JP2000341044A - Electronic device provided with crystal oscillation circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the stability of an oscillated frequency by effectively correcting a change in the oscillated frequency due to humidity and to make the circuit small and to reduce the cost. SOLUTION: Humidity characteristic data are stored in a memory 510 together with temperature characteristic data and time characteristic data, a main control circuit 500 obtains a temperature correction value on the basis of the temperature data and the temperature characteristic data of a temperature sensor 540, a time correction value is obtained on the basis of a terminal operating time obtained from current time data of a clock circuit 530 and the time characteristic data, and current humidity data and the time data are extracted respectively from a humidity sensor 550 and the clock circuit 530 to obtain how many hours the state of humidity continue and a humidity correction value is obtained on the basis of the humidity consecutive time and the humidity characteristic data. Then an overall correction value is calculated by summing the temperature correction value, the time correction value and the humidity correction value and the oscillated frequency of a crystal oscillation circuit 140 is corrected on the basis of the overall correction value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device having a crystal oscillation circuit, such as a base station for mobile communication, a mobile terminal device, an automatic meter reading terminal device, etc., and more particularly to a function of stabilizing an oscillation frequency. The present invention relates to an electronic device provided.

[0002]

2. Description of the Related Art Generally, an oscillation circuit such as a frequency synthesizer is used in an electronic device such as a base station or a terminal device for mobile communication. This type of oscillation circuit generally uses a reference oscillation circuit using a crystal oscillator, but the crystal oscillator generally has a temperature characteristic. This temperature characteristic forms, for example, a cubic curve as shown in FIG. 6, and in order to obtain a stable oscillation frequency, it is essential to correct the temperature in consideration of the temperature characteristic.

Therefore, conventionally, for example, the temperature characteristics of a capacitor having characteristics opposite to those of a crystal unit and an oscillation circuit are used, or the bias voltage of the oscillation circuit is changed by combining a thermistor and a variable capacitance element. Or TCXO or VCTCX as a crystal oscillator
The temperature is corrected using a constant temperature element called O, oven TCXO, or the like. As a result, a stable oscillation frequency can be obtained with respect to a change in the ambient temperature.

However, not only the temperature but also the humidity affects the oscillation frequency of the quartz oscillator. On the other hand, for example, attention is paid to the fact that a constant temperature element such as an oven TCXO generally has constant humidity, and it is conceivable to use this type of element to ensure stability against humidity. However, this type of constant humidity oscillator is generally expensive and unsuitable for integration, so it is difficult to reduce the size of the circuit and reduce the cost.

On the other hand, it has been attempted to mount the constant humidity oscillation element in a package and mount it on a circuit board together with other circuit elements. When the oscillation element and the like are provided on-board in this way, the size of the oscillation circuit can be reduced and the cost can be reduced. However, in such an on-board circuit, the package material itself is a parameter that determines the oscillation frequency of the constant temperature vibration element, and the oscillation frequency changes due to the moisture absorption and moisture release functions of the circuit board. It is difficult to stabilize the oscillation frequency.

[0006]

As described above, the conventional oscillation circuit has not yet established an effective countermeasure against humidity, and there is a need for an effective countermeasure.

The present invention has been made in view of the above circumstances, and an object of the present invention is to make it possible to effectively correct the change in the oscillation frequency due to humidity, thereby improving the stability of the oscillation frequency and improving the circuit. It is an object of the present invention to provide an electronic device including a crystal oscillation circuit that enables a reduction in size and cost of the electronic device.

[0008]

According to the present invention, there is provided an electronic apparatus having a crystal oscillation circuit for generating and outputting a predetermined oscillation frequency with reference to an oscillation output of a crystal resonator. Storage means for storing in advance humidity characteristic information indicating the correspondence between the humidity around the crystal oscillation circuit, the elapsed time, and the oscillation frequency; humidity detection means for detecting the humidity around the crystal oscillation circuit; A time measuring means having a function of measuring a time during which the crystal oscillation circuit is placed at the humidity detected by the means; and a correction control means. And in this correction control means,
The humidity detected by the humidity detecting means, the time measured by the time measuring means, and based on the humidity characteristic information stored in the storage means, configured to perform the humidity correction of the oscillation frequency. is there.

