JPH09321335A - Light projector and optical apparatus using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable accurate monitoring of the emission power of a light emitting element to control the quantity of emission by a light projector which an optical apparatus uses, if the emission power or wavelength of this element varies, improve the temp. and enable it to accurately identify information about optical characteristics of an object e.g. color from signals of a reflected or transmitted light resulting from projection of a light on the object. SOLUTION: The projector comprises light emitting electrodes 1-1, 1-2, 1-3 for emitting lights which are different in wavelength, a glass plate 3a, i.e., an optical member for combining the lights emitted therefrom to project light, and a photo detector 4 for monitoring the transmitted or reflected light resulting from the light projected on the plate 3a. This plate is made of a material having a transmittivity or reflective index unchangeable by the temp. and wavelength and hence, if any temp. variation, etc., occurs, the photo detector 4 never malfunctions at monitoring the received light but is capable of accurate feeding back for emission control.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light projecting device that synthesizes lights having a plurality of wavelengths and projects the light onto a target object, and an optical device that uses the light projecting device to output information on the optical characteristics of the target object.

[0002]

2. Description of the Related Art A light projecting device for projecting light of a plurality of wavelengths toward a target object, and an optical characteristic of the object for receiving transmitted light or reflected light from the target object projected by the light projecting device, For example, there are optical devices that identify colors. In this type of light projecting device, FIG.
The configuration shown in (1) is possible (unknown). This light projecting device has light emitting elements 1-1, 1-2, such as LEDs emitting light of red, green, and blue, respectively, which have different emission wavelengths.
1 to 3, dichroic mirrors 3-1 and 3-2, a light receiving element 4 for monitoring which includes a photodiode and the like, and a lens 51. The dichroic mirror 3-1 transmits the light of the blue wavelength (λ3) by the light emitting element 1-3, reflects the light of the green wavelength (λ2) by the light emitting element 1-2, and the dichroic mirror 3-2 is Most of the light of the blue wavelength (λ3) and most of the light of the green wavelength (λ4) are transmitted (the remaining light is reflected and received by the monitor light receiving element 4), and the red wavelength (λ1). Most of the light) is reflected (the remaining light is transmitted and is received by the monitor light receiving element 4). In this configuration, since it is possible to detect the variation in the light emission power of the light emitting element by monitoring the light power, it becomes possible to feed back the light emission control.

[0003]

However, in the conventional device as described above, when the ambient temperature rises,
The wavelength of a light emitting element such as an LED shifts to a longer direction, and the optical power decreases. Further, the light emission power of the light emitting element also changes due to changes over time. In contrast, the dichroic mirror, which is an optical multi-layer film, generally has its transmittance characteristics shifted to shorter wavelengths as the temperature rises, as shown in FIG. That is, for example, when only the signal of the monitor light receiving element 4 is observed at a high temperature, whether the light emitting wavelength of the light emitting element is shifted or the light emitting power is decreased depending on the signal fluctuation amount, the dichroic mirror 3-2. It is not possible to determine whether the characteristics of No. have been shifted, and accurate feedback control cannot be applied.
For example, when the temperature is high, the dichroic mirror 3-2 has λ2.
Of the monitor light receiving element 4 increases, and the light emission wavelength of the light emitting element of λ2 shifts in the longer direction, the reflectance further increases, and the monitor light receiving element 4
Signal increases. Since the signal of the monitor light-receiving element 4 is increased, the power is fed back in the direction of lowering the power. However, since the light-emitting power of the light-emitting element is reduced with the increase of the temperature, feedback in the opposite direction is applied.

The present invention has been made in order to solve the above-mentioned problems, and relates to a light projecting device for controlling the light emission amount by monitoring the light emission power of a light emitting element which is a light source. Even if the light emission power of the light emitting element changes or the wavelength shifts due to the change, accurate light emission can be monitored without erroneous detection, correct feedback control can be performed, and a light projecting device with good temperature characteristics can be provided. The purpose is to Further, the present invention, by projecting a target object using the above-mentioned light projecting device, receives the reflected light or the transmitted light, from the received light signal, the optical characteristics of the target object, for example, information about color, It is an object of the present invention to provide an optical device having good temperature characteristics that can be output correctly due to temperature fluctuation.

[0005]

In order to achieve the above object, the present invention provides a light projecting device for synthesizing and projecting light of a plurality of wavelengths, and a plurality of light sources for emitting light of a plurality of wavelengths,
An optical member that synthesizes and emits light emitted from multiple light sources, and a position that receives part of the transmitted light or reflected light of the light incident on the optical member, and monitors the light of part of the light source. The optical member is made of a material whose transmittance or reflectance does not change depending on temperature and wavelength. In the above configuration, a part of the transmitted light or the reflected light of the light incident on the optical member that combines and projects the light of a plurality of wavelengths is received by the light receiving element for monitoring. Since this optical member is made of a material whose transmittance or reflectance does not change depending on temperature and wavelength, monitor light reception by the light receiving element does not malfunction even if there is temperature fluctuation, and accurate feedback can be applied to light emission control. You can

Further, according to the present invention, in a light projecting device for synthesizing and projecting light of a plurality of wavelengths, a plurality of light sources which emit light of a plurality of wavelengths and light emitted from the plurality of light sources are synthesized. And a light receiving element which is arranged at a position for receiving a part of the projected light and which receives the light quantity of the light source for monitoring. A transparent member that separates light for detecting an object or the like and light for monitoring is used, and the transparent member is made of a material whose transmittance or reflectance does not change depending on temperature and wavelength. In this configuration, the combined light of the light from all the light sources is separated by the transparent member into light for detecting an object or the like and light for monitoring, so that the influence of temperature fluctuation can be further reduced. Moreover, if a light projecting lens is used as the transparent member, it is not necessary to provide a special transparent member. Further, the present invention combines light of a plurality of wavelengths, projects the light onto a target object, receives reflected light or transmitted light from the target object, and receives information on optical characteristics of the target object based on the received light signal. In an optical device that outputs, a plurality of light sources that emit light of a plurality of wavelengths, an optical member that combines the light emitted from the plurality of light sources, and a transmitted light or a reflected light of the light that has entered the optical member is received. The first light receiving element, which is arranged at a position and receives a part of the light of the light source for monitoring, and the light combined by the optical member are applied to the target object, and the reflected light or the transmitted light from the target object is received. And a second light receiving element, wherein the optical member is made of a material whose transmittance or reflectance does not change depending on temperature and wavelength, and the first light receiving element has a difference in signal of the second light receiving element due to a difference in light receiving wavelength. Of the target object based on And outputs information about sex. In the above configuration, even if there are temperature fluctuations,
The monitor light reception by the light receiving element does not malfunction, accurate feedback can be applied to the light emission control, and information regarding the optical characteristics of the target object can be accurately output.

