Abstract:
Measurement points for display on a two-dimensional pixel-based display device are formed by scanned and digitized measurement values. To this end, the resolution of each measurement point according to time and/or value is higher than the resolution of the two-dimensional pixel-based display device. The measurement points are connected into a continuous measurement point curve if they are not located on directly adjoining pixels. In order to determine the pixels to be depicted of the continuous measurement point curve between two measurement points not located on directly adjoining pixels, the positions of the adjoining measurement points within the associated pixels are taken into consideration.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a method and a device for displaying digital measurement values on pixel-based display devices, in particular, display devices in measuring devices. 
     2. Related Technology 
     For the display of digital measurement values on pixel-based displays, the measurement values are conventionally imaged as precisely as possible onto individual pixels. However, if the measurement values are disposed far apart, an image of poor legibility, which only consists of individual points, is obtained. For this reason, an interpolation between the measurement values is conventionally implemented. This produces a more readily legible image, but is associated with high calculation costs. However, if the sampling times of the digital signal are not synchronized with the image change of the display, an unstable image is also obtained with this method, because different measurement curves result from the different interpolation points of the interpolation. 
     Accordingly, a method and a device for the presentation of waveforms are disclosed in EP 0 919 818 B1. The method uses an interpolation of displayed points between measurement values. On one hand, this requires a high calculation cost. On the other hand, a stable image is not always produced, since the position of the interpolation points of the interpolation varies because of lack of synchronicity of the sampling times with the structuring of the image. 
     SUMMARY OF THE INVENTION 
     The invention provides a method and a device, which present digital measurement values on a display with a stable image, good legibility and low calculation costs. 
     Accordingly, the invention provides a method for displaying measurement values on a two-dimensional, pixel-based display device of a measuring device, wherein the measurement values are sampled and digitized, the sampled and digitized measurement values form measurement points within a two-dimensional coordinate system, the resolution of each measurement point according to time and/or value is higher than the resolution of the two-dimensional, pixel-based display device, the measurement points on the two-dimensional, pixel-based display device are connected to form a continuous measurement-point curve, if the measurement points are not disposed on directly adjacent pixels, wherein, to determine the pixels of the continuous measurement-point curve between two measurement points to be displayed, the position of the adjacent measurement points within the associated pixels is taken into consideration, if the measurement points are not disposed on directly adjacent pixels. 
     Further, the invention provides a device for displaying measurement values on a two-dimensional, pixel-based display device, with a scaling device, a pixel-assignment device, and a pixel-connecting device, wherein the scaling device scales the sampled and digitized measurement values of the two-dimensional, pixel-based display device corresponding to measurement points, the resolution according to time and/or value of each measurement point is higher than the resolution of the two-dimensional, pixel-based display device, the pixel-assignment device assigns the measurement points to pixels of the two-dimensional, pixel-based display device, the pixel-connecting device connects the measurement points to form a continuous measurement-point curve, if the measurement points are not disposed on directly adjacent pixels, and the pixel-connecting device communicates the continuous measurement-point curve to the display device, wherein, to determine the pixels of the continuous measurement-point curve between two measurement points to be displayed, the pixel-connecting device takes into consideration the position of the adjacent measurement points within the associated pixel, if the measurement points are not disposed on directly adjacent pixels. 
