JP2012198373A - Integrated circuit device, electro-optical device, and electronic equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an integrated circuit device that can be equipped near an electro-optical panel by reducing the capacity of a waveform memory that stores waveform information which is set for each environmental information such as temperature.SOLUTION: An integrated circuit device 100 includes: a driving voltage output section 150 that updates an image of an electro-optical panel; a waveform information storage section 120 that stores driving waveform information; driving waveform information output sections 130 and 140 that output, to the driving voltage output section, driving waveform information selected from the waveform information storage section; and an acquiring section 170 that acquires environmental information. The waveform information storage section 120 includes at least one basic waveform table that stores basic waveform data and an environmental information/driving condition table that sets different plural driving conditions for pieces of environmental information for the basic waveform data. The driving waveform information output sections 130 and 140 output, to the driving voltage output section 150, the driving conditions for the environmental information acquired by the acquiring section and the basic waveform data.

Description

  The present invention relates to an integrated circuit device, an electro-optical device, an electronic apparatus, and the like.

  Conventionally, an EPD (Electrophoretic Display) panel is known as an electro-optical panel (Patent Document 1). In driving such an EPD panel (electrophoresis panel), the drive voltage is changed sequentially. Therefore, a voltage transition table is required for driving the EPD panel.

JP 2009-251615 A

  The electro-optical material has a driving characteristic that changes depending on the environment such as temperature, or the electro-optical panel becomes difficult to see depending on the environment such as brightness. Therefore, it is necessary to prepare a voltage transition table corresponding to a plurality of environment information in advance and drive using a voltage transition table that matches the environment information acquired by measurement. This means an increase in memory capacity and makes it difficult to search for desired waveform data.

  On the other hand, the display controller, waveform memory, temperature sensor, and power supply module disclosed in Patent Document 1 are required to be integrated on the electro-optical panel. Since the electro-optic panel cannot be enlarged unnecessarily, the increase in memory capacity prevents the controller / driver IC from being COG (Chip On Glass) on the panel or COF (Chip On Film) on the film substrate connected to the panel. It becomes.

  Some embodiments of the present invention provide an integrated circuit device, an electro-optical device, and an electronic apparatus that can be mounted on the electro-optical panel side by reducing the capacity of a waveform memory that stores waveform information set for each environmental information such as temperature. Can be provided.

(1) One aspect of the present invention is
A drive voltage output unit that outputs a drive voltage to a plurality of pixel electrodes of the electro-optic panel to update an image;
A display data storage unit including a first storage unit storing first display data and a second storage unit storing second display data;
A waveform information storage unit for storing drive waveform information for changing a display state at a pixel from a first display state corresponding to the first display data to a second display state corresponding to the second display data;
A drive waveform information output unit that outputs the drive waveform information selected from the waveform information storage unit based on the first display data and the second display data to the drive voltage output unit;
An acquisition unit for acquiring environmental information;
Have
The waveform information storage unit sets a plurality of different drive conditions for each environment information for at least one basic waveform table storing basic waveform data and the basic waveform data in the at least one basic waveform table Environment information / driving condition table,
The drive waveform information output unit outputs the basic waveform data in the at least one basic waveform table to the drive voltage output unit together with the drive conditions corresponding to the environmental information acquired by the acquisition unit. About.

  In one aspect of the present invention, the drive waveform information output unit outputs the basic waveform data in at least one basic waveform table to the drive voltage output unit together with the drive conditions corresponding to the environmental information acquired by the acquisition unit. The drive voltage output unit generates a drive voltage based on the basic waveform data and the drive condition corresponding to the environment information. In this way, an electro-optical panel having an electro-optical material having a strong environment dependency can be driven. At this time, the waveform information storage unit only needs to store drive waveform information including basic waveform data and a plurality of drive conditions different for each piece of environment information with respect to the basic waveform data. In this case, it is not necessary to store waveform data for each environment information, so that the data capacity of the waveform information storage unit can be reduced, and downsizing of the integrated circuit device is maintained.

  (2) In one aspect of the present invention, the basic waveform data may be a voltage level of each of a plurality of subframes.

  Thereby, as the basic waveform data, the number of subframes of the voltage drive waveform and the voltage level in each subframe are shared for a plurality of environment information. Therefore, the data capacity of the waveform information storage unit can be reduced.

  (3) In one aspect of the present invention, the plurality of driving conditions different for each environment information may include a plurality of types of frame rates set for the plurality of subframes.

  As described above, by changing the frame rate of a plurality of sub-frames of the basic waveform data as the driving condition of the basic waveform data, the electro-optic material can be driven in accordance with the environment dependency. For example, when the environmental information is temperature, and the electro-optic material is a temperature-dependent viscous first material and a second material moving in the first material, the frame rate can be varied. In this case, the lower the temperature, the lower the frame rate (frequency) and the longer the voltage application time per subframe. The higher the temperature, the higher the frame rate (frequency) and the shorter the voltage application time per subframe. In that sense, the frame rate is equivalent to the time width (unit pulse width) of the subframe.

  (4) In one aspect of the present invention, the plurality of driving conditions different for each environment information may include a plurality of types of voltage values set for the voltage level.

