JP2005345328A - Optical object discrimination device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical object discrimination device having a small size and high reliability, capable of detecting accurately the irregularity state of the measuring object. <P>SOLUTION: This optical object discrimination device is equipped with a floodlighting part comprising a collimator lens 2 for irradiating the measuring object 9 with laser light emitted from a semiconductor laser 1 as the first light flux 5, a diaphragm 3, a non-polarized beam splitter 4 and the first condensing lens 8; a light receiving part 12 for receiving a reflected light flux 7 reflected by the measuring object 9; a linear polarizer 13a arranged between the light receiving part 12 and the measuring object 9, for selecting a polarization direction which is the same direction as the polarization direction of the first light flux 5 and allowing the light flux to pass; and a signal processing circuit 12 for processing a signal outputted from the light receiving part 12, and measuring the light intensity in the polarization direction in the reflected light flux 7. The polarization state of the reflected light flux 7 has information of the irregularity state of the reflecting surface of the measuring object 9. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical object identification device, for example, an optical object identification for identifying the type of an object to be measured by irradiating the object to be measured with laser light and measuring a depolarization characteristic due to reflection of the laser light. For example, the present invention relates to an optical object identification device that discriminates types of floors such as carpets, inter-board spaces, and tatami mats.

  As an example, the present invention relates to an optical object identification device suitable for determining the type of floor surface and realizing optimization of the operation state of the vacuum cleaner due to the difference in floor surface such as carpets, tatami mats, and boards, Furthermore, the present invention relates to a cleaner and a self-propelled cleaner incorporating the optical object identification device.

  The floor discrimination sensor mounted on a household vacuum cleaner can be roughly classified into a mechanical sensor, a suction pressure sensor, an ultrasonic sensor, and an optical sensor.

  As a mechanical floor surface detection sensor, (1) a method of pressing a movable part against the floor surface (Patent Document 1 (Japanese Patent Laid-Open No. 2-52619)), (2) rotational state of a polygonal column or a gear-shaped roller (Patent Document 2 (Japanese Patent Laid-Open No. 2-52623) and Patent Document 3 (Japanese Patent Laid-Open No. 3-106325))), (3) Depending on the resistance value of the conductive rubber that changes due to the pressure received from the floor surface There are methods for discriminating (Patent Document 4 (JP-A-5-56888) and Patent Document 5 (JP-A-5-56889)).

  Further, Patent Document 6 (Japanese Patent Laid-Open No. 6-78862) describes a suction pressure type floor surface discrimination sensor. This suction pressure type floor surface discrimination sensor detects the pressure of the front part of the dust collecting filter and discriminates the type of the floor surface. This sensor uses the fact that when the floor is a carpet, the degree of vacuum increases due to the carpet adsorbing to the suction port, while the space between the plates does not adsorb to the suction port, so the degree of vacuum does not increase. Identify the face.

  Patent Document 7 (JP-A-1-232255), Patent Document 8 (JP-A-3-77519, and Patent Document 9 (JP-A-3-212249)) disclose an ultrasonic floor surface discrimination sensor. In this ultrasonic type floor surface discrimination sensor, an ultrasonic pulse transmitted from a transmission unit mounted opposite to the floor surface is reflected multiple times as an echo between the floor surface and the sensor. After the repetition, the signal is received by the receiving unit, and the type of the floor surface is determined based on the received signal.

  Further, Patent Document 10 (Japanese Patent Laid-Open No. 3-123522) and Patent Document 11 (Japanese Patent Laid-Open No. 3-228724) describe an optical floor discrimination sensor. This optical floor discrimination sensor has a first light emitting / receiving element that receives and emits light that is horizontal to the floor, and a second light emitting and receiving element that receives and emits light perpendicular to the floor, The type of the floor surface is discriminated from the outputs of these two sets of light emitting / receiving elements.

  By the way, in general, in a configuration having a contact portion such as a mechanical floor surface discrimination sensor, particularly in an apparatus having a movable portion whose contact portion is movable by contact, wear of the contact portion (movable portion). There are many problems such as aging and deterioration of mechanical reliability.

  Therefore, an optical floor discrimination sensor that can obtain a desired effect in a non-contact manner is excellent in the reliability of the apparatus. Note that the floor type discrimination sensor of each of the above methods (2) and (3) in the mechanical type also has a contact part and a movable part, and measures the physical quantity due to the displacement, so that the optical type There is a problem in reliability compared with the floor surface detection sensor.

  On the other hand, in the suction pressure type floor surface discrimination sensor, the degree of vacuum changes not only due to the type of floor surface to be cleaned but also due to other factors such as clogging of the dust collecting filter. There is a fear.

  In addition, in the ultrasonic floor sensor, the transmission / reception element needs some kind of horn, so when it is attached to a general vacuum cleaner, the size is increased and the usability is deteriorated. In addition, it is necessary to consider impact resistance and cost reduction.

  In addition, the optical floor surface detection sensor determines that the floor surface is a carpet by detecting that the light emitted horizontally on the floor surface is blocked by the carpet hair and the amount of received light is reduced. In the case of a carpet with short hairs, it is difficult to detect that the floor is a carpet because the light is not blocked.

As described above, various methods have been proposed as floor surface detection sensors, but the current situation is that there are pros and cons, and basically distinguishes between carpets and other floor surfaces. It is not a device that can be distinguished from tatami, which is a general indoor environment.
Japanese Patent Laid-Open No. 2-52619 JP-A-2-52623 JP-A-3-106325 JP-A-5-56888 JP-A-5-56889 Japanese Patent Laid-Open No. 6-78862 JP-A-1-232255 Japanese Patent Laid-Open No. 3-77519 JP-A-3-212249 Japanese Patent Laid-Open No. 3-123522 JP-A-3-228724

  SUMMARY OF THE INVENTION An object of the present invention is to provide a highly reliable and compact optical object identification device that can accurately detect the uneven state of an object to be measured.

In order to solve the above problems, an optical object identification device of the present invention includes a light projecting unit that irradiates a measurement object with light emitted from a semiconductor light emitting element,
A light receiving unit that receives reflected light reflected by the object to be measured;
A polarization state selection unit that is disposed between the light receiving unit and the object to be measured and transmits polarized light in a predetermined polarization direction;
And a signal processing unit that processes a signal output from the light receiving unit and measures the intensity of the light in the predetermined polarization direction out of the reflected light.

  According to the optical object identification device of the present invention, the light emitted from the semiconductor light emitting element is applied to the object to be measured from the light projecting unit, and the light is emitted according to the uneven state of the reflection surface of the object to be measured. The polarization state of the reflected light changes.

  Therefore, the polarization state of the reflected light has information on the uneven state of the reflection surface of the object to be measured. The reflected light is incident on the light receiving unit via the polarization state selecting unit, and the signal processing unit processes a signal output from the light receiving unit, thereby the predetermined polarization direction of the reflected light. Is measured to identify the type of the object to be measured.

  In this invention, the polarization state of the light incident on the object to be measured is known, and the uneven state of the surface of the object to be measured can be measured by measuring the polarization information of the reflected light with respect to the incident light in the known polarization state. Object identification can be performed.

  In one embodiment of the optical object identification device, the polarization state of the light incident on the object to be measured is linearly polarized light.

  In the optical object identification device of this embodiment, since the incident light to the object to be measured is linearly polarized light, the incident light is vibration in only one direction. For this reason, it becomes easy to evaluate the depolarization characteristic in which the polarization state of the incident light is canceled by reflection on the object to be measured.

  In one embodiment, the linearly polarized light incident on the object to be measured is an S wave with respect to the object to be measured.

  In the optical object identification device of this embodiment, since the incident light beam incident on the object to be measured is an S wave, it is reflected as an S wave when the incident surface of the object to be measured is an optically smooth surface. . Therefore, the polarization direction of the reference direction is maintained by reflection on the smooth surface. Thereby, it becomes possible to evaluate the unevenness | corrugation state of the surface of the said to-be-measured object with high precision. On the contrary, when the incident light beam incident on the object to be measured is a P wave, only a part of the polarization direction component contributes to the reflection, so that the uneven state of the surface of the object to be measured can be accurately detected. It is unsuitable for evaluation.

  In one embodiment, the polarization direction selected by the polarization state selection unit and the polarization direction of the light incident on the object to be measured are substantially the same direction.

  In the optical object identification device of the above embodiment, since the polarization direction of the light incident on the light receiving unit is the same as the polarization direction of the incident light, the depolarization characteristic due to the unevenness of the reflection surface can be measured with the highest accuracy. .

Further, in the optical object identification device of one embodiment, a light branching element that splits the light emitted from the semiconductor light emitting element into a first light flux and a second light flux,
First condensing means for condensing and irradiating the first light flux on the object to be measured;
Second light collecting means for collecting light that has passed through the first light collecting means among the light reflected by the object to be measured;
A pinhole portion disposed between the second light collecting unit and the light receiving element;

  In the optical object identification device of the above embodiment, there is a pinhole part between the light receiving element and the second light condensing means, and the signal light is condensed so as to pass through the pinhole on the pinhole part surface. For this reason, noise light can be cut and the light reflected by the measurement object can be received efficiently.

  Further, the optical object identification device according to one embodiment includes stray light preventing means for the second light flux and reflected light of the second light flux.

  In the optical object identification device of this embodiment, light that does not contribute to a signal does not become a noise source.

Further, in the optical object identification device of one embodiment, the stray light prevention means has a linear polarizer,
The linear polarizer is installed on the optical axis of the second light beam, and the polarization direction that the linear polarizer passes is a direction orthogonal to the polarization direction of the second light beam.

  In the optical object identification device of this embodiment, a linear polarizer that transmits light having a polarization direction orthogonal to the polarization direction of the second light beam is installed on the optical axis of the second light beam. The second light flux is absorbed by the child. For this reason, the second light flux is not reflected by the side wall of the apparatus and mixed into the light receiving portion as noise light.

  Moreover, in the optical object identification device according to one embodiment, the second condensing unit includes a condensing lens, and the pinhole portion is installed at a position of a focal length of the condensing lens.

  In the optical object identification device of this embodiment, since the pinhole portion is disposed at the focal position of the second condenser lens, the reflected light beam is pinned when the object to be measured is at the focal position of the first condenser lens. Most condensed on the surface of the hall. When the object to be measured is at the focal position of the first condenser lens, the incident light is most condensed on the object to be measured, and the light density becomes the largest. Therefore, at this time, the amount of light passing through the pinhole portion is maximized, and the S / N can be improved.

  In one embodiment, the diameter of the reflected light beam at the position where the pinhole portion is arranged is smaller than the hole diameter of the pinhole portion.

  In the optical object identification device of this embodiment, since the hole diameter of the pinhole portion is larger than the beam diameter on the surface of the pinhole portion, the signal light is not cut by the pinhole portion.

  In the optical object identification device according to one embodiment, the first light flux is incident on substantially the center of the first light collecting means.

  In the optical object identification device of this embodiment, since the first light beam is incident substantially at the center of the first light collecting means, light having a symmetric depolarization characteristic centered on a specularly reflected light component that preserves the polarization state is emitted. Light can be received by the light receiver.

  In the optical object identification device according to an embodiment, the first light beam is incident on an end of the first light collecting unit.

  In the optical object identification device of this embodiment, since the first light beam is incident on the end of the first light collecting unit, the regular reflection component of the reflected light beam is collected at the end of the first light collecting unit. Since the reflected light beam collected in the vicinity of the incidence of the first light beam is a light beam exhibiting more depolarization characteristics, the object to be measured can be identified with higher accuracy.

Further, in the optical object identification device according to one embodiment, the optical object identification device includes a first condensing unit that condenses the light emitted from the semiconductor light emitting element on the object to be measured.
The light reflected from the object to be measured has light guiding means for excluding a portion overlapping the light beam incident on the first light collecting means, and directing a reflected light beam in a peripheral portion other than the overlapping portion to the light receiving portion. ,
The reflected light beam at the peripheral part is detected by the light receiving part.

  In the optical object identification device of this embodiment, the amount of light that does not contribute to the signal among the light beams emitted from the semiconductor light emitting element can be significantly reduced, and the contribution ratio of the emitted light to the signal light can be increased. Therefore, the light emission amount of the semiconductor light emitting element can be reduced, and the current consumption can be reduced.

  Further, in the optical object identification device according to an embodiment, the optical object identification device includes an optical axis changing unit that changes a traveling direction of the second light beam divided by the light branching element. The first light flux has a substantially parallel optical axis, and the first and second light fluxes are incident on the same first light collecting means.

  In the optical object identification device of the above-described embodiment, it is possible to increase the contribution ratio of the light emitted from the semiconductor light emitting element to the signal light, reduce the current consumption of the device, and do not require special processing. Since it can be configured with optical components, the device can be easily manufactured.

In one embodiment of the optical object identification device, a first light branching element that splits a light beam emitted from the semiconductor light emitting element into a first light beam and a second light beam;
A second optical branching element that divides the light reflected by the device under test into first and second reflected light fluxes,
The light receiving unit is
A first light receiving element for receiving the first reflected light beam;
A second light receiving element for receiving the second reflected light beam,
And a polarization state selection element that selects a polarization state of light incident on the first light receiving element,
The signal processing unit calculates a ratio between a signal output from the first light receiving element and a signal output from the second light receiving element.

  In the optical object identification device of this embodiment, the reflected light beam is divided into two first and second reflected light beams by the second light branching element, and one of the first reflected light beams is a polarization state selection element (for example, a straight line). The light is received by the first light receiving element via the polarizer) and the depolarization characteristic is measured. Further, the other second reflected light beam is received by the second light receiving element without passing through the linear polarizer, and light in all directions is received. A signal received by the second light receiving element without passing through a polarization state selection element such as a linear polarizer includes information on the reflectance of the object to be measured. Therefore, the signal processing unit calculates the ratio between the signal output from the first light receiving element and the signal output from the second light receiving element, thereby identifying the object to be measured due to variations in the reflectance of the surface of the object to be measured. It is possible to prevent a decrease in accuracy.

In one embodiment of the optical object identification device, a first light branching element that splits a light beam emitted from the semiconductor light emitting element into a first light beam and a second light beam;
A second optical branching element that divides the light reflected by the device under test into first and second reflected light fluxes,
The light receiving unit is
A first light receiving element for receiving the first reflected light beam;
A second light receiving element for receiving the second reflected light beam,
A first polarization state selection element that selects a polarization state of light incident on the first light receiving element;
A second polarization state selection element that selects a polarization state of light incident on the second light receiving element;
The polarization direction selected by the first polarization state selection element and the polarization direction selected by the second polarization state selection element are substantially orthogonal to each other.

  In the optical object identification device of this embodiment, the reflected light beam is divided into first and second reflected light beams, and the first and second reflected light beams are selected by the first and second polarization directions orthogonal to each other. Light is received by the first and second light receiving elements through a polarization state selection element (for example, a linear polarizer), respectively. As a result, the signals output from the two light receiving elements extract the two components having the most different depolarization characteristics, so that the accuracy of identification of the object to be measured can be improved.

In one embodiment, the polarization direction selected by the first polarization state selection element is substantially parallel to the polarization direction of the first light flux,
The polarization direction selected by the second polarization state selection element is substantially perpendicular to the polarization direction of the first light flux.

  In the optical object identification device of this embodiment, the reflected light beam is divided into two first and second reflected light beams, and the first reflected light beam has a first polarization direction arranged in the same direction as the polarization direction of the first light beam. The depolarization characteristic is measured by the first light receiving element through the one polarization state selection element (linear polarizer). On the other hand, the second reflected light beam has a depolarization characteristic at the second light receiving element via a second polarization state selection element (linear polarizer) whose selected polarization direction is arranged in a direction orthogonal to the polarization direction of the first light beam. taking measurement. The signal intensity output from both light receiving elements is that the selected polarization directions of the first and second polarization state selection elements (linear polarizers) are orthogonal to each other. Get smaller. For this reason, it becomes possible to evaluate the depolarization characteristic with higher accuracy.

  In one embodiment of the optical object identification device, the first and second polarization state selection elements are linear polarizers.

  Since the optical object identification device of this embodiment uses a linear polarizer, it is suitable for receiving light polarized in a specific direction.

  The optical object identification device according to one embodiment is characterized in that the second light branching element and the first and second polarization state selection elements are configured by a polarization beam splitter.

  In the optical object identification device of this embodiment, the number of components can be reduced by using a polarizing beam splitter, compared to an optical system using a non-polarizing beam splitter and a linear polarizer.

  In one embodiment, the signal processing unit calculates a ratio between a signal output from the first light receiving element and a signal output from the second light receiving element.

  In the optical object identification device of this embodiment, the signal processing unit can improve the accuracy of identification of the object to be measured by calculating the ratio of the outputs of both light receiving elements.

  In the optical object identification device of one embodiment, the signal processing unit calculates a difference between a signal output from the first light receiving element and a signal output from the second light receiving element.

  In the optical object identification device of this embodiment, since the selected polarization directions of the respective polarization state selection elements (linear polarizers) corresponding to both light receiving elements are orthogonal, the signal intensity output by both light receiving elements is When one signal strength is high, the other is small. Therefore, by calculating the difference between the two output signals, the output signal difference increases as the measured object has a smaller degree of depolarization, and the measured object can be identified with high accuracy.

In the optical object identification device according to one embodiment, the signal processing unit includes:
Calculating the difference between the signal output from the first light receiving element and the signal output from the second light receiving element;
A ratio between the difference and the sum of the signal output from the first light receiving element and the signal output from the second light receiving element; or
A ratio between the difference and the signal output from the first light receiving element or the signal output from the second light receiving element is calculated.

  In the optical object identification device of this embodiment, the signal processing unit includes a ratio of an output signal difference between both light receiving elements and a sum of output signals from both light receiving elements, or an output signal difference between both light receiving elements, A ratio with the output signal of the light receiving element or the output signal of the second light receiving element is calculated.

  In the calculation of these ratios, for example, when the output signal difference is a numerator, this numerator represents the depolarization characteristic due to the surface state of the object to be measured, and the sum of the output signals of both light receiving elements is the denominator. This denominator becomes a light reception signal resulting from the reflectance of the surface of the object to be measured. Therefore, it becomes possible to identify the object to be measured with high accuracy while reducing the influence of the variation in the reflectance of the surface of the object to be measured.

  In one embodiment of the optical object identification device, the semiconductor light emitting element is a semiconductor laser.

  In the optical object identification device of the above embodiment, since a semiconductor laser is used as the semiconductor light emitting element, the light density on the object to be measured can be increased, the received light signal intensity can be increased, and high accuracy can be achieved. The object to be measured can be identified.

  In one embodiment of the optical object identification device, the light receiving element is formed of a photodiode.

  In the optical object identification device of this embodiment, the use of a photodiode as a light receiving element is suitable for downsizing the device configuration, and its cost can be reduced, which is very suitable. .

  In one embodiment of the optical object identification device, the first light receiving element and the second light receiving element are formed on the same semiconductor substrate.

  In the optical object identification device of the above embodiment, since the first light receiving element (photodiode) and the second light receiving element (photodiode) are formed on the same semiconductor substrate, the number of parts can be reduced. Therefore, the manufacturing cost can be reduced.

