JP4532928B2 - Optical device and voltage control method for optical device - Google Patents

Description

  The present invention relates to an optical device and a voltage control method for the optical device.

With the progress of optical communication technology, the development of optical components has become active. One such optical component is an optical device for an optical modulator. This optical device supplies different voltages to a plurality of electrodes of an optical element in which a resistor is electrically connected to a plurality of electrodes provided on at least one transparent substrate of a pair of transparent electrodes sandwiching a liquid crystal. By doing so, an optical function peculiar to the optical element is expressed.
As described above, a method of providing electrodes on the transparent substrate and supplying different voltages between the electrodes to provide a potential gradient can be realized by providing resistors between the electrodes and dividing the voltages.
That is, a potential gradient is realized by arranging electrodes named gradient potential electrodes in a substantially vertical direction with respect to electrodes arranged in a stripe shape (see, for example, Patent Document 1).
JP 2000-214429 A

By the way, in the above-described prior art, control of the voltage applied to the electrode is not considered.
For example, in the prior art, when a voltage is applied to the resistor, the voltage application is simply turned ON or OFF.
When the voltage is low, the conventional method is considered to have few problems. However, when the voltage is high (in the case of several hundred V to several kV / cm), a problem may occur depending on the state of the resistor.
Depending on the storage state of the device that generates the potential gradient (environment immediately before driving), it is expected that the resistor itself absorbs moisture and the resistance value decreases. In some cases, condensation on the resistor surface is also expected. As the resistor itself, a resistor having a high resistance is used so as to withstand a high voltage. However, when moisture is adsorbed or condensation is formed on the surface, the resistance can be lowered.

In the prior art, since the voltage is turned on or off, if the resistance is reduced, a current flows more than expected and heat is generated. For this reason, the possibility that the resistor itself may break due to thermal expansion has not been solved in the prior art.
Accordingly, an object of the present invention is to provide an optical device and a voltage control method for the optical device that can avoid the tearing of the optical element even when an abnormality occurs in the resistor.

In order to solve the above-described problems, according to a first aspect of the present invention, a liquid crystal is sandwiched between a pair of transparent substrates, and a resistor is electrically connected to a plurality of electrodes provided on at least one transparent substrate. Detection means for detecting the state of the resistor in an optical device comprising: a connected optical element; and a voltage applying means for expressing an optical function unique to the optical element by supplying different voltages to the plurality of electrodes. When the detection result by the detection means is within a predetermined condition, the voltage is set to a preset value, and when the detection result is outside the predetermined condition, the voltage is within the predetermined condition. Control means for controlling the value of the voltage, and the detection means is at least one of the resistance value of the resistor and the rate of change of the resistance value, or the resistor or the resistor. Neighborhood Detecting at least one of a temperature value and a rate of change of the temperature value, and the control means adjusts a voltage applied to the resistor by one or a combination of detection results of the detection means; and The detection means includes transmission means for transmitting the detection result while maintaining the floating state from the ground potential when the detection result is used at least in a state of floating from the ground potential .

According to the first aspect of the invention, the condition of the resistor is monitored and compared with a predetermined condition in order to control the voltage value so as to operate within a preset condition. When deviating from the above, the power value can be controlled to be equal to or lower than the maximum power consumption of the optical element. In addition, by controlling the voltage so as to operate within preset conditions, the optical element can be normally operated within constant conditions. That is, according to the first aspect of the present invention, the voltage applied to the electrode of the resistor is controlled so that when the abnormality occurs in the resistor, the voltage is applied to the electrode of the resistor so that an overvoltage is applied to the resistor. It is possible to avoid damage to the optical element.
According to the first aspect of the present invention, the rate of change is measured so that the characteristics of the resistor can be monitored at an early stage by measuring not only the changed result but also the changing process. Thus, it is possible to monitor the resistor including the prediction condition that will be reached, and it is possible to cope with the increase in the amount of heat generated due to the abnormality.
According to the first aspect of the present invention, the floating is used to cope with the case where a high voltage is applied, and to prevent an increase in the withstand voltage of the measuring instrument and an increase in cost (component cost) associated therewith. Thus, measurement can be performed by a device other than a measuring device having a high withstand voltage regardless of the applied voltage, and cost reduction can be realized.

