by dividing the dot clock.

  The correction data CD (serial data) transferred via the correction data read bus CDBUS is temporarily stored in the read buffer RBF. The operation timing (correction data input / output timing) of the read buffer RBF is controlled by a timing control signal PK output from the correction sequencer 241.

  The read buffer RBF is not particularly limited, and includes, for example, first and second latches 237 and 239 (that is, a first buffer and a second buffer). In this case, the correction data transferred to the first latch 237 can be stored, and at the same time, the correction data can be output from the second latch 239 toward the host interface 300a. Therefore, efficient data transfer is possible without interrupting serial data transfer.

  The correction data CDout output from the read buffer RBF is sent to the host interface 300a via the second switch 251. Then, serial data is converted into parallel data by a serial / parallel conversion shift register (S / P shift register) 311 included in the host interface 300a. The parallel data (read correction data CD) is output to the host (CPU) 400. Note that the transfer operation of the correction data CD from the read buffer RBF to the host interface 300a can be controlled by the host interface 300a, for example, or can be controlled by the correction sequencer 241.

  The host (CPU) 400 receives the read correction data CDR, and stores the received correction data CDR in a memory (correction data storage unit: for example, a nonvolatile memory such as an EEPROM or an HDD).

  The correction data saving operation described above is merely an example, and the present invention is not limited to this. For example, the image display controller 410 may control the correction data saving operation. In addition, a memory 420 for storing correction data can be provided on the image display controller 410 side.

  When the correction data CD is transferred (saved) during an off-sequence period for turning off the power, the image processing unit 243 reads a plurality of data lines in parallel with the reading of the correction data CD. Each can be supplied with a given gradation voltage (for example, in the case of normally black liquid crystal, for example, a voltage corresponding to black).

  That is, in the case of a liquid crystal panel, it is desirable to execute, for example, writing black data a plurality of times (for example, twice) in order to prevent liquid crystal burn-in before the power is turned off. The operation of supplying the given gradation voltage is executed asynchronously with reading (saving) of the correction data CD, for example. The off sequence is executed when the host (CPU) 400 outputs an off sequence command.

  The above-described correction data reading (saving) operation is summarized as shown in FIG. That is, when the host (CPU) 400 transmits a correction data request command (step ST1), the control unit (gate array) 100 in the integrated circuit device ends the correction processing (ST2), and stores the data in the correction shift register 354. Clear (step ST3).

  Next, the control unit (gate array) 100 in the integrated circuit device outputs the correction data CD from the correction data register 356 and outputs the correction data CD to the read buffer RBF via the correction data read bus CDBUS. Transfer (step ST4). The correction data CD is transferred from the read buffer RBF to the host (CPU) 400 via the host interface 300a (step ST5).

  On the other hand, when the off sequence is executed, it corresponds to a given gradation voltage (black in the case of normally black liquid crystal) in parallel with the correction data saving and asynchronously with the correction data saving operation. Voltage) is written a plurality of times (for example, twice), thereby preventing liquid crystal burn-in (step ST6).

  The host (CPU) 400 stores the correction data CD in the memory 420 (nonvolatile memory, HDD, etc.) (step S7).

  Further, as described above, for example, when testing (inspecting) a liquid crystal panel connected to the integrated circuit device, only the correction data stored in the correction register corresponding to the data line to be tested is It can also be retracted outside the integrated circuit device. In this case, the correction shift register 354 selects one or a plurality of correction data registers corresponding to the test target data line from the plurality of correction data registers 356. For example, when vertical stripes are visible only on a part of the display panel, the correction data for the data lines that are visible in the vertical stripes and the multiple data lines located in the surrounding area is acquired, and the acquired correction data is accumulated. By transferring the data to the outside of the circuit device and analyzing the correction data, it is possible to accurately specify the display defect location and to check the degree of the display defect.

5.2. Specific Circuit Configuration and Operation FIG. 17 is a diagram illustrating an example of a specific circuit configuration of the integrated circuit device according to the second embodiment. In FIG. 17, parts that are the same as those in the previous drawings are given the same reference numerals. The circuit configuration shown in FIG. 17 is common to the circuit configuration described with reference to the previous drawings, and the circuit operation is also common. Description of the common configuration is omitted. Hereinafter, a configuration, a control signal, and the like that are not described in the above drawings will be mainly described.

