JP2013205731A - Image processing system, display control method of the same, program and information storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image processing system or the like that can display an image at a high speed in response to input operation in an application in combination with drawing processing and has high general-purpose properties.SOLUTION: An image processing system 1 includes: a display section 50 provided with electronic paper 52; a storage section 30 including a frame buffer 36; a display control section 40 that performs control for causing an image corresponding to image data written into the frame buffer 36 to be displayed on the electronic paper 52; an input operation detection processing section 12 for detecting input operation; an application processing section 14 operating on the basis of an application program 32; and a drawing processing section 16 operating on the basis of a program. The application processing section 14 writes the image data into the frame buffer in response to a predetermined event on the basis of the input operation and performs an update request of cache information. The drawing processing section 16 updates the cache information on the basis of the image data written into the frame buffer in response to the update request.

Description

  The present invention relates to an image processing apparatus, a display control method for the image processing apparatus, a program, and an information storage medium.

  In recent years, there has been an increasing demand for electronic paper with advantages such as excellent visibility and low power consumption, and it is used for electronic book readers (electronic book readers), electronic signage (digital signage), and some mobile phones. ing.

  Applications that generate images to be displayed on electronic paper in these electronic devices are diverse and complex, and in order to facilitate their development, application frameworks (in which data structures and library functions are defined in advance) ( "GUI toolkit") is used. This application framework is stored in a memory of an electronic device and operates as a GUI (Graphical User Interface) system (also referred to as a “graphic system”) on an embedded OS.

  Basically, it is essential that drawing of an application in the GUI system is completed within a handler of the drawing event when a drawing event is notified from the GUI system. As a result, the management of the drawing process can be left to the GUI system, so that the application does not have to manage the drawing process in detail. However, as a compensation, since the relationship between the GUI system, the display controller of the electronic paper, and the frame buffer thereof is hidden by the GUI system, the drawing timing optimum for the architecture of the display controller cannot be controlled from the application. Since a piecewise drawing process according to the convenience of the GUI system is performed through the mediation of the GUI system, there is a problem that a delay due to the influence of the overhead of the GUI system itself, other tasks and threads occurs before the image is displayed. There is. Another problem is that the original performance of a display controller for electronic paper having an architecture capable of high-speed display by fast batch writing cannot be fully exhibited.

  Although not related to electronic paper, for example, Patent Document 1 and Patent Document 2 propose a technique for improving the drawing speed.

JP 5-128264 Japanese Laid-Open Patent Publication No. 2005-275028

  However, the technique of Patent Document 1 improves the drawing speed by providing dedicated hardware for processing attribute data that may be commonly specified for all types of drawing figures in an application. Yes, it is not applicable to any application and lacks versatility. Further, the technique of Patent Document 2 improves the drawing speed as a whole by properly using high-speed drawing and normal drawing according to the type of application, and does not mean that the drawing process of an arbitrary application can be accelerated. After all it lacks versatility.

  The present invention has been made in view of the above problems, and according to some aspects of the present invention, versatility that enables high-speed display of an image according to an input operation in an application involving a drawing process. Image processing apparatus, a display control method for the image processing apparatus, a program, and an information storage medium can be provided.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following aspects or application examples.

[Application Example 1]
An image processing apparatus according to this application example includes a display unit including electronic paper, a storage unit including a frame buffer for storing image data, and an image corresponding to the image data written in the frame buffer. A display control unit that performs control to be displayed on the electronic paper, an input operation detection processing unit that detects an input operation, an application processing unit that operates based on an application program and performs processing according to the input operation, A drawing processing unit that operates based on a program, generates image data according to a drawing request using cache information for the frame buffer, and writes the image data in the frame buffer, and In response to a predetermined event based on the input operation, the application processing unit In response to the update request, the rendering processing unit writes the cache information based on the image data written in the frame buffer by the image processing unit. Update.

  According to the image processing apparatus according to this application example, the application processing unit writes the image data directly into the frame buffer without using the drawing processing unit in response to a predetermined event based on the input operation, thereby enabling electronic paper It is possible to speed up drawing. The application processing unit makes a cache information update request, and the rendering processing unit updates the cache information based on the image data written in the frame buffer, thereby maintaining the consistency between the contents of the frame buffer and the cache information. can do.

  Therefore, according to the image processing apparatus according to this application example, it is possible to compensate for the drawbacks of electronic paper, which is inferior in display speed as compared with a liquid crystal display (LCD), and to realize an image processing apparatus excellent in operability. Can do.

  Further, according to the image processing apparatus according to this application example, it is possible to maintain high compatibility of the application development / execution environment of the drawing processing unit while avoiding performance degradation due to the overhead of the drawing processing unit.

[Application Example 2]
In the image processing apparatus according to the application example, the application processing unit may make the drawing request for generating the same image data as the image data written in the frame buffer as the update request.

  According to the image processing apparatus according to this application example, even when the drawing processing unit cannot update only the cache information without performing drawing, the application processing unit issues a drawing request to the drawing processing unit. This makes it possible to update cache information reliably and easily.

[Application Example 3]
The image processing apparatus according to the application example further includes an image data transfer processing unit that performs a process of transferring the image data written in the frame buffer to the display control unit, and the application processing unit stores the image data in the frame buffer. Each time data is written, a transfer request for transferring the image data to the display control unit is performed, and the image data transfer processing unit receives the image data written in the frame buffer in response to the transfer request. You may make it transfer to a display control part.

  According to the image processing apparatus according to this application example, every time the application processing unit writes image data to the frame buffer, the image data is transferred to the display control unit. Since it is updated, the operability can be improved.

[Application Example 4]
In the image processing apparatus according to the application example, the application processing unit detects a timing at which the input operation is interrupted based on a detection result of the input operation detection processing unit, and the update request is performed at the timing at which the input operation is interrupted. May be performed.

  According to the image processing apparatus according to this application example, the cache information can be updated at once based on the image data written in the frame buffer in accordance with the input operation after a series of input operations is completed. The load on the drawing processing unit can be reduced.

[Application Example 5]
In the image processing apparatus according to the application example, the application processing unit detects an event accompanied by an update of the image data written in the frame buffer, and performs the update request before the image data is updated. Also good.

  The image processing apparatus according to this application example can maintain the consistency between the contents of the frame buffer and the cache information even if an event accompanied by the update of the frame buffer occurs during the input operation.

[Application Example 6]
In the image processing apparatus according to the application example, the display unit further includes a contact position detection unit that detects a contact position with respect to the electronic paper, and the input operation detection processing unit is based on a detection result of the contact position detection unit. The input operation on the electronic paper is detected, and the application processing unit detects the input operation based on the contact position information detected by the contact position detection unit when the input operation on the electronic paper is detected. Image data representing the locus of the operation may be generated and the image data may be written into the frame buffer.

  According to the image processing apparatus according to this application example, it is possible to draw a handwritten character or figure by pen input or the like on an electronic paper at high speed, so that the operability is improved and the user-friendly image processing apparatus is provided. can do.

[Application Example 7]
In the image processing apparatus according to the application example, the display control unit stores history information of image data corresponding to an image displayed on the electronic paper of the display unit, and based on the history information, Depending on the display characteristics, control may be performed to display an image corresponding to the next image data on the electronic paper.

  According to the image processing apparatus according to the application example, the display control unit performs complicated display control such as control of the number of times of applying the drive pulse according to the characteristics of the electronic paper, so that the development of the application program becomes easy, The load on the application processing unit and the drawing processing unit can be reduced. In particular, high-speed drawing can be realized by mounting the display control unit by hardware.

[Application Example 8]
In the image processing apparatus according to the application example, the electronic paper of the display unit may display an image by an electrophoresis method.

[Application Example 9]
The display control method of the image processing apparatus according to this application example includes an input operation detection processing unit that detects an input operation, a display unit including electronic paper, a storage unit that includes a frame buffer for storing image data, A display control method for an image processing apparatus including: an application processing step for performing processing according to the input operation based on an application program; and drawing using the cache information for the frame buffer based on the program A drawing processing step of generating image data according to a request and writing the image data in the frame buffer, and a control for displaying an image corresponding to the image data written in the frame buffer on the electronic paper of the display unit Display control step to perform, the application processing step In response to a predetermined event based on the input operation, the image data is written to the frame buffer, the cache information is updated, and the application processing step writes the cache information in the frame buffer. The cache information is updated based on the image data.