According to a second aspect of the present invention, in the first aspect of the invention, the detection means detects at least one of the temperature value of the resistor or the vicinity of the resistor and the resistance value of the resistor. It is characterized by.
According to the second aspect of the present invention, in order to provide a specific means capable of directly monitoring the abnormality of the resistor and the influence of the abnormality, the resistance value or the temperature is measured, so that when the abnormality occurs in the resistor, Therefore, it is possible to quickly cope with the abnormality of the generated resistor.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the detection means has a function of detecting a resistance value of the resistor before the voltage is applied. The voltage is controlled at least according to the measured resistance value.
According to the third aspect of the present invention, in order to prevent the failure of the resistor in the starting state (humidity, surface wetting, etc.), the voltage caused by the lowering of the resistance value with respect to the lowering of the resistance value due to the starting state. It is possible to prevent a failure caused by controlling the voltage so as not to cause a rapid increase in power consumption during application.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the control means has a plurality of driving conditions therein, and switches the plurality of driving conditions depending on the state of the resistor.
According to the fourth aspect of the present invention, when the conditions of the resistor fluctuate, a plurality of conditions can be used by switching a plurality of settings to enable use under more optimal conditions and reducing the cost for this control. Since the optimum operation can be performed by switching, and a response is made only by switching a plurality of driving conditions, the number of components can be reduced and the cost can be reduced.

According to a fifth aspect of the present invention, in the fourth aspect of the invention, the plurality of driving conditions can be individually rewritten from the outside.
According to the fifth aspect of the present invention, in order to provide a control circuit capable of dealing with changes in the parameters of the resistor and the resistor itself, it is possible to cope with parameter changes caused by resistor replacement or the like by simply rewriting information individually. It is possible to reduce the cost of repair.

The invention according to claim 6 is the invention according to any one of claims 1 to 3 , further comprising a calculation unit that determines a voltage to be applied to the resistor according to a detection result of the detection means. .
According to the sixth aspect of the present invention, in order to realize fine voltage control, it is possible to realize voltage adjustment finely corresponding to the condition detected by performing calculation based on the detection result in the calculation unit.

The invention according to claim 7 is the invention according to any one of claims 1 to 6 , wherein the detection means is configured to be separable from the voltage application means and the resistor at least when the voltage is applied. Features.
According to the invention of claim 7 , in order to prevent the increase in the withstand voltage of the measuring instrument and the accompanying cost (part cost), it is possible to cope with the case where a high voltage is applied (10 to 10 kV / mm). By separating the measuring means from the resistor, it is possible to cope with a measuring instrument that does not require a withstand voltage, and the cost of parts can be kept low.

According to an eighth aspect of the present invention, in the invention according to any one of the first to seventh aspects, the detection means includes a dedicated extraction electrode for detecting a resistance value.
According to the invention of claim 8, since the resistance can be measured separately from the resistor to be used in order to detect the state of the resistor without applying a voltage to the resistor for generating the potential gradient, At any time, the resistance value can be detected without applying a load to the resistor regardless of the driving state of the resistor.

According to a ninth aspect of the present invention, in the invention according to any one of the first to eighth aspects, when the detection result of the detection means during application of the voltage is out of the condition in advance. Stops the voltage application to the resistor.
According to the ninth aspect of the present invention, the voltage application is stopped when the detection result is out of the condition in order to ensure the optimization and prevent the expansion of the failure by terminating the operation as soon as an abnormal state is detected. Thus, it is possible to avoid continuing use in an abnormal state, and it is possible to prevent failure of the resistor and also other than the resistor by continuing to use for a long time in the abnormal state.

The invention according to claim 10 is the invention according to any one of claims 1 to 9 , wherein the control means includes means for notifying a detection result of the detection means.
According to the tenth aspect of the present invention, in order to provide an optical device that allows the user to understand the state of the resistor, the user can grasp the current state by providing means for notifying the state of the resistor. It becomes possible to respond early in the event of an abnormality. Further, use (including continuous use) can be avoided in an abnormal state by the user, and it becomes possible to notice and respond to the abnormality of the resistor early.

According to an eleventh aspect of the present invention, in the invention according to any one of the first to tenth aspects, the resistor is formed by applying a resistance material in which fine powder of conductive particles is dispersed in an insulating material on the transparent substrate. It is characterized by being.
According to the eleventh aspect of the present invention, the resistor can be manufactured at low cost by applying the material in order to manufacture the resistor at low cost. Moreover, an optical element can be used on optimal conditions by using a control circuit with a resistor produced by coating.

