JPH11281402A - Waveform shaping circuit, rotation detection device, and rotation detection method - Google Patents

Abstract

(57) [Problem] To detect a rotation direction and a rotation angle with higher accuracy without an adjustment process and without being affected by a change with time. A first reference level signal SREF1 and a first reference level signal SREF1 are set based on a predetermined signal level during an initial operation, and based on two peak hold signals corresponding to each detection signal in an operation state other than the initial operation. Since the second reference level signal SREF2 is generated and the waveforms of the first detection signal A and the second detection signal are shaped, the first reference signal level SREF1 and the second reference signal level SREF2 to be shaped are automatically optimized. The rotation direction and the rotation angle can be reliably detected without providing an adjustment step, reducing the influence of a change over time. Further, in the initial operation state, the sampling frequency of the peak hold signal is increased, so that the first reference signal level SRE is more quickly.
F1 and the second reference signal level SREF2 can be automatically set to optimal values.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waveform shaping circuit, a rotation detecting device, and a rotation detecting method, and more particularly to an information processing device capable of inputting information by using a rotator, in which a rotation direction and a rotation direction are detected. The present invention relates to a waveform shaping circuit, a rotation detection device, and a rotation detection method used for detecting a rotation angle.

[0002]

2. Description of the Related Art Conventionally, a device using a rotating bezel BZ as shown in FIG. 21 has been known as a mode switching device or a time correction device for a small device such as a wristwatch. In these devices, a mechanical switch is switched by the operation of a rotating bezel BZ. For example, there is a device in which a pin is made to penetrate a body of a wristwatch and a mode is switched by pressing a circuit spring with the pin. In this device,
The pin is engaged with the back surface of the rotating bezel BZ, and the user switches the plurality of circuits by rotating the rotating bezel BZ to move the position of the pin. In a desktop tape printer and the like, a rotary character input device using a rotary switch is used.

[0003]

However, this is an input device configured to switch the mechanical switch such as a pin or the like by rotating the rotating bezel as described above, and to switch a large number of tens of circuits such as character input. However, there is a problem in that the structure becomes complicated, and the device becomes large-scale, and it is difficult to mount the device on a small portable information device such as a wristwatch.

[0004] In the above-mentioned rotary character input device,
There is no one that is small and thin, and it is not mounted on a small information processing device such as a wristwatch. Furthermore, assuming that a rotary character input device that performs other types of character input is mounted on a small portable information device such as a wristwatch, the device configuration is simple, and the rotational position can be accurately determined without being affected by aging. A device capable of detecting and accurately inputting characters is desired.

Further, assuming that rotation detection is performed by an optical encoder, it is necessary to provide a waveform shaping circuit for shaping the output signal of the optical sensor (light emitting diode + photodiode). ,
If the configuration can be made so as not to be affected by the individual difference and the aging of the output level of the optical sensor, the output level adjustment process at the time of shipment can be omitted, the manufacturing cost can be reduced, and the maintenance-free rotational position detecting device can be configured. Can be.

Accordingly, a first object of the present invention is to provide a waveform shaping circuit, a waveform shaping method, and a waveform shaping method capable of performing more accurate waveform shaping without being affected by individual differences of optical sensors and aging. An object of the present invention is to provide a detection device and a rotation detection method capable of detecting a rotation direction and a rotation angle with high accuracy. A second object of the present invention is to provide a waveform shaping circuit, a rotation detecting device, a waveform shaping method, and a waveform shaping circuit that can quickly set a reference level signal (threshold signal) when shaping a waveform of an output signal of an optical sensor. It is to provide a rotation detection method.

[0007]

According to a first aspect of the present invention, there is provided a configuration for holding a predetermined signal level in an initial state and using a positive peak signal level of an input signal as a first peak hold signal. First peak hold means for holding, and a second peak hold means for holding the predetermined signal level in an initial state and holding a negative peak signal level of the input signal as a second peak hold signal
A peak hold means, a reference level signal generation means for generating and outputting a reference level signal based on the first peak hold signal and the second peak hold signal, and comparing the input signal with the reference level signal. Waveform shaping means for shaping the waveform of the input signal and outputting it as a waveform shaping signal.

According to a second aspect of the present invention, in the configuration of the first aspect, the first peak hold means performs sampling at a timing having a predetermined period, and uses a signal level of the input signal as the first peak hold signal. Holding, wherein the second peak hold means performs sampling at a timing having a predetermined period and holds the signal level of the input signal as the second peak hold signal.

According to a third aspect of the present invention, in the configuration of the second aspect, the timing cycle is set shorter than the timing cycle after a lapse of the predetermined time for a predetermined time from the start of operation. , Is characterized.

According to a fourth aspect of the present invention, in the configuration according to any one of the first to third aspects, the predetermined signal level held in the initial state is the highest among the assumed input signals. A signal level between the maximum signal level of the input signal having a low signal level and the minimum signal level of the input signal having the highest signal level among the assumed signal levels of the input signal, Features.

According to a fifth aspect of the present invention, there is provided a first peak detector which holds a predetermined signal level in an initial state, and holds a positive peak signal level of an input signal as a first peak hold signal, and the first peak detector in an initial state. A second peak detector that holds a negative peak signal level of the input signal as a second peak hold signal, and a reference level based on the first peak hold signal and the second peak hold signal. A reference level signal generation circuit that generates and outputs a signal; and a comparator that performs waveform shaping of the input signal by comparing the input signal with the reference level signal and outputs the input signal as a waveform shaped signal. And

According to a sixth aspect of the present invention, there is provided a reflecting member on which a predetermined optical pattern having an absorbing area and a reflecting area is formed, and the reflecting member is irradiated with first detection light and reflected by the reflecting member. A first detection unit that receives the first detection light and outputs a first detection signal corresponding to the optical pattern; and a first detection unit that is disposed at a predetermined angle from a rotation center with respect to the first detection unit; A second detection unit that irradiates the member with the second detection light, receives the reflected second detection light, and outputs a second detection signal corresponding to the optical pattern; and a predetermined first signal level in an initial state. And a first peak hold means for holding a positive peak signal level of the first detection signal as a first peak hold signal; and holding a predetermined first signal level in an initial state, and Second peak hold means for holding the negative peak signal level of the output signal as a second peak hold signal; and generating and outputting a first reference level signal based on the first peak hold signal and the second peak hold signal. First reference level signal generating means;
First waveform shaping means for shaping the waveform of the first detection signal by comparing the detection signal with the first reference level signal and outputting it as a waveform shaping signal; and holding a predetermined second signal level in an initial state. A third peak hold means for holding a positive peak signal level of the second detection signal as a third peak hold signal; and a predetermined second signal level in an initial state, and a negative peak of the second detection signal. Fourth peak holding means for holding a signal level as a fourth peak hold signal, and a second reference level signal for generating and outputting a second reference level signal based on the third peak hold signal and the fourth peak hold signal.
Reference level signal generation means, second waveform shaping means for performing waveform shaping of the second detection signal by comparing the second detection signal with the second reference level signal, and outputting the resulting signal as a second waveform shaping signal; Signal processing means for calculating a relative rotation direction and a rotation angle of the reflection member with respect to the first detection means and the second detection means based on the first waveform shaping signal and the second waveform shaping signal. It is characterized by that.

According to a seventh aspect of the present invention, there is provided a light transmitting member on which a predetermined optical pattern having an absorption area and a transmission area is formed, and the light transmitting member is irradiated with first detection light, and the light transmitting member is irradiated with the first detection light. A first detection unit that receives the transmitted first detection light and outputs a first detection signal corresponding to the optical pattern; and is disposed at a predetermined angle from the rotation center with respect to the first detection unit; Irradiating the light transmitting member with second detection light;
Receiving a second detection light transmitted through the light transmitting member and outputting a second detection signal corresponding to the optical pattern;
Detecting means; first peak hold means for holding a predetermined first signal level in an initial state, and holding a positive peak signal level of the first detection signal as a first peak hold signal; A second peak hold unit that holds one signal level and holds a negative peak signal level of the first detection signal as a second peak hold signal, based on the first peak hold signal and the second peak hold signal. First reference level signal generating means for generating and outputting a first reference level signal, and performing waveform shaping of the first detection signal by comparing the first detection signal with the first reference level signal. First waveform shaping means for outputting a signal as a signal, holding a predetermined second signal level in an initial state, and outputting the second detection signal. A third peak hold means for holding a positive peak signal level as a third peak hold signal, and a fourth peak hold for holding a predetermined second signal level in an initial state and a negative peak signal level of the second detection signal. Fourth peak hold means for holding as a signal, second reference level signal generation means for generating and outputting a second reference level signal based on the third peak hold signal and the fourth peak hold signal,
A second waveform shaping means for performing waveform shaping of the second detection signal by comparing the detection signal with the second reference level signal and outputting the same as a second waveform shaping signal; and the first waveform shaping signal and the second waveform shaping signal. Signal processing means for calculating a rotation direction and a rotation angle of the reflection member relative to the first detection means and the second detection means based on a waveform shaping signal.

According to an eighth aspect of the present invention, in the configuration of the sixth or seventh aspect, the first peak hold means performs sampling at a timing having a predetermined first cycle and performs signal level of the first detection signal. The first
The second peak hold means holds the signal level of the first detection signal as the second peak hold signal by sampling at a timing having a predetermined first period, and holds the third peak hold signal. The means performs sampling at a timing having a predetermined second cycle and holds the signal level of the second detection signal as the third peak hold signal, and the fourth peak hold means performs sampling at a timing having a predetermined second cycle. And holding the signal level of the second detection signal as the fourth peak hold signal.

According to a ninth aspect of the present invention, in the configuration of the eighth aspect, the first cycle is set to be shorter than the first cycle after the lapse of the predetermined time for a predetermined time from the start of the operation, The second cycle is set to be shorter than the second cycle after the lapse of the predetermined time for a predetermined time from the start of the operation.

