JPH02641B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a light beam incident position detection device for detecting the incident position of a light beam on a predetermined surface.

For example, in the field of devices that measure the distance to a target or detect the focused point of an imaging optical system on a target object, a light projecting means is provided on the device side and the light is directed from this light projecting means toward the target object. Emit a light beam, and detect the distance to the device or the focal point of the imaging optical system on the target object by using changes in the incident position of the reflected light beam from the target object on a predetermined surface. There are so-called active distance measuring devices or focus detecting devices that attempt to do this. An example in which a self-scanning element is applied as a reflected light flux detecting means in such an active distance measuring device and a focus detecting device has already been proposed in Japanese Patent Application No. 53-64747 by the applicant of the present invention.

As an example of this proposal, as a method for detecting the incident position of a reflected light beam by using the output of a photosensor array device as a self-scanning element, the peak value of the output is detected. A slice level is determined at a fixed ratio, and based on this slice level, the output of the photosensor array device obtained during the next readout is sliced, and the sliced signal portion is A device has been proposed that detects the incident position of a reflected light beam by detecting which position it falls on in a series of output signals, and thereby detects whether it is in focus, front focus, or rear focus. However, even with the device according to the embodiment of this proposal, there are still some problems that need to be further improved. For example, in the embodiment described above, the peak value of the envelope of the first time-series signal read out from the optical sensor array device is detected, and the slice is determined at a predetermined ratio from this value. By setting and holding the level, the signal envelope read out the second time is sliced, and it is possible to determine whether the part of the signal envelope that was sliced is in the center of the entire signal envelope, or whether it is shifted left or right from the center. The incident position of the reflected light beam is determined by digital discrimination, and the focus, front focus, and rear focus is therefore determined. In order to make a judgment, it is necessary to read out the time-series signal sent from the optical sensor array device twice, which makes it take a long time to make a judgment, and the signal detection limit depends on the slice level. If the peak of the signal becomes low due to the blurring of the light flux due to the slicing As a result, it becomes difficult to distinguish between the upper and lower signal envelopes, and therefore errors are likely to occur in determining the incident position of the reflected light beam, that is, in determining focus, front focus, and rear focus, so there is still room for improvement. left behind.

On the other hand, in the device described in Japanese Patent Application Laid-Open No. 50-80155, the light beam incident position is detected by comparing the amount of light incident on a pair of light receivers. However, when actually manufacturing this type of device, the detection accuracy depends on how accurately the boundary line between the pair of light receivers is aligned with the planned position in the design. Mounting the light receiver requires a high degree of skill, and there are limits to what can be achieved, which is one of the obstacles to improving detection accuracy.

The present invention has been made in view of the above circumstances, and is, for example, a light beam incident position detecting device that can be applied to an active distance detecting device or a focus detecting device as described above. In addition to using a scanning image sensor such as It is an object of the present invention to provide a new and better luminous flux incident position detecting device capable of detecting a light beam incident position. By arranging a scanning image sensor, dividing the time-series output signal from the image sensor into predetermined sections, and comparing the signal amount for each section, the incident position of the light beam on the light beam incident surface can be determined. so that it is detected,
This is characterized in that the dividing positions are electrically specified according to the planned positions in the design.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on embodiments with reference to the accompanying drawings.

First, FIG. 1 shows a particular optical arrangement of a TTL type active focus detection device according to Japanese Patent Application No. 1983-64747 as an application example of the present invention.
is an imaging lens, 6 is its intended focal plane (film surface in the case of a camera), 5 is an object plane, 2 is a light source using a light emitting body such as an LED or a semiconductor laser diode, and 3 is a scanning image sensor As, for example,
It has a linear array of a plurality of optical sensors.
A self-scanning photosensor array device (self-scanning solid-state image sensor) such as a CCD, BBD, MOS, photo diode array, or CCD photo diode; 4 is a prism having reflective surfaces 4a and 4b; .

