JP2002014763A - Position measuring instrument and position input device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a position measuring instrument which has good operability and is inexpensive and can accurately measure a position. SOLUTION: Two photodetecting elements 2 and 3 are provided in one measurement unit. The photodetection surfaces of the photodetecting elements 2 and 3 have their center axes on the straight line nearly perpendicular to a two-dimensional plane as an object to be measured and are arranged one over the other while having an opening angle of 90 deg.. Two photodetecting elements 4 and 5 of another measurement unit are the same. The photodetecting elements 2 to 5 photodetect the light from a light source 1 and outputs photodetection quantities. The photodetecting elements 2 and 3 or 4 and 5 in the measurement unit have their center axes crossed and then errors of distances from the light source 1 cancel each other, so that a computation part 6 can accurately compute the position of the light source 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for measuring a position of a pointer or the like.

[0002]

2. Description of the Related Art Conventionally, a pointing device in a personal computer or the like includes a mouse, a trackball, a joystick, and various sheet-like devices. According to reports on these operability, mice are most superior in terms of speed and accuracy in positioning. Therefore, even in a mobile environment, it is necessary to add a mouse when giving priority to operability. However, in the future, it is expected that the mobile environment to be used will be more diversified, and the necessity of inputting characters and pictures will be increased. In response to this, there has been a demand for the development of devices other than a mouse that can perform pointing with better operability.

Some devices have been invented to satisfy these requirements. For example, the position on a plane is measured using a dedicated tablet such as a position input tablet manufactured by Wacom, or a two-dimensional semiconductor sensor (PS) is described in Japanese Utility Model Laid-Open No. 5-25525.
D) and a technique for measuring a position on a plane using a lens. In the technology using a tablet, a tablet having the same area as the display screen must be installed separately from the display screen, and thus is not suitable for applications requiring a small size such as a mobile device. Further, in the technique using the PSD, the PSD is expensive, and therefore cannot be used as a pointing device of a mobile device whose cost is remarkably reduced.

Further, as described in Japanese Patent Application Laid-Open No. 10-9812, light from an input device is measured with an apparatus in which photoelectric conversion elements (PDs) are combined in an L-shape, so that the size and the size are reduced. There is a technology for measuring the position of a light source at a price. FIG. 21 is an explanatory diagram of an example of a conventional position measuring device. In the figure, 41 to 44 are photoelectric conversion elements, and 45 is a light source. In this example, the photoelectric conversion elements 41 and 42 and the photoelectric conversion elements 43 and 44 are combined and arranged in an L-shape to be opposed to each other. A light source 45 is provided in an input device such as a pen, and light from the light source 45 is received by each of the photoelectric conversion elements 41 to 44. The light source 4 is calculated based on the received light amount according to a predetermined calculation formula.
5 is calculated.

[0005] However, there is a problem that the distribution of the amount of light incident on each of the photoelectric conversion elements 41 to 44 changes due to a change in the position of the input device, and a large error occurs in the calculation of the position. For example, light incident on the photoelectric conversion element 41 in FIG. 21 is light in a region indicated by l _1x . The light in this area is applied to the light receiving surface of the photoelectric conversion element 41 without much change in distance. However, the light in the region indicated by l _1y incident on the photoelectric conversion element 42 has a significantly different distance at both ends of the photoelectric conversion element 2, and thus the light intensity differs depending on the light receiving portion. Further, since the photoelectric conversion element 41 and the photoelectric conversion element 42 are in contact with each other on one side, the distance to the light source 45 with respect to this side is equal, but the distance from the opposing side to the light source 45 is greatly different. Become. Since the amount of light attenuates in proportion to the square of the distance from the light source, such a difference in distance has a large effect on subsequent calculations, causing an error. It is conceivable to correct such an error at the time of position calculation. However, if the error is large, the error cannot be corrected.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and provides a position measuring apparatus which has good operability, is inexpensive, and can accurately measure a position. It is an object of the present invention to provide a position input device using such a position measuring device.

[0007]

According to the present invention, a plurality of measuring units are provided and a plurality of light receiving plane regions for measuring the amount of received light are provided in each of the measuring units, and the centers of the light receiving plane regions are the same or coincide with each other. A plurality of light receiving plane regions are set such that the connecting straight line is substantially orthogonal to the two-dimensional plane to be measured. As a result, in each of the light receiving plane regions, the right and left portions across the center cancel out the intensity of the light amount, so that a difference in the distance from the light source hardly appears in any of the light receiving plane regions in the measurement unit. Therefore, the position can be accurately measured without causing a large measurement error as in the related art.

Preferably, the plurality of light receiving plane regions are provided substantially perpendicular to the two-dimensional plane of the object to be measured, and are arranged at right angles to each other or at a predetermined angle. Usually, the light receiving element is arranged in the light receiving plane area, but the optical path may be changed by, for example, a half mirror or a mirror. In addition, the amount of light in a plurality of light receiving plane regions may be acquired by using one light receiving element and rotating or swinging the light receiving element, or rotating or swinging a mirror in the optical path.

When light-receiving elements are arranged in each light-receiving plane area, the light-receiving elements are superposed and arranged in a direction perpendicular to the two-dimensional plane. The light receiving elements corresponding to the light receiving plane areas of the different light receiving plane area groups may be superposed. At this time, the light receiving amounts output from the light receiving elements in the light receiving plane region belonging to the same light receiving plane group may be averaged. Thereby, an error in a direction perpendicular to the two-dimensional plane can be reduced. Further, with respect to the measurement units arranged close to each other, the light receiving elements arranged at the same height may be overlapped so as not to face the same direction, thereby reducing an error due to a change in the amount of light in a direction perpendicular to the two-dimensional plane. be able to.

In performing the position calculation, two of the plurality of measurement units that are not close to each other are set as a measurement unit pair, and each light receiving plane output from each measurement unit of the measurement unit pair is set. The position of the light source can be calculated using the received light amount for each area. If a plurality of measurement unit pairs can be set, the values calculated by each measurement unit pair may be averaged.

In order to prevent the influence of light reflection between the measurement units, a light shielding means may be provided therebetween, or a cover for covering the measurement units may be provided.

Further, the light source can be driven, for example, by blinking the light source, and can perform a process for more accurate position measurement, such as measuring the influence of ambient light when the lamp is turned off. In addition to a light source that emits light by itself, a diffuse reflection member, a fluorescent member, or the like may be used, and light emitted from outside may be used. Alternatively, a reflecting member may be provided on a two-dimensional plane, and the reflected light may be incident on the measurement unit together with the direct light from the light source to increase the amount of incident light.

Even in the above-described configuration, an error occurs in the measured position due to a difference between each light receiving element and an assembly error. In order to correct such an error, for example, the gain and the parameters at the time of position calculation can be adjusted so that the same amount of received light is obtained when the same amount of light is applied to each light receiving plane area. In addition, in order to correct an error between the respective light receiving plane regions, four light receiving plane regions or two light receiving plane region groups in the measurement unit are centered on the center axis.
The light source is arranged on a straight line at an angle of 5 degrees, and at this time, the gain and the parameters at the time of position calculation are adjusted so that the amount of light received in the two light receiving plane regions or the two light receiving plane region groups is substantially the same. it can. Furthermore, when the light source is installed at one or more specific positions where the coordinates are known, the position of the light source and the true position obtained by calculating based on the amount of light received from the measurement unit at the position The position of the light source can be corrected using a correction table that associates

The position measuring apparatus according to the present invention is not limited to a position on a two-dimensional plane, but may be, for example, a second two-dimensional plane substantially perpendicular to the two-dimensional plane.
By setting a two-dimensional plane and providing one or more measurement units with respect to the second two-dimensional plane, it is possible to measure the position of the light source in a three-dimensional space.

