JPH07280515A - Method and apparatus for measuring amount of optical displacement - Google Patents

Abstract

PURPOSE:To provide a method for measuring the amount of optical displacement that is hard to be influenced by a disturbance light. CONSTITUTION:A light is emitted on a scale 90 that is provided with parts having different two optical characteristics which are periodically arranged one after the other so that a periodic image pattern is formed thereon. The periodic image pattern is detected by a one-dimensional image sensor 94, then the amount and the direction of relative displacement between the scale 90 and the image sensor 94 are judged from the variation of the periodic image pattern that is detected by the image sensor 94. The magnitudes of outputs of adjacent pixels of the image sensor are compared with each other so that a measurement pulse corresponding to the periodic image pattern is formed at a time point when the relationship of the magnitudes is inverted. The amount and direction of the relative displacement between the scale 90 and image sensor 94 are judged from the amount and the direction of movement of each unit of pixel of the image sensor 94 of the measurement pulse.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical displacement amount measuring device used for linear scales, rotary encoders and the like.

[0002]

2. Description of the Related Art FIG. 27 is a schematic view for explaining the principle of an optical displacement amount measuring device. The optical displacement amount measuring device includes a scale 90 in which portions having two types of reflection coefficients and having the same length are alternately arranged in the displacement direction (left and right direction in the figure), and an LED or the like which projects light to the scale 90. The light projecting element 91 and the light projecting lens 9 installed between the light projecting element 91 and the scale 90 and for narrowing the light beam from the light projecting element 91.
2, a light receiving lens 93 that is placed opposite to the scale 90 and forms an image of the light beam from the light projecting lens 92 reflected by the scale 90, and at least one light receiving lens 93 installed on the image forming surface.
Dimensional CCD (Charge Coupled Device) 94.

The light beam from the light projecting element 91 narrowed down by the light projecting lens 92 is reflected on the surface of the scale 90 and is imaged on the light receiving surface of the CCD 94 by the light receiving lens 93. On the surface of the scale 90, portions having two different reflection coefficients are alternately arranged periodically in the displacement direction (left and right direction in the drawing), so that the light receiving surface of the CCD 94 is imaged.
As shown in FIG. 28 (a), the periodic pattern of the reflection coefficient is similar to the periodic pattern of the light and dark parts, and the output of the CCD 94 shows the bright / dark pattern as shown in FIG. 28 (b). A pulse waveform corresponding to the periodic pattern of parts is obtained. The light receiving element of each pixel of the CCD 94 is turned on and outputs when the brightness of the bright portion which is in contact with the light receiving surface exceeds a certain value (threshold value). When the scale 90 moves to the right or left in FIG. 27 (when the optical system excluding the scale 90 and the CCD 94 move to the left or right), the periodic pattern of the bright and dark portions of the light receiving surface of the CCD 94 is left or Move to the right. By measuring the amount of displacement on the CCD 94 light receiving surface of the periodic pattern of the bright and dark portions, the scale 90 (the object fixed to it), the optical system, and C
It is possible to determine the relative displacement amount and relative displacement direction with respect to (the object fixed to CD94). As an example of such an optical displacement measuring device, Japanese Patent Laid-Open No. 59-1098 is available.
No. 13 has already been disclosed.

[0004]

FIG. 29 (a) shows a CC
FIG. 9 is a waveform diagram showing the intensity (brightness) of a periodic pattern of the light and dark portions on the light receiving surface of D94, but when the intensity (brightness) of the reflected light fluctuates due to light from the outside, CCD9
Although the light input to each pixel of No. 4 changes, the ON / OFF threshold VTH of the light receiving element of each pixel of the CCD 94 does not change. Therefore, as shown in FIG. The width of the pulse waveform corresponding to the periodic pattern of the part varies. Therefore, an accurate determination result could not be obtained. A complicated optical system is required to reduce the influence of external light.

The magnification between the periodic pattern of the reflection coefficient on the surface of the scale 90 and the periodic pattern of the bright and dark portions of the light receiving surface of the CCD 94 is determined by the distance between the scale 90 and the light receiving lens 93. Since the periodic pattern is fine (for example, (0.5 mm / period) × magnification), it is difficult to set, and the accuracy is determined by the magnification, so that it is strongly affected by blurring. It also requires a complicated optical system. Further, since the displacement amount is measured by paying attention to one cycle of the periodic pattern of the reflection coefficient on the surface of the scale 90, when one cycle of the pattern is soiled or crushed, an accurate determination result is obtained. Couldn't get Further, in order to improve the measurement accuracy, the optical system may be complicated, or the periodic pattern of the reflection coefficient on the surface of the scale 90 may be made finer than in the past (0.5 mm / cycle). To make the pattern finer, special printing technology is required. Further, when the phase of the periodic pattern is displaced by 180 ° or more during one scanning period of the CCD 94, the displacement amount and displacement direction cannot be discriminated.
Inaccurate judgment results may occur. Further, the resolution and the response speed of the displacement amount measurement cannot be switched because they depend on the period of the periodic pattern of the reflection coefficient on the surface of the scale 90 and the optical system.

The present invention has been made in view of the above-mentioned circumstances. In the first invention, the magnitudes of the outputs of adjacent pixel units of the image sensor are compared with each other, and based on the time point when this magnitude relationship is reversed. An object of the present invention is to provide an optical displacement amount measuring method which is less likely to be affected by ambient light by a method of generating a measurement pulse corresponding to a periodic image pattern.
According to the second aspect of the invention, the set of the adjacent pixel unit outputs for comparing the magnitudes is limited to either the odd / even number set or the even / odd set, so that the influence of the ambient light is exerted. An object is to provide a difficult optical displacement amount measuring method. According to the third aspect of the invention, based on the comparison means for comparing the magnitudes of the pixel units adjacent to each other of the image sensor and the time point when the magnitude relation of the pixel units output by the comparison means is reversed,
An object of the present invention is to provide an optical displacement amount measuring device which is hardly affected by ambient light by providing a measurement pulse generating means having a first measurement pulse generating means for generating a measurement pulse corresponding to a periodic image pattern. And

According to the fourth aspect of the invention, the first gate that allows the output of the odd-numbered pixel output from the image sensor to pass therethrough, the second gate that allows the output of the even-numbered pixel to pass therethrough, the first gate and the Of the input comparison means for comparing the inputs from the two gates and the comparison result output of the input comparison means,
By providing a third gate that selectively passes only the comparison result of odd-numbered / even-numbered or even-numbered / odd-numbered, it is possible to provide an optical displacement amount measuring device that is not easily affected by ambient light. The purpose is to In the fifth invention,
The waveform of the measurement pulse corresponding to the periodic video pattern generated from the output of one scan of the image sensor is stored, and when the measurement pulse is generated from the output of the next scan, the measurement pulse is added to the pixel unit of the image sensor. It is an object of the present invention to provide an optical displacement amount measuring method that is less susceptible to the influence of ambient light by a method of generating a measurement pulse by synchronously feeding back the stored measurement pulse waveform for the previous scan. .

According to the sixth aspect of the invention, the first storage means for storing the waveform of the measurement pulse corresponding to the periodic video pattern generated from the output of one scan of the image sensor and the pixel unit of the image sensor are synchronized. , By providing the second measurement pulse generating means for generating the measurement pulse for one scan by feeding back the waveform of the measurement pulse for the previous scan stored in the first storage means, the influence of the ambient light It is an object of the present invention to provide an optical displacement amount measuring device that is hard to be affected by the light.
According to the seventh aspect of the invention, the first shift register having a capacity equal to the number of pixels for one scan of the image sensor and the output from the image sensor are used as comparison inputs, and feedback to the reference input terminal by the output of the first shift register is performed. It is an object of the present invention to provide an optical displacement amount measuring device which is less likely to be affected by ambient light by providing a multiplying comparator.

According to the eighth aspect of the present invention, the measurement pulse corresponding to the periodic video pattern generated from the output of the image sensor is sequentially input to the second shift register, and the measurement pulse has a center pulse of the same phase at the initial stage and the measurement pulse. A plurality of reference pulses with equal width and equal intervals are stored in the third shift register, and the disagreement time with the measurement pulse is sequentially counted for each reference pulse, and the mutual length of these timing results is compared and judged. Then, the mismatch time between the measurement pulse and the center pulse and its direction are determined based on this comparison result. When the mismatch time is equal to or more than the first predetermined value, the movement direction and the movement indicating the movement of the first predetermined value are performed. While outputting the signal, the measurement pulse stored in the second shift register is used as a new center pulse, and the reference pulse is stored in the second shift register. The measurement pulse is sequentially input to the shift register, and the disagreement time and the direction of the measurement pulse and the center pulse are sequentially determined by the same method as described above. Each time the disagreement time becomes the first predetermined value or more, the movement signal is generated. Is output and the method of repeating the alternation of the second and third shift registers described above, the measurement accuracy can be improved, the distance of the optical system can be easily set, and the error caused by the magnification change of the optical system can be reduced. An object of the present invention is to provide an optical displacement amount measuring method that can be corrected and is less affected by dirt and crushing of a periodic pattern on the scale surface.

According to the ninth aspect of the invention, the second or third shift register for sequentially inputting the measurement pulses generated by the measurement pulse generating means, and the center pulse having the same phase as the measurement pulse at the initial stage and having the same width as the measurement pulse. A third or second shift register for storing a plurality of reference pulses at equal intervals, a plurality of first time measuring means for sequentially measuring the disagreement time with the measurement pulse for each reference pulse and its direction, and a first First comparison / determination means for comparing and determining the mutual length of each time measurement result of the time measuring means, and the mismatch time and the direction of the measurement pulse and the central pulse are judged from this comparison result, and the mismatch time is the first predetermined value. If the above is the case, the movement signal output means for outputting a movement signal indicating the movement direction and the movement of the first predetermined value, and if the disagreement time is the first predetermined value or more, the second
The reference pulse is stored in the second or third shift register using the measurement pulse stored in the shift register of No. 3 as a new center pulse, and thereafter the measurement pulse is sequentially input to the third or second shift register. By providing a switching signal output means for outputting a signal for switching to, and a switching means for receiving the switching signal and performing the switching, it is possible to improve the measurement accuracy,
An object of the present invention is to provide an optical displacement amount measuring device in which the distance of an optical system can be easily set, an error caused by a change in magnification of the optical system can be corrected, and which is less susceptible to contamination and crushing of a periodic pattern on a scale surface. .

According to the tenth aspect of the invention, there is provided a first clocking means having a logic means for taking an exclusive OR of the measurement pulse and the reference pulse, and counting means for counting the clock pulse during the period output by this logic means. By doing so, the measurement accuracy can be improved, the distance setting of the optical system is easy,
It is an object of the present invention to provide an optical displacement amount measuring device capable of correcting an error caused by a change in magnification of an optical system and less susceptible to contamination and crushing of a periodic pattern on a scale surface. In the eleventh aspect, the first predetermined value of the non-coincidence time is provided with the movement signal output means that is set to correspond to one bit of the driving clock of the image sensor, whereby the measurement accuracy can be improved. An object of the present invention is to provide an optical displacement amount measuring device in which the distance of an optical system can be easily set, an error caused by a change in magnification of the optical system can be corrected, and which is less susceptible to contamination and crushing of a periodic pattern on a scale surface. .

According to the twelfth aspect of the invention, by providing reference pulse switching means for switching the interval between the reference pulses in response to a signal from the outside, the resolution of the displacement measurement and the response speed can be switched. The purpose is to provide a device. In the thirteenth aspect, the first aspect outputs a speed alarm to the speed alarm display section when the disagreement time is equal to or more than a second predetermined value.
It is an object of the present invention to provide an optical displacement amount measuring device capable of notifying that the displacement amount and the displacement direction cannot be discriminated by providing the speed alarm output means. In the fourteenth aspect, each measurement pulse of the measurement pulse waveform corresponding to the periodic image pattern generated from the output of one scan of the image sensor and each measurement pulse of the measurement pulse waveform of the next scan rises or The size of each pixel unit of the image sensor at the time of falling is compared, and the absolute value of the difference between the large number and the small number in one scanning is larger than the first predetermined number determined from the number of measurement pulses. At this time, the measurement accuracy can be improved and the distance setting of the optical system can be easily performed by outputting the movement signal in pixel units and the movement direction signal obtained from the sign of the difference between the large number and the small number. Therefore, it is an object of the present invention to provide an optical displacement amount measuring method capable of correcting an error caused by a change in magnification of an optical system and less susceptible to contamination and crushing of a periodic pattern on a scale surface.

In the fifteenth aspect of the invention, the second storage means for storing the measurement pulse waveform output from the measurement pulse generation means, each measurement pulse of the measurement pulse waveform stored in the second storage means, and the next image sensor. Of each of the measurement pulse waveforms of one scan at the time of rising or falling of each pixel of the image sensor is compared, and the difference between the number of large pixels and the number of small pixels in one scanning is counted. The moving pulse counting means and the absolute value of the count value of the moving pulse counting means are compared with the first predetermined number, and when the absolute value of the count value of the moving pulse counting means is larger than the first predetermined number, the image sensor Moving amount determining means for outputting a moving signal in pixel units, moving direction determining means for determining the moving direction by the sign of the counting result of the moving pulse counting means, and measuring pulse counting hand for counting the measuring pulses. And the reference level setting means for calculating the first predetermined number from the counting result of the measurement pulse counting means and outputting it to the movement amount determining means, it is possible to improve the measurement accuracy and set the distance of the optical system. Is easy and can correct the error caused by the variation of the magnification of the optical system,
An object of the present invention is to provide an optical displacement measuring device which is less susceptible to dirt and crushing of a periodic pattern on the scale surface.

