JP3461910B2 - Sign direction detector - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sign direction detecting device, and more specifically, it detects the direction in which a sign such as a light emitter or reflector such as a gaze point or a bright spot is present by an image position detecting element. The present invention relates to a sign direction detecting device.

[0002]

2. Description of the Related Art As a method for measuring the shape, position, direction, movement, etc. of an object, various types such as a contact type and a non-contact type have been proposed.

By the way, the contact type method is used when a living body is measured as an object such as accurately measuring eye movements while driving a vehicle or during rehabilitation, or an object which is deformed or destroyed by contact. In such a case, the optical non-contact type method is often used because it cannot be applied to the case of measuring.

In such an optical non-contact type measuring method, a light beam is projected on the surface of an object to generate a bright spot (light image), which is used as a marker, and the bright spot is observed at different positions. There are many known devices that detect the direction of the bright spot and determine the three-dimensional position of the sign based on the principle of triangulation.

The sign direction detecting device plays an important role in the measurement in these three-dimensional position measuring devices.

As shown in FIG. 14, the basic principle of a conventional optical marker direction detecting device is, for example, an L marker as a marker.
Light source 101 and light source 102 such as ED (light emitting diode)
(The light source 101 and the light source 102 emit light in a time-division manner, and the direction in which the light from the shining light source comes, that is, the direction in which the light source exists, is detected as the direction of the sign.) In order to detect the direction in which the points exist, the imaging lens 10
3 and the image position detecting element 104 are combined, and the bright spot image 105a (when the light source 102 is illuminated) or the bright spot image 105b (when the light source 101 is illuminated) on the detection surface of the image position detecting element 104 is output electrode 106. , 107 as the current value of the light source, and the calculation is performed to obtain a bright spot (light source 10
1 or the direction of existence of the light source 102).

[0007]

However, in each of the above-mentioned conventional optical marker direction detecting devices, since a usual single image forming lens and a single image position detecting element are used. , In order to secure a desired amount of light used for detection of the sign direction, it is necessary to keep the imaging lens aperture large, so it is difficult to downsize the entire device,
There is a problem that it is difficult to apply it to an object in which the equipment part is limited in space.

Further, it has been proposed to miniaturize the imaging lens and the image position detecting element to reduce the size, but for that reason, the opening of the imaging lens also becomes small. Therefore, the amount of light used for detecting the sign direction is significantly reduced, the level of the output signal (detection signal) from the image position detection element is also lowered, and the signal-to-noise ratio (S / N ratio) is significantly reduced. However, there is a problem that the stability of detection of the sign direction is deteriorated.

The present invention has been made in view of the above-mentioned various problems of the prior art. The object of the present invention is to reduce the size of the entire apparatus and to narrow the equipment portion spatially. An object of the present invention is to provide a sign direction detecting device that can be applied to a limited object.

Another object of the present invention is to prevent the S / N ratio from decreasing even when the entire apparatus is downsized,
It is intended to provide a sign direction detection device that enables stable measurement.

[0011]

In order to achieve the above object, a sign direction detecting device according to the present invention has a plurality of image position detecting elements arranged regularly in a plane, and A plurality of image-forming lenses corresponding to the respective image-position detecting elements are arranged in a close contact state with each other, and substantially parallel incident light is the incident light on each detection surface of the plurality of image-position detecting elements. Are focused on the positions corresponding to the incident direction of.

Further, the sign direction detecting device according to the present invention is
A plurality of image position detection elements are regularly arranged in a plane, and a shielding member having an opening corresponding to each of the plurality of image position detection elements is arranged in close contact with each of the plurality of image position detection elements. However, the substantially parallel incident light is projected onto the respective detection surfaces of the plurality of image position detection elements at positions corresponding to the incident direction of the incident light.

Further, in the sign direction detecting device according to the present invention, the output terminals of the plurality of image position detecting elements are connected in parallel, and the output signals of the plurality of image position detecting elements connected in parallel are added and output. It is something that is done.

[0014]

The individual image position detecting elements are miniaturized and arranged regularly on the plane, and the plurality of miniaturized image forming lenses corresponding to the respective image position detecting elements are arranged in a close contact state. Since the size in the direction of the optical axis can be remarkably reduced, it becomes easy to apply to an object in which the equipment part is limited in space.