According to a tenth aspect, in the configuration according to any one of the sixth to ninth aspects, the predetermined first signal level held in the initial state is the expected first detection level. A signal level between a maximum signal level of the first detection signal having the lowest signal level among the signals and a minimum signal level of the first detection signal having the highest signal level among the assumed first detection signals. Is set in the initial state, the predetermined second signal level is the maximum signal level of the second detection signal having the lowest signal level among the assumed second detection signals,
The signal level is set to a signal level between the minimum signal level of the second detection signal having the highest signal level among the assumed second detection signals.

According to an eleventh aspect of the present invention, in the configuration according to any one of the sixth to tenth aspects, the first
A reference level signal generation unit configured to generate the first reference level signal by dividing a voltage difference between the first peak hold signal and the second peak hold signal by a predetermined first voltage division ratio;
The second reference level signal generation means generates the second reference level signal by dividing a voltage difference between the third peak hold signal and the fourth peak hold signal by a predetermined second voltage division ratio. And

According to a twelfth aspect of the present invention, in the configuration according to any one of the sixth to eleventh aspects, the optical pattern is rotated relatively to the first detection means and the second detection means. The separation angle between the first detection means and the second detection means is set such that the phase of the first detection signal and the phase of the second detection signal output in the event of It is characterized by:

According to a thirteenth aspect of the present invention, in the configuration according to any one of the sixth to eleventh aspects, the optical pattern is such that the absorption area and the reflection area or the transmission area include the rotation center. Are formed alternately so that the angle θ2 around the center is 360 / n [゜] (n is an even number), and a line connecting each of the first detecting means or the second detecting means and the rotation center is The angle θ1 to be formed is characterized in that θ1 = (θ2 × m) + θ2 / 2 (where m is an integer).

According to a fourteenth aspect of the present invention, in the configuration of the sixth aspect, the reflecting member is formed in an annular rotating bezel, and the first detecting means and the second detecting means are provided by a user. And a band portion that can be wound around the wrist, and the rotating bezel is formed on the side of the wristwatch-type main body that is rotatably mounted.

According to a fifteenth aspect of the present invention, there is provided a reflecting member on which a predetermined optical pattern having an absorbing area and a reflecting area is formed, and the reflecting member is irradiated with the first detection light and reflected by the reflecting member. A first optical sensor that receives the first detection light and outputs a first detection signal corresponding to the optical pattern; and a first optical sensor that is arranged at a predetermined angle away from the rotation center with respect to the first detection unit; Irradiating the member with second detection light;
A second optical sensor that receives the reflected second detection light and outputs a second detection signal corresponding to the optical pattern; and holds a predetermined first signal level in an initial state, and the first detection signal A first peak detector for holding the positive peak signal level of the first peak hold signal as a first peak hold signal;
A second peak detector that holds a predetermined first signal level in an initial state and holds a negative peak signal level of the first detection signal as a second peak hold signal; and the first peak hold signal and the second peak signal. A first reference level signal generation circuit that generates and outputs a first reference level signal based on a hold signal; and a waveform shaping of the first detection signal by comparing the first detection signal with the first reference level signal. And a third comparator that holds a predetermined second signal level in an initial state and holds a positive peak signal level of the second detection signal as a third peak hold signal. A detector for maintaining a predetermined second signal level in an initial state and a negative peak signal level of the second detection signal; A fourth peak detector that holds the second peak level as a fourth peak hold signal, a second reference level signal generation circuit that generates and outputs a second reference level signal based on the third peak hold signal and the fourth peak hold signal. A second comparator that performs waveform shaping of the second detection signal by comparing the second detection signal with the second reference level signal and outputs the resulting signal as a second waveform shaping signal; and a signal of the first waveform shaping signal. The second waveform shaping signal is sampled at the level transition timing to perform the first waveform shaping.
While obtaining sampling data, the first waveform shaping signal is sampled at a signal level transition timing of the second waveform shaping signal to obtain second sampling data, and based on the first sampling data and the second sampling data. A signal processing circuit for calculating a rotation direction and a rotation angle of the reflection member relative to the first detection means and the second detection means.

According to a sixteenth aspect of the present invention, the first detection light is irradiated on the reflection member on which the predetermined optical pattern having the absorption area and the reflection area is formed, and the first detection light is reflected by the reflection member. Receiving a first detection signal corresponding to the optical pattern and outputting a first detection signal corresponding to the optical pattern; and irradiating a second detection light to a position irradiated by the first detection light and a position separated by a predetermined angle with respect to a rotation center. A second detection step of receiving the reflected second detection light and outputting a second detection signal corresponding to the optical pattern;
A first peak hold step of holding a signal level and a positive peak signal level of the first detection signal as a first peak hold signal; and holding a predetermined first signal level in an initial state, A second peak hold step of holding a negative peak signal level of the detection signal as a second peak hold signal; and generating and outputting a first reference level signal based on the first peak hold signal and the second peak hold signal. A first reference level signal generating step, a first waveform shaping step of performing a waveform shaping of the first detection signal by comparing the first detection signal with the first reference level signal, and outputting the waveform as a waveform shaping signal; In the initial state, the predetermined second signal level is maintained, and the positive peak signal level of the second detection signal is changed to the third peak signal level. A third peak hold step of holding a predetermined second signal level in an initial state, and a negative peak signal level of the second detection signal as a fourth peak hold signal. A second reference level signal generating step of generating and outputting a second reference level signal based on the third peak hold signal and the fourth peak hold signal; and transmitting the second detection signal to the second reference level signal. A second waveform shaping step of performing waveform shaping of the second detection signal by comparing with the second waveform shaping signal and outputting the second detection signal as a second waveform shaping signal; A signal processing step of calculating a rotation direction and a rotation angle relative to the first detection means and the second detection means. To have.

[0023]

Preferred embodiments of the present invention will now be described with reference to the drawings. [1] Embodiment [1.1] Configuration of Embodiment [1.1.1] Configuration of Wristwatch-Type Data Information Processing Apparatus FIG. 1 is a front view of a wristwatch-type data information processing apparatus having a rotation detection device of the present invention. Show. Wristwatch type information processing device 10
A rotating bezel 102 formed in an annular shape is slidably disposed on the upper portion (front side in the drawing) of the main body 101 of the main body 101. On the upper surface of the rotating bezel 102, characters such as "A, I, U, ..., 9, ..." are formed at regular intervals by printing or the like. A cover glass 103 is provided on the inner peripheral side of the rotating bezel 102, and information and the like input to the wristwatch-type information processing apparatus 100 are displayed on the lower surface side (back side of the paper) of the cover glass 103. A display unit 104 is provided. On the upper side of the display unit 104 in the drawing, an instruction mark 110 for indicating one of characters and the like formed on the rotating bezel 102 is formed by printing or the like. A decision switch 10 is provided around the main body 101.
5, a delete switch 106, a turbid spot switch 107, and an origin switch 108 are provided. Note that these switches may be provided on the cover glass 103.

FIG. 2 shows a state in which the rotating bezel 102 has been removed from the wristwatch-type information processing apparatus 100. As shown in FIG. 2, holes 31a and 31b are formed in the main body 101, and a first sensor unit 32 functioning as a first detecting means and a second sensor functioning as a second detecting means are formed in the holes 31a and 31b. The sensor units 33 are arranged respectively. In this case, the first sensor unit 32 and the line connecting the first sensor unit 32 and the rotation center O of the rotating bezel 102 and the line connecting the second sensor unit 33 and the rotation center O form an angle θ1. And the second sensor unit 33 are arranged. In addition, the first sensor unit 32 is disposed below (in the back side of the paper of FIG. 2) below the character or the like (“A” in FIG. 2) indicated by the above-described instruction mark 110. The angle θ1 will be described later.

FIG. 3 is a view taken along the line IV-IV in FIG. As shown in FIG. 3, an optical pattern 41 is formed on a lower surface of the rotating bezel 102 at a position corresponding to a character or the like formed on an upper surface of the rotating bezel 102. A sensor cover glass 42 is attached to the main body 101 below the surface on which the optical pattern 41 is formed. At this time, a packing 43 is provided between the main body 101 and the sensor cover glass 42, thereby preventing entry of water or the like into a lower portion of the sensor cover glass 42. The first sensor unit 32 is provided below the sensor cover glass 42. First sensor unit 32
Is composed of an LED (Light Emitting Diode) 44, a photodiode 45, a light-shielding plate 44a disposed between the LED 44 and the photodiode 45, and a substrate 46. The LED 44 faces the optical pattern 41. The first detection light L1 is emitted and irradiated, the reflected light is received by the photodiode 45, and the first detection signal A is generated based on the received first detection light L1. Similarly, the second sensor unit 33 includes an LED 46 (see FIG. 7), a photodiode 47 (see FIG. 7), a light shielding plate disposed between the LED 46 and the photodiode 47, and a substrate. The LED 46 emits and irradiates the second detection light L2 toward the optical pattern 41, the photodiode 47 receives the reflected light, and generates the second detection signal B based on the received second detection light L2. As described above, the first detection signal A generated by the first sensor unit 32 and the second detection signal B generated by the second sensor unit 33 are counted by the information processing unit 81 (see FIG. 6) described later. The rotation angle and the rotation direction of 102 are detected.

A contact spring 47 is provided below the substrate 46 of the first sensor unit 32.
7, the first sensor unit 32 and the second sensor unit 33 are electrically connected to the CPU of the wristwatch-type information processing apparatus 100 and the like. Note that a lead wire may be provided instead of the contact spring 47. As shown in FIGS. 2 and 3, a groove 34 is formed on the circumference of the upper part of the main body 101. On the other hand, as shown in FIG.
On the lower surface of 2, a ridge 46 projecting downward is formed, and the ridge 46 is slidably fitted in the groove 34. The right side of the rotating bezel 102 in the figure and the main body 1
An O-ring 47 is arranged between the wristwatch-type information processing apparatus 100 and the O-ring 47.