  In one embodiment, the light receiving unit and the signal processing unit are formed on the same semiconductor substrate.

  In the optical object identification device of this embodiment, the light receiving unit (photodiode as an example) and the signal processing unit are formed on the same semiconductor substrate. A wire for connecting to the circuit becomes unnecessary, so that the noise level can be reduced and the number of parts can be reduced. Therefore, the manufacturing cost can be reduced.

  In one embodiment of the present invention, the first light receiving element, the second light receiving element, and the signal processing unit are formed on the same semiconductor substrate.

  In the optical object identification device of this embodiment, since the first and second light receiving elements (photodiodes) and the signal processing unit are formed on the same semiconductor substrate, the number of parts can be further reduced and the noise level is also reduced. can do.

  In one embodiment, the light receiving unit includes a light receiving element group in which a plurality of light receiving elements are aligned.

  In the optical object identification device of this embodiment, it is possible to measure the position dependency of the depolarization characteristic due to reflection, and the object to be measured can be identified with higher accuracy than when one photodiode is used. It becomes possible.

  In the optical object identification device according to one embodiment, the signal processing unit normalizes the signal of each light receiving element of the light receiving element group according to the signal intensity of the light receiving element having the maximum intensity among the light receiving element groups. It is characterized by doing.

  In the optical object identification device of this embodiment, since the position dependence of the depolarization characteristic is normalized by the maximum value of the signal intensity of the light receiving element, the influence due to the variation in the reflectance of the surface of the object to be measured can be reduced, The object to be measured can be identified with higher accuracy.

Moreover, in the optical object identification device of one embodiment, the first condensing means is configured by a first condensing lens,
The distance between the focal position of the first condenser lens and the surface of the object to be measured is changed.

  In the optical object identification device of this embodiment, since the distance between the focal position of the first condenser lens and the surface of the object to be measured is changed, the first condenser lens is used even when the surface of the object to be measured is large. The surface of the object to be measured can be positioned at the focal position. Therefore, it is possible to widen the range of objects to be measured that can be identified.

In one embodiment, the optical object identification device has a lens vibration mechanism that vibrates the first condenser lens,
By changing the lens position of the first condenser lens by the lens vibration mechanism, the distance between the focal position of the first lens and the surface of the object to be measured is changed.

  Since the optical object identification device of this embodiment has a lens vibration mechanism that vibrates the first condenser lens, it is suitable as means for changing the distance between the focal position of the first condenser lens and the surface of the object to be measured. It is.

  In the optical object identification device according to one embodiment, the lens vibration mechanism has a cam.

In the optical object identification device of this embodiment, since the lens vibration mechanism is constituted by a cam, it is suitable as a lens vibration mechanism.
In one embodiment, the cam curve of the cam is a sine wave curve.

  In the optical object identification device of this embodiment, since the cam curve of the cam is a sine wave curve, the vibration state of the lens can be calculated by simple calculation, the lens position at an arbitrary time can be easily obtained, and an appropriate The reflected light signal can be processed by the signal processing unit.

  In the optical object identification device according to one embodiment, the lens vibration mechanism includes a solenoid coil.

  In the optical object identification device of the above-described embodiment, a lens vibration mechanism using a suction force or pushing force by a solenoid coil and a spring can be configured.

  In one embodiment, the lens vibration mechanism includes a crank mechanism that converts a rotational motion into a linear reciprocating motion.

In the optical object identification device of this embodiment, the configuration of the lens vibration mechanism can be simplified by using a crank mechanism as the lens vibration mechanism.
In one embodiment of the optical object identification device, the lens vibration mechanism has an actuator.

  In the optical object identification device of the above embodiment, the device configuration can be reduced in size by using an actuator as the lens vibration mechanism.

  In the optical object identification device according to an embodiment, the lens vibration mechanism receives a wind with a blade attached to a lens holder to vibrate the lens.

  In the optical object identification device according to this embodiment, the lens vibration mechanism does not require a component such as a motor that requires a driving force, so that the manufacturing cost of the device configuration can be reduced.

  Moreover, in the optical object identification device according to an embodiment, the first condenser lens is a progressive lens, and the position of the first light beam incident on the progressive lens is changed to change the position of the first condenser lens. The distance between the focal position and the surface of the object to be measured is changed.

  In the optical object identification device of the above embodiment, the device configuration can be reduced in size by using a progressive lens.

  In the optical object identification device of one embodiment, the distance between the focal position of the progressive lens and the surface of the object to be measured is moved by moving the progressive lens in a plane substantially perpendicular to the first light beam. To change.

In the optical object identification device of this embodiment, the vibration width of the progressive lens that forms the first condenser lens can be reduced, so that the device configuration can be reduced in size.
Moreover, in the optical object identification device of one embodiment, the optical switch including the liquid crystal is disposed on the optical axis of the first light beam incident on the progressive lens.

  In the optical object identification device of this embodiment, by using an optical switch using liquid crystal, the focal position of the progressive lens forming the first condenser lens and the measured object are made without vibrating any component constituting the device. The distance between the object surface and the object surface can be changed. For this reason, the simplification, size reduction, and reliability of the apparatus configuration can be improved.

  Further, in the optical object identification device of one embodiment, the amount of change in the distance between the focal position of the first condenser lens and the surface of the object to be measured is greater than the unevenness level difference on the surface of the object to be measured. It is characterized by being enlarged.

  In the optical object identification device of this embodiment, since the amount of change in the distance between the focal position of the first condenser lens and the surface of the object to be measured is larger than the unevenness level difference on the surface of the object to be measured, it is ensured. A reflected light signal from the focal position of the first condenser lens can be obtained.

  In the optical object identification device according to one embodiment, the amount of change in the distance between the focal position of the first condenser lens and the surface of the object to be measured is 5 mm to 15 mm.

  In the optical object identification device of this embodiment, the majority of measurement objects that can be identified are covered by setting the amount of change in the distance between the focal point of the first condenser lens and the surface of the object to be measured to 5 mm to 15 mm. can do.

In one embodiment of the optical object identification device, the first light collecting means for condensing and irradiating the first light flux on the object to be measured;
A second condensing unit that condenses light that has passed through the first condensing unit among the light reflected by the object to be measured;
A pinhole portion disposed between the second light collecting means and the first and second light receiving elements;
The first condensing means comprises a first condensing lens;
A mechanism for changing the distance between the focal position of the first condenser lens and the surface of the object to be measured;
The signal processor is
A focus signal that is an output of the first light receiving element at the time of focusing when the distance between the first condenser lens and the surface of the object to be measured is approximately equal to the focal length of the first condenser lens;
The ratio between the defocus signal, which is the output of the second light receiving element at the time of defocus, in which the distance between the first condensing lens and the surface of the object to be measured is different from the focal length of the first condensing lens is calculated. It is characterized by doing.

  According to the optical object identification device of this embodiment, the accuracy of identification of the object to be measured can be improved by dividing the reflected light signal into two and using the signals at the time of focusing and at the time of defocusing.

In one embodiment of the optical object identification device, the first light collecting means for condensing and irradiating the first light flux on the object to be measured;
A second condensing unit that condenses light that has passed through the first condensing unit among the light reflected by the object to be measured;
A pinhole portion disposed between the second light collecting means and the first and second light receiving elements;
The first condensing means comprises a first condensing lens;
A mechanism for changing the distance between the focal position of the first condenser lens and the surface of the object to be measured;
The signal processor is
A focus signal that is an output of the first light receiving element at the time of focusing when the distance between the first condenser lens and the surface of the object to be measured is approximately equal to the focal length of the first condenser lens;
Processing a defocus signal, which is an output of the second light receiving element at the time of defocus, in which a distance between the first condenser lens and the surface of the object to be measured is different from a focal length of the first condenser lens; It is characterized by.

  In the optical object identification device of this embodiment, the reflected light is divided into two light beams, a first reflected light beam and a second reflected light beam, which are received by the first and second light receiving elements, respectively, and output by the first light receiving element. The focus signal at the time and the defocus signal at the time of defocus output from the second light receiving element are measured as orthogonal polarization components. Thereby, the precision of identification of a to-be-measured object can be improved.

  In the optical object identification device according to one embodiment, the signal processing unit calculates a ratio between the focus signal and the defocus signal.

  In the optical object identification device of this embodiment, the accuracy of identification of the object to be measured can be improved by calculating the ratio between the focus signal and the defocus signal that are orthogonal polarization components.

  In the optical object identification device according to one embodiment, the signal processing unit calculates a difference between the focus signal and the defocus signal.

  In the optical object identification device according to this embodiment, the signal processing unit calculates the difference between the focus signal and the defocus signal, thereby improving the accuracy of identification of the object to be measured.

  In the optical object identification device of one embodiment, the signal processing unit calculates a difference between the focus signal and the defocus signal, and calculates a ratio between the difference and the focus signal. To do.

  In the optical object identification device of this embodiment, the influence of the variation in the reflectance of the surface of the object to be measured can be reduced, so that the accuracy of identification of the object to be measured can be improved.

Further, in the optical object identification device of one embodiment, light intensity modulation is applied by applying a modulation signal to the semiconductor light emitting element,
The signal processor is
The difference between the first output signal output from the light receiving unit when the modulation signal is at the H level and the second output signal output from the light receiving unit when the modulation signal is at the L level is calculated.

  In the optical object identification device of this embodiment, the semiconductor light emitting element is subjected to intensity modulation to calculate the difference between the first output signal and the second output signal when the modulation signal is at the H level and the L level. Thereby, the influence of the disturbance light noise which injects into a light-receiving part can be removed.

  In one embodiment of the optical object identification device, the modulation signal applied to the semiconductor light emitting element is a rectangular wave.

  In the optical object identification device of the above embodiment, since the modulation signal applied to the semiconductor light emitting element is a rectangular wave, the effect of removing ambient light noise can be improved.

  In the optical object identification device of one embodiment, the light emission amount of the semiconductor light emitting element at the L level is approximately 0 W.

  In the optical object identification device of this embodiment, since the light emission amount at the L level is approximately 0 W, only the disturbance light noise can be measured by the second output signal at the L level. Therefore, the effect of removing ambient light noise can be improved.

  Moreover, in the optical object identification device according to one embodiment, the modulation frequency of the light intensity modulation is 50 kHz or more.

  In the optical object identification device of this embodiment, the semiconductor light emitting element is modulated in the general frequency band of ambient light noise, so that the effect of removing ambient light noise can be improved.

  In one embodiment of the optical object identification device, the modulation frequency of the light intensity modulation is 100 Hz to 10 kHz.

  In the optical object identification device of this embodiment, since the general disturbance light noise frequency band and the modulation frequency of the semiconductor light emitting element do not overlap, the effect of removing the disturbance light noise can be enhanced.

In the optical object identification device according to one embodiment, the signal processing unit includes:
When the modulation signal is at the H level, the first output signal from the light receiving unit is passed as it is, and when the modulation signal is at the L level, the first output signal when the modulation signal is at the H level is sampled. A first sample and hold circuit for holding;
When the modulation signal is at L level, the second output signal from the light receiving section is passed as it is, and when the modulation signal is at H level, the second output signal when the modulation signal is at L level is sampled. A second sample and hold circuit for holding;
And a differential circuit for taking a difference between a signal output from the first sample hold circuit and a signal output from the second sample hold circuit.

  In the optical object identification device of this embodiment, the first sample and hold circuit samples and holds the first output signal at the H level, and the second sample and hold circuit samples and holds the second output signal at the L level. Then, the differential circuit calculates a difference between the first output signal and the second output signal. Thereby, a circuit configuration that removes disturbance light noise can be realized.

In the optical object identification device according to one embodiment, the signal processing unit includes:
An amplifying unit for amplifying the signal detected by the light receiving unit;
An amplification degree switching unit that switches the amplification degree of the amplification unit according to the signal intensity of the light receiving unit;

In the optical object identification device of one embodiment, the amplification degree switching unit is
The signal intensity of the amplifying unit at a predetermined time is held, and the degree of amplification of the amplifying unit is determined by comparing the held value with a reference value.

  In the optical object identification device of this embodiment, by holding the signal intensity at a predetermined time, the amplification degree can be switched using the signal intensity at a desired time in the signal intensity changing with time.

In the optical object identification device according to one embodiment, the signal processing unit includes:
An amplifying unit for amplifying the signal detected by the light receiving unit;
An amplification degree switching unit that switches the amplification degree of the amplification unit according to the signal intensity of the light receiving unit;
The amplification degree switching unit is
Hold the signal strength of the amplification unit at a predetermined time, and determine the amplification degree of the amplification unit by comparing the held value and a reference value,
Further, the amplification unit includes a first amplifier and a second amplifier, and the amplification degree switching unit includes a first amplification degree switch, a second amplification degree switch, a peak hold circuit unit, and a sample hold circuit unit. ,
The signal processor is
A first signal processing circuit that receives the signal detected by the first light receiving element and includes the first amplifier, the peak hold circuit, and the first amplification degree switch;
A second signal processing circuit that receives the signal detected by the second light receiving element and has the second amplifier, the sample hold circuit, and the second amplification degree switch;
The first amplification degree switch determines an amplification degree of the first amplifier based on an output value of the peak hold circuit,
The second amplification degree switch determines the amplification degree of the second amplifier based on the output of the sample and hold circuit.

  In the optical object identification device of this embodiment, the first amplification degree switching unit determines the amplification degree of the first amplifier based on the output value of the peak hold circuit, while the second amplification degree switching unit is the sample hold circuit. The amplification factor of the second amplifier is determined on the basis of the output value. Thus, it is preferable to use the peak hold circuit for determining the amplification degree of the first amplifier and to use the sample and hold circuit for determining the amplification degree of the second amplifier.

In the optical object identification device according to one embodiment, the signal processing unit includes:
Having a function of holding the output signal of the amplifying unit;
The timing for holding the output signal of the amplifying unit for comparison with the reference value is determined using a modulation signal applied to the semiconductor light emitting element.

  In the optical object identification device of this embodiment, it is possible to easily hold the output signal of the amplifying unit at a required time by using the pulse signal used as the modulation signal of the semiconductor light emitting element.

In the optical object identification device of one embodiment, the first signal processing circuit is
A peak position detector for detecting, as a reference time, a time at which the peak hold circuit holds a peak value of the focus signal, which is an output of the first light receiving element during the focus,
The second signal processing circuit includes:
Based on the reference time detected by the peak position detector and the modulation signal applied to the semiconductor light emitting element, the sample hold circuit samples a defocus signal that is an output of the second light receiving element at the time of the defocus. It has a timing detection part which determines the timing to hold.

  In the optical object identification device of this embodiment, the time at which the peak position of the focus signal is detected by the peak position detector of the first signal processing circuit is used as the reference time, and the sample and hold circuit of the second signal processing circuit uses the time. Determine the time to sample and hold the focus signal. As a result, it is possible to easily and accurately determine the timing for sampling and holding the defocus signal.

In the optical object identification device of one embodiment, the amplification degree switching unit is
When the output signal level of the amplification unit is outside the set reference value range, the amplification degree of the amplification unit is increased or decreased by one step.

  In the optical object identification device according to this embodiment, when the amplification degree switch switches the amplification degree, the circuit configuration having a circuit function for selecting a target amplification degree is simplified by switching one step at a time. Can be

  In the optical object identification device of one embodiment, the amplification unit included in the signal processing unit includes an amplifier group in which a plurality of amplifiers are connected in series.

  In the optical object identification device of this embodiment, the amplification unit is configured in series so that a plurality of amplifiers are connected in series, so that even when a circuit configuration with a large amplification is required, the amplification is divided by the plurality of amplifiers. Therefore, the circuit operation can be stabilized.

In the optical object identification device of one embodiment, the amplification degree switching unit is
When the amplification unit has a predetermined amplification degree, an input connection resistance of a predetermined amplifier in the amplifier group is opened.

  In the optical object identification device of this embodiment, when the dynamic range for amplifying the signal is very wide, it is necessary to use the amplifier group having a small amplification degree, but the input resistance of the amplifier is reduced. By releasing, the degree of amplification can be made 1. Thereby, the dynamic range of the amplification degree is wide and stable circuit operation can be realized.

In one embodiment, the first signal processing circuit outputs a first signal including the focus signal,
The second signal processing circuit outputs a second signal including the defocus signal,
The signal processor is
An A / D converter for converting the first signal and the second signal into a digital signal;
A first amplification signal representing the amplification degree of the first amplifier; a second amplification signal representing the amplification degree of the second amplifier; and the first and second signals converted into digital signals by the A / D converter. Digital signal processing circuit for calculating the ratio of the focus signal and the defocus signal, the difference between the focus signal and the defocus signal, or the ratio between the focus signal and the defocus signal and the focus signal Have

  In the optical object identification device of this embodiment, the signal processing unit serves as a means for calculating a ratio or difference between the focus signal and the defocus signal, and outputs the first and second signal processing circuits from the first and second signal processing circuits. By performing A / D conversion on the second signal by the A / D converter and digital processing by the digital signal processing circuit, desired calculation can be easily performed.

In the optical object identification device of one embodiment, the digital signal processing circuit is
A memory for storing the first and second digital signals,
The memory has a storage capacity capable of storing waveform data corresponding to at least a half cycle in the variation of the focal position for each of the first signal and the second signal.

  The optical object identification device of this embodiment has a memory capable of storing at least half a period or more of the waveform data of each of the first and second signals converted into digital signals, so that a signal at a target time can be stored from the memory. It can be taken out and used reliably.

In the optical object identification device of one embodiment, the digital signal processing circuit is
A memory for storing the first and second digital signals,
The memory stores, for each of the first signal and the second signal, waveform data for one period in the variation of the focal position.

  In the optical object identification device according to this embodiment, the waveform data of each of the first and second signals converted into digital signals is accumulated for one period, so that a signal at a target time can be used more efficiently. .

In the optical object identification device of one embodiment, the first signal processing circuit is
A peak position detector that detects a peak time of the focus signal by the peak hold circuit as a reference time;
The second signal processing circuit includes:
A timing detection unit for determining a timing at which the sample hold circuit unit samples and holds the defocus signal based on the reference time detected by the peak position detection unit and a modulation signal applied to the semiconductor light emitting element; ,
The A / D converter is
A / D conversion is started with a trigger signal that the peak position detection unit of the first signal processing circuit detects the reference time,
The digital signal processing circuit includes a memory for storing digital data that is A / D converted.

  In the optical object identification device of this embodiment, A / D conversion by the A / D conversion unit is started with a reference time for the peak position of the focus signal detected by the peak position detection unit of the first signal processing circuit as a trigger signal. . Then, by storing each A / D converted signal waveform in a memory, a means for calculating desired data can be simply configured.

In one embodiment of the optical object identification device, in the process of storing digital data in the memory from the reference time detected by the peak position detection unit included in the first signal processing circuit,
The peak position detection unit detects a new reference time between the reference time and the time when the sample hold circuit unit starts sample hold at the timing determined by the timing detection unit of the second signal processing circuit. Clear all the digital data stored in the memory by this new reference time,
The A / D conversion unit starts A / D conversion of the first and second signals using the detection of the new reference time by the peak position detection unit as a trigger signal, and stores the digital data in the memory To do.

