JP5321487B2 - Display device and image display method - Google Patents

Description

  The present invention relates to a display device and an image display method for displaying an image on a screen.

  2. Description of the Related Art Conventionally, for example, a liquid crystal display device has mainly a horizontal display screen for displaying a horizontal image having a long aspect ratio in the horizontal direction and a vertical image having a long aspect ratio in the vertical direction. Those having a vertically long display screen for display (for example, see Patent Document 1 below) are manufactured.

  FIG. 6A is a diagram illustrating an example of a liquid crystal display device having a vertically long display screen for displaying a vertically oriented image having an aspect ratio that is long in the vertical direction. The liquid crystal display device 50 has a vertically long display screen 51. As a normal usage pattern, an image P1 having a vertically long aspect ratio is displayed on the display screen 51. At this time, as shown in FIG. 6B, the next image data P2, which is the image data of the image to be displayed next, is one line in the horizontal direction (one line at a time) and sequentially in the vertical direction. It is written in the RAM 52. Similarly, the gate scan is performed one line at a time in the horizontal direction from the uppermost end, and is sequentially performed in the vertical direction.

  Therefore, as shown in FIG. 6C, in the RAM, if the remaining data is rewritten prior to the gate scan, all the data of one line read along with the gate scan is a component of the same image data. Therefore, no tearing occurs.

JP 2000-171830 A

  However, the liquid crystal display device 50 for exclusively displaying such a vertically oriented image having a long aspect ratio in the vertical direction is used as it is, and a long aspect ratio in the horizontal direction shown in FIG. It is assumed that it is used for an apparatus that displays a landscape image P3. In this case, as shown in FIG. 7B, the next image data P4 is written to the RAM 52 in the vertical direction from the right end line by line (line by line) and sequentially in the left direction. Become. However, as in the case of FIG. 6, the gate scan is performed for each line in the horizontal direction and sequentially in the vertical direction (FIGS. 6B and 6C). As a result, as shown in FIG. 7C, tearing T composed of diagonal lines occurs.

That is, when the case is described in which by the writing to the gate scan and RAM simultaneously, when reading of the image data of one line, as shown in FIG. 8 (a), the image data components DO1 before in one line next The image data component DN1 is mixed. When reading two lines of image data, as shown in FIG. 8B, the previous image data component DO2 and the next image data component DN2 are mixed in one line, and three lines of image data are read. At the time, as shown in FIG. 8C, the component DO3 of the previous image data and the component DN3 of the next image data are mixed in one line. As shown in d), the component DO4 of the previous image data and the component DN4 of the next image data are mixed in one line.

  Therefore, on the display screen 51, diagonal line tearing T composed of diagonal line segments is formed on the boundary line between the components DO1, DO2,... Of the previous image data and the components DN1, DN2,. It will occur.

  The present invention has been made in view of such conventional problems, and uses a display screen for displaying a portrait image having an aspect ratio that is long in a predetermined direction as it is, and is long in other directions. An object is to provide a display device and an image display method that do not cause tearing even when an image having an aspect ratio is displayed.

To solve the above problems, an aspect of the display device of the present invention includes a plurality of pixels arranged in horizontal and vertical directions, have a long aspect ratio to the longitudinal direction, in the transverse direction A display screen unit having a smaller number of pixel columns along the vertical direction than the number of pixel rows along the memory, and a storage area having the same number of rows as the number of pixel rows and the same number of columns as the number of pixel columns A storage unit for storing image data representing an image; a transfer unit for transferring the image data written in the storage unit line by line to the display screen unit; and the image data transferred by the transfer unit Based on the above, each time the transfer unit transfers the image data of one row, the driving unit that drives the display screen unit to display the next image data representing the image to be displayed next on the display screen unit, Each column is less than or equal to the maximum number of rows that do not reach the transferred row , And a writing means for writing in the storage unit, and wherein the.

To solve the above problems, one aspect of the image display method of the display device of the present invention includes a plurality of pixels arranged in horizontal and vertical directions, have a long aspect ratio to the longitudinal direction, The number of pixel columns along the vertical direction is smaller than the number of pixel rows along the horizontal direction, the display screen unit, the same number of rows as the number of pixel rows, and the same number of columns as the number of pixel columns has a storage area having, e Bei a storage unit, a storing image data representing an image, transferring the image data written in the storage unit on the display screen unit line by line, is the transfer the Based on the image data, the display screen unit is driven to display, and each time the image data in one row is transferred, the next image data representing the image to be displayed next on the display screen unit is transferred. The maximum number of rows that do not reach a row is equal to or smaller than the maximum number of rows in each storage unit. Burn them, characterized in that.