Therefore, according to the present invention, when the oscillation circuit is kept in a certain humidity state for a certain period of time, correction data of the oscillation frequency corresponding to the humidity and the elapsed time at this time is obtained from the humidity characteristic information, The oscillation frequency is corrected. For this reason, the oscillation frequency of the oscillation circuit is always kept constant irrespective of the humidity, whereby the stability of the oscillation frequency is enhanced. Also, there is no need to use an expensive constant humidity element such as an oven type TCXO, and there is no need to take special measures to absorb and release moisture on the circuit board even when it is made on-board, so it is small and inexpensive. A simple oscillation circuit can be provided.

Further, according to the present invention, when a temperature correction function is provided in addition to the humidity correction function, temperature characteristic information required for the temperature correction is stored together with the humidity characteristic information in common storage means, and one piece of data is stored. In the correction control means, a correction value for the temperature correction and a correction value for the humidity correction are respectively obtained and then synthesized to obtain an integrated correction value, and the correction control of the oscillation frequency is performed based on the comprehensive correction value. Another feature is that it is performed.

In this way, the oscillation frequency of the oscillation circuit is corrected not only by humidity but also by temperature, thereby further increasing the stability of the oscillation frequency. Moreover, the temperature characteristic information and the humidity characteristic information are stored in a common storage means, and the temperature correction and the humidity correction can be performed comprehensively by one correction control means. Thus, the circuit configuration can be simplified and miniaturized as compared with the case where the operation is performed independently, and there is no fear that the temperature correction and the humidity correction influence each other and the oscillation frequency becomes unstable.

Further, in addition to the humidity correction function and the temperature correction function, the present invention has a function of correcting a change in the oscillation frequency caused by a prolonged use time of the oscillation circuit, that is, a change in the oscillation frequency with time. I have. In this case, the time characteristic information necessary for correcting the aging is stored in a common storage unit together with the humidity characteristic information and the temperature characteristic information, and the measurement of the use time of the oscillation circuit is performed by the humidity correction. It is also characterized in that it is performed by a common timing means together with the measurement of the elapsed time, and that temperature correction, humidity correction and aging correction can be comprehensively performed by one correction control means.

By doing so, the oscillation frequency of the oscillation circuit is corrected not only by the humidity and temperature but also by the operating time of the oscillation circuit, whereby the oscillation frequency is made more stable over a long period of time. Become. Moreover, the storage means for storing the time characteristic information is shared with the means for storing the temperature characteristic information and the humidity characteristic information, and the means for measuring the operating time of the oscillation circuit is also used as the time measuring means for measuring the elapsed time of the humidity. Shared. Furthermore, the circuit configuration can be simplified and miniaturized compared to the case where the above temperature correction, humidity correction and aging correction are independently performed by separate correction control means, and the temperature correction, humidity correction and aging correction affect each other. Therefore, there is no fear that the oscillation frequency becomes unstable.

[0014]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit block diagram showing a configuration of a PHS terminal which is an embodiment of an electronic device according to the present invention.

The PHS terminal includes a radio unit 10 having an antenna 11, a modem unit 20, a TDMA unit 30, a communication unit 40, a control unit 50, an information storage unit 60, a data communication unit 70, A key input unit 80 and a liquid crystal display (LC
D) using a display unit 90.

That is, a radio carrier signal arriving from a base station (not shown) is received by an antenna 11 and then passed through a high-frequency switch (SW) 12 of a radio section 10 to a receiving section 1.
3 is input. In the receiving unit 13, the received radio carrier signal is mixed with a local oscillation signal generated from the frequency synthesizer 14 and down-converted into a received intermediate frequency signal. The local oscillation signal frequency generated from the frequency synthesizer 14 is
In response to the instruction of 0, it is set to a value corresponding to the radio channel frequency. The radio unit 10 includes a reception electric field strength detection unit (R
SSI) 16 is provided. The reception electric field strength detection section 16 detects the reception electric field strength of the radio carrier signal arriving from the base station, and notifies the control section 50 of the detected value, for example, to judge and display the reception quality.