In such an arrangement, the light beam emitted by the light source 2 is reflected by the reflective surface 4a of the prism 4, passes through the imaging lens 1, and then projects a spot image of the light source 2 onto the object plane 5. Here, the light source 2 is the planned focal plane 6
It is arranged in a conjugate relationship with the predetermined position above.
Such a conjugate arrangement is used for optical sensors, arrays,
The same applies to device 3. The light beam reflected by the object surface 5 passes through a virtual aperture corresponding to the reflective surface 4b in the prism 4 of the imaging lens 1, and projects a spot image by the light source 2 onto the light receiving surface of the photosensor array device 3. do. Here, Figure 1 a,
The difference between b and c will be explained. Figure 1b
If the position of the imaging lens 1 shown in FIG. In such a state, the spot image projected onto the object plane 5 is blurred and shifted. In FIG. 1a, ' is the position where the spot image on the object plane 5 at this time is formed in the sharpest state by the imaging lens '. The incident light flux is reflected by the reflecting surface 4b of the prism 4 so as to form an image in the sharpest state at the position of ', and is further blurred from the center c to the light receiving surface of the photosensor array device 3. The image is shifted to the side. In addition, in the position of the front pin shown in FIG. 1c, it is located more forward than the position of
Even in such a state, the spot image projected onto the object plane 5 is blurred and shifted. Figure 1c
In the figure, '' is the position where the spot image on the object plane 5 at this time is formed in the sharpest state by the imaging lens 1. The incident light beam is reflected by the reflective surface 4b of the prism 4 so as to form an image in the sharpest state at the position of The image is shifted to the side. In Fig. 1b, '' indicates the position where the spot image on the object plane 5 at this time is formed in the sharpest state by the imaging lens 1 in the focused state. The incident light flux is reflected by the reflective surface 4b of the prism 4 so that the image is formed at the sharpest position at the position of The image is formed almost in agreement with C. Figure 1 a, b,
In c, the light intensity distribution of the projected spot image on the object plane 5 and the light receiving surface of the photosensor array device 3 is schematically shown by dotted lines. By unevenly distributing the virtual apertures for light projection and light reception in the imaging lens 1 in this way, the spot image that is focused on the conjugate point in the focused state can be seen in the imaging lens position state ( Therefore, using the output of the photosensor array device 3, the above-mentioned spot image, that is, the reflection from the object surface 5, is By detecting the position of the light beam on the light-receiving surface of the photosensor array device 3 (particularly its relative position relative to the center), the in-focus, front-focus, and rear-focus states can be determined. . still,
Arrow Y in the figure indicates the reading direction of the sensor device output.

Next, referring to Fig. 2, as explained in Fig. 1,
The principle of light-speed incident position detection in an embodiment in which the present invention is applied to a TTL type active focus detection device will be described. First, Fig. 2a schematically shows the energy distribution of the received light beam on the sensor surface of the optical sensor array device 3, and _E1 shows the distribution in the focused state, which is similar to Fig. 1b. This corresponds to the sharpest imaging state. Here, a point C that is conjugate with the center of the light source 2 is selected as a reference point for detecting the incident position of the light beam on the sensor surface of the photosensor array device 3, and this conjugate point C is j The boundary between the th sensor element and the j+1th sensor element is selected in advance. Therefore, in the focused state, the energy distribution on the sensor surface is almost equally divided to the left and right with the conjugate point C as the border, and in this state, the energy distribution on the sensor surface of the optical sensor array device 3 is The total amount of energy incident on sensor elements from i to j and the total amount of energy incident on sensor elements from j+1 to k (however, j−i
=k-(j+1)) are equivalent within a predetermined error range.

