JPH10254599A - Input reader - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an input reader capable of specifying a scanning line connected to a key operated by a user on a key matrix in a short time with the small number of times of outputting scanning signals. SOLUTION: The plural scanning lines L connected to the key matrix 4 are divided into two groups, the scanning signals are simultaneously outputted to the scanning lines L belonging to one of the groups and the presence/absence of key input are detected on the side of an input line I. In the case of not detecting the key input relating to one of the groups, the scanning signals are simultaneously outputted to the scanning lines L belonging to the other one of the two groups and the presence/absence of the key input are detected. The scanning lines L belonging to the group for which the key input is detected of the two groups are divided into the two groups further, the scanning signals are simultaneously outputted to the scanning lines L belonging to one of the groups and the presence/absence of the key input are detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an input reading device. More specifically, the present invention relates to a device provided with input means having a plurality of keys arranged in a matrix (hereinafter referred to as a “key matrix”), and for reading a signal input by a user operating the keys.

[0002] A "key" means a switch capable of outputting two values, ON and OFF, according to a user operation.

[0003]

2. Description of the Related Art An electronic device such as a calculator (electronic desk calculator) has a plurality of keys arranged in a matrix as a means for a user to input data. Each row is often provided with a key matrix in which one scanning line is connected for each column, and keys arranged in each row are connected to one input line for each row.

Conventionally, as a scanning method for a key matrix of this type, a scanning signal is output to all scanning lines in advance, and the scanning signals are sequentially output to the scanning lines one by one when a key input is made. A method for specifying a scanning line connected to a key pressed by the user (this is called an “operation key” for convenience), a scanning signal for each scanning line sequentially from the beginning in synchronization with a display signal or the like. Is output, and a scanning line connected to an operation key is specified when a key is input (Japanese Patent Laid-Open Nos. 50-152638 and 52-1).
28019, JP-A-54-109324, etc.).

[0005]

However, in each of the conventional systems, the scanning signals are output one by one to the scanning lines, so that the first scanning line and the last scanning line are output. There is a difference in the scanning timing between and, and this difference increases as the number of scanning lines increases. For this reason, when the operation key is connected to the last scanning line to be scanned, reading may not be possible if the user presses the key for a short time.

Here, means for shortening the interval between scanning signals so that reading can be performed even on the last scanning line is considered. In this case, when a certain scanning signal is output, it is caused by the previous scanning signal. There is a danger that a read error may occur due to waveform distortion.

SUMMARY OF THE INVENTION An object of the present invention is to provide an input reading device capable of specifying a scan line (referred to as a "target scan line" for convenience) connected to an operation key in a short time with a small number of scan signal outputs. is there.

[0008]

According to a first aspect of the present invention, there is provided an input / reading apparatus having a plurality of keys arranged in a matrix, wherein one key is arranged in each column. Scan lines are connected, and one key per row
An input reading device, comprising: a key matrix to which the input lines are connected, wherein a binary signal input by a user operating the keys is output to the scanning line by scanning signals and detected on the input line side. The plurality of scanning lines connected to the key matrix are divided into two groups, and scanning signals are simultaneously output to the scanning lines belonging to one of the groups to detect the presence or absence of a key input. If the key input is not detected, a scanning signal is simultaneously output to the scanning lines belonging to the other of the two groups to detect the presence or absence of a key input, and the scanning belonging to the group of the two groups in which the key input is detected is performed. The line is further divided into two groups, and a scanning signal is simultaneously output to the scanning lines belonging to one of the groups to detect the presence or absence of a key input.

Note that throughout this specification, the columns and rows of the key matrix are not necessarily limited to those extending in the vertical direction and the horizontal direction, but mean those extending in any one direction and the direction intersecting it.

In the input reading device according to the first aspect, first, a scanning signal is simultaneously output to all the scanning lines connected to the key matrix, and the presence or absence of a key input is detected on the input line side. At this time, the key input is always detected if the user has performed the key input. When a key input is detected, all the scanning lines are divided into two groups, and a scanning signal is simultaneously output to the scanning lines belonging to one of the groups to detect the presence or absence of the key input. If no key input is detected for one of the groups, a scanning signal is simultaneously output to the scanning lines belonging to the other of the two groups to detect the presence or absence of a key input. As long as the first key input is not caused by noise, the key input is detected for one of the groups and the other group. Therefore, the scanning lines belonging to the group in which the key input is detected among the two groups are further divided into two groups, and the scanning signals are simultaneously output to the scanning lines belonging to one of the groups to detect the presence or absence of the key input. I do. By repeating the above series of processes, the range including the target scan line among all the scan lines is narrowed. Finally, if one scan line remains, it is the target scan line.

In such a case, the number of times of scanning signal output required for reading is averaged, and the maximum value of the number of times of scanning signal output becomes smaller than in the prior art. Along with this,
The reading time (the time from the key input by the user until the target scan line is specified) is averaged, and the maximum value of the reading time is shorter than before.

For example, when the total number of scanning lines is 32, the number of times of output of the scanning signal is 33 in the prior art, whereas the number of times of output of the scanning signal is 1 in the prior art.
One time. When the total number of scanning lines is 64, the number of times of output of the scanning signal becomes 65 at the maximum in the related art, whereas the number of times of output of the scanning signal becomes 13 at the maximum according to the first aspect. It should be noted that the maximum value of the number of times of output of the scanning signal in claim 1 is smaller than that in the related art because the total number of scanning lines is 8
It's more than a book.

The input reading device according to the first aspect is more reliable and resistant to noise than the input reading device according to the second aspect.

According to a second aspect of the present invention, there is provided an input reading device having a plurality of keys arranged in a matrix, one scan line for each column connected to the keys arranged in each column, and a plurality of keys arranged in each row. A key matrix in which one input line is connected to each row is provided. A binary signal input by a user by operating a key of the key matrix is output to the scanning line, and a scanning signal is output to the input line side. An input reading device for detecting, wherein a plurality of scanning lines connected to the key matrix are divided into two groups, and a scanning signal is simultaneously output to the scanning lines belonging to one of the groups to detect the presence or absence of a key input. When a key input is detected for one group, the one group is selected, and when a key input is not detected for the one group, the other group is selected. The selected group is further divided into two groups. , While outputs simultaneously scan signals to the scan lines belonging to the group of the and detecting the presence or absence of the key input.