     For the display of measurement values on a two-dimensional pixel-based display device, measurement points in a two-dimensional coordinate system are formed from sampled and digitized measurement values. In this context, the resolution of each measurement point according to time and/or value is higher than the resolution of the two-dimensional, pixel-based display. The measurement points are connected to form a continuous measurement-point curve, if they are not disposed on directly adjacent pixels. To determine the pixels of the continuous measurement-point curve between two measurement points to be displayed, which are not disposed on directly adjacent pixels, the position of the adjacent measurement points within the associated pixels is taken into consideration. The continuous measurement-point curve displayed becomes clearer as a result and, over the time course of the measurement with a constant signal, is more stable than with conventional display methods. 
     To determine the pixels of the continuous measurement-point curve between two adjacent measurement points to be displayed, which are horizontally offset by precisely one pixel, one or more transition points of the continuous measurement-point curve are preferably calculated across the boundaries between the pixel rows. The continuous measurement-point curve from the first of the two adjacent measurement points to the first transition point is advantageously displayed in the pixel row of the first measurement point. The continuous measurement-point curve from the first transition point to the last transition point is advantageously displayed in each case in the scanned pixel row. The continuous measurement-point curve from the last transition point to the second of the two adjacent measurement points is advantageously displayed in the pixel row of the second measurement point. 
     To determine the pixels of the continuous measurement-point curve between two adjacent measurement points to be displayed, which are vertically offset, a transition point of the continuous measurement-point curve is preferably calculated across the boundaries between the pixel columns. The continuous measurement-point curve from the first of the two adjacent measurement points to the first transition point is advantageously displayed in the pixel column of the first measurement point. The continuous measurement-point curve from the first transition point to the last transition point is advantageously displayed in each case in the scanned pixel column. The continuous measurement-point curve from the last transition point to the second of the two adjacent measurement points is advantageously displayed in the pixel column of the second measurement point. Accordingly, it is unambiguously specified how the measurement-point curve is to be displayed. An unambiguous, clear and at the same time stable curve, which largely corresponds to the characteristic of the analog measurement value is obtained. 
     The transition point or points are preferably calculated from the proportions of the length of a direct connecting line of the two measurement points extending in the pixel columns or respectively the pixel rows. With a curve obtained in this manner, the proximity to the analog measurement values can be further increased. 
     The two adjacent measurement points to be connected to form a continuous measurement-point curve are advantageously horizontally or vertically offset by precisely one pixel column or respectively pixel row. 
     As an alternative, all pixels exceeded by a direct connecting line of the two measurement points to be connected are displayed as a part of the continuous measurement-point curve. As a result of this alternative method, a sufficiently stable and clear curve is achieved with a very low calculation cost. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention is described by way of example with reference to the drawings, in which an advantageous exemplary embodiment of the invention is illustrated. The drawings are as follows: 
         FIG. 1  shows the characteristic of a first exemplary, analog signal and of the associated sampled signal; 
         FIG. 2  shows the characteristic of a second exemplary, analog signal and of the associated sampled signal in several sampling runs; 
         FIG. 3  shows exemplary connection options between measurement points on a two-dimensional display device; 
         FIG. 4  shows exemplary connection options between measurement points on a two-dimensional display device with superimposed, possible, associated analog signal characteristics; 
         FIG. 5  shows a first exemplary analog signal superimposed over associated measurement points of several sampling runs on a two-dimensional display device; 
         FIG. 6  shows a first exemplary output of a two-dimensional display device resulting from the signal from  FIG. 5 ; 
         FIG. 7  shows exemplary signals with connections according to the invention of measurement points on a two-dimensional display device; 
         FIG. 8  shows a second exemplary analog signal superimposed over associated measurement points of several sampling runs on a two-dimensional display device; 
         FIG. 9  shows a second exemplary output of a two-dimensional display device here resulting from the signal from  FIG. 8 ; and 
         FIG. 10  shows a block-circuit diagram of an exemplary embodiment of the device according to the invention. 
     
