JPH0416117B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a cathode ray tube waveform display device that includes:
In addition to sequentially sampling the input signal waveform and performing linear interpolation between the sampling dot data of adjacent time axis addresses, luminance interpolation is performed at the joint between the sampling dot data of adjacent time axis addresses to display the waveform. It is about the method.

[Problems to be solved by conventional technology and invention]

Conventionally, in such waveform display devices, various brightness interpolation methods have been known in order to not only perform linear interpolation but also to smooth out jaggedness that occurs at the seam between displays of adjacent time axis addresses.

However, both methods change the level of the image signal in stages, which not only complicates the configuration of the image circuit, but also makes it difficult to adjust the brightness as expected by operating the panel of the cathode ray tube waveform display device. In some cases, brightness levels could no longer be obtained, and the effect of brightness interpolation was impaired.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a brightness interpolation method that can perform brightness interpolation at a binary logic image signal level in a cathode ray tube waveform display device.

[Means and actions for solving problems]

First, the present invention will be exemplified and explained based on FIG. 1 for a case where one type of auxiliary linear interpolation data for luminance interpolation is created.

As is well known, the input signal waveform is sequentially sampled and each time axis address on the display screen is...;N;
Sampling dot data corresponding to the amplitude of...
Create D _N-2 , D _N-1 , D _N , D _N+1 , D _N+2 , ... (Figure 1 a), and create adjacent time axis addresses (...; N, N+
Linear interpolation data is created to connect the sampling dot data of 1;...) with a bright line (...;L _N ;...) (Fig. 1b). Then, for each time axis address (...;N;...), extend the bright line (...;L _N ;...) defined by the associated linear interpolation data,
And the number of bright lines is the same in the time axis address direction (2 lines)
Auxiliary linear interpolation data for brightness interpolation is created to generate a bright line (...; La _N ;...) (indicated by a thin line for explanation) with a length of (FIG. 1b). Then,
Luminance (…;L N ;…) defined by the associated linear interpolation data at each time axis address (…; _N ;…)
and the bright line defined by the auxiliary linear interpolation data (...;
La _N ;...) are displayed multiplexed in two scans using the same luminance input level. (Figure 1c.
No mark indicates one bright line, hatching indicates two lines).
As a result, the number of bright lines is always two in the time axis address direction, and the brightness is constant.

Next, as shown in Fig. 2, three types of auxiliary linear interpolation data are created by dividing the data of adjacent time axis address pairs in both time axis directions into two based on each linear interpolation data as a reference. The present invention will be described by way of example.

That is, from each time-axis address pair (...;N, N+1;...) to which this linear interpolation data is given, adjacent time-axis address pairs (...;N-1,...) in both time-axis directions are
N+2: N-2, N+3: N-3, N+4;...)
Select the dot position of the sampling value on each time axis (...; D _N-1 , D _N+2 :D _N-2 ,
D _N+3 : D _N-3 , D _N+4 ;...), the previous time axis address pair (...; N, N+1: N-1, N+2:
Dot position of sampling value of N-2, N+3;...) (...D _N , D _N+1 ; D _N-1 , D _N+2 ; D _N-2 , D _N+3 ;
) while dividing the space into two, the bottom and top address data for auxiliary linear interpolation...; [D _N +D _N-1 /2] +1, [D _N+1 +D _N+2 /2]: D _{N- 1} +1, D _N+2 ; [D _N-1 +D _N-2 /2] +1, [D _N+3 +D _N+2 /2]: D _N-2 +1, D _N+3 ;... Create (Fig. 2b-d). However, [ ] in the above description represents an integer with the decimal point truncated.

When displaying waveforms, each time axis address...;
N; . . . displays superimposed bright lines of the same luminance input level between the bottom and top address values of the four types of linear interpolation data (FIG. 2e).
That is, for each time axis address as shown in the figure,
Four bright lines (black), three bright lines (x), two bright lines (○), and one bright line (no mark) are displayed, which corresponds to 10 bright lines at all times in the time axis address direction. displayed at the brightness level.