In the input reading device according to the second aspect, first, a scanning signal is simultaneously output to all the scanning lines connected to the key matrix, and the presence or absence of a key input is detected on the input line side. At this time, the key input is always detected if the user has performed the key input. When a key input is detected, all the scanning lines are divided into two groups, and a scanning signal is simultaneously output to the scanning lines belonging to one of the groups to detect the presence or absence of the key input. When a key input is detected for the one group, the one group is selected, and when a key input is not detected for the one group, the other group is selected. This means that a keystroke is detected for the one group unless the first keystroke is due to noise, or
If no key input is detected for one of the groups, a key input should be detected for the other group. Next, the scanning lines belonging to the selected group are further divided into two groups, and a scanning signal is simultaneously output to the scanning lines belonging to one of the groups to detect the presence or absence of a key input. By repeating the above series of processes, the range including the target scan line among all the scan lines is narrowed. Finally, if one scan line remains, it is the target scan line.

In this case, the number of times of scanning signal output required for reading is averaged, and the maximum value of the number of times of scanning signal output becomes smaller than in the conventional case. Along with this,
The read time is averaged, and the maximum value of the read time is shorter than before.

For example, when the total number of scanning lines is 32, the number of times of output of the scanning signal is 33 at the maximum in the prior art, whereas the number of times of output of the scanning signal is 7 at the maximum according to claim 1
Times. In the case where the total number of scanning lines is 64, the number of times of output of the scanning signal is up to 65 in the prior art, whereas the number of times of output of the scanning signal is up to 8 according to the first aspect. In the first aspect, the maximum value of the number of times of output of the scanning signal is smaller than that of the conventional case when the total number of scanning lines is 6 or more.

It is to be noted that the input reading device of the second aspect is the first aspect.
The number of times of output of the scanning signal is further reduced as compared with the input reading device.

According to a third aspect of the present invention, in the input reading apparatus according to the first or second aspect, the input reading apparatus comprises a number of bits corresponding to the total number of scanning lines, and scans the scanning lines according to the value of each bit. A first storage unit that holds a fixed number of bit patterns indicating division into two groups, and a number of bits corresponding to the total number of scanning lines, and represents a scanning line to which a scanning signal is to be output simultaneously among all the scanning lines. A second storage unit capable of storing a scan pattern, and a current scan pattern stored in the second storage unit and a bit pattern corresponding to the current scan signal output count stored in the first storage unit, A control unit is provided for obtaining a logical product for each corresponding bit and storing the obtained pattern as the next scanning pattern in the second storage unit.

According to the input reading device of the third aspect, the next scanning pattern is relatively easily created based on the current scanning pattern. No complicated calculation is required, and the processing time is relatively short.

According to a fourth aspect of the present invention, in the input reading apparatus according to the third aspect, a priority is provided between all of the scanning lines, and a priority is relatively set in each of the bit patterns. Bits corresponding to high scan lines
A value indicating the one of the two groups is given with a relatively high probability.

In the input reading device according to the fourth aspect, the scanning line having a relatively high priority has a probability of belonging to the one of the two groups, that is, the group to which the scanning signal is output first. Relatively high. Therefore, a scan line having a relatively high priority is specified by a relatively small number of scan signal outputs. This is particularly true for claim 1.
This is effective when the scanning lines are divided into two groups and the scanning signals are output to both groups.

According to a fifth aspect of the present invention, in the input reading apparatus according to the third aspect, a priority is provided between all the scanning lines, and the priority is provided over all the bit patterns corresponding to the number of times of the scanning signal output. A bit corresponding to a scan line having a specific priority is provided with a value of each digit when the specific priority is expressed by a binary number in order from the lower digit.

In the input reading device according to the fifth aspect, the scanning line having a relatively high priority has a probability that it belongs to the one of the two groups, that is, the group to which the scanning signal is output first. Relatively high. As a result, a scanning signal is output relatively many times for a scanning line having a relatively higher priority. Therefore, reading is performed reliably. This is particularly effective when the scanning lines are divided into two groups and the scanning signal is output only to one of the two groups.

According to a sixth aspect of the present invention, in the input reading device according to the third aspect, the input reading device further includes a third storage unit capable of storing a scanning pattern when a target scan line is specified last. Determines whether a bit pattern corresponding to the number of times of scanning signal output held in the first storage unit includes the scanning pattern stored in the third storage unit, and according to the determination result, It is characterized in that the bit pattern is adopted as a bit pattern as it is or in a state where the value of each bit is inverted.

Some electronic devices have a low frequency of successive key presses, and some have a high frequency of continuous key presses. Therefore, the input reading device according to the sixth aspect includes the third storage unit that can store the scan pattern when the target scan line was specified last. And the first
It is determined whether or not the bit pattern corresponding to the number of times of the scanning signal output held in the storage unit includes the scanning pattern stored in the third storage unit. Alternatively, a bit pattern is adopted with the value of each bit inverted. For example, when the frequency at which the keys are continuously pressed is low, a bit pattern corresponding to the number of times of the current scanning signal output held in the first storage unit includes the scanning pattern stored in the third storage unit. At this time, the bit pattern is adopted as a current bit pattern in an inverted state. On the other hand, when the bit pattern corresponding to the number of times of the scanning signal output held in the first storage unit does not include the scanning pattern stored in the third storage unit, the bit pattern is directly used as the current bit pattern. This increases the probability that the target scan line can be specified. On the other hand, if the frequency with which the keys are continuously pressed is low, the bit pattern corresponding to the number of times of the current scan signal output held in the first storage unit is stored in the scan pattern stored in the third storage unit. Is included, the above-mentioned bit pattern is adopted as it is as the current bit pattern. On the other hand, when the bit pattern corresponding to the current scan signal output count held in the first storage unit does not include the scan pattern stored in the third storage unit, the bit pattern is inverted in the current state. Adopted as a bit pattern. This increases the probability that the target scan line can be specified. As a result, when the scan lines are divided into two groups and the scan signals are output to both groups, the target scan line can be specified with a smaller number of scan signal output times. . In the case where the scanning lines are divided into two groups and the scanning signal is output only to one of the two groups, the target scanning line can be specified more reliably.

According to a seventh aspect of the present invention, in the input reading apparatus according to the third aspect, all the scanning lines are divided into a plurality of phase groups, and the phase groups are different from each other in a steady display state. A scanning signal is output in phase, and all the scanning lines are divided into sets each of which selects one scanning line from each of the phase groups, and correspond to scanning lines belonging to the same set in each bit pattern. It is characterized in that the same value is given to the bit to be executed.

In some electronic devices, all scanning lines are divided into a plurality of phase groups, and in a steady display state in which no key input is made by a user, a scanning signal may be output to each phase group at a different phase. In such a case, according to the input reading device of the seventh aspect, it is smoothly detected that the user has made a key input in the steady display state. That is, there is no need to add special processing and no need to output useless scanning signals.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the input reading device of the present invention will be described in detail.

(1) Device Configuration FIG. 1 shows a schematic block configuration of an input reading device according to an embodiment of the present invention. This input reading device includes a control unit 1, a key scanning port 2, a key input port 3, a key matrix 4, and a ROM (read / write) as a first storage unit.
Only memory 5 and RAM (random access memory)
Memory) 10.