[Application Example 10]
The program according to this application example is written in the input buffer detection processing unit that detects an input operation, a display unit that includes electronic paper, a storage unit that includes a frame buffer for storing image data, and the frame buffer. An image corresponding to the rendering request using the cache information for the frame buffer, which operates based on a program and a display control unit that performs control to display an image corresponding to the image data on the electronic paper of the display unit A program that is executed in an image processing apparatus including a drawing processing unit that generates data and writes the image data in the frame buffer, and operates based on an application program, in accordance with the input operation The computer functions as an application processing unit that performs processing, and the application Deployment processing unit, in response to the predetermined event based on the input operation, writes the image data into the frame buffer, performs an update request of the cache information to the drawing processor.

[Application Example 11]
The information storage medium according to this application example is a computer-readable information storage medium in which the program according to the application example is stored.

1 is a diagram illustrating a configuration example of an image processing apparatus according to an embodiment. The figure which shows an example of the flowchart of the drawing process in this embodiment. The figure which shows an example of the flowchart of the drawing process in this embodiment. 1 is an external view of an electronic book terminal according to an embodiment. The figure which shows the hardware structural example inside the electronic book terminal of this embodiment. 1 is a block diagram of an electrophoretic display device according to an embodiment. FIG. 3 is a diagram illustrating a configuration example of a pixel of an electrophoretic display device according to an embodiment. FIG. 8A is a diagram illustrating a configuration example of an electrophoretic element, and FIGS. 8B and 8C are explanatory diagrams of the operation of the electrophoretic element. Explanatory drawing about the outline | summary of the handwriting process in this embodiment. The figure which shows the hardware / software hierarchy in this embodiment, and the flow of data. The figure which shows the flowchart of the handwriting process in this embodiment. The figure which shows an example of the image data stored in the frame buffer before handwriting processing is performed. The figure which shows an example of the image data memorize | stored in the cache before handwriting processing is performed. The figure which shows an example of the flowchart of a process of a pen touch event handler. The figure which shows an example of the flowchart of a process of a pen movement event handler. The figure which shows an example of the flowchart of a process of a pen release event handler. The figure which shows an example of the flowchart of a direct drawing process. The figure which shows an example of a mode that the image data stored in a frame buffer changes by a direct drawing process. The figure which shows an example of the flowchart of a process of a drawing event handler. The figure which shows an example of the flowchart of an indirect drawing process. The figure which shows an example of the image data preserve | saved at cache by an indirect drawing process. 1 is a diagram illustrating an example of an image processing apparatus according to an embodiment. The figure which shows an example of the flowchart of a process of the pen movement event handler in a modification.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. The embodiments described below do not unduly limit the contents of the present invention described in the claims. Also, not all of the configurations described below are essential constituent requirements of the present invention.

1. Image processing apparatus 1-1. Configuration FIG. 1 is a diagram illustrating a configuration example of an image processing apparatus according to the present embodiment. As shown in FIG. 1, the image processing apparatus 1 according to the present embodiment includes a processing unit (CPU) 10, an operation unit 20, a storage unit 30, a display control unit 40, a display unit 50, a sound output unit 60, and a communication unit 70. It is configured to include. The image processing apparatus 1 of the present embodiment may have a configuration in which some of the components (each unit) in FIG. 1 are omitted or changed, or other components are added.

  The operation unit 20 is an input device including operation keys, button switches, and the like, and outputs an operation signal corresponding to an operation by a user to the processing unit (CPU) 10.

  The storage unit 30 stores programs, data, and the like for the processing unit (CPU) 10 to perform various types of calculation processing and control processing. In particular, in the present embodiment, the storage unit 30 stores various application programs 32 accompanied with a drawing request to the display unit 50, a data file 34 storing image data, and the like.

  The storage unit 30 is also used as a work area for the processing unit (CPU) 10. In particular, in this embodiment, a frame buffer 36 and a cache 38 for the frame buffer 36 are provided in a part of the storage area. Yes.

  The frame buffer 36 is a storage area for storing image data included in the data file 34, image data created in response to a predetermined input operation by the user, and the like.

  The cache 38 is a storage area for storing information (hereinafter referred to as “cache information”) for speeding up the processing of writing image data into the frame buffer 36 by the drawing processing unit 16 described later. The cache information is, for example, information such as image data that was previously stored in the frame buffer 36 or image data that is frequently referenced.

  The sound output unit 60 is a device that outputs sound, such as a speaker, and outputs various sounds (including sound) based on signals input from the processing unit (CPU) 10.

  The communication unit 70 is for performing data communication with other devices connected to a wired or wireless communication network under the control of the processing unit (CPU) 10.

  The display unit 50 is a display device that includes an electronic paper 52, and an image corresponding to the image data stored in the frame buffer 36 is displayed on the electronic paper 52. Various types of electronic paper 52 can be used. For example, an electrophoresis type that switches charged particles by moving the display, a particle rotation type that switches charged particles by rotating the charged particles, or a magnetophoretic method that switches particles by moving the particles by magnetism A display method using a thin liquid crystal driven by a small battery or an EL element, a display method using a liquid crystal having a memory property represented by a ferroelectric liquid crystal, or the like can be appropriately employed as the electronic paper 52.

  The display unit 50 may include a contact position detection unit 54. The contact position detection unit 54 detects a contact position with respect to the electronic paper 52 and outputs information on the contact position.

  The display control unit 40 performs control to display an image corresponding to the image data written in the frame buffer 36 on the electronic paper 52 of the display unit 50. The display control unit 40 stores the history information 42 of the image data corresponding to the image displayed on the electronic paper 42, and corresponds to the next image data according to the display characteristics of the electronic paper 52 based on the history information 42. You may make it perform control which displays an image on the electronic paper 52. FIG.

  The processing unit (CPU) 10 performs various calculation processes and control processes in accordance with various programs stored in the storage unit 30. In particular, in the present embodiment, the processing unit (CPU) 10 includes an input operation detection processing unit 12, an application processing unit 14, a drawing processing unit 16, and an image data transfer processing unit 18. However, the processing unit (CPU) 10 of the present embodiment may have a configuration in which some of these configurations (elements) are omitted or changed, or other configurations (elements) are added.

  The input operation detection processing unit 12 performs a process of detecting an input operation by the user based on an operation signal from the operation unit 20 or the like. Further, the input operation detection processing unit 12 may detect a user input operation on the electronic paper 52 based on the detection result of the contact position detection unit 54.

  The application processing unit 14 operates based on the application program 32 and performs processing according to the input operation detected by the input operation detection processing unit 12. That is, the processing unit (CPU) 10 functions as the application processing unit 14 by executing the application program 32.

  The drawing processing unit 16 operates based on a given program, generates image data corresponding to a drawing request from the application processing unit 14 or the like using the cache information, writes the image data in the frame buffer 36, Performs processing to update cache information.

  The application program 32 and the data file 34 may be stored in the storage unit 30 from the beginning. However, the application program 32 and the data stored in the computer-readable information storage medium by the processing unit (CPU) 10 may be used. The file 34 may be read and downloaded to the storage unit 30. The computer-readable information storage medium is, for example, an optical disc (compact disc (CD), digital versatile disc (DVD), Blu-ray disc (BD), laser disc (registered trademark) (LD), etc.), magneto-optical disc (MO). ), Magnetic disk (hard disk drive (HDD), flexible disk (FD), etc.), magnetic tape (digital data storage (DDS), etc.), memory (flash memory, memory card, USB memory, etc.), and the like.

  Alternatively, the processing unit (CPU) 10 may receive the application program 32 and the data file 34 stored in a device such as a personal computer (server) via the communication unit 70 and download them to the storage unit 30. .