A position input device can be constructed by using such a position measuring device and providing one or more light sources on the position indicating member. The position input device may be provided with a plate provided in a range where position measurement is possible. If the plate is provided with a display function, the measured position of the position indicating member can be displayed as it is.
It is also possible to write on the displayed image in accordance with the position change. The plate may be provided with a display or a specific shape so that an appropriate orientation for use or an orientation for assembling the position measuring device to the plate is known.

[0016]

FIG. 1 is a perspective view showing a first embodiment of a position measuring apparatus according to the present invention. In the figure, 1 is a light source, 2 to 5 are light receiving elements, and 6 is a calculation unit. In this example, a measurement unit including the light receiving element 2 and the light receiving element 3
Measurement unit 2 composed of light receiving element 4 and light receiving element 5
An example in which three measurement units are arranged is shown. The light receiving elements 2 and 3 are arranged in a two-dimensional plane (x
When viewed from above (in the z-direction) from the top (in the z-direction), they are superposed at an angle of about 90 degrees so that their respective central axes coincide. The same applies to the light receiving elements 4 and 5. In this example, the light receiving surfaces of the light receiving elements 2 to 5 are light receiving plane regions.

The light receiving elements 2 to 5 can be constituted by, for example, photodiodes. These light receiving elements 2
5 is irradiated with diffused light emitted from the light source 1,
Electric signals indicating the amount of received light are output from the light receiving elements 2 to 5.

By providing the light receiving surfaces of the respective light receiving elements 2 to 5 so as to be perpendicular to the two-dimensional plane for performing the position measurement, light from the light source 1 can be satisfactorily received. It is not limited. Even when the light receiving surfaces of the light receiving elements 2 to 5 are not perpendicular to the two-dimensional plane, the amount of received light decreases, but the position can be measured in the same manner. At this time, for the light receiving elements in the same measuring unit, the straight line connecting the centers may be perpendicular to the two-dimensional plane.

The light source 1 only needs to be capable of emitting diffused light, and it is desirable that the light amount to each of the light receiving elements 2 to 5 does not change even if the light is directed in different directions at the same position. By causing the light source to blink and emit light, the influence of disturbance light (environmental light) can be removed. That is, disturbance light can be removed by subtracting the output when the light source 1 is turned off from the output when the light source 1 is turned on in the output of each of the light receiving elements 2 to 5. The configuration of a circuit that removes disturbance light by reducing the points in this way is described in, for example, Transistor Technology, Aug. 1990, p.
A general configuration such as the circuit shown in FIG.

The calculator 6 calculates the ratio of the amount of received light between the light receiving elements in each measurement unit, that is, the ratio of the amount of received light between the light receiving elements 2 and 3, and the ratio of the amount of received light between the light receiving elements 4 and 5. Is used to calculate the position of the light source on the two-dimensional plane.
This calculation method will be described below.

FIG. 2 is a view for explaining the principle of position measurement in the position measuring apparatus of the present invention. Here, in order to simplify the description, two light receiving elements are overlapped in one measurement unit, and the light receiving area of each light receiving element and the length as viewed from above are the same. The angle between the light receiving elements is 90 degrees, and one is arranged so as to be parallel to the direction in which the measuring units are arranged, and the other is arranged so as to be at a right angle thereto. Two such measurement units are provided. At this time, the intersection of the two light receiving elements 2 and 3 of the left measuring unit in the figure is set as the origin of coordinates (0, 0), and the coordinate of the intersection of the two light receiving elements 4 and 5 of the right measuring unit in the figure is used. Is (d, 0). The coordinates of the light source are (x, y).

Each of the light receiving elements 2 to 5 is bisected around (0, 0) and (d, 0), and the length of the bisected is L. Consider a right triangle having this length L as the hypotenuse and a part of a straight line connecting the center (0, 0) or (d, 0) and the light source 1 as one side, and the length of the other side of this right triangle To Llhi, Llho, Llpi, Llpo,
Lrhi, Lrho, Lrpi, Lrpo. Further, the electric signals corresponding to the amounts of light received from the respective light receiving elements include the output Vlh = Vlhi + Vlho of the light receiving element 2, the output Vlp = Vlpi + Vlpo of the light receiving element 3, the output Vrh = Vrhi + Vrho of the light receiving element 4, and the output of the light receiving element 5. Vrp = Vrpi + Vrpo.

However, regarding these names, i and o
For the symbols with, i and o are omitted in the following calculation. This means that for symbols with i and o,
This is because the calculation contents are exactly the same. As described above, when the light receiving element is divided into two equal parts, the calculated output ratio is equal to the output ratio when the light receiving element is not bisected. For example, Vlhi / Vlpi = Vlho / Vlpo = Vlh
/ Vlp. Therefore, the coordinates (x,
The ratio of the output of the light receiving element used in obtaining y) is a value obtained when the light is divided into two equal parts (for example, Vlhi / Vlpi, Vl
ho / Vlpo) can be calculated and handled as an output ratio (for example, Vlh / Vlp) in a state where the output is not bisected as it is.

First, in the two light receiving elements provided in each of the measuring units, four right-angled triangles each having an equally-lengthed length L as a hypotenuse are congruent. That is, a right triangle with a base of Llhi, a right triangle with a base of Llpi, a right triangle with a base of Llho, and a right triangle with a base of Llpo are congruent, and a right triangle with a base of Lrhi and a right triangle with a base of Lrpi and a base with The right-angled triangle of Lrho and the right-angled triangle of the base Lrpo are congruent. Also,
The right triangle and the right triangle each having a hypotenuse defined by a line segment connecting the intersection of the two light receiving elements and the light source are similar to each other. From these, the following equations hold. Llp / Llh = x / y Expression 1 Lrp / Lrh = (d−x) / y Expression 2

On the other hand, since the output of each of the light receiving elements 2 to 5 is proportional to the base of the right triangle having the light receiving element as the hypotenuse, the following equation is established. Llp / Llh = Vlp / Vlh Expression 3 Lrp / Lrh = Vrp / Vrh Expression 4

From equations 1, 2, 3, and 4, the following equation is established. (Vrp / Vrh) / (Vlp / Vlh) = (Lrp / Lrh) / (Llp / Llh) = ((d−x) / y) / (x / y) = d / x−1 Equation 5

From Expression 5, an expression relating to x is obtained. x = d · (1 / (1+ (Vrp / Vrh) / (Vlp / Vlh))) = d · (Vlp / Vlh) / ((Vrp / Vrh) + (Vlp / Vlh)) Equation 6

By substituting equation (6) into equations (1) and (3), an equation for y is obtained. y = (Vlh / Vlp) x = (Vlh / Vlp) · d · (VIp / Vlh) / ((Vrp / Vrh) + (VIp / VIh)) = d / ((Vrp / Vrh) + (Vlp / Vlh) )) Equation 7 In this manner, the coordinates (x, y) of the light source 1 can be obtained.

In the above calculation, Vlhi / Vlpi = V
lho / Vlpo = Vlh / Vlp, Vrhi / Vrp
i = Vrho / Vrpo = Vrh / Vrp.
However, as described above, due to the difference in the distance from the light source 1, strictly speaking, Llpi / Llhi = Vlpi / Vlh
i, Llpo / Llho = Vlpo / Vlho, Lrp
i / Lrhi = Vrpi / Vrhi, Lrpo / Lrh
Since o does not satisfy Vrpo / Vrho, an error is included.