The control section 1 controls the entire processing by the input reading device. In this example, the control unit 1 performs a NOT
(Logical negation), a CPU (central processing unit) including an arithmetic processing unit for performing AND (logical product), and a program for controlling the CPU. In addition, it can also be comprised by a logic circuit.

The key matrix 4 has a plurality of keys K arranged in 4 rows and 8 columns in this example. Each key K is 1
It is a normally open switch for contacts, and is turned on only when pressed by the user. The keys K arranged in one column of the key matrix 4 are connected to one scanning line L extending from one of the key scanning ports 2. The keys K arranged in one row of the key matrix 4 are connected to one input line I extending to one port of the key input port 3.

The key scanning port 2 is an 8-bit output buffer that holds a scanning pattern (8-digit bit value) written by the control unit 1 and outputs a scanning signal to a scanning line L according to the scanning pattern. I do. Bit value "1"
Indicates that a scanning signal (a positive rectangular pulse in this example) should be output, and a bit value “0” indicates that the scanning signal is not output.

The key input port 3 is a 4-bit input buffer, and receives and holds a 4-digit bit value corresponding to an operation key from the key matrix 4. By reading the bit value of the key input port 3 by the control unit 1, the presence or absence of a key input is detected.

The ROM 5 holds (stores) a bit pattern table created in advance in the design stage of the device. As illustrated in FIG. 5, the bit pattern table includes bit patterns b1, b2, and b3 of eight digits each according to the total number of scanning lines.

The work area of the RAM 10 has a register 6 for storing the number of repetitions (the number of loops) in a key reading process (FIGS. 2 and 3) described later, and a second storage section for storing the current scanning pattern. Register 7 as
And a register 8 for storing the previous scanning pattern.
And a register 9 as a third storage unit for storing the scan pattern when the target scan line was specified last. Note that the registers 6 to 9 store the C
It may be set in the PU. Since the register 7 basically holds the same value as that of the key scanning port 2, if there is no problem with the timing of the output signal, the register 7 is omitted and the value of the key scanning port 2 is used as it is for control. May be.

In reality, two or more keys may be pressed at the same time by the user. In the following key reading process, if two or more keys are operated at the same time, is it not recognized as a valid key input? , Or only one of the operated keys is assumed to be valid.

(2) First Example of Key Reading Process A first example of the key reading process will be described with reference to the flow shown in FIG.

First, during the steady display state, all key strobes are periodically output in order to confirm the presence or absence of a key input. Alternatively, it waits for an interrupt due to key input to occur with all key strobe outputs. In any case, the key scanning port 2 is set to the state "111111111" in which the scanning signal is output to all the scanning lines (S1). At the same time, the value “11111111” of the key scanning port 2 is stored in the register 7 as a scanning pattern.

The presence or absence of a key input is detected based on the value of the key input port 3 (S 2). If there is no key input, the display returns to the normal display state. On the other hand, if there is a key input, the contents (the number of loops) of the register 6 are initialized, and the process proceeds to the next step S3.

In step S3, the scan line group including the target scan line is divided into two groups, and one of the scan line groups is set as a range in which a new scan signal is to be output.

Specifically, as shown in FIG. 4, first, the previous scanning pattern held in the register 7 is saved (evacuated) to the register 8 (S21).

Next, the bit pattern table of the ROM 5 (FIG. 5)
), A bit pattern corresponding to the number of loops (incremented as described later) held in the register 6 is selected (S22). Here, when the number of loops is the first time, the bit pattern b1 is selected.
When the number of loops is the second time, the bit pattern b2 is selected. If the number of loops is the third, the bit pattern b3 is selected.

Then, between the current scan pattern held in the register 7 and the bit pattern selected from the bit pattern table of the ROM 5,
Taking D, the obtained 8-digit value is stored in the register 7 as a new scanning pattern (S23). Thus, a new scanning pattern can be created relatively easily.

Thereafter, the operation proceeds to step S4 in FIG.

In step S 4, a scan signal is output to key scan port 2 according to the scan pattern held in register 7.

Next, the presence or absence of a key input is detected based on the value of the key input port 3 (S5). If there is a key input, it is determined that the target scan line is included in the range where the current scan signal was output, and the process proceeds to step S9. On the other hand, if there is no key input, it is determined that the target scan line was included in the range where the previous scan signal was output, but the target scan line was not included in the range where the current scan signal was output. Proceed to.

In step S6, 2 in step S3
The other scanning line group among the scanning line groups divided into groups is set as a range in which the next scanning signal is to be output. Specifically, for the current scan pattern held in the register 7, N
An AND may be obtained for each corresponding bit between the pattern obtained by taking the OT and the previous scan pattern held in the register 8. The obtained eight-digit value is stored in the register 7 as a new scanning pattern.

Next, a scanning signal is output to the key scanning port 2 in accordance with the scanning pattern held in the register 7 (S 7).

Next, the presence or absence of a key input is detected based on the value of the key input port 3 (S 8). If there is a key input, it is determined that the target scan line is included in the range where the current scan signal was output, and the process proceeds to step S9. If there is no key input, it is determined that the key input detected in step S2 is noise, and the display returns to the steady display state.

When the processing proceeds to a state where the pattern held in the register 7 represents the output of only one scan line, it is determined that the target scan line has been specified, and this key reading processing is terminated (S 9). ). If not, the process returns to step S3 to perform division again.

The number of times this loop is repeated, in which the processing is performed from steps S3 to S9 and returns to step S3, is determined by the total number of scanning lines and the method of grouping in step S3. That is, it is determined at the design stage of this input reading device. Therefore, in step S2, a process of initializing the number of loops held in the register 6 is performed, and each time the loop is repeated, the number of loops held in the register 6 is incremented (1 is added), and the number of loops becomes a predetermined number. When the number of times (three times in this example) has been reached, the loop is exited. Thus, the processing time for specifying the target scan line can be reduced.

When the key reading process is normally completed, a display process corresponding to the key input is executed. After returning to the normal display state, all key strobes are periodically output (S1), and it is detected whether or not there is a key input by the user (S2).

FIG. 6 shows another example of the bit pattern table. This bit pattern table is created by setting priorities between the eight scan lines (and, therefore, between the corresponding bits), and accordingly. The priority is represented by eight numbers 0 to 7, and the higher the number, the higher the priority. In this example, the priorities are set to 7, 6, 4, 0, 1, 2, 3, 5 in order from the left. The bit corresponding to the scan line with the lowest priority 0 is set to the value 0 for all of the bit patterns b11, b12, and b13. In addition, priority 1, 2, 3
Are set to a value of 1 for only one bit pattern, and set to a value of 0 for the remaining two bit patterns. Bits corresponding to the scanning lines of priorities 4, 5, and 6 are set to a value of 1 for a 2-bit pattern, and set to a value of 0 for the remaining 1-bit pattern. The bit corresponding to the scanning line having the highest priority 7 is set to the value 1 for all of the bit patterns b11, b12, and b13. In this bit pattern table, the use order of the bit patterns is not particularly limited, but hereinafter, the bit patterns are assumed to be used in the order of b11, b12, and b13.