    
    
     DETAILED DESCRIPTION 
     Initially, the problem and the signals occurring are explained with reference to  FIGS. 1-6 . The functioning of an exemplary embodiment of the method according to the invention is visualized with reference to  FIGS. 7 and 9 . On the basis of  FIG. 10 , the functioning of the device according to the invention is explained. In some cases, a repetition of the presentation and description of identical elements in similar drawings has not been provided. 
     The following table provides a summary of the formula characters used below. 
     
       
         
               
               
               
             
           
               
                   
                   
               
               
                   
                 Abbreviation 
                 Description 
               
               
                   
                   
               
             
             
               
                   
                 f a   
                 Sampling rate 
               
               
                   
                 N Line (k) 
                 Length of the line between the k-th and the 
               
               
                   
                   
                 k + 1-th point 
               
               
                   
                 N Line, 1 (k), 
                 Partial lines 
               
               
                   
                 N Line, 2 (k) 
               
               
                   
                 N S     —     PX   
                 Sample number per column 
               
               
                   
                 N PX   
                 Number of pixel columns on the screen 
               
               
                   
                 S PX (k) 
                 Image column of the k-th point 
               
               
                   
                 T Display   
                 Time on the whole screen 
               
               
                   
                 T PX   
                 Time per pixel column 
               
               
                   
                 T S   
                 Time interval between two samples 
               
               
                   
                 t S (k) 
                 Time of the k-th sample 
               
               
                   
                 T Trigger   
                 Triggering time 
               
               
                   
                   
               
             
          
         
       
     
     In  FIG. 1 , the characteristic of a first exemplary analog and sampled signal is presented. Let an analog measurement curve be given. This can initially extend horizontally and then ascend and then extend horizontally again. To record this measurement curve  12 , let a trigger threshold be defined. Let the timing point T Trigger    10 , at which the analog measurement curve  12  exceeds the trigger threshold  11 , be selected in the following section as a reference point for the display. The display is realized on a two-dimensional, pixel-based display device, which is subdivided into pixel columns  14  and pixel rows  15 . The measurement curve  12  is sampled. The sampled points  17  are disposed on the measurement curve  12  in the display. To simplify the following description, let it be assumed that the measurement curve  12  is only to be displayed on the screen from the triggering time T Trigger    10 . For this purpose, a new time axis is defined, wherein the triggering time  10  represents the zero point. In general, the image display could also begin at a random time before or after the triggering time T Trigger    10 . 
     Since triggering and sampling are independent of one another, the first sampled value is not generally disposed exactly at the triggering time, but is offset in time by the trigger offset T TO    16 . 
     Let f a  be the sampling rate, then
 
 T   S =1 /f   a   (1)
 
is the interval between two sampled values  13 . The first sampled value  13  is then disposed after the triggering event randomly within the range
 
0 ≦T   TO   &lt;T   S   (2)
 
     If this first sampled value  13  has the index k=0, then the k-th sampled value  13  is disposed at the time t S (k) with
 
 t   S ( k )= k·T   S   +T   TO .  (3)
 
     If a time
 
T Display   (4)
 
is displayed on the whole screen, with N PX  pixel columns  14 , a time T PX  per pixel column  14  is calculated as
 
 T   PX   =T   Display   /N   PX .  (5)
 
     A sample x S (k) is displayed in the m-th pixel column  14 , if
 
 m·T   PX   ≦k·T   S ( k )+ T   TO &lt;( m+ 1)· T   PX  with 0 ≦m≦N   PX −1  (6)
 
applies. This equation can also be reformulated as follows:
 
                         S   PX     ⁡     (   k   )       =     floor   ⁢     {         k   ·       T   S     ⁡     (   k   )         +     T   TO         T   PX       }         ,           (   7   )               
wherein S PX (k) indicates the pixel column  14 , to which the k-th sample is assigned. The function floor rounds off the argument. This results in an average sample number N S     —     PX  per column of
 
     
       
         
           
             
               
                 
                   
                     N 
                     
                       S 
                       ⁢ 
                       _ 
                       ⁢ 
                       PX 
                     
                   
                   = 
                   
                     
                       
                         T 
                         Display 
                       
                       
                         
                           T 
                           S 
                         
                         · 
                         
                           N 
                           PX 
                         
                       
                     
                     . 
                   
                 
               
               
                 
                   ( 
                   8 
                   ) 
                 
               
             
           
         
       
     
     By way of example: if
 
f a =1 GHz,  (9)
 
it follows that
 
 T   S =1 /f   a =1 n  sec.  (10)
 
     If the screen has N PX =1000 columns and if a time of T Display =20 μs is displayed, the following results:
 
 T   PX   =T   Display   /N   PX =20 μsec/1000=2 n sec   (11)
 
and furthermore
 
     
       
         
           
             
               
                 
                   
                     N 
                     
                       S 
                       ⁢ 
                       _ 
                       ⁢ 
                       PX 
                     
                   
                   = 
                   
                     
                       
                         20 
                         ⁢ 
                         
                             
                         
                         ⁢ 
                         μ 
                         ⁢ 
                         
                             
                         
                         ⁢ 
                         sec 
                       
                       
                         1 
                         ⁢ 
                         n 
                         ⁢ 
                         
                             
                         
                         ⁢ 
                         
                           sec 
                           · 
                           1000 
                         
                       
                     
                     = 
                     2. 
                   