In the sixteenth aspect, at the time of rising or falling of each measurement pulse of the measurement pulse waveform stored in the second storage means and each measurement pulse of the measurement pulse waveform for one scan of the next image sensor. And a logic means for taking an exclusive OR in pixel units of, and a period output by this logic means,
By providing the moving pulse counting means including the up-down counter that counts the output from the logic means by using the output from the second storage means as the up-count signal or the down-count signal, the measurement accuracy can be improved. An object of the present invention is to provide an optical displacement amount measuring device in which the distance of an optical system can be easily set, an error caused by a change in magnification of the optical system can be corrected, and which is less susceptible to contamination and crushing of a periodic pattern on a scale surface. .

In the seventeenth aspect of the present invention, the count value of the moving pulse counting means is compared with the count value of the moving pulse counting means and the second predetermined number which is larger than the first predetermined number. When it is larger than the second predetermined number, a second speed alarm output means for outputting a speed alarm to the speed alarm display means, and a first predetermined number from the counting result of the measurement pulse counting means to calculate the movement amount judging means. And that the displacement amount and the displacement direction cannot be discriminated by providing a reference level setting means for outputting to the moving direction determination means and calculating a second predetermined number to output to the second speed alarm output means. It is an object of the present invention to provide an optical displacement measuring device that can be used. In the eighteenth aspect of the invention, a two-phase measurement pulse is generated from every other pixel-by-pixel output of the image sensor of the measurement pulse corresponding to the periodic video pattern by the output of the image sensor, and each of the two-phase measurement pulses is generated. By the method of measuring the movement amount and relative position of
Optical displacement measurement that can improve measurement accuracy, can easily set the distance of the optical system, can correct errors caused by fluctuations in the magnification of the optical system, and is not easily affected by dirt and crushing of the periodic pattern on the scale surface. The purpose is to provide a method.

In the nineteenth aspect of the invention, A-phase measurement pulse generating means and B-phase measurement pulse generating means for generating A- and B2-phase measurement pulses from the output of every other measurement pulse in pixel units of the image sensor; By providing the measuring pulse detecting means for each of the measuring pulses of the B2 phase, it is resistant to noise, the measuring accuracy can be improved, the distance of the optical system can be easily set, and the error caused by the variation of the magnification of the optical system can be eliminated. It is an object of the present invention to provide an optical displacement amount measuring device that can be corrected and is not easily affected by dirt and crushing of a periodic pattern on the scale surface. In the twentieth aspect of the present invention, the measurement pulse of the phase A is provided with a speed alarm display section and third and fourth speed alarm output means for outputting a speed alarm to the speed alarm display section when the disagreement time is equal to or more than the second predetermined value. An object of the present invention is to provide an optical displacement amount measuring device capable of notifying that a displacement amount and a displacement direction cannot be discriminated by providing a detection unit and a B-phase measurement pulse detection unit.

In the twenty-first aspect of the invention, the measurement pulse corresponding to the periodic video pattern generated from the output of the image sensor is sequentially input to the fourth shift register, and the measurement pulse has a center pulse of the same phase at the initial stage and the measurement pulse. A plurality of reference pulses of equal width and equal intervals are stored in the fifth shift register, and the disagreement time with the measurement pulse is sequentially counted for each reference pulse, and the mutual length of these timing results is compared and judged. Then, the mismatch time between the measurement pulse and the center pulse and its direction are determined based on this comparison result. When the mismatch time is equal to or more than the first predetermined value, the movement direction and the movement indicating the movement of the first predetermined value are performed. While outputting the signal, the measurement pulse stored in the fourth shift register is set as a new center pulse, and the reference pulse is stored again in the fifth shift register. The measurement pulse is sequentially input to the shift register of No. 4, and the disagreement time and the direction of the measurement pulse and the center pulse are sequentially determined by the above method, and the movement signal is sent every time the disagreement time becomes the first predetermined value or more. With the method of outputting the measurement pulse stored in the fourth shift register as a new center pulse and storing the reference pulse in the fifth shift register again, the measurement accuracy can be improved, and the measurement accuracy of the optical system can be improved. An object of the present invention is to provide an optical displacement amount measuring method in which a distance can be easily set, an error caused by a variation in magnification of an optical system can be corrected, and an influence of stains and crushing of a periodic pattern on a scale surface is less likely to occur.

In the twenty-second aspect of the invention, a fourth shift register for sequentially inputting the measurement pulses generated by the measurement pulse generating means, and a center pulse having an equal phase in the initial stage with the measurement pulse and having an equal interval with the measurement pulse. A fifth shift register for storing a plurality of reference pulses, a plurality of first time measuring means for sequentially measuring a mismatch time with the measurement pulse for each reference pulse, and a mutual measurement result of the first time measuring means. Of the measurement pulse and the center pulse based on the result of the comparison, and when the non-coincidence time is greater than or equal to a first predetermined value, the moving direction is determined. And a movement signal output means for outputting a movement signal indicating the movement of the first predetermined value, and when the disagreement time is the first predetermined value or more, the measurement pulse stored in the fourth shift register By providing the first capturing means for capturing the center pulse into the fifth shift register, the measurement accuracy can be improved, the distance of the optical system can be easily set, and the error caused by the variation of the magnification of the optical system can be improved. It is an object of the present invention to provide an optical displacement amount measuring device capable of compensating for the above, and being hardly affected by dirt and crushing of a periodic pattern on the scale surface.

According to the twenty-third aspect of the invention, there is provided the first clocking means having a logic means for obtaining an exclusive OR of the measurement pulse and the reference pulse, and a counting means for counting the clock pulse during the period output by the logic means. By this, the measurement accuracy can be improved, the distance of the optical system can be easily set, the error caused by the magnification change of the optical system can be corrected, and the optical displacement that is not easily affected by the dirt and crushing of the periodic pattern on the scale surface. An object is to provide a quantity measuring device. In the twenty-fourth aspect of the present invention, the first predetermined value of the non-coincidence time can be improved in measurement accuracy by providing the movement signal output means corresponding to one bit of the driving clock of the image sensor, and the distance setting of the optical system can be performed. An object of the present invention is to provide an optical displacement amount measuring device which is easy to correct an error caused by a change in magnification of an optical system, and is not easily affected by dirt and crushing of a periodic pattern on a scale surface.

In the twenty-fifth aspect of the present invention, by providing a reference pulse switching means for receiving a signal from the outside and switching the interval between the reference pulses, the optical displacement amount measurement capable of switching the resolution and the response speed of the displacement amount measurement. The purpose is to provide a device. In the twenty-sixth aspect, the first aspect outputs a speed alarm to the speed alarm display section when the disagreement time is equal to or more than a second predetermined value.
It is an object of the present invention to provide an optical displacement amount measuring device capable of notifying that the displacement amount and the displacement direction cannot be discriminated by providing the speed alarm output means. In the twenty-seventh invention, a sixth shift register which has a central pulse having an equal phase in the initial stage with the measurement pulse and which stores a plurality of first reference pulses having an equal width and the same width as the measurement pulse, and a first shift register sequentially. A plurality of second time measuring means for measuring the non-coincidence time with the measurement pulse for each reference pulse, and a second comparison / determination means for comparing and judging the mutual length of each time measurement result of the second time measuring means,
When the mismatch time between the measurement pulse and the center pulse and its direction are determined based on the result of this comparison, and the phase of the measurement pulse moves by a substantially predetermined cycle, and the mismatch time becomes equal to or less than the first predetermined value, Periodic signal output means for outputting a periodic signal, and second capturing means for receiving the periodic signal and capturing the measurement pulse stored in the fourth shift register as a new center pulse in the sixth shift register are provided. Accordingly, it is an object of the present invention to provide an optical displacement amount measuring device capable of correcting an error caused by a change in magnification of an optical system.

[0021]

According to a first aspect of the present invention, there is provided a method for measuring an optical displacement amount, wherein a portion having two kinds of optical characteristics is projected on a scale in which portions are alternately arranged periodically to form a periodic image pattern. Is generated to cause the periodic image pattern to be received by at least a one-dimensional image sensor, and from the change in the periodic image pattern received by the image sensor, the relative displacement and relative amount between the scale and the image sensor. In the optical displacement amount measuring method for determining the dynamic displacement direction, the magnitudes of the outputs of adjacent pixel units of the image sensor are compared, and the measurement pulse corresponding to the periodic image pattern is based on the time point when the magnitude relationship is reversed. And a relative displacement amount between the scale and the image sensor according to a movement amount and a movement direction of the measurement pulse in pixel units of the image sensor. And judging the relative displacement direction.

The optical displacement measuring method according to the second invention is
It is characterized in that the pair of adjacent pixel-based outputs for comparing the magnitudes is either an odd-numbered / even-numbered pair or an even-numbered / odd-numbered pair.

An optical displacement amount measuring device according to the third invention is
A scale in which portions having two kinds of optical characteristics are alternately arranged periodically, an optical system for projecting light onto the scale to generate a periodic image pattern, and at least a one-dimensional structure for receiving the periodic image pattern From the image sensor and the change in the periodic image pattern received by the image sensor,
In an optical displacement amount measuring device for determining a relative displacement amount and a relative displacement direction between the scale and the image sensor, comparing means for comparing the magnitudes of outputs of adjacent pixel units of the image sensor, and the 1 comparison. Measuring pulse generating means having first measuring pulse generating means for generating a measuring pulse corresponding to the periodic image pattern based on a time point at which the magnitude relationship of the output of the pixel unit by the means is reversed, and the measuring pulse generating means. A measurement pulse detection unit that determines the position of each pixel of the image sensor, and a relative displacement amount and a relative displacement direction between the scale and the image sensor are determined based on a change with time of a determination result of the measurement pulse detection unit. It is characterized by comprising a displacement amount determining means and a displacement direction determining means.

An optical displacement measuring device according to the fourth invention is
The comparing means may include a first gate that passes an output of an odd-numbered pixel output from the image sensor, a second gate that passes an output of an even-numbered pixel, a first gate and a second gate. An input comparing means for comparing inputs from the gate, and a third comparing element for selectively passing only an odd-numbered / even-numbered or even-numbered / odd-numbered comparison result of comparison result outputs of the input comparison means. Gate, first, second,
And a gate control unit for controlling each third gate.

An optical displacement amount measuring method according to the fifth invention is
The portions having two kinds of optical characteristics are projected onto a scale in which the portions are alternately arranged periodically to generate a periodic image pattern, and the periodic image pattern is received by at least a one-dimensional image sensor. In an optical displacement amount measuring method for determining a relative displacement amount and a relative displacement direction between the scale and the image sensor based on a change in the periodic image pattern received by the image sensor, one scan of the image sensor. The waveform of the measurement pulse corresponding to the periodic video pattern generated from the output is stored, and when the measurement pulse is generated from the output for the next scan, the waveform is stored in synchronization with the pixel unit of the image sensor. The measurement pulse is generated by applying feedback according to the waveform of the measurement pulse for the previous scan, and the movement amount of the measurement pulse in pixel units of the image sensor. The fine movement direction, and judging the relative displacement and relative direction of displacement between the image sensor and the scale.

An optical displacement measuring device according to the sixth invention is
The measurement pulse generation means stores first a waveform of a measurement pulse corresponding to the periodic image pattern generated from the output of one scan of the image sensor,
Second measurement pulse generation means for generating a measurement pulse for one scan by applying feedback according to the waveform of the measurement pulse for the previous scan stored in the first storage means in synchronization with the pixel unit of the image sensor. And is provided.

An optical displacement amount measuring device according to the seventh invention is
The first storage means is a first shift register having a capacity equal to the number of pixels for one scan of the image sensor, and the second measurement pulse generation means compares and inputs the output from the image sensor. The comparator is characterized by being fed back to the reference input terminal by the output of the first shift register.

An optical displacement amount measuring method according to the eighth invention is
The portions having two kinds of optical characteristics are projected onto a scale in which the portions are alternately arranged periodically to generate a periodic image pattern, and the periodic image pattern is received by at least a one-dimensional image sensor. In an optical displacement amount measuring method for determining a relative displacement amount and a relative displacement direction between the scale and the image sensor from a change in the periodic image pattern received by the image sensor, it is generated from the output of the image sensor. Measuring pulses corresponding to the periodic image pattern are sequentially input to a second shift register,
The measurement pulse and a plurality of reference pulses having an equal phase center pulse in the initial stage and having the same width as the measurement pulse are equally spaced.
Stored in the shift register, sequentially measures the non-match time with the measurement pulse for each of the reference pulses, compares and judges the mutual length of these timing results, and the measurement pulse and the central pulse are compared by this comparison result. And the direction of the disagreement are determined. When the disagreement time is equal to or greater than the first predetermined value, a movement signal indicating the movement direction and the movement of the first predetermined value is output and the second shift register The reference pulse is stored in the second shift register by using the measurement pulse stored in the second shift register as a new center pulse, and thereafter, the measurement pulse is sequentially input to the third shift register, and the measurement pulse is sequentially obtained by the above method. The time of disagreement with the center pulse and its direction are determined, and the movement signal is output each time the time of the disagreement becomes equal to or more than a first predetermined value, and the second and third shifts are performed. Repeated alternation of registers, and judging the relative displacement and relative direction of displacement between the image sensor and the scale.