Further, the amount of light used for the detection by the plurality of image position detecting elements as a whole is the sum of the amounts of light used by the individual image position detecting elements for the detection. Therefore, the conventional image position detecting device is miniaturized as it is. The total amount of light used for detection does not decrease remarkably unlike the thing. Then, by connecting the output terminals of the plurality of image position detecting elements in parallel, the output signals from the respective image position detecting elements can be added and output, so that the conventional image position detecting device can be downsized as it is. In comparison, the S / N ratio does not decrease.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a sign direction detecting device according to the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic sectional explanatory view of a sign direction detecting device 10 according to a first embodiment of the present invention.

A plurality of image position detecting elements I arranged in a plane
S ₁ , IS ₂ , IS _3, ... IS _n (in the first embodiment, a semiconductor image position detecting element (PSD) described later was used), and a plurality of elements arranged in correspondence therewith. It is configured by combining the imaging lenses L ₁ , L ₂ , L ₃ ... L _n .

At this time, the plurality of imaging lenses L ₁ , so that the substantially parallel incident light rays are focused on the detection surfaces of the plurality of image position detecting elements IS ₁ , IS ₂ , IS ₃ ... IS _n . L ₂ , L ₃
... L _n are arranged at positions substantially separated by the focal length f of the imaging lens from the detection surfaces of the corresponding plurality of image position detection elements IS ₁ , IS ₂ , IS _3, ... IS _n. ing.

That is, a plurality of miniaturized image position detecting elements I
S ₁ , IS ₂ , IS ₃ ... IS _n are regularly arranged on a plane, and a plurality of these image position detecting elements IS ₁ , IS ₂ , IS ₃ are arranged.
Almost close contact with the · · · IS _n, substantially parallel incident light a plurality of the image position detecting element _{IS 1, IS 2, IS 3} ··· IS n
Individual image position detecting elements I so as to focus on the detection surface of
A plurality of imaging lenses L ₁ , L ₂ , L ₃ ... L _n, which are miniaturized corresponding to S ₁ , IS ₂ , IS ₃ ... IS _n , are arranged substantially apart by a focal length f. There is.

Here, the parallel incident light rays are light rays from a light source that is sufficiently distant, such as laser light and sunlight, and the "substantially parallel incident light rays" are as follows.
It means a light beam from a light source located at a position sufficiently distant from the size of the sign direction detecting device 10.

The emitted in time division and its serving labeled to be detected direction existing light source S _a or the light source S _b (light source S _a and the light source S _b, the direction coming of light emitted from the lighted towards the light source,
That is, the direction in which the light source exists is detected as the direction of the sign. ), The light rays emitted from each of the image forming lenses L ₁ , L ₂ , L ₃ ... L _n are incident on the corresponding image position detecting elements IS ₁ , IS ₂ , IS ₃ ... IS _n. Images of the light source S _a are focused on the detection surface of the image I _1a , I _2a , I _3a ...
I _na or the images I _1b , I _2b , I _3b ... I _{nb of the} light source S _b
To generate. Each image position detection element IS ₁ , IS ₂ , IS ₃
..The positions of these images generated on the detection surface of IS _n correspond to the direction of the light source viewed from the nodes of the corresponding imaging lenses L ₁ , L ₂ , L ₃ ... L _n. There is.

Therefore, each image position detecting element IS ₁ , IS ₂ ,
By detecting the position of the image of the light source generated on the detection surface of IS ₃ ... IS _n , the direction of the light source S _a or the light source S _{b as} the marker can be detected.

In FIG. 1, since the light source S _a or the light source S _b as a marker is shown in a position close to the marker direction detecting device 10, the respective imaging lenses L ₁ , L ₂ , L ₃ ...
Direction of incidence of light rays on L _n , that is, each image position detection element I
Although the image forming positions of S ₁ , IS ₂ , IS ₃ ... IS _{n on} the detection surface are drawn to be considerably different, the light source S _a or the light source S _b as a marker is sufficient from the marker direction detecting device 10. In the case where they are present at positions distant from each other, that is, when the incident light beams are substantially parallel to each other, the respective image position detecting elements IS ₁ , IS ₂ , IS
₃ ... Imaged at almost the same position on the detection surface of IS _n ,
Multiple image position detecting elements IS ₁ , IS ₂ , IS ₃ ... IS _n
The output signals (detection signals) from the respective output terminals T _a and T _b of the image position detection elements IS ₁ , IS ₂ and IS
₃ ... IS _n outputs as a signal corresponding to almost the same position.