Further, according to the present invention, light of a plurality of wavelengths is combined and projected to a target object, reflected light or transmitted light from the target object is received, and the optical signal of the target object is received based on the received light signal. In an optical device that outputs information regarding characteristics, a first optical member that emits light having different wavelengths, and a second optical member that synthesizes light emitted from the first and second light sources And a first optical member for combining the light combined by the second optical member and the light emitted from the third light source, and the transmission of the light emitted from the third light source by the first optical member. A first light receiving element, which is arranged at a position for receiving light or reflected light and receives a part of the light for monitoring, and the light combined by the first optical member are irradiated to the target object, and the target object Second, which receives reflected light or transmitted light from
And the first optical member is made of a material whose transmittance or reflectance does not change depending on temperature and wavelength, and the third light source has the strongest emitted light intensity among the three light sources, The output light amount of the light source is controlled based on the signal amount of the first light receiving element, and the information regarding the optical characteristics of the target object is output based on the signal amount of the second light receiving element. In the above configuration, the first light receiving element monitors and receives the transmitted light or the reflected light of the light emitted from the third light source by the first optical member, and since the third light source has the strongest emitted light intensity,
Even if a glass plate having a low reflectance such as a glass plate having a small change in transmittance or reflectance depending on temperature and wavelength is used as the first optical member, a desired light projection power can be secured, and temperature fluctuations, etc. However, the light emission power can be correctly monitored, and accurate feedback can be applied to the light emission control, and the information regarding the optical characteristics of the target object can be accurately output.

Further, according to the present invention, light having a plurality of wavelengths is combined and projected to a target object, reflected light or transmitted light from the target object is received, and the optical signal of the target object is received based on the received light signal. In an optical device that outputs information regarding characteristics, first, second, and third light sources, which are light-emitting elements that emit green, blue, and red light, and first, second, and third light sources, are emitted. An optical member composed of a material that combines light and does not change in transmittance or reflectance depending on temperature and wavelength, and is disposed at a position for receiving transmitted light or reflected light of the light emitted from the third light source by the optical member, A first light receiving element that receives a part of the light of the third light source for monitoring, and a light that is combined by the optical member is applied to the target object, and the reflected light or the transmitted light from the target object is received. Based on the outputs of the second light receiving element and the first light receiving element. And control means for controlling the emitted light quantity of the light source Te, in which a identification means for identifying the color of the target object based on the output of the second light receiving element. In the above-described configuration, the monitor light reception by the light receiving element does not malfunction even if there is a temperature change, accurate feedback can be applied to the light emission control, and the color of the target object can be accurately identified. Further, the present invention, the optical member in the above configuration may have a transparent member for separating the combined light, the light for the target object and the light for monitoring, The transparent member may be a light projecting lens. As a result, it is possible to reduce the influence of temperature fluctuations as described above. Also, the present invention
Instead of the transparent member in the above configuration, a metal plate provided with slits may be used. Further, the optical member may be composed of a lens that collects the combined light, a light projecting lens, and a slit member arranged between these lenses. Further, a condenser lens that condenses the combined light, a slit member, and a light projecting lens may be integrally configured, and the reflected light from the slit member may be received for monitoring. Further, the transparent member may be arranged such that the light projecting axis passing through the member and the light receiving axis coincide with each other. When the slit member is used as described above, the positional accuracy of the slit member can be more easily increased than the positional accuracy of the light source, and thus the performance of detecting and positioning the detection object can be improved.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of an optical system of a light projecting device according to an embodiment of the present invention (corresponding to claim 1). The light projecting device is a light emitting element 1-1 composed of a red LED.
And a light emitting element 1-2 composed of a green LED and a light emitting element 1-3 composed of a blue LED, and the optical axes of light from the green and blue light emitting elements 1-2 and 1-3 are formed by an optical member. A dichroic mirror 3-1 is used to combine and emit in the same direction. Furthermore, this combined light and red light emitting element 1-
The optical axis of the light from 1 is combined by the transmission and reflection of the glass plate 3a which is another optical member, and the combined light is projected in the same direction toward the target object through the light projecting lens 51. In addition, a monitor light receiving element 4 such as a photodiode (PD) is arranged at a position for receiving the light emitted from the red light emitting element 1-1 and transmitted through the glass plate 3a. The dichroic mirror 3-1 includes a green light emitting element 1- as shown in FIG.
A material having a characteristic of transmitting light in the wavelength range of 2 and reflecting light in the wavelength range of the blue light emitting element 1-3 is used. In the wavelength range of each light emitting element, the peak wavelengths of red (R), green (G), and blue (B) are 680 nm, 565 nm, and 450 nm, respectively.
Something can be used.

FIG. 3 shows an example of characteristics of transmittance and reflectance of the glass plate 3a. In other words, regardless of the wavelength of R, G, B,
About 10% of the light is reflected (5% on one side) and about 90% of the light is transmitted. Therefore, in the optical system shown in FIG.
About 10% of the G and B light is reflected by the glass plate 3a and enters the monitor light receiving element 4, and the remaining about 90% of the light is on the glass plate 3a.
The light is transmitted through a. Also, of the R light, about 90
% Of the light passes through the glass plate 3a, and the monitor light receiving element 4
The remaining approximately 10% of the light is reflected by the glass plate 3a and projected. Red light emitting elements are more
Since there is light emission power that is large, the red component of the projection power can be sufficiently obtained by using it.

With the above arrangement, the light emission power of each light emitting element can be monitored. Therefore, even if the light emission power of each light emitting element fluctuates due to temperature changes, changes over time, etc., it is based on the monitor output. Thus, it is possible to obtain a light projecting module capable of correcting the variation amount. By using one dichroic mirror 3-1 and the glass plate 3a, the variation of the transmittance of the glass plate due to the temperature is sufficiently smaller than that of the dichroic mirror, so compared to the case of using two dichroic mirrors. A more stable optical power monitor can be realized.

FIG. 4 shows the glass plate 3 used in the above apparatus.
A specific configuration example of a is shown. One surface of the glass plate 3a is coated with an antireflection film. When the antireflection film is not coated, the reflection on the front surface of the glass plate becomes the optical path (1) shown in FIG. 4, and the reflection on the back surface becomes the optical path (2). The light in the two optical paths is condensed as two spots when condensed on the target object via the light projecting lens. That is,
The light of (1) is condensed at the same position as the green and blue lights,
It is difficult to obtain a small spot in which the three light sources are uniformly mixed, because the light is condensed at the deviated position of (2). By coating, the light in the optical path of (2) disappears (is incident on the monitor light receiving element 4), and a spot in which the three light sources are uniformly mixed can be obtained. Further, since the antireflection film has less layer films and generally has better temperature characteristics than the dichroic film, fluctuations in transmittance and reflectance due to temperature do not pose a problem. Red light is reflected by the glass surface without coating, but by coating a metal film on this surface, the reflectance of red can be increased. In general, the metal film has better temperature characteristics than the dichroic mirror film.

As an alternative construction of the glass plate 3a,
By adopting a shape other than the parallel plate, it is possible to have one optical path to the light projecting lens. FIG. 5 shows an example of a cube-shaped structure in which triangular prisms are attached. As for the material,
The same effect can be obtained not only with glass but also with transparent plastic or the like.

FIG. 6 shows an electric circuit block for feedback-controlling the variation amount of the light emission power based on the output of the monitor light receiving element 4 in the light projecting device shown in FIG. This circuit corresponds to the output of the monitor light receiving element 4 and corresponds to the light emitting elements 1-1 (red), 1-2 (green), 1-3.
It drives (blue). As shown in the figure, in this embodiment, the output of the monitor light-receiving element 4 is converted into a current-voltage (I / V) converter 12, and then the sample-hold circuit (S / H) 13-1. , 13-2, 13-
2 (R, G, B, hereinafter, the abbreviations are used). Sample and hold circuit R, G, B
The signals output from the comparison circuits 14-1, 14-2,
14-3 (R, G, B) and are compared with predetermined reference voltages VR, VG, VB, respectively. Comparing circuit R,
The outputs of G and B are drive circuits 11-1, 11-2, 11-.
3 (R, G, B). Drive circuit R, G, B
Correspond to the signals respectively input from the comparison circuits R, G, B, and the light-emitting elements 1-1, 1-2, 1-3 (R, G,
B) is configured to be driven. Further, the oscillator circuit 15 generates a pulse so as to drive the light emitting elements R, G, B in a time division manner (different timings), and supplies the pulses to the sample hold circuits R, G, B and the drive circuits R, G, B, respectively. are doing.

