JPH0512822Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial field of application This invention is a method for determining whether numerically codeable data that circulates along a color wheel, such as color data handled in image analysis or image processing, is within a predetermined range. The present invention relates to a window discriminator for separating

2. Description of the Related Art Conventionally, a window discriminator for determining whether or not data that changes from a numerical minimum value to a maximum value is within a set range is well known. An exemplary configuration of such a window discriminator is shown in FIGS. 2 and 3.

In Figure 2, the numerical change range of the data is MIN.
~MAX, and the upper limit of the window is shown as a setting value A, and the lower limit is shown as a setting value B.
The discriminator shown here has two comparators 1
and 2, each of which inputs a data signal to one input section b. Also, the other input section a
To the first comparator 1, a signal with a set value A indicating an upper limit is input, and to the second comparator 2, a signal with a set value B indicating a lower limit is input. Both of these comparators 1 and 2 are designed so that when the input level of input part b is higher than the input level of input part a, output part c becomes true, and these outputs are exclusive ORed. It is input to an XOR gate that performs calculations, and the output of this XOR gate determines whether or not the data signal is within the window. That is, for data signals whose levels are outside the range of set values A and B, both comparators 1 and 2 obtain the same output, and as a result, the output of the XOR gate is "0".
Therefore, when the output of the XOR is "1", it is determined that the data signal is within the window.

The discriminator in Fig. 3 is an example of the discriminator in Fig. 2 in which the input signal in the first comparator 1 is switched and an AND gate is used instead of the XOR gate, so that similar discrimination can be performed. I understand what you can do.

Problems with the conventional technology As mentioned above, the data does not change from the numerical minimum value to the maximum value, but instead changes from the numerical minimum value MIN to the maximum value MAX as shown in Figure 4. When dealing with cyclic data that continues back to the minimum value MIN after reaching the minimum value, for example, it is necessary to use numerically encoded data that circulates along the color wheel, such as color data handled in image analysis and image processing. When dealing with this, the following problems arose: That is, in the conventional discriminator as described above, the range including the connection point (connection point) for circulation, that is, the connection point of MAX and MIN in FIG. It is not possible to perform classification using the range leading to value A as a window.

In the range that includes the connection point, the upper and lower limits cannot be simply set, which makes the separation circuit complicated, or it is not possible to determine which side of the arc range connecting the two set values.

Purpose of the invention The purpose of the invention is to find the numerically minimum value MIN
It is an object of the present invention to provide a window discriminator with a simple structure for circulating data that continues from MAX to a maximum value MAX and then again to a minimum value MIN.

Summary of the invention The window discriminator according to the invention inputs a data input signal and a threshold signal that determines the lower limit (FROM) in the window, and outputs an output when the data input signal is larger than the threshold signal. A first comparator that is true, a data input signal and a threshold signal defined by the upper limit (TO) in the window are input, and the output is true when the data input signal is smaller than the threshold signal. a second comparator, a first XOR gate inputting the outputs of the first comparator and the second comparator, and a threshold signal that determines the lower limit (FROM); A third comparator that inputs a threshold signal that determines the (TO) and outputs true when the threshold signal that determines the lower limit (FROM) is greater than the threshold signal that determines the upper limit (TO). and a second XOR gate inputting the first XOR gate or the output of the third comparator.

A detailed explanation will be given below with reference to FIG. 1 showing an embodiment.

Embodiment The window discriminator according to the invention shown in FIG. 1 has three comparators 10, 11, 12 and two XOR gates. All three comparators are indicated by the symbol a.The input of the input section is indicated by the symbol b.
When the output part c is larger than the input of the input part shown by
It is assumed that "1" is output from this point, and "0" is output at all other times. The first and second comparators 10 and 11 each input a signal to be separated into an input part a, and a threshold hold signal indicating an upper limit setting value to each input part b.
Threshold signal THR1 indicating THR2 and the lower limit set value is input. Here, the input signals of the comparators 10, 11, and 12 may be analog or digital, and are not limited. The outputs from the output parts c of these comparators 10 and 11 are input to the first XOR gate 13, and as in the case of FIG. 2, only when the data signal is within the range from the lower limit to the upper limit, 1" is output.

However, when the range including the connection point is set as a window, the lower limit set value appears to be larger than the upper limit set value, the output of the XOR gate is inverted, and correct classification is not performed. To solve this problem, in Figure 1, the lower limit setting value THR1
and the upper limit set value THR2 are input to the third comparator 12, and this output and the output of the XOR gate 13 are input to the second XOR gate 14, so that the exclusive OR operation result is output. ing.

Explanation of operation When using the above configuration, especially if a range including the connection point is set and the lower limit (FROM) set value THR1 is larger than the upper limit (TO) set value THR2, the input data included in this range As for
Since the output of the third comparator 12 becomes "1", the final output of the second XOR gate 14 becomes "1". Regarding input data that is not included in this range, the output of the first comparator 10 is "1" and the output of the second comparator 11 is "0", so the first
The output of the XOR gate becomes "1". Also, the output of the third comparator remains at "1". As a result, the final output of the second XOR gate 14 becomes "0". Therefore, the output of the second XOR gate 14 is correctly classified regardless of the setting range.

It goes without saying that the present invention can also realize a circuit equivalent to that shown in FIG. 1 using other logic elements.

Effects of the invention As described above, the window discriminator according to the invention has an extremely simple structure that enables classification of circulating data and can be manufactured at low cost. This simplifies data handling and greatly contributes to the development of this type of technology.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing the configuration of a window discriminator according to the first embodiment of the present invention;
2 and 3 are circuit diagrams showing the configuration of a conventional window discriminator, and FIG. 4 is an explanatory diagram showing the relationship between MIN and MAX in circulating data. 10...first comparator, 11...second comparator, 12...third comparator, 13...first
XOR gate, 14... second XOR gate,
THR1...lower limit set value, THR2...upper limit set value.

Claims (1)

[Scope of Claim for Utility Model Registration] To determine whether data having a numerical code that circulates from the minimum numerical code to the maximum numerical code and then back to the minimum numerical code has a numerical code within a predetermined range. A window discriminator that receives a data input signal and a threshold signal that determines the lower limit (FROM) in the window, and outputs true when the data input signal is greater than the threshold signal. a first comparator, a data input signal and a threshold signal defining an upper limit (TO) in the window; a second comparator whose output is true when the data input signal is less than the threshold signal; and a first XOR gate inputting the outputs of the first comparator and the second comparator, a threshold signal that defines the lower limit (FROM), and the upper limit (TO).
a third comparator input with a threshold signal that defines the lower limit (FROM) and whose output becomes true when the threshold signal that defines the lower limit (FROM) is greater than the threshold signal that defines the upper limit (TO); a second XOR gate inputting the first XOR gate and the output of the third comparator; and a data window discriminator having a circulating numerical code. .