As shown in FIG. 1, when the light source S _a or the light source S _b as a marker is close to the marker direction detecting device 10, the individual image position detecting elements IS ₁ , IS ₂ , I.
The detection direction in S ₃ ... IS _n is different,
As will be described later, a plurality of image position detection elements IS ₁ , IS ₂ ,
When the output signals from IS ₃ ... IS _n are added and output, an output signal indicating the entire average direction is obtained.

By the way, the individual image position detecting elements IS ₁ ,
The amount of light reaching IS ₂ , IS ₃ ... IS _n decreases proportionally with respect to the apertures of the corresponding individual imaging lenses L ₁ , L ₂ , L ₃ ... L _n . The total amount of light received by the sign direction detecting device 10 according to the first embodiment is determined by the individual imaging lenses L ₁ , L ₂ , L corresponding to the image position detecting elements IS ₁ , IS ₂ , IS ₃ ... IS _{n. 3} ... Since the total amount of light received by the aperture of L _n is, the amount of light used to detect the direction in which a sign exists is extremely small, as in the case where a conventional sign direction detection device is simply downsized. Never falls to.

FIG. 2 is a schematic cross-sectional explanatory view of a sign direction detecting device 20 showing a second embodiment according to the present invention. Individual image position detection in the sign direction detecting device 10 shown in the first embodiment. The image position detecting elements IS ₁ , IS ₂ , IS ₃ ... IS _n are installed so that the output signals of the elements IS ₁ , IS ₂ , IS ₃ ... IS _n can be added and output. The output terminals T _a and T _b are connected in parallel, and the output terminals of the image position detecting elements IS ₁ , IS ₂ , IS ₃ ... IS _n are output by the integrated terminals T _A and T _{B which} are output terminals of the parallel connection. It is configured so that the total sum can be detected.

That is, the imaging lenses L ₁ , L ₂ , L ₃ ... L _n
The photocurrent output signal corresponding to the total amount of light received by the aperture can be used to detect the sign direction.

In this way, each image position detecting element I
By adding and outputting the output signals of S ₁ , IS ₂ , IS ₃ ... IS _n , the level of the output signal used for detecting the direction in which the sign is present is high, that is, the S / N ratio is increased. It becomes possible to increase the detection error, and the detection error can be remarkably reduced, and stable measurement can be performed.

In the state where the marker position is relatively close to the marker direction detecting device 20, the incident light deviates from the parallel to a considerable extent, and it is seen from the individual image position detecting elements IS ₁ , IS ₂ , IS ₃ ... IS _n . The direction of existence of the sign is determined by the image position detecting elements IS ₁ , I.
The image position detection elements IS ₁ , IS ₂ , IS ₃ ... IS _n are slightly different depending on the positions of S ₂ , IS ₃ ... IS _n , as in the second embodiment. When the installed output terminals T _a and T _b are connected in parallel, the average direction of the sign is detected between the image position detection elements IS ₁ , IS ₂ , IS ₃ ... IS _n. It will be.

FIG. 3 is a schematic cross-sectional explanatory view of a sign direction detecting device 30 showing a third embodiment according to the present invention. Each image position detecting element in the sign direction detecting device 30 shown in the first embodiment. IS ₁ , IS ₂ , IS _3, ... IS _n are divided into predetermined groups, and the output terminals T _a and T _{b provided} in each image position detection element are connected in parallel for each divided group. Total terminals T _A1 , T _B1 ... T _An , T for each group
_Bn is configured to be able to detect the sum of the output signals of the image position detecting elements of each group.

According to the sign direction detecting device 30 according to the third embodiment, the average sign direction for each group is detected.

Therefore, when the image position detecting elements IS ₁ , IS ₂ , IS ₃ ... IS _n in the sign direction detecting device 30 are divided into predetermined groups, each image position detecting element I
By dividing for each area of the surface formed by S ₁ , IS ₂ , IS ₃ ... IS _n, it is possible to detect the average direction of the sign in each area, and thus output for each group By processing the signal, it is possible to obtain more sophisticated information such as the distance to the sign as well as the direction of the sign.