Next, the operation of the circuit block shown in FIG. 6 will be described. The oscillator circuit 15 first controls the drive circuit R to drive the light emitting element 1-1. As a result, red light is emitted from the light emitting element 1-1. Part of this light is
As described above, the light enters the monitor light receiving element 4, and a part of the light is projected onto the target object through the light projecting lens 51. The monitor light receiving element 4 generates a current corresponding to the input red light. This current is converted into a voltage by the current-voltage conversion circuit 12 and input to the sample hold circuits R, G, B. However, since the oscillation circuit 15 supplies the pulse only to the sample hold circuit R corresponding to the light emitting element 1-1 (since it does not supply the pulse to the sample hold circuits G and B), the current voltage is supplied only to the sample hold circuit R. The output of the conversion circuit 12 is sampled and held. Since the pulse supplied to the sample hold circuit R is the same as the pulse supplied to the drive circuit R, the sample hold circuit R uses the light amount (intensity) of the red light generated by the light emitting element 1-1. Will be sampled. The comparator circuit R compares the output of the sample hold circuit R with a preset reference voltage VR. Then, the comparison circuit R outputs a signal corresponding to the difference between the output of the sample hold circuit R and the reference voltage VR to the drive circuit R. The drive circuit R drives the light emitting element 1-1 with a constant current in response to the error signal supplied from the comparison circuit R.

As described above, the servo is applied so that the light quantity (intensity) of the light output from the light emitting element 1-1 becomes a constant value defined by the reference voltage VR, and the light output from the light emitting element 1-1 is driven. The amount of light is always constant, regardless of temperature and aging. Keeping the optical power from a plurality of light sources constant at all times is suitable as a light projecting unit of a sensor that detects the ratio of reflected light or transmitted light from a target object in each light source. When the power of each light source fluctuates independently, the light power of each light source must be constant because it will be recognized as a change in the ratio and will cause a false detection.

FIG. 7 shows the construction of an optical system of a color identification device (color sensor) which is an embodiment of the optical device of the present invention (corresponding to claims 4 and 5). In this embodiment, the green light generated by the light emitting element 1-2 made of a green LED and the blue light generated by the light emitting element 1-3 made of a blue LED are combined by the dichroic mirror 3-1 to form a glass. It is incident on the plate 3a. The glass plate 3a transmits the combined light to the red LE.
The red light generated by the light emitting element 1-1 composed of D is combined, and a part of the combined light is emitted to the light projecting lens 51, and the remaining part is emitted toward the monitor light receiving element 4. The light projecting lens 51 irradiates the detection object 53 with the combined light. The light reflected by the detection object 53 is collected by the light receiving lens 61 and received by the signal light receiving element 62. In addition, 5 is a circuit board to which each element is attached.

FIG. 8 shows an electric circuit block of a color discriminating apparatus having the optical system shown in FIG. 7 (corresponding to claim 6). The circuit of the light projecting portion in this embodiment is configured similarly to the case shown in FIG. That is, the output of the monitor light receiving element 4 is converted into a current-voltage by the current-voltage conversion circuit 12, and then the sample-hold circuits 13-1 to 13-3.
Is supplied to Then, the sample hold circuit 13
-1 to 13-3 outputs the comparison circuits 14-1 to 14-3.
-3 and is compared with the reference voltages VR, VG, VB. Then, the drive circuits 11-1 to 11-3 correspond to the outputs of the comparison circuits 14-1 to 14-3, and the light emitting element 1
-1 to 1-3 are driven. The oscillator circuit 15 supplies a pulse to each circuit so as to drive the drive circuits 11-1 to 11-3 and the sample hold circuits 13-1 to 13-3 in a time division manner.

The output of the signal light receiving element 62 of the light receiving portion is converted into a current voltage by the current voltage conversion circuit 71 and then supplied to the sample hold circuits 72-1 to 72-3.
It is designed to be sample-held. The sample hold circuits 72-1 to 72-3 include the drive circuit 11
The same pulse as that supplied to -1 to 11-3 is supplied as a sampling pulse. Color identification circuit 8
1 outputs color identification processing from the outputs of the sample hold circuits 72-1 to 72-3 and outputs the identification result.

Next, the operation of the above embodiment will be described. As in the case of the embodiment shown in FIG. 6, the oscillator circuit 15 generates pulses for driving the light emitting elements 1-1 to 1-3 in a time division manner. As a result, similarly to the case described with reference to FIG. 4, the driving circuits 11-1 to 11-3 sequentially apply the light emitting elements 1-1 to 1-3 to the reference voltages VR, VG,
The control operation is performed so as to generate a constant amount of light defined by VB. On the other hand, when the light emitting element 1-1 emits red light, the sampling pulse is supplied to the sample hold circuit 72-1. Therefore, the sample hold circuit 72-1 receives the signal corresponding to the red light received by the signal light receiving element 62 via the current-voltage conversion circuit 71, and samples and holds the value. Similarly, the sample and hold circuits 72-2 and 72-3 output the signal light receiving element 62 when the light emitting element 1-2 is emitting green light, and the light emitting element 1-3 outputs blue light. The output of the signal light receiving element 62 when the signal is generated is sampled and held, respectively. The color identification circuit 81 stores R, held by the sample hold circuits 72-1 to 72-3.
The color of the detection object 53 is identified from the level of each value of G and B as follows.

That is, the color identification circuit 81 first adds the values R, G, B output from the sample hold circuits 72-1 to 72-3, and obtains the sum T (= R + G + B). Next, the ratio (ratio) R of each value R, G, B to the sum T
1 (= R / T), G1 (= G / T), and B (= B / T) are calculated. Further, the color identification circuit 81 identifies a color from the size of the ratio of each color according to the flowchart shown in FIG. This identification processing is performed for each color and ratio R1, shown in FIG.
This is based on the relationship with G1 and B1. That is, for example, the values of the ratios R1, G1, and B1 are 43.
3,28.3,28.7, and in the case of orange, 42.8,
It becomes 30.6 and 26.6. Similarly, for each color such as pink, brown, yellow, yellow-green, green, blue, navy blue, purple, white, and black,
Since the values of the ratios R1, G1, B1 are determined, the color can be identified from these values.

In step S1, it is determined whether or not R1 is larger than 40. If R1 is larger than 40, the process proceeds to step S2, where G
It is determined whether 1 is larger than 29. When G1 is larger than 29, it is determined to be orange, and when it is 29 or less, it is determined to be red. When R1 is 40 or less, the process proceeds to step S3, and it is determined whether R1 is greater than 33. R1 is 3
When it is greater than 3, the process proceeds to step S4, and it is determined whether G1 is greater than 38. When G1 is greater than 38, it is determined to be yellow, and when G1 is 38 or less, the process proceeds to step S5, and it is determined whether T is greater than 7. T
Is larger than 7, it is judged as pink, and when it is 7 or smaller, it is judged as brown.