The received intermediate frequency signal output from the receiving section 13 is input to a demodulating section 21 of the modem section 20. The demodulation section 21 performs digital demodulation of the received intermediate frequency signal, thereby reproducing a digital demodulated signal.

TDMA decoding section 31 of TDMA section 30
Separates the digital demodulated signal for each reception time slot. If the data of the separated slot is voice data, the voice data is input to the communication unit 40. On the other hand, if the data of the separated slot is packet data or control data, these data are input to the data communication unit 70.

The communication unit 40 has an ADPCM (Adaptive Dif).
ferential Pulse Code Modulation) Transcoder 4
1, a PCM codec 42, a speaker 43, and a microphone 44. The ADPCM transcoder 41 decodes the audio data output from the TDMA decoding unit 31. The PCM codec 42 converts the digital audio signal output from the ADPCM transcoder 41 into an analog signal, and outputs this audio signal from the speaker 43.

The data communication unit 70 receives the data supplied from the TDMA decoding unit 31 and supplies the data to the control unit 50. If the received data is control data, the control unit 50 analyzes the control data and performs necessary control. On the other hand, if the received data is packet data arriving from a server or the like, the packet data is depacketized, stored in the information storage unit 60, and displayed on the display unit 9.
0 is supplied and displayed.

On the other hand, the user's voice signal input to the microphone 44 is PCM-coded by the PCM codec 42 and then compression-coded by the ADPCM transcoder 41. Then, the encoded audio data is TDM
It is input to the A encoding unit 32. The control data and packet data output from the control unit 50 are input to the TDMA encoding unit 32 via the data communication unit 70.

The TDMA encoding unit 32 has the above ADP
The digital audio data of each channel output from the CM transcoder 41 and the control data and packet data output from the data communication unit 70 are inserted into the transmission time slot designated by the control unit 50 and multiplexed.
The modulation unit 22 digitally modulates the transmission intermediate frequency signal with the multiplexed digital communication signal output from the TDMA encoding unit 32, and inputs the modulated transmission intermediate frequency signal to the transmission unit 15.

The transmitting section 15 mixes the modulated transmission intermediate frequency signal with the local oscillation signal generated from the frequency synthesizer 14, upconverts the mixed signal into a radio carrier frequency, and further amplifies the signal to a predetermined transmission power level. The wireless carrier signal output from the transmitting unit 15 is transmitted from the antenna 11 to a base station (not shown) via the high frequency switch 12.

The PHS terminal according to this embodiment has a function for correcting the oscillation frequency of a crystal oscillation circuit provided as a reference oscillator in the frequency synthesizer 14 according to temperature, humidity, and aging. I have. FIG. 2 shows a configuration of a crystal oscillation circuit 140 of the frequency synthesizer 14 which is a main part thereof, and an oscillation frequency correction function in the control unit 50.

The crystal oscillation circuit 140 has a crystal oscillator 141 made of, for example, TCXO.
The reference oscillation frequency is generated by the transistor oscillation circuit 143 based on the oscillation output of the
Output from 4. Further, an energizing circuit using the variable capacitance element 142 is provided, and the reference oscillation frequency can be corrected by supplying a control voltage from the control unit 50 to the energizing circuit.

The oscillation frequency correction function in the control unit 50 includes a main control circuit 500, a memory 510, a setting unit 520,
Clock circuit 530, temperature sensor 540, humidity sensor 5
50 and a digital / analog converter (D / A) 560
It is composed of

The memory 510 stores initial value data, temperature characteristic data, humidity characteristic data, time characteristic data, temperature sensor data, and humidity characteristic data as data necessary for the oscillation frequency correction processing. It is memorized.

As the initial value data, control voltage data at the time of initial adjustment, temperature data at that time, and control voltage versus oscillation frequency data are stored. As the temperature characteristic data, for example, cubic curve characteristic data as shown in FIG. 6 created based on theoretical values or measured values is stored.

