JP3952828B2 - Waveform display device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a waveform display device using electronic image conversion means for converting a waveform drawn on a fluorescent screen into electrical information, and in particular, adjusting the height of a luminance level over a specific width in a bright line of a displayed waveform. The present invention relates to a waveform display device suitable for measuring electrical waveforms.
[0002]
[Prior art]
Conventionally, in order to measure the electrical waveform of an input signal, an electronic image conversion device has been developed that converts a drawing formed on a phosphor screen into electrical information by a solid-state imaging unit (CCD). Based on the obtained electrical information, the waveform of the input signal is displayed on the display screen of the waveform display device to form an analog oscilloscope. The electronic image conversion apparatus is specifically disclosed in, for example, Japanese Patent Application Laid-Open No. 2-156162. An outline of the configuration of the electronic image conversion apparatus will be described with reference to FIG.
[0003]
The electronic image conversion apparatus includes an electron gun section 2 including a cathode for generating an electron beam B, a control grid, an acceleration electrode, a focusing electrode, and an astig electrode in a casing 1 whose interior is kept in a vacuum. , A deflection unit 3 in which a vertical deflection plate and a horizontal deflection plate are arranged, and a post-acceleration unit 4 having an acceleration electrode. An end portion of the housing 1 is provided with an image conversion output unit 5 that receives the electron beam B and converts it into electrical information.
[0004]
Here, the image conversion output unit 5 provided at the rear end of the casing 1 on the downstream side of the electron beam B mainly includes a phosphor screen 51, a rear acceleration electrode 52, an optical fiber plate (OFP) 53, a transparent member. A conductive film 54 and a solid-state imaging unit (CCD) 55 are included. On the back side of the phosphor screen 51, a post acceleration electrode 52 made of a transparent conductive film is provided. The optical fiber plate 53 is formed of an optical fiber bundle and is supported on a glass plate portion formed at the end of the housing 1 via a frit (powder glass). The solid-state imaging unit 55 is disposed close to or in close contact with the output end surface of the fluorescent screen 51, and output light from the optical fiber plate 53 is input to the imaging unit 55. Fluorescence emitted according to the shape drawn on the fluorescent screen 51 by the electron beam B is converted into electrical information by the solid-state imaging unit 55.
[0005]
Next, FIG. 10 shows a case where a waveform display device is configured using the electronic image conversion device described above. In the figure, a schematic configuration for displaying a waveform of electrical information obtained by the electronic image conversion device is shown by processing blocks. The waveform display device includes an input signal processing unit 6 in addition to the electronic image conversion device. A video signal conversion processing unit 7, a display processing control unit 8, and a waveform output display unit 9. The waveform output display unit 9 is provided with a display panel 10 for displaying the waveform of the measurement signal on the screen, together with a function of taking the measurement signal information as a video signal to the outside. In FIG. 10, the configuration of the electronic image conversion apparatus is as shown in FIG. 9, but for the sake of simplicity of illustration, the image conversion output unit 5 provided at the end of the housing 1 Only the solid-state imaging unit 55 included in the output unit is shown.
[0006]
First, the measured input signal is input to the input signal processing unit 6 of the waveform display device. In the input signal processing unit 6, level adjustment according to switching of the measurement channel and sweep information / luminance information according to the input signal are generated and supplied to the electronic image conversion apparatus. With these pieces of information, the waveform of the input signal is drawn on the fluorescent screen 51 provided in the output unit 5 of the electronic image conversion apparatus.
[0007]
Therefore, the fluorescent screen 51 emits fluorescence corresponding to the drawn waveform, and this fluorescence is projected to the solid-state imaging unit 55 via the optical fiber plate 53. In the solid-state imaging unit 55, a pixel located at a position corresponding to the projected waveform converts the fluorescence into an electric signal. However, a pixel on which no fluorescence is projected outputs an electric signal of 0 level.
[0008]
Next, the video signal conversion processing unit 7 reads the converted electric signal while scanning the pixel surface of the solid-state imaging unit 55, and converts the electric signal into a video signal. The scanning at this time is performed on a plurality of lines from the upper end to the lower end for each horizontal line on the pixel surface of the solid-state imaging unit 55, and an electric signal read by scanning one pixel surface is one frame. Video signal in minutes.
[0009]
The video signal created in this way is usually formed by a plurality of continuous frames, and this video signal is transmitted to the display processing control unit 8. The display processing control unit 8 digitizes the video signal and edits the displayed video signal in order to display the received video signal on the display panel. Thereafter, the video signal is converted into an analog signal and transmitted to the waveform output display device 9. On the screen of the display panel 10, a waveform corresponding to the input signal drawn on the pixel surface of the solid-state imaging unit 55 is displayed.
[0010]
[Problems to be solved by the invention]
As described above, the waveform display apparatus using the electronic image conversion apparatus can display the waveform of the measured input signal on the display panel 10 of the waveform display apparatus and observe the waveform of the input signal.
[0011]
However, in the electronic image conversion apparatus, the drawn fluorescent image is converted into an electrical signal by the CCD of the solid-state imaging unit. As the drawing means, an electron beam is employed, and the electron beam is projected onto the phosphor screen and scanned. When scanning the electron beam on the fluorescent screen, the electron beam is narrowed down and projected. However, there is a limit to this narrowing down, and the size of the spot formed on the fluorescent screen of the electron beam depends on the solid-state imaging unit. This is larger than the size of the CCD element to be constructed. Therefore, the bright line due to the waveform of the measurement signal displayed on the display panel is a thick line having a certain width.
[0012]
Here, in the display panel 10, an example of waveform display for an input signal is shown in FIG. In the example of FIG. 5A, the input signal is shown as a signal having a certain level for the sake of simplicity. This input signal is represented by a horizontal straight line on the screen of the display panel 10. In the figure, a part of the straight line is enlarged and shown beside the screen of the display panel 10.