An optical displacement amount measuring device according to the ninth invention is
The measurement pulse detection means has a second or third shift register for sequentially inputting the measurement pulses generated by the measurement pulse generation means, a center pulse having an equal phase in the initial stage with the measurement pulse, and having the same width as the measurement pulse. A third or second shift register for storing a plurality of reference pulses at even intervals, a plurality of first time measuring means for sequentially measuring a mismatch time with the measurement pulse for each of the reference pulses, and a first time measuring means A first comparison / determination means for comparing and judging the mutual length of each time measurement result of the means, and a mismatch time and a direction of the measurement pulse and the central pulse are judged based on the comparison result, and the mismatch time is a first predetermined time. When it is equal to or more than the value, movement signal output means for outputting a movement signal indicating the movement direction and movement of the first predetermined value, and when the disagreement time is equal to or more than the first predetermined value,
The reference pulse is stored in the second or third shift register using the measurement pulse stored in the second shift register as a new center pulse, and thereafter the measurement pulse is sequentially input to the third or second shift register. A switching signal output means for outputting a signal for switching as described above and a switching means for receiving the switching signal and performing the above switching are provided.

In the optical displacement amount measuring device according to the tenth aspect of the present invention, the first clocking means has a logic means for obtaining an exclusive OR of the measurement pulse and the reference pulse, and a period output by the logic means, Counting means for counting the clock pulses.

An optical displacement amount measuring device according to an eleventh aspect of the invention is characterized in that the first predetermined value of the non-coincidence time corresponds to one bit of a drive clock of the image sensor.

In the optical displacement amount measuring device according to the twelfth aspect of the invention, the measurement pulse detecting means is provided with a reference pulse switching means for receiving a signal from the outside and switching the interval between the reference pulses. .

An optical displacement amount measuring device according to a thirteenth aspect of the present invention includes a speed alarm display section, and the measurement pulse detecting means displays the speed alarm display section when the disagreement time is a second predetermined value or more. It is characterized by comprising a first speed alarm output means for outputting a speed alarm.

In the optical displacement amount measuring method according to the fourteenth aspect of the invention, a portion having two kinds of optical characteristics is projected onto a scale in which portions are alternately arranged periodically to generate a periodic image pattern, Optical displacement amount measurement in which at least a one-dimensional image sensor receives a periodic image pattern, and a relative amount of displacement between the scale and the image sensor is determined from a change in the periodic image pattern received by the image sensor. In the method, at the time of rising of each measurement pulse of the measurement pulse waveform corresponding to the periodic image pattern generated from the output of one scan of the image sensor and each measurement pulse of the measurement pulse waveform of the next scan, or At the time of falling, the size of the pixel unit of the image sensor is compared, and the absolute value of the difference between the large number and the small number in one scanning is measured. Is greater than the first predetermined number determined from the number of pixels, a movement signal in the pixel unit and a movement direction signal obtained from the sign of the difference between the large number and the small number are output to output the image sensor Depending on the amount of movement in pixel units,
The relative displacement amount between the scale and the image sensor is determined.

In the optical displacement measuring device according to the fifteenth aspect of the present invention, the measuring pulse detecting means has second storing means for storing the measuring pulse waveform output from the measuring pulse generating means, and second storing means. Comparing the measured pulse waveforms stored in the measurement pulse waveform and the measured pulse waveforms for one scan of the image sensor of the next scanning pulse at the time of rising or falling in pixel units of the image sensor, The moving pulse counting means for counting the difference between the large number and the small number in one scanning is compared with the absolute value of the count value of the moving pulse counting means and the first predetermined number to count the moving pulse. A movement amount determining means for outputting a movement signal in pixel units of the image sensor when the absolute value of the count value of the means is larger than a first predetermined number, and a sign of the counting result of the moving pulse counting means. Moving direction judging means for judging the moving direction, measuring pulse counting means for counting the measuring pulses, and a reference level for calculating a first predetermined number from the counting result of the measuring pulse counting means and outputting it to the moving amount judging means. And a setting means.

In the optical displacement amount measuring device according to the sixteenth aspect of the present invention, the moving pulse counting means includes each measurement pulse of the measurement pulse waveform stored in the second storage means and one scan of the next image sensor. Logic means for taking an exclusive OR of pixel units at the time of rising or falling with each measurement pulse of the measurement pulse waveform, and a period output by the logic means,
An up-down counter for counting the output from the logic means by using the output from the second storage means as an up-count signal or a down-count signal.

An optical displacement amount measuring device according to a seventeenth aspect of the present invention includes speed alarm display means, and displays the count value of the moving pulse counting means and a second predetermined number which is larger than the first predetermined number. In comparison, when the count value of the moving pulse counting means is larger than a second predetermined number, a second speed alarm output means for outputting a speed alarm to the speed alarm display means is provided, and the reference level setting means, A first predetermined number is calculated from the counting result of the measurement pulse counting means and output to the movement amount determination means and the movement direction determination means, and a second predetermined number is calculated to the second speed alarm output means. It is characterized by outputting.

An optical displacement amount measuring method according to the eighteenth aspect of the invention is to project a periodic image pattern by projecting light onto a scale in which portions having two kinds of optical characteristics are alternately arranged periodically. Optical displacement amount measurement in which at least a one-dimensional image sensor receives a periodic image pattern, and a relative amount of displacement between the scale and the image sensor is determined from a change in the periodic image pattern received by the image sensor. In the method, a two-phase measurement pulse is generated from every other pixel-by-pixel output of the image sensor of the measurement pulse corresponding to the periodic image pattern by the output of the image sensor. It is characterized in that the relative displacement amount between the scale and the image sensor is determined from the respective movement amounts and relative positions.

An optical displacement amount measuring apparatus according to a nineteenth aspect of the present invention is an A-phase measurement pulse generating means for generating A- and B2-phase measurement pulses from the output of every other measurement pulse in pixel units of the image sensor, and The measurement pulse generation means has a B-phase measurement pulse generation means, and the measurement pulse detection means is provided for each of the A and B2-phase measurement pulses.

An optical displacement amount measuring device according to a twentieth aspect of the present invention includes a speed alarm display section, and the A-phase measurement pulse detecting means and the B-phase measurement pulse detecting means have the second predetermined time. It is characterized by further comprising third and fourth speed alarm output means for outputting a speed alarm to the speed alarm display section when the value is equal to or more than the value.

An optical displacement amount measuring method according to a twenty-first aspect of the invention is to project a periodic image pattern by projecting light on a scale in which portions having two kinds of optical characteristics are alternately arranged periodically. At least a one-dimensional image sensor receives a periodic image pattern, and a relative displacement amount and a relative displacement direction between the scale and the image sensor are determined from a change in the periodic image pattern received by the image sensor. In the optical displacement amount measuring method, a measurement pulse corresponding to the periodic image pattern generated from the output of the image sensor is sequentially input to a fourth shift register, and a measurement pulse and a center pulse having an equal phase in the initial stage are measured. A plurality of reference pulses having the same width as the pulse and having equal intervals are stored in the fifth shift register, and the measurement pulse is sequentially measured for each reference pulse. The time of disagreement with is measured, and the mutual length of these timing results is compared and determined, and the time of disagreement between the measurement pulse and the central pulse and its direction are determined by this comparison result. When it is equal to or more than the predetermined value, a movement signal indicating the movement direction and movement of the first predetermined value is output, and the reference pulse is set as the new center pulse using the measurement pulse stored in the fourth shift register. Stored again in the fifth shift register,
The measurement pulse is sequentially input to the fourth shift register, the mismatch time and the direction of the measurement pulse and the center pulse are sequentially determined by the method, and each time the mismatch time becomes equal to or more than a first predetermined value, While outputting the movement signal,
Using the measurement pulse stored in the fourth shift register as a new center pulse, the reference pulse is stored again in the fifth shift register, and the relative displacement amount and the relative amount between the scale and the image sensor are stored. The feature is that the displacement direction is determined.

In the optical displacement measuring device according to the twenty-second aspect of the invention, the measuring pulse detecting means has a fourth shift register for sequentially inputting the measuring pulses generated by the measuring pulse generating means, the measuring pulse and the initial stage, etc. A fifth shift register having a central pulse of phase and storing a plurality of reference pulses at equal intervals and having the same width as the measurement pulse, and a plurality of first shift registers for sequentially measuring the disagreement time with the measurement pulse for each reference pulse No. 1 time-measurement means, first comparison-judgment means for comparing and judging the mutual length of each time-measurement result of the first time-measurement means, and the non-coincidence time of the measurement pulse and the central pulse and its direction are judged by this comparison result If the disagreement time is greater than or equal to the first predetermined value, a movement signal output unit that outputs a movement signal indicating the movement direction and movement of the predetermined value, and the disagreement time is greater than or equal to the first predetermined value. When it is characterized by comprising a first capture means for capturing the fifth shift register a measurement pulse which is stored in the fourth shift register as a new central pulse.

In the optical displacement amount measuring device according to the twenty-third aspect of the present invention, the first clocking means has a logic means for obtaining an exclusive OR of the measurement pulse and the reference pulse, and a period output by the logic means. Counting means for counting the clock pulses.

The optical displacement amount measuring device according to the twenty-fourth aspect of the invention is characterized in that the first predetermined value of the non-coincidence time corresponds to one bit of the drive clock of the image sensor.

In the optical displacement amount measuring device according to the twenty-fifth aspect of the present invention, the measurement pulse detecting means is provided with a reference pulse switching means for receiving a signal from the outside and switching the interval between the reference pulses. .

An optical displacement amount measuring device according to a twenty-sixth aspect of the present invention includes a speed alarm display section, and the measurement pulse detecting means displays the speed alarm display section when the disagreement time is a second predetermined value or more. It is characterized by comprising a first speed alarm output means for outputting a speed alarm.

In the optical displacement amount measuring device according to the twenty-seventh aspect of the present invention, the measurement pulse detection means has a plurality of first pulses having a center pulse having an equal phase in the initial stage with the measurement pulse and having the same width as the measurement pulse. A sixth shift register for storing the reference pulse of, and a plurality of second time counting means for sequentially measuring the mismatch time with the measurement pulse for each first reference pulse,
Second comparison and determination means for comparing and determining the mutual lengths of the respective timing results of the second timing means, and the mismatch time between the measurement pulse and the central pulse and the direction thereof are determined based on this comparison result. The phase of moves about a predetermined period,
When the disagreement time becomes equal to or less than the first predetermined value, the periodic signal output means for outputting the periodic signal and the measurement pulse stored in the fourth shift register for receiving the periodic signal as a new center. It is characterized in that it is provided with a second fetching means for fetching into the sixth shift register as a pulse.

[0048]

In the optical displacement amount measuring method according to the first aspect of the invention, the time point at which the magnitude relationship between the outputs of adjacent pixel units of the image sensor is reversed is regarded as the rising time point or the falling time point of the pulse and corresponds to the periodic image pattern. Generate a measurement pulse.

In the optical displacement amount measuring method according to the second aspect of the present invention, the group of adjacent pixel-by-pixel outputs whose magnitude is compared is limited to either an odd / even group or an even / odd group. By doing so, a stable measurement pulse is generated.

In the optical displacement amount measuring device according to the third aspect of the invention, the first comparing means compares the magnitudes of the outputs of adjacent pixel units of the image sensor, and the pulse rises at the time when the magnitude relation of the outputs is reversed. As the time point or the falling time point, the first measurement pulse generating means generates the measurement pulse corresponding to the periodic image pattern.

In the optical displacement measuring device according to the fourth aspect of the present invention, the first gate passes the output of the odd-numbered pixel output from the image sensor, and the second gate passes the output of the even-numbered pixel. Then, the input comparing means compares the inputs from the first gate and the second gate. Then, the third gate selectively passes only one of the odd / even-numbered and even / odd-numbered comparison results of the comparison result outputs of the input comparison means.

In the optical displacement amount measuring method according to the fifth aspect of the invention, when the measurement pulse is generated from the output of one scan of the image sensor, the measurement pulse of the previous scan is synchronized with the pixel unit of the image sensor. Apply feedback by waveform,
A stable measurement pulse with small fluctuation is generated.

In the optical displacement measuring device according to the sixth aspect of the present invention, the first storage means stores the waveform of the measurement pulse corresponding to the periodic video pattern generated from the output of one scan of the image sensor, In synchronism with the pixel unit of the sensor, the second measurement pulse generating means generates a measurement pulse for one scanning by feeding back the waveform of the measurement pulse for the previous scanning stored in the first storage means. To do.