                 
               
               
                 
                   ( 
                   12 
                   ) 
                 
               
             
           
         
       
     
     By analogy, for
 
f a =0.5 GHz,  (13),
 
the following applies
 
     
       
         
           
             
               
                 
                   
                     N 
                     
                       S 
                       ⁢ 
                       _ 
                       ⁢ 
                       PX 
                     
                   
                   = 
                   
                     
                       
                         20 
                         ⁢ 
                         
                             
                         
                         ⁢ 
                         μ 
                         ⁢ 
                         
                             
                         
                         ⁢ 
                         sec 
                       
                       
                         2 
                         ⁢ 
                         
                             
                         
                         ⁢ 
                         n 
                         ⁢ 
                         
                             
                         
                         ⁢ 
                         
                           sec 
                           · 
                           1000 
                         
                       
                     
                     = 
                     1. 
                   
                 
               
               
                 
                   ( 
                   14 
                   ) 
                 
               
             
           
         
       
     
       FIG. 2  shows the characteristic of a second exemplary analog and sampled signal  20  in several sampling runs. In this context, the sampled points  21 ,  22 ,  23  correspond to three different sampling runs. The distance between sampled points  21 ,  22 ,  23  of the same sampling run is greater than the distance between the pixel rows. Accordingly, pixels, in which no sampled points occur, are disposed between the sampled points. 
     The simplest display mode is the so-called point mode: only the sampled values are presented on the screen as points. If only one measurement curve and a small N S     —     PX  is available, that is to say, a few points per pixel column, only individual points are shown on screen. In order to show a continuous curve on the screen in point mode, the following conditions are necessary:
         either N S     —     PX  must be selected to be sufficiently large, which is not always possible,   or, in the case of a periodic signal, several measurement curves must be superimposed. Since the trigger offset varies in a random manner, a continuous curve is obtained.       

     In general, the brightness of a pixel on the screen is proportional to the frequency of how often this image point has been “hit”. 
     Another mode is the linear mode; in this mode, in each case, two sampled values k and k+1 following one another in time succession are connected by a line in the screen display. In the case of current measuring devices, if these two points are not disposed in the same screen column, three different methods are used for the line display. In  FIG. 3 , exemplary connecting options for measurement points on a two-dimensional display device are illustrated. A first option is that the line  30  extends completely within the column of the measurement point k  33 . A further option is that the line  31  extends completely in the column of the measurement point k+1  34 . A final option is that half of the line  32  extends in the column of measurement point k  33  and half in the column of measurement point k+1  34 . 
     The disadvantages of these illustrated methods are that the line does not reflect the actual characteristic of the measured curve. This applies in particular, if the line is drawn completely in the column of measurement point k  33  or of measurement point k+1  34 . 
       FIG. 4  shows these exemplary connecting options for measurement points on a two-dimensional display device with superimposed, possible, associated analog signal characteristics. Accordingly, the line  30  is displayed completely in the column of measurement point  33 . This provides a good reflection of the possible characteristic  40  of the analog signal. However, as in the case of measurement points  33  and  34 , analog signals  41  and  42  are only poorly imaged. Artefacts are formed. Pixels are displayed, which are not passed by the actual analog signal. Similar considerations apply for the linear characteristic  31  and the possible analog signals  44 ,  45 ,  46 . The linear characteristic  32  achieves better results with the possible analog signals  46 ,  47 ,  48 , but also fails to provide an optimum for all possible analog signals. 
     In  FIG. 5 , a first exemplary analog signal  53  is superimposed over associated measurement points  50 ,  51 ,  52  of several sampling runs on a two-dimensional display device. Let a measurement curve  53  have a gradient of five pixel rows 15 per pixel column  14  and let the sampling be implemented once per pixel column  14 , that is to say, N S     —     PX =1. Let this periodic measurement curve  53  be sampled and recorded five times—each time with a slight time offset. Let these sampled points  50 ,  51 ,  52  be marked in the image with X; those of the first sampling are marked with a circle. Here, the connecting line is drawn completely within the column of the measurement point k  33 . The connection with the following measurement point of the same sampling run is drawn in for every measurement point. 
       FIG. 6  shows a first exemplary output of a two-dimensional display device resulting from the signal from  FIG. 5 . The artefacts explained with reference to  FIG. 4  are displayed here. If the pixel frequencies are displayed on screen as brightnesses  54 ,  55 ,  56 ,  57 ,  58 , the display is blurred by the drawing of the line on screen. 
     In  FIG. 7 , exemplary signals with connections according to the invention between measurement points on a two-dimensional display device are presented. Let N Line (k) be the length of the line between the k-th point  63 ,  66 ,  68 , which occurs in the pixel column S PX (k)=m  14 , and the k+1-th point  64 ,  65 ,  67 , which occurs in the pixel column S PX (k+1)=m+1  14 . The line  60 ,  61 ,  62  is then drawn across two columns. For the subdivision of the line  60 ,  61 ,  62  in the two columns, the following relationship applies, wherein N Line,1 (k) is the length of the line  60 ,  61 ,  62  in the column m and N Line,2 (k) is the length of the line  60 ,  61 ,  62  in the column m+1: 
     