[0013]
As can be seen in this enlarged view, on the screen of the display panel 10, the luminance level L0 is 0 in a portion where there is no waveform information as an input signal, and the screen is displayed black on the screen. In FIG. 11, for the convenience of illustration, the black and white are inverted, the black portion is expressed in white, and the bright portion is expressed in dark (the same applies hereinafter). In the observation of the input signal, even though it can be grasped as a single straight line as a whole, in reality, a band of level L1 having a slightly lower luminance is formed around the level L2 having the highest luminance, and the drawn electrons are formed. The emission line is thicker than the width of the beam.
[0014]
This phenomenon is caused by a structural problem in the electronic image conversion apparatus, for example, the fact that the solid-state imaging unit reacts to scattered light from the fluorescent screen and the characteristics of the CCD itself that constitutes the solid-state imaging unit. Therefore, as described above, depending on the luminance level, the displayed bright line is observed as a thick line, or the bright part and the dark part are not clear or are observed as blurred. is there.
[0015]
Furthermore, in order to improve such a situation, when the luminance level in the solid-state imaging unit is increased to clarify the displayed waveform, as shown in FIG. Although the luminance level L21 of the central portion of the region becomes higher, the width on the both sides sandwiching the higher portion becomes wider than the bright line in the case of FIG. Even in this case, even if a bright line is displayed at the center of the width, the bright part and the dark part are still unclear, and the blur spreads back, making it difficult to observe the waveform. .
[0016]
On the other hand, when the luminance of the screen display is increased, the luminance level L2 of the line that should be originally displayed as the bright line also increases, but the scattered light from the phosphor screen also increases, and as a result, the luminance level L0 should be zero. However, the brightness level according to the level of scattered light may be obtained, and the entire display screen may become bright. In such a case, there is a problem that even if the luminance of the waveform portion is high, it is difficult to observe the waveform on the display screen.
[0017]
In such a case, the waveform can be clearly displayed by removing the portion with the lowest luminance level and removing the portion with the lower luminance level as the bright line representing the waveform. However, the calculation process for removing the low luminance level portion is complicated. This means that the response characteristic with respect to the measured input signal is deteriorated and the cost is increased, so that it is not suitable as processing in the waveform display device.
[0018]
Accordingly, an object of the present invention is to display a high luminance level portion in a bright line of a waveform to be displayed relative to other luminance levels when displaying electrical information based on an input signal obtained by using an electronic image conversion means in a waveform. An object of the present invention is to provide a waveform display device in which bright lines of a displayed waveform to be displayed are emphasized by adjusting to a high level.
[0019]
[Means for Solving the Problems]
  In order to solve the above problems, in the waveform display device according to the present invention,MeasuredBy an electron beam deflected according to the input signalOf the input signalA phosphor screen on which a waveform is drawn;Of the waveformLight generated from the phosphor screen during drawingBrightness levelAn electronic image conversion means having a solid-state imaging unit for converting the electrical signal into an electrical signal, and the electrical signal taken out while scanning the solid-state imaging unitOn the basis of theVideo signal processing means for converting into video signal data for each frame, and for each frame in the video signal dataOf the brightness levelA detection unit for detecting the minimum value, a storage unit for storing the detected minimum value, and video signal data of the next frame in which the minimum value is detectedThe brightness level ofAnd a subtracting section for subtracting the minimum value from the processing control means, wherein the processing control means generates video signal data in which the minimum value of the video signal data is adjusted to zero level, and the video signal Data was output to the waveform display means.
[0020]
  Also according to the present invention,Measure the electrical waveform of the input signalIn the waveform display device,MeasuredBy an electron beam deflected according to the input signalOf the input signalA phosphor screen on which a waveform is drawn;Of the waveformLight generated from the phosphor screen during drawingBrightness levelAn electronic image conversion means having a solid-state imaging unit for converting the electrical signal into an electrical signal, and the electrical signal taken out while scanning the solid-state imaging unitOn the basis of theVideo signal processing means for converting into video signal data for each frame, and for each frame in the video signal data, the waveform data included in the frameOf the brightness levelA detection unit for detecting a maximum value, a storage unit for storing the detected maximum value, and a specific range from the maximum value.LuminanceA processing control unit having a multiplication unit that multiplies the waveform data included in the next frame corresponding to the level by a predetermined coefficient, and the processing control unit includes:LuminanceThe video signal data whose level is adjusted is generated, and the video signal data is output to the waveform display means.
[0021]
  The specific range is set within a range that is lower than the detected maximum value by a predetermined value, and the specific range is set with a plurality of ranges below the detected maximum value, and the multiplication unit The waveform data of the video signal data is multiplied by the coefficient set to a different size corresponding to the plurality of ranges.
[0022]
  Further, the processing control means is configured to receive the video signal data.Luminance included inA level discriminating unit that discriminates a level into the plurality of ranges for each frame; and a level adjusting unit that outputs the coefficient having a magnitude corresponding to the discriminated range. The multiplying unit includes the level adjusting unit The waveform data is multiplied by the coefficient, and the video signal data is input to the level discriminating unit, particularly when the maximum luminance level in one frame of the video signal data is less than or equal to a predetermined value. A selection unit is provided.
[0023]
  The processing control means includes a level comparison unit that sequentially compares levels before and after the data included in the video signal data that is sequentially input, and the level comparison unit sequentially increases the data sequence that has subsequently decreased. When detected, the waveform data included in the video signal data is used, and the processing control means further includes the waveform data of the video signal data sequentially input.Luminance level atA maximum value detector that outputs a predetermined coefficient when a maximum value of the video signal is detected; a delay processor that delays the video signal data by a predetermined amount; and the waveform data of the delayed video signal data in the waveform data. And a multiplication unit for multiplying the fixed amount.