Next, the energy distribution states E ₂ and E ₃ are the states of FIG. It shows. The energy distribution changes as the imaging lens 1 moves away from the focused position in the optical sensor array.
Place the left (B side) or right (A side) on the sensor surface of device 3.
(side) direction while blurring. Therefore, there is a correspondence between the maximum extension amount of the imaging lens 1 and the maximum deviation amount of the spot image on the sensor surface, and from this, the sensor length of the optical sensor array device 3, that is, the number of sensor elements is determined. Ru. In this case, the sensor length cannot be made very long, so
The energy distribution corresponding to the front focus and back focus cannot completely cover the maximum deviation of the spot image.
Even if E ₂ and E ₃ are maximally blurred (that is, expanded) and the distribution at the left or right end is cut off, it does not have much effect in practice. In FIG. 2a, the boundaries of the sensor elements corresponding to the left and right ends are designated as i and k. Here, in the present invention, among the signals of each sensor element sent out in time series from the optical sensor array device 3, components from i to k are sequentially integrated, and i from j to j
Integrate from +1 to k with the polarity reversed between j and j+1. That is, if the signal corresponding to the energy distribution is V(t), then the integral value s is, when the gain of the integrator is K, S=K[∫ ^tj _ti V(t) dt−∫ ^tk _tj V(t) dt]. There is essentially no problem whether the polarity of K is positive or negative. FIG. 2b schematically shows the signal V(t) whose polarity is inverted at time _tj . In addition, Fig. 2c shows the signals obtained by integrating each signal in Fig. 2b for each energy distribution state, that is, the energy distributions E ₁ , E ₂ , and E ₃ in each focus state. It is shown schematically. As a result of inversion integration at time t _j , as can be understood from the equation, the difference S between the integral value of the time interval from time t _i to time t _j and the integral value of the time interval from time t _j to time t _k is the time Output as _tk passes. As shown by _S1 in Figure 2c, when this difference S is zero, the energy distribution is equal on the left and right sides around the conjugate point C set on the sensor surface of the optical sensor array device 3. This state corresponds to the in-focus state b in Fig. 1, and the second
In the figure, the energy distribution E ₁ at a, which shows an enlarged portion of the optical sensor array device 3.
corresponds to the state of Also, S ₂ in Figure 2c
and S ₃ are the energy distributions E ₂ and E ₃ on the sensor surface of the optical sensor array device 3 shown in Figure a.
It corresponds to In other words, regarding S ₂ , the signal envelope corresponding to the energy distribution on sensor elements from i to j is integrated, and the signal envelope corresponding to the energy distribution on sensor elements from j+1 to k is As time t _k passes, the difference between the integrated value and
The result of the inversion integral at t _j is output as -V as shown at the right end of the curve S ₂ in FIG. 2c. Similarly, +V is output for _S3 . In this way, the signal light energy distribution on the sensor surface of the optical sensor array device 3 changes according to the degree of movement of the imaging lens 1 back and forth from the focusing position corresponding to a certain object. The lens moves left and right around the conjugate point C while being blurred, but the level of the integrated output shown in Fig. 2c corresponding to such lens movement immediately after time _tk elapses, i.e. The change in the level of the output S after the inversion integration expressed by the equation becomes a curve as shown in FIG. This is a curve of S = S (X) with the value of S expressed by the formula on the vertical axis (described as the S axis) and the amount of movement of the imaging lens 1 from the focusing position on the horizontal axis (described as the X axis). This is a schematic representation. S(X) curve is
A point that intersects the axis, that is, when S(X)=O, is in focus. Since the curve S(X) is almost point symmetrical with the origin as the midpoint, the polarity of S(X) and S(X)=
By finding the position X of the imaging lens 1 that is O, it is possible to detect focus and whether it is front focus or rear focus. For example, the third
In the figure, , corresponds to the imaging lens position, , in FIGS. 1a, b, and c, and each value of S(X) corresponds to the amount of deviation.