       
         
           
             
               
                 
                   
                     
                       
                         N 
                         
                           Line 
                           , 
                           1 
                         
                       
                       ⁡ 
                       
                         ( 
                         k 
                         ) 
                       
                     
                     = 
                     
                       
                         
                           
                             ( 
                             
                               
                                 ⌊ 
                                 
                                   
                                     k 
                                     · 
                                     
                                       
                                         t 
                                         S 
                                       
                                       ⁡ 
                                       
                                         ( 
                                         
                                           k 
                                           + 
                                           1 
                                         
                                         ) 
                                       
                                     
                                   
                                   
                                     T 
                                     PX 
                                   
                                 
                                 ⌋ 
                               
                               - 
                               
                                 
                                   k 
                                   · 
                                   
                                     
                                       t 
                                       S 
                                     
                                     ⁡ 
                                     
                                       ( 
                                       k 
                                       ) 
                                     
                                   
                                 
                                 
                                   T 
                                   PX 
                                 
                               
                             
                             ) 
                           
                           · 
                           
                             
                               N 
                               Line 
                             
                             ⁡ 
                             
                               ( 
                               k 
                               ) 
                             
                           
                         
                         ⁢ 
                         
                             
                         
                         ⁢ 
                         in 
                         ⁢ 
                         
                             
                         
                         ⁢ 
                         
                           
                             S 
                             PX 
                           
                           ⁡ 
                           
                             ( 
                             k 
                             ) 
                           
                         
                       
                       = 
                       m 
                     
                   
                   ⁢ 
                   
                     
 
                   
                   ⁢ 
                   
                     
                       
                         N 
                         
                           Line 
                           , 
                           2 
                         
                       
                       ⁡ 
                       
                         ( 
                         k 
                         ) 
                       
                     
                     = 
                     
                       
                         
                           
                             ( 
                             
                               
                                 
                                   k 
                                   · 
                                   
                                     
                                       t 
                                       S 
                                     
                                     ⁡ 
                                     
                                       ( 
                                       
                                         k 
                                         + 
                                         1 
                                       
                                       ) 
                                     
                                   
                                 
                                 
                                   T 
                                   PX 
                                 
                               
                               - 
                               
                                 ⌊ 
                                 
                                   
                                     k 
                                     · 
                                     
                                       
                                         t 
                                         S 
                                       
                                       ⁡ 
                                       
                                         ( 
                                         
                                           k 
                                           + 
                                           1 
                                         
                                         ) 
                                       
                                     
                                   
                                   
                                     T 
                                     PX 
                                   
                                 
                                 ⌋ 
                               
                             
                             ) 
                           
                           · 
                           
                             
                               N 
                               Line 
                             
                             ⁡ 
                             
                               ( 
                               k 
                               ) 
                             