In the case of a downward slope waveform, it is similarly displayed with a brightness equivalent to 10 bright lines.

In addition, when creating linear interpolation data for two-tone luminance interpolation that connects between the dot positions of the sampling values for adjacent time-axis address pairs without creating divided data in Fig. 2, In this case, data creation in FIGS. 2b and d is omitted. Furthermore, it is also possible to omit the creation of the data in FIG. 2d and mix each kind of non-divided data and divided data to obtain three gradations.

As for the scanning method, one image is completed with a plurality of types of frame images, multiple scanning is performed continuously multiple times at each raster scanning position, or a waveform is displayed by a mixture of these. The scanning speed, frame switching speed, etc. are set in consideration of the afterglow of the cathode ray tube and the afterimage characteristics of the eye.

[Embodiments of the invention]

FIG. 3 shows two-gradation luminance interpolation according to the present invention, that is, odd frames for normal linear interpolation data and luminance interpolation data connecting two divided positions for the dot positions of the next adjacent pair of time axis addresses. A vertical raster scanning type waveform display device is shown in which one image is formed from even frames. In the same figure, 10 is sampling dot data for the input waveform signal as shown in FIG. 4a...; D _N-1 ; D _N ;
This is a waveform processing device that creates top and bottom address data for linear interpolation of odd and even frames shown in FIGS. 4b and 4c for D _N+1 ;...
In other words, this device has each time axis address...;N;
The top address and bottom address data for ... are stored in RAM, and when displaying a waveform, the top and bottom address data of odd frames and the top and bottom address data of even frames are output alternately for each frame.

Reference numeral 20 denotes an image signal generation circuit attached to the cathode ray tube display device 30, which converts the data read from the waveform processing device 10 and generates image signals of odd and even frames alternately at 30 Hz. This circuit includes a latch circuit 22 that sequentially holds the top address of each time address...;N;... on the display surface, a latch circuit 21 that holds the bottom address thereof,
A clock generator 23 that generates a clock to advance the sweep of the cathode ray tube display 30, an address counter 24 that is cleared for each vertical raster scan of the cathode ray tube display 30, and a bottom address value held by the latch circuit 21. A comparator circuit 25 detects that the count value of the address counter 24 coincides with the count value of the address counter 24, a flip-flop circuit 26 generates an output signal a which is inverted from L level to H level by the output of the comparator circuit 25, and a latch circuit 22. The address counter 24 uses the held top address value.
Comparison circuit 27 detects that the counted values of
and a flip-flop 28 which generates an output signal b inverted from H level to L level by its output.
and an AND gate 29 which receives the output signals of both flip-flop circuits 26 and 28 and generates an image signal c.

The cathode ray tube display device 30 sequentially displays the image signal c of each time axis of odd or even frames by vertical raster scanning in the time axis direction, and alternately displays odd and even frame images.

The operation of the waveform display device configured as described above will be explained with reference to FIGS. 4 and 5.

The waveform processing device 10 stores sampling dot data in its RAM... ;D _N-1 ;D _N ;
D _N+1 ; D _N+2 ;... Based on (Figure 4 a), bottom and top address data for linear interpolation of odd frames for each time axis address...; N-1; N; N+1;... ...D _N-1 +1, D _N ;D _N +1, D _N+1 ;D _N+1
+1, D _N+2 ...; (Fig. 4b) and for auxiliary linear interpolation of even frames [D _N-1 +D _N-2 /2] +1, [D _N+1 +D _N /2]; [ D _N +D _N-1 /2]+1, [D _N+2 +D _N+1 /2]; [D _N+1 +D _N /2]+1, [D _N+3 +D _N+2 /2]...( Figure 4 c) is created and the respective bottom and top address values are stored in RAM.

During this linear interpolation process, in order to keep the bright line in the direction perpendicular to the scanning line constant, +1 is added to the bottom address to the top address data to prevent the data from overlapping, and when dividing into two, the number below the decimal point is performs truncation.