  In the optical object identification device of this embodiment, the first and second signal processing circuits having the above-described configuration have a large unevenness on the surface of the object to be measured, and the second position after the peak position is detected by the first signal processing circuit. Even if the peak position is detected again by the first signal processing circuit by the time when the desired sample hold is started by the signal processing circuit, the digital data of the signal waveform is again stored in the memory from the time of the new peak position detection. Start accumulating. Thereby, it is possible to improve the accuracy of identification of an object to be measured without performing calculation using an incorrect waveform.

In the optical object identification device of one embodiment, the digital signal processing circuit is
Based on the reference time detected by the peak position detector, the focus signal at the reference time included in the first signal is extracted from the digital data stored in the memory and included in the second signal. Take out the defocus signal at a predetermined time,
The focus signal is based on a first amplification signal representing the amplification of the first amplifier of the first signal processing circuit and a second amplification signal representing the amplification of the second amplifier of the second signal processing circuit. And a defocus signal ratio, or a difference between the focus signal and the defocus signal, or a ratio between the focus signal and the defocus signal and the focus signal.

  In the optical object identification device of this embodiment, the digital signal processing circuit is configured to select a focus signal at a reference time based on the first signal and a predetermined time based on the second signal from digital data having a signal waveform stored in a memory. Defocus signal is extracted and calculated. In this signal processing, the digital signal processing circuit includes a first signal processing circuit unit, a first signal of the second signal processing circuit unit, a desired timing signal representing a predetermined time, and a first timing signal based on the second signal. The second amplification signal is used. This simplifies signal processing and enables quick calculation.

In the optical object identification device of one embodiment, the digital signal processing circuit is
A digital signal calculation unit for detecting a peak position of the first signal based on the first signal converted into the digital signal in the digital data stored in the memory;
The time data of the peak position detected by the digital signal calculation unit is set as the reference time, and the focus signal at this reference time is taken out,
A defocus signal at a predetermined time determined by a timing detection unit based on the reference time and the modulation signal is extracted from the second digital signal converted from the digital data stored in the memory,
The ratio of the focus signal to the defocus signal or the focus signal based on the first amplification signal representing the amplification degree of the first amplifier and the second amplification signal representing the amplification degree of the second amplifier. And a ratio between the focus signal and the difference between the focus signal and the defocus signal.

  In the optical object identification device according to this embodiment, the digital signal processing circuit includes the digital signal calculation unit, and the digital signal representing the signal waveform stored in the memory is used to determine the time of the peak position of the first signal. Digital signal processing is performed on the defocus signal at the desired time of the data (reference time) and the second signal. Thereby, a circuit for timing measurement of the first signal processing circuit and the second signal processing circuit is not necessary, and the circuit configuration can be simplified.

In the optical object identification device of one embodiment, the digital signal processing circuit is
In the process of extracting the focus signal and the defocus signal from the digital data stored in the memory,
Average value of a plurality of focus signals at a plurality of times before and after the reference time, a plurality of times before the reference time, or a plurality of times after the reference time in the digital data stored in the memory As a focus signal,
Among the digital data stored in the memory, a plurality of times before and after a predetermined time determined by the timing detection unit based on the reference time and the modulation signal, or a plurality of times before the reference time, or the reference The average value of a plurality of defocus signals at a plurality of times after the time is taken out as a defocus signal,
The focus signal is based on a first amplification signal representing the amplification of the first amplifier of the first signal processing circuit and a second amplification signal representing the amplification of the second amplifier of the second signal processing circuit. And a defocus signal ratio, or a difference between the focus signal and the defocus signal, or a ratio between the focus signal and the defocus signal and the focus signal.

  In the optical object identification device of this embodiment, when a focus signal and a defocus signal at a desired time are extracted from digital data representing a signal waveform stored in a memory, a plurality of focus signals and defocuses near the desired time are extracted. The average value of the signal strength of the signal is used. Thereby, an error due to noise can be reduced.

In the optical object identification device of one embodiment, the digital signal processing circuit is
The object to be measured is identified by calculating a ratio between the focus signal and the defocus signal, a difference between the focus signal and the defocus signal, or a ratio between the focus signal and the defocus signal and the focus signal. In the process
The calculation is performed a plurality of times, and the measurement object is identified by calculating an average of the calculation results of the plurality of times.

  In the optical object identification device of this embodiment, it is possible to improve the identification accuracy of the measurement object by identifying the measurement object by averaging a plurality of calculation results using the focus signal and the defocus signal. it can.

  In one embodiment, when the distance to the object to be measured is larger than a predetermined value, the light emission of the semiconductor light emitting element is turned off or reduced.

  In the optical object identification device of this embodiment, when the distance to the object to be measured exceeds a predetermined value, the output of the semiconductor light emitting element is turned off or reduced, thereby reducing standby power when measurement is not required. The emitted light can be prevented from harming the human body or the like.

  In the optical object identification device according to one embodiment, the light emitting state of the semiconductor light emitting element satisfies the safety standard class 1 of the laser product.

  In the optical object identification device of this embodiment, even if the laser beam from the device is directly incident on the eyes of one person, there is no harm to the human body.

  In one embodiment, the optical object identification device has an optical window formed in a part of a housing, and the distance between the first condenser lens and the optical window is the first condenser. It is shorter than the focal length of the lens.

  In the optical object identification device of this embodiment, with the above configuration, even when an object that scatters light, such as dust, adheres to the optical window from which the first light flux exits, the reflected light from the attached matter is collected in the first collection. Since it is outside the focal length of the optical lens, it hardly enters the light receiving portion. Accordingly, it is possible to prevent malfunction during identification of the object to be measured.

  Moreover, in the cleaner of one Embodiment, the said optical object identification device was mounted in the head part of the cleaner. This vacuum cleaner is suitable because it can automatically identify the floor surface to be measured.

  Moreover, in the self-propelled cleaner of one embodiment, it is most preferable that the optical object identification device is installed, so that the type of the floor surface can be automatically detected while self-propelled.

  According to the optical object identification device of the present invention, a change in the received light signal corresponding to the surface roughness can be obtained by irradiating the object to be measured and evaluating the depolarization characteristics of the reflected light. The type of the measurement object can be identified.

  In addition, by mounting the optical object identification device of the present invention on a vacuum cleaner or a self-propelled cleaner, it is possible to have a function of automatically determining the type of floor and optimizing the operation status of the cleaner. It becomes possible.

  Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

(First embodiment)
FIG. 1 is a schematic configuration diagram of an optical object identification device according to a first embodiment of the present invention. In FIG. 1, the locus of light rays and main optical components are illustrated, and illustrations of components that hold the optical components are omitted. Here, as a semiconductor light emitting element as a light source, there are a light emitting diode (LED (Light Emitting Diode)), a semiconductor laser (LD (Laser Diode)), etc., and the light density on the object to be measured 9 exceeds a desired value. Either is acceptable. However, the LD is more preferable than the LED because the LD has higher collimating properties, the beam diameter can be reduced, and the amount of light per unit area can be increased. As described above, in the embodiment of the present invention, the LD is shown as an example of the semiconductor light emitting element, and in the following embodiments, the LD is adopted as an example of the semiconductor light emitting element.

  The optical object identification device according to the first embodiment includes a semiconductor laser 1, a collimator lens 2, a diaphragm 3 having a circular aperture, a non-polarizing beam splitter 4, and a first condenser lens 8. The semiconductor laser 1, the collimator lens 2, the stop 3, the non-polarizing beam splitter 4 as the light branching element, and the first condensing lens 8 as the first condensing means form a light projecting unit.

  The first embodiment also includes a second condenser lens 10, a pinhole unit 11, a linear polarizer 13a forming a polarization state selection unit, a light receiving unit 12 including a light receiving element such as a photodiode, And a signal processing circuit 14 as a signal processing unit.

  The light emitted from the semiconductor laser 1 is converted into a parallel light beam by the collimator lens (CL) 2, and only the portion where the light intensity near the center of the beam is substantially uniform passes through the stop 3 by the stop 3 of the circular aperture. The beam cross-sectional shape is deformed into a circle. Thereafter, the light beam is split into a first light beam 5 that passes through the non-polarizing beam splitter 4 and a second light beam 6 that is reflected by the non-polarizing beam splitter 4 and travels substantially parallel to the surface of the object 9 to be measured.

  Here, the second light beam 6 reflected by the non-polarizing beam splitter 4 deviates from the optical system. The second light beam 6 may be reflected by, for example, a housing side wall (not shown) surrounding the optical system and detected by the light receiving unit 12 as noise light. In order to remove the noise light, a linear polarizer 13b as stray light preventing means is installed on the optical axis of the second light beam 6 so as to be orthogonal to the polarization direction of the second light beam 6. Thereby, since the 2nd light beam 6 cannot pass through the linear polarizer 13b, it does not irradiate to a housing | casing side wall and does not become a noise light source.

  The first light beam 5 that has passed through the non-polarizing beam splitter 4 is incident on the center of the first condenser lens 8 and is condensed on the object 9 to be measured by the first condenser lens 8. Here, the object to be measured 9 is disposed at substantially the focal length of the first condenser lens 8. The first light beam 5 reflected by the object to be measured 9 is diffused in all directions. Here, since the distance between the first condenser lens 8 and the object 9 to be measured is substantially the focal length of the first condenser lens 8, the first condenser lens out of the light reflected by the object 9 to be measured. The light passing through 8 forms a parallel reflected light beam 7 having the lens diameter of the first condenser lens 8 as shown in FIG. On the other hand, of the light reflected by the object 9 to be measured, the light that does not pass through the first condenser lens 8 is diffused and does not contribute to the signal thereafter.

  Further, in the optical object identification device shown in FIG. 1, a light shielding means (not shown) is provided so that the reflected light that does not pass through the first condenser lens 8 does not enter the light receiving unit 12. The light shielding means described above is provided similarly in the following embodiments, but the description thereof is omitted.

  The reflected light beam 7 is converted into a parallel light beam by the first condenser lens 8, and then split into a light beam that again enters the non-polarizing beam splitter 4 and passes through the non-polarizing beam splitter 4 and a light beam that is reflected by the non-polarizing beam splitter 4. The However, in FIG. 1, the light beam passing through the non-polarizing beam splitter 4 is omitted. The light beam reflected by the non-polarizing beam splitter 4 is condensed by the second condenser lens 10, and the light beam that has passed through the pinhole 11 disposed at the focal length of the second condenser lens 10 is used as a polarization state selection unit. It is detected by the light receiving element 12 via the linear polarizer 13a.

  Since the pinhole portion 11 is disposed at the focal position of the second condenser lens 10, it is condensed by the second condenser lens 10 when the object 9 to be measured is located outside the focal position of the first condenser lens 8. The reflected reflected light beam 7 is defocused on the surface of the pinhole portion 11, and the amount of light passing through the pinhole 11a of the pinhole portion 11 is greatly reduced.

  By arranging in this way, the signal intensity of the optical signal to the light receiving unit 12 can be increased with respect to the measurement object 9 arranged at the focal length of the first condenser lens 8. The beam diameter can be reduced. Thereby, the light quantity of the reflected light beam 7 becomes large, and it becomes possible to identify the measurement object 9 with high accuracy.

  The light receiving unit 12 converts the incident optical signal into an electrical signal, and then sends the electrical signal to the signal processing circuit 14 at the subsequent stage.

  By the way, the first light beam 5 irradiated on the measurement object 9 is reflected and scattered by the surface of the measurement object 9. Generally, when light is reflected, the polarization state of the reflected light changes depending on the shape of the reflecting surface. For example, in the case of reflection on a surface having surface accuracy sufficiently smaller than the wavelength of the incident light, such as the surface of an optical mirror, the polarization state of the incident light is maintained, but the unevenness of the reflecting surface with respect to the wavelength of the incident light is maintained. When the level difference is large, the reflected light causes multiple scattering, and thus exhibits depolarization characteristics.

  In other words, by measuring the polarization information of the reflected light, the uneven state of the surface of the object to be measured 9 can be known. In this embodiment, as shown in FIG. 1, a linear polarizer 13a as a polarization state selection unit is installed immediately before the light receiving unit 12, and the light receiving unit 12 receives only a polarized component that vibrates in a specific direction. It comes to detect.

  Now, in FIG. 1, assuming that the linearly polarized light of light emitted from an LD (semiconductor laser) 1 is in a direction perpendicular to the paper surface, the linear polarizer 13a is also arranged to pass light having a polarization direction perpendicular to the paper surface. ing. With this arrangement, the light receiving unit 12 measures the light intensity of the component in the polarization direction of the reflected light beam 7, and the signal processing circuit 14 detects the light intensity level.

  Here, since the degree of depolarization of the reflected light beam 7 depends on the degree of unevenness of the surface of the object 9 to be measured, the signal processing circuit 14 measures the light intensity of the component in the polarization direction. Thus, the type (material) of the DUT 9 can be determined. In particular, when identifying the type (material) of the object 9 to be measured from among a plurality of objects having different known materials (surface shapes), the memory M included in the signal processing circuit 14 stores a plurality of known objects in advance. By inputting information on the degree of depolarization by the object to be measured of a different material and comparing this known information with the measurement result, the type (surface shape) of the object 9 to be measured can be more effectively discriminated.

  The first light beam 5 is incident on the device under test 9 almost perpendicularly and is incident as an S wave. Here, the S wave will be briefly described. When the vibration direction of the incident light is perpendicular to the incident surface including the optical axis of the incident light and its regular reflection light, the incident light becomes an S wave. On the other hand, when the vibration direction of the incident light is parallel to the incident surface, the incident light becomes a P wave. The P wave has a component in which the vibration direction of light is perpendicular to the reflection surface, and this vertical vibration direction is perpendicular to the vibration direction of light that passes through the linear polarizer 13a disposed immediately before the light receiving element 12. It becomes a relationship. For this reason, the component with the perpendicular vibration direction included in the P wave becomes a noise component with respect to the degree of depolarization due to reflection. Therefore, it is preferable that the first light beam 5 is incident on the surface of the DUT 9 perpendicularly and is incident as an S wave.

  Since the object to be measured 9 is disposed at the focal position of the first condenser lens 8, the light reflected and diffused by the object to be measured 9 becomes a parallel light flux by the first condenser lens 8. Further, since the pinhole portion 11 is disposed at the focal position of the second condenser lens 10, the reflected light beam 7 is most condensed on the surface of the pinhole portion 11. In general, when the reflected light is ideally a parallel light beam, the beam diameter (beam waist) at the most condensed surface depends on the lens used, but it is about several μm to several tens of μm. Become. The diameter of the pinhole 11a is somewhat larger than the beam waist.

  With this arrangement, when the DUT 9 deviates from the focal length of the first condenser lens 8, the reflected light beam does not become a parallel light beam, and the reflected light beam is degenerated on the surface of the pinhole portion 11. The focus state is reached and hardly passes through the pinhole portion 11. For this reason, it is possible to prevent erroneous detection and improve the identification accuracy by extracting and identifying the signal when the object 9 is near the focus having a large S / N as the signal necessary for the identification. . As described at the beginning of this embodiment, as a semiconductor light emitting device, a semiconductor capable of increasing the light density by focusing light on the device under test 9 in order to improve the S / N as described above. A laser (LD) is preferred.

  On the other hand, the light receiving unit 12 can satisfy the functions of the present invention as long as it can convert an optical signal into an electrical signal. In particular, by using a photodiode, the device configuration can be reduced in size. It is suitable, and the cost can be reduced, which is very suitable. Furthermore, when the photodiode and the signal processing circuit 14 in the subsequent stage are manufactured on the same semiconductor substrate, noise on the wire connecting the photodiode and the signal processing circuit 14 is greatly reduced. it can. Further, when the photodiode and the signal processing circuit 14 are formed on the same substrate, the chip area can be reduced and the cost can be reduced.

  In addition, the light receiving portion may have a structure in which a plurality of photodiodes are aligned. For example, it is also possible to use a structure in which a plurality of divided photodiodes are arranged in a row, or an image sensor such as a CCD or a CMOS imager.

  In the case where the light receiving part is constituted by one photodiode, the information obtained from the one photodiode is only the light intensity, but when the light receiving part having a structure including a plurality of photodiodes is used as described above. The light intensity distribution can be measured by the output signals of a plurality of photodiodes. As a result, it is possible to more accurately identify the object 9 to be measured, which is a measurement object, as compared with the measurement of intensity alone.

  FIG. 2 shows a value obtained by normalizing the light intensity detected by the photodiode at each position with the maximum value of the light intensity at each position when the light receiving unit 12 includes a plurality of photodiodes as described above. The distribution of (normalized value) is shown.

  When the surface of the object to be measured 9 is smooth, the reflected light beam 7 has a low degree of depolarization, so that the light passing through the linear polarizer 13a as the polarization state selection unit becomes strong near the center of the optical axis. Therefore, as shown by the waveform (3) in FIG. 2, the light intensity distribution is sharp with the optical axis as the center.

  On the other hand, when the unevenness of the surface of the object to be measured 9 is large and the reflected light beam 7 has a large degree of multiple scattering, the maximum value of the shape of the light intensity distribution is as shown by the waveform (1) in FIG. The light intensity distribution is low and broad. Further, the waveform (2) shown in FIG. 2 shows that the unevenness of the surface of the object 9 is smaller than that of the waveform (1) of FIG. 2 and more uneven than the waveform (3) of FIG. The shape of the light intensity distribution when it is large is shown.

  In addition, although the effect by having comprised the light-receiving part mentioned above by the light receiving element group which consists of a some light receiving element is applicable also in subsequent embodiment, description is abbreviate | omitted in subsequent embodiment.

  Next, FIG. 3A shows a schematic configuration of an optical object identification device according to a modification of the first embodiment. In this modification, as shown in FIG. 3A, all the components are the same as those in the first embodiment shown in FIG. 1, and the incident position of the first light beam 5 on the first condenser lens 8 is the first. It is different from the embodiment.

  In this modified example, since the first light beam 5 is incident on the DUT 9 as an S wave, the polarization direction of the emitted light from the semiconductor laser 1 is perpendicular to the paper surface. In accordance with this, the linear polarizer 13a is The polarization direction of the light to be transmitted is also set in the direction perpendicular to the paper surface.

  In this modification, since the first light beam 5 is incident on the edge portion 8 a of the first condenser lens 8, the first light beam 5 is incident on the object to be measured 9 with a predetermined incident angle. When the first light beam 5 is reflected by the object 9 to be measured, the component in which the polarization is maintained is the strongest in the regular reflection direction, so that the incident light (first light beam 5) to the object 9 is obliquely incident. As a result, the spatial distribution of depolarization due to reflection and diffusion changes.

  In this modification, as compared with the first embodiment in which the first light beam 5 is incident on the central portion of the first condenser lens 8, the light is condensed by the first condenser lens 8 and detected by the light receiving portion 12. The light intensity in the direction of polarization changes. In this modification, in particular, more backscattered light from the object to be measured 9 can be guided to the light receiving unit 12, so that the reflected light beam 7 directed to the light receiving unit 12 has a larger amount of depolarized light components. Therefore, in this modified example, it is possible to identify the object 9 to be measured with higher accuracy than in the first embodiment described above.

