JPH02311769A - Waveform display apparatus - Google Patents

Abstract

PURPOSE:To enhance visibility by differentiating the brightness between envelopes in a PP (peak-to-peak) display waveform from the brightness of the straight part between the envelopes. CONSTITUTION:The min. and max. values of waveform data D at every rasters R1 - Rn are stored in a memory 1. This stored waveform data D is read on the first and second video signal forming circuits 3, 4 from a reading circuit 2 by the control signal S1 synchronous to raster scanning. At this time, the control signals S2, S3 based on vertical and horizontal synchronous signals are respectively applied to the circuits 2, 3, 4 from a display control circuit 5. The circuit 3 forms the video signal V1 corresponding to the respective min. and max. value data points and the circuit 4 forms the video signal V2 corresponding to the respective min. and max. value data points and the straight line connecting the min. and max. value data points. These signals are applied to a brightness modulating circuit 6 and AND and OR are calculated and added to be applied to a display device 10.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a waveform display device using a raster scan type display, and more specifically, a peak-to-peak display (hereinafter referred to as PP display). This relates to improving the visibility of

<Prior Art> One type of digital oscilloscope uses a raster scan type display.

In this device, the waveform data stored in the memory is read out sequentially for each raster and displayed on the display.

By the way, in a conventional digital oscilloscope using such a raster scan type display, when displaying the measured waveform in PP, all line segments between the maximum value and the minimum value of each raster are displayed at a constant brightness. was configured to be displayed.

<Problems to be Solved by the Invention> As a result, the maximum and minimum values, which should originally have meaning in PP display, are not emphasized at all, resulting in a problem of low visibility.

Especially when multiple such PP display waveforms overlap,
When it is desired to compare the PP display waveform and other waveforms on the same screen, it may be difficult to distinguish between the waveforms.

The present invention has focused on such points, and its purpose is to provide a waveform display device that improves visibility by making the brightness of the envelope in the PP display waveform different from the brightness of the straight line portion between the envelopes. It's about doing.

Means for Solving the Problems> The waveform display device of the present invention is a waveform display device using a raster scan type display, and includes a memory for storing maximum value data and minimum value data of waveform data in each raster period. , a first video signal generation circuit that generates a video signal corresponding to the maximum value data point and the minimum value data point of the waveform data for each raster read from the memory; and the waveform data for each raster read from the memory. a second video signal generation circuit that generates a video signal corresponding to a maximum value data point and a minimum value data point and a straight line connecting these maximum value data points and minimum value data points; and an output signal of each of these video signal generation circuits. The present invention is characterized by comprising a brightness modulation circuit that applies brightness modulation to a display waveform according to an AND signal of.

Effect> The envelope portion of the PP display waveform has a higher luminance than the straight line portion between the envelope lines due to the AND of the output signal of the first video signal generation circuit and the output signal of the second video signal generation circuit. Is displayed.

As a result, the envelope line of the PP display waveform is displayed more emphasized than other straight line parts.

<Example> Embodiments of the present invention will be described in detail below with reference to the drawings.

In FIG. 1, which is a block diagram showing an embodiment of the present invention, a memory 1 stores a minimum value min and a maximum value max of waveform data for each raster R1 to R1. The waveform data D stored in this memory 1 is
According to the control signal S applied from the readout circuit 2 in synchronization with raster scanning, a video signal generation circuit 3 and a second video signal generation circuit whose minimum value min and maximum value max are 1 for each raster R1-R1 in sequence. 4. A readout circuit 2 and each video signal generation circuit 3.
A control signal S2+83 based on a vertical synchronization signal, a horizontal synchronization signal, etc. is applied to each of the display control circuits 4 and 4 from the display control circuit 5. The first video signal generation circuit 3 generates a video signal V corresponding to the maximum value data point and minimum value data point of the waveform data D for each raster read from the memory 1, and outputs it to the brightness modulation circuit 6. A second video signal generation circuit 4 generates a video signal corresponding to the maximum value data point and minimum value data point of the waveform data D for each raster read from the memory 1 and the straight line connecting these maximum value data point and minimum value data point. v2 is generated and output to the brightness modulation circuit 6. The ff degree modulation circuit 6 receives the output signal V of each video signal generation circuit 3.4.
an AND gate 7 that outputs the logical product of V1, V2, and an OR gate 8 that outputs the logical sum of the output signal v1 + V2 of each video signal generation circuit 3.4. It consists of a resistor network 9 that adds the output signals of these gates 7.8.

The output signal vcu of the brightness modulation circuit 6 configured in this way
t is applied to a raster scan type display 10 such as a CRT.

FIG. 2 is a timing chart illustrating the operation of the apparatus shown in FIG. 1, and shows the operation of each raster. (a)
is the output signal v1 of the first video signal generation circuit 3,
The portion corresponding to the minimum value min and maximum value max is at H level.

(b) is the output signal v2 of the second video signal generation circuit 4, in which the portion corresponding to the minimum value min and maximum value max and the entire section connecting the minimum value min and maximum value max are at H level. (C) is the output signal V of the brightness modulation circuit 6
O, the output signal v of the first video signal generation circuit 3
1 and the output signal V2 of the second video signal generation circuit 4 are added.

FIG. 3 is an example of a raster display when the output signal van of the brightness modulation circuit 6 is input to the display 10.

That is, the portion corresponding to the minimum value min and maximum value max is highlighted and displayed with higher brightness than the section connecting the minimum value min and maximum value max.

With this configuration, the maximum and minimum values that should have meaning when displaying PP are displayed in an emphasized manner, resulting in high visibility.

Further, each waveform can be easily distinguished even when a plurality of PP display waveforms overlap or when it is desired to compare a PP display waveform and another waveform on the same screen.

<Effects of the Invention> As explained above, according to the present invention, it is possible to realize a waveform display device in which the brightness of the envelope line in the PP display waveform is made different from the brightness of the straight line portion between the envelope lines to improve visibility. Suitable for digital oscilloscopes, etc.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is a timing chart explaining the operation of FIG. 1, and FIG. 3 is a display example diagram.

Claims (1)

[Claims] A waveform display device using a raster scan type display, including a memory that stores maximum value data and minimum value data of waveform data in each raster period, and a waveform for each raster read from this memory. a first video signal generation circuit that generates a video signal corresponding to a maximum value data point and a minimum value data point of data; a maximum value data point and a minimum value data point of waveform data for each raster read from the memory; A second video signal generation circuit that generates a video signal corresponding to a straight line connecting these maximum value data points and minimum value data points, and a display waveform with brightness according to the AND signal of the output signals of these video signal generation circuits. A waveform display device comprising: a brightness modulation circuit that applies modulation.