As the humidity characteristic data, for example, FIG.
The moisture absorption characteristic data shown in FIG. 7A and the moisture release characteristic data shown in FIG. These moisture absorption characteristics and moisture release characteristics represent changes in the oscillation frequency over time using humidity as a parameter, and the time required for the oscillation frequency to become substantially constant is generally as long as several days to several weeks.

As the time characteristic data, a long-term fluctuation characteristic and a short-term fluctuation characteristic are respectively stored. These time fluctuation characteristics generally have individual differences for each crystal oscillator, and for example, as shown in FIG. 8, there are a type in which the oscillation frequency gradually increases with time and a type in which the oscillation frequency decreases. The temperature sensor data and the humidity sensor characteristic are the characteristic of the detection voltage of the sensor with respect to the temperature and the characteristic of the detection voltage of the sensor with respect to the humidity, respectively.

The setting section 520 includes, for example, the key input section 80 and the LCD 90, and is used for input setting of initial value data and the like. Clock circuit 530 performs a normal clock operation and outputs the time data. Temperature sensor 540
Detects the temperature in the crystal oscillation circuit 140 and supplies the detection signal to the main control circuit 500. Humidity sensor 550
Detects the humidity in the crystal oscillation circuit 140 and supplies the detection signal to the main control circuit 500. D / A converter 560
Converts the control voltage output from the main control circuit 500 from a digital value to an analog value and supplies it to the energizing circuit of the crystal oscillation circuit 140.

The main control circuit 500 includes a processing unit 501 using a CPU as shown in FIG. 3, for example, and a ROM 502 storing an operation program of the processing unit 501;
And various interface circuits.

The interface circuit includes a memory interface 503 for reading and writing data from and to the memory 510, and a setting interface 504 for transmitting and receiving input data and display data to and from the setting unit 520.
A clock circuit interface 505 for capturing the time data output from the clock circuit 530, and a temperature sensor 540
A temperature sensor interface 506 that converts the temperature detection signal output from the digital sensor into a digital value and captures the digital signal, a humidity sensor interface 507 that converts the humidity detection signal output from the humidity sensor 550 into a digital value and captures the digital value,
An output interface 508 for outputting the control voltage data output from the processing unit 501.

Next, the frequency correction operation in the PHS terminal configured as described above will be described. First, the initial adjustment of the oscillation frequency correction function is performed. For example, when the inspector performs an initial setting operation using the setting unit 520 prior to shipment, the main control circuit 500 enters an initial setting mode, and thereafter, an initial adjustment operation of the oscillation frequency correction function is performed as follows. FIG. 4 is a flowchart showing the control procedure and control contents.

That is, the main control circuit 500 first fetches the digital value (temperature data) of the temperature detection signal output from the temperature sensor 540 in step 4a via the temperature sensor interface 506, and stores the fetched temperature data in step 4b. Is stored in the memory 510. Subsequently, in step 4c, a default value of the control voltage corresponding to the detected temperature is read from the memory 510 and output to the crystal oscillation circuit 140. Then, in the crystal oscillation circuit 140, the capacitance of the variable capacitance element 142 changes according to the default value of the control voltage, and the oscillation frequency f corresponding to the capacitance value is output from the transistor oscillation circuit 143.

In this state, for example, the examiner measures the value f of the oscillation frequency and manually inputs the value from the setting unit 520, or
Alternatively, the main control circuit 50
When the value is automatically input to 0, the main control circuit 500 proceeds to step 4d.
In this case, the detected value f of the oscillation frequency is previously stored in a memory 510.
Then, it is determined whether the oscillation frequency detection value f is a correct value by comparing with the normal value of the oscillation frequency stored in.