1-2. Drawing Process FIG. 2 is a diagram illustrating an example of a flowchart of a drawing process performed by the image processing apparatus according to the present embodiment.

  When an event for updating the display image of the electronic paper 52 occurs (Y in S10), if the event is not a predetermined event based on the user's input operation (N in S12), the application processing unit 14 determines that the event has occurred. In response, a drawing request for image data is made to the drawing processing unit 16 (S14).

  Next, in response to the drawing request, the drawing processing unit 16 generates image data corresponding to the drawing request from the application processing unit 14 using the cache information for the frame buffer 36, and the image data is stored in the frame buffer 36. (S16).

  On the other hand, if the generated event is a predetermined event (Y in S12), the application processing unit 14 writes the image data in the frame buffer 36 according to the generated event, and requests the cache processing unit 16 to update the cache information. (S18). For example, when an input operation on the electronic paper 52 is detected, the application processing unit 14 generates image data representing a locus of the input operation based on the information on the contact position detected by the contact position detection unit 54. Alternatively, the image data may be written into the frame buffer 36 and a cache information update request may be sent to the drawing processing unit 16.

  Next, in response to the cache information update request, the rendering processing unit 16 updates the cache information based on the image data written in the frame buffer 36 by the application processing unit 14 (S20).

  Next, the image data transfer processing unit 18 transfers the image data written in the frame buffer 36 in step S16 or S18 to the display control unit 40 (S22).

  Next, the display control unit 40 performs control to display an image corresponding to the image data transferred in step S22 on the electronic paper 52 of the display unit 50 (S24).

  Note that the processes in steps S22 and S24 are performed in parallel with the process in step S20.

  Then, the image processing apparatus 1 repeats the processes in steps S10 to S24 until an application end event occurs (N in S26).

  Note that the application processing unit 14 detects the timing when the input operation by the user is interrupted based on the detection result of the input operation detection processing unit 12, and cache information to the drawing processing unit 16 at the timing when the input operation is interrupted. An update request may be made.

  Further, for example, the application processing unit 14 may detect an event that involves updating the image data written in the frame buffer 36 and make the update request before the image data is updated. In response to the update request, the drawing processing unit 16 updates the cache information based on the image data before the image data written in the frame buffer 36 by the application processing unit 14 is updated.

  In addition, when the application processing unit 14 writes the image data to the frame buffer 36 in a plurality of times for one event, the application processing unit 14 writes the image data to the frame buffer 36 each time the image data is written to the frame buffer 36. Thus, a transfer request for transferring the image data to the display control unit 40 may be made. The image data transfer processing unit 18 sequentially transfers each image data written in the frame buffer 36 to the display control unit 40 in response to the transfer request.

  The application processing unit 14 may make a drawing request for generating the same image data as the image data written in the frame buffer 36 as a cache information update request. In response to the drawing request, the drawing processing unit 16 generates the image data, writes it in the frame buffer 36, and updates the cache information.

  FIG. 3 is a diagram illustrating an example of a flowchart of a drawing process when the application processing unit 14 makes a drawing request as an update request (when the drawing request also serves as an update request).

  When an update event of the display image of the electronic paper 52 occurs (Y in S30), if the event is not a predetermined event based on the user's input operation (N in S32), the application processing unit 14 determines that the event has occurred. In response, a drawing request for image data is sent to the drawing processing unit 16 (S34).

  On the other hand, if the event that has occurred is a predetermined event (Y in S32), the application processing unit 14 writes at least a part of the image data in the frame buffer in accordance with the event that has occurred, and the image data is stored in the drawing processing unit. Is made (S36).

  Next, the image data transfer processing unit 18 transfers the image data written in the frame buffer 36 in step S36 to the display control unit 40 (S38).

  Next, the display control unit 40 performs control to display an image corresponding to the image data transferred in step S38 on the electronic paper 52 of the display unit 50 (S40).

  Next, in response to the drawing request in step S34 or S36, the drawing processing unit 16 uses the cache information to generate image data corresponding to the drawing request from the application processing unit 14, and the image data is stored in the frame buffer 36. And the cache information is updated (S42). The process of step S42 is performed in parallel with the processes of steps S38 and S40.

  Next, the image data transfer processing unit 18 transfers the image data written in the frame buffer 36 in step S42 to the display control unit 40 (S44).

  Next, the display control unit 40 performs control to display an image corresponding to the image data transferred in step S44 on the electronic paper 52 of the display unit 50 (S46).

  Then, the image processing apparatus 1 repeats the processes in steps S30 to S46 until an application end event occurs (N in S48).

  As an image processing apparatus according to the present embodiment that performs such processing, an arbitrary electronic device using electronic paper is conceivable. Hereinafter, an electronic book terminal will be described as an example and described in more detail.

2. Electronic book terminal 2-1. Configuration of Electronic Book Terminal FIG. 4 is an external view of the electronic book terminal of the present embodiment, and FIG. 5 is a diagram illustrating an example of a hardware configuration inside the electronic book terminal of the present embodiment.

  As shown in FIG. 5, the electronic book terminal 100 according to the present embodiment includes components such as a CPU 110, an input button 120, an internal memory 130, an EPD controller 140, a display 150, a speaker 160, and a USB interface 170. These components can exchange various data via the bus 180. The electronic book terminal 100 of the present embodiment may have a configuration in which some of the components (each unit) in FIG. 5 are omitted or changed, or other components are added.

  The input button 120 is used for an input operation by the user, and includes various hard buttons 120a and various soft buttons 120b (see FIG. 4). The input button 120 corresponds to the operation unit 20 in FIG.

  The internal memory 130 stores programs, data, and the like for the CPU 110 to perform various calculation processes and control processes. The internal memory 130 has an operating system 131 that performs basic processing such as file operations and hardware interface processing, a data structure (class) for drawing, and various library functions, and general-purpose drawing processing. A graphics system 132 to be installed is installed. Since the graphic system 132 is incorporated, various applications involving drawing can be developed using various data structures (classes) and library functions, thereby reducing development costs and bugs. There are advantages such as being able to.

  In addition, the internal memory 130 stores a handwriting application 133 for writing (adding) handwritten characters, graphics, and the like by pen input to a page displayed on the display 150. The handwriting application 133 may be installed from the beginning, or may be installed from a personal computer or the like via the USB interface 170, for example.

  The internal memory 130 stores a content file 134 that stores image data of each page of the electronic book (content). The content file 134 may be stored in the internal memory 130 from the beginning, or may be downloaded from a personal computer, a USB memory, or the like via the USB interface 170, for example.

  The internal memory 130 also includes a work area of the CPU 110. In particular, in this embodiment, image data included in the content file 134, image data created in response to a predetermined input operation by the user, and the like are part of the storage area. And a cache 136 for storing cache information for speeding up the process of writing image data to the frame buffer 135.

  In general, the internal memory 130 includes a plurality of physically separated memories that are optimal for each application. The internal memory 130 corresponds to the storage unit 30 in FIG. The handwriting application 133 and the content file 134 correspond to the application program 32 and the data file 34 in FIG. 1, respectively. The frame buffer 135 and the cache 136 correspond to the frame buffer 36 and the cache 38 in FIG. 1, respectively.

  The speaker 160 outputs various sounds and sounds under the control of the CPU 110. The speaker 160 corresponds to the sound output unit 60 of FIG.

  The USB interface 170 is connected to a USB cable, a USB memory, or the like, and performs data communication with a personal computer, a USB memory, or the like under the control of the CPU 110. The USB interface 170 corresponds to the communication unit 70 in FIG.

  The display 150 includes an EPD panel 152, and an image corresponding to the image data stored in the frame buffer 135 is displayed on the surface of the EPD panel 152.

  FIG. 6 is a diagram illustrating a configuration example of the display 150. The example of FIG. 6 is an active matrix type electrophoretic display (EPD). In FIG. 6, the digitizer 154 is not shown.

  As shown in FIG. 6, the display 150 includes an EPD panel 152, a scanning line driving circuit 221, a data line driving circuit 222, and a common power supply modulation circuit 224.