However, the light receiving elements 2 and 3 and the light receiving elements 4
5 intersect at the center (0, 0) or (d, 0), respectively, and have opposite characteristics in distance on both sides.
That is, as can be understood with reference to FIG.
For L3, Llpi is closer to the light source 1 and Llhi is farther from the light source 1 in the bases Llpi and Llhi of the right triangle. Therefore, Vlhi tends to be small and Vlpi tends to be large. However, the base Llpo of the right triangle
And Llho, Llpo is farther from light source 1 and Llpo
ho is closer to the light source 1. Therefore, Vlho tends to be large and Vlpo tends to be small. Output Vlh of light receiving element 2 = Vlhi + Vlho, output Vl of light receiving element 3
When p = Vlpi + Vlpo is considered, each term includes a term having a smaller tendency and a term having a larger tendency, and both tendencies cancel each other. Therefore, as a result, if the coordinates of the light source 1 are calculated by the equations (6) and (7), the coordinates can be almost accurately obtained without including the error due to the difference in the distance to the light source as in the related art.

In the above example, the case where the number of measurement units is two is shown. However, in order to improve measurement accuracy, the number of measurement units having the same configuration may be increased to three or more. In that case, two measurement units are used as a measurement unit pair, the position of the light source 1 is calculated for each measurement unit pair, and the average value of the position of the light source 1 calculated from the plurality of measurement unit pairs is obtained. What is necessary is just to calculate the position of the light source 1.

FIG. 3 is a perspective view showing a second embodiment of the position measuring device of the present invention. In the figure, the same parts as those in FIG. Reference numerals 7 and 8 are light receiving elements. In this example, an example is shown in which the number of light receiving elements overlapped in one measurement unit is three or more. In this case, all the light receiving elements in one measuring unit are installed so that the angles of the light receiving elements intersect at 90 degrees. Thereby, the light receiving surface of the light receiving element (light receiving plane area)
Are divided into two groups. And as the order of stacking,
Light receiving elements having light receiving surfaces included in each group are alternately stacked. In the example shown in FIG. 3, the light receiving element 2 and the light receiving element 7 constitute one group, and the light receiving element 3 constitutes another group. Then, the groups are stacked alternately, that is, the light receiving element 7, the light receiving element 3, and the light receiving element 2 are stacked in this order. Similarly, the light receiving element 4 and the light receiving element 8 form one group, and the light receiving element 5 forms another group. The groups are alternately arranged, that is, the light receiving element 8, the light receiving element 5, and the light receiving element 4 are stacked in this order. Two measurement units having such a configuration are provided.

When calculating the position of the light source 1 in the configuration shown in FIG. 3, it is preferable to calculate the output of the light receiving elements belonging to the same group in one measuring unit using an average value. Thereby, it is possible to correct the light amount difference in the direction (vertical direction) orthogonal to the two-dimensional plane of the measurement target. That is, in the configuration shown in FIG.
And 3, and the light receiving elements 4 and 5 are arranged vertically,
The distance to the light source 1 is slightly different. However, the light receiving elements 2 and 7 and the light receiving element 4 are configured as shown in FIG.
By taking the average of and 8, the same value as in the case where light is received at the same position as the light receiving elements 3 and 5 can be obtained as the vertical position. As a result, errors in the vertical direction can be reduced. Note that the method of calculating the position coordinates of the light source 1 after calculating the average value for each group is the same as in the above-described first embodiment, and the outputs Vlh and Vlp of the light receiving elements in Expressions 6 and 7 described above. , Vrh, Vrp
May be substituted for the average value of each group.

FIG. 4 is a perspective view showing a third embodiment of the position measuring apparatus according to the present invention. In the figure, the same parts as those in FIG. Reference numerals 9 and 10 are light receiving elements. In this example, three or more measurement units described in the first embodiment are installed, and two of them are arranged close to each other. Regarding the two measuring units arranged close to each other, the light receiving elements are overlapped so that the light receiving elements arranged at the same height do not point in the same direction with respect to the two light receiving elements that are installed in each case. ing. In the example shown in FIG. 4, the light receiving elements 2 and 3
Constitute one measurement unit, and a measurement unit including the light receiving element 9 and the light receiving element 10 is arranged close to each other.
At this time, the light receiving elements 2 and 10 are arranged such that the light receiving surfaces of the light receiving elements 10 and 10 are parallel, and the light receiving surfaces of the light receiving elements 3 and 9 are parallel. Thereby, the light receiving elements 2 and 9 and the light receiving elements 3 and 10 arranged at the same height have different directions.

When the position of the light source 1 is calculated in the configuration shown in FIG. 4, the output of the light receiving elements belonging to the group is defined as a group of light receiving elements having a parallel light receiving surface in a plurality of measurement units arranged close to each other. Should be calculated using the average value. Thereby, it is possible to correct the light amount difference in the direction (vertical direction) orthogonal to the two-dimensional plane of the measurement target. In the example shown in FIG. 4, the average values of the outputs of the light receiving elements 2 and 10 and the outputs of the light receiving elements 3 and 9 are calculated. As a result, the outputs from the light receiving elements having different heights are averaged, and errors in the height direction can be reduced. Then, this average value is used as the output Vl of the light receiving element in the above equations (6) and (7).
By substituting into h, Vlp, Vrh, Vrp,
As in the above-described first embodiment, the position coordinates of the light source 1 can be accurately calculated.

The coordinates of the light source 1 are calculated using a measuring unit composed of the light receiving elements 4 and 5 and a measuring unit composed of the light receiving elements 2 and 3 as a measuring unit pair. Measuring unit and light receiving element 9.1
The coordinates of the light source 1 may be calculated using the measurement unit constituted by 0 as a measurement unit pair, and the average of both may be calculated.
In this case, the measurement units that are close to each other are not formed as a measurement unit pair, and the coordinates of the light source 1 may be calculated by configuring the measurement unit pairs that are not close to each other.

FIG. 5 is a plan view showing a fourth embodiment of the position measuring device according to the present invention. In the figure, the same parts as those in FIG. 11 is a light-shielding plate. When a plurality of measurement units are arranged, light incident on a certain measurement unit may be reflected on the surface of a light receiving element in the measurement unit and incident on another measurement unit. When such reflection occurs, the amount of light received by the light receiving element that has received the reflected light increases, and an error occurs in the position of the light source 1. In order to prevent such reflected light from entering another measurement unit, in this example, a light shielding plate 11 is provided between the measurement units.

Of course, the number of the light-shielding plates 11 is not limited to one between each measuring unit, and a plurality of light-shielding plates 11 may be provided, for example, one light-shielding plate may be arranged close to both measuring units. It is desired that the shadow of the light shielding plate 11 does not reach the measurement unit. In addition, the cover is not limited to the plate shape as shown in FIG. 5 and, for example, a cover that covers the measurement unit may be provided. The cover may be configured such that a portion where the light from the light source 1 is incident is made of a transparent body, or is formed by removing the portion, so as not to prevent the light from entering the measurement unit. Further, the cover may have any shape, such as covering the entire measurement unit and being formed in a cylindrical shape. In addition, various light-shielding means can be provided. Further, when reflected light enters between the light receiving elements in the measurement unit, another light blocking means for blocking the reflected light may be provided.

FIG. 6 is a plan view showing an example of one measuring unit in the fifth embodiment of the position measuring device of the present invention. In the figure, the same parts as those in FIG. In each of the above embodiments, an example has been described in which the plurality of light receiving elements in one measurement unit are arranged so as to be orthogonal at the center. In the fifth embodiment, a case where the angle at which the light receiving elements intersect is other than 90 degrees will be described. As an example, only the measurement unit on the left side in FIG. 2 described above, that is, only the measurement unit including the light receiving elements 2 and 3 is shown.

In FIG. 6, the light receiving element 2 is arranged at a position rotated by an angle Slh from the x axis about the center thereof. The light receiving element 3 has an angle S from the y axis with its center as an axis.
It is arranged at a position rotated by lp. in this way,
A plurality of measurement units each having a light receiving element disposed at a position rotated about the center of each light receiving element are arranged, and the position of the light source 1 is calculated based on the amount of light received from each light receiving element.