If the way of creating this bit pattern table is generalized to the case where there are n bit patterns, the bit corresponding to the scan line with the lowest priority 0 is set to the value 0 for all the bit patterns. . Further, the bit corresponding to the n scan lines having the next lowest priority is set to 1
The value is set to 1 only for the bit pattern (the position where the value is 1 is not duplicated), and set to 0 for the remaining (n-1) bit patterns. Next, bits corresponding to n (n-1) / 2 scan lines having the lowest priority are set to a value of 1 for a 2-bit pattern, and the remaining (n-
2) Set the value to 0 for the bit pattern. The bits corresponding to the scanning line having the highest priority 7 are set to the value 1 for all the bit patterns.

FIG. 7 shows the transition of the scanning pattern when the key connected to the scanning line of priority 7 is pressed when the ROM 5 has the bit pattern table shown in FIG. 6 in the key reading process according to the flow of FIG. Is shown.

First, when all key strobes are output in step S1 of FIG. 2, the scanning pattern becomes the state "11111111" in FIG. 7A. Since the scanning signal is output to the scanning line of the priority order 7, step S in FIG.
At 2, it is determined that a key input has been made, and the process proceeds to step S3.

Next, in step S3, the scan pattern "11111111" held in the register 7 and the bit pattern b11 "10101001" in FIG.
An AND operation is performed for each corresponding bit, and the obtained eight-digit value “10101001” is stored in the register 7 as a new scanning pattern, as shown in FIG. 7B.

At step S4 in FIG. 2, a scanning signal is output to the scanning lines of the priorities 1, 4, 5, and 7.
Since the scanning signal has been output to the scanning line of the priority order 7, it is determined in step S5 that there is a key input, and the process proceeds to step S9. Since the pattern held in the register 7 this time indicates output to four scan lines, it is determined in step S9 that the output is not only one scan line, and the process returns to step S3.

Next, in step S3, the scan pattern "10101001" held in the register 7 and the bit pattern b12 "11100100" in FIG.
An AND is calculated for each corresponding bit, and the obtained eight-digit value “10100000” is stored in the register 7 as a new scanning pattern as shown in FIG. 7C.

At step S4 in FIG. 2, the output is performed on the scanning lines of the priorities 4 and 7. Since the scanning signal is output to the scanning line of the priority order 7, step S
It is determined in step 5 that a key input has been made, and the flow advances to step S9.
Since the pattern held in the register 7 this time indicates output to two scanning lines, 1 is set in step S9.
It is determined that the output is not the scan line only, and the process returns to step S3.

Next, in step S3, the scan pattern "10100000" held in the register 7 and the bit pattern b13 "11000011" in FIG.
An AND operation is performed for each corresponding bit, and the obtained eight-digit value “10000000” is stored in the register 7 as a new scanning pattern as shown in FIG.

By the step S4 in FIG.
Is output to the scan line of the second line. Since the scanning signal has been output to the scanning line of the priority order 7, it is determined in step S5 that there is a key input, and the process proceeds to step S9. Since the pattern held in the register 7 this time represents output to one scan line, it is determined in step S9 that the output is only one scan line, and the process exits from the series of processing loops S3 to S9. I do. Thereby, it is determined that the key connected to the scanning line of the priority order 7 has been pressed, and the key reading process ends.

As described above, when the key connected to the scanning line having the highest priority is pressed, the number of times of outputting the scanning signal can be reduced to a minimum of four times.

FIG. 8 shows the transition of the scanning pattern when the key connected to the scanning line of priority 0 is pressed when the ROM 5 has the bit pattern table shown in FIG. 6 in the key reading process according to the flow of FIG. Is shown.

First, when all key strobes are output in step S1 of FIG. 2, the scanning pattern becomes the state "11111111" in FIG. 8A. Since the scanning signal is output to the scanning line of the priority 0, step S in FIG.
At 2, it is determined that a key input has been made, and the process proceeds to step S3.

Next, in step S3, the scan pattern "11111111" held in the register 7 and the bit pattern b11 "10101001" in FIG.
An AND operation is performed for each corresponding bit, and the obtained eight-digit value “10101001” is stored in the register 7 as a new scanning pattern, as shown in FIG.

At step S4 in FIG. 2, a scanning signal is output to the scanning lines of the priorities 1, 4, 5, and 7.
Since no scanning signal is output to the scanning line of priority 0, it is determined in step S5 that there is no key input, and the flow advances to step S6.

Next, in step S 6, the pattern “010101110” obtained by NOTing the scan pattern held in the register 7 and the previous scan pattern “11111111” held in the register 8 are set. , By taking an AND for each corresponding bit, FIG.
As shown in the figure, the obtained eight-digit value “010101110”
Is stored in the register 7 as a new scanning pattern.

By the step S7 in FIG. 2, a scanning signal is output to the scanning lines of the priority order 0, 2, 3, and 6.
Since the scanning signal has been output to the scanning line of priority 0, it is determined in step S8 that a key input has been made, and the process proceeds to step S9. Since the pattern held in the register 7 this time indicates output to four scan lines, it is determined in step S9 that the output is not only one scan line, and the process returns to step S3.

Next, in step S3, the scan pattern "010101110" held in the register 7 and the bit pattern b12 "11100100" in FIG.
An AND operation is performed for each corresponding bit, and the obtained 8-digit value “01000100” is stored in the register 7 as a new scanning pattern, as shown in FIG.

In step S4 in FIG. 2, the output is performed on the scanning lines of the priority order 2 and 6. Since no scanning signal is output to the scanning line of priority 0, it is determined in step S5 that there is no key input, and the flow advances to step S6.

Next, in step S 6, the pattern “10111011” obtained by NOTing the scan pattern held in the register 7 and the previous scan pattern “01010110” held in the register 8 are set. 8 (E) by taking an AND for each corresponding bit.
As shown in the figure, the obtained 8-digit value "00010010"
Is stored in the register 7 as a new scanning pattern.

By the step S7 in FIG. 2, a scanning signal is output to the scanning lines of the priorities 0 and 3. Since the scanning signal has been output to the scanning line of priority 0, it is determined in step S8 that a key input has been made, and the process proceeds to step S9. Since the pattern held this time in the register 7 represents the output to two scanning lines, step S9
It is determined that the output is not only one scan line,
It returns to step S3.