  Further, in this modification, the light intensity is maximum with respect to the regular reflection axis. Therefore, when the light receiving unit 12 is configured by the light receiving element group in which the plurality of light receiving elements described above are arranged. The peak intensity position of the light intensity distribution detected by the light receiving unit 12 moves from the center of the light receiving element group to the end side. As shown in FIG. 3B, the light intensity distribution in this case can measure the shape of the tail (tail) in the light intensity distribution in more detail, and can identify the object 9 to be measured with high accuracy. It becomes possible.

(Second Embodiment)
FIG. 4 shows a schematic configuration of an optical object identification device according to the second embodiment of the present invention. In FIG. 4, the locus of light rays and main optical components are illustrated, and illustrations of components that hold the optical components are omitted. In FIG. 4, the same reference numerals as those in FIG. 1 are assigned to the same components as those in the first embodiment shown in FIG. This second embodiment differs from the above-described modified example of the first embodiment in that it includes a mirror 15 as a light guide instead of the non-polarizing beam splitter 4 of the modified example of the above-described first embodiment. .

  In the second embodiment, the first light beam 5 emitted from the diaphragm 3 is directly incident on the edge 8 a of the first condenser lens 8, and the object to be measured 9 disposed at the focal length of the first condenser lens 8. Focused on top. Further, since the first light beam 5 is incident on the DUT 9 as an S wave, the polarization direction of the semiconductor laser 1 is perpendicular to the paper surface, and the polarization direction transmitted by the linear polarizer 13 is also perpendicular to the paper surface. It is installed in the direction. The light reflected and diffused by the object to be measured 9 becomes the parallel reflected light beam 7 again by the first condenser lens 8.

  This second embodiment has a mirror 15 as a light guide, and this mirror 15 changes the traveling direction of the parallel reflected light beam 7 and directs it toward the light receiving unit 12. The mirror 15 is disposed so as not to overlap the first light beam 5.

  Thus, by arranging the mirror 15, it is possible to eliminate the extra light lost as the second light beam 6 in the first embodiment or its modification. Therefore, the ratio of the amount of light that can be used as signal light out of the amount of light emitted from the semiconductor laser 1 can be increased. As a result, the emission intensity of the semiconductor laser 1 can be reduced, and the current consumption of the entire apparatus can be reduced.

  As the light guiding means, for example, a mirror in which a hole having a diameter larger than the beam diameter of the first light beam 5 is most suitable (not shown), and the first light beam 5 passes through the hole of this mirror. It is more preferable to arrange them as described above.

(Third embodiment)
Next, FIG. 5 shows a schematic configuration of an optical object identification device according to a third embodiment of the present invention. In FIG. 5, the locus of light rays and main optical components are illustrated, and illustrations of components that hold the optical components are omitted. In FIG. 5, the same reference numerals as those in FIG. 1 are given to the same components as those in the first embodiment shown in FIG.

  This third embodiment is different from the first embodiment described above in that it does not have the linear polarizer 13b and is provided with a mirror 15 as an optical axis changing means adjacent to the non-polarizing beam splitter 4.

  In the third embodiment, the first light beam 5 that has passed through the non-polarizing beam splitter 4 enters the first condenser lens 8, while the second light beam 6 that has reflected off the non-polarizing beam splitter 4 is reflected by the mirror 15. Thus, the traveling direction becomes parallel to the first light beam 5 and enters the first condenser lens 8 in the same manner as the first light beam 5. The two light beams 5 and 6 incident on the first condenser lens 8 are applied to the same point on the object 9 to be measured arranged at the focal position of the lens 8.

  The two light beams 5 and 6 reflected by the object to be measured 9 are refracted by the first condenser lens 8 again to become a parallel reflected light beam 7. As indicated by a broken line in FIG. 5, the traveling direction of a part of the reflected light beam 7 is changed by the non-polarizing beam splitter 4, and the traveling direction of another part of the reflected light beam 7 is changed by the mirror 15. As a result, the reflected light beam 7 becomes the same light beam directed toward the light receiving unit 12 and enters the second condenser lens 10. The processing of the light beam 7 after entering the second condenser lens 10 is the same as in the first and second embodiments.

  According to the optical system as in the third embodiment, excess light lost by the second light beam 6 in the first embodiment and its modifications can be eliminated, so that it is the same as in the second embodiment. The ratio of the amount of light that can be used as signal light out of the total amount of light emitted from the semiconductor laser 1 can be increased. As a result, the emission intensity of the semiconductor laser 1 can be reduced, and the current consumption of the entire apparatus can be reduced.

  Further, in the third embodiment, since a general optical component in which the beam splitter 4 and the mirror 15 are incorporated in the same unit can be adopted, a special hole for the mirror as exemplified in the second embodiment is adopted. It can be realized very easily without the need for processing.

(Fourth embodiment)
Next, FIG. 6 shows a schematic configuration of an optical object identification device according to a fourth embodiment of the present invention. In FIG. 6, the locus of light rays and main optical components are illustrated, and illustrations of components that hold the optical components are omitted. Further, in FIG. 6, the same reference numerals as those in FIG. 1 are assigned to the same components as those in the first embodiment shown in FIG.

  In the fourth embodiment, in addition to the first unpolarized beam splitter 4a as the first optical branching element having the same configuration as the unpolarized beam splitter 4 in the first embodiment, the second unpolarized light as the second optical branching element. A beam splitter 4b is provided. The second non-polarizing beam splitter 4b is disposed between the pinhole portion 11 and the linear polarizer 13a, and the third condenser lens 10b is interposed between the pinhole portion 11 and the second non-polarizing beam splitter 4b. Is arranged. A fourth condenser lens 10d is disposed between the second non-polarizing beam splitter 4b and the linear polarizer 13a.

  In addition, the mirror 15 that reflects the light reflected by the second non-polarizing beam splitter 4b toward the second light receiving element 12a, and another first light disposed between the mirror 15 and the second light receiving element 12a. 4 condenser lens 10c is provided. The second light receiving element 12a and the first light receiving element 12b constitute a light receiving portion.

  In the fourth embodiment, the reflected light beam 7 reflected by the object 9 to be measured and converted into a parallel light beam by the first condenser lens 8 passes through the first non-polarizing beam splitter 4a and the second condenser lens 10a. After passing through the pinhole portion 11, the light enters the third condenser lens 10b. A pinhole portion 11 is disposed at the focal position of the third condenser lens 10b.

  Therefore, the reflected light beam 7 is again converted into a parallel light beam by the third condenser lens 10b, and is divided into two by the second non-polarizing beam splitter 4b to become the second reflected light beam 7a and the first reflected light beam 7b. Here, as shown in FIG. 6, the second reflected light beam 7a represents the light beam reflected upward by the second non-polarized beam splitter 4b, and the first reflected light beam 7b represents the light beam that has passed through the second non-polarized beam splitter 4b. Represents. The traveling direction of the second reflected light beam 7a is changed by the mirror 15 and becomes parallel to the first reflected light beam 7b. As a result, the second and first light beams 7a and 7b whose traveling directions are the same are condensed by the fourth condenser lenses 10c and 10d, respectively, and the second light receiving element 12a and the first light receiving element 12b are collected. Is detected. However, a linear polarizer 13 a is disposed between the first light receiving element 12 b and the fourth condenser lens 10 d, and the polarization direction of the linear polarizer 13 a is the same as the polarization direction of the first light beam 5. It is arranged to be.

  In the fourth embodiment, the second light receiving element 12a receives light in all polarization directions of the second reflected light beam 7a divided by the second non-polarizing beam splitter 4b. On the other hand, since the first light receiving element 12b receives the first reflected light beam 7b via the linear polarizer 13a, the first light receiving element 12b receives light of a component having a predetermined polarization direction selected by the linear polarizer 13a. Thereby, as described in the first to third embodiments, the signal detected by the first light receiving element 12b reflects the surface state of the object 9 to be measured.

  By the way, since the device under test 9 has various reflectances, when the surface state of the device under test 9 is measured only with the absolute value of the intensity signal detected by the first light receiving element 12b, the absolute value of the intensity signal is measured. With respect to the contribution to the value, it cannot be distinguished whether the polarization disturbance on the surface of the object 9 to be measured is dominant or whether the reflectance of the object 9 to be measured is dominant. In other words, even if the degree of depolarization by the object to be measured 9 is large, if the reflectance of the surface of the object to be measured 9 is large, the intensity signal may show an output intensity higher than a certain level, which may cause false detection. There is.

  On the other hand, in the fourth embodiment, since the second light receiving element 12a receives the light in all the polarization directions of the second reflected light beam 7a, the signal output from the second light receiving element 12a is reflected by the object 9 to be measured. Equivalent to measuring rate. Therefore, the signal processing circuit 14 calculates the ratio of the outputs of the second and first light receiving elements 12a and 12b. The surface state of the DUT 9 is measured with the calculated output signal ratio. Thereby, when measuring the surface state of the object 9 to be measured, it is possible to reduce the influence of variations in signal intensity due to the reflectance of the surface of the object 9 to be measured. Therefore, according to the fourth embodiment, the surface state of the DUT 9 can be identified with high accuracy.

(Fifth embodiment)
Next, FIG. 7 shows a schematic configuration of an optical object identification device according to a fifth embodiment of the present invention. In FIG. 7, only the trajectory of light rays and main optical components are shown, and illustrations of components for holding the optical components are omitted. In FIG. 7, the same reference numerals as those in FIG. 6 are assigned to the same components as those in the fourth embodiment shown in FIG.

  The fifth embodiment is provided with a second linear polarizer 13c as a second polarization state selection element disposed between the fourth condenser lens 10c and the second light receiving element 12a. Different from the fourth embodiment. In addition, this 5th Embodiment is provided with the same linear polarizer 13a as the above-mentioned 4th Embodiment as the 1st linear polarizer 13a as a 1st polarization state selection element. In the fifth embodiment, the second linear polarizer 13c is installed on the optical axes of the second light receiving element 12a and the fourth condenser lens 10c.

  The polarization direction selected by the first linear polarizer 13a and the polarization direction selected by the second linear polarizer 13c are substantially orthogonal to each other, and the polarization direction selected by the first linear polarizer 13a is that of the first light beam 5. The polarization direction selected by the second linear polarizer 13 c is substantially parallel to the polarization direction, and is substantially perpendicular to the polarization direction of the first light beam 5.

  That is, the polarization direction selected by the second linear polarizer 13c is arranged to be orthogonal to the polarization direction selected by the first linear polarizer 13a, and the polarization direction of the first light beam 5 emitted from the semiconductor laser 1 It is arranged in a direction orthogonal to.

  As described above, the polarization state of the reflected light beam 7 after the first light beam 5 is reflected by the device under test 9 is caused by the surface state of the device under test 9. For this reason, the smoother the reflecting surface of the DUT 9 is, the higher the proportion of the same component as the polarization direction of the incident light beam (first light beam 5) is in the polarization direction of the reflected light beam 7, and the incident light beam (first light beam 5). The ratio of the polarization direction orthogonal to the polarization direction of) is low. For example, if the amount of light of the reflected light beam 7 is 2I (arbitrary unit), the reflected light beam 7 is divided into a second reflected light beam 7a having a light amount I and a first reflected light beam 7b having a light amount I. The light quantity I of the first and second reflected light beams 7b and 7a is a light quantity including all polarization direction components.

  Assuming that the surface state of the object to be measured 9 is in a certain state, the light amounts of the components polarized in the same direction as the first light beam 5 in the first and second reflected light beams 7b and 7a are αI, The component orthogonal to that is βI, and the other component of the sum of the polarization directions is (1−α−β) I. At this time, when the first reflected light beam 7b passes through the first linear polarizer 13a, the first reflected light beam 7b becomes a light amount αI and is incident on the first light receiving element 12b, while the second reflected light beam 7a is incident on the second linear polarizer. By passing through 13c, the light quantity becomes βI and enters the second light receiving element 12a.

  Therefore, the measurement result according to the fifth embodiment, that is, the signal processing circuit 14 calculates the ratio between the output signal from the first light receiving element 12b and the output signal from the second light receiving element 2a, and αI / βI = α / A result of β is obtained.

  On the other hand, in the fourth embodiment, the signal processing circuit 14 calculates the ratio between the output signal from the first light receiving element 12b and the output signal from the second light receiving element 2a. As a result, αI / I = α. Results are obtained.

  Here, both the coefficients α and β are values of 1 or less, and β decreases as α increases. Therefore, according to the ratio α / β calculated in the fifth embodiment, it is calculated in the fourth embodiment. Compared with the ratio α, the influence of depolarization due to the surface state of the DUT 9 is better reflected. Therefore, according to the fifth embodiment, the identification accuracy is improved as compared with the fourth embodiment.

  In the fifth embodiment, instead of calculating the ratio by the signal processing circuit 14, the difference between the output signal from the first light receiving element 12b and the output signal from the second light receiving element 12a may be calculated. . Also in this case, the identification accuracy can be improved. However, in order to reduce errors due to variations in the reflectance of the surface of the object 9 to be measured, it is preferable to calculate the ratio between the difference and the sum of the output signals of the light receiving elements 12a and 12b after calculating the difference. preferable. That is, the calculation result is (α−β) / (α + β). The smoother the reflective surface of the object 9 to be measured, the larger the difference between α and β, and the rougher the surface, the smaller the difference between the values α and β. Therefore, the object 9 to be measured can be identified with higher accuracy. It becomes. Note that the value of the denominator (α + β) is a value that does not exceed 1, reducing variations in calculation results due to the reflectance of the surface of the DUT 9.

  The same effect as that of the fifth embodiment can be obtained by replacing the second non-polarizing beam splitter 4b shown in FIG. 7 with a polarizing beam splitter and removing the first linear polarizer 13a and the second linear polarizer 13c. can get. The polarization beam splitter divides an incident light beam so that the polarization direction of passing light and the polarization direction of reflected light are orthogonal to each other. In this case, the same effect as the configuration shown in FIG. 7 can be obtained, and the number of parts can be reduced by the amount not having the linear polarizer.

  Further, the optical system in the fourth and fifth embodiments may be housed in a housing 80 having an optical window 80a as shown in FIG. The first light beam 5 is emitted from the optical window 80a. In this configuration, the non-polarizing beam splitter 4b and the mirror 15 are unitized, and the second reflected light beam 7a and the first reflected light beam 7b are obtained by using a lens group in which the fourth condenser lenses 10c and 10d are formed on the same plate. The distance between can be reduced. As a result, the second light receiving element (photodiode) 12a and the first light receiving element (photodiode) 12b can be fabricated on the same semiconductor substrate, and the manufacturing cost can be reduced.

  Further, as shown in FIG. 8C, by forming the signal processing circuits 14a and 14b between the photodiodes 12a and 12b, not only has a significant noise reduction effect as described above, but also a significant cost reduction. Can be realized. 8B shows a light projecting unit when the semiconductor laser 1, the collimator lens 2, the diaphragm 3, the first non-polarizing beam splitter 4a, and the first condenser lens 8 are accommodated in one casing 81. FIG. Show.

(Sixth embodiment)
Next, a sixth embodiment of the optical object identification device of the present invention will be described. As described above, in each of the optical object identification devices according to the first to fifth embodiments, since the pinhole portion 11 is disposed at the focal position of the second condenser lens 10, the object 9 to be measured is the first object. A strong signal can be obtained when the condenser lens 8 is at the focal position.

  However, actually, the magnitude of the height difference of the surface of the object to be measured 9 is various, and depending on the object to be identified, there is a concern that the surface of the object to be measured 9 is hardly located at the focal position of the first condenser lens 8. Is done.

  The sixth embodiment can be applied even when the surface height of the object 9 is large and the probability that the object 9 is located at the focal position of the first condenser lens 8 is low. An optical object identification device is provided.

  FIG. 9A schematically shows a configuration of a part of the optical object identification device corresponding to a case where the surface of the DUT 9 has a height difference. As shown in FIG. 9A, when the first condenser lens 8 is located in the region A with respect to the surface of the object 9 to be measured, the object to be measured is positioned at the focal length f of the first condenser lens 8. There are 9 surfaces. In this case, a strong light reception signal can be obtained, and the object to be measured 9 can be identified with high accuracy.

  However, in FIG. 9A, when the first condenser lens 8 is located in the region B, the focal position of the first condenser lens 8 is separated from the surface of the object 9 to be measured. Is not positioned at the focal position of the first condenser lens 8.

  Therefore, the first condenser lens 8 is vibrated in the direction indicated by the arrow G in FIG. 9A so that the distance from the object 9 to be measured changes. Due to this vibration, the focal position of the first condenser lens 8 can be positioned on the surface of the DUT 9 as indicated by a broken line in FIG. 9A.

  The lens vibration system that vibrates the first condenser lens 8 may be composed of an actuator. However, since the actuator has a small driving range, it is very difficult to position the focal point of the first condenser lens 8 on the surface of the measurement object 9 with respect to the measurement object 9 having a large surface height difference. .

  Next, FIG. 9B shows a schematic configuration of a specific configuration example 1 of the sixth embodiment. This configuration example 1 basically includes the configuration of the above-described fifth embodiment, and differs from the above-described fifth embodiment in that a mechanism for vibrating the first condenser lens 8 is provided. Therefore, in the configuration example 1, points different from the above-described fifth embodiment will be mainly described.

  As shown in FIG. 9B, the lens vibration system can be composed of a spring 19 and a solenoid coil 17. A pulse power supply 16 is connected to the solenoid coil 17. The first condenser lens 8 is held by a lens holder 18, and an iron core 21 is fixed to the lens holder 18. In addition, one end of a coil spring 19 is connected to the lens holder 18 on the opposite side of the iron core 21, and the other end of the coil spring 19 is connected to a fixed plate 20. The iron core 21 is partially inserted along the substantially central axis of the solenoid coil 17.

  According to the configuration of the lens vibration system, the first condensing lens 18 is vibrated by causing the lens holder 18 to vibrate in the direction of arrow G with the force of the solenoid coil 17 attracting the iron core 21 and the restoring force of the spring 19. Can be vibrated in the direction of arrow G. A current subjected to pulse modulation from the pulse power supply 16 flows through the solenoid coil 17. When the pulse signal output from the pulse power supply 16 is on, an attractive force acts on the solenoid coil 17 and the first condenser lens 18 swings toward the solenoid 17 side. On the other hand, when the pulse signal is off, a tensile force is exerted by the spring 19 fixed to the fixing base 20, and the first condenser lens 18 is swung to the measured object 9 side.

  Lens vibration at an arbitrary frequency is possible by the modulation frequency of the pulse signal. In the vibration system using the solenoid coil 17, since the movable range is large, the object to be measured 9 having a large difference in height on the detection surface can be positioned at any position in the vibration range of the first condenser lens 8. The focal position of the first condenser lens 8 can be positioned on the surface of the object 9 to be measured.

