Rotation determination device

Abstract

To provide a rotation determination device that can determine a rotation operation even if the operation start position of a rotating body is an intermediate position.SOLUTION: A rotation determination device includes: an encoder unit 100 that generates two pulse signals with phases shifted from each other due to rotation of a rotating body 111; an acquisition unit 210 that acquires levels of the two pulse signals; a detection unit 220 that detects a signal change of the two pulse signals; an edge pattern determination unit 230 that determines an edge pattern, when the detection unit 220 detects a signal change, from one pulse signal in which the signal change is detected and an input signal level of the other pulse signal; and a setting unit 240 that sets a reference signal level with the input signal level as an initial value. When a specific edge pattern changed according to the reference signal level matches an edge pattern determined by the edge pattern determination unit 230, the rotation determination unit 250 determines that the rotating body 111 has been subjected to a rotation operation.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a rotation determination device.

Background Art

[0002] Conventionally, a dial has been used for setting operations of the temperature and air volume of a vehicle air conditioner, and there is a device that determines the rotation operation of this dial using an encoder.

[0003] When using such an encoder, a method has been proposed to prevent misjudgment and accurately determine the rotation operation. For example, a rotation determination method capable of preventing misjudgment due to chattering is disclosed by detecting the rising edge and falling edge of a two-phase pulse signal output from an encoder, and determining count-up or count-down according to the edge state of one of the pulse signals where an edge is detected and the signal level of the other pulse signal (see, for example, Patent Document 1).

[0004] By the way, when determining the rotation operation by the edge of the pulse signal as in the above-described conventional technology, it is generally set such that either edge of the two-phase pulse signal is detected near the stop position of the dial. Here, when the operation start position of the dial is between two adjacent dial stop positions, that is, at an intermediate position, and a rotation operation is performed from this intermediate position to one of the dial stop positions, only the rising edge or falling edge of one of the two-phase pulse signals is detected.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, according to the technique described in Patent Document 1, in order to determine the rotation operation of the dial, it is necessary to detect both edges of the two-phase pulse signals. Therefore, when power is supplied to the device for determining the rotation operation of the dial and the dial is rotated from the intermediate position, there is a problem that it is impossible to determine at the position where it should be determined that the rotation has occurred.

[0007] Therefore, the present invention has been made in view of the above problems, and an object thereof is to provide a rotation determination device capable of determining a rotation operation even when the operation start position of the dial is the intermediate position.

Means for Solving the Problems

[0008] Aspect 1; One or more embodiments of the present invention include an encoder connected to a rotating body and generating two pulse signals whose phases are shifted from each other due to the rotation of the rotating body, a detection unit that detects the rising edge and falling edge of the two pulse signals as signal changes, an acquisition unit that acquires the levels of the two pulse signals input from the encoder as input signal levels, a setting unit that sets a reference signal level with the input signal level when power is supplied to the encoder as an initial value, and when the signal change is detected in either one of the two pulse signals by the detection unit, an edge pattern determination unit that determines an edge pattern based on information regarding the change in the pulse signal in which the signal change is detected and the input signal level of the other pulse signal in which the signal change is not detected, and the input signal levels of the two pulse signals are the same ("H, H", "L, L") state the reference signal level and the input signal levels of the two pulse signals are different ("H, L", "L, H") state to the reference signal levelA rotation determination device is proposed, which includes a storage unit that stores a specific edge pattern set correspondingly, a rotation determination unit that compares the edge pattern determined by the edge pattern determination unit with the specific edge pattern stored in the storage unit and determines that the rotating body has rotated when the edge pattern determined by the edge pattern determination unit matches the specific edge pattern.

[0009] The rotation determination device according to one or more embodiments of the present invention includes an encoder that generates two pulse signals, an acquisition unit that acquires the levels of the two pulse signals, a detection unit that detects changes in the two pulse signals, a setting unit that sets a reference signal level, an edge pattern determination unit that acquires a signal level and determines an edge pattern when a change in either of the two pulses is detected, and a rotation determination unit that determines whether the rotating body has been rotated. And the rotation determination unit determines that the rotating body has rotated when the specific edge pattern determined by the reference signal level matches the edge pattern determined by the edge pattern determination unit. That is, in the rotation determination device, the reference signal level is set at the operation start position of the rotating body, and when the edge pattern determined by the signal level change detected by one of the two pulse signals matches the specific edge pattern set by the reference signal level, it is determined that the rotating body has been rotated. Therefore, even if the operation start position of the rotating body is the intermediate position, since the reference signal level is set at the intermediate position, the rotation operation of the rotating body can be determined.

[0010] Embodiment 2; One or more embodiments of the present invention are such that the specific edge pattern is It is assumed that when the rotating body rotates clockwise with respect to the state where the rotating body is at the reference signal level, it will be detected distinguished into a first edge pattern and It is assumed that it will be detected when the rotating body rotates counterclockwise a second edge pattern, and is set , The rotation determination unit when the edge pattern and is the first edge pattern match in this case in it is determined that the rotating body has been rotated clockwise, and when the edge patternand the second edge pattern match case in , a rotation determination device is proposed that determines that the rotating body has been rotated counterclockwise. That is, in the rotation determination device, a specific edge pattern determined based on the reference signal level is distinguished into two types: a first edge pattern and a second edge pattern. Therefore, the specific edge pattern for determining that the rotating body has been rotated is distinguished into a first edge pattern for determining that the rotating body has been rotated clockwise and a second edge pattern for determining that the rotating body has been rotated counterclockwise, so that the rotation operation direction can be determined.

[0011] Embodiment 3; One or more embodiments of the present invention relate to the edge pattern and the specific edge pattern match , a rotation determination device is proposed in which the reference signal level is updated to the input signal level when the specific edge pattern is determined. That is, in the rotation determination device, when the edge pattern matches the specific edge pattern, the reference signal level is updated to the input signal level when the edge pattern and the specific edge pattern match. Therefore, it is possible to correctly determine continuous rotation operations of the rotating body.

Advantages of the Invention

[0012] According to one or more embodiments of the present invention, there is an effect that even if the operation start position of the rotating body is an intermediate position, the rotation operation of the rotating body can be correctly determined.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Mode for Carrying Out the Invention

[0014] <Embodiment> The rotation determination device 1 according to the present embodiment will be described with reference to FIGS. 1 to 13.

[0015] <Configuration of Rotation Determination Device 1> The rotation determination device 1 according to the present embodiment is, for example, a rotation determination device for a temperature adjustment dial of vehicle air conditioning, and as shown in FIG. 1, includes an encoder unit 100 and a CPU 200.

[0016] <Configuration of the encoder unit 100> As shown in FIG. 1, the encoder unit 100 includes an encoder 110, a resistor 120, and a resistor 121. In addition, the encoder unit 100 has a structure in which a click occurs when the rotating body 111 is rotated, and stops at the click stop positions indicated by the black circles in FIGS. 2 and 3.

[0017] As shown in FIG. 1, the encoder 110 includes a rotating body 111, a switch 112, and a switch 113. The rotating body 111 is a dial that is rotated when setting the temperature of the vehicle air conditioner. The switch 112 and the switch 113 are, for example, composed of mechanical sliding contacts, and are interlocked with the rotation of the rotating body 111, and the switch is turned on and off.

[0018] For example, as shown in FIG. 2, there is a 90° phase difference between the on / off states of the switch 112 and the switch 113. When the rotating body 111 is rotated clockwise from the click stop position, the on / off state of the switch 113 changes before the on / off state of the switch 112. Also, as shown in FIG. 3, when the rotating body 111 is rotated counterclockwise from the click stop position, the on / off state of the switch 112 changes before the on / off state of the switch 113.

[0019] One end of the switch 112 is connected to one end of the switch 113 and is also connected to the ground of the rotation determination device 1. The other end of the switch 112 is connected to one end of the resistor 120 and the CPU 200. The signal input to the CPU 200 from the other end of the switch 112 is a signal (A-phase input signal) indicating the state of the switch 112.

[0020] The other end of the switch 113 is connected to one end of the resistor 121 and the CPU 200. The signal input to the CPU 200 from the other end of the switch 113 is a signal (B-phase input signal) indicating the state of the switch 113. Then, the other end of the resistor 120 and the other end of the resistor 121 are connected and also connected to the encoder power supply (5V). Here, in the case of the rotation determination device 1 mounted on the vehicle, after the CPU power supply (5V) is supplied to the CPU 200, the CPU 200 controls a switching element (not shown), and the encoder power supply (5V) is supplied to the encoder unit 100. Note that the CPU 200 is supplied with the CPU power supply (5V) in conjunction with the ACC (accessory) switch or the IG (ignition) switch. <Configuration of CPU 200>

[0021] As shown in FIG. 1, the CPU 200 includes an acquisition unit 210, a detection unit 220, an edge pattern determination unit 230, a setting unit 240, and a rotation determination unit 250. Note that the acquisition unit 210, the detection unit 220, the edge pattern determination unit 230, the setting unit 240, and the rotation determination unit 250 are some functions of the CPU 200 provided with a well-known RAM, ROM, I / O bus, etc. (not shown). And in the CPU 200, the control of the entire rotation determination device 1 is executed according to the control program stored in the ROM. For example, when the CPU power supply (5V) is supplied to the CPU 200, the processing of the rotation determination device 1 starts, and when the CPU power supply (5V) is cut off, the processing of the rotation determination device 1 ends.

[0022] In the acquisition unit 210, the signal levels of the A-phase input signal and the B-phase input signal input from the encoder unit 100 are acquired.

[0023] In the detection unit 220, rising edges and falling edges of the A-phase input signal and the B-phase input signal input from the encoder unit 100 are detected. Specifically, the A-phase input signal and the B-phase input signal are connected to input terminals of the CPU 200 capable of edge detection, and based on the A-phase input signal and the B-phase input signal input to the detection unit 220 via this input terminal, rising edges and falling edges of the A-phase input signal and the B-phase input signal are detected.

[0024] In the edge pattern determination unit 230, an edge pattern is determined based on the signal level acquired by the acquisition unit 210 and the input signal in which a rising edge or a falling edge is detected by the detection unit 220. Note that the determination process of the edge pattern will be described later.

[0025] In the setting unit 240, a reference signal level is set based on the signal level acquired by the acquisition unit 210. Note that the setting of the reference signal level will be described later.

[0026] In the rotation determination unit 250, it is determined whether or not the rotating body 111 has been rotated based on the edge pattern determined by the edge pattern determination unit 230 and the reference signal level set by the setting unit 240. Note that the rotation determination process will be described later.

[0027] <Processing of the rotation determination device 1> The processing of the rotation determination device 1 according to the present embodiment will be described with reference to FIGS. 4 to 8.

[0028] The process of determining the rotation operation of the rotating body 111 will be described with reference to FIG. 4.

[0029] In the CPU 200, it is determined whether or not the rotation determination state is valid (step S110). In the CPU 200, when it is determined that the rotation determination state is valid ( "YES" in step S110), the process proceeds to step S120. On the other hand, in the CPU 200, when it is determined that the rotation determination state is not valid ( "NO" in step S110), the process returns to step S110 and waits. Note that the rotation determination state is set to be valid when the CPU power is supplied to the CPU 200, or is set to be valid by the user operating an operation switch (not shown) after the CPU power is supplied to the CPU 200.

[0030] In the acquisition unit 210, the A-phase input signal level a and the B-phase input signal level b are acquired (step S120). That is, in the acquisition unit 210, the A-phase input signal level a and the B-phase input signal level b before the rotating body 111 is rotated are acquired. Note that the signal levels acquired by the acquisition unit 210 are High level (hereinafter referred to as H) or Low level (hereinafter referred to as L).

[0031] Next, in the setting unit 240, based on the signal levels acquired by the acquisition unit 210, reference signal levels (α, β) are set (step S130). That is, the A-phase input signal level a and the B-phase input signal level b before the rotating body 111 is rotated, which are acquired in step S120, are set in the setting unit 240 as the reference signal levels (α, β) = (a, b).

[0032] Next, in the detection unit 220, it is determined whether there is a change in the A-phase input signal or the B-phase input signal (step S140). That is, in the detection unit 220, the rising edge or the falling edge of the A-phase input signal and the B-phase input signal is detected.

[0033] And when a signal change is detected in the detection unit 220 ( "YES" in step S140), the process proceeds to step S150. On the other hand, when no signal change is detected in the detection unit 220 (''NO'' in step S140), the process proceeds to step S160.

[0034] Next, in the acquisition unit 210, the A-phase input signal level a and the B-phase input signal level b are acquired (step S150).

[0035] Then, based on the input signal in which a rising edge or a falling edge is detected by the detection unit 220 in step S140 and the signal level acquired by the acquisition unit 210 in step S150, edge pattern determination processing by the edge pattern determination unit 230 is executed (step S200). Note that the edge pattern determination processing (step S200) will be described later.

[0036] Next, in the rotation determination unit 250, rotation determination processing of the rotating body 111 is executed based on the edge pattern determined in step S200 (step S300). Note that the rotation determination processing (step S300) processed in the rotation determination unit 250 will be described later.

[0037] Then, in the CPU 200, it is determined whether the rotation determination state is valid (step S160). When it is determined in the CPU 200 that the rotation determination state is valid (''YES'' in step S160), the process returns to step S140 and the process continues. On the other hand, when it is determined in the CPU 200 that the rotation determination state is not valid (''NO'' in step S160), the process ends.

[0038] <Edge pattern determination processing (step S200)> The edge pattern determination processing executed in the edge pattern determination unit 230 when the rotating body 111 is rotationally operated will be described with reference to FIGS. 5 and 6. Note that, as shown in FIG. 5, in the edge pattern determination process (step S200), based on the information of the signal change detected by the detection unit 220 in step S140 and the input signal level acquired by the acquisition unit 210 in step S150, the edge pattern is classified into four types: E1 to E4. Hereinafter, while exemplifying that the data table shown in FIG. 5 is stored in the edge pattern determination unit 230 or a storage unit (not shown), the edge pattern determination process in the edge pattern determination unit 230 will be described in detail.

[0039] As shown in FIG. 6, in the edge pattern determination unit 230, it is determined whether the signal change detected by the detection unit 220 in step S140 is a change in the A-phase input signal (step S210). If it is determined that it is a change in the A-phase input signal (''YES'' in step S210), the process proceeds to step S220. On the other hand, if it is determined that it is not a change in the A-phase input signal (''NO'' in step S210), the process proceeds to step S250.

[0040] Next, in the edge pattern determination unit 230, it is determined whether the B-phase input signal level b acquired in step S150 is L (step S220). If it is determined that the B-phase input signal level b acquired in step S150 is L (''YES'' in step S220), in the edge pattern determination unit 230, the edge pattern is determined to be E1 (step S230). On the other hand, if it is determined that the B-phase input signal level b acquired in step S150 is not L (''NO'' in step S220), in the edge pattern determination unit 230, the edge pattern is determined to be E2 (step S240).

[0041] Then, in the edge pattern determination unit 230, it is determined whether the A-phase input signal level a acquired in step S150 is L (step S250). When it is determined that the A-phase input signal level a acquired in step S150 is L (``YES'' in step S250), the edge pattern determination unit 230 determines that the edge pattern is E3 (step S260). On the other hand, when it is determined that the A-phase input signal level a acquired in step S150 is not L (``NO'' in step S250), the edge pattern determination unit 230 determines that the edge pattern is E4 (step S270).

[0042] Then, when the edge pattern is determined in step S230, step S240, step S260, and step S270, the edge pattern determination process ends. <Rotation determination process (step S300)>

[0043] The rotation determination process (step S300) will be described with reference to FIGS. 7 and 8. Steps S301 to S312 described below are all processes executed by the rotation determination unit 250. In the rotation determination process (step S300), based on the edge pattern determined in the edge pattern determination process (step S200) and the reference signal levels (α, β) set in the setting unit 240, it is determined whether the rotating body 111 has been rotated. Hereinafter, while exemplifying that the data table shown in FIG. 8 is stored in the rotation determination unit 250 or a storage unit (not shown), the rotation determination process in the rotation determination unit 250 will be described in detail.

[0044] As shown in FIG. 7, the rotation determination unit 250 determines whether the reference signal level set in the setting unit 240 is the reference signal level (α, β) = (H, L) (step S301). When the rotation determination unit 250 determines that the reference signal level (α, β) = (H, L) (``YES'' in step S301), the process proceeds to step S304. On the other hand, when it is determined in the rotation determination unit 250 that the reference signal levels (α, β) ≠ (H, L) (step S301, "NO"), the process proceeds to step S302.

[0045] Next, in the rotation determination unit 250, it is determined whether the reference signal level set in the setting unit 240 is the reference signal level (α, β) = (L, H) (step S302). When it is determined in the rotation determination unit 250 that the reference signal levels (α, β) = (L, H) (step S302, "YES"), the process proceeds to step S305. On the other hand, when it is determined in the rotation determination unit 250 that the reference signal levels (α, β) ≠ (L, H) (step S303, "NO"), the process proceeds to step S303.

[0046] Then, in the rotation determination unit 250, it is determined whether the reference signal level set in the setting unit 240 is the reference signal level (α, β) = (L, L) (step S303). When it is determined in the rotation determination unit 250 that the reference signal levels (α, β) = (L, L) (step S303, "YES"), the process proceeds to step S306. On the other hand, when it is determined in the rotation determination unit 250 that the reference signal levels (α, β) ≠ (L, L) (step S303, "NO"), the process proceeds to step S307.

[0047] Next, in the rotation determination unit 250, specific edge patterns (the first edge pattern and the second edge pattern) are set based on the reference signal levels determined in steps S301 to S303. Specifically, in the rotation determination unit 250, by referring to the data table shown in FIG. 8, specific edge patterns (the first edge pattern and the second edge pattern) are set. Here, the specific edge pattern is the edge pattern that is assumed to be first detected by the edge pattern determination unit 230 when the rotation operation is started from the position of the rotating body 111 indicated by the values of the reference signal levels (α, β). At this time, in the rotation determination unit 250, since rotation operations in two directions, i.e., a clockwise rotation operation and a counterclockwise rotation operation of the rotating body 111, are conceivable, a first edge pattern and a second edge pattern are set.

[0048] That is, when the reference signal levels (α, β) = (H, L) (the "YES" in step S301), E2 = the first edge pattern and E3 = the second edge pattern are set (step S304), and the process proceeds to step S308. Also, when the reference signal levels (α, β) = (L, H) (the "YES" in step S302), E1 = the first edge pattern and E4 = the second edge pattern are set (step S305), and the process proceeds to step S308. Also, when the reference signal levels (α, β) = (L, L) (the "YES" in step S303), E1 = the first edge pattern and E3 = the second edge pattern are set (step S306), and the process proceeds to step S308. Also, when the reference signal levels (α, β) = (H, H) (the "NO" in step S303), E2 = the first edge pattern and E4 = the second edge pattern are set (step S307), and the process proceeds to step S308.

[0049] Then, in the rotation determination unit 250, it is determined whether or not the edge pattern determined in the edge pattern determination process (step S200) matches the first edge pattern set in any of the processes from step S304 to step S307 (step S308). When it is determined that the edge pattern determined in the edge pattern determination process (step S200) matches the first edge pattern set in any of the processes from step S304 to step S307 (\"YES\" in step S308), the rotation determination unit 250 determines that the rotating body 111 has been rotated clockwise by one click (step S309), and the process proceeds to step S312. On the other hand, when it is determined that the edge pattern determined in the edge pattern determination process (step S200) does not match the first edge pattern set in any of the processes from step S304 to step S307 (\"NO\" in step S308), the process proceeds to step S310.

[0050] Then, in the rotation determination unit 250, it is determined whether the edge pattern determined in the edge pattern determination process (step S200) matches the second edge pattern set in any of the processes from step S304 to step S307 (step S310).

[0051] When it is determined that the edge pattern determined in the edge pattern determination process (step S200) matches the second edge pattern set in any of the processes from step S304 to step S307 (\"YES\" in step S310), the rotation determination unit 250 determines that the rotating body 111 has been rotated counterclockwise by one click (step S311), and the process proceeds to step S312. On the other hand, when it is determined that the edge pattern determined in the edge pattern determination process (step S200) does not match the second edge pattern set in any one of the processes from step S304 to step S307 (\"NO\" in step S310), the rotation determination process (step S300) ends.

[0052] Then, in the rotation determination unit 250, the reference signal levels (α, β) are updated to the A-phase input signal level a and the B-phase input signal level b acquired in step S150 (step S312), and the rotation determination process (step S300) is terminated.

[0053] <Timing chart when the rotating body 111 is rotated> Using FIGS. 9 to 13, the timing chart when the rotating body 111 is rotated will be described. Note that this timing chart will be described by exemplifying the timing chart when the rotating body 111 is rotated in the clockwise direction.

[0054] (When the rotating body 111 is rotated from the state where the reference signal levels = (H, L)) Using FIG. 9, the timing chart when the rotating body 111 is rotated clockwise by one click will be described.

[0055] At t1, when the CPU power supply (5V) is supplied to the CPU 200 and the rotation determination state is set to valid, in the acquisition unit 210, the input signal levels (a, b) = (H, L) are acquired. Then, the input signal levels (a, b) acquired in the setting unit 240 are set to the reference signal levels (α, β). That is, in the setting unit 240, the reference signal levels (α, β) = (H, L) are set.

[0056] When the rotating body 111 is rotated in the clockwise direction and at t2, the rising edge of the B-phase input signal is detected by the detection unit 220, the input signal levels (a, b) are acquired in the acquisition unit 210, and further, in the edge pattern determination unit 230, the edge pattern determination process is executed. That is, in the acquisition unit 210, the input signal levels (a, b) = (H, H) are acquired, and in the edge pattern determination unit 230, the edge pattern is determined to be E4.

[0057] Next, in the rotation determination unit 250, a specific edge pattern is set based on the reference signal levels (α, β). When the reference signal levels (α, β) = (H, L), E2 = the first edge pattern and E3 = the second edge pattern are set. Since the edge pattern (= E4) determined by the edge pattern determination unit 230 does not match the first edge pattern (= E2) and the second edge pattern (= E3) set by the rotation determination unit 250, in the rotation determination unit 250, it is not determined that a rotation operation has been performed, and the rotation determination process ends.

[0058] Furthermore, when the rotating body 111 is rotated clockwise and a falling edge of the A-phase input signal is detected by the detection unit 220 at t3, the acquisition unit 210 acquires the input signal levels (a, b), and further, the edge pattern determination unit 230 executes an edge pattern determination process. That is, the acquisition unit 210 acquires the input signal levels (a, b) = (L, H), and the edge pattern determination unit 230 determines that the edge pattern is E2.

[0059] Next, in the rotation determination unit 250, a specific edge pattern is set based on the reference signal levels (α, β). When the reference signal levels (α, β) = (H, L), E2 = the first edge pattern and E3 = the second edge pattern are set. Since the edge pattern (= E2) determined by the edge pattern determination unit 230 matches the first edge pattern (= E2) set by the rotation determination unit 250, in the rotation determination unit 250, it is determined that the rotating body 111 has been rotated clockwise by one click. Then, in the setting unit 240, the reference signal levels (α, β) are updated to (L, H), and the rotation determination process ends.

[0060] (When the rotating body 111 is rotated from the state where the reference signal levels = (L, H)) Using FIG. 10, a timing chart when the rotating body 111 is rotated clockwise by one click will be described.

[0061] At t1, when CPU power supply (5V) is supplied to the CPU 200 and the rotation determination state is enabled, in the acquisition unit 210, the input signal levels (a, b) = (L, H) are acquired. Then, the input signal levels (a, b) acquired in the setting unit 240 are set to the reference signal levels (α, β). That is, in the setting unit 240, the reference signal levels (α, β) = (L, H) are set.

[0062] When the rotating body 111 is rotated clockwise and at t2, the falling edge of the B-phase input signal is detected by the detection unit 220, the input signal levels (a, b) are acquired in the acquisition unit 210, and further, the edge pattern determination process is executed in the edge pattern determination unit 230. That is, in the acquisition unit 210, the input signal levels (a, b) = (L, L) are acquired, and in the edge pattern determination unit 230, the edge pattern is determined to be E3.

[0063] Next, in the rotation determination unit 250, a specific edge pattern is set based on the reference signal levels (α, β). When the reference signal levels (α, β) = (L, H), E1 = the first edge pattern and E4 = the second edge pattern are set. And since the edge pattern (=E3) determined in the edge pattern determination unit 230 does not match the first edge pattern (=E1) and the second edge pattern (=E4) set in the rotation determination unit 250, it is not determined that a rotation operation has been performed in the rotation determination unit 250, and the rotation determination process ends.

[0064] When the rotating body 111 is rotated clockwise and, at t3, the rising edge of the A-phase input signal is detected by the detection unit 220, the input signal levels (a, b) are acquired by the acquisition unit 210, and further, the edge pattern determination unit 230 executes an edge pattern determination process. That is, in the acquisition unit 210, the input signal levels (a, b) = (H, L) are acquired, and in the edge pattern determination unit 230, the edge pattern is determined to be E1.

[0065] Next, in the rotation determination unit 250, a specific edge pattern is set based on the reference signal levels (α, β). When the reference signal levels (α, β) = (L, H), E1 = the first edge pattern and E4 = the second edge pattern are set. Since the edge pattern (= E1) determined by the edge pattern determination unit 230 matches the first edge pattern (= E1) set by the rotation determination unit 250, the rotation determination unit 250 determines that the rotating body 111 has been rotated clockwise by one click. Then, in the setting unit 240, the reference signal levels (α, β) are updated to (H, L), and the rotation determination process ends.

[0066] (When the rotating body 111 is rotated from the state where the reference signal levels = (L, L)) As shown in FIG. 2, the state where the input signal levels (a, b) = (L, L) indicates that the rotating body 111 has stopped at an intermediate position between two adjacent click stop positions. That is, even if it is an encoder unit with a structure where clicks occur, depending on the operation of the operator, the rotating body 111 may stop at an intermediate position between two adjacent click stop positions. Therefore, the rotation determination device 1 needs to correctly detect the rotation operation from this position. Therefore, using FIG. 11, the processing of the rotation determination device 1 when the rotating body 111 stopped at the intermediate position is rotated clockwise will be described below.

[0067] At t1, when CPU power supply (5V) is supplied to the CPU 200 and the rotation determination state is set to be valid, in the acquisition unit 210, the input signal levels (a, b) = (L, L) are acquired. Then, the input signal levels (a, b) acquired in the setting unit 240 are set to the reference signal levels (α, β). That is, in the setting unit 240, the reference signal levels (α, β) = (L, L) are set.

[0068] When the rotating body 111 is rotated clockwise and at t2, when the rising edge of the A-phase input signal is detected by the detection unit 220, the input signal levels (a, b) are acquired in the acquisition unit 210, and further, in the edge pattern determination unit 230, the edge pattern determination process is executed. That is, in the acquisition unit 210, the input signal levels (a, b) = (H, L) are acquired, and in the edge pattern determination unit 230, the edge pattern is determined to be E1.

[0069] Next, in the rotation determination unit 250, based on the reference signal levels (α, β), a specific edge pattern is set. When the reference signal levels (α, β) = (L, L), E1 = the first edge pattern and E3 = the second edge pattern are set. And since the edge pattern (= E1) determined in the edge pattern determination unit 230 matches the first edge pattern (= E1) set in the rotation determination unit 250, in the rotation determination unit 250, it is determined that the rotating body 111 has been rotated clockwise by one click.

[0070] Note that in the above timing chart, since the rotation operation of the rotating body 111 starts from the intermediate position between two adjacent click stop positions, when the rotating body 111 is rotated by half a click, the rotation determination unit 250 can determine the rotation operation. Then, in the setting unit 240, the reference signal levels (α, β) are updated to (H, L), and the rotation determination process ends.

[0071] (When the rotating body 111 is rotated from the state where the reference signal level = (H, H)) As shown in FIG. 2, the state where the input signal levels (a, b) = (H, H) indicates that the rotating body 111 has stopped at an intermediate position between two adjacent click stop positions. Therefore, with reference to FIG. 12, the processing of the rotation determination device 1 when the rotating body 111 stopped at an intermediate position between two adjacent click stop positions is rotated clockwise will be described below.

[0072] At t1, when the CPU power supply (5V) is supplied to the CPU 200 and the rotation determination state is set to be valid, the acquisition unit 210 acquires the input signal levels (a, b) = (H, H). Then, the input signal levels (a, b) acquired by the setting unit 240 are set as the reference signal levels (α, β). That is, in the setting unit 240, the reference signal levels (α, β) = (H, H) are set.

[0073] When the rotating body 111 is rotated clockwise and at t2, the falling edge of the A-phase input signal is detected by the detection unit 220, the acquisition unit 210 acquires the input signal levels (a, b), and further, the edge pattern determination unit 230 executes the edge pattern determination process. That is, in the acquisition unit 210, the input signal levels (a, b) = (L, H) are acquired, and in the edge pattern determination unit 230, the edge pattern is determined to be E2.

[0074] Next, in the rotation determination unit 250, a specific edge pattern is set based on the reference signal levels (α, β). When the reference signal levels (α, β) = (H, H), E2 = the first edge pattern and E4 = the second edge pattern are set. Since the edge pattern (=E2) determined by the edge pattern determination unit 230 matches the first edge pattern (=E2) set by the rotation determination unit 250, the rotation determination unit 250 determines that the rotating body 111 has been rotated clockwise by one click. Note that in the above timing chart, since the rotation operation of the rotating body 111 starts from the intermediate position between two adjacent click stop positions, when the rotating body 111 is rotated by half a click, the rotation determination unit 250 can determine the rotation operation. Then, in the setting unit 240, the reference signal levels (α, β) are updated to (L, H), and the rotation determination process ends.

[0075] (Prevention of misjudgment due to chattering of A-phase input signal and B-phase input signal) As shown in FIG. 13, when the rotating body 111 is rotated, chattering may occur in the waveforms of the A-phase input signal and the B-phase input signal at the rising and falling edges. Therefore, the chattering waveforms generated when the rotating body 111 is rotated clockwise are classified into four types: chattering A to chattering D, and the processes executed in the rotation determination device 1 when each chattering waveform occurs will be described.

[0076] (Processing when chattering A occurs) As shown in FIG. 13, chattering A is the chattering that occurs when the B-phase input signal rises. At t1, when the CPU power supply (5V) is supplied to the CPU 200 and the rotation determination state is set to be valid, the acquisition unit 210 acquires the input signal levels (a, b) = (H, L). Then, the input signal levels (a, b) acquired by the setting unit 240 are set as the reference signal levels (α, β). That is, in the setting unit 240, the reference signal levels (α, β) are set to (H, L).

[0077] When the rotating body 111 is rotated clockwise and the rising edge of the B-phase input signal is detected by the detection unit 220 at t2, the input signal levels (a, b) are acquired by the acquisition unit 210, and further, the edge pattern determination unit 230 executes an edge pattern determination process. That is, the input signal levels (a, b) = (H, H) are acquired by the acquisition unit 210, and the edge pattern is determined to be E4 by the edge pattern determination unit 230.

[0078] Next, in the rotation determination unit 250, specific edge patterns are set based on the reference signal levels (α, β). Specifically, when the reference signal levels (α, β) = (H, L), E2 = the first edge pattern and E3 = the second edge pattern are set. Since the edge pattern (= E4) determined by the edge pattern determination unit 230 does not match the first edge pattern (= E2) and the second edge pattern (= E3) set by the rotation determination unit 250, it is not determined that a rotation operation has been performed in the rotation determination unit 250, and the rotation determination process ends.

[0079] Furthermore, when the falling edge of the B-phase input signal is detected by the detection unit 220 at t3, which is the timing when chattering occurs, the input signal levels (a, b) are acquired by the acquisition unit 210, and further, the edge pattern determination unit 230 executes an edge pattern determination process. That is, the input signal levels (a, b) = (H, L) are acquired by the acquisition unit 210, and the edge pattern is determined to be E4 by the edge pattern determination unit 230. Next, in the rotation determination unit 250, specific edge patterns are set based on the reference signal levels (α, β). When the reference signal levels (α, β) = (H, L), E2 = the first edge pattern and E3 = the second edge pattern are set. Since the edge pattern (=E4) determined by the edge pattern determination unit 230 does not match the first edge pattern (=E2) and the second edge pattern (=E3) set by the rotation determination unit 250, it is not determined that the rotation operation has been performed by the rotation determination unit 250, and the rotation determination process ends.

[0080] Then, at time t4 when chattering further occurs, the same processing as the chattering that occurred at t2 is executed. In the rotation determination unit 250, it is not determined that the rotating body 111 has been rotationally operated, and the rotation determination process ends. That is, no matter how many times the chattering A that occurs when the B-phase input signal rises is detected, the rotation determination unit 250 does not misjudge the rotation operation.

[0081] (Processing when chattering B occurs) As shown in FIG. 13, chattering B is chattering that occurs when the A-phase input signal falls. At time t5, when the detection unit 220 detects the falling edge of the A-phase input signal, the acquisition unit 210 acquires the input signal levels (a, b), and further, the edge pattern determination unit 230 executes edge pattern determination processing. That is, the acquisition unit 210 acquires the input signal levels (a, b) = (L, H), and the edge pattern determination unit 230 determines that the edge pattern is E2. Next, in the rotation determination unit 250, a specific edge pattern is set based on the reference signal levels (α, β). When the reference signal levels (α, β) = (H, L), E2 = the first edge pattern and E3 = the second edge pattern are set. Since the edge pattern (=E2) determined by the edge pattern determination unit 230 matches the first edge pattern (=E2) set by the rotation determination unit 250, the rotation determination unit 250 determines that the rotating body 111 has been rotationally operated clockwise by one click. Then, in the setting unit 240, the reference signal levels (α, β) are updated to (L, H), and the rotation determination process is terminated.

[0082] Furthermore, at t6 which is the timing when chattering occurs, when the rising edge of the A-phase input signal is detected by the detection unit 220, the input signal levels (a, b) are acquired by the acquisition unit 210, and further, the edge pattern determination process is executed by the edge pattern determination unit 230. That is, the input signal levels (a, b) = (H, H) are acquired by the acquisition unit 210, and in the edge pattern determination unit 230, the edge pattern is determined to be E2. Next, in the rotation determination unit 250, specific edge patterns are set based on the reference signal levels (α, β). When the reference signal levels (α, β) = (L, H), E1 = the first edge pattern and E4 = the second edge pattern are set. Then, since the edge pattern (= E2) determined by the edge pattern determination unit 230 does not match the first edge pattern (= E1) and the second edge pattern (= E4) set by the rotation determination unit 250, in the rotation determination unit 250, it is not determined that a rotation operation has been performed, and the rotation determination process is terminated.

[0083] Then, at t7 which is the timing when further chattering occurs, when the falling edge of the A-phase input signal is detected by the detection unit 220, the input signal levels (a, b) are acquired by the acquisition unit 210, and further, the edge pattern determination process is executed by the edge pattern determination unit 230. That is, the input signal levels (a, b) = (L, H) are acquired by the acquisition unit 210, and in the edge pattern determination unit 230, the edge pattern is determined to be E2. Next, in the rotation determination unit 250, specific edge patterns are set based on the reference signal levels (α, β). When the reference signal levels (α, β) = (L, H), E1 = the first edge pattern and E4 = the second edge pattern are set. Then, since the edge pattern (=E2) determined by the edge pattern determination unit 230 does not match the first edge pattern (=E1) and the second edge pattern (=E4) set by the rotation determination unit 250, the rotation determination unit 250 determines that no rotation operation has been performed, and the rotation determination process ends. That is, after t5, no matter how many times the change in the A-phase input signal due to chattering occurs, the rotation determination unit 250 will not misjudge the rotation operation.

[0084] (Processing when chattering C occurs) As shown in FIG. 13, chattering C is chattering that occurs when the B-phase input signal falls. At t8, when the detection unit 220 detects the falling edge of the B-phase input signal, the acquisition unit 210 acquires the input signal levels (a, b), and further, the edge pattern determination unit 230 executes the edge pattern determination process. That is, the acquisition unit 210 acquires the input signal levels (a, b) = (L, L), and the edge pattern determination unit 230 determines that the edge pattern is E3. Next, in the rotation determination unit 250, a specific edge pattern is set based on the reference signal levels (α, β). When the reference signal levels (α, β) = (L, H), E1 = the first edge pattern and E4 = the second edge pattern are set. Then, since the edge pattern (=E3) determined by the edge pattern determination unit 230 does not match the first edge pattern (=E1) and the second edge pattern (=E4) set by the rotation determination unit 250, the rotation determination unit 250 determines that no rotation operation has been performed, and the rotation determination process ends.

[0085] Furthermore, at t9, which is the timing when chattering occurs, when the detection unit 220 detects the rising edge of the B-phase input signal, the acquisition unit 210 acquires the input signal levels (a, b), and further, the edge pattern determination unit 230 executes the edge pattern determination process. That is, in the acquisition unit 210, the input signal levels (a, b) = (L, H) are acquired, and in the edge pattern determination unit 230, the edge pattern is determined to be E3. Next, in the rotation determination unit 250, a specific edge pattern is set based on the reference signal levels (α, β). When the reference signal levels (α, β) = (L, H), E1 = the first edge pattern and E4 = the second edge pattern are set. Then, since the edge pattern (= E2) determined by the edge pattern determination unit 230 does not match the first edge pattern (= E1) and the second edge pattern (= E3) set by the rotation determination unit 250, it is not determined that a rotation operation has been performed in the rotation determination unit 250, and the rotation determination process ends.

[0086] Then, at t10 which is the timing when chattering further occurs, the same processing as the chattering that occurred at t8 is executed. In the rotation determination unit 250, it is not determined that the rotating body 111 has been rotationally operated, and the rotation determination process ends. That is, after t8, no matter how many times the change in the B-phase input signal due to chattering occurs, the rotation operation is not misjudged in the rotation determination unit 250.

[0087] (Processing when chattering D occurs) As shown in FIG. 13, chattering D is chattering that occurs when the A-phase input signal rises. At t11, when the rising edge of the A-phase input signal is detected by the detection unit 220, the input signal levels (a, b) are acquired in the acquisition unit 210, and further, the edge pattern determination process is executed in the edge pattern determination unit 230. That is, in the acquisition unit 210, the input signal levels (a, b) = (H, L) are acquired, and in the edge pattern determination unit 230, the edge pattern is determined to be E1. Next, in the rotation determination unit 250, a specific edge pattern is set based on the reference signal levels (α, β). When the reference signal levels (α, β) = (L, H), E1 = the first edge pattern and E4 = the second edge pattern are set. And since the edge pattern (= E1) determined by the edge pattern determination unit 230 matches the first edge pattern (= E1) set by the rotation determination unit 250, the rotation determination unit 250 determines that the rotating body 111 has been rotated clockwise by one click. Then, in the setting unit 240, the reference signal levels (α, β) are updated to (H, L), and the rotation determination process ends.

[0088] Furthermore, at time t12 which is the timing when chattering occurs, when the rising edge of the A-phase input signal is detected by the detection unit 220, the input signal levels (a, b) are acquired by the acquisition unit 210, and further, the edge pattern determination process is executed by the edge pattern determination unit 230. That is, the input signal levels (a, b) = (L, L) are acquired by the acquisition unit 210, and the edge pattern determination unit 230 determines that the edge pattern is E1. Next, in the rotation determination unit 250, a specific edge pattern is set based on the reference signal levels (α, β). When the reference signal levels (α, β) = (H, L), E2 = the first edge pattern and E3 = the second edge pattern are set. And since the edge pattern (= E1) determined by the edge pattern determination unit 230 does not match the first edge pattern (= E2) and the second edge pattern (= E3) set by the rotation determination unit 250, the rotation determination unit 250 does not determine that a rotation operation has been performed, and the rotation determination process ends.

[0089] Then, at t13 which is the timing when chattering further occurs, when the rising edge of the A-phase input signal is detected by the detection unit 220, the input signal levels (a, b) are acquired by the acquisition unit 210, and further, the edge pattern determination process is executed by the edge pattern determination unit 230. That is, the input signal levels (a, b) = (H, L) are acquired by the acquisition unit 210, and the edge pattern is determined to be E1 by the edge pattern determination unit 230. Next, in the rotation determination unit 250, a specific edge pattern is set based on the reference signal levels (α, β). When the reference signal levels (α, β) = (H, L), E2 = the first edge pattern and E3 = the second edge pattern are set. And since the edge pattern (= E1) determined by the edge pattern determination unit 230 does not match the first edge pattern (= E2) and the second edge pattern (= E3) set by the rotation determination unit 250, in the rotation determination unit 250, it is determined that the rotating body 111 has not been rotated, and the rotation determination process ends. That is, after t11, no matter how many times the change in the A-phase input signal due to chattering occurs, the rotation operation is not misjudged in the rotation determination unit 250.

[0090] As described above, the processing of the rotation determination device 1 has been exemplified and described when the rotating body 111 is rotated clockwise. However, the processing executed when the rotating body 111 is rotated counterclockwise is the same as the above-described processing.

[0091] <Function and Effect> As described above, the rotation determination device 1 according to the present embodiment includes an encoder unit 100 that generates two pulse signals (A-phase input signal and B-phase input signal) with phases shifted from each other due to the rotation of the rotating body 111, an acquisition unit 210 that acquires the levels of the two pulse signals, a detection unit 220 that detects the rising and falling edges of the two pulse signals, an edge pattern determination unit 230 that determines an edge pattern from one of the pulse signals in which a signal change is detected and the input signal level in the other pulse signal when a signal change is detected by the detection unit 220, a setting unit 240 that sets a reference signal level with the input signal level as an initial value, and a rotation determination unit 250 that determines rotation based on a specific edge pattern changed according to the reference signal level and the edge pattern determined by the edge pattern determination unit 230.

[0092] In the rotation determination device 1 according to the present embodiment, there are provided an encoder unit 100 that generates two pulse signals (A-phase input signal and B-phase input signal), an acquisition unit 210 that acquires the levels of the two pulse signals, a detection unit 220 that detects signal changes in the two pulse signals, an edge pattern determination unit 230 that acquires a signal level and determines an edge pattern when a change in any of the two pulses is detected, a setting unit 240 that sets a reference signal level, and a rotation determination unit 250 that determines whether the rotating body 111 has been rotated. When a specific edge pattern determined by the reference signal level matches the edge pattern determined by the edge pattern determination unit 230, the rotation determination unit 250 determines that the rotating body 111 has been rotated. That is, in the rotation determination device 1, the reference signal level is set at the operation start position of the rotating body 111, and when the edge pattern determined by the signal change detected in one of the two pulse signals matches the specific edge pattern set by the reference signal level, it is determined that the rotating body 111 has been rotated. Therefore, even if the operation start position of the rotating body 111 is an intermediate position, since the reference signal level is set at the intermediate position, it is possible to determine the rotation operation of the rotating body 111. In addition, since the reference signal level is set based on the input signal level, even if chattering occurs in the two pulse signals, rotation determination can be performed without false determination.

[0093] In the rotation determination device 1 according to the present embodiment, a specific edge pattern is distinguished into a first edge pattern and a second edge pattern. When the edge pattern is the first edge pattern, it is determined that the rotating body 111 is rotated clockwise, and when the edge pattern is the second edge pattern, it is determined that the rotating body 111 is rotated counterclockwise. That is, in the rotation determination device 1, a specific edge pattern determined based on the reference signal level is distinguished into two types: a first edge pattern and a second edge pattern. Therefore, the specific edge pattern for determining that the rotating body 111 has been rotated is distinguished into a first edge pattern for determining that it has been rotated clockwise and a second edge pattern for determining that it has been rotated counterclockwise, so that the rotation operation direction can be determined.

[0094] In the rotation determination device 1 according to the present embodiment, when the edge pattern is a specific edge pattern, the reference signal level is updated to the input signal level when the specific edge pattern is determined. That is, in the rotation determination device 1, when the edge pattern matches the specific edge pattern, the reference signal level is updated to the input signal level when the edge pattern and the specific edge pattern match, so that continuous rotation operations of the rotating body 111 can be correctly determined. In addition, when the edge pattern matches the specific edge pattern, the reference signal level is updated to the input signal level when the edge pattern and the specific edge pattern match. Therefore, even when chattering occurs in the two pulse signals, rotation determination can be performed without false determination.

[0095] In the rotation determination device 1 according to this embodiment, in the acquisition unit 210, when the CPU power supply is supplied and the rotation determination state is set to be valid, the A-phase input signal level and the B-phase input signal level are acquired. Based on the acquired input signal levels, in the setting unit 240, the reference signal level is set. Thereby, the operation start position of the rotating body 111 can be specified. Further, in the edge pattern determination unit 230, when the rotating body 111 is rotated and a change in the input signal is detected, the edge pattern generated by the rotation operation of the rotating body 111 is classified into four (E1 to E4) from the change in the input signal, the input signal in which the change occurs, and the level of the other input signal. That is, in the edge pattern determination unit 230, it is determined which edge pattern among the four edge patterns (E1 to E4) determined from the combination of the changes in the two pulse signals and the signal levels (H or L) is detected. Further, in the rotation determination unit 250, an edge pattern (specific edge pattern) that is assumed to be first determined by the edge pattern determination unit 230 when the rotating body 111 is rotated from the operation start position is set. That is, in the rotation determination unit 250, since the operation start position of the rotating body 111 can be specified from the reference signal level, the edge pattern that first occurs when the rotating body 111 is rotated can be uniquely set. At this time, since there is an edge pattern determined by the edge pattern determination unit 230 when the rotating body 111 is rotated clockwise and an edge pattern determined by the edge pattern determination unit 230 when the rotating body 111 is rotated counterclockwise, in the rotation determination unit 250, the first edge pattern and the second edge pattern are set. Then, in the rotation determination unit 250, the two edge patterns (specific edge patterns) set in the rotation determination unit 250 are compared with the edge pattern determined by the edge pattern determination unit 230, and when they match, it is determined that the rotating body 111 has been rotated. That is, in the rotation determination device 1 according to the present embodiment, the rotation operation of the rotating body 111 is determined based on the signal levels of the A-phase input signal and the B-phase input signal before the rotation operation, and the edge pattern detected by the rotation operation of the rotating body 111. Therefore, even when the operation start position of the rotating body 111 is the intermediate position, it is possible to determine in which direction the rotating body 111 has been rotated.

[0096] <Modification Example> Although the rotation determination device 1 described above has been described by exemplifying an encoder unit having a structure in which a click occurs, an encoder unit having a structure in which no click occurs may be used. Since the A-phase input signal level a and the B-phase input signal level b before the rotating body 111 is rotated are set to the reference levels (α, β), even in the case of an encoder unit having a structure in which no click occurs, the rotation of the rotating body 111 can be determined by the above-described rotation determination process.

[0097] Note that the processes of the acquisition unit 210, the detection unit 220, the edge pattern determination unit 230, the setting unit 240, and the rotation determination unit 250 are recorded on a computer system-readable recording medium, and the program recorded on this recording medium is read by the acquisition unit 210, the detection unit 220, the edge pattern determination unit 230, the setting unit 240, and the rotation determination unit 250 and executed, whereby the rotation determination device of the present invention can be realized. Here, the computer system includes hardware such as an OS and peripheral devices.

[0098] In addition, the "computer system" shall include a homepage providing environment (or display environment) if the WWW (World Wide Web) system is used. Further, the above program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the "transmission medium" for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line.

[0099] Also, the above program may be for realizing a part of the functions described above. Furthermore, it may be a so-called difference file (difference program) that can realize the functions described above in combination with a program already recorded in the computer system.

[0100] As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and designs and the like within the scope not departing from the gist of the present invention are also included.

Explanation of Reference Numerals

[0101] 1; Rotation determination device 100; Encoder unit 110; Encoder 111; Rotating body 112; Switch 113; Switch 200; CPU 210; Acquisition unit 220; Detection unit 230; Edge pattern determination unit 240; Setting unit 250; Rotation determination unit

Claims

1. An encoder connected to a rotating body and generating two pulse signals whose phases are shifted from each other by the rotation of the rotating body; A detection unit that detects rising edges and falling edges of the two pulse signals as signal changes; An acquisition unit that acquires the levels of the two pulse signals input from the encoder as input signal levels; A setting unit that sets a reference signal level with the input signal level when power is supplied to the encoder as an initial value; When the signal change is detected in either one of the two pulse signals by the detection unit, based on information regarding the change in the pulse signal in which the signal change is detected and the input signal level of the other pulse signal in which the signal change is not detected, an edge pattern determination unit that determines an edge pattern; A storage unit that stores a specific edge pattern set corresponding to the reference signal level in a state where the input signal levels of the two pulse signals match (“H, H”, “L, L”) and the reference signal level in a state where the input signal levels of the two pulse signals are different (“H, L”, “L, H”); A rotation determination unit that compares the edge pattern determined by the edge pattern determination unit with the specific edge pattern stored in the storage unit, and determines that the rotating body has rotated when the edge pattern determined by the edge pattern determination unit matches the specific edge pattern; A rotation determination device characterized by comprising the above.

2. The specific edge pattern is distinguished and set into a first edge pattern that is assumed to be detected when the rotating body is rotated clockwise and a second edge pattern that is assumed to be detected when the rotating body is rotated counterclockwise, with respect to the state where the rotating body is in the reference signal level. The rotation determination unit according to claim 1, wherein when the edge pattern matches the first edge pattern, it is determined that the rotating body has been rotated clockwise, and when the edge pattern matches the second edge pattern, it is determined that the rotating body has been rotated counterclockwise.

3. The rotation determination device according to claim 1 or 2, characterized in that when the edge pattern and the specific edge pattern match, the reference signal level is updated to the input signal level when the specific edge pattern is determined.

Images