Hereinafter, specific embodiments of the light beam incident position detection device of the present invention based on the basic principle as described above will be described in detail. First of all, FIG. 4 mainly shows the basic configuration of the electric circuit system of this example device, and the arrangement relationship of the imaging lens 1, light source 2, photosensor array device 3, prism 4, and predetermined focal plane 6 is shown below. It is assumed that this is as explained with reference to FIG. The optical sensor array device 3 uses a four-phase driven one-dimensional CCD in this embodiment. Reference numeral 7 denotes a drive circuit for driving the optical sensor array device _{3 ,} and as shown in _FIG . A pulse φ _RS and a shift pulse φ _SH having a predetermined period and synchronized with φ ₄ are output. Note that here, the transfer clock pulse φ ₁ ,
φ ₂ , φ ₃ , and φ ₄ are for driving the CCD analog shift register for charge transfer.
It is used to transfer the signal charge to the output point through the shift register. In this example, φ ₁ to _{φ 4}
Although four-phase clock pulses are used, it is not necessary to specify the number of phases and the transfer method.
The shift pulse φ _SH is a pulse applied to the shift gate electrode in order to transfer the signal charge accumulated in the sensor section to the CCD analog shift register for a predetermined accumulation time. Further, the reset pulse _φRS is provided for resetting the charge of the output section. The time-series signal voltage waveform output from the output section is schematically shown as Vout.
In this embodiment, the optical sensor array device 3 outputs a signal in synchronization with _φ2 . 8 is a circuit for removing offset voltage (for example, dark current component) of the time-series signal voltage output from the photosensor array device 3; for example,
It consists of a differential amplifier, and by inputting a signal voltage to one input terminal and inputting a voltage for offset adjustment (for example, dark current level) to the other input terminal, the offset (noise) of the signal voltage can be adjusted. components). As shown in FIG. 5, the output of the photosensor array device 3 is obtained here as a negative voltage signal, but this is inverted and amplified in the offset voltage removal circuit and becomes a positive voltage. It is output as a signal. 9 is
Analog circuits consisting of FET analog switches, etc.
In the gate circuit, the control signal φ ₁₁ from the control circuit 12
(shown in FIG. 7), the switch is controlled to be in the ON state only in the time period from time ti to time tk explained in FIG. 10 is a signal inversion circuit, and control circuit 1
Based on the control signal φ ₁₂ (shown in FIG. 7) from No. 2, the signal is controlled to be inverted at the timing of time t _j explained in FIG. 2. 11 is an integrating circuit that integrates the output of the signal inversion circuit 10, and a shift pulse φ _SH
It is reset by Reference numeral 13 denotes a sample and hold circuit for sampling and holding the output (S) of the integrating circuit 11, and the integrating circuit is activated at the timing of time t _k according to the control signal φ ₁₃ (shown in FIG. 7) from the control circuit 12. Sample the output (S) of 11,
From then on, it will be controlled to hold this. 1
4 and 14' constitute a window comparator circuit for comparing the output (Vs) of the sample and hold circuit 13 with respect to a predetermined voltage range -Vref. to +Vref. determined by resistors R1 and R2. The comparator 14 converts the output (Vs) of the sample-and-hold circuit 13 into the reference voltage +Vref.
The comparator 14' receives the output (Vs) of the sample-and-hold circuit 13 at its non-inverting input and the reference voltage +Vref. at its inverting input for comparison with the reference voltage -Vref. Vref.
The output (Vs) is received at its inverting input and the reference voltage -Vref. is received at its non-inverting input for comparison with respect to -Vref.≦Vs.
If ≦+Vref・, comparator 14,1
Both outputs of comparator 14' become low, and in the case of Vs>+Vref., the output of comparator 14' remains low.
The output of comparator 14 becomes high, while
When Vs>-Vref., the output of the comparator 14 remains low and the output of the comparator 14' becomes high. 15 is a display control circuit that controls the display LEDs 18 and 19 according to the logical conditions of the outputs of the comparators 14 and 14';
When the output of comparator 14' is high, LED18 is activated, and when the output of comparator 14' is high, LED19 is activated.
and when the outputs of the comparators 14 and 14' are both low, the control is performed so that both the LEDs 18 and 19 are turned on. 16 is a motor 17 for automatically focusing the imaging lens 1 based on the outputs of the comparators 14 and 14'.
This is a motor control circuit that controls the The control circuit 12 receives the shift pulse φ _SH and the transfer clock pulse φ ₂ from the drive circuit 7, and based on these, determines the range of the sensor elements to be used and the inversion integral position of the optical sensor array device 3, i.e. ,
Control signals φ ₁₁ , φ ₁₂ , and φ ₁₃ are outputted to define the timings of ti, tj, and tk explained in FIG. 2.