[1.1.2] Optical Pattern Next, the optical pattern 41 will be described. FIG. 4 is a diagram illustrating the lower surface of the rotating bezel 102 functioning as a reflecting member. The optical pattern 41 is, as shown in FIG.
D44 and an absorption area 41a for absorbing the light emitted by D44
Forty-four reflection areas 41b for reflecting light are formed alternately. At this time, the absorption region 41a and the reflection region 41b are formed at every angle θ2 about the rotation center O. In this case, when the number of characters formed on the upper surface of the rotating bezel 102 is n (n is an even number),
θ2 = 360 / n [゜].

When the user rotates the rotating bezel 102, the first sensor unit 32 alternately reads the absorption area 41a and the reflection area 41b of the optical pattern 41 shown in FIG. The first detection signal A having a substantially sinusoidal waveform as shown in FIG. 5 (b) can be generated. On the other hand, the second sensor unit 33 also
The second detection signal B having a substantially sinusoidal waveform as shown in FIG.
Will be generated. In this case, the phases of the first detection signal A and the second detection signal B are as described in detail below.
The arrangement of the absorption region 41a and the reflection region 41b, and the first sensor unit 32 and the second sensor unit 33 is set so as to be shifted by １ ／ wavelength.

[1.1.3] Arrangement of Sensor Unit Next, the first sensor unit 32 and the second sensor unit 3
3 will be described. In the present embodiment, the first sensor unit 32 and the second sensor unit 33 are arranged such that θ1 = (θ2 × m) + θ2 / 2 (where m is an integer). Thereby, when the rotating bezel 102 is rotated by the user, the first
A 1/4 phase difference occurs between the first detection signal A generated by the sensor unit 32 and the second detection signal B generated by the second sensor unit 33.

As shown in FIG. 5, when the rotating bezel 102 is rotated clockwise, the second sensor unit 33 is rotated.
Generates a 1/4 phase advance from the first detection signal A generated by the first sensor unit 32 in the second detection signal B generated by
When the rotating bezel 102 is rotated counterclockwise,
The pulse signal generated by the second sensor unit 33 has a 遅 れ phase delay from the pulse signal generated by the first sensor unit 32. By detecting such a phase delay / phase advance, it is possible to detect the rotation direction of the rotating bezel 102 as described later.

[1.1.4] Functional Configuration Next, information such as characters is generated from the rotation angle and rotation direction of the rotating bezel 102 detected as described above, displayed on the display unit 104, and stored. Fig. 6
This will be described with reference to FIG. The information processing section 111 has a pulse number counter and a forward / reverse inversion detecting section, and outputs a first detection signal A generated by the first sensor unit 32 and a second detection signal B generated by the second sensor unit 33. The information data is generated based on the information data, and the information data determined by the user is stored in the memory 113. At this time, the information processing unit 111 generates an information signal by referring to the information table 112 in which information data corresponding to the rotation position of the rotating bezel 102 is stored. The character generator 114 displays information such as characters on the display unit 104 based on the information signal thus generated.

The origin switch 108 switches the wristwatch type information processing apparatus 100 to an information input state. When the origin switch 108 is turned on, the pulse number counter of the information processing section 81 is reset to 0, and the first sensor The detection of the rotation angle and the rotation direction of the rotating bezel 102 by the unit 32 and the second sensor unit 33 is started. Confirm switch 105, delete switch 10
Reference numeral 6 is for confirming or deleting the information data generated in the information processing section 81, respectively. When the information generated by the information processing unit 111 is a kana character, the voiced dot switch 107 is used to add a voiced dot. When the information is in English characters, the voiced dot switch 107 has a function of switching between lowercase and uppercase. In addition,
The information generated by the information processing unit 111 is not limited to character information.
It is also possible to generate command data such as character editing such as line feed and mode switching (for example, switching between a time display mode and a character input mode) in the information processing apparatus. In this case, command information such as character editing and mode switching is stored in the information table 112 in correspondence with the rotation position of the rotating bezel 102, and the detected rotating bezel 1
The information processing section 81 generates the command data based on the rotational position 02.

[1.1.5] Configuration of information processing section and sensor unit [1.1.5.1] Explanation of principle of information processing section Next, information processing section 111, first sensor unit 32, and second sensor unit Prior to the description of the configuration of 33, the principle of the main part of the information processing unit 111 will be described. FIG. 7 is a diagram illustrating the principle of the main part of the information processing unit 111. Information processing unit 111
Is an initial signal level generation circuit PIN that divides the power supply voltage VDD by a predetermined voltage division ratio to generate an initial signal voltage VINIT of a predetermined signal level (corresponding to the first signal level and the second signal level).
IT and a first peak hold circuit PH1 that holds the initial signal voltage VINIT in the initial state and holds the positive peak signal level of the first detection signal A output from the first sensor unit 32 as the first peak hold signal SPH1.
A second peak hold circuit PH2 that holds the initial signal voltage VINIT in the initial state and holds the negative peak signal level of the first detection signal A as the second peak hold signal SPH2; A first voltage dividing circuit SP1 (first circuit) that divides the two peak hold signal SPH2 to generate and outputs a first reference level signal SR1.
A first comparator CP1 (corresponding to a reference level signal generating means) which compares the first detection signal A with the first reference level signal SR1 to shape the waveform of the first detection signal A and outputs it as a waveform shaping signal SA. (Equivalent to one waveform shaping means)
And a third peak hold PH3 that holds the initial signal voltage VINIT in the initial state and holds the positive peak signal level of the second detection signal B as the third peak hold signal SPH3, and holds the initial signal voltage VINIT in the initial state. And holding the negative peak signal level of the second detection signal B as the fourth peak hold signal SPH4.
The peak hold circuit PH4, the third peak hold signal SPH3, and the fourth peak hold signal SPH4 are divided into second and third signals.
Second voltage dividing circuit SP for generating and outputting reference level signal SR2
2 (corresponding to the second reference level signal generating means) and the second detection signal B are compared with the second reference level signal SR2 to perform the waveform shaping of the second detection signal B to perform the second waveform shaping signal SB.
A second comparator CP2 (corresponding to a second waveform shaping means) which outputs the second waveform shaping signal SB at the signal level transition timing of the first waveform shaping signal SA to obtain first sampling data, The first waveform shaping signal SA is sampled at the signal level transition timing of the waveform shaping signal SB to obtain second sampling data, and the first sensor unit 32 of the optical pattern and the second sampling data are obtained based on the first sampling data and the second sampling data. Signal processing unit SPU for calculating the relative rotation direction and rotation angle with respect to two sensor unit 33
And the first to fourth peak hold circuits PH1 to PH1 when the initialization signal INIT is input.
4 and connect the first sensor unit 32 to the first
The second sensor unit 33 is disconnected from the peak hold circuit PH1 and the second peak hold circuit PH2, and the second sensor unit 33 is connected to the third peak hold circuit PH3 and the fourth peak hold circuit P.
And switches SW1 to SW4 for disconnecting from H4.

According to this configuration, the initial signal level generation circuit PINIT divides the power supply voltage VDD at a predetermined voltage dividing ratio to a predetermined signal level (corresponding to the first signal level and the second signal level).
Is generated. Then, when the initialization signal INIT is input, the switches SW1 to SW4 become
The initial signal level generation circuit PINIT is connected to the first to fourth peak hold circuits PH1 to PH4, and the first sensor unit 32 is separated from the first peak hold circuit PH1 and the second peak hold circuit PH2. To the third peak hold circuit PH3 and the fourth peak hold circuit PH4.
Disconnect from the peak hold circuit PH4. This allows
The first peak hold circuit PH1 to the fourth peak hold circuit PH4 hold the initial signal voltage VINIT. As a result, the first voltage dividing circuit SP1 converts the initial signal voltage VINIT as the voltage of the first reference level signal SR1 into the first comparator CP1.
And the second voltage dividing circuit SP2 outputs the second reference level signal S
As R2, the initial signal voltage VINIT is applied to the second comparator CP
Output to 2.

As a result, the first comparator CP1
Performs the waveform shaping of the first detection signal A by comparing the first detection signal A with the first reference level signal SR1, that is, the initial signal voltage VINIT, and outputs the waveform as the waveform shaping signal SA. The second comparator CP2 shapes the waveform of the second detection signal B by comparing the second detection signal B with the second reference level signal SR2, that is, the initial signal voltage VINIT, and outputs it as a waveform shaping signal SB. . The signal processing unit SPU samples the second waveform shaping signal SB at the signal level transition timing of the first waveform shaping signal SA to obtain the first sampling data, and obtains the first sampling data at the signal level transition timing of the second waveform shaping signal SB. The second sampling data is obtained by sampling the one waveform shaping signal SA, and based on the first sampling data and the second sampling data, the relative rotation direction of the optical pattern with respect to the first sensor unit 32 and the second sensor unit 33 and Calculate the rotation angle.

Therefore, the first sensor unit 32 and the second
The initial value (threshold voltage initial value) for waveform shaping can be set without being affected by the characteristics of the sensor unit 33, more specifically, the voltage and amplitude of the first detection signal A or the second detection signal B. It is possible to accurately calculate the accurate rotation direction and rotation angle without providing an adjustment step. When the input of the initialization signal INIT is completed, the switches SW1 to SW4 switch the initial signal level generation circuit PINIT to the first to fourth peak hold circuits PH1 to PH4.
H4, the first sensor unit 32 is connected to the first peak hold circuit PH1 and the second peak hold circuit PH2, and the second sensor unit 33 is connected to the third peak hold circuit PH3 and the fourth peak hold circuit P2.
Connect to H4. Thereby, the first peak hold circuit PH1 holds the positive peak signal level of the first detection signal A output from the first sensor unit 32 as the first peak hold signal SPH1, and the second peak hold circuit PH2
Is the first detection signal A output from the first sensor unit 32
Of the second peak hold signal SPH2
Hold as.