  The scanning line driving circuit 221, the data line driving circuit 222, and the common power supply modulation circuit 224 are each connected to the EPD controller 140 (not shown in FIG. 6).

  In the EPD panel 152, a plurality of scanning lines 226 extending from the scanning line driving circuit 221 and a plurality of data lines 228 extending from the data line driving circuit 222 are formed, and a plurality of pixels corresponding to these intersection positions are formed. 200 is provided.

  The scanning line driving circuit 221 is connected to each pixel 200 by j scanning lines 226 (Y1, Y2,..., Yj). The scanning line driving circuit 221 sequentially selects the scanning lines 226 from the first row to the j-th row under the control of the EPD controller 140, so that a driving TFT (Thin Film Transistor) 208 provided in the pixel 200 (FIG. 7). A selection signal that defines the on-timing of reference).

  The data line driving circuit 222 is connected to each pixel 200 by k data lines 228 (X1, X2,..., Xk). The data line driving circuit 222 supplies a 1-bit image signal to each of the pixels 200 according to the control of the EPD controller 140 based on the transfer data. In this embodiment, when defining pixel data “0”, a low-level image signal is supplied to the pixel 200, and when defining pixel data “1”, a high-level image signal is applied to the pixel 200. 200.

The EPD panel 152 also includes a low potential power supply line 209 (Vss), a high potential power supply line 210 (Vdd), a common electrode wiring 215 (Vcom), and a first pulse signal line 251 (S) extending from the common power supply modulation circuit 224. ₁ ), a second pulse signal line 252 (S ₂ ) is provided, and each wiring is connected to the pixel 200. The common power supply modulation circuit 224 generates various signals to be supplied to each of the wirings under the control of the EPD controller 140, and electrically connects and disconnects these wirings (high impedance, Hi-Z).

  FIG. 7 is a circuit configuration diagram of the pixel 200 of FIG. In FIG. 7, the same numbers are assigned to the same wirings as in FIG. In FIG. 7, the common electrode wiring 215 common to all pixels is not shown.

  As shown in FIG. 7, the pixel 200 is provided with a driving TFT 208, a latch circuit 230, and a switch circuit 240. The pixel 200 has an SRAM (Static Random Access Memory) type configuration in which an image signal is held as a potential by the latch circuit 230.

  The driving TFT 208 is a pixel switching element composed of an N-MOS transistor. The gate terminal of the driving TFT 208 is connected to the scanning line 226, the source terminal is connected to the data line 228, and the drain terminal is connected to the data input terminal of the latch circuit 230. The latch circuit 230 includes a transfer inverter 230t and a feedback inverter 230f. A power supply voltage is supplied to the inverters 230t and 230f from the low potential power supply line 209 (Vss) and the high potential power supply line 210 (Vdd).

  The switch circuit 240 includes transmission gates TG1 and TG2, and outputs a signal to the pixel electrode 195 (see FIGS. 8B and 8C) according to the level of the pixel data stored in the latch circuit 230. . Note that Va means a potential applied to the pixel electrode of one pixel 200.

And pixel data "1" in the latch circuit 230 (a high-level image signal) is stored, the transmission gate TG1 is turned on, the switch circuit 240 is a pulse signal to be supplied (drive pulse) S ₁ as Va. On the other hand, the pixel data "0" in the latch circuit 230 (image signal of a low level) is stored, when the transmission gate TG2 is turned on, the switch circuit 240 supplies a pulse signal (drive pulse) S ₂ as Va. With such a circuit configuration, the potential applied to the pixel electrode of each pixel 200 can be controlled by the control unit.

  The EPD panel 152 of the present embodiment may be, for example, a two-particle microcapsule type electrophoretic EPD panel. If the dispersion is colorless and transparent, and the electrophoretic particles are white or black, at least two colors can be displayed with two colors of white or black as basic colors.

  FIG. 8A is a diagram illustrating a configuration example of the electrophoretic element 262. The electrophoretic element 272 is sandwiched between the element substrate 270 and the counter substrate 271 (see FIGS. 8B and 8C). The electrophoretic element 272 is configured by arranging a plurality of microcapsules 260. The microcapsule 260 encloses, for example, a colorless transparent dispersion, a plurality of white particles (electrophoretic particles) 267, and a plurality of black particles (electrophoretic particles) 266. In the present embodiment, for example, it is assumed that the white particles 267 are negatively charged and the black particles 266 are positively charged.

  FIG. 8B is a partial cross-sectional view of the EPD panel 152. The element substrate 270 and the counter substrate 271 sandwich an electrophoretic element 272 in which microcapsules 260 are arranged. The EPD panel 152 includes a drive electrode layer 280 in which a plurality of pixel electrodes 195 are formed on the electrophoretic element 272 side of the element substrate 270. In FIG. 8B, a pixel electrode 195A and a pixel electrode 195B are shown as the pixel electrode 195. The pixel electrode 195 can supply a potential to each pixel (for example, Va and Vb). Here, a pixel having the pixel electrode 195A is referred to as a pixel 200A, and a pixel having the pixel electrode 195B is referred to as a pixel 200B. The pixel 200A and the pixel 200B are two pixels corresponding to the pixel 200 (see FIGS. 6 and 7).

  On the other hand, the counter substrate 271 is a transparent substrate, and an image is displayed on the counter substrate 271 side in the display unit. The EPD panel 152 includes a common electrode layer 282 in which a common electrode 197 having a planar shape is formed on the electrophoretic element 272 side of the counter substrate 271. The common electrode 197 is a transparent electrode. Unlike the pixel electrode 195, the common electrode 197 is an electrode common to all the pixels, and the potential Vcom is applied.

  An electrophoretic element 272 is disposed on an electrophoretic display layer 290 provided between the common electrode layer 282 and the drive electrode layer 280, and the electrophoretic display layer 290 becomes a display region. A desired display color can be displayed for each pixel in accordance with a potential difference between the common electrode 197 and a pixel electrode (for example, 195A and 195B).

  In FIG. 8B, the common electrode side potential Vcom is higher than the potential Va of the pixel electrode of the pixel 200A. At this time, the negatively charged white particles 267 are attracted to the common electrode 197 side, and the positively charged black particles 266 are attracted to the pixel electrode 195A side, so that the pixel 200A is visually recognized as displaying white.

  In FIG. 8C, the common electrode side potential Vcom is lower than the potential Va of the pixel electrode of the pixel 200A. At this time, on the contrary, the positively charged black particles 266 are attracted to the common electrode 197 side, and the negatively charged white particles 267 are attracted to the pixel electrode 195A side, so that it is visually recognized that the pixel 200A displays black. Is done. Note that the structure in FIG. 8C is similar to that in FIG. 8 (B) and 8 (C), Va, Vb, and Vcom are described as fixed potentials. However, in reality, Va, Vb, and Vcom change with time.

  Here, in the example of the pixel 200A in FIGS. 8B and 8C, the white particles 267 and the black particles 266 are all drawn toward the common electrode 197 side (so-called saturated state), respectively. Yes. However, it is possible not only to display the basic colors (white and black) in a saturated state but also to display intermediate colors (light gray and dark gray) by applying an electric field in the opposite direction for an appropriate time, for example.

  Returning to FIG. 5, the display 150 further includes a digitizer 154. The digitizer 154 is provided so as to face the back surface of the EPD panel 152, detects a position where an input touch pen (hereinafter simply referred to as “pen”), a user's finger, or the like touches the EPD panel 152, and provides information on the contact position. Is output. For example, when the user performs operations such as inputting characters or figures using a pen, or sliding a finger to perform page operations such as page advance or page return, page enlargement or reduction, the digitizer 154 performs these operations. Outputs the information of the contact position when.

  The display 150 corresponds to the display unit 50 in FIG. The EPD panel 152 and the digitizer 154 correspond to the electronic paper 52 and the contact position detection unit 54 in FIG. 1, respectively.