In the optical displacement measuring device according to the seventh aspect of the invention, the first shift register stores the waveform of the measuring pulse corresponding to the periodic image pattern generated from the output of one scan of the image sensor, and the comparator The output from the image sensor is used as a comparison input, and the reference input terminal is fed back by the output of the first shift register.

In the optical displacement amount measuring method according to the eighth aspect of the present invention, the measurement pulse corresponding to the periodic image pattern generated from the output of the image sensor, the measurement pulse having the central pulse of the same phase at the initial stage with the measurement pulse, etc. The time of non-coincidence with a plurality of reference pulses having equal widths is measured. These disagreement times differ for each measurement pulse, and their mutual length relationship is uniquely determined by the disagreement time between the measurement pulse and the center pulse and its direction. The discrepancy time between the measurement pulse and the center pulse and its direction are determined by. And
When the disagreement time is equal to or longer than the first predetermined value, the movement signal indicating the movement direction and the movement of the first predetermined value is output, and the measurement pulse stored in the second shift register is newly updated. The reference pulse is stored in the second shift register as the center pulse. After that, the measurement pulse is sequentially input to the third shift register, and the disagreement time and the direction of the measurement pulse and the central pulse are sequentially determined by the same method as described above, and the disagreement time becomes the first predetermined value or more. Each time the movement signal is output, the alternation of the second and third shift registers is repeated.

In the optical displacement measuring device according to the ninth aspect of the invention, the second or third shift register sequentially inputs the measurement pulses generated by the measurement pulse generating means, and the third or second shift register receives the measurement pulse. In the initial stage, a plurality of reference pulses having an equal phase center pulse and having the same width as the measurement pulse are stored in advance, and the first timing means sequentially
The time of disagreement with the measurement pulse is measured for each reference pulse.
Then, the first comparison / determination means compares the respective timing results of the first timing means with each other, and determines the mismatch time between the measurement pulse and the center pulse based on the comparison result. When the disagreement time is equal to or longer than the first predetermined value, the movement signal output means outputs the movement signal indicating the movement direction and the movement of the first predetermined value. When the disagreement time is equal to or greater than the first predetermined value, the reference pulse is stored in the second or third shift register by using the measurement pulse stored in the second shift register as a new center pulse, and switching is performed. After that, the signal output means outputs a signal for switching so that the measurement pulses are sequentially input to the third or second shift register. Upon receiving this switching signal, the switching means performs the above switching.

In the optical displacement measuring device according to the tenth aspect of the invention, the logic means takes the exclusive OR of the measurement pulse and the reference pulse, and the counting means counts the clock pulses during the period when the logic means outputs.

In the optical displacement amount measuring device according to the eleventh aspect of the present invention, the first predetermined value of the mismatch time corresponds to one bit of the drive clock of the image sensor.

In the optical displacement amount measuring device according to the twelfth aspect of the invention, the reference pulse switching means switches the interval between the reference pulses in response to a signal from the outside to switch the resolution and response speed of the displacement amount measurement.

In the optical displacement measuring device according to the thirteenth aspect of the present invention, when the disagreement time is equal to or greater than the second predetermined value, the first speed alarm output means outputs a speed alarm to the speed alarm display section, thereby causing displacement. Notify the operator that the amount and displacement direction cannot be determined.

In the optical displacement amount measuring method according to the fourteenth aspect of the present invention, of the respective measuring pulses of the measuring pulse waveform corresponding to the periodical image pattern generated from the output of one scanning of the image sensor, in the next scanning amount. The number of measurement pulses displaced per pixel of the image sensor is counted inclusive of the direction, and the absolute value of the difference between the count values for different directions in one scan is the first predetermined number determined from the number of measurement pulses. When it is larger, the movement signal in pixel units and the movement direction signal obtained from the sign of the difference between the count values in different directions are output.

In the optical displacement measuring device according to the fifteenth aspect of the invention, the second storage means stores the measurement pulse waveform output from the measurement pulse generating means, and the moving pulse counting means is the second.
Of each of the measurement pulse waveforms stored in the storage means of the image sensor and each measurement pulse of the measurement pulse waveform of one scan of the next image sensor are compared in magnitude at the rising or falling edge of the image sensor in pixel units. The difference between the large number and the small number in one scanning is counted. And
The moving amount judging means compares the absolute value of the count value of the moving pulse counting means with the first predetermined number, and the moving direction judging means judges the moving direction by the sign of the counting result of the moving pulse counting means, and the moving pulse. The absolute value of the count value of the counting means is first
Is larger than a predetermined number, the moving signal indicating the pixel unit movement of the image sensor and its direction is output. The reference level setting means calculates a first predetermined number from the counting result of the measurement pulse counting means, and outputs it to the movement amount determining means.

In the optical displacement measuring device according to the 16th aspect of the invention, the logic means includes each measurement pulse of the measurement pulse waveform stored in the second storage means and the next one of the image sensor.
Take the exclusive OR of the pixel unit at the time of rising or falling with each measurement pulse of the measurement pulse waveform for scanning,
The up-down counter counts the output from the logic means by using the output from the second storage means as the up-count signal or the down-count signal during the period in which the logic means outputs.

In the optical displacement measuring device according to the seventeenth aspect of the invention, the reference level setting means calculates a first predetermined number from the counting result of the measurement pulse counting means and outputs it to the moving amount judging means and the moving direction judging means. At the same time, a second predetermined number, which is larger than the first predetermined number, is calculated and output to the second speed alarm output means. The second speed alarm output means compares the count value of the moving pulse counting means with a second predetermined number,
When the count value of the moving pulse counting means is larger than the second predetermined number, a speed alarm is output to the speed alarm display means.

In the optical displacement amount measuring method according to the eighteenth aspect of the invention, one of the measurement pulses corresponding to the periodic image pattern by the output of the image sensor is output for each pixel of the image sensor.
A measurement pulse of two phases is generated from every other output, and the movement amount and the movement direction of the measurement pulse are determined by measuring the movement amounts and relative positions of the measurement pulses of the two phases.

In the optical displacement measuring device according to the nineteenth aspect of the present invention, the A-phase measurement pulse generating means and the B-phase measurement pulse generating means output A, B2 phases from the output of every other measurement pulse in pixel units of the image sensor. Generates measurement pulse of A, B
Each measurement pulse detection means of the two-phase measurement pulse measures the moving amount and relative position of each measurement pulse.

In the optical displacement measuring device according to the twentieth aspect of the invention, the third and fourth velocity alarm output means have the second time when the measurement pulse of the A phase or the B phase does not match the central pulse of the reference pulse. When the value is equal to or more than a predetermined value, a speed alarm is output to the speed alarm display section.

In the optical displacement amount measuring method according to the twenty-first aspect of the invention, the measurement pulse corresponding to the periodic image pattern generated from the output of the image sensor, the measurement pulse having the central pulse of the same phase at the initial stage with the measurement pulse, etc. The time of non-coincidence with a plurality of reference pulses having equal widths is measured. These disagreement times differ for each measurement pulse, and their mutual length relationship is uniquely determined by the disagreement time between the measurement pulse and the center pulse and its direction. The discrepancy time between the measurement pulse and the center pulse and its direction are determined by. And
When the disagreement time is equal to or longer than the first predetermined value, the movement signal indicating the movement direction and the movement of the first predetermined value is output, and the measurement pulse stored in the fourth shift register is newly updated. As the center pulse, the reference pulse is stored again in the fifth shift register, and thereafter, the measurement pulse is sequentially input to the fourth shift register, and the mismatch time between the measurement pulse and the center pulse is sequentially determined by the above method, Every time the disagreement time becomes equal to or greater than the first predetermined value, a movement signal is output and the reference pulse is stored in the fifth shift register while using the measurement pulse stored in the fourth shift register as a new center pulse. Do it again.

In the optical displacement measuring apparatus according to the twenty-second aspect of the invention, the fourth shift register sequentially inputs the measurement pulses generated by the measurement pulse generating means, and the fifth shift register causes the measurement pulse to have the same phase at the initial stage. A plurality of reference pulses having a center pulse of, and equally spaced as the measurement pulse are stored. Then, the first time measuring means sequentially measures the non-coincidence time with the measurement pulse for each reference pulse, and the first comparing and judging means compares and judges the mutual length of each time measuring result of the first time measuring means. The movement signal output means determines the disagreement time and the direction of the measurement pulse and the center pulse based on the comparison result. When the disagreement time is equal to or more than the first predetermined value, the movement direction and the movement of the first predetermined value are moved. A movement signal indicating is output. When the disagreement time is equal to or larger than the first predetermined value, the first capturing means captures the measurement pulse stored in the fourth shift register as a new center pulse in the fifth shift register.

In the optical displacement measuring device according to the twenty-third aspect of the invention, the logic means takes the exclusive OR of the measurement pulse and the reference pulse, and the counting means counts the clock pulses during the period when the logic means outputs.

In the optical displacement amount measuring device according to the twenty-fourth invention, the first predetermined value of the mismatch time corresponds to one bit of the drive clock of the image sensor.

In the optical displacement amount measuring device according to the twenty-fifth aspect of the invention, the reference pulse switching means receives a signal from the outside and switches the interval between the reference pulses.

In the optical displacement amount measuring device according to the twenty-sixth aspect of the present invention, when the disagreement time is equal to or longer than the second predetermined value, the first speed alarm output means outputs a speed alarm to the speed alarm display section, whereby the displacement Notify the operator that the amount and displacement direction cannot be determined.

In the optical displacement amount measuring device according to the twenty-seventh aspect of the present invention, the sixth shift register has a plurality of first intervals which have center pulses of the same phase in the initial stage with the measurement pulse and have the same width as the measurement pulse. The reference pulse is stored in advance, and the plurality of second timing means sequentially measure the time of disagreement with the measurement pulse for each first reference pulse. The second comparison and determination means compares and determines the mutual lengths of the respective timing results of the second timing means, and the periodic signal output means determines the mismatch time and the direction of the measurement pulse and the center pulse based on this comparison result. Then, when the phase of the measurement pulse moves substantially by a predetermined period and the disagreement time becomes equal to or less than the first predetermined value, the periodic signal is output. The second capturing means receives the periodic signal, captures the measurement pulse stored in the fourth shift register as a new center pulse into the sixth shift register, and thereby, the optical system during the predetermined period. The error caused by the change in magnification of is corrected.

[0075]

Embodiments of an optical displacement amount measuring method and an optical displacement amount measuring device according to the present invention will be described below with reference to the accompanying drawings. FIG. 27 is a schematic diagram for explaining the principle of the optical displacement amount measuring method and the optical displacement amount measuring device. This optical displacement amount measuring device includes a scale 90 in which portions having two types of reflection coefficients and having the same length are alternately arranged in the displacement direction (left and right direction in the drawing), and an LED or the like which projects light to the scale 90. The light projecting element 91, a light projecting lens 92 which is installed between the light projecting element 91 and the scale 90 and narrows the light beam from the light projecting element 91, and the scale 9
The ray from the light projecting lens 92 is placed on the scale 9
A light receiving lens 93 for forming an image of the light beam reflected by 0,
At least one-dimensional CCD (Charge Cou is used for one-dimensional output in the case of two-dimensional) installed on the image plane.
pled Device) 94.

The light beam from the light projecting element 91 narrowed down by the light projecting lens 92 is reflected by the surface of the scale 90 and is imaged on the light receiving surface of the CCD 94 by the light receiving lens 93. On the surface of the scale 90, portions having two different reflection coefficients are alternately arranged periodically in the displacement direction (left and right direction in the figure), so that the image formation on the light receiving surface of the CCD 94 is performed by this reflection coefficient. It is a periodic pattern of bright and dark parts that is similar to the periodic pattern of. Scale 90
When moving to the right or left in the figure (scale 90
(When the optical system except for the above and the CCD 94 move leftward or rightward), the periodic pattern of the light and dark portions of the light receiving surface of the CCD 94 moves leftward or rightward. By measuring the amount of displacement on the CCD 94 light receiving surface of the periodic pattern of the bright and dark portions, the scale 90 (the object fixed to it), the optical system, and C
It is possible to determine the relative displacement amount and relative displacement direction with respect to (the object fixed to CD94).

FIG. 1 shows an optical displacement amount measuring method according to the first and second aspects of the invention and an optical displacement amount measuring apparatus according to the third and fourth aspects of the invention. FIG. 3 is a block diagram showing a configuration example of a processing determination unit that determines a relative displacement amount and a relative displacement direction of an object) and an optical system and the CCD 94 (an object fixed to the optical system). The clock generated by the clock generator 1 is the CCD 94
And the drive unit 2 for driving the light projecting element 91 (FIG. 27) and the measurement pulse detection means 4. The output from the CCD 94 is generated by the measurement pulse generating means 3 into a measurement pulse corresponding to the periodic pattern of the bright and dark portions of the light receiving surface of the CCD 94, and given to the measurement pulse detecting means 4. The measurement pulse detection means 4 determines the position (phase) of the measurement pulse, and the result is sent to the displacement amount displacement direction determination means 5. The displacement amount displacement direction determination means 5 determines the amount of change and the displacement direction based on the change over time in the position (phase) of the measurement pulse, and the result is sent to the single-phase pulse generation means 6. Depending on the determination result of the displacement amount, a speed alarm is output to the speed alarm display unit 8. The output of the single phase pulse generation means 6 is sent to the two phase pulse generation means 7 and is output as A and B phase pulses.