                           
                         
                         ⁢ 
                         
                             
                         
                         ⁢ 
                         in 
                         ⁢ 
                         
                             
                         
                         ⁢ 
                         
                           
                             S 
                             PX 
                           
                           ⁡ 
                           
                             ( 
                             
                               k 
                               + 
                               1 
                             
                             ) 
                           
                         
                       
                       = 
                       
                         m 
                         + 
                         1 
                       
                     
                   
                   ⁢ 
                   
                     
 
                   
                   ⁢ 
                   
                       
                   
                   ⁢ 
                   
                     
                       with 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       
                         
                           N 
                           Line 
                         
                         ⁡ 
                         
                           ( 
                           k 
                           ) 
                         
                       
                     
                     = 
                     
                       
                         
                           N 
                           
                             Line 
                             , 
                             1 
                           
                         
                         ⁡ 
                         
                           ( 
                           k 
                           ) 
                         
                       
                       + 
                       
                         
                           N 
                           
                             Line 
                             , 
                             2 
                           
                         
                         ⁡ 
                         
                           ( 
                           k 
                           ) 
                         
                       
                     
                   
                 
               
               
                 
                   ( 
                   15 
                   ) 
                 
               
             
           
         
       
     
     Equation (15) can also be reformulated: the distance between the k-th and the k+1-th point according to equation (10) is T S . With
 
Δ t   1 ( k )= S   PX ( k+ 1)· T   PX   −k·t   S ( k )=( m+ 1)· T   PX   −k·t   S ( k ) Δ t   2 ( k )=( k+ 1)· t   S ( k+ 1)− S   PX ( k+ 1)· T   PX =( k+ 1)· t   S ( k+ 1)−( m+ 1)· T   PX  with  T   S   =Δt   1 ( k )+Δ t   2 ( k )  (16),
 
     Δt 1 (k) is the time interval of the k-th point  63 ,  66 ,  68  at the start of the next image column m+1, while Δt 2 (k) indicates how far the k+1-th point  64 ,  65 ,  67  is already disposed in the column m+1. If equation (15) is reformulated using equation (16), the following is obtained 
     
       
         
           
             
               
                 
                   
                     
                       
                         N 
                         
                           Line 
                           , 
                           1 
                         
                       
                       ⁡ 
                       
                         ( 
                         k 
                         ) 
                       
                     
                     = 
                     
                       
                         
                           
                             Δ 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             
                               
                                 t 
                                 1 
                               
                               ⁡ 
                               
                                 ( 
                                 k 
                                 ) 
                               
                             
                           
                           
                             T 
                             PX 
                           
                         
                         · 
                         
                           
                             N 
                             Line 
                           
                           ⁡ 
                           
                             ( 
                             k 
                             ) 
                           
                         
                       
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       in 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       
                         
                           S 
                           PX 
                         
                         ⁡ 
                         
                           ( 
                           m 
                           ) 
                         
                       
                     
                   
                   ⁢ 
                   
                     
 
                   
                   ⁢ 
                   
                     
                       
                         N 
                         
                           Line 
                           , 
                           2 
                         
                       
                       ⁡ 
                       
                         ( 
                         k 
                         ) 
                       
                     
                     = 
                     
                       
                         
                           
                             Δ 
                             ⁢ 
                             
                                 
                             
                             ⁢ 
                             
                               
                                 t 
                                 2 
                               
                               ⁡ 
                               
                                 ( 
                                 k 
                                 ) 
                               
                             
                           
                           
                             T 
                             PX 
                           
                         
                         · 
                         
                           
                             N 
                             Line 
                           
                           ⁡ 
                           
                             ( 
                             k 
                             ) 
                           
                         
                       
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       in 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       
                         
                           S 
                           PX 
                         
                         ⁡ 
                         
                           ( 
                           
                             m 
                             + 
                             1 
                           
                           ) 
                         
                       
                     
                   
                   ⁢ 
                   
                     
 
                   
                   ⁢ 
                   
                     
                       with 
                       ⁢ 
                       
                           
                       