  As described above, by changing the voltage level value (voltage value) of each of the plurality of sub-frames of the basic waveform data as the driving condition of the basic waveform data, the electro-optic material is driven in accordance with the environment dependency. be able to. In the above example, the voltage value can be increased as the temperature is lower, and conversely, the voltage value can be decreased as the temperature is higher.

  (5) In an aspect of the invention, the image processing apparatus further includes a scanning line controller that controls supply of a scanning voltage to a scanning line connected to a gate of a pixel selection transistor to which each of the plurality of pixel electrodes of the electro-optical panel is connected. In addition, the plurality of driving conditions different for each environment information may include a plurality of types of scanning voltage values set corresponding to the plurality of types of voltage levels.

  The pixel selection transistor provided in the active electro-optical panel performs an on / off operation based on a voltage (Vgs−Vth) obtained by subtracting a threshold value Vth from the gate-source voltage Vgs. Therefore, the pixel selection transistor can be turned on / off even when the scanning voltage (gate voltage) is changed in accordance with the driving voltage (source voltage). Thus, since it is not necessary to use an excessively high scanning voltage, power consumption can be reduced.

  (6) In one aspect of the present invention, the drive voltage output unit includes a frequency variable unit, and the frequency variable unit can vary the frequency based on the frame rate output from the drive waveform output unit.

  As described above, the drive voltage output unit can generate a drive voltage having a different voltage application time for each environment information using the same basic waveform data by changing the frequency based on the frame rate according to the environment information. it can.

  (7) In one aspect of the present invention, the drive voltage output unit includes a voltage variable unit, and the voltage variable unit can vary the voltage level based on a voltage value output from the drive waveform output unit. .

  As described above, the drive voltage output unit can generate a drive voltage having a different voltage value for each environment information using the same basic waveform data by changing the voltage level based on the voltage value corresponding to the environment information. it can.

  (8) In one aspect of the present invention, the at least one basic waveform table may include a plurality of basic waveform tables each storing basic waveform data having a different number of subframes for each waveform mode.

  Within the same environment information, the number of subframes can be made different in correspondence with a plurality of waveform modes, and a plurality of basic waveform tables for storing basic waveform data with different numbers of subframes can be prepared. A typical example that requires a plurality of basic waveform tables is a difference in gradation values. The number of subframes differs depending on the combination of the gradation mode of the current display data CI (first display data: Current Image) and the gradation mode of the next display data NI (second display data: Next Image). Can be made. The waveform mode is not limited to this, and may be, for example, an image quality emphasis mode or a low power consumption mode. If the image quality is important, for example, a method of increasing the image update time by increasing the number of subframes can be considered. Further, if the image quality can be neglected, a method of shortening the image update time by reducing the number of subframes can be considered, thereby achieving a low power consumption mode. Also in this case, each has a different number of subframes and different basic waveform data.

  (9) According to another aspect of the present invention, there is provided an electro-optical device including the integrated circuit device described above, the electro-optical panel driven by the integrated circuit device, and the host device connected to the integrated circuit device. Defined. In this electro-optical device, the burden on the host device is greatly reduced.

  (10) Another aspect of the present invention defines an electronic apparatus having the above-described electro-optical device.

1 is a schematic explanatory diagram of an electro-optical device according to an aspect of the present invention. It is a figure which shows the pixel of an electro-optical panel. It is operation | movement explanatory drawing of the electrophoresis microcapsule which is an electro-optic element. It is a figure which shows an example of a sub-frame drive waveform. 1 is a schematic block diagram of an integrated circuit device that controls driving of data lines and scanning lines. FIG. It is a schematic explanatory drawing which shows the whole format of a waveform information storage part. FIG. 7A to FIG. 7D are diagrams showing the relationship between the number K of subsections in the second waveform information storage unit and the number of CI / NI combinations. It is a figure which shows the waveform data of the mode 0 in the basic waveform data table shown in FIG. It is a figure which shows the waveform data of the mode 1 in the basic waveform data table shown in FIG. It is a figure which shows the temperature / frame rate table in the temperature / driving condition table shown in FIG. It is a figure which shows the temperature / voltage value table in the temperature / driving condition table shown in FIG. 12A and 12B are diagrams showing different drive voltage waveforms obtained by applying different drive conditions to the same basic waveform data. It is a block diagram which shows the specific example of the display engine shown in FIG. It is a figure for demonstrating an image update area. FIG. 14 is a schematic block diagram of the data line driver shown in FIGS. 5 and 13. It is an operation | movement flowchart. It is a block diagram which shows an 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.

1. Outline of Electro-Optical Panel FIG. 1 shows an EPD that is an electro-optical device. An EPD panel (electro-optical panel) 10 shown in FIG. 1 includes an active matrix substrate (first substrate) 12 on which a plurality of scanning lines 14, a plurality of data lines 16, and a plurality of pixels 20 are formed. As shown in FIG. 2, the pixel 20 is provided with a pixel selection transistor 22, a storage capacitor 24, and a pixel electrode 26. In the pixel selection transistor 22, the scanning line 14 is connected to the gate, the data line 16 is connected to the source, and the drain is connected to the storage capacitor 24 and the pixel electrode 26. The EPD panel 10 can be line-sequentially driven by sequentially applying scanning voltages to the plurality of scanning lines 14 one by one.