According to a twelfth aspect of the present invention, the plurality of electrodes of the optical element in which a resistor is electrically connected to the plurality of electrodes provided on at least one transparent substrate of the pair of transparent electrodes sandwiching the liquid crystal. In a voltage control method for an optical device that expresses an optical function unique to the optical element by supplying different voltages, the state of the resistor is detected, and the detection result is within a predetermined condition. The voltage is set to a preset value, and when the detection result is outside the specified condition, the voltage value is controlled to be within the specified condition, the resistance value of the resistor, and the resistance value At least one of the change rate values, or the temperature value of the resistor or the vicinity of the resistor, and / or the change rate of the temperature value is detected, and the detection result is based on one or a plurality of combinations. , Characterized in that the voltage applied to the resistor to adjust, and transmits the detection result detected while maintaining the float from the ground potential results when used in a state where the float at least a ground potential And
According to the invention of claim 12, since the voltage applied to the electrode of the resistor is controlled so that the abnormality occurs in the resistor, the overvoltage is not applied to the resistor, Damage to the optical element can be avoided.
According to the invention of claim 12, the rate of change is measured so that the characteristics of the resistor can be monitored at an early stage by measuring not only the changed result but also the changing process. Thus, it is possible to monitor the resistor including the prediction condition that will be reached, and it is possible to cope with the increase in the amount of heat generated due to the abnormality.
According to the twelfth aspect of the present invention, the floating is used in order to cope with the case where a high voltage is applied, and to prevent an increase in the withstand voltage of the measuring instrument and an increase in costs (part costs) associated therewith. Thus, measurement can be performed by a device other than a measuring device having a high withstand voltage regardless of the applied voltage, and cost reduction can be realized.

  Since the voltage applied to the electrode of the resistor is controlled so that when the abnormality occurs in the resistor, the overvoltage is not applied to the resistor, so that the optical element can be used even if an abnormality occurs in the resistor It is possible to provide an optical device and a voltage control method for the optical device that can avoid tearing of the optical device.

(Structure of the invention)
The present invention is characterized in that a potential gradient is applied on a transparent substrate, a resistor is formed on the transparent electrode, and a resistance is applied when a voltage is individually applied to a plurality of electrodes electrically connected to the resistor. Ru der controls a voltage to be applied to the body.
For resistors used to generate a potential gradient by applying a voltage to the resistor antibodies, the state of the resistor is intended to prevent the occurrence of abnormality to be monitored.
Here, the state of the resistor means the appearance (surface state, particularly reflectance change and color change due to surface property change due to condensation), resistance value, temperature value, and the like.
As a means for monitoring the state of the surface of the resistor, there is a method of monitoring with illumination and an imaging device. As the illumination, an LED (light emitting diode), a lamp, or the like can be used. As the image pickup device, a lens system, a CCD (charge coupled device), a CMOS (complementary metal oxide semiconductor) sensor, or the like can be used. In particular, since it is not necessary to observe detailed changes such as the shape of the resistor, the imaging device may have a simple configuration.

Images captured by the camera are digitized, and the original resistors (no condensation, etc., no temperature rise, no change in surface condition due to the surrounding environment, and no flammables attached) are stored in advance. Then, compare the observation results. As described above, detailed comparison is not so meaningful, so image processing is performed, and there are differences in multiple items such as foreign matter adhesion, decrease in reflectance due to condensation, change in reflected light spectrum due to discoloration, etc. It is good to detect by presence or absence. Although this method can directly monitor the surface state of the object, there is a problem that the cost becomes very high.
In the present invention, an abnormality can be immediately detected by measuring the temperature at which the resistor reacts quickly (the temperature of the resistor or the temperature in the vicinity of the resistor).
As a method for measuring the temperature, a thermometer for measuring infrared radiation or a thermocouple near the resistor may be used for measurement. Temperature measurement using these thermometers and thermocouples can be realized at low cost.

Moreover, measurement of a resistance value is mentioned as another means for monitoring a resistor of the present invention.
While the resistor body maintains a constant resistance value, the maximum power consumption is set according to the resistance value and material characteristics. When using below this maximum power consumption, there is no problem, but if a state where the resistance value decreases, the current will flow above the set value if only the specified voltage is applied. The drive will exceed the maximum power consumption.
In the present invention, by predicting at least one of the temperature, the resistance value, or a state assumed from the rate of change of each value, avoid applying a load exceeding the maximum power consumption to the resistor, As a result, heat generation is prevented.
As the voltage control means, it is possible to use a combination of a D / A converter and an amplifier including an emergency attenuator circuit (a voltage is reduced at once by switching the path).
In a D / A converter, a digital signal used for an input portion is very preferable because it can be easily controlled. In addition to the D / A converter, a voltage can be switched depending on conditions using a group of electronically controlled switches.
As a comparison method with the pre-defined conditions, normal resistance values, temperatures, and the like are stored in the ROM as a lookup table, and one condition (for example, resistance value data) By reading the normal resistance value from the ROM using time, temperature, etc. as an index, it can be used as a comparative control. The comparison method can use a comparator that compares magnitudes after digitization.