  According to the present invention, a display screen for displaying a portrait image having a long aspect ratio in a predetermined direction is used as it is, and a landscape image having a long aspect ratio in another direction is displayed. Even if it exists, an image can be displayed without causing tearing.

It is a block diagram which shows an example of the circuit structure of the liquid crystal display device concerning one embodiment of this invention. It is a circuit diagram which shows the basic composition of the liquid crystal panel of TFT-LCD. It is a flowchart which shows operation | movement of a TG circuit. It is a transition diagram which shows operation | movement of this Embodiment. FIG. 5 is a transition diagram following FIG. 4. It is a figure which shows the liquid crystal display device which has a portrait display screen for displaying the portrait image which has an aspect ratio long in the vertical direction, and its display example. It is a figure which shows the case where the horizontal image which has a long aspect ratio in a horizontal direction is displayed as it is using the liquid crystal surface device for displaying only the vertical image which has a long aspect ratio in the vertical direction. It is a figure which shows a tearing generation | occurrence | production situation.

  Hereinafter, embodiments of the present invention will be described. FIG. 1 is a diagram illustrating an example of a circuit configuration of a liquid crystal display device 1 according to the present embodiment. The liquid crystal display device 1 includes a liquid crystal display screen unit 2, a gate driver 3, a source driver 4, a RAM 5, a data I / O 6, a timing generation circuit (hereinafter referred to as a TG circuit 7), and a control I / O 8.

  The liquid crystal display screen unit 2 has a long aspect ratio in the vertical direction in order to exclusively display a vertical image having a long aspect ratio in the vertical direction. The liquid crystal display screen unit 2 displays an image in response to signals supplied from the gate driver 3 and the source driver 4. In the present embodiment, the TFT-LCD (active matrix drive TFT ( A thin film transistor type liquid crystal panel) is used. A TFT-LCD is a panel in which thin film transistors (TFTs) and liquid crystal pixels are arranged in an array on a glass substrate.

That is, the liquid crystal display screen unit 2 mainly includes an opposing glass substrate, a color filter, and a backlight, and scanning lines (gate lines) in the horizontal direction on one glass substrate are in the vertical direction. data lines being respectively arranged, are arranged each pixel electrode at the intersection corresponding to the position of the gate lines and data lines, and a common electrode and a color filter to the glass substrate is formed. Liquid crystal is filled between the glass substrates, and the arrangement of the liquid crystal between the pixel electrode and the common electrode is changed according to the signal (voltage) supplied from the gate line and the data line, and the light incident from the backlight is changed. Controls the amount of transmission. In addition, red (R), green (G), and blue (B) color filters are arranged on the other glass substrate, showing the shade of color according to the amount of light transmitted through each pixel, and various combinations thereof Realize the display of various colors.

  The data I / O 6 outputs an externally input signal to the RAM 5, and the control I / O 8 outputs an externally input display signal and control signal to the TG circuit 7, The control signal output from 7 is output to the outside.

FIG. 2 is a circuit diagram showing a basic configuration of the liquid crystal display screen 2, that is, the TFT-LCD. A position corresponding to the intersection of the gate line 10 and data line 11, a TFT 12, a pixel electrode connected to the drain electrode D of the TFT, the pixel capacitor 14 composed of a liquid crystal sandwiched between the common electrode 13, and the insulating film An auxiliary capacitor 15 including an auxiliary capacitor electrode connected to the common electrode 13 is disposed, the gate line 10 is connected to the gate electrode G of the TFT 12, and the data line 11 is connected to the source electrode S of the TFT 12. When a pulse voltage (scanning signal) is sequentially applied to the gate line 10, a voltage is applied to the gate electrode G of the TFT 12 connected thereto, and a channel is formed between the source electrode S and the drain electrode D of the TFT 12. At the same time, when a signal voltage is applied from the data line 11, a current flows between the source and drain of the TFT 12, and charges are accumulated in the pixel capacitor 14 and the auxiliary capacitor 15. When the scanning of one line is completed and the voltage applied to the gate of the TFT 12 is interrupted, the TFT 12 is turned off, the current flow between the source and the drain is stopped, and the charge is held in the pixel capacitor 14 and the auxiliary capacitor 15. . A liquid crystal sandwiched between the common electrode and the pixel electrode, and thus changing the sequence voltage is applied by the charge stored in the pixel capacitor 14. Thus, in the TFT-LCD, the TFT serves as a switching element to control the voltage applied to the pixel.