Next, in step S3, the scan pattern "00010010" held in the register 7 and the bit pattern b13 "11000011" in FIG.
An AND operation is performed for each corresponding bit, and the obtained eight-digit value “00000010” is stored in the register 7 as a new scanning pattern as shown in FIG.

The priority order 3 is determined by step S4 in FIG.
Is output to the scan line of the second line. Since no scanning signal is output to the scanning line of priority 0, it is determined in step S5 that there is no key input, and the flow advances to step S6.

Next, in step S 6, the pattern “11111101” obtained by NOTing the scan pattern held in the register 7 is compared with the previous scan pattern “00010010” held in the register 8. , And AND for each corresponding bit, FIG.
As shown in the figure, the obtained 8-digit value "00010000"
Is stored in the register 7 as a new scanning pattern.

In step S7 of FIG.
The scanning signal is output to the scanning line of. Since the scanning signal has been output to the scanning line of priority 0, step S
At 8 it is determined that there is a key input, and the process proceeds to step S9.
Since the pattern held in the register 7 this time represents output to one scanning line, 1 is set in step S9.
It is determined that the output is only the scan lines of the book, and the processing exits from the series of processing loops S3 to S9. As a result, it is determined that the key connected to the scanning line of the priority order 0 has been pressed, and the key reading process ends.

As described above, when the key connected to the scanning line with the lowest priority is pressed, the number of times of output of the scanning signal is seven at the maximum. However, even in this case, the number of output times can be smaller than the maximum output number of nine times when scanning is performed one by one as in the related art. Therefore,
The key reading process can be completed in a short time.

(2) Second Example of Key Reading Process Next, a second example of the key reading process will be described with reference to the flow of FIG.

First, all key strobes are output as in step S1 of FIG. 2 (S11).

Next, the presence or absence of a key input is detected as in step S2 of FIG. 2 (S12).

Next, similarly to step S3 in FIG. 2, the scan line group including the target scan line is divided into two groups, and one of the scan line groups is set as a range for outputting the next scan signal. (S13).

Next, as in step S 4 of FIG. 2,
A scan signal is output to the key scan port 2 according to the scan pattern held in the register 7 (S14).

As in step S5 of FIG. 2, the presence or absence of a key input is detected (S15). If there is a key input, the process proceeds to step S17. On the other hand, if there is no key input, step S
Proceed to 16.

As in step S6 of FIG. 2, the other of the two scanning line groups in step S13 is set as a range in which the next scanning signal should be output (S16).
A pattern representing this range is created and stored in the register 7.

Unlike the example of FIG. 2, the process (S8) of actually outputting a scanning signal in this range to confirm the presence or absence of a key input is not performed, and the target scanning line is included in this range. And use it for the subsequent processing.

As in step S9 of FIG. 2, if the processing proceeds to a state where the pattern held in the register 7 indicates the output of only one scan line, it is determined that the target scan line has been specified (S17). . If not, the process returns to step S13 to perform the division again. Note that FIG.
It is desirable to control this branch by the number of loops, as in step S9.

In order to confirm the presence or absence of a key input, a scan signal in a range held in the register 7 is output to the key scan port 2 (S18).

The reason for performing the processing in step S18 is as follows.
When passing through step S16 immediately before the determination in step S17, the key input is not actually detected for the scan lines in the range held in the register 7, and there is a possibility that a false determination is made due to noise. Because there is. When the process proceeds from step S15 to step S17 without passing through step S16, the same is confirmed twice, but priority is given to the simplicity of the process of specifying the target scan line in the process groups from step S13 to S17. Because it is.

Then, the presence or absence of a key input is detected based on the value of the key input port 3 (S19). If there is a key input, it is determined that the operation key is connected to the scanning line from which the current scanning signal has been output, and the key reading process ends.
If there is no key input, it is determined that the key input detected in steps S12 and S15 is noise, and the display returns to the steady display state.

In this case, the number of loops can be reduced as compared with the method of detecting the presence or absence of a key input twice per loop (FIG. 2), and the key reading process can be performed in a short time as a whole. Can be terminated.

FIG. 9 shows another example of the bit pattern table. As in FIG. 6, the priority of the scanning lines is set to 7, 6, 4, 0, 1, 2, 3, and 5 in order from the left.
In this bit pattern table, all bit patterns b21,
Over b22 and b23, the value of each digit when the priority is represented by a binary number is sequentially assigned to the bit corresponding to the scanning line of the specific priority from the lower digit. For example, to the bit corresponding to the scanning line of the priority order 6, the value of “110” when the priority order 6 is represented by a binary number is assigned to all the bit patterns b21, b22, and b23 in order from the lower digit. . This bit pattern table stores bit patterns b21 and b2 in accordance with the number of times of scanning signal output.
2, b23.

FIG. 10 shows the transition of the scanning pattern when the key connected to the scanning line of priority 7 is pressed when the ROM 5 has the bit pattern table shown in FIG. 9 in the key reading process according to the flow of FIG. Is shown.

First, when all key strobe outputs are performed in step S11 of FIG. 3, the scanning pattern is as shown in FIG.
State "11111111". Since the scanning signal is output to the scanning line of the priority order 7, it is determined in step S12 in FIG.
Proceed to.

Next, in step S13, the scanning pattern “11111111” held in the register 7 is
10B, an AND operation is performed for each corresponding bit between the bit pattern b21 “10001011” of FIG.
As shown in the figure, the obtained 8-digit value “10001011”
Is stored in the register 7 as a new scanning pattern.

By the step S14 in FIG. 3, a scanning signal is outputted to the scanning lines of the priorities 1, 3, 5, and 7.
Since the scanning signal has been output to the scanning line of the priority order 7, it is determined in step S15 that there is a key input, and the process proceeds to step S17. Since the pattern held in the register 7 this time represents output to four scanning lines,
In step S17, it is determined that the output is not one scan line, and the process returns to step S13.

Next, in step S13, the scan pattern "10001011" held in the register 7 is
Between the corresponding bit pattern b22 “11000110” and the corresponding bit, and FIG.
As shown in the figure, the obtained eight-digit value "10000010"
Is stored in the register 7 as a new scanning pattern.

In step S14 in FIG. 3, the output is performed on the scanning lines of the priorities 3 and 7. Since the scanning signal is output to the scanning line of the priority order 7, step S
At 15 it is determined that there is a key input, and the flow advances to step S17. Since the pattern held in the register 7 this time represents the output to two scanning lines, step S17
It is determined that the output is not only one scan line,
It returns to step S13.

Next, in step S13, the scan pattern "10000010" held in the register 7 is read as shown in FIG.
Between the corresponding bit pattern b33 “11100001” and the corresponding bit, and FIG.
As shown in the figure, the obtained 8-digit value "10000000"
Is stored in the register 7 as a new scanning pattern.