If the result of this determination is that the oscillation frequency detection value f is different from the normal value, the main control circuit 500 proceeds to step 4
The process proceeds to step e, where it is determined whether the oscillation frequency detection value f is higher or lower than a normal value, and the difference is obtained. If the oscillation frequency detection value f is higher than the normal value according to this determination result, the process proceeds to step 4f to decrease the default value of the control voltage according to the difference. On the other hand, if the oscillation frequency detection value f is lower than the normal value, step 4
The process proceeds to g, and the default value of the control voltage is increased according to the difference. Thereafter, the main control circuit 500 repeats the initial adjustment of the control voltage in steps 4c to 4g until it is confirmed in step 4d that the oscillation frequency detection value f has become equal to the normal value.

When the oscillation frequency detection value f becomes a normal value, the main control circuit 500 proceeds to step 4h,
Here, the initial value data of the control voltage and the temperature data at this time are stored as initial setting data in the memory 510. Thus, the setting of the initial data is completed.

Now, the PHS adjusted as described above.
When the use of the terminal is started, the PHS terminal performs an automatic control operation of the oscillation frequency. FIG. 5 is a flowchart showing the control procedure and control contents.

That is, the main control circuit 500 first takes in current temperature data from the temperature sensor 540 in step 5a. Then, the temperature data is corrected based on the temperature sensor data in the memory 510, and then, in step 5b, the currently acquired temperature data is compared with the previously acquired temperature data to determine whether there is any change. If the result of this determination is that the temperature has changed compared to the previous time, the correction value of the oscillation frequency f corresponding to the current temperature data is read by accessing the temperature characteristic data in the memory 510 in step 5c. . If the temperature change is not detected, the process of step 5c is not performed.

Next, the main control circuit 500 proceeds to step 5d, where the current humidity data is read from the humidity sensor 550 and the current time data is read from the clock circuit 530. At this time, the above humidity data is stored in memory 5.
The correction is made based on the humidity sensor data in 10. Then, based on the humidity data and the time data, it is determined in step 5e how many hours the humidity state has continued, and in step 5f, by accessing the humidity characteristic data in the memory 510, the continuation of this humidity is performed. A correction value of the oscillation frequency f corresponding to time is read.

Further, the main control circuit 500 executes step 5g.
Fetches the current time data from the clock circuit 530, and calculates the time from the start of use of the PHS terminal to the present time in step 5h based on the time data. Then, by accessing the time characteristic data in the memory 510 in step 5i, the correction value of the oscillation frequency corresponding to the use time of the PHS terminal is read.

When the temperature correction value, the humidity correction value, and the time correction value are obtained, the main control circuit 500 proceeds to step 5
The process proceeds to j, where the above-described correction values are added to calculate a total correction value. Then, in step 5 k, a corrected control voltage is generated by adding the total correction value to the initial value of the control voltage, and this control voltage is supplied to the crystal oscillation circuit 140. Thus, the crystal oscillation circuit 14
The oscillation frequency of 0 is corrected according to the temperature, humidity, and use time.

As described above, in this embodiment, the humidity characteristic data of the crystal unit 141 is stored in the memory 510 together with the temperature characteristic data and the time characteristic data, and the main control circuit 500 fetches the humidity characteristic data from the temperature sensor 540. A temperature correction value is obtained based on the current temperature data and the temperature characteristic data, and a use time of the PHS terminal is obtained from the current time data fetched from the clock circuit 530, and a time correction is performed from the use time and the time characteristic data. A value is obtained, the current humidity data is taken in from the humidity sensor 550, and the current time data is taken in from the clock circuit 530.
From these data, it is determined how long the state of the humidity continues, and a humidity correction value is calculated based on the humidity continuation time and the humidity characteristic data. And the temperature correction value,
The total correction value is calculated by adding the time correction value and the humidity correction value, and the oscillation frequency of the crystal oscillation circuit 140 is corrected based on the total correction value.

Therefore, even if the oscillation frequency fluctuates in accordance with the change in the ambient temperature and the terminal usage time, this fluctuation is corrected by the temperature correction and the time correction, respectively. The oscillation frequency is corrected based on the moisture absorption characteristics and the moisture release characteristics. For this reason, the oscillation frequency of the crystal oscillation circuit 140 is always kept constant with respect to not only the ambient temperature and the operating time but also the humidity, and the stability of the oscillation frequency is enhanced.