The long-term storage at a storage environment, also at the start of operation after the stop temperature difference intense environment, the resistance value of the resistor due moisture and dust which may have decreased.
The present invention measures the resistance value of a resistor at least before applying a voltage to the resistor, and drives under the condition that the maximum power consumption of the resistor is not exceeded.
The method for measuring the resistance value of the resistor can be realized by using a power supply that applies voltage, keeping the output voltage of the power supply low, and measuring the flowing current with an ammeter installed in series with the power supply and resistor. .
In the resistor used in the optical element of the present invention, a dummy electrode is provided in a portion not actually used, and resistance measurement is performed, so that a voltage for measurement is not applied to the resistor actually used for potential division. also, the resistance value of the resistor Ru can be measured at an arbitrary timing.
In this method, the same conditions (width, thickness, resistivity, etc.) as the part that the resistor actually uses are most preferable, but it is possible to use it as a substitute characteristic by calibrating in advance with the dummy electrode part. is there.

As a form of the dummy electrode, it is possible to use it as a resistance for confirmation separately from the part to be normally used by providing it other than the electrode part to be originally used. However, since there is a possibility that a factor different from the original resistance may occur (resistance value, state, temperature) at an extremely distant position, the vicinity of the portion to be used is preferable.
By using a part of the electrode for extracting the potential gradient, the number of electrodes can be reduced. However, by providing at least two individual electrodes, it is possible to take out a potential gradient that is originally used or measure resistance regardless of the electrode to which a voltage is applied.
In order to measure the electrical resistance using the dummy electrode portion, a resistance measurement voltage is applied to the dummy electrode portion. At this time, if a voltage for generating a potential gradient is not applied, the resistance is measured only by the voltage applied to the dummy electrode. There is no problem in measuring current for measuring resistance by connecting a resistor and a power source in series.
In actual use, it is assumed that, for example, a voltage (electric field) of 100 V / mm is applied alternately with a ground potential and a voltage of 1 kV to an end having a resistance length of 10 mm. When the device for resistance measurement connected to the dummy electrode is connected to the ground, the required withstand voltage is required to be a maximum withstand voltage of 1 kV (the dummy electrode is installed in the vicinity of the electrode actually used) It is possible to make a circuit configuration in which a breakdown voltage is secured (assuming that the resistors included therein are ignored).
However, since the measuring device that ensures the withstand voltage is very expensive, the cost becomes high.

In the present invention, a method is used in which a portion used for measurement is floated with respect to the ground, and data (detection result) extraction (transmission) is not electrically connected directly.
As a method of using the present invention, transmission that is not electrically connected, such as a photocoupler, can be used. Specifically, non-contact transmission of measurement data can be realized by outputting a measurement result with a photodiode and receiving the measurement result with a photodetector. In addition, data can be received by a phototransistor, a photocup, or the like.
It can also be realized by performing transmission and reception by radio waves.
In these inventions, measurement can always be performed without considering the withstand voltage of the measuring means regardless of the voltage application state.
As another method, a circuit for measurement is electrically excluded from the circuit.
In this case, it is possible to use a measuring instrument that does not require a withstand voltage, but care must be taken because measurement cannot be performed when a voltage for applying a potential gradient is applied. Further, it is necessary to adjust the voltage application method and the measurement method such as providing an interval as the voltage application method.

Information for comparison can be achieved by using a rewritable device such as a mask ROM and most inexpensive, in this case, change over time or a resistor in the middle used, properties such as replacement of the resistor itself Be careful as it cannot respond to changes in
In the present invention, at least one characteristic is rewritten from the outside, so that an inexpensive countermeasure can be provided in these cases.
The process used is most preferably an EEPROM (electrical erasure write ROM) such as a flash ROM capable of electrical write / erase.
Since it can be electrically controlled, the system can be configured at the lowest cost. Although it is possible to use an ultraviolet erasable EPROM, care must be taken because the system becomes larger in reality because ultraviolet irradiation is required for erasing information.