FIG. 2 is a block diagram showing the configuration of the measurement pulse generating means 3. The measurement pulse generation means 3 is a CCD
The odd-numbered control gate 10 that passes the odd-numbered pixel output, the even-numbered control gate 11 that passes the even-numbered pixel output, and the outputs of the odd-numbered control gate 10 and the even-numbered control gate 11 Respective integrating circuits R1 and C1 for integrating the
And a comparator 12 that compares the outputs of the even-numbered control gates 11, a comparison output control gate 13 that selectively passes the output of the comparator 12, and a comparison output control gate 1.
3, a measurement pulse generator 15 including a shift register for generating a measurement pulse, and a gate controller controlling the odd number control gate 10, the even number control gate 11, and the comparison output control gate 13. Has been done.

The operation of the measurement pulse generating means 3 having such a configuration will be described below. The output of the CCD 94 is shown in FIG.
It is as shown in (b). This output is shown in Figure 3.
As shown in (c), the odd-numbered pixel output is used by using the odd-numbered control gate 10 that passes the odd-numbered pixel output and the even-numbered control gate 11 that passes the even-numbered pixel output in the output order of the pixel unit. And an even-numbered pixel output, and the comparator 12 compares them. The comparator 12 outputs this comparison result as a positive / negative signal. Of the comparison results, the comparison output control gate 13 passes only the comparison result of either the odd / even number or the even / odd number, and inputs the result to the measurement pulse generating section 15. In the measurement pulse generator 15, as shown in FIG. 3A, the pulse rises at the positive / negative conversion point of the positive / negative signal from the comparison output control gate 13.
A measurement pulse is generated at the falling edge.

FIG. 4 shows an optical displacement amount measuring method according to the fifth invention and an optical displacement amount measuring apparatus according to the sixth and seventh inventions.
It is a circuit diagram showing the composition of the measurement pulse generation means of the example. The measurement pulse generating means according to the present invention is a CCD 94.
A comparator 21 for converting the output from the pulse waveform into a pulse waveform with a predetermined threshold voltage determined by resistors R4 and R3;
It has the same bit capacity as the number of pixels of the CCD 94 and is composed of a shift register 22 for storing the output from the comparator 21. It is hung.

The operation of the measurement pulse generating means having such a configuration will be described below. The shift register 22 is shown in FIG.
From the output for one scan of the CCD 94 as shown in (a),
The waveform of the measurement pulse as shown in FIG. 5B corresponding to the periodic image pattern generated by the comparator 21 is stored. The output of one scan of CCD94 this time is shown in FIG.
Waveform as shown in (c) (compared to the previous scan, CCD
The output of 94 is decreasing. ), When the feedback by the resistor R2 is not applied, the comparator 21 generates a measurement pulse as shown in FIG. 5D (the width is narrower than that of the previous scan).

As in the present invention, by the clock CLK,
When the output of the shift register 22 is fed back to the threshold voltage side terminal of the comparator 21 via the resistor R2 in synchronization with the pixel unit of the CCD 94 (the pixel address for the current scan and the pixel address for the previous scan are combined), Is induced (or pulled down) by being induced by the waveform of the measurement pulse for the previous scan, and as shown in FIG. 5E, a measurement pulse close to the waveform of the measurement pulse for the previous scan (FIG. 5B) is generated. Is generated. This measurement pulse is output to the measurement pulse detection means and at the same time, input to the shift register 22 and used for feedback of the next scan. Other configurations and operations of the optical displacement amount measuring method according to the fifth invention and the optical displacement amount measuring device according to the sixth and seventh inventions are the optical displacement amount measuring method according to the first and second inventions and the third and third aspects. Since the configuration and the operation of the optical displacement amount measuring device according to the invention are the same as those of the fourth invention, description thereof will be omitted.

FIG. 6 is a block diagram showing the construction of a measuring pulse detecting means of one embodiment of the optical displacement amount measuring method according to the eighth invention and the optical displacement amount measuring devices according to the ninth to eleventh inventions. The measuring pulse detecting means according to the present invention is a CCD 9
The same shift register 31 and shift register 32 having the same bit capacity as the number of pixels of 4 (FIG. 1) and the measurement pulse from the measurement pulse generating means 3 are transferred to the shift register 3
1 or switching means 30 for switching and inputting to the shift register 32, shift register 31 and shift register 3
Each of 2 to 5 is composed of a bit comparison section 33 to which five output lines shifted by 1 bit are connected, and the bit comparison section 33 is connected to the switching means 30 by a moving output line.

The operation of the measuring pulse detecting means having such a configuration will be described below. The shift register 31 or the shift register 32 is generated by the measurement pulse generation means 3 in FIG.
Measurement pulses as shown in (b) are sequentially input. on the other hand,
The shift register 32 or the shift register 31 has a center pulse (0) (in FIG.
(E)) a plurality of reference pulses (+2), (+1), which have the same width as the measurement pulse and are equally spaced (one bit interval),
(0), (-1), (-2) (FIGS. 8C to 8G) are stored. In the bit comparison unit 33, the mismatch time with the measurement pulse (hatched portion in FIG. 8) is sequentially counted for each reference pulse by counting the drive clock (FIG. 8A) of the CCD 94 (FIG. 1). These count values are represented as a monogram in FIG. In the monogram of FIG. 9, the horizontal axis represents the measurement pulse and the reference pulse (+2), (+1), (0), (−1), when the rising position of the central pulse (0) of the reference pulse is 0. The relative position of the driving clock of the CCD 94 (FIG. 1) at each rising edge of (-2) is represented, and the vertical axis represents the disagreement time between the reference pulse and the measurement pulse by the number of clocks.

For example, the number of clocks representing the disagreement time of the reference pulse (+1) with the measurement pulse changes like a bold line depending on the relative position of the rising edge of the measurement pulse to the rising edge of the central pulse (0). For example, in the case of FIG. 8, the position of the reference pulse (+1) with the smallest number of clocks is the position of the measurement pulse (when they match, the number of clocks becomes 0), and the measurement pulse of the center pulse (0) at that time The number of clocks representing the disagreement time with is represented by point p in FIG. These disagreement times differ for each measurement pulse, and their mutual magnitude relationship is represented by the vertical relationship of the diagonal lines in FIG. 9, and since the disagreement time between the measurement pulse and the center pulse and its direction are uniquely determined, their mutual relationship is determined. The magnitude relation is compared and determined, and the mismatch time between the measurement pulse and the center pulse and the direction thereof are determined based on the comparison result. When the measurement pulse (FIG. 8 (b)) and the center pulse (FIG. 8 (e)) do not coincide with each other and the direction is 1 bit or −1 bit, the bit comparison unit 33 moves the moving direction and 1 bit. Is output to the displacement amount displacement direction determination means 5 (FIG. 1) and the switching means 30.

Receiving the movement signal, the switching means 30 switches the connection between the measurement pulse generating means 3 and the shift register 31 and the shift register 32, and newly changes the measurement pulse stored in the shift register 31 and the shift register 32. The reference pulse is stored in the shift register 31 or the shift register 32 as the central pulse. After that, the shift register 32 or the shift register 31 sequentially inputs the measurement pulses generated by the measurement pulse generation means 3, while
The shift register 31 or the shift register 32 stores the reference pulse, and the bit comparison unit 33 sequentially counts the mismatch time with the measurement pulse for each reference pulse in the same manner as described above, and the bit comparison unit 33 performs the measurement. Mismatch time between pulse and center pulse and its direction is 1 bit or -1
Whenever a bit is reached, a movement signal indicating the movement direction and 1-bit movement is output to the displacement amount displacement direction determination means 5 (FIG. 1) and the switching means 30.

The switching means 30 receives the movement signal and switches the connection between the measurement pulse generating means 3 and the shift register 31 and the shift register 32. The displacement amount displacement direction determination means 5 receives the movement signal and determines the displacement amount and displacement direction of the measurement pulse. The bit comparison unit 33 indicates to the speed alarm display unit 8 (FIG. 1) the displacement amount displacement direction determination means 5 (when the mismatch time between the measurement pulse and the center pulse and the direction thereof exceed, for example, 2 bits or −2 bits. A speed alarm is output via (Fig. 1).

FIG. 7 is a block diagram showing a detailed structure of the bit comparison unit 33. Measurement pulse and each reference pulse (+
2), (+1), (0), (-1), and (-2) are input to the exclusive OR circuits 34 to 38, respectively, and these exclusive ORs are for matching the timings. Are converted into clocks CLK by the flip-flops 34a to 38a, and these clocks CLK are logical product circuits 34b to 3b.
Clock CL inverted by the inverter 39 by 8b
After being logically ANDed with K, it is counted by the counters 34c to 38c.

These count values are set for each pair of adjacent reference pulses (+2), (+1), (0), (-1), (-2) (counters 34c / 35c, 35c / 36).
c, 37c / 36c, 38c / 37c) are input to the A / B terminals of the comparators 40 to 43. Regarding the comparison results of the comparators 40 to 43, the inverted output of the comparator 40 and the output of the comparator 41 are input to the logical product circuit 45, and the output of the comparator 42 and the inverted output of the comparator 43 are input to the logical product circuit 46. The logical product circuit 45 outputs a movement output in the (+) direction, and the logical product circuit 46 outputs a movement output in the (−) direction. The outputs of both are logically ORed by the logical sum circuit 47 and sent to the switching means 30. It is output as a switching signal. The OR circuit 47 may be provided inside the switching means 30. Comparators 40 and 43
The output of is logically ORed by the logical sum circuit 48 and output as a speed alarm.

The operation of the bit comparison unit 33 having such a configuration will be described below. Measurement pulse and each reference pulse (+
2), (+1), (0), (-1), and (-2) are input to exclusive OR circuits 34 to 38, respectively, and these exclusive ORs are flip-flops 34a to 38a and The logical product circuits 34b to 38b convert the clock CLK and the counters 34c to 38c count it. These count values correspond to the corresponding reference pulses (+2), (+1),
For each set (0), (-1), (-2) next to each other (counters 34c / 35c, 35c / 36c, 36c / 37c, 3
7c / 38c), and is input to the comparators 40 to 43.

The comparators 40 to 43 detect the vertical relationship of the diagonal lines in FIG. 9, and for example, the measurement pulse is +
When it is near 1.2, counters 34c> 35c, 35
c <36c, 36c <37c, 37c <38c,
When the output of the comparator when the input from the counter is A <B is “1”, the input to the AND circuit 45 is “1”, “1”, the input to the AND circuit 46 is “0”,
The logical product circuit 45 outputs a movement output in the (+) direction, and the logical sum circuit 47 outputs a switching signal. When the measurement pulse is near -1.2, the counters 34c> 35c, 35c> 36c, 36
c> 37c, 37c <38c, the inputs to the logical product circuit 45 are "0" and "0", the inputs to the logical product circuit 46 are "1" and "1", and the logical product circuit 46 outputs (- ) Movement output is output, and a switching signal is output from the OR circuit 47.

When the measurement pulse is near -0.3, the counters 34c> 35c, 35c> 36c, 36c <37.
c, 37c <38c, the inputs to the AND circuit 45 are "0" and "0", the inputs to the AND circuit 46 are "0",
Since it becomes "0", no movement output is output from the AND circuits 45 and 46, and no switching signal is output from the OR circuit 47. When the measurement pulse is around +1.8, the counters 34c <35c, 35c <36c, 36c <37
c, 37c <38c, the inputs to the AND circuit 45 are "0" and "1", the inputs to the AND circuit 46 are "0",
It becomes "0", the movement output is not output from the AND circuits 45 and 46, and the switching signal is not output from the OR circuit 47, but "1" is output from the comparator 40.
A speed alarm is output from the OR circuit 47.

When the measurement pulse is in the vicinity of -1.8, counters 34c> 35c, 35c> 36c, 36c> 37.
c, 37c> 38c, the inputs to the AND circuit 45 are "1" and "0", the inputs to the AND circuit 46 are "1",
The logical product circuits 45 and 46 do not output a movement output, and the logical sum circuit 47 does not output a switching signal, but the comparator 43 outputs "1".
A speed alarm is output from the OR circuit 47. Figure 10
Steps S1 to S36 are a flow chart when the above-described operation is executed by the microcomputer. Optical displacement amount measuring method according to eighth invention and ninth to first
Another configuration and operation of the optical displacement amount measuring device according to the first invention are the optical displacement amount measuring method according to the first and second inventions and the configuration and operation of the optical displacement amount measuring device according to the third and fourth inventions. The description is omitted because it is the same.