FIGS. 7 and 8 are explanatory diagrams of an example of a method of calculating the position of the light source in the fifth embodiment of the position measuring device of the present invention. FIG. 6 shows a process of calculating the position of the light source 1 when the two light receiving elements 2 and 3 intersect at an angle other than 90 degrees. The angle formed by the light receiving element 2 with the x axis is Slh, and the angle formed by the light receiving element 3 with the y axis is Slp.
In both cases, the direction in which the projected area from the light source increases is defined as positive (+). In this example, both the angle Slh and the angle Slp are positive directions. The angle between the x axis and the light source is S
1h + Slp.

First, as a first stage, consider a case where the light receiving element 2 is rotated by Slh + Slp in FIG. Vlp / Vlh = Llp / Llh = L · (sin (90−Sl)) / L · (sin (Sl + (Slh + Slp))) = cosSl / (sinSl · cos (Slh + Slp) + cosSl · sin (Slh + Slp)) 1 / (tanSl · cos (Slh + Slp) + sin (Slh + Slp)) Equation 8

From equation 8, tanSl = (Vlp / Vlh-sin (Slh + Slp)) / cos (Slh + Slp) = (Vlp / Vlh) / cos (Slh + Slp) -tan (Slh + Slp) From equation 9, Sl = Arctan ((Vlp / Vlh) / cos (Slh + Slp) -tan (Slh + Slp)) Equation 10

Next, as a second stage, in FIG.
When both the light receiving element 2 and the light receiving element 3 in the stage state are rotated by the angle Slp, the angle that the light receiving element 2 forms with the x-axis is Slh, and the angle that the light receiving element 3 forms with the y-axis is Slp, which is the desired state. Become. At this time, the angle Sl + Slp between the x-axis and the light source can be expressed as follows using Expression 10. Sl + Slp = arctan ((Vlp / VIh) / cos (Slh + Slp) -tan (Slh + Slp)) + Slp Equation 11

Using equation 11, tan (S + Slp) can be expressed as follows. tan (Sl + Slp) = tan (arctan ((Vlp / Vlh) / cos (Slh + Slp) -tan (Slh + Slp)) + Slp) = (Vlh / Vlp-sin (Slh + Slp) + cos (Slh + Slp) t (t)) (Cos (Slh + Slp)-(Vlh / Vlp) tanSlp + sin (Slh + Slp) tanSlp)) Equation 12

Similarly, consider the right measuring unit in FIG. Also in the light receiving elements 4 and 5 constituting this measuring unit, the angle formed between the x axis and the light source is Sr +
Assuming Srp, the following equation is obtained. tan (Sr + Srp) = tan (arctan ((Vrp / Vrh) / cos (Srh + Srp) -tan (Srh + Srp)) + Srp) = (Vrh / Vrp-sin (Srh + Srp) + cos (Srh / Srp) .tan) (Cos (Srh + Srp)-(Vrh / Vrp) .tanSrp + sin (Srh + Srp) .tanSrp)) Equation 13

In the equations (12) and (13), tan (Sl + Sl
p) and tan (Sr + Srp) correspond to the angle of a straight line from the intersection of the light receiving elements in each measurement unit to the light source. That is, these are Vlh of Equation 6 when the angle between the light receiving elements in each measurement unit is 90 degrees.
/ Vlp and Vrh / Vrp in equation (7). Therefore, the following equations are obtained by substituting Equations 12 and 13 into Equations 6 and 7. x = d. ((cos (Slh + Slp)-(Vlh / Vlp) .tanSlp + sin (Slh + Slp) .tanSlp) / (Vlh / Vlp-sin (Slh + Slp) + cos (Slh + Slp) .tanSlp (Slp) / San (Slp / Slp) )-(Vlh / Vlp) .tanSlp + sin (Slh + Slp) .tanSlp) / (Vlh / Vlp-sin (Slh + Slp) + cos (Slh + Slp) .tanSlp) + (cos (Srh + Srp)-(Sr + Srp / Sr + Srp) TanSrp) / (Vrh / Vrp-sin (Srh + Srp) + cos (Srh + Srp) .tan Srp)) Expression 14 y = d / ((cos (Slh + Slp)-(Vlh / Vlp) .tanSl) p + sin (Slh + Slp) .tanSlp) / (Vlh / Vlp-sin (Slh + Slp) + cos (Slh + Slp) .tanSlp) + (cos (Srh + Srp)-(Vrh / Vrp) .tanSrp + Srp + Srp + Sin + srp + Sin + Srp + Sin + Srp + Sin + Srp + Sin + Srp + Sin + Srp + Sin + Srp + Sin + Srp + Sin + Srp + Sin + Srp + Sin + Srp + Sin + Srp + Sin + Srp + Sin + Srp + Sin + Srp + Sin + Sin + Sin + Sin + Sin + Sin + Sin + Sin + Sin + Sin /Vrp-sin(Srh+Srp)+cos(Srh+Srp).tanSrp)) Equation 15

Thus, even when the angle between the light receiving elements in each measurement unit is other than 90 degrees, the coordinates of the light source 1 can be obtained using the output and the angle of each light receiving element.

As described above, the angle between the light receiving elements is 9
The arrangement of the light receiving elements other than 0 degrees is not limited to the application to the above-described first embodiment, but can be applied to the second to fourth embodiments.

FIG. 9 is a plan view showing an example of one measuring unit in the sixth embodiment of the position measuring device of the present invention. In the figure, the same parts as those in FIG. 12 is a half mirror, and 13 is a virtual light receiving plane area. In this example, the light receiving element 2 shown in FIG.
And a measurement unit constituted by the light receiving element 3, the half mirror 12 is installed in parallel with the x axis on the light source 1 side with respect to the light receiving elements 2 and 3, and the position of the light receiving element 2 arranged in parallel with the x axis Is changed to a position to receive the reflected light from the half mirror 12. The center position of the light receiving element 2 coincides with the center position of the light receiving element 3 when the half mirror 12 is not used, but when the half mirror 12 is used, the center position of the light receiving element 3 is shifted from the center position to the half mirror. The length of the lowered perpendicular and the length of the perpendicular lowered from the center position of the light receiving element 2 to the half mirror are the same length t, and these perpendiculars need to be on a straight line.

In this case, the virtual light receiving plane area 13 when the half mirror 12 is not used is orthogonal to the light receiving surface (light receiving plane area) of the light receiving element 3 at the center of both. Therefore, although the light receiving elements themselves do not actually intersect and the central axes do not coincide with each other, the light receiving plane region virtually intersects at the center, which is the same as the principle described in the first embodiment. Similarly, the position of the light source 1 can be calculated. In addition, by using the half mirror 12, the output obtained in each light receiving element is reduced to half compared with the configuration in FIG. However, since the output ratio does not change, it is not necessary to particularly change the above-described equations 6 and 7, and the equations 6 and 7 can be calculated as they are.

Although the vertical positional relationship between the light receiving elements 2 and 3 is not shown in FIG. 9, the height of the two light receiving elements 2 and 3 can be made equal by using a half mirror. Thereby, even when the light amount from the light source has a distribution in the vertical direction, it is possible to remove the influence.

In the example shown in FIG. 9, the light receiving element 2 is configured to receive the reflected light, but the present invention is not limited to this. For example, the light receiving element 3 may be configured to receive the reflected light. In this case, direct light from the light source 1 may enter the light receiving element 3 that receives the reflected light. Therefore, it is preferable to take measures such as providing a light shielding member so that light from the light source 1 does not enter directly.

Normally, when the half mirror 12 is not used, when the light source 1 is present at a certain distance in a direction perpendicular to the two-dimensional plane, the light from the light source 1 is blocked by one of the light receiving elements. In some cases, the light does not enter the other light receiving element. In such a state, the position of the light source 1 cannot be accurately measured. However, when the half mirror 12 is used, since light is not blocked between the light receiving elements as described above, even if the light source 1 moves in a direction perpendicular to the two-dimensional plane, the light source 1 always moves regardless of the distance. The position on the two-dimensional plane can be obtained.