  The EPD controller 140 performs control to display an image corresponding to the image data written in the frame buffer 135 on the EPD panel 152 of the display 150. The EPD controller 140 is provided with a memory pipeline 142 for managing a history of image data corresponding to an image displayed on the EPD panel 152. The memory pipeline 142 holds history information of image data (image data written in the frame buffer 135) corresponding to the image displayed on the EPD panel 152 in time series. The EPD controller 140 determines the optimum number of times considering the display characteristics of the EPD panel 152 based on the characteristic information (color and brightness of each pixel) to be displayed next and the history information held in the memory pipeline 142. Control is performed to generate drive pulses at intervals and display the next image on the EPD panel 152.

  The EPD controller 140 corresponds to the display control unit 40 in FIG. The history information held in the memory pipeline 142 corresponds to the history information 42 in FIG.

  The CPU 110 performs various processes of the operating system 131, the graphic system 132, and the handwriting application 133. In particular, in the present embodiment, when a predetermined input operation is performed on the input button 120 or the EPD panel 152, the CPU 110 operates according to an operation signal (an operation signal such as page feed or page return) corresponding to the input operation. The information on the contact position (pen input position, finger contact position, etc.) is received from the digitizer 154, and at least a part of the image displayed on the EPD panel 152 is drawn at high speed. The CPU 110 corresponds to the processing unit (CPU) 10 in FIG.

  Next, a method of drawing a handwritten character or figure by pen input on the display image of the EPD panel 152 (hereinafter referred to as “handwriting process”) will be described as an example, and a method of high-speed drawing processing in this embodiment will be described. To do.

2-2. Handwriting process 2-2-1. Overview of Handwriting Processing FIG. 9 is an explanatory diagram about the overview of handwriting processing in the present embodiment. As shown in FIG. 9, the user touches the surface of the EPD panel 152 with the pen 122 in a state where the image P including the page image and the input button 120 b is displayed on the display 150 (EPD panel 152) of the electronic book terminal 100. Suppose that the operation of writing the curve P is performed. When such an operation is performed, the CPU 110 first detects a pen input area of the EPD panel 152. Next, the CPU 110 overwrites the image data (hereinafter referred to as “trajectory image data”) PD of the trajectory corresponding to the curve P in the storage area corresponding to the pen input area of the frame buffer 135 by the handwriting application 133. As a result, the trajectory image data PD is overwritten on a part of the image data QD stored in the frame buffer 135 corresponding to the image Q (image consisting of the page image and the input button 120b) displayed on the EPD panel 152. The The trajectory image data PD written in the frame buffer 135 is input to the memory pipeline 142 of the EPD controller 140, and propagates from the input side to the output side of the memory pipeline 142 under the control of the EPD controller 140, and is transmitted to the EPD panel 152. A curve P is displayed. In FIG. 9, the thicker line indicates the flow of data for direct drawing by the handwriting application 133.

  In the present embodiment, the CPU 110 performs indirect drawing via the graphic system 132 in parallel with direct drawing by the handwriting application 133. Specifically, the CPU 110 requests the handwriting application 133 to redraw the input button 120b and draw the curve P in the pen input area via the library function of the graphic system 132. Next, the CPU 110 creates the image data of the input button 102 b and the locus image data PD corresponding to the curve P by the graphic system 132 and writes these data in the corresponding storage area of the frame buffer 135. The image data of the input button 102b and the trajectory image data PD written in the frame buffer 135 are input to the memory pipeline 142 of the EPD controller 140, and from the input side to the output side of the memory pipeline 142 under the control of the EPD controller 140. Propagate. As a result, the image of the input button 102b is displayed again on the EPD panel 152 and the curve P is displayed. In FIG. 9, the thin line indicates the flow of data for indirect drawing via the graphic system 132.

  As described above, in the present embodiment, by performing direct drawing without using the slow processing graphic system 132, a handwritten locus is drawn on the EPD panel 152 at high speed, and operability is improved. On the other hand, since the graphic system 132 updates the cache information stored in the cache 136 by performing indirect drawing via the graphic system 132, the consistency between the contents of the frame buffer 135 and the contents of the cache 136 can be maintained. it can. Note that, by this indirect drawing, a handwritten locus is written twice at the same position on the EPD panel 152. However, since the user cannot visually recognize that the handwritten locus has been written twice, there is no particular problem.

2-2-2. Hardware / Software Hierarchy FIG. 10 is a diagram showing the hardware / software hierarchy and the flow of pen input data in this embodiment.

  In the present embodiment, software executed by the CPU 110 is hierarchized in order of the operating system 131, the graphic system 132, and the handwriting application 133 from the lowest layer. The operating system 131 interfaces with the hardware. The graphic system 132 mediates data exchange between the operating system 131 and the handwriting application 133.

  When the user performs pen input (handwriting with a touch pen) on the EPD panel 152, the digitizer 154 detects the xy coordinates of the pen operation and sends the xy coordinates to the digitizer driver 131a of the operating system 131.

  The digitizer driver 131a receives the xy coordinates of the pen movement, analyzes the pen movement, and sends the pen movement information and the xy coordinates to the graphic system 132.

  The graphic system 132 receives the pen motion information and the xy coordinates, generates a pen motion event (pen touch, pen movement, and pen release events), and sends the pen motion event and the xy coordinates to the handwriting application 133.

  The handwriting application 133 receives the pen action event and the xy coordinates, divides the pen input trajectory information (handwriting information) into linearly approximated parts, calculates the coordinates of each straight line (starting point and end point coordinates), and stores the internal memory. The data is stored in 130 handwritten trajectory data.

  The handwriting application 133 sequentially reads the coordinates of each straight line from the handwritten trajectory data stored in the internal memory 130, creates image data of each straight line, and directly draws it in the frame buffer 135 without using the graphic system 132.

  Further, the handwriting application 133 issues a transfer command for transferring the image data of each straight line to the EPD controller 140 to the frame buffer driver 131b via the graphic system 132. Upon receiving this transfer command, the frame buffer driver 131b sends the image data of each straight line drawn in the frame buffer 135 to the EPD controller 140 with the highest priority. Then, under the control of the EPD controller 140, each straight line image is sequentially displayed on the EPD panel 152.

  Such a data flow realizes a high-speed display of a handwritten locus.

  On the other hand, when the handwriting application 133 detects the end of the pen input by the user based on the pen operation event, the handwriting application 133 sequentially reads the coordinates of each straight line from the handwriting locus data stored in the internal memory 130, and the graphic system 132 prepares. The graphic system 132 is requested to draw each straight line by calling the drawing function.

  In response to the drawing request, the graphic system 132 creates image data for each straight line and draws it in the frame buffer 135 via the frame buffer driver 131b of the operating system 131.

  The image data of each straight line drawn in the frame buffer 135 is sequentially sent to the EPD controller 140, and the image of each straight line is sequentially displayed on the EPD panel 152 under the control of the EPD controller 140.

  With such a data flow, although the handwriting trajectory is written twice on the EPD panel 152, the cache 136 is updated, and the consistency between the contents of the frame buffer 135 and the contents of the cache 136 is maintained.

  The operating system 131 (particularly, the digitizer driver 131a) corresponds to the input operation detection processing unit 12 in FIG. The handwriting application 133 corresponds to the application processing unit 14 in FIG. The graphic system 132 corresponds to the drawing processing unit 16 in FIG. The frame buffer driver 131b corresponds to the image data transfer processing unit 18 in FIG.

2-2-3. Flowchart of Handwriting Processing FIG. 11 is a diagram illustrating a flowchart of handwriting processing by the CPU 110 (handwriting application 133). As illustrated in FIG. 11, as control of the handwriting application 133, the CPU 110 receives a drawing event that permits drawing of a pen operation event or a handwriting locus from the graphic system 132, and performs processing according to each event.

  In the present embodiment, the graphic system 132 generates three types of pen motion events based on the pen motion information and the xy coordinates. That is, the graphic system 132 generates a pen touch event when detecting the moment when the pen 122 touches the surface of the EPD panel 152 and detects the moment when the pen 122 moves while touching the surface of the EPD panel 152. Generates a pen movement event, and if it detects the moment when the pen 122 leaves the surface of the EPD panel 152, it generates a pen release event.