FIG. 11 is a block diagram showing the configuration of the measurement pulse detecting means of one embodiment of the optical displacement amount measuring device according to the twelfth and thirteenth inventions. In the measurement pulse detecting means according to the present invention, an external switching signal is connected to the bit comparing section 33a, and the shift register 31 and the shift register 32 respectively output 2 bits, 1 bit, 1 bit, 1 bit, 2 bits.
The seven output lines shifted in the order of bits are the bit comparison unit 3
3a. FIG. 12 shows the bit comparison unit 33a.
3 is a block diagram showing a detailed configuration of FIG. The exclusive OR circuits 34, 35, 37 and 38 are connected to the input line of the measurement pulse and the output lines of the data selectors 49 to 52. Reference pulses (+4), (+2), (+1), (0), (-) which are shifted in the order of 2 bits, 1 bit, 1 bit, 1 bit, 2 bits from the center pulse of the reference pulse.
Of the input lines 1), (-2), and (-4), the reference pulse (+4) input line is the B input terminal of the data selector 49, and the reference pulse (+2) input line is the data selector 49.
To the A input terminal of and the B input terminal of the data selector 50,
The input line of the reference pulse (+1) is A of the data selector 50.
The input line of the reference pulse (-1) is the A input terminal of the data selector 51, the input line of the reference pulse (-2) is the B input terminal of the data selector 51 and the A input terminal of the data selector 52. The input lines of the reference pulse (-4) are connected to the B input terminals of the data selector 52, respectively.

The operation of the bit comparison unit 33a having such a configuration will be described below. When the external switching signal is input to the switching terminal X of each of the data selectors 49 to 52, each of the data selectors 49 to 52 selectively passes the reference pulse input to the A input terminal or the B input terminal. Therefore,
If the A input terminal is selected, the reference pulse (+2), (+
1), (0), (-1), and (-2) are bit comparison units 33.
If the B input terminal is selected by the input pulse a, the reference pulses (+4), (+2), (0), (-2), (-4) are input by the bit comparison unit 33a, and the reference pulse interval is changed. Can be switched from 1 bit to 2 bits, and the resolution and response speed of displacement amount measurement can be switched. Other configurations and operations of the optical displacement amount measuring device according to the twelfth invention are the optical displacement amount measuring method according to the eighth invention and the ninth to first aspects.
The configuration and operation of the optical displacement amount measuring device according to the first aspect of the invention are the same as those of the first aspect, so description thereof will be omitted.

FIG. 13 is a block diagram showing the structure of the measuring pulse detecting means of one embodiment of the optical displacement amount measuring method according to the fourteenth invention and the optical displacement amount measuring device according to the fifteenth and sixteenth inventions. The measurement pulse detection means is a shift register 55 that stores the measurement pulse waveform output from the measurement pulse generation means 3, each measurement pulse of the measurement pulse waveform stored in the shift register 55, and the next CCD 94 (FIG. 1).
Of each of the measurement pulse waveforms for one scan at the time of rising or falling and comparing the size of the CCD 94 (FIG. 1) in pixel units, and the difference between the number of large and the number of small in one scanning. When the absolute value of the count value of the moving pulse counter 56 is larger than the first predetermined number, the absolute value of the count value of the moving pulse counter 56 is compared with the first predetermined number. A moving amount moving direction judging means 60 for outputting a moving signal in a pixel unit of the CCD 94 to a moving pulse counter 56, and judging and outputting the moving direction by the sign of the counting result of the moving pulse counter 56, an output from the measuring pulse generating means 3 and the shift register 55. A logical sum circuit 57 for taking the logical sum of the output from the logical sum circuit and a measurement pulse counter 58 for counting the measured pulses by counting the output of the logical sum circuit 57
A reference level setting means 59 for calculating a first predetermined number from the counting result of the measurement pulse counter 58 and outputting it to the movement amount movement direction determination means 60.

FIG. 14 is a block diagram showing the structure of the moving pulse counter 56 in more detail. The moving pulse counter 56 outputs an exclusive OR circuit 56a for exclusive ORing the output from the measurement pulse generating means 3 and the output from the shift register 55, and the output from the exclusive OR circuit 56a as an enable signal and an output signal. An up / down counter 56 that receives a data signal and inputs the output from the shift register 55 as an up / down count signal.
and b.

The operation of the measurement pulse detecting means having such a configuration will be described below. The shift register 55 stores the measurement pulse waveform output from the measurement pulse generating means 3. The exclusive OR circuit 56a includes the shift register 55.
Each measured pulse of the measured pulse waveform stored in
The exclusive OR of the pixel unit at the time of rising or falling with each measurement pulse of the measurement pulse waveform for one scan of the CD94 is taken, and is input to the up / down counter 56b as an enable signal and a data signal. If the up / down counter 56b is determined to count up when the pixel output from the shift register 55 is “1” and down when it is “0”, for example, at the rising edge of each measurement pulse or Pixel unit at the time of falling,
Whether the output of the shift register 55 or the output of the measurement pulse generating means 3 is large or small can be up-down counted, and the measurement pulse from the shift register 55 and the measurement pulse from the measurement pulse generating means 3 can be detected. Of the pixel unit and the direction thereof are up / down counters 56.
It is output from b.

On the other hand, the reference level setting means 59 determines that the measurement pulse is displaced pixel by pixel when some of the measurement pulses (first predetermined number) are displaced pixel by pixel from the count result of the measurement pulse counter 58. Whether or not to do so is calculated and output to the movement amount movement direction determination means 60. The movement amount movement direction determination means 60 is latched at the time when the count of the measurement pulse waveform for one scan of the CCD 94 is completed, and the numerical value input from the reference level setting means 59 and the up / down counter 56b.
The absolute value of the numerical value input from is compared, and when the numerical value input from the up / down counter 56b is larger, a movement amount output signal indicating the movement in pixel units is output, and is input from the up / down counter 56b. The direction of movement is determined from the sign of the numerical value thus obtained, and a movement direction output signal is output. Optical displacement amount measuring method according to fourteenth invention and first
Other configurations and operations of the optical displacement amount measuring device according to the fifth and sixth inventions are the same as those of the optical displacement amount measuring method according to the first and second inventions and the configuration of the optical displacement amount measuring device according to the third and fourth inventions. Since the operation is the same as that of the operation, description thereof will be omitted.

FIG. 15 is a block diagram showing the structure of the measurement pulse detecting means of one embodiment of the optical displacement measuring device according to the 17th invention. The measuring pulse detecting means of the present invention is the same as that of the optical displacement measuring device according to the fifteenth and sixteenth inventions.
The absolute value of the output of the moving pulse counter 56 is compared with the speed alarm set value (second predetermined number) from the reference level setting means 59a, and a speed alarm output means 62 for outputting a speed alarm is added. ing. FIG. 17
FIG. 9 is a block diagram showing a configuration example of a reference level setting means 59a. Assuming that the measured pulse count value from the measured pulse counter 58 is Do, the calculator 63 calculates, for example, 1/2
The division result Do / 2 is sent to the movement amount movement direction determination means 60 as a first predetermined number. The measured pulse count value Do is added by the calculator 64, and the addition result 3Do / 2 is input to the speed alarm output means 62 as a speed alarm set value (second predetermined number).

FIG. 16 is a block diagram showing the structure of the measurement pulse detecting means of another embodiment of the optical displacement amount measuring device according to the 17th invention. In this embodiment, the moving pulse counter 56 is replaced with a moving bit counter 61 in the structure of the optical displacement measuring device according to the fifteenth and sixteenth inventions. The moving bit counter 61 inputs and counts a clock as a data signal of the up / down counter 56b. Other configurations are similar to those of the embodiment shown in FIG. Other configurations and operations of the optical displacement measuring device according to the seventeenth invention are the same as the configurations and operations of the optical displacement measuring method according to the fourteenth invention and the optical displacement measuring device according to the fifteenth and sixteenth inventions. Therefore, the description is omitted.

FIG. 18 is a block diagram showing the construction of the measuring pulse generating means of one embodiment of the optical displacement amount measuring method according to the eighteenth invention and the optical displacement amount measuring device according to the nineteenth and twentieth inventions. The measuring pulse generating means according to the present invention is C
The measurement pulse corresponding to the periodic video pattern generated from the CD 94 (FIG. 1) is input to the logical product circuits 73 and 74, and the other input terminals of the logical product circuits 73 and 74 are inverted by the inverter 70. The generated clock and the non-inverted clock are provided in different flip-flops 71 and 7 respectively.
The A-phase clock and the B-phase clock, which have been created by inputting to 2 and are inverted from each other, are input.

This will be described with reference to FIG. The A-phase clock (c) and the B-phase clock (j) have a cycle twice that of the drive clock (b) and are inverted from each other. An A phase measurement pulse (d) is generated from the A phase clock (c) and the measurement pulse (a), and a B phase measurement pulse is generated from the B phase clock (j) and the measurement pulse (a). The A-phase measurement pulse (d) and the B-phase measurement pulse are out of phase with each other by one drive clock by respective detection means similar to the measurement pulse detection means of the optical displacement amount measuring device according to the ninth to thirteenth inventions. 20A and 20B, respectively, according to the A-phase reference pulses (e) to (i) and the B-phase reference pulses (l) to (p).
As shown in (b), the displacement amount and its direction are determined.
By doing so, the single-phase pulse generating means 6, 2
It is possible to directly output a two-phase pulse of A phase and B phase without passing through the phase pulse generating means 7 (FIG. 1). Outputting a speed alarm is also the same as the optical displacement measuring device according to the ninth to thirteenth inventions. The other configurations and operations are the ninth.
~ 13 is the same as the optical displacement amount measuring device according to the invention, so description thereof will be omitted.

FIG. 21 is a block diagram showing the configuration of the measuring pulse detecting means of one embodiment of the optical displacement amount measuring method according to the 21st invention and the optical displacement amount measuring device according to the 22nd to 27th inventions. . The measurement pulse detection means according to the present invention,
The shift registers 32a, 80, 82 having a bit capacity equal to the number of pixels of the CCD 94 (FIG. 1) and the shift register 80 for inputting the measurement pulse from the measurement pulse generating means 3
In the shift register 80 by receiving the periodic signal from the bit comparison unit 33b and the bit comparison unit 33b to which the three output lines, which are shifted by 1 bit from the shift register 82, are connected. Switching means 81 for switching and inputting the measurement pulse of
Is connected to the shift register 80 by a measurement pulse input line, and is shifted by 1 bit from the shift register 32a.
Output from the logical sum circuit 84, and a bit comparator 33c to which the output line of the book is connected, a logical sum circuit 84 that takes the logical sum of the shift output from the bit comparator 33c and the periodic signal from the bit comparator 33b In response to this, the switching means 83 is provided for switching and inputting the measurement pulse in the shift register 80 to the shift register 32a.
An external switching signal line is connected to c.

The operation of the measuring pulse detecting means having such a configuration will be described below. The configurations and operations of the bit comparison unit 33c and the bit comparison unit 33b are the same as those of the bit comparison unit 33 and the bit comparison unit 33a shown in FIGS. 6 and 11. The shift register 80 sequentially inputs the measurement pulses (FIG. 25B) generated by the measurement pulse generation means 3. On the other hand, the shift register 32a has a plurality of reference pulses (+1 bit interval) at equal intervals (1 bit interval), which has a central pulse (0) (FIG. 25 (d)) of the same phase as the measurement pulse at the beginning and has the same width as the measurement pulse. ), (0), (-1) (FIG. 25 (c))
(E) are stored. In the bit comparison unit 33c, the mismatch time with the measurement pulse (hatched portion in FIG. 25) is sequentially counted for each reference pulse by counting the drive clock (FIG. 25A) of the CCD 94 (FIG. 1). These count values are represented as the monograms of FIGS. The description of the monogram of FIG. 22 is the same as the description already given for the monogram of FIG.
The bit comparison unit 33c determines that the mismatch time between the measurement pulse (FIG. 25B) and the central pulse (FIG. 25D) and the direction thereof are 0.5 bit (FIG. 22B) or −0.5 bit. 22 (c), a movement signal indicating the movement direction and movement of 0.5 bit is output to the switching means 83 via the displacement amount displacement direction determination means 5 (FIG. 1) and the OR circuit 84. .

Receiving the movement signal, the switching means 83 connects the shift register 80 and the shift register 32a to take in the measurement pulse stored in the shift register 80 as a new center pulse, and set the reference pulse as the reference pulse. The shift pulse is stored again in the shift register 32a, and the position of the measurement pulse becomes the position of the center pulse (FIG. 22 (a)). After that,
The shift register 80 sequentially inputs the measurement pulses generated by the measurement pulse generating means 3, while the shift register 32a
Stores the reference pulse, and the bit comparison unit 33c sequentially counts the mismatch time with the measurement pulse for each reference pulse, and the bit comparison unit 33c determines the mismatch time between the measurement pulse and the center pulse and its direction. Each time the value becomes 0.5 bit or −0.5 bit, a movement signal indicating the movement direction and movement of 0.5 bit is output to the displacement amount displacement direction determination means 5 (FIG. 1) and the switching means 83.

Receiving the movement signal, the switching means 83 connects the shift register 80 and the shift register 32a to fetch the measurement pulse stored in the shift register 80 as a new center pulse, and to set the reference pulse as the reference pulse. It is stored again in the shift register 32a. The displacement amount displacement direction determination means 5 receives the movement signal and determines the displacement amount and displacement direction of the measurement pulse. The bit comparison unit 33c sends a displacement amount displacement direction determination unit 5 to the speed alarm display unit 8 (FIG. 1) when the mismatch time between the measurement pulse and the center pulse and the direction thereof exceed, for example, 1 bit or -1 bit.
A speed alarm is output via (Fig. 1). Further, when the bit comparison unit 33c receives the external switching signal,
Similar to the bit comparison unit 33a shown in FIG. 11, the interval between reference pulses is switched.

By the way, the periodic image pattern of the CCD 94 is, for example, as shown in FIG.
In the case of 5 mm, 20 pixels of the CCD 94 (FIG. 24 (c)) correspond to one cycle. However, when the magnification changes due to a change in the optical system, 21 pixels correspond to one cycle as shown in FIG. 24B, or 20.5 pixels per cycle as shown in FIG. Will correspond. 23 (a) to 23 (c) show these errors on a monogram. In the case of FIG. 24 (b), there is an error of one pixel for one periodic video pattern, and in the case of FIG. 24 (d), there is an error of 0.5 pixel. When an error of 0.5 pixel is generated for one cyclic image pattern, it is not output in the period of one cycle, but it is accumulated internally and one error is generated in two cycles.

Therefore, in the present invention, the bit comparison unit 33b.
In FIG. 26, the reference pulse stored in the shift register 82 is used to look at the movement of the measurement pulse in cycle units, the measurement pulse moves in a substantially predetermined cycle, and enters the range shown in FIG. And outputs a periodic signal. The switching means 81 receives the periodic signal, connects the shift register 80 and the shift register 82, and shifts the shift register 80.
The measurement pulse stored in 1 is taken in as a new center pulse, and the reference pulse is stored in the shift register 82 again. As a result, the error accumulated inside is canceled.

Other configurations and operations of the optical displacement amount measuring method according to the twenty-first invention and the optical displacement amount measuring device according to the twenty-second to twenty-seventh inventions are the same as those of the eighth invention. The structure and operation of the optical displacement amount measuring device according to the invention are the same as those of the invention, and thus the description thereof will be omitted. In each of the above embodiments, the case of the reflection type scale is described, but the same applies to the case of the diffuse reflection type, the regular reflection type, and the transmission type scale. Further, each of the embodiments described above can be configured by a software program using a microcomputer or the like.

[0111]

According to the optical displacement amount measuring method according to the first and second aspects of the present invention, it is possible to measure the optical displacement amount less susceptible to the influence of ambient light.

According to the optical displacement amount measuring device of the third and fourth inventions, it is possible to realize an optical displacement amount measuring device which is hardly influenced by ambient light.

According to the optical displacement amount measuring method of the fifth aspect of the present invention, it is possible to perform the optical displacement amount measurement which is hardly influenced by the ambient light.

According to the optical displacement amount measuring device of the sixth and seventh inventions, it is possible to realize an optical displacement amount measuring device which is hardly influenced by ambient light.

According to the optical displacement amount measuring method of the eighth aspect of the present invention, the measurement accuracy can be improved, the distance of the optical system can be easily set, the error caused by the variation of the magnification of the optical system can be corrected, and the scale can be adjusted. It is possible to perform an optical displacement amount measurement that is less susceptible to dirt and crushing of the periodic pattern on the surface.

According to the optical displacement amount measuring device of the ninth to eleventh inventions, the measurement accuracy can be improved, the distance of the optical system can be easily set, and the error caused by the variation of the magnification of the optical system can be corrected. It is possible to realize an optical displacement amount measuring device that is not easily affected by dirt and crushing of the periodic pattern on the scale surface.

According to the optical displacement amount measuring apparatus of the twelfth invention, it is possible to realize an optical displacement amount measuring apparatus capable of switching the resolution and the response speed of displacement amount measurement.

According to the optical displacement amount measuring device of the thirteenth invention, it is possible to realize an optical displacement amount measuring device capable of notifying that the displacement amount and the displacement direction cannot be determined.

According to the optical displacement amount measuring method of the fourteenth invention, the measurement accuracy can be improved, the distance of the optical system can be easily set, and the error caused by the variation of the magnification of the optical system can be corrected. It is possible to perform an optical displacement amount measurement that is less susceptible to dirt and crushing of the periodic pattern on the surface.

According to the optical displacement amount measuring device of the fifteenth and sixteenth inventions, the measurement accuracy can be improved, the distance of the optical system can be easily set, and the error caused by the magnification change of the optical system can be corrected. It is possible to realize an optical displacement amount measuring device that is not easily affected by dirt and crushing of the periodic pattern on the scale surface.

According to the optical displacement amount measuring device of the seventeenth aspect of the invention, it is possible to realize an optical displacement amount measuring device capable of notifying that the displacement amount and the displacement direction cannot be determined.

According to the optical displacement amount measuring method of the eighteenth invention, it is resistant to noise, the measuring accuracy can be improved, the distance of the optical system can be easily set, and the error caused by the variation of the magnification of the optical system can be prevented. It is possible to perform correction, and it is possible to perform an optical displacement amount measurement that is less affected by dirt and crushing of the periodic pattern on the scale surface.

According to the optical displacement amount measuring device of the nineteenth aspect of the present invention, it is resistant to noise, the measurement accuracy can be improved, the distance of the optical system can be easily set, and the error caused by the variation of the magnification of the optical system can be prevented. It is possible to realize an optical displacement amount measuring device that can be corrected and is not easily affected by dirt and crushing of the periodic pattern on the scale surface.

According to the optical displacement amount measuring device of the twentieth invention, it is possible to realize an optical displacement amount measuring device capable of notifying that the displacement amount and the displacement direction cannot be determined.

According to the optical displacement amount measuring method of the twenty-first invention, the measurement accuracy can be improved, the distance of the optical system can be easily set, the error caused by the variation of the magnification of the optical system can be corrected, and the scale can be reduced. It is possible to perform an optical displacement amount measurement that is less susceptible to dirt and crushing of the periodic pattern on the surface.

According to the optical displacement amount measuring device of the twenty-second to twenty-fourth inventions, the measurement accuracy can be improved, the distance of the optical system can be easily set, and the error caused by the variation of the magnification of the optical system can be corrected. It is possible to realize an optical displacement amount measuring device that is not easily affected by dirt and crushing of the periodic pattern on the scale surface.

According to the optical displacement amount measuring device of the twenty-fifth aspect of the invention, it is possible to realize an optical displacement amount measuring device capable of switching the resolution and the response speed of displacement amount measurement.

According to the optical displacement amount measuring device of the twenty-sixth aspect of the invention, it is possible to realize an optical displacement amount measuring device capable of notifying that the displacement amount and the displacement direction cannot be determined.

According to the optical displacement amount measuring device of the twenty-seventh aspect of the present invention, it is possible to realize an optical displacement amount measuring device capable of correcting an error caused by a change in magnification of an optical system.

[Brief description of drawings]

FIG. 1 is an optical displacement amount measuring device according to the second to fourth aspects of the invention.
It is a block diagram which shows the structure of an Example.

FIG. 2 is a block diagram showing a configuration of a measurement pulse generation unit of an optical displacement amount measuring device according to second to fourth inventions.

FIG. 3 is a waveform diagram showing a waveform of a measurement pulse generator of the optical displacement amount measuring device according to the second to fourth aspects of the invention.

FIG. 4 is a block diagram showing a configuration of a measurement pulse generation unit of an optical displacement amount measuring device according to sixth and seventh inventions.

FIG. 5 is a waveform diagram showing a waveform of a measurement pulse generator of the optical displacement amount measuring device according to the sixth and seventh inventions.

FIG. 6 is a block diagram showing a configuration of a measurement pulse detection unit of an optical displacement amount measuring device according to ninth to eleventh inventions.

FIG. 7 is a block diagram showing a main configuration of a measurement pulse detection unit of an optical displacement amount measuring device according to ninth to eleventh inventions.

FIG. 8 is a waveform diagram showing waveforms of a measurement pulse and a reference pulse of a measurement pulse detector of the optical displacement measurement device according to the ninth to eleventh inventions.

FIG. 9 is a monogram showing the relationship between measurement pulses and clock count values.

FIG. 10 is a flow chart showing the operation of the measurement pulse detector of the optical displacement amount measuring device according to the ninth to eleventh inventions.

FIG. 11 is a block diagram showing a configuration of a measurement pulse detector of the optical displacement amount measuring device according to the twelfth and thirteenth inventions.

FIG. 12 is a block diagram showing a main configuration of a measurement pulse detection unit of an optical displacement amount measuring device according to twelfth and thirteenth inventions.

FIG. 13 is a block diagram showing a configuration of a measurement pulse detecting means of one embodiment of the optical displacement amount measuring device according to the fifteenth and sixteenth inventions.

FIG. 14 is a block diagram showing a configuration of a moving pulse counter.

FIG. 15 is an optical displacement amount measuring device 1 according to a seventeenth invention.
It is a block diagram which shows the structure of the measurement pulse detection means of an Example.

FIG. 16 is a block diagram showing a configuration of a measurement pulse detecting means of another embodiment of the optical displacement amount measuring device according to the 17th invention.

FIG. 17 is a block diagram showing a configuration example of reference level setting means.

FIG. 18 is a block diagram showing a configuration of a measurement pulse generating means of an embodiment of the optical displacement amount measuring device according to the nineteenth and twentieth inventions.

FIG. 19 is a waveform diagram showing a waveform of a measurement pulse generating means of one embodiment of the optical displacement amount measuring device according to the nineteenth and twentieth inventions.

FIG. 20 is a monogram showing the relationship between measurement pulses and clock count values.

FIG. 21 is a block diagram showing a configuration of a measurement pulse detecting means of one embodiment of the optical displacement amount measuring device according to the 22nd to 27th inventions.

FIG. 22 is a monogram showing the relationship between measurement pulses and clock count values.

FIG. 23 is a monogram showing the relationship between measurement pulses and clock count values.

FIG. 24 is a waveform diagram showing the relationship between the measurement pulse and the clock.

FIG. 25 is a waveform diagram showing waveforms of a measurement pulse and a reference pulse of the measurement pulse detector of the optical displacement amount measuring device according to the twenty-first to twenty-seventh inventions.

FIG. 26 is a monogram showing the relationship between measurement pulses and clock count values.

FIG. 27 is a schematic view showing the principle of an optical displacement amount measuring device.

FIG. 28 is a waveform diagram showing a relationship between a periodic image pattern and a measurement pulse.

FIG. 29 is a waveform diagram showing a relationship between a periodic image pattern and a measurement pulse.

[Explanation of symbols]

1 clock generator 3 measurement pulse generation means 4 measurement pulse detection means 5, displacement amount displacement direction determination means 8 speed alarm display section 10 odd number control gate 11 even number control gate 12, 21 comparator 13 comparison output control gate 15 measurement pulse generation section 22, 31, 32, 31a, 32a, 55, 80, 82
Shift register 30, 30a, 30b, 81, 83 Switching means 33, 33a, 33b, 33c Bit comparing section 56 Moving pulse counter 56b Up-down counter 58 Measuring pulse counter 59 Reference level setting means 60 Moving amount moving direction judging means 62 Speed alarm Output means 90 scale 94 CCD

Claims (27)

[Claims] 1. An image sensor having at least a one-dimensional image sensor for projecting a periodic image pattern by projecting light on a scale in which portions having two kinds of optical characteristics are alternately and periodically arranged. An optical displacement amount measuring method for determining relative displacement amount and relative displacement direction between the scale and the image sensor from a change in the periodic image pattern received by the image sensor. Of the adjacent pixel units are compared, and based on the time point at which the magnitude relationship is reversed, a measurement pulse corresponding to the periodic image pattern is generated, and the movement amount of the measurement pulse in the pixel unit of the image sensor is generated. And the displacement direction, the relative displacement amount and the relative displacement direction of the scale and the image sensor are determined. Measurement method. 2. The pair of adjacent pixel-based outputs for comparing the magnitudes is either an odd-numbered / even-numbered pair or an even-numbered / odd-numbered pair. Optical displacement measurement method. 3. A scale in which portions having two kinds of optical characteristics are alternately and periodically arranged, an optical system for projecting light onto the scale to generate a periodic image pattern, and receiving the periodic image pattern. And an optical displacement amount measuring device for determining a relative displacement amount and a relative displacement direction between the scale and the image sensor based on a change in the periodic image pattern received by the image sensor. In the above, the measurement pulse corresponding to the periodic image pattern is based on the comparison means for comparing the magnitudes of the outputs of the pixel units adjacent to each other of the image sensor and the time point when the magnitude relation of the outputs of the pixel units by the comparison means is reversed. Measuring pulse generating means having a first measuring pulse generating means, and a position of the measuring pulse in pixel units of the image sensor. And a displacement amount determining means and a displacement direction determining means for determining a relative displacement amount and a relative displacement direction between the scale and the image sensor based on a change with time of a determination result of the measurement pulse detecting means. An optical displacement amount measuring device comprising: 4. The comparing means includes a first gate that passes an output of an odd-numbered pixel output from the image sensor, a second gate that passes an output of an even-numbered pixel, and a first gate. Input comparing means for comparing inputs from the gate and the second gate, and selectively, of the comparison result output of the input comparing means, only the comparison result of any one of odd-numbered / even-numbered and even-numbered / odd-numbered. 4. The optical displacement amount measuring device according to claim 3, further comprising a third gate that passes through and a gate control unit that controls each of the first, second, and third gates. 5. A sensor having two types of optical characteristics is projected onto a scale in which parts having two kinds of optical characteristics are alternately arranged periodically to generate a periodic image pattern, and the periodic image pattern is at least a one-dimensional image sensor. An optical displacement amount measuring method for determining relative displacement amount and relative displacement direction between the scale and the image sensor from a change in the periodic image pattern received by the image sensor. The waveform of the measurement pulse corresponding to the periodic video pattern generated from the output for one scan of is stored, and when the measurement pulse is generated from the output for the next scan, the measurement pulse is added to the pixel unit of the image sensor. Synchronously, the measured pulse waveform stored in the previous scan is fed back to generate a measured pulse, and the measured pulse is displayed on the image sensor. The moving amount and the moving direction of the unit, the scale and the optical displacement measuring method characterized by determining the relative displacement and relative direction of displacement of said image sensor. 6. The measurement pulse generating means stores a waveform of a measurement pulse corresponding to the periodic image pattern generated from the output of one scan of the image sensor.
And a second storage unit for generating one measurement pulse by feeding back the measurement pulse waveform stored in the first storage unit according to the waveform of the measurement pulse for the previous scan in synchronization with the pixel unit of the image sensor. 5. The optical displacement amount measuring device according to claim 3 or 4, further comprising: 7. The first storage means is a first shift register having a capacity equal to the number of pixels for one scan of the image sensor, and the second measurement pulse generation means is
7. The optical displacement amount measuring device according to claim 6, wherein the output from the image sensor is used as a comparison input, and the comparator is a comparator in which the reference input terminal is fed back by the output of the first shift register. 8. A sensor for projecting a periodic image pattern by projecting light on a scale in which portions having two kinds of optical characteristics are alternately arranged periodically, and the periodic image pattern is at least a one-dimensional image sensor. An optical displacement amount measuring method for determining relative displacement amount and relative displacement direction between the scale and the image sensor from a change in the periodic image pattern received by the image sensor. The measurement pulses corresponding to the periodic video pattern generated from the output of are sequentially input to the second shift register, and a plurality of equidistant intervals having a center pulse having an equal phase in the initial stage with the measurement pulse and having the same width as the measurement pulse are sequentially input. The reference pulse is stored in the third shift register, and the disagreement time with the measurement pulse is sequentially counted for each of the reference pulses, and these timings are measured. Compared determine the mutual length of the fruit,
The discrepancy time and the direction of the measurement pulse and the central pulse are judged from this comparison result, and when the discrepancy time is equal to or more than a first predetermined value, a movement signal indicating the movement direction and the movement of the first predetermined value. And the measurement pulse stored in the second shift register as a new center pulse, the reference pulse is stored in the second shift register, and thereafter the measurement pulses are sequentially input to the third shift register. Then, the discrepancy time and the direction of the measurement pulse and the central pulse are sequentially determined by the method, and the movement signal is output each time the discrepancy time becomes equal to or more than a first predetermined value. An optical displacement amount measuring method, characterized in that the relative displacement amount and the relative displacement direction between the scale and the image sensor are determined by repeating the alternation of the second and third shift registers. Method. 9. The second measuring pulse detecting means sequentially inputs the measuring pulses generated by the measuring pulse generating means.
Alternatively, a third shift register, a third or second shift register that stores a plurality of reference pulses having an equal phase center pulse in the initial stage with the measurement pulse and having the same width as the measurement pulse, and sequentially, A plurality of first timing means for timing the non-coincidence time with the measurement pulse for each of the reference pulses, and a first comparison determination means for comparing and determining the mutual length of each timing result of the first timing means. The discrepancy time between the measurement pulse and the central pulse and its direction are determined from the result, and when the discrepancy time is equal to or greater than the first predetermined value, a movement signal indicating the movement direction and movement of the first predetermined value is output. When the disagreement time is equal to or more than the first predetermined value, the measurement pulse stored in the second shift register is used as a new center pulse and the reference pulse is set to the second or third reference signal. Schiff Register is stored, thereafter, the third
Or a switching signal output means for outputting a signal for switching so that the measurement pulse is sequentially input to the second shift register, and a switching means for receiving the switching signal and performing the switching. The optical displacement amount measuring device according to claim 3, 4, 6, or 7. 10. The first clocking means comprises logic means for taking an exclusive OR of the measurement pulse and the reference pulse, and counting means for counting clock pulses during a period output by the logic means. The optical displacement amount measuring device according to claim 9. 11. The optical displacement amount measuring device according to claim 9, wherein the first predetermined value of the mismatch time corresponds to one bit of a drive clock of the image sensor. 12. The measurement pulse detecting means includes a reference pulse switching means for receiving a signal from the outside and switching the interval between the reference pulses. Optical displacement measuring device. 13. A speed alarm display section is provided, and
13. The measurement pulse detection means includes first speed alarm output means for outputting a speed alarm to the speed alarm display section when the mismatch time is equal to or more than a second predetermined value. The optical displacement measuring device according to any one of 1. 14. An image sensor having at least a one-dimensional image pattern formed by projecting a periodic image pattern by projecting light onto a scale in which portions having two kinds of optical characteristics are alternately arranged periodically. In the optical displacement amount measuring method for determining the relative displacement amount between the scale and the image sensor from the change in the periodic image pattern received by the image sensor, Pixel unit of the image sensor at the time of rising or falling of each measurement pulse of the measurement pulse waveform corresponding to the periodic video pattern generated from the output and each measurement pulse of the measurement pulse waveform of the next scan And the absolute value of the difference between the large number and the small number in one scanning is compared with the first predetermined number determined from the number of measurement pulses. When it is large, a movement signal in the pixel unit and a movement direction signal obtained from the sign of the difference between the large number and the small number are output, and the scale and the image are output according to the movement amount in the pixel unit of the image sensor. An optical displacement amount measuring method characterized by determining a relative displacement amount with respect to a sensor. 15. The measurement pulse detection means includes second storage means for storing the measurement pulse waveform output from the measurement pulse generation means, and each measurement pulse of the measurement pulse waveform stored in the second storage means. And the next measurement pulse of the measurement pulse waveform for one scan of the image sensor at the time of rising or falling, the size of the pixel unit of the image sensor at the time of rising or falling is compared, and the number and the number of the large in one scanning are compared. The moving pulse counting means for counting the difference from the number and the absolute value of the counted value of the moving pulse counting means are compared with the first predetermined number, and the absolute value of the counted value of the moving pulse counting means is the first value. A moving amount determining means for outputting a moving signal in pixel units of the image sensor when the number is larger than a predetermined number, and a moving direction determining means for determining a moving direction by a sign of a counting result of the moving pulse counting means, A measuring pulse counting means for counting the measuring pulses; and a reference level setting means for calculating a first predetermined number from the counting result of the measuring pulse counting means and outputting it to the movement amount determining means. The optical displacement measuring device according to claim 3, 4, 6, or 7. 16. The moving pulse counting means at the time of rising of each measurement pulse of the measurement pulse waveform stored in the second storage means and each measurement pulse of the next measurement pulse waveform of one scan of the image sensor. Alternatively, a logic means for taking an exclusive OR of the pixel unit at the time of the fall, and an output from the logic means by using the output from the second storage means as an up-count signal or a down-count signal during the period when the logic means outputs. 16. An optical displacement amount measuring device according to claim 15, further comprising an up / down counter for counting. 17. A count value of the moving pulse counting means, comprising a speed alarm display means, comparing the count value of the moving pulse counting means with a second predetermined number which is larger than the first predetermined number. Is greater than a second predetermined number, a second speed alarm output means for outputting a speed alarm to the speed alarm display means is provided, and the reference level setting means is the first based on the counting result of the measurement pulse counting means. A predetermined number is calculated and output to the movement amount determination means and the movement direction determination means, and a second predetermined number is calculated and output to the second speed alarm output means.
5. The optical displacement amount measuring device according to 5 or 16. 18. A sensor having two kinds of optical characteristics is projected onto a scale in which parts having two kinds of optical characteristics are alternately arranged periodically to generate a periodic image pattern, and the periodic image pattern is at least a one-dimensional image sensor. In the optical displacement amount measuring method of determining the relative displacement amount between the scale and the image sensor from the change of the periodic image pattern received by the image sensor, the period according to the output of the image sensor. A two-phase measurement pulse is generated from every other pixel-by-pixel output of the image sensor of the measurement pulse corresponding to the dynamic image pattern,
An optical displacement amount measuring method characterized in that the relative displacement amount between the scale and the image sensor is determined from the respective movement amounts and relative positions of the two-phase measurement pulses. 19. An A-phase measurement pulse generation means and a B-phase measurement pulse generation means for generating A and B 2-phase measurement pulses from the output of every other measurement pulse in pixel units of the image sensor. Means have, A, B2
The measurement pulse detection means is provided for each of the phase measurement pulses, and the measurement pulse detection means is provided.
The optical displacement measuring device according to any one of 1. 20. A speed alarm display section is provided, and
The A-phase measurement pulse detection means and the B-phase measurement pulse detection means, when the disagreement time is a second predetermined value or more,
A third for outputting a speed alarm to the speed alarm display section
20. The optical displacement amount measuring device according to claim 19, further comprising: a fourth speed alarm output means. 21. A portion having two kinds of optical characteristics is projected onto a scale in which portions are alternately arranged periodically to generate a periodic image pattern, and the periodic image pattern is at least a one-dimensional image sensor. An optical displacement amount measuring method for determining relative displacement amount and relative displacement direction between the scale and the image sensor from a change in the periodic image pattern received by the image sensor. The measurement pulses corresponding to the periodic video pattern generated from the output of are sequentially input to the fourth shift register, and a plurality of equidistant intervals having a center pulse having an equal phase at the beginning with the measurement pulse and having the same width as the measurement pulse are sequentially input. The reference pulse is stored in the fifth shift register, and the disagreement time with the measurement pulse is sequentially counted for each of the reference pulses. Result mutual long and short of the comparison determination is made,
The discrepancy time and the direction of the measurement pulse and the central pulse are judged from this comparison result, and when the discrepancy time is equal to or more than a first predetermined value, a movement signal indicating the movement direction and the movement of the first predetermined value. And the measurement pulse stored in the fourth shift register as a new center pulse, the reference pulse is stored again in the fifth shift register, and thereafter the measurement pulses are sequentially stored in the fourth shift register. By inputting, the discrepancy time and the direction of the measurement pulse and the central pulse are sequentially determined by the method, and the movement signal is output every time the discrepancy time becomes equal to or more than a first predetermined value. Using the measurement pulse stored in the fourth shift register as a new center pulse, the reference pulse is stored again in the fifth shift register, and the scale and the image are stored. Optical shift measuring method characterized by determining the relative displacement and relative direction of displacement of the capacitor. 22. The measurement pulse detection means has a fourth shift register for sequentially inputting the measurement pulses generated by the measurement pulse generation means, and a center pulse of the same phase as the measurement pulse in the initial stage, and the like. A fifth shift register for storing a plurality of reference pulses of equal width, a plurality of first time measuring means for sequentially measuring a mismatch time with the measurement pulse for each of the reference pulses, and a first time measuring means The first comparison and determination means for comparing and determining the mutual length of each time measurement result, and the mismatch time and the direction of the measurement pulse and the central pulse are determined based on this comparison result, and the mismatch time is the first predetermined value. When the above is the case, the movement signal is output to the movement signal indicating the movement direction and the movement of the predetermined value, and when the disagreement time is the first predetermined value or more, the fourth shift register 20. The optical device according to claim 3, further comprising: first capturing means for capturing the stored measurement pulse into a fifth shift register as a new center pulse. Displacement measuring device. 23. The first timing means comprises logic means for taking an exclusive OR of the measurement pulse and the reference pulse, and counting means for counting clock pulses during a period output by the logic means. 23. The optical displacement amount measuring device according to claim 22. 24. The optical displacement amount measuring device according to claim 22, wherein the first predetermined value of the mismatch time corresponds to one bit of a drive clock of the image sensor. 25. The measurement pulse detection means comprises a reference pulse switching means for receiving a signal from the outside and switching the interval between the reference pulses. Optical displacement measuring device. 26. A speed alarm display section is provided, and
26. The measurement pulse detection means is provided with a first speed alarm output means for outputting a speed alarm to the speed alarm display section when the disagreement time is a second predetermined value or more. The optical displacement measuring device according to any one of 1. 27. A sixth shift register, wherein the measurement pulse detecting means has a plurality of first reference pulses having an equal phase center pulse in the initial stage with the measurement pulse and having an equal width as the measurement pulse. And a second comparison for sequentially judging the mutual lengths of the respective timing results of the second timing means and a plurality of second timing means for timing the mismatch time with the measurement pulse for each first reference pulse. The determining means and the comparison result determine the mismatch time between the measurement pulse and the central pulse and the direction thereof, and the phase of the measurement pulse moves in a substantially predetermined cycle so that the mismatch time is less than a first predetermined value. When it becomes, the periodic signal output means for outputting the periodic signal and the periodic signal are received and the measurement pulse stored in the fourth shift register is fetched into the sixth shift register as a new center pulse. The optical displacement amount measuring device according to any one of claims 22 to 26, further comprising a second capturing means.