  As shown in FIG. 2, a counter electrode (common electrode) 28 facing a plurality of pixel electrodes 26 formed on an active matrix substrate (first substrate) 12 is formed on a counter substrate (second substrate) not shown. A plurality of microcapsules 30 for forming an electrophoretic layer with an electro-optic material is provided between two substrates. Each microcapsule 30 includes a fluid 31 as a first material having a temperature-dependent viscosity, a positively charged black particle 32 and a negatively charged white as a second material floating in the fluid 31. Particles 33 are included.

  Here, the counter electrode 28 can be held at a predetermined voltage. The voltage applied to the pixel electrode 26 can be controlled by using the scanning line 14 and the data line 16 of FIG. When the electric field is positive, the black particles 32 move in the direction of the counter electrode 28 as shown in the microcapsule 30a. As a result, the pixel 20 viewed from the transparent counter electrode 28 side becomes black. Conversely, when the electric field is negative, the white particles 33 move in the direction of the counter electrode 28 as shown in the microcapsule 30b, and as a result, the pixel 20 viewed from the counter electrode 28 side becomes white. The microcapsule 30c shows a pixel that completely displays gray other than white or black. For example, to generate a pixel having black, white or gray, a sequence of voltage pulses is applied to the pixel electrode 26. When the display of the electro-optical panel 10 is updated, a driving waveform voltage is applied to the pixel 20 via the data line 16. The specific waveform to be applied is selected based on the display state after the update of the pixel 20 and the display state before the update.

  By applying voltage pulses of appropriate polarity, duration, and amplitude to the pixel electrode 26, the pixel 20 can be driven to black, white, or a dark gray intensity. The voltage pulse applied to the pixel 20 can be modulated in duration, amplitude, or both duration and amplitude, depending on environmental information such as temperature and waveform mode.

  Here, the viscosity of the fluid 31 has environment dependency, for example, temperature dependency. Therefore, the movement of the black particles 32 and the white particles 33 that move in the fluid 31 depends on the viscosity of the fluid 31. In general, when the temperature is low, the viscosity of the fluid 31 is high and the black particles 32 and the white particles 33 are difficult to move. On the contrary, when the temperature is high, the viscosity of the fluid 31 is low and the black particles 32 and the white particles 33 are easy to move.

  The EPD pixel 20 is driven by a pulse train as shown in FIG. The pulse train is composed of a plurality of pulses, and is also called a “waveform” or a “voltage transition sequence”. The application time of a single pulse corresponds to one subframe (SF). The pulse train (waveform) can be composed of several tens to several tens of subframes. In order to drive the EPD pixel 20 having the environment dependency as described above, the pulse train pattern is made common and the frame rate of the sub-frame is changed to change the application time of the single pulse, or instead of it. At the same time, it is effective to change the peak value of the single pulse. This point will be described later.

  EPD can operate using several different waveform modes. In the present embodiment, for example, an initialization mode, a 2 gradation (monochrome) mode (1 bpp: bit per pixel), a 4 gradation mode (2 bpp), an 8 gradation mode (3 bpp), and a 16 gradation mode (4 bpp) are used. EPD can be activated.

  For example, there are 16 × 2 = 32 types of pulse trains (waveforms) for updating the pixel 20 from any value in the maximum 16 gradation mode to any value in the 2 gradation mode. There are 16 × 4 = 64 types of pulse trains (waveforms) for updating the pixel 20 from any value in the maximum 16 gradation mode to any value in the 4 gradation mode. There are 16 × 8 = 128 types of pulse trains (waveforms) for updating the pixel 20 from any value in the maximum 16 gradation mode to any value in the 8 gradation mode. There are 16 × 16 = 256 types of pulse trains (waveforms) for updating the pixel 20 from any value in the maximum 16 gradation mode to any value in the 16 gradation mode. The waveform mode according to the number of gradations is displayed by, for example, 2 bits, (0, 0) is a two gradation mode, (0, 1) is a four gradation mode, (1, 0) is an eight gradation mode, ( 1, 1) is a 16 gradation mode.

2. 1. Outline of Electro-Optical Device An active matrix substrate (glass substrate) 12 shown in FIG. 1 includes a scanning line driving unit 40 that drives scanning lines 14, a data line driving unit 100 that drives data lines 16, and a data line driving unit. A temperature sensor 200 connected to 100 is provided. Both drive units 40 and 100 are formed by an integrated circuit device (IC) and can be COG mounted on the active matrix substrate 12. Alternatively, when a flexible film substrate is connected to the active matrix substrate 12, the data line driving unit 100 may be COF mounted on the film substrate. The scanning line driving unit 40 may be configured by a TFT (thin film transistor) formed on the active matrix substrate (glass substrate) 12 or may be accommodated in the data line driving unit 100. The data line driving unit 100 can function as a master that controls the scanning line driving unit 40 that is a slave.

  The host device 50 connected to the data line driving unit 100 includes a CPU 51, an image memory 52, a host waveform memory (second driving waveform storage unit) 53, and an interface (I / F) 54. The host device 50 transmits various commands and data (control data such as waveform mode data, image data, or driving waveform data) to the data line driving unit 100. This embodiment is characterized by the data format of the host waveform memory 53 of the host device 50 and the configuration of the data line driving unit 100, and the scanning line driving unit 40 can use the conventional device as it is. Hereinafter, the driver IC refers to the data line driving unit 100.