It is intended to prevent permanent damage by blocking the voltage depending on the state of the resistor antibody.
The power supply itself usually has an excessive current prevention means for preventing an output of an excessive current such as a fuse in order to cope with a short circuit (accident) of the load. However, this excessive current prevention means is to prevent destruction of the power supply itself and is a necessary function, but a power supply having a performance higher than the maximum output required by design is prepared.
In the method of use shown in the present invention, the resistor itself having only a lower maximum power consumption is broken before the power supply is destroyed. Of course, it is possible to turn off the power supply with respect to the change of the resistor by the fuse of the power supply. In this case, it may be set so that the fuse of the power supply is blown when the maximum power consumption of the resistor is output in advance. However, in reality, the fuse itself has a power consumption regulation, but it is considered that special measures are required for the one that instantaneously shuts off with that power. It is actually difficult to prepare a fuse together.
As a method of shutting off the power supply, a method of shutting off a circuit such as a relay is desirable. Other thyristor and also, Ru can use the photo relay or the like to ensure the breakdown voltage.

In the present invention, when a deviation from the original use conditions is made, it is possible to promptly cope with an abnormal state by notifying the user.
Naturally, when deviating from normal use conditions, it is natural that the expected effect cannot be realized. However, if the user continues to use the product without noticing it, it can be assumed that the performance deteriorates. There is also a possibility that it will eventually reach a non-operational state. According to the present invention, in this case as well, it is possible to avoid the breakage of the resistor by the control circuit. However, by using the function of notifying the user of the state, the user can take an early action.
A method of notifying the user of the abnormality can be realized at a relatively low cost by attaching a lamp to the main body. However, it may not be preferable to install a lamp that is too flashy depending on the usage conditions and location. In such a case, as an example, changing the emission color of the lamp that indicates power-on (usually attached to the housing to indicate that it is energized) notifies the user not too much. can do.
An example is a method in which the green display when the power is turned on emits orange light when it deviates from the normal condition, and the display is red when the power is cut off. In this case, it can be easily realized by using a red LED and a green LED. Moreover, it is possible to use an LED in which a red LED and a green LED are mounted as one element. It is also possible to display a degree of deviation from a normal state by arranging a plurality of LEDs.
It is also possible to display the current state by a switch operation. This is very effective when you want to manage the current state in detail.

A resistive material is formed by dispersing a fine powder of conductive particles in an insulating material to form a resistive material, and applying the resistive material on a transparent substrate. Insulating materials that are fixed on a transparent substrate by evaporation of the solvent, those that are fixed on a transparent substrate by irradiating UV (ultraviolet rays) to cause a crosslinking reaction or a condensation reaction, by heating What causes a crosslinking reaction can be used.
As the conductive particles, fine powders such as ATO (antimony-containing tin oxide), ITO (tin-containing indium oxide), zinc oxide, ferrite, carbon, and silver can be used.
As the insulator, UV curable resin, thermosetting resin, resin + solvent, and the like can be used.
Examples will be described below.

As a substrate to which a resistor, a stripe electrode, and a potential gradient are applied, a stripe electrode having a line width of 10 μm, a pitch of 100 μm, and a number of lines of 100 is formed of ITO on a glass substrate.
FIG. 1 shows a schematic diagram of a resistor (the parentheses indicate the corresponding numbers in FIG. 1).
ITO (102) was fabricated on a glass substrate (101) (for simplicity, only the structure is shown).
A pad (103) is provided to apply a voltage, and a voltage for applying a potential gradient is applied thereto. A resistor is manufactured in a portion (resistor manufacturing region) indicated by 104 in FIG.
As a resistor, a coating solution was prepared by diffusing fine powder of ATO (antimony-attached tin oxide) into the resin, and coating was performed on a transparent substrate.
The solvent was dried by heating to obtain a resistor to which a potential gradient was applied.
FIG. 2 shows a block diagram of a control circuit used in the optical apparatus of the present invention.
A thermocouple was installed in the vicinity of the resistor (installed at a position where leakage or short-circuit due to the thermocouple does not occur according to the applied voltage).

The arrows extending from the power source 201 and the current detection unit 202 shown in FIG. 2 are connected to the pads 103 in FIG.
The power source 201 can adjust the voltage with an external signal.
The current detection unit 202 detects the value of current flowing through the resistor.
The controller 203 calculates the resistance value of the resistor from the voltage and current applied to the resistor.
Further, the control unit 203 monitors the temperature of the resistor based on the output of the thermocouple (206) installed in the vicinity of the resistor.
Based on the calculated resistance value, processing necessary for voltage application is performed by the power supply control unit 204 to control the voltage of the power supply 201. In the power supply control unit 204, Switching between conditions 205 for driving the input signal. That is, the power supply control unit 204 controls the voltage of the power supply 201 by switching the condition 205 based on the output of the control unit 203 that monitors the temperature with a thermocouple.