When R1 is 33 or less, step S6
Then, it is determined whether G1 is larger than 41.5.
When G1 is larger than 41.5, the process proceeds to step S7,
When B1 is 29 or less, the process proceeds to step S8 and B1
Is greater than 30 is determined. When B1 is larger than 30, it is judged as yellow, and when it is 30 or less, it is judged as yellowish green. When G1 is 41.5 or less, the process proceeds to step S9, and it is determined whether B1 is greater than 37.5. B
When 1 is larger than 37.5, the process proceeds to step S10,
It is determined whether G1 is larger than 38. When G1 is greater than 38, it is determined to be blue. When G1 is 38 or less, the process proceeds to step S11, and it is determined whether R1 is greater than 25. When R1 is greater than 25, it is determined to be purple, and when R1 is 25 or less, it is determined to be dark blue. B1 is 37.5
When it is less than or equal to, it progresses to step S12 and it is determined whether T is larger than 5. When T is greater than 5, it is determined to be white, and when T is 5 or less, it is determined to be black.

By monitoring the light emission power in this way, the output can be feedback-controlled at a constant level.
It is possible to perform stable color identification from the received light signal with high accuracy.

FIG. 11 shows another configuration example of the optical system of the color identification apparatus (corresponding to claim 5). In this embodiment, the configuration of the light source device 50 is basically the same as that shown in FIG. 6, but the light focused by the light projecting lens 51 is transmitted to the detection object 53 via the optical fiber 91. It is designed to be irradiated. Then, the light reflected by the detection object 53 is guided to the signal light receiving element 62 by the optical fiber 92. Other configurations are the same as those in FIG. The electrical configuration of the color identification device in this case is the same as that shown in FIG.

FIG. 12 is an electric circuit block according to another embodiment of the optical device, which is a C block for identifying a detected object.
An example using PU is shown. The sample hold value of each color of the monitor light receiving element 4 and the sample hold value of each color from the signal light receiving element 62 are input to the CPU 90. The light emitting elements 1-1, 1-2, 1-3 are driven in a time division manner.
The CPU 90 performs the following processing. Now, for example, if the output of the red monitor light receiving element 4 (after sample and hold) is Vm, the output of the signal light receiving element 62 (after sample and hold) is Vs, and the reference voltage is Vr, the CPU 90
The comparison circuit can be replaced by calculating Vs × Vr / Vm and using the value to perform the same process calculation as that of the color identification circuit 81 (FIG. 8) described above. According to the present embodiment, more accurate correction can be performed without being influenced by the circuit configuration.

FIG. 13 shows the structure of a transmissive color sensor which is an embodiment of the optical device (corresponding to claim 1). In this embodiment, the light projecting section has the same structure as that of FIG. 1, and the light receiving section is arranged to receive the light transmitted through the detection object 53. According to this embodiment, when the detection object 53 is transparent or translucent, its color or mark can be detected by the transmission type.

FIG. 14 shows a modification of the light projecting portion, that is, the light source of the embodiment shown in FIG. 13 (corresponding to claim 1). In this example, L that emits two colors, blue and green, of a plurality of wavelengths of the light source
A light emitting element 1-4 in which an ED chip is contained in one package,
The red light emitting element 1-1 is used, and the glass plate 3a is used for light synthesis.
Is used.

FIG. 15 shows the configuration of another embodiment of the light projecting device, in which the arrangement position of the monitor light receiving element 4 is devised (corresponding to claim 1). In the optical system of FIG. 1 described above, regarding the optical power incident on the monitor light receiving element 4,
The power incident on the red light emitting element 1-1 is extremely larger than the power incident on blue and green. The reason is that the red light emitting element 1-1 generally has high emission intensity, and further, the transmittance of the glass plate 3a is about 90%, and the reflectance of the green and blue glass plates 3a is about 10%. Significantly larger than In order to deal with such a difference in level, it is possible to widen the dynamic range of the circuit.
This can be improved by adopting the optical arrangement of the monitor light receiving element 4 as shown in FIG. That is, when the monitor light receiving element 4 is viewed from the red light emitting element 1-1, the glass plate 3a
On the rear surface of the red light emitting element 1-1 in the region where the incident angle θ of the transmitted light is as large as possible. Regarding the characteristics of the glass plate 3a, the reflectance increases and the transmittance decreases as the incident angle θ increases. Therefore, by adopting the arrangement as shown in FIG. 15, the incident angle θ becomes large, the transmitted light is reduced, and the difference in the optical power from other light emitting elements can be somewhat improved.

FIG. 16 shows still another embodiment of the light projecting device (corresponding to claim 2). In this embodiment, two dichroic mirrors 3-1 and 3-2 and a glass plate 3a are used for projecting light.
Is used. The dichroic mirror 3-1 transmits red light and reflects green light. Dichroic mirror 3-
Reference numeral 2 transmits red light and green light and reflects blue light. In this configuration, the red, green, and blue light emitting elements 1-1,
The optical power incident on the monitor light receiving element 4 from 1-2 and 1-3 is substantially constant. It is also possible to coat the glass plate 3a with a metal film to obtain an arbitrary monitor amount.

FIG. 17 shows the construction of an embodiment of a mark sensor to which the above-mentioned light projecting device is applied (claim 4).
Correspondence). This mark sensor is composed of a light source device 50 and a light receiving device 60, and has a wavelength of λ1 (for example, red light) generated by the light emitting element 1-1 of the light source device 50 and a wavelength of λ2 generated by the light emitting element 1-2. Light (for example, blue light) is the glass plate 3
The divergent light is combined as it is by a, and a part of the light is applied to the detection object 53 (for example, a white object) by the light projecting lens 51. A part of the light is incident on the monitor light receiving element 4. A mark 52 (for example, a yellow mark) is attached to or printed on the detection object 53. Detection object 53
The light reflected by (or the mark 52) is condensed by the light receiving lens 61 of the light receiving device 60 and received by the signal light receiving element 62.

FIG. 18 shows an example of an electric circuit of the mark sensor shown in FIG. As shown in the figure, after the output of the monitor light receiving element 4 is converted into a current voltage by the current voltage conversion circuit 12, the sample hold circuits 13-1, 13-
2 is input and sample-held. Then, the signals sampled and held by the sample and hold circuits 13-1 and 13-2 are input to the comparison circuits 14-1 and 14-2 and compared with the reference voltages V1 and V2. Comparison circuit 14-
The signals output from the output terminals 1 and 14-2 are the drive circuits 11-
1, 11-2, and drive circuits 11-1, 11-2
Are light emitting elements 1-
1, 1-2 are driven. Oscillation circuit 1
Reference numeral 5 denotes a drive circuit 11-1 and a sample hold circuit 13- so that the light emitting elements 1-1 and 1-2 are time-division driven.
1, the drive circuit 11-2 and the sample hold circuit 1
A pulse is supplied to each of 3-2. On the other hand, the output of the signal light receiving element 62 is converted into a current-voltage by the current-voltage conversion circuit 71, and then the sample-hold circuits 71-1 and 7-1
2-2 is supplied. Then, the sample hold circuit 7
The outputs of 2-1 and 72-2 are input to the division circuit 73,
Is divided. The comparison circuit 74 outputs the output of the division circuit 73 as
It compares with a preset reference value and outputs the comparison result as an identification signal of the mark 52. The sample hold circuits 72-1 and 72-2 are respectively connected to the drive circuit 11-
The same pulse as that supplied to 1 and 11-2 is supplied.