By the step S14 in FIG. 3, the output is performed to the scanning line of the priority order 7. Since the scanning signal has been output to the scanning line of the priority order 7, step S15
It is determined that there is a key input, and the process proceeds to step S17.
Since the pattern held in the register 7 this time represents the output to one scan line, it is determined in step S17 that the output is only one scan line, and the process exits from the series of processing loops S13 to S17. I do. Finally, in step S18, the same scanning pattern "10000000" is again used.
Is output, and it is confirmed in step S19 that there is a key input. Thereby, it is determined that the key connected to the scanning line of the priority order 7 has been pressed, and the key reading process ends.

As described above, when a key having the highest priority is pressed, a scanning signal is always output to the key every time a key strobe is output, so that reading is ensured.

FIG. 11 shows the transition of the scanning pattern when the key connected to the scanning line of priority 0 is pressed when the ROM 5 has the bit pattern table shown in FIG. 9 in the key reading process according to the flow of FIG. Is shown.

First, when all key strobes are output in step S11 in FIG. 3, the scanning pattern is as shown in FIG.
State "11111111". Since the scanning signal is output to the scanning line of priority 0, it is determined in step S12 of FIG.
Proceed to.

Next, in step S13, the scan pattern “11111111” held in the register 7 is
11B is ANDed with the corresponding bit pattern b21 “10001011” for each corresponding bit.
As shown in the figure, the obtained 8-digit value “10001011”
Is stored in the register 7 as a new scanning pattern.

At step S14 in FIG. 3, a scanning signal is output to the scanning lines of the priorities 1, 3, 5, and 7.
Since no scanning signal is output to the scanning line of priority 0, it is determined in step S15 that there is no key input, and the flow advances to step S16.

Next, in step S16, the pattern "01110100" obtained by NOTing the scan pattern held in the register 7 and the previous scan pattern "11111111" held in the register 8 are set. An AND is obtained for each corresponding bit, and the obtained 8-digit value “01110100” is stored in the register 7 as a new scanning pattern (however, no corresponding scanning signal is output). Since the pattern held this time in the register 7 indicates output to four scan lines, it is determined in step S17 that the output is not one scan line, and the process returns to step S13.

Next, in step S13, the scan pattern “01110100” held in the register 7 is
Between the corresponding bit pattern b22 “11000110” and the corresponding bit, and FIG.
As shown in the figure, the obtained 8-digit value “01000100”
Is stored in the register 7 as a new scanning pattern.

At step S14 in FIG. 3, the data is output to the scanning lines of the priority order 2 and 6. Since no scanning signal is output to the scanning line of priority 0, it is determined in step S15 that there is no key input, and the flow advances to step S16.

Next, in step S16, the pattern "10111011" obtained by NOTing the scan pattern held in the register 7 is compared with the previous scan pattern "01110100" held in the register 8. An AND is obtained for each corresponding bit, and the obtained eight-digit value “00110000” is stored in the register 7 as a new scanning pattern (however, no corresponding scanning signal is output). Since the pattern held in the register 7 this time represents output to two scanning lines, it is determined in step S17 that the output is not only one scanning line, and the process returns to step S13.

Next, in step S13, the scan pattern “00110000” held in the register 7 is
Between the corresponding bit pattern b33 “11100001” and the corresponding bit, and FIG.
As shown in the figure, the obtained 8-digit value “00100000”
Is stored in the register 7 as a new scanning pattern.

At step S14 in FIG. 3, the output is performed on the scanning line of the priority order 4. Since no scanning signal is output to the scanning line of priority 0, step S1
It is determined in step 5 that there is no key input, and the flow advances to step S16.

Next, in step S16, the pattern "11011111" obtained by NOTing the scan pattern held in the register 7 is compared with the previous scan pattern "00110000" held in the register 8. The AND is obtained for each corresponding bit, and the obtained 8-digit value “00010000” is stored in the register 7 as a new scanning pattern. Since the pattern held in the register 7 this time represents output to one scan line, it is determined in step S17 that the output is only one scan line, and a series of processing loops S13 to S17
Get out of Finally, in step S18, a scan signal corresponding to the scan pattern "00010000" held in the register 7 is output, and in step S19, it is confirmed that there is a key input. As a result, it is determined that the key connected to the scanning line of the priority order 0 has been pressed, and the key reading process ends.

As described above, in this key reading process, the number of scan signal output times becomes the same regardless of the priority of the target scan line. Therefore, it is possible to prevent the input reading time from increasing. However, when the scan line with the lowest priority is the target scan line, the number of scan signal outputs for that target scan line is two, which is the lowest.

(3) Applicability to Devices Where Keys Are Pressed Continuously Highly or Infrequently For devices where keys are continuously pressed infrequently, the processing of step S3 in FIG. 2 and step S13 in FIG. (Scan line grouping) may be performed as follows.

It is assumed that the scan pattern held by the register 7 at the time when the previous key reading process is completed, that is, the scan pattern when the target scan line is specified last is stored in the register 9 in advance.

First, as in step S21 of FIG. 4, the previous scanning pattern held in the register 7 is stored in the register 8.

Next, as shown in step S31 of FIG. 12, a bit pattern corresponding to the number of loops held in the register 6 is selected from the bit pattern table of the ROM 5 and stored in the register 7 (S31). .

An AND operation is performed for each corresponding bit between the bit pattern stored this time in the register 7 and the scan pattern stored in the register 9, and the obtained eight-digit value is completely 0, ie, It is determined whether it is "00000000" (S32). The 8-digit value is "0000"
If it is “0000”, since the previous target scan line is not included in the range where the current scan signal is to be output, the process directly proceeds to step S23 in FIG. This is because it is assumed that the frequency at which the keys are continuously pressed is low, so that the probability that the target scan line can be specified is higher.

On the other hand, if the 8-digit value is not "00000000" in step S32, the range in which the current scan signal is to be output includes the previous target scan line. Then, the process proceeds to the next step S33, in which the bit pattern held in the register 7 is NOTed for each bit, and the obtained inverted bit pattern is stored in the register 7. This is because it is assumed that the frequency at which the keys are continuously pressed is low, so that the probability that the target scan line can be specified is higher. Thereafter, the process proceeds to step S23 in FIG.

On the other hand, in a device where the key is frequently pressed continuously, the determination in step S32 is reversed.
That is, in step S32, the 8-digit value is “0000”.
0000 ", then step S23 in FIG.
Proceed to. On the other hand, if the 8-digit value is “00000000”, the process proceeds to the next step S33, and the bit pattern stored this time in the register 7 is NOT
And the obtained inverted bit pattern is stored in the register 7.