  The host (CPU) 400 has an output terminal for a read / write enable signal XCS, an output terminal for a read / write signal R / W, an output terminal for a system clock SCK, and an input / output terminal for data SDATA. The image display controller (LCDC) 410 has an output terminal for the polarity signal POL, an output terminal for the image data DATA, an output terminal for the dot clock DCK, an output terminal for the horizontal synchronization signal HSYNC, and an output terminal for the vertical synchronization signal VSYNC. .

  The host interface 300a includes two gate circuits 301 and 303, a clock counter 305 that outputs a command execution clock CMACLK, a register 307 that temporarily stores a read command, and two parallel / serial shift registers (S / P shift). Registers) 309 and 311 and four switches SWK1 to SWK4.

  The control unit (gate array) 100 includes a third switch 249 for reading out register information of the internal register group 245. Note that the read buffer RBF has two latches (a primary latch 237 as a first buffer and a secondary latch 239 as a second buffer). The latch operation of the correction data of the primary latch 237 is controlled by the primary latch clock PK1 output from the correction sequencer 241. Similarly, the correction data latching operation of the secondary latch 239 is controlled by the secondary latch clock PK 2 output from the correction sequencer 241.

  In addition, as described above, the comparator 180 for actually measuring the deviation of the data line driving voltage is provided.

  The correction sequencer 241 also includes a comparator enable signal CPEN, a correction switching enable SREN for switching the changeover switch SWX, a correction data output polarity (correction data output phase) signal CPOL, and a correction output from the correction data calculation unit 102. Data CD (CD1 to CDn), latch clock RCLK, correction shift start pulse SSP, correction shift register clear pulse CLEAR1, and correction shift clock CCLK are output.

  As described above, the correction data register 356 is designated by the output signal (TP) of the correction shift register 354, and the first switch SWQ is turned on. The changeover switch SWX is turned on by the output signal (TP) of the correction shift register 354.

  The image processing unit 243 outputs image data GD, an image shift start pulse GSP, an image shift register clear pulse CLEAR2, and an image shift clock GCLK. The image data GD is latched in the image data register 352 by the output signal of the image shift register 350.

  FIG. 18 is a timing chart showing the timing of the data saving operation in the integrated circuit device shown in FIG. As shown in FIG. 18, a correction data request command (CMA) is input from the host (CPU) 400 to the integrated circuit device at time t1.

  At time t2, the command execution clock CMACLK is output from the clock counter 305. At time t3, the correction data latch clock RCLK is output. At time t4, the correction signal in the correction sequencer (not shown in FIG. 17) changes from H to L, thereby completing the image data correction operation. Similarly, at time t4, the correction data output polarity (output phase) CPOL is fixed to, for example, positive polarity. At time t5, the corrected shift register clear pulse CLEAR1 is output.

  Next, at time t6, the correction shift start pulse SSP is input to the correction shift register 354. After time t7, the corrected shift clock CCLK is output periodically. After time t7, the correction data CD is read via the correction data read bus CDBUS. The primary latch clock PK1 is output at time t8, and the secondary latch clock PK2 is output at time t9. From time t9 to time t10, the first correction data (correction data 1) is output.

  After time t10, the command execution clock CMACLK is generated every time reading of n-bit serial data (correction data) is completed. Thereafter, the same operation is repeated. For example, when the correction data is saved during the off-sequence period, the above operation is repeated until all the correction data is saved.

  FIG. 19 is a timing chart showing the timing of passing control signals and data between the host (CPU) and the host interface. From time t21 to time t24, the read / write signal R / W becomes L level, and becomes H level after time t24. Accordingly, the period from time t20 to time t24 is a period for writing a correction read command (correction data request command), and the period after time t24 is a period for reading correction data.