FIG. 10 is a sectional view and a plan view showing another example of one measuring unit in the sixth embodiment of the position measuring device of the present invention. In the figure, reference numeral 14 denotes a light shielding plate. In the example shown in FIG. 9, the half mirror 12 is provided substantially perpendicular to the two-dimensional plane for measuring the position, but in the example shown in FIG.
2 is provided, and the light receiving element 2 is provided above the half mirror 12. Also in this example, the half mirror 12
Is provided parallel to the x-axis. The light receiving element 2 is installed at a position where the light reflected by the half mirror 12 can be received at the center with respect to the light having the same optical axis as the light received at the center of the light receiving element 3. As a result, the virtual light receiving plane area 13 of the light receiving element 2 is orthogonal to the light receiving surface (light receiving plane area) of the light receiving element 3 at the center of both. Therefore, there is no need to change Equations 6 and 7 above, and it is possible to calculate them as they are. Note that the diffused light from the light source 1 is not directly incident on the light receiving element 2.
It is preferable to provide a light shielding plate 14.

In the examples shown in FIGS. 9 and 10, the half mirror 12 is arranged parallel to the x-axis, but the invention is not limited to this. For example, the half mirror 12 may be arranged parallel to the y-axis. Also in this case, the case where the reflected light is received by the light receiving element 2 and the case where the reflected light is received by the light receiving element 3 can be considered. When the reflected light is received by the light receiving element 2, a light shielding member or the like may be provided so that the light from the light source 1 is not directly incident. The half mirror 12 is shown in FIGS.
When arranged in parallel to the x-axis as shown by 0, a plurality of measurement units such as the left and right measurement units in FIG. 2 can be shared.

FIG. 11 is a sectional view and an overall plan view showing an example of a measuring unit added when performing three-dimensional measurement in the sixth embodiment of the position measuring device of the present invention. In the figure, 15 and 16 are light receiving elements. As described above, when the half mirror 12 is used, no light is blocked between the light receiving elements. Therefore, even if the light source 1 moves in the direction perpendicular to the two-dimensional plane, the light source 1 is always two-dimensional. The position on the plane can be obtained. Therefore, the position of the light source 1 in a three-dimensional space can be obtained by adding a measurement unit that measures a position in a direction perpendicular to a two-dimensional plane.

The additional measuring unit is configured so that the line of intersection of the two light receiving plane regions is parallel to the x-axis. In this case, the virtual light receiving plane area 1 of the light receiving element 15
The line of intersection between 3 and the light receiving surface of the light receiving element 16 is parallel to the x-axis, and the light receiving element 15 is configured to receive the light reflected by the half mirror 12. Also in this case, the light receiving element 15 is installed at a position where the light reflected by the half mirror 12 can be received at the center with respect to the light having the same optical axis as the light received at the center of the light receiving element 16.

In such a configuration, the light source 1 is determined by the ratio of the amount of light received by the light receiving elements 15 and 16.
Can be measured in the direction orthogonal to the two-dimensional plane. Further, the position of the light source 1 in a three-dimensional space can be measured by measuring the position of the light source 1 on a two-dimensional plane by using the two measurement units shown above and below in FIG.

In the example shown in FIG. 11, the 2 shown in FIG.
The example in which the half mirror 12 arranged at approximately 45 degrees with the dimensional plane is shared is shown. Of course, the present invention is not limited to this configuration. For example, the measurement unit having the configuration shown in FIG. 9 is used for position measurement on a two-dimensional plane, and the measurement unit having the configuration shown in FIG. Various configurations are possible, such as a configuration used for position measurement.

FIG. 12 is a perspective view showing an example of one measuring unit in the seventh embodiment of the position measuring device of the present invention. In the figure, 14 is a light receiving element, and 15 is a drive unit. In each of the above embodiments, a plurality of light receiving elements are used for one measurement unit. However, in the seventh embodiment, one light receiving element 17 is rotated or rocked by the drive unit 18. Thus, the amount of received light in a plurality of light receiving plane regions is to be obtained.

The light receiving element 17 rotates or swings, and as shown in FIG.
By obtaining the amount of received light at the position 2 (A), for example, it can be handled in the same manner as the output from the light receiving elements 2 and 4 in FIG. In addition, by obtaining the amount of received light when the light receiving element 17 is rotated or rocked to the position shown in FIG. 12B, for example, in the same manner as the output from the light receiving elements 3 and 5 in FIG. Can handle. The coordinates of the axis at the time of rotation or swing are represented by coordinates (0,
0) and (d, 0), the position of the light source 1 can be calculated by the calculation method described in the first embodiment. At this time, there is no need to change Equations 6 and 7 above, and the equations can be calculated as they are.

In the configuration in which the light receiving element is rotated or oscillated as shown in FIG. 12, there is no difference in the vertical position of the light receiving plane area (light receiving surface) unlike the configuration shown in FIG. In addition, it is possible to obtain the amount of received light in different directions at the same height. Therefore, even when the amount of light from the light source has a distribution in the vertical direction, it is possible to remove the influence. This effect is the same as when the half mirror 12 shown in the sixth embodiment is installed.

It should be noted that the angle between the plurality of light receiving plane regions for obtaining the amount of received light from the light receiving element 17 is not limited to 90 degrees, but is 90 degrees as described in the fifth embodiment.
The angle may be other than degrees. In this case, the position of the light source 1 may be calculated using Expressions 14 and 15.

Further, by adding a plurality of measurement units for measuring the position of the light source 1 on the two-dimensional plane and a measurement unit shown in FIG. It is also possible to measure a position in a dimensional space.

FIG. 13 is a perspective view showing another example of one measuring unit in the seventh embodiment of the position measuring device of the present invention. In the figure, 16 is a mirror, 17 is a drive unit, 1
8 is a light receiving element. In the example shown in FIG.
7, a mirror 19 is provided, and the mirror 19 is
An example of turning or swinging by 0 is shown. The mirror 19 is provided with a rotation axis substantially at its center.
1 so that light from the light source 1 is reflected to the light receiving element 21.
As shown in FIG. Note that the light receiving element 21 may be fixed. Further, for example, a lens or the like may be provided in an optical path from the mirror 19 to the light receiving element 21 to prevent scattering of light from the light source 1 and to collect light.

When the mirror 19 is rotated or rocked by the drive unit 20 and reaches the positions shown in FIGS. 13A and 13B, the light receiving element 21 obtains the amount of light received. It is possible to acquire the amount of received light in the orthogonal light receiving plane region. The position of the light source 1 can be calculated by the calculation method described in the above-described first embodiment using the acquired value of the received light amount. of course,
The light receiving plane area at an arbitrary angle can be set according to the angle of the mirror 19, and the position of the light source 1 can be calculated by the calculation method described in the fifth embodiment.

FIG. 14 is a perspective view showing an eighth embodiment of the position measuring device according to the present invention. In the figure, the same parts as those in FIG. 19 is an external light source, and 20 is a reflection member. In this example, an example in which a reflecting member 23 is used instead of the light source 1 is shown. Reflecting member 2
3 diffusely reflects, for example, light emitted from the external light source 22 or the like. As the reflecting member 23, for example, an optical element such as a cat's eye can be used. In this case, due to the characteristics of the cat's eye, it is necessary to provide the external light source 22 near the light receiving element as shown in FIG. Of course, another optical member such as a diffuse reflection member can be used as the reflection member 23, and the external light source 22 may be arranged according to the optical member to be used. The external light source 2
Light from 2 must be kept from entering the measuring unit. Further, the light from the external light source 22 may not be diffused light, but it is necessary to illuminate the entire range in which the reflecting member 23 may move (range for performing position measurement). For example, it is possible to apply a method such as providing a diffusion plate or scanning the illumination direction. of course,
The position of the external light source is not limited to this example, and the external light source may be configured to illuminate from the left and right positions of the measurement unit or the vertical direction orthogonal to the two-dimensional plane.