On the other hand, the third peak hold circuit PH3
The positive peak signal level of the second detection signal B output from the second sensor unit 33 is held as the third peak hold signal SPH3, and the fourth peak hold circuit PH4 outputs the second detection signal B output from the second sensor unit 33. Is held as the fourth peak hold signal SPH4. As a result, the first voltage dividing circuit SP1 divides the first peak hold signal SPH1 and the second peak hold signal SPH2 and generates the first reference level signal SR1 by the first comparator C1.
Output to P1.

Further, the second voltage dividing circuit SP2 divides the third peak hold signal SPH3 and the fourth peak hold signal SPH4 and outputs them as a second reference level signal SR2 to the second comparator CP2. As a result, the first comparator CP1 shapes the waveform of the first detection signal A by comparing the first detection signal A with the first reference level signal SR1, and outputs the same as the waveform shaping signal SA. Further, the second comparator CP2 converts the second detection signal B into the second reference level signal S
By comparing with R2, the waveform of the second detection signal B is shaped and output as a waveform shaping signal SB.

The signal processing unit SPU samples the second waveform shaping signal SB at the signal level transition timing of the first waveform shaping signal SA to obtain the first sampling data, and obtains the signal level transition of the second waveform shaping signal SB. At the timing, the first waveform shaping signal SA is sampled to obtain second sampling data, and the optical pattern is relative to the first sensor unit 32 and the second sensor unit 33 based on the first sampling data and the second sampling data. The rotation direction and the rotation angle will be calculated. Therefore, the first sensor unit 32 and the second
The rotation direction and the rotation angle can be calculated without being affected by the characteristics of the sensor unit 33, more specifically, the voltage and the amplitude of the first detection signal A or the second detection signal B. The rotation direction and the rotation angle can be calculated without being affected.

[1.1.5.2] Specific Configuration of Information Processing Unit and Sensor Unit Next, a specific configuration of the information processing unit and the sensor unit will be described with reference to FIG. First sensor unit 32
Is an LED (Light Emitting) that emits the first detection light L1.
A photodiode 45 which receives the first detection light L1 reflected by the optical pattern 41 and outputs the first detection light A via the first transistor Q1.
And is provided. Similarly, the second sensor unit 33 also has an LED 46 for emitting the second detection light L2.
And the second detection light L2 reflected by the optical pattern 41
, And a photodiode 47 that outputs the second detection signal B via the second transistor Q2.

The information processing section 111 roughly divides the first detection signal A into the first sampling timing signal SAMP1.
A first sampling and holding circuit 120 that samples and holds the first reference level signal SREF1 based on the first detection signal A held by the first sampling and holding circuit 120 and outputs the first reference level signal SREF1 By comparing the signal generation circuit 121 with the output signal of the first sampling and holding circuit 120, that is, the first detection signal A and the first reference level signal SREF1, the first signal is obtained.
A first comparator 122 for shaping the waveform of the detection signal A and outputting a first waveform shaping signal SA; and a second sampling and holding circuit 123 for sampling and holding the second detection signal B based on the second sampling timing signal SAMP2. And the second sampling and holding circuit 123
A second reference level signal generation circuit 124 for generating and outputting a second reference level signal SREF2 based on the second detection signal B held by the second sampling signal B;
3 by comparing the second detection signal B, ie, the second detection signal B with the second reference level signal SREF2.
A second comparator 125 for performing waveform shaping to output a second waveform shaping signal SB, and a first sensor unit 32 and a second sensor unit of an optical pattern based on the first waveform shaping signal SA and the second waveform shaping signal SB. A signal processing unit 126 for calculating a rotation direction and a rotation angle relative to the first sampling timing signal SAMP
1, a first switch S1 for enabling the first sensor unit 32 to be in an operable state and causing the first sampling and holding circuit 120 to sample the first detection signal A.
And the second sensor unit 33 is enabled based on the second switch S2 and the second sampling timing signal SAMP2, and the second sampling and holding circuit 123
For sampling the second detection signal B
A switch S3 and a fourth switch S4 are provided.

[1.1.5.2.1] Configuration of Signal Processing Unit The signal processing unit 126 is configured to output the first sensor unit 32 of the optical pattern based on the first waveform shaping signal SA and the second waveform shaping signal SB. A forward / reverse determination circuit 130 that detects a relative rotation direction (= forward direction or reverse direction) with respect to the second sensor unit 33 and outputs a forward / reverse determination signal SRD.
And a first edge detection circuit 131 that detects an edge of the first waveform shaping signal SA and outputs a first edge detection signal SE1
And the first sensor unit 32 and the second sensor unit of the optical pattern based on the forward / reverse determination signal SRD and the first edge detection signal SE1.
A first up / down counter 132 for obtaining a count value corresponding to a rotation angle with respect to the sensor unit 33;
A 分 frequency divider circuit 133 that divides the LSB value of the up / down counter 132 by を to generate a first control signal CNT1, and generates and outputs a first sampling timing signal SAMP1 based on the first control signal CNT1. The first timing generator 134 performs the edge detection of the second waveform shaping signal SB, and outputs the second edge detection signal SE2, and outputs the second edge detection signal SE2 to the forward / reverse determination signal SRD and the second edge detection signal SE2. A second up / down counter 136 for obtaining a count value corresponding to a rotation angle of the optical pattern with respect to the first sensor unit 32 and the second sensor unit 33, and dividing the LSB value of the second up / down counter 136 by １ ／ 1/2 frequency divider 137 for generating the second control signal CNT2
And a second timing generator 138 that generates and outputs a second sampling timing signal SAMP2 based on the second control signal CNT2.

[1.1.5.2.2] Configuration of reference level signal generation circuit Next, the configuration of the reference level signal generation circuit will be described.
In this case, the first reference level signal generation circuit 121
Since the first reference level signal generation circuit 124 and the second reference level signal generation circuit 124 have the same configuration, the first reference level signal generation circuit 121 will be described with reference to FIG. The first reference level signal generation circuit 121 sets the positive peak signal level of the first detection signal A to the first
A first peak hold circuit 140 for holding as a peak hold signal SP1, a second peak hold circuit 141 for holding a negative peak signal level of the first detection signal A as a second peak hold signal SP2, and a first peak hold signal S
Divide the voltage difference between P1 and the second peak hold signal SP2,
Voltage divider circuit 1 for generating and outputting first reference level signal SREF1
42 and a first for inhibiting the input of the first detection signal A to the first peak hold circuit 140 when the initialization signal INIT is input.
A switch 143, a second switch 144 for inhibiting input of the first detection signal A to the second peak hold circuit 141 when the initialization signal SINIT is input, and a power supply voltage divided at a predetermined voltage division ratio to generate an initial signal voltage VINIT Voltage divider 145
When the initialization signal INIT is input, the voltage dividing circuit 145 is switched to the first
Third switch 14 connected to peak hold circuit 140
6 and a fourth switch 1 that connects the voltage dividing circuit 145 to the second peak hold circuit 141 when the initialization signal INIT is input.
47.

Here, the setting of the initial signal voltage VINIT will be described with reference to FIG. Initial signal voltage VINIT
Is the maximum signal voltage VMINMAX of the first detection signal A that would be obtained when the signal level is the lowest among the assumed first detection signals A, that is, when the sensitivity of the first sensor unit 32 is the minimum. The signal level of the assumed first detection signal A is the highest, that is, the first sensor unit 32
Is set to a voltage (signal level) between the minimum signal voltage VMAXMIN of the first detection signal A which would be obtained when the sensitivity is the highest. This makes it possible to reliably perform waveform shaping.

[1.1.5.2.2] Configuration of Timing Generator Next, the configuration of the timing generator will be described.
In this case, the first timing generator 134
Since the first and second timing generators 138 have the same configuration, the first timing generator 134 will be described with reference to FIG. The first timing generator 134 generates and outputs a reference frequency signal fREF having a predetermined reference frequency, and an oscillator 150 that divides the frequency of the reference frequency signal fREF to a higher frequency (for example, 8 k [H]).
z]) and a second frequency signal fL having a low frequency (eg, 512 [Hz]).
, And a logical product (AN) of the second frequency signal fL and the first control signal CNT1.
D) to output a first AND signal AND1
AND circuit 15 which obtains the logical product (AND) of the D circuit 152 and the inverted signal of the first frequency signal fH and the first control signal CNT1, and outputs the second logical product signal AND2
3, the first AND signal AND1 and the second AND signal AN
An OR circuit 154 that takes the logical sum (OR) of D2 and outputs a logical sum signal OR1, a delay circuit 155 that delays the logical sum signal OR1 for a predetermined time and outputs the result as a delayed logical sum signal DOR1, and a logical sum signal OR1 And the delayed OR signal D
AND circuit 156 that takes the logical product (AND) of OR1 and outputs first sampling timing signal SAMP1
And is provided.

Here, the first timing generator 13
4 will be described with reference to FIG. 8 and FIG.
The oscillator 150 of the first timing generator 134
A reference frequency signal fREF having a predetermined reference frequency is output to the frequency divider 151. The frequency divider 151 divides the frequency of the reference frequency signal fREF to a higher frequency (for example, 8 k [H
z]) and a second frequency signal fL having a low frequency (eg, 512 [Hz]).
Is generated, and the first frequency signal fH is output to the AND circuit 153.
And outputs the second frequency signal fL to the AND circuit 152. In parallel with these operations, the initialization signal INIT
Becomes "H" level, the 1/2 frequency dividing circuit 133 is reset, and the first control signal CNT1 becomes "L".
Level.

