JPH08247935A - Optical device and detection device - Google Patents

Abstract

PURPOSE: To accurately detect the optical characteristics of an object by providing first and second light source means, a synthesis means, a light-reception means, and a control means and always making constant the quantity of light regardless of temperature change. CONSTITUTION: Light with a wavelength λ1 or λ2 generated by a light emitting element 1-1 (a first light source means) or 1-n (including a second light source means) is synthesized by an optical element 3-1 (a synthesis means) or 3-(n-1). Part of the synthesized light is received by a monitor light reception element 4 (a light reception means) and each light reception element 1-1 to 1-n is controlled corresponding to the light reception result, thus making constant the quantity of the generated light. Namely, a constant quantity of light may always be applied regardless of ambient temperature and change with time, thus accurately obtaining the optical characteristics of an object.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical device and a detection device, and more particularly, to an optical device and a detection device that suppress the influence of, for example, aging and temperature changes.

[0002]

2. Description of the Related Art In order to determine an optical characteristic of an object, light is applied to the object and its reflected light is sometimes analyzed. In such a case, light of a plurality of wavelengths is combined and the combined light is applied to the object. Then, the light from the object is received, and the relationship between the wavelength and the amount of the received light is analyzed to obtain information about the optical characteristics of the object.

[0003]

By the way, in such a case, the light applied to the object is generated by driving a light emitting element such as an LED or a semiconductor laser at a constant current. However, the light emitting element has a characteristic that the light emission power changes according to the temperature.

For example, the relationship between the ambient temperature and the emission power of LEDs that emit red, green, and blue light is illustrated as follows.
47 and 49, respectively. In each case, the horizontal axis represents the ambient temperature, and the vertical axis represents the emission power (relative luminous intensity or relative emission output).

As shown in FIG. 47, L which emits red light is used.
The relative light emission output of the ED decreases as the temperature increases. Also, as shown in FIG. 48, L that emits green light is used.
Similar to an LED that emits red light, the ED has a lower relative luminous intensity as the temperature rises. Furthermore, as shown in FIG. 49, an LED that emits blue light has the highest relative luminous intensity around 15 degrees, and the relative luminous intensity decreases when the temperature becomes lower or higher than that. To do.

As described above, if the light emission power fluctuates with a change in temperature, it becomes difficult to accurately detect the optical characteristics of the object.

The present invention has been made in view of the above circumstances, and is intended to make it possible to detect optical characteristics more accurately.

[0008]

An optical device according to a first aspect of the present invention includes a first light source means (for example, the light emitting element 1-1 of FIG. 1) for generating light having a first wavelength distribution, and a first light source means. Second light source means for generating light having a second wavelength distribution in a wavelength region different from the wavelength distribution of (for example, the light emitting element 1-2 of FIG. 1)
, A combining means for combining the light emitted from the first light source means and the light emitted from the second light source means (for example, the optical element 3-1 in FIG. 1), and a light receiving means for receiving the light combined by the combining means (for example, FIG. No. 1 monitor light receiving element 4) and control means for controlling the amount of light emitted from at least one of the first light source means and the second light source means in response to the output of the light receiving means (for example, the comparison circuit of FIG. 4). 14-1, 14-2) are provided.

According to a sixth aspect of the present invention, there is provided a detection device including an irradiation means for irradiating an object with light (for example, the light source device 50 of FIG. 22).
Object light receiving means for receiving light from an object (see, for example, FIG.
And the output of the object light receiving means,
In the detection device including a processing unit (for example, the division circuit 73 and the comparison circuit 74 in FIG. 23) that outputs information about the optical characteristics of the object, the irradiation unit generates the light having the first wavelength distribution. Light source means (for example, the light emitting element 1-1 in FIG. 22) and second light source means (for example, the light emitting element in FIG. 22) for generating light having a second wavelength distribution in a wavelength region different from the first wavelength distribution. 1-2), combining means for combining the light emitted from the first light source means and the light emitted from the second light source means (for example, the optical element 3-1 in FIG. 22), and the light combined by the combining means At least one of the first light source means or the second light source means corresponding to the output of the irradiation light receiving means (for example, the monitor light receiving element 4 in FIG. 22) for receiving the light before being irradiated to the irradiation light receiving means. One of the control means for controlling the amount of light emitted ( The example comparison circuit of FIG. 23 14-1,1
4-2) is provided.

According to a ninth aspect of the present invention, there is provided a detection device including an irradiation means for irradiating an object with light (for example, the light source device 50 in FIG. 22).
Object light receiving means for receiving light from an object (see, for example, FIG.
Of the signal light receiving element 62) and the processing means (for example, the color identification circuit 81 of FIG. 31) that processes the output of the object light receiving means and outputs the information regarding the optical characteristics of the object. Is a first light source means for generating light having a first wavelength distribution (for example, the light emitting element 1- of FIG. 22.
1), a second light source means (for example, the light emitting element 1-2 in FIG. 22) that generates light having a second wavelength distribution in a wavelength region different from the first wavelength distribution, and a first light source means. A synthesizing means for synthesizing the light emitted from the second light source means (for example, FIG. 22).
Optical element 3-1) and the irradiation light receiving means (for example, the monitoring light receiving element 4 in FIG. 22) that receives the light before being irradiated to the object among the lights combined by the combining means. The means is a dividing means for dividing the output of the object light receiving means and the output of the irradiation light receiving means (for example, the dividing circuit 91- in FIG. 31).
To 91-3) are included.

[0011]

In the optical device according to the first aspect, the light emitted from the first light source means and the light emitted from the second light source means are combined by the combining means. The light combined by the combining means is received by the light receiving means, and the light amount of at least one of the first light source means and the second light source means is controlled in accordance with the light reception result. Therefore, the amount of light can always be constant regardless of the temperature change.

In the detecting device according to the sixth aspect, information on the optical characteristics of the object is obtained in correspondence with the light from the object. The amount of light emitted to the object is controlled in accordance with the light receiving output of the light before being emitted to the object.
Therefore, the optical characteristics can be accurately detected regardless of the temperature change.

In the detector of the ninth aspect, the output of the object light receiving means and the output of the irradiation light receiving means are divided. Therefore, it is possible to accurately detect the optical characteristics without directly controlling the light amount.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a structural example of a light source device used in an optical device of the present invention. As shown in the figure, in this embodiment, the n light emitting elements 1-1 to 1-n are
Light of wavelengths λ _{1 to} λ _n is generated, and the respective lights are combined by the optical elements 3-1 to 3- (n-1) and emitted.

That is, the light of wavelength λ ₁ generated by the light emitting element 1-1 is converted into parallel light by the collimator lens 2-1 and is incident on the optical element 3-1. Similarly,
The light of wavelength λ ₂ generated by the light emitting element 1-2 is converted into parallel light by the collimator lens 2-2, and then the optical element 3
It is incident on -1. As shown in FIG. 2, the optical element 3-1 has a characteristic of transmitting light of wavelength λ ₁ and wavelengths longer than that, and reflecting light of wavelength λ ₂ (λ ₂ <λ ₁ ) and wavelengths shorter than that. Has been done. Therefore, the light of wavelength λ ₁ emitted from the light emitting element 1-1 passes through the optical element 3-1, and the light of wavelength λ ₂ emitted from the light emitting element 1-2 is transmitted by the optical element 3-.
The wavelength λ ₁ emitted from the light emitting element 1-1 after being reflected by
Light is combined so that the optical axis thereof coincides with the light and is incident on the optical element 3-2 at the subsequent stage.

The light of wavelength λ ₃ emitted from the light emitting element 1-3 is incident on the optical element 3-2 after being converted into parallel light by the collimator lens 2-3. Optical element 3-
As shown in FIG. 2, ₂ transmits light of wavelength λ ₂ and wavelengths longer than that, and reflects light of wavelength λ ₃ (λ ₃ <λ ₂ ) and wavelengths shorter than that. Therefore, the light is emitted from the optical element 1-1 and the optical element 1-2, and the optical element 3-
The light of wavelengths λ ₁ and λ ₂ (λ ₁ > λ ₂ > λ ₃ ) combined in ₁ is transmitted through the optical element 3-2, and the light of wavelength λ ₃ emitted by the light emitting element 1-3 is optical. The light is reflected by the element 3-2 and is combined so that the light from the optical element 3-1 and the optical axis coincide with each other.

In the same manner, the final stage optical element 3-
The light having wavelengths λ _{1 to} λ _n-1 generated by the light emitting elements 1-1 to 1- (n-1) is synthesized by the configuration up to the optical element 3- (n-2) in the preceding stage of (n-1). To be done.

The wavelength λ ₁ thus synthesized is
The light of λ _{n-1 to} λ _n-1 is incident on the optical element 3- (n-1). The optical element 3- (n-1) includes the optical element 1-n.
The light having the wavelength λ _n generated by is converted into parallel light by the collimator lens 2-n and is incident. Optical element 3-
(N-1) is set to the characteristic shown in FIG. That is, 90% of light of wavelength λ _n-1 and wavelengths longer than that (λ _{n-2 to} λ ₁ ) are transmitted, and wavelength λ _n (λ _n <λ _n-1 )
And 10% of shorter wavelength light is transmitted, and the remaining 90%
Reflect%. Therefore, 90% of the light having the wavelengths λ _{1 to} λ _n-1 incident from the optical element 3- (n-2) is transmitted through the optical element 3- (n-1), and 10% thereof is the optical element. 3-
The light is reflected by (n-1), and a part of it is received by the monitor light-receiving element 4
Is incident on. In addition, the wavelength λ generated by the light emitting element 1-n
90% of the light of _n is reflected by the optical element 3- (n-1), and 10% thereof is transmitted through the optical element 3- (n-1). A part of the light transmitted through the optical element 3- (n-1) is incident on the monitor light receiving element 4.

Therefore, each of the optical elements 3-1 to 3- (n-
Considering an ideal state, ignoring the loss in 1), 90% of the light having wavelengths λ _{1 to} λ _n generated by the light emitting elements 1-1 to 1-n is combined to form an optical element. Three
-(N-1) is emitted to the right side in FIG.
0% is emitted to the upper side of the optical element 3- (n-1) in FIG. 1, and a part thereof is received by the monitor light receiving element 4.

FIG. 4 shows an example of the configuration of a drive device for driving the light emitting elements 1-1 to 1-n corresponding to the output of the monitor light receiving element 4. As shown in the figure, in this embodiment, the output of the monitor light receiving element 4 is a current voltage (I /
V) Current-voltage conversion is performed by the converter 12, and then the sample-hold circuits (S / H) 13-1 to 13-n are input. The signals output from the sample hold circuits 13-1 to 13-n are input to the comparison circuits 14-1 to 14- _n and compared with predetermined reference voltages V _{1 to} V _n , respectively. Comparison circuit 14
The outputs of -1 to 14-n are drive circuits 11-1 to 11
-N is entered. Drive circuits 11-1 to 11-n
Are configured to drive the light emitting elements 1-1 to 1-n corresponding to the signals input from the comparison circuits 14-1 to 14-n, respectively.

Further, the oscillator circuit 15 generates a pulse so as to drive the light emitting elements 1-1 to 1-n in a time division manner (different timings), and the sample hold circuit 1 respectively.
3-1 to 13-n and the drive circuits 11-1 to 11-n.

Next, the operation will be described. The oscillator circuit 15 first controls the drive circuit 11-1 to drive the light emitting element 1-1. As a result, light of wavelength λ ₁ is generated from the light emitting element 1-1. This light is converted into parallel light by the collimator lens 2-1, and then the optical element 3-1.
90% of the light is applied to an object (not shown) through 3- (n-1). The remaining 10% of the light is reflected by the optical element 3- (n-1), and part of it is received by the monitor light receiving element 4.

The monitor light-receiving element 4 has an input wavelength λ.
Generates a current corresponding to ₁ light. This current is converted into a voltage by the current-voltage conversion circuit 12 and input to the sample hold circuits 13-1 to 13-n. However, since the oscillation circuit 15 supplies the pulse only to the sample hold circuit 13-1 corresponding to the light emitting element 1-1 (since the pulse is not supplied to the sample hold circuits 13-2 to 13-n), the sample hold Circuit 13-1
The output of the current-voltage conversion circuit 12 is sampled and held only at. Since the pulse supplied to the sample hold circuit 13-1 is the same as the pulse supplied to the drive circuit 11-1, the sample hold circuit 13-1
Will sample the light quantity (intensity) of the light of wavelength λ ₁ generated by the light emitting element 1-1.

The comparison circuit 14-1 outputs the output of the sample hold circuit 13-1 to a preset reference voltage V ₁
Compare with Then, the comparison circuit 14-1 outputs a signal corresponding to the difference between the output of the sample hold circuit 13-1 and the reference voltage V ₁ to the drive circuit 11-1. Drive circuit 1
Reference numeral 1-1 drives the light emitting element 1-1 at a constant current in response to the error signal supplied from the comparison circuit 14-1.

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 V ₁ , and the light emitting element 1-1 outputs the light. The amount of light is always constant regardless of temperature and aging.

The oscillating circuit 15 then drives the drive circuit 11-2 so as to drive the light emitting element 1-2, and also drives the sample hold circuit 13-2. As a result, the light having the wavelength λ ₂ generated by the light emitting element 1-2 is transmitted to the optical element 3-1.
After being reflected by the optical elements 3-2 to 3- (n-
The light is emitted via 1) and a part of the light is received by the monitor light receiving element 4. This monitor light receiving element 4
The signal corresponding to the light amount of the light received by is converted into a voltage by the current-voltage conversion circuit 12, and the sample-hold circuit 13-
The sample is held at 2. Then, in the comparison circuit 14-2, the reference voltage V ₂ and the output of the sample hold circuit 13-2 are compared, and the drive circuit 11-2 is
The light emitting element 1-2 is driven according to the error signal. As a result, the light emitting element 1-2 generates a constant amount of light (intensity) defined by the reference voltage V ₂ .

The same process is then performed on the other light emitting elements 1-3 to 1-n. As a result, each light emitting element generates a constant amount of light regulated by its corresponding reference voltage.

The above embodiment is an embodiment in which a photodiode such as a silicon photodiode which cannot separate light of each wavelength is used as the light receiving element 4 for monitoring, but the light receiving element for monitoring is used. As 4, it is also possible to use a color sensor that can obtain an output for each predetermined wavelength.

For example, FIG. 5 shows a configuration example of a color sensor using a color filter. In the color sensor 20 in this embodiment, R is placed on the glass substrate 22.
Color filters 21R, 21G, and 21B that transmit only lights of respective wavelengths (red), G (green), and B (blue) are arranged. A transparent electrode 23 is arranged below the glass substrate 22, and amorphous silicon (a-Si layer) 24 is further formed below the transparent electrode 23.
Further below the R, G, B color filters 21
Transparent electrodes 25R, 25 corresponding to R, 21G, 21B
G and 25B are provided.

Light incident from above in FIG. 5 is decomposed into R, G, and B components by color filters 21R, 21G, and 21B, respectively. As a result, the transparent electrode 2
3 and the transparent electrode 25R, the transparent electrode 23 and the transparent electrode 25
Between G and between the transparent electrode 23 and the transparent electrode 25B,
Currents corresponding to the light amounts of the R, G, and B components are obtained.

Therefore, for example, when a dyeing filter or an interference filter is used as the color filter 21, it corresponds to the light of each color (wavelength) of R, G, B as shown in FIG. 6A or 6B, respectively. , A signal corresponding to the light amount (intensity) can be obtained.

FIG. 7 shows the spectral sensitivities of such an optical sensor using amorphous silicon and an optical sensor using single crystal silicon. As shown in the figure, a characteristic that covers human visibility can be obtained by the amorphous silicon optical sensor.

FIG. 8 shows a configuration example of a semiconductor color sensor as another color sensor. As shown in the figure, a P layer 34 is formed below the insulating film 31, an N layer 35 is further formed below the insulating film 31, and a P layer 36 is further formed below the P layer 34. An electrode 37 is further formed on the lower side. The P layer 34 and the N layer 35 are provided with electrodes 32 and 33, respectively.

FIG. 9 shows an equivalent circuit of the semiconductor color sensor shown in FIG. As shown in the figure, in this semiconductor color sensor, substantially two photodiodes PD1 and PD2 are formed. Photodiode P
The output of D1 can be taken out from the electrodes 32 and 33, and the output of the photodiode PD2 can be taken out from the electrodes 33 and 37.
You can take out more.

FIG. 10 shows photodiodes PD1 and PD.
2 represents the spectral sensitivity characteristic of No. 2. As shown in the figure, the photodiode PD1 can detect light having a shorter wavelength than the photodiode PD2.

When light is incident on such a semiconductor color sensor, as shown in FIG. 11, blue light having a shorter wavelength is absorbed most by the uppermost P layer 34, and red light is in the middle. The most red light having the longest wavelength is absorbed by the N layer 35 which is the layer of the above, and the most red light having the longest wavelength is absorbed by the P layer 36 which is the lowermost layer. As a result, as shown in FIG. 9, when the current flowing through the photodiode PD1 is I _SC1 and the current flowing through the photodiode PD2 is I _SC2 , the short circuit current ratio (I _SC2 / I _SC1 ) is Figure 1
The relationship is as shown in 2. That is, when the value of the short circuit current ratio is determined, the wavelength of the light received by the semiconductor color sensor at that time is uniquely determined. However, the characteristic representing the relationship between the short circuit current ratio and the wavelength is the ambient temperature Ta.
It changes a little depending on.

In this way, as the monitor light receiving element 4,
When a color sensor is used, each light emitting element 1-
The drive circuit for driving 1 to 1-n can be configured as shown in FIG. 13, for example. That is, in the embodiment of FIG. 13, of the outputs of the monitor light receiving element 4 (color sensor), the output corresponding to the wavelength λ ₁ is supplied to the current-voltage conversion circuit 12-1 and the output corresponding to the wavelength λ _2. Is
The output corresponding to the wavelength λ _n is similarly supplied to the current-voltage conversion circuit 12-2, and is then supplied to the current-voltage conversion circuit 12-n.

The outputs of the current-voltage conversion circuits 12-1 to 12-n are respectively output from the corresponding sample hold circuits 13-.
1 to 13-n, and is sample-held. The oscillator circuit 15 includes the sample hold circuits 13-1 to 13-n and the drive circuit 11-1.
To 11-n, a predetermined pulse is simultaneously output. Other configurations are the same as those in FIG.

When the color sensor 20 having the color filter 21 shown in FIG. 5 is used as the monitor light-receiving element 4, each color λ ₁ is used as the color filter 21.
It is necessary to prepare color filters corresponding to λ _n . When the color sensor 20 shown in FIG. 5 is used as it is, n shown in FIG. 13 is 3. That is, the monitor light receiving element 4 has wavelengths λ ₁ (R), λ
_The signal components corresponding to ₂ (G) and λ ₃ (B) are output.

When the semiconductor color sensor having the structure shown in FIG. 8 is used as the monitor light receiving element 4, n in FIG. 13 is 2.

Next, the operation of the embodiment shown in FIG. 13 will be described. In the embodiment shown in FIG. 13, the oscillator circuit 15
Outputs a pulse for driving the drive circuits 11-1 to 11-n at the same time, and the sample hold circuit 13-
The pulses for sample-holding are simultaneously output to 1 to 13-n. Therefore, the light emitting elements 1-1 to 1-n simultaneously generate lights of wavelengths λ _{1 to} λ _n , respectively.

Since the light emitting elements 1-1 to 1-n are arranged as shown in FIG. 1, light of wavelengths λ _{1 to} λ _n are combined, and a part of the combined light is an object not shown. And a part of the light is received by the monitor light receiving element 4 (color sensor in this case).

The monitor light-receiving element 4 has wavelengths λ _{1 to} λ _n.
The current corresponding to the amount of light of is independently output. The current-voltage conversion circuits 12-1 to 12-n perform current-voltage conversion on the components of the corresponding wavelengths, and the sample-hold circuit 13
-1 to 13-n, respectively. The sample and hold circuits 13-1 to 13-n sample and hold the components of the corresponding wavelengths, and supply the sampled and held components to the comparison circuits 14-1 to 14-n. The comparison circuits 14-1 to 14-n compare their respective inputs with the reference voltages V _{1 to} V _n and supply the error signals to the drive circuits 11-1 to 11-n. The drive circuits 11-1 to 11-n correspond to the inputs from the comparison circuits 14-1 to 14-n and the light emitting elements 1-1 to 1
-N is driven.

As described above, in this embodiment, the light emitting elements 1-1 to 1-n are simultaneously and independently controlled.

As shown in FIG. 4, when the light emitting elements 1-1 to 1-n are driven in a time division manner, the number of light emitting elements can be increased. In addition, the light receiving element 4 for monitoring
Since a photodiode can be used and only one current-voltage conversion circuit 12 is required, it is possible to realize a smaller device at a lower cost.

On the other hand, as shown in FIG. 13, when a color sensor is used as the monitor light receiving element 4, since the light emitting elements 1-1 to 1-n can be driven simultaneously, the response is This enables quick and quick control. Further, each of the light emitting elements 1-1 to 1-n can be continuously driven instead of being pulse driven. In this case, the oscillator circuit 15 and the sample hold circuits 13-1 to 13-n are unnecessary.

FIG. 14 shows another configuration example of the light source device. In this embodiment, the optical elements 3-1 to 3-
(N-2) has the same characteristics as those in FIG. 1 (the same characteristics as in the case shown in FIG. 2), but the last optical element 3- (n-1) is shown in FIG. It is said to have such characteristics. That is, 10% of the light having the wavelength λ _n-1 and longer wavelengths are transmitted and 90% of the light is reflected, and the light having the wavelength λ _n and shorter wavelengths is
% Is transmitted and 10% is reflected. Therefore, in this embodiment, 90% of the combined light of the wavelengths λ _{1 to} λ _n is the optical element 3- (n-
The light is emitted above 1), 10% of which is emitted to the right, and a part of the light is received by the monitor light receiving element 4.

Also in the embodiment shown in FIG.
Alternatively, the light-emitting elements 1-1 to 1-n can be controlled by the same control circuit as in the case illustrated in FIG.

FIG. 16 shows still another configuration example of the light source device. In this embodiment, the light having the wavelength λ _{1 and} the light having the wavelength λ ₂ generated by the light emitting element 1-1 and the light emitting element 1-2 are combined by the optical element 3-1 to form the optical element 3-2.
It is designed to be incident on.

The wavelength λ ₃ generated by the light emitting element 1-3
Light and the light of wavelength λ ₄ generated by the light emitting element 1-4 are combined by the optical element 3-3, and then are incident on the optical element 3-4, and the wavelength λ ₅ generated by the light emitting element 1-5. Is combined with the light of. Then, the combined light is made incident on the optical element 3-2. Other configurations are similar to those in FIG.

Optical elements 3-1 to 3 in this embodiment
The characteristic of -4 is as shown in FIG. That is, the same characteristics as those shown in FIG. 1 (FIG. 2) may be used. Of course, the optical elements after the optical element 3-5 may have the same characteristics as those shown in FIG. 1 (FIGS. 2 and 3).

With the structure shown in FIG. 16, the length of the entire light source device can be shortened as compared with the structure shown in FIG. 1 or 14.

The drive circuit for driving the light source device having the structure shown in FIG. 16 can have the structure shown in FIG. 4 or 13 as in the case of the embodiment shown in FIGS.

FIG. 18 shows still another configuration example of the light source device. In this embodiment, after the lights of wavelengths λ ₁ and λ ₂ generated by the light emitting element 1-1 and the light emitting element 1-2 are combined by the optical element 3-1, the optical element 3 as the final stage optical element is used. -3.

Similarly, the light of wavelength λ ₃ generated by the light emitting element 1-3 and the light of wavelength λ ₄ generated by the optical element 1-4 are combined by the optical element 3-2, and then the optical It is incident on the element 3-3.

The optical elements 3-1 and 3-2 are respectively shown in FIG.
The characteristics are as shown in FIG. That is, the optical element 3-1 transmits the light having the wavelength λ ₁ and the wavelength longer than that,
The optical element 3-2 is configured to reflect the wavelength λ ₂ and shorter wavelengths, and the optical element 3-2 transmits the wavelength λ ₃ and longer wavelengths and transmits the wavelength λ ₄ and shorter wavelengths. It is configured to reflect. Also, the optical element 3-3
As shown in FIG. 20, 90% of the light having the wavelength λ ₂ and longer wavelengths are transmitted (reflecting 10%), and 10% of the light having wavelength λ ₃ and shorter wavelengths are transmitted (reflecting 10%). It is configured to reflect 90%).

Therefore, 90% of the combined light of the wavelengths λ ₁ and λ ₂ emitted from the optical element 3-1 is transmitted through the optical element 3-3, 10% thereof is reflected, and a part thereof is reflected. The light is incident on the monitor light receiving element 4. In addition, 90% of the light of wavelengths λ ₃ and λ ₄ combined by the optical element 3-2 is reflected by the optical element 3-3, and 10% of the light is transmitted through the optical element 3-3, and a part thereof Is received by the monitor light receiving element 4.

Therefore, also in this embodiment, each optical element can be driven by the drive circuit having the configuration shown in FIG. 4 or 13.

In the above embodiments, the light of each wavelength emitted from each light emitting element is converted into parallel light by a corresponding collimating lens and then combined by each optical element. For example, as shown in FIG. As described above, each optical element may be arranged in the divergent optical path, and the finally combined light may be converted into parallel light by a lens.

That is, in the embodiment shown in FIG. 21, the divergent light of the wavelengths λ ₁ and λ ₂ generated by the light emitting element 1-1 and the light emitting element 1-2 is combined by the optical element 3-1 as divergent light, It is incident on the optical element 3-2. And the optical element 3-2
Is configured to combine the divergent light of the wavelength λ ₃ generated by the light emitting element 1-3 with the combined divergent light of the wavelengths λ ₁ and λ ₂ incident from the optical element 3-1 and make the combined light incident on the lens 2. The lens 2 converts the divergent light incident from the optical element 3-2 into parallel light and emits it. The monitor light receiving element 4 is the optical element 3-2 at the final stage.
The combined light of the wavelengths λ ₁ and λ ₂ from the optical element 3-1 reflected by the optical element 3-1 and the light of the wavelength λ ₃ generated by the light emitting element 1-3 that has passed through the optical element 3-2 are received.

By disposing each optical element in the divergent optical path and using a single lens as in this embodiment, it is possible to reduce the size and cost of the apparatus.

Also in this embodiment, each light emitting element can be driven by the driving device shown in FIGS.

FIG. 22 shows an example of the structure of a mark sensor as a detecting device of the present invention to which the above light source device is applied. In this embodiment, light having a wavelength λ ₁ generated by the light emitting element 1-1 of the optical device 50 (for example, red light)
And light of wavelength λ ₂ (for example, blue light) generated by the light emitting element 1-2 is combined as divergent light by the optical element 3-1 and 90% of the light is detected by the light projecting lens 51 by the detection object 53.
(For example, a white object) is irradiated.
A mark 52 (for example, a yellow mark) is attached to or printed on the detected object 53.

The light reflected by the detection object 53 (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. 23 shows an electrical configuration example of a mark sensor having the light source device 50 and the light receiving device 60 shown in FIG. As shown in the figure, the output of the monitor light-receiving element 4 is converted into a current-voltage by the current-voltage conversion circuit 12 and then input to the sample-hold circuits 13-1 and 13-2 to be sample-held. ing. 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 V ₁ and V ₂ . Comparison circuit 14-1
And the signals output from 14-2 are supplied to the drive circuits 11-1 and 11-2, and the drive circuits 11-1 and 11-2
The light emitting elements 1-1 and 1-2 are driven according to the respective input signals. Oscillator circuit 15
Drives the light emitting elements 1-1 and 1-2 in a time division manner,
Drive circuit 11-1 and sample hold circuit 13-1, drive circuit 11-2 and sample hold circuit 13-2
The pulse is supplied to each.

On the other hand, the output of the signal light receiving element 62 is supplied to the sample hold circuits 72-1 and 72-2 after being converted into a current voltage by the current voltage conversion circuit 71. Then, the sample hold circuit 72-1
The outputs 72 and 72-2 are input to the division circuit 73 to be divided. The comparison circuit 74 is the division circuit 7
The output of No. 3 is compared with a preset reference value, and the comparison result is output as an identification signal of the mark 52. Sample and hold circuits 72-1 and 72-
2 is supplied with the same pulse as that supplied to the drive circuits 11-1 and 11-2, respectively.

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 (red) light having a wavelength λ ₁ . This light is
90% of the light passes through the optical element 3-1, and the projection lens 51
And is focused on the object 53 to be illuminated.

On the other hand, 10% of the light generated by the light emitting element 1-1 is reflected by the optical element 3-1 and is 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 path 12, and then supplied to the sample hold circuits 13-1 and 13-2. At this time, the sample-hold circuit 13-2 includes an oscillating circuit 15
Since the pulse is not supplied from the sample hold circuit 13-1 to the sample hold circuit 13-1, the output of the current-voltage conversion circuit 12 is sampled and held only by the sample hold circuit 13-1.

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 V ₁ and outputs the error signal thereof to 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 intensity (intensity) of the light generated by -1 is controlled to a constant value set by the reference voltage V ₁ .

After that, the oscillation circuit 15 operates the light emitting element 1-2.
In order to drive, the pulse is output to the drive circuit 11-2 and the sample hold circuit 13-2. Drive circuit 11-2
Drives a light emitting element 1-2 when a pulse is input, and emits light of wavelength λ ₂ (blue). This light is reflected by the optical element 3-1 and then focused by the light projecting lens 51 to be applied to the detection object 53. Also, one of them
0% of the light passes through the optical element 3-1 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 V ₂ 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 V ₂ .

On the other hand, when the light emitting element 1-1 generates light of wavelength λ ₁ , 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 supplied to the sample hold circuits 72-1 and 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 light of wavelength λ ₁ (red).

Similarly, the light emitting element 1-2 has a wavelength λ ₂ (blue).
When the above light is generated, 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, this sample hold circuit 72-2 holds a value corresponding to the amount of reflected light of wavelength λ ₂ (blue).

FIG. 24 shows the relationship between the color of the detection object 53 and its reflectance. As shown in FIG.
If 3 is white, the light with wavelength λ ₁ (red) will also have wavelength λ 1.
_{The 2} (blue) 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 wavelength λ ₁ (red) is
About 84% of it is reflected, and about 4% of the light of wavelength λ ₂ (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 hold circuit 72-1 and the sample 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, from the logic of the comparison circuit 74, the mark 52
The presence or absence (change in reflectance distribution) can be identified.

FIG. 25 shows an example of the configuration of the optical system of the color identification device as the detection device of the present invention. In this embodiment, the light of wavelength λ ₁ (red) generated by the light emitting element 1-1 and the light of wavelength λ ₂ (green) generated by the light emitting element 1-2 are
The light is combined by the optical element 3-1 and is incident on the optical element 3-2. The optical element 3-2 outputs the combined light to the light emitting element 1-
3 is combined with the light of wavelength λ ₃ (blue) generated, 90% of the combined light is emitted to the projection lens 51, and the remaining 10%
Is emitted toward the monitor light receiving element 4. Emitter lens 5
1 is configured to irradiate the detection object 53 with the combined light in a convergent manner.

The light reflected by the detection object 53 is condensed by the light receiving lens 61 and received by the signal light receiving element 62.

FIG. 26 shows an example of the electrical construction of a color identification device having the optical system shown in FIG. The drive circuit in this embodiment has the same configuration as that 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 supplied to the sample hold circuits 13-1 to 13-3. Then, the outputs of the sample hold circuits 13-1 to 13-3 are supplied to the comparison circuits 14-1 to 14-3 and compared with the reference voltages V _{1 to} V ₃ . 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 elements 1-1 to 1-1-.
3 is designed to drive. 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 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 to be sample-held. . The same pulses as the pulses supplied to the drive circuits 11-1 to 11-3 are supplied to the sample hold circuits 72-1 to 72-3 as sampling pulses. The color identification circuit 81 receives the outputs from the sample hold circuits 72-1 to 72-3,
The color identification processing is executed and the identification result is output.

Next, the operation will be described. As in the case of the embodiment shown in FIG. 4, 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, as in the case described with reference to FIG. 4, the drive circuits 11-1 to 11-3 sequentially perform the light emitting element 1 operation.
-1 to 1-3 control operation so as to generate a constant amount of light defined by reference voltages V ₁ to V ₃ is performed.

On the other hand, when the light emitting element 1-1 emits light of wavelength λ ₁ (red), the sample hold circuit 72-1
Is supplied with a sampling pulse. Therefore, the sample hold circuit 72-1 receives the signal corresponding to the light of the wavelength λ ₁ (red) received by the signal light receiving element 62 via the current-voltage conversion circuit 71, and sample-holds the value. To do.

Similarly, in the sample hold circuits 72-2 and 72-3, the light emitting element 1-2 has the wavelength λ ₂ (green).
Of the signal light receiving element 62 when the light emitting element 1-3 is emitting light and the output of the signal light receiving element 62 when the light emitting element 1-3 is emitting light of the wavelength λ ₃ (blue). Hold on. 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), G ₁ (= G / T), B ₁ (= 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 R shown in FIG.
It is based on the relationship with ₁ , G ₁ and B ₁ . That is,
For example, the values of the ratios R ₁ , G ₁ , and B ₁ 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 R ₁ , G ₁ and B ₁ are determined, the color can be identified from this value.

In step S1, it is determined whether or not R ₁ is larger than 40, and if it is larger, the process proceeds to step S2, where G
_It is determined whether ₁ is larger than 29. When G ₁ is larger than 29, it is judged as orange, and when it is 29 or less, it is judged as red.

When R ₁ is 40 or less, step S3
Then, it is determined whether R ₁ is larger than 33. When R ₁ is larger than 33, the process proceeds to step S4, and G ₁ is 38.
Determine if greater than. When G ₁ is greater than 38, it is determined to be yellow, and when G ₁ 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 to be pink, and when it is 7 or smaller, it is judged to be brown.

When R ₁ is 33 or less, step S6
Then, it is determined whether G ₁ is larger than 41.5.
When G ₁ is larger than 41.5, the process proceeds to step S7,
It is determined whether B ₁ is larger than 29. When B ₁ is greater than 29, it is determined to be green, and when B ₁ is 29 or less,
The process proceeds to step S8, B ₁ is equal to or 30 or greater. When B ₁ is larger than 30, it is judged as yellow, and 30
When it is below, it is determined to be yellowish green.

When G ₁ is 41.5 or less, the process proceeds to step S9, and it is determined whether B ₁ is larger than 37.5. When B ₁ is greater than 37.5, the process proceeds to step S10, and it is determined whether G ₁ is greater than 38. G ₁ is 3
When it is greater than 8, it is determined to be blue, and when G ₁ is 38 or less, the process proceeds to step S11, and it is determined whether R ₁ is greater than 25. When R ₁ is larger than 25, it is judged as purple, and when it is 25 or less, it is judged as dark blue.

When B ₁ is 37.5 or less, the process proceeds to step S12, and it is determined whether T is larger than 5. T
Is greater than 5, it is determined to be white, and when it is 5 or less,
Judge as black.

FIG. 29 shows another configuration example of the optical system of the color identification device. In this embodiment, the light source device 50
25 is basically the same as that shown in FIG. 25, but the light focused by the projection lens 51 is converted into the optical fiber 91.
The detection object 53 is irradiated with the light through the. 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 similar to those in FIG.

The electrical configuration of the color identification device in this case is the same as that shown in FIG.

FIG. 30 shows the light receiving element for monitoring 4 and the light receiving element for signal 62 in the embodiment shown in FIG. 25 or 29.
As an example, an electrical configuration example when the color sensor shown in FIG. 5 is used is shown.

That is, in this embodiment, the R, G, B signals independently output by the monitor light receiving element 4 are converted into current / voltage by the current / voltage conversion circuits 12-1 to 12-3, and then, Sample hold circuits 13-1 to 13
In -3, the sample is held. Then, the sample hold circuits 13-1 to 13-
3 output and the error voltage of the reference voltages V _{1 to} V ₃ are calculated by the comparison circuits 14-1 to 14-3, and the drive circuits 11-1 to 11-3 correspond to the error voltages and the driving circuits 11-1 to 11-3 operate. 1 to 1-3 are driven independently of each other.

The R, G, and B currents independently output by the signal light receiving element 62 are respectively converted into the current-voltage conversion circuit 71.
After being converted from current to voltage by -1 to 71-3, it is supplied to the sample hold circuits 72-1 to 72-3 and sample-held. Identification circuit 81
Is configured to identify the color of the detected object 53 from the outputs of the sample hold circuits 72-1 to 72-3 and output the identification result. The oscillator circuit 15 includes a drive circuit 11-1.
To 11-3 and sample and hold circuits 13-1 to 13-1
A drive pulse or a continuous drive signal is output so as to drive 3-3 and 72-1 to 72-3 at the same time.

That is, the oscillation circuit 15 is driven by the drive circuit 11-
When pulses for driving 1 to 11-3 and the sample hold circuits 13-1 to 13-3 are output at the same time, R, G, and B lights generated by the light emitting elements 1-1 to 1-3 are incident on the detection object 53. The light is emitted, and part of the light is received by the monitor light receiving element 4. Then, the currents corresponding to the R, G, and B components independently output by the monitor light receiving element 4 are converted into voltages by the current-voltage conversion circuits 12-1 to 12-3,
The sample and hold circuits 13-1 to 13-3 perform sample and hold. The comparison circuits 14-1 to 14-3 calculate the error between the outputs of the sample hold circuits 13-1 to 13-3 and the reference voltages V _{1 to} V _3, and the drive circuit 11-1.
11 to 11-3 are light-emitting elements 1-corresponding to this error voltage.
1 to 1-3 are driven. Thereby, the light emitting element 1-1
1 to 3 are controlled so as to generate light having a constant light amount (intensity) defined by the reference voltages V _{1 to} V ₃ .

On the other hand, R, which is simultaneously irradiated to the detection object 53,
The G and B lights are reflected there and are received by the signal light receiving element 62. The signal light receiving element 62 receives the incident R,
The currents corresponding to the G and B components are independently output. The currents are respectively converted into current-voltage conversion circuits 71-1 to 71-.
3 is converted into a voltage, and sampled and held by the sample hold circuits 72-1 to 72-3. Color identification circuit 81
Identifies the color of the detection object 53 from the values sample-held by the sample-hold circuits 72-1 to 72-3.

FIG. 31 shows another electrical configuration when the color monitor shown in FIG. 5 is used as the monitor light-receiving element 4 and the signal light-receiving element 62 of the embodiment shown in FIG. 25 or 29. Shows an example. In this embodiment, the drive circuits 11-1 to 11-3 are simultaneously driven by the oscillator circuit 15 to drive the light emitting elements 1-1 to 1-3 at the same time and simultaneously generate the lights of R, G, and B colors. It is designed to let you.

The monitor light-receiving element 4 includes R, G,
When the B light is received, components corresponding to the respective lights are independently generated and supplied to the current-voltage conversion circuits 12-1 to 12-3. Current-voltage conversion circuit 12-1
The output of each of FIGS.
After being sample-held by 13 to 13-3, the division circuit 9
It is adapted to be supplied to 1-1 to 91-3.

The R, G, and B components independently output from the signal light receiving element 62 are converted into current / voltage by the current / voltage conversion circuits 71-1 to 71-3, and then the sample / hold circuits 72-1 to 72-1. The sample is held at 72-3. And a sample hold circuit 72
-1 to 72-3 outputs the division circuits 91-1 to 91-1.
-3 is entered. The oscillator circuit 15 includes sample hold circuits 13-1 to 13-3 and 72-1 to 72-.
3 is also supplied with the same pulse as that for driving the drive circuits 11-1 to 11-3. The division circuits 91-1 to 91-3 are sample hold circuits 13-1 to 13-.
3 and the sample and hold circuits 72-1 to 72-
The output of No. 3 is divided, and the calculation result is supplied to the color identification circuit 81.

The light emitting elements 1-1 to 1-3 have R, G, B
When the above light is simultaneously generated, a part of the light is received by the monitor light receiving element 4, and the monitor light receiving element 4 receives R, G, B
The signal corresponding to each component of is independently output. The R, G, and B outputs of the monitor light-receiving element 4 are the current-voltage conversion circuit 12
After current-voltage conversion by -1 to 12-3, sample-hold circuits 13-1 to 13-3 perform sample-holding and further supply to division circuits 91-1 to 91-3, respectively.

On the other hand, R, which is reflected by the detection object 53,
The G and B lights are received by the signal light receiving element 62. The signal light receiving element 62 independently generates signals corresponding to the incident R, G, and B components. Current-voltage conversion circuit 71-
1 to 71-3 perform current-voltage conversion on these signals and output them to the sample hold circuits 72-1 to 72-3.
The components sample-held by the sample-hold circuits 72-1 to 72-3 are divided by the divider circuits 91-1 to 91-3.
Is supplied to.

As described above, in this embodiment, the light emitting elements 1-1 to 1-3 are not servoed so that their outputs have a constant value regardless of the ambient temperature.
Therefore, the amount of light generated changes with temperature and changes over time. As a result, the sample hold circuit 13
The values held in -1 to 13-3 also change corresponding to the change in the light amount. However, this also applies to the sample hold circuits 72-1 to 72-3.

For example, if the value of the R component held by the sample hold circuit 13-1 decreases by 10%, the value held by the sample hold circuit 72-1 also decreases by 10%. As a result, when the output of the sample hold circuits 13-1 and 72-1 is divided by the division circuit 91-1 to obtain the quotient, the value of the quotient becomes constant irrespective of temperature change and secular change. . Of course, the same applies to the division circuits 91-2 and 91-3 as in the division circuit 91-1.

Therefore, if the color identification circuit 81 executes the color identification processing based on the outputs of the division circuits 91-1 to 91-3, the light emitting elements 1-1 to 1-3 are generated. It is possible to perform stable color identification processing without directly controlling the light amount of light.

Next, the light emitting element 1 in the above-mentioned embodiment
-I and a specific configuration example of the optical element 3-i will be described.

For example, as the light emitting elements 1-1 to 1-n shown in FIG. 1, when n = 4, the light emitting elements having the emission spectra shown in FIGS. 32 to 35 can be used. As shown in these figures, the light emitting device 1 shown in FIG.
-1 has a peak intensity at a wavelength of about 900 nm,
The light emitting element 1-2 shown in FIG. 33 has a peak at a wavelength of about 680 nm. The light emitting element 1-3 shown in FIG. 34 has a peak at a wavelength of about 563 nm, and the light emitting element 1-4 shown in FIG. 35 has a peak at a wavelength of about 450 nm.

The optical element 3-i, for example, as shown in FIG. 36, comprises a glass substrate 101 and a dielectric multilayer film 102 formed thereon. An optical element 3-1 that combines light generated by the light emitting element 1-1 having the emission spectrum characteristic shown in FIG. 32 and light generated by the light emitting element 1-2 having the emission spectrum characteristic shown in FIG. 33 is realized. In addition, the dielectric multilayer film 102 can be configured as shown in FIG. 37, for example.

That is, in this embodiment, the multilayer film is composed of 15 layers shown by the numbers 1 to 15 in order from the substrate 101 side, and each layer is as shown in the material column of FIG. TiO ₂ (refractive index 2.26) and S
The layers are alternately formed of iO ₂ (refractive index 1.36). And the thickness of each layer number is described in the column of optical film thickness. For example, TiO ₂ layer number 1 is the thickness of 0.4029, SiO ₂ layer number 2 is a thickness of 0.9560. The optical film thickness is represented by the product of the refractive index of each material and the physical film thickness (the film thickness that is actually stacked).
(Λ = 750 nm) / 4 is set to 1.

As a result, the optical element 3-1 having the transmittance as shown in FIG. 38 can be realized. As is clear from FIG. 38, almost 100% of the light having the wavelength of 900 nm shown in FIG. 32 is transmitted, and the light shown in FIG.
Almost all the light with a wavelength of 80 nm is reflected.

6 output from the light emitting element 1-2 shown in FIG.
An optical element 3-2 that transmits a wavelength of 80 nm or a longer wavelength and reflects the wavelength of 563 nm generated by the light emitting element 1-3 shown in FIG. 34 has the same configuration as that shown in FIG. It can be realized by configuring the dielectric multilayer film 102. However, the reference wavelength (λ of λ / 4) in that case is 580 nm. That is,
When the reference wavelength is 580 nm and the dielectric multilayer film 102 is configured as shown in FIG. 37, the optical element 3-2 having the transmittance characteristics shown in FIG. 39 can be obtained. As is clear from FIG. 39, the wavelength 900 nm shown in FIG. 32 and FIG.
Most of the light of the wavelength of 680 nm and the light of 680 nm are transmitted,
Most of the light with a wavelength of 563 nm shown in FIG. 34 is reflected.

Further, as shown in FIG. 40, nine layers of layer number 1 to layer number 9 are formed on the dielectric multilayer film 102 as shown in FIG.
The optical element 3-3 having the transmittance characteristics shown in FIG. 41 can be obtained by forming the material shown in the column of 0 material in the film thickness shown in the column of optical film thickness. As is apparent from FIG. 41, in this optical element 3-3, 900 nm, 680 nm and 563 shown in FIGS.
About 90% of the light with the wavelength of nm is transmitted, and the light with the wavelength of 450 nm generated by the light emitting device 1-4 shown in FIG.
Is transmitted.

In the embodiment shown in FIG. 14, n =
4 is used as the light emitting elements 1-1 to 1-4.
32 to 35, the light emitting elements 1-1 to 1- having the emission spectrum characteristics shown in FIGS.
4 can be used.

Then, as in the case of the embodiment of FIG. 1, the dielectric multilayer film 102 is constructed as shown in FIG.
The reference wavelength λ is set to 750 nm or 580 nm, respectively, and the optical elements 3-1 and 3-2 having the transmittance characteristics shown in FIG. 38 or 39 can be obtained.

By forming the dielectric multilayer film 102 with the layers shown in FIG. 42 and setting the reference wavelength λ to 600 nm, the optical element 3-3 having the transmittance characteristics shown in FIG. 43 can be obtained. The refractive index of Al ₂ O ₃ is 1.63.

As is apparent from FIG. 43, FIG.
Of the wavelengths shown in FIG. 34 to FIG. 34, about 15% of the wavelengths of 900 nm and 680 nm shown in FIGS. 32 and 33 are transmitted, and the wavelength of 563 nm shown in FIG.
0% is transmitted. On the other hand, 450 shown in FIG.
About 90% of the nm light is transmitted.

Next, a specific example of the embodiment shown in FIG. 18 will be described. Also in this embodiment, the light emitting elements 1-1 to 1-4 are composed of the light emitting elements 1-1 to 1-4 having the emission spectra shown in FIGS. 32 to 35.

As the optical element 3-1, as shown in FIG. 37, by forming the dielectric multilayer film 102, an optical element having the transmittance characteristic shown in FIG. 38 can be obtained.

As the optical element 3-2, the dielectric multilayer film 10 is used.
2 is configured as shown in FIG. 37, and the reference wavelength λ is 465 nm.
By doing so, an optical element having a transmittance characteristic as shown in FIG. 44 can be obtained.

As shown in FIG. 44, in this embodiment, most of the light with a wavelength of 563 nm output from the optical element 1-3 shown in FIG. 34 is transmitted, and the light emitting element 1-4 shown in FIG. Most of the light having a wavelength of 450 nm generated by is reflected.

As the optical element 3-3 of the embodiment shown in FIG. 18, as shown in FIG.
46 and a reference wavelength λ of 590 nm, an optical element having a transmittance characteristic as shown in FIG. 46 can be obtained.

As shown in the figure, in this example, the wavelength of 900 nm shown in FIG. 32 and 68 shown in FIG.
About 90% of light with a wavelength of 0 nm is transmitted (10
% Is reflected), and light having a wavelength of 563 nm shown in FIG.
About 10% of the light having a wavelength of 450 nm shown in FIG. 35 is transmitted (90% of the light is reflected).

The case where the present invention is applied to the light source device, the mark sensor, and the color identification device has been described as an example.
The present invention is another device, and can be applied to a case where light of a plurality of wavelengths is combined and the combined light is used to identify the optical characteristics of an object.

[0125]

As described above, according to the optical device of the first aspect, the first light source means or the second light source means corresponds to the output of the light receiving means for receiving the light combined by the combining means. Since the amount of light emitted from at least one of the two is controlled, it is possible to always irradiate a constant amount of light regardless of the ambient temperature, changes over time, and the like.

According to the detection device of the sixth aspect, the first light is received corresponding to the output of the irradiation light receiving means for receiving the light before being irradiated to the object among the lights combined by the combining means. Since the light amount of the light emitted from at least one of the light source means and the second light source means is controlled, it is possible to accurately obtain the optical characteristics of the object regardless of the ambient temperature and the change over time. .

According to the detecting device of the ninth aspect, the output of the object light receiving means and the output of the irradiation light receiving means are divided, so that the first light source means or the second light source is used. It is possible to accurately obtain the optical properties of the object without directly controlling the means.

[Brief description of drawings]

FIG. 1 is a diagram showing an optical configuration of a light source device used in an optical device of the present invention.

2 is an optical element 3-1 to 3-in the embodiment of FIG.
It is a graph which shows the transmittance characteristic of (n-2).

3 is an optical element 3- (n-1) in the embodiment of FIG.
3 is a graph showing the transmittance characteristics of

4 is a block diagram showing an electrical configuration example of a drive circuit for driving the light emitting elements 1-1 to 1-n of the embodiment of FIG.

FIG. 5 is a sectional view showing a configuration of a color sensor.

6 is a diagram showing the characteristics of a color filter in the embodiment shown in FIG.

FIG. 7 is a graph showing the sensitivity characteristic of the embodiment of FIG.

FIG. 8 is a sectional view showing a configuration of a semiconductor color sensor.

9 is a diagram showing a configuration of an equivalent circuit of the embodiment shown in FIG.

10 is a graph showing the spectral sensitivity characteristics of the photodiode shown in FIG.

FIG. 11 is a diagram for explaining the relationship between the wavelength and absorption of light in the embodiment shown in FIG.

FIG. 12 is a graph showing the relationship between the short circuit current ratio output by the circuit shown in FIG. 9 and the wavelength.

FIG. 13 is a block diagram showing a configuration example of a drive circuit when a color sensor is used.

FIG. 14 is a diagram showing another configuration example of the optical system of the light source device.

15 is a graph showing the transmittance characteristics of the optical element 3- (n-1) shown in FIG.

FIG. 16 is a diagram showing another configuration example of the optical system of the light source device.

FIG. 17 is a graph showing the transmittance characteristics of the optical element shown in FIG.

FIG. 18 is a diagram showing another configuration example of the optical system of the light source device of the present invention.

19 is a graph showing the transmittance characteristics of the optical elements 3-1 and 3-2 shown in FIG.

20 is a graph showing the transmittance characteristics of the optical element 3-3 shown in FIG.

FIG. 21 is a diagram showing another configuration example of the optical system of the light source device of the present invention.

FIG. 22 is a diagram showing a configuration example of an optical system of a mark sensor to which the detection device of the present invention is applied.

23 is a block diagram showing an electrical configuration example of a mark sensor having the optical system shown in FIG.

FIG. 24 is a graph illustrating the reflection characteristic of the detection object in FIG.

FIG. 25 is a diagram showing a configuration example of an optical system of a color identification device to which the detection device of the present invention is applied.

26 is a block diagram showing an electrical configuration example of a color identification device having the optical system of FIG. 25.

FIG. 27 is a flowchart showing an example of color identification processing of FIG. 26.

FIG. 28 is a diagram illustrating a relationship between a color and a signal, which is a basis of color identification in FIG. 26.

FIG. 29 is a diagram showing another configuration example of the optical system of the color identification device to which the detection device of the present invention is applied.

30 is a block diagram showing an electrical configuration example of a color identification device in the case where the color sensor shown in FIG. 5 is used as the monitor light receiving element 4 and the signal light receiving element 62 in the embodiments of FIGS. 25 and 29. .

31 is a block diagram showing a modified example of the electrical configuration example of the color identification device shown in FIG. 30. FIG.

FIG. 32 is a diagram showing an emission spectrum characteristic of the light emitting element 1-1.

FIG. 33 is a diagram showing an emission spectrum characteristic of the light emitting element 1-2.

FIG. 34 is a characteristic diagram showing an emission spectrum of the light emitting device 1-3.

FIG. 35 is a diagram showing an emission spectrum of the light emitting element 1-4.

FIG. 36 is a diagram showing a configuration example of an optical element 3-i.

FIG. 37 is a diagram illustrating a configuration example of a dielectric multilayer film that realizes the optical element 3-1.

FIG. 38 is a graph showing a transmittance characteristic example of the optical element 3-1.

FIG. 39 is a graph showing an example of the transmittance characteristic of the optical element 3-2.

FIG. 40 is a diagram illustrating a configuration example of a dielectric multilayer film of the optical element 3-3.

FIG. 41 is a graph showing a transmittance characteristic example of the optical element 3-3.

42 is a diagram illustrating a configuration example of a dielectric multilayer film of the optical element 3-3 in the example of FIG.

43 is a graph showing an example of transmittance characteristics of the optical element 3-3 in the example of FIG.

FIG. 44 is a graph showing a transmittance characteristic example of the optical element 3-2 in the example of FIG.

45 is a diagram illustrating a configuration example of a dielectric multilayer film of the optical element 3-3 in the example of FIG.

FIG. 46 is a graph showing an example of transmittance characteristics of the optical element 3-3 in the example of FIG.

FIG. 47 is a characteristic diagram showing a relationship between ambient temperature and light output in a red LED.

FIG. 48 is a characteristic diagram showing a relationship between ambient temperature and luminous intensity of an LED that emits green light.

FIG. 49 is a characteristic diagram showing a relationship between ambient temperature and luminous intensity of an LED that emits blue light.

[Explanation of symbols]

 1-1 to 1-n Light emitting element 2-1 to 2-n Collimating lens 3-1 to 3- (n-1) Optical element 4 Monitor light receiving element 12, 12-1 to 12-n Current-voltage conversion circuit 13 -1 to 13-n Sample and hold circuit 14-1 to 14-n Comparing circuit 11-1 to 11-n Drive circuit 15 Oscillation circuit

Claims (9)

[Claims] 1. A first light source means for generating light having a first wavelength distribution, and a second light source for generating light having a second wavelength distribution in a wavelength region different from the first wavelength distribution. Means, a combining means for combining the lights emitted from the first light source means and the second light source means, a light receiving means for receiving the light combined by the combining means, and an output of the light receiving means. An optical device comprising: a control unit that controls the amount of light emitted from at least one of the first light source unit and the second light source unit. 2. The first light source means has at least one light emitting element for generating light constituting the first wavelength distribution, and the second light source means emits light from the first light source means. At least one light emitting element that generates the light having the second wavelength distribution is provided at a timing different from that of the element, and the control unit controls the light amount of the light generated by the light emitting element of the first light source unit. The optical device according to claim 1, wherein the light amount of light generated by the light emitting element of the second light source means is controlled independently. 3. The first light source means includes at least one optical element that generates light forming the first wavelength distribution, and the second light source means changes the second wavelength distribution. At least one light-emitting element that generates the constituent light is provided, and the light-receiving unit outputs the light generated by the light-emitting element of the first light source unit and the light generated by the light-emitting element of the second light source unit. The light amount of the light generated by the light emitting element of the first light source device in response to the result of the separation and light reception of the light receiving device, The optical device according to claim 1, wherein the amount of light generated by the light emitting element of the second light source means is controlled independently of each other. 4. The combining means emits the combined light in at least two directions, and the light receiving means receives one of the lights in the two directions emitted from the combining means. The optical device according to claim 1. 5. At least one of the first light source means and the second light source means optically emits a plurality of light emitting elements that emit light of different wavelengths and a plurality of the light emitting elements. The optical device according to claim 1, further comprising an optical element for combining. 6. An irradiation means for irradiating an object with light, an object light receiving means for receiving light from the object, an output of the object light receiving means, and information about optical characteristics of the object is output. In the detection device, the irradiation unit includes a first light source unit that emits light having a first wavelength distribution, and a second wavelength distribution in a wavelength region different from the first wavelength distribution. A second light source means for generating light, a synthesizing means for synthesizing the light emitted from the first light source means and the light emitted by the second light source means, and the light synthesized by the synthesizing means to the object. Irradiation light receiving means for receiving the light before being irradiated, and controlling the light quantity of the light emitted by at least one of the first light source means and the second light source means in accordance with the output of the irradiation light receiving means. And a control means. Detecting device for. 7. The detection device according to claim 6, wherein the optical characteristic of the object is a wavelength distribution of reflectance of the object. 8. The optical characteristic of the object is a change in wavelength distribution of reflectance of the object.
The detection device according to 1. 9. An irradiation unit that irradiates an object with light, an object light receiving unit that receives light from the object, an output of the object light receiving unit, and outputs information about optical characteristics of the object. In the detection device, the irradiation unit includes a first light source unit that emits light having a first wavelength distribution, and a second wavelength distribution in a wavelength region different from the first wavelength distribution. A second light source means for generating light, a synthesizing means for synthesizing the light emitted from the first light source means and the light emitted by the second light source means, and the light synthesized by the synthesizing means to the object. Irradiation light receiving means for receiving light before being irradiated, wherein the processing means comprises division means for dividing the output of the object light receiving means and the output of the irradiation light receiving means. Detector.