That is, as in the third embodiment shown in FIG.
In the case where the image position detecting elements IS ₁ , IS ₂ , IS ₃ ... IS _n are divided into two groups, an upper side and a lower side, the output signals from the respective groups correspond to the average sign direction. It becomes a value, and if the difference between these values is taken, a value almost inversely proportional to the distance to the sign is obtained. Therefore, by dividing each of the image position detecting elements IS ₁ , IS ₂ , IS ₃ ... IS _n into two groups, an upper side group and a lower side group, almost the same as the triangulation by the upper side group and the lower side group. The measurement effect can be obtained.

Here, as the image position detecting element used in the above-mentioned first to third embodiments, a photoelectric layer is provided with a resistance layer and a photocurrent generated by light projected onto the photoelectric film layer. Of the semiconductor image position detecting element (Position Sensitivity) which is configured to calculate the position of the light on the photoelectric film layer by detecting the output current output from the output electrodes on both ends of the resistance layer and calculating the output currents.
ve Device: Hereinafter referred to as “PSD”. ) And a split type semiconductor image position detecting element (split type photoelectric sensor) are widely used.

FIG. 4 is a cross-sectional view showing a schematic structure of a one-dimensional PSD. A P-type resistance layer P and an N-type resistance layer N, which are uniform resistance layers, are superposed on both surfaces of an insulating layer I of a high resistance semiconductor. P-type resistive layer P pair of electrodes T _a taking out an output signal (output current) across the, provided with a T _b, is intended to obtain the photoelectric effect is provided a common electrode C in N-type resistive layer N.

In the above-mentioned one-dimensional PSD, when a light beam is projected from the light source S _{n on} the upper surface of the P-type resistance layer, the photocurrent generated by the projected light beam is transmitted through the resistance layer P, and the light incident position and the electrode T _a, divided current values i _a in accordance with the resistance ratio of the resistance layer P between T _b, detects the i _b, electrode T _a, the output current is outputted from the T _b I _a, I _b It is possible to detect the position of the optical image on the resistance layer P and the like irrespective of the light intensity and its change by detecting the difference between the two and calculating them.

Further, FIG. 5 shows a two-division type photoelectric sensor, in which electrodes T _a and T _b are provided.

Furthermore, FIG. 6 shows a four-division type photoelectric sensor, which is provided with electrodes T _a , T _b , T _c and T _d .

When the PSD or the split type photoelectric sensor is regularly arranged in a plane as the image position detecting element of the present invention to manufacture the marker direction detecting device of the present invention,
Instead of regularly arranging the individually manufactured PSDs or divided photoelectric sensors on a plane, a plurality of PSDs or divided photoelectric sensors are regularly arranged on the same semiconductor substrate by integrated circuit technology. It is possible to manufacture a sign direction detection device.

When a PSD or a split type photoelectric sensor is adopted as an image position detecting element and the output signals from the output terminals of a plurality of image position detecting elements are added and output, FIG. 7 and FIG. As shown in FIG. 8, it suffices to simply connect the output terminals of the corresponding image position detecting elements in parallel by conductors.

That is, a plurality of PSs are formed on the same semiconductor substrate.
The D or split type photoelectric sensor is arranged with a predetermined gap maintained, and a conductor pattern is generated in the gap, and each PS is
Corresponding positive / negative output electrodes t of D and split photoelectric sensor
_x, a t _y can be constituted by connecting in parallel to the conductor pattern.

FIG. 7 shows a case where a one-dimensional sign direction detecting device adopting a one-dimensional PSD is used.
FIG. 8 shows a case of a two-dimensional sign direction detecting device that uses a two-dimensional PSD and has a two-dimensional sign detection direction.

On the other hand, in order to construct an imaging lens which is arranged in close contact with the image position detecting element so that substantially parallel incident light rays are focused on the detection surface of the image position detecting element, You can do it like this.

For example, FIGS. 9 and 10 show an example of a sign direction detecting device in which the sign detection direction is one-dimensional, and a predetermined length as a cylindrical lens is provided on the upper surface of a one-dimensional PSD as an image position detecting element. The uniform cylindrical glass fiber rod 40 cut into pieces or the lenses formed in the shape of a semi-cylindrical glass fiber or the like may be regularly arranged in a single layer, and the periphery thereof may be adhesively fixed with a resin or the like.