As a result, the first AND signal AND1 output from the AND circuit 152 becomes "L" level. On the other hand, the signal level of the inverted signal of the first control signal CNT1 becomes “H” level, and the logical product (AN) of the first frequency signal fH and the inverted signal of the first control signal CNT1 is obtained.
D), the second AND signal AND output from the AND circuit 153 is synchronized with the first frequency signal fH.
2 becomes "H" level. Therefore, the OR circuit 154
An OR signal OR1 that becomes “H” level at the frequency of the first frequency signal fH is output to the delay circuit 155 and the AND circuit 156. As a result, the delay circuit 155 delays the OR signal OR1 by a predetermined time and outputs the result as the delayed OR signal DOR1 to the AND circuit 156.
The logical AND of the delayed OR signal DOR1 and the OR signal OR1 is calculated to generate a first sampling signal SAMP1.

As a result, the first sampling signal SA
MP1 is delayed by the delay circuit 155 for a predetermined time, and then the frequency of the first frequency signal fH (for example, 8 k [H
z]), the signal becomes “H” level. Then the first
When the edge detection signal SE1 becomes “H” level,
When the LSB value of the first up / down counter 132 becomes “H”, the first control signal CNT1 becomes “H”.
Level. As a result, the second logical product signal AND2 output from the AND circuit 153 becomes “L” level.
On the other hand, the second frequency signal fH and the first control signal C
By taking the logical product (AND) of the inverted signal of NT1, the AND circuit 152 is synchronized with the second frequency signal fL.
Output at the "H" level. Therefore, the OR circuit 154 outputs the logical sum signal OR1 which becomes “H” level at the frequency of the second frequency signal fL to the delay circuit 155 and the AND circuit 156.

As a result, the delay circuit 155 delays the logical sum signal OR1 by a predetermined time to delay the logical sum signal DOR1.
Is output to the AND circuit 156, and the AND circuit 156
Takes the logical product of the delayed logical sum signal DOR1 and the logical sum signal OR1, and generates a first sampling signal SAMP1. As a result, the first sampling signal SAMP1
Is, after being delayed by the delay circuit 155 for a predetermined time, the frequency of the second frequency signal fL (= for example, 512 [H
z]), the signal goes to the “H” level, and then the operation is continued until the initialization signal INIT goes to the “H” level again. Therefore, only at the time of the initial operation, the frequency of the first sampling timing signal SAMP1 can be increased, so that the first reference level signal SREF1 can be quickly increased.
Can be shifted to the signal level of the normal operation state,
It is possible to quickly and accurately shift to the normal operation state.

[1.1.6] Specific Operation of Information Processing Unit and Sensor Unit Next, specific initial operation and normal operation of the information processing unit 11, the first sensor unit 32, and the second sensor unit 33 will be described. This will be described with reference to FIG. [1.1.6.1] Initial Operation In the initial operation, the initialization signal INIT is set to the “H” level. First, the operation of the reference level signal generation circuit will be described. In the following description, the first reference level signal generation circuit 121 and the second reference level signal generation circuit 12
4 has the same configuration, and therefore the operation of the first reference level signal generation circuit 121 will be mainly described. Initialization signal IN
When IT becomes “H” level, the first switch 143 is turned off (opened) to inhibit the input of the first detection signal A to the first peak hold circuit 140 when the first switch 143 is input. Further, the second switch 144 is turned off (open) to inhibit the input of the first detection signal A to the second peak hold circuit 141. On the other hand, the third switch 146 includes a voltage dividing circuit 145.
Is turned on (closed) to connect the first peak hold circuit 140 to the first peak hold circuit 140. The fourth switch 147 is turned on (closed) to connect the voltage dividing circuit 145 to the second peak hold circuit 141 when the initialization signal INIT is input. Further, voltage dividing circuit 145 generates an initial signal voltage VINIT by dividing the power supply voltage by a predetermined voltage dividing ratio.

As a result, the first peak hold circuit 1
40 holds the initial signal voltage VINIT as a first peak hold signal SP1, and the second peak hold circuit 141
The initial signal voltage VINIT is held as the second peak hold signal SP2. The voltage dividing circuit 142 divides a difference voltage between the first peak hold signal SP1 and the second peak hold signal SP2 to generate a first reference level signal S having an initial signal voltage VINIT.
REF1 is output to the first comparator 122. Similarly, the second reference level signal generation circuit 124 outputs the second reference level signal SREF2 having the initial signal voltage VINIT to the second comparator 125. Further, the first up / down counter 132, the 1/2 frequency divider 133, the second up / down counter 136, and the 1/2 frequency divider 137 are initialized by setting the initialization signal INIT to "H" level. You. At this time, the first timing generator 134
Generates a first sampling timing signal SAMP1 based on the "L" level first control signal CNT1 (see FIG. 12) and outputs the first sampling timing signal SAMP1 to the first switch S1 and the second switch S2.

Similarly, the second timing generator 13
8 generates the second sampling timing signal SAMP2 based on the "L" level second control signal CNT2, and outputs it to the third switch S3 and the fourth switch S4. At this time, the first sampling signal SAM
As described above, P1 is a signal that becomes the “H” level at the frequency of the first frequency signal fH (for example, 8 kHz) after being delayed by the delay circuit 155 for a predetermined time. The switch S1 and the second switch S2 are
Making the first sensor unit 32 operable based on the first sampling timing signal SAMP1, that is, at the frequency of the first frequency signal fH, and causing the first sampling and holding circuit 120 to sample the first detection signal A; Become. Similarly, the second sampling signal S
AMP2 is a signal having a high frequency in the same initial operation state as the first frequency signal fH by the second timing generator 138, so that the third switch S
The third and fourth switches S4 make the second sensor unit 33 operable at a high frequency based on the second sampling timing signal SAMP2, and cause the second sampling and holding circuit 123 to sample the second detection signal B. Becomes

Thus, the first comparator 122
Is the first detection signal A held by the first sampling and holding circuit 120 and the first reference level signal generation circuit 1
21, the first reference level signal SREF1,
The waveform of the first detection signal A is shaped by comparing the first detection signal A with the initial signal voltage VINIT, and the first waveform shaping signal SA is converted to the first edge detection circuit and the forward / reverse determination circuit of the signal processing unit 126. Output to 130. Further, the second comparator 125 is connected to the second sampling and holding circuit 1
By comparing the second detection signal B and the second reference level signal SREF2 held at 23, that is, the second detection signal B with the initial signal voltage VINIT, the second detection signal B is shaped into a second waveform. The shaped signal SB is output to the second edge detection circuit 135 and the forward / reverse determination circuit 130 of the signal processing unit 126.

[1.1.6.2] Normal Operation After the above-described initial operation, when the initialization signal INIT goes to the "L" level, the operation shifts to the normal body bond. First, the operation of the reference level signal generation circuit will be described. In the following description, the first reference level signal generation circuit 121 and the second reference level signal generation circuit 124 have the same configuration.
The operation of the reference level signal generation circuit 121 will be mainly described. When the initialization signal INIT goes to "L" level, the first
The switch 143 is turned on (closed) to permit the input of the first detection signal A to the first peak hold circuit 140. Further, the second switch 144 allows the input of the first detection signal A to the second peak hold circuit 141.
It is turned on (closed). On the other hand, the third switch 146
In order to disconnect the voltage dividing circuit 145 from the first peak hold circuit 140, the voltage dividing circuit 145 is turned off (open). Further, the fourth switch 147 is turned off (open) to disconnect the voltage dividing circuit 145 from the second peak hold circuit 141.

As a result, the first peak hold circuit 1
40 holds the positive peak signal level of the first detection signal A as the first peak hold signal SP1, and the second peak hold circuit 141 sets the negative peak signal level of the first detection signal A as the second peak hold signal SP2. Hold. Therefore, the voltage dividing circuit 142 divides the voltage difference between the first peak hold signal SP1 and the second peak hold signal SP2, and
A reference level signal SREF1 is generated, and the first reference level signal S
REF1 is output to the first comparator 122. Similarly, the second reference level signal generation circuit 124 generates a second reference level signal SREF2, and outputs the second reference level signal SREF2 to the second comparator 125. At this time, the first timing generator 134 outputs the first control signal CNT1 (refer to FIG. 12) at the “L” level.
A sampling timing signal SAMP1 is generated and output to the first switch S1 and the second switch S2. Similarly,
The second timing generator 138 generates a second sampling timing signal SAMP2 based on the "L" level second control signal CNT2, and generates a third switch SAMP2.
This is output to the third and fourth switches S4. At this time, the first sampling signal SAMP1 is, as described above, a signal that becomes “H” level at the frequency of the first frequency signal fH (for example, 8 k [Hz]) after being delayed by the delay circuit 155 for a predetermined time. Therefore, the first switch S1 and the second switch S2 make the first sensor unit 32 operable based on the first sampling timing signal SAMP1, that is, at the frequency of the first frequency signal fH, This causes the hold circuit 120 to sample the first detection signal A.