  The gate driver 3 sequentially applies scanning signals to the individual gate lines 10 of the liquid crystal display screen unit 2. Specifically, it has a shift register, applies a scanning signal to each gate line at a timing instructed by the TG circuit 7, and sequentially applies the scanning signal to all the gate lines 10.

  The source driver 4 supplies a signal voltage to each data line of the liquid crystal display screen unit 2. Specifically, it has a shift register, and at a timing designated by the TG circuit 7, a signal voltage generated based on image data transferred from a RAM 5 in which image data is stored as described later is applied to the data line. Apply. The TG circuit 7 calculates the address of data read from the RAM 5 in response to the shift of the gate line and the data line by the gate driver 3 and the source driver 4. Then, at the timing of reading data, the data is read from the RAM 5 and transferred to the source driver 4. In addition, the set value of each color pixel is applied from the TG circuit 7 to the source driver 4 as a display data signal.

The RAM 5 has a storage area corresponding to each pixel of the liquid crystal display screen unit 2, writes a display data signal input from the data I / O 6 to an address specified by the TG circuit 7, and specifies from the TG circuit 7. The display data signal at the address to be read is read and output to the source driver 4. Note that the RAM 5 has, for example, 132 × 176 × 16 (bits) when the liquid crystal display screen unit 2 has a number of dots of 132 × 176 (1 dot = 3 pixels of red, green, and blue). Has storage capacity. The breakdown of 16 bits is 5 bits for red and blue, and 6 bits for green. That is, for the red and blue, up to 2 5 gradation to allow the representation, for the green, is made possible representation of up to 2 6 tone.

  The TG circuit 7 generates timing pulses to instruct the driving timing of the gate driver 3 and the source driver 4, and performs processing such as controlling the timing of the read / write operation of the RAM 5. Also, processing such as reading to the RAM 5 and address calculation processing at the time of writing is performed.

  Next, in the liquid crystal display device 1 for displaying a portrait image having a long aspect ratio in the vertical direction according to the above configuration, an operation in the case of displaying a landscape image having a long aspect ratio in the horizontal direction. Will be described. Therefore, in the following description, image data represents a landscape image, and image data of an image already displayed on the liquid crystal display screen unit 2 is referred to as image data PA, and an image to be displayed next to the current image data PA. Is called the next image data PB, and the image data to be displayed next to the image based on the next image data PB is called the image data PC one after another.

  FIG. 3 is a flowchart showing the operation of the TG circuit 7. 4 and 5 are diagrams showing the operation of the present embodiment, where the left column (column (a)) shows the storage state of the RAM 5 over time, and the right column (column (b)) corresponds. The display state of the liquid crystal display screen unit 2 to be displayed is shown with time. In FIG. 4, (1 a) shows a state in which all data of the next image data PB has been stored in the RAM 5.

  In this state, as shown in the flowchart of FIG. 3, the TG circuit 7 sets a variable r for designating the read line address of the RAM 5 to “1” (step S1), and uses this variable r to set the scan position (first line). ) Is specified. Further, the TG circuit 7 sets the variable g for storing the gate line address to “1” (step S2), and outputs an instruction to apply the scanning signal to the first gate line to the gate driver 3.

  On the other hand, as shown in FIG. 4 (1 b), the liquid crystal display screen unit 2 holds the current image data PA, but the instruction to apply the scanning signal to the first gate line by the TG circuit 7 described above. As a result, the first line of the next image data PB is in a writing state.

  Then, the TG circuit 7 increments the variable r for designating the read line address of the RAM 5 to “2” (step S3), and by this variable r = 2, as shown in FIG. Specify the second line). Further, the TG circuit 7 increments the variable g for storing the gate line address to “2” (step S4), and outputs an instruction to apply the scanning signal to the second gate line to the gate driver 3. In response to an instruction to apply a scanning signal to the second gate line by the TG circuit 7, the second line of the next image data PB is in a writing state as shown in FIG. 4 (2b).

  The TG circuit 7 has an initial value of “0” (see step S8 described later), and increments the variable w for designating the read line address of the RAM 5 to “1” (step S5). Specify a line. At this time, the TG circuit 7 writes the image data PC one after another by limiting the number of lines to be written based on the variable r-1 using the variable r (step S6).

  That is, since the variable r = 2 and the variable w = 1 at the present time, the column line of the RAM 5 indicated by the variable w = 1 is the first column. Further, since the variable r-1 = 1, the number of lines written to the RAM 5 is limited to one line. Therefore, the image data PC is written one after another up to the first row in the RAM 5.

  At this time, the reading of the next image data PB in the first row of the RAM 5 has been completed. Therefore, as shown in FIG. 4 (2a), in the state where the scan position is the second line, the image data PC is written one after another up to one column on the first line where the reading of the next image data PB is completed. It is.