As described above, even when the reflecting member 23 is used as the light source 1, the components described in the first to seventh embodiments can be used as they are. The same applies to the calculation of the position of the reflection member 23.

The same applies to the case where, for example, a fluorescent member is used instead of the reflecting member 23, and the light having the wavelength for emitting fluorescence is received by the light receiving element.

FIG. 15 is a perspective view showing a ninth embodiment of the position measuring device of the present invention. In the figure, the same parts as those in FIG. 21 is a reflection plate. In this example, a reflector 24 that reflects light from the light source 1 in a position measurement range is provided in parallel with a two-dimensional plane for performing position measurement. With this reflecting plate 24, the light receiving elements 2 to 5 and the like together with direct light from the light source 1
Both light reflected by the reflection plate 24 enters. Therefore, the amount of light received by the light receiving elements 2 to 5 increases. This makes it possible to reduce relative noise and improve accuracy.

The direction of the light reflected by the reflection plate 24 may have a strong reflection component in a specific direction depending on the reflection plate 24. In such a case, the light receiving elements 2
The incidence of reflected light on 5 causes an error instead. However, usually, components diffusely reflected in random directions,
Since there is only a specularly reflected component, it is unlikely to cause an error.

As described above, some embodiments of the position measuring apparatus of the present invention have been described. However, the position of the light source (including the reflecting member and the like) calculated as described above includes some error. Have been. Hereinafter, several methods for correcting the error will be described.

FIG. 16 is an explanatory diagram of an example of the adjusting unit applied to each embodiment of the position measuring device of the present invention. In the figure, reference numeral 22 denotes an adjusting unit, and 23 denotes an amplifier. The first error may be caused by a variation in the area of the light receiving element. To cope with such a case, it is desirable to irradiate the light receiving elements 2 to 5 with uniform light and adjust the gains g1 to g4 of the amplifier 26 so that the outputs at that time become the same. Specifically, the light source may be installed so that the position of the light source is set at an angle of 1/2 of the opening angle of the light receiving element around the intersection of the plurality of light receiving elements in each measurement unit. For example, in a configuration in which two light receiving elements are orthogonal to each other as shown in FIG. 2, light may be emitted by setting the light receiving elements on a straight line at an angle of 45 degrees with respect to the x-axis. At this time, the outputs of the plurality of light receiving elements in the measurement unit should be essentially the same. What is necessary is just to adjust the gains g1 to g4 of the amplifier 26 in the adjustment unit 25 so that these become the same.

Alternatively, instead of adjusting the gain of the amplifier 26, the calculation unit 6 may adjust a coefficient used for position calculation. Of course, the coefficient adjustment in the calculation unit 6 may be performed together with the gain adjustment.

The causes of the second error include the in-plane variation of the transmittance of the coating film applied to the light receiving surface of the light receiving element and the case where the half mirror 12 is used as described in the sixth embodiment. There are in-plane variations in the reflectance and transmittance, and these must be corrected. Since such an error cannot be easily corrected by the gain of the circuit as shown in FIG. 16, it is necessary to use another correction method. For example, on a two-dimensional plane where the position of a light source is measured, several points whose coordinates are known are provided, the light source is set there, the calculated position is obtained, and the difference between the original position and the calculated position is corrected. Create a correction table or correction formula to be performed. Then, when actually measuring the position, the light source position may be corrected using the correction table or the correction formula that has been created. The correction equation can be approximated by, for example, a polynomial.

FIG. 17 is an explanatory diagram of an example of the position measurement result when no correction is performed, and FIG. 18 is an explanatory diagram of an example of the position measurement result when the correction is performed. In the figure, a broken line indicates a true position, and a solid line indicates a calculation result by the position measuring device of the present invention. The light receiving element used here is, for example, 6 × 6
mm PiN-type Si photodiode.

First, in FIG. 17, the position calculation is performed assuming that the light receiving elements are orthogonal without considering the inclination of the light receiving elements described in FIG. 6, and the above-described correction table is not used. The position measurement result in the case is shown. In this case, it can be seen that the calculation result indicated by the solid line includes a large error with respect to the true position indicated by the broken line. A specific error was found to reach about 70 mm.

Next, in FIG. 18, calculations are performed by Expressions 14 and 15 including the inclination of the light receiving element described with reference to FIG.
Also, the results are obtained when the above-described correction table is used. In this case, it can be seen that the calculation result for the true position includes only a small error. In FIG. 17, for convenience,
Although the true position and the calculation result are exaggerated, the dashed line indicating the almost true position and the solid line calculated for the position overlap in reality. A specific error can be suppressed to about 0.5 mm.

FIG. 19 is a perspective view showing an embodiment of the position input device of the present invention. In the figure, the same parts as those in FIG. Reference numeral 31 denotes a position indicator, and 32 denotes a plate. In the example of the position input device shown in FIG. 19, an example is shown in which the first embodiment shown in FIG. 1 is used as an example of the above-described position measurement device, and the plate 32 is installed on a two-dimensional plane for performing position measurement. I have. As long as the light from the light source 1 of the position indicator 31 is incident on the light receiving surfaces of all the light receiving elements, the position of the light source 1 can be measured, and the plate may be set within that range.

The light source 1 is provided on the position indicator 31. In this example, the position indicator 31 is shown as a pen-shaped shape. In the case of use in an office environment or the like, the position indicator 31 is designated as such a pen by pointing on the plate 32 with the position indicator 31.
It is possible to measure the entire position and the position of the pen tip of the position indicator 31. The position of the position indicator 31 can be calculated from a plurality of light source positions by installing the light sources 1 at a plurality of positions in the position indicator 31 and sequentially lighting each light source to measure the position. Also becomes possible.

The position indicator 31 may be provided with a switch for turning the light source 1 on and off, or may emit light in response to a stimulus such as external light. Further, as described in the eighth embodiment of the position measuring device, the reflecting member may be provided on the position pointing tool 31 instead of the light source.

The shape of the position indicator 31 is not limited to the pen shape but may be any shape. For example, the shape of the mouse or the shape of the pointing rod may be used. Further, in a place other than the office environment, for example, if the light source 1 is attached to a working arm of a robot, it is possible to measure the position of the tip of the arm and the like. In this way, it can be easily applied to general position measurement in general.

The plate 32 shown in FIG. 19 can have a function of displaying an image. By using the display function of the plate 32, for example, it is possible to display options and select them with the position indicator 31. Further, it is also possible to display a material on the plate 32 and write a memo with the pen-shaped position indicator 31. It is also possible to select a mode in which the position of the pen tip is only displayed as a cursor without writing.

Further, the image is not displayed on the plate 32, but is simply used as an input plate, and the image is displayed on another screen, and writing is performed on another display screen by the instruction of the position pointing tool 31. It is also possible to display the position of the position indicator 31 with a cursor. In such a configuration, it is not necessary to connect a power cord or a signal line to the plate 32. Further, for example, as in the ninth embodiment of the position measuring device described above, the surface of the plate 32 can be used as a reflecting plate having a specular reflection component.

FIG. 20 is a perspective view showing another embodiment of the position input device of the present invention. In the figure, the same parts as those in FIG. 19 are denoted by the same reference numerals, and description thereof will be omitted. 33 is a mark. In the example of the position input device shown in FIG. 20, an example in which a mark 33 is provided on the plate 32 is shown. This mark 33 can be used, for example, as a mark for aligning the directions of the plate 32 and the measuring unit of the position measuring device in the production process. The mark 33 in this case is not limited to printing or writing on the plate 32, but may be engraved or have a predetermined shape to be guided when combining both the measurement unit and the plate. By adding the mark 33, the assembly can be performed without erroneous positional relationship between the measurement unit and the plate 32. For example, in a rectangular plate 32, even when the long side and the short side have the same length and are easy to be confused, it is necessary to clarify which side of the side and the position where the measuring unit should be connected. Can be.