Similarly, the second sampling signal SAMP2
Is a signal having a high frequency in the same initial operation state as the first frequency signal fH by the second timing generator 138, the third switch S3 and the fourth switch S4 output the second sampling timing signal SH.
Based on AMP2, the second sensor unit 33 is made operable at a high frequency, and the second sampling and holding circuit 123 performs sampling of the second detection signal B. As a result, the first comparator 122
First detection signal A held by first sampling and holding circuit 120 and first reference level signal generation circuit 121
Is compared with the first reference level signal SREF1 output from the first processing unit 126, and the first detection signal A is subjected to waveform shaping, and the first waveform shaping signal SA is converted into the first edge detection circuit and the forward / reverse determination circuit 130 of the signal processing unit 126. Output to

The second comparator 125 shapes the waveform of the second detection signal B by comparing the second detection signal B held by the second sampling and holding circuit 123 with the second reference level signal SREF2. The second waveform shaping signal SB is output to the second edge detection circuit 135 and the forward / reverse determination circuit 130 of the signal processing unit 126. Thereby, the forward / reverse determination circuit 130 of the signal processing unit 126 determines the relative position of the optical pattern with respect to the first sensor unit 32 and the second sensor unit 33 based on the first waveform shaping signal SA and the second waveform shaping signal SB. The rotation direction (= forward direction or reverse direction) is detected, and the forward / reverse determination signal SRD is supplied to the first up / down counter 132 and the second
Output to the up / down counter 136. On the other hand, the first edge detection circuit 131 detects the edge (rising and falling) of the first waveform shaping signal SA, and outputs the first edge detection signal SE1 to the first up / down counter 132.

As a result, the first up / down counter 13
2 is to count up or down the count value based on the first edge detection signal SE1 and the forward / reverse determination signal SRD.
The count value of 32 corresponds to the rotation angle of the optical pattern with respect to the first sensor unit 32 and the second sensor unit 33. Also, the second edge detection circuit 135
Detects the edge (rising and falling) of the second waveform shaping signal SBA and outputs the second edge detection signal SE2 to the first up / down counter 132. As a result, the second
The up / down counter 136 outputs the second edge detection signal SE2
And the count value is counted up or down based on the forward / reverse determination signal SRD.
The count value of the up / down counter 136 corresponds to the rotation angle of the optical pattern with respect to the first sensor unit 32 and the second sensor unit 33.

Along with this, the ３ divider circuit 133 divides the LSB value of the first up / down counter 132 by 第 to generate a first control signal CNT 1 and outputs it to the first timing generator 134. , 1/2 frequency divider 1
37 generates the second control signal CNT2 by dividing the LSB value of the second up / down counter 136 by １ ／, and outputs the second control signal CNT2 to the second timing generator. The first timing generator 134 outputs the first control signal C
First sampling timing signal SA based on NT1
MP1 is generated and the first switch S1 and the second switch S2
Output to Also, the second timing generator 138
Generates the second sampling timing signal SAMP2 based on the second control signal CNT2, and outputs it to the third switch S3 and the fourth switch S4. At this time, as described above, the first sampling signal SAMP1 is delayed by the delay circuit 155 for a predetermined time, and then the frequency of the second frequency signal fL (for example, 512 [H
z]), the first switch S1 and the second switch S2 are based on the first sampling timing signal SAMP1, that is,
The first sensor unit 32 at the frequency of the second frequency signal fL
In an operable state, and the first sampling and holding circuit 1
20 causes the first detection signal A to be sampled.

Similarly, the second sampling signal SAMP2
Is a signal having the same low frequency as the second frequency signal fL by the second timing generator 138. Therefore, the third switch S3 and the fourth switch S4 operate based on the second sampling timing signal SAMP2.
The second sensor unit 33 is made operable at a low frequency, and the second sampling and holding circuit 123 performs sampling of the second detection signal B. As a result, the first comparator 122 compares the first detection signal A held by the first sampling and holding circuit 120 with the first reference level signal SREF1 output from the first reference level signal generation circuit 121, thereby obtaining the first signal. Detection signal A
And outputs the first waveform shaping signal SA to the first edge detection circuit and the forward / reverse determination circuit 130 of the signal processing unit 126. Also, the second comparator 125
The waveform of the second detection signal B is shaped by comparing the second detection signal B held by the second sampling and holding circuit 123 with the second reference level signal SREF2, and the second
The waveform shaping signal SB is output to the second edge detection circuit 135 and the forward / reverse determination circuit 130 of the signal processing unit 126.

Thus, the forward / reverse determination circuit 130 of the signal processing unit 126 outputs the first waveform shaping signal SA and the second
A relative rotation direction (= forward or reverse direction) of the optical pattern with respect to the first sensor unit 32 and the second sensor unit 33 is detected based on the waveform shaping signal SB, and a forward / reverse determination signal SRD is detected by a first up / down counter. 132 and the second up / down counter 136. On the other hand, the first edge detection circuit 131 detects the edge (rising and falling) of the first waveform shaping signal SA, and outputs the first edge detection signal SE1 to the first up / down counter 132. As a result, the first up / down counter 132
Performs up-counting or down-counting of the count value based on the first edge detection signal SE1 and the forward / reverse determination signal SRD.
The count value of 2 corresponds to the rotation angle of the optical pattern with respect to the first sensor unit 32 and the second sensor unit 33. Also, the second edge detection circuit 135
Detects the edge (rising and falling) of the second waveform shaping signal SBA and outputs the second edge detection signal SE2 to the first up / down counter 132. As a result, the second
The up / down counter 136 outputs the second edge detection signal SE2
And the count value is counted up or down based on the forward / reverse determination signal SRD.
The count value of the up / down counter 136 corresponds to the rotation angle of the optical pattern with respect to the first sensor unit 32 and the second sensor unit 33.

As described above, the signal processing unit 1
26 is a first waveform shaping signal SA and a second waveform shaping signal SB
Based on the optical pattern and thus the rotating bezel 102
The rotation angle and the rotation direction relative to the first sensor unit 32 and the second sensor unit are calculated. In this way, as shown in FIG. 13, even when the amplitude of the first detection signal A is small and the amplitude of the second detection signal B is large, as shown in FIG. Are sequentially adjusted to an appropriate signal level in accordance with the variation of the first detection signal A, the first waveform shaping signal SA close to the ideal first waveform shaping signal shown in FIG. Even without the adjustment step, the rotation direction and the rotation angle of the rotating bezel 102 can be reliably detected without sequentially providing the adjustment accuracy without providing the adjustment step. Also, as shown in FIG. 15, even when the amplitude of the first detection signal A is large and the amplitude of the second detection signal B is small, the first reference level signal SREF1 is detected by the first detection signal as shown in FIG. Since the signal level is sequentially set to an appropriate level in accordance with the fluctuation of the signal A, a first waveform shaping signal SA close to the ideal first waveform shaping signal shown in FIG. 16B can be obtained, and an adjustment step is provided. Without this, it is possible to automatically increase the detection accuracy sequentially and reliably detect the rotation direction and the rotation angle of the rotating bezel 102.

[1.1.6.3] Summary of Operation To summarize the above operation, the first operation state is the first operation state.
Using the initial signal voltage VINIT as an initial threshold voltage for performing waveform shaping on the detection signal A and the second detection signal B,
The first waveform shaping signal SA and the second waveform shaping signal SB are generated by performing waveform shaping, and the first reference signal level SREF1 and the second reference signal level of the comparator for rapidly performing waveform shaping by increasing the sampling frequency. SRE
F2 can be automatically set to an optimal value. Therefore, without providing an adjustment step, the influence of the change over time is reduced,
The rotation direction and the rotation angle of the rotating bezel 102 can be reliably detected.

[1.2] Next, the operation of detecting the rotation direction and the rotation position will be described with reference to FIGS. [1.2.1] When Rotating in the Forward Direction When the rotating bezel 102 is rotating in the forward direction, the second waveform shaping signal SB as indicated by the reference numeral in FIG.
In both the case where the rotation direction is reversed just before the peak and the case where the rotation direction is reversed after exceeding the peak of the second waveform shaping signal SB as shown by reference numerals in FIG. 11, as shown in FIG. In addition, at the rising timing of the first waveform shaping signal SA, the second waveform shaping signal SB
= "L", and at the fall timing of the first waveform shaping signal SA, the second waveform shaping signal SB = "H". Similarly, when the rotating bezel 102 is rotating in the forward direction, at the rising timing of the second waveform shaping signal SB, the first waveform shaping signal SA = “H”, and the rising edge of the second waveform shaping signal SB. At the falling timing, the first waveform shaping signal SA becomes "L".

Accordingly, for example, as shown in FIG. 19, the signal processing unit 53 calculates the rising timing of the first waveform shaping signal SA → the rising timing of the second waveform shaping signal SB → the falling timing of the first waveform shaping signal SA. → Fall timing of the second waveform shaping signal SB →
Observe the second waveform shaping signal SB and the second waveform shaping signal SB in..., And the second waveform shaping signal SB = “L” → the first waveform shaping signal SA = “H” → the second waveform shaping signal SB = “ H "
→ If the first waveform shaping signal SA = “L” →..., It is determined that the rotating bezel 102 is rotating in the forward direction, and a count-up (or count-down) corresponding to the forward direction is performed. By adding the count value to the position, the rotational position of the rotating bezel 102 is detected. In this case, the signal level is mutually referred to using both the signal transition timing of the first waveform shaping signal SA and the signal transition timing of the second waveform shaping signal SDIF. １ ／ of the cycle of the second detection signal. Therefore, the position can be detected with double accuracy as compared with the case where one sensor unit is used.

[1.2.2] When rotating in the reverse direction When the rotating bezel 102 is rotating in the reverse direction, as shown in FIG. 17, the rising of the first waveform shaping signal SA At the timing, the second waveform shaping signal SB =
It becomes "H", and at the falling timing of the first waveform shaping signal SA, the second waveform shaping signal SB becomes "L". Similarly, when the rotating bezel is rotating in the reverse direction, at the rising timing of the second waveform shaping signal SB, the first waveform shaping signal SA = “L”, and the falling edge of the second waveform shaping signal SB At the timing, the first waveform shaping signal SA becomes "H". Therefore, for example, as shown in FIG. 19, the signal processing unit 53 generates the rising timing of the first waveform shaping signal SA → the falling timing of the second waveform shaping signal SB → the first waveform shaping signal SA.
Of the second waveform shaping signal SB → the rising timing of the second waveform shaping signal SB →.
And the second waveform shaping signal SB is observed, and the second waveform shaping signal SB = “H” → the first waveform shaping signal SA = “H” → the second waveform shaping signal SB = “L” → the first waveform shaping signal SA. = “L” →
If so, it is determined that the rotating bezel 102 is rotating in the reverse direction, a count-up (or countdown) corresponding to the reverse direction is performed, a count value is added to the origin position, and the rotation bezel 102 is rotated. The rotation position will be detected. Also in this case, the first waveform shaping signal SA
, And the signal transition timing of the second waveform shaping signal SDIF, the signal level is referred to each other. Therefore, the position detection accuracy is 1/1 of the period of the first detection signal and the second detection signal. There are eight periods. Therefore, the position can be detected with double accuracy as compared with the case where one sensor unit is used.