[0024]
[Action]
According to the present invention, in a waveform display device using electronic image conversion means for converting an electric signal in accordance with a measured input signal, video signal data extracted from a solid-state imaging screen on which the measured input signal is drawn is obtained. As a brightness level adjustment process for the generated video signal data, the lowest brightness level is detected among the data included in one frame of the video signal data, and the brightness level is subtracted from the brightness level of all data. As a result, it is possible to prevent the entire screen from becoming bright when the brightness of the screen display is increased.
[0025]
Since the data of the maximum luminance level is detected among the data included in one frame of the video signal data, the luminance level at the top of the luminance level profile related to the bright line can be emphasized, so that the signal waveform is displayed with increased luminance. When the brightness level around the bright line increases, the original bright line of the waveform can be emphasized.
[0026]
Since the brightness level of the data is changed and emphasized according to the brightness level of the data included in the video signal data, only the center part of the dark bright line is displayed brightly when displaying with reduced brightness. Can do.
[0027]
Since the peak portion of the luminance level is detected from the data related to the bright line included in the video signal data, and the luminance level is emphasized only for the peak portion, the vertical direction of the rectangular wave signal displayed darkly It is possible to emphasize the original bright line of the waveform with respect to the bright line.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a waveform display device according to the present invention will be described below with reference to FIGS. The embodiments shown here are divided into first to fourth embodiments depending on how the luminance level is adjusted.
[0029]
(First embodiment)
In the first embodiment, when the input signal is drawn on the fluorescent screen 51 with the electron beam B, the luminance level is set high. As a result, the scattered light of the fluorescent light spreads over the entire screen. It is intended to improve that the original bright line indicating the waveform has become difficult to see because it has become brighter, and by reducing the brightness level that brightens the entire screen from the video signal data, Provided is a brightness level adjustment processing technique for making bright lines stand out.
[0030]
FIG. 1 is a brightness level profile for explaining a processing method for adjusting a brightness level in video signal data of a display waveform adopted in the present embodiment. FIGS. 1A and 1B show the luminance level for the luminance level of the bright line portion of the video signal generated by digitization by the video signal conversion processing unit 7 in the waveform display device shown in FIG. The profile before and after adjustment is shown.
[0031]
As described above, the video signal is an electric signal that is read with respect to the pixel surface of the solid-state imaging unit 55 for each line in the horizontal direction with a plurality of lines from the upper end to the lower end of one pixel surface as one frame. The entire signal is composed of continuous frames.
[0032]
Here, specifically, as shown in FIG. 11A, a video signal when the input signal has a certain signal level will be described.
[0033]
When an input signal of a certain level is measured and input to the input signal processing unit 6, the electron beam B is one horizontal on the phosphor screen 51 as shown in FIG. 11A according to the input signal. Draw a straight line. Fluorescence is emitted from the phosphor screen 51 along the straight line, and the fluorescence is projected to the solid-state imaging unit 55 via the optical fiber plate 53. Each CCD element on which the fluorescence is projected in the solid-state imaging unit 55 generates an electrical signal corresponding to the amount of fluorescence emitted.
[0034]
Therefore, for example, if the solid-state image pickup unit 55 forms an image pickup surface by arranging 600 pixels in the horizontal direction and 480 pixels in the vertical direction, for example, the video signal conversion processing unit 7 First, with respect to the imaging surface, one row in the horizontal direction at the upper end of the imaging surface, that is, 600 pixels, is scanned pixel by pixel from one end to extract an electrical signal, and data for one line is acquired. Next, the 600 pixels in the second row in the horizontal direction are scanned in the same manner to acquire data for one line. In this way, 480 lines of data are acquired sequentially from the upper end to the lower end in the vertical direction of the pixel surface, and this is used as one frame of video signal data. Furthermore, video signal data of the number of frames necessary for displaying the waveform on the display panel 10 is sequentially acquired.
[0035]
In the case of a horizontal straight line waveform displayed on the display panel 10 shown in FIG. 11A, the luminance level profile P1 related to the video signal data for one frame is indicated by the bold line in FIG. It is expressed as follows. In other words, if the input signal indicates a horizontal straight line, the scanning direction of data extraction is the same direction as the straight line, so that the luminance levels of 600 pixels included in one line are all the same size and 480 lines. Among them, a high luminance level appears only on the lines existing within the width of the bright line.
[0036]
A profile P1 represented by a thick line in FIG. 1A schematically shows a luminance level corresponding to a horizontal straight line waveform as shown in FIG. In the figure, the luminance level L0 indicates a dark part without a bright line. In the figure, a profile P1 for one frame out of a plurality of consecutive video signal data is representatively shown.
[0037]
In FIG. 1A, in the profile P1 for one frame, a line in which data of 600 dots in the horizontal direction are sequentially arranged is one scan line, and 480 scan lines from the upper end to the lower end of the imaging screen are arranged in order. It is out. Therefore, data of 600 × 480 dots are arranged as one frame.
[0038]
By the way, since the luminance level profile P1 of the video signal data in FIG. 1A is set to a high luminance level when the input signal is drawn on the fluorescent screen 51 with the electron beam B, the scattered light of the fluorescence is applied to the entire screen. As a result of spreading over the entire screen, the entire screen is brightened. Therefore, it represents that the data of the luminance level L1 exists over the entire range of one frame of the video signal data. In the profile P11 of the line position corresponding to the waveform straight line, although there is the luminance level L1 in spite of having the luminance level L11, the bright line corresponding to the waveform straight line is displayed. It is difficult to observe.