  On the other hand, as shown in FIG. 4 (2b), the liquid crystal display screen unit 2 holds the current image data PA in the pixel, but the TG circuit 7 mentioned above applies a scanning signal to the second gate line. As a result, the second line of the next image data PB is in a writing state.

  Next, the TG circuit 7 performs an operation of checking whether or not the value of the variable w has reached m which is the total number of columns in the RAM 5 (step S7). If w = m is not satisfied, the TG circuit 7 performs an operation as to whether or not the value of the variable r has reached the total gate number n which is the total number of gate lines (step S8), and r = n. If not, the operation from step S3 is repeated.

  That is, the TG circuit 7 increments the variable r designating the read line address of the RAM 5 to “3” (step S3), and the variable r = 3 causes the scan position (3a) as shown in FIG. Specify the third line). Further, the TG circuit 7 increments the variable g for storing the gate line address to “3” (step S4), and outputs an instruction to apply the scanning signal to the third gate line to the gate driver 3. In response to an instruction to apply a scanning signal to the third gate line by the TG circuit 7, the third line of the next image data PB is being written on the liquid crystal display screen unit 2 as shown in FIG. 4 (3b). .

  Further, the TG circuit 7 increments the variable w for designating the read line address of the RAM 5 to “2” (step S5), and designates the write column line of the RAM 5. At this time, the TG circuit 7 limits the number of lines to be written based on the variable r-1 using the variable r and writes the image data PC to the RAM 5 one after another (step S6).

  That is, since the variable r = 3 and the variable w = 2 at the present time, the column line of the RAM 5 indicated by the variable w = 2 is the second column. Since the variable r-1 = 2, the image data PC is written one after another up to the second row in the RAM 5 and up to the second row. Therefore, as shown in FIG. 4 (3a), in the state where the scan position is the third line, the image data PC is successively written only up to two columns on the second line where the reading of the next image data PB has been completed. It is.

  On the other hand, as shown in FIG. 4 (3 b), the liquid crystal display screen unit 2 holds the current image data PA in the pixel, but the instruction to apply the scanning signal to the third gate line by the TG circuit 7 described above. As a result, the third line of the next image data PB is being written.

  If w = m is not satisfied and r = n is not satisfied, the TG circuit 7 repeats the operation from step S3.

  Therefore, as shown in FIG. 4 (4a), the scan position (fourth line) is designated, and an instruction to apply the scan signal to the fourth gate line is output to the gate driver 3, and FIG. As shown in FIG. 4, the fourth line of the next image data PB is in a writing state. Further, since the variable r-1 = 3, the image data PC is successively written up to the third row and the third row of the RAM 5. Therefore, as shown in FIG. 4 (4a), in the state where the scan position is the fourth line, the image data PC is successively written in the RAM 5 only up to three columns in the third line.

  Also, as shown in FIG. 4 (5a), the scan position (fifth line) is designated, and an instruction to apply a scan signal to the fifth gate line is output to the gate driver 3, as shown in FIG. 4 (5b). As described above, the fifth line of the next image data PB is in a writing state. At this time, since the variable r−1 = 4, the image data PC is successively written to the fourth column of the RAM 5 and up to the fourth row. Therefore, as shown in FIG. 4 (5a), in the state where the scan position is the fifth line, the image data PC is successively written only up to four columns on the fourth line.

  In this way, when writing is performed so as not to touch the read line in the RAM 5, the value of the variable w eventually becomes m, which is the total number of columns in the RAM 5 (step S7).

  That is, since the RAM 5 stores image data (data for each pixel) of a vertically oriented image having an aspect ratio that is long in the longitudinal direction, the RAM 5 includes an area having a smaller number of columns than the number of rows. Therefore, when stepping one by one, the variable w that designates the column of the RAM 5 becomes equal to or larger than the total number m of columns of the actual RAM 5, as indicated by point P in FIG. 5 (6a), and the column is designated by the variable w. Is impossible.

  Therefore, the TG circuit 7 performs an operation of resetting the variable w to “0” when w = m (step S7: YES) (step S9). Thereafter, the TG circuit 7 repeats the operation from step S3.

  Therefore, the writing of the α portion shown in FIG. 5 (6a) is performed in the RAM 5 until w = m. When w = m, w = 0 is reset in step S9, and the operation from step S3 is repeated thereafter. Therefore, the operation from step S3 after w = m is reset to w = 0. As a result, the β portion shown in FIG. 5 (6a) is written.