[1.3] Information Input Method and Operation of Wrist Watch Information Processing Apparatus Next, an information input method and operation of the wrist watch information processing apparatus 100 will be described. First, the user adjusts the rotating bezel 102 to a predetermined origin position. In the present embodiment, the origin position is set to the state shown in FIG. 2, that is, the state where “A” is indicated by the instruction mark 110. In this state, the user presses the origin switch 108, whereby the wristwatch-type information processing apparatus 100 enters an information input state, and the first sensor unit 32 and the second sensor unit 33 detect the rotation angle and the rotation direction of the rotating bezel 102. To start. Then, when the user wants to input information to be input, for example, the character “f”, the user can input the information shown in FIG.
As shown in FIG.
Turns the rotating bezel counterclockwise to the position indicated by the instruction mark 110. At this time, the pulse number detection sensor unit 32 detects the rotation angle θ of the rotating bezel 102, and the second sensor unit 33 detects the rotation direction of the rotating bezel 102. Based on the rotation angle and the rotation direction detected in this way, the input information “f” is
And is displayed on the display unit 104. When the confirm switch 105 is pressed in this state, the character "f" is decided, and a state of waiting for input of the next information is entered. When the delete switch 106 is pressed, the character "" is deleted, and the input wait state is entered. Also, when the cloud spot switch 107 is pressed,
“Ga” is displayed on the display unit 104.

[1.4] Effects The information processing apparatus according to the present invention has a simple configuration even when it is possible to input a large amount of information such as information such as characters and command information such as mode selection. Conversion is easy.
Therefore, it is possible to use a wristwatch type as described above. In addition, when inputting information by rotating the rotating bezel 102 as described above, the wristwatch-type information processing apparatus 100 performs both the signal transition timing of the first waveform shaping signal SA and the signal transition timing of the second waveform shaping signal SB. , The signal level is referred to each other, so that the position detection accuracy can be set to 1/8 of the period of the first detection signal and the second detection signal, and the rotational position of the rotating bezel 102 can be accurately determined. Is detected, and information can be input reliably. Further, since the first waveform shaping signal SA and the second waveform shaping signal SB associated with each other are referred to each other, it is possible to reduce the influence of the change over time of the sensor unit.

[2] Modified Example [2.1] First Modified Example In the above embodiment, a reflection type sensor was used as the first sensor unit 32 and the second sensor unit 33. By forming the optical pattern 41 with an absorption area (non-transmission area) and a transmission area by using a light transmission member, the same effect can be obtained even if a transmission type sensor unit is used. [2.2] Second Modification The rotation detecting device according to the present invention is not limited to the wristwatch-type information processing device described above, and may be applied to other types of information processing devices such as a mobile phone. It is possible. In this case, the rotating part is not limited to the rotating bezel, but may be a disk, a cylinder,
Other shapes such as hemispheres can be used.

[0070]

According to the present invention, in the initial operation, the first peak hold signal and the second peak hold signal are changed based on the predetermined first signal level, and in the operation state other than the initial operation. A first reference level signal is generated based on the first detection signal, and the first detection signal is compared with the first reference level signal to perform waveform shaping of the first detection signal and output as a waveform shaping signal. A second reference level signal is generated based on a predetermined second signal level, and in a normal operation state, based on a third peak hold signal and a fourth peak hold signal, and the second detection signal is generated based on a second reference signal. Since the waveform of the second detection signal is shaped by comparing with the level signal and output as the second waveform shaping signal, the first reference signal level and the second reference signal for shaping the waveform are output. Level can be automatically optimum value, without providing the adjusting step, to reduce the influence of aging, it is possible to reliably detect the rotation direction and the rotation angle.

Further, during a predetermined time from the start of the operation, that is, in the initial operation state, after the first period, which is the sampling timing period in the first peak hold means and the second peak hold means, has passed a predetermined time, Set shorter than the first cycle in the operating state,
During a predetermined time from the start of operation, that is, in the initial operation state, after a lapse of a predetermined time from the second period, which is the period of the sampling timing in the third peak hold means and the fourth peak hold means, that is, in the normal operation state. Since the period is set shorter than the second period, the first reference signal level and the second reference signal level for rapidly shaping the waveform can be automatically set to optimal values, and more rapid rotation detection can be performed.

[Brief description of the drawings]

FIG. 1 is a front view of a wristwatch-type information processing apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a state in which a rotating bezel is removed from the wristwatch-type information processing apparatus of FIG. 1;

FIG. 3 is a view taken along line IV-IV in FIG. 1;

FIG. 4 is a diagram showing a lower surface of a rotating bezel.

FIG. 5 is a diagram illustrating a relationship between an optical pattern formed on a rotating bezel, a first detection signal, and a second detection signal.

FIG. 6 is a functional configuration block diagram for generating an input information signal of the wristwatch-type information processing apparatus.

FIG. 7 is a diagram illustrating the principle of an information processing unit.

FIG. 8 is a specific configuration block diagram of a sensor unit and an information processing unit.

FIG. 9 is a schematic configuration block diagram of a first reference level signal generation circuit.

FIG. 10 is an explanatory diagram of setting of an initial signal voltage VINIT.

FIG. 11 is a schematic block diagram of a first timing generator.

FIG. 12 is an operation timing chart of the first timing generator.

FIG. 13 is a diagram (part 1) illustrating a waveform shaping operation according to the embodiment.

FIG. 14 is a diagram (part 2) for explaining the waveform shaping operation of the embodiment.

FIG. 15 is a diagram (part 3) for explaining the waveform shaping operation of the embodiment.

FIG. 16 is a diagram (part 4) for explaining the waveform shaping operation of the embodiment.

FIG. 17 is a diagram (part 1) for explaining a rotation direction detection and a rotation position detection operation.

FIG. 18 is a diagram (part 2) for explaining the rotation direction detection and the rotation position detection operation.

FIG. 19 is a diagram (part 2) for explaining the rotation direction detection and the rotation position detection operation.

20 is a diagram showing a state in which the rotating bezel of the wristwatch-type information processing device shown in FIG. 2 is rotated counterclockwise by θ [゜].

FIG. 21 is a perspective view showing a wristwatch equipped with a conventional rotating bezel.

[Explanation of symbols]

 32 first sensor unit 33 second sensor unit 41 optical pattern 41a absorption area 41b reflection area 44, 46 LED 45, 47 photodiode 50 first waveform shaping circuit 51 first up / down determination Circuit 52: First normal / reverse determination circuit 53: Second waveform shaping circuit 54: Second up / down determination circuit 55: Second normal / reverse determination circuit 56: First detection timing generation circuit 57: Second detection timing generation circuit DESCRIPTION OF SYMBOLS 100 ... Wristwatch type information processing apparatus 102 ... Rotating bezel 111 ... Information processing section 112 ... Information table 113 ... Memory 114 ... Character generator 120 ... 1st sampling and holding circuit 121 ... 1st reference level generation circuit 122 ... 1st comparator 123 ... 1st 2 sampling hold circuit 124... 2nd reference level generation circuit 1 5 Second comparator 126 Signal processing unit 130 Forward / reverse inverting circuit 131 First edge detecting circuit 132 First up / down counter 133 1/2 frequency divider 134 First timing generator 135 Second edge Detection circuit 136: second up / down counter 137: 1/2 frequency divider 138: second timing generator

Claims (16)