  From time t21 to time t23, from time t24 to time t26, and from time t27 to time t29, the read / write enable signal XCS becomes L (active level). A correction read command (correction data request command) and correction data (correction data 1, correction data 2,...) Are transferred in synchronization with the system clock SCK. Further, every time transfer of the correction read command (correction data request command) and correction data (correction data 1, correction data 2...) Is completed, the command execution clock CMACLK is output (time t22 to t23, time t25). To t26, times t28 to t29).

  FIG. 20 is a diagram illustrating a configuration example of a conversion circuit that converts a low-speed signal into a high-speed signal. For example, when generating a low-frequency readout clock from a high-frequency dot clock, the conversion circuit of FIG. 20 is used. The conversion circuit in FIG. 20 includes a three-stage D flip-flop (430, 431, 432) with a reset terminal and an inverter 433. FIG. 21 is a timing diagram showing an example of the timing of the low-speed signal, the high-speed clock, and the high-speed signal.

(Third embodiment)
In the present embodiment, for example, the saved correction data is transferred to the integrated circuit device together with the image data via the interface unit, and the correction data is set in the correction data register (writing correction data from the outside). Operation) will be described.

  When calculating the correction data based on the actually measured data, a certain amount of time is required for obtaining the correction data. Therefore, for example, if the measurement of the deviation data of the drive output and the calculation of the correction data based on the measured deviation data are performed after the power is turned on, the image may not be corrected during that time.

  Therefore, in the present embodiment, for example, when executing a power-on sequence, it is possible to set correction data in the correction data register from the outside, thereby correcting the image data in real time immediately after power-on, so that an appropriate image can be obtained. Display (image formation) is enabled.

6). Writing correction data 6.1. Configuration Example for Writing Correction Data FIG. 22 shows a correction data register in which correction data (for example, correction data saved in the memory using the configuration of the second embodiment) is input from the host device to the integrated circuit device. It is a figure which shows an example of the structure for writing in. The circuit configuration shown in FIG. 22 is a part of the circuit configuration shown in FIG. The circuit configuration shown in FIG. 22 is as described above with reference to FIG.

  However, in this embodiment, the correction data CD is input to the integrated circuit device (IC) together with the image data, the input correction data CD is separated from the image data DATA, and the separated correction data CD is corrected to the correction data. It is possible to write in the register (correction data storage unit) 356 (however, the present invention is not limited to this, and correction data can be input alone).

  For example, when the power is turned on, the correction data CD saved at the previous power-off and stored in the non-volatile memory 420 (however, the correction data is not limited to this, and may be newly created correction data). ) Is input to the image interface 300b via the image data input line (input bus) GL.

  The correction data CD is input to the image interface 300b, for example, in a form included in the image data DATA or in a form added to the image data DATA.

  The correction data CD input to the integrated circuit device is separated from the image data DATA by the image processing unit 243 included in the control unit (gate array) 100, for example. The separated correction data CD is sent to the correction sequencer 241, transferred to the correction data register 356 via the correction data bus KBUS, and latched in the correction data register 356. On the other hand, the image data DATA is transferred to the image data register 352 via the image data bus GBUS and latched in the image data register 352.

  The transfer operation and the latch operation of the correction data CD are preferably performed in synchronization with the transfer operation and the latch operation of the image data DATA. That is, when the control unit (the image processing unit 243 in the gate array 100 receives the image data DATA including the correction data CD or the image data DATA to which the correction data CD is added, the correction data CD is extracted and the correction data CD is corrected. The image data DATA is transferred to the sequencer 241 via the image data bus.

  The correction sequencer 241 receives the correction data CD, and transfers the correction data CD in synchronization with the transfer timing of the image data DATA via the correction data bus KBUS. The correction data CD is latched in the correction data register 356 in synchronization with the timing at which the image data DATA is latched in the image data register 352.

  As described above, the correction shift register 354 is used to sequentially latch the correction data CD in the correction data register 356, and the image shift register to sequentially latch the image data DATA in the image data register 352. 350 is used. The transfer of the correction data CD, the latch timing and the transfer of the image data DATA, and the latch timing are controlled based on a common clock (for example, dot clock DCK).

  Thus, for example, immediately after the power is turned on, each of the image data and the correction data can be simultaneously set (written) in each of the image data register and the correction data register.