In the above configuration, a light beam is now projected by the light emission from the light source 2, and the reflected light beam is in the focusing state of the imaging lens 1 with respect to the object at this time on the sensor surface of the photosensor array device 3. When the output of the optical sensor array device 3 is read out by the operation of the drive circuit 7 in a state where the light is incident on the corresponding position, first, the shift pulse φ _SH at this time causes the integration circuit 11 to be read out. is reset, and the control circuit 12 responds to this shift pulse φ _SH to start the timing specified operation based on the transfer clock pulse φ ₂ . Meanwhile, the sensor device output read at this time is After the offset voltage (noise component) is removed by the offset voltage removal circuit 8, it is applied to the analog gate circuit 9. Here, from the start of reading the sensor device output until reaching time ti, the control circuit 12 sets the analog gate circuit 9 to the gate-off state by setting the control signal _φ11 to low. When the time ti is reached, the analog gate circuit 9 is set to the gate-on state by making the control signal φ ₁₁ high until the time tk is reached, and therefore the signal inversion circuit 1
0 is given the sensor device output in the time interval from time ti to time tk, but here, until time tj is reached, the control circuit 12
By setting the control signal φ ₁₂ to low, the signal inverting circuit 10 is set to the signal non-inverting output mode in which the input signal is output as it is without inverting it, and when time tj is reached, the time tk
By setting the control signal φ ₁₂ to high until reaching , the signal inverting circuit 10 is set to the signal inverting output mode in which the input signal is inverted and output. Therefore, the integrating circuit 11 first integrates the signal in the time interval from time ti to time tk, and then integrates the signal in the time interval from time ti to time tj.
For the signal in the time interval up to tk, inversion integration is performed, and thus, depending on the integration circuit 11,
When the calculation shown in the above formula is performed and the time tk is reached, the integration circuit 11 outputs the information from the time ti to the time tk.
The difference (S) between the signal amount in the time interval up to tj and the signal amount in the time interval from time tj to time tk is output. Then, when the time tk is reached, the control circuit 12
sets the control signal φ ₁₃ to high, so that the sample-and-hold circuit 13 samples and holds the output (S) of the integrating circuit 11 at this time tk. Thus, the output (Vs) of the sample-and-hold circuit 13 at this time is the output of the optical sensor array.
This represents the incident position of the reflected light beam on the sensor surface of the device 3. At this time, as explained in FIG. 2, if Vs=0, the incident position of the reflected light beam is the j-th and j+1-th It coincides with the boundary of the sensor element, that is, the conjugate point C, and if Vs>0, then
Further, if Vs<0, it means that the conjugate point C is biased toward the A side, and the absolute value level |Vs| at this time represents the amount of the bias. Here, the incident position of the reflected light beam on the sensor surface of the photosensor array device 3 is detected as described above, and the result is the output (Vs) of the sample and hold circuit 13, that is, the integration circuit 11 The instruction is given depending on the output (S) of .
Hereinafter, the output (Vs) of the sample-and-hold circuit 13 at this time is compared with a predetermined voltage range -Vref. to +Vref. by the comparators 14 and 14'.
Based on the result, the display control circuit 15 controls the LED.
18 and 19, and the lens driving motor 17 is controlled by the motor control circuit 16.
becomes controlled. In this case, the second and third
From what has been explained in the figure, the high output of comparator 14 indicates the front pin state, the high output of comparator 14' indicates the back pin state, and comparator 1
Both output rows of 4 and 14' are in focus (i.e.,
Here, as shown in Figure 3, the range δ determined by +Vref. and -Vref. is used as the focusing range), so the lighting of LED 18 indicates the front focus state, and the lighting of LED 19 indicates The rear focus state and the lighting of both LEDs 18 and 19 indicate the in-focus state. Also, from this, the motor control circuit 16 rotates the motor 17 in a predetermined direction to move the imaging lens 1 backward depending on the high output of the comparator 14, and moves the imaging lens 1 forward depending on the high output of the comparator 14'. Motor 17 to make
and comparators 14, 14'
It is sufficient if the motor 17 is controlled so as to stop the motor 17 depending on the low output of both.