Here, as an example, when a decrease in electrical resistance is observed during driving, a condition for reducing the applied voltage is selected, and the voltage is set so that the voltage of the condition is applied to the power supply. In addition, when the temperature rise near the resistor exceeds a predetermined temperature during use by the thermocouple 206, it is output from the power source 201 by similarly switching the driving condition 205 by the power source control unit 204. The voltage can be reduced.
The driving condition 205 can hold a plurality of driving conditions by a look-up table method. Specifically, the drive condition of the power source 201 is written in advance in the ROM, and the drive condition is output to the power source 201 by the power supply control unit 204 performing address designation. The drive condition 205 (such as a look-up table composed of a memory) can be produced at low cost by using a mask ROM or the like. By creating the drive condition 205 by an electrically erasable and erasable process such as an EEPROM (electrically rewritable ROM), it is possible to cope with a change in the parameter of the resistor due to replacement of the resistor or the like.

(Adjustment according to dummy electrode and start-up conditions)
As shown in FIG. 3, an electrode was produced on a transparent substrate 301 under the conditions shown in FIG.
An electrode for detecting resistance as shown in FIG. 3 is provided in a portion related to the inside of the resistor at a position that is not originally used for the potential gradient at a portion indicated by a broken line 305.
By using this electrode, the resistance value of the resistor can be measured regardless of the state of use.
By measuring the resistance value at the start of use, if the resistance value is less than the specified resistance value, adjustments such as a gradual increase in voltage at the start of driving are performed.

As an example, a case where moisture in the air is adsorbed by leaving the resistor 304 shown in FIG.
When the resistance film adsorbs moisture, the resistance value may decrease. This tendency is particularly strong in a resistive film having an uneven surface or a resistive film having a minute hole (some resistive films formed by applying a material have this tendency). Further, when the humidity is extremely high, in the worst case, condensation may occur on the surface of the resistor. In this case, the resistance value decreases uniformly.
In the conventional method in which the voltage is turned on or off, in this case, a current exceeding the expected value flows through the resistor and there is a risk of tearing due to heat generation.

In the present invention, the resistance value is measured before use or during driving, and the voltage is adjusted by referring to the resistance value.
FIG. 4 shows a block diagram of another embodiment of the control circuit used in the optical apparatus of the present invention.
The power supply 401 can adjust the voltage with an external signal.
An output from a resistance detection terminal 402 (a broken line 305 in FIG. 3) provided in the resistor is input to the control unit 403. Here, temperature detection by input from the thermocouple 406 and resistance value detection of the resistor by the terminal 402 are performed. By inputting this result to the power supply control unit 404, the driving condition 405 of the power supply 401 is selected, and the voltage applied to the resistor is controlled.
Specifically, when the resistance value at the initial stage of driving is low, the voltage is gradually increased while detecting the temperature. When a voltage is applied to the resistor, the temperature of the resistor rises due to Joule heat. Moisture condensed on the resistor surface is reduced by evaporating with this temperature rise. In the case of low resistance in which moisture condensed on the resistor surface becomes a path, if the moisture decreases to some extent, the current path becomes only the resistor, so that the resistance value rapidly increases. Thereafter, the resistance decreases due to the adsorbed moisture, but this also decreases as the temperature of the resistor increases. It is only possible to control the drive voltage while detecting the resistance value and temperature value to drive after removing the moisture due to the temperature rise caused by energizing the resistor or reducing the influence of moisture. is there.

On the other hand, in the conventional voltage control of only ON or OFF, a current larger than an assumed current value flows at the moment of energization, and there is a risk of tearing due to thermal expansion. When the resistor breaks due to excessive current, as well as when the power supply itself fails, parts related to the power supply need to be replaced, and the repair cost increases.
In the present invention, it is possible to realize driving in an optimal state regardless of the environment at the time of complementation.

(Calculation processing)
Based on these information (temperature value, resistance value) as a method of detecting the temperature value of the resistor or the vicinity of the resistor and / or the resistance value of the resistor and adjusting the driving conditions. By determining the driving conditions by calculation, it is possible to determine detailed driving conditions. The lower the applied voltage, the less the resistor load.
However, as an example of use, there are cases where the absolute value of the potential gradient itself is meaningful.
In an optical element that uses liquid crystal and deflects light by using a potential gradient, it is necessary to ensure that the voltage for the potential gradient is not less than a certain level as well as applying the potential gradient.
Therefore, if the highest voltage can be applied within a range that does not place an excessive burden on the resistor, better driving can be realized.