  If the correction data CD is input to the integrated circuit device alone, it is necessary to newly construct a transfer path for inputting the correction data CD. The correction data CD, together with the image data, is input to the image data input line. If the data is input to the integrated circuit device via the GL, a new transfer path is unnecessary, and the circuit configuration is not complicated.

  Further, the correction data CD may be included in the image data DATA, and may be added to the image data DATA. As a specific mode in which the correction data CD is included in the image data DATA, for example, there is a mode in which the correction data CD is embedded instead of a part of the image data DATA. As an aspect in which the correction data CD is added to the image data DATA, for example, 4-bit correction data is added to 12-bit image data, and a total of 16-bit data is sent via an image data input line or the like. There is a mode of inputting to the image interface 300b.

  As described above, by providing the function of writing the correction data CD to the integrated circuit device, for example, the image can be corrected in real time immediately after the power is turned on. Therefore, an extremely high quality image display and image formation can be performed immediately after the power is turned on without being affected by the deviation of the drive characteristics of the data line drive circuit.

6.2. Example Using Initial Image Data FIGS. 23A and 23B are diagrams illustrating an example in which correction data is input to an integrated circuit device together with image data of an initial screen.

  In the example shown in FIG. 23A, correction data CD (4 bits) is added to the initial screen image data DATA (12 bits) and input to the integrated circuit device. In the example shown in FIG. 23B, the correction data CD is included in the lower 4 bits of the image data DATA (12 bits) for the initial screen.

  In the on-sequence period, generally, an initial screen showing a manufacturer name, a computer operating system name, and the like is generally displayed short. FIG. 23A and FIG. 23B show an example in which the company name “Company A” is displayed.

  The host device (host computer 400, image display controller 410, etc.) inputs correction data CD together with image data DATA for displaying the initial screen to the integrated circuit device. In this way, it is possible to input (write) correction data into the integrated circuit device without difficulty.

  In the example shown in FIG. 23B, the effective image data of the image data DATA is only the upper image data GU. However, since it is sufficient for the initial screen to ensure a certain level of image quality, there is no particular problem. In the example of FIG. 23B, it is not necessary to expand the bit width of the image data input line for inputting the image data DATA to the image interface 300b.

6.3. Examples Corresponding to Polarity Reversal FIGS. 24A and 24B are diagrams showing examples of using positive correction data and negative correction data separately. For example, in a liquid crystal display device, line inversion driving, dot inversion driving, and the like are executed in order to prevent liquid crystal burn-in.

  If the value of the correction data CD is the same (that is, the absolute value is the same and only the sign is different) regardless of the positive polarity and the negative polarity, the inverter INV2 is used as shown in FIG. For example, the correction data DQ2 for the negative polarity can be obtained by inverting the voltage level of the correction data DQ1 for the positive polarity, and there is no particular problem.

  In the example of FIG. 24A, positive correction data DQ1 and negative correction data DQ2 are stored in registers 901 and 903, respectively, in correction sequencer 241. Then, the switch SW10 is switched according to the polarity control signal POL, and either the positive correction data DQ1 or the negative correction data DQ2 is selectively output according to the polarity control signal POL. Further, as the correction data register 356, a first correction data storage unit A for storing correction data for positive polarity and a second correction data storage unit B for storing correction data for negative polarity are prepared. The positive correction data DQ1 and the negative correction data DQ2 are latched in the first storage unit A and the second storage unit B, respectively. Whether the correction data is latched in the first storage unit A or the second storage unit B is controlled by, for example, a correction data output polarity (correction data output phase) signal CPOL.

  On the other hand, it may be better to finely adjust the value of the correction data according to the polarity. In this case, the value of the correction data DQ1 for positive polarity and the value of the correction data DQ2 for negative polarity are different. In this case, as shown in FIG. 24B, for example, the host controller 410, which is a host device, prepares positive correction data DQ3 and negative correction data DQ4, and the polarity control signal POL The correction data corresponding to the polarity indicated by is transferred to the integrated circuit device.

  Here, the positive correction data DQ3 is, for example, correction data read from the first storage unit A in the correction data register 356 in the off-sequence period. Similarly, the negative polarity correction data DQ4 is, for example, correction data read from the second storage unit B in the correction data register 356 in the off-sequence period.