Next, the operation will be described. The oscillator circuit 15 first drives the drive circuit 11-1 and the sample hold circuit 13-1. When a pulse is supplied from the oscillator circuit 15, the drive circuit 11-1 drives the light emitting element 1-1 to generate blue light of wavelength λ1. 90% of this light passes through the glass plate 3a which is an optical member, is focused by the light projecting lens 51, and is applied to the detection object 53. On the other hand, 10% of the light generated by the light emitting element 1-1 is reflected by the glass plate 3a and received by the monitor light receiving element 4. The monitor light receiving element 4 outputs a current corresponding to the amount of incident light. This current is converted into a voltage by the current-voltage conversion circuit 12, and then the sample-hold circuit 13
-1, 13-2 are supplied. At this time, the pulse is not supplied from the oscillation circuit 15 to the sample hold circuit 13-2, but is supplied only to the sample hold circuit 13-1, so that the output of the current-voltage conversion circuit 12 is the sample hold circuit 13-2. Only -1 is sample-held.

The comparison circuit 14-1 calculates the difference between the voltage sampled and held by the sample and hold circuit 13-1 and the reference voltage V1 and outputs the error signal thereof as the drive circuit 11-1.
Output to The drive circuit 11-1 drives the light emitting element 1-1 in response to this error signal. Thereby, the light emitting element 1
The light amount (intensity) of the light generated by -1 is controlled to a constant value set by the reference voltage V1. After that, the oscillation circuit 15
In order to drive the light emitting element 1-2, a pulse is output to the drive circuit 11-2 and the sample hold circuit 13-2. When a pulse is input, the drive circuit 11-2 drives the light emitting element 1-2 to generate red light having a wavelength λ2. This light is reflected by the glass plate 3 a, then focused by the light projecting lens 51, and irradiated onto the detection object 53. Further, 90% of the light passes through the glass plate 3a and is received by the monitor light receiving element 4.

The monitor light receiving element 4 outputs a current corresponding to the incident light, and the current is the current-voltage conversion circuit 1.
Converted to voltage at 2. Then, the current-voltage conversion circuit 12
Is sampled and held by the sample and hold circuit 13-2, and an error signal with respect to the reference voltage V2 is generated by the comparison circuit 14-2. The drive circuit 11-2 drives the light emitting element 1-2 in response to this error signal. This allows
The light amount (intensity) of the light output from the light emitting element 1-2 is controlled to a constant value set by the reference voltage V2.

On the other hand, when the light emitting element 1-1 generates light of wavelength λ1, this light is reflected by the detection object 53, focused by the light receiving lens 61, and received by the signal light receiving element 62. The signal light receiving element 62 outputs a current corresponding to the input signal. This current is converted into a voltage by the current-voltage conversion circuit 71, and then the sample-hold circuit 72-1
72-2. When the light emitting element 1-1 emits light, the sampling pulse is not supplied to the sample hold circuit 72-2, and the sample hold circuit 7-2
Since the sampling pulse is supplied only to 2-1, the output of the current-voltage conversion circuit 71 is sample-held by the sample-hold circuit 72-1. That is, the sample hold circuit 72-1 holds the value corresponding to the reflected light amount of the blue light of the wavelength λ1.

Similarly, when the light emitting element 1-2 emits red light of wavelength λ2, the reflected light from the detection object 53 is received by the signal light receiving element 62. Then, the output is sampled and held by the sample and hold circuit 72-2.
That is, the sample hold circuit 72-2 holds a value corresponding to the amount of red reflected light of wavelength λ2.

FIG. 19 shows the relationship between the color of the detection object 53 and its reflectance. As shown in FIG.
When 3 is white, the light of wavelength λ1 (blue) also has wavelength λ2.
The (red) light also has a high reflectance of about 95%, which is almost the same. That is, the sample hold circuits 72-1 and 72-
The values sampled and held in 2 are almost the same.
On the other hand, when the detection object 53 is yellow (when the light reflected by the yellow mark 52 is received by the signal light receiving element 62), the light of the wavelength λ2 (red) is about 84% thereof.
Is reflected, and only about 4% of the light of wavelength λ1 (blue) is reflected. Therefore, the value held by the sample hold circuit 72-2 is smaller than the value held by the sample hold circuit 72-1.

The division circuit 73 is, for example, the output of the sample and hold circuit 72-1 and the sample and hold circuit 72-2.
Divide the output of. As described above, the signal light receiving element 6
When 2 receives the light reflected by the detection object 53 (light reflected in white), the division result is almost 1.
On the other hand, when the reflected light from the yellow mark 52 is received, the division result of the division circuit 73 becomes a value (eg, 0.05) that is sufficiently smaller than 1. The reference value supplied to the comparison circuit 74 is set to an intermediate value between the value 1 of the division result of the division circuit 73 and a value sufficiently smaller than 1. Therefore, for example, when the output of the division circuit 73 is close to 1, the reference value is smaller and the comparison circuit 74 outputs, for example, a high level signal. On the other hand, when the output of the division circuit 73 is sufficiently smaller than 1, the reference value becomes larger and the comparison circuit 74 outputs a low level signal. Therefore, the presence or absence of the mark 52 (change in reflectance distribution) can be identified from the logic of the comparison circuit 74.

FIG. 20 is a block diagram of a light projecting device according to another embodiment (corresponding to claim 1). This light projecting device is basically the same as the optical system in FIG. 1, and the same members are given the same numbers. Each part is fixed to the body 93 of the device,
A body 9 is provided in front of each light emitting element 1-1, 1-2, 1-3.
A slit 94 is provided integrally with the slit 3, and the light of the light emitting element is emitted through the slit 94. With this configuration, the light spot on the target object does not shift even if there is a difference in the arrangement of the light emitting elements or a difference in the light emitting pattern. This is shown in FIG. FIG. 10A shows the case where there is no slit. In this case, if the arrangement of the light emitting element 1 is displaced, the spots are displaced, and the displacements are different for the three colors of R, G, and B, so the three spots are displaced. On the other hand,
FIG. 6B shows a case where the slit 94 is provided. In this case, since the emitted light is limited, the spot position does not change. Usually, the positional accuracy of the slit is better than the positional accuracy of the light emitting element, so that the three spots of the light emitting element can be almost overlapped with each other, and the accuracy in detecting the positioning of the object is improved. FIG. 22 is a diagram for explaining the size of the slits. The slit 94 on the front surface of the R light emitting element is made smaller than the slit 94 on the front surface of the G and B light emitting elements so that the R light emission on both surfaces of the glass plate 3a. The size of the spot + formed by the element is made equal to the sizes of the G and B spots. This configuration improves the positioning detection performance of the sensor.

23 (a) and 23 (b) are sectional views showing the structure of a light projecting device according to still another embodiment (claims 2, 3).
Correspondence). This light projecting device is similar to the above-described FIG. 16 in that the combined light from all the light emitting elements is used as the monitor light for monitoring the light projection of the target object and the light quantity of the light emitting element (light source). 16 is an example in which there is a transparent member that is separated into two parts. The difference from FIG. 16 is that the glass plate that is a transparent member is omitted and the monitor light receiving element 4 is configured to receive the surface reflected light of the light projecting lens 51 that is an optical member. Is the point. With this configuration,
Since the light projecting lens 51 can also have the function of a transparent member, it is not necessary to provide a special transparent member, the number of parts can be reduced, and the cost can be reduced. Further, in this embodiment, the monitor light is obtained by the reflection of the light projecting lens 51 made of the same material as glass whose transmittance and reflectance do not change depending on the temperature and the wavelength. The dichroic mirror 3-2 can be used instead of the glass plate for the synthesis of the light from the blue light emitting element 1-3 and the red light emitting element 1-1 after the synthesis by the dichroic mirror (DCM) 3-1.

FIGS. 24 (a) and 24 (b) are configuration diagrams of another embodiment of a color sensor (optical device) in which a light projecting device and a light receiving device are combined (corresponding to claims 7 and 10). The sensor includes a main body body 93b having a basic optical system for light emission and light reception provided in a sensor case 93a, a light emission attachment 95 for long-distance detection, which is replaceably mounted on the main body body 93b, and a small size. It is composed of a fiber attachment 97 for spot short distance detection. Body body 9
Reference numeral 3b denotes a light receiving element 6 for a detection signal, which is formed of a photodiode or the like, in addition to the same structure as the light projecting device shown in FIG.
2 is provided. The light projecting attachment 95 includes a slit member 96 facing the condensing lens 51-1 of the main body 93b, the light projecting lens 51-2, and a light receiving lens 61 that collects the reflected light from the detection object 53 on the light receiving element 62. Is equipped with. The fiber attachment 97 includes a light projecting fiber 91, a light receiving fiber 92, and a sensor head 98 having a light projecting lens 51 and a light receiving lens 52. The main body 93b is equipped with a light emitting attachment 95 for long distance detection.
When it is attached to the
Since the positioning detection performance of the slit member 9 is deteriorated, the slit member 9 is interposed between the two light projecting lenses 51-1 and 51-2.
6 is provided, thereby eliminating three spot deviations. When the fiber attachment 97 is attached, the light is emitted from the main body 93b side,
With respect to the light to be focused on, it is not necessary to limit the deviation of the light from each light source by using a slit or the like, and thus the slit may not be provided on the front surface of the light emitting element.

When the fiber attachment 97 is not mounted, that is, when the structure shown in FIG. 24A is integrally formed, the monitor light receiving element 4 is arranged so as to receive the reflected light from the slit member 96. You may. The structure is shown in FIGS. 25 (a) and 25 (b) (corresponding to claims 9 and 11). With this configuration, the glass plate 3a (FIG. 24) can be changed to a dichroic mirror, so that the light projecting power of the red light emitting element can be increased. As the slit member 96, for example, a metal plate having a hole or a glass plate 96a provided with a reflective film except the central portion thereof as shown in FIG. 25C can be used.

FIG. 26 shows a modification of FIG. 24 (a) (corresponding to claims 8 and 10). In this example, the monitor light receiving element 4 is arranged at a position for receiving the reflected light from the surface of the condenser lens 51-1 on which the combined light of the light from the respective light emitting elements is incident, and as a result, the glass plate. It is possible to use a dichroic mirror (DCM) 3-2 instead of 3a (FIG. 24). The light-receiving element 4 for monitoring is a main body 9
It is attached so as to face the opening provided in 3b from the outside. R, G, B light emitting elements (LED) 1-1, 1-
The arrangement of 2, 1-3 is also different from that shown in FIG. The wall of the light projection attachment 95 itself constitutes the slit member 96. With this configuration, the positioning accuracy of the slit can be easily improved.

FIGS. 27 (a) and 27 (b) show another example in which all the R, G, and B lights are combined and then split into a projection light and a monitoring light by a glass plate (claim). Item 2). In this example, instead of the dichroic mirror, an optical fiber (bundle fiber 97, fiber coupler 9
8) is used to synthesize a plurality of lights, and then the glass plate 3a is used to split the lights. The light source referred to in the claims also includes a light irradiation section at the tip of the optical fiber. 28 (a) and 28 (b) show still another embodiment (corresponding to claim 12). As shown in FIG. 3B, when the branching glass plate is replaced with the half mirror 3b, the reflected light from the detection object 53 is received by the light receiving element 6 for signal along the same axis as the projection axis.
By guiding to 2, the light projecting axis and the light receiving axis can be aligned with each other, and the sensor can be downsized. Further, instead of the half mirror, the transparent member 3a may be vapor-deposited with a reflective film 3c such as metal.

In each of the embodiments described above, the optical member for guiding the light to the monitor light receiving element is made of glass or metal whose transmission or reflection characteristics do not change depending on the temperature. Although it is possible to correct the optical power, for example, as shown in FIG.
In the case of the configuration shown in 0, the light utilization efficiency is originally higher when the dichroic mirror (DCM) is used than when the glass plate 3a is used. Therefore, a configuration in which temperature compensation can be performed to some extent, though not necessarily sufficient, using a dichroic mirror will be described below.

29 (a) and 29 (b) show the light emission power of the optical system and the LED and the reflectance of the DCM. In this example, the monitor PD 4 applies optical feedback to the B and G LEDs, while the R LED is used.
No optical feedback is applied to. Here, no optical feedback is applied to the LED (here, R) that changes the reflectance due to the wavelength fluctuation of the DCM that guides the light to the monitor PD 4. At this time, the other G and B L
The ED can be fed back so that the projection power is constant. FIG. 30 is a signal system circuit diagram in this case. For the R LED, the electrical projection current is corrected by using the drive circuit adjustment resistor composed of the temperature sensitive element as shown in FIG. , Temperature correction can be performed. In FIG. 30, the same members as those in FIG. 6 are given the same numbers.

FIG. 31A is a signal system circuit diagram according to still another embodiment. The projection optical system is the same as that shown in FIG. For an LED that causes a change in reflectance due to a wavelength change of a DCM that guides light to the monitor PD 4, the LED is corrected by electrically correcting the light projection current using a temperature-sensitive resistor.
The temperature characteristic of is corrected, and the influence of the temperature characteristic of DCM is corrected by the variation in the amount of received light of the monitor PD 4. The processing by the CPU 90 is as follows. Now
When the light emission power of the LED is P0, the light projection amount is as shown in FIG.
As shown in (b), it becomes P0 (1-r). here,
If the reflectance of the DCM changes from r to αr due to the temperature change, the light projection amount becomes P0 (1-αr). Therefore,
If the value of P0 is held as the CPU 90, it is possible to make the projection amount constant by multiplying the emission power by (1-r) / (1-αr) from the change of the monitor light amount.

32 (a) and 32 (b) show characteristics of a light projecting device and a DCM according to still another embodiment. The LED having the shortest wavelength (B in this case) is reflected by the DCM 3-2 and irradiates the target object with light. LED, D
In both CMs, the wavelength shift amount due to temperature change is larger as the wavelength is larger. Therefore, by arranging the LED having the shortest wavelength in this way, it becomes possible to monitor the monitor which is hardly affected by the wavelength shift.

FIGS. 33 (a) and 33 (b) show the light emission power of the light projecting optical system and LED and the reflectance of DCM according to still another embodiment. The optical system is the same as that in FIG. R
The peak wavelength of the LED is about 700 nm. This sensor is an application of the so-called stimulus value direct reading method,
The light of the R, G, and B LEDs is applied to the object, and the color of the object is measured from the reflectance of the light of each LED. This time,
Even if the peak wavelength of the R LED is near 700 nm, the influence on the measuring ability is small. If you use an R LED with a peak wavelength of 700 nm, you will see a G LED.
In the sensor that synthesizes light with DCM, the change in the transmittance (reflectance) of DCM due to temperature change can be reduced.

FIG. 34 is a diagram for explaining another embodiment.
In the same figure (a), only one optical projection system is shown.
In the case of the optical system as shown in FIG.
The light of the R LED incident on D is significantly larger than the light of the G and B LEDs. In this case, when variations in the light emission of the LEDs and variations in the outgoing optical axis are taken into consideration, it is necessary to set a large dynamic range of the I / V converter 12 of the light receiving element 4 as shown in the monitor of FIG. 6, which makes designing difficult. become. Therefore, without reducing the projection power,
In order to narrow the dynamic range of the monitor light emitting element, as shown in FIG. 35, the LED emits the projected light and the monitor light separately. Then, in the case of the optical system as shown in FIG. 20, the emission power for monitoring the LED of R is set to G, B.
It may be made smaller according to the monitor light amount.

FIG. 36 shows a case where the reflection type sensor according to the embodiment of the present invention is applied to the positioning by the register mark. A register mark is previously attached to the packaging film 53f to be detected, and the color mark is detected by the reflective sensor 100, and the feeding amount of the packaging film 53f is stopped by stopping the feeding of the packaging film 53f based on the signal. Keep on. In addition, when the register mark is not attached, the positioning can be performed by the color of the pattern of the packaging film, for example. FIG. 37 shows a configuration for detecting the register mark 52 attached to the packaging film 53f using the transmissive sensor 101 according to the embodiment of the present invention, similarly to FIG.

In the present invention, a plurality of LEDs which emit light of different colors (wavelengths different from each other) are usually used as a light source. Are different depending on the temperature. On the other hand, in many cases, the rate of change of the light-receiving sensitivity of the light-receiving element for monitoring and the light-receiving element for signal are almost the same. In such a case, as in the present invention, the light emission power is monitored on the light projecting side to control the light emission amount, and moreover, the optical for synthesizing the light of a plurality of wavelengths on the light projecting side and receiving the monitor light. Using a material (for example, a glass plate) that has extremely little characteristic change such that the transmission wavelength range shifts due to temperature change, in order to improve temperature characteristics and improve detection accuracy. It is extremely significant. The present invention is not limited to the configuration of the above embodiment, and various modifications are possible. For example, as the optical member, a resin, a metal thin film, or the like can be used in addition to the glass plate.

[0054]

As described above, according to the light projecting device of the present invention, the light having a plurality of wavelengths emitted from the light source is combined by the optical member to be projected, and the light transmitted through the optical member is transmitted. Alternatively, a part of the reflected light is received by the light receiving element, and the optical member is made of a material whose transmittance or reflectance does not change depending on temperature and wavelength. Therefore, even if the light emission power of the light emitting element is changed or the wavelength is deviated due to the temperature fluctuation, there is no erroneous detection in the monitor light reception by the light receiving element. Feedback control can be performed, and temperature characteristics can be improved.

Further, according to the light projecting device of the present invention, the transparent member for separating the light after combining the light emitted from the plurality of light sources into the light for detecting an object and the light for monitoring. Since this transparent member is made of a material whose transmittance or reflectance does not change depending on temperature and wavelength, the influence of temperature fluctuation can be further reduced. Further, if a light projecting lens is used as the transparent member, it is possible to reduce the size and cost without the need to provide a transparent member.

Further, according to the optical device of the present invention, light of a plurality of wavelengths is combined by the optical member using the above-mentioned light projecting device to project the light onto the target object, and the light incident on the optical member is The transmitted light or the reflected light is received by the first light receiving element for monitoring, and the optical member is made of a material whose transmittance or reflectance does not change depending on temperature and wavelength. Light is received by the light receiving element and the optical characteristic of the target object, for example, information about color is output based on the difference in the signal of the second light receiving element due to the difference in the light receiving wavelength and the signal amount of the first light receiving element. There is. Therefore, even if the light emission power of the light emitting element changes or the wavelength shifts due to temperature fluctuation, erroneous detection does not occur in the monitor light reception by the light receiving element, and information regarding the optical characteristics of the target object can be accurately output. Can be improved.

Further, according to the optical device of the present invention, the optical member having the above-mentioned structure has a transparent member for separating the combined light into the light projected onto the target object and the light for monitoring. If the transparent member is a light projecting lens, the number of parts can be reduced.

Further, according to the optical device of the present invention, a metal plate provided with a slit is used instead of the transparent member in the above-mentioned structure, and the light after the optical members are combined is condensed. The lens, the light projecting lens, and the slit member arranged between these lenses make it possible to integrate the condensing lens for condensing the combined light, the slit member, and the light projecting lens into one body. Since the reflected light of the slit member is received for the monitor, the positional accuracy of the slit member can be more easily increased than the positional accuracy of the light source. The detection performance can be improved. Further, since the transparent member is arranged so that the light projecting axis and the light receiving axis passing through the member are aligned with each other, the sensor can be downsized.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an optical system of a light projecting device according to an embodiment of the present invention.

FIG. 2 is a characteristic diagram of transmittance and reflectance of a dichroic mirror used in the above optical system.

FIG. 3 is a characteristic diagram of transmittance and reflectance of a glass plate used in the above optical system.

FIG. 4 is a diagram showing a specific configuration example of a glass plate used in the above apparatus.

FIG. 5 is a diagram showing an alternative configuration of a glass plate.

FIG. 6 is a block diagram of an electric circuit in the light projecting device.

FIG. 7 is a configuration diagram of an optical system of a color identification device that is an example of an optical device.

8 is a block diagram of an electric circuit of a color identification device having the optical system shown in FIG.

FIG. 9 is a flowchart showing a processing procedure of a color identification circuit.

FIG. 10 is a relationship diagram between each color and a component.

FIG. 11 is a diagram showing another configuration example of the optical system of the color identification device.

FIG. 12 is a block diagram of an electric circuit according to another embodiment of the optical device.

FIG. 13 is a configuration diagram of a transmissive color sensor that is an example of an optical device.

FIG. 14 is a configuration diagram showing a modification of the light source of the embodiment of FIG.

FIG. 15 is a configuration diagram showing another embodiment of the light projecting device.

FIG. 16 is a configuration diagram showing still another embodiment of the light projecting device.

FIG. 17 is a configuration diagram of an embodiment of a mark sensor to which a light projecting device is applied.

18 is a block diagram of an electric circuit of the mark sensor shown in FIG.

FIG. 19 is a diagram showing the relationship between the color of a detected object and its reflectance.

FIG. 20 is a configuration diagram of a light projecting device according to another embodiment.

FIG. 21 (a) is a diagram for explaining how the spots are displaced when the arrangement of the light emitting elements is deviated when there is no slit,
(B) is a figure which shows that the position of a spot does not change when there is a slit.

FIG. 22 is a diagram illustrating the size of a slit.

23A is a configuration diagram of a light projecting device according to still another embodiment, and FIG. 23B is a sectional view taken along the line AA ′ of FIG.

FIG. 24A is a sectional view of a color sensor which is an optical device according to another embodiment, and FIG. 24B is a sectional view of a replaceable attachment.