  Next, FIGS. 10A and 10B show a schematic configuration of configuration example 2 of the sixth embodiment. FIG. 10A is a schematic diagram showing a state in which the configuration example 2 is viewed toward a predetermined plane including the normal line of the surface of the DUT 9, and FIG. 10B is a plane perpendicular to the plane. It is a schematic diagram which shows a mode that the said structural example 2 was seen toward.

  In this configuration example 2, the lens vibration system is constituted by the cam 28 and the motor 22. The motor 22 is fixed to the motor fixing plate 23, and the motor fixing plate 23 is fixed to the base 31. A cam 28 is directly connected to the rotating shaft of the motor 22. The motor fixing plate 23 is connected to an auxiliary plate 26 with a spring 24.

  A bearing 27 is pivotally supported at one end of the auxiliary plate 26, and the bearing 27 is biased toward the cam 28 by the biasing force of the spring 24.

  A lens holder 30 is fixed to the other end of the auxiliary plate 26, and the first condenser lens 8 is attached to the lens holder 30. A guide 25 is fixed to an intermediate portion of the auxiliary plate 26. The guide 25 is guided by another auxiliary plate 29 so as to be slidable along the optical axis J. The auxiliary plate 29 is fixed to a fixed base 88, and the fixed base 88 is fixed to the base 31.

  The guide 25 can move only in the same one-dimensional direction as the optical axis J. The spring 24 needs a spring constant such that there is no gap between the bearing 27 and the cam 28 when the cam 28 rotates. Further, the motor 22 needs to have a torque enough to rotate the cam 28. As shown in FIG. 10B, the height of the motor 22 from the base 31 is set so that the extension line of the rotation center axis of the cam 28 intersects the optical axis J. By appropriately selecting the shape of the cam 28, the first condenser lens 8 can be set to have a desired lens vibration amplitude. The lens position at an arbitrary time can be calculated by making the outer peripheral contour shape of the cam 28 a sine curve shape and making the cam 28 a sine curve cam. In this case, the distance R from the center P of the cam 28 to the outer diameter can be written as R = r + asin θ (mm). For example, by setting a = 5 mm, the first condenser lens 8 vibrates linearly along the optical axis J corresponding to a sine curve having an amplitude of 5 (mm), that is, a vibration width of 10 mm.

  Next, FIG. 11A shows a schematic configuration of configuration example 3 of the sixth embodiment. In FIG. 11A, the main cross section of Configuration Example 3 is schematically shown in the center, the upper surface shape is schematically shown in the upper part, the partial cross section is schematically shown in the lower part, and the partial cross section as viewed from the left side. The shape is schematically shown. In this configuration example 3, the lens vibration system is configured by a vibration system having a crank mechanism that converts the rotational movement of the motor 22 into the reciprocating movement of the lens vibration.

  As shown in FIG. 11A, the first condenser lens 8 is held by the lens holder 30 and fixed to the slider 33. The slider 33 slides only in a one-dimensional direction along the optical axis along the guide 32 whose position is fixed in the housing 83. The slider 33 is pivotally attached to a location shifted from the center of the disc 34. This disk 34 is a perfect circle. Since the motor 22 is directly connected to the disc 34, the first condenser lens 8 reciprocates for one cycle along the optical axis while the motor 22 rotates once. Since the radius of the disc 34 corresponds to the amplitude of the lens vibration, the radius of the disc 34 may be set to be equal to or higher than the height difference of the surface of the object 9 to be measured.

  In the structure of the configuration example 3, since no spring is used, there is no fear that the spring is extended, and the mechanical reliability is high. In the lens vibration system using the cam 28 shown in the configuration example 2 above, when the spring 24 is extended, the spring constant decreases, the bearing 27 moves away from the cam 28, and the lens vibration is different from the design. Become. On the other hand, in the configuration example 3, there is no such concern.

  Next, FIG. 11B shows a schematic configuration of Configuration Example 4 of the sixth embodiment. In FIG. 11B, the cross section of the configuration example 4 is schematically shown at the center, and the propeller 36 is seen in the direction of the rotation axis on the left side. In the configuration example 4 illustrated in FIG. 11B, the lens vibration system is a vibration system using a flow of water or wind. 11B differs from the above-described configuration example 3 in that the motor 22 used in the configuration example 3 in FIG. 11A described above has a propeller 36 attached to the rotating shaft.

  That is, the optical object identification device of Configuration Example 4 is installed adjacent to the water or wind channel M, and the propeller 36 obtains a rotational motion using the force of the medium flowing in the channel M, and the crank mechanism Thus, the first condenser lens 8 is reciprocated to vibrate. In this configuration example 4, since a power source such as a motor is not required, the power consumption of the apparatus can be greatly reduced.

  In addition, the configuration example 4 of FIG. 11B is an embodiment that is particularly effective when the optical object identification device of the present invention is applied to a vacuum cleaner or a self-propelled cleaner, as will be described later in a twelfth embodiment. That is, in this configuration example 4, the first condenser lens 8 can be vibrated by using the intake air of the cleaner as the medium flow. In this case, generally, the floor surface to be identified as the object to be measured 9 may be a board surface such as flooring, or a woolen fabric such as a tatami mat or a carpet. The height difference of the surface of the measurement object is about 10 mm. It is preferable that the vibration range of the focal position is set to 5 mm to 15 mm when covering a thing with a long bristle can be covered. This vibration range is similarly established for all the embodiments, but only the configuration example 4 will be described.

  Next, FIG. 11C shows a progressive lens 37 included in the first modification of the sixth embodiment as a first condenser lens. The progressive lens 37 shown in FIG. 11C is a lens having a plurality of regions with different focal lengths in one lens. As shown in FIG. 11C, the progressive lens 37 has areas A to G divided into seven, and the areas A to G have mutually different focal lengths FA to FG. In the progressive lens 37, the focal position can be changed from FA to FG by changing the light incident position in the regions A to G.

  Next, FIG. 11D shows a schematic configuration of Modification 1 including the progressive lens 37. This modification 1 has the basic configuration shown in FIG. 8A as an example of the fourth and fifth embodiments. In the first modification, a disk 34 connected to the rotation shaft of the motor 22 and a slider 33 whose one end is pivotally supported by the disk 34 are provided. By driving the motor 22, the disk 34 rotates, and the slider 33 moves along a guide 32 fixed in position within the housing 80 in a direction perpendicular to the optical axis of the first light beam 5 (outlined). Reciprocate in the direction indicated by the arrow. As a result, the progressive lens 37 mounted on the lens holder fixed to the other end of the slider 33 is vibrated in the radial direction. Thereby, by changing the position of the first light beam 5 incident on the progressive lens 37 in the radial direction, the focal position is changed, and the object 9 having a large surface height difference can be identified.

  Next, FIG. 11E shows an optical object identification device including a progressive lens 37 and a liquid crystal switch 38 as a second modification of the sixth embodiment. This modification 2 has a liquid crystal switch 38 in place of the crank mechanism constituted by the motor 22, the slider 33, the guide 32, the disc 34, etc. in the modification 1.

  In the second modification, a liquid crystal switch 38 is arranged on the semiconductor laser 1 side with respect to the progressive lens 37. The liquid crystal switch 38 is configured by sandwiching liquid crystal between two linear polarizers 39a and 39b whose transmission polarization directions are orthogonal to each other. The liquid crystal switch 38 is an optical component that can transmit light only in a specific region using liquid crystal. The liquid crystal can selectively function by emitting the polarization direction of incident light as it is or by deflecting it by 90 ° by turning on or off the applied electric signal. For this reason, in this liquid crystal switch 38, for example, only the electric signal applied to the region HE among the regions HA to HG is turned on to deflect the incident light 5a. Thereby, only the light incident on the region HE of the incident light 5a is transmitted through the linear polarizer 39b and is incident on the region E of the progressive lens 37 as the incident light 5b. The incident light 5b is incident on the progressive lens 37. The light is condensed at a focal position FE corresponding to the region E.

  Thus, by turning on only the electrical signal applied to a desired region among the regions HA to HG in the liquid crystal switch 38, only this region transmits incident light. Therefore, the incident light can be incident on only a desired region among the regions A to G of the progressive lens 37, and the incident light can be condensed at a desired desired focal length among the focal lengths FA to FG.

  As a result, it is possible to identify the object to be measured 9 having a large surface height difference. In the structure of the modification 2 shown in FIG. 11E, unlike the configuration examples 1 to 4 and the modification 1, the lens vibration mechanism does not exist. For this reason, it is not necessary to consider various problems such as physical space caused by vibrating the lens and displacement of each component caused by vibration, and the design of the optical system can be facilitated.

  As described above, in Configuration Examples 1 to 4 and Modifications 1 and 2 of the optical object identification device according to the sixth embodiment, the position of the first condenser lens 8 is vibrated or the first condenser lens is used. It is possible to cope with a case where the height difference of the surface of the object 9 to be measured is changed by changing the incident position on the progressive lens 37 to change the position of the focal point more than the height difference of the surface of the object 9 to be measured. It can be done.

  However, by varying the focal position of the first condenser lens in this way, the signal output from the light receiving unit 12 including the first and second light receiving elements 12b and 12a has the surface of the object 9 to be measured at the focal position. Both the focus signal at the time and the defocus signal when the surface of the object 9 to be measured deviates from the focal position are input to the signal processing circuit 14 and observed as a function of time.

  In the previous fifth embodiment, in order to improve the accuracy of identification of the object to be measured, the configuration has been described in which the received light signals are divided and their ratio and difference are calculated and used for identification. In the fifth embodiment, signals at the same time are handled, and in particular, a signal when the surface of the object to be measured has reached the focal position of the first condenser lens 8 is extracted and processed.

  In the sixth embodiment, the focal position of the first condenser lens 8 is constantly oscillating, and the focus signal and the defocus signal are observed continuously in time, so the ratio and difference are calculated. Sometimes it is also possible to use a focus signal and a defocus signal. Also in the fifth embodiment of FIG. 7, the defocus signal is observed due to the unevenness of the surface of the object 9 to be measured, but the temporal change is left to the surface shape of the object 9 to be measured. That is, since the fifth embodiment is different from the sixth embodiment in which the focal position is intentionally changed, it is very difficult to detect a signal when defocused by a known distance.

  On the other hand, in the configuration of the sixth embodiment, since the focal position of the first condenser lens 8 can be changed with time calculated in advance, the focal position is determined from the output waveform of the light receiving unit 12. It is possible to detect a signal deliberately defocused by a specific distance from the focal position.

  As described in the fifth embodiment, in order to use the output signals of the first light receiving element 12b and the second light receiving element 12a as identification signals, normalization is performed so that the influence of the reflectance of the surface can be reduced. It is preferable. At this time, the signal component of the identification signal can be further increased by using the defocus signal as a signal corresponding to the denominator to be normalized.

  This will be described using the equation shown in the fifth embodiment described above. The signal intensity in the same polarization direction as that of the incident light, that is, the first light beam 5 can be expressed as a light amount αI using a focus signal. A component in the polarization direction orthogonal to the polarization direction of the first light beam 5 is defined as a light amount γI.

  Now, assuming that the coefficient γ is a constant related to the degree of depolarization at a certain defocus amount, β >> γ is established as compared with the coefficient β (during focusing) in the fifth embodiment described above. Therefore, (α / β) << (α / γ) holds. Therefore, the signal processing circuit 14 standardizes the light amount αI at the time of focusing with the light amount γI at the time of defocusing, so that the signal level is compared with the case where the light amount αI at the time of focusing is normalized with the light amount βI at the time of focusing. Becomes larger. Thus, by using the defocus signal, it is possible to further improve the accuracy of identifying the object 9 to be measured.

(Seventh embodiment)
Next, a seventh embodiment of the optical object identification device of the present invention will be described. The seventh embodiment is different from the first embodiment described above in that light intensity modulation is performed by applying a modulation signal to the semiconductor laser 1 in the first embodiment described above. Therefore, in the seventh embodiment, points different from the first embodiment will be mainly described. The seventh embodiment can also be applied to the above-described second to sixth embodiments.

  In the case of an optical sensor, measures against disturbance light are essential. In the seventh embodiment, the semiconductor laser 1 has a function of causing pulsed light emission and electrically removing noise caused by disturbance light. Hereinafter, it will be described in detail with reference to the timing chart shown in FIG. 12A.

  In FIG. 12A, reference numeral 40 denotes an LD (semiconductor laser) modulation pulse, and 41 denotes a pulse obtained by inverting the LD modulation pulse. Further, 42 is an original signal obtained by removing disturbance light noise from the output signal of the light receiving unit 12, and 43 is DC disturbance light noise in the output signal of the light receiving unit 12. Reference numeral 44 denotes AC disturbance light noise in the output signal of the light receiving unit 12. Reference numeral 45 denotes a first processing signal after the signal processing circuit 14 samples and holds the output signal of the light receiving unit 12 in synchronization with the LD modulation pulse 40. Reference numeral 46 denotes a second processing signal after the signal processing circuit 14 samples and holds the output signal of the light receiving unit 12 in synchronization with the pulse 41 obtained by inverting the LD modulation pulse. Reference numeral 47 denotes a third processing signal obtained by subtracting the second processing signal from the first processing signal 45 (taking a differential).

  First, the concept of disturbance light removal will be described. When the LD modulation pulse 40 is on, the signal processing circuit 14 subtracts the output signal of the light receiving unit 12 immediately before the LD modulation pulse 40 is turned on (takes a differential) from the output signal output from the light receiving unit 12. That is, the signal processing circuit 14 corresponds to the original signal 42 obtained by subtracting (DC disturbance light signal 43 + AC disturbance light signal 44) from (original signal 42 + DC disturbance light signal 43 + AC disturbance light signal 44) to remove noise due to disturbance light. A differential signal 47 is obtained.

  On the other hand, when the LD modulation pulse 40 is off, the signal processing circuit 14 outputs the output of the light receiving unit 12 when the LD modulation pulse 40 is off from the output signal of the light receiving unit 12 immediately before the LD modulation pulse 40 is turned off. Subtract signal (take differential). In other words, the signal processing circuit 14 subtracts (DC disturbance light signal 43 + AC disturbance light signal 44) from (original signal 42 + DC disturbance light signal 43 + AC disturbance light signal 44) to cope with the original signal 42 from which noise due to disturbance light is removed. The obtained differential signal 47 is obtained.

  Next, a configuration in which the signal processing circuit 14 realizes the above-described signal processing will be described with reference to FIG. 12B. The signal processing circuit 14 includes a first sample hold circuit SH1, a second sample hold circuit SH2, and a differential amplifier DA.

  The output signal PD of the light receiving unit 12 is divided into two and enters the first sample hold circuit SH1 and the second sample hold circuit SH2. The first sample and hold circuit SH1 creates a first waveform signal when the LD modulation pulse 40 is on, and the second sample and hold circuit SH2 creates a second waveform signal when the LD modulation pulse 40 is off. .

  In the first sample hold circuit SH1, when the LD modulation pulse 40 is on, the output signal PD (original signal 42 + DC disturbance light signal 43 + AC disturbance light signal 44) of the light receiving unit 12 at this time is passed as it is.

  On the other hand, when the LD modulation pulse 40 is off, the first sample hold circuit SH1 samples and holds the output signal PD (original signal 42 + DC disturbance light signal 43 + AC disturbance light signal 44) immediately before the LD modulation pulse 40 is turned off. As a result, the first sample-and-hold circuit SH1 obtains a first processing signal 45 corresponding to (original signal 42 + DC disturbance light signal 43 + AC disturbance light signal 44).

  On the other hand, in the second sample and hold circuit SH2, when the LD modulation pulse 40 is off, the output signal PD (DC disturbance light signal 43 + AC disturbance light signal 44) of the light receiving unit 12 at this time is passed as it is. On the other hand, when the LD modulation pulse 40 is on, the second sample and hold circuit SH2 samples and holds the output signal PD (DC disturbance light signal 43 + AC disturbance light signal 44) immediately before the LD modulation pulse 40 is turned on. As a result, the second sample-and-hold circuit SH2 obtains a second processing signal 46 corresponding to (DC disturbance light signal 43 + AC disturbance light signal 44).

  Then, the differential amplifier DA subtracts the second processing signal 46 output from the second sample hold circuit SH2 from the first processing signal 45 output from the first sample hold circuit SH1 (takes a differential). That is, the differential amplifier DA has a second processing signal 46 corresponding to (DC disturbance light signal 43 + AC disturbance light signal 44) from a first processing signal 45 corresponding to (original signal 42 + DC disturbance light signal 43 + AC disturbance light signal 44). Is subtracted (differential is taken) to obtain a differential signal 47 from which noise due to disturbance light is removed from the output signal PD of the light receiving unit 12.

  In order to remove DC disturbance light such as sunlight and AC disturbance light such as 50 Hz / 60 Hz illumination (fluorescent lamp) or an inverter fluorescent lamp of about 30 to 50 kHz, an LD modulation pulse 40 is used as an inverter fluorescent lamp. The modulation frequency is preferably 50 kHz or higher, which is higher than the above frequency. Desirably, the LD modulation pulse 40 may have a modulation frequency of about 1 MHz, which is sufficiently higher than the frequency of the inverter fluorescent lamp. Alternatively, the LD modulation pulse 40 may be set to an LD modulation frequency of about 100 to 10 kHz, and the frequency component of the inverter fluorescent lamp may be separated by an LPF (low pass filter).

(Eighth embodiment)
Next explained is an optical object identification apparatus according to the eighth embodiment of the invention. In the eighth embodiment, the configuration of the signal processing circuit 14 is different from that of the sixth embodiment.

  As described at the end of the sixth embodiment, it is desirable that the signal processing circuit 14 performs signal processing on the signal output from the light receiving unit 12 not only when the first condenser lens 8 is focused but also during defocusing.

  By the way, the dynamic range between the level of the defocus signal at the time of defocusing and the level of the focus signal at the time of focusing exceeds 4000 times under certain conditions. For this reason, it is difficult to amplify in one range including the case where the type of the device under test 9 changes.

  Therefore, in the eighth embodiment, as shown in FIG. 13C, the signal processing circuit 14 includes an amplifier unit AMP as an amplification unit that amplifies the output signal from the light receiving unit 12, and the output signal from the light receiving unit 12. An amplification degree switching unit GS that monitors the level and switches the gain of the amplifier unit AMP according to the level of the output signal is provided. By the amplification degree switching unit GS, the output signal amplified by the amplifier unit AMP is set to an optimum level.

  Hereinafter, the operation of the signal processing circuit 14 of the eighth embodiment will be described in detail with reference to timing charts shown in FIGS. 13A and 13B.

  FIG. 13A shows a signal having the same polarization direction as the emitted light (LD emitted light) of the semiconductor laser 1. In FIG. 13A, a signal 14-1 is an output signal of the light receiving unit 12. Since the semiconductor laser 1 is pulse-modulated, the output signal 14-1 is turned on / off in response to a light emission pulse of a predetermined period (for example, 13.3 μsec) of the semiconductor laser 1.

  The signal 14-2 is a first sample hold signal 14-2 obtained by sampling and holding the PD output signal 14-1 when the semiconductor laser 1 is on. The signal 14-3 is the second sample hold signal 14-3, which is the PD output signal 14-1 when the semiconductor laser 1 is off. The second sample and hold signal 14-3 indicates the disturbance light level. The signal 14-4 is a differential signal 14-4 obtained by subtracting the second sample hold signal 14-3 from the first sample hold signal 14-2 (taken differential).