3. Outline of Data Line Drive Unit The data line drive unit 100 is a driver IC having a controller function. As shown in FIG. 5, the data line driving unit 100 includes a host interface 101 connected to the host device 50, a register 102 and a memory interface 103 connected to the host interface 101. The register 102 stores various information such as control data transmitted from the host device 50. A display memory (display data storage unit) 110, a waveform decoder (decoding unit) 121, and a waveform memory (first waveform information storage unit) 120 are connected to the memory interface 103.

  The display memory 110 includes a current image (CI) buffer 111 and a next image (NI) buffer 112. The display memory 110 may be a RAM. The current image memory 111 and the next image memory 112 may not exist in one memory, and may be different memories. A DMAC (direct memory access controller: transfer controller in a broad sense) 113 transfers the image data in the NI buffer 112 to the CI buffer 111 for the next image update immediately after the image update.

  The CI buffer 111 stores the current image or a part of the image as first display data. The host device 50 or another image data source stores the next image or a part of the image as the second display data in the NI buffer 112. The CI buffer 111 and the NI buffer 112 store a current pixel CP (Current Pixel) and a next pixel NP (Next Pixel) for each pixel of the electro-optical panel 10.

  Here, the current image is image data corresponding to the image displayed on the electro-optical panel 10. When the image of the electro-optical panel 10 is being updated, the current image is image data corresponding to the image before update, and the next image is image data corresponding to the image after update. The same applies to the current pixel CP and the next pixel NP.

  The waveform RAM 120 stores waveform information of the entire temperature region. Waveform information in the entire temperature region will be described later. The waveform information of the entire temperature region encoded and sent from the host device 50 may be decoded by the waveform decoder 121 and stored. By prohibiting direct access to the waveform RAM 120 from the outside, the confidentiality of the waveform data is maintained.

  The display engine 130 acquires, for example, a waveform mode designated by the host device 50 from the register 102, acquires a current temperature from a temperature detection unit 170 described later, and current pixel CP data and next pixel NP data from the display memory 110. To get. As a result, the display engine 130 reads out the corresponding temperature and waveform mode all drive waveform data from the waveform RAM 120 for one subframe and outputs it to the timing controller 140.

  The timing controller 140 repeatedly stores drive waveform data corresponding to the temperature and the waveform mode from the waveform RAM 120 for each subframe by the number of subframes and sequentially stores them in the FIFO 141. ) Drive waveform information is output to the data line driver 150 together with a control signal based on the clock from the counter 131A. The control signal from the timing controller 140 is also sent to the scanning line driving unit 40 via the scanning line controller 160. The display engine 130 and the timing controller 140 constitute a drive waveform information output unit.

  The temperature detection unit (environment information acquisition unit) 170 detects the temperature based on, for example, a signal from the external temperature sensor 200. The external temperature sensor 200 can be configured by a thermistor, for example. The temperature sensor 200 can also be provided in the data line driving unit 100. The temperature detected by the temperature detection unit 170 is stored in the register 102.

4). Waveform RAM for data line driver
The waveform RAM 120 of the data line driving unit 100 stores waveform information for the entire temperature region. The driving waveform information in the entire temperature region includes at least one basic waveform data and driving conditions that differ for each temperature or temperature range with respect to at least one basic waveform data.

  For this purpose, the waveform RAM 120 can have a basic waveform data table 120A and a temperature / driving condition table 120B as shown in FIG. The basic waveform data table 120A can include, for example, 16 waveform mode 0 to waveform mode 15 basic waveform data tables 120A0 to 120A15.

  Here, as the plurality of waveform modes, the above-described initialization mode, 2-gradation mode, 4-gradation mode, 8-gradation mode, and 16-gradation mode can be cited, and different basic waveform data tables 120A0 to 120A15 are provided. Different basic waveform data can be stored for each waveform mode. The basic waveform data that is different for each waveform mode differs in the number of subframes, for example.

  The capacities of the basic waveform data tables 120A0 to 120A15 may be fixed or variable. The basic waveform number K for each waveform mode is different as shown in FIGS. 7 (A) to 7 (D). For example, when there are 16 gradations at the maximum and the waveform mode is the two gradation mode, as shown in FIG. 7A, there are 16 possible CI gradation levels, and the NI gradation level after the transition is Since there are two types, K = 16 × 2 = 32. In the four gradation mode, K = 16 × 4 = 64 (see FIG. 7B), in the eight gradation mode, K = 16 × 8 = 128 (see FIG. 7C), and in the 16 gradation mode, K = 16 X16 = 256 (see FIG. 7D). As described above, since the number K of basic waveforms differs depending on the waveform mode, the required storage capacity differs for each waveform mode. However, the storage capacity may be set to be the same by fixing K to Kmax = 256 or the like for all waveform modes and fixing the maximum number K.

  Here, the size of the drive waveform data table 120 will be considered. For example, consider an example in which 16 temperature conditions, 8 modes, K = 256 transitions, 64 subframes, and the number of bits per pixel is 2 bits. In this case, assuming that basic waveform data is provided for every 16 temperature conditions, the size is as large as 512 kbytes (= 16 × 8 × 256 × 64/4). If the same basic table is used under all temperature conditions as in the present embodiment, the size is 1/16 of 32 kbytes. By reducing the data capacity in this way, the present embodiment makes it possible for the first time to incorporate a drive waveform table for the entire temperature range in the data line drive unit (driver IC) 100. This also means that it is not necessary to update the drive waveform table, which was conventionally required every time the operating environment such as operating temperature changes. That is, a great effect of reducing the display speed of EPD and eliminating power consumption by updating the drive waveform table can be obtained.

  8 shows a mode 0 table 120A0 in the basic waveform data table 12A1 in the waveform RAM 120 shown in FIG. FIG. 9 shows a mode 1 table 120A1 in the basic waveform data table 12A1 in the waveform RAM 120 shown in FIG. The number of subframes of each basic waveform data is different between the two tables 120A0 and 120A1. The basic waveform data shown in FIG. 8 has 14 subframes, whereas the basic waveform data shown in FIG. 9 has 20 subframes. Thus, the basic waveform data can change the number of subframes according to, for example, the gradation mode.

  The waveform mode is a factor in which the drive waveform information is different when driving the electro-optical panel 10 in one temperature region, and a representative example is the above-described difference in gradation value. The waveform mode is not limited to this, and may be, for example, an image quality emphasis mode or a low power consumption mode. If the image quality is important, for example, a method of increasing the image update time by increasing the number of subframes can be considered. Further, if the image quality can be neglected, a method of shortening the image update time by reducing the number of subframes can be considered, thereby achieving a low power consumption mode. Also in this case, the number of subframes is different and the basic waveform data is different.

  FIG. 10 shows a temperature / frame rate table 120B1 as an example of the temperature / driving condition table 120B in the waveform RAM 120 shown in FIG. This temperature / frame rate table 120B1 stores the frame rate in correspondence with the temperature (or temperature range). As shown in FIG. 10, when the temperature is low, the frame rate is set as low as 1.0 Hz and 1.2 Hz, and when the temperature is high, the frame rate is set as high as 100 Hz.

  FIG. 11 shows a temperature / voltage value table 120B2 as another example of the temperature / drive condition table 120B in the waveform RAM 120 shown in FIG. The temperature / driving condition table 120B shown in FIG. 6 may have only one of the two types of tables 120B1 and 120B2 shown in FIG. 10 or FIG. 11, or both. good. In the temperature / voltage value table 120B2, voltage values are stored in correspondence with temperatures (or temperature ranges). As shown in FIG. 11, when the temperature is low, the data voltage ± Vs supplied to the data line (source line) 16 is set to a large absolute value (large amplitude) of ± 15 V, and when the temperature is high, the data voltage ± Vs is set. Is set to have an absolute value as small as ± 5 V (small amplitude).

In addition, FIG. 11 includes scanning voltages (+ Vg, −Vg) supplied to the scanning lines (gate lines) 14 corresponding to the data voltages ± Vs supplied to the data lines (source lines) 16. .
As shown in FIG. 11, when the temperature is low, the scanning voltage (+ Vg, −Vg) supplied to the scanning line (gate line) 14 is set to a large absolute value of + 22V and −20V, and when the temperature is high, (+ Vg, -Vg) is set to a small absolute value of + 12V and -10V. Note that the data voltages ± Vs for the same temperature (same temperature range) are made to have the same absolute value of the positive and negative data voltages in order to maintain the DC balance so that the cumulative DC voltage becomes positive and negative in the long term. Yes. The scanning voltage (+ Vg, −Vg) may have the same absolute value at the same temperature (same temperature range) as in the data voltage ± Vs, but in the present embodiment, the absolute value is changed between positive and negative. The reason for this is that the scanning voltage is for turning on the pixel selection transistor 22 shown in FIG. 2 and applying a data voltage to the electro-optical element 30. The pixel selection transistor 22 formed of a TFT (Thin Film Transistor) or the like is used. This is because it depends on the characteristics of In this way, by making the scanning voltage dependent on the characteristics of the pixel selection transistor 22 and changing the absolute value between positive and negative at the same temperature (same temperature range), it is advantageous in terms of power consumption and transistor breakdown voltage. Note that the scanning voltage table may not be provided for each temperature, and may be implemented in the form of + Vg = + Vs + 7V, −Vg = −Vs−5V, for example.

  FIGS. 12A and 12B show drive voltage waveforms in which different drive conditions are applied due to different temperatures while using the same basic waveform data. FIG. 12B shows a driving voltage waveform when the temperature is higher than that in FIG. The drive voltage waveform in FIG. 12B has a higher frame rate than the drive voltage waveform in FIG. 12A, and the absolute value of the data voltage ± Vs is smaller than the drive voltage waveform in FIG. Thus, since the drive voltage waveforms in FIGS. 12A and 12B have different frame rates, the drive time differs between T1 and T2 even if the number of subframes is the same (T1> T2). The time (single pulse width) of one subframe is different from ΔT1 and ΔT2 (ΔT1> ΔT2). In this way, even if the electro-optical materials 30a to 30c shown in FIG. 3 having temperature dependency are used, the electro-optical panel 10 can be driven with a driving voltage suitable for the temperature.

5. Specific Example of Display Engine FIG. 13 shows a specific example of the display engine 130 in the data line driving unit 100 shown in FIG. In FIG. 13, the display engine 130 can include a pipeline control unit 131, an image data read control unit 132, a waveform data read control unit 133, and a waveform data buffer 134.

  For example, the pipeline control unit 131 can perform parallel drawing processing of the plurality of regions 11A and 11B on the screen 11 of the electro-optical panel 10 illustrated in FIG. For this purpose, the pipeline control unit 131 includes a plurality of pipelines 0, 1, 2,. The pipeline control unit 131 manages the count number of subframes, selection of the waveform mode used for updating, and management of the image update areas 11A and 11B for a plurality of pipelines 0, 1, 2,. Specifically, in the management of the image update area, the position information of the pixel to be updated is acquired from the image data read control unit 132, and the acquired pixel position is any of the plurality of pipelines 0, 1, 2,. It is determined whether it is included in one processing area. When the pixel being processed is included in the areas of the plurality of pipelines 0, 1, 2,..., The pipeline is identified, and information on the identified pipeline is sent to the waveform data read control unit 133. Further, it is necessary to update the waveform data and driving conditions stored in the waveform data buffer 134 for each subframe. The pipeline control unit 131 manages the subframe counts of the plurality of pipelines 0, 1, 2,... Based on the output from the H / V (horizontal / vertical) counter 131A, and at the start of the subframe, the waveform A request to update the data in the waveform data buffer 134 is issued to the data read control unit 133, and at the same time, the number of subframes and the waveform mode necessary for updating the waveform data are sent. Since the pipeline control unit 131 individually manages a plurality of pipelines 0, 1, 2,..., A plurality of pipelines 0, 1, 2,. Drawing processing can be performed.

  The image data read control unit 132 is a circuit that reads image data from the display memory 110, generates an address of the waveform data buffer 134, and reads waveform data and driving conditions. The address of the waveform data buffer 134 is read from the display memory 110 and generated based on the NI / CI data.

  The image data read control unit 132 can update the entire screen 11 shown in FIG. 14 and the entire screen in the designated areas 11A and 11B. At that time, the CI data and the NI data in the update area may be compared to update only the pixels whose values have changed, and 0 V may be applied to the pixels having the same value.

  The waveform data read control unit 133 reads the waveform data for one subframe and the driving conditions corresponding to the measured temperature from the waveform RAM 120 for each subframe, and writes them in the waveform data buffer 134. The update of the drive waveform information stored in the waveform data buffer 134 is started by a request from the pipeline control unit 131. The pipeline control unit 131 individually controls the update request of the drive waveform information for each pipeline 0, 1, 2,..., And the waveform data read control unit 133 has each pipeline 0, 1, 2,. Arbitrary update requests are arbitrated for processing.

  The waveform data buffer 134 is a buffer composed of flip-flops for storing driving conditions corresponding to temperature and waveform data for one subframe for all pipelines 0, 1, 2,. If the reading speed of the waveform RAM 120 is faster than the refresh rate of the EPD panel 10, the waveform data buffer 134 may be omitted. The waveform data buffer 134 may be a double buffer, and the waveform may be read out in one area and written in the other area. However, it should be avoided because it increases memory capacity. In this embodiment, the waveform data buffer 134 is a single buffer, and new waveform data corresponding to the pipeline being updated is acquired from the waveform RAM 120 every time one subframe is completed. The time for acquiring the waveform data from the waveform RAM 120 is about several tens of μs, which is sufficiently small as compared with 20 ms of one subframe period and does not cause a problem.

  In the DMAC 113, immediately after the image update, the image data in the NI buffer 112 is transferred to the CI buffer 111 for the next image update. The pipeline control unit 131 individually sends a data transfer request from the NI buffer 112 to the CI buffer 111 to the DMAC 113 for an area corresponding to a desired pipeline after each pipeline 0, 1, 2,. When data transfer requests for a plurality of pipelines 0, 1, 2,... Conflict, the DMAC 113 can arbitrate the plurality of requests and proceed with processing in a time division manner. By the time division processing, the circuit scale can be reduced as compared with the parallel processing.

6). Data Line Driver FIG. 15 is a schematic block diagram of the data line driver 150 shown in FIGS. As shown in FIG. 15, the data line driver 150 can include an analog switch group 151, a stitch control circuit 152, a frequency variable unit 153, and a voltage variable unit 154. The analog switch group 151 switches and outputs three types of voltages (+ Vs, 0, −Vs) to the plurality of data lines 16. The switch control circuit 152 controls the switching operation in the analog switch group 150 based on the voltage level (+, 0, −) for each subframe from the timing controller 140.

  The frequency variable unit 153 varies the input reference frequency based on the frame rate from the timing controller 140 and outputs the variable to the switch control circuit 152. Thereby, in the analog switch group 151, the time (single pulse width) of one subframe shown in FIGS. 12A and 12B is controlled to ΔT1, ΔT2, and the like.

  The voltage variable unit 154 varies the input reference voltage based on the voltage value from the timing controller 140, and outputs it to the switch control circuit 152. Thereby, in the analog switch group 151, the amplitude of the data voltage ± Vs shown in FIGS. 12A and 12B is controlled.

7). Description of Operation Next, the operation from power-on to image display of the apparatus according to the embodiment will be described with reference to FIG. FIG. 16 shows the operation of the CPU 51 of the host device 50 and the operation of the data line driving unit (driver IC) 100.

  First, when the power of the apparatus is turned on (S1), the CPU 51 turns on the external clock (S2). Further, the driver IC 100 is turned on to supply the internal clock of the driver IC 100 (S3).

  Thereafter, the CPU 51 issues a firmware write command for the driver IC 100 (S4), and the driver IC 100 writes the firmware in a dedicated memory (not shown) (S10).

  Next, the CPU 51 issues a command for initializing the driver IC 100 (S5). Thereby, the driver 1C100 initializes the register 102 (S11). Further, based on the sensing result of the temperature sensor 200, the temperature detection unit 170 detects the temperature and stores the current temperature in the register 102.

  In order to drive the EPD panel 10, drive waveform information that matches the environment information acquired by the temperature detection unit (acquisition unit) 170 is necessary, and the current temperature is stored in the register 102.

  Next, the CPU 51 issues a command for initializing the CI buffer 111 (S6). The driver IC 100 initializes the image in the CI buffer 111 (S12). Thereafter, when the CPU 51 issues an image writing command (S7), the driver IC 100 stores the image sent from the host device 50 or the like in the NI buffer 112 (S13).

  Thereafter, when a panel image update start command is issued from the CPU 51 (S8), the waveform mode designated by the panel image update command is stored in the register 102, and the first subframe of the waveform data corresponding to the waveform mode is By the operations of the pipeline control unit 131 and the waveform data read control unit 133, the data is read from the waveform RAM 120 and transferred to the waveform data buffer 134 (S14).

  Here, the waveform RAM 120 includes a basic waveform data table 120A and a temperature / driving condition table 120B as shown in FIG. The pipeline control unit 131 and the waveform data read control unit 133 in the display engine 130 read out the driving condition of the corresponding temperature from the temperature / driving condition table 120B of the waveform RAM 120 based on the current temperature information in the register 102, and the waveform. The data is sent to the data buffer 134. Further, the pipeline control unit 131 and the waveform data read control unit 133 in the display engine 130 can select any of the basic waveform data tables 120A0 to 120A15 of the corresponding waveform mode in the waveform RAM 120 based on the waveform mode in the register 102. The basic waveform data is read out from one of them. Of the multiple subframes stored in any one of the basic waveform data tables 120A0 to 120A15, all the basic waveform data for one subframe is read and stored in the waveform data buffer 134. All the basic waveform data for one subframe includes the CI / CI when shifting from the current display data CI (Current Image) to the next display data NI (Next Image) in the selected one waveform mode. Basic waveform data is included corresponding to all combinations of NIs.

  Thereafter, the panel image is updated using the extracted waveform data (S15). For this purpose, the image data read control unit 132 reads the image data from the C1 buffer 111 and the NI buffer 112, and sets the addresses of the pipelines 0, 1, 2,... Being read and updated based on the CI / NI data. Generate and make a read request to the waveform data buffer 134. Then, the timing controller 140 fetches the waveform data from the waveform data buffer 134 and stores it in the FIFO 141. The waveform data of the FIFO 141 is transmitted to the data line driver 150 at an appropriate timing simultaneously with the driver control signal. The timing controller 140 sends a control signal to the scanning line driving unit 40 via the scanning line controller 160. As a result, the image of the electro-optical panel 10 of FIG. 1 is updated in a line sequential manner. These operations are repeated every time one subframe is completed, and all subframes necessary for image update are completed.

  At this time, the data line driver 150 controls the switch control circuit 152, the frequency variable unit 153, and the voltage variable unit 154 shown in FIG. 15 based on the signal from the timing controller 140. In this way, as shown in FIGS. 12A and 12B, the electro-optical panel 10 is driven with the drive voltage waveform of the data voltage generated by adapting the frame rate and voltage value in the basic drive waveform to the measured temperature. can do.

  As shown in FIG. 11, when the scan voltage is varied together with the data voltage based on the measured temperature, the scan line controller 160 shown in FIG. 5 acquires the scan line voltage value from the timing controller 140 and scans. What is necessary is just to drive-control the line drive part 40. FIG. In this manner, the variable scanning voltage value may be generated by the scanning line controller 160 or may be generated by the scanning line driving unit 40 based on a signal from the scanning line controller 160.

  Finally, the CI buffer 111 is updated (S16). For this purpose, the pipeline control unit 131 requests the DMAC 113 to transfer the data in the NI buffer 112 to the CI buffer 111. As a result, the DMAC 113 transfers the data in the NI buffer 112 to the CI buffer 111.

  Here, as shown in FIG. 14, when updating the image for the designated area 11A of the screen 11, the CPU 51 sends the start address (X1, Y1) and the rectangular sizes a1, b1 of FIG. Data is stored in the register 102. Therefore, if the image data read control unit 132 reads data from the CI buffer 111 and the NI buffer 112 only for the designated area 11A in FIG. 14, the image data can be updated only in the designated area 11A in the same manner as described above. it can.

  The image can be updated in the same manner for the designated area 11B in FIG. At this time, in order to simultaneously update the images of the designated areas 11A and 11B, the pipeline control unit 131 performs simultaneous parallel control on the designated area 11A using, for example, pipeline 0 and the designated area 11B using, for example, pipeline 1 simultaneously. Can be commanded. At that time, in the designated areas 11A and 11B, the waveform mode, that is, the gradation of the NI image can be made different from one of two gradations and the other of 16 gradations.

8). Electronic Device FIG. 17 shows a configuration example of an electronic device 300 including the electro-optical device of this embodiment. The electronic apparatus 300 includes an electro-optical panel 10, a host device 50, an integrated circuit device 100, an operation unit 310, a storage unit 320, and a communication unit 330. Various modifications such as omitting some of these components and adding other components are possible.

  The electro-optical panel 10 is for displaying various images (information) as an output device of the electronic apparatus 300, and is, for example, an EPD panel or an ECD panel. The operation unit 310 is used by the user to input various information, and can be realized by various buttons, a keyboard, and the like. The storage unit 320 stores various information such as image data, and can be realized by a RAM, a ROM, or the like. The communication unit 330 performs communication processing with the outside.

  Note that examples of the electronic device realized by the present embodiment include various devices such as an electronic card (credit card, point card, etc.), electronic paper, a remote control, a clock, a mobile phone, a portable information terminal, and a calculator. it can.

  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, a term (such as an EPD panel) that is described at least once together with a different term (such as an electro-optical panel) in a broader or synonymous manner in the specification or drawings is referred to as the different term in any part of the specification or drawings. Can be replaced. Further, the configurations and operations of the integrated circuit device and the electronic device are not limited to those described in this embodiment, and various modifications can be made.

  For example, the environmental information may be other parameters such as brightness, humidity, and atmospheric pressure that affect the display characteristics of the electro-optical panel, in addition to the environmental temperature detected by an internal circuit device or an external temperature sensor. . Further, the electro-optical panel may be a passive type instead of an active type as in the present embodiment. The electro-optic material is not limited to this embodiment, and any material that can be driven by a voltage transition waveform, such as a microcup or an electronic powder fluid, may be used.

DESCRIPTION OF SYMBOLS 10 Electro-optical panel (EPD panel), 12 1st board | substrate, 20 pixels, 14 Scan electrode, 22 Pixel selection transistor, 26 Pixel electrode, 28 Counter electrode, 30 Electro-optical material, 40 Scan line drive part, 50 Host apparatus, 51 CPU, 100 data line drive unit (integrated circuit device), 110 display data storage unit (display memory), 113 transfer control unit (DMAC), 120 waveform RAM (waveform information storage unit), 121 decoding unit, 130, 140 drive waveform Information output unit (display engine, timing controller), 150 Drive voltage output unit (data line driver), 151 Analog switch group, 152 Switch control circuit, 153 Frequency variable unit, 154 Voltage variable unit, 160 Scan line controller, 170 Part (temperature detection part), 2 0 temperature sensor, 300 electronic devices,

Claims (10)

A drive voltage output unit that outputs a drive voltage to a plurality of pixel electrodes of the electro-optic panel to update an image;
A display data storage unit including a first storage unit storing first display data and a second storage unit storing second display data;
A waveform information storage unit for storing drive waveform information for changing a display state at a pixel from a first display state corresponding to the first display data to a second display state corresponding to the second display data;
A drive waveform information output unit that outputs the drive waveform information selected from the waveform information storage unit based on the first display data and the second display data to the drive voltage output unit;
Have
An acquisition unit for acquiring environmental information;
Have
The waveform information storage unit sets a plurality of different drive conditions for each environment information for at least one basic waveform table storing basic waveform data and the basic waveform data in the at least one basic waveform table Environment information / driving condition table,
The drive waveform information output unit outputs the basic waveform data in the at least one basic waveform table to the drive voltage output unit together with the drive condition corresponding to the environmental information acquired by the acquisition unit. An integrated circuit device. In claim 1,
The integrated circuit device, wherein the basic waveform data is a voltage level of each of a plurality of subframes. In claim 2,
The integrated circuit device, wherein the plurality of driving conditions different for each environment information includes a plurality of types of frame rates set for the plurality of subframes. In claim 2 or 3,
The integrated circuit device, wherein the plurality of driving conditions different for each environment information include a plurality of types of voltage values set for the voltage level. In claim 4,
A scanning line controller for controlling supply of a scanning voltage to a scanning line connected to a gate of a pixel selection transistor to which each of the plurality of pixel electrodes of the electro-optical panel is connected;
The integrated circuit device, wherein the plurality of driving conditions different for each environment information includes a plurality of types of scanning voltage values set corresponding to the plurality of types of voltage levels. In claim 3,
The integrated circuit device, wherein the drive voltage output unit includes a frequency variable unit, and the frequency variable unit varies the frequency based on the frame rate output from the drive waveform output unit. In claim 4 or 5,
The integrated circuit device, wherein the drive voltage output unit includes a voltage variable unit, and the voltage variable unit varies the voltage level based on a voltage value output from the drive waveform output unit. In any one of Claims 1 thru | or 7,
The integrated circuit device, wherein the at least one basic waveform table includes a plurality of basic waveform tables each storing basic waveform data having a different number of subframes for each waveform mode. An integrated circuit device according to any one of claims 1 to 8,
The electro-optical panel driven by the integrated circuit device;
The host device connected to the integrated circuit device;
An electro-optical device comprising:   An electronic apparatus comprising the electro-optical device according to claim 9.

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