Further, by adding such a mark 33, when the position input device of the present invention is used,
The positional relationship between the user and the plate 32 or the measurement unit can be clarified. In addition, the mark 33 can be used for various purposes such as indicating a possible input range of position coordinates. The mark 33 in this case may be printed or entered as described above, may be engraved, or may have a predetermined shape.

In the above-described embodiment of the position input device, the position of the position indicator 31 on the two-dimensional plane can be input. Furthermore, the three-dimensional position of the position indicator 31 can be input by appropriately combining a position measuring device that can measure the position of the above-described two-dimensional plane. For example, the light source position of the position indicator 31 on the first two-dimensional plane is measured using a measurement unit as shown in FIG. 5, and at the same time, on the second two-dimensional plane perpendicular to the first two-dimensional plane. By providing a measurement unit for measuring the light source position of the position indicator 31 of the above, the position of the position indicator 31 in a three-dimensional space can be input. Further, as described above, the position measuring device of the present invention can also be configured to be capable of three-dimensional measurement, and using such a position measuring device of the present invention capable of three-dimensional measurement, You may comprise so that a three-dimensional position can be input.

[0089]

As is apparent from the above description, according to the present invention, the light receiving planes are arranged such that the centers of the plurality of light receiving plane areas are the same or a straight line connecting the centers is substantially orthogonal to the two-dimensional plane of the object to be measured. A plurality of measurement units having regions are provided. For example, when each light receiving plane area is the light receiving surface of the light receiving element, the characteristics of the distance from the light source are opposite on both sides of the center of each light receiving element in the measurement unit. This cancels out errors due to differences in distance from the light source,
Accurate position measurement can be performed. Also, as described above, a very simple configuration is sufficient, and an inexpensive position measuring device can be provided. Furthermore, by using such a position measuring device, there is an effect that a position input device capable of performing a pointing operation smoothly with good operability can be provided.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a position measuring device according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating the principle of position measurement in the position measurement device of the present invention.

FIG. 3 is a perspective view showing a second embodiment of the position measuring device of the present invention.

FIG. 4 is a perspective view showing a position measuring device according to a third embodiment of the present invention.

FIG. 5 is a plan view showing a position measuring device according to a fourth embodiment of the present invention.

FIG. 6 is a plan view showing an example of one measuring unit in a fifth embodiment of the position measuring device of the present invention.

FIG. 7 is an explanatory diagram of a first stage of an example of a method of calculating a position of a light source in a fifth embodiment of the position measuring device of the present invention.

FIG. 8 is an explanatory diagram of a second stage of an example of a method of calculating a position of a light source in the fifth embodiment of the position measuring device of the present invention.

FIG. 9 is a plan view showing an example of one measuring unit in a sixth embodiment of the position measuring device of the present invention.

FIGS. 10A and 10B are a cross-sectional view and a plan view showing another example of one measuring unit in the position measuring device according to the sixth embodiment of the present invention.

FIGS. 11A and 11B are a cross-sectional view and an overall plan view illustrating an example of a measurement unit added when performing three-dimensional measurement in the sixth embodiment of the position measurement device of the present invention.

FIG. 12 is a perspective view showing an example of one measuring unit in a seventh embodiment of the position measuring device of the present invention.

FIG. 13 is a perspective view showing another example of one measuring unit in the position measuring device according to the seventh embodiment of the present invention.

FIG. 14 is a perspective view showing an eighth embodiment of the position measuring device of the present invention.

FIG. 15 is a perspective view showing a ninth embodiment of the position measuring device of the present invention.

FIG. 16 is a diagram illustrating an example of an adjustment unit applied to each embodiment of the position measurement device of the present invention.

FIG. 17 is an explanatory diagram of an example of a position measurement result when no correction is performed.

FIG. 18 is an explanatory diagram of an example of a position measurement result when correction is performed.

FIG. 19 is a perspective view showing an embodiment of the position input device of the present invention.

FIG. 20 is a perspective view showing another embodiment of the position input device of the present invention.

FIG. 21 is an explanatory diagram of an example of a conventional position measuring device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Light source, 2-5 ... Light receiving element, 6 ... Calculation part, 7,8 ... Light receiving element, 9,10 ... Light receiving element, 11 ... Light shielding plate, 12 ... Half mirror, 13 ... Virtual light receiving plane area, 14 ... Light shielding Board,
15-17: light receiving element, 18: drive unit, 19: mirror,
Reference numeral 20: drive unit, 21: light receiving element, 22: external light source, 23
.. Reflecting member, 24 reflecting plate, 25 adjusting section, 26 amplifier, 31 position indicator, 32 plate, 33 mark, 41 to 44 photoelectric conversion element, 45 light source.

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Shoji Hisada 2274 Hongo, Ebina-shi, Kanagawa Prefecture F-Xerox Co., Ltd. BD17 BE08 BE15 CC17 5B087 AA02 CC12 CC26 CC33 DD03

Claims (34)