  The signal 14-5 is a differential signal 14-5 obtained by differentiating the differential signal 14-1. The signal 14-6 is a bottom hold signal 14-6 obtained by bottom holding the PD output signal 14-1.

  On the other hand, FIG. 13B shows a signal having a polarization direction orthogonal to the polarization direction of the light emitted from the semiconductor laser 1. In FIG. 13B, a signal 14-7 is an output signal of the light receiving unit 12. The signal 14-8 is a first sample hold signal 14-8 obtained by sample holding the level of the output signal 14-7 when the semiconductor laser 1 is on. The signal 14-9 is a second sample hold signal 14-9 obtained by sample holding the level of the output signal 14-7 when the semiconductor laser 1 is off. The signal 14-10 is a differential signal 14-10 obtained by subtracting the second sample hold signal 14-9 from the first sample hold signal 14-8 (taking the differential).

  The signal 14-11 is a differential signal 14-11 of the differential signal 14-10. The signal 14-12 is a third sample hold signal 14-12 obtained by sampling and holding the first sample hold signal 14-8 at the sample hold timing ST.

  Next, for light having the same polarization direction as the light emitted from the semiconductor laser 1, the signal processing circuit 14 detects a focus signal (focus signal), and a polarization direction orthogonal to the polarization direction of the light emitted from the semiconductor laser 1. With respect to the above light, a case where a signal at the time of defocus (focus signal) is detected will be described. The concept is the same in other cases.

  First, the basic concept of gain switching of the amplifier unit AMP will be described. The amplification degree switching unit GS receives the output signals 14-1 and 14-7 from the light receiving unit 12, and sets the level at the time of focusing for the output signal 14-1 by light having the same polarization direction as the light emitted from the semiconductor laser 1. When the level of the output signal 14-1 at the time of focusing is lower than the lower limit setting level, the gain of the amplifier AMP is increased by one step, and conversely, the level of the output signal 14-1 at the focusing time is the upper limit setting level If the value exceeds the value, the gain of the amplifier AMP is lowered by one step.

  Details will be described below. As described above, the output signal 14-1 shown in FIG. 13A is an output signal of the light receiving unit 12 by light having the same polarization direction as the light emitted from the semiconductor laser 1. This output signal is, for example, the output signal of the first light receiving element 12b shown in FIG. 9B. FIG. 13A shows a case where the semiconductor laser 1 is modulated with a modulation pulse having a frequency of 75 kHz.

  The amplification degree switching unit GS generates a bottom hold signal 14-6 by bottom-holding the output signal 14-1 in order to monitor the signal level at the time of focusing. When the level of the bottom hold signal 14-6 falls below the lower limit setting level, the amplification degree switching unit GS increases the gain of the amplifier AMP by one step, and the level of the signal 14-6 exceeds the upper limit setting level. The operation of lowering the gain of the amplifier unit AMP by one step is performed. Note that the amplification degree switching unit GS may generate a sample hold signal instead of the bottom hold signal of the output signal 14-1, and compare the sample hold signal with the lower limit and upper limit setting levels. In this case, the amplification degree switching unit GS performs an operation of increasing the amplifier gain by one step when the level of the sample hold signal is lower than the lower limit setting level, and lowering the amplifier gain by one step when exceeding the upper limit setting level. Here, the timing at which the amplification degree switching unit GS switches the gain of the amplifier unit AMP is the moment when the differential signal 14-5 obtained by differentiating the differential signal 14-4 changes from minus to plus.

  On the other hand, the output signal 14-7 shown in FIG. 13B is an output signal of the light receiving unit 12 by light having a polarization direction orthogonal to the polarization direction of the light emitted from the semiconductor laser 1 as described above. This output signal is, for example, the output signal of the second light receiving element 12a shown in FIG. 9B. FIG. 13B shows a case where the semiconductor laser 1 is modulated with a 75 kHz modulation pulse.

  The amplification degree switching unit GS monitors the third sample hold signal 14-12 in order to monitor the signal level at the time of defocusing. As described above, the third sample and hold signal 14-12 samples the first sample and hold signal 14-8 obtained by sampling and holding the level of the output signal 14-7 when the semiconductor laser 1 is turned on at the sample and hold timing ST. This is a held signal.

  The amplification degree switching unit GS increases the gain of the amplifier unit AMP by one when the level of the third sample hold signal 14-12 is lower than the lower limit set level, and the level of the signal 14-12 exceeds the upper limit set level. In this case, an operation of lowering the gain of the amplifier unit AMP by one step is performed.

  Here, the sample and hold timing ST is the moment when the timer starts from the moment when the differential signal 14-11 obtained by differentiating the differential signal 14-10 turns from minus to plus. This timer counts a set number of light emission pulses.

  Further, the release timing of the sample hold is the moment when a predetermined time t0 has elapsed from the moment when the differential signal 14-11 obtained by differentiating the differential signal 14-10 changes from minus to plus. Furthermore, the timing of switching the gain of the amplifier unit AMP is the moment when the differential signal 14-11 obtained by differentiating the differential signal waveform 14-10 turns from minus to plus.

  The configuration in which the amplification degree switching unit GS switches the gain of the amplifier unit AMP can be realized by adopting, for example, a multistage gain switching amplifier unit having a circuit configuration shown in FIG. That is, a plurality of gain setting resistors R may be arranged and the gain of the amplifier unit AMP may be switched using a switching function of the analog switches 141 and 142. When the output signal 14-1 and the output signal 14-7 of the light receiving unit 12 are very small and the amplification degree of the amplifier unit AMP must be set high, there is a problem of stability if the amplification degree is increased too much in one stage. As illustrated in FIG. 14, the amplifier amp having an appropriate amplification degree is connected in a plurality of stages. In this case as well, the gain setting resistors of the plurality of amplifiers amp may be switched simultaneously by the analog switches 141 and 142.

  Further, when the amplifier unit AMP has a plurality of stages, if the gains of the amplifiers amp of each stage are set evenly, the amplification degree of each stage may slightly exceed one time.

  In such a case, the gain setting resistors corresponding to the appropriate number of stages illustrated in FIG. 14 should be open (the gain of this stage is 1), and the gains of the other stages should be set larger. The reason is that when the gain of the amplifier at each stage is set close to 1, peaking increases in frequency characteristics.

  As described above, the amplifier unit AMP of the signal processing circuit 14 has the configuration shown in FIG. 14, so that it has a wide dynamic range and can appropriately amplify the output signal of the light receiving unit 12 to perform signal processing. It becomes.

(Ninth embodiment)
Next, the block diagram of FIG. 15A shows the configuration of the signal processing unit included in the ninth embodiment of the optical object identification device of the present invention. In this block diagram, the first and second light receiving elements 12b and 12a, the semiconductor laser 1, the oscillation frequency dividing circuit 54 for driving the semiconductor laser 1 by pulse modulation, and the LD modulation signal unit 56 are shown. Show. In FIG. 15A, a multistage gain switching amplifier section 48, a gain switching control section 50, and a noise removing section 52 constitute a first signal processing circuit, and a multistage gain switching amplifier section 49, a gain switching control section 51, and a noise removing section 53. Constitutes a second signal processing circuit. The first and second signal processing circuits, the A / D converter 55, and the signal processor 57 constitute a signal processing unit.

  The signal processing unit of the ninth embodiment can be applied to the signal processing circuit 14 included in the fifth, sixth, seventh, and eighth embodiments described above.

  In further description, the ninth embodiment has the optical system of the fifth embodiment shown in FIG. 7 and includes any one of the focal position fluctuation mechanisms of the focal position fluctuation mechanisms shown in FIGS. 9A to 11E. Have. Further, the optical object identification device of the ninth embodiment has the disturbance light noise removal circuit shown in FIG. 12B and the amplification degree switching circuit shown in FIGS. 13C and 14.

  In the ninth embodiment, a signal processing function will be described. In the ninth embodiment, the first light receiving element 12b illustrated in FIG. 15A receives the first reflected light beam 7b via the first linear polarizer 13a illustrated in FIG. 7, and the second light illustrated in FIG. 15A. The light receiving element 12a receives the second reflected light beam 7a via the second linear polarizer 13c illustrated in FIG. The first linear polarizer 13a and the second linear polarizer 13b are perpendicular to each other in the polarization direction of the transmitted light.

  Here, how to describe the directions of the orthogonal polarization directions of the linear polarizers 13a and 13b is defined. That is, the polarization component in the same direction as the polarization direction of the emitted light of the semiconductor laser 1 is described as “// polarization component”, and the polarization component in the direction orthogonal to the // polarization component is described as “⊥-polarization component”. The signal output from the second light receiving element 12 a and the signal output from the first light receiving element 12 b have substantially the same flow until they are input to the A / D converter 55.

  The // polarized component signal output from the first light receiving element 12b will be described. When the first light receiving element 12b detects the // polarized light component, the output // polarized light component signal is amplified by the multistage gain switching amplifier unit 48 having the configuration shown in FIG. The output of the amplifier unit 48 is sent to the // polarization component side gain switching control unit 50, which determines whether the gain is rounded up, fixed, or rounded down, and repeats this routine until an appropriate signal level is reached. The // polarized component signal having an appropriate signal level is sent to the // polarized component side noise removing unit 52. In the noise removing unit 52, as described with reference to FIGS. 12A and 12B, disturbance light noise is removed and sent to the A / D converter 55 as a // polarized component signal. At this time, a polarization component side gain control signal (amplifier amplification degree signal) representing the amplification degree determined by the gain switching control unit 50 is also sent to the A / D converter 55 at the same time.

  On the other hand, the second polarized light component signal output by detecting the second polarized light component by the second light receiving element 12a is amplified by the multistage gain switching amplifier 49 having the configuration shown in FIG. The output of the amplifier unit 49 is sent to the polarization component side gain switching control unit 51, which determines whether the gain is rounded up, fixed, or rounded down, and repeats this routine until an appropriate signal level is reached. The ⊥ polarization component signal having an appropriate signal level is sent to the ⊥ polarization component side noise removal unit 53. In the noise removing unit 53, as described with reference to FIGS. 12A and 12B, disturbance light noise removal is performed and sent to the A / D converter 55 as a polarization component signal. At this time, the polarization component side gain control signal (amplifier amplification degree signal) indicating the amplification degree determined by the gain switching control unit 51 is also sent to the A / D converter 55 at the same time.

  In this A / D converter 55, a total of 4 channels of the above-mentioned // polarized component signal, // polarized component side amplifier amplification signal, ⊥polarized component optical signal, and ⊥polarized component side amplifier amplification signal are received. Simultaneous sampling is used.

  FIG. 15B shows a flowchart representing data processing between the A / D converter 55 and the signal processor 57.

  First, the A / D converter 55 takes in signal data for one period of lens vibration (when a lens vibration system is provided). The trigger of A / D conversion by the A / D converter 55 is immediately triggered (step AD1-ST1).

  Next, the A / D converter 55 performs A / D conversion, and takes the signal data for one period of the lens vibration into the memory M included in the signal processor 57 (step AD1-ST2). The sampling period of this signal data is preferably a time interval for acquiring about several thousand signal data for one lens period.

  The signal intensity of the // polarized component signal at the time of focusing is the signal data at the time of focusing in the signal data string representing the intensity of the // polarized component signal that is A / D converted by the A / D converter 55 and stored in the memory M. It is desirable to use an average value of signal data at a plurality of points with reference to. This is to reduce the influence of noise and improve the accuracy of discrimination of the object 9 to be measured. Further, the amplification factor α of the amplifier unit 48 at the focus time is determined based on the signal data string indicating the amplification degree of the A / D converted // polarized component signal (step AD1-ST4).

  Also, the defocus time is determined based on the focus time. In order to give the position of the lens vibration with respect to time as a mathematical expression, a sine curve cam 28 as shown in FIG. 10 is used as an example in the lens driving system.

  Thereby, the deviation X from the focal position of the first condenser lens 8 is given by X = a · sin ωt (mm), the frequency ω and the amplitude a of the lens vibration are known, and the desired defocusing is achieved. If the position X is given, the time t at the defocus position X can be calculated. By making the current flowing through the lens driving motor 22 constant, the lens vibration frequency ω can be made constant. The time t obtained by the above calculation is set as the time at the time of defocusing (step AD1-ST5).

  The signal intensity at the time of defocus is an intensity obtained by averaging signal data at a plurality of points at the defocus time in a signal data string representing the intensity of the high polarization component signal. This averaging is to reduce the influence of noise, similar to the explanation with the // polarized component signal. Further, the amplification factor β of the amplifier unit 49 at the defocus time is determined based on the signal data string indicating the amplification degree of the A / D converted ⊥ polarization component signal (step AD1-ST6).

By dividing the signal intensity S _// at the time of focusing by the signal amplification factor α described above, the intensity of the polarization component signal (S _// / α) at the time of focusing before passing through the amplifier unit 48 is calculated. (Step AD1-ST7). Further, the signal amplification factor of the aforementioned beta, by dividing the signal intensity S _⊥ at the defocus, the intensity of the ⊥-polarization component signal during the previous defocus passing through the amplifier section 49 (S _⊥ / beta) Calculate (step AD1-ST8).

Next, the ratio (S _// / α) / () of the intensity of the polarization component signal (S _// / α) at the time of focusing and the intensity of the polarization component signal at the time of defocus (S _⊥ / β) to calculate the S _⊥ / β).

As described in the fifth and sixth embodiments, the intensity of the // polarized component signal at the time of focusing (S _/// α) and the intensity of the negatively polarized component signal at the time of defocusing (S _⊥ / β ) ((S _// / α) − (S _⊥ / β)). Furthermore, this difference - and _{((S // / α) (} S ⊥ / β)), may be calculated the ratio of the intensity of the focus when // polarized component signal (S _// / α) ( Step AD1-ST9).

  The ratio or difference value calculated in step AD1-ST9 is compared with the statistical data of the known measured object inputted in advance in the memory M to identify the type of measured object 9 (step AD1- ST10). That is, it is preferable to previously input the values calculated by measuring in advance as described above to the memory M as known data for a plurality of objects of different types.

  Thus, after identifying the type of the object 9 to be measured and outputting the identification result to the identification result display 58, the process immediately returns to the process of step AD1-ST1, and A / D conversion starts. In order to obtain a more reliable result, a ratio of (// polarization component signal intensity at the time of focusing) / ((polarization component signal intensity at the time of defocusing)), which is a result of the processing from step AD1-ST1 to step AD1-ST9, is set. calculate. It is also conceivable that this process is repeated a plurality of times, an average value of a plurality of signal ratios obtained by the plurality of processes is calculated, and the type of the device under test 9 is identified by the calculated average value. Note that a control unit (not shown) continues the signal processing from step AD1-ST1 to step AD1-ST10 until the operator notifies the end of measurement.

(Modification 1 of 9th Embodiment)
Next, with reference to the flowchart shown in FIG. 15C, Modification 1 of the ninth embodiment will be described.

  In the first modification, as shown in the flowchart of FIG. 15C, the peak position (time) of the // polarized component signal at the time of focusing is detected.

  First, the signal processing unit (signal processing circuit 14) in FIG. 15A monitors the // polarized component signal output from the first light receiving element 12b (step AD2-ST1).

  Next, when the extreme value determination circuit ZC included in the signal processing unit determines that the // polarized component signal has taken the minimum value, the A / D converter 55 generates a trigger for starting A / D conversion (Step S1). AD2-ST2). The extreme value determination circuit ZC includes a differentiation circuit and a zero cross determination circuit.

  The A / D converter 55 starts 2-channel simultaneous A / D conversion of the // polarized component signal and the negatively polarized component signal by the trigger (step AD2-ST3).

  Simultaneously with the start of the A / D conversion, the signal processor 57 takes in the amplification factor α of the polarization component signal and the amplification factor β of the polarization component signal from the A / D converter 55 (step AD2- ST4).

  Even after the A / D conversion is started, the extreme value determination circuit ZC monitors the // polarization component signal, and the extreme value determination circuit ZC determines that the // polarization component signal has taken the minimum value. Sometimes, by this time, the A / D converter 55 clears the data acquired by the A / D conversion, and the A / D converter 55 redoes the A / D conversion.

  Usually, a waveform of a polarization component signal having one peak is obtained within a period of a half cycle of vibration of the first condenser lens 8, but when the height difference of the surface of the object to be measured 9 is large, The // polarized component signal may have a waveform having two or more peaks within a half period of vibration of the first condenser lens 8. In order to cope with the case where the // polarization component signal has a plurality of peak waveforms, if the waveform of the // polarization component signal has two or more peaks, the peak with the slowest time in the half cycle of vibration is obtained. Considered as a true peak (step AD2-ST5).

  The A / D conversion is completed after acquiring data corresponding to a quarter of the lens vibration period. As a result, only the data used for surface discrimination can be acquired, so the time required for A / D conversion compared to the case where the signal data for one period of lens vibration described in the flowchart of FIG. Can be significantly reduced (step AD2-ST6).

  However, the amount of data captured by A / D conversion is not limited to a quarter of the lens vibration cycle, and may be a portion of the lens vibration cycle as in the ninth embodiment. The time at the time of focusing in the lens vibration is the time when the trigger is generated (the time when A / D conversion is started). The focus signal is an average value of a plurality of points after the focused time. As a result, the influence of noise or the like can be reduced (step AD2-ST7).

  Further, the time at the time of defocusing is obtained based on the time when the trigger is generated. In order to give the position of the lens vibration with respect to time by a mathematical expression, a sine curve cam is used as an example in the lens driving system. Thereby, the deviation x from the focal position of the first condenser lens 8 is given by x = a · sin ωt (mm), the frequency ω and the vibration width a of the lens vibration are known, and a desired defocus is achieved. If the position x is given, the time t can be calculated. By making the current flowing through the motor that drives the first condenser lens 8 constant, the frequency ω of the lens vibration can be made constant. As described above, the time when the time t has elapsed from the time when the trigger is generated becomes the time at the time of defocusing (step AD2-ST8).

  The signal intensity at the time of defocusing is the intensity obtained by averaging the signal data at a plurality of points at the defocusing time in the signal data string representing the intensity of the high polarization component signal (step AD2-ST9).

Next, as in the case of the flowchart of FIG. 15B, the intensity (S _// / α) of // polarization component signal at the time of focusing before passing through the amplifier unit 48 is calculated using the signal amplification factor α ( Step AD2-ST10), using the signal amplification factor β, the intensity (S _⊥ / β) of the defocused ⊥ polarization component signal before passing through the amplifier unit 49 is calculated (Step AD2-ST11).

Then, the ratio of the intensity of the // polarized component signal when the focus (S _// / alpha) and intensity of the ⊥-polarization component signals defocus _{(S ⊥ / β) (S} // / α) / (S _⊥ / β) is calculated. As described in the fifth and sixth embodiments, instead of the above ratio, the intensity of the // polarized component signal during focusing (S _/// α) and the negative polarized component signal during defocusing the difference between the intensity (S _⊥ / β) of the or, may be calculated the ratio or the like of the intensity of the // polarized component signal during this difference and the focus (S _// / α) (step AD2-ST12 ).