[0039]
Therefore, in the first embodiment, the minimum value of the luminance level in one frame is detected, and in the example shown in FIG. 1A, the luminance level L1 is detected. Then, the luminance level L1 is subtracted from the luminance level of the video signal data of the next one frame. In this manner, the minimum value of the luminance level detected in the previous frame is sequentially reduced from the luminance level in the next frame. In the waveform observation of the measured input signal, the displayed image is a still image, and the waveform displayed in successive frames hardly moves, so even if the value detected in the previous frame is applied to the next frame, it changes. It doesn't matter.
[0040]
Next, a specific example of performing the luminance level adjustment processing of the present embodiment in the waveform display device shown in FIG. 10 will be described with reference to the block configuration of FIG.
[0041]
The brightness level adjustment processing of the present embodiment is executed by the display processing control unit 8 in the waveform display device shown in FIG. The display processing control unit 8 receives the video signal data generated by the video signal conversion processing unit 7 as input data, and performs editing processing necessary for displaying the video signal data on the display panel 10. Therefore, the brightness level adjustment processing unit shown in FIG. 2 is inserted into the input unit of the display processing control unit 8.
[0042]
The luminance level adjustment processing unit in FIG. 2 includes a data comparison unit 11, a minimum value data detection unit 12, a minimum value data storage unit 13, and a subtraction unit 14. The luminance level adjustment processing unit is supplied with video signal data having the luminance level profile P1 shown in FIG. 1A as input data.
[0043]
First, the data of the first frame is sequentially input in dot units. The input data is input to one input terminal of the data comparison unit 11 and compared with the immediately preceding data input to the other input terminal. The minimum value data detection unit 12 detects data indicating the lowest luminance level in the frame among the data sequentially compared with the data input immediately before by the data comparison unit 11.
[0044]
Therefore, the minimum value data detection unit 12 stores the minimum value data in the minimum value storage unit 13 after the comparison of all the data of the frame is completed and the minimum value is detected. In the case of FIG. 1A, the minimum value data is the luminance level L1. Next, when the data of the next frame is input, the subtracting unit 14 reads L1 which is the minimum value data from the minimum value data storage unit 13, and subtracts L1 from each data of the next frame and outputs it. Since the minimum value cannot be detected for the data of the first frame, L1 is set to 0, and the data is output as it is without being reduced. For subsequent frames, the minimum value data is detected in the previous frame, reflected in the next frame, and this process is repeated one after another.
[0045]
A luminance level profile P of the video signal data subjected to the luminance level adjustment processing in this way is shown in FIG. In the brightness level adjustment process according to the first embodiment, since the minimum value data of the previous frame is reduced over the entire frame, the brightness of the entire screen can be removed. Further, in the example of FIG. 1A, the case where the entire screen is uniformly bright is shown. However, when the brightness is non-uniform and bright and dark when viewed on the entire screen, the first embodiment is used. According to the brightness level adjustment process, the brightness level of the dark part is set to the minimum value L1, and L1 is subtracted from the video signal data of one frame. Is done.
[0046]
However, in these cases, the brightness level L12 in the bright line after the brightness level adjustment is also reduced by the minimum value L1, but the brightness of the entire screen can be removed, and the surrounding brightness is reduced. Bright line brightness is clarified, making it easier to observe waveforms on the display screen.
[0047]
(Second Embodiment)
In the first embodiment, the brightness level of the bright line portion is intended to be clearly shown by removing the brightness of the entire display screen. In the second embodiment, FIG. As shown, when a bright line having a higher luminance level L21 exists at the center of the bright line having a somewhat brighter luminance level L2, the luminance level L2 is left as it is to clarify the bright line of the waveform. The object is to perform the brightness level adjustment process so that only the portion of the brightness level L21 that is the original bright line is further emphasized.
[0048]
Here, the waveform of FIG. 11B is taken as an example, and the luminance level profile of the video signal data generated by the video signal conversion processing unit 7 is shown in FIG. The luminance level profile in the figure has the same characteristics as the luminance level profile in FIG. 1A described in the first embodiment, and the periphery around the bright line in one frame in the video signal data. Only the brightness level profile of the part was shown. In the luminance level profile P2 of the video signal data shown in FIG. 3A, the luminance level profile P21 is a portion corresponding to the original bright line corresponding to the signal waveform line, and has the size of the luminance level L2. . On both sides of the profile P21, for example, a band of a luminance level L2 having a width caused by bleeding or the like is attached.
[0049]
Therefore, FIG. 3B shows a profile after performing a brightness level adjustment process for further emphasizing only the portion of the brightness level L21, which is the original bright line, with respect to the brightness level profile P2. In the drawing, only the brightness level profile P21 is level-enhanced and adjusted to the brightness level profile P22. The emphasized luminance level profile P22 is indicated by a broken line. The luminance level L21 is greatly emphasized to the luminance level L22 without changing the luminance level L2.
[0050]
When emphasizing in this way, in the luminance level adjustment processing for video signal data, first, the maximum value of the luminance level appearing in one frame is detected. In the example of the profile in FIG. 3A, the luminance level L21 is the maximum value. The maximum value L21 is stored. Then, each data of the next frame is compared with the maximum value L21, and when the brightness level of the data matches the maximum value L21, the data is multiplied by a preset coefficient k1 to obtain the brightness level of the data. To increase.
[0051]
The target to be compared with the data is the maximum value L21. However, in the example of the brightness level profile P21 of the bright line in FIG. 3A, there are a plurality of dots having the brightness level of the maximum value L21. The level profile P21 is emphasized by the brightness level profile P22 with a width. For example, when only one dot protrudes and is bright at the head of the profile P21, the brightness level of this dot is set. Since it is detected as the maximum value, the brightness level of only the dot is emphasized by the enhancement in the brightness level adjustment process, and the enhancement effect is weak.