  The CPU 110 (handwriting application 133) performs the pen touch event handler process when a pen touch event occurs (Y in S100) (S102), and the pen move event handler process when a pen move event occurs (Y in S104). When a pen release event occurs (Y in S108), the pen release event handler is processed (S110).

  Further, when a drawing event occurs (Y in S112), the CPU 110 (handwriting application 133) performs a drawing event handler process (S114).

  Then, the CPU 110 (handwriting application 133) repeatedly performs a process corresponding to the event that occurs each time each event occurs until an application end event occurs due to a user input operation or the like (Y in S116).

  Next, details of the pen touch event handler processing (S102), the pen movement event handler processing (S106), the pen release event handler processing (S110), and the drawing event handler processing (S114) by the CPU 110 (handwriting application 133). Will be described in turn. In the following description, before the pen touch event occurs, the image data QD is stored in the frame buffer 135 as shown in FIG. 12, and in any storage area of the cache 136 as shown in FIG. It is assumed that the same image data QD is stored.

  FIG. 14 is a diagram illustrating an example of a flowchart of the pen touch event handler process (the process of step S102 of FIG. 11) by the CPU 110 (handwriting application 133).

  As shown in FIG. 14, the CPU 110 (handwriting application 133) first performs area determination / correction processing of the xy coordinates based on the xy coordinates of the pen contact position received together with the pen touch event from the graphic system 132 (S200).

  Next, CPU110 (handwriting application 133) determines whether it is a handwritten coordinate (S202). The CPU 110 (handwriting application 133) receives not only the handwritten xy coordinates but also the xy coordinates of, for example, page operations (page feed, page return, page enlargement / reduction, etc.), so it is determined whether or not the coordinates are handwritten coordinates. There is a need. Since the user selects the handwriting mode or the page operation mode in advance by operating the input button 102 or the like, the CPU 110 (handwriting application 133) determines whether or not the received xy coordinates are handwritten coordinates from the current mode information. Can be determined.

  If the coordinates are handwritten coordinates (Y in S202), the CPU 110 (handwriting application 133) stores the current xy coordinates of the pen 122 as the handwriting start point (S204), ends the processing of the handler, and starts the graphics system 132 from the application 133. Control is returned to (S206).

  On the other hand, if the coordinates are not handwritten coordinates (N in S202), the CPU 110 (handwriting application 133) ends the processing of the handler without performing the processing in step S204, and returns control from the handwriting application 133 to the graphic system 132 ( S206).

  FIG. 15 is a diagram illustrating an example of a flowchart of the pen movement event handler process (the process of step S106 in FIG. 11) by the CPU 110 (handwriting application 133).

  As shown in FIG. 15, the CPU 110 (handwriting application 133) first performs area determination / correction processing of the xy coordinates based on the xy coordinates of the pen contact position received together with the pen movement event from the graphic system 132 (S300). .

  Next, the CPU 110 (handwriting application 133) determines whether or not the coordinates are handwritten (S302). If the coordinates are handwritten (Y in S302), the current xy coordinates of the pen 122 are stored as a handwriting end point (S302). S304).

  Next, the CPU 110 (handwriting application 133) writes a straight line starting from the xy coordinate in front of the pen 122 and ending at the current xy coordinate in the frame buffer 135 (S306, direct drawing process).

  Then, the CPU 110 (handwriting application 133) repeats the processes of S304 and S306 in units of straight lines until a pen release event occurs (N in S308). When a pen release event occurs (Y in S308), the handler process And the control is returned from the handwriting application 133 to the graphic system 132 (S310).

  On the other hand, if the coordinates are not handwritten coordinates (N in S302), the CPU 110 (handwriting application 133) ends the processing of the handler without performing the processes of steps S304 to S308, and controls the graphic system 132 from the handwriting application 133. Return (S310).

  FIG. 16 is a diagram illustrating an example of a flowchart of the pen release event handler process (the process of step S110 in FIG. 11) by the CPU 110 (handwriting application 133).

  As shown in FIG. 16, the CPU 110 (handwriting application 133) first performs area determination / correction processing of the xy coordinates based on the xy coordinates of the pen contact position received together with the pen release event from the graphic system 132 (S400). .

  Next, the CPU 110 (handwriting application 133) determines whether or not the coordinates are handwritten (S402). If the coordinates are handwritten (Y in S402), the current xy coordinates of the pen 122 are stored as a handwriting end point (S402). S404).

  Next, the CPU 110 (handwriting application 133) writes a straight line starting from the xy coordinate in front of the pen 122 and ending at the current xy coordinate in the frame buffer 135 (S406, direct drawing process).

  Next, the CPU 110 (handwriting application 133) adds the latest stroke to the handwritten data of the target page (S408).

  Next, the CPU 110 (handwriting application 133) requests the graphic system 132 to generate a drawing area update event (S410). In response to this request, the graphic system 132 causes the handwriting application 133 to generate a drawing event when drawing processing of the handwriting locus becomes possible.

  Then, the CPU 110 ends the processing of the handler and returns the control from the handwriting application 133 to the graphic system 132 (S412).

  FIG. 17 is a diagram illustrating an example of a flowchart of a direct drawing process (the process in step S306 in FIG. 15 and the process in step S406 in FIG. 16) by the CPU 110 (handwriting application 133).

  As shown in FIG. 17, the CPU 110 (handwriting application 133) first acquires the address of the update buffer from the frame buffer driver 135 (S500).

  Next, the CPU 110 (handwriting application 133) determines the absolute value (dx) of the distance in the x direction from the start point (xs, ys) and the end point (xe, ye) of the straight line, the absolute value (dy) of the distance in the y direction, x The direction code (sx) and the y direction code (sy) are calculated (S502).

  Next, the CPU 110 (handwriting application 133) initializes the drawing target point to x coordinate tx = xs, y coordinate ty = ys (S504).

  Next, the CPU 110 (handwriting application 133) determines the magnitude of dx and dy (S506), and if dx ≦ dy (N in S506), the corresponding position of the coordinates (tx, ty) of the frame buffer update buffer. The designated color and the designated thickness point are written in (S508), and it is determined whether or not the y coordinate ty of the drawing point matches the y coordinate ye of the end point (S510).

  If the y coordinate ty of the drawing point does not match the y coordinate ye of the end point (N in S510), the CPU 110 (handwriting application 133) updates the y coordinate ty of the drawing point to ty = ty + sy (S512).

  Next, the CPU 110 (handwriting application 133) calculates an update determination value of the x coordinate tx of the drawing point with respect to the y coordinate ty of the drawing point from the inclination of the straight line (S514).

  Next, when the x coordinate of the drawing point needs to be updated (Y in S516), the CPU 110 (handwriting application 133) updates the x coordinate tx of the drawing point to tx = tx + sx (S518).

  The CPU 110 (handwriting application 133) repeats the processing of steps S508 to S518 until the y coordinate ty of the drawing point matches the y coordinate ye of the end point (N in S510). End the process.

  On the other hand, if dx> dy is determined as a result of the determination of dx and dy (S506) (Y in S506), the CPU 110 (handwriting application 133) moves to the corresponding position of the coordinates (tx, ty) of the frame buffer update buffer. The point of the designated color and the designated thickness is written (S520), and it is determined whether or not the x coordinate tx of the drawing point matches the x coordinate xe of the end point (S522).

  If the x coordinate tx of the drawing point does not match the x coordinate xe of the end point (N in S522), the CPU 110 (handwriting application 133) updates the x coordinate tx of the drawing point to tx = tx + sx (S524).

  Next, the CPU 110 (handwriting application 133) calculates an update determination value of the y coordinate ty of the drawing point with respect to the x coordinate tx of the drawing point from the inclination of the straight line (S526).

  Next, if the y coordinate of the drawing point needs to be updated (Y in S528), the CPU 110 (handwriting application 133) updates the y coordinate ty of the drawing point to ty = ty + sy (S530).

  The CPU 110 (handwriting application 133) repeats the processing of steps S520 to S530 until the x coordinate tx of the drawing point coincides with the x coordinate xe of the end point (N in S522). End the process.