Note that registers other than the register 9,
The contents of 7 and 8 may be used for another purpose after one key reading process, but the contents of the register 9 must be stored until the next key reading process is performed.

(4) Application to a device that outputs a scanning signal of a plurality of phases in a steady display state As shown in FIG. 13, depending on an electronic device, for example, a scanning signal of three phases (a positive rectangular pulse) may be output in a steady display state. ) May be used. The entire scanning line group is divided into three phase groups, and scanning signals of different phases α, β or γ are output to each phase group in the steady display state. The three phases are for convenience of explanation. The reason for providing such a phase group is that, when the display signal output terminal and the key scanning terminal are shared, by performing scanning in accordance with the phase of the display signal, it is possible to prevent the display from being adversely affected. is there. Therefore, the phase of the scanning signal also changes according to the phase of the display signal.

In this example, the number of all the scanning lines is 24, and the bit pattern table held in the ROM 5 also has a 24-digit bit pattern b3 as shown in FIG.
1, b32 and b33 (used in this order).

In such a case, as shown in the upper part of FIG. 14, 24 scanning lines are divided into eight sets (one set of three scanning lines) formed by selecting one scanning line from each of the phase groups. It is desirable to give the same priority to the scan lines belonging to the same set.

For example, when the key connected to the scan line of the phase β in the priority order 3 is pressed, the scan signal transitions as shown in FIG.

As shown in FIG. 15A, the scanning signal is strobed to all the scanning lines of the phase α in the steady display state. At this time, since no scan signal is output on the target scan line (the scan line having the priority β and the phase β), it is determined that there is no key input. Therefore, the scanning signal output in the steady display state is continued.

As shown in FIG. 15B, a key strobe is output to all the scanning lines of the phase β. Since the scanning signal has been output to the target scanning line, it is determined that there is a key input. Therefore, the key reading process of FIG. 3 is started as follows.

First, the scanning pattern shown in FIG.
Then, an AND operation is performed for each corresponding bit with the bit pattern b31 in No. 4 to output a scanning signal according to the obtained scanning pattern as shown in FIG.

Since a scan signal has been output to the target scan line, it is determined that a key input has been made. Therefore, FIG.
14C and the bit pattern b32 in FIG.
And AND for each corresponding bit between
As shown in (D), a scanning signal is output according to the obtained scanning pattern.

Since a scan signal has been output to the target scan line, it is determined that a key input has been made. Therefore, FIG.
The scanning pattern of (D) and the bit pattern b33 of FIG.
And AND for each corresponding bit between
As shown in (E), a scanning signal is output according to the obtained scanning pattern.

Since no scan signal has been output to the target scan line, it is determined that there is no key input. Therefore, FIG.
Between the scan pattern obtained by NOTing the scan pattern of (E) and the scan pattern of FIG.
AND is performed for each corresponding bit. A scanning signal is output as shown in FIG. 15F in accordance with the scanning pattern obtained by taking the AND. Since the scanning signal is output to only one scanning line and it is determined that there is a key input, it is determined that this is the target scanning line, and the key reading process ends. Thereafter, the display returns to the normal display state.

In this way, it is possible to first smoothly detect that the user has made a key input in the steady display state. There is no need to add special processing, and no useless scan signal output occurs.

[0134]

As is apparent from the above description, the input reading device according to the first aspect has a plurality of keys arranged in a matrix, and the keys arranged in each column have one scanning line per column. A key matrix in which one input line is connected to each row of keys arranged in each row, and a binary signal input by a user operating the keys is output to the scanning line. A plurality of scanning lines connected to the key matrix are divided into two groups, and a scanning signal is simultaneously output to the scanning lines belonging to one of the groups, and a key input is performed. If no key input is detected for one of the groups, a scanning signal is simultaneously output to the scanning lines belonging to the other group of the two groups to detect the presence or absence of the key input.
The scanning lines belonging to the group in which the key input is detected among the groups are further divided into two groups, and the scanning signals are simultaneously output to the scanning lines belonging to one of the groups to detect the presence or absence of the key input. By repeating a series of processing of
The target scan line can be specified by narrowing the range including the target scan line among all the scan lines. In this case, the number of times of scanning signal output required for reading can be averaged, and the maximum value of the number of times of scanning signal output can be reduced as compared with the related art. Accordingly, the reading time can be averaged, and the maximum value of the reading time can be shortened as compared with the related art.

The input reading device according to claim 2 divides a plurality of scanning lines connected to the key matrix into two groups,
A scanning signal is simultaneously output to the scanning lines belonging to one of the groups to detect the presence or absence of a key input. If a key input is detected for the one group, the key input is performed for the one group and the one group. If not detected, the other group is selected, the selected group is further divided into two groups, and a scanning signal is simultaneously output to the scanning lines belonging to one of the groups to detect the presence or absence of a key input. By repeating the above-described series of processing, the range including the target scan line among all the scan lines can be narrowed, and the target scan line can be specified. In this case, the number of times of scanning signal output required for reading can be averaged, and the maximum value of the number of times of scanning signal output can be reduced as compared with the related art. Accordingly, the reading time can be averaged, and the maximum value of the reading time can be shortened as compared with the related art.

According to a third aspect of the present invention, in the input reading device according to the first or second aspect, the input reading device comprises a number of bits corresponding to the total number of scanning lines, and scans the scanning lines in accordance with the value of each bit. A first storage unit for holding a bit pattern representing a division into two groups by a fixed number corresponding to the number of times of scanning signal output, and a number of bits corresponding to the total number of scanning lines, wherein the scanning signal A second storage unit capable of storing a scan pattern representing a scan line to be output, a current scan pattern stored in the second storage unit, and a current scan signal output count stored in the first storage unit. And a control unit for calculating the logical product of the corresponding bit pattern for each corresponding bit and storing the obtained pattern as the next scan pattern in the second storage unit. It is possible to create a next scan pattern relatively easily on the basis of the turn. No complicated calculation is required, and the processing time is relatively short.

According to a fourth aspect of the present invention, in the input reading apparatus according to the third aspect, a priority is provided between all of the scanning lines, and a priority is relatively set in each of the bit patterns. Bits corresponding to high scan lines
Since the value indicating one of the two groups is assigned with a relatively high probability, a scanning line having a relatively high priority can be specified with a relatively small number of scanning signal outputs. .

According to a fifth aspect of the present invention, in the input reading apparatus according to the third aspect, priority is provided between all of the scanning lines, and the priority is provided over all bit patterns corresponding to the number of times of outputting the scanning signal. Since the value of each digit when the specific priority is represented by a binary number is assigned to the bit corresponding to the scanning line having the specific priority in order from the lower digit, the scanning having a relatively higher priority is performed. The scanning signal can be output to the line relatively many times, and the reading can be reliably performed.