FIG. 11 shows an example of a sign direction detection device in which the sign detection direction is two-dimensional.
A uniform cylindrical glass fiber rod 40 cut into a predetermined length may be arranged vertically in two layers, and the periphery thereof may be adhesively fixed with a resin or the like.

FIG. 12 also shows an example of a sign direction detection device in which the sign detection direction is two-dimensional.
The spherical lens groups are regularly arranged and arranged in correspondence with the arrangement of the two-dimensional PSD, and they are bonded together with a resin or the like.

Further, as the imaging lens according to the present invention,
The gradient index type is not limited to the ones described above, and is manufactured by diffusing or injecting another material into a flat glass material so that the refractive index partially changes. Micro lenses of can also be used.

As the image forming lens, a uniform cylindrical glass fiber rod 40 cut into a predetermined length as the above-mentioned cylindrical lens, a lens or spherical lens group shaped like a kamaboko, a gradient index is used. Appropriate ones may be selected from (refractive index gradient) type microlenses or those having a configuration other than the above depending on the design of the marker direction detection device.

Further, in both the sign direction detecting device having a one-dimensional sign detecting direction and the sign direction detecting device having a two-dimensional sign detecting direction, an image forming lens corresponding to the image position detecting element is formed by an integrated circuit manufacturing technique. It is possible to superimpose it on the image position detection element and integrally manufacture it. For example, a photoresist (PMM) widely used for transferring integrated circuit patterns is used.
A) and the like) can form a minute lens as an imaging lens.

That is, as shown in FIG. 13, after a predetermined PSD is regularly arranged and manufactured on a substrate such as silicon, a PMMA film is applied, and a mask pattern corresponding to the imaging lens group is printed. The PMMA film itself may be used as an imaging lens by developing it so that the surface becomes spherical or cylindrical.

It is also possible to arrange a shielding member having an aperture (opening) corresponding to each image position detecting element. However, as compared with the imaging lens, there is a problem that the amount of light received by the image position detection element is reduced.
This configuration is effective when a sufficient amount of light from the light source can be obtained.

[0053]

Since the present invention is constructed as described above, it has the following effects.

The individual image position detecting elements are miniaturized and regularly arranged in a plane, and a plurality of miniaturized imaging lenses corresponding to the respective image position detecting elements are arranged in close contact with each other. Since the size in the direction of the optical axis can be remarkably reduced, it becomes easy to apply to an object in which the equipment part is limited in space.

Further, the amount of light used by the individual image position detecting elements for detection as a whole is the sum of the amounts of light used by the individual image position detecting elements for detection, so that the conventional image position detecting device can be downsized as it is. In this case, it is possible to prevent the amount of light used for detection from being significantly reduced.

Furthermore, by connecting the output terminals of the respective image position detecting elements in parallel, the output signals from the respective image position detecting elements can be added and output, so that the conventional image position detecting device can be downsized as it is. S / N ratio does not decrease as compared with the above, and stable measurement with less error can be performed.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional explanatory view of a sign direction detecting device according to a first embodiment of the present invention.

FIG. 2 is a schematic sectional explanatory view of a sign direction detecting device according to a second embodiment of the present invention.

FIG. 3 is a schematic sectional explanatory view of a sign direction detecting device according to a third embodiment of the present invention.

FIG. 4 is a cross-sectional explanatory view showing a schematic configuration of a one-dimensional PSD.

FIG. 5 is an explanatory diagram showing a two-division photoelectric sensor.

FIG. 6 is an explanatory diagram showing a four-division photoelectric sensor.

FIG. 7 is a connection state explanatory diagram of a sign direction detection device according to the present invention in which a sign detection direction is one-dimensional when a one-dimensional PSD is adopted as an image position detection element.

FIG. 8 is a connection state explanatory diagram of a sign direction detection device according to the present invention in which a sign detection direction is two-dimensional when a two-dimensional PSD is adopted as an image position detection element.

FIG. 9 is a perspective view showing an arrangement of lenses by a glass fiber of a marker direction detection device according to the present invention in which a marker detection direction is one-dimensional.

FIG. 10 is a perspective view showing the arrangement of a semi-cylindrical lens of the marker direction detection device according to the present invention in which the marker detection direction is one-dimensional.