Further, it is not necessary to use an expensive constant humidity element such as an oven-type TCXO, which facilitates on-boarding, and further uses an alumina substrate as a measure against moisture absorption.
Since there is no need to provide a circuit board with measures for moisture release such as through holes and moisture release structures, a small and inexpensive crystal oscillation circuit can be provided.

Further, the temperature correction, the humidity correction and the time correction are collectively realized by one function (main control circuit 500) of the control unit 50 already provided in the PHS terminal. The circuit configuration can be made simpler and smaller than in the case where a separate control circuit is newly provided and performed independently, and there is a concern that the temperature correction, humidity correction and time correction affect each other and the oscillation frequency becomes unstable. Disappears.

The present invention is not limited to the above embodiment. For example, a change in the oscillation frequency due to temperature, a change due to humidity, and an aging change have different time ranges, so that it is not always necessary to correct them at the same time interval. Therefore, for example, the temperature correction may be performed every few minutes or several hours, the humidity change may be performed every half day or every other day, and the aging change may be performed every six months or one year. In this way, the processing load on the main control circuit can be reduced.

In the above-described embodiment, the case where the oscillation frequency of the crystal oscillation circuit 140 provided in the synthesizer 14 of the PHS terminal is stabilized has been described as an example. However, other mobile terminals such as mobile phones and mobile communication systems have been described. The present invention can be similarly applied to a base station, and can also be applied to an automatic meter reading terminal device and the like. In short, any electronic device having a crystal oscillation circuit can be applied to any electronic device.

In addition, the configuration of the oscillation frequency correction function, the correction control procedure, the control content, and the like can be variously modified without departing from the gist of the present invention.

[0051]

As described above in detail, according to the present invention, the humidity characteristic information indicating the correspondence between the humidity around the crystal oscillation circuit, the elapsed time, and the oscillation frequency is stored in the storage means in advance, and the crystal oscillation circuit periphery is stored. Humidity detecting means for detecting the humidity of the air, and a time measuring means for measuring a time during which the crystal oscillation circuit is placed at the humidity detected by the humidity detecting means, wherein the humidity detected by the humidity detecting means is provided. And the humidity correction of the oscillation frequency is performed based on the time measured by the timer and the humidity characteristic information stored in the storage.

Therefore, according to the present invention, when the crystal oscillation circuit is continuously placed in a certain humidity state for a certain period of time, the correction data of the oscillation frequency corresponding to the humidity and the elapsed time at this time is obtained from the humidity characteristic information. , The oscillation frequency is corrected. For this reason, the oscillation frequency of the crystal oscillation circuit is always kept constant irrespective of the humidity, whereby the stability of the oscillation frequency is enhanced.

Also, there is no need to use an expensive constant humidity element such as an oven type TCXO, and it is not necessary to take special measures for absorbing and releasing moisture on a circuit board and the like even when the circuit board is formed on a board. And an inexpensive crystal oscillation circuit can be provided.

That is, according to the present invention, a change in the oscillation frequency due to humidity can be effectively corrected, whereby the stability of the oscillation frequency can be increased, and the size and the cost of the crystal can be reduced. An electronic device including an oscillation circuit can be provided.

[Brief description of the drawings]

FIG. 1 is a circuit block diagram showing a configuration of a PHS terminal which is an embodiment of an electronic apparatus according to the present invention.

FIG. 2 is a circuit diagram showing a configuration of an oscillation frequency correction function of the PHS terminal shown in FIG.

FIG. 3 is a circuit block diagram showing a configuration of a main control circuit having the configuration shown in FIG. 2;

FIG. 4 is a flowchart showing a control procedure and control contents of an initial data setting operation.

FIG. 5 is a flowchart showing a control procedure and control contents of an oscillation frequency correction control operation.

FIG. 6 is a view showing general temperature characteristics of a crystal unit.

FIG. 7 is a view showing general moisture absorption characteristics and moisture release characteristics of a crystal resonator.