  The value calculated in step AD2-ST12 is compared with the statistical data of the calculated value for the surface of the measured object of a known material input in advance in the memory M, and the surface state of the measured object 9 to be detected Is discriminated (step AD2-ST13). That is, it is preferable to previously input the values calculated by measuring in advance as described above to the memory M as known data for a plurality of objects of different types.

  Thus, after the surface of the object to be measured 9 is discriminated and the discriminated result is output to the discrimination result display 58, the process immediately returns to the processing of step AD2-ST1, and the // polarization component signal is monitored, and the extreme value is obtained. It waits for the trigger of the determination circuit ZC.

  By performing the above processing multiple times, the ratio of multiple (focus // polarized component received signal) / (defocus⊥polarized component received signal) ratios is averaged, and multiple average values provide higher accuracy. Surface discrimination can be performed.

(Modification 2 of the ninth embodiment)
Next, the block diagram of FIG. 16A shows the configuration of the signal processing unit provided in the second modification of the ninth embodiment. As shown in FIG. 16A, this signal processing unit is a system that performs processing after amplifier units 48 and 49 in FIG. 15A by digital signal processing. // The first light receiving element 12b on the polarization component side receives the first reflected light beam 7b and converts it from an optical signal to an electric signal. Since the emitted light emitted from the semiconductor laser 1 is pulse modulated, the light receiving element 12b having a response speed capable of following the frequency of the pulse modulation is desirable.

  // The polarization component signal converted into an electrical signal by the first light receiving element 12b on the polarization component side is amplified by the amplifier unit 48. The amplifier unit 48 can switch the gain in multiple stages. The gain switching control signal is output from the signal processor 57 to the amplifier unit 48.

  Further, the second light receiving element 12a on the side of the polarized light component receives the second reflected light beam 7a and converts it from an optical signal to an electric signal. The ⊥ polarization component signal converted into an electrical signal by the first light receiving element 12 b on the ⊥ polarization component side is amplified by the amplifier unit 49. The amplifier unit 49 can switch the gain in multiple stages. The gain switching control signal is output from the signal processor 57 to the amplifier unit 49.

  A baseband signal used for pulse modulation of the semiconductor laser 1 is output from the oscillation frequency dividing circuit 54. This baseband signal is also input to the A / D converter 55 as a clock signal. Using the data A / D converted by the A / D converter 55, the DUT 9 is identified. In the signal processor 57, the gain control signal is determined based on the input signal strength, and the gains of the amplifier unit 48 and the amplifier unit 49 are switched to the optimum ones and reflected at the time of data acquisition for the next A / D conversion. The

  Next, processing in the A / D converter 55 and the signal processor 57 shown in FIG. 16A will be described with reference to the flowchart shown in FIG. 16B.

  First, the A / D converter 55 samples the // polarization component signal and the negative polarization component signal simultaneously. The A / D conversion trigger by the A / D converter 55 is immediately triggered (step AD3-ST1).

  Next, by A / D conversion by the A / D converter 55, signal data having a waveform corresponding to one period of the lens vibration period is taken into the memory M included in the signal processor 57, and the A / D conversion is stopped (step). AD3-ST2).

  Next, the signal processor 57 performs a differential operation on both the // polarization component signal and the ⊥ polarization component signal with reference to the clock signal for LD pulse modulation. That is, as described with reference to FIGS. 13A and 13B in the eighth embodiment, for the // polarized component signal, the signal at the time “1” of the clock signal and the signal at the time “0” of the clock signal. The differential operation is performed. Further, as described with reference to FIG. 13B, the differential calculation of the signal at the time “1” of the clock signal and the signal at the time “0” of the clock signal is performed on the high polarization component signal. By this differential operation, the influence of disturbance light noise is reduced (step AD3-ST3).

  Next, a peak search is performed on the // polarized component signal, and the peak time of the // polarized component signal is set as the time at the time of focusing of the lens vibration (step AD3-ST4).

  The intensity of the // polarization component signal at the time of focusing is the intensity data of the signal at the time of focusing in the intensity data string of the // polarization component signal stored in the memory M by the A / D conversion of the A / D converter 55. The average intensity of the intensity data at a plurality of points with reference to. This is to reduce the influence of spike noise and improve the accuracy of identification of the object to be measured. With reference to the intensity of the // polarized component signal at the time of focusing, the signal processor 57 determines the gain switching control signal of the next // polarized component side amplifier unit 48. That is, the signal processor 57 changes the gain switching control signal in a direction to increase the gain of the amplifier unit 48 when the light intensity of the // polarized component is weak. Conversely, when the light intensity of the // polarized component is strong, the signal processor 57 changes the gain switching control signal in a direction to lower the gain of the amplifier unit 48. If the light intensity is good, the signal processor 57 does not change the gain switching control signal and maintains the gain of the amplifier unit 48 as it is (step AD3-ST5).

  On the other hand, the defocus time is determined based on the focus time. In order to give the position of the lens vibration with respect to time by a mathematical expression, a sine curve cam is used as an example in the lens driving system. Thereby, the deviation x from the focal position of the first condenser lens 8 is given by x = a · sin ωt (mm), the frequency ω and the vibration width a of the lens vibration are known, and a desired defocus is achieved. If the position x is given, the time t can be calculated. By making the current flowing through the motor that drives the first condenser lens 8 constant, the frequency ω of the lens vibration can be made constant. The time t thus given is set as the time at the time of defocusing (step AD3-ST6).

  The signal intensity at the time of defocusing is an intensity obtained by averaging signal data at a plurality of points at the defocus time in a signal data string representing the intensity of the high polarization component signal. This averaging is to reduce the influence of noise as in the case of the // polarized component signal. Further, the gain switching control signal of the amplifying unit 49 on the polarization component side is determined in the same manner as the gain switching control signal of the amplifying unit 48 on the polarization component side (step AD3-ST7).

Here, the gain switching control signal for the amplifier unit 48 for the // polarized component signal when A / D conversion was performed last time is left in the memory M of the signal processor 57. Thus, the amplification factor α of the amplifier unit 48 at the current focus time is determined. Also, by dividing the intensity of the // polarized component signal at the focus position by α, the intensity of the // polarized component signal (S _/// α) by the light received by the light receiving element 12b on the // polarized component side is obtained. It can be calculated (step AD3-ST8).

Similarly, by leaving the gain switching control signal for the previous amplifier unit 49 in the memory M of the signal processor 57, the polarization component signal is also amplified by the polarization component side amplifier unit 49 at the current defocus time. The rate β is determined. The intensity (S _⊥ / β) of the ⊥ polarization component signal by the light received by the light receiving element 12a on the ⊥ polarization component side is calculated by dividing the signal intensity at the defocus position of the ⊥ polarization component signal by the amplification factor β. (Step AD3-ST9).

The intensity of the // polarized component signal at the time of focus (S _/// α) calculated in step AD3-ST8 and step AD3-ST9 and the intensity of the ⊥-polarized component signal at the time of defocus (S _ＳＴ / β) Ratio ((S _// / α) / (S _⊥ / β)) is calculated (step AD3-ST10).

  In addition, as described in the fifth and sixth embodiments, the calculation method of the polarization component signal at the time of focusing and the polarization component signal at the time of defocusing is the difference between the two, the difference between the two, // A ratio with the polarization component signal may be used.

  Next, the value calculated in step AD3-ST10 is compared with the statistical data about the known measured object input in advance in the memory M to identify the measured object (step AD3-ST11).

  Next, the signal processor 57 outputs the result of identification of the object to be measured to the surface discrimination result display 58, and provides a gain switching control signal to the polarization component side amplifier unit 48 and the polarization component side amplifier unit 49. Is output (step AD3-ST12).

  In step AD3-ST12, immediately after the signal processor 57 outputs the signal processing result, the process returns to step AD3-ST1, and A / D conversion starts.

In order to obtain a more reliable result, as a result of the processing from step (AD3-ST1) to step (AD3-ST12), the intensity of the polarization component signal (S _// / α) at the time of focusing and A ratio ((S _// / α) / (S _⊥ / β)) to the intensity (S _⊥ / β) of the ⊥ polarization component signal at the time of defocusing is calculated, and this ratio ((S _// / α) / The process of storing ( _S⊥ / β)) in the memory is repeated a plurality of times. Then, a plurality of average values of this ratio may be calculated, and the object to be measured may be identified based on this average value. In this case, the signal processor 57 continues the processing from step (AD3-ST1) to step (AD3-ST12) until the measurement end notification operation is performed by the operator.

(Tenth embodiment)
Next, a description will be given of a tenth embodiment of the optical object identification device of the present invention. The tenth embodiment is an embodiment applicable to the first to ninth embodiments described above.

  When using the semiconductor laser 1 as a light source, it is necessary to consider eye-safety. In particular, it is desirable to satisfy Class 1 when mounted on home appliances such as a vacuum cleaner.

  When mounting on an electric vacuum cleaner, as a basic matter, a device that does not turn on the semiconductor laser 1 is necessary except when the vacuum cleaner is installed on the floor surface. In the case of a vacuum cleaner equipped with a floor surface discrimination sensor as the optical object identification device of the present invention, the presence or absence of reflection from the floor surface is detected by the light emission of the semiconductor laser 1 at a level satisfying the eye safe class 1. Thus, the floor surface can be determined. Of course, it may be additionally detected by another sensor.

  In addition, as an operation condition for pulse-modulating the semiconductor laser 1 as a semiconductor light emitting element provided in the floor surface discrimination sensor, for example, with a pulse waveform shown in FIG. 17A or a pulse waveform signal shown in FIG. By driving the semiconductor laser 1, the eye-safe class 1 can be satisfied.

(Eleventh embodiment)
Next, an eleventh embodiment of the optical object identification device of the present invention will be described. This eleventh embodiment has the configuration of configuration example 3 of the sixth embodiment shown in FIG. 11A provided with a crank mechanism as an example of a lens vibration mechanism. As shown in FIG. 11A, the first light beam 5 is emitted from the optical window 35 attached to the housing 83 that houses the integrated circuit (IC) that forms the optical system and the signal processing circuit 14, and is reflected by the object 9 to be measured. The reflected reflected light beam 7 passes through the optical window 35 and enters the housing 83. The optical window 35 is installed so as to be within the focal position of the first condenser lens 8 at any position within the range where the first condenser lens 8 vibrates.

  As described above, since the object to be measured 9 is identified by the polarization disturbance of the reflected light beam from the object to be measured 9, if a light scatterer such as dust adheres to the optical window 35, the noise source disturbs the polarization state of the light. End up.

  However, in the eleventh embodiment, since the pinhole portion 11 is disposed at the focal position of the fourth condenser lenses 10a and 10b, light from other than the focal position of the first condenser lens 8 is received by the light receiving element 12a. And 12b receive little light. Therefore, in any vibration state of the first condenser lens 8, even if dust adheres to the optical window 35 due to the configuration in which the optical window 35 is disposed within the focal length of the first condenser lens 8, In this case, the first light beam is not focused on, and the dust does not become a noise factor, so that the influence of dust or dirt can be removed when the object to be measured 9 is identified.

(Twelfth embodiment)
FIG. 18A shows a schematic configuration diagram in which the optical object identification device shown in any of the above embodiments of the present invention is applied to a vacuum cleaner. 18A shows an overall outline of the cleaner A on the upper side, and FIG. 18A shows an enlarged head portion E of the cleaner A on the lower side. The head part E includes wheels C, and the optical object identification device B is incorporated in the head part E. An optical window (not shown) is formed on the lower surface of the head portion E, and the first light beam 5 is emitted from the optical window.

  FIG. 18B shows a schematic configuration in which the optical object identification device shown in any of the above embodiments of the present invention is applied to a self-propelled cleaner A2. An optical window (not shown) is formed on the lower surface of the self-propelled cleaner main body, and the first light beam 5 is emitted from the optical window as in the cleaner A of FIG. In addition, C is a wheel, D is a guide member attached to the outer edge of the main body lower surface.

  In general, floor types to be cleaned with vacuum cleaners include flooring and other boards, and woven fabrics such as tatami mats and carpets. Currently, vacuum cleaners that are in widespread use depend on the floor type. The operator of the vacuum cleaner needs to switch manually, which is very troublesome.

  Furthermore, in a self-propelled cleaner that automatically moves and performs cleaning, an operator cannot switch the driving state, and a sensor that determines the type of the floor surface is indispensable. In such a vacuum cleaner, by including the optical object identification device of the above-described embodiment according to the present invention, it is possible to accurately determine the type of the floor surface. That is, as described in the above embodiment, the depolarization information based on the reflection of light from a known floor surface (plate, tatami mat, carpet, etc.) is input to the memory of the signal processing circuit 14 in advance, and the known depolarization information is input. And the measurement result of the measurement object can be compared to accurately determine the type of the floor surface. In addition, the optical object identification device of the seventh embodiment also has a function of removing ambient light such as sunlight and fluorescent lamps, so that it can be used in a bright environment such as indoors under illumination. This is particularly effective for self-propelled cleaners.

It is a figure which shows the structure of 1st Embodiment of the optical object identification device of this invention. It is a conceptual diagram which shows the light reception intensity distribution at the time of providing the light-receiving part which has a light-receiving element group in the said 1st Embodiment. FIG. 3A is a diagram showing a configuration of a modification of the first embodiment, and FIG. 3B is a diagram showing a light intensity distribution in the modification. It is a figure which shows the structure of 2nd Embodiment of this invention. It is a figure which shows the structure of 3rd Embodiment of this invention. It is a figure which shows the structure of 4th Embodiment of this invention. It is a figure which shows the structure of 5th Embodiment of this invention. FIG. 8A is a diagram illustrating a configuration in which the optical system is accommodated in the casing 80 in the fifth embodiment, and FIG. 8B is a diagram illustrating an example in which the light projecting unit is accommodated in the casing. FIG. 8C shows an example in which a photodiode is formed with a signal processing circuit on the same semiconductor substrate. It is a figure for demonstrating the concept of the optical object identification device of 6th Embodiment of this invention, and is a schematic diagram which shows the positional relationship of the to-be-measured object with a height difference of a surface, and a 1st condensing lens. It is the schematic which shows the structural example 1 of the said 6th Embodiment. FIG. 10A is one side view of Configuration Example 2 of the sixth embodiment, and FIG. 10B is another side view of Configuration Example 2. It is a figure which shows the structural example 3 of the said 6th Embodiment. It is a figure which shows the structural example 4 of the said 6th Embodiment. It is a figure which shows the progressive lens with which the modification 1 of the said 6th Embodiment is provided. It is a figure which shows schematic structure of the modification 1 of the said 6th Embodiment. It is a figure which shows schematic structure of the modification 2 of the said 6th Embodiment. It is a timing chart explaining the signal processing operation of 7th Embodiment of this invention. It is a block diagram which shows the circuit which the signal processing circuit with which the said 7th Embodiment is provided has. It is a timing chart explaining the signal processing operation | movement of the optical object identification device of 8th Embodiment of this invention. It is a timing chart explaining the signal processing operation | movement of the optical object identification device of 8th Embodiment of this invention. It is a block diagram which shows the circuit which the signal processing circuit of the said 8th Embodiment has. It is a figure which shows the more concrete circuit structure which the signal processing circuit of the said 8th Embodiment has. It is a circuit block diagram which shows the structure of the signal processing system of 9th Embodiment of this invention. It is a flowchart which shows the signal processing operation in the said 9th Embodiment. It is a flowchart which shows the signal processing operation in the modification 1 of the said 9th Embodiment. It is a circuit block diagram which shows the structure of the signal processing system of the modification 2 of the said 9th Embodiment. It is a flowchart which shows operation | movement of the signal processing system of the modification 2 of the said 9th Embodiment. 17A and 17B are waveform diagrams showing an example of the emission pulse waveform of the semiconductor laser for realizing the optical object identification device according to the tenth embodiment of the present invention. FIG. 18 (A) is a schematic diagram showing the configuration of a cleaner as a twelfth embodiment of the present invention, and FIG. 18 (B) is a schematic diagram showing the configuration of a self-propelled cleaner as an embodiment of the present invention. It is.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Semiconductor laser 2 Collimator lens 3 Aperture 4 Beam splitter 5 1st light beam 6 2nd light beam 7 Reflected light beam 8 1st condensing lens 9 Measured object 10 2nd condensing lens 11 Pinhole part 12 Light receiving part 12a 2nd light receiving element 12b 1st light receiving element 13a, 13b, 13c Linear polarizer 14 Signal processing circuit 15 Mirror 16 Pulse power supply 17 Solenoid coil 18 Lens holder 19 Spring 20 Fixing plate 21 Iron core 22 Motor 23 Motor fixing plate 24 Spring 25 Guide 26 Auxiliary plate 27 Bearing 28 Fixed base 29 Auxiliary plate 30 Lens holder 31 Base 32 Guide 33 Slider 34 Disk 35 Window 36 Propeller 37 Progressive lens 38 Liquid crystal switch 39a, 39b Linear polarizer 40 LD modulation pulse 41 Inversion pulse 42 Original signal 43 DC disturbance light signal 4 AC disturbance light signal 45 First processing signal 46 Second processing signal 47 Differential signal 48 // Polarization component side multistage gain switching amplifier section 49 ⊥Polarization component side multistage gain switching amplifier section 50 // Polarization component side gain switching control Unit 51 ⊥ Polarization component side gain switching control unit 52 // Polarization component side noise removal unit 53 ⊥ Polarization component side noise removal unit 54 Oscillation frequency divider 55 A / D converter 56 LD modulation signal unit 57 Signal processor 58 Identification result display

Claims (74)

A light projecting unit that irradiates the object to be measured with light emitted from the semiconductor light emitting element;
A light receiving unit that receives reflected light reflected by the object to be measured;
A polarization state selection unit that is disposed between the light receiving unit and the object to be measured and transmits polarized light in a predetermined polarization direction;
An optical object identification apparatus comprising: a signal processing unit that processes a signal output from the light receiving unit and measures the intensity of the light in the predetermined polarization direction out of the reflected light. The optical object identification device according to claim 1,
An optical object identification device, wherein a polarization state of light incident on the object to be measured is linearly polarized light. In the optical object identification device according to claim 2,
An optical object identification device, wherein linearly polarized light incident on the object to be measured is an S wave with respect to the object to be measured. In the optical object identification device according to claim 2,
An optical object identification device, wherein a polarization direction selected by the polarization state selection unit and a polarization direction of light incident on the object to be measured are substantially the same direction. The optical object identification device according to claim 1,
A light branching element that splits light emitted from the semiconductor light emitting element into a first light flux and a second light flux;
First condensing means for condensing and irradiating the first light flux on the object to be measured;
Second light collecting means for collecting light that has passed through the first light collecting means among the light reflected by the object to be measured;
An optical object identification device comprising: a pinhole portion disposed between the second light collecting means and the light receiving element. In the optical object identification device according to claim 5,
An optical object identification device comprising: stray light preventing means for the second light beam and reflected light of the second light beam. In the optical object identification device according to claim 6,
The stray light prevention means has a linear polarizer,
The linear polarizer is installed on the optical axis of the second light beam, and the polarization direction that the linear polarizer passes is a direction orthogonal to the polarization direction of the second light beam. Type object identification device. In the optical object identification device according to claim 5,
The second condensing means includes a condensing lens;
An optical object identification device, wherein the pinhole portion is installed at a focal length position of the condenser lens. In the optical object identification device according to claim 5,
An optical object identification device, wherein a diameter of a reflected light beam at a position where the pinhole portion is disposed is smaller than a hole diameter of the pinhole portion. In the optical object identification device according to claim 5,
The optical object identification device, wherein the first light beam is incident on a substantial center of the first light collecting means. In the optical object identification device according to claim 5,
The optical object identification device, wherein the first light beam is incident on an end of the first light collecting means. The optical object identification device according to claim 1,
A first condensing means for condensing the light emitted from the semiconductor light emitting element on the object to be measured;
The light reflected from the object to be measured has light guiding means for excluding a portion overlapping the light beam incident on the first light collecting means, and directing a reflected light beam in a peripheral portion other than the overlapping portion to the light receiving portion. ,
An optical object identification device, wherein the reflected light beam of the peripheral portion is detected by the light receiving portion. In the optical object identification device according to claim 5,
An optical axis changing means for changing a traveling direction of the second light beam divided by the light branching element;
The second light flux with the changed optical axis and the first light flux have a substantially parallel optical axis,
The optical object identification device, wherein the first and second light beams are incident on the same first light collecting means. The optical object identification device according to claim 1,
A first light branching element that splits a light beam emitted from the semiconductor light emitting element into a first light beam and a second light beam;
A second optical branching element that divides the light reflected by the device under test into first and second reflected light fluxes,
The light receiving unit is
A first light receiving element for receiving the first reflected light beam;
A second light receiving element for receiving the second reflected light beam,
And a polarization state selection element that selects a polarization state of light incident on the first light receiving element,
The optical object identification device, wherein the signal processing unit calculates a ratio between a signal output from the first light receiving element and a signal output from the second light receiving element. The optical object identification device according to claim 1,
A first light branching element that splits a light beam emitted from the semiconductor light emitting element into a first light beam and a second light beam;
A second optical branching element that divides the light reflected by the device under test into first and second reflected light fluxes,
The light receiving part is
A first light receiving element for receiving the first reflected light beam;
A second light receiving element for receiving the second reflected light beam,
A first polarization state selection element that selects a polarization state of light incident on the first light receiving element;
A second polarization state selection element that selects a polarization state of light incident on the second light receiving element;
An optical object identification device, wherein a polarization direction selected by the first polarization state selection element and a polarization direction selected by the second polarization state selection element are substantially orthogonal to each other. The optical object identification device according to claim 15,
The polarization direction selected by the first polarization state selection element is substantially parallel to the polarization direction of the first light flux,
The optical object identification device, wherein the polarization direction selected by the second polarization state selection element is substantially perpendicular to the polarization direction of the first light beam. The optical object identification device according to claim 15,
The optical object identification device, wherein the first and second polarization state selection elements are linear polarizers. The optical object identification device according to claim 15,
An optical object identification device, wherein the second light branching element and the first and second polarization state selection elements are configured by a polarization beam splitter. The optical object identification device according to claim 15,
The optical object identification device, wherein the signal processing unit calculates a ratio between a signal output from the first light receiving element and a signal output from the second light receiving element. The optical object identification device according to claim 15,
The optical object identification device, wherein the signal processing unit calculates a difference between a signal output from the first light receiving element and a signal output from the second light receiving element. The optical object identification device according to claim 15,
The signal processor is
Calculating the difference between the signal output from the first light receiving element and the signal output from the second light receiving element;
A ratio between the difference and the sum of the signal output from the first light receiving element and the signal output from the second light receiving element; or
A ratio between the difference and a signal output from the first light receiving element or a signal output from the second light receiving element is calculated. The optical object identification device according to claim 1,
An optical object identification device, wherein the semiconductor light emitting element is a semiconductor laser. The optical object identification device according to claim 1,
An optical object identification device, wherein the light receiving unit includes a photodiode. The optical object identification device according to any one of claims 14 to 21,
An optical object identification device, wherein the first light receiving element and the second light receiving element are formed on the same semiconductor substrate. The optical object identification device according to claim 23,
An optical object identification device, wherein the light receiving unit and the signal processing unit are formed on the same semiconductor substrate. 25. The optical object identification device according to claim 24.
An optical object identification device, wherein the first light receiving element, the second light receiving element, and the signal processing unit are formed on the same semiconductor substrate. The optical object identification device according to claim 1,
The optical object identification device, wherein the light receiving unit includes a light receiving element group in which a plurality of light receiving elements are arranged. The optical object identification device according to claim 27,
The optical object identification device, wherein the signal processing unit normalizes a signal of each light receiving element of the light receiving element group based on a signal intensity of the light receiving element having the maximum intensity among the light receiving element groups. The optical object identification device according to any one of claims 1 to 28,
The first condensing means comprises a first condensing lens;
An optical object identification apparatus, wherein a distance between a focal position of the first condenser lens and the surface of the object to be measured is changed. The optical object identification device according to claim 29.
A lens vibration mechanism for vibrating the first condenser lens;
An optical object identification characterized in that the distance between the focal position of the first lens and the surface of the object to be measured is changed by changing the lens position of the first condenser lens by the lens vibration mechanism. apparatus. The optical object identification device according to claim 30,
An optical object identification device, wherein the lens vibration mechanism has a cam. The optical object identification device according to claim 31,
An optical object identification device, wherein the cam curve of the cam is a sine wave curve. The optical object identification device according to claim 30,
An optical object identification device, wherein the lens vibration mechanism has a solenoid coil. The optical object identification device according to claim 30,
An optical object identification device, wherein the lens vibration mechanism has a crank mechanism for converting rotational motion into linear reciprocating motion. The optical object identification device according to claim 30,
An optical object identification device, wherein the lens vibration mechanism has an actuator. The optical object identification device according to claim 30,
The lens vibration mechanism is an optical object identification device that vibrates a lens by receiving wind with a blade attached to a lens holder. The optical object identification device according to claim 29.
The first condenser lens is a progressive lens;
An optical object identification characterized in that the distance between the focal position of the first condenser lens and the surface of the object to be measured is changed by changing the position at which the first light beam is incident on the progressive lens. apparatus. The optical object identification device according to claim 37,
An optical object identification device characterized in that the distance between the focal position of the progressive lens and the surface of the object to be measured is changed by moving the progressive lens in a plane substantially perpendicular to the first light beam. . The optical object identification device according to claim 37,
An optical object identification device, wherein an optical switch including a liquid crystal is disposed on an optical axis of a first light beam incident on the progressive lens. 40. The optical object identification device according to any one of claims 29 to 39,
An optical object identification device characterized in that the amount of change in the distance between the focal position of the first condenser lens and the surface of the object to be measured is larger than the level difference of the irregularities on the surface of the object to be measured. . The optical object identification device according to claim 40,
An optical object identification device characterized in that the amount of change in the distance between the focal position of the first condenser lens and the surface of the object to be measured is 5 mm to 15 mm. The optical object identification device according to claim 14,
First condensing means for condensing and irradiating the first light flux on the object to be measured;
A second condensing unit that condenses light that has passed through the first condensing unit among the light reflected by the object to be measured;
A pinhole portion disposed between the second light collecting means and the first and second light receiving elements;
The first condensing means comprises a first condensing lens;
A mechanism for changing the distance between the focal position of the first condenser lens and the surface of the object to be measured;
The signal processor is
A focus signal that is an output of the first light receiving element at the time of focusing when the distance between the first condenser lens and the surface of the object to be measured is approximately equal to the focal length of the first condenser lens;
The ratio between the defocus signal, which is the output of the second light receiving element at the time of defocus, in which the distance between the first condenser lens and the surface of the object to be measured is different from the focal length of the first condenser lens An optical object identification device. The optical object identification device according to claim 15,
First condensing means for condensing and irradiating the first light flux on the object to be measured;
A second condensing unit that condenses light that has passed through the first condensing unit among the light reflected by the object to be measured;
A pinhole portion disposed between the second light collecting means and the first and second light receiving elements;
The first condensing means comprises a first condensing lens;
A mechanism for changing the distance between the focal position of the first condenser lens and the surface of the object to be measured;
The signal processor is
A focus signal that is an output of the first light receiving element at the time of focusing when the distance between the first condenser lens and the surface of the object to be measured is approximately equal to the focal length of the first condenser lens;
Processing a defocus signal, which is an output of the second light receiving element at the time of defocus, in which a distance between the first condenser lens and the surface of the object to be measured is different from a focal length of the first condenser lens; An optical object identification device. The optical object identification device according to claim 43,
The signal processor is
An optical object identification device for calculating a ratio between the focus signal and the defocus signal. The optical object identification device according to claim 43,
The signal processor is
An optical object identification device for calculating a difference between the focus signal and the defocus signal. The optical object identification device according to claim 43,
The signal processor is
Calculate the difference between the focus signal and the defocus signal,
An optical object identification device that calculates a ratio between the difference and the focus signal. In the optical object identification device according to any one of claims 1 to 46,
By applying a modulation signal to the semiconductor light emitting element, light intensity modulation is applied,
The signal processor is
A difference between a first output signal output from the light receiving unit when the modulation signal is at an H level and a second output signal output from the light receiving unit when the modulation signal is at an L level is calculated. Optical object identification device. The optical object identification device of claim 47,
An optical object identification device, wherein the modulation signal applied to the semiconductor light emitting element is a rectangular wave. The optical object identification device of claim 47,
An optical object identification device, wherein the light emission amount of the semiconductor light emitting element at the L level is approximately 0 W. The optical object identification device of claim 47,
An optical object identification device, wherein a modulation frequency of the light intensity modulation is 50 kHz or more. The optical object identification device of claim 47,
An optical object identification device, wherein a modulation frequency of the light intensity modulation is 100 Hz to 10 kHz. The optical object identification device of claim 47,
The signal processor is
When the modulation signal is at the H level, the first output signal from the light receiving unit is passed as it is, and when the modulation signal is at the L level, the first output signal when the modulation signal is at the H level is sampled. A first sample and hold circuit for holding;
When the modulation signal is at L level, the second output signal from the light receiving section is passed as it is, and when the modulation signal is at H level, the second output signal when the modulation signal is at L level is sampled. A second sample and hold circuit for holding;
An optical object identification device comprising: a differential circuit that takes a difference between a signal output from the first sample hold circuit and a signal output from the second sample hold circuit. In the optical object identification device according to any one of claims 1 to 52,
The signal processor is
An amplifying unit for amplifying the signal detected by the light receiving unit;
An optical object identification device comprising: an amplification degree switching unit that switches the amplification degree of the amplification unit according to the signal intensity of the light receiving unit. 54. The optical object identification device of claim 53.
The amplification degree switching unit is
An optical object identification device that holds the signal intensity of the amplifying unit at a predetermined time and determines the amplification degree of the amplifying unit by comparing the held value with a reference value. The optical object identification device according to claim 42 or 43,
The signal processor is
An amplifying unit for amplifying the signal detected by the light receiving unit;
An amplification degree switching unit that switches the amplification degree of the amplification unit according to the signal intensity of the light receiving unit;
The amplification degree switching unit is
Hold the signal strength of the amplification unit at a predetermined time, and determine the amplification degree of the amplification unit by comparing the held value and a reference value,
Further, the amplification unit includes a first amplifier and a second amplifier, and the amplification degree switching unit includes a first amplification degree switch, a second amplification degree switch, a peak hold circuit unit, and a sample hold circuit unit. ,
The signal processor is
A first signal processing circuit that receives the signal detected by the first light receiving element and includes the first amplifier, the peak hold circuit, and the first amplification degree switch;
A second signal processing circuit that receives the signal detected by the second light receiving element and has the second amplifier, the sample hold circuit, and the second amplification degree switch;
The first amplification degree switch determines an amplification degree of the first amplifier based on an output value of the peak hold circuit,
The optical object identification device, wherein the second amplification degree switch determines an amplification degree of the second amplifier based on an output of the sample and hold circuit. The optical object identification device of claim 54,
The signal processor is
Having a function of holding the output signal of the amplifying unit;
An optical object identification device, wherein a timing for holding an output signal of the amplifying unit for comparison with the reference value is determined using a modulation signal applied to the semiconductor light emitting element. 56. The optical object identification device of claim 55.
The first signal processing circuit includes:
A peak position detector for detecting, as a reference time, a time at which the peak hold circuit holds a peak value of the focus signal, which is an output of the first light receiving element during the focus,
The second signal processing circuit includes:
Based on the reference time detected by the peak position detector and the modulation signal applied to the semiconductor light emitting element, the sample hold circuit samples a defocus signal that is an output of the second light receiving element at the time of the defocus. An optical object identification device comprising a timing detection unit for determining a holding timing. 54. The optical object identification device of claim 53.
The amplification degree switching unit is
An optical object identification device, wherein when the output signal level of the amplification unit is outside a set reference value range, the amplification degree of the amplification unit is increased or decreased by one step. 54. The optical object identification device of claim 53.
The amplification unit included in the signal processing unit includes:
An optical object identification device comprising an amplifier group in which a plurality of amplifiers are connected in series. 60. The optical object identification device of claim 59.
The amplification degree switching unit is
An optical object identification device, wherein an input connection resistance of a predetermined amplifier in the amplifier group is opened when the amplification unit has a predetermined amplification degree. 56. The optical object identification device of claim 55.
The first signal processing circuit outputs a first signal including the focus signal,
The second signal processing circuit outputs a second signal including the defocus signal,
The signal processor is
An A / D converter for converting the first signal and the second signal into a digital signal;
A first amplification signal representing the amplification degree of the first amplifier; a second amplification signal representing the amplification degree of the second amplifier; and the first and second signals converted into digital signals by the A / D converter. Digital signal processing circuit for calculating the ratio of the focus signal and the defocus signal, the difference between the focus signal and the defocus signal, or the ratio between the focus signal and the defocus signal and the focus signal An optical object identification device comprising: The optical object identification device of claim 61,
The digital signal processing circuit is
A memory for storing the first and second digital signals,
The optical object identification device, wherein the memory has a storage capacity capable of storing waveform data for at least a half cycle of the variation in the focal position for each of the first signal and the second signal. The optical object identification device of claim 61,
The digital signal processing circuit is
A memory for storing the first and second digital signals,
The optical object identification device, wherein the memory stores waveform data for one cycle in the variation of the focal position for each of the first signal and the second signal. The optical object identification device of claim 61,
The first signal processing circuit includes:
A peak position detector that detects a peak time of the focus signal by the peak hold circuit as a reference time;
The second signal processing circuit includes:
A timing detection unit for determining a timing at which the sample hold circuit unit samples and holds the defocus signal based on the reference time detected by the peak position detection unit and a modulation signal applied to the semiconductor light emitting element; ,
The A / D converter is
A / D conversion is started with a trigger signal that the peak position detection unit of the first signal processing circuit detects the reference time,
An optical object identification device, wherein the digital signal processing circuit includes a memory for storing A / D converted digital data. The optical object identification device of claim 64,
In the process of storing digital data in the memory from the reference time detected by the peak position detector included in the first signal processing circuit,
The peak position detection unit detects a new reference time between the reference time and the time when the sample hold circuit unit starts sample hold at the timing determined by the timing detection unit of the second signal processing circuit. Clear all the digital data stored in the memory by this new reference time,
The A / D conversion unit starts A / D conversion of the first and second signals using the detection of the new reference time by the peak position detection unit as a trigger signal, and stores the digital data in the memory An optical object identification device. The optical object identification device of claim 61,
The digital signal processing circuit is
Based on the reference time detected by the peak position detector, the focus signal at the reference time included in the first signal is extracted from the digital data stored in the memory and included in the second signal. Take out the defocus signal at a predetermined time,
The focus signal is based on a first amplification signal representing the amplification of the first amplifier of the first signal processing circuit and a second amplification signal representing the amplification of the second amplifier of the second signal processing circuit. A defocus signal ratio, a difference between the focus signal and the defocus signal, or a ratio between the focus signal and the defocus signal and the focus signal is calculated. The optical object identification device of claim 61,
The digital signal processing circuit is
A digital signal calculation unit for detecting a peak position of the first signal based on the first signal converted into the digital signal in the digital data stored in the memory;
The time data of the peak position detected by the digital signal calculation unit is set as the reference time, and the focus signal at this reference time is taken out,
A defocus signal at a predetermined time determined by a timing detection unit based on the reference time and the modulation signal is extracted from the second digital signal converted from the digital data stored in the memory,
The ratio of the focus signal to the defocus signal or the focus signal based on the first amplification signal representing the amplification degree of the first amplifier and the second amplification signal representing the amplification degree of the second amplifier. An optical object identification device that calculates a difference between a focus signal and a defocus signal or a ratio between the focus signal and the defocus signal and a focus signal. The optical object identification device according to claim 66 or 67,
The digital signal processing circuit is
In the process of extracting the focus signal and the defocus signal from the digital data stored in the memory,
Average value of a plurality of focus signals at a plurality of times before and after the reference time, a plurality of times before the reference time, or a plurality of times after the reference time in the digital data stored in the memory As a focus signal,
Among the digital data stored in the memory, a plurality of times before and after a predetermined time determined by the timing detection unit based on the reference time and the modulation signal, or a plurality of times before the reference time, or the reference The average value of a plurality of defocus signals at a plurality of times after the time is taken out as a defocus signal,
The focus signal is based on a first amplification signal representing the amplification of the first amplifier of the first signal processing circuit and a second amplification signal representing the amplification of the second amplifier of the second signal processing circuit. A defocus signal ratio, a difference between the focus signal and the defocus signal, or a ratio between the focus signal and the defocus signal and the focus signal is calculated. The optical object identification device of claim 61,
The digital signal processing circuit is
The object to be measured is identified by calculating a ratio between the focus signal and the defocus signal, a difference between the focus signal and the defocus signal, or a ratio between the focus signal and the defocus signal and the focus signal. In the process
An optical object identification device characterized in that the calculation is performed a plurality of times, and an average of the calculation results of the plurality of times is calculated to identify the object to be measured. The optical object identification device according to any one of claims 1 to 69,
The optical object identification device characterized in that the light emission of the semiconductor light emitting element is turned off or reduced when the distance to the object to be measured is larger than a predetermined value. In the optical object identification device according to any one of claims 1 to 70,
An optical object identification device characterized in that a light emitting state of the semiconductor light emitting element satisfies a safety standard class 1 of a laser product. In the optical object identification device according to any one of claims 1 to 71,
Having an optical window formed in part of the housing;
The optical object identification device, wherein a distance between the first condenser lens and the optical window is shorter than a focal length of the first condenser lens.   A vacuum cleaner comprising the optical object identification device according to any one of claims 1 to 72 mounted on a head portion. A self-propelled cleaner equipped with the optical object identification device according to any one of claims 1 to 72.

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