FIG. 11 is a perspective view showing an arrangement of lenses by a glass fiber of a sign direction detection device according to the present invention in which a sign detection direction is two-dimensional.

FIG. 12 is a perspective view showing a configuration in which spherical lenses of a marker direction detection device according to the present invention in which a marker detection direction is two-dimensional are regularly arranged.

FIG. 13 is a cross-sectional explanatory view when a minute lens formed of photoresist itself is used as an imaging lens.

FIG. 14 is an explanatory diagram showing the basic principle of a conventional optical marker direction detection device.

[Explanation of symbols]

10, 20, 30 Marking direction detecting devices IS ₁ , IS ₂ , IS ₃ ... IS _n image position detecting elements L ₁ , L ₂ , L ₃ ... L _n imaging lenses S _a , S _b light source T _a , T _b output terminals T _A , T _B , general terminals T _A1 , T _B1 ... T _An , T _Bn general terminals

Claims (8)

(57) [Claims] 1. A plurality of image position detecting elements are regularly arranged in a plane, and a plurality of imaging lenses corresponding to each of the plurality of image position detecting elements are substantially in close contact with the plurality of image position detecting elements. In the marker direction detection device, the substantially parallel incident light is focused on a position corresponding to the incident direction of the incident light on each detection surface of the plurality of image position detection elements. Output terminals of a plurality of image position detection elements are connected in parallel, and an output signal from the output terminals of the plurality of image position detection elements connected in parallel is added and output by a general terminal which is an output terminal of the parallel connection. Characteristic sign direction detection device. 2. A plurality of image position detecting elements are regularly arranged in a plane, and a plurality of imaging lenses corresponding to each of the plurality of image position detecting elements are substantially in close contact with the plurality of image position detecting elements. In the marker direction detection device, the substantially parallel incident light is focused on a position corresponding to the incident direction of the incident light on each detection surface of the plurality of image position detection elements. Divide multiple image position detection elements into multiple groups,
The output terminals of the plurality of image position detection elements divided into the plurality of groups are connected in parallel for each group, and are connected in parallel by the total terminal for each group that is the output terminal of the parallel connection for each group. A sign direction detecting device, wherein the output signals from the output terminals of the plurality of image position detecting elements for each group are added and output for each of the plurality of groups. 3. The plurality of image position detecting elements are one-dimensional image position detecting elements, and the plurality of imaging lenses are cylindrical lenses cut into a predetermined length or lenses shaped like a kamaboko. The sign direction detection device according to claim 1. 4. The plurality of image position detection elements are two-dimensional image position detection elements, and the plurality of imaging lenses are spherical lenses or cylindrical surface lenses intersecting two layers above and below. The sign direction detection device according to any one of 2 above. 5. A plurality of image position detecting elements are regularly arranged in a plane, and a shielding member having an opening corresponding to each of the plurality of image position detecting elements is closely attached to the plurality of image position detecting elements. A marker direction detection device which is arranged in such a state that substantially parallel incident light is projected on positions on the respective detection surfaces of the plurality of image position detection elements corresponding to the incident direction of the incident light. , Output terminals of the plurality of image position detecting elements are connected in parallel, and output signals from the output terminals of the plurality of image position detecting elements connected in parallel are added and output by a general terminal which is an output terminal of the parallel connection. A sign direction detecting device characterized by the above. 6. A plurality of image position detecting elements are regularly arranged in a plane, and a shielding member having an opening corresponding to each of the plurality of image position detecting elements is brought into close contact with the plurality of image position detecting elements. A marker direction detection device which is arranged in such a state that substantially parallel incident light is projected on positions on the respective detection surfaces of the plurality of image position detection elements corresponding to the incident direction of the incident light. , Dividing the plurality of image position detection elements into a plurality of groups,
The output terminals of the plurality of image position detection elements divided into the plurality of groups are connected in parallel for each group, and are connected in parallel by the total terminal for each group that is the output terminal of the parallel connection for each group. A sign direction detecting device, wherein the output signals from the output terminals of the plurality of image position detecting elements for each group are added and output for each of the plurality of groups. 7. The marker direction detecting device according to claim 1, wherein the plurality of image position detecting elements are semiconductor image position detecting elements. 8. The marker direction detection device according to claim 1, wherein the plurality of image position detection elements are split semiconductor image position detection elements.