                       ⁢ 
                       
                         
                           N 
                           Line 
                         
                         ⁡ 
                         
                           ( 
                           k 
                           ) 
                         
                       
                     
                     = 
                     
                       
                         
                           N 
                           
                             Line 
                             , 
                             1 
                           
                         
                         ⁡ 
                         
                           ( 
                           k 
                           ) 
                         
                       
                       + 
                       
                         
                           N 
                           
                             Line 
                             , 
                             2 
                           
                         
                         ⁡ 
                         
                           ( 
                           k 
                           ) 
                         
                       
                     
                   
                 
               
               
                 
                   ( 
                   17 
                   ) 
                 
               
             
           
         
       
     
     Accordingly, it is evident that with the measurement points  63  and  64 , which are both disposed at the left-hand edge of their respective pixel column  14 , the connecting line  60  extends completely within the pixel column  14  of measurement point  63 . In the case of measurement points  65 ,  66  disposed centrally in the pixels, the connecting line  61  extends in equal portions within the pixel columns  14  of measurement points  65 ,  66 . The measurement points  67 ,  68  are both disposed at the right-hand edge of their respective pixel column  14 . Accordingly, the connecting line  62  extends completely within the pixel column  14  of measurement point  67 . The characteristic of the curve for every measurement-point distribution is therefore reflected in an optimum manner within the pixel. Furthermore, the artefacts, as seen in the example from  FIG. 6 , do not occur. 
       FIG. 8  shows a second exemplary analog signal  73  superimposed over associated measurement points  70 ,  71 ,  72  of several sampling runs on a two-dimensional display device with pixel column  14  and pixel rows  15 . By contrast with  FIG. 5 , the connecting lines between the measurement points  70 ,  71 ,  72  here are orientated very much more strongly to the characteristic of the analog signal  73 . Only pixels, which are exceeded by the analog signal  73 , are touched by the connecting lines. 
     In  FIG. 9 , a second exemplary output  74  of a two-dimensional display device, resulting here from the signal  73  from  FIG. 8 , is illustrated. Since the frequency of the exceeding of each of the pixels, which touch the connecting lines of the measurement points  70 ,  71 ,  72 , is identical, there is no blurring of the resulting curve. The curve  74  is continuous, clear and adapted in an optimal manner to the analog signal  73 . 
     Accordingly, with the method according to the invention, no artefacts occur. By contrast, with a conventional linear interpolation with N Interpolation  interpolation points, artefacts can occur under the following conditions:
         if the number of interpolation points N Interpolation  is selected too low relative to the current line length N(k) Line , for example, 10 interpolation points, while the vertical distance between two image points is 200 lines, then only one point in every 20th line is set. If these 10 interpolation points are connected, artefacts once again occur.   if the number of interpolation points N Interpolation  is selected to be large, for example, 100 interpolation points, while the vertical distance between two image points is 10 lines, considerable, superfluous calculation costs are incurred.   moreover, with a fixed number of N Interpolation  interpolation points, a further artefact is provided: for example, if N Interpolation    100 , then every linear point with N(k) Line =10 is set a total of 10 times and appears considerably brighter, than if the line were to have a length of N(k) Line =100, wherein each image point is set only once.       

     In  FIG. 10 , a block-circuit diagram of an exemplary embodiment of the device according to the invention is illustrated. The sampled, digitized measurement values  104  are transmitted to a scaling device  100 . This scales the measurement values  104  in such a manner that they can be displayed on the display device  103 . The scaled measurement values  105  are re-routed to the pixel-assignment device  101 . This assigns the measurement value pixels to the display device  103 . The pixel-connecting device  102  generates the continuous measurement-point curve, if the pixels assigned by the pixel-assignment device  101  are not directly adjacent. The display device  103  displays the continuous measurement-value curve, which was generated by the pixel-connecting device  102 . 
     The invention is not restricted to the exemplary embodiment presented. As already mentioned, both horizontal and also vertical transitions of the measurement-point curve can be processed across the pixel rows or respectively columns. Similarly, the use of the method in three-dimensional, pixel-based displays is conceivable. All the features described above or illustrated in the diagrams can be combined with one another as required within the framework of the invention.