  In FIG. 24B, an image display controller (LCDC) 410 as a host device outputs a polarity control signal POL for controlling inversion driving. That is, the image display controller (LCDC) 410 mainly controls the polarity inversion. Therefore, the image display controller (LCDC) 410 can selectively output each of the positive polarity correction data DQ3 and the negative polarity correction data DQ4 in correspondence with the polarity control signal POL.

  The correction sequencer 241 refers to the polarity control signal POL supplied from the image display controller 410 which is the host device, and supplies the positive correction data DQ3 to the first correction data storage unit A in the correction data register 356. The negative correction data DQ4 is transferred to and stored in the second correction data storage B in the correction data register 356.

  In this way, the correction data can be properly used according to the polarity. Therefore, it is possible to correct image data more accurately according to the polarity.

  FIG. 25A and FIG. 25B are diagrams illustrating a mode for inputting positive correction data and negative correction data from the host device to the integrated circuit device. In the example of FIG. 25A, the positive polarity image data DQ3 is transferred from the image display controller 410, which is the host device, to the integrated circuit device in the display period of the first frame of the initial screen. The transferred positive polarity image data DQ3 is temporarily stored in the register 905 in the correction sequencer 241, for example. Similarly, the image data DQ4 for negative polarity is transferred from the image display controller 410 to the integrated circuit device in the display period of the second frame of the initial screen. The transferred negative polarity image data DQ4 is temporarily stored in, for example, the register 907 in the correction sequencer 241.

  In the example of FIG. 25B, positive correction data DQ3 and negative correction data DQ4 are embedded in each of two image data constituting a data set used for multiplex driving. .

  As described above, there is a case where multiplex driving is performed in which one data line driver (unit driver) drives n data lines in a time-sharing manner. In this case, a data set including n image data to be supplied to each of the n data lines is input to the image interface 300b.

  In order to correct the fluctuation of the driving characteristic of one data line driver (unit driver) used for driving n data lines, there is only one correction data for positive polarity and one for negative polarity. Therefore, the correction data DQ3 for positive polarity is embedded in the lower bit of one of the two pieces of image data (image data 1 in FIG. 25B) included in the data set (or positive polarity). Sexual correction data DQ3 may be added to the image data 1). In addition, correction data DQ4 for negative polarity is embedded in the lower bits of the other of the two image data (image data 2 in FIG. 25B) of the n pieces of image data included in the data set (or negative polarity). Correction data DQ4 for sex may be added to the image data 2).

  Thus, when multiplex driving is executed, each of the positive correction data DQ3 and the negative correction data DQ4 can be efficiently written to the integrated circuit device.

  Further, as in the aspect shown in FIG. 24A, if only the correction data for positive polarity needs to be supplied from the host device, for example, one of n pieces of image data included in the data set. The correction data DQ3 for positive polarity may be embedded in one piece of image data (for example, image data 1 in FIG. 25B) (or correction data DQ3 for positive polarity may be added to the image data 1).

6.4. Example of image data correction in the host device (variation)
FIG. 26 is a diagram illustrating an example in which image data correction is performed in the host device. In some cases, a host device (for example, an image display controller) corrects image data using correction data instead of writing correction data to the integrated circuit device, and inputs the corrected image data to the integrated circuit device. possible. It is desirable that the integrated circuit device can cope with this case.

  In the example of FIG. 26, an image correction circuit 920 is included in the image display controller 410, and the image correction circuit 920 uses the correction data DQ3 for positive polarity or the correction data DQ4 for negative polarity to output image data DATA. Correct. Then, the corrected image data DATA is supplied to the integrated circuit device.

  In this case, the image processing unit 243 in the integrated circuit device uses the input corrected image data DATA as it is in the state where the correction data CD is not set in the correction data register 356 (initialized state). Transfer to 352. The image data DATA is latched in the image data register 352, and the image data DATA is output from the image data register 352 and output toward the data line.

(Fourth embodiment)
7). Electronic equipment 7.1. Projector FIG. 27 shows a configuration example of a projector (electronic apparatus) to which the integrated circuit device of this embodiment is applied.