An input reading device according to a sixth aspect of the present invention is the input reading device according to the third aspect, further comprising a third storage unit capable of storing a scan pattern when a target scan line is specified last, and the control unit. Determines whether a bit pattern corresponding to the number of times of scanning signal output held in the first storage unit includes the scanning pattern stored in the third storage unit, and according to the determination result, Since the bit pattern is employed as it is or as a bit pattern in which the value of each bit is inverted, it is possible to increase the probability that the target scan line can be specified according to the frequency with which keys are continuously pressed. As a result, when the scan lines are divided into two groups and the scan signals are output to both groups, the target scan line can be specified with a smaller number of scan signal output times. . In the case where the scanning lines are divided into two groups and the scanning signal is output only to one of the two groups, the target scanning line can be specified more reliably.

According to a seventh aspect of the present invention, in the input reading apparatus according to the third aspect, all the scanning lines are divided into a plurality of phase groups, and the phase groups are different from each other in a steady display state. A scanning signal is output in phase, and all the scanning lines are divided into sets each of which selects one scanning line from each of the phase groups, and correspond to scanning lines belonging to the same set in each bit pattern. Since the same value is assigned to each bit to be executed, it is possible to smoothly detect that the user has made a key input in the steady display state without outputting useless scanning signals.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of an input reading device according to an embodiment of the present invention.

FIG. 2 shows a first example of a key reading process performed by the input reading device.
6 is a flowchart showing an example of the above.

FIG. 3 shows a second key reading process performed by the input reading device.
6 is a flowchart showing an example of the above.

FIG. 4 is a flowchart showing a specific procedure for grouping scan lines.

FIG. 5 is a diagram showing one example of a bit pattern table.

FIG. 6 is a diagram illustrating an example of a bit pattern table in a case where priorities are assigned to scanning lines.

FIG. 7 is a diagram showing a transition of a scanning pattern when a key connected to a scanning line of priority 7 is pressed when the bit pattern table of FIG. 6 is used in the key reading process of FIG. 2;

8 is a diagram showing a transition of a scanning pattern when a key connected to a scanning line of priority 0 is pressed when the bit pattern table of FIG. 6 is used in the key reading process of FIG.

FIG. 9 is a diagram showing another example of a bit pattern table in the case where priorities are assigned to scanning lines.

FIG. 10 is a diagram showing a transition of a scanning pattern when a key connected to a scanning line of priority 7 is pressed when the bit pattern table of FIG. 9 is used in the key reading process of FIG. 3;

11 is a diagram showing a transition of a scanning pattern when a key connected to a scanning line of priority 0 is pressed when the bit pattern table of FIG. 9 is used in the key reading process of FIG. 3;

FIG. 12 is a flowchart illustrating a bit pattern selection method suitable for a case where the frequency of continuous key presses is high or low.

FIG. 13 is a diagram showing three-phase scanning signals output in a steady display state.

FIG. 14 is a diagram illustrating an example of a bit pattern table suitable for a case where three-phase scanning signals are output in a steady display state.

FIG. 15 is a diagram showing transition of a scanning pattern when a key reading process is performed using the bit pattern table of FIG. 14 when a three-phase scanning signal is output in a steady display state.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Control part 2 Key scanning port 3 Key input port 4 Key matrix 5 ROM 6-9 register 10 RAM L Scan line I Input line

Claims (7)

[Claims] A plurality of keys arranged in a matrix,
A key matrix in which keys arranged in each column are connected to one scanning line for each column, keys arranged in each row are connected to one input line for each row, and the user operates the keys to perform input An input reading device for outputting a scan signal to the scan line and detecting the binary signal on the input line side, wherein a plurality of scan lines connected to the key matrix are divided into two groups, and one of the groups is divided into two groups. At the same time, a scanning signal is output to the scanning lines belonging thereto to detect the presence / absence of a key input. Then, the presence or absence of a key input is detected, and the scanning lines belonging to the group in which the key input is detected among the two groups are further divided into two groups, and the scanning signals are simultaneously applied to the scanning lines belonging to one of the groups. Force to input reading apparatus characterized by detecting the presence or absence of the key input. 2. It has a plurality of keys arranged in a matrix,
A key matrix in which one row of scanning lines is connected to each row of keys and one input line of each row is connected to each row of keys, and the user operates the keys of the above key matrix An input reading device that outputs a scanning signal to the scanning line and detects the input binary signal on the input line side, wherein a plurality of scanning lines connected to the key matrix are divided into two groups, A scanning signal is simultaneously output to the scanning lines belonging to the group to detect the presence or absence of a key input. If a key input is detected for the one group, no key input is detected for the one group and the one group. In this case, the other group is selected, the selected group is further divided into two groups, and a scanning signal is simultaneously output to the scanning lines belonging to one of the groups to detect the presence or absence of a key input. Input taking device, characterized in that. 3. The input reading device according to claim 1, comprising a number of bits corresponding to the total number of scanning lines, and representing a division of the scanning lines into two groups according to the value of each bit. And a second storage unit comprising a number of bits corresponding to the total number of scanning lines and capable of storing a scanning pattern representing scanning lines to which a scanning signal is to be output simultaneously among all the scanning lines. And the second
The logical product is obtained for each corresponding bit between the current scan pattern stored in the storage unit and the bit pattern corresponding to the current scan signal output count stored in the first storage unit. An input reading device comprising a control unit for storing a pattern in the second storage unit as a next scanning pattern. 4. The input reading device according to claim 3, wherein a priority is provided between all of the scanning lines, and a bit corresponding to a scanning line having a relatively higher priority in each of the bit patterns. An input reading device, wherein a value indicating one of the two groups is given with a relatively high probability. 5. The input reading device according to claim 3, wherein a priority is provided between all of the scan lines, and a scan line of a specific priority is provided over all bit patterns corresponding to the number of times of output of the scan signal. An input reading device, wherein the value of each digit when the specific priority is expressed by a binary number is assigned to the bit to be executed in order from the lower digit. 6. The input reading device according to claim 3, further comprising a third storage unit capable of storing a scan pattern when a target scan line is specified last, wherein the control unit stores the scan pattern in the first storage unit. It is determined whether or not the bit pattern corresponding to the number of times of the output of the scanning signal includes the scanning pattern stored in the third storage unit. According to the determination result, the bit pattern is used as it is or for each bit. An input reading device characterized in that a value is inverted and employed as a bit pattern. 7. The input reading device according to claim 3, wherein all the scanning lines are divided into a plurality of phase groups, and a scanning signal is output to the phase groups in different phases in a steady display state. All scan lines are divided into sets each of which selects one scan line from each of the phase groups. In each of the bit patterns, the same value is assigned to bits corresponding to scan lines belonging to the same set. An input reading device comprising: