JP5207732B2 - Display device - Google Patents

Description

    The present invention relates to a projection display device such as a liquid crystal projector device or a DLP (Digital Light Processing) projector device, or a display device such as a liquid crystal display.

    A display device such as a projection display device converts and displays a video signal from a computer or the like so as to match the resolution of the display device at an aspect ratio specified by a user. For example, when the display device resolution is XGA (horizontal direction 1024 pixels, vertical direction 768 pixels) and the input signal resolution is UXGA (horizontal direction 1600 pixels, vertical direction 1200 pixels), the conversion shown in FIG. It is carried out. In FIG. 8, the aspect ratios that can be specified by the user are 4: 3 and 16: 9, and are selected according to the user's preference.

    Many display devices have a function (digital zoom function) for digitally enlarging a display image in order to emphasize or confirm details of a displayed video. In the digital zoom, as shown in the example of FIG. 9, it is common to select a magnification that the user prefers from a plurality of fixed magnification options.

Japanese Patent Application Laid-Open No. 2004-271802 (Patent Document 1) discloses a technique in which a user designates an arbitrary area on a display image and displays the enlarged image in order to improve the operability of the above method.
JP 2004-271802 A

    However, as described above, when the magnification is determined for the display image, depending on the resolution of the input signal, regardless of which magnification is selected, as shown in the example of FIG. There is a problem of losing. With respect to this point, even if an arbitrary area is enlarged and displayed as in Patent Document 1, the area is specified for the display image, and thus there is a similar problem.

    Since the digital zoom function for enlarging or reducing the display area of interest functions at a magnification (or reduction ratio) depending on the resolution of the display unit, the high frequency component of the pixel data of the input signal is lost.

    In view of the above problems, the present invention provides a display device that prevents deterioration of an output image obtained by digital zoom.

In order to achieve the above object, a display device of the present invention includes an input unit that inputs a first video signal having a first resolution, and a process for reducing or enlarging the first video signal input from the input unit. Resolution conversion means for generating a second video signal having the second resolution, display means for displaying the second video signal having the second resolution, and reduction or enlargement magnification by the resolution conversion means and the magnification selecting means having a plurality of magnifications choice to select a first magnification based on the second resolution as the first resolution to have a control means for adding to the magnification selecting means, wherein The first magnification is a magnification that is an integral multiple of a value of a ratio between the first resolution and the second resolution .

    Further objects and other features of the present invention will become apparent from the examples described below.

    ADVANTAGE OF THE INVENTION According to this invention, the display apparatus which prevents degradation of the output image obtained by digital zoom can be provided.

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

    First, Example 1 in the present invention will be described.

    The configuration of the display device 100 according to the present embodiment will be described with reference to FIG. The display device 100 includes a digital zoom unit that reduces or partially cuts out the entire video area of the input signal by a magnification selection unit that can select a desired magnification from a plurality of magnification options.

    The control unit 1 controls each unit in the display device 100 according to various programs stored in the memory 2. As will be described later, the control unit 1 is also used as a control unit that adds a first magnification based on the first resolution and the second resolution to the magnification option. In the present embodiment, the first magnification is a magnification that is an integral multiple of the ratio of the first resolution to the second resolution.

    The video input terminal 3 is an input terminal for inputting a first video signal output from a computer, an AV device, or the like. The video input terminal 3 is used as input means for inputting a first video signal having a first resolution.

    The input signal processing unit 4 determines a signal format from the video signal input from the video input terminal 3, extracts each pixel data of the video signal according to the signal format, and sequentially stores it in the frame buffer 5. The frame buffer 5 has a buffer function for each pixel data of the input video signal.

    The resolution conversion unit 6 is resolution conversion means for generating a second video signal having a second resolution by reducing or enlarging the first video signal input from the video input terminal 3. The resolution conversion unit 6 reads out pixel data of an area set by the control unit 1 from the frame buffer 5 and performs an enlargement or reduction process, and also performs an aspect ratio conversion process. As described above, the resolution conversion unit 6 includes digital zoom means for reducing the whole area of the first video signal or cutting out and enlarging a part thereof, and performs digital zoom processing of the first video signal.

    The OSD processing unit 7 superimposes the image signal stored in the OSD image memory on the video signal (second video signal) output from the resolution conversion unit 6. The image stored in the OSD image memory unit 8 is read and superimposed on the area set by the control unit 1. The OSD image memory unit 8 is a nonvolatile memory and stores images such as menus.

    The OSD (On-Screen Display) refers to a function for displaying the setting content of the display unit 9 on the display unit 9 itself. The image output from the OSD image memory unit 8 is displayed by being superimposed on the second video signal output from the resolution conversion unit 6, and an operation unit disposed on the front surface or the side surface of the display unit 9 is used. Is operated. The OSD processing unit 7 works as a GUI (Graphical User Interface) in conjunction with the control unit 1 to display a menu when the user sets an aspect ratio and a digital zoom magnification.

    The display unit 9 displays the video signal (second video signal) input from the OSD processing unit 7. Thus, the display unit 9 is used as display means for displaying the second video signal having the second resolution.

    In this embodiment, there are three types of user setting values (first aspect ratio) of aspect ratio conversion realized by the resolution conversion unit 6: 4: 3, 16: 9, and 5: 4. The user can select an appropriate one from the three types of first aspect ratios. In addition, there are four types of initial zoom options for digital zoom: 1.0 times, 1.5 times, 2.0 times, and 4.0 times. The user can select an appropriate one from four types of magnifications. The display device 100 is provided with a magnification selection means 10 having a plurality of magnification options in order to select a reduction or enlargement magnification by the digital zoom means (resolution conversion unit 6).

    Note that the selection values for the aspect ratio and the digital zoom are not limited to the above values, and options having other values may be provided. Further, the display unit 9 of the present embodiment is a fixed pixel of XGA (eXtended Graphics Array: horizontal direction 1024 pixels, vertical direction 768 pixels, aspect ratio 4: 3). However, display units having other numbers of pixels may be used.

    Next, based on an example in which the display device of this embodiment is connected to a computer, a flow until a magnification depending on an input resolution is added to a digital zoom magnification option will be described.

    As shown in FIG. 3, there are various types of first video signals output from the computer. Each video signal has different horizontal resolution and vertical resolution. In this embodiment, a case will be described in which a UXGA (Ultra eXtended Graphics Array: horizontal direction 1600 pixels, vertical direction 1200 pixels) signal is input among these first video signals.

    The first video signal (UXGA) output from the computer is input to the projection display device 100 from the video input terminal 3 and supplied to the input signal processing unit 4. The display device 100 stores in the memory 2 a signal timing table equivalent to the video signal standard shown in FIG. For this reason, the input signal processing unit 4 determines from the frequency of the synchronization component of the first video signal that the format of the first video signal is UXGA. When the resolution of the first video signal (first resolution) is determined, the control unit 1 calculates a digital zoom magnification option.

    Next, with reference to FIG. 1, a calculation flow of magnification options for digital zoom executed by the control unit 1 will be described.

In step S1 to step S3, five variables used for the calculation of the magnification option are substituted. In step S1, 1024 is assigned to the horizontal resolution H _Disp of the display unit 9, and 768 is assigned to the vertical resolution V _Disp of the display unit 9. In step S2, 1600 is assigned to the horizontal resolution H _In of the input signal, and 1200 is assigned to the vertical resolution V _In of the input signal. In step S3, 1.333 (4: 3) is substituted for the currently selected aspect ratio (horizontal / vertical) AR (first aspect ratio).

    When the substitution of the five variables is completed in steps S1 to S3, the determination in step S4 is performed. In step S4, it is determined whether or not the aspect ratio (second aspect ratio) of the display unit 9 is equal to the aspect ratio (first aspect ratio) currently selected by the user. In this embodiment, since the aspect ratio currently set by the user is 1.333 (4: 3), it is equal to the aspect ratio of the display unit 9. Therefore, the process proceeds from step 4 to step S6.

In step S6, the ratio H _In / H _Disp of the horizontal resolution of the input signal (first video signal) and the horizontal resolution of the display unit 9, and the ratio of the vertical resolution of the input signal and the vertical resolution of the display unit 9 are determined. The value V _In / V _Disp is calculated. H _In / H _Disp and V _In / V _Disp are magnifications for canceling the reduction by setting the aspect ratio in each of the horizontal direction and the vertical direction.

In this embodiment, the value (H) of the ratio between the horizontal resolution (first resolution) of the input first video signal and the horizontal resolution (second resolution) of the second video signal displayed on the display unit 9. _In / H _Disp ) is 1.56. Further, the ratio value (V _In / V _Disp ) of the vertical resolution (first resolution) of the first video signal and the vertical resolution (second resolution) of the second video signal displayed on the display unit 9 is also obtained. 1.56. Since the calculation result of the ratio value of the horizontal resolution and the vertical resolution is 1.56, the control unit 1 adds 1.56 times to the magnification option of the magnification selection means 10.

    The control unit 1 of the present embodiment adds the first magnification (1.56 times) that is the value of the ratio between the first resolution and the second resolution to the magnification option. However, the first magnification is not limited to this. If the first magnification is an integral multiple of the value of the ratio between the first resolution and the second resolution, the same effect can be obtained. For this reason, in this embodiment, a plurality of magnifications of 1.56 × n (n is a positive integer (n = 1, 2,...)) Can be added as the first magnification. Therefore, for example, 3.12 times may be added in addition to 1.56 times.

    In the above embodiment, the case where the selected aspect ratio (first aspect ratio) is 4: 3 has been described. Next, the case where the selected aspect ratio is 16: 9 or 5: 4 will be described.

    First, when the selected aspect ratio (first aspect ratio) is 16: 9, the process proceeds to step S5 by the determination in step S4. In step S5, it is determined whether or not the aspect ratio (second aspect ratio) of the display unit 9 is larger than the selected aspect ratio. The aspect ratio of the display unit 9 is 1.333 (4: 3), which is smaller than the selected aspect ratio of 1.778 (16: 9). For this reason, the process proceeds from step S5 to step S8.

In step S8, the ratio H _In / H _Disp between the horizontal resolution of the input signal and the horizontal resolution of the display unit 9 and the ratio of the vertical resolution of the input signal and the horizontal resolution of the display unit 9 divided by the aspect ratio AR. V _In / (H _Disp / AR) is calculated. H _In / H _Disp and V _In / (H _Disp / AR) are magnifications for canceling reduction by setting the aspect ratio in each of the horizontal direction and the vertical direction. From the calculation result, H _In / H _Disp is 1.56, V _In / (H _Disp / AR) is 2.08 (second magnification), and 1.56 times and 2.08 times are added to the magnification options. The

    On the other hand, if the selected aspect ratio (first aspect ratio) is 5: 4, the process proceeds to step S5 by the determination in step S4. In step S5, it is determined whether or not the aspect ratio (second aspect ratio) of the display unit 9 is larger than the selected aspect ratio. The aspect ratio of the display unit 9 is 1.333 (4: 3), which is larger than the selected aspect ratio 1.25 (5: 4). For this reason, the process proceeds from step S5 to step S7.

In step S7, the ratio V _In / V _Disp between the vertical resolution of the input signal and the vertical resolution of the display unit 9 and the ratio of the horizontal resolution of the input signal and the value obtained by integrating the aspect ratio AR to the vertical resolution of the display unit 9 H _In / (V _Disp × AR) is calculated. V _In / V _Disp and H _In / (V _Disp × AR) are magnifications for canceling reduction by setting the aspect ratio in each of the horizontal direction and the vertical direction. From the calculation results, V _In / V _Disp is 1.56, H _In / (V _Disp × AR) is 1.67 (second magnification), and 1.56 times and 1.67 times are added to the magnification options. The

    As described above, the control unit 1 compares the selected first aspect ratio with the second aspect ratio of the display unit 9, and the first aspect ratio is different when the first aspect ratio and the second aspect ratio are different. A second ratio dependent magnification is added to the magnification option.

    In this embodiment, a case is described in which the resolution of the input signal (first video signal) is UXGA (horizontal direction 1600 pixels, vertical direction 1200 pixels). However, even if the input signal has another resolution, the calculation is performed in the same flow.

    As an example, FIG. 4 shows the calculation results for the magnification added when the resolution of the input signal is SXGA (1280 pixels in the horizontal direction and 1024 pixels in the vertical direction) and 1080p (1920 pixels in the horizontal direction and 1080 pixels in the vertical direction). 4, the input resolution (first resolution) is SXGA, UXGA, 1080p, respectively, and the selected aspect ratio AR is 1.333 (4: 3), 1.25 (5: 4), For each case of 78 (16: 9), the magnification options are shown.

    By performing the above calculation, a digital zoom magnification option is added. As a result, when the selected aspect ratio AR is 4: 3, the user has five types of digital zoom menu: 1.00 times, 1.50 times, 1.56 times, 2.00 times, and 4.00 times. Can be selected. FIG. 5 shows output images at five selectable magnifications.

    As shown in FIG. 5, the added digital zoom 1.56 times output image most faithfully reproduces the high-frequency component of the input video signal. The reason why the high-frequency component can be faithfully reproduced when the magnification is 1.56 is that there is no enlargement or reduction processing by the resolution conversion unit 6.

    On the other hand, output images with other magnifications are blurred due to the influence of processing during resolution conversion. In the enlargement or reduction processing by the resolution conversion unit 6, it is necessary to generate pixels originally not included in the input video signal by interpolation using peripheral pixels. At that time, the frequency distribution of the input video signal is distorted and the output image is blurred.

    As described above, by adding a digital zoom magnification option, the user can select a magnification for maintaining a high-frequency component in the pixel data of the input signal (first video signal). In the present embodiment shown in FIG. 5, the resolution (second resolution) of the display unit 9 is XGA, and selectable aspect ratios are 4: 3, 5: 4, and 16: 9. However, the present invention is not limited to these. It is also possible to employ a display unit having a resolution other than XGA or another selectable aspect ratio.

    In the present embodiment shown in FIG. 5, the additional magnification is only 1.56. However, a high-frequency component in the image data of the input image can be maintained at a magnification obtained by multiplying this additional magnification by an integer, that is, 1.56 × n (n: positive integer). Therefore, for example, it is possible to add 3.12 times as well as 1.56 times.

    Further, when the added magnification is selected, the resolution conversion unit 6 does not require processing for enlarging or reducing in the horizontal direction or the vertical direction. For this reason, when an additional magnification is selected, a path for passing through a processing block that is enlarged or reduced in the horizontal direction or the vertical direction can be provided.

    Next, the reason why the output image becomes clear when the above-described additional magnification is applied will be described. First, the internal configuration of the resolution conversion unit 6 will be described with reference to FIGS.

    FIG. 10 shows the configuration of the resolution conversion unit 6.

The resolution conversion unit 6 includes an upsampling unit that upsamples the first video signal and an interpolation unit that interpolates a signal output from the upsampling unit. Further, the resolution conversion unit 6 includes a downsampling unit that samples the signal output from the interpolation unit at an interval instructed by the control unit 1 to generate a second video signal. The resolution converter 6 is provided with detour paths 70 and 71 that bypass the upsampling unit, the interpolation unit, and the downsampling unit. When the first magnification is selected by the magnification selection means 10, the control unit 1 outputs the first video signal that has passed through the detour paths 70 and 71 as the second video signal.

The resolution conversion unit 6 performs processing in the horizontal direction and the vertical direction in series. For this reason, a horizontal upsampling unit 61 and a vertical upsampling unit 64 are provided as upsampling units. Further, a horizontal interpolation unit 62 and a vertical interpolation unit 65 are provided as interpolation units. Further, a horizontal downsampling unit 63 and a vertical downsampling unit 66 are provided as downsampling units.

    The signal output from the frame buffer 5 is input to the horizontal upsampling unit 61. The horizontal upsampling unit 61 upsamples the input signal eight times with respect to the horizontal direction of the input signal. All the gradations of points added during upsampling are set to zero. The horizontal interpolation unit 62 performs a convolution operation using an interpolation filter in order to optimize the gradation of the point added by the horizontal upsampling unit 61. An example of the interpolation filter is shown in FIG.

    The horizontal downsampling unit 63 performs sampling at intervals specified by the control unit 1. The vertical upsampling unit 64, the vertical interpolation unit 65, and the vertical downsampling unit 66 perform the same processing as the horizontal upsampling unit 61, the horizontal interpolation unit 62, and the horizontal downsampling unit 63, respectively, in the vertical direction.

    The multiplexers 67 and 68 are used to bypass the resolution conversion process. The multiplexer 67 vertically converts either the processing signal that has passed through the horizontal upsampling unit 61, the horizontal interpolation unit 62, and the horizontal downsampling unit 63, or the detour signal that has passed through the detour path 70 for detouring these signals. This is supplied to the upsampling unit 64.

    The operation of the multiplexer 67 is controlled by the control unit 1. The control unit 1 determines which of the processing signal and the bypass signal is output from the multiplexer 67.

    Similarly, the multiplexer 68 converts either the processing signal that has passed through the vertical upsampling unit 64, the vertical interpolation unit 65, and the vertical downsampling unit 66, or the detour signal through the detour path 71 for detouring them, to the OSD. This is supplied to the processing unit 7. The multiplexer 68 is controlled by the control unit 1. The control unit 1 determines which of the processing signal and the bypass signal is output from the multiplexer 68.

    With the above configuration, when the first magnification is selected by the magnification selecting unit 10, the control unit 1 outputs the first video signal that has passed through the detour path 70 as the second video signal.

Next, a series of processing examples in the horizontal direction by the horizontal upsampling unit 61, the horizontal interpolation unit 62, and the horizontal downsampling unit 63 will be described with reference to FIG. In this figure, as described above, the horizontal resolution H _Disp of the display unit 9 is 1024, the vertical resolution V _Disp of the display unit 9 is 768, the horizontal resolution H _In of the input video signal is 1600, and the vertical resolution V of the input video signal A case where _In is 1200 is shown.

    FIG. 12A shows the input level of the input signal of 13 pixels in a certain section. Processing steps when the input signal is set to 1.56 times and 1.50 times by digital zoom will be described below. For simplicity of explanation, it is assumed that the gradations of the pixels other than the target section are all zero.

    The input level of the input signal shown in FIG. 12A is multiplied by 8 in the horizontal upsampling unit 61. The output level of the horizontal upsampling unit is shown in FIG. As shown in FIG. 12B, all zeros are substituted for the points added in the horizontal upsampling unit 61.

    The output level of the horizontal upsampling unit 61 is subjected to a convolution operation in the horizontal interpolation unit 62 using the interpolation filter shown in FIG. FIG. 12C shows the output level of the horizontal interpolation unit obtained from this calculation result.

The output level of the horizontal interpolation unit 62 is determined by the horizontal down sampling unit 63.
_Downsampling processing is performed at intervals given by 8 × (H _In / H _Disp ) / digital zoom magnification. When the digital zoom magnification is 1.56 times, this interval is 8.00. On the other hand, when the digital zoom magnification is 1.50 times, this interval is 8.33. As described above, the horizontal downsampling unit 63 performs the downsampling process on the output level of the horizontal interpolation unit 62 at intervals according to the digital zoom magnification.

  FIG. 12D shows the output level of the horizontal down dumpling unit when the digital zoom magnification is 1.56 times. FIG. 12E shows the output level when the digital zoom magnification is 1.50.

    Comparing FIG. 12D and FIG. 12E, it can be seen that the output level of FIG. 12D is close to the input level of FIG. On the other hand, the output level of FIG. 12E is a value close to the input level of FIG. 12A for the left pixel, but the right pixel is far from the input level of FIG. Go. That is, the right pixel has a large error with respect to the input signal.

    Therefore, when the digital zoom magnification is set to 1.56 times, an output image can be obtained with almost no deterioration in the image quality of the input signal. Note that the above description also applies to a series of processes in the vertical direction by the vertical upsampling unit 64, the vertical interpolation unit 65, and the vertical downsampling unit 66.

    Incidentally, although the output level in FIG. 12D is a value close to the input level in FIG. 12A, there is a slight difference between these levels. For this reason, when the additional magnification (1.56 in this embodiment) is selected, it is desirable to control the controller 1 so that the multiplexers 67 and 68 output a bypass signal.

    When the control unit 1 controls the multiplexer 67 to output a bypass signal, the multiplexer 67 outputs the bypass signal directly input from the frame buffer 5. Since the bypass signal does not go through processing by the horizontal upsampling unit 61, the horizontal interpolation unit 62, and the horizontal downsampling unit 63, the input signal itself of the horizontal upsampling unit 61 becomes the output signal of the multiplexer 67.

    Similarly, when the control unit 1 controls the multiplexer 68 to output a bypass signal, the multiplexer 68 outputs the bypass signal directly input from the multiplexer 67. Since this bypass signal does not go through processing by the vertical upsampling unit 64, the vertical interpolation unit 65, and the vertical downsampling unit 66, the output signal of the multiplexer 67 itself becomes the output signal of the multiplexer 68.

    As described above, when either the horizontal or vertical magnification is an additional magnification that maintains a high-frequency component, either the horizontal or vertical processing in the resolution converter 6 can be omitted. For this reason, it becomes possible to prevent the output image from deteriorating.

    When both the horizontal and vertical magnifications are additional magnifications that maintain high-frequency components, both the horizontal and vertical processing in the resolution converter 6 can be omitted. For this reason, it is possible to effectively prevent the degradation of the output image.

    A display device according to a second embodiment of the present invention will be described. Since the basic configuration of the present embodiment is the same as that of the first embodiment, description of the same parts as those of the first embodiment will be omitted, and only parts different from the first embodiment will be described.

    The display device of this embodiment has only a 1.0 × magnification option as a fixed magnification option for digital zoom. All other options are determined depending on the setting of the first aspect ratio and the resolution of the input video signal (first video signal).

    First, a method for selecting a magnification option will be described. First, list integer values or fractional values with small denominator and numerator values as possible magnification options for the input resolution. Secondly, an unnecessary magnification option is deleted from the list in consideration of balance. In this state, assuming that the aspect ratio is 4: 3, it is as shown in FIG. 6 to visually represent the area of each magnification to be displayed with respect to the input resolution. Third, for each input resolution, determine the criteria for which magnification is actually allowed. For example, on the basis of the value of (output resolution / input resolution), it is possible to determine 5 points on the high magnification side, 2 points on the low magnification side, and the like.

In this manner, the first magnification selected based on the first resolution and the second resolution from among a plurality of magnification option candidates prepared in advance is added to the magnification selection means.

    Next, an example of a method for selecting a magnification option will be specifically described.

    The display unit 9 has a resolution of XGA, an input video signal of SVGA (800 pixels in the horizontal direction and 600 pixels in the vertical direction), XGA, and UXGA, and the aspect ratio that permits setting is 4: 3 and 16: 9. To do.

    Eleven types of 1/4, 1/3, 1/2, 2/3, 3/4, 1/4/3, 3/2, 2, 3, and 4 as magnification option candidates for the input resolution Suppose that the following magnification is prepared. The number of magnification options actually permitted is 5 on the high magnification side and 2 on the low magnification side with respect to the value of (output resolution / input resolution) for each of the horizontal direction and the vertical direction.

    When the magnification option determined under the above conditions is calculated, when the input signal is SVGA and the set aspect ratio is 4: 3, (output resolution / input resolution) is 1.28 in both the horizontal and vertical directions. At this time, 3/4, 1, 4/3, 3/2, 2, 3, 4 are selected as the magnification for the input resolution.

    On the other hand, when the aspect ratio is set to 16: 9, the horizontal magnification is the same as the above result. In the vertical direction, the value of (output resolution / input resolution) is 0.96. For this reason, 2/3, 3/4, 1, 4/3, 3/2, 2, and 3 are selected as the magnification for the input resolution.

    The magnification option actually displayed in the digital zoom menu is not the input resolution standard but the output resolution standard. For this reason, the value of (input resolution / output resolution) is integrated. When the aspect ratio is 4: 3, the first magnification is 0.59, 0.78, 1.00, 1.04, 1.17, 1.56, 2.34, 3.13 times. When the aspect ratio is 16: 9, the first magnification is 0.59, 0.69, 0.78, 1.00, 1.04, 1.17, 1.39, 1.56, 2. It becomes 08, 2.34, 3.13 times. When the same calculation is performed for input video signals of other resolutions, the result of FIG. 7 is obtained.

    As described above, in this embodiment, the digital zoom magnification option can be made to depend on the resolution of the input video signal and the aspect ratio selected by the user. As a result, the number of choices that are an integral multiple of the resolution of the input video signal can be increased, and the user can further expand while maintaining the frequency distribution of the input video signal. In addition, even in an area where an option that is an integer multiple of the resolution of the input video signal cannot be obtained, the pixel data of the input video signal can be further reduced by enlarging or reducing the denominator and numerator values with small fraction values. Can output clearly.

    As described above, according to the first and second embodiments, the first magnification based on the first resolution of the input signal and the second resolution of the video signal is added to the magnification option of the magnification selecting unit. According to this configuration, the user can select an appropriate magnification for each resolution of the input signal. For example, a magnification for adding the pixel data of the input signal to an integer multiple of the pixels of the display unit is added. According to this configuration, since the magnification for maintaining the high frequency component of the pixel data of the input video signal is added, the input video signal can be displayed more faithfully.

    Further, when the display device includes an aspect ratio conversion unit that converts the video of the input signal into an output aspect ratio that the user likes, a magnification that depends on the output aspect ratio is added. According to this configuration, it is possible to provide the user with a choice of magnifications suitable for each output aspect ratio.

    Although the embodiments of the present invention have been specifically described above, the present invention is not limited to the above-described embodiments and can be appropriately changed within the scope of the technical idea of the present invention.

    For example, in the above embodiment, the display unit 9 is described as having a resolution of XGA and an aspect ratio of 4: 3 or 16: 9. However, the present invention is not limited to these, and can be similarly applied to other resolutions or other aspect ratios. Further, the resolution of the input video signal is not limited to the resolution described in the above embodiment. Also, the number of magnification options that can be set is merely an example in the above embodiment, and is not limited to that number.

It is a calculation flowchart of the additional magnification option of the digital zoom according to the first embodiment of the present invention. It is a block diagram of the display apparatus which concerns on Example 1 of this invention. It is an example of a signal timing output from a computer. It is the additional magnification calculation result of the digital zoom by the input resolution and aspect setting which concern on Example 1 of this invention. It is a figure which shows the display state of the output image by the digital zoom setting which concerns on Example 1 of this invention. It is a figure which shows the display area of each magnification at the time of expansion or reduction with respect to the input resolution which concerns on Example 2 of this invention. It is the additional magnification calculation result of the digital zoom by the input resolution and aspect setting which concern on Example 2 of this invention. It is a figure which shows the display state of the output image by aspect ratio setting. It is a figure which shows the display state of the output image by the digital zoom setting in a conventional system. It is a block diagram of the resolution conversion part which concerns on Example 1 of this invention. It is an example of the interpolation filter of the horizontal interpolation part which concerns on Example 1 of this invention. It is an image figure of horizontal resolution conversion concerning Example 1 of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Control part 2 Memory 3 Video | video input terminal 4 Input signal processing part 5 Frame buffer 6 Resolution conversion part 7 OSD processing part 8 OSD memory part 9 Display part 10 Magnification selection means 61 Horizontal upsampling part 62 Horizontal interpolation part 63 Horizontal downsampling part 64 Vertical upsampling unit 65 Vertical interpolation unit 66 Vertical downsampling unit 67, 68 Multiplexer 70, 71 Detour path

Claims (3)

Input means for inputting a first video signal having a first resolution;
And resolution conversion means for generating a second video signal having a second resolution by reducing or enlarging processing said first video signal input from said input means,
Display means for displaying the second video signal having the second resolution;
A magnification selection means having a plurality of magnification options for selecting a reduction or enlargement magnification by the resolution conversion means;
It possesses a control means for adding a first magnification based on the second resolution as the first resolution to the magnification selecting means,
The display device according to claim 1, wherein the first magnification is a magnification that is an integral multiple of a value of a ratio between the first resolution and the second resolution . The control means compares the selected first aspect ratio with the second aspect ratio of the display means, and when the first aspect ratio and the second aspect ratio are different, the first aspect ratio The display device according to claim 1, wherein a second magnification depending on the selection is added to the magnification option. The resolution conversion means includes an upsampling unit that upsamples the first video signal;
An interpolation unit for interpolating a signal output from the upsampling unit;
A downsampling unit that samples the signal output from the interpolation unit at an interval commanded by the control unit to generate the second video signal;
A detour path detouring the upsampling unit, the interpolation unit, and the downsampling unit,
The control means, when the first magnification is selected by the magnification selection means, outputs the first video signal that has passed through the detour path as the second video signal. The display device according to 1 or 2 .