[0052]
Therefore, in the brightness level adjustment processing according to the second embodiment, a coefficient having a predetermined value slightly smaller than the detected maximum value is compared with the data of the next frame so that the brightness level for one dot is not emphasized. Assume that k1 is calculated. In this way, by setting the value smaller than the maximum value, the luminance level of the entire head including the maximum value is emphasized as in the luminance level profile P22 indicated by the broken line in FIG.
[0053]
Next, a specific example of performing the brightness level adjustment processing according to the second embodiment in the waveform display device shown in FIG. 10 will be described with reference to the block configuration of FIG.
[0054]
Since the brightness level adjustment process of the present embodiment is executed by the display process control unit 8 in the waveform display device shown in FIG. 10, the brightness level adjustment process shown in FIG. Part will be inserted.
[0055]
4 includes a data comparison unit 21, a maximum value data detection unit 22, a maximum value data storage unit 23, a predetermined value data comparison unit 24, and a multiplication unit 25. Video signal data having the luminance level profile P2 shown in FIG. 3A is supplied to the luminance level adjustment processing unit as input data.
[0056]
First, the data of the first frame is sequentially input in dot units. The input data is input to one input terminal of the data comparison unit 21 and compared with the immediately preceding data input to the other input terminal. The maximum value data detection unit 22 detects data indicating the highest luminance level in the frame among the data sequentially compared with the data input immediately before by the data comparison unit 21.
[0057]
Therefore, the maximum value data detection unit 12 stores the maximum value data in the maximum value storage unit 23 after the comparison of all the data of the frame is completed and the maximum value is detected. In the case of FIG. 3A, the maximum value data is the luminance level L21. The maximum value data is sent to the predetermined value data comparison unit 24, and a predetermined value having a luminance level smaller than the maximum value is calculated. Then, a coefficient 1 and a coefficient a corresponding to a predetermined value are created as the coefficient k1. Here, the coefficient a is 1 <a, and the magnitude of a is assumed to be adjusted in advance so that the multiplication result does not reach the white MAX level.
[0058]
Next, when data of the next frame is input to the luminance level adjustment processing unit, the predetermined value data comparison unit 24 sequentially compares the luminance level of the sequentially input dots with the predetermined value, and data of a predetermined value or more. Select. Then, the multiplier 25 multiplies the selected data by the coefficient a. When the sequentially input data is equal to or less than the predetermined value, the multiplier 25 multiplies the data by a coefficient 1 and outputs the data with the luminance level of the input data.
[0059]
For subsequent frames, the maximum value data is detected in the previous frame, reflected in the next frame, and this process is repeated one after another.
[0060]
In this way, as shown in FIG. 3B, the brightness level profile of the video signal data subjected to the brightness level adjustment process is such that only the profile P21 is level-enhanced to become the profile P22, and the peripheral portion thereof is inputted. The brightness level profile P2 is maintained while maintaining the above state.
[0061]
In the luminance level adjustment processing according to the second embodiment, the maximum value of the luminance level in the previous frame is detected, and the level of the data of the next frame is compared based on a predetermined value generated with reference to the maximum value. Since the coefficient a is multiplied with the data having the luminance level equal to or higher than the predetermined value, the luminance level of only the original bright line can be emphasized, and even if the surrounding portion is bright, only the bright line is The bright line is clearly observed.
[0062]
(Third embodiment)
In the second embodiment, as shown in FIG. 11B, the brightness of the screen is high to some extent, and the bright line that protrudes in the center of the brightness level L2 and has the bright brightness level L21 is the target of level adjustment. Then, a brightness level adjustment process for enhancing the brightness level of only the protruding bright line portion was performed. When this adjustment process is applied to the bright line of the signal waveform as shown in FIG. 11A, the data of a predetermined value or more is multiplied by the coefficient a. Therefore, in the brightness level profile of the bright line, Has a certain width, the multiplication coefficient is a constant value a, so that the head in the luminance level profile of the bright line is emphasized with the width. Then, even when the brightness of the screen is low or the brightness level of the bright line itself is low, when the screen is displayed, the bright line remains bright and warped, making it difficult to observe the waveform. .
[0063]
Therefore, in the third embodiment, instead of fixing the coefficient to be multiplied to a constant value, the input data is level-determined in a plurality of ranges, and coefficients of different sizes are input to the input data corresponding to the plurality of ranges. It was decided to multiply. The brightness level profile of the bright line that has been subjected to such brightness level adjustment is enhanced stepwise in the vicinity of the maximum brightness level in the head. Therefore, even when the brightness of the screen is low, the brightness in the width direction of the bright lines is changed. As a result, the width of the bright lines that are brightly emphasized is suppressed, and the bright portions are not made thicker than necessary. To make it easier.
[0064]
Here, taking the waveform of FIG. 11A as an example, the luminance level profile of the video signal data generated by the video signal conversion processing unit 7 is shown in FIG. The luminance level profile in the figure has the same characteristics as the luminance level profile in FIG. 1A described in the first embodiment, but shows a case where the luminance level of the bright line is low, and the video signal The brightness level profile of only the peripheral part centering on the bright line in one frame of data is indicated by a bold line.
[0065]
In the luminance level profile P3 of the video signal data shown in FIG. 5, the luminance level profile P31 is a portion corresponding to a bright line corresponding to the signal waveform line, and has a luminance level L31 at the center.