25A, 25B and 25C are partial cross-sectional views according to another example.

26A is a sectional view of a color sensor according to a modification of FIG. 24, and FIG. 26B is a sectional view taken along the line AA ′ of FIG.

27 (a) and 27 (b) are diagrams showing another example of a case in which all the lights are combined and then divided into a projection light and a monitoring light by a glass plate.

28A and 28B are diagrams showing still another embodiment.

29A and 29B are an optical system for projecting light and an LED.
It is a figure which shows the light emission power of and the reflectance of DCM.

FIG. 30 is a signal system circuit diagram.

31A is a signal system circuit diagram according to still another embodiment, and FIG. 31B is a diagram for explaining the operation of the DCM.

32A and 32B are characteristic diagrams of a floodlighting device and a DCM according to still another embodiment.

FIGS. 33 (a) and 33 (b) are diagrams showing the emission power of an optical system for projecting light and LEDs and the reflectance of DCM according to still another embodiment.

34A and 34B are a partial configuration diagram and a time chart of its operation according to another embodiment.

FIG. 35 is a time chart of a light emitting operation.

FIG. 36 is a configuration diagram when a reflective sensor is applied to register mark detection.

FIG. 37 is a configuration diagram when a transmissive sensor is applied to register mark detection.

FIG. 38 is a configuration diagram of a conventional light projecting device used in an optical device for identifying an optical characteristic of an object.

FIG. 39 is a diagram showing a transmittance characteristic of a dichroic mirror.

[Explanation of symbols]

 1-1 Light emitting element (light source or third light source) 1-2 Light emitting element (light source or second light source) 1-3 Light emitting element (light source or first light source) 3-1 Dichroic mirror (second optical member) ) 3-2 Dichroic mirror (optical member) 3a Glass plate (optical member or first optical member) 3b Half mirror (optical member) 4 Light receiving element for monitoring (first light receiving element) 51 Projection lens (optical member) 51-1 Condensing lens (optical member) 51-2 Light projecting lens (optical member) 53 Detecting object (target object) 62 Light receiving element for signal (second light receiving element) 81 Color identification circuit 90 CPU 96 Slit member

Front Page Continuation (72) Inventor Hayami Hosokawa, 10 Hanazono Todocho, Ukyo-ku, Kyoto City, Kyoto Prefecture Omron Co., Ltd. (72) Inventor Shizuru Yasuda 10 Hanazono Todocho, Kyoto City, Kyoto Prefecture Inside the company (72) Maki Yamashita 10 Ouron Co., Ltd., Hanazono-Tudocho, Ukyo-ku, Kyoto-shi, Kyoto Omron Co., Ltd.

Claims (12)

[Claims] 1. A light projecting device for synthesizing and projecting light of a plurality of wavelengths, a plurality of light sources for emitting light of a plurality of wavelengths, and light for synthesizing light emitted from the plurality of light sources. And an optical member that is arranged at a position for receiving a part of transmitted light or reflected light of light incident on the optical member, and is configured by a light receiving element that receives a part of light of the light source for monitoring, A light projecting device, wherein the optical member is made of a material whose transmittance or reflectance does not change depending on temperature and wavelength. 2. A light projecting device for synthesizing and projecting light of a plurality of wavelengths, and a plurality of light sources for emitting light of a plurality of wavelengths, and light for synthesizing light emitted from the plurality of light sources. An optical member and a light receiving element that is disposed at a position for receiving a part of the projected light and that receives a light amount of the light source for monitoring, and the optical member is configured to receive the combined light. A transparent member which separates light for detecting an object and the like and light for monitoring, and the transparent member is made of a material whose transmittance or reflectance does not change depending on temperature and wavelength. And a floodlighting device. 3. The light projecting device according to claim 1, wherein the transparent member is a light projecting lens. 4. The light of a plurality of wavelengths is combined and projected to a target object, and the reflected light or the transmitted light from the target object is received,
In an optical device that outputs information regarding the optical characteristics of the target object based on the received light signal, a plurality of light sources that emit light of a plurality of wavelengths, and an optical member that combines the light emitted from the plurality of light sources, A first light receiving element, which is arranged at a position for receiving transmitted light or reflected light of light incident on the optical member, and which receives a part of light of the light source for monitoring, and light combined by the optical member A second light that is emitted to a target object and receives reflected light or transmitted light from the target object
The optical member is made of a material whose transmittance or reflectance does not change depending on temperature and wavelength, and the first light receiving element and the signal difference of the second light receiving element due to the difference in the light receiving wavelength. An optical device which outputs information about optical characteristics of a target object based on the signal amount of the optical device. 5. The light of a plurality of wavelengths is combined and projected to a target object, and the reflected light or the transmitted light from the target object is received,
In an optical device that outputs information on the optical characteristics of the target object based on the received light signal, first, second, and third light beams that emit different wavelengths are emitted.
Second light source for synthesizing the light emitted from the first and second light sources
Optical member, a first optical member for combining the light combined by the second optical member and the light emitted from the third light source, and the first optical member for the light emitted from the third light source. A first light receiving element which is arranged at a position for receiving transmitted light or reflected light by the optical member, and which receives a part of the light for monitoring, and the light combined by the first optical member to the target object. A second light receiving element for receiving reflected light or transmitted light from the target object, wherein the first optical member is made of a material whose transmittance or reflectance does not change depending on temperature and wavelength, Of the three light sources, the third light source has the strongest emitted light intensity, and controls the emitted light amount of the light source based on the signal amount of the first light receiving element to obtain the signal amount of the second light receiving element. Output information about the optical properties of the target object based on Optical device according to claim. 6. The light of a plurality of wavelengths is combined and projected to a target object, and the reflected light or the transmitted light from the target object is received,
An optical device for outputting information on optical characteristics of the target object based on the received light signal, comprising: first, second and third light sources each including a light emitting element for emitting green, blue and red light; An optical member made of a material that combines the light emitted from the second and third light sources and whose transmittance or reflectance does not change depending on temperature and wavelength; and the optical member for the light emitted from the third light source. Is arranged at a position for receiving transmitted light or reflected light by
A first light receiving element for receiving a part of the light from the light source for monitoring, and a second light for irradiating the target object with the light combined by the optical member and receiving the reflected light or the transmitted light from the target object.
A light receiving element, control means for controlling the amount of light emitted from the light source based on the output of the first light receiving element, and identification means for identifying the color of the target object based on the output of the second light receiving element. An optical device comprising: 7. The light after the optical member is combined,
The optical device according to claim 4, further comprising a transparent member that separates the light projected onto the target object and the light used for monitoring. 8. The light after the optical member is combined,
7. The optical device according to claim 4, further comprising a transparent member that separates the light projected onto the target object and the light used for monitoring, and the transparent member is a light projecting lens. 9. The optical device according to claim 8, wherein a metal plate provided with a slit is used instead of the transparent member. 10. The optical member comprises a lens for condensing the combined light, a light projecting lens, and a slit member arranged between these lenses. The optical device according to any one of claims 4 to 6. 11. A condensing lens that condenses the combined light, a slit member, and a light projecting lens are integrally formed, and the reflected light of the slit member is received for monitoring. 7. The optical device according to claim 4, which is characterized in that. 12. The optical device according to claim 4, wherein the transparent member is arranged so that a light projecting axis and a light receiving axis passing through the member are aligned with each other.