FIG. 8 is a diagram showing general time characteristics of a crystal resonator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Radio | wireless part 20 ... Modem part 30 ... TDMA part 40 ... Talk part 50 ... Control part 60 ... Information storage part 70 ... Data communication part 80 ... Key input part 90 ... Display part (LCD) 11 ... Antenna 12 ... High frequency switch ( SW) 13 receiving section 14 synthesizer 15 transmitting section 16 received electric field strength detecting section (RSSI) 21 demodulating section 22 modulating section 31 TDMA decoding section 32 TDMA encoding section 41 ADPCM transcoder 42 PCM codec 43 Speaker 44 Microphone 140 Crystal Oscillator 141 Crystal Oscillator 142 Variable Capacitance Element 143 Transistor Oscillator 144 Buffer Circuit 500 Main Control Circuit 501 Processing Unit 502 ROM 503 Memory Interface 504 Setting Interface 505: Clock circuit interface Esu 506 ... temperature sensor interface 507 ... humidity sensor interface 508 ... output interface 510 ... memory 520 ... setting unit 530 ... clock circuit 540 ... temperature sensor 550 ... humidity sensor

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5J079 AA04 BA01 BA02 BA03 BA12 CB02 DA13 FA00 FA13 FA14 FA21 FB38 FB39 FB40 GA02 KA05 5J081 AA01 CC00 CC02 CC17 DD03 EE05 EE18 FF01 FF12 FF13 GG05 HH01 KK22 MM09 KK09

Claims (3)

[Claims] 1. An electronic device comprising a crystal oscillation circuit for generating and outputting a predetermined oscillation frequency with reference to an oscillation output of a crystal oscillator, wherein the humidity around the crystal oscillation circuit, the elapsed time, and the oscillation frequency are Storage means for storing in advance humidity characteristic information indicating a correspondence relationship; humidity detection means for detecting humidity around the crystal oscillation circuit; and the crystal oscillation circuit being placed at the humidity detected by the humidity detection means. A time measuring means having a function of measuring the time during which the humidity is detected by the humidity detecting means, the time measured by the time measuring means, and the humidity characteristic information stored in the storage means. An electronic device comprising a crystal oscillation circuit, comprising: a correction control unit having a function of performing humidity correction of an oscillation frequency. 2. The apparatus according to claim 1, further comprising a temperature detecting unit configured to detect a temperature of the crystal oscillation circuit, wherein the storage unit further stores temperature characteristic information indicating a correspondence between the temperature of the crystal oscillator and the oscillation frequency. The correction control unit calculates a temperature correction value of the oscillation frequency based on the temperature detected by the temperature detection unit and the temperature characteristic information stored in the storage unit, and detects the temperature correction value by the humidity detection unit. A humidity correction value of the oscillation frequency is obtained based on the humidity, the time measured by the timer, and the humidity characteristic information stored in the storage unit, and the temperature correction value and the humidity correction value are combined to obtain a total correction value. 2. An electronic device having a crystal oscillation circuit according to claim 1, further comprising a function of correcting the oscillation frequency based on the total correction value. 3. The storage unit further stores time characteristic information indicating a change with time of an oscillation frequency of the crystal oscillation circuit, and the time measurement unit measures a use time of the crystal oscillation circuit. The correction control unit further obtains a temperature correction value of the oscillation frequency based on the temperature detected by the temperature detection unit and the temperature characteristic information stored in the storage unit, and counts the time by the timing unit. A time correction value of the oscillation frequency is obtained based on the used time of the crystal oscillation circuit and the time characteristic information stored in the storage means, and the humidity detected by the humidity detection means and the time measured by the time measurement means are measured. A humidity correction value of the oscillation frequency is obtained based on time and humidity characteristic information stored in the storage unit, and the temperature correction value, the time correction value, and the humidity correction value are calculated. Electronic apparatus provided with a crystal oscillation circuit according to claim 2, wherein the seeking the total correction value, characterized by comprising a function of correcting the oscillation frequency of the total correction value on the basis of forms.