[0066]
Therefore, the profile P32 after performing the brightness level adjustment process in a stepwise manner on the head portion of the brightness level profile P31 is indicated by a broken line in FIG. A profile P32 in the figure shows an example in which the luminance level changes in three steps. The luminance level of the input data is determined by dividing the range according to the set determination levels Ln1 to Ln3. As a result of multiplying the input data by the coefficient kn corresponding to, the level of the entire head of the luminance level profile is enhanced, and a stepwise change appears in the luminance level. In the example of FIG. 5, since it is assumed that the luminance level L31 related to the bright line is small, the stepwise luminance level adjustment processing for the head of the bright line has a predetermined value of the maximum luminance level in one frame. It is performed in the following cases.
[0067]
When emphasizing in this way, in the luminance level adjustment processing for video signal data, first, it is determined whether or not the maximum value detected in the previous frame is less than or equal to a predetermined value. The brightness level of the input data is determined. When the maximum value exceeds the predetermined value, the luminance level of the input data is not determined. Therefore, in the example of FIG. 5, level determination is performed in four ranges of level Ln1 or lower, levels Ln1 to Ln2, levels Ln2 to Ln3, and level Ln3 or higher. Next, after determining which level range the luminance level of the input data is in, the coefficient kn corresponding to the range is multiplied by the data and output.
[0068]
It should be noted that the coefficient kn to be multiplied with the input data is as follows: coefficient 1 below level Ln1, coefficient b1 at levels Ln1 to Ln2, b2 at levels Ln2 to Ln3, and coefficient b3 above level Ln3. Different coefficients are set corresponding to the ranges. For example, the coefficient kn may have a relationship of 1 <b1 <b2 <b3, and the stepwise change in the luminance level of the head is changed by changing the size of each coefficient or the reverse order. be able to. Here, with respect to input data in the range of the coefficient 1 level Ln1 or less, the level of the input data is kept and no level enhancement is performed.
[0069]
In setting the size of the coefficient kn, the enhanced luminance level is prevented from reaching the white MAX data. Further, the height of the level Ln1 is set so as not to increase the noise signal.
[0070]
Next, a specific example of performing the luminance level adjustment processing according to the third embodiment in the waveform display device shown in FIG. 10 will be described with reference to the block configuration of FIG.
[0071]
Since the brightness level adjustment process of the present embodiment is executed by the display process control unit 8 in the waveform display device shown in FIG. 10, the brightness level adjustment process shown in FIG. Part will be inserted. Since it is determined whether the maximum value detected in the previous frame is equal to or less than a predetermined value, the maximum value data storage unit 23 shown in FIG. 4 is required.
[0072]
The luminance level adjustment processing unit in FIG. 6 includes an input data level determination unit 31, a level adjustment unit 32, a multiplication unit 33, and a selection unit 34. The luminance level adjustment processing unit is supplied with video signal data having the luminance level profile P3 shown in FIG. 5 as input data.
[0073]
First, the video signal data of the frame is sequentially input in units of dots to the selection unit 34 of the luminance level adjustment processing unit. The selection unit 34 receives the maximum value data related to the previous frame from the maximum value data storage unit 23. To determine whether the maximum value is equal to or less than a predetermined value set in advance. If the maximum value is less than or equal to the predetermined value, the brightness level adjustment process is selected to be performed. If not, the output is performed without performing the process. The input data level determination unit 31 determines whether the level of the input data falls within any of the four ranges described above. The determination result is sent to the level adjustment unit 32, and the coefficient kn corresponding to the determined range is read out.
[0074]
On the other hand, since the data input to the input data level determination unit 31 is input to the multiplication unit 33 at the same time, the multiplication unit 33 reads the input data read by the level adjustment unit 32 with respect to this input data. Multiply the coefficient kn corresponding to the data, and output the multiplied data.
[0075]
In this way, for each dot of video signal data that is sequentially input, the range of the level of the data is determined, and the coefficient kn corresponding to the range determination result is multiplied by the data one by one. Therefore, as shown in FIG. 5, the luminance level profile of the video signal data subjected to the luminance level adjustment is subjected to level enhancement in a stepwise manner only at the head of the profile P31 to form a profile P32. Is a luminance level profile P3 maintaining the input state.
[0076]
The brightness level profile P31 has a trapezoidal shape in which the maximum value L31 of the brightness level has the range x1 before the brightness level adjustment process, but after the brightness level adjustment process, the range at the head of the profile P31. At x1, the luminance level is emphasized up to level L32, and the level is enhanced stepwise in the range of x2 according to the brightness of the dots. If the profile P31 is seen as a whole, the range x1 is widened to the range x2 by emphasizing the luminance level. The number of stages is not limited to three, but can be a plurality of stages as necessary.
[0077]
As described above, according to the brightness level adjustment process of the third embodiment, when the brightness is dark, the bright line becomes thin and it is difficult to observe the waveform. Bright lines can be created and dark data can be displayed brighter.
[0078]
(Fourth embodiment)
In the first to third embodiments so far, as illustrated in FIG. 11, a uniform straight line has been described as an example, but in reality, the measured signal is often a rectangular wave. . When this rectangular wave signal is input to the input processing unit 6 of the waveform display device shown in FIG. 10, the rectangular wave is displayed on the screen of the display panel 10 as shown in FIG. Is done.
[0079]
When the rectangular wave displayed on the screen is viewed, in the normal display state, the horizontal bright line is thick and the vertical bright line is thin, and the brightness of the vertical bright line is darker than the horizontal bright line. It has become. When the overall display brightness is lowered, it is difficult to know whether there is a vertical bright line. On the other hand, when the luminance is increased in order to make the vertical bright line easy to see, the horizontal bright line becomes brighter, but the effect is difficult to appear for the vertical bright line. Regarding such a vertical bright line, the brightness level profile of one vertical bright line at the position of the broken line in FIG. 7A is shown by a thick line in FIG. 7B.
[0080]
As shown in FIG. 7B, the vertical bright line of the rectangular wave is thin and has a low luminance level. In the waveform display device of FIG. 10, the electronic image conversion device shown in FIG. 9 is used in the waveform display device of FIG. 10, and the electron beam B is applied to the phosphor screen 51 by the electron beam B according to the input signal. This is due to drawing. That is, as the rising edge of the rectangular wave is steeper, when the electron beam B moves from one horizontal emission line to the next horizontal emission line, assuming that the intensity of the electron beam B is constant, the movement of the beam at the rising part Is faster than when it is horizontal, the amount of light emitted from the phosphor screen 51 is reduced.
[0081]
Corresponding to the vertical bright line, the luminance level profile P41 appears in the luminance level profile P4 of the video signal data, and in the example of the rectangular wave in FIG. 7A, four profiles P41 appear in one scan line. become. Then, the brightness level of the profile P41 stops at the level L41 at the maximum, and the width x3 having the level 41 is also narrow, for example, about one dot or several dots.
[0082]
Therefore, in the fourth embodiment, a brightness level adjustment process is performed to make it easy to see the thin and dark bright lines generated when a rectangular wave signal is displayed on the screen. Since it is only necessary to display that the vertical bright line is clearly present, in this luminance level adjustment process, the bright line width of the luminance level profile P41 is kept as it is, and only the peak portion showing the highest level L41 is emphasized.
[0083]
In this brightness level adjustment process, in order to emphasize only the peak portion, first, a peak (convex) portion appearing in the brightness level profile P41 of FIG. The data of the part is multiplied by a preset coefficient k2.
[0084]
Next, a specific example of performing the luminance level adjustment processing according to the fourth embodiment in the waveform display device shown in FIG. 10 will be described with reference to the block configuration of FIG.
[0085]
Since the brightness level adjustment process of the present embodiment is executed by the display process control unit 8 in the waveform display device shown in FIG. 10, the brightness level adjustment process shown in FIG. Part will be inserted.
[0086]
8 includes an input data level detection unit 41, a convex data detection unit 42, a delay processing unit 43, and a multiplication unit 44. The luminance level adjustment processing unit is supplied with video signal data having the luminance level profile P4 shown in FIG. 5 as input data.
[0087]
First, video signal data is sequentially input to the luminance level adjustment processing unit in dot units. For the input data, the input data level detection unit 41 detects the level of the input data, and sequentially transmits the level of each data to the convex data detection unit 42. The convex data detection unit 42 sequentially compares the levels of the preceding and succeeding data with respect to the levels of data that are sequentially transmitted. Then, data is detected in which the level increases one after another, and then the level starts to decrease, and the peak portion is extracted assuming that the portion where the level changes is the peak portion.
[0088]
The convex data detection unit 42 supplies a coefficient k2 set in advance to the multiplication unit 44 at a timing when the level of the input data can be detected. The coefficient k2 includes the coefficient 1 and the coefficient b (1 <b), and the convex data detection unit 42 supplies the coefficient b to the multiplication unit 44 when the peak data is extracted, and the peak portion For data other than the above, a coefficient of 1 is supplied.
[0089]
Since it takes time to detect the peak portion of the input data sequentially input, the delay processing unit 44 delays the input data by a predetermined amount so that the detected peak portion data can be multiplied by the coefficient k2 in time. I am letting. The multiplication unit 44 multiplies each data of the input signal output from the delay processing unit 44 by the coefficient k2 supplied from the convex data detection unit 42 and outputs the result.
[0090]
In the luminance level profile P4 of the video signal data output from such a luminance level adjustment processing unit, as shown by a broken line in FIG. 7B, the peak portion width x3 remains unchanged, and the luminance level of the peak portion is the same. The profile P42 emphasized from the level L41 to the level L42 is added. Therefore, in the case of a thin and dark bright line such as a vertical bright line in a rectangular wave signal, only the peak portion of the bright line can be emphasized to an appropriate level, and the waveform of the measured signal can be easily observed.
[0091]
【The invention's effect】
As described above, according to the waveform display device of the present invention, the video signal data extracted from the solid-state imaging screen on which the measured input signal is drawn is generated, and as the luminance level adjustment processing related to the video signal data, Since the lowest luminance level among the data included in one frame of the video signal data is detected and the luminance level is subtracted from the luminance level of all data constituting the frame, for example, the luminance of the screen display is reduced. When it is raised, the entire screen can be prevented from being brightened. It becomes possible to observe the signal waveform clearly.
[0092]
In addition, as the luminance level adjustment processing for the generated video signal data, the maximum luminance level data is detected from the data included in one frame of the video signal data, and the luminance level at the top of the luminance level profile related to the bright line is detected. When the signal waveform is displayed with increased brightness, even if the brightness level around the bright line increases, the original bright line can be emphasized, and the waveform of the input signal can be clearly observed. It can be done.
[0093]
Further, as the brightness level adjustment process for the generated video signal data, the brightness level for the data is changed according to the brightness level of the data included in the video signal data and emphasized. When displaying, when the bright line of the signal waveform becomes thin and the luminance level of the bright line becomes low, only the central part of this dark bright line can be displayed brightly, which makes it easy to observe the waveform of the input signal. .
[0094]
Then, as a luminance level adjustment process for the generated video signal data, a peak portion of the luminance level is detected from the data related to the bright line included in the video signal data, and the luminance level is emphasized only for the peak portion. Therefore, if the brightness of the screen is sufficient, but there is a dark part in the bright line indicating the waveform, for example, the original bright line of the waveform can be emphasized with respect to the vertical bright line of the rectangular wave signal, and the input signal It will be possible to clearly observe the waveform.
[0095]
Moreover, according to the present invention, the brightness level adjustment processing unit as described above can perform real-time image display without so-called frame dropping, and can perform appropriate waveform display as an analog oscilloscope. Further, it is not necessary to perform complicated image processing, and the luminance level adjustment processing unit can be realized with a simple hardware configuration.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a waveform brightness level adjustment process according to a first embodiment of the present invention, using a brightness level profile.
FIG. 2 is a diagram illustrating a block configuration for luminance level adjustment processing according to the first embodiment;
FIG. 3 is a diagram illustrating a luminance level adjustment process for a waveform in the second embodiment of the present invention using a luminance level profile.
FIG. 4 is a diagram illustrating a block configuration for luminance level adjustment processing according to the second embodiment;
FIG. 5 is a diagram illustrating a waveform luminance level adjustment process using a luminance level profile according to a third embodiment of the present invention.
FIG. 6 is a diagram illustrating a block configuration for luminance level adjustment processing according to the third embodiment;
FIG. 7 is a diagram illustrating a waveform luminance level adjustment process using a luminance level profile according to a fourth embodiment of the present invention.
FIG. 8 is a diagram illustrating a block configuration for luminance level adjustment processing according to the fourth embodiment;
FIG. 9 is a diagram illustrating a specific configuration of a conventional electronic image conversion apparatus.
FIG. 10 is a diagram illustrating a block configuration of a waveform display device that displays a waveform of an electrical signal obtained from an electronic image conversion device.
FIG. 11 is a diagram illustrating a luminance level in a signal waveform displayed by a conventional waveform display device.
[Explanation of symbols]
1 ... Case
2 ... electron gun
3. Deflection part
4 ... latter stage acceleration part
5. Image conversion output unit
6 ... Input signal processor
7 ... Video signal conversion processing section
8 ... Display processing control unit
9 ... Waveform output display
10 ... Display panel
11, 21 ... Data comparison section
12 ... Minimum value data detector
13 ... Minimum value data storage unit
14 ... Subtraction unit
22 ... Maximum value data detection unit
23 ... Maximum value data storage unit
24: Predetermined value data comparison unit
25, 33, 44 ... multiplication section
31 ... Input data level determination unit
32 ... Level adjustment section
34 ... Selection part
41 ... Delay processing unit
42: Input data level detector
43: Convex data detector
51 ... phosphor screen
52, 54 ... Transparent conductive film
53 ... Optical fiber plate
55 ... Solid-state imaging unit

Claims (8)

Solids into an electric signal representing the phosphor screen waveform of the input signal is drawn by an electron beam deflected in accordance with the measured input signal, the luminance level of light generated from the fluorescent surface at a waveform drawing An electronic image conversion means having an imaging unit;
Video signal processing means for converting into video signal data for each frame based on the electrical signal taken out while scanning the solid-state imaging unit;
A detection unit that detects the minimum value of the luminance level for each frame in the video signal data, a storage unit that stores the detected minimum value, and the luminance of the video signal data of the next frame in which the minimum value is detected A process control means having a subtracting unit for subtracting the minimum value from the level ,
The processing control unit generates video signal data in which the minimum value of the video signal data is adjusted to a luminance level of a dark portion without a bright line, and outputs the video signal data to a waveform display unit. A waveform display device that measures the electrical waveform of an input signal . Solids into an electric signal representing the phosphor screen waveform of the input signal is drawn by an electron beam deflected in accordance with the measured input signal, the luminance level of light generated from the fluorescent surface at a waveform drawing An electronic image conversion means having an imaging unit;
Video signal processing means for converting into video signal data for each frame based on the electrical signal taken out while scanning the solid-state imaging unit;
For each frame in the video signal data, a detection unit that detects the maximum value of the luminance level related to the waveform data included in the frame, a storage unit that stores the detected maximum value, and a specific range from the maximum value Processing control means having a multiplication unit that multiplies the waveform data included in the next frame corresponding to the luminance level of the predetermined coefficient by a predetermined coefficient,
It said processing control means generates the video signal data to adjust the brightness level of the waveform data, waveform display device for measuring the electrical waveform of the input signal and outputs the video signal data to the waveform display unit . The specific range, the waveform display apparatus according to claim 2, characterized in that it is set in a range below from the detected said maximum value by a predetermined value. In the specific range, a plurality of ranges are set below the detected maximum value,
The multiplication unit is configured waveform display according to claim 2 or 3, characterized in that multiplying the coefficients set in different sizes corresponding to said plurality of ranges in the waveform data of the video signal data apparatus. The processing control means includes a level discriminating unit that discriminates a luminance level included in the video signal data into the plurality of ranges for each frame, and a level adjusting unit that outputs the coefficient having a magnitude corresponding to the discriminated range. And
The multiplication unit, the waveform display apparatus according to the coefficient output from the level adjuster to claim 4, characterized by multiplying the waveform data. Said processing control means, wherein when the maximum value of the luminance level in one frame of the video signal data is equal to or less than the predetermined value, the according to claim 5 having a selection unit for inputting the video signal data to said level discriminator Waveform display device. The processing control means includes a level comparison unit that sequentially compares levels before and after the data included in the video signal data that is sequentially input, and the level comparison unit sequentially increases the data sequence that has subsequently decreased. upon detecting the waveform display device according to any one of claims 2 to 6, characterized in that said waveform data included in the video signal data. The processing control means includes a maximum value detector for outputting a predetermined coefficient when the maximum value of the luminance level in the waveform data of the video signal data sequentially input is detected, and delays the video signal data by a predetermined amount The waveform display apparatus according to claim 7, further comprising: a delay processing unit that causes the waveform data of the delayed video signal data to be multiplied by the predetermined amount.

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