  Further, when the line-by-line reading from the RAM 5 is sequentially performed, the value of the variable r reaches the total gate number n which is the total number of gate lines (step S8). Thereby, the reading of the next image data PB up to the last line is completed, and the entire image based on the next image data PB including the last line is displayed on the liquid crystal display screen unit 2 as shown in FIG. 5 (6b). Will be.

  However, even if all of the next image data PB is read from the RAM 5 and the display of the entire image on the liquid crystal display screen unit 2 based on this is completed as described above, the image data PC is successively displayed as shown in FIG. Only the α part and the β part are written in the RAM 5, and the data of the γ part has not yet been written.

  Therefore, the TG circuit 7 performs the operation of step S10 subsequent to the operation of step S8, transfers the remaining data of the image data PC to the RAM 5 one after another, and writes the remaining data. Thereby, as shown in FIG. 5 (7a), writing of the image data PC into the RAM 5 can be completed. Thereafter, the TG circuit 7 repeats the operation from step S1 described above.

  Therefore, according to the present embodiment, the liquid crystal display screen unit 2 for displaying a portrait image having a long aspect ratio in the vertical direction is used as it is, and the landscape direction having a long aspect ratio in the horizontal direction is used. Even when an image is displayed, the image data can be read from the RAM 5 without mixing image data that are temporally different from each other. Therefore, it is possible to prevent tearing caused by reading and transferring to the liquid crystal display screen unit 2 in a state where image data that precede and follow are mixed.

  In the present embodiment, every time the next image data PB is read from the RAM 5 and transferred to the liquid crystal display screen unit 2 by one line, the image data PC is successively written in the RAM 5 with the maximum number of lines. However, without being limited to the maximum number of lines, the image data PC may be written to the RAM 5 one after another with a margin and not more than the maximum number of lines. In this way, it is possible to reliably avoid reading out and transferring the image data in a mixed state to the liquid crystal display screen unit 2 by the margin, and to prevent tearing more reliably. Can do.

  In this embodiment, a horizontal image having a long aspect ratio in the horizontal direction is used as it is by using a liquid crystal display screen for displaying a vertical image having a long aspect ratio in the vertical direction. The case of displaying was explained. However, on the contrary, a liquid crystal display screen for displaying a horizontal image having a long aspect ratio in the horizontal direction is used as it is to display a vertical image having a long aspect ratio in the vertical direction. Even in this case, the same effect can be obtained by applying the present invention.

DESCRIPTION OF SYMBOLS 1 Liquid crystal display device 2 Liquid crystal display screen part 3 Gate driver 4 Source driver 5 RAM
6 Data I / O
7 TG circuit 8 Control I / O
10 Gate line 11 Data line PA Current image data PB Next image data PC Next image data

Claims (5)

A plurality of pixels arranged in horizontal and vertical directions, have a long aspect ratio to the longitudinal direction, the pixel columns along the longitudinal direction than the number of pixel row along the horizontal direction There are few display screens,
A storage unit having a storage area having the same number of rows as the number of pixel rows and the same number of columns as the number of pixel columns, and storing image data representing an image;
A transfer unit that transfers the image data written in the storage unit to the display screen unit line by line;
Based on the image data transferred by the transfer unit, a drive unit that displays and drives the display screen unit;
Each time the transfer unit transfers one line of the image data, the next image data representing an image to be displayed next on the display screen unit is equal to or less than the maximum number of lines not reaching the transferred line. Writing means for writing to the storage unit for each column;
Comprising
A display device characterized by that.   The display device according to claim 1, wherein the writing unit sequentially writes the next image data in an area in which the transfer unit of the storage unit stores the image data that has been transferred.   The display device according to claim 1, wherein the writing unit writes the next image data in the storage unit with a maximum number of rows that do not reach the transferred row.   The writing unit is configured so that the transfer unit does not write to the storage unit until the transfer unit finishes transferring the last row of the image data. 4. The display device according to claim 1, wherein writing is performed after the transfer of. A plurality of pixels arranged in horizontal and vertical directions, have a long aspect ratio to the longitudinal direction, the pixel columns along the longitudinal direction than the number of pixel row along the horizontal direction There are few display screens,
A storage unit having a storage area having the same number of rows as the number of pixel rows and the same number of columns as the number of pixel columns, and storing image data representing an image;
Bei to give a,
Transferring the image data written in the storage unit to the display screen unit line by line;
Based on the transferred image data, the display screen unit is driven to display,
Each time the image data of one row is transferred, the next image data representing the image to be displayed next on the display screen unit is equal to or less than the maximum number of rows not reaching the transferred row, Write to the storage unit,
An image display method for a display device .