  FIGS. 18A to 18C show an example of how the image data stored in the frame buffer 135 is changed by the direct drawing processing of the CPU 110 (handwriting application 133). FIG. 18A shows the image data after the first several straight line parts (parts approximated by a straight line) of the handwriting locus P are written in the frame buffer 135 by the direct drawing process in step S306 of FIG. Show. FIG. 18B shows image data after several straight line parts (parts approximated by a straight line) following the handwritten locus P are further written in the frame buffer 135 by the direct drawing process in step S306 of FIG. Is shown. FIG. 18C shows the image data after the last straight line portion (the straight line approximated portion) of the handwriting locus P is written in the frame buffer 135 by the direct drawing process in step S406 of FIG. .

  FIG. 19 is a diagram illustrating an example of a flowchart of the process of the drawing event handler (the process of step S114 in FIG. 11) by the CPU 110 (handwriting application 133). As the drawing event, in addition to the drawing event generated by the graphic system 132 by the processing of step S410 in FIG. 16, the graphic system 132 responds to input operations such as page feed, page return, page enlargement / reduction, and image deletion. Some drawing events occur.

  As shown in FIG. 19, the CPU 110 (handwriting application 133) first draws a graphic component (such as the input button 102) other than handwriting by a standard function call of the graphic system 132 (S600).

  Next, the CPU 110 (handwriting application 133) reads handwritten locus data of the target page from the internal memory 130 (S602).

  Then, the CPU 110 (handwriting application 133) draws all handwriting trajectories of the target page by a standard function call of the graphics system 132 (S604, indirect drawing processing), ends the processing of the handler, and the graphics system 132 from the handwriting application 133. Control is returned to (S606).

  FIG. 20 is a diagram illustrating an example of a flowchart of indirect drawing processing (processing in step S604 in FIG. 19) by the CPU 110 (handwriting application 133).

  As shown in FIG. 20, the CPU 110 (handwriting application 133) first initializes the start and end points of a straight line with the first handwriting stroke (S700).

  Next, the CPU 110 (handwriting application 133) calls a straight line drawing function of the graphic system 132 and draws it with the current coordinates, color, and line thickness (S702).

  If the handwritten stroke drawn in step S702 is not the final handwritten stroke (N in S704), the CPU 110 (handwriting application 133) updates the coordinate value to the next handwritten stroke (S706), and performs the process in step S702. If it is the last handwritten stroke (Y in S704), the process is terminated.

  FIG. 21 shows an example of image data stored in the cache 136 by the indirect drawing process in step S604 of FIG.

  In the present embodiment, while the image data in the frame buffer 135 changes from FIG. 18A to FIG. 18C, the image data in the cache 136 does not change, and remains as the image data shown in FIG. is there. Accordingly, the consistency between the contents of the frame buffer 135 and the contents of the cache 136 is temporarily lost, but the load on the CPU 110 can be reduced because there is no processing for rewriting the cache 136 in units of line segments. The handwriting application 133 requests the graphic system 132 to perform batch drawing of handwritten trajectory data when the pen release event occurs, that is, at the timing when the handwriting operation is interrupted, and the indirect drawing process corresponding to this is performed. The image data in the cache 136 (FIG. 21) matches the image data in the frame buffer 135 (FIG. 18C), and the consistency is restored.

  As described above, according to the electronic book terminal 100 (image processing apparatus 1) of the present embodiment, the handwriting application 133 causes the graphic system 132 to be directly drawn according to a predetermined event based on an input operation. By writing the image data in the frame buffer 135 without intervention, the drawing on the electronic paper 52 can be speeded up. Therefore, according to the present embodiment, the electronic book terminal 100 (image processing apparatus 1) that is easy to use for the user and is excellent in operability is compensated for the drawbacks of electronic paper that is inferior in display speed as compared with a liquid crystal display (LCD). Can be provided.

  Further, according to the electronic book terminal 100 (image processing apparatus 1) of the present embodiment, the graphic system 132 updates the cache 136 when the handwriting application 133 performs indirect drawing processing, so that the frame buffer 135 and the cache 136 are updated. It is possible to maintain consistency.

  In addition, according to the electronic book terminal 100 (image processing apparatus 1) according to the present embodiment, it is not necessary to draw a straight line of a handwritten trajectory by the graphic system 132, and heavy processing by the CPU 110 can be avoided. Electric power can be reduced.

  Also, according to the electronic book terminal 100 (image processing apparatus 1) according to the present embodiment, high compatibility of the application development / execution environment of the graphic system 132 is maintained while avoiding performance degradation due to the overhead of the graphic system 132. can do.

  Further, according to the electronic book terminal 100 (image processing apparatus 1) according to the present embodiment, even if the graphic system 132 does not have a function for performing only the update of the cache 136 without performing drawing, The cache 136 can be reliably and easily updated by the handwriting application 133 calling the drawing function.

  Further, according to the electronic book terminal 100 (image processing apparatus 1) according to the present embodiment, every time the handwriting application 133 writes image data to the frame buffer 135, the image data is transferred to the EPD controller 140. Since the handwritten locus is displayed immediately following the input operation, the operability can be improved.

  Further, according to the electronic book terminal 100 (image processing apparatus 1) according to the present embodiment, the cache 136 needs to be updated only once by the graphic system 132 after a series of handwriting input operations is completed. The load can be reduced.

  Also, according to the electronic book terminal 100 (image processing apparatus 1) according to the present embodiment, it is possible to speed up drawing and optimize the EPD controller 140 without optimizing the graphic system 132. In particular, according to the electronic book terminal 100 (image processing apparatus 1) according to the present embodiment, the EPD controller 140 manages the history information by the memory pipeline 142, so that the drive pulse according to the characteristics of the electronic paper 152 is applied. Complex display control such as control of the number of times can be performed at high speed, and the load on the CPU 110 can be reduced. Further, since the handwriting application 133 does not need to be conscious of display control in the direct drawing process, the application program can be easily developed.

3. Other Image Processing Apparatus FIGS. 22A and 22B show examples of the image processing apparatus 1 of the present embodiment other than the electronic book terminal 100. FIG.

  FIG. 22A is an external view of the smartphone 500. The smartphone 500 includes a case 502. Three operation buttons 511, 512 and 513 are provided on the front surface of the case 502. In addition, a display unit 504 including electronic paper such as an EPD panel is provided on the front surface of the case 502, and various types of information (images) are displayed on the surface of the electronic paper. In response to a predetermined operation by a pen (not shown) or operation buttons 511, 512, 513, etc., a direct drawing process from the built-in CPU (application) to the frame buffer is performed, and on the surface of the electronic paper of the display unit 504, An image corresponding to each operation is displayed at high speed.

  FIG. 22B is an external view of the wristwatch 600. The wristwatch 600 includes a case 602 and a pair of bands 603 connected to the case 602. Two operation buttons 611 and 61 are provided on the side surface of the case 602. A display unit 604 including electronic paper such as an EPD panel is provided on the front surface of the case 602, and various information (images) are displayed on the surface of the electronic paper in addition to time. In accordance with a predetermined operation using a pen (not shown) or the operation buttons 611, 612, a built-in CPU (application) performs direct drawing processing on the frame buffer, and each operation is performed on the surface of the electronic paper of the display unit 604. The image corresponding to is displayed at high speed.

  In addition to this, as the image processing apparatus 1 of the present embodiment, for example, an electronic signboard (digital signage), a personal computer, a mobile phone, a digital still camera, a television, a video camera, a video tape recorder, a car navigation device, An electronic notebook, an electronic game machine, etc. are mentioned.

4). The present invention is not limited to this embodiment, and various modifications can be made within the scope of the present invention.

[Modification 1]
In the present embodiment, in the processing of the handwriting application 133, data in the cache 136 is updated until a pen release event occurs. However, depending on the system, a pen touch event occurs and a pen release event occurs. During this time, the frame buffer may be updated by another task. Therefore, in the pen movement event handler process, an event involving an update of the frame buffer 135 is detected, and the graphic system 132 is requested to update the cache information before the frame buffer 135 is updated. Also good.