  The projector 700 (projection display device) includes a display information output source 710, a display information processing circuit 720, a driver 60 (display driver), a liquid crystal panel 12 (electro-optical panel in a broad sense), a clock generation circuit 750, a power supply circuit 760, A nonvolatile memory (storage unit for storing saved correction data) 420 is included.

  The display information output source 710 includes a ROM (Read Only Memory) and a RAM (Random Access Memory), a memory such as an optical disk device, a tuning circuit that tunes and outputs an image signal, and the like. Based on this, display information such as an image signal in a predetermined format is output to the display information processing circuit 720.

  The display information processing circuit 720 can include an amplification / polarity inversion circuit, a phase expansion circuit, a rotation circuit, a gamma correction circuit, a clamp circuit, and the like. The driver 60 includes a scanning driver (gate driver) and a data driver (source driver), and drives the liquid crystal panel 12 (electro-optical panel). The power supply circuit 760 supplies power to each circuit described above.

  By using the integrated circuit device of the present invention, a higher-definition, multi-output, multi-gradation electro-optical device can be realized, and an electro-optical device capable of correcting an image in real time immediately after the power is turned on. Can be realized. In addition, the display performance of the electronic device is improved, and the reliability related to the display performance is improved.

7.2. PDA
FIG. 28 shows a configuration example of a PDA (electronic device) to which the integrated circuit device of this embodiment is applied.
PDA 900 (Personal Digital Assistants) includes a camera module 910, a modem unit 950, a display controller 40, a host 940 (host controller, CPU), an operation input unit 970, a driver 60 (display driver), a power supply circuit 50, and a liquid crystal panel 12 (electrical). An optical panel), and a non-volatile memory (storage unit for storing saved correction data) 420.

  The camera module 910 includes a CCD camera and supplies image data captured by the CCD camera to the display controller 40 in, for example, a YUV format.

  The driver 60 includes a scan driver 38 (gate driver) and a data driver 20 (source driver). The scanning driver 38 drives a plurality of scanning lines (gate lines) included in the liquid crystal panel 12. The data driver 20 drives a plurality of data lines (source lines) included in the liquid crystal panel 12.

  The display controller 40 supplies, for example, RGB format gradation data to the data driver 20, and supplies, for example, a horizontal synchronization signal to the scan driver 38.

  The power supply circuit 50 supplies a drive power supply voltage to the data driver 20 (source driver) and the scan driver 38 (gate driver). Further, the counter electrode voltage VCOM is supplied to the counter electrode of the display panel 12.

  The host 940 controls the display controller 40. In addition, the host 940 demodulates the modulation signal received via the antenna 960 by the modulation / demodulation unit 950 to generate gradation data, and then supplies the gradation data to the display controller 40. The host 940 modulates the gradation data generated by the camera module 910 by the modulation / demodulation unit 950 and then instructs transmission to another communication apparatus via the antenna 960. Furthermore, the host 940 performs gradation data transmission / reception processing, imaging of the camera module 910, and display processing of the display panel 12 based on operation information from the operation input unit 970.

  By using the integrated circuit device of the present invention, a higher-definition, multi-output, multi-gradation electro-optical device can be realized, and image data can be corrected in real time immediately after the power is turned on. An electro-optical device can be realized. In addition, the display performance of the electronic device is improved, and the reliability related to the display performance is improved.

  Although the present embodiment has been described in detail as described above, it will be easily understood by those skilled in the art that many modifications can be made without departing from the novel matters and effects of the present invention. Accordingly, all such modifications are intended to be included in the scope of the present invention. For example, in the specification or drawings, terms (electro-optical panel, inverting input terminal, non-inverting input terminal, gradation voltage, VGMH, VGML, etc.) described at least once together with different terms having a broader meaning or the same meaning are described in the specification. Alternatively, the different terms can be used in any place in the drawings. In addition, the configurations and operations of the reference voltage generation circuit, selection circuit, sample hold unit, data line drive circuit, gradation generation amplifier, drive amplifier, electro-optical device, electronic device, and the like are also limited to those described in this embodiment. However, various modifications can be made.