Here, specific configuration examples of the control circuit 12, offset voltage removal circuit 8, and signal inversion circuit 10 will be explained.

First, FIG. 6 shows an example of the configuration of the control circuit 12. Reference numeral 21 is a counter for counting the transfer clock pulse _φ2 , and is configured to be reset by the shift pulse _φSH . 22 is the above time based on the count output of the counter 21.
A programmable logic array whose contents are programmed in advance to define the timings of ti, tj, and tk. Specifically, after the shift pulse φ _SH is applied to the optical sensor array device 3,
Assuming that α transfer clock pulses φ ₂ are applied until the signal from the first sensor element is read out, the signal is output from output terminal A at the point when the count value of the counter 21 reaches “α+i”. Then, from the output terminal B, when the count value of the counter 21 becomes "α+j", and from the output terminal C, the count value of the counter 21 becomes "α+j".
k'', a single pulse (as shown in Figure 7)
The content is pre-programmed to output the following. 23 is an RS flip-flop configured to be set by a pulse from the output terminal A of the programmable logic array 22 and then reset by a pulse from the output terminal C.
Flop 24 is also an RS flip flop configured to be set by a pulse from output terminal B of programmable logic array 22 and then reset by a pulse from output terminal C.
Here, the Q output of the flip-flop 23 (shown in FIG. 7) becomes the control signal φ ₁₁ for the analog gate circuit 9 shown in FIG. 4, and the Q output of the flip-flop 24 (shown in FIG. ) becomes the control signal φ ₁₂ for the fourth illustrated signal inversion circuit 10, and the output from the output terminal C of the programmable logic array 22 becomes the control signal φ ₁₃ for the fourth illustrated sample and hold circuit 13.

Next, FIG. 8 shows an example of the configuration of the offset voltage removal circuit 8. In the example shown here, the output from the photosensor array device 3 is AC amplified and then clamped to reduce the signal voltage. The offset component (DC component) is removed. That is, in the figure, 31 is an AC amplifier, 32 is a clamping (i.e., DC cutting) capacitor,
33 is an analog pin for resetting the capacitor 32.
The switch 34 is an output buffer amplifier, and the capacitor 32 removes the offset component (here mainly the DC component) in the signal voltage, so that the buffer amplifier 34 outputs a signal with the offset component removed. It will look like this. Note that the analog switch 33 is turned on in order to reset the capacitor 32 by the shift pulse _φSH .

Finally, FIG. 9 shows three configuration examples of the signal inverting circuit 10. First, the example shown in a shows the output of an inverting amplifier circuit formed by connecting an operational amplifier 41 and resistors R3 and R4 as shown. , an operational amplifier 42 and resistors R5, R6, R7, and R8 are connected as shown in the figure, and the outputs of the non-inverting amplifier circuits are respectively analog-amplified.
The analog switch 43 receives the control signal _φ12 , and the analog switch 44 receives the inverted signal ₁₂ from the inverter 45. - equal to the output of flop 28) is given. Further, in the example shown in b, in the configuration of a non-inverting amplifier circuit formed by connecting an operational amplifier 46, resistors R9, R10, R11, and an analog switch 47 as shown in the figure, the analog switch 4
By turning on the analog switch 47, the operation mode can be switched from the non-inverting amplification mode to the inverting amplification mode, and the analog switch 47 is given the control signal _φ12 . Also, the example shown in c is
In an inverting amplifier circuit configured by connecting an operational amplifier 48, resistors R12, R13, R14, and an analog switch 49 as shown in the figure, turning on the analog switch 49 changes the operating mode from the inverting amplification mode. The analog switch 49 is configured to be able to switch to a non-inverting amplification mode, and an inverted signal ₁₂ of the control signal φ ₁₂ is applied to the analog switch 49 by an inverter 50.