  FIG. 23 is a diagram illustrating an example of a flowchart of the pen movement event handler process (the process of step S106 in FIG. 11) by the CPU 110 (handwriting application 133) in the first modification. In FIG. 23, the same processes as those in FIG. 15 are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIG. 23, after performing the direct drawing process of step S306, the CPU 110 (handwriting application 133) determines whether or not an event accompanied by an update of the frame buffer 135 has occurred (S307a).

  The CPU 110 (handwriting application 133) then requests the graphic system 132 to generate a drawing area update event when an event accompanied by an update of the frame buffer 135 occurs (Y in S307a). In response to this request, the graphic system 132 causes the handwriting application 133 to generate a drawing event when drawing processing of the handwriting locus becomes possible.

  The CPU 110 (handwriting application 133) receives this drawing event and performs the indirect drawing process in step S604 in the drawing event handler process shown in FIG. 19, whereby the image data in the cache 136 is updated.

  In this way, even if an event accompanied by an update of the frame buffer 135 occurs while a handwriting operation is being performed, the consistency between the contents of the frame buffer 135 and the contents of the cache 136 can be maintained.

  Note that when the CPU 110 (handwriting application 133) detects an event involving the update of the frame buffer 135, it is better to make an update request (request to generate an update event of the drawing area) to the graphic system 132 as soon as possible. For example, this update request may be made by interrupt processing.

[Modification 2]
In the present embodiment, the handwritten trajectory is divided into linear unit data and direct drawing processing is performed for each straight line unit. For example, the handwritten trajectory is divided at regular time intervals, and the direct drawing processing is performed at regular time intervals. You may deform | transform so that.

[Modification 3]
In the present embodiment, the high-speed drawing method of the present invention has been described by taking handwriting processing as an example. However, the present invention is not limited to handwriting processing, but is not limited to page turning, page returning, page enlargement or reduction, object display or deletion. It can be applied to various processes such as.

  The above-described embodiments and modifications are merely examples, and the present invention is not limited to these. For example, it is possible to appropriately combine each embodiment and each modification.

  The present invention includes configurations that are substantially the same as the configurations described in the embodiments (for example, configurations that have the same functions, methods, and results, or configurations that have the same objects and effects). In addition, the invention includes a configuration in which a non-essential part of the configuration described in the embodiment is replaced. In addition, the present invention includes a configuration that exhibits the same operational effects as the configuration described in the embodiment or a configuration that can achieve the same object. Further, the invention includes a configuration in which a known technique is added to the configuration described in the embodiment.

DESCRIPTION OF SYMBOLS 1 Image processing apparatus, 10 process part (CPU), 12 input operation detection process part, 14 application process part, 16 drawing process part, 18 image data transfer process part, 20 operation part, 30 memory | storage part, 32 application program, 34 data File, 36 frame buffer, 38 cache, 40 display control unit, 42 history information, 50 display unit, 52 electronic paper, 54 contact position detection unit, 60 sound output unit, 70 communication unit, 100 electronic book terminal, 110 CPU, 120 120a, 120b Input button, 130 Internal memory, 131 Operating system, 131a Digitizer driver, 131b Frame buffer driver, 132 Graphics system, 133 Handwritten application, 134 Content file, 135 frames Uffer, 136 cache, 140 EPD controller, 142 memory pipeline, 150 display, 152 EPD panel, 154 digitizer, 160 speaker, 170 USB interface, 195, 195A, 195B pixel electrode, 197 common electrode, 200, 200A, 200B pixel, 208 driving TFT, 209 low potential power line (Vss), 210 high potential power line (Vdd), 215 common electrode wiring (Vcom), 221 scanning line driving circuit, 222 data line driving circuit, 224 common power source modulation circuit, 226 scanning line, 228 data line, 230 a latch circuit, 240 a switch circuit, 251 a first pulse signal line _(S 1), 252 second pulse signal line _(S 2), 260 microcapsules, 266 black particles, 267 white 270 element substrate, 271 counter substrate, 272 electrophoretic element, 280 drive electrode layer, 282 common electrode layer, 290 electrophoretic display layer, 500 smartphone, 502 case, 504 display unit, 511, 512, 513 operation button, 600 Wristwatch, 602 case, 603 band, 604 display unit, 611, 612 operation buttons

Claims (11)

A display unit equipped with electronic paper;
A storage unit including a frame buffer for storing image data;
A display control unit that performs control to display an image corresponding to the image data written in the frame buffer on the electronic paper of the display unit;
An input operation detection processing unit for detecting an input operation;
An application processing unit that operates based on an application program and performs processing according to the input operation;
A drawing processing unit that operates based on a program, generates image data according to a drawing request using cache information for the frame buffer, and performs processing of writing the image data in the frame buffer;
The application processing unit
In response to a predetermined event based on the input operation, image data is written to the frame buffer, a request for updating the cache information is performed,
The drawing processing unit
An image processing apparatus that updates the cache information based on image data written in the frame buffer by the application processing unit in response to the update request. In claim 1,
The application processing unit
An image processing apparatus that performs the drawing request for generating the same image data as the image data written in the frame buffer as the update request. In claim 1 or 2,
An image data transfer processing unit that performs processing for transferring the image data written in the frame buffer to the display control unit;
The application processing unit
Each time image data is written to the frame buffer, a transfer request for transferring the image data to the display control unit is performed,
The image data transfer processing unit
An image processing apparatus that transfers image data written in the frame buffer to the display control unit in response to the transfer request. In any one of Claims 1 thru | or 3,
The application processing unit
An image processing apparatus that detects a timing at which the input operation is interrupted based on a detection result of the input operation detection processing unit, and makes the update request at a timing at which the input operation is interrupted. In any one of Claims 1 thru | or 4,
The application processing unit
An image processing apparatus that detects an event associated with an update of image data written in the frame buffer and makes the update request before the image data is updated. In any one of Claims 1 thru | or 5,
The display unit further includes a contact position detection unit that detects a contact position with respect to the electronic paper,
The input operation detection processing unit
Based on the detection result of the contact position detection unit, the input operation on the electronic paper is detected,
The application processing unit
When the input operation on the electronic paper is detected, based on the information on the contact position detected by the contact position detection unit, image data representing a locus on which the input operation has been performed is generated, and the image data is An image processing device that writes to the frame buffer. In any one of Claims 1 thru | or 6,
The display control unit
The history information of the image data corresponding to the image displayed on the electronic paper of the display unit is stored, and the image corresponding to the next image data is stored based on the history information based on the display characteristics of the electronic paper. An image processing apparatus that performs control to be displayed on electronic paper. In any one of Claims 1 thru | or 7,
The image processing apparatus, wherein the electronic paper of the display unit displays an image by an electrophoresis method. A display control method for an image processing apparatus, comprising: an input operation detection processing unit for detecting an input operation; a display unit including electronic paper; and a storage unit including a frame buffer for storing image data.
An application processing step for performing processing according to the input operation based on an application program;
Based on the program, using the frame buffer cache information, generating image data according to the drawing request, and writing the image data in the frame buffer,
A display control step for performing control to display an image corresponding to the image data written in the frame buffer on the electronic paper of the display unit,
In the application processing step,
In response to a predetermined event based on the input operation, image data is written to the frame buffer, a request for updating the cache information is performed,
In the drawing process step,
A display control method for an image processing apparatus, wherein the cache information is updated based on image data written in the frame buffer in the application processing step. An input operation detection processing unit for detecting an input operation, a display unit provided with electronic paper, a storage unit including a frame buffer for storing image data, and an image corresponding to the image data written in the frame buffer A display control unit that performs control to display on the electronic paper of the display unit, operates based on a program, generates image data according to a rendering request using the cache information for the frame buffer, and the image data A program that is executed in an image processing apparatus including a drawing processing unit that performs processing for writing the data into the frame buffer,
Operates based on an application program, causes the computer to function as an application processing unit that performs processing according to the input operation,
The application processing unit
A program for writing image data to the frame buffer in response to a predetermined event based on the input operation, and making an update request for the cache information to the drawing processing unit.   A computer-readable information storage medium in which the program according to claim 10 is stored.