FIG. 5 shows a block diagram of another embodiment of the control circuit used in the optical apparatus of the present invention.
The power source 501 can adjust the voltage by an external signal.
As in Example 3, the resistor was provided with a resistance value detection terminal 502.
A resistance detection terminal 502 provided on the resistor is input to the control unit 503. Here, temperature detection by input from the thermocouple 506 and detection of the resistance value of the resistor by the terminal 502 are performed.
The resistance value and temperature condition from the control unit 503 are input to the calculation unit 504.
The arithmetic unit 504 reads the conditions of the resistor to be used in advance (upper limit temperature, maximum power consumption, etc.) from the data ROM 505 as necessary, uses the RAM 507 to store the results during the processing, and the like, and controls the control unit 503. The drive conditions suitable for the following conditions are output to the power source 501 (Claim 7).
Thereby, the voltage close | similar to the voltage most required in an optimal state can be applied, without exceeding the maximum power consumption of a resistor.

(Shutdown during heat generation and notification to users)
When voltage is applied to the resistor, the most inconvenient case is to reduce the resistance.
Here, it corresponds to the sudden decrease in resistance that occurs during use.
When a conductive liquid adheres to a resistor that is being driven at a high voltage, or the humidity increases due to a temperature change, the resistance value decreases. At this time, if the voltage drop can be dealt with by the processing of the present invention, the voltage drop is realized without any problem, and it is confirmed that the resistance increases due to the removal of moisture, etc. It can be used without.
If not covered by the control circuit of the present invention, the optimum method, Ru der blocking voltage by detecting the resistance value and temperature.
Usually, a fuse or the like is installed in the power supply, and the apparatus itself stops when the output power of the power supply itself exceeds a specified value.

However, this fuse mechanism operates for the first time under conditions that exceed a preset output for the power supply itself. That is, the maximum power consumption of the resistor to be used does not necessarily match the condition for stopping the power supply. Of course, it is possible to match the power cutoff condition to the resistor itself, but the maximum power consumption of the resistor has a factor that fluctuates in the process of manufacturing the resistor (reproducibility of film thickness, width, etc.). In addition, there is a possibility that the conditions may be different from the initial conditions due to replacement or changes in diameter, and it is impossible to deal with these only by the power-off condition.
In this embodiment, a preset value is provided before exceeding the maximum power consumption of the resistor to be used in advance, and the resistor is prevented from being broken by shutting off the power supply.

FIG. 6 shows a block diagram of another embodiment of the control circuit used in the optical apparatus of the present invention.
The power supply 601 can adjust the voltage with an external signal.
Similar to Example 3, the resistor was provided with a resistance value detection terminal 602.
A resistance detection terminal 602 provided on the resistor is input to the control unit 603. Here, temperature detection by an input from the thermocouple 606 and detection of the resistance value of the resistor by the terminal 602 are performed.
The resistance value and temperature condition from the control unit 603 are input to the calculation unit 604.
In the calculation unit 604, the conditions of the resistor to be used in advance (upper limit temperature, maximum power consumption, etc.) are read from the data ROM 605 as necessary, and the RAM 607 is used to store the results during the processing from the control unit 603. A condition for outputting a necessary voltage is output to the power source 601 according to the state of the resistor.
At this time, when the power consumption of the resistor increases for some reason, such as a reduction in resistance of the resistor, the blocking unit 608 having a function of cutting off the power of the blocking unit 608 without waiting for the blocking of the power source 601 by a fuse or the like. By directly controlling the calculation unit 604, power supply to the resistor can be stopped instantaneously.
The blocking unit 608 can select a solid state relay, a mechanical relay, a coupler, or the like within a power range to be used if power permits.

(Temperature increase rate, resistance decrease rate)
It is effective to change the setting with the set numerical value, but it adjusts before serious damage by predicting the arrival point from the rate of change.
A block diagram of another embodiment of the control circuit used in the optical apparatus of the present invention is shown in FIG.
The power source 701 can adjust the voltage with an external signal.
As in the third embodiment, the resistor is provided with a resistance value detection terminal 702.
A resistance detection terminal 702 provided on the resistor is input to the control unit 703. Here, temperature detection by input from the thermocouple 706 and detection of the resistance value of the resistor by the terminal 702 are performed.
Based on the data input from the control unit 703, the power supply control unit 704 obtains a change amount with respect to time (or time required for the change amount) by calculation, and takes measures before reaching a certain arrival point.
The clock used for calculation can be used for time measurement.
The condition of the resistor from the control unit 703 is read using the RAM 707 in order to read out the conditions of the resistor to be used in advance (upper limit temperature, maximum power consumption, etc.) from the data ROM 705 as necessary, and to store the results during the processing. Accordingly, a condition for outputting a necessary voltage in advance is output to the power supply 701 in accordance with the predicted arrival condition.
As a result, even if troubles such as serious deformation occur, the drive conditions are adjusted before the conditions that lead to permanent destruction, and the occurrence of tearing can be avoided.