Now, as described in detail above, in the light flux incident position detection device of the present invention, a scanning type image sensor is arranged almost coincident with the incident light flux, and a time-series output signal from the image sensor is detected in a predetermined interval. The incident position of the light beam on the light beam incident surface is detected by dividing the signal into each section and comparing the signal amount for each section. By using a scanning image sensor such as the above, it is possible to make the incident of the light beam on a predetermined surface in a simpler way and always with high precision and accuracy without complicating the configuration of the electric circuit system. This makes it possible to detect the position, and is very useful especially when applied to active distance detection devices or focus detection devices as mentioned at the beginning.
In addition, in the example, TTL is used as an application example of the device of the present invention.
Although the description has been made using a type active focus detection device, it goes without saying that the application of the device of the present invention is not limited to such a focus detection device. It can be widely applied, and the beneficial advantages described above can also be obtained in that case. Furthermore, in the embodiment, a self-scanning solid-state image sensor known as an optical sensor array device is used as the scanning image sensor, but in addition to this, image sensor functions known as videcon, saticon, carnicon, etc. can also be used. be. Furthermore, in the embodiment, the integrated amount of the signal was determined as the signal amount for each divided section, but in addition to this, the peak value of the signal for each section or the average value of the signal for each section was determined and used. It would be good to make a comparison. Furthermore, in the embodiment, a method called inversion integration was adopted as a method of comparing the signal amount for each section, but in addition to this, the signal for each section may be integrated separately, or the peak value thereof may be determined, These may be added to a differential amplifier circuit to determine the difference (S), or a comparison circuit may be used for comparison.

Furthermore, when manufacturing the device of the present invention, after installing the image sensor in the device, a predetermined position of the image sensor is electrically specified according to the planned position in the design, and if this is used as a reference, the installation error can be reduced in practical terms. This has the effect of eliminating this problem, thereby making it possible to improve accuracy.

Furthermore, since the incident light beam can be imaged using an image sensor and the form of the light beam can be observed, this information can be used as a checking means during assembly and adjustment.

[Brief explanation of drawings]

Figure 1 shows TTL as an application example of the device of the present invention.
FIG. 2 is a schematic diagram showing the optical arrangement of a type active focus detection device, in which a shows the rear focus state, b shows the focused state, and c
indicate the front pin state, respectively. FIG. 2 is a diagram for explaining the principle of detecting the light flux incident position when the device of the present invention is applied to a focus detection device as explained in FIG. FIG. 1 shows the distribution states of each light energy corresponding to the states a, b, and c in FIG. Figure 3 shows the output signal (S) obtained by the inverted integration explained in Figure 2.
FIG. 4 is a block diagram showing an example of the case where the device of the present invention is applied to the focus detection device shown in FIG. 1, and FIG. The figure is a timing chart showing the output of the driver circuit in the circuit system shown in FIG. 4 and the output signal from the optical sensor array device based on this, and FIG. A block diagram showing an example of the configuration, FIG. 7 is a timing chart showing the operational relationship of the circuit shown in FIG. 6, and FIG. 8 is a partial circuit diagram showing an example of the configuration of the offset voltage removal circuit in the circuit system shown in FIG. , FIGS. 9A, 9B, and 9C are partial circuit diagrams showing three configuration examples of the signal inverting circuit in the circuit system shown in FIG. 1... Imaging lens, 2... Light source, 6... Planned focal plane, 3... Optical sensor as a scanning type image sensor.
Array device (self-scanning solid-state image sensor),
9...Analog gate circuit for capturing valid signals,
10, 11, 12... Components of an inverting and integrating means as a means for comparing the signal amount for each divided section, 10 is a signal inverting circuit, 11 is an integrating circuit, 1
2 is a signal section setting control circuit.

Claims (1)

[Scope of Claims] 1. A device that guides a light beam from an object to a light receiving means through an optical system and performs measurement or detection by utilizing the effect that the energy intensity distribution of the incident light beam moves on the light receiving surface of the light receiving means. In this, the light receiving means is a scanning image sensor, and a position on the scanning image sensor corresponding to a predetermined optical position determined by the optical system is specified as a reference for signal processing, and the scanning image sensor is A light flux incident position detecting device comprising: an electric means for reading an electric signal related to the energy intensity distribution from the element and processing the read electric signal according to a predetermined algorithm using the reference.