JPS5955490A - Lcd logic scope - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a logic scope capable of displaying timing, etc. of digital signals of electronic circuits.

Due to advances in electronics, many digital circuits are now being used in electronic devices, and these 1TL+
Logic scopes are used to check digital signals when designing and repairing equipment, and the need for logic scopes is increasing.

FIG. 3 is a conceptual diagram of a logic scope using a conventional ORT. In the figure, 1 is an input circuit. When a signal for checking the digital signal of an electronic device enters the input circuit, when the signal is higher than the already set signal, it is treated as a high signal, and when it is lower, it is treated as a low signal, and is sampled by the sampling signal of the control circuit 4. ,
It is stored in the memory circuit 2. In this specific example, since there are eight channels of input, memory circuits are set for eight circuits, and symbols are time-divisionally controlled and stored for each channel. The stored data is stored in the control circuit 4 like the timing that has already been stored.
', the vertical amplifier 11 circuit 3. It passes through the horizontal amplification circuit 5 and the high voltage amplification circuit 6 and is supplied to 0RT7. The signals of each channel input here are simultaneously projected onto the CRT.

FIG. 4 shows an example of signal display on a CRT of a logic scope using a conventional CRT. As in the example, eight channels of signals are displayed at once, and the timing between each signal and whether the signals are actually as designed are checked. As described above, although the conventional logic scope has a simple structure, it has many drawbacks. One of these is that logic scopes simultaneously display 8 or 16 channels of signals on a narrow CRT, so the intervals between the displayed signals between each channel become narrow, making it difficult to see and the signals indicating high levels. It becomes difficult to tell whether it is indicating low or low.

Another drawback is that the time axis of the displayed signal may be expanded 10 or 20 times using a switch to check it, but in this case the signal line on the CRT becomes thin and thin, making it difficult to measure well. Another drawback is that since it is displayed using ORT, even if you adjust the brightness with the brightness control knob, it may not be sufficient in bright places.
Hard to see. Also, if the signal is displayed with the brightness too high, burn-in may occur due to the nature of CRTs, causing O
The life of the RT will be extremely shortened. Another disadvantage is that since ORT is used, a high-voltage circuit is also required, which increases power consumption and makes it difficult to miniaturize the device. In order to eliminate the above-mentioned drawbacks, some devices use an LCD panel instead of a CRT.

FIG. 5 shows part of the display signals of a part of the display of a logic scope using a conventional LCD display. In the figure, 10 represents a dot that is not lit, and 11 represents a dot that is lit. To display the signal, dots are lit continuously and timing measurements are performed. The conventional method using an LCD display has advantages such as being smaller and lighter because it does not require a CRT, but has many disadvantages. The reason is that two sets of vertical dot rows are always required for both the rising edge (rising from low to high) and the falling edge (falling from high to low) of the signal waveform. This leads to a reduction in resolution on the time axis in the lateral direction. Another drawback is that since high and low signals are represented by a series of dots, it becomes difficult to distinguish between high and low signals when multiple channels are used when ORT is used.

Another disadvantage is that when trying to increase the number of channels or increase the resolution of the time axis, the size of the display cannot be increased unnecessarily, and each dot must therefore be made smaller. As a result, the displayed signal line becomes thin, difficult to measure, and display quality is poor.

The present invention solves these drawbacks of conventional logic scopes.
By installing a lighting correction circuit, the signal is displayed on the LCD display, which solves the problem.At the same time, it is compact and compact.
It provides a lightweight and highly portable logic scope.

This will be explained below according to the drawings.

FIG. 1 is a conceptual diagram of the LCD logic scope of the present invention.

The present invention differs greatly from the conventional one in that a lighting correction circuit is provided and that the lighting correction circuit lights up all the columns in the high part of the signal.