When displaying a waveform on the cathode ray tube display device 30, the top and bottom addresses of odd frames of each time axis address . . . ;N; . For time axis N, bottom address data
D _N +1 is latched into the latch circuit 21, and top address data D _N+1 is latched into the latch circuit 22.
When the count value of the address counter 24 reaches D _N +1, the comparison circuit 25 and the flip-flop circuit 2
6 generates an H level output signal a, and further
When D _N+1 is reached, the comparison circuit 27 and the flip-flop circuit 28 generate an output signal b. As a result, the AND gate 29 generates the image signal c during the address periods D _N +1 and D _N+1 , and the cathode ray tube display device 30 displays a constant luminance input level on the cathode ray tube surface during this period.

In this way, as shown in FIG. 4b, the latch circuit 21,
Bright line display occurs during the associated bottom and top addresses latched at 22.

Next, when scanning even frames, the latch circuit 2 is activated for each time axis address...;N;...
1 and 22, the top and bottom address values obtained by dividing the top and bottom address values of time axis addresses adjacent in both directions into two are latched (FIG. 4c).

Therefore, when the even frames are displayed, the odd and even frames are apparently superimposed at each raster scanning position, and the image signals shown in FIG. A two-tone bright line display is displayed. That is, when viewed in the horizontal direction, there are three bright lines, and a waveform display with constant brightness is performed.

In addition, in the above-mentioned embodiment, the waveform processing device 10
Because it stores the top and bottom address values of linear auxiliary tube data for odd and even frames.
Although the RAM capacity can be significantly reduced, the linear interpolation data may be stored as a dot pattern corresponding to the display surface as in the conventional method.

〔Effect of the invention〕

As described above, according to the brightness interpolation method for multiple display of bright lines of a single brightness input level having a length that makes the number of bright lines the same in the time axis address direction according to the present invention, there is no need to set the brightness level of the cathode ray tube in multiple stages.
Therefore, not only the brightness circuit for interpolation is simplified, but also the joint portion of the linear display is always displayed smoothly even if the observer freely adjusts the brightness.

[Brief explanation of drawings]

1 and 2 are diagrams each explaining the luminance interpolation method of the present invention, FIG. 3 is a waveform display device implementing the method of the present invention, and FIGS. 4 and 5 are diagrams showing the operation of the same embodiment, respectively. FIG.

Claims (1)

[Claims] 1. Sequentially sampling the input signal waveform to create sampling dot data corresponding to the amplitude for each time axis address on the display screen, and then connecting the sampling dot data of adjacent time axis addresses with a bright line. In addition to linear interpolation, in a luminance interpolation method for displaying a waveform on a cathode ray tube waveform display device by performing luminance interpolation at least at a joint portion with sampling dot data of adjacent time axis addresses, the method includes: For each time axis address (...; N; Create at least one type of auxiliary linear interpolation data for luminance interpolation, and at each time axis address (...;N;...), the bright line defined by the linear interpolation data belonging to it;
A brightness interpolation method characterized in that the brightness lines defined by the auxiliary linear interpolation data are input to a cathode ray tube with the brightness input level set to be the same, and are displayed in a multiplex manner. 2 As auxiliary linear interpolation data, for each adjacent time axis address pair (...;N, N+1;...), for the next adjacent time axis address pair (...;N-1, N+2;...) in both directions of the time axis address 2. The brightness interpolation method according to claim 1, wherein the brightness interpolation method includes data (...; from D _N-1 to D _N+2 ;...) connecting dot positions of sampling values with bright lines. 3 As auxiliary linear interpolation data, dot position data (...;
D _N , D _N+1 ;…) and the next adjacent time axis address pair in both directions of the time axis address (…; N-1, N+2
The dot position data of the sampling value for (...) is divided into two and connected by a bright line (...;
From the two-divided dot position of D _N+1 and D _N+2 to D _N-2 and
2. The luminance interpolation method according to claim 1, characterized in that the luminance interpolation method includes: up to the two-division dot position with D _N-1 ;