[Claims] 1. A position measuring apparatus for measuring a position of a light source emitting diffused light on at least a two-dimensional plane, wherein the light receiving unit receives diffused light from the light source in a light receiving plane region provided on a plurality of planes crossing each other. A plurality of measurement units each outputting an amount, and calculating means for calculating the position of the light source based on a ratio of the amount of light received between the light receiving plane regions in each of the measurement units, wherein the plurality of measurement units in each of the measurement units Wherein the center of the light receiving plane region is the same or a straight line connecting the centers is substantially orthogonal to the two-dimensional plane. 2. The position measuring apparatus according to claim 1, wherein the plurality of light receiving plane regions are provided substantially perpendicular to the two-dimensional plane. 3. The light-receiving plane areas are orthogonal to each other.
The position measuring device according to claim 1, wherein the position measuring device is provided on a plane. 4. A light-receiving element is provided in each of the plurality of light-receiving plane areas so that the light-receiving plane area becomes a light-receiving surface, and the light-receiving elements are arranged so as to overlap in a direction perpendicular to the two-dimensional plane. The position measuring device according to any one of claims 1 to 3, wherein: 5. The light-receiving plane area includes two or more light-receiving plane area groups each including one or a plurality of the light-receiving plane areas provided on three or more planes and provided on the same or parallel plane. The calculating means averages the amount of light received in one or more of the light receiving plane regions included in each of the light receiving plane region groups, and calculates the position of the light source based on a ratio of the average value of the light reception amounts in the two light receiving plane region groups. The position measuring device according to any one of claims 1 to 3, which calculates 6. A light receiving element is provided in each of the plurality of light receiving plane areas so that the light receiving plane area becomes a light receiving surface, and light receiving elements arranged in light receiving plane areas belonging to each light receiving plane area group are alternately arranged. The position measuring device according to claim 5, wherein the position measuring device is arranged so as to overlap with the two-dimensional plane in a vertical direction. 7. When the light receiving elements are sequentially superimposed in a direction perpendicular to the two-dimensional plane in two adjacent measurement units among a plurality of the measurement units, the light reception elements belonging to the same measurement unit belong to different measurement units. 7. The position measuring device according to claim 4, wherein the light receiving elements arranged at a height overlap in an order in which the light receiving plane regions are not parallel. 8. The measurement unit further includes a half mirror, one or a plurality of light receiving elements having the light receiving plane area disposed at a position transmitted through the half mirror as a light receiving surface, and the light receiving plane area; 2. The light receiving device according to claim 1, wherein one or more light receiving elements are provided in which a light receiving surface is provided in an actual light receiving plane region reflected by the half mirror, with the light receiving plane region intersecting as a virtual light receiving surface. 4. The position measuring device according to any one of 3. 9. The measuring unit has one light receiving element and driving means for rotating or rocking the light receiving element about an axis including the center thereof, and a plurality of points during rotation or rocking of the light receiving element. The position measuring device according to claim 1, wherein the amount of light received is output in the plurality of light receiving plane regions by outputting the amount of received light. 5. 10. The measurement unit includes one light receiving element and an optical system including a mirror that rotates or swings about an axis including a center, and the light receiving unit receives light at a plurality of positions during rotation or swinging of the mirror. The position measuring device according to any one of claims 1 to 3, wherein an amount of received light is output from an element to obtain the amount of received light in the plurality of light receiving plane regions. 11. A plurality of measurement units that are not close to each other among a plurality of measurement units are set as a measurement unit pair, and the calculation unit calculates the light receiving plane output from each measurement unit of the measurement unit pair. The position measuring device according to claim 1, wherein the position of the light source is calculated using a received light amount for each area. 12. The position measuring device according to claim 11, wherein the calculating means calculates the position of the light source by averaging values calculated by a plurality of measuring unit pairs. 13. The position measuring device according to claim 1, wherein a light shielding means is provided between said measuring units. 14. The measurement unit according to claim 1, wherein a cover is provided to cover the measurement unit, and at least a portion of the cover facing the light receiving plane area and the light source is transparent. The position measuring device according to claim 12. 15. The position measuring apparatus according to claim 1, wherein the light source blinks. 16. The apparatus according to claim 1, further comprising a reflecting member parallel to the two-dimensional plane, wherein the measuring unit receives light reflected by the reflecting member together with direct light from the light source. Item 16. The position measuring device according to any one of Items 15. 17. The light source according to claim 1, wherein the light source is formed of a diffuse reflection member or a fluorescent member, and is used as a light source for position measurement by diffusely reflecting or fluorescently emitting light incident from outside. The position measuring device according to claim 14. 18. The calculating means according to claim 1, wherein the two-dimensional plane is an xy plane with respect to two light receiving plane regions or two light receiving plane region groups in the two measurement units, The coordinates of a point corresponding to the intersection of the light receiving plane area or the group of the light receiving plane areas on the xy plane are (0, 0), and the light receiving plane area or the light receiving plane area group in the second measurement unit is set. The coordinates of a point corresponding to the intersection of the orthogonal projections on the xy plane are (d, 0), the coordinates of the light source are (x, y), and in the first measurement unit, the light receiving plane area or The amount of light received or the average amount of received light when the group of light receiving plane regions is substantially parallel to the x axis is Vlh, and the angle formed by the light receiving plane region or the group of light receiving plane regions with the x axis is S.
lh, the received light amount or the average received light amount when the light receiving plane region or the light receiving plane region group is substantially parallel to the y axis is Vlp, and the angle formed by the light receiving plane region or the light receiving plane region group with the y axis is Slp. In the second measurement unit, the light receiving amount or the average light receiving amount when the light receiving plane region or the light receiving plane region group is substantially parallel to the x-axis is Vrh, and the light receiving plane region or the light receiving plane region group is The angle formed with the x axis is Srh, and the light receiving plane area or the light receiving plane area group is y
When the amount of received light or the average amount of received light when substantially parallel to the axis is Vrp, and the angle between the light receiving plane region or the group of light receiving plane regions and the y axis is Srp, the coordinates (x, y) of the light source are x = D · ((cos (Slh + Slp) − (Vlh / V
lp) · tanSlp + sin (Slh + Slp) · t
anSlp) / (Vlh / Vlp-sin (Slh + S
lp) + cos (Slh + Slp) .tanSlp))
/ ((Cos (Slh + Slp)-(Vlh / Vlp)
・ TanSlp + sin (Slh + Slp) ・ tanS
lp) / (Vlh / Vlp-sin (Slh + Slp)
+ Cos (Slh + Slp) · tanSlp) + (co
s (Srh + Srp)-(Vrh / Vrp) tanS
rp + sin (Srh + Srp) · tanSrp) /
(Vrh / Vrp-sin (Srh + Srp) + cos
(Srh + Srp) .tanSrp)) y = d / ((cos (Slh + Slp)-(Vlh / V
lp) · tanSlp + sin (Slh + Slp) · t
anSlp) / (Vlh / Vlp-sin (Slh + S
lp) + cos (Slh + Slp) .tanSlp) +
(Cos (Srh + Srp)-(Vrh / Vrp) .t
anSrp + sin (Srh + Srp) · tanSr
p) / (Vrh / Vrp-sin (Srh + Srp) +
The position measuring device according to any one of claims 1 to 17, wherein the position is calculated by cos (Srh + Srp) .tanSrp)). 19. An adjusting means for adjusting the amount of received light such that the amount of received light in each of the light receiving plane areas output from the measurement unit is substantially the same for the same amount of light. The position measuring device according to any one of claims 1 to 18, wherein 20. When the light source is arranged on a straight line at an angle of 45 degrees around a central axis of two light receiving plane regions or two light receiving plane region groups in the measurement unit, the two light receiving plane regions or 2. An adjusting means for adjusting the light receiving amount so that the light receiving amounts in the two light receiving plane region groups are substantially the same.
19. The position measuring device according to claim 18. 21. The position measuring apparatus according to claim 19, wherein said adjusting means adjusts a gain for a signal indicating the amount of received light output from said measuring unit. 22. The position measuring apparatus according to claim 19, wherein the adjusting means adjusts a coefficient used in the position calculation in the calculating means. 23. The calculation means calculates the light source based on the amount of light received from the measurement unit at each position when the light source is installed at one or more specific positions whose coordinates are known. 19. The light source position is corrected using a correction table or a correction formula in which the obtained light source position is associated with a true position.
The position measuring device according to any one of claims 1 to 7. 24. The position measuring apparatus according to claim 23, wherein said calculating means uses a polynomial as said correction equation. 25. A three-dimensional space for the light source, wherein a second two-dimensional plane substantially perpendicular to the two-dimensional plane is set, and one or more measurement units are provided for the second two-dimensional plane. The position measuring device according to any one of claims 1 to 24, wherein the position is measured at: 26. The position measuring device according to claim 1, wherein the position measuring device emits diffused light.
Or a position indicating member having a plurality of light sources therein, wherein the position indicated by the position indicating member is input by measuring one or more light source positions of the position indicating member by the position measuring device. Input device. 27. A plate parallel to the two-dimensional plane, wherein the plate is configured such that diffused light from the light source moving on the plate is not shadowed by another member on the light receiving plane area. 27. The position input device according to claim 26, wherein the position input device is provided in a range where direct incidence is possible. 28. The method according to claim 27, wherein the plate is configured to reflect light on its surface, and reflects the light emitted from the light source to make it incident on the measuring unit. Position input device. 29. The apparatus according to claim 27, wherein the plate has a function of displaying an image, and displays a position of the position indicating member acquired by the position measuring device. Position input device. 30. The plate has a function of displaying an image, and can be written on the image based on information on the position of the position indicating member acquired by the position measuring device. The position input device according to claim 27 or 28. 31. The display device according to claim 27, wherein the plate is provided with a display indicating an appropriate orientation of the plate when used.
The position input device according to the paragraph. 32. The plate according to claim 27, wherein the plate is provided with a shape indicating an appropriate orientation of the plate when used.
The position input device according to the paragraph. 33. The plate according to claim 27, wherein the plate is provided with an indication indicating an appropriate direction of the plate when the position measuring device is assembled. The position input device according to the above. 34. The apparatus according to claim 27, wherein the plate is provided with a shape indicating an appropriate orientation of the plate when assembling the position measuring device. The position input device according to the above.