In FIG. 1, 2o is an input terminal, and in this specific example, there are manual terminals for 8 channels. Input terminal 20J
The input digital signal from the electronic circuit is converted as a high signal when the voltage is higher than a preset voltage in the input circuit, and as a low signal when it is lower than the voltage preset in the input circuit. The data is stored in the memory circuit 22 for each channel.

The signals stored in the necessary amount are controlled by the O'PU 26 and sent to the memory circuit 22, display control circuit 23. sent to. At this time, the signal is corrected by the lighting correction circuit 27 and displayed on the LCD display 24.
When there is a high signal on the top, all parts of that channel, from the bottom part to the high part, are lit.

Figure 2 shows the LOD logic oscilloscope of the present invention]1
．． FIG. 6 is a diagram of a display example showing part of a waveform displayed on a +OD display.

In the figure, 3o represents a non-lit dot, and 31 represents a lit dot. In this specific example, when the input signal is at a low level, only the bottom row of the five vertical dots of each channel lights up, and when the input signal is at a high level, all five dots light up. In this way, each channel follows the signal, and when it is at a low level, the bottom row lights up, and when it is at a high level, all the channels are lit up, and the parts that are all lit up are displayed as if they were filled in black.

As explained above, since the 'IJOD logic scope according to the present invention lights up all the high level parts of the signal, it has many advantages as listed below. (1) When the input signal is low level, , only the bottom row of the channel lights up, and when it is high, the lights go from the bottom row to the top row, so it is easy to distinguish between high and low signals and there is no misreading.

(2) Furthermore, even if each dot becomes smaller when the number of display channels is increased, by lighting all the high signals, it becomes easier to read and the display quality improves.

(3) Sampled input data is displayed directly on the LCD
Since it can be displayed on a display, there is no reduction in time axis resolution. Furthermore, it becomes easier to see even when the time axis is multiplied by 10 or 20 times.

(4) Since the signal is displayed on the LOD display with stipple correction, it is easy to see even in bright places (there is no deterioration such as burn-in that occurs on CRTs).

(5) Since it uses an LOD display, it is small, lightweight, and has low power consumption.

In the above description, the LCD logic scope according to the present invention uses a lighting correction circuit to perform lighting correction to achieve full lighting when the signal is at a high level, but the invention is not limited to this.

If the CPU being used has a margin, it is also possible to perform lighting correction using the CPU. In this case, the production cost will be lower, and at the same time, L will be smaller, lighter, and consume less power.
It provides a CD logic scope. In addition, an A/D conversion circuit (
A circuit that converts analog signals to digital signals) is installed,
It is also possible to measure the level of the input signal and display the voltage value on the LCD display. This makes it easy to check the signal level, and there is no need to use the multimeter 5-, oscilloscope, etc. that have been required up until now. In addition, A/D converter (an element that converts analog signals to digital signals) and video RA for waveform display.
By providing M (memory element), it is possible to provide a logic scope that is easy to see, has good display quality, and is further multifunctional.

As described above, the present invention provides a compact and lightweight LCD logic scope that is easy to see and has good display quality by completely lighting up the high portion of the signal on the LCD display.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a conceptual diagram of the LCD logic scope of the present invention. FIG. 2 is a display example diagram showing a part of the waveform displayed on the LCD display of the LCD logic scope of the present invention. FIG. 3 is a conceptual diagram of a logic scope using a conventional ORT. Figure 4 shows logic scope C using conventional ORT.
FIG. 5 is an example diagram showing a part of the signal display on the display of a logic scope using a conventional LOD display. 2. Memory circuit 7...CRT 10...Non-lighting dot 11...Lighting dot 24...LOD display 27...Lighting correction circuit 30...Non-lighting dot 31...Lighting dot and beyond Applicant: Shiojiri Kogyo Co., Ltd. Agent: Tsutomu Mogami, Patent Attorney

Claims (1)

[Claims] In a logic scope that displays the timing of digital signals in electronic circuits, the signal is displayed on the TJOD panel by dot control.
OD logic scope.