1 is a diagram illustrating a configuration example of an integrated circuit device according to a first embodiment. 2A shows a voltage waveform example of the data line drive voltage in the correction data calculation mode, and FIG. 2B shows a voltage waveform example of the comparison result in the correction data calculation mode. FIG. 3 is a diagram illustrating a configuration example of a liquid crystal display device Diagram showing an example of the data driver configuration The figure which shows the voltage waveform example of the data line in a multiplex drive The figure which shows the voltage waveform example of the data line in correction data calculation mode Explanation of correction factor The figure which shows the detailed structural example of 1st Embodiment. The figure which shows the signal waveform example of 1H mode Diagram showing examples of signal waveforms in burst mode The figure which shows the detailed structural example of a control part and a correction data calculating part. The figure which shows the example of control flow of a correction data calculating part The figure which shows the modification of the control flow of a correction data calculating part The figure which shows the layout arrangement example of this embodiment The figure which shows the circuit structure of the part regarding the saving of correction data of the integrated circuit device concerning 2nd Embodiment. Flow chart showing an example of correction data reading (saving) operation The figure which shows an example of the concrete circuit structure of the integrated circuit device concerning 2nd Embodiment. FIG. 17 is a timing chart showing the timing of the data saving operation in the integrated circuit device shown in FIG. Timing diagram showing timing of control signal and data exchange between host (CPU) and host interface The figure which shows the structural example of the conversion circuit which converts a low-speed signal into a high-speed signal FIG. 21 is a timing chart showing an example of the timing of a low-speed signal, a high-speed clock, and a high-speed signal. The figure which shows an example of the structure for inputting correction data into an integrated circuit device from a high-order apparatus, and writing in a correction data register FIGS. 23A and 23B are diagrams showing an example in which correction data is input to an integrated circuit device together with image data of an initial screen. FIG. 24A and FIG. 24B are diagrams showing examples of properly using positive correction data and negative correction data. FIGS. 25A and 25B are diagrams showing modes for inputting correction data for positive polarity and correction data for negative polarity from the host device to the integrated circuit device. The figure which shows the example which corrects image data in a high-order apparatus Diagram showing an example of projector configuration A diagram showing a configuration example of a PDA

Explanation of symbols

12 electro-optic panel, 20 data driver, 22 shift register,
24 line latch, 28 multiplexing circuit, 30 reference voltage generating circuit, 32 DAC,
34 data line drive circuit, 36 multiplex drive control unit, 38 scan driver,
40 display controller, 50 power supply circuit, 60 driver, 100 control unit,
102 correction data calculation unit, 120 selection circuit,
140-1 to 140-n first to n-th data line driving circuits,
160-1 to 160-n 1st to n-th correction circuits, 180 comparators,
200 counter section, 202 index counter, 204 measurement start counter,
206 measurement period counter, 208 interval counter,
210 data counter for measurement, 220 register section, 222 index register,
224 measurement start register, 226 measurement period register,
228 interval register, 230 correction calculation data register,
237 first buffer (first latch), 239 second buffer (second latch),
238 Command decoder, 240 sequencer, 241 correction sequencer,
243 Image processing unit, 245 internal register group, 247 status register,
260 edge detection unit, 280 processing unit, 300a host interface (I / F),
300b image interface (I / F), 350 image shift register,
352 image data register, 354 correction shift register,
356 (CDR) correction data register,
SWQn correction data read switch (first switch),
CDBUS correction data read bus, RBF read buffer,
400 CPU (host), 410 LCDC (display controller),
420 memory (nonvolatile memory, HDD, etc.),
LDRn data line driver (unit driver), 700 projector,
710 display information output source, 720 display information processing circuit, 750 clock generation circuit,
760 power supply circuit, 900 PDA, 910 camera module, 940 host,
950 modulation / demodulation unit, 970 operation input unit, VP comparator reference voltage,
CPQ comparison result, MD measurement data, CD (CD1 to CDn) correction data,
PD1 to PDn image data, PCD1 to PCDn corrected image data,
MGD1 to MGDk measurement gradation data, S1 to Sn data line drive voltage supply lines,
SV1 to SVn data line drive voltage, Vsync vertical synchronization signal,
Hsync horizontal sync signal, Dclk (DCK) dot clock,
KBUS correction data bus, GBUS image data bus,
GL image data input line (image data input bus)

