JP2010119026A - Image display apparatus and vertical synchronization control method of image display apparatus - Google Patents

Abstract

An image display apparatus and an image which do not need to reset the vertical synchronization signal of the display device each time the device connected to the image signal input terminal changes or the state of the still image / moving image of the image changes. An object of the present invention is to provide a vertical synchronization control method for a display device.
When an image signal A and an image signal B whose vertical synchronization signals are asynchronous with each other are displayed side by side on one display device 8 at the same time, a control unit 6 includes a predetermined frame between the image signal A and the image signal B, For example, the motion vector amount of each image between two frames is detected, and the memory control unit 5 is automatically synchronized with the vertical synchronization signal of the display device 8 and the image whose motion amount is determined to be large. The frequency of the synchronization signal when reading the image signal from the frame memory 3 is set.
[Selection] Figure 1

Description

  The present invention relates to an image display apparatus that displays a plurality of input images whose vertical synchronization is asynchronous with each other on one display device, and a vertical synchronization signal control method for the image display apparatus.

  In recent years, many image display devices such as projectors have been put on the market by various companies as means for displaying various input image information.

  Moreover, the image information and usage methods are diverse, and a function of displaying a plurality of input images at the same time has been installed.

  A plurality of input images are displayed in synchronization with the vertical synchronization signal of the display device of the image display device. However, there are cases where the vertical synchronization is asynchronous with each other, and these are displayed side by side on one display device. The vertical synchronization signal of the display device can be synchronized with only one of a plurality of displayed images.

  For still images such as personal computer data, images that do not feel uncomfortable can be displayed even if the vertical synchronization is not correct. However, for a moving image such as a DVD (Digital Versatile Disk), the image is not required if the vertical synchronization is not correct. Discontinuity occurs in the movement of the camera, and an appropriate image cannot be displayed.

  For this reason, when displaying still images and moving images side by side, the vertical synchronization of the display device is usually matched to the vertical synchronization of moving images. However, when moving images with different vertical synchronizations are displayed side by side. Causes a problem in that the continuity of the frame is lost in the moving image that cannot be synchronized vertically.

  Conventionally, the user has set on the on-screen or the like which image is prioritized and the vertical synchronization is adjusted.

  Further, as shown in Patent Document 1, there has been a method of making an overtaking line inconspicuous in an image for which vertical synchronization cannot be achieved.

  FIG. 3 is a principal block diagram showing a multi-screen display device disclosed in Patent Document 1, and FIG. 4 is a multi-screen display example. In FIG. 3, 11a, 11b, and 11n are a plurality of input moving image signals, 12 is a sync separator for separating and outputting vertical and horizontal synchronizing signals from the input moving image signal, and 13 is a memory writing phase-synchronized with the vertical and horizontal synchronizing signals. It is a timing pulse generator for generating a pulse.

  Reference numeral 14 denotes a memory write control unit which has means for converting an input analog moving image signal into digital image data, and controls writing of the digital image data in a designated section of the memory. Reference numeral 15 denotes a memory which stores the digital image data. Reference numeral 16 denotes a memory. Reference numerals 17a, 17b, and 17n denote image data storage / reproduction units for reading and reproducing a plurality of digital image data.

  Reference numeral 18 denotes a sampling pulse for memory read control synchronized with the pulse signal from the vertical timing generation means, a timing pulse generation (R) section for generating horizontal pulses and vertical pulses, or an integer multiple or an integral part of the vertical period of the input moving image signal. 1 is a sampling clock for memory read control with a period different from 1, a timing pulse generating (R) unit for generating horizontal and vertical pulses, 19 is an internal oscillator, 20 is a synthesis circuit for synthesizing and outputting a plurality of digital image data, Reference numeral 21 denotes a matrix type display unit such as a PDP.

  It consists of the above elements, and will be described in detail along the signal flow. The plurality of input moving image signals 11a, 11b,... 11n are input to the image data storage / reproduction units 17a, 17b,. The following description is limited to 17a.

  The input moving image signal 11a is separated and output into a vertical synchronization signal and a horizontal synchronization signal by the synchronization separation unit 12. A sampling clock CLK for writing, a horizontal pulse H, and a vertical pulse that are phase-synchronized with the input moving image signal 11a by a timing pulse generator 13 composed of a PLL (Phase Locked Loop) circuit, a VCO (Voltage Controlled Oscillator), and a frequency divider. A pulse V is generated.

  The memory write control unit 14 includes an A / D (analog / digital converter) and a memory control unit.

  The input moving image signal 11a is converted into digital image data by A / D driven by the writing sampling clock CLK, and is written and stored continuously and cyclically in the memory 15 by the memory write control unit. This means that when one field or one frame of memory is full, new image data is written in order starting from the beginning of the memory while discarding the old image data. This means that discontinuous image data is generated in the part.

  The timing pulse generation (R) unit 18 generates a sampling clock CLKr, a horizontal pulse Hr, a vertical pulse Vr, and the like for control of the memory read control unit 16 and supplies them to the memory read control unit 16. The image data stored in the memory 15 is read by the memory read control unit 16, input to the combining circuit 20, and combined and output as a multi-screen signal.

  Since the read vertical pulse Vr and the write vertical pulse V are different in both period and phase, the image data read from the memory 15 is the discontinuous image data, and is shown on the display unit 21 in FIG. Such an overtaking line a1 is generated. If the period of the vertical pulse Vr for reading and the vertical pulse V for writing coincides with each other or close to each other, the displayed overtaking line is displayed at a fixed position or slowly moving on the screen, which is very disturbing to the viewer. It is.

  In order to alleviate this phenomenon, the overtaking line is not displayed at a certain place, and the display position is moved at a speed that does not obstruct the eyes. The internal oscillator 19 oscillates a reference signal having a period that is 10% earlier or later than the period of the writing vertical pulse V and supplies it to the timing pulse generation (R) unit 18. The timing pulse generator (R) 18 generates a read vertical pulse Vr synchronized with the reference signal and supplies it to the memory read controller 16.

In this way, the sampling clock for memory reading control, the horizontal pulse and the vertical pulse are signals having a cycle different from an integer multiple or a fraction of an integer of the vertical cycle of the input moving image signal, and overwriting of writing and reading of the display output screen is performed. By preventing the line part from being fixedly displayed, it is possible to make the display of the overtaking line part inconspicuous.
JP-A-11-27600

  However, in the above-described conventional configuration, even if the setting is once made, if the device connected to the image signal input terminal changes or the state of the still image / moving image of the image changes, it is necessary to reset the setting each time. There was a problem that there was.

  In the method of Patent Document 1, the above setting is not required, but the display unit must be capable of displaying at an arbitrary period of horizontal and vertical frequencies.

  The present invention solves the above-mentioned conventional problems, and the vertical synchronization signal of the display device can be automatically adjusted to the vertical synchronization of the most suitable input image signal, and the discontinuity of the frame is more easily noticeable. An object of the present invention is to provide an image display device and a vertical synchronization control method for the image display device that can be made difficult.

  In order to achieve this object, an image display device and a vertical synchronization signal control method for an image display device according to the present invention include a plurality of image input terminals, a frame memory, a control unit, and an image corresponding to a processed image signal. A vertical synchronization signal control method for an image display device having a display device to be formed, comprising: means for detecting a motion amount of each of a plurality of input image signals every predetermined period; and means for comparing them; When a plurality of images whose signals are asynchronous with each other are displayed side by side on one display device, the vertical synchronization of the image having the largest amount and the vertical synchronization of the display device are automatically matched.

  At this time, the display device only needs to be able to display at the vertical frequency of the moving image signal.

  With this configuration, in an image display apparatus that displays a plurality of input images whose vertical synchronization signals are asynchronous with each other on a single display device, a device connected to the image signal input terminal is changed, or a still image / moving image Thus, it is possible to provide an image display device that does not need to be reconfigured to make the frame discontinuity inconspicuous each time the state changes.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a block diagram of an image display apparatus according to a first embodiment of the present invention.

  In FIG. 1, 1 is an image signal input terminal A to which an image signal A is input, 2 is an image signal input terminal B to which an image signal B is input, and 3 is an image signal from the image input terminals 1 and 2 temporarily. Frame memory to be stored, 4 is an image processing unit that synthesizes a plurality of image signals, 5 is a memory control unit that controls writing / reading of image signals to / from the frame memory 3, and 6 is a vertical synchronization signal of the image signal and the vertical of the display device A control unit for synchronously controlling the synchronization signal, 7 is a display device driving unit for processing an image that can be displayed on the display device, and 8 is a display device such as a liquid crystal panel.

  The operation of the image display apparatus configured as described above will be described. First, the image signal A input from the image signal input terminal A1 is written into the frame memory 3 in synchronization with the vertical synchronization signal of the image signal A itself. Similarly, the image signal B input from the image signal input terminal B2 is written into the frame memory 3 in synchronization with the vertical synchronization signal of the image signal B itself.

  The image signal writing control to the frame memory 3 is performed by the memory control unit 5 in the image processing unit 4.

  The memory control unit 5 also controls reading of the image signal from the frame memory 3, and synchronizes with the vertical synchronization signal of the display device 8 at that time.

  On the other hand, when the control unit 6 displays the image signal A and the image signal B side by side on one display device 8 at the same time, the movement of each image between predetermined frames of the image signal A and the image signal B, for example, between two frames. The image signal is read from the frame memory 3 to the memory control unit 5 so as to automatically synchronize the image signal of which the vector amount is detected and the image signal determined to have a large amount of motion and the vertical synchronization signal of the display device 8. Set the frequency of the sync signal.

  For example, when the image signal A has a larger motion vector amount than the image signal B, the vertical synchronization signal of the display device 8 is matched with the synchronization signal of the image signal A. Specifically, when the frequency of the vertical synchronization signal of the image signal A is 60 Hz and the frequency of the vertical synchronization signal of the image signal B is 50 Hz, the frequency of the vertical synchronization signal of the display device 8 is set to 60 Hz.

  The reason why the other vertical synchronizing signal is matched with the larger amount of motion is that if the amount of motion is small, the continuity of the frame is impaired and it is difficult to stand out.

  Then, the image signal A and the image signal B read from the frame memory 3 by the vertical synchronization signal of the selected image signal A are combined by the image processing unit 4, and are displayed on the display device 8 by the display device driving unit 7. The image is processed into a displayable image and displayed on the display device 8.

  As described above, according to the present embodiment, the motion vector amounts of a plurality of input image signals are detected, the vertical synchronization signal of which input image signal is synchronized with the vertical synchronization signal of the display device, and the synchronization is performed. Thus, the vertical synchronization signal can be automatically matched to the input image signal having the larger amount of motion, and the discontinuity of the frames can be made inconspicuous.

  Further, since the vertical synchronization frequency of the display device is set to the same frequency as the vertical synchronization signal of the input image signal, it is not necessary to drive the display device at a frequency equal to or higher than the input image signal as in Patent Document 1, and accordingly, The operation speed performance of the drive circuit and the display device can be suppressed and can be realized more easily. Similarly, it is not necessary to drive the display device at a frequency equal to or lower than the input image signal, and flicker is not increased.

(Embodiment 2)
FIG. 2 is a block diagram of an image display apparatus according to the second embodiment of the present invention.

  2 is different from FIG. 1 of the first embodiment in that a frame difference calculation unit 9 is provided in the image processing unit 41.

  The operation of the image display apparatus configured as described above will be described below. First, the image signal A input from the image signal input terminal A1 is written into the frame memory 3 in synchronization with the vertical synchronization signal of the image signal A itself. Similarly, the image signal B input from the image signal input terminal B2 is written into the frame memory 3 in synchronization with the vertical synchronization signal of the image signal B itself.

  Write control to the frame memory 3 is performed by the memory control unit 5 in the image processing unit 41. The above operation is the same as in the first embodiment.

  The memory control unit 5 also controls reading from the frame memory 3 and synchronizes with the vertical synchronization of the display device 8 at that time.

  When the image signal A and the image signal B are displayed side by side on one display device 8 at the same time, the frame difference calculation unit 9 detects the amount of motion of the image signal A and the amount of motion of the image signal B, and the difference between these amounts. Are compared and the calculation result is sent to the controller 61.

  The control unit 61 sets the frequency of the synchronization signal when reading the image signal from the frame memory 3 to the memory control unit 5 so as to synchronize the input image with the larger amount of motion and the vertical synchronization signal of the display device 8. To do.

  As in the first embodiment, when the image signal A has a larger motion vector amount than the image signal B, the vertical synchronization signal of the display device 8 is matched with the synchronization signal of the image signal A.

  In this way, only the image signal B becomes asynchronous with the display device 8, but the image signal B has a smaller amount of motion than the image signal A, so that it is less noticeable even if the continuity of frames is impaired.

  Then, the image signal A and the image signal B read from the frame memory 3 by the vertical synchronization signal of the selected image signal A are combined by the image processing unit 41, and the display device driving unit 7 supplies the display device 8. The image is processed into a displayable image and displayed on the display device 8.

  As described above, according to the present embodiment, the most suitable vertical synchronization of the input image signal is selected by selecting the vertical synchronization signal of the input image signal with the larger amount of motion and using it as the vertical synchronization signal of the display device. It can be automatically adjusted to the signal, and the discontinuity of the frame can be made inconspicuous.

  In the above description, the input image types are the two types of the image signal A and the image signal B, but the same applies to a plurality of types of input signals.

  Furthermore, in the first embodiment, the motion amount is detected based on the motion vector amount. However, the present invention is not limited to this. For example, a change amount of APL (average luminance level) between predetermined frames is detected. The larger input image signal and the vertical synchronization signal of the display device may be synchronized.

  As described above, according to the present invention, in an image display apparatus that displays a plurality of input images whose vertical synchronization signals are asynchronous with each other on a single display device, a device connected to the image signal input terminal changes, In order to make the discontinuity of frames less noticeable when the state of a still image / moving image changes, it is possible to provide an image display device that does not require resetting the vertical synchronization each time. It is useful as an image display device.

1 is a block diagram of an image display device according to Embodiment 1 of the present invention. Block diagram of an image display apparatus according to Embodiment 2 of the present invention Main block diagram showing a conventional multi-screen display device Figure showing a conventional multi-screen display example

Explanation of symbols

1 Image signal input terminal A
2 Image signal input terminal B
3 Frame memory 4, 41 Image processing unit 5 Memory control unit 6, 61 Control unit 7 Display device drive unit 8 Display device 9 Frame difference calculation unit

Claims (9)

An image input terminal for inputting a plurality of image signals, a frame memory for temporarily storing the plurality of image signals from the image input terminal, a vertical synchronizing signal of any of the plurality of image signals, and a vertical of a display device A control unit that matches the synchronization signal, a frame memory control unit that controls writing to and reading from the frame memory, and the plurality of image signals read from the frame memory are combined according to control by the control unit An image processing unit, a display device driving unit that inputs a composite image signal from the image processing unit and processes the display device into a desired form, and a display device that displays an image from the display device driving unit An image display device,
When the plurality of image signals whose vertical synchronization signals are asynchronous with each other are combined and displayed on the display device, the control unit selects any one of the plurality of image signals based on a predetermined condition. An image display apparatus characterized by combining a vertical synchronization signal of the selected image signal with a vertical synchronization signal of the display device. The image display apparatus according to claim 1, wherein the predetermined condition is obtained by comparing motion amounts of the plurality of image signals. By detecting and comparing the motion amounts of the plurality of image signals at predetermined intervals, the vertical synchronization signal of the image signal having the largest amount is automatically matched with the vertical synchronization signal of the display device. The image display device according to claim 2. 4. The image display device according to claim 2, wherein the amount of motion of the image signal is compared based on the amount of motion vector. 4. The image display device according to claim 2, wherein the amount of movement of the image signal is compared by calculating a difference in amount of movement. By comparing the magnitude of change in APL (average luminance level) between predetermined frames, the vertical synchronization signal of the image signal having the largest amount is automatically matched with the vertical synchronization signal of the display device. The image display device according to claim 2. 7. The image according to claim 1, wherein a vertical synchronization frequency of the display device is the same as a vertical synchronization signal of any one of the plurality of input image signals. Display device. The image display apparatus according to claim 1, wherein the display device is a liquid crystal panel. A step of inputting a plurality of image signals; a step of temporarily storing the plurality of image signals; a step of combining a vertical synchronization signal of any of the plurality of image signals and a vertical synchronization signal of a display device; A step of reading a plurality of stored image signals; a step of combining the plurality of stored image signals; a step of processing the combined image signals into a desired form of the display device; A method of controlling the vertical synchronization signal of the image display device comprising the steps of displaying an image, comprising: detecting a motion amount of the plurality of image signals every predetermined period; and comparing them; When a plurality of image signals whose vertical synchronization signals are asynchronous with each other are displayed on the display device, the vertical synchronization signal of the image signal having the largest amount of motion Vertical synchronizing signal control method for an image display device characterized by combining the vertical synchronizing signal shown device automatically.

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