JPS602630B2 - Casa display device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cursor display device used in a chart display device, and more particularly to a display device that displays data and cursor in a time-sharing manner.

Conventional digital display devices of this type generally do not utilize data display input when displaying a cursor, and therefore cannot provide accurate data display.

The present invention has been made in view of the above-mentioned circumstances, and uses a voltage obtained by D/A converting a digital signal to sweep the digital signal, and performs a time-division display within a cursor display timing period corresponding to a unit step change period of the digital signal. It is an object of the present invention to provide a cursor display device that can perform accurate data display by using data input even at the cursor display timing by performing data display and cursor display.

An embodiment of the present invention will be described in detail below with reference to the drawings.

The sweep counter 11 shown in FIG. 1 starts counting clock pulse inputs in synchronization with the striping trigger input.

The count output of this counter 11 is led to a D/A converter 12 and converted into an analog voltage.
V is supplied as a voltage to the display 13 using T.
In this case, a one-step change in the clock pulse period of the count output corresponds to a change in count output, and by making this period sufficiently short compared to the period of the data display input signal of the display 13, the time axis of the display data can be changed. can be done smoothly. On the other hand, the casa display timing setting circuit 14
is, for example, a preset counter with the same bits as the sweep counter 11, and has the same count output as the count output of the sweep counter 11 when generating the sweep voltage corresponding to the cursor display timing on the sweep counter (maximum count of the sweep counter 11). (a predetermined value less than or equal to the specified value).

The output of the setting circuit 1 and the output of the sweep counter 11 are led to a matching circuit 15, where a matching pulse (see FIG. 2a) is generated for a period during which both inputs match (corresponding to one period of a clock pulse). occurs. This coincidence pulse is guided to the switching pulse generator 16, where the coincidence pulse period is temporally divided into, for example, four divisions, and the first to fourth switching pulses corresponding to the first to fourth divisions (Fig. 2) are generated. b～e
) occurs. The configuration of the switching pulse generator 16 is such that, for example, four monomulti circuits are connected in cascade, and switching pulses can be sequentially generated from each circuit. The output of the switching pulse generator 16 becomes the control input of the switching circuit 17, and the switching circuit 17 is supplied with display data consisting of, for example, a digital signal and a digital signal corresponding to the maximum value of the display data (for example, each bit of the digital signal is “1”
level, and is hereinafter referred to as an all "1" signal. ) and a digital signal corresponding to the minimum value of the display data (for example, each bit of the digital signal is at the "0" level, hereinafter referred to as an all "0" signal) are led as inputs. The first and fourth switching pulses b and e respectively select and derive display data inputs, the second switching pulse e selects and derives all "1" signal inputs, and the third switching pulse d selects and derives all "0" signal inputs. ``Switching control is performed to selectively derive the signal input. Furthermore, the same pulse as the first switching pulse b is applied as a control input to the switching circuit 17 except during the cursor display timing period, and at this time, display data input is derived. Therefore, the digital signal for generating the sweep voltage (count output of the sweep counter 11).

) The display data input and the cursor display input (all "1" signals, all "0" signals) are derived in a time-division manner within the unit step change period. The output derived in this way is converted into an analog signal by the D/A converter 18 and is supplied as a display input of the display 13. For this reason, on the display 13, the time axis is bordered on the main axis, and the display data input is displayed vertically according to its level, so that, for example, a display as shown in FIG. 3 is obtained.

Then, within the casa display timing period, data is displayed in the first section, the data maximum level point is displayed in the second section, the data minimum level point is displayed in the third section, and the data minimum level point is displayed in the third section. Data is displayed in four sections. In this case, due to the delay characteristic that normally exists in the display input circuit system of the display 13, during the transition from the data display point of the first section to the display point of the second section, and from the display point of the second section to the display point of the third section. A display is also made while moving from the display point of the third section to the data display point of the fourth section, and this display forms a cursor line.Note that the first (or fourth)
A set pulse generator 19 is provided so as to generate a set pulse (see FIG. 2 f) during the generation period of the switching pulse.
If stored to 0, the output of this register 20 can be used to display the data level during the cursor display timing period.

In addition, the casa display timing period does not necessarily have to be divided into four sections; for example, it is divided into three sections, and the display data input is selected by the switching pulse of the first and third sections, and the display data input is selected by the switching pulse of the second section. If you select the "1" signal, you can display the cursor between the small data level and the maximum level as shown in Figure 4, and conversely, if you select the all "0" signal, you can display the cursor as shown in Figure 5. Force display can be performed between the data level and the minimum value level.

Further, the number of divisions in the cursor display timing period is not particularly limited, and it is possible to select any level of cursor display input in any division.

According to the above-described cursor display device, the digital signal is swept by a voltage obtained by D/A conversion, and the cursor display device sweeps the digital signal in a time-division manner within a predetermined cursor display timing period corresponding to a unit step change period of the digital signal. By performing data display and cursor display, data can be displayed even at the cursor display timing, and accurate data display and therefore accurate data discussion are possible.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the cursor display device according to the present invention, FIG. 2 a to f are timing charts shown to explain the operation of FIG. 1, and FIG. 3 is a display according to FIG. 1. FIGS. 4 and 5 are diagrams showing display examples obtained by other embodiments of the present invention. 11...Sweep counter, 13...Display unit, 16...
- Switching pulse generator, 17... switching circuit. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1. A sweep counter that counts external clock pulses in synchronization with the sweep trigger, a cursor display timing setting circuit that sets the cursor display timing by presetting a predetermined value that is less than the maximum count value of this sweep counter, and this cursor display. a matching circuit that outputs a matching pulse with a pulse width corresponding to the period of the clock pulse when the output signal of the timing setting circuit and the output signal of the sweep counter are supplied and the values of both signals match; and a matching circuit that outputs a matching pulse with a pulse width corresponding to the period of the clock pulse; a switching pulse generator that receives pulses and sequentially outputs a plurality of switching pulses having a pulse width shorter than the period of the clock pulse within a time period of a matching pulse width; A switching circuit that is controlled by switching pulses sequentially output from a pulse generator and switches and outputs a data signal and a cursor display signal in a time division manner within the time of the matching pulse width, and converts the output digital signal of this switching circuit into an analog signal. a first D/A converter that converts the digital count output of the sweep counter into an analog signal and outputs a sweep signal;
The first D/A is swept by a sweep signal from a converter.
A casa display device comprising a display device for displaying an output signal of a converter.