Claims (10)

An integrated circuit device for driving each of a plurality of data lines,
Based on the result of comparing the data line drive voltage to be corrected with a reference voltage, a correction data calculation unit that calculates correction data for correcting variations in the data line drive voltage;
A correction data storage unit for storing the correction data;
A correction circuit that corrects image data based on the correction data output from the correction data storage unit;
An interface unit for inputting the image data;
A control unit that controls a transfer operation of the image data input via the interface unit, a storage operation of the correction data in the correction data storage unit, and a correction operation of the image data by the correction circuit;
Including
The controller is
Upon receipt of the image data including the correction data transferred via the interface unit, the correction data is extracted, and the extracted correction data is stored in the correction data storage unit ,
The correction data included in the image data is embedded in the lower bits of the image data, and the control unit extracts the correction data embedded in the lower bits and stores it in the correction data storage unit An integrated circuit device. An integrated circuit device according to claim 1, wherein
In the on period sequence is executed for the power-on, the integrated circuit device in which the image data including the correction data, and wherein the input to the interface section. An integrated circuit device according to claim 2, wherein
Wherein the image data including the correction data, in the execution period of the ON sequence, an integrated circuit device which is characterized in that image data for the initial screen which is displayed by the electro-optical device. An integrated circuit device according to any one of claims 1 to 3 ,
Wherein the said correction data included in the image data includes a correction data and correction data for a negative polarity for positive polarity,
The correction data storage unit includes a first correction data storage unit that stores the correction data for positive polarity, and a second correction data storage unit that stores the correction data for negative polarity,
The control unit refers to a polarity control signal supplied from a host device provided outside the integrated circuit device, stores the correction data for positive polarity in the first correction data storage unit, and stores the negative polarity Correction data is stored in the second correction data storage unit. An integrated circuit device according to any one of claims 1 to 3 ,
When multiplex driving in which image data after correction output from the correction circuit is supplied in a time-sharing manner to n (n is an integer of 2 or more) data lines is performed, the n data lines A data set including n image data to be supplied to each of the image data is input to the interface unit,
Integrated circuit device, characterized in that the Ru contains correction data into one image data among the n image data included in the data set. An integrated circuit device according to claim 4 , wherein
When multiplex driving in which image data after correction output from the correction circuit is supplied in a time-sharing manner to n (n is an integer of 2 or more) data lines is performed, the n data lines A data set including n image data corresponding to each of the image data is input to the interface unit,
The correction data for positive polarity is included in one of the n pieces of image data included in the data set ,
And an integrated circuit device, characterized in that the Ru contains correction data for negative polarity to the other one of the image data among the n image data. An integrated circuit device according to any one of claims 1 to 6 ,
A plurality of correction data registers as the correction data storage unit;
A correction data bus for transferring the correction data to each of the plurality of correction data registers;
A correction shift register for designating the latch timing of the correction data in the correction data register;
A plurality of image data registers for storing the image data;
An image data bus for transferring the image data to each of the plurality of image data registers;
An image shift register for designating the latch timing of the image data in the image data register;
Have
The controller is
Upon receipt of the image data including the correction data transferred via the interface unit, the correction data is extracted,
In synchronization with the transfer timing of the image data via the image data bus, the correction data is transferred via the correction data bus,
In synchronization with the timing at which the image data is latched in the image data register, the correction data is latched in the correction data register.
An integrated circuit device. An integrated circuit device according to any one of claims 1 to 7 ,
The control unit, when image data corrected using the correction data is input from the host device to the interface unit, the correction data register that is the correction data storage unit is initialized, An integrated circuit device, wherein the corrected image data is supplied to each of the plurality of data lines. An integrated circuit device according to any one of claims 1 to 8 ,
An image display unit including a plurality of data lines driven by the integrated circuit device;
At least one of a host computer and an image display controller as a host device of the integrated circuit device;
An electro-optical device comprising: An electronic apparatus comprising the electro-optical device according to claim 9 .

Images