  The present invention can be applied to optical components such as an optical modulator, an optical shutter, and an optical filter.

It is a schematic diagram of a resistor. It is a block diagram which shows one Example of the control circuit used for the optical apparatus of this invention. It is the plane schematic diagram of the transparent substrate 301 which produced the electrode on the conditions shown in FIG. It is a block diagram which shows the other Example of the control circuit used for the optical apparatus of this invention. It is a block diagram which shows the other Example of the control circuit used for the optical apparatus of this invention. It is a block diagram which shows the other Example of the control circuit used for the optical apparatus of this invention. It is a block diagram which shows the other Example of the control circuit used for the optical apparatus of this invention.

Explanation of symbols

101 glass substrate 102 ITO (tin-containing indium oxide)
103 Pad 104 Resistor Fabrication Area

Claims (12)

The liquid crystal is sandwiched between a pair of transparent substrates, and an optical element in which a resistor is electrically connected to a plurality of electrodes provided on at least one of the transparent substrates, and a different voltage is supplied to the plurality of electrodes. In an optical device having a voltage application means for expressing an optical function unique to the optical element, when the detection means for detecting the state of the resistor and the detection result by the detection means are within a predetermined condition Takes the voltage as a preset value,
And control means for controlling the value of the voltage to be within a prescribed condition when the detection result is out of the prescribed conditions,
The detection means includes at least one of a resistance value of the resistor and a change rate value of the resistance value, or a temperature value of the resistor or the vicinity of the resistor, and a change rate of the temperature value. Detect
The control means adjusts the voltage applied to the resistor by one or a combination of detection results of the detection means, and
The optical apparatus according to claim 1, wherein the detection means includes a transmission means for transmitting the detection result while maintaining the float state from the ground potential when the detection result is used at least in a state of floating from the ground potential .   The optical device according to claim 1, wherein the detection unit detects at least one of a temperature value in the vicinity of the resistor or the resistor and a resistance value of the resistor. The detection means has a function of detecting a resistance value of the resistor before the voltage is applied, and the control means controls at least the voltage according to the measured resistance value. The optical device according to claim 1 or 2 .   The optical apparatus according to claim 1, wherein the control unit has a plurality of driving conditions therein and switches the plurality of driving conditions depending on the state of the resistor. 5. The optical apparatus according to claim 4 , wherein the plurality of driving conditions can be individually rewritten from the outside. The detection result of the detecting means, the optical device according to any one of claims 1 to 3, characterized in that it has an arithmetic unit for determining a voltage applied to the resistor. It said detection means, at least the voltage applying time of the voltage applying means and an optical device according to any one of 6 claim 1, characterized in that it has a configurable disconnected from the resistor to. The detecting device, the optical device of any one of claims 1 to 7, characterized in that it has a dedicated extraction electrodes for detecting the resistance value. Said control means, a detection result of said detecting means during applying the voltage, when the in advance conditions outside of claims 1 to 8, characterized in that stopping the application of voltage to the resistor The optical device according to claim 1.   The optical device according to claim 1, wherein the control unit includes a unit that notifies a detection result of the detection unit. The optical device according to any one of claims 1 to 10 , wherein the resistor is obtained by applying a resistive material in which fine powder of conductive particles is dispersed in an insulating material on the transparent substrate. . By supplying different voltages to the plurality of electrodes of an optical element in which a resistor is electrically connected to a plurality of electrodes provided on at least one transparent substrate of a pair of transparent electrodes sandwiching a liquid crystal In a voltage control method for an optical device that expresses an optical function unique to an optical element,
The state of the resistor is detected, and when the detection result is within a predetermined condition, the voltage is set to a predetermined value. When the detection result is outside the predetermined condition, the voltage is within the predetermined condition. controlling the value of the voltage such that,
Detecting at least one of the resistance value of the resistor and the rate of change of the resistance value, or the temperature value of the resistor or the vicinity of the resistor, and the rate of change of the temperature value;
The voltage applied to the resistor is adjusted by one or a combination of detection results, and
A voltage control method for an optical apparatus, comprising: transmitting a detection result while maintaining a floating state from the ground potential when the detection result is used in a state where the ground potential is at least floating .

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