[Claims] 1. A signal level is maintained in an initial state, and a positive peak signal level of an input signal is set to a first level.
First peak hold means for holding as a peak hold signal, second peak hold means for holding the predetermined signal level in an initial state, and holding a negative peak signal level of the input signal as a second peak hold signal, Reference level signal generation means for generating and outputting a reference level signal based on the first peak hold signal and the second peak hold signal; and a waveform of the input signal by comparing the input signal with the reference level signal A waveform shaping circuit, comprising: a waveform shaping unit configured to perform shaping and output as a waveform shaping signal. 2. The waveform shaping circuit according to claim 1, wherein the first peak hold means performs sampling at a timing having a predetermined period, and holds a signal level of the input signal as the first peak hold signal. The waveform shaping circuit, wherein the second peak hold means performs sampling at a timing having a predetermined period and holds the signal level of the input signal as the second peak hold signal. 3. The waveform shaping circuit according to claim 2, wherein the period of the timing is set shorter than a period of the timing after the lapse of the predetermined time for a predetermined time from the start of the operation. Waveform shaping circuit. 4. The waveform shaping circuit according to claim 1, wherein the predetermined signal level held in the initial state has the lowest signal level among the assumed input signals. A waveform characterized by being set to a signal level between a maximum signal level of the input signal and a minimum signal level of the input signal having the highest signal level among the assumed signal levels of the input signal. Shaping circuit. 5. A method according to claim 1, wherein a predetermined signal level is maintained in an initial state, and a positive peak signal level of the input signal is set to a first level.
A first peak detector for holding as a peak hold signal, a second peak detector for holding the predetermined signal level in an initial state, and holding a negative peak signal level of the input signal as a second peak hold signal; A reference level signal generation circuit for generating and outputting a reference level signal based on the one peak hold signal and the second peak hold signal; and a waveform shaping of the input signal by comparing the input signal with the reference level signal. A waveform shaping circuit, comprising: 6. A reflection member on which a predetermined optical pattern having an absorption area and a reflection area is formed, and a first detection light is applied to the reflection member, and the first detection light reflected by the reflection member is irradiated with the first detection light. A first detection unit that receives light and outputs a first detection signal corresponding to the optical pattern; a first detection unit that is disposed at a predetermined angle from the rotation center with respect to the first detection unit; And a second detection unit that receives the reflected second detection light and outputs a second detection signal corresponding to the optical pattern, while maintaining a predetermined first signal level in an initial state, First peak hold means for holding a positive peak signal level of the first detection signal as a first peak hold signal; and holding a predetermined first signal level in an initial state and negative peak of the first detection signal. Second peak hold means for holding a signal level as a second peak hold signal; a first reference level signal for generating and outputting a first reference level signal based on the first peak hold signal and the second peak hold signal Generating means, first waveform shaping means for performing waveform shaping of the first detection signal by comparing the first detection signal with the first reference level signal, and outputting the shaped signal as a waveform shaping signal; Third peak holding means for holding the second signal level and holding the positive peak signal level of the second detection signal as a third peak hold signal, and holding a predetermined second signal level in an initial state; Fourth peak hold means for holding a negative peak signal level of the second detection signal as a fourth peak hold signal; A second reference level signal generating means for generating and outputting a second reference level signal based on the peak hold signal and the fourth peak hold signal; and comparing the second detection signal with the second reference level signal. A second waveform shaping unit configured to perform waveform shaping of the second detection signal and output as a second waveform shaping signal; and a first detection of the reflection member based on the first waveform shaping signal and the second waveform shaping signal. And a signal processing means for calculating a rotation direction and a rotation angle relative to the second detection means. 7. A light transmitting member on which a predetermined optical pattern having an absorption area and a transmission area is formed, and a first detection light is applied to the light transmitting member, and the first detection transmitted through the light transmitting member. A first detection unit that receives light and outputs a first detection signal corresponding to the optical pattern; a first detection unit that is disposed at a predetermined angle away from the rotation center with respect to the first detection unit; A second detection unit that irradiates the second detection light, receives the second detection light transmitted through the light transmitting member, and outputs a second detection signal corresponding to the optical pattern; A first peak hold means for holding a positive peak signal level of the first detection signal as a first peak hold signal, and holding a predetermined first signal level in an initial state, and A second peak hold means for holding a negative peak signal level of the signal as a second peak hold signal; and a second reference level signal for generating and outputting a first reference level signal based on the first peak hold signal and the second peak hold signal. First reference level signal generation means, first waveform shaping means for performing waveform shaping of the first detection signal by comparing the first detection signal with the first reference level signal, and outputting as a waveform shaping signal, Third peak hold means for holding a predetermined second signal level in a state and holding a positive peak signal level of the second detection signal as a third peak hold signal; and holding a predetermined second signal level in an initial state. And a fourth peak hole for holding a negative peak signal level of the second detection signal as a fourth peak hold signal. Means, a second reference level signal generating means for generating and outputting a second reference level signal based on the third peak hold signal and the fourth peak hold signal, and the second detection level as the second reference level. A second waveform shaping unit configured to perform waveform shaping of the second detection signal by comparing the signal with a signal, and to output the resulting signal as a second waveform shaping signal; Signal processing means for calculating the direction and angle of rotation of the member relative to the first detection means and the second detection means. 8. The rotation detecting device according to claim 6, wherein the first peak hold means performs sampling at a timing having a predetermined first period to change the signal level of the first detection signal to the first level. The second peak hold means performs sampling at a timing having a predetermined first period, holds the signal level of the first detection signal as the second peak hold signal, and holds the third peak hold signal. The means performs sampling at a timing having a predetermined second cycle and holds the signal level of the second detection signal as the third peak hold signal. The fourth peak hold means performs sampling at a timing having a predetermined second cycle. And the signal level of the second detection signal is changed to the fourth peak signal. Held as field signal, rotation detection device, characterized in that. 9. The rotation detection device according to claim 8, wherein the first cycle is set shorter than the first cycle after the lapse of the predetermined time for a predetermined time from the start of the operation, and the second cycle Is set to be shorter than the second cycle after the lapse of the predetermined time for a predetermined time from the start of the operation. 10. The rotation detection device according to claim 6, wherein the predetermined first signal level held in the initial state is the highest among the assumed first detection signals. A signal level between a maximum signal level of the first detection signal having a low signal level and a minimum signal level of the first detection signal having a highest signal level among the assumed first detection signals; The predetermined second signal level held in the initial state is a maximum signal level of the second detection signal having the lowest signal level among the assumed second detection signals, and the assumed second detection signal. A signal level between the minimum signal level of the second detection signal having the highest signal level and the second detection signal. 11. The rotation detecting device according to claim 6, wherein the first reference level signal generating unit calculates a voltage difference between the first peak hold signal and the second peak hold signal. The first reference level signal is generated by dividing the voltage by a predetermined first voltage dividing ratio, and the second reference level signal generating means calculates a voltage difference between the third peak hold signal and the fourth peak hold signal by a predetermined voltage. A rotation detecting device, wherein the second reference level signal is generated by dividing a voltage by a 2 division ratio. 12. The rotation detection device according to claim 6, wherein the optical pattern is output when the optical pattern is rotated relatively to the first detection unit and the second detection unit. The phase of the first detection signal and the phase of the second detection signal are 1 /
A rotation detecting device, wherein a separation angle between the first detecting means and the second detecting means is set so as to be shifted by four wavelengths. 13. The rotation detecting device according to claim 6, wherein the optical pattern is such that the absorption area and the reflection area or the transmission area are centered on the rotation center. The angle θ2 is alternately formed so that the angle θ2 becomes 360 / n [゜] (n is an even number). A rotation detecting device, wherein θ1 = (θ2 × m) + θ2 / 2 (where m is an integer). 14. The rotation detection device according to claim 6, wherein the reflection member is formed in an annular rotation bezel, and the first detection unit and the second detection unit are wound around a user's wrist. A rotation detecting device, comprising a band portion capable of being rotated, and wherein the rotating bezel is formed on a wristwatch-type main body to which the rotating bezel is attached. 15. A reflection member on which a predetermined optical pattern having an absorption area and a reflection area is formed, and a first detection light is applied to the reflection member, and the first detection light reflected by the reflection member is irradiated with the first detection light. A first optical sensor that receives light and outputs a first detection signal corresponding to the optical pattern; a first detection sensor that is disposed at a predetermined angle from the rotation center of the first detection unit; And a second optical sensor that receives the reflected second detection light and outputs a second detection signal corresponding to the optical pattern, while maintaining a predetermined first signal level in an initial state, A first peak detector for holding a positive peak signal level of the first detection signal as a first peak hold signal; and a first peak detector for holding a predetermined first signal level in an initial state and for receiving a negative peak signal of the first detection signal. A second peak detector that holds a level as a second peak hold signal; and a first reference level signal generation circuit that generates and outputs a first reference level signal based on the first peak hold signal and the second peak hold signal. A first comparator that shapes the waveform of the first detection signal by comparing the first detection signal with the first reference level signal and outputs the shaped signal as a waveform shaping signal; and a predetermined second signal level in an initial state. And a third peak detector that holds a positive peak signal level of the second detection signal as a third peak hold signal, and holds a predetermined second signal level in an initial state, A fourth peak detector for holding a negative peak signal level as a fourth peak hold signal; A second reference level signal generating circuit for generating and outputting a second reference level signal based on the signal and the fourth peak hold signal; and comparing the second detection signal with the second reference level signal. A second comparator for shaping the waveform of the second detection signal and outputting it as a second waveform shaping signal; the first detection means of the reflection member and the second comparator based on the first waveform shaping signal and the second waveform shaping signal. A signal processing circuit for calculating a rotation direction and a rotation angle relative to the second detection means. 16. A method of irradiating a reflection member on which a predetermined optical pattern having an absorption region and a reflection region is formed with first detection light, receiving the first detection light reflected by the reflection member, and performing the optical detection. A first detection step of outputting a first detection signal corresponding to the pattern; and irradiating the first detection light with a second detection light at a position separated by a predetermined angle from a rotation center with respect to an irradiation position of the first detection light and reflected. A second detection step of receiving the second detection light and outputting a second detection signal corresponding to the optical pattern; and maintaining a predetermined first signal level in an initial state, and a positive peak of the first detection signal. A first peak hold step of holding the signal level as a first peak hold signal; holding a predetermined first signal level in an initial state, and setting a negative peak signal level of the first detection signal to a second peak level; A second peak hold step of holding as a hold signal; a first reference level signal generation step of generating and outputting a first reference level signal based on the first peak hold signal and the second peak hold signal; A first waveform shaping step of performing waveform shaping of the first detection signal by comparing the one detection signal with the first reference level signal and outputting the waveform as a waveform shaping signal; and holding a predetermined second signal level in an initial state. A third peak hold step of holding a positive peak signal level of the second detection signal as a third peak hold signal; and holding a predetermined second signal level in an initial state, and holding a negative level of the second detection signal. Fourth peak hold means for holding a peak signal level as a fourth peak hold signal; and the third peak hold signal And a second reference level signal generating step of generating and outputting a second reference level signal based on the fourth peak hold signal; and comparing the second detection signal with the second reference level signal to generate the second reference level signal. A second waveform shaping step of shaping the waveform of the detection signal and outputting it as a second waveform shaping signal; and the first detecting means and the first detecting means of the reflecting member based on the first waveform shaping signal and the second waveform shaping signal. A signal processing step of calculating a